Preserving The Mechanical Properties of Metakaolin-Based Geopolymer
Composite Exposed to Thermal Stress by Using Refractory Filler Wastes
LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania,
lucianpaunescu16@gmail.com ADRIAN IOANA, National University of Science and Technology POLITEHNICA
Bucharest, Faculty of Science and Materials Engineering, Romania ENIKÖ
VOLCEANOV, National University of Science and Technology POLITEHNICA
Bucharest, Faculty of Science and Materials Engineering, Romania,
Metallurgical Research Institute SA Bucharest, Romania
Abstract Metakaolin-based geopolymer composite with addition of
refractory filler wastes (super-aluminous concrete and silica fire brick)
recycled from heating oven demolition was designed and tested under thermal
stress conditions at temperatures up to 900°C. The method of alkaline
activating patented by Davidovits was applied. The originality of the work
consists in choosing the super-aluminous concrete waste from the demolition
as the main raw material of the process, increasing the heat treatment
temperature to 90°C, and adopting the storage for a much longer period (28
days). Tests to thermal stress by exposure to 600 and 750°C showed the
favourable influence of the addition of refractory fillers on preserving the
mechanical stability of the geopolymer composite. The loss of compression
and flexural resistance after exposure to 900°C compared to the reference
sample is acceptable for using this technique in the case when the stability
at high temperature is required. Keywords: geopolymer composite,
refractory filler waste, metakaolin, thermal stress, mechanical strength.
Quantitative Spectrophotometric Determination of Au(III) Ions in Aqueous
Solution with Basic Violet 10 Dye
BIANCA-MARIA HĂISAN, “Gheorghe Asachi” Technical University of Iaşi,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iaşi, Romania ALEXANDRA-GEORGIANA APOSTICĂ, “Gheorghe
Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of
Chemical Engineering and Environmental Protection, Iaşi, Romania LAURA
BULGARIU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor
Simionescu” Faculty of Chemical Engineering and Environmental Protection,
Iaşi, Romania, lbulg@ch.tuiasi.ro
Abstract Spectrophotometric determination of Au(III) ions with Basic
Violet 10 dye is a rapid, sensitive and accurate method that can be used in
quantitative analysis. The colour reaction occurs immediately in acidic
aqueous solution (pH = 0, HCl solution), and this represents an important
advantage from a practical point of view. The qualitative parameters of
coloured Au(III)-complex (maximum wavelength (500 nm), width of the spectral
band (120 nm) and molar absorption coefficient (2.55·104 L·mol-1·cm-1))
suggest the possibility of using this reaction in quantitative analysis.
Lambert-Beer’s law was obeyed in the Au(III) concentration range of 0.4 –
2.0 mg·L-1, while the detection limit and limit of quantification were found
to be 0.067 mg·L-1 and 0.22 mg·L-1. This colour reaction is quite selective
for Au(III) ions in the presence of some interfering ions (Cu(II), Zn(II),
Na(I)), while other metal ions (such as Ca(II), Mg(II), Co(II)) interfere to
a great extend. The measurements performed using tap water as a background,
showed that there are significant differences between the concentration of
Au(III) ions, added and calculated from the calibration curve, which limits
the applicability of this method in the analysis of real samples.
Keywords: Spectrophotometric method; Au(III) ions; Basic Violet 10;
quantitative analysis.
Visible-Light Photocatalytic Degradation of Tartrazine Using ZnO
Nanoparticles: Preliminary Phytotoxicity Investigations on Treated Solutions
MARIA PAIU, “Gheorghe Asachi” Technical University of Iași, “Cristofor
Simionescu” Faculty of Chemical Engineering and Environmental Protection,
Iași, Romania LIDIA FAVIER, Univ Rennes, Ecole Nationale Supérieure de
Chimie de Rennes, CNRS, ISCR – UMR6226, Rennes, France DOINA LUTIC,
“Alexandru Ioan Cuza” University from Iași, Faculty of Chemistry, Iași,
Romania RALUCA-MARIA HLIHOR, “Ion Ionescu de la Brad” Iași University of
Life Sciences, Faculty of Horticulture, Department of Horticultural
Technologies, Iași, Romania MARIA GAVRILESCU, “Gheorghe Asachi”
Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical
Engineering and Environmental Protection, Iași, Romania, Academy of Romanian
Scientists, Bucharest, Romania,
mgav@tuiasi.ro
Abstract Effluents containing synthetic dyes are often discharged
untreated, contributing to widespread contamination and disrupting aquatic
ecosystems. Advanced oxidation processes (AOPs), particularly
photocatalysis, offer promising alternative solutions to address this issue.
