bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Analysis and Investigation for Thermal Performance of Ventilated Disc Brake Rotor Using CFD
Authors: Chopade Mahesh R. , Valavade Avinash P.
Published: November 2016

In the present work, different ventilated disc brake rotor configurations were analyzed to enhance the heat transfer rate and obtain the uniform temperature distribution in the rotor. CFD code used in this work was validated using experimental results obtained by conducting experiments on a test rig. The experimental analysis was performed to calculate the mass flow rate and heat dissipation through the rotor. Further, different types of rotor configurations viz. straight radial vane (SRV), Tapered radial vane (TRV), Alternate long and short vane (ALSV), variable diameter circular pillars (VDCP) were considered for the analysis. A rotor segment of 20° was considered for the numerical analysis due to its rotational symmetry. CFD results were in good agreement with the experimental analysis. The maximum deviation of the numerical results were about 12% from the experimental results. It is found from the analysis that among the different types of rotor configurations; variable diameter circular pillars (VDCP) rotor gives better rate of heat dissipation with more uniform temperature distribution in the flow passages. Hence for modern high speed vehicles VDCP rotor may be more appropriate.
Heat Transfer Analysis of Phase Change Microcapsules With Thin Film Evaporation
Authors: Guo Yang , Fu Benwei , Ji Yulong , Su Fengmin , Wilson Corey , Ma Hongbin
Published: November 2016

A number of seawater desalination technologies have been developed and widely used during the last several decades. In the current investigation, a new approach of seawater desalination process is presented, which utilizes phase change microcapsules (PCμCs) and thin film evaporation. In this process, the PCμCs are placed into hot seawater. Then the hot seawater and the PCμCs containing the liquid phase change material (PCM) are ejected into a vacuum flash chamber. A thin liquid film of seawater is formed on the surface of the PCμCs, which subsequently vaporizes. This evaporation significantly increases the evaporation heat transfer coefficient and enhances desalination efficiency. Film evaporation on the PCμCs’ surfaces decreases their temperature by releasing sensible heat. If their temperature is lower than the PCM phase change temperature, then the PCμCs change phase from liquid to solid releasing their latent heat, resulting in further evaporation. The PCμCs with solid PCM are pumped back into the hot seawater, and the salt residue left on the PCμCs can be readily dissolved. In this way, the efficiency can be increased and the corrosion reduced. A mathematical model was developed to determine the effects of PCμCs and thin film evaporation on the desalination efficiency. An analytical solution using Lighthill’s approach was obtained. Results show that when PCμCs with a radius of 100 μm and a water film of 50 μm are used, the evaporation rate and evaporative capacity can be significantly increased.
Experimental Investigation of Thermal Management of Tablet Computers Using Phase Change Materials (PCMs)
Authors: Ahmed Tousif , Bhouri Maha , Kahwaji Samer , Groulx Dominic , White Mary Anne
Published: November 2016

This paper presents a study of thermal management of tablet computers (tablet PCs) using phase change materials (PCMs) encapsulated in aluminized laminated film under continuous operation. The experimental setup consists of original tablet PC parts and a simplified dummy printed circuit board (PCB) with a thermal response similar to the original PCB. Two PCMs were used in the experiments, n-eicosane and PT-37 (a commercial PCM from PureTemp). These PCMs have similar melting temperatures (n-eicosane – 35.6 °C; PT-37 – 36.3 °C) but different latent heats of fusion (n-eicosane – 236 kJ/kg; PT-37 – 206 kJ/kg). Two encapsulations with different sizes (6″ × 2.6″, 7″ × 1.5″) but the same thickness (0.0792″ (2 mm)) were used in this study. The effects of inclination and power input level on the thermal behavior of the tablet were investigated. Experiments showed that PCM encapsulated in laminate film led to lower back cover temperature for constant heat flux applications. As much as a 20 °C temperature reduction of the back cover hotspot was achieved with encapsulated PCM. It was also observed that better thermal behavior was achieved both by the melting of PCMs and heat spreading through the laminate film. It was found that the rate of PCM melting is directly related to the power input. No significant effect on PCM melting and temperature history was observed in relation to the system inclination.
Transient Two-Dimensional Heat Conduction Problem With Partial Heating Near Corners
Authors: McMasters Robert L. , de Monte Filippo , Beck James V. , Amos Donald E.
Published: November 2016

