Cristiana Radulescu

Valahia University of Târgoviste · Institute of Multidisciplinary Research for Science and Technology

The food industry is a high consumer of polymer packing materials, sealing materials, and engineering components used in production equipment. Biobased polymer composites used in the food industry are obtained by incorporating different biogenic materials into the structure of a base polymer matrix. Renewable resources such as microalgae, bacteria,...

Plasma electrolytic oxidation method was used to form ceramic coatings on pure Ti substrates, using various aqueous solutions of sodium aluminate (15 g/L and 20 g/L, with or without the addition of NaOH, 2 g/L). The PEO process was carried out at constant time and voltage (300 seconds, 200 V). The ceramic coatings obtained by PEO were investigated...

Chemical analysis was performed on sediment core samples collected from three salt lakes, Amara Lake, Caineni Lake, and Movila Miresii Lake, located in the northeast of the Romanian Plain. The concentration of 10 main elements, 6 heavy metals (HMs), 8 rare earth elements (REEs), and 10 trace elements (TEs)—determined using neutron activation analys...

Abstract: Graphite was oxidized to graphene oxide and activated by thionyl chloride, for further covalently linking three hydrazides with potential biological activity. The obtained materials were characterized by scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared and Raman spectroscopies. The presence of v...

This study is the third in a series of investigations conducted by the authors, and certainly the most comprehensive research regarding the former uranium, copper, and charcoal mines from a particular geographical area of Romania. In this respect, the present scientific incursion focused on two areas containing former extraction uranium ore sites,...

The wastewater treatment process significantly decreases the negative impact of the effluent on human health compared to the influent. This probabilistic study, based on mathematical formulas, which does not involve clinical studies, investigates the impact of polluting chemical elements on health, which may be higher or lower, depending on other d...

Groundwater, which is the main source of water for human consumption in many rural areas, has its quality determined by the complex interaction of environmental factors and anthropogenic activities. The present study evaluated the quality of shallow groundwater (1 to 25 m depth) in the rural area of the Târgovişte Plain, a densely populated area (2...

Scope: Development of bio-based polymeric composites using algal biomass as filler, study of their physico-chemical and mechanical properties, and behavior under thermal, radiative and oxidative stress Bio-based polymeric composites are obtained by incorporating into the structure of the base polymer matrix different biogenic materials from renewab...

Heavy metals can reach into surface water mainly as a result of domestic and industrial activities. Copper, zinc, manganese, iron, etc. are just a few examples of heavy metals that are naturally present in soil and water, some are considered indispensable for life but, in high concentrations may become toxic. If external factors (domestic and indus...

The wastewater treatment process also includes the removal of heavy metals, which are characterized by high toxicity for the environment. In this study, the monitoring process of heavy metals (Cu, Ni, Cd, Pb, Zn) over a period of 91 days was described. The determinations were performed by flame atomic absorption spectrometry (FAAS) and graphite fur...

In this study, it was reported the preliminary results on the chemical and structural composition of decorative elements remains from original Roman mosaic fragments collected from the Roman Mosaic Museum, Constanta (Romania). These investigations were carried out by using non-destructive and micro-invasive techniques such as optical microscopy, X-...

In this study, it was reported the preliminary results on the chemical and structural composition of decorative elements remains from original Roman mosaic fragments collected from the Roman Mosaic Museum, Constanta (Romania). These investigations were carried out by using non-destructive and micro-invasive techniques such as optical microscopy, X-...

Chlorophyll-a is the pigment whose concentration is an important indicator for the development of microalgae biomass. This study aims at evaluating the concentration of chlorophylls in the biomass of granular activated algae, using acetone and 90% ethanol for the extraction procedures applied. Concentrations of chlorophyll a, b and c were determine...

In this paper was studied eight bivalve shells (with pigments traces) were collected from Cheia archaeological site (Eneolitihic site, dated between the end of the 6th millennium and the beginning of the 5th millennium cal BC, Romania), in order to establish correlations related to morphology, composition, longevity and belonging to the archaeologi...

The Scythian necropolis of Sâncrai (Alba County) was investigated in 2016, which led to the discovery of 95 burials (inhumation and cremation). The study of the tombs revealed a rich funerary inventory, composed mainly of ceramic vessels of different shapes and sizes; weapons such as akinakes daggers, spearheads, and arrowheads; ornaments including...

