bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bernoulli-Langevin Wind Speed Model for Simulation of Storm Events
Authors: Fürstenau Norbert , Mittendorf Monika 
Published: October 2016

Abstract
We present a simple nonlinear dynamics Langevin model for predicting the instationary wind speed profile during storm events typically accompanying extreme low-pressure situations. It is based on a second-degree Bernoulli equation with δ-correlated Gaussian noise and may complement stationary stochastic wind models. Transition between increasing and decreasing wind speed and (quasi) stationary normal wind and storm states are induced by the sign change of the controlling time-dependent rate parameter k(t). This approach corresponds to the simplified nonlinear laser dynamics for the incoherent to coherent transition of light emission that can be understood by a phase transition analogy within equilibrium thermodynamics [H. Haken, Synergetics, 3rd ed., Springer, Berlin, Heidelberg, New York 1983/2004.]. Evidence for the nonlinear dynamics two-state approach is generated by fitting of two historical wind speed profiles (low-pressure situations “Xaver” and “Christian”, 2013) taken from Meteorological Terminal Air Report weather data, with a logistic approximation (i.e. constant rate coefficients k) to the solution of our dynamical model using a sum of sigmoid functions. The analytical solution of our dynamical two-state Bernoulli equation as obtained with a sinusoidal rate ansatz k(t) of period T (=storm duration) exhibits reasonable agreement with the logistic fit to the empirical data. Noise parameter estimates of speed fluctuations are derived from empirical fit residuals and by means of a stationary solution of the corresponding Fokker-Planck equation. Numerical simulations with the Bernoulli-Langevin equation demonstrate the potential for stochastic wind speed profile modeling and predictive filtering under extreme storm events that is suggested for applications in anticipative air traffic management.
Twelve Weeks of Plyometric Training Improves Motor Performance of 7- to 9-Year-Old Boys Who Were Overweight/Obese: A Randomized Controlled Intervention
Authors: Nobre Gabriela G. , de Almeida Marcelus B. , Nobre Isabele G. , dos Santos Fernanda K. , Brinco Raphael A. , Arruda-Lima Thalison R. , de-Vasconcelos Kenya L. , de-Lima Jociellen G. , Borba-Neto Manoel E. , Damasceno-Rodrigues Emmanuel M. , Santos-Silva Steve M. , Leandro Carol G. , Moura-dos-Santos Marcos A. 
Published: October 2016

Abstract
Nobre, GG, de Almeida, MB, Nobre, IG, dos Santos, FK, Brinco, RA, Arruda-Lima, TR, de-Vasconcelos, KL, de-Lima, JG, Borba-Neto, ME, Damasceno-Rodrigues, EM, Santos-Silva, SM, Leandro, CG, and Moura-dos-Santos, MA. Twelve weeks of plyometric training improves motor performance of 7- to 9-year-old boys who were overweight/obese: a randomized controlled intervention. J Strength Cond Res 31(8): 2091–2099, 2017—The prevalence of childhood overweight/obesity has increased, and physical training at school may to be effective to combat this scenario. We analyzed the effects of a protocol of plyometric training on body composition and motor performance of boys who were overweight/obese aged 7–9 years. The sample was randomly assigned into 2 groups: plyometric training group (T, n = 40) and control group (C, n = 19). Training consisted of 20 min·d−1 (twice a week, during 12 weeks) of lower extremity plyometric exercise. Health-related physical fitness was measured by handgrip strength, standing long jump (SLJ), curl-ups, sit and reach, square test, running speed, and mile run test. Gross motor coordination was evaluated by means of the Körperkoordinations-test für Kinder (KTK) tests. Baseline and postintervention differences were investigated, and effect size was estimated through Cohen's d coefficient. Both groups showed increased body weight, height, and sitting height after intervention with a negligible effect size. Only T group showed increased fat-free mass (p = 0.011) compared with baseline values with small effect size. Plyometric training improved handgrip strength (d = 0.23), sit and reach (d = 0.18), curl-ups (d = 0.39), SLJ (d = 0.80), agility (d = 0.48), and time in the mile run test (d = 0.38). For gross motor coordination results, T group showed better performance in all tests after plyometric training with moderate/large effect size. Thus, 12 weeks of PT improved health-related physical fitness components and motor coordination acquisition of 7- to 9-year-old boys who were overweight/obese.
Running Performance, Nationality, Sex, and Age in the 10-km, Half-Marathon, Marathon, and the 100-km Ultramarathon IAAF 1999–2015
Authors: Nikolaidis Pantelis T. , Onywera Vincent O. , Knechtle Beat 
Published: October 2016

