Nikolaos A. Kazakis

• PhD in Chemical Engineering and PhD in Physics
• Principal Investigator at Athena - Research and Innovation Center in Information, Communication and Knowledge Technologies

The use of living Arthrospira platensis (A. platensis) cultures emerges as a promising green solution for the bioremediation of water contaminated by toxic metal waste. The scope of the present study is to evaluate the microalga’s potential in heavy metal remediation, in the case of multi-metal-treated (multi-MT) systems. For this reason, A. platen...

This CIDACC dataset was created to determine the cell population of Chlorella vulgaris microalga during cultivation. Chlorella vulgaris has diverse applications, including use as food supplement, biofuel production, and pollutant removal. High resolution images were collected using a microscope and annotated, focusing on computer vision and machine...

Food sterilization with ionizing radiation is a well-established technology, which is constantly extending to several products due to its numerous advantages. However, radiosterilization is prohibited to several food categories, such as baby food products since it could cause nutrient degradation of such foods with significant effects on the infant...

Silicate minerals extracted by dried herbs are broadly used for the determination of food products that are sterilized by means of radiation. At the same time, it is necessary to calculate the applied sterilization dose for these products, since there are certain pre-defined dose limits for the variant food categories. In addition, researchers seek...

Disaster risk management of movable and immovable cultural heritage is a highly significant research topic. In this work, we present a pipeline for 3D digitisation, segmentation and annotation of large scale urban areas in order to produce data that can be exploited in disaster management simulators (e.g fire spreading, crowd movement, firefighting...

Retrospective/accidental dosimetry seeks for materials that can be used as probes for the dose assessment by means of several methods when there is no dose data available (e.g. from personal dosimeters). In the same respect, researchers also seek materials appropriate for forensic purposes, which would allow to identify the prior presence of radioa...

Marble has been used as decorative or building material since ancient times. Various archaeological marble materials of cultural heritage (e.g., statues) are frequently encountered in excavation sites amongst other finds. The scope of the present work is to investigate whether natural marble could be used for dosimetric purposes in cultural applica...

Recent trends in archaeological research dictate the incorporation of various analytical methods for dating, chemical/mineralogical characterization, morphological description, etc. of various excavation findings and landscapes to support and corroborate the archaeologists' observations. Each method, when used individually, provides a different fee...

The present work explores the luminescence behavior of animal bones and more specifically, chicken bones, using OSL in order to investigate whether they can be used for the dose assessment in the case of an accident or as dosimeters at the post-sterilization dosimetry of foods. Results indicate that the OSL sensitivity is rather low and the lower...

This study uses chemical analysis (micro-XRF) to study a group of ceramic roof tiles from the Early Christian basilica in Paliambela (N Greece) that carry a number of different fingerline signatures, in order to collect compositional data on the provenance of the tile materials. It analyses the interrelatedness of the signatures and discusses alter...

The present work presents a new user-friendly and dynamic tool, TLDecoxcel, for the computerised curve deconvolution analysis (CCDA) of simple or complex TL glow peaks using Microsoft® Excel. TLDecoxcel can be applied for the fitting of glow curves consisting of discrete-energy peaks (general or mixed order) or continuous-energy-distribution peaks...

The present comment concerns the correct presentation of the equations giving the CW-OSL intensity in the case of second- and general-order kinetics. Those Equations have also been published with their wrong formulation in two eminent books in their topic. Since most researchers (especially early stage) would use directly the proposed functions as...

Sterilization with gamma irradiation has been established as an acceptable method highly advantageous compared to other methods for the sterilization of several products, including pharmaceutical preparations. However, the effects of irradiated drugs on the consumer when they are introduced in the human body are still unknown. Thus, consumers shoul...

The present comment concerns the correct presentation of an algorithm proposed in the above paper for the glow-curve deconvolution in the case of continuous distribution of trapping states. Since most researchers would use directly the proposed algorithm as published, they should be notified of its correct formulation during the fitting of TL glow...

