Miracle-dz/UniFAR-FTUs huggingface dataset:
Nonlinear gain coefficients in semiconductor quantum-well lasers: effects of carrier diffusion, capture, and escape

Effective nonlinear gain coefficients due to the effects of carrier diffusion, capture, and escape are derived from the carrier transport equations. The quantum capture and escape processes between the confined states and the unconfined states are calculated from first principles by evaluating the carrier-polar longitudinal optical phonon interactions. The dc and ac capture times and escape times are derived from evaluating the net capture current of carriers. The differences in capture and escape times between dc and ac operating conditions are numerically investigated. We find that both dc and ac escape times are strongly dependent on the quantum well structure. This differs from the dc and ac capture times that are not sensitive to the quantum well structure. We also find that the dc escape time predicted by the classical thermionic emission theory will no longer be valid for narrow or shallow quantum wells. We show that both dc and ac capture and escape time ratios will increase as the carrier temperature and the carrier density in the quantum well increase. Therefore, we suggest that the possible cause of the resonant frequency degradation and dramatic increase in the damping rate results from the increase of the ac capture to escape time ratio by the effects of carrier heating. Two theoretical models (2N and 3N models) were used to study the effects of carrier diffusion-capture-escape on the modulation response of quantum-well lasers and a distributed model of carrier transport in quantum-well lasers is proposed. Their implications in designing high-speed quantum-well lasers are discussed. >
Characterization of Bread Wheat Genotypes Using Spike Related Traits for Sustainable Yield Potential

Wheat is a cereal that is majorly consumed around the world. There is a dire need for the advancement of wheat cultivars that are producing high yield. The experiment was conducted to characterize the spike related traits of wheat genotypes. Twenty wheat genotypes comprising three replications were experimented using randomized complete block design. The difference was significant among the studied twenty genotypes revealed by analysis of variance. Correlation Pearson’s revealed that the number of grains per spike (GPS) has positive relationship among all the studied traits such as the number of tillers per plant (NTP), spike weight (SWT), spike length (SL), and grain yield per plant (GYP). The GYP has a strong positive association with GPS (0.81**), GYS (0.78**), and SL (0.68**). The biological yield had a non-significant association with GYS (0.28) and GPS (0.13). All studied attributes have variations in the mean values which were represented by Radar analysis. The genotype Sadiq-21 was the best performing genotype among the SWT, GYS and BY followed by genotype Nawab-21 which performed best among the NTP, GYS and GPS and genotype Ghazi-19 which performed good among BY, SWT and GPS. The genotypes that were among the worst performing were Suren-10, Galaxy-13 and Borluag-16. The result of our study showed grain yield was mainly affected by NTP, GYS and GPS. For the improvement of wheat yield, these attributes must be improved for selection so that the yield of the wheat can be increased because these have a strong association with the grain yield.
Non-linear wave-number interaction in near-critical two-dimensional flows

This paper deals with a system of equations which includes as special cases the equations governing such hydrodynamic stability problems as the Taylor problem, the Bénard problem, and the stability of plane parallel flow. A non-linear analysis is made of disturbances to a basic flow. The basic flow depends on a single co-ordinate η. The disturbances that are considered are represented as a superposition of many functions each of which is periodic in a co-ordinate ξ normal to η and is independent of the third co-ordinate direction. The paper considers problems in which the disturbance energy is initially concentrated in a denumerable set of ‘most dangerous’ modes whose wave-numbers are close to the critical wave-number selected by linear stability theory. It is a major result of the analysis that this concentration persists as time passes. Because of this the problem can be reduced to the study of a single non-linear partial differential equation for a special Fourier transform of the modal amplitudes. It is a striking feature of the present work that the study of a wide class of problems reduces to the study of this single fundamental equation which does not essentially depend on the specific forms ofthe operators in the original system of governing equations. Certain general conclusions are drawn from this equation, for example for some problems there exist multi-modal steady solutions which are a combination of a number of modes with different spatial periods. (Whether any such solutions are stable remains an open question.) It is also shown in other circumstances that there are solutions (at least for some interval of time) which are non-linear travelling waves whose kinematic behaviour can be clarified by the concept of group speed.
Affective Assesment Instrument to Assess Student Attitudes Towards Science, Technology, Engineering and Mathematics