This study investigates the photocatalytic degradation of tartrazine (TZ)
using elaborated zinc oxide. The toxicity of the transformation products
generated during this process was also examined. Preliminary phytotoxicity
tests using Lepidium sativum L. seeds revealed significant growth of
vegetative organs in untreated solutions. Similar values to the control
sample were observed in photocatalytically treated solutions, possibly due
to the conversion of toxic intermediates into less harmful by-products. The
successful elimination of TZ under visible-light irradiation conditions
confirms the potential of ZnO-based photocatalysis as a viable solution for
mitigating water pollution caused by food dye contaminants. Keywords:
degradation, food dyes, Lepidium sativum, photocatalysis, phytotoxicity.
Squalene – Background and Perspectives in Cosmeceuticals Formulas
CLAUDIA MAXIM, “Gheorghe Asachi” Technical University of Iași,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iași, Romania DELIA TURCOV, “Gheorghe Asachi” Technical
University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering
and Environmental Protection, Iași, Romania, ”Grigore T. Popa” University of
Medicine and Pharmacy Iași, Faculty of Medical Bioengineering, Iași, Romania ANDREEA GABRIELA BULGARIU, “Gheorghe Asachi” Technical University of
Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and
Environmental Protection, Iași, Romania DANIELA ȘUTEU, “Gheorghe Asachi”
Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical
Engineering and Environmental Protection, Iași, Romania,
danasuteu67@yahoo.com
Abstract The barrier function of the skin layers is particularly
important for skin health. Risk factors that compromise the integrity of
this function act continuously, so that the daily skin ritual must ensure,
among other things, the restoration of the basic elements necessary for this
purpose. One of the modern assets included with this purpose in
dermatocosmetic formulas is squalene. Its role is multiple: restores lipid
balance on the skin surface, prevents transepidermal water loss, protects
against oxidative damage. It can also act as a carrier for other active
substances in the deep layers of the skin. As much is already known about
squalene, so many aspects are still being researched on its optimal
obtaining and use. This article summarizes the current information about
this undeniably valuable and necessary ingredient in modern dermatocosmetic
formulas. Keywords: dermatocosmetic, skin lipid, squalene, plant
resource.
Detection of High CH4 Concentrations at Natural Gas End-Use
Distribution Network in Urban Areas
MUSTAFA HMOUDAH, Faculty of Environmental Science and Engineering,
University of Babeş-Bolyai, Cluj-Napoca, Romania,
mustafa.hmoudah@gmail.com CRISTIAN POP, Faculty of Environmental Science and Engineering, University
of Babeş-Bolyai, Cluj-Napoca, Romania CĂLIN BACIU, Faculty of
Environmental Science and Engineering, University of Babeş-Bolyai,
Cluj-Napoca, Romania
Abstract Since the industrial revolution, CH4 emissions have
increased by 150%. Urban Areas are responsible for approximately 60% of
these emissions, mainly coming from anthropogenic activities. Besides,
urbanization caused changes in land use and reduced CH4 sinks. The sources
of CH4 emissions in Urban Areas still have a high degree of uncertainty.
