Svetlana Pelemis - Academia.edu (original) (raw)

Papers by Svetlana Pelemis

Contemporary materials, 2017

Nano-engineered materials are playing an ever growing role in the rapidly developing field of sus... more Nano-engineered materials are playing an ever growing role in the rapidly developing field of sustainable energy production. Besides providing numerous opportuni-ties for innovations in this domain, utilisation of nanostructured materials raises numerous doubts regarding their impact on the environment and possible adverse effects on human health. Providing reliable methods for analysis, evaluation and dealing with the environ-mental and health effects of nanotechnology is therefore crucial. In this article we will try to give an outline of possible approaches to deployment of Life Cycle Assessment (LCA) tools to nanomaterials used in certain applications for sustainable energy production. Use of such methods should also provide the possibility of comparing these new, emerging, technologies with that of already existing conventional ones in terms of their environmental, health and safety impacts.

Currently used technologies in energy industry are oftentimes potentially harmful for the environ... more Currently used technologies in energy industry are oftentimes potentially harmful for the environment and/or not sustainable in the long run (e.g. fossil and mineral based fuels, nuclear energy). Therefore the oncoming energy crisis must be solved by developing new sustainable energy supply that has lower or, preferably, negligible impact on the environment. Any new sustainable energy solutions will have to envelope three important sets of technologies: production, storage and transportation. Additionally, in order to determine whether these solutions are truly sustainable, adequate life cycle assessment methodology (LCA) needs to be developed and properly applied. This article gives a general survey of state of the art and current research trends in application of nanostructured materials for sustainable energy production, storage and transportation, as well as review of LCA methodology implemented in this domain. A special attention is given to already existent applications and po...

Polymeric biomaterials represent large and very adaptable class of biomaterials, which makes them... more Polymeric biomaterials represent large and very adaptable class of biomaterials, which makes them very suitable for diversity of biomedical applications. Polymers can be synthesized to have a variety of structures and suitable chemical, physical, biomimetic and surface properties. An overabundance of polymeric biomaterials with different compositions and physicochemical properties have already been developed and investigated; however, there are still many active studies about these materials. This chapter ensures a structural review of biodegradable polymers and discusses their physicochemical characteristics, structure property, applications and limitations in medicine. It is the authors’ intent to provide an insight over the available synthetic and natural polymer classes. Some types of polymer materials are less discussed than the other more relevant. A biocompatible, degradable polymer, polylactic acid is very popular so called green ‘eco-friendly’ material with a most promising...

We have investigated transport properties of higher acenes pentacene and hexacene and compared it... more We have investigated transport properties of higher acenes pentacene and hexacene and compared it with the transport properties of their BN analogues. Charge hopping from one structure to another was investigated through calculations of reorganization energies based on DFT and Marcus semiempiric approach, while the investigation of charge transport along the investigated structures was based on DFT calculations and non-equilibrium Green's function (NEGF) method. Attention was also paid to the energy separation between the lowest excited singlet (S1) and triplet (T1) state, which is quantity that is important for the field of thermally activated delayed fluorescence (TADF). The obtained results indicate that both groups of investigated structures have certain advantages and drawbacks. According to the reorganization energies and I-V characteristics, pentacene and hexacene have better properties, while from the aspect of TADF, BN analogues of pentacene and hexacene have better pro...

There are a lot of cosmetic products on the market based on nanotechnology. Those products contai... more There are a lot of cosmetic products on the market based on nanotechnology. Those products contain nanomaterials since they have many advantages such as improved delivery of active ingredients, stability and photostability of potentially unstable cosmetic ingredients, increased efficacy and tolerance of the skin for various UV filters. Nanomaterials contribute to easiness of application and aesthetic appearance of final products. Although they offer many possibilities, their use demands caution. Nanoparticles have a large surface to volume ratio leading to their reactivity and alteration in biological activity compared to the parent bulk materials. The shape and size of the particles are the cause if their toxic effects, rather than their chemical properties. There are various nanosystems currently in use, in pharmaceutical and cosmetic industry, and many new ones, waiting to be applied. In this article we are going to introduce those who find an application in personal care product...