Problemele legate de conservarea descoperirilor arheologice excavate au cea mai mare relevanță astăzi. De cele mai multe ori, acestea au fost asimilate într-o manieră eronată, ca un amestec dintre o disciplină de cercetare (arheologie) și o profesie care urmărește păstrarea și îngrijirea obiectelor de patrimoniu (conservare). Conform acestui punct...

In this study, a resistive humidity sensor for moisture detection at room temperature is presented. The thin film proposed as a critical sensing element is based on a quaternary hybrid nanocomposite CNHox//SnO2/ZnO/PVP (oxidated carbon nanohorns–tin oxide–zinc oxide–polyvinylpyrrolidone) at the w/w/w/w ratios of 1.5/1/1/1 and 3/1/1/1. The sensing s...

The present paper is focused on the microclimatic investigation and weather-climatic phenomena matrix assessment, which can be generated for heritage objectives at different spatial and temporal resolutions, correlated with physicochemical analysis of the particulate matter (PM2.5-10). In the literature the importance of atmospheric PM monitoring i...

In this paper, we present the relative humidity (RH) sensing response of a chemiresistive sensor, employing sensing layers based on a ternary nanohybrids comprised of holey carbon nano-horns (CNHox), titanium (IV) oxide, and polyvinylpyrrolidone (PVP) at 1/1/1/ (T1), 2/1/1/ (T2), and with 3/1/1 (T3) mass ratios. The sensing device is comprised of a...

Food plants provide a regulated source of delivery of functional compounds, plant secondary metabolites production being also tissue specific. In grape berries, the phenolic compounds, flavonoids and non-flavonoids, are distributed in the different parts of the fruit. The aim of this study was to investigate the applicability of FTIR and Raman scre...

The use of natural ingredients with active functions has been intensively studied in the last years, as a consequence to consumer preferences for organic products. Application of circular economy principles determined a significant research activity in the viticulture field. The use or re-use of vines parts for so-called nutra-ceuticals or other co...

The relative humidity (RH) sensing response of a chemoresistive sensor using a novel ternary hybrid nanocomposite film as a sensing element is presented. The sensitive layer was obtained by employing the drop-casting technique for depositing a thin film of nanocomposite between the electrodes of an interdigitated (IDT) structure. The sensing suppor...

This paper presents the relative humidity (RH) sensing response of a resistive sensor employing sensing layers based on a ternary nanocomposite comprising graphene oxide-oxidized carbon nanohorns-polyvinylpyrrolidone (GO-CNHox–PVP), at 1/1/1, 1/2/1, and 1/3/1 w/w/w mass ratios. The sensing structure is composed of a silicon substrate, a SiO2 layer,...

We report the relative humidity (RH) sensing response of a resistive sensor, employing sensing layers, based on a quaternary organic–inorganic hybrid nanocomposite comprising oxidized carbon nanohorns (CNHox), graphene oxide (GO), tin dioxide, and polyvinylpyrrolidone (PVP), at 1/1/1/1 and 0.75/0.75/1/1/1 mass ratios. The sensing structure comprise...

The aim of this paper is to find out - for the first time - through archaeometric analysis the provenance of the Precucuteni-type pottery from Alba Iulia-Lumea Nouă settlement and whether it has a local origin or is an imported ceramic. The presence of so-called Precucuteni-type pottery in Transylvanian sites, decorated by motifs using excision tec...

This study aims to investigate a small wild cave, called Floriilor Cave, from the morphological structure and mineral composition point of view. This cave was accidentally discovered in 1991 and is currently closed to tourists; access is achieved only by the speleologists. The samples, including stalactites and stalagmites, rocks, and sediments, we...

This work attempts to show the usefulness of vibrational spectroscopy (i.e., FTIR and Raman) in the analysis of major components of the original structure materials of a heritage monument (Tropaeum Traiani, Adamclisi). The features of materials and indoor microclimatic variables (i.e., temperature and relative humidity), on the periods of the monit...

