Miracle-dz/UniFAR-FTUs huggingface dataset:
Geometrization for Energy Levels of Isotropic Hyperfine Hamiltonian Block and Related Central Spin Problems for an Arbitrarily Complex Set of Spin-1/2 Nuclei

Description of interacting spin systems relies on understanding the spectral properties of the corresponding spin Hamiltonians. However, the eigenvalue problems arising here lead to algebraic problems too complex to be analytically tractable. This is already the case for the simplest nontrivial (Kmax−1) block for an isotropic hyperfine Hamiltonian for a radical with spin-12 nuclei, where n nuclei produce an n-th order algebraic equation with n independent parameters. Systems described by such blocks are now physically realizable, e.g., as radicals or radical pairs with polarized nuclear spins, appear as closed subensembles in more general radical settings, and have numerous counterparts in related central spin problems. We provide a simple geometrization of energy levels in this case: given n spin-12 nuclei with arbitrary positive couplings ai, take an n-dimensional hyper-ellipsoid with semiaxes ai, stretch it by a factor of n+1 along the spatial diagonal (1, 1, …, 1), read off the semiaxes of thus produced new hyper-ellipsoid qi, augment the set {qi} with q0=0, and obtain the sought n+1 energies as Ek=−12qk2+14∑iai. This procedure provides a way of seeing things that can only be solved numerically, giving a useful tool to gain insights that complement the numeric simulations usually inevitable here, and shows an intriguing connection to discrete Fourier transform and spectral properties of standard graphs.
Use of Fourier Series in X-ray Diffraction (XRD) Analysis and Fourier-Transform Infrared Spectroscopy (FTIR) for Estimation of Crystallinity in Cellulose from Different Sources

Cellulose crystallinity can be described according to the crystal size and the crystallinity index (CI). In this research, using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods, we studied the crystallinity of three different types of cellulose: banana rachis (BR), commercial cellulose (CS), and bacterial cellulose (BC). For each type of cellulose, we analyzed three different crystallization grades. These variations were obtained using three milling conditions: 6.5 h, 10 min, and unmilled (films). We developed a code in MATLAB software to perform deconvolution of the XRD data to estimate CI and full width at half-maximum (FWHM). For deconvolution, crystalline peaks were represented with Voigt functions, and a Fourier series fitted to the amorphous profile was used as the amorphous contribution, which allowed the contribution of the amorphous profile to be more effectively modeled. Comparisons based on the FTIR spectra and XRD results showed there were no compositional differences between the amorphous samples. However, changes associated with crystallinity were observed when the milling time was 10 min. The obtained CI (%) values show agreement with values reported in the literature and confirm the effectiveness of the method used in this work in predicting the crystallization aspects of cellulose samples.
The Behaviour of Tracer Particles in Flow Visualization by Electrolysis of Water

Flow visualization methods based on the electrolytic technique have not only many superior merits but also some drawbacks. One of the drawbacks is that when a tracer-generating wire is located upstream of a test body, tracer particles do not approach the test body. Consequently, the tracer particles can not indicate the true flow pattern. This phenomenon is more conspicuous if the tracer-generating wire is thicker, and nearer to the test body.
Analytical Description of Pinching, Degrading Hysteretic Systems

Physically based analytical models capable of describing the behavior of general hysteretic systems are formulated. The formulation includes the effects of pinching, stiffness degradation, and load deterioration. Two types of pinching, one due to the system encountering additional stiffness and one due to unequalness of strengths for loading in opposite directions, are considered. The latter pinching is represented in terms of strength ratios. Both stiffness degradation and load deterioration are described in terms of functions of total absorbed hysteretic energy. Two possible forms for each of these functions are presented. All of the system parameters are in terms of definite physical materials or system properties that can be measured through tests. To show that the proposed analytical models provide realistic descriptions of the resistance-deformation behavior for general hysteretic systems, examples of bilinear and quatrolinear systems are presented, using harmonic excitations as examples of the applied forcing functions.
Phase evolution for oxidizing bismuth selenide

The novel Bi2O2Se, produced by the oxidation of the layered Bi2Se3, has been considered as one of the most promising candidates for the next-generation electronics owing to its high carrier mobility and air-stability. In this work, by using crystal structure prediction and first-principles calculations, we report the phase transformations from the hexagonal Bi2Se3 to the monoclinic Bi2OSe2, and then to the tetragonal Bi2O2Se with the gradual oxidization. Owing to the difference in electronegativity between selenium (Se) and oxygen (O), the oxidation process is accompanied by an increase in bond ionicity. Our results shed light on the phenomena occurring in the interaction between the precursors Bi2Se3 and O2 and have a potential contribution to the application of optoelectronic devices. The intermediate Bi2OSe2 with calculated band gap of 1.01 eV, may be a candidate for photovoltaic application in future.
A Theoretical and Experimental Study of the Internal Circulation in Water Drops Falling at Terminal Velocity in Air

