66 research outputs found
Documentary film and ethics: child on screen ("Alone" by Audrius Stonys)
No full text„Filmas, atvedęs prie etinės problemos,“ - rašoma juostos „Viena“ (2001) pristatyme Audriaus Stonio tinklalapyje*. Režisierius jau buvo sukūręs devynis dokumentinius filmus, pirmąjį „Atverti duris ateinančiam“ - daugiau kaip prieš dešimtmetį, tačiau tik dešimtasis, paties autoriaus žodžiais tariant, atvedė jį prie etinės problemos, įrašytos pirmu sakiniu anotacijoje. Yra pagrindo manyti, jog dėl to „kaltas“ vaikas ekrane - šešerių metų filmo herojė Sigita. Šio straipsnio dėmesio centre - etikos klausimai, filmuojant vaikus, ir galimi etinių problemų sprendimo būdai, pasitelkiant Stonio filmą „Viena“ kaip pavyzdį ir svarstymų pagrindą, pasirenkant dekonstrukcinę prieigą bei lyginamosios analizės metodą ir vertinant filmo recepciją Lietuvoje bei užsienyje. Reikšminiai žodžiai: Audrius Stonys; Dokumentika; Etika; Filmas „Viena"; Lietuvių kinas; Režisierius Audrius Stonys; Vaikai; Vaikas; Audrius Stonys; Children; Documentary; Ethics; Film "Viena" ("One"); Film director Audrius Stonys; Lithuanian cinema; Movie „Alone""The film brought me up to an ethical issue," writes Audrius Stonys on his website introducing the documentary 'Alone' (2001). The director had already made nine documentaries (the first of which, 'Opening the Door for the One Who Is Coming’ being created over a decade ago), yet only the tenth one, according to its author, brought him up to an ethical issue, which is stated in the first sentence of its annotation. Presumably, this is because of the child appearing on screen, namely, the six-year-old character of the film Sigita. This article focuses on ethical issues related to capturing children on screen, and possible ways of solving the ethical problems. The documentary 'Alone' by Stonys serves as an example and a subject of consideration; the author employs the deconstructive approach and method of comparative analysis, evaluating the reception of this documentary both in Lithuania and abroad
First-principles calculations of defects and electron-phonon interactions: Seminal contributions of Audrius Alkauskas to the understanding of recombination processes
No full textFirst-principles calculations of defects and electron-phonon interactions play a critical role in the design and optimization of materials for electronic and optoelectronic devices. The late Audrius Alkauskas made seminal contributions to developing rigorous first-principles methodologies for the computation of defects and electron-phonon interactions, especially in the context of understanding the fundamental mechanisms of carrier recombination in semiconductors. Alkauskas was also a pioneer in the field of quantum defects, helping to build a first-principles understanding of the prototype nitrogen-vacancy center in diamond, as well as identifying novel defects. Here, we describe the important contributions made by Alkauskas and his collaborators and outline fruitful research directions that Alkauskas would have been keen to pursue. Audrius Alkauskas' scientific achievements and insights highlighted in this article will inspire and guide future developments and advances in the field. (c) 2024 Author(s).CSE
Energy level alignment and site-selective adsorption of large organic molecules on noble metal surfaces
No full textIn recent two decades, there has been a large interest in organic molecules on metallic as
well as insulating substrates. This interest is caused by the need to understand fundamental
properties of large organic molecules on solid surfaces at the level that properties
of smaller adsorbates, like carbon monoxide or oxygen molecule, are understood. In addition,
theoretical and experimental studies in this field are driven by potential applications
of organic materials as active components in light-emitting diodes (OLEDs) and fieldeffect transistors (FETs), as well as by on-going efforts to use single molecules as building
blocks in nano-electronic and nano-mechanical devices.
This Thesis deals with two aspects of large organic molecules on metal surfaces: local
adsorption geometry and energy level alignment. Molecules bind to specific sites on
metallic surfaces which correspond to the lowest total energy of the molecule-substrate
system. It is of fundamental interest to understand the electronic causes of the interaction
between the molecule and the surface. Ultimately, one would like to gain understanding
of what causes molecule-substrate attraction and why this attraction is stronger for some
particular geometries than for others. Another important aspect is the alignment of
molecular levels with respect to the Fermi level of the metal. This level alignment governs
the electron injection from the metal to the molecule (or vice versa) in electronic devices.