The assessment instrument is part of the learning toolkit which includes the process of measuring and collecting data and information to be processed and interpreted in it to consider how decisions on student learning outcomes are achieved in accordance with learning objectives. Instruments are used to measure cognitive, psychomotor, and affective dimensions. So far there has not been much research on the development of an affective instrument, mostly focusing on students' cognitive and psychomotor aspects. Thus, this study aims to develop affective instruments, namely students' attitudes towards STEM (Science, Technology, Engineering and Mathematics). This research is research and development using the ADDIE development model. The ADDIE model consists of five steps: analysis, design, development, implementation, and evaluation. The initial instrument that was developed was 45 items which contained every STEM aspect which was then tested on test subjects totaling 72 high school students. Based on the results of data analysis, a good and effective attitude assessment instrument has been produced to assess students' attitudes to see students' attitudes towards STEM. Through this development, it is hoped that it can become a foundation that can be used by educators before giving appropriate treatment to students in preparing students who have an attitude towards STEM aspects so that students can face various challenges of the 21st century which are so tight and growing rapidly.
PreserFlo™ MicroShunt Versus Ab Externo Canaloplasty in Patients With Moderate to Advanced Open-Angle Glaucoma: 12-Month Follow-Up of a Single-Center Retrospective Study

Purpose To evaluate and compare the efficacy and safety of the PreserFlo MicoShunt and the canaloplasty in patients with moderate to advanced glaucoma. Methods In this retrospective study, 300 patients with moderate to advanced glaucoma underwent either the implantation of the PreserFlo™ MicroShunt (group A) or a canaloplasty (group B). All patients underwent regular follow-up examinations in our department every two days, every two weeks, and every three, six, and 12 months postoperatively. Examinations included measurement of the best corrected visual acuity (BCVA), slit-lamp biomicroscopy of the anterior and posterior segments, intraocular pressure (IOP) measurement using Goldmann applanation tonometry, visual field perimetry, and measurement of the endothelial cell density (ECD). Efficacy was shown by the absolute and qualified success rates calculated with the Kaplan-Meyer analysis. Results In group A, IOP was significantly reduced at 12 months (13.37 ± 3.94 mmHg, p≤ 0.01) postoperatively in comparison to baseline (23.47 ± 8.39 mmHg). In group B, there was also a reduction in IOP at 12 months (14.32 ± 3.59 mmHg, p≤ 0.01) in comparison to the baseline (18.86 ± 5.82 mmHg). Comparing both groups, the IOP of patients who received the PreserFlo™ MicroShunt was significantly lower than the IOP of patients receiving canaloplasty after 12 months (p=0.049). Patients in both groups were treated with significantly fewer topical agents after 12 months (group A: baseline = 2.53±1.56; 12 months: 0.43 ± 0.83, p≤0.01; group B: baseline 2.62 ± 0.87; 12 months: 1.52 ± 0.99, p≤0.01). Patients receiving the PreserFlo™ MicroShunt applied significantly fewer topical agents than patients who underwent canaloplasty (p≤ 0.01). One year after surgery, the cumulative probability of absolute success was 81.33% in group A and 14.67% in group B. After one year, the cumulative probability of qualified success was 93.33% in group A and 82.00% in group B. Conclusion The PreserFlo™ as well as the canaloplasty offer many advantages and only a few disadvantages for patients with glaucoma. However, the respective patient’s history and individual risk profile play an important role in the decision of the glaucoma specialist regarding the most appropriate surgical treatment for each patient. Patients with a high risk of conjunctival scarring and postoperative complications may benefit more from a canaloplasty, whereas patients who need a lower average IOP and show intolerance to any topical agents may require the PreserFlo™ implantation.
Spatial distributions of trapping centers in HfO2∕SiO2 gate stacks

