Miracle-dz/UniFAR-FTUs huggingface dataset:
Optical absorption by colloidal precipitates in bismuth‐implanted fused silica: Annealing behavior

The near‐surface regions of high‐purity fused silica disks (Corning 7940) were modified by implantation with Bi2+ ions at 160 keV and at room temperature. The glasses implanted with a nominal dose of 6×1016 Bi2+ ions/cm2 at ∼5 μA/cm2 were subsequently annealed in oxidizing and inert atmospheres. The annealing temperature ranged from 500 to 1100 °C. The doses retained before and after the anneals were determined from Rutherford backscattering. A broad optical‐absorption band at ∼5 eV (248 nm) was resolved and attributed to surface plasmon resonance from colloidal bismuth metal particles precipitated after implantation and observed by transmission electron microscopy. After annealing in oxygen for 60 min at temperatures ≥1000 °C the bismuth in the sample decreased by ∼70%. Annealing in an oxidizing atmosphere oxidized the metallic precipitates, and oxidation changed the optical absorption of the samples. For samples annealed in argon, a relatively small decrease in retained dose by ∼12% was observed for tem.
Determining the Number of Interpretable Factors

A major weakness of current methods of determining the number of factors is that they require this decision to be made before rotation; therefore, information on the possible interpretability of factors cannot be considered in determining the appropriate number. An objective, noninferential index for determining the number of interpretable factors is developed and applied to several examples selected from the literature. The effects of type of rotation, type of communality estimate, and statistical sampling on the index were investigated. Results indicate that this is a promising method for determining number of interpretable factors and that principal components factors are less interpretable than are squared multiple correlation and image factors. Determining the number of factors is one of the most important problems facing the researcher wishing to use factor analysis. Rotation procedures require a prior, independent estimate of the number of factors because the rotated loadings are dependent on the number of factors rotated (Cliff & Hamburger, 1967). The inclusion of too few factors in the rotation results in the loss of potentially interpretable factors. Orthogonally rotating too many factors causes factor splitting, resulting in pseudospecific factors (Cattell, 1966). Rotating too many oblique factors may produce high interfactor correlations or cause the factor space to collapse. One of the key issues in a recent dispute between Eysenck (1971) and Cattell (1972) about the nature of the extraversion and neuroticism factors involved a difference in views on the number of factors that should be rotated and interpreted. Many similar examples could be cited. Most tests for determining the number of factors are based on either statistical or psychometric principles. In the classical statistical approach (Lawley, 1963; Rao, 1955), the N individuals are considered to be a sample from a population of individuals, and an attempt is made to make inferences about this population from the characteristics of the sample. Statistical tests are actually tests of the importance of the last (« — k) factors,
The ethanol sensing characteristics of ZnO thin films with low operating temperatures synthesized by pulsed laser deposition

ZnO thin films (ZTFs) are deposited on Si (1 1 1) substrates by a pulsed laser deposition (PLD) method and characterized by x-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The ethanol sensing properties of ZTFs are investigated by exposing them to different concentrations of gaseous ethanol at various temperatures. At an operating temperature of 120 °C, the ZTFs have a high response value to 5 ppm gaseous ethanol, and the detection limit can be as low as 0.1 ppm. The corresponding response and recovery times are 20 and 15 s, respectively. The results indicate that ZTFs synthesized by PLD have potential applications for fabricating high performance ethanol sensors.
Torque and force on a magnetic dipole

Recent controversies about torque and force on a magnetic dipole are discussed. Three essentially different current loop models are analyzed. Although all models yield the same expression for the torque, N=m×B, the detailed mechanisms that give rise to the torque in each case are very different. The expression for the force on a magnetic dipole is derived and analyzed for all models. The force expression is the same for all current loop models but it differs from the force on a magnetic charge dipole. The expression, obtained for the force on a current loop magnetic dipole, FCL=■(m⋅B)−(d/dt)(m×E/c), differs from what usually appears in the educational literature. The standard ‘‘naive’’ calculation of the force yields the correct expression for the rate of change of the total momentum, dP/dt=∇(m⋅B). However, the current loop in an externa l electric field has an internal ‘‘hidden momentum’’ m×E/c, which is not related to the motion of the center of mass of the dipole. Thus, for the force, defined as mass t.
Single and Multiple Solar Flare Loops: Hydrodynamics and Ca XIX Resonance Line Emission

