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In solar cells, the absorbers are the key components for capturing solar energy and converting photons into electron-hole pairs. The search for high-performance absorbers with advantageous characteristics is an ongoing task for researchers. In this work, we investigated promising and environmentally benign Ba-based ternary chalcogenides for photovoltaic applications. The total number of Ba-based ternary chalcogenides in the Materials Project database was found to be 279. Materials screening based on bandgap size and stability reduced the number of compounds to 19. The performance of an absorber depends on the charge carrier lifetime, which is controlled by non-radiative processes involving defects. Hence, we investigated the intrinsic defects and p-type dopability of the compounds. We identified two Ba-based compounds, namely \ch{BaCu2Se2} and \ch{ZrBaSe3}, as promising absorbers for single-junction and tandem cells and investigated them in detail.

In this paper we investigate the chaotic behavior of the class of oscillators denoted as Clapp oscillators. Clapp oscillator is a simple oscillator containing one transistor and a few reactive elements - inductors and capacitors. This oscilllator is chosen for its design simplicity and a good performance. Oscillator with chaotic behavior can be used to construct chaotic radar. For that matter, in this paper is investigated approach for construction of the chaotic Clapp oscillator, which can be further verified experimentally using microstrip technology.

The study of microscopic protein dynamics has historically presented significant challenges to researchers seeking to develop a comprehensive and detailed description of its diverse and intriguing features. Recent experimental and theoretical studies have proposed the hypothesis that protein dynamics may be non-ergodic. The implications of this finding are of paramount importance from both a practical and theoretical standpoint. In this study, we employ all-atom molecular dynamics simulations to examine these results over a time window spanning from picoseconds to nanoseconds. To this end, we utilize widely used statistical tools. Our findings challenge the conclusions of previous studies, which suggested that proteins exhibit non-ergodic dynamics. Instead, we demonstrate that deviations from ergodic behavior are due to incomplete convergence of the investigated quantities. Additionally, we discuss the implications of findings that suggest a potential breaking of the ergodic hypothesis over larger time windows, which were not directly investigated in this study.

The time dynamics of spin-injected, electrically contacted quantum dots were investigated with a focus on the time evolution of photon statistics. Photon statistics can provide insights into whether the device functions as an effective single-photon emitter or exhibits higher-order emissions. Through these investigations, we found that the shape of the electrical excitation pulse has a direct impact on photon statistics. Specifically, the rising edge of the pulse corresponds to a significantly higher number of higher-order photon states, which decay much faster than single photons associated with the falling edge of the electrical pulse. This relationship implies that the pulse shape can be tailored to optimize the device as either a better single-photon source or a generator of higher-order photon states, with potential applications in creating deterministic higher-order photon Fock states. The ability to easily modify the pulse shape is a unique feature of electrically excited quantum dots.

The parallelism of Transformer-based models comes at the cost of their input max-length. Some studies proposed methods to overcome this limitation, but none of them reported the effectiveness of summarization as an alternative. In this study, we investigate the performance of document truncation and summarization in text classification tasks. Each of the two was investigated with several variations. This study also investigated how close their performances are to the performance of full-text. We used a dataset of summarization tasks based on Indonesian news articles (IndoSum) to do classification tests. This study shows how the summaries outperform the majority of truncation method variations and lose to only one. The best strategy obtained in this study is taking the head of the document. The second is extractive summarization. This study explains what happened to the result, leading to further research in order to exploit the potential of document summarization as a shortening alternative. The code and data used in this work are publicly available in https://github.com/mirzaalimm/TruncationVsSummarization.

Quantum harmonic oscillator (QHO) battery models have been studied with significant importance in the recent past because these batteries are experimentally realizable and have high ergotropy and capacity to store more than one quanta of energy. QHO battery models are reinvestigated here to answer a set of fundamental questions: Do such models have any benefit? Is unbounded charging possible? Does the use of a catalyst system enhance the energy transfer to quantum batteries? These questions are answered both numerically and analytically by considering a model that allows a laser to shine on a QHO charger that interacts with a QHO battery. In contrast to some of the existing works, the obtained answers are mostly negative. Specifically, in the present work, the laser frequency is tuned with the frequency of the global charger-battery system, which is affected by the interaction between QHOs. It is reported that for a fixed laser field amplitude $\textit{F}$, the battery can store more energy when tuned with the frequency of the global charger-battery system compared to energy stored by tuning the laser frequency with local frequencies of the charger and battery. The charging process

We present a study of two-photon electron capture by H-like uranium ions. The energy of the incident electron was chosen to be in the region with the most significant contribution of the dielectric recombination. We studied the photon emission spectrum, including the main resonance groups corresponding to the cascade transition, and the low-energy photon region, where the infrared divergence required special processing. The calculations were performed within the framework of QED theory. The importance of generalized Breit interaction was discussed. We investigated the roles of the dielectric recombination and the radiative recombination. We introduced and investigated the resonance approximation and the single-photon approximation, which are commonly used to describe radiation spectra.

Neural Networks have been proved to work as decoders in telecommunications, so the ways of making it efficient will be investigated in this thesis. The different parameters to maximize the Neural Network Decoder's efficiency will be investigated. The parameters will be tested for inversion errors only.

