Miracle-dz/UniFAR-FTUs huggingface dataset:
The influence of internal friction on rotordynamic instability

The Influence of Internal Friction on Rotordynamic Instability. (May 2003) Anand Srinivasan, B.E. , University of Madras Chair of Advisory Committee: Dr. John M. Vance Internal friction has been known to be a cause of whirl instability in built-up rotors since the early 1900’s. This internal damping tends to make the rotor whirl at shaft speeds greater than a critical speed, the whirl speed usually being equal to the critical speed. Over the years of research, although models have been developed to explain instabilities due to internal friction, its complex and unpredictable nature has made it extremely difficult to come up with a set of equations or rules that can be used to predict instabilities accurate enough for design. This thesis suggests improved methods for predicting the effects of shrink fits on threshold speeds of instability. A supporting objective is to quantify the internal friction in the system by measurements. Experimental methods of determining the internal damping with non-rotating tests are investigated, and the results are correlated with appropriate mathematical models for the system. Rotating experiments were carried out and suggest that subsynchronous vibration in rotating machinery can have numerous sources or causes. Also, subsynchronous whirl due to internal friction is not a highly repeatable phenomenon.
A statistical survey of electrostatic electron cyclotron harmonic waves based on THEMIS FFF wave data

Based on the high‐resolution FFF wave spectral data obtained from the three innermost Time History of Events and Macroscale Interactions during Substorms spacecraft, electrostatic electron cyclotron harmonic (ECH) emissions are identified, using automatic selection criteria, for the period from May 2010 to December 2015. A statistical analysis of wave spectral intensity, peak wave frequency, and wave occurrence rate is performed for the first harmonic ECH waves that are predominantly strongest among all harmonic bands, in terms of dependence on L shell, magnetic local time (MLT), magnetic latitude, and the level of geomagnetic activity. Our results indicate that ECH emissions are preferentially a nightside phenomenon primarily confined to the MLT interval of 21–06 and that the most intense ECH waves are commonly present at L = 5–9 and MLT = 23–03 within 3° of the magnetic equator. As the geomagnetic activity intensifies, averaged nightside ECH wave amplitude can increase from a few tenth mV/m to well above 1 mV/m. The presence of >0.1 mV/m ECH emissions extends from L < 10 to L > ~12 with a broad MLT coverage from the evening to postdawnside at the occurrence rate above 20% for the equatorial emissions and at a rate up to ~7% for higher‐latitude waves. Overall, the average peak wave frequency of the first harmonic ECH waves is located ~1.5 fce (where fce is the electron gyrofrequency) for L < 10 and becomes smaller at higher L shells. It also exhibits a tendency to shift to lower frequencies with increasing geomagnetic activity level. By finalizing a numeric table that gives the statistically average values of wave amplitude and peak wave frequency for different ranges of L shell, MLT, and geomagnetic activity level, our detailed investigation provides an improved statistical model of ECH wave global distribution in the Earth's inner and outer magnetosphere, which can be readily adopted as critical inputs in diffusion codes to evaluate the rates of ECH wave‐driven pitch angle scattering and to determine the precise contributions of ECH waves to the plasma sheet electron dynamics and diffuse auroral electron precipitation.
Nonlinear Time-Domain Analysis of a Sliding Block on a Plane

A time domain finite difference numerical model of a sliding rigid block on a plane is developed using a simple elastic-perfectly plastic Mohr-Coulomb interface model. The model is shown to accurately predict the slip-stick and slip-slip behavior deduced from an analytical solution for behavior of a sliding block on a horizontal plane and the results of physical model tests of a block on both horizontal and inclined planes subject to harmonic and non-uniform excitation provided the appropriate interface strength is employed. Back analyses of the physical model tests show that for some geosynthetic interfaces, the interface shear strength depends upon the velocity of sliding. The numerical model developed herein provides a basis for rigorous evaluation of several important problems in geotechnical earthquake engineering, including the cumulative permanent seismic deformation of landfills, embankments, slopes, and retaining walls and the stresses induced by seismic loading in geosynthetic elements of landfill liner and cover systems.
Algebraic independence by Mahler’s method and $S$-unit equations