This paper provides a solution for two-dimensional heating over a rectangular region on a homogeneous plate. It has application to verification of numerical conduction codes as well as direct application for heating and cooling of electronic equipment. Additionally, it can be applied as a direct solution for the inverse heat conduction problem, most notably used in thermal protection systems for re-entry vehicles. The solutions used in this work are generated using Green’s functions. Two approaches are used which provide solutions for either semi-infinite plates or finite plates with isothermal conditions which are located a long distance from the heating. The methods are both efficient numerically and have extreme accuracy, which can be used to provide additional solution verification. The solutions have components that are shown to have physical significance.

The extremely precise nature of analytical solutions allows them to be used as prime standards for their respective transient conduction cases. This extreme precision also allows an accurate calculation of heat flux by finite differences between two points of very close proximity which would not be possible with numerical solutions. This is particularly useful near heated surfaces and near corners. Similarly, sensitivity coefficients for parameter estimation problems can be calculated with extreme precision using this same technique. Another contribution of these solutions is the insight that they can bring. Important dimensionless groups are identified and their influence can be more readily seen than with numerical results. For linear problems, basic heating elements on plates, for example, can be solved to aid in understanding more complex cases. Furthermore these basic solutions can be superimposed both in time and space to obtain solutions for numerous other problems.

This paper provides an analytical two-dimensional, transient solution for heating over a rectangular region on a homogeneous square plate. Several methods are available for the solution of such problems. One of the most common is the separation of variables (SOV) method. In the standard implementation of the SOV method, convergence can be slow and accuracy lacking. Another method of generating a solution to this problem makes use of time-partitioning which can produce accurate results. However, numerical integration may be required in these cases, which, in some ways, negates the advantages offered by the analytical solutions. The method given herein requires no numerical integration; it also exhibits exponential series convergence and can provide excellent accuracy. The procedure involves the derivation of previously-unknown simpler forms for the summations, in some cases by virtue of the use of algebraic components. Also, a mathematical identity given in this paper can be used for a variety of related problems.
A Mie-Metamaterial Based Thermal Emitter for TPV Applications
Authors: Ghanekar Alok , Zheng Yi
Published: November 2016

We theoretically demonstrate a novel, efficient and cost effective thermal emitter using a Mie-resonance metamaterial for thermophotovoltaic (TPV) applications. We propose for the first time the design of a thermal emitter which is based on nanoparticle-embedded thin film. The emitter consists of a thin film of SiO2 on the top of tungsten layer deposited on a substrate. The thin film is embedded with tungsten nanoparticles which alter the refractive index of the film. This gives rise to desired emissive properties in the wavelength range of 0.4 μm to 2 μm suitable for GaSb and InGaAs based photovoltaics. Effective dielectric properties are calculated using Maxwell-Garnett-Mie theory. Our calculations indicate this would significantly improve the efficiency of TPV cells. We introduce a new parameter to gauge the efficacy of thermal emitters and use it to compare different designs.
Design of a Magnetic Cooling Device Using Gadolinium Alloy and Permanent Magnets
Authors: Abdelmessih Amanie N. , Bartholomae Paul W. , Casillas Matthew L. , DeLyon Rocky E. , Flaherty Joshua F. , Goolsby Bradley D. , Langley Moriah M. , Livoni Lindsey A. , Logan Trevor W. , Perhach Nicolas J. , Replogle Jonathan J. , Swann Daniel R. , Williams Garrett M.
Published: November 2016

Traditionally, heat pumps and refrigerators utilize the vapor compression cycle to achieve cooling. These vapor compression cycles use hydrochlorofluorocarbons (R134a) as the cycle’s working fluid. This refrigerant contributes to global warming and is expected to be phased out. Consequently, new refrigerants as well as new refrigeration methods need to be developed.