Abstract
Nikolaidis PT, Onywera VO, and Knechtle B. Running performance, nationality, sex, and age in the 10-km, half-marathon, marathon, and the 100-km ultramarathon IAAF 1999–2015. J Strength Cond Res 31(8): 2189–2207, 2017—The aim of this study was to examine the performance of the world's best runners in the 10-km, half-marathon, marathon, and 100-km races by age, sex, and nationality during 1999–2015, using data from the International Association of Athletics Federations (IAAF). A total of 38,895 runners (17,136 women and 21,759 men) were evaluated, with 2,594 (1,360 women and 1,234 men) in the 10-km; 11,595 (5,225 women and 6,370 men) in the half-marathon; 23,973 (10,208 women and 13,765 men) in the marathon; and 733 (343 women and 390 men) in 100-km events. Most runners in the 10-km event (women 40%, men 67%) and the half-marathon (women 30%, men 57%) were Kenyans. In the marathon, most female and male runners were Ethiopians (women 17%, men 14%) and Kenyans (women 15%, men 43%), respectively. In the 100-km event, most runners were Japanese (20% women, and 80% men). Women were older than the men in the 10-km (32.0 ± 6.0 vs. 25.3 ± 4.3 years, p < 0.001), half-marathon (27.5 ± 4.7 vs. 25.9 ± 4.1 years, p < 0.001), and marathon events (29.5 ± 5.5 vs. 29.1 ± 4.3 years, p < 0.001), but not in 100-km event (36.6 ± 6.1 vs. 35.9 ± 5.5 years, p = 0.097). Men were faster than the women in the 10-km (28:04 ± 0:17 vs. 32:08 ± 0.31 (minutes:seconds), p < 0.001), half-marathon (1:01:58 ± 0:00:52 vs. 1:11:21 ± 0:01:18 (hours:minutes:seconds), p < 0.001), marathon (2:13:42 ± 0:03:01 vs. 2:35:04 ± 0:05:21 (hours:minutes:seconds), p < 0.001), and 100-km events (6:48:01 ± 0:11:29 vs. 7:53:51 ± 0:16:37 (hours:minutes:seconds), p < 0.001). East Africans were not the fastest compared with athletes originating from other countries where only the Ethiopian men were faster than all other men in the marathon. In summary, (a) in the 10-km, half-marathon and marathon events, most runners were from Kenya and Ethiopia, and from Japan and Russia in the 100-km event; (b) women were older than the men in all distance events except the 100-km event; (c) men were the fastest in all distances; and (d) Ethiopian men were faster than all other men in the marathon.
Influence of Scapular Position on the Core Musculature Activation in the Prone Plank Exercise
Authors: Cortell-Tormo Juan M. , García-Jaén Miguel , Chulvi-Medrano Iván , Hernández-Sánchez Sergio , Lucas-Cuevas Ángel G. , Tortosa-Martínez Juan 
Published: October 2016

Abstract
Cortell-Tormo, JM, García-Jaén, M, Chulvi-Medrano, I, Hernández-Sánchez, S, Lucas-Cuevas, ÁG, and Tortosa-Martínez, J. Influence of scapular position on the core musculature activation in the prone plank exercise. J Strength Cond Res 31(8): 2255–2262, 2017—Prone plank is a widely used exercise in core stability training. Research has shown that pelvic tilt plays an important role on the electromyographic (EMG) activation of core musculature. However, the influence of scapular position on EMG activation is currently unknown. Therefore, this study evaluated the influence of scapular position on the core muscles during a prone plank. Surface EMG of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) was collected in 15 participants (10 men and 5 women). Four variations of the prone plank were evaluated: scapular abduction with anterior (ABANT) and posterior (ABRET) pelvic tilt; and scapular adduction with anterior (ADANT), and posterior (ADRET) pelvic tilt. Individual muscle EMG and overall EMG for each plank exercise was analyzed. Joint positions were controlled with a 2D kinematic analysis. Ratings of perceived exertion (RPE) were also registered. The ADRET resulted in higher overall EMG activity compared with ABANT (p = 0.04) and ADANT (p = 0.04). Moreover, ADRET resulted in greater EMG activity compared with ADANT, ABANT, and ABRET for EO (p = 0.000; p = 0.000; p = 0.035), IO (p = 0.000; p = 0.000; p = 0.005), and ES (p = 0.019; p = 0.001; p = 0.014). Regarding RA, ADRET was significantly higher compared with ADANT (p = 0.002) and ABANT (p = 0.005). Finally, ADRET provoked a higher RPE compared with ABANT (p = 0.000), ABRET (p = 0.001), and ADANT (p = 0.015). These findings demonstrate the influence of the scapular and pelvic position on the EMG response of the core muscle groups analyzed in this study, and highlight the greater contribution of these muscles to the postural stabilizing demands during posterior pelvic tilt positions, particularly when the scapulae are in adduction.
Influence of Temperature on the Dynamic Reading Performance of UHF RFID System: Theory and Experimentation
Authors: Yu Yinshan , Yu Xiaolei , Zhao Zhimin , Liu Jialing , Wang Donghua 
Published: October 2016