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Biased polls and the psychology of voter indecisiveness

Accounting for undecided and uncertain voters is a challenging issue for predicting election results from public opinion polls. Undecided voters typify the uncertainty of swing voters in polls but are often ignored or allocated to each candidate in a simplistic manner. Historically this has been adequate because first, the undecided tend to settle on a candidate as the election day draws closer, and second, they are comparatively small enough to assume that the undecided voters do not affect the relative proportions of the decided voters. These assumptions are used by poll authors and meta-poll analysts, but in the presence of high numbers of undecided voters these static rules may bias election predictions. In this paper, we examine the effect of undecided voters in the 2016 US presidential election. This election was unique in that a) there was a relatively high number of undecided voters and b) the major party candidates had high unfavorability ratings. We draw on psychological theories of decision making such as decision field theory and prospect theory to explain the link between candidate unfavorability and voter indecisiveness, and to describe how these factors likely contributed to a systematic bias in polling. We then show that the allocation of undecided voters in the 2016 election biased polls and meta-polls in a manner consistent with these theories. These findings imply that, given the increasing number of undecided voters in recent elections, it will be important to take into account the underlying psychology of voting when making predictions about elections.
Evaluation of Upper Body and Lower Limbs Kinematics through an IMU-Based Medical System: A Comparative Study with the Optoelectronic System

In recent years, the use of inertial-based systems has been applied to remote rehabilitation, opening new perspectives for outpatient assessment. In this study, we assessed the accuracy and the concurrent validity of the angular measurements provided by an inertial-based device for rehabilitation with respect to the state-of-the-art system for motion tracking. Data were simultaneously collected with the two systems across a set of exercises for trunk and lower limbs, performed by 21 healthy participants. Additionally, the sensitivity of the inertial measurement unit (IMU)-based system to its malpositioning was assessed. Root mean square error (RMSE) was used to explore the differences in the outputs of the two systems in terms of range of motion (ROM), and their agreement was assessed via Pearson’s correlation coefficient (PCC) and Lin’s concordance correlation coefficient (CCC). The results showed that the IMU-based system was able to assess upper-body and lower-limb kinematics with a mean error in general lower than 5° and that its measurements were moderately biased by its mispositioning. Although the system does not seem to be suitable for analysis requiring a high level of detail, the findings of this study support the application of the device in rehabilitation programs in unsupervised settings, providing reliable data to remotely monitor the progress of the rehabilitation pathway and change in patient’s motor function.
Front-Ends Are the Way to Go

People have been saying for the last five years that something exciting is hap­ pening in science publishing. The reality is somewhat different. While visionaries predicting the imminent downfall of the publishing establishment are almost too numerous to mention, it seems that little has been able to shake the status quo yet. Does this mean that, despite the electronic communications revolution, nothing will change after all ? Nobody really knows, but it does seem a relatively safe bet that some kind of dramatic sea-change could still be just around the corner. As many readers will know, ever since the beginning of the decade, new preprint initiatives (such as the famous Los Alamos preprint server http://xxx.lanl.gov/ pio­ neered by the string theorist Paul Ginsparg) have challenged the way particle physicists traditionally publish their results. As a matter of course, new papers are now routinely posted on the preprint servers for international distribution long before any kind of peer review or conven­ tional publication has taken place. International laboratories such as CERN have chosen to cease hard-copy mailing of preprints in favour of their own electronic systems (http://www.cern.ch/). There can also be little doubt that the new servers, along with electronic versions of some existing journals are here to stay (e.g., Elsevier Science’s Nuclear Physics Electronic at http://www.elsevier. nl/ and, as from January 1996,14 IOPP journals at http://www.iopp. org/, including Physics Express Letters. But what do the changes really mean for the world of scientific publishing ? Paul Ginsparg believes that the technolog­ ical developments will have some profound implications: “Since publication in a journal no longer gives a particularly useful guide, readers are forced to perform the majority of their selections by their own criteria. The current implementation of peer review should be entirely re­ thought in view of the new methods of
Development of a Physics Module Based on Augmented Reality Integrated with Al-Quran Verses on Electricity