Abstract Four theoretical approaches are presented for quantitatively determining the intensity of the internal circulation and the flow patterns inside and outside liquid water spheres falling at terminal velocity in air. The first approach assumes creeping flow outside and inside a water sphere, the second assumes potential flow outside and inviscid motion inside a water sphere, the third makes use of boundary layer theory, and the fourth approach uses a numerical method to solve the full Navier-Stokes equation of motion inside and outside a water sphere. The theoretical predictions are compared with data obtained from new quantitative wind tunnel experiments on spherical and deformed water drops. The results show that the creeping flow analysis greatly underestimates the strength of the internal velocity while the inviscid flow analysis greatly overestimates it. On the other hand, the results of the boundary layer approach and of the numerical approach agree reasonably well with the experimental data f.
An adaptive constraint tightening approach to linear model predictive control based on approximation algorithms for optimization

In this paper, we propose a model predictive control scheme for discrete‐time linear invariant systems based on inexact numerical optimization algorithms. We assume that the solution of the associated quadratic program produced by some numerical algorithm is possibly neither optimal nor feasible, but the algorithm is able to provide estimates on primal suboptimality and primal feasibility violation. By adaptively tightening the complicating constraints, we can ensure the primal feasibility of the approximate solutions generated by the algorithm. We derive a control strategy that has the following properties: the constraints on the states and inputs are satisfied, asymptotic stability of the closed‐loop system is guaranteed, and the number of iterations needed for a desired level of suboptimality can be determined. The proposed method is illustrated using a simulated longitudinal flight control problem. Copyright © 2014 John Wiley & Sons, Ltd.
Scatterometry for EUV lithography at the 22-nm node

Moore's Law continues to drive improvements to lithographic resolution to increase integrated circuit transistor density, improve performance, and reduce cost. For the 22 nm node and beyond, extreme ultraviolet lithography (EUVL) is a promising technology with λ=13.5 nm, a larger k1 value and lower cost of ownership than other available technologies. For small feature sizes, process control will be increasingly challenging, as small features will create measurement uncertainties, yet with tighter specifications. Optical scatterometry is a primary candidate metrology for EUV lithography process control. Using simulation and experimental data, this work will explore scatterometry's application to a typical lithography process being used for EUV development, which should be representative of lithography processes that will be utilized for EUV High Volume manufacturing (HVM). EUV lithography will be performed using much thinner photoresist thicknesses than were used at the 248nm or 193nm lithography generations, and will probably include underlayers for adhesion improvement; these new processes conditions were investigated in this metrological study.
Photocatalytic Activity and Wettability Properties of ZnO/Sawdust/Epoxy Composites

In this work, zinc oxide nanoparticles (ZnONPs) and sawdust/epoxy composite (20:80) were mixed using a simple molding method with different ZnONPs concentrations of (0.1, 0.3, 0.5, 0.7, and 1.0 %). The samples of the nanocomposites were characterized by the Scanning Electron Microscopy (SEM) technique to demonstrate the homogeneity of the prepared ZnONPs/nanocomposites. The photocatalytic activity of the samples was examined using the methylene blue (MB) dye as a pollutant solution, through evaluation of the efficiency of the prepared compound in the treatment of organic pollutants under illumination by sunlight. The photocatalytic results showed that after 240 minutes of exposure to sunlight, the sample prepared using (0.5 vol.% of ZnONPs) appeared to rapid degradation of MB dye, with photolysis efficiency of 89% and 71% for dye concentrations 5 and 10 ppm, respectively. Wettability results confirmed that the water contact angles of samples (WCAs) were affected by the concentration of ZnONPs.
Proximate Composition of Selected Freshwater Fish from Kampung Peta, Johor, Malaysia

Four species of freshwater fish from Kampung Peta, Johor namely Osteochilus flavicauda (Rong batu sirip), Labiobarbus festivus (Kawan), Barbonymus gonionotus (Lampam Jawa) and Puntioplites bulu (Tenggalan) were investigated in this study. The selected freshwater fishes from the Cyprinidae family were analyzed for their physical properties and proximate composition. The fishes exhibited weight of less than 400 g and have body length between 16 to 23 cm. Proximate analysis revealed that all fish species had comparable (p > 0.05) crude protein (13.40 - 13.75%) and ash content (2.76 - 3.27%) with each other. The moisture content was found to be between 77.02-82.65% where B. gonionotus exhibited a significantly (p < 0.05) higher percentage than the other species. The freshwater fishes were identified to be a lean fish containing crude fat of less than 2%. The highest (1.09 %) and lowest (0.48 %) amount of fat were recorded for O. flavicauda and B. gonionotus respectively. Meanwhile, the carbohydrate value ranging from 0.46 % to 5.26 % was inversely related to the protein content. Significant differences in carbohydrate value (p < 0.05) were observed between O. flavicauda (5.26%), L. festiva (2.91 %) and B. gonionotus (0.46%) while L. festiva and P. bulu (3.57%) showed insignificant differences (p > 0.05). These values are useful as a baseline data on the nutritional quality of freshwater fish from Kampung Peta, Johor.
Karyotypes and COI Gene Sequences of Chironomus sp. Le1 (Kiknadze and Salova, 1996), Ch. laetus (Belyanina and Filinkova, 1996) and Their Hybrid from the Yamal Peninsula, Arctic Zone of Russia

