scholarly journals Multi-Analytical Characterization of Corvins’ Castle—Deserted Tower. Construction Materials and Conservation Tests

Heritage ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 941-964
Author(s):  
Rodica Mariana Ion ◽  
Lorena Iancu ◽  
Madalina Elena David ◽  
Ramona Marina Grigorescu ◽  
Bogdan Trica ◽  
...  

The aim of this paper is to analyze the construction materials (mortars) of an architectural monument (Deserted Tower (Lilly Tower) from Corvins’ Castle, Romania). The mortars were characterized following a multidisciplinary approach, combining macroscopic observation with petrographic microscopy, mineralogical analysis (X-ray diffraction) and elemental analysis (X-ray fluorescence), hydric properties, and color of representative samples of the monument. The results revealed the use of gypsum mortars (produced by lumps with higher Fe content), with minor concentrations of crystalline dolomites of the Southern Carpathians, calcite, and quartz. The materials’ effective porosity and their water absorption capacity were high. A possible solution to consolidate the damaged area with some consolidation products (hydroxyapatite carbonate and its derivatives with Ag and Sr) was investigated, too. The interactions between the mortar’s specimens and the effectiveness of the consolidation treatments were evaluated by physico-chemical analyses (molecular structure by X-ray powder diffraction (XRPD), wavelength dispersive X-ray fluorescence (WDXRF), dynamic light scattering (DLS)), morphological characterization by microscopic techniques as SEM-EDS, TEM, and physical and mechanical investigations (peeling test and compressive strength). Results were drawn based on historical, in situ observations, and analytical data, and put into evidence the composition, high weathering degree, and the possibility to surface consolidate with Sr-CHAp.

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 241
Author(s):  
Freire-Lista ◽  
Kahraman ◽  
Carter

This study characterises the original construction materials (building stones and mortars) of a collapsed two-storey colonnaded structure in the Ismail Mandani house, located in the old city centre of Doha (Qatar). Results were drawn based on interpretation and integration of historical, in situ observations and analytical data. The mortars and stones were characterised following a multidisciplinary approach, combining macroscopic observation with petrographic microscopy, mineralogical analysis (X-ray diffraction) and elemental analysis (handheld X-ray fluorescence) of samples. Moreover, hydric properties, ultrasonic pulse velocity and colour of representative samples of the house were studied. The results revealed the use of two types of stones and three different types of gypsum mortars. The original construction materials came from nearby coastal stones. Gypsum of the most used mortar had a calcination temperature between 120 and 160 °C and its colour was produced by lumps with higher Fe content. The materials’ effective porosity and water absorption were high, and their ultrasonic pulse velocity was low. These petrophysical results indicated they had low quality for construction purposes. The composition and colour of the original construction materials were quantified, which will allow the reproduction of their aesthetic characteristics and improvement of their quality in future reconstruction works.


2012 ◽  
Vol 18 (3) ◽  
pp. 373-383 ◽  
Author(s):  
Anja Terzic ◽  
Zagorka Radojevic ◽  
Ljiljana Milicic ◽  
Ljubica Pavlovic ◽  
Zagorka Acimovic

The disposal of the fly ash generated in coal based power-plants may pose a significant risk to the environment due to the possible leaching of hazardous pollutants, such as toxic metals. Also, there is a risk of leaching even when fly ash is built-in the construction composites. Fly ashes from various landfills were applied in several composite samples (mortar, concrete and brick) without any physical or thermal pre-treatment. The leachability of the potentially toxic pollutants from the fly ash based products was investigated. The leaching behavior and potential environmental impact of the 11 potentially hazardous elements was tracked: Pb, Cd, Zn, Cu, Ni, Cr, Hg, As, Ba, Sb and Se. A detailed study of physico-chemical characteristics of the fly ash, with accent on trace elements and the chemical composition investigation is included. Physico/chemical properties of fly ash were investigated by means of X-ray fluorescence, differential thermal analysis and X-ray diffraction methods. Scanning electron microscope was used in microstructural analysis. The results show that most of the elements are more easily leachable from the fly ash in comparison with the fly ash based composites. The leaching of investigated pollutants is within allowed range thus investigated fly ashes can be reused in construction materials production.