Studies made so far with one-dimensional hydrodynamic simulations have shown that it is difficult to reproduce the soft X-ray spectral line profile observed in the early phase of solar flares. Simulated line profiles predict a dominant emission from a large blueshifted component, while observations show persistently strong stationary components. We resolve these discrepancies by utilizing a multiple-loop system instead of just a single loop for conductively heated flare simulations. Under a fixed heat input rate, we examine how the heating duration τheat affects the Ca XIX resonance (w) line emission from single and multiple flare loops. In the multiple-loop model, the flare energy is released into individual loops with a specified time delay, which implicitly mimics the successive formation of flare loops due to continuous reconnection. We find that whether or not τheat is longer than τc affects the hydrodynamic response in an individual flare loop, where τc corresponds to the time when the loop is filled with evaporated plasma. The Ca XIX spectral line shape is characterized by an intensity ratio of emission from evaporated plasma to emission from accumulated plasma after evaporation. This ratio is mainly determined by the parameter τheat/τc. Our findings suggest that the following scenario can naturally explain the observed spectral line features. Flare energy is injected into a bundle of loops successively in two steps: in the preflare stage, τheat ≤ τc for the inner loops, and then in the main flare stage, τheat > τc for the outer loops. A large initial coronal density is not necessary in this scenario.
Selection of a Suitable Wall Pressure Spectrum Model for Estimating Flow-Induced Noise in Sonar Applications

Flow-induced structural noise of a sonar dome in which the sonar transducer is housed, constitutes a major source of self-noise above a certain speed of the vessel. Excitation of the sonar dome structure by random pressure fluctuations in turbulent boundary layer flow leads to acoustic radiation into the interior of the dome. This acoustic radiation is termedflow-induced structural noise. Such noise contributes significantly to sonar self-noise of submerged vessels cruising at high speed and plays an important role in surface ships, torpedos, and towed sonars as well. Various turbulent boundary layer wall pressure models published were analyzed and the most suitable analytical model for the sonar dome application selected while taking into account high fre­ quency, fluid loading, low wave number contribution, and pressure gradient effects. These investigations included type of coupling that exists between turbulent boundary layer pressure fluctuations and dome wall structure of a typical sonar dome. Compari­ son of theoretical data with measured data onboard a ship are also reported. © 1995 John Wiley & Sons, 1nc.
Kloosterman Sums and a Mean Value for Dirichlet Polynomials

Abstract Let a 1 , a 2 , a 3 ,. be complex numbers. Then, for ϵ > 0, M ≥ 1 and T ≥ 1, [formula] where ζ( s ) is Riemann′s zeta-function and C ϵ depends only on ϵ. The proof is based on a technical refinement within the circle of ideas to be found in Deshouillers and Iwaniec′s paper: Kloosterman sums and Fourier coefficients of cusp forms ( Invent. Math. 70 (1982), 219-288).
The class of suboptimal and optimal solutions to the discrete Nehari problem : characterization and computation

Simple and explicit formulae, in a linear fractional transformation (LFT) form, for all suboptimal and optimal solutions to the discrete-time version of the one-block Nehari problem, are derived under no restrictive conditions imposed on the initial data. Using the so-called ‘signature condition’—a generalized Popov-theory type argument—general solvability conditions in terms of a certain type of discrete-time Kalman-Szego-Popov-Yakubovich system are obtained. For the class of optimal approximations, derived via singular perturbation techniques, the LFT coefficients are all of McMillan degree n - r, where n and r are the McMillan degree and the multiplicity of the largest Hankel singular value of the system to be approximated, respectively. The results also lead directly to a simple numerical algorithm.
Some new families of optical orthogonal codes for code-division multiple-access fibre-optic networks