A methodology to analyze charge pumping (CP) data, which allows positions of probing traps in the dielectric to be identified, was applied to extract the spatial profile of traps in SiO2∕HfO2 gate stacks. The results suggest that traps accessible by CP measurements in a wide frequency range, down to few kilohertz, are located within or near the interfacial SiO2 layer rather than in the bulk of the high-k film.
Antibacterial activity of essential oils: potential applications in food

Due to its antibacterial activity, oregano oil has lately become interesting as a potential 'natural' food preservative. Oregano oil was found to be a fast acting and effective inhibitor of a strain of Escherichia coli O157:H7, the causative agent of a serious gastro-enteritis, and was lethal to this strain when used in high enough concentrations. Starting with 106 bacteria per millilitre broth, 156 ppm was lethal within 5 min; 625ppm was lethal within 1 min. Treated bacterial cells observed under an electron microscope were lysed and apparently empty of cell contents. The chemical composition of two oregano oils was determined. Carvacrol and thymol, both phenolic compounds, appeared to be responsible for the antibacterial activity. The other two major components p-cymene and gamma-terpinene were found to be inactive against bacteria. The food stabiliser agar improved the antibacterial action of oregano oil in broth and the action of carvacrol was improved by both agar and stabiliser carrageenan. This enhancement is presumed to be due to the delayed separation of the essential oil or carvacrol droplets from suspension. The emulsifier lecithin markedly reduced the efficacy of oregano oil, possibly because it enclosed the carvacrol in micelles so that it came less into contact with bacterial cells. Changes in protein synthesis in E. coli O157:H7 cells during overnight incubation with a sub-lethal concentration of carvacrol were demonstrated. Heat shock protein 60 (HSP60) was induced in significant amounts and flagellin synthesis was almost completely inhibited, resulting in bacteria without flagella. Flagella are essential to bacterial motility and there is some evidence to indicate that they mediate adherence of pathogenic E. coli to epithelial cells in the gut and urinary tract. Further research is planned to investigate whether carvacrol can render E. coli O157:H7 aflagellate in vivo and whether this inhibits adhesion and colonisation of gut epithelial cells. Carvacrol in the form of a vapour was effective in significantly reducing viable numbers of Salmonella enteritidis on raw chicken at temperatures ranging from 4C to 37 C. This is promising for practical applications in the food sector since many foods are stored and transported at low temperatures. Possible uses could be the inclusion of a carvacrol carrier within the packaging for fresh products to reduce growth of spoilage bacteria. Alternatively, small carcases or pieces of meat could be decontaminated by vapour before further processing. In conclusion, there are several possible applications for oregano essential oil, and the constituent carvacrol in particular, in improving food safety. The addition of essential oil or carvacrol to food products could inhibit growth and reduce numbers of spoilage bacteria and pathogens. The use of carvacrol vapour within food packaging to extend the shelf life and improve safety or as a novel decontaminant for fresh meat is another possibility. A further potential application is in improving the intestinal health of food animals, when used as a feed additive.
Bifurcation of steady-state solutions in predator-prey and competition systems

Synopsis We discuss steady-state solutions of systems of semilinear reaction-diffusion equations which model situations in which two interacting species u and v inhabit the same bounded region. It is easy to find solutions to the systems such that either u or v is identically zero; such solutions correspond to the case where one of the species is extinct. By using decoupling and global bifurcation theory techniques, we prove the existence of solutions which are positive in both u and v corresponding to the case where the populations can co-exist.
Determining material stiffness using piezoelectric bimorphs

The dynamic behavior of homogeneous, elastic piezoelectric bimorphs clamped at one end were determined in the case where the tip of the other end of the bimorph was constrained by a Hookean spring of stiffness k. It was found that the frequency at which the bimorph resonated increased by an amount related to k when compared to the case where the end was free. Therefore, a cantilever bimorph provides a technique to assess stiffness of a material by a simple measurement of the resonant frequency. Since the bimorph behavior scales with its geometry, the device can be designed specifically for mechanical measurement of microscopic systems such as living cells and molecules.
Investigation and modelling of rubber stationary friction on rough surfaces