Author(s):  
Michael E. Rock ◽  
Vern Kennedy ◽  
Bhaskar Deodhar ◽  
Thomas G. Stoebe

Cellophane is a composite polymer material, made up of regenerated cellulose (usually derived from wood pulp) which has been chemically transformed into "viscose", then formed into a (1 mil thickness) transparent sheet through an extrusion process. Although primarily produced for the food industry, cellophane's use as a separator material in the silver-zinc secondary battery system has proved to be another important market. We examined 14 samples from five producers of cellophane, which are being evaluated as the separator material for a silver/zinc alkaline battery system in an autonomous underwater target vehicle. Our intent was to identify structural and/or chemical differences between samples which could be related to the functional differences seen in the lifetimes of these various battery separators. The unused cellophane samples were examined by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Cellophane samples were cross sectioned (125-150 nm) using a diamond knife on a RMC MT-6000 ultramicrotome. Sections were examined in a Philips 430-T TEM at 200 kV. Analysis included morphological characterization, and EDS (for chemical composition). EDS was performed using an EDAX windowless detector.


2020 ◽  
Vol 7 (04) ◽  
Author(s):  
SATYA NARAYAN SINGH ◽  
RAJESH G BURBADE ◽  
HITESH SANCHAVAT ◽  
P S PANDIT

The cereals of today are more nutritious and healthful than ever before. Cereals processing is one of the oldest and the most essential part of all food technologies. Pasta products and noodles have been staple foods since ancient times in many countries all over the world. In this study pasta formulation was substituted with blending sapota powder in different proportions (4 levels i.e. 0%, 10%, 20%, 30%) into semolina and maida flour separately. Pasta products were prepared using eight different formulations and adding water (approximately 31% of total weight) in DOLLY pasta extruder machine. All the samples were evaluated for physical properties: specific length (mm/g), bulk density (kg/m3), specific density (kg/m3) and porosity (%); functional properties: water absorption index (%), water solubility index (%) and oil absorption capacity (ml/g) and nutritional compositions: moisture (%), crude protein (%), fat (%) and carbohydrate (%). Highest specific length 36.20 mm/g was observed for T5 treatment, low bulk density 368.10 kg/m3 was observed for T5 and highest porosity 9.24% was found for T1 treatment. The maximum WAI, WSI values 325.83%, 17.33% respectively was observed for T1 treatment and minimum value of oil absorption capacity 1.06 ml/g for T8 treatment. The moisture content of dried pasta products was found in the range of 6 to 7%. The maximum value of crude protein 13.07% was found for T5 and minimum value 8.81% for T4 treatments. The fat contents were varied from 1.02% to 1.28 %. The maximum value of carbohydrate was 76.20% for T1 and minimum value 65.41% for T8.


Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.


2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3132
Author(s):  
Paweł Wityk ◽  
Dorota Kostrzewa-Nowak ◽  
Beata Krawczyk ◽  
Michał Michalik ◽  
Robert Nowak

Radiation and photodynamic therapies are used for cancer treatment by targeting DNA. However, efficiency is limited due to physico-chemical processes and the insensitivity of native nucleobases to damage. Thus, incorporation of radio- and photosensitizers into these therapies should increase both efficacy and the yield of DNA damage. To date, studies of sensitization processes have been performed on simple model systems, e.g., buffered solutions of dsDNA or sensitizers alone. To fully understand the sensitization processes and to be able to develop new efficient sensitizers in the future, well established model systems are necessary. In the cell environment, DNA tightly interacts with proteins and incorporating this interaction is necessary to fully understand the DNA sensitization process. In this work, we used dsDNA/protein complexes labeled with photo- and radiosensitizers and investigated degradation pathways using LC-MS and HPLC after X-ray or UV radiation.


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