Abstract
The radio frequency identification (RFID) system is vulnerable to a variety of factors (metal, liquid, temperature, and so on) in the practical application. In this paper, the reading distance of tags, as the evaluation criteria for the reading performance of the RFID system, is focused on to study the influence of environmental temperature on the dynamical performance of an ultra-high frequency (UHF) RFID system. An experimentation system, including temperature control system and detection platform, is devised to control temperature and measure the reading distance of the RFID tag. According to the experimental data of the tag's reading distance at different temperature, a fitting model between temperature and tag's reading distance is established. Experimental results show that the tag's reading distance decreases with the increase of temperature. Finally, the corresponding temperature compensation mechanism is deduced to get the reading distance under the same reference temperature. This paper provides an effective method for selection and evaluation of UHF RFID tags at different temperature.
Effect of Pozzolanic Admixtures on Thermal Properties of Lightweight Cement-Based Foams
Authors: Batool F. , Bindiganavile V. 
Published: October 2016

Abstract
This experimental study was conducted to investigate the effect of pozzolanic admixtures on the thermal conductivity of lightweight cement-based foam (LW-CBF). The foam mixes were cast and tested for three different densities namely, 800, 600, and 400 kg/m3. Three different pozzolanic admixtures namely, fly ash, silica fume, and metakaolin, were examined here. Fly ash was incorporated at up to 50 % mass substitution of cement, while silica fume and metakaolin were incorporated in the binder at up to 20 % replacement by cement mass. Density, moisture content, and thermal conductivity were measured experimentally, while porosity was evaluated theoretically. The transient line source (TLS), which conformed to ASTM standards, was used to assess the thermal conductivity in this study. It was found that the thermal conductivity of the cement-based foam samples was proportional to the cast density in the range examined with, on average, a 20 % drop in conductivity between 800 and 400 kg/m3. In addition, it was found that adding pozzolanic admixtures resulted in a higher moisture content. Furthermore, of the three pozzolanic admixtures, silica fume was the most efficient, causing a 30 % drop, whereas metakaolin was the least at a mere 10 % decline for equal dosage.
Theory and Simulation Investigation of Low-Energy Neutron Shielding for Different Boron Compounds
Authors: Adeli R. , Shirmardi S. P. , Bagheri R. 
Published: October 2016

Abstract
Neutron absorbers, especially boron, exhibit a comparatively large neutron absorption cross section, in particular, with regard to thermal neutrons. In this study, four boron compounds, including boron carbide (B4C), boron nitride (BN), boron trioxide (B2O3), and boric acid (H3BO3) were considered for shielding the thermal neutrons, both theoretically and in simulation. The shielding ability and secondary gamma-ray production of compounds were studied, using the MCNP-4C Monte Carlo code. The theory shows that B4C has the greatest and B(OH)3 the least total neutron macroscopic cross section. Simulation results also show that B2O3 and H3BO3 create more high-energy secondary gamma rays that may cause a significant photoneutron reaction, in addition to unwanted dose radiation. Among these, BN and, especially, B4C, create secondary photons with lower energy. From a shielding point of view, we can confirm that B4C and BN in the second order have the best performance when epithermal and, particularly, thermal neutron absorption is concerned. Result shows that H3BO3 has the worst performance among the candidates considered.
Experimental-Statistical Investigation of Testing Variables of a Semicircular Bending (SCB) Fracture Test Repeatability for Bituminous Mixtures
Authors: Nsengiyumva G. , You T. , Kim Y.-R. 
Published: October 2016