Metals concentrations of Cr, Ni, Co, Cu, Zn, Cd, and Pb in nettle (Urtica dioica) and soil samples, collected in April 2019 from several villages around Targoviste City, were determined. The samples were collected in the springtime (April 2019) when it is considered that the plants have reached the maturity and because inhabitants pick nettles for...

All water treatment plants (WWTPs) produce waste/residue known as sewage sludge (SS) during the purification of raw water. Typically, treatment procedures involve coagulation, flocculation, sedimentation, and filtration processes for removing colloidal as well as suspended solids from wastewater, then it follows chemical and biological processes. I...

The heavy metal concentration in plant tissues of Ranunculus ficaria, Plantago major, Taraxacum officinale, and Achillea millefolium, frequently consumed or used in traditional medicine, collected from one of radioactive area of Romania, not been previously reported by any research group. The content of Cr, Mn, Ni, Cu, Zn, Cd, Pb were determined by...

The therapeutic benefits of extracts obtained from different red grape fractions were thoroughly studied, however, data regarding the comparison of phytochemical extracts prepared from the same varieties coming from organic versus conventional management systems are rather lacking. The present study aimed at comparing some of the phytochemical char...

One of the most common problems encountered in everyday life is the pollution of the environment. Therefore, regardless of the nature of the daily activities of the population, this destructive effect of the natural balance finds its origin perhaps in the lack of capacity over time to treat the problem of waste (industrial and domestic) as it shoul...

Starting from isoniazid and carboxylic acids as precursors, thirteen new hydrazides and 1,3,4-oxadiazoles of 2-(4-substituted-phenoxymethyl)-benzoic acids were synthesized and characterized by appropriate means. Their biological properties were evaluated in terms of apoptosis, cell cycle blocking, and drug metabolism genes expression on HCT-8 and H...

In this study, the chemical composition of Juglandis semen extracts obtained by different extraction solvents and methods, were determined by Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The multivariate analyses: principal component analysis, k-means clustering and hierarchical cluster analysis of the FTIR and Raman spect...

Here we report on the results of the 2015 moss survey, when mosses were sampled at about 5,100 sites across Europe and beyond, either in 2015, 2016 or both. In 2015, reporting for metals has greatly increased from about 28 countries in previous surveys to 36 countries, mainly due to participation of more countries in the EECCA region. Nitrogen and...

The study aims a chemometric-based vibrational spectroscopy investigation, Fourier transform infrared (FTIR) and Raman spectroscopy, on the hydroalcoholic extracts obtained from four variety of red grapes (skin). The multivariate analysis, by combining both principal component analysis (PCA) and linear discriminant analysis (LDA) approaches (called...

Featured Application: This article may serve as a database for other research into mosaics and, also, as a guide for what methods may be applied. Abstract: The color characteristics, vibration spectra, phase and mineral composition, internal structural organization of several fragments of the ancient Roman mosaics from the Roman Mosaic Museum, Cons...

The water quality from rural areas, south of Targoviste city (e.g., with limited access to water sources) is essential to ensuring the well-living conditions for inhabitants and for sustainer the economic activities, including tourism. In this study, a total of 20 water wells were selected in order to provide a better spatial distribution across th...

Heavy metal concentrations of Pb, Cd, Zn, Ni, Cr, Mn, and Cu in drinking water collected from capture groundwater stations were determined. These values were correlated with physicochemical indicators. Concentrations of all metals were lower than maximum admitted limits established by Romanian Law 311/2004. The health risk index values for all dete...

AISI 316 steel has good corrosion behavior and high-temperature stability, but often prolonged exposure to temperatures close to 700 • C in aggressive environments (e.g., in boilers and furnaces, in nuclear installations) can cause problems that lead to accelerated corrosion degradation of steel components. A known solution is to prepare alumina ce...

This study aims to demonstrate that the investigated sample is nickel-rich, a signature of the meteorites composed of iron, in order to establish if studied sample belongs or not to Campo del Cielo meteorite group. The discrete structure found in meteorites is a fingerprint fully justified by structural analysis using optical microscopy (OM) and sc...

The invention relates to a composite biomaterial made of hydroxyapatite HAp reinforced with strontium titanate SrTiO, having improved physical, chemical and mechanical properties, compatible with the biological medium, applicable in implantology and tissue engineering, being intended for bone substitutes capable to replace, partially or totally, da...