The research detailed in this article attempts to implement the magnetocaloric effect of gadolinium alloy in a designed apparatus to lower the temperature of air. Gadolinium alloy has a noticeable magnetocaloric effect within a strong magnetic field (5 T). This research is aimed at producing a noticeable temperature change (2–3 °C) in a relatively smaller magnetic field (1 T) produced with permanent magnets. This work tests the feasibility of magnetic cooling by introducing the design of a magnetic cooling apparatus, using Gadolinium alloy (Gd5Si2Ge2). Small pebbles were used as opposed to a solid plate in order to have an increased surface area to enhance the convection heat transfer process. Permanent magnets were used in the apparatus, to decrease the operating cost. The maximum temperature change encountered in the heat exchanger of the apparatus built was 2.3 °C in a 1 T magnetic field.
Modeling of Heat Transfer and Energy Efficiency Performance of Transient Cold Storage in Phase Change Thermal Storage Components
Authors: Helmns Andrea , Carey Van P.
Published: November 2016

This paper presents a design analysis framework for a transient cold storage unit that uses solid-liquid phase change for thermal storage. The analytical framework developed in this study establishes non-dimensional parameters that dictate the energy efficiency of the transient energy input and extraction processes, and specifies the links between physical parameters for the system and dimensionless parameters. The resulting governing equations in non-dimensional form are partial differential equations that can be solved numerically. Solutions of the equations predict the thermodynamic efficiency (effectiveness) of the energy storage and retrieval processes, and the time required to input or extract energy from storage for specified values of the dimensionless parameters. The paper illustrates how a high efficiency design target can be established for specified operating conditions using this framework. Application of this framework to a typical example application involving cold thermal storage is described, and the usefulness of this methodology is demonstrated. The use of this methodology for predicting the performance of cold thermal storage for a broad range of potential applications is also discussed.
Cooling Performances of Perforated-Finned Heat Sinks
Authors: Shaeri Mohammad Reza , Richard Bradley , Bonner Richard
Published: November 2016

Cooling performances of perforated-finned heat sinks (PFHS) are investigated in the laminar forced convection heat transfer mode, through detailed experiments. Perforations like windows with square cross sections are placed on the lateral surfaces of the fins. Cooling performances are evaluated due to changes in both porosities and perforation sizes. Thermal characteristics are reported based on pumping power, in order to provide more practical insight about performances of PFHSs in real applications. It is found that at a constant perforation size, there is an optimum porosity that results in the largest heat transfer coefficient. For a fixed porosity, increasing the number of perforations (reducing the perforation size) results in an enhancement of heat transfer rate due to repeated interruption of the thermal boundary layer. The opposite trend is observed for PFHSs with larger perforation sizes. This indicates that there is an optimum perforation size and distance between perforations in order to achieve the maximum heat transfer coefficients at a constant porosity. Also, a PFHS results in a smaller temperature non-uniformity across the heat sink base, as well as a more rapid reduction in temperature non-uniformity on the heat sink base by increasing pumping power. In addition, the advantage of a PFHS to reduce the overall weight of the cooling system is incorporated into thermal characteristics of the heat sinks, and demonstrated by the mass specific heat transfer coefficient.
LES Simulations of Rotating Two-Pass Ribbed Duct With Coriolis and Centrifugal Buoyancy Forces at Re=100,000
Authors: Dowd Cody , Tafti Danesh
Published: November 2016