This thesis presents techniques to investigate transactions in uncharted cryptocurrencies and services. Cryptocurrencies are used to securely send payments online. Payments via the first cryptocurrency, Bitcoin, use pseudonymous addresses that have limited privacy and anonymity guarantees. Research has shown that this pseudonymity can be broken, allowing users to be tracked using clustering and tagging heuristics. Such tracking allows crimes to be investigated. If a user has coins stolen, investigators can track addresses to identify the destination of the coins. This, combined with an explosion in the popularity of blockchain, has led to a vast increase in new coins and services. These offer new features ranging from coins focused on increased anonymity to scams shrouded as smart contracts. In this study, we investigated the extent to which transaction privacy has improved and whether users can still be tracked in these new ecosystems. We began by analysing the privacy-focused coin Zcash, a Bitcoin-forked cryptocurrency, that is considered to have strong anonymity properties due to its background in cryptographic research. We revealed that the user anonymity set can be considerabl

We consider certain star versions of the Menger, Hurewicz and Rothberger properties. Few important observations concerning these properties are presented, which have not been investigated in earlier works. A variety of investigations is performed using Alster covers and critical cardinalities $\mathfrak{d}$, $\mathfrak{b}$ and ${\sf cov}(\mathcal{M})$. Our study explores further ramifications on the extent and Alexandroff duplicate. In the process we present investigations on the star versions of the Rothberger property and compare with similar prior observations of the star versions of the Menger and Hurewicz properties. We sketch few tables that interpret (mainly preservation-kind of) properties of the star selection principles obtained so far. We also present implication diagrams to explicate the interplay between the star selection principles.

Thai Finger Spelling (TFS) sign recognition could benefit a community of hearing-difficulty people in bridging to a major hearing population. With a relatively large number of alphabets, TFS employs multiple signing schemes. Two schemes of more common signing -- static and dynamic single-hand signing, widely used in other sign languages -- have been addressed in several previous works. To complete the TFS sign recognition, the remaining two of quite distinct signing schemes -- static and dynamic point-on-hand signing -- need to be sufficiently addressed. With the advent of many off-the-shelf hand skeleton prediction models and that training a model to recognize a sign language from scratch is expensive, we explore an approach building upon recently launched MediaPipe Hands (MPH). MPH is a high-precision well-trained model for hand-keypoint detection. We have investigated MPH on three TFS schemes: static-single-hand (S1), simplified dynamic-single-hand (S2) and static-point-on-hand (P1) schemes. Our results show that MPH can satisfactorily address single-hand schemes with accuracy of 84.57% on both S1 and S2. However, our finding reveals a shortcoming of MPH in addressing a point-on

In this work, the Z-average, effective, apparent diffusion coefficients and their poly-dispersity indexes were investigated for dilute poly-disperse homogeneous spherical particles in dispersion where the Rayleigh-Gans-Debye approximation is valid. The results reveal that the values of the apparent and effective diffusion coefficients at a scattering angle investigated are consistent and the difference between the effective and Z-average diffusion coefficients is a function of the mean particle size, size distribution and scattering angle. For the small particles with narrow size distributions, the Z-average diffusion coefficient can be got directly at any scattering angle. For the small particles with wide size distributions, the Z-average diffusion coefficient should be measured at a small scattering angle. For large particles, in order to obtain a good approximate value of Z-average diffusion coefficient, the wider the particle size distribution, the smaller the scattering angle that the DLS data are measured. The poly-dispersity index of the effective diffusion coefficient at a scattering angle investigated is consistent with that of the Z-average diffusion coefficient and with

The 16O nucleus was investigated through the 15N(p,α)12C reaction at excitation energies from Ex = 12 231 to 15 700 keV using proton beams from a 5 MeV Van de Graaff accelerator at beam energies of Ep = 331 to 3800 keV. Alpha decay from resonant states in 16O was strongly observed for ten known excited states in this region. The candidate 4-alpha cluster state at Ex = 15.1 MeV was investigated particularly intensely in order to understand its particle decay channels.

The evolution of the low-energy electromagnetic dipole response with the neutron excess is investigated along the Sn isotopic chain within an approach incorporating Hartree-Fock-Bogoljubov (HFB) and multi-phonon Quasiparticle-Phonon-Model (QPM) theory. General aspects of the relationship of nuclear skins and dipole sum rules are discussed. Neutron and proton transition densities serve to identify the Pygmy Dipole Resonance (PDR) as a generic mode of excitation. The PDR is distinct from the GDR by its own characteristic pattern given by a mixture of isoscalar and isovector components. Results for the $^{100}$Sn-$^{132}$Sn isotopes and the several N=82 isotones are presented. In the heavy Sn-isotopes the PDR excitations are closely related to the thickness of the neutron skin. Approaching $^{100}$Sn a gradual change from a neutron to a proton skin is found and the character of the PDR is changed correspondingly. A delicate balance between Coulomb and strong interaction effects is found. The fragmentation of the PDR strength in $^{124}$Sn is investigated by multi-phonon calculations. Recent measurements of the dipole response in $^{130,132}$Sn are well reproduced.

Deformation of the easy-axis ferromagnetic state in asymmetric bilayer systems are investigated numerically. Using the exact diagonalization the easy-axis to easy-plane ferromagnetic transition at total filling factor 3 or 4 is investigated. At still higher filling, novel stripe state in which stripes are aligned in the vertical direction occurs. The Hartree-Fock energies of relevant ordered states are calculated and compared.