Recent studies have stated that leaks from natural gas distribution networks
are significant sources of CH4 in the atmosphere, and they also represent a
potential loss of energy resources. However, emissions from end-use natural
gas networks are poorly explored in the literature. The main contributors in
the Romanian CH4 budget are the agriculture and energy sectors. Over the
period 1989–2000, methane emissions rate decreased by 34% due to sectoral
changes in agriculture and fossil fuels. Nevertheless, the Romanian national
inventory doesn’t report CH4 emissions from urban areas. This study
investigates CH4 concentration from the end-use natural gas distribution
networks in Cluj-Napoca, the second-largest city in Romania in terms of
population. These points can be identified as part of the natural gas
distribution networks that serve natural gas to end users for gas
consumption. The detected points were pipeline junctions and natural gas
meters. The estimation of CH4 concentration in the atmosphere was carried
out based on a laser CH4 sensor Tunable Diode Laser Absorption Spectroscopy
(TDLAS) with high measuring accuracy of 0.1 ppmv. This CH4 concentration
detection was performed from December 2022 to January 2023 at 74 natural gas
end-use points. The determination of whether to represent leaks or not was
quite after estimating the background level in the city and comparing the
obtained concentrations with this background. This study has revealed that
76% of the detected end-use natural gas distribution points have gas leaks
and represent continuous contributors to CH4 annual budget. However, this
contribution to the annual budget should be estimated. Moreover, the results
of this study indicate the presence of high leaks from natural gas end-use
points in urban areas. They suggest in-depth investigation and allocation of
all natural gas leaks at the end-use points, in order to take certain
reduction measures regarding CH4 mitigation. Keywords: greenhouse gas,
methane, atmosphere, urban areas, natural gas end-use networks, gas leaks.
Strength and Porous Building Material Prepared from Recycled Residual
Glass Through Microwave Radiation
LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania, lucianpaunescu16@gmail.com SORIN MIRCEA AXINTE, Daily Sourcing & Research SRL Bucharest, Romania,
National University of Science and Technology POLITEHNICA Bucharest, Faculty
of Applied Chemistry and Materials Science, Bucharest, Romania
Abstract New method of producing strength and porous cellular glass
with load-bearing properties from recycled flat glass using simultaneously
two expanding agents: glycerol (liquid) and eggshell (solid) recycled as a
by-product from the food industry was designed and tested by microwave
heating. Eggshell was used as a substitute for the usual calcium carbonate
and the microwave heating was made by the original method of predominantly
direct and partially indirect heating leading to energy saving. Results
showed that cellular glass with low bulk density (0.16-0.19 g·cm-3) and high
compression strength (up to 7.6 MPa) were obtained. Keywords: cellular
glass, flat glass waste, microwave heating, glycerol, eggshell.
Exploring Hesperidin's Therapeutic Potential in Cancer Therapy: A Review
MĂLINA MARIA CERNĂTESCU, “Grigore T. Popa” University of Medicine and
Pharmacy Iași, Faculty of Medicine, Iași, Romania, malinacernatescu1@gmail.com CLAUDIA COBZARU, “Gheorghe Asachi” Technical University of Iași,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iași, Romania CORINA CERNĂTESCU, “Gheorghe Asachi” Technical
University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering
and Environmental Protection, Iași, Romania
Abstract Hesperidin, a flavonoid abundant in citrus fruits, has
gathered attention for its promising anti-cancer properties. This review
explores the complex mechanisms through which hesperidin influences
oncogenesis and tumour progression. Studies reveal hesperidin's ability to
target key pathways involved in cancer development, including
hypoxia-induced HIF-1α activation, oxidative stress-mediated signalling, and
epithelial-mesenchymal transition (EMT). In vitro and in vivo experiments
showed hesperidin's capacity to inhibit angiogenesis, to suppress cell
proliferation, and to induce apoptosis in various cancer models.
Furthermore, hesperidin has been demonstrated to exhibit synergistic effects
with conventional chemotherapy, thereby enhancing its anti-cancer efficacy,
while simultaneously reducing its associated risks. Aside from the promising
preclinical findings, further clinical studies are needed in order to
elucidate hesperidin's therapeutic potential and to optimize its use in
cancer treatment strategies. Understanding the complex interaction between
hesperidin and cancer-related pathways could accelerate the development of
novel therapeutic approaches, with the goal of preventing cancer progression
and improving patient outcomes. Keywords: Hesperidin, Cancer therapy,
Hypoxia, Oxidative stress, Epithelial-mesenchymal transition.