At the beginning of the Thesis, we review our main theoretical tool, density functional
theory (DFT), and present details of the plane-wave implementation of DFT. We
introduce concepts which are useful in analyzing surface science systems, such as surface
energy, work function, electron density difference, difference in density of states, etc. We
present calculations of copper and silver bulk and surfaces to assess how density functional
theory performs for noble metals. We then investigate a specific surface science
system to demonstrate these concepts, namely, chlorine adsorbed on the Ag(111) surface
at submonolayer coverages. We find that the adsorption energy of Cl on Ag(111) is about
2.9 eV and depends only weakly on coverage. The Ag-Cl bond is very strong and can
be best described as ionic. Adsorption of Cl on the Ag(111) surface leads to electron
charge transfer from the metal to the adsorbate. Each chlorine atom acquires about 0:2
additional electrons upon adsorption. Because of this charge transfer the work function
of adsorbate-covered substrate increases. We find a very good agreement between theory
and available experimental data. Small dependence of adsorption energy on coverage can
be explained by lateral repulsion of adsorption-induced dipoles.
Chapter 4 of the Thesis is devoted to site-selective adsorption of one specific molecule,
1,4,5,8-naphthalene tetracarboxylic dianhydride (NTCDA), on the Ag(110) surface. We
perform large-scale density functional calculations of several local adsorption sites and
analyze the results in great detail. Calculations reveal that NTCDA prefers adsorption
geometry in which the peripheral oxygen atoms lie directly above the silver atoms in the
[1�10] atomic rows. This nicely agrees with available experimental data. From the analysis
of DFT calculations we are able to understand why this happens. Firstly, NTCDA is a
molecule with electron accepting properties. In the gas-phase molecule the oxygens of
the side groups are negatively charged while the central naphthalene core is positively
charged. When the molecule is adsorbed on the Ag(110) surface, about 0:4 electrons are
transfered to the lowest occupied molecular orbital (LUMO). Silver atoms in the topmost
atomic layer become positively charged and this causes electrostatic attraction between
negatively charged oxygen atoms of NTCDA and positively charged silver atoms. This
attraction is maximum when oxygens are just above the silver atoms in the [1�10] atomic
rows. Thus, on the basis of DFT calculations, we have developed a model for site-selective
adsorption of NTCDA on the Ag(110) surface. This model should also be applicable in
case of adsorption of a related molecule, PTCDA, on the same surface.
In Chapter 5 we analyze the energy level alignment of copper octaethylporphyrin
(CuOEP) on three metal surfaces: Ag(001), Ag(111) and Cu(111). The experiments that
this analysis is based on were performed in the Institute of Physics of University of Basel,
in the NanoLab group. We first critically review and discuss different physical mechanisms
that lead to a formation of the interface dipole at metal-organic interfaces. These different
mechanisms are: charge transfer (as described by the so-called induced density of interface
states (IDIS) model), polarization of the adsorbate near the metal surface, push-back
effect, which is a consequence of the Pauli exclusion principle, permanent electrostatic
dipoles at interfaces, and charge transfer caused by chemical interactions. Then we discuss
in detail experimental results and evaluate the contribution of each mechanism to the
total interface dipole. We conclude that the push-back effect is the most important for
CuOEP/metal interfaces
The nursing needs of hospital patients undergoing the amputation of limbs.