An optical orthogonal code (OOC) is a collection of binary sequences with good auto- and cross-correlation properties; they were defined by Chung and others as a means of obtaining code division multiple access on optical networks. In the paper three new families of OOCs are constructed from the balanced incompleted block design techniques. The first family of the codes is with ideal auto- and cross-correlation properties and they have optimal cardinalities. The other two families of the codes are with ideal auto-correlation and nearly ideal cross-correlation properties. The second family of the codes is demonstrated to have twice as many codewords as the optimal codes. The third family of the codes is demonstrated to have more codewords than the quadratic congruence codes when the weight of the codeword is less than eight.
Effect of strong electrostatic interactions of microparticles on the dust acoustic waves

It is shown that strong electrostatic interaction of highly charged microparticles (which is common for many laboratory experiments) can significantly modify the behavior of dust acoustic waves in a complex plasma giving rise to their transition, at large wave numbers, into a new regime similar to the dust thermal mode. Examples of the dispersion curves are calculated for realistic complex plasma parameters and a comparison with a recent experiment is presented. Excellent agreement is found between the theory and the experiment.
A Prospective Study on the Reliability of First-Trimester Ultrasound in Identifying the Gestational Sac Implantation Site

Objectives: Normal and abnormal implantation of the gestational sac may affect obstetrical outcomes. We sought to evaluate whether ultrasound can correctly identify the first-trimester gestational sac implantation wall compared to diagnostic hysteroscopy. Methods: Consecutive women diagnosed with first-trimester pregnancy loss who opted for surgical termination of pregnancy were prospectively recruited to the study. Pre-operatively, an ultrasound scan was performed to assess for the gestational sac implantation wall. Subsequently, the surgical procedure of diagnostic hysteroscopy combined with suction and curettage was performed. The sonographers were blinded to the hysteroscopy results. The gestational sac implantation wall was determined and compared between the two modalities. Results: Twenty-three women were included in the study. The median gestational age 9 (range: 6 to 13) weeks, and the median crown-rump length was 7 (range 6-9) mm. In one case, the implantation site was determined only by the U.S. In the remaining, the U.S. and hysteroscopy gestational sac location were identical (21/22, 95%). Thus, the correlation between the sonographic and hysteroscopy findings was 0.96. Conclusion: Ultrasound is a reliable method for the detection of the early gestational sac implantation site.
Synchronous servo scheme using maximum-likelihood detectors

For magnetic disk drives, we have developed a scheme for synchronous servo with maximum-likelihood (SSML) detection that is synchronous around the entire circumference of the track and utilizes ML estimation to detect head position, clock mark phase, and track addresses. Compared to the conventional asynchronous sector servo scheme, the SSML scheme has many, much shorter, servo areas-typically several hundred-distributed on the disk. This results in higher servo information rate, which will be needed for future high-track-density disk drives with a wide servo bandwidth. We analyze the performance of the SSML scheme, including the format efficiency. We discuss a limitation of the synchronous servo scheme with respect to the number of servo areas, and we show an appropriate region for its application. Feasibility of the SSML scheme has been demonstrated in prototype 2.5-in hard disk drives.
Overcoming Original Sin: Insights from a New Dataset

: This paper introduces a new dataset on emerging market sovereign bonds, distinguishing between the currency of denomination and the residence of investors. Our dataset is on long-term government bonds and provides a more complete coverage of bonds issued in domestic markets. We document several salient trends. While a preponderance of foreign currency bonds is associated with greater holdings by foreign investors, the correlation is weak at best. Over time, emerging market governments have enhanced their ability to borrow abroad in their own currency, reducing their reliance on foreign currency debt. In this sense, EME sovereigns have made progress toward overcoming original sin. Nevertheless, the greater role of market and duration risk and the activity of foreign non-bank financial intermediaries (NBFIs) mean that emerging markets remain subject to fluctuations in global financial conditions.
Morphology and Fractal Dimension of Size‐Resolved Soot Particles Emitted From Combustion Sources