Abstract
Given the fact that fracture is a primary distress causing pavement failure, it is important to identify and characterize the fracture/cracking properties of asphalt concrete mixtures and to include them in pavement design processes. This study examined the testing variables for a reliable and practical semicircular bending (SCB) fracture test to evaluate the fracture characteristics of asphalt concrete mixtures at intermediate service temperatures. An integrated experimental-statistical approach was employed to identify testing variables by which repeatable SCB test results can be achieved. Using a typical Nebraska asphalt mixture, five critical testing variables (i.e., the number of testing specimens, specimen thickness, notch length, loading rate, and testing temperature) of the SCB test were investigated due to their significant effects on mixture fracture characteristics. Statistical analysis of test results indicated that approximately six specimens/replicates were a reasonable sample size that could properly represent asphalt concrete fracture behavior of a typical dense-graded mixture. Then, the coefficient of variation (COV) of the mixture fracture energy for six specimens was used to evaluate the effects of other remaining test variables. A range of a specimen thickness of 40 to 60 mm, a notch length from 5 to 40 mm, and a testing temperature between 15 and 40°C showed the reasonably low COV value of fracture energy at around or less than 10 %. The loading rates (0.1 to 10 mm/min.) attempted in this study did not show any significant differences in the testing repeatability.
An Investigation into the Continuous High-Temperature Grade and Elastic Recovery of Asphalt Binders Measured Using the Creep-Recovery Test
Authors: Arega Z. , Sakib N. , Bhasin A. , Peterson J. 
Published: October 2016

Abstract
The multiple stress creep recovery (MSCR) test has been developed and is gradually being adopted as a more accurate indicator of the ability of an asphalt binder to resist permanent deformation compared to the G*/sin δ parameter from the Superpave binder specifications. This paper presents the findings from a study conducted using over 100 different asphalt binders from producers in and around the state of Texas. The study determined the continuous high temperature grade of asphalt binders based on the non-recoverable compliance (Jnr) measured using the MSCR test analogous to the continuous high temperature grade measured using the Superpave performance grade (PG) system. Also, the elastic recovery determined from the MSCR test was compared to the elastic recovery measured using the conventional elastic recovery test using a ductilometer. The results from this study show that: (i) some binders have an anomalous continuous high temperature grade based on the (Jnr) values, (ii) the elastic recovery measured using the MSCR method had a much higher sensitivity compared to the elastic recovery measured using a ductilometer, although the results from both methods showed similar trends, and (iii) a direct comparison of binder grades based on AASHTO M320 to the grades based on AASHTO MP19 indicated that, in some cases, the latter method and recommended specification limits result in the use of a binder that is stiffer compared to the conventional Superpave PG specification.
Objective Fuzziness Assessment of Multi-Colored Fabrics Using 3D Images
Authors: Wang L. , Gao W. , Xu B. 
Published: October 2016

Abstract
A quantitative evaluation method based on a three-dimensional (3D) laser-scanning technique is presented for the objective assessment of fabric fuzziness. Fabric fuzziness, referring to severity of protruding fibers on a fabric surface, has a direct effect on fabric serviceability and needs to be evaluated routinely for quality assurance. In this research, the characterization of fabric fuzziness was realized by using a customized laser scanning system that can produce the 3D surface image of a fabric in a high resolution, and by analyzing the parameters of roughness amplitude distributions extracted from the 3D image. Multi-colored fabrics with different levels of fuzziness were first visually evaluated to obtain the subjective fuzziness grades in reference to a set of expert-rated cotton samples. Then, the fabrics were scanned by the laser system and the surface roughness parameters were calculated from the 3D images for the regression analysis with the subjective fuzziness grades. The result of multivariable regression analysis indicated that the fuzziness grade has a strong correlation with the roughness parameters, and can be estimated automatically after a fabric is scanned. The system demonstrated its fuzziness ratings are invariant to fabrics’ colors, prints, and structures.
Surface Topography Quantification of Super Hard Abrasive Tools by Laser Scanning Microscopy
Authors: Fang S. , Llanes L. , Engstler M. , Baehre D. , Soldera F. , Muecklich F. 
Published: October 2016