No full textThe author of work: Rimantienė Aušra Title:The nursing needs of hospital patients undergoing the amputation of limbs The tutor of work: Gradauskas Audrius, docent The Vilnius University Institute of Rehabilitation, Sports Medicine and Nursing Lithuania 2008-05-14 Number of pages 74 The number of amputations remains large in Lithuania. Nursing after amputations is of great importance, because the subsequent aftercare and life quality depends on the nursing quality. The nursing care after amputations is insufficient due to a great number of psychological, rehabilitation, disability problems as well as needs for care, which are important in present day practice and nursing science. The aim of this work is to assess needs for nursing care of patients with amputated lower extremities in hospital settings. The objectives of the work: To determine expectations, specifics of nursing care and problems of patients after amputations; to investigate, whether the cause of amputation influences patient' needs and the quality of life, to evalaute nurse's atitude and expectations towards nursing care of patiens after amputations. METHODS The objectives of the survey – problems, nursing needs, and expectations of selected patients, experiencing amputation of lower extremities as well as the attitude of nurses to the nursing care of such patients. Questionnaires and analyses of statistical data were chosen as methods of the survey. 82 patients with amputated lower extremities participated in the inquiry. The respondents were questioned at the Vilnius University Hospital and at the Traumatological Department of the Vilnius University Emergency Hospital. 61 general practice nurses, working at the Vascular Surgery Centre of Vilnius University Hospital, at the Surgery Clinic and at the Orthopaedics Traumatological Unit of the Vilnius University Emergency Hospital, participated in the inquiry. 64 histories of diseases of patients with amputated lower extremities were analysed. The online database was used for the work; the statistical analysis was carried out by SPSS 12 h online program. CONCLUSIONS The needs of patients after amputations are physical, psychological and social, particularly for patients, with amputated lower extremities due to frostbites and chilblains, because in most cases they do not possess permanent shelter. Nursing needs of patients with amputated lower extremities are satisfied only partially because the information on care peculiarities of amputated patients is insufficient for a majority of nurses, whereas the patients expect a greater individual attention and personal contacts. The complex assistance is necessary for patients, because the hospitalisation period is prolonged. The intolerance to amputated patients belittles nursing needs. A great number of amputations due to frostbites could be avoided if social services would pay greater attention to the homeless people
Angus beef cattle bull growing applying new feed technology
No full textAuthor: Audrius Stelmokas, student of Lithuanian University of Health Sciences of Veterinary Academy Faculty in animal science master’s degree program. Work manager: Professor, doctor Rolandas Stankevičius. Master thesis: “Angus beef cattle bull growing applying new feed technology” The aim of the thesis: to evaluate if the feeding technology until weaning will have any impact on bulls daily gain weight and what affect it will have later on fattening. The tasks of the thesis: to clarify benefits of cereal grain feed until weaning by weighing bulls after weaning and in the fattening. The research methods and results: to complete the research we picked 3 test groups from 3 different Angus cattle breeders in Lithuania which had different feeding technologies until weaning. Fattening took place in White sheep cooperative farm in fattening station. Weights were done every 3 weeks. To collect weights we used “Load Bars MP1010”. First test group – Pure Fields breeder gave bulls cereal grains “ad libitum” which averagely consumed about 1.83 kg. per day. Second group – Black Angus Hill’s bulls consumed 1 kg per day for one bull. The third test group – Red Angus bulls didn’t get any cereal grains until weaning. Cereal grains were produced and supplied by company “Kauno Grūdai”. Quality of forage feed in fattening were determined by “Lietuvos žemės ūkio konsultavimo tarnyba“ using “AgriNir” pasture analyzer. At the start of fattening the best group with 1.229 daily gain were bulls that received cracked grains ad libitum. Second best bulls were from Black Angus Hill breeder with 0.998 daily gain. And the lowest group was cattle from Red Angus breeder which didn’t give any cereal grains with 0.901 daily gain. Nevertheless all 3 groups produced significantly good results in fattening farm gaining from 1.320 kg per day to 1.491 daily gain
Impact of Heat Exchanger Effectiveness and EGR on Energy and Emission Performance of a CI Engine
No full textThis study explores the impact of intake air cooling intensity, defined by heat exchanger effectiveness (HEE) and exhaust gas recirculation (EGR), on the energy and environmental performance of a turbocharged compression ignition (CI) engine. Experimental investigations were conducted on a 1.9-litre CI engine operating at 2000 rpm under three brake mean effective pressure (BMEP) conditions (0.2, 0.4, and 0.6 MPa), which correspond to part-load engine operation. HEE was varied at 0%, 50%, and 100%, in both EGR-on and EGR-off modes. Additional numerical simulations were carried out using AVL BOOST software to analyze combustion dynamics, including engine operating cycle modeling to validate the accuracy of the combustion analysis. The results demonstrate that increasing HEE significantly improves cylinder filling and excess air ratio, leading to enhanced combustion efficiency and lower in-cylinder temperatures. This, in turn, reduces specific NOx emissions by approximately 40% with EGR and approximately 60% without EGR; however, under EGR-on conditions, the reduced combustion intensity leads to increased smoke and unburned hydrocarbon emissions—particularly at high cooling intensities. This effect is primarily associated with the engine control unit’s (ECU) limitations on intake air mass flow to maintain the target EGR ratio. Integrated control of HEE and EGR systems improves engine performance and reduces emissions across varying conditions, while highlighting trade-offs that inform the refinement of air management strategies
Orientalizm i dyskurs postkolonialny: kilka problemów metodologicznych
No full textGłówną inpiracją dla autora artykułu jest książka Edwarda Saida Orientalizm, a celem – podjęcie dyskusji na temat rozwoju pojęcia „orientalizm” w kontekście studiów postkolonialnych. Autor zwraca uwagę na materialną i kulturową przemoc kolonializmu zachodniego. Jednocześnie podkreśla konieczność wzięcia pod uwagę takich aspektów, jak pluralizm religijny, czy różnorodność kulturowa. Ma to ułatwić stworzenie platformy komunikacyjnej między pasywnym Wschodem a opresyjnym Zachodem.The main inspiration for this article’s author is Edward Said’s book Orientalism and the main goal discussion over the development of the conception of the orientalism in the context of postcolonial discourse. The author pays attention to cultural and material violence of Western colonialism. At the same time he highlights the necessity of taking into account such aspects as religious pluralism and cultural variety. It can enable a creation of a communication platformbetween a passive East and an oppressive West
Taškiniai defektai kaip pavienių fotonų šaltiniai heksagoniniame boro nitride: teorinis tyrimas.
