scholarly journals Chemical and physical investigations of historic mortars in St. John’s Church (Cesis, Latvia)

2019 ◽  
Author(s):  
Inta Kirilovica ◽  
Margarita Karpe
Keyword(s):  
Visual Observation ◽  
Soluble Salts ◽  
Hydraulic Lime ◽  
Granulometric Analysis ◽  
Stone Material ◽  
Wet Chemical ◽  
Historic Mortars ◽  
The City ◽  
Brick Dust

This paper deals with the stone material investigation of St. John’s Church, located in Cesis, the city in central region of Latvia. Following aspects were considered – chemical, physical and granulometrical characterization of historic mortars, as well as the level of soluble salts in the masonry. The chemical and physical properties of the historical mortars were characterized by visual observation, granulometric analysis, classical wet chemical analysis, XRD, SEM and hydro tests. The results showed that the historic mortars are based on two types of weakly hydraulic lime – calcitic and dolomitic – with brick dust additive. The main crystallized salt in the object was KNO3. The aim of the investigation was to provide compatibility of restoration materials and sustainability of the ancient building.

scholarly journals How to Estimate the Binder: Aggregate Ratio From Lime-Based Historic Mortars for Restoration?

2020 ◽  
Vol 7 ◽  
Author(s):  
Alexandre Máximo Silva Loureiro ◽  
Simone Patrícia Aranha da Paz ◽  
Rômulo Simões Angélica
Keyword(s):  
Chemical Analysis ◽  
Preparation Methods ◽  
Materials Analysis ◽  
Accuracy And Precision ◽  
Adequate Accuracy ◽  
Northern Brazil ◽  
Wet Chemical ◽  
Historic Mortars ◽  
Sample Preparation Methods

One of the most important studies from historic mortars is the binder:aggregate ratio, which is usually obtained through wet chemical analysis. Instrumental techniques and benchtop equipment have become increasingly important tools in the characterization of historic materials. The analysis of such materials has become more practical, faster and more accurate, and the sample preparation methods require less and less material. Thus, this article aims to investigate the validity of the results obtained by some of the methods and techniques used in historic materials analysis and determine the possibility of estimating the binder:aggregate ratio with adequate accuracy and precision. For this purpose, historic mortars from Belém do Pará, in northern Brazil, were selected, and the following quantification techniques were employed: wet chemical analysis, XRD, DSC and XRF. The results showed that the amounts of the components in the mortars could be quantified with the use of approximately 3 g of sample, thus providing one of the main pieces of information needed for the production of a restoration mortar: the binder:aggregate ratio.

Pre-Restoration Investigation of Historical Stone Materials and Corrosion Damage of VEF Culture Palace in Riga, Latvia

2019 ◽  
Vol 800 ◽  
pp. 235-239
Author(s):  
Inta Kirilovica ◽  
Margarita Karpe ◽  
Inta Vitina ◽  
Viktorija Sucevana
Keyword(s):  
Corrosion Damage ◽  
Visual Observation ◽  
Chemical Analyses ◽  
Soluble Salts ◽  
Stone Materials ◽  
Physico Chemical ◽  
Complete Restoration ◽  
Lime Mortars ◽  
Wet Chemical

This study deals with the restoration of columns of the VEF Culture Palace. A complete restoration of the building was performed in 2016–2017 [1]. The methodology of physico-chemical investigation of the stone materials of two facade columns includes visual observation, granulometric analyses, classic wet chemical analyses, XRD and determination of soluble salts’ content. The data obtained indicate, that for rendering of columns dolomitic and calcitic lime mortars were used. An efflorescence of sulphates on the bricks’ surface is observed.

scholarly journals Genomic investigation of a dengue virus outbreak in Thiès, Senegal, in 2018

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amy Gaye ◽  
Tolla Ndiaye ◽  
Mouhamad Sy ◽  
Awa B. Deme ◽  
Alphonse B. Thiaw ◽  
...  
Keyword(s):  
West Africa ◽  
Dengue Virus ◽  
Clinical Signs ◽  
Health Concern ◽  
Public Health Concern ◽  
Local Circulation ◽  
Viral Genomes ◽  
Genomic Characterization ◽  
The City

AbstractDengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.

scholarly journals Synthesis and characterization of nano-hydroxyapatite added with magnesium obtained by wet chemical precipitation

2021 ◽  
Author(s):  
Brandon A. Correa-Piña ◽  
Omar M. Gomez-Vazquez ◽  
Sandra M. Londoño-Restrepo ◽  
Luis F. Zubieta-Otero ◽  
Beatriz M. Millan-Malo ◽  
...  
Keyword(s):  
Chemical Precipitation ◽  
Synthesis And Characterization ◽  
Wet Chemical ◽  
Wet Chemical Precipitation

scholarly journals Characterization of Spatial Planning in Brazil: The Right to the City in Theory and Practice

2019 ◽  
Vol 34 (4) ◽  
pp. 419-437 ◽  
Author(s):  
Roberto Rocco ◽  
Luciana Royer ◽  
Fábio Mariz Gonçalves
Keyword(s):  
Spatial Planning ◽  
Theory And Practice ◽  
Right To The City ◽  
The Right ◽  
The City