Metal production sites are characterized by slag heaps which are often difficult to date due to a general lack of diagnostic pottery. This problem has been countered in recent years by the use of absolute dating techniques. Furnace fragments of severely fired clay, which are usually present in such production sites, represent an ideal material for...

Drug sterilization with ionizing radiation is a well-established technology, which allows the adequate sterilization of heat-sensitive pharmaceutical preparations. However, the effects of irradiated drugs on the consumer when they are introduced in the human body are still unknown. Moreover, appropriate methods and protocols for the detection of ir...

Recent trends in archaeological research dictate the incorporation of various analytical methods for dating, chemical/mineralogical characterization, morphological description, etc. of various excavation findings and landscapes to support and corroborate the archaeologists’ observations. Each method, when used individually, provides a different fee...

The present study constitutes the first part of a meteorite project, currently in progress, towards the full and thorough dosimetric study (TL and OSL) of two different meteorites of recent fall, Norton County and Holbrook. Both meteorites exhibit strong TL sensitivity, linear dose response and no saturation for doses up to 2 kGy. However, the two...

Accurate estimation of the radiation released at incidents, such as nuclear accidents or radiological terrorist events is of major importance for the prediction of health effects following such an incident. The luminescence properties of several materials are studied in order to assess their potential use as dosimeters in such cases. However, the p...

Estimation of the radiation released during nuclear accidents or radiological terrorist events is imperative for the prediction of health effects following such an exposure. In addition, in several cases there is a need to identify the prior presence of radioactive materials at buildings or sites (nuclear forensics). To this direction, several mate...

Extensive measurements of (222)Rn in the town of Xanthi in N Greece show that the part of the town overlying granite deposits and the outcrop of a uranium ore has exceptionally high indoor radon levels, with monthly means up to 1500 Bq m(-3). A large number of houses (40%) in this part of the town exhibit radon levels above 200 Bq m(-3) while 11% o...

Signals acquired during thermoluminescence or optically stimulated luminescence measurements must be completely free of any spurious and/or contamination signals to assure the credibility of the results, especially during exploratory research investigating the luminescence behavior of new materials. Experiments indicate that such unwanted signals m...

The present work constitutes the first two phases of the archaeometric study of the so-called “Siphnian” ware found in two different geographical regions in Greece, Argilos, in eastern Macedonia, and its metropolis in southern Greece, Andros island. Identification of the provenance of the Siphnian-type pottery found in the above regions is the prin...

The object of the present study is the evaluation of the research quality of the three Greek chemical engineering departments (Athens, Thessaloniki, Patras) by means of several advanced bibliometric indices calculated separately for each academic using a twofold approach, namely in department and academic rank level. This allows the ranking of the...

Quality evaluation and its assurance in higher education institutions constitute an obligation and scope of most European Universities. To accomplish this, quantitative indices, known as bibliometrics, are recruited which are considered a useful evaluation tool particularly for academics’ and Universities’ research performance. In the present study...

Quality in Higher Education Institutions is the subject of several debates in the academic community in a worldwide basis and various efforts are made towards identifying ways to quantify it. In this respect, the use of bibliometrics gains significant ground as an effective tool for the evaluation of universities’ research output. In the present st...

Various types of Late Neolithic decorated pottery excavated in Polyplatanos (Imathia, Greece) such as Crusted (C), Classical Dimini (CD), Black-on-Red (BoR), Cream-on-Red (CoR) and Graphite (G) were archaeometrically studied in order to investigate their provenance and to clarify specific technological features. The clay bodies, the paints and the...

The development and organization of iron production in northern Greece and its concomitant economic importance has rarely attracted scholarly attention. The region of northern Greece and in particular eastern Macedonia and Thrace has been one of the most important metal producing regions in the ancient Aegean. Until quite recently the spatial analy...

The Cultural and Educational Technology Institute in Xanthi (“Athena” Research Centre, www.athena-innovation. gr, www.ipet.gr) is carrying out an archaeometrical study in collaboration with the excavators of Argilos (Z. Bonias and J. Perreault) and Andros (S. Paspalas and Ch. Televantou) in order to investigate the archaeological issue regarding th...