The focus of this research is to predict the flow and heat transfer in a rotating two-pass duct geometry with staggered ribs using Large-Eddy Simulations (LES). The geometry consists of a U-Bend with 17 ribs in each pass. The ribs are staggered with an e/Dh = 0.1 and P/e = 10. LES is performed at a Reynolds number of 100,000, a rotation number of 0.2 and buoyancy parameters (Bo) of 0.5 and 1.0. The effects of Coriolis forces and centrifugal buoyancy are isolated and studied individually. In all cases it is found that increasing Bo from 0.5 to 1.0 at Ro = 0.2 has little impact on heat transfer. It is found that in the first pass, the heat transfer is quite receptive to Coriolis forces which augment and attenuate heat transfer at the trailing and leading walls, respectively. Centrifugal buoyancy, on the other hand has a bigger effect in augmenting heat transfer at the trailing wall than in attenuating heat transfer at the leading wall. On contrary, it aids heat transfer in the second half of the first pass at the leading wall by energizing the flow near the wall. The heat transfer in the second pass is dominated by the highly turbulent flow exiting the bend. Coriolis forces have no impact on the augmentation of heat transfer on the leading wall till the second half of the passage whereas it attenuates heat transfer at the trailing wall as soon as the flow exits the bend. Contrary to phenomenological arguments, inclusion of centrifugal buoyancy augments heat transfer over Coriolis forces alone on both the leading and trailing walls of the second pass.
Two-Step Raman Method for Interface Thermal Resistance and In-Plane Thermal Conductivity Characterization of Graphene Interface Materials
Authors: Li Man , Yue Yanan
Published: November 2016

The negative influence of substrate on in-plane phonon transport in graphene has been revealed by intensive research, whereas the interaction between phonons couplings across graphene/substrate interface and within graphene is still needed to figure out. In this work, we put forward a two-step Raman method to accomplish interface thermal resistance characterization of graphene/SiO2 and in-plane thermal conductivity measurement of supported graphene by SiO2. In order to calculate the interfacial thermal resistance, the temperature difference between graphene and its substrate was probed using Raman thermometry after the graphene film was uniformly electrically heated. Combing the ITR and the temperature response of graphene to laser heating, the thermal conductivity was computed using the fin heat transfer model. Our results shows that the thermal resistance of free graphene/SiO2 is enormous and the thermal conductivity of the supported graphene is significantly suppressed. The phonons scattering and leakage at the interface are mainly responsible for the reduction of thermal conductivity of graphene on substrate. The morphology change of graphene caused by heating mainly determines the huge interfacial thermal resistance and partly contributes to the suppression of thermal conductivity of graphene. This thermal characterization approach simultaneously realizes the non-contact and non-destructive measurement of interfacial thermal resistance and thermal conductivity of graphene interface materials.
Molecular Dynamics Simulation on Diffusion Welding Between Cu and Al Under Different Pressures and Roughnesses
Authors: Li Xiong-hui , Chu Wen-xiao , Ma Ting , Wang Qiu-wang
Published: November 2016

As an advanced welding method, the diffusion welding is widely applied in aerospace, instrumentation industry, engine manufacturing, etc. Not only the diffusion welding can realize the connection of different metals, but also it solves the difficult welding problem between metals and ceramics. Aiming to research the diffusion process during welding, this study investigates the diffusion behavior and mechanisms of Cu and Al under different pressures and surface roughnesses in the aspect of atomic level by using the molecular dynamics (MD) method. From the results, we can find that the pressure influences obviously the second thickness growth stage, which is one of the three stages in the whole diffusion process. The grooves generated by the surface roughness, is filled mainly by the deformation of Al, which fits the initial surface profile. The diffusion is promoted as the contacting area increases. Whether the surface is smooth or rough, the pressure has little impact on the final thickness. This study succeeds in explaining the diffusion mechanism, which is significant for the experiments of diffusion welding in practice.
First-Order Model of Free-Jet Hydrodynamic Evolution for Heat Transfer Prediction, Including Nozzle and Flow Rate Effects
Authors: Harnik Ron S. , Haustein Herman D.
Published: November 2016

Jet impingement flow is known to generate one of the highest single-phase heat transfer rates, with potential for micro-electronics cooling applications. Although free-surface jets have been studied extensively, existing models are either too complex for practical use or do not consider all relevant parameters, such as the impinging jet’s velocity profile. Recently the authors have shown that the stagnation zone heat transfer is dictated by the jet’s centerline velocity upon impingement, and that going between the limiting cases (uniform vs. parabolic profiles, laminar flow) corresponds to a two-fold increase in heat transfer.