The Photocatalytic Degradation of Ceftriaxone in Wastewater Using Hybrid
ZnS-ZnO Photocatalyst
GABRIELA ANTOANETA APOSTOLESCU, “Gheorghe Asachi” Technical University
of Iași, Romania, “Cristofor Simionescu” Faculty of Chemical Engineering and
Environmental Protection, Iași, Romania MIHAELA AURELIA VIZITIU,
“Gheorghe Asachi” Technical University of Iași, Romania, “Cristofor
Simionescu” Faculty of Chemical Engineering and Environmental Protection,
Iași, Romania ISABELA CONSTANȚA LUCHIAN, “Gheorghe Asachi” Technical
University of Iași, Romania, “Cristofor Simionescu” Faculty of Chemical
Engineering and Environmental Protection, Iași, Romania VALERIA
DUBĂSARI, “Gheorghe Asachi” Technical University of Iași, Romania,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iași, Romania IOANA IZABELA ZAHARIA, “Gheorghe Asachi”
Technical University of Iași, Romania, “Cristofor Simionescu” Faculty of
Chemical Engineering and Environmental Protection, Iași, Romania ȘTEFANIA ALESANDRA BOBEȘ, “Grigore Alexandrescu” Emergency Children’s
Hospital, Bucharest, Romania CĂTĂLIN DUMITREL BALAN, “Gheorghe Asachi”
Technical University of Iași, Romania, “Cristofor Simionescu” Faculty of
Chemical Engineering and Environmental Protection, Iași, Romania RAMONA
ELENA TĂTARU-FĂRMUȘ, “Gheorghe Asachi” Technical University of Iași,
Romania, “Cristofor Simionescu” Faculty of Chemical Engineering and
Environmental Protection, Iași, Romania NICOLAE APOSTOLESCU, “Gheorghe
Asachi” Technical University of Iași, Romania, “Cristofor Simionescu”
Faculty of Chemical Engineering and Environmental Protection, Iași, Romania,
nicolae.apostolescu@academic.tuiasi.ro
Abstract The elimination of organic pollutants from water poses a
considerable challenge in environmental remediation in this study, the
potential of ZnS-ZnO semiconductors as efficient photocatalysts for
degrading aqueous solutions of ceftriaxone (CEF) was investigated in a
mini-UV reactor. The ZnS-ZnO heterostructures were synthesized via the
hydrothermal method and characterized using analytical techniques (SEM,
FTIR), demonstrating considerable photocatalytic activity (UV-Vis
monitoring), with degradation of CEF occurring within a relatively short
period of time. Keywords: ceftriaxone, degradation, photocatalysis, ZnS
- ZnO.
Synthesis and Characterization of Azobenzene Alkylated Mesogen with
Fluorine Substituent
IULIAN BERLADEAN, “Gheorghe Asachi” Technical University of Iași,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iași, Romania AUREL SIMION, “Gheorghe Asachi” Technical
University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering
and Environmental Protection, Iași, Romania IRINA CÂRLESCU, “Gheorghe
Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of
Chemical Engineering and Environmental Protection, Iași, Romania,
icarlescu@ch.tuiasi.ro NICOLAE HURDUC, “Gheorghe Asachi” Technical University of Iași, “Cristofor
Simionescu” Faculty of Chemical Engineering and Environmental Protection,
Iași, Romania
Abstract The paper presents synthesis and characterization of
azobenzene compound that contains 10 carbon atoms as flexible terminal chain
and one fluorine atom as lateral polar substituent. The synthesis was
achieved by diazotization of 4-amino benzoic acid and coupling of diazonium
salt to 2-fluorophenole, followed by alkylation with a bromoalkyl compound.
The synthetized compounds were purified and their structures were confirmed
by 1H-NMR and 13C-NMR studies. Keywords: diazotization, coupling,
fluorine, alkylation.