The paper presents the results of an archaeometric study of G 2-3 Ware samples conducted between 2008 and 2011 in the Cultural and Technological Institute/ R.C. “Athena” in Xanthi, Greece. It aimed to determine the chemical composition of 118 ceramic samples found in Samothrace (Fig. 2), Thassos (Fig. 7), Neapolis (Fig. 6), Eion (Fig. 5), Argilos (...

New experimental data concerning the gas holdup in bubble columns equipped with porous sparger were acquired. The effect of surfactant additives on gas holdup in the pseudo-homogeneous regime has been studied. Three different commercial surfactants (Triton X-100 (R), SDS (R), CTAB (R)) were used and four aqueous solutions of each one were employed,...

This work presents experiments in a bubbly flow comparable to the one observed during decompression sickness (DCS) in humans. Experiments are conducted in a tube dimensionally similar to vena cava of the human body with liquids of various properties (surface tension, viscosity, conductivity) and liquid flow rates equivalent to those of human blood...

This work studies the effect of the liquid properties and the operating conditions on the interactions between under-formation bubbles in a cell equipped with two adjacent micro-tubes (i.d. ) for the gas injection, placed 210, 700 and apart. This set-up simulates, though in a simplified manner, the operation of the porous sparger in a bubble column...

This work is a study of the effect of liquid properties and pore size on the initial bubble size distribution of a bubble column equipped with fine pore sparger. Various liquids covering a wide range of surface tension and viscosity values are employed, while the gas phase is atmospheric air. A fast video recording technique is used for both the vi...

Bubble columns are gas-liquid contactors encountered in a wide range of applications, e.g., coal liquefaction. The effect of surfactant additives on gas holdup in the homogeneous regime in bubble columns with porous sparger was studied. Three different commercial surfactants (Triton X-100®, SDS®, and CTAB®) were used and four aqueous solutions of e...

This work is a study of the effect of liquid properties and the operating conditions on the interactions between under-formation bubbles. Experiments were conducted in a cell equipped with two adjacent micro-tubes (i.d. 110 μm) for the gas injection whose relative position was 210, 700 and 1370 μm. This set-up simulates, though in a simplified mann...

New experimental data concerning the gas holdup in bubble columns equipped with porous sparger were acquired. The effect of liquid properties and sparger characteristic (i.e., pore size, dimensions) on gas holdup at the pseudo-homogeneous regime has been studied and a correlation regarding the prediction of the transition point from the pseudo-homo...

The study of nanofluids has lately gained scientific interest, due to their enhanced thermal conductivity, which would significantly improve the performance of heat transfer equipment. This work is part of a bilateral scientific program between the AUTh and the Institute of Chemical Process Fundamentals of the Czech Academy of Sciences, whose purpo...

This work is a study of the effect of liquid properties and pore size on the initial bubble size distribution of a bubble column equipped with fine pore sparger. Various liquids covering a wide range of surface tension and viscosity values are employed, while the gas phase is atmospheric air. A fast video recording technique is used both for visual...

New experimental data concerning the gas holdup in bubble columns equipped with porous sparger were acquired. The effect of liquid properties and sparger characteristic (i.e. pore size, dimensions) on gas holdup in the homogeneous regime has been studied and a correlation regarding the prediction of the transition point from the homogeneous to the...

Bubble columns are widely used in industrial gas-liquid operations because of their simple construction, low operating cost and high-energy efficiency. However, their design and scale up is still a difficult task and subject to errors due to the generally complex structure of the multiphase flow encountered in this type of equipment. Bubble size an...

This work investigates the effect of spray drying conditions on some properties of tomato powder prepared by spray drying of tomato pulp. A pilot scale spray dryer (Buchi, B-191) with cocurrent regime and a two-fluid nozzle atomizer was employed. Sixty-four different experiments were conducted keeping constant the feed rate, the feed temperature, a...

This work is motivated by the need to develop reliable predictive tools for bubble column reactor design. Although bubble columns are widely used in industrial gas-liquid operations, their design and scale up is still a difficult task and subject to errors, due to the generally complex structure of the multiphase flow encountered in this type of eq...