Simple Summary Chironomids, or non-biting midges, are one of the most abundant insect families. Their larvae are an important component of various aquatic ecosystems. In the Chironomus genus, sibling species are found that are not distinguished by morphology. Due to the presence of giant polytene chromosomes in their salivary gland, it is more convenient to use cytogenetics for species identification. The molecular genetic method also has limitations and depends on the level of intra- and interspecific variability of species. We used morphological, cytogenetic, and molecular genetic approaches to the study of chironomid larvae from two lakes on the Yamal Peninsula. We found a few larvae, which by morphology were very similar to the Chironomus riihimakiensis group. By cytogenetics, we identified the species as Ch. laetus, the first species with arm combinations AE BC DF G and propose the name of a new cytocomplex—“laetus”. We also found a hybrid, Ch. laetus × Ch. sp. Le1, which is the first hybrid between species from different cytocomplexes. Molecular-genetic analysis of COI gene sequences has shown high values of genetic distance between Ch. laetus and species from the Ch. riihimakiensis group. Molecular genetic data suggests the presence of a subgroup with Ch. laetus. Abstract The study of the biological diversity of the Arctic zone yields intriguing results. Initial research on the lakes of the Yamal Peninsula resulted in the identification of Chironomus laetus and the hybrid Ch. laetus × Ch. sp. Le1. To avoid misidentification, we used morphological, cytogenetic, and molecular genetic approaches. By cytogenetics, in Ch. sp. Le1, seven banding sequences were found: Le1A1, Le1B1, Le1C1, Le1D1, Le1E1, Le1F1, and Le1G1. The karyotype of Ch. laetus was mapped for the first time; it is the first species with the arm combinations AE BC DF G. We propose the name of a new cytocomplex—“laetus”. DNA-barcoding of the COI gene was carried out for Ch. laetus and Ch. laetus × Ch. sp. Le1 for the first time. The estimated genetic distance between the sequences of Ch. laetus and Ch. riihimakiensis is 2.3–2.5%. The high similarity in morphology, banding sequences, and the possibility of hybridization indicate a close relationship between Ch. laetus and Ch. sp. Le1, which is assumed to be the northern variant of Ch. riihimakiensis. Molecular genetic data suggests the presence of a subgroup with Ch. laetus.
Adapting EEG based MI-BMI depending on alertness level for controlling a lower-limb exoskeleton

Motor imagery (MI) has been used as a control paradigm of external devices for brain-machine interfaces (BMI). One of the main limitations of EEG based MI-BMI systems is the sensitivity of the performance to changes in the environment, signal properties, and subjects’ state of mind, especially the ability to stay focused and their alertness. This paper presents a new approach for improving the accuracy of a MI-BMI for controlling a lower-limb exoskeleton by adapting the classifier depending on the level of alertness. Results showed that the performance of MI-BMI sightly improves when predictions are modified based on alertness level, especially for subjects that had lower baseline accuracy.
Principals’ transformational leadership in strengthening character education at senior high school level (SMA) in Indonesia

Character education reinforcement in secondary schools is one of the educational programmes aimed at anticipating the tendency of moral perversion as a result of moral decadence. Various forms of moral deviations that occur among high school students result in them being alienated from life because they conflict with cultural norms, school discipline, and life ethics in society. In this article we aim to discuss the relation of character value reinforcement and the principal’s transformational leadership strategy to shape students’ characters in a descriptive-critical manner. The objective of this study was investigating school strategies for optimising the implementation of character education reinforcement. In this research we used a qualitative method with a case study design. The data validity measurement was based on the levels of credibility, transferability, dependability, and confirmability. The results emphasise the importance of shaping student character as an anticipatory step to minimise moral distortions among high school students, and the effectiveness of the principal’s transformational leadership role in optimising the implementation of education programmes for the strengthening of students’ characters in schools.
Robust Predictive Control of a Class of Nonlinear Systems