Encyclopedia of Materials: Composites

Environmentally responsible behaviour should be promoted in all spheres of life. This issue appli... more Environmentally responsible behaviour should be promoted in all spheres of life. This issue applies to the automotive industry as much as it does elsewhere. This is one of the most important reasons for the expansion of the use of biomaterials in car manufacturing. They have numerous advantages in terms of eco-friendly production technologies, reduction in the exploitation of fossil resources and waste minimization due to their features of biodegradability and recyclability. The paper shows an overview of the basic definitions of and methods for obtaining certain biomaterials. Here, the emphasis is placed on bio-based plastics, rubber and composites, because of their overwhelming presence in newly oriented industries. Due to the various applications and characteristics of bio-plastics, an overview of the tensile strength of each variation is given, with an emphasis that similar tests were conducted for all of them. Furthermore, knowing that the mechanical, chemical, thermal and other characteristics of biomaterials are all considered to be satisfactory, there has been a reasonable attempt to use them instead of conventional materials whenever possible. Consequently, the work contains an overview of the application of biomaterials in making different parts in the automotive industry and descriptions of their incorporation into branded vehicles, as a tool for increasing human consciousness of the fact that making a profit and preserving nature can result from the same activity. The paper also involves analysis of the conditions that biomaterials have to satisfy in order to expand their usage in the production of parts for the automotive industry.

Biomaterials in Clinical Practice

The hip joint is one of the largest joints in the body and is a major weight-bearing joint. The f... more The hip joint is one of the largest joints in the body and is a major weight-bearing joint. The function of the hip is to withstand body weight during standing and walking; during single leg stance the hip joint must carry a load three times greater the body weight. However, Joint degeneration is the final phase of the joint cartilage destruction, leading to severe pain, loss of mobility, and sometimes even angular deformity of the limbs. The primary reasons for a large number of total hip replacements are osteoarthritis and osteoporosis of the femoral neck, which often leads to hip fractures. One of the most successful techniques to restore function of a degenerated joint is the total joint replacement. In this surgical procedure, diseased cartilage and parts of the bone are removed and replaced with an appropriate joint prosthesis. Several types of materials and techniques have been developed for this purpose: glass, polymer, metal alloy, ceramics, etc. Earliest prosthesis designs and biomaterials that have been developed to treat osteoarthritic hip degenerated joint surfaces were for the most part empirical and unsuccessful. Joint replacement heralded a revolution after the materials and replacement procedures developed by Sir John Charnley. A modern total hip prosthesis consists of a femoral and acetabular component, where the femoral head is made of cobalt-chrome alloy, alumina or zirconium, and the stem component is now usually made of Ti- or Co-Cr-based alloy. The search for improved designs and new hip implant biomaterials with better biocompatibility and more desirable mechanical properties is still underway.

Advances in Applications of Industrial Biomaterials, 2017

In the original version of the book, the belated correction to change the 4th volume editor's nam... more In the original version of the book, the belated correction to change the 4th volume editor's name from "Maria Baró" to "Maria Dolors Baró" in Frontmatter and cover page has to be incorporated. The erratum book has been updated with the change.

Materials Chemistry and Physics

Abstract We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, he... more Abstract We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, heptacene, octacene, nonacene, decacene and their boron-nitride (BN) analogues, within the framework of density functional theory (DFT). We have also investigated the optoelectronic properties of acenes modified by BN substitution. Calculated optoelectronic properties encompasses: oxidation and reduction potentials, electron and hole reorganization energies and energy difference between excited first singlet and triplet states ΔE(S1−T1). Oxidation and reduction potentials indicate significantly better stability of BN analogues, comparing with their all-carbon relatives. Although higher acenes possess lower electron and hole reorganization energies, with both best values much lower than 0.1 eV, their BN analogues also have competitive values of reorganization energies, especially for holes for which reorganization energy is also lower than 0.1 eV. On the other hand ΔE(S1−T1) is much better for BN analogues, having values that indicate that BN analogues are possible applicable for thermally activated delayed fluorescence.

$Research paper thumbnail of Selective infrared absorption and refraction of symmetrical two-layered molecular nanofilms$

Optica Applicata

We have supplemented the already formulated microscopic theory of optical properties of very ultr... more We have supplemented the already formulated microscopic theory of optical properties of very ultrathin molecular films (quantum nanofilms), i.e., quasi 2D systems parallel to XY planes bounded by two surfaces. The exposure of nanofilms to the external electromagnetic fields has resulted in the creation of excitons, but different than bulk ones in one direction perpendicular to surfaces. The analysis of the dielectric response of the system to perturbation of an external electromagnetic field shows that optical properties of these crystalline nanosystems for low exciton concentration of Frenkel's excitons strongly depend on boundary parameters and the thickness of the film. In addition, the dynamical absorption and the refraction coefficient show a very narrow and discrete dependence of external electromagnetic field frequency, which is the consequence of both resonance and quantum size effects. Influences of boundary conditions on optical characteristics (through the analyses of...