Databases of the morphological parameters of fresh size‐resolved soot particles and their systematic comparisons among various combustion sources are important to trace the soot aging process and evaluate their optical properties. Here, the mixing state, effective density (ρeff), monomer number and diameter (N and dp), and fractal dimension (Df) of size‐resolved soot particles from vehicle emissions (VE), biomass burning (BB), coal combustion (CC), tunnel air (TA) and urban air (UA) were characterized based on electron microscopy observations and analysis. We determined that freshly‐emitted soot particles from combustion sources contain not only bare‐like soot but also some coated‐soot particles. ρeff (157–689 kg/m3) decreased while N (46–1,500) and dp (24–42 nm) increased with the increased diameter of soot particles. The Df of BB and CC were independent of the diameter changes and fluctuated between 1.65 and 1.80, while the Df of VE and TA (1.62–1.71) increased and UA Df (1.87–1.80) decreased with increasing diameter. Based on Df obtained in this study, we found that the ensemble Df of VE, BB, CC, TA, and UA could not represent the finer (<150 nm) soot particles and coarser soot particles (>600 nm) in VE, TA, and UA. This study highlights that the morphological parameters of freshly‐emitted soot particles vary among different combustion sources and have a size effect, particularly for finer and coarser soot particles. The database of size‐resolved soot particles will be helpful to improve soot models based on numerical simulation and better evaluate atmospheric optical properties.
The Kinetostatic Optimization of Robotic Manipulators: The Inverse and the Direct Problems

The design of a robotic manipulator begins with the dimensioning of its various links to meet performance specifications. However, a methodology for the determination of the manipulator architecture, i.e., the fundamental geometry of the links, regardless of their shapes, is still lacking. Attempts have been made to apply the classical paradigms of linkage synthesis for motion generation, as in the Burmester Theory. The problem with this approach is that it relies on a specific task, described in the form of a discrete set of end-effector poses, which kills the very purpose of using robots, namely, their adaptability to a family of tasks. Another approach relies on the minimization of a condition number of the Jacobian matrix over the architectural parameters and the posture variables of the manipulator. This approach is not trouble-free either, for the matrices involved can have entries that bear different units, the matrix singular values thus being of disparate dimensions, which prevents the evaluation of any version of the condition number. As a means to cope with dimensional inhomogeneity, the concept of characteristic length was put forth. However, this concept has been slow in finding acceptance within the robotics community, probably because it lacks a direct geometric interpretation. In this paper the concept is revisited and put forward from a different point of view. In this vein, the concept of homogeneous space is introduced in order to relieve the designer from the concept of characteristic length. Within this space the link lengths are obtained as ratios, their optimum values as well as those of all angles involved being obtained by minimizing a condition number of the dimensionally homogeneous Jacobian. Further, a comparison between the condition number based on the two-norm and that based on the Frobenius norm is provided, where it is shown that the use of the Frobenius norm is more suitable for design purposes. Formulation of the inverse problem—obtaining link lengths—and the direct problem—obtaining the characteristic length of a given manipulator—are described. Finally a geometric interpretation of the characteristic length is provided. The application of the concept to the design and kinetostatic performance evaluation of serial robots is illustrated with examples.
A slender–wing theory in potential flow

Consider uniform, steady potential flow past a slender wing. By considering a horseshoe vortex in the limit as γ/Us → ∞, where γ is the circulation, U is the uniform stream velocity and s is the span, a model representing a vortex sheet is obtained from which the lift on the slender wing can be determined. (This is in contrast to the textbook approach of Batchelor and Katz & Plotkin, who discretize the vortex sheet with horseshoe vortices in the limit as γ/Us → ∞, but then relate the vortex strength to lift by using the two–dimensional limit γ/Us → 0. We shall argue that using these different limits in the same analysis is inconsistent and leads to an incorrect result.) The resulting potential term is shown to be the same as the potential term of the lift Oseenlet in Oseen flow. In the limit of high–Reynolds–number flow, only half the contribution to the lift integral comes from the potential–velocity part of the lift Oseenlet. The other half comes from the vortex–wake–velocity part of the lift Oseenlet. We therefore assume potential flow everywhere except at the vortex sheet, along which we allow a singular vortex–wake–velocity term of the lift Oseenlet. From this, a slender–wing theory is presented together with integral expressions for the lift and change in lift over the wing surface. Applications to slender bodies and large–aspect–ratio wings, in particular, the Lanchester–Prandtl lifting line, are then considered.
Uninodal 4-connected 3D nets. III. Nets with three or four 4-rings at a vertex

