română Insights on the mechanisms of seawater-mixing calcium silicate slag-based alkali-activated materials
DI SHI, JIAYUAN YE, WENSHENG ZHANG, WEIGUO SHEN
Abstract
In order to get a full understanding of the mechanisms of seawater-mixing alkali-activated materials, calcium silicate slag (CSS)-based alkali-activated materials (AAMs) with various content of Cl- were synthesized, and then the effect of Cl- on the properties, products, hydration heat evolution, microstructure of AAMs, as well as the characteristics of alkaline solution were investigated. The results showed that the Cl- introduced in the form of solid NaCl significantly decreased the mechanical properties of CSS-based AAMs in the range higher than 1 wt%. This properties degradation can be attributed to the hydration inhibitions caused by the dissolution of solid NaCl and the interaction between NaCl and sodium silicate solution, as well as the formation of non-cementitious sodalite other than C(N)-A-S-H gels. Despite this, the findings of this study provided further evidence for the application potentialities of seawater in AAMs as mixing water due to the limited content of Cl- in seawater.
Keywords
calcium silicate slag; alkali-activated materials; Cl-; interaction; seawater-mixing
ECEM DOGAN, MUSTAFA SENGOR, OGUZHAN GUNDUZ, CEM BULENT USTUNDAG
Abstract
This study aims to obtain nanoparticles by electrospinning method using xanthan gum (XG) and gelatine (GEL) polymers. For the development of these nanoparticles, ten different groups were produced. In some groups, nanofiber was obtained instead of particles. The nanofiber formation was determined in the 10 wt% GEL, 12 wt% GEL, 3 wt% XG, 8 wt% GEL + 3 wt% XG. 12 wt% GEL + 0.1 wt% XG groups. 4 wt% GEL + 1 wt% XG and 8 wt% GEL + 3 wt% XG groups showed nanoparticles structure. To assess the nanofibers chemical properties, Fourier transform infrared spectroscopy (FTIR) were used. Scanning electron microscopy (SEM) was used to characterize mechanical and morphological properties. Physical properties and swelling behaviours were examined to analyse the samples. As a result of the swelling test, 3 wt% XG was degraded, 10 wt% and 12 wt% gelatin groups started to degrade after the fourth day. Our work deduced that GEL/XG nanoparticles could use for carrier purposes. Also, this study was beneficial in finding the right ratios in the production of nanoparticles and nanofibers from the XG/GEL mixture by electrospinning. In addition, proper electrospinning parameters in nanofiber and nanoparticles production are also important results of the study and will be further used in developing composite nanostructures with regenerative or drug release capability.
Keywords
gelatin; xanthan gum; electrospinning; particle; fiber
Keywords
Experimental, behavior, polystyrene, light backfill, polyglass, uni-axial, reinforcement.
CONSTANTIN C. BUNGAU, TUDOR BUNGAU, MARCELA FLORINA PRADA, IOANA FRANCESCA PRADA, RADU DUMITRU MOLERIU
Abstract
Green buildings (GBs) aim to improve the characteristic performance of buildings throughout their entire life cycle, to conserve resources and increase the comfort of residents. The theme of GBs is very specific to the field of construction. However, a relevant, current analysis of the specialized literature in the field, to evaluate the scientific impact and citations, is missing. This study aims to identify and analyze already published scientific papers. In this context, the Scopus database was comprehensively explored. Therefore, the records and citations of the 8612 identified manuscripts were imported into VOSviewer to perform this bibliometric analysis. Most of the manuscripts were published after 2010. The publications were mainly focused on terminology characteristics of sustainable development (i.e. sustainability, GBs, construction). The publication share increased every year. The main contributors to this area are the United States of America, China, Italy, and the United Kingdom. The most prolific journals were Energy and Buildings, Sustainability, Building and Environment and Journal of Cleaner Production. Temporal analysis of citation patterns revealed an intense growth of scientific interest, focusing especially on green/sustainable buildings especially in the recent period. Romania is only at the beginning of approaching this topic, the first work being published only in 2003 and oscillations in the publication tendency being observed.