This paper presents novel aspects regarding the physically motivated modelling of rubber stationary sliding friction on rough surfaces. The description of dynamic contact is treated within the framework of a generalized Greenwood–Williamson theory for rigid/soft frictional pairings. Due to the self-affinity of rough surfaces, both hysteresis and adhesion friction components arise from a multi-scale excitation of surface roughness. Beside a complete analytical formulation of contact parameters, the morphology of macrotexture is considered via the introduction of a second scaling range at large length scales which mostly contribute to hysteresis friction. Moreover, adhesion friction is related to the real area of contact combined with the kinetics of interfacial peeling effects. Friction experiments carried out with different rubbers on rough granite and asphalt point out the relevance of hysteresis and adhesion friction concepts on rough surfaces. The two scaling ranges approach significantly improves the description of wet and dry friction behaviour within the range of low sliding velocity. In addition, material and surface effects are predicted and understood on a physical basis. The applicability of such modelling is of high interest for materials developers and road constructors regarding the prediction of wet grip performance of tyres on road tracks.
Automorphism groups of relatively free groups

For each positive integer n, let Fn be a free group of rank n with basis (in other words, free generating set) {x1, …, xn} . If θ is an automorphism of Fn then {x1θ, …, xnθ} is also a basis of Fn and every basis of Fn has this form. For any variety of groups [Vfr ], let [Vfr ](Fn) denote the verbal subgroup of Fn corresponding to [Vfr ]. (See [10] for information on varieties and related concepts.) Let Gn = Fn/[Vfr ](Fn). Then Gn is a relatively free group of rank n in the variety [Vfr ]. By a basis of Gn we mean a subset S such that every map of S into Gn extends, uniquely, to an endomorphism of Gn. Write x¯i = xi[Vfr ](Fn) for i = 1, …, n. Then {x¯1, …, x¯n} is a basis of Gn. If λ is an automorphism of Gn then {x¯1λ, …, x¯nλ} is also a basis of Gn and every basis of Gn has this form. Any automorphism θ of Fn induces an automorphism θ of Gn in which x¯iθ = (xiθ)[Vfr ](Fn) for i = 1, …, n. Thus every basis of Fn induces a basis of Gn. The converse however is not always true; in general, there are automorphisms of Gn which are not induced by automorphisms of Fn.
The temperature and magnetic field dependence of superconducting critical current densities of multifilamentary Nb 3 Sn and NbTi composite wires

Commercial NbTi and Nb 3 Sn multifilamentary superconducting wire is becoming increasing important for use in research and commercial magnet systems. In both materials the temperature dependence of J c plays a major role in the determination of magnet system operating parameters and design stability margins. We report here critical current density measurements as a function of temperature from 4.2 to 19 K and of applied magnetic field upto 8 T for multifilamentary Nb 3 Sn wire and for 2 alloys of NbTi superconducting wire. From this data [ \partial J_{c}(H_{a})/\partialT ] and [\partialH_{c2}/\partialT]T=T_{c} can be obtained and stability criteria and other superconducting parameters of the wires may be extracted.
Crystalline Fundamental Groups II — Log Convergent Cohomology and Rigid Cohomology

In this paper, we investigate the log convergent coho- mology in detail. In particular, we prove the log convergent Poincare lemma and the comparison theorem between log convergent cohomology and rigid cohomology in the case that the coefficient is an F a -isocrystal. We also give applications to finiteness of rigid cohomology with coeffi- cient, Berthelot-Ogus theorem for crystalline fundamental groups and independence of compactification for crystalline fundamental groups.
Clinical, electrophysiological, and genetic characteristics of cerebrotendinous xanthomatosis in South Korea

ABSTRACT Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid storage disorder caused by 27-hydroxylase deficiency. We report the clinical characteristics of six Korean CTX patients. The median age of onset was 22.5 years, the median age at diagnosis was 42 years, and the diagnostic delay was 18.1 years. The most common clinical symptoms were tendon xanthoma and spastic paraplegia. Four of five patients exhibited latent central conduction dysfunction. All patients carried the same mutation in CYP27A1 (c.1214 G>A [p.R405Q]). CTX is a treatable neurodegenerative disorder; however, our results revealed that patients with CTX in Korea might receive the diagnosis after a prolonged delay.
Two Cases of COVID-19 With Concomitant Unexplained Dental Pain: Coincidence or Related?