This study aims to investigate the chemical composition of nineteen painted pottery fragments belonging to Eneolithic Petresti culture, in order to establish a link between the ceramic artifacts and the potential clay sources identified in the proximity of the archaeological site. In this respect, two analytical techniques (attenuated total reflect...

This study is the first attempt to decipher the effect of particulate matter (PM) composition on people's health and on historic sites, in correlation with the daily and seasonal microclimate monitoring of the indoor and outdoor areas of the Roman Mosaic Edifice museum (the maritime port of Constanta, Romania). More specifically, the increase of me...

Water quality is essential for ensuring humane living conditions for inhabitants around the world. In this context, an important aspect that must be taken into consideration is the water quality in rural areas. Special attention must be given in such cases due to a large number of possible pollution sources, from industrial or agricultural, to wast...

The archaeometric study of some samples from New gate TowerfromCorvins’Castle are analyzed in this paper in order to identify the raw materialsnature and weathering/deterioration processes of these artefacts. Modern analytical techniques, as XRD, FTIR, Raman, SEM-EDS, colorimetry, porosimetry, thermal analysis are used to evaluate the structure and...

For a better description and chronology of the liturgical art of the Russian-Lipovan community of Romania and, in view of correct attestation, a set of five icons presumed painted in the first half of the 19th century belonging to the patrimony of Antim Monastery (Bucharest) and One-wood Monastery (Valcea county), have been investigated by means of...

Characterization of several wild growing and cultivated mushrooms from geographical area of Dambovita County, Romania, in terms of enzymatic and non-enzymatic antioxidants, through a chemometrics approach, was the aim of this study. Related to the authors’ previous studies, the novelty of this paper consists in deepening research towards the comple...

This study aims to determine the elemental composition and the morphological structure of salt lake sediments collected from the Romanian Plain, in order to characterize their origin and evolution. Sediment cores were collected from Movila Miresii Lake in August 2017. Volumetric sampling was continuously performed for the composite profiles with 1...

Some samples from the towers of the Corvins’Castle, Hunedoara, are analyzed in this paper in order to identify the provenance of the raw materials and weathering / deterioration processes. Modern analytical techniques, as XRD, FTIR, Raman, SEM-EDS, colorimetry, porosimetry are used to evaluate the structure and chemical composition (quartz, mica, d...

The antioxidant properties of different plant extracts are usually claimed and used by food, medicine and cosmetic industry due to their health promoting capacities. In this study the presence of antioxidant compounds and the total antioxidant capacity of water-soluble extracts, prepared using two extraction methods and a variety of solvents, have...

Carbonated hydroxyapatite derivatives (CHAp) and its metallic derivatives (Ag, Sr, Ba, K, Zn) have been prepared and characterized in this paper and their coating capacity on some model stone samples have been evaluated and discussed. These compounds were characterized by using several analytical tools, including X-ray diffraction analysis (XRD), t...

This study aims to investigate the dose rate and pollution level of Ciudanovita, Lisava, Anina, and Moldova Noua mining tailings dumps. In order to accomplish this, soil samples were collected according to LUCAS 2009/2012, in the summer of 2017. To start with, these samples were measured in situ for dose rate and revealed some interesting aspects,...

The aim of this study is to explore in-depth microstructural changes induced by Plasma Electrolytic Saturation nitriding and carburizing treatments applied to the AISI 304L steel. The obtained structures were characterized by X-Ray Diffraction, Metallography, X-ray Photoelectron Spectroscopy and Small Angle Neutron Scattering; an assessment of the...

Chemical compounds from plant extracts offer unlimited opportunities as cosmetic additives due to their availability and chemical diversity. Increasing demand for chemical compounds from different classes made the plant extracts, edible plant extracts in particular, useful for cosmetic products. The profile of bioactive compounds contained by the s...

In recent years, natural plants experience a growing interest in many fields (cosmetic, pharmaceutical, food etc.), and represent an important source of bioactive molecules. The aim of this work was to investigate the antioxidant activity of Hippophae rhamnoides L. berries extracts obtained by three methods (i.e. ultrasound-assisted extraction, rap...