No full textFuture light-based quantum technologies will depend on generation and manipulation of single photons, thus any quantum device will contain one crucial component within – single-photon emitter. So far, among the frontrunners are solid-state single-photon emitters, and they are expected to play an essential role in a plethora of quantum tasks. The recent discovery that hexagonal boron nitride can host robust, narrow-linewidth, bright, photostable, and indistinguishable single-photon sources operating at room temperature and above has sparked interest in this material. This Thesis synthesizes the results of theoretical work on the understanding the role of point defects in hexagonal boron nitride, in particular for the observed single-photon emission, by performing first-principles calculations. A significant step forward in the study was provided by giving a broad and comprehensive picture of the defect chemistry in hexagonal boron nitride. The author of this Thesis ensured a correct treatment of defect physics, and thereby illustrated ability to predict and assign microscopic identity of single-photon emitters in hexagonal boron nitride on scales unreachable for the experiment, using a purely first-principles approach. Physical model for quenching of 2 eV single-photon emission in this material was proposed. The author of this Thesis unpretentiously believes that the study covered in the last chapter of Thesis has also made its small contribution towards a more in-depth understanding of ultraviolet single-photon emission in hexagonal boron nitride by giving convincing explanations for obtained results
New product entrance into the market.
No full textThe aim of the study is to formulate a model that Lithuanian enterprises could use in practice getting a new product entry into the market. The object of the study is the enterprises which are selling water heaters established in Kaunas city. The main argument of the study was that these enterprises do not have clearly delineated, prepared after methodological concepts new product entry to the market matrix, that the enterprises do not possess proper assessment criteria for the new product entry to the market success measurement. The author of the study has made a theoretical analysis of the papers and presented the new product entry to the market scientific approaches. It is estimated the new product entry to the market models proposed by the number of scientists in various papers and studies. The empirical research was held in 2005-2006 study years. 10 enterprises took part into the research. According to the research data and theory analysis the author formulated a new product entry to the market model that Lithuanian enterprises can use in their practice
Point defects as single-photon emitters in hexagonal boron nitride: theoretical study.
No full textFuture light-based quantum technologies will depend on generation and manipulation of single photons, thus any quantum device will contain one crucial component within – single-photon emitter. So far, among the frontrunners are solid-state single-photon emitters, and they are expected to play an essential role in a plethora of quantum tasks. The recent discovery that hexagonal boron nitride can host robust, narrow-linewidth, bright, photostable, and indistinguishable single-photon sources operating at room temperature and above has sparked interest in this material. This Thesis synthesizes the results of theoretical work on the understanding the role of point defects in hexagonal boron nitride, in particular for the observed single-photon emission, by performing first-principles calculations. A significant step forward in the study was provided by giving a broad and comprehensive picture of the defect chemistry in hexagonal boron nitride. The author of this Thesis ensured a correct treatment of defect physics, and thereby illustrated ability to predict and assign microscopic identity of single-photon emitters in hexagonal boron nitride on scales unreachable for the experiment, using a purely first-principles approach. Physical model for quenching of 2 eV single-photon emission in this material was proposed. The author of this Thesis unpretentiously believes that the study covered in the last chapter of Thesis has also made its small contribution towards a more in-depth understanding of ultraviolet single-photon emission in hexagonal boron nitride by giving convincing explanations for obtained results
- …