Keywords
Green buildings; sustainability; constructions; energy performance; bibliometric analysis
IULIANA PAUN, CRISTINA ILEANA COVALIU- MIERLA, EUGENIU VASILE
Abstract
Benzalkonium chlorides are among the active ingredients of the products with biocidal properties used for disinfection of hands and surfaces. After use, a large part of benzalkonium chlorides end up in the wastewater from the treatment plants where they can cause imbalances of the biological treatment step by destroying the bacteria in the activated sludge. Having bactericidal properties, these pollutants are unlikely to be removed by conventional wastewater treatment techniques. In this paper we present an unconventional method for wastewater treatment using TiO2 nanomaterial with a particle size of 10 nm having the photocatalytic activity for degrading two components of benzalkonium chloride, namely tetradecyldimethyl benzyl ammonium chloride (C14-BAC) and hexadecyldimethylbenzyl ammonium chloride (C16-BAC) from wastewater. The concentration of the two compounds was analyzed using a high-performance liquid chromatograph equipped with a diode array detector (HPLC-DAD). The wastewater treatment yield was 100 %, and the half-life was for C14-BAC of 7.56 h and for C16-BAC of 10.67 h.
Keywords
benzalkonium chloride, nanomaterial, TiO2 powder, wastewater treatment
MUSA AYRAN, ZEKIYE AKDAG, SONGUL ULAG, OGUZHAN GUNDUZ
Abstract
Diabetic wounds pose a significant challenge in clinical settings, primarily due to uncontrolled blood sugar levels and compromised immune systems observed in diabetes mellitus. Curcumin (CUR), a well-known anti-inflammatory and antioxidant agent, has shown potential for wound regeneration. However, its limited bioavailability and stability necessitate the development of a novel scaffold to overcome these limitations. In this study, we investigated the wound-healing properties of extracted CUR from Curcuma longa rhizomes and their combination with organic polymers by developing and evaluating a biomimetic composite 3D scaffold specifically designed for diabetic wounds. Incorporating CUR and Ethyl cellulose (EC) nanoparticles onto Alginate and Chitosan (SA/CS) scaffolds was achieved through the electrospraying method, resulting in an average particle size of 784±35.1 nm for CUR/EC nanoparticles. The interaction between different concentrations of CUR1 and CUR3 (1mg/1ml and 3mg/1ml) with EC on scaffolds was analyzed using FTIR spectroscopy, providing insights into the chemical composition of the scaffolds. The structural properties of the scaffolds and nanoparticles were examined to assess their morphological characteristics. Furthermore, the swelling and degradation behaviors of the scaffolds were investigated under in vitro conditions. The release profile of CUR was determined, and cytotoxicity testing was performed on the L929 cell line using an MTT assay to evaluate the biocompatibility of CUR/EC-coated scaffolds, as indicated by viable and proliferating cells in vitro study. In addition, the potential of CUR/EC-coated scaffolds to support tissue regeneration was evaluated using a DAPI staining assay and scanning electron microscopy (SEM).
Keywords
alginate, chitosan, curcumin, electrospraying, wound healing, 3D printing
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Year
2023
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Issue
53 (3)
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Pages
189-204
PAVEL TOPALĂ, ALEXANDR OJEGOV, VITALIE BEȘLIU, DANIELA RĂILEANU
Abstract
Micro- and nano-technology is nowadays a field of production that grows up vigorously and attempts to solve the material and energy crisis that has affected all mankind on the one hand, and, on the other hand, it comes with new solutions in miniaturization of the technique and solving the problems faced by the compatibility of existing materials with the living matter, i.e. it comes with apply for a better life. The recent studies regarding the interaction of surface materials with plasma pulsed electrical discharges caused by a solitary discharge have shown that under the action of PEDM the active surfaces of the parts applied in machine building, electronics, chemical industry, food industry, medicine, etc. micro-modifications of these surfaces can take place, along with the formation of 3D-structured carbon films with micrometric thicknesses, synthesis of amorphous films of oxides and hydroxides of nanometres thicknesses. The application of surface micro-geometry modifications ensures the increase of the thermoelectric current of the electrons up to 10 times, the surface-active resistance by 107 times, the resistance to corrosion in the aggressive media from 2 to 100 times.
Keywords
micro-, nanotechnologies, pellicle, film, corrosion, emission, resistance