Learning resources in the form of teaching materials that are interesting, innovative, communicative, contextual, and technology-based is a demand for public learning now. In line with the West Sumatra Regional Government program in integrating Al-Qur'an education in subjects in Senior High School, especially physics subjects, it is also something that must be included in the teaching materials. Even though there are many teaching materials and technology-based electronics that have been created, printed teaching materials remain the choice for the convenience of students in the study. Therefore, a physics module based on augmented reality integrated verses of the Qur'an on electricity is developed. The purpose of this study is to find out the validity and practicality of the module. This research is development research (R&D) using a 4D model (Define, Design, Develop, and Disseminate). This research is up to develop stage (validity and practicality). The results of the study indicate that the teaching material in the form of integrated augmented reality-based modules of electricity is very valid. This result is according to four experts in terms of the feasibility of content, presentation, language, and graphics. The average score for the module is 90.09%. This module then tested 18 students in grade XII and the physics teacher of Raudatul Jannah Islamic School to gain the practicality aspect. The result was 85.48% (students) and 90.90% (teachers), which are very practical. In conclusion, the module was very valid criteria according to the expert and was very practical based on the questionnaire filled out by students and teachers.
The Electromagnetic Energy-Momentum Tensor in Expanding Universes

In two previous papers the authors have investigated the characteristics of freely propagating cosmic photons in expanding homogenous flat universes from particle and wave points of view, respectively. The result was that the energy density of these freely propagating photons scales with 1/S3 instead with the generally accepted and redshift-related 1/S4, with S being the cosmic scale factor. This is a surprising result at first glance but finally very understandable if energy conservation has to be required also for cosmic photons without creating a conflict with observations. In this paper we treat freely propagating cosmic photons with a totally different approach, namely with the electromagnetic energy-momentum tensor (from now on abbreviated with EMT). The implementation of the EMT, when correctly interpreted for freely propagating photons, into Einstein’s field equations then automatically leads to the same 1/S3-scaling law for the energy density of cosmic photons, herewith confirming the results found earlier for the particle and wave view. We conclude that the observed cosmological redshift of photons (energy density ∝ 1/S4) is compatible with the law of energy conservation, i.e energy density ∝ 1/S3 if interpreted on a new physical basis.
ESTIMATION OF HERITABILITY, GENETIC CORRELATION OF BODY WEIGHT, AND MODELING OF GROWTH CURVE IN TWO CHICKEN STRAINS

: The purpose of this study was to use nonlinear models (NLN)to characterize the growth pattern and estimate the heritability (h 2 ), the genetic (r g ), and phenotypic(r p ) correlation of the body weight (BW) in two distinct genotypes of chicken raising under Egyptian conditions. A data set of 500 chickens with pedigree information was gathered for this study. For this purpose, the BW was measured at hatching (BW0),4 weeks (BW4), 8 weeks (BW8), and 12 weeks (BW 12) of age. Three NLN models (Logistic, Gompertz, and Von Bertalanffy) were used. Using Wombat software, a multi-trait animal model with a restricted maximum likelihood procedure was used to estimate h 2 , r g, and r p for BW.The results showed that Golden Sabahi (GS) had a significantly higher weight than White Leghorn (WL). The growth curve parameters A (mature body weight), B (biological constant), and K (growth rate) were 3989.9, 0.7853, and 0.0624 for WL and 4332.6,0.7897, and 0.0642 for GS in the von Bertalanffy model, 2152.8, 3.8096, and 0.1322 for WL chickens and 2368, 3.8594, and 0.1350 for GS chickens in the Gompertz model, 1304.5, 19.0421, and 0.3382 for WL chickens and 1455.6, 19.6116, and 0.3411 for GS chickens in the logistic model. Three models represented the growth of the two breeds using goodness-of-fit metrics (R2, MSE, and AIC). Heritability estimates of BW at 0, 4, and 8 were higher in GS than WL, while the estimate of BW at 12 weeks of age was almost similar in the both strains GS and WL (0.1). Between BW0 and BW12, there were strong positive genetic and phenotypic correlations compared by the rest of growth traits . Based on the findings of this investigation, we recommend that the two strains can be utilized for selective breeding between the ages of 4 and 8 weeks to increase the overall genetic improvement of growth traits.
Comparative study on the antimicrobial activity of propolis, catechin, quercetin and gallic acid