Abstract
Non-conventional super hard abrasive tools are made of composite materials containing super hard grains, e.g., diamond or cubic boron nitride (CBN) grains, bound by a metallic constitutive phase. These tools are usually produced by means of sintering, and are widely applied in the abrasive machining processes of modern manufacturing, especially in precision machining. The abrasive grains, which induce the material removal processes, are embedded in the metallic binder. They emerge as a consequence of self-dressing, resulting in a self-sharping effect. Therefore, the cutting surface of the tool displays an irregular topography. Quantification of surface topography scenario may supply valuable information to evaluate and understand its correlation to wear mechanisms. In this study, an experimental protocol consisting of five steps: specimen preparation, surface scanning, image assembly, image digital processing and surface quantification, was proposed and validated by characterizing two CBN honing tools used for precision machining: B151/L2/2010/50 (B151) and B91/128/x44/35 (B91) CBN honing stones. It involved the use of laser scanning microscopy and digital imaging processing for assessing significant dimensional, geometrical, and positional properties of CBN grains at the surface of super hard abrasive tools. It was shown that surface topography quantification is an effective method to evaluate and obtain the defined parameters. However, smaller grains may require images with higher resolution; thus, scanning must be refined. Finally, a critical comparative analysis of the experimental results attained for the studied tools pointed out honing stone B91 as more appropriated than B151 one for achieving a higher machining quality of the workpiece.
Microstructural Characterization and Mechanical Properties of Fusion Welded Dissimilar Joints of AA2219-AA5083 at RT, 77K and 20K
Authors: Narayana Murty S. V. S. , Manwatkar Sushant K. , Sunil M. , Joseph Reji , Ramesh Narayanan P. 
Published: October 2016

Abstract
In the present study, 3 mm thick sheets of aluminium-copper alloy AA2219 were welded to aluminium-magnesium alloy AA5083 by tungsten inert gas (TIG) welding using AA2319 filler wire. The welded specimens were evaluated for mechanical properties at RT, 77 K, and 20 K. The failure of the tensile specimens was predominantly on the AA2219 side of the weld bead at all test temperatures down to 20 K. Microstructural analysis was carried out by optical and scanning electron microscopy. Based on extensive analysis of the weld joints tested at room and cryogenic temperatures down to 20 K, it was observed that the grain boundary copper rich films formed at the partially melted zone on the AA2219 side of the weld joint were weaker compared to the eutectics formed at fusion line/HAZ on the AA5083 side. This is further aided by the absence of phase mixtures of undesirable morphology in the weld region. This phenomenon is further corroborated with the dependence of the orientation of AA2219 grains with loading axis in repair welded AA2219–AA5083 weld specimens. When the tensile axis is perpendicular to AA2219 grains, failure was on the AA2219 side of the weld indicating that the strength of copper rich films in a partially welded zone decides the strength of weld joints. Finally, it is concluded that reliable dissimilar weld joints of AA2219–AA5083 of aerospace quality can be manufactured.
Micro-Abrasive Wear Testing of Surface Engineered Surgical Grade CoCrMo Alloy for Biotribological Applications
Authors: Ortega-Saenz J. A. , Hernandez-Rodriguez M. A. L. , Michalczewski R. 
Published: October 2016

Abstract
Wear of metal-on-metal hip joints is a concern due to the toxicity and biological reaction of wear debris. Retrieved CoCrMo hip implants have shown that abrasive wear is the predominant failure mechanism in such joints. There have been some efforts to improve the wear resistance of joint implants through the application of hard biocompatible ceramic coatings. However, the adhesion of the coatings has been a concern. The aim of the present work was to study the wear resistance of surface engineered CoCrMo alloy intended for biotribological applications by means of an abrasive wear test, based on the ball-crater technique. Different surface conditions were obtained on surgical grade wrought CoCrMo alloy: plasma nitrided, physical vapor deposition (PVD) coated (monolayer CrN and multilayer (TiN/CrN)×3) and modified using duplex surface engineering technology (a combination of the two previous approaches: plasma nitriding followed by plasma assisted PVD). The engineered surfaces were characterized by scanning electron microscopy, nanoindentation and, atomic force microscopy (AFM). Scratch test was used to determine the influence of the duplex technology on the adhesion of the coatings to substrate. The wear resistance of the different surface conditions was determined using a slurry abrasive micro-abrasion testing device. It was found that the duplex engineering technology enables a significant rise in the resistance of surfaces against concentrated loading modes, improving the adhesion of the coatings to the substrate; however, it has no significant influence improving the wear resistance of the samples during the abrasive wear tests.