In this work, a continuous-time predictive controller designed for a class of nonlinear systems is robustified using an extended state observer. The predictive controller formulation requires the availability of an accurate mathematical model of the plant and the complete state vector. In this work, the extended state observer is employed to address these issues. The extended state observer simultaneously estimates the state and the effect of uncertainty and disturbances in an integrated manner. The estimated states and disturbances are used to robustify the predictive controller designed for nominal system. Closed-loop stability for the overall system is established. As an illustrative example, missile autopilot design using the proposed approach is presented along with simulation results. Finally, comparison results of the proposed approach with existing techniques appeared in the literature toward the robustification of the predictive controller are presented. The study clearly brings out the efficacy .
Post-processing of direct metal deposited AlCrCoCuFeNi HEA using centrifugal barrel finishing

Stainless steels, Ni-based alloys, Ti-based alloys, and more recently high entropy alloys have been used in the aerospace industry to improve the exterior properties of components and coatings that require a fine surface finishing with over high temperature range. High- entropy alloys (HEA) have become a ground-breaking research field that provides solutions for structural/ functional materials in the aerospace industry. These alloys, fabricated via direct metal deposition, have better properties than those produced by arc melting. However, the poor surface finish acquired by the layer-by-layer laser deposition process fails to meet the industrial requirements. The implementation of surface treatment by centrifugal barrel finishing is employed to improve the surface roughness of AlCoCrCuFeNi laser deposited HEA. The results have shown a minimum surface roughness decrease of 40%. Thus, an improved surface finish was achieved.
Self-aligned top-gate amorphous gallium indium zinc oxide thin film transistors

We have demonstrated a self-aligned top-gate amorphous gallium indium zinc oxide thin film transistor (a-GIZO TFT). It had a field effect mobility of 5 cm2/V s, a threshold voltage of 0.2 V, and a subthreshold swing of 0.2 V/decade. Ar plasma was treated on the source/drain region of the a-GIZO active layer to reduce the series resistance. After Ar plasma treatment, the surface of the source/drain region was divided into In-rich and In-deficient regions. The a-GIZO TFT also had a constant sheet resistance of 1 kΩ/◻ for a film thickness of over 40 nm. The interface between the source/drain Mo metal and the Ar plasma-treated a-GIZO indicated a good Ohmic contact and a contact resistivity of 50 μΩ cm2.
NGC 188, the age of the galactic disk, and the evolution of the Li abundance

The implications of an age for the open cluster NGC 188 only slightly larger than that of M67 are investigated. It is demonstrated that a differential and absolute comparison of the cluster color-magnitude diagrams leads to no inconsistencies if the reddening for NGC 188 is 0.09 mag larger than that for M67, while the apparent modulus of NGC 188 is 1.8 mag larger. Assuming E(B-V) = 0.03 and (m-M) = 9.7 for M67 results in an age of approximately 5 billion yr for M67 and 6.5 billion yr for NGC 188. The shift required by the differential reddening and distance modulus also removes the Li anomaly recently found by Hobbs and Pilachowski (1988) for NGC 188. If the metallicity of NGC 188 is significantly higher than that of M67, the required reddening differential would be smaller for the same age difference. A younger age for NGC 188 produces no inconsistencies with current theories of stellar and Galactic evolution, and may actually be more consistent than an age similar to the metal-rich globular cluster 47 Tucanae. 55 references.
Polarization Meridian Plane-Based 3-D Attitude Measurements: A Bio-Inspired Approach

As a bionic sensor inspired by the behaviors of insects, a polarized light compass determines the attitude information from the polarization distribution of the sunlight with its biomimetic optical structure. In this article, focusing on the problem that the existing attitude determination method can only obtain the 1-D heading angle from polarization mode, a polarization meridian plane (PMP)-based 3-D attitude determination method is presented. In our work, the solar polarization meridional plane is modeled as introduced information independent of the solar vector. It connects more polarization vectors (solar vector, zenith direction, and neutral point) in the measurement system and contributes to an additional relational model, that is, the PMP frame conversion model. Then, by combining with the solar vector conversion model, the proposed method obtains the real-time three-axis attitude angles by the image-based polarized light compass itself. Finally, numerical simulations and outdoor experiments are conducted to verify the effectiveness of the proposed method. The proposed PMP-based method makes it possible for the polarized light compass to have the ability of 3-D attitude determination, that is, pitch, roll, and yaw angles.
Optical communication components

We review and contrast key technologies developed to address the optical components market for communication applications. We first review the component requirements from a network perspective. We then look at different material systems, compare their properties, and describe the functions achieved to date in each of them. The material systems reviewed include silica fiber, silica on silicon, silicon on insulator, silicon oxynitride, sol-gels, polymers, thin-film dielectrics, lithium niobate, indium phosphide, gallium arsenide, magneto-optic materials, and birefringent crystals. We then describe the most commonly used classes of optical device technology and present their pros and cons as well as the functions achieved to date in each of them. The technologies reviewed include passive, actuation, and active technologies. The passive technologies described include fused fibers, dispersion-compensating fiber, beam steering, Bragg gratings, diffraction gratings, holographic elements, thin-film filters, photo.