Propolis, considered one of the most effective natural broad-spectrum antibiotics, which do not induce resistance or destroy the organism’s commensal flora, together with catechin, quercetin and gallic acid (at different concentrations), have been tested against Gram positive bacteria Streptococcus pyogenes ATTC 19615, Stapylococcus aureus ATCC 25923 and Gram negative Escherichia coli ATCC 25922 Pseudomonas aeruginosa ATCC 27853, Salmonella enterica ATCC 14028, Shigella flexneri ATTC 12022, as well as the yeast Candida albicans ATTC 10231, using the agar diffusion method. Propolis and the three compounds showed antimicrobial potential at most concentrations. The highest sensitivity to propolis (conc. 0.001-1%) was shown by the Gram-positive bacterial strain S. pyogenes, followed by the Gram-negative bacterium Escherichia coli, while the other species had an equal and reduced reaction. Gallic acid showed high antibacterial activity on S. aureus, P. aeruginosa and S. enterica, and a reduced effect on other bacterial strains. The antibacterial efficiency of 3.0224% quercetin was high against the bacterium S. pyogenes and catechin (2.9028%) proved to be the best antifungal, followed by propolis 1%, and quercetin 3.0224%. At certain concentrations, propolis and the three compounds could supplement gentamicin and ampicillin, as they have shown similar or even higher antibacterial efficacy than conventional drugs.
Statistical analysis of the galaxy cluster distribution from next generation cluster surveys

I aim to study to which accuracy it is actually possible to recover the real-space to-point correlation function from cluster catalogues based on photometric redshifts. I make use of cluster sub-samples selected from a light-cone simulated catalogue. Photometric redshifts are assigned to each cluster by randomly extracting from a Gaussian distribution having a dispersion varied in the range σ (z=0) = 0.005 a 0.050. The correlation function in real-space is computed through deprojection method. Four masse ranges and six redshifts slices covering the redshift range 0<z<2 are investigated, using cosmological redshifts (Zc) and then using photometric redshifts. A clear increase of the corretation amplitude with redshift and mass is found. The evolution of the bias parameter b(M,z) is in fair agreement with the theoretical expectations. The existence of the r0-d relation up to the highest mass, highest redshift sample is tested and is confirmed. It is found that the real-space correlation function can be recovered within and accuracy of 10% for σ (z=0) = 0.030. The best-fit parameters as well as the bias for all σz, are within the 1σ uncertainty of the Zc sample.
Signature of large-scale motions on turbulent/non-turbulent interface in boundary layers

The effect of large-scale motions (LSMs) on the turbulent/non-turbulent (T/NT) interface is examined in a turbulent boundary layer. Using flow fields from direct numerical simulation, the shape of the interface and near-interface statistics are evaluated conditional on the position of the LSM. The T/NT interface is identified using the vorticity magnitude and a streak detection algorithm is adopted to identify and track the LSMs. Two-point correlation and spectral analysis of variations in the interface height show that the spatial undulation of the interface is longer in streamwise wavelength than the boundary-layer thickness, and grows with the Reynolds number in a similar manner to the LSMs. The average variation in the interface height was evaluated conditional on the position of the LSMs. The result provides statistical evidence that the interface is locally modulated by the LSMs in both the streamwise and spanwise directions. The modulation is different when the coherent structure is high- versus low-speed motion: high-speed structures lead to a wedge-shaped deformation of the T/NT interface, which causes an anti-correlation between the angles of the interface and the internal shear layer. On the other hand, low-speed structures are correlated with crests in the interface. Finally, the sudden changes in turbulence statistics across the interface are in line with the changes in the population of low-speed structures, which consist of slower mean streamwise velocity and stronger turbulence than the high-speed counterparts.
Stellar populations, formation and evolution of quiescent galaxies since intermidiate redshifts fromo multifilter surveys