As the rapidly evolving Covid-19 pandemic spread and became a global concern and the study of the disease’s features became possible, its signs and symptoms were elucidated in many studies around the world. In addition to other fairly typical symptoms including fever, cough, sore throat, and shortness of breath, the Covid-19 pandemic has several neurological symptoms that have been noted and documented, including headaches, muscle, and joint discomfort, loss of taste and smell, as well as generalized body aches. However, there were a few unusual symptoms that were noted, one of which we will focus on in this report, namely, tooth pain. The Covid-19 virus has caused tooth pain and discomfort in two Lebanese patients. The reported pain is not related to any local aggression; therefore, it is likely a neurological consequence of the viral infection by the SARS-Cov-2 virus.
Collisionless damping of parametrically unstable Alfvén waves

[1] Linear Vlasov theory and one-dimensional hybrid simulations are used to study the parametric instabilities of a circularly polarized parallel propagating Alfven wave in a homogeneous, magnetized, and collisionless plasma. We discuss the linear and the weakly nonlinear development of the instabilities of the Alfven waves, including kinetic effects, and investigate the structure, the growth, and the damping of the driven ion acoustic-like waves. The dispersion relation reproduces the fluid characteristics of the instabilities in the case that protons are cold but contains an infinite number of roots in the general case. We show that at low proton plasma βp (βp ≈ 0.1), kinetic effects break the degeneracy of the mode-coupling solutions of the fluid theory, and we unambiguously identify the growing and the damped modes. We find that contrary to traditional thought, kinetic effects are important even for very low-βp in the late stages of the linear evolution, leading to a dephasing effect between the plasma pressure and the density fluctuations. The relevance of the results to the experimental identification of the instabilities, to the generation of local turbulence, and to the reduction of cross helicity in the solar wind are pointed out.
Three-Dimensional Vortical Structures of a Backward-Facing Step Flow at Moderate Reynolds Numbers

The three-dimensional vortical structures created in the downstream of the moderate-Reynolds-number ( Re ≤700) backward-facing step flow are studied based on the direct numerical simulation (DNS). The flow is assumed to be periodic in the spanwise direction. The vortical structure manifests itself in the form of zig-zag arrangement of alternating quasi-streamwise structures with positive and negative streamwise vorticity, which has been observed in the buffer region of the turbulent channel flow by DNS [J. Fluid Mech. 332 (1997) 185]. In order to excite the perturbation, we triggered the flow by giving discontinuity of the time derivative of the inlet flow initially. It is found that the condition whether the three-dimensional vortical structures appear depends on the rate of temporal increase of the perturbation amplitude as t > 0. The present study is closely related to the generation mechanism of the coherent vortical structures in the wall turbulence.
The development of gender assignment and agreement in English-Greek and German-Greek bilingual children

The aim of this experimental study is to examine the development of Greek gender in bilingual English-Greek and German-Greek children. Four gender production tasks were designed, two targeting gender assignment eliciting determiners and two targeting gender agreement eliciting predicate adjectives for real and novel nouns. Participant performance was assessed in relation to whether the ‘other’ language was a gender language or not (English vs. German) along with the role of the bilinguals’ Greek vocabulary knowledge and language input. The results are argued to contribute significantly to disentangling the role of crosslinguistic influence in gender assignment and agreement by bringing together a variety of input measures such as early and current amount of exposure to Greek, the role of area of residence (i.e. whether Greek is the minority or the majority language), the effect of maternal education and the amount of exposure to Greek in a school setting.