In the present study, which is motivated by cooling at micro-scales (predominantly laminar flows), this simplified analysis is extended leading to a first-order analytical approximation, which is valid not only for the limiting cases but over the entire profile range. Thereby, the development of the jet flow both in the nozzle (pipe-type) and subsequently during its flight (before impingement) is incorporated in this model over a broad range of parameters.

For validation of the model, as well as for additional insight into the governing physics, direct numerical simulations were conducted. Through which it is shown that the jet’s velocity profile and its evolution during free “flight” are dependent on the level of the flow’s upstream development in the nozzle, both of which depend on a single self-similar scale: distance travelled normalized by the nozzle diameter and Reynolds number. This one-way coupling requires incorporation of both stages of development for an accurate description, as done in the present model. During pipe-flow, the first-order model employs a more-rapid development rate than during jet-flight (due to the additional pressure-driven flow) — converging to more complex, well-known models, within a few pipe diameters (for Re = 200 to 2300). During flight, the model describes velocity profile relaxation, which is dominated by viscous diffusion and assisted by jet contraction. Jet contraction is dependent on the emerging velocity profile and liquid-vapor surface tension. For most relevant conditions surface tension is negligible, under which the first-order model centerline velocity decay prediction agrees well with both present simulations and previous works.

Thereby, the present work lays the foundation for a simpler, more useable model for predicting heat transfer under an impinging free-surface jet, over a wide range of conditions (various liquids, pipe-type nozzles of different lengths, flow-rates and nozzle-to-plate distances), as part of an ongoing study into micro-jet array heat transfer.
Transient Analysis of a Cylindrical Heat Pipe Considering Different Wick Structures
Authors: Famouri Mehdi , Abdollahzadeh M. Mahdi , Abdulshaheed Ahmed , Huang GuangHan , Carbajal Gerardo , Li Chen
Published: November 2016

Heat pipes have been shown to be one of the most efficient passive cooling devices for electronic cooling. Only a handful of studies were capable of solving transient performances of heat pipes based on realistic assumptions. A segregated finite volume base scheme using SIMPLE algorithm is used along with system pressurization and overall mass balance to solve mass transfer at the interface, continuity, momentum and energy equations. The fluid flow and heat transfer are solved throughout the wick and vapor core and no assumptions are made at the locations where evaporation and condensations occur. Water is the working fluid and variable densities are used for both liquid and vapor phases to account for continuity at the interface as well as inside of wick and vapor core. The wick is modeled as a non-homogeneous porous media and the effective thermal conductivities and viscous properties are calculated for each type of structure separately using the available relations from the literature. In this study, an axisymmetric two-dimensional solver for cylindrical heat pipe is developed using FLUENT package with the help of User Defined Functions (UDFs) and User Defined Scalar (UDS). The model is tested for grid and time step independency and the results show the stability and accuracy of the proposed method. The numerical results of the present study were in good agreement with the data from previous numerical and experimental studies available in the literature. Additionally, two different wick structures were studied to determine its effect on the thermal performance of heat pipes.
Binding of single stranded nucleic acids to cationic ligand functionalized gold nanoparticles
Authors: Nash Jessica A. , Tucker Tasha L. , Therriault William , Yingling Yaroslava G.
Published: November 2016