This Ph. D. thesis aims at improving our understanding of the evolution of quiescent galaxies since z 1, with the ultimate goal of providing a general picture for the formation and evolution of these objects along the history of the Universe. Making use of data from the ALHAMBRA survey and the SED-fitting code MUFFIT, developed as part of this work, this thesis is novel at facing for the first time an extensive, observational study that comprises the time evolution of the number density of quiescent galaxies, as well as their masses, stellar populations (ages, metallicities and extinctions) and sizes, to ultimately build up a phenomenological evolutionary model based on the merger, "frosting" and "progenitor bias" scenarios that tries to reconcile the observed trends in the above parameters. The stellar population parameters of quiescent galaxies are obtained by the novel and generic code MUFFIT. This code was created and fully developed by us, and it is specifically designed to analyse the stellar content of galaxies with available multi-filter data. MUFFIT performs an error-weighted 2-test, for comparing the multi-filter fluxes of galaxies with the synthetic photometry of mixtures of two SSPs, to provide the most likely range of stellar population parameters: ages, metallicities, extinctions, redshifts, and stellar masses, and uncertainties. To improve the diagnostic reliability, MUFFIT identifies and removes from the analysis those bands that are significantly affected by emission lines. For the construction of a reliable sample of quiescent galaxies, we combine the efficiency of the empiric colour-colour UVJ-diagrams and the extinctions retrieved via MUFFIT, to built a dust-corrected UVJdiagram of intrinsic colours clean of dusty star-forming galaxies. Moreover, we carry out a one-by-one visual inspection to remove those sources whose photometry can be compromised and spurious detections, as well as a removal of contaminating cool stars. The stellar mass completeness is obtained by a novel methodology based on stellar mass functions, yielding a final sample of 8 547 galaxies at 0:1 z 1:1 with a photo-z accuracy of NMAD = 0:006, which constitutes the reference sample of quiescent galaxies for this work.
Prevalence of cesarean section and its associated factors in a tertiary care centre

Introduction: Cesarean section (CS) is one of the oldest and most commonly done surgeries throughout the world. CS rates have raised dramatically over the last two decades worldwide which is an alarming concern for public health and obstetrician due to increase in financial burden and risk to health of the mother in comparison to vaginal delivery. The present study aims to study the prevalence of CS in a tertiary care hospital and its indications. Methods: A cross sectional study conducted in a tertiary care in south India from August 2017 to July 2018. All the pregnant women who got admitted for delivery and gave consent were included in the study. If patient underwent CS then indications for the same and complications if any were recorded and data was entered and analysis was done using Microsoft SPSS software. Results: Out of 476 deliveries conducted during the study period, 316 were normal vaginal deliveries, 138 were CS and 22 were instrumental deliveries. The CS rate was 28.99%. Incidence of CS is more in multigravida than primigravida. 62.31% had emergency LSCS and 37.69% had elective LSCS. Most common indication is previous LSCS seen in 30.43%. Other indications like Cephalo pelvic disproportion, arrest of labour, failed induction, oligohydramnios and fetal distress contributes in the range of 7% to 13% each for LSCS. Conclusions: Cesarean section rate and its trend is increasing worldwide and its judicious employment can improve maternal and fetal outcome when genuinely indicated, avoiding unnecessary surgeries should be the ideal approach.