A description is given of 4-connected nets with one kind of vertex in which at least three of the shortest rings containing each pair of edges are 4-rings. 21 such nets are identified and characterized topologically. Some correspond to well known zeolite structures, but most are believed to be new.
The impact of blinding on trial results: A systematic review and meta-analysis

Background: Blinding, the concealment of the arm to which participants have been randomized, is an important consideration for assessing risk of bias of randomized trials. A growing body of evidence has, however, yielded inconsistent results on whether trials without blinding produce biased findings. Objective: To conduct a systematic review and metaanalysis of the evidence addressing whether trials with and without blinding produce different results. Methods: We searched MEDLINE, EMBASE, Cochrane Reviews, JBI EBP, and Web of Science, from inception to May 2022, for studies comparing the results of trials with and without blinding. Pairs of reviewers, working independently and in duplicate, reviewed search results for eligible studies and extracted data. We pooled the results of studies comparing trials with and without blinding of patients, healthcare providers/investigators, and outcome assessors/adjudicators using frequentist random-effects meta-analyses. We coded study results such that a ratio of odds ratio (ROR) < 1 and difference in standardized mean difference (dSMD) < 0 indicate that trials without blinding overestimate treatment effects. Results: We identified 47 eligible studies. For dichotomous outcomes, we found low certainty evidence that trials without blinding of patients and healthcare providers, outcome assessors/adjudicators, and patients may slightly overestimate treatment effects. For continuous outcomes, we found low certainty evidence that trials without blinding of outcome assessors/adjudicators and patients may slightly overestimate treatment effects. Conclusion: Our systematic review and meta-analysis suggests that blinding may influence trial results in select situations, albeit the findings are of low certainty and the magnitude of effect is modest. In the absence of high certainty evidence suggesting that trials with and without blinding produce similar results, investigators should be cautious about interpreting the results of trials without blinding.
Relationship between blood pressure and the risk of acute myocardial infarction in Chinese adults: a prospective study

Objective To explore the relationship between blood pressure and the risk of acute myocardial infarction (AMI) in Chinese adults. Methods This prospective cohort study included 26,794 participants which were recruited from 60 surveillance sites in 2010 China Chronic Disease Risk Factor Surveillance and followed-up survey was conducted from 2016 to 2017. Data were collected by questionnaires, physical measurements and laboratory tests. Blood pressure was grouped by systolic blood pressure and diastolic blood pressure, and cox proportional hazards regression models were used to analyze the relationship between blood pressure and risk of AMI. Results A total of 256 AMI events occurred among 160,386.38 person-years follow-up and the incidence of AMI was 159.6/100,000 person-years. After adjusting for age, sex, income, education, marital status, physical activity, drinking, abdominal obesity, BMI, dyslipidemia and diabetes, compared with normotension group, the risk of AMI onset was increased by 61% (HR=1.61, 95% CI: 1.17? 2.21), 60% (HR=1.60, 95% CI: 1.17? 2.20), 84% (HR=1.84, 95% CI: 1.26? 2.68) and 120% (HR=2.20, 95% CI: 1.43? 3.38) in systolic diastolic hypertension(SDH), hypertension grade 1(mild), hypertension grade 2(moderate), hypertension grade 3(severe), respectively. In addition, after adjusting for relevant factors, the relationship between hypertension and the risk of AMI may be influenced by abdominal obesity, diabetes and lack of physical activity. Conclusions The incidence of AMI appears to be considerable among Chinese adults and hypertension is an independent risk factor for its onset. The risk of AMI is higher in participants with more severe hypertension.