The interactions of nanoparticles (NPs) with single stranded nucleic acids (NAs) have important implications in gene delivery, and nanotechnological and biomedical applications. Here, the complexation of cationic ligand functionalized gold nanoparticles with single stranded deoxyribose nucleic acid (DNA) and ribonucleic acid (RNA) are examined using all atom molecular dynamics simulations. The results indicated that complexation depends mostly on charge of nanoparticle, and, to lesser extent, sequence and type of nucleic acid. For cationic nanoparticles, electrostatic interactions between charged ligands and the nucleic acid backbone dominate binding regardless of nanoparticle charge. Highly charged nanoparticles bind more tightly and cause compaction of the single-stranded NAs through disruption of intrastrand π–π stacking and hydrogen bonding. However, poly-purine strands (polyA-DNA, polyA-RNA) show less change in structure than poly-pyrimidine strands (polyT-DNA, polyU-RNA). Overall, the results show that control over ssNA structure may be achieved with cationic NPs with a charge of more than 30, but the extent of the structural changes depends on sequence.
Relationship Between Preseason Training Load and In-Season Availability in Elite Australian Football Players
Authors: Murray Nick B. , Gabbett Tim J. , Townshend Andrew D.
Published: November 2016

Objectives:

To investigate the relationship between the proportion of preseason training sessions completed and load and injury during the ensuing Australian Football League season.

Design:

Single-cohort, observational study.

Methods:

Forty-six elite male Australian football players from 1 club participated. Players were divided into 3 equal groups based on the amount of preseason training completed (high [HTL], >85% sessions completed; medium [MTL], 50–85% sessions completed; and low [LTL], <50% sessions completed). Global positioning system (GPS) technology was used to record training and game loads, with all injuries recorded and classified by club medical staff. Differences between groups were analyzed using a 2-way (group × training/competition phase) repeated-measures ANOVA, along with magnitude-based inferences. Injury incidence was expressed as injuries per 1000 h.

Results:

The HTL and MTL groups completed a greater proportion of in-season training sessions (81.1% and 74.2%) and matches (76.7% and 76.1%) than the LTL (56.9% and 52.7%) group. Total distance and player load were significantly greater during the first half of the in-season period for the HTL (P = .03, ES = 0.88) and MTL (P = .02, ES = 0.93) groups than the LTL group. The relative risk of injury for the LTL group (26.8/1000 h) was 1.9 times greater than that for the HTL group (14.2/1000 h) (χ2 = 3.48, df = 2, P = .17).

Conclusions:

Completing a greater proportion of preseason training resulted in higher training loads and greater participation in training and competition during the competitive phase of the season.
Quantifying Training Loads in Contemporary Dance
Authors: Jeffries Annie C. , Wallace Lee , Coutts Aaron J.
Published: November 2016

Purpose:

To describe the training demands of contemporary dance and determine the validity of using the session rating of perceived exertion (sRPE) to monitor exercise intensity and training load in this activity. In addition, the authors examined the contribution of training (ie, accelerometry and heart rate) and non-training-related factors (ie, sleep and wellness) to perceived exertion during dance training.

Methods:

Training load and ActiGraphy for 16 elite amateur contemporary dancers were collected during a 49-d period, using heart-rate monitors, accelerometry, and sRPE. Within-individual correlation analysis was used to determine relationships between sRPE and several other measures of training intensity and load. Stepwise multiple regressions were used to determine a predictive equation to estimate sRPE during dance training.

Results:

Average weekly training load was 4283 ± 2442 arbitrary units (AU), monotony 2.13 ± 0.92 AU, strain 10677 ± 9438 AU, and average weekly vector magnitude load 1809,707 ± 1015,402 AU. There were large to very large within-individual correlations between training-load sRPE and various other internal and external measures of intensity and load. The stepwise multiple-regression analysis also revealed that 49.7% of the adjusted variance in training-load sRPE was explained by peak heart rate, metabolic equivalents, soreness, motivation, and sleep quality (y = –4.637 + 13.817%HRpeak + 0.316 METS + 0.100 soreness + 0.116 motivation – 0.204 sleep quality).