This paper represents an overview about exciton systems in the molecular nanostructures (ultra th... more This paper represents an overview about exciton systems in the molecular nanostructures (ultra thin films and superlattices) and their implications on optical properties, primarily on absorption coefficient, which is given in the form of dielectric permittivity. With utilization of Green's function method, we have calculated dispersion law, spectral weight of exciton states and dielectric permittivity for every type of nanostructures. All obtained results are compared with optical properties in bulk crystals. Dielectric permittivity in all types of nanostructures shows very narrow and discrete dependence of external electromagnetic field frequency, which is a consequence of the expressed quantum effects, very thin thickness in these structures (or at least one dimension confinement) and boundary conditions.

Nanotechnology is a common word these days, although only 15 years ago it was a quite obscure ter... more Nanotechnology is a common word these days, although only 15 years ago it was a quite obscure term used almost exclusively in scientific community. It is a fact that nanotechnology is widely present today with numerous applications, especially regarding novel materials. This is a technology that draws a lot of attention not only in the scientific community but also among investors, governments and industry. There is a great deal of expectations connected with it and especially, amongst others, concerning sustainable energy production. This paper briefly explores some of possible implementations of nanotechnology for new and improved energy conversion methods, considering a need for this to be done without doing harm to our environment. Focus is placed on advanced photovoltaic and hydrogen production technology. Keywords: nanotechnology, materials, solar energy, photovoltaic, solar cells.

Contemporary Materials, 2011

This paper presents the results of research of behavior of phonon subsystem in ultrathin coatings... more This paper presents the results of research of behavior of phonon subsystem in ultrathin coatings that are applied on electrodes in Li-ion batteries and that increase the efficiency of ion transport. Using the method of Green functions it was demonstrated that in ultrathin films, increased mechanical oscillating of crystalline lattice and forming of standing waves occur, while, thermal capacitiveness and conduction of the overall coating decreases. With their increased oscillating, phonons release the ions captured on and within electrodes, and thus influence an increase in efficiency of ion conductivity.

Superlattices and Microstructures, 2015

ABSTRACT Optoelectronic properties of ultra-thin boron nitride nanotubes and charge carrier hoppi... more ABSTRACT Optoelectronic properties of ultra-thin boron nitride nanotubes and charge carrier hopping properties between them were investigated within density functional theory. The study encompassed calculations of optoelectronic quantities, such as reorganization energies, oxidation and reduction potentials and charge carrier hopping rates between mentioned nanotubes. Charge coupling was calculated applying full quantum mechanical treatment, while Marcus theory was used for calculations of charge carrier hopping rates. Results indicate differences between investigated types of boron nitride nanotubes. With the increase in dimensions of boron nitride nanotubes optoelectronic properties are improving, while charge carrier hopping rates are the highest for (6,0) boron nitride nanotube.

A microscopic theory of dielectric properties of symmetrical ultrathin molecular films, was formu... more A microscopic theory of dielectric properties of symmetrical ultrathin molecular films, was formulated in bosonic and nearest-neighbor approximation. The dispersion law of harmonic exciton states were calculated using the method of two-time, temperature dependent Green's functions. It has been shown that two types of excitations can be occurred: bulk and surface exciton states. Exciton spectral weights and space distribution along the direction of broken symmetry were analyzed as well. Calculating of dynamical permittivity by the single-pole Green's functions have shown that the threshold of light absorption can be moved along frequencies, changing the film thickness and the intensity of boundary perturbations. This can give a great contribution to practical ultrathin film engineering.

Journal of Computational and Theoretical Nanoscience, 2009

Application of nanomaterials in biomedicine has an important place in research of nanomaterials. ... more Application of nanomaterials in biomedicine has an important place in research of nanomaterials. Nanomedical approaches are a major transforming factor in medical diagnosis and therapies. The great advantages of using nanomaterials in biomedical areas lies in their ability to operate on the same small scale as all the intimate biochemical functions involved in the growth, development and ageing of the human body. Achieving full potential of nanomedicine may be years of even decades away, however, potential advances in drug delivery, diagnosis, and development of nanotechnology-related drugs start to change the landscape of medicine. One of the main issues is certainly related to long-term safety of nanomaterials, both developed for in vitro and in vivo applications.

Physica Scripta, 2009

Interest in the study of the exciton subsystem in crystalline structures (in this case nanostruct... more Interest in the study of the exciton subsystem in crystalline structures (in this case nanostructures, i.e. thin films) occurred because dielectric, optical, photoelectric and other properties of materials can be explained by means of it. The basic question to be solved concerning theoretical research into the spatially strongly bounded structures is the inability to apply the standard mathematical tools: differential equations and Fourier analysis. In this paper, it is shown how the Green function method can also be efficiently applied to crystalline samples so constrained that quantum size effects play a significant role on them. For the purpose of exemplification of this method's application, we shall consider a molecular crystal of simple cubic structure: spatially unbounded (bulk) and strongly bounded alongside one direction (ultrathin film).