Synthesis and Structural Characterization of Zinc and Magnesium Doped Hydroxyapatite

2012 ◽  
Vol 531-532 ◽  
pp. 250-253 ◽  
Author(s):  
Hong Quan Zhang ◽  
Ming Zhang ◽  
Lu Wei Fu ◽  
Yu Ning Cheng
Keyword(s):  
Hydrothermal Treatment ◽  
Structural Characterization ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Starting Solution ◽  
Wet Chemical ◽  
Zn Ions ◽  
Wet Chemical Precipitation ◽  
Surface Of Crystals

Zn or Mg ions doped hydroxyapatite (HA) particles were successfully developed by introducing various concentration of Zn or Mg in the starting solution using wet chemical precipitation method and followed a hydrothermal treatment. The products were identified as HA by XRD and FTIR, and the precipitated particles had a rod-like morphology. All the products for Mg and Zn ions concentration in the preparation solution less than 40 mol% were identified as HA. Substitution of Mg and Zn in HA crystal would impair the crystallization of HA and significantly reduce the length of a, c values of HA unit cell, which clearly demonstrated that Mg or Zn ions were structurally incorporated into the apatite crystals, they were not just absorbed on the surface of crystals.

Study of Painting Materials and Techniques in the 18th Century St.Athanasius Church in Moschopolis, Albania

2007 ◽  
Vol 1047 ◽  
Author(s):  
Eleni Pavlidou ◽  
N. Civici ◽  
E. Caushi ◽  
L. Anastasiou ◽  
T. Zorba ◽  
...  
Keyword(s):  
18Th Century ◽  
Orthodox Church ◽  
Wall Paintings ◽  
Cultural Center ◽  
Green Earth ◽  
Almost All ◽  
The City ◽  
The Church ◽  
Compositional Characterization

AbstractIn this paper are presented the studies of the paint materials and the technique used in 18th century wall paintings, originated from the orthodox church of St Athanasius, in the city of Maschopolis, a flourishing economical and cultural center, in Albania. The church was painted in 1745 by Konstantinos and Athanasios Zografi, and during the last years, restoration activities are being performed at the church. Samples that included plasters and pigments of different colors were collected from important points of the wall paintings. Additionally, as some parts of the wall-paintings were over-painted, the analysis was extended to the compositional characterization of these areas. The identification of the used materials was done by using complementary analytical methods such as Optical Microscopy, Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM-EDS) and X-ray fluorescence (TXRF).The presence of calcite in almost all the pigments is indicative for the use of the fresco technique at the studied areas, while the detection of gypsum and calcium oxalate, indicates an environmental degradation along with a biodegradation. Common pigments used in this area at 15-16th centuries, such as cinnabar, green earth, manganese oxide, carbon black and calcite were identified.

scholarly journals Surface and Underground Geomechanical Characterization of an Area Affected by Instability Phenomena in Zaruma Mining Zone (Ecuador)

2021 ◽  
Vol 13 (6) ◽  
pp. 3272
Author(s):  
Paúl Carrión-Mero ◽  
Maribel Aguilar-Aguilar ◽  
Fernando Morante-Carballo ◽  
María José Domínguez-Cuesta ◽  
Cristhian Sánchez-Padilla ◽  
...  
Keyword(s):  
Mass Movement ◽  
Mining Activity ◽  
Mining District ◽  
Mean Values ◽  
Surface Areas ◽  
Definition Of ◽  
Action Measures ◽  
Geomechanical Characterization ◽  
The City

In the last decade, in the mining district of Zaruma-Portovelo, there has been significant land subsidence related to uncontrolled mining activity. The purpose of this work was to carry out a surface and underground geomechanical characterization of a mining sector north of the city of Zaruma that allows the definition of potentially unstable areas susceptible to the mass movement. The methodology used consists of the following stages: (i) compilation of previous studies; (ii) surface and underground characterization of rocky material to establish its susceptibility to mass movement; (iii) interpretation of results; and (iv) proposal of action measures. Among the most relevant results, it stands out that 26.1% of the 23 stations characterized on the surface present conditions that vary from potentially unstable to unstable. In underground galleries, the studied mean values of the 17 stations indicate that the rock has a medium to good quality, representing a medium susceptibility to gallery destabilization. The results obtained for the surface areas (depths up to 50 m, where altered materials predominate) and the underground areas (depths > 50 m, where the alterations are specific) can be used to identify the areas with a more significant potential for instability. For both cases, it has been possible to define specific monitoring, control, and planning actions for sensitive areas.

scholarly journals Characterization of ferrite nanoparticles for preparation of biocomposites

2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko
Keyword(s):  
Chemical Method ◽  
Ferrite Nanoparticles ◽  
Chemical Activity ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Transmission Electron ◽  
Wet Chemical

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).

Synthesis and characterization of Li1.3Al0.3Ti1.7(PO4)3-coated LiMn2O4 by wet chemical route

Rare Metals ◽  
2009 ◽  
Vol 28 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Xianming Wu ◽  
Runxiu Li ◽  
Shang Chen ◽  
Zeqiang He
Keyword(s):  
Synthesis And Characterization ◽  
Chemical Route ◽  
Wet Chemical ◽  
Wet Chemical Route
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