Conclusion:

The current findings demonstrate the validity of the sRPE method for quantifying training load in dance, that dancers undertake very high training loads, and a combination of training and nontraining factors contribute to perceived exertion in dance training.
A Comparison of Speed Profiles During Training and Competition in Elite Wheelchair Rugby Players
Authors: Rhodes James M. , Mason Barry S. , Paulson Thomas A.W. , Goosey-Tolfrey Victoria L.
Published: November 2016

Purpose:

To investigate the speed profiles of individual training modes in comparison with wheelchair rugby (WCR) competition across player classifications.

Methods:

Speed profiles of 15 international WCR players were determined using a radio-frequency-based indoor tracking system. Mean and peak speed (m/s), work:rest ratios, and the relative time spent in (%) and number of high-speed activities performed were measured across training sessions (n = 464) and international competition (n = 34). Training was classified into 1 of 4 modes: conditioning (n = 71), skill-based (n = 133), game-related (n = 151), and game-simulation drills (n = 109). Game-simulation drills were further categorized by the structured duration, which were 3-min game clock (n = 44), 8-min game clock (n = 39), and 10-min running clock (n = 26). Players were grouped by their International Wheelchair Rugby Federation classification as either low-point (≤1.5; n = 8) or high-point players (≥2.0; n = 7).

Results:

Conditioning drills were shown to exceed the demands of competition, irrespective of classification (P ≤ .005; effect size [ES] = 0.6–2.0). Skill-based and game-related drills underrepresented the speed profiles of competition (P ≤ .005; ES = 0.5–1.1). Mean speed and work:rest ratios were significantly lower during 3- and 8-min game-simulation drills in relation to competition (P ≤ .039; ES = 0.5–0.7). However, no significant differences were identified between the 10-min running clock and competition.

Conclusions:

Although game-simulation drills provided the closest representation of competition, the structured duration appeared important since the 10-min running clock increased training specificity. Coaches can therefore modify the desired training response by making subtle changes to the format of game-simulation drills.
Predicting Critical Power in Elite Cyclists: Questioning the Validity of the 3-Minute All-Out Test
Authors: Bartram Jason C. , Thewlis Dominic , Martin David T. , Norton Kevin I.
Published: November 2016

Purpose:

New applications of the critical-power concept, such as the modeling of intermittent-work capabilities, are exciting prospects for elite cycling. However, accurate calculation of the required parameters is traditionally time invasive and somewhat impractical. An alternative single-test protocol (3-min all-out) has recently been proposed, but validation in an elite population is lacking. The traditional approach for parameter establishment, but with fewer tests, could also prove an acceptable compromise.

Methods:

Six senior Australian endurance track-cycling representatives completed 6 efforts to exhaustion on 2 separate days over a 3-wk period. These included 1-, 4-, 6-, 8-, and 10-min self-paced efforts, plus the 3-min all-out protocol. Traditional work-vs-time calculations of CP and anaerobic energy contribution (W′) using the 5 self-paced efforts were compared with calculations from the 3-min all-out protocol. The impact of using just 2 or 3 self-paced efforts for traditional CP and W′ estimation was also explored using thresholds of agreement (8 W, 2.0 kJ, respectively).

Results:

CP estimated from the 3-min all-out approach was significantly higher than from the traditional approach (402 ± 33, 351 ± 27 W, P < .001), while W′ was lower (15.5 ± 3.0, 24.3 ± 4.0 kJ, P = .02). Five different combinations of 2 or 3 self-paced efforts led to CP estimates within the threshold of agreement, with only 1 combination deemed accurate for W′.

Conclusions:

In elite cyclists the 3-min all-out approach is not suitable to estimate CP when compared with the traditional method. However, reducing the number of tests used in the traditional method lessens testing burden while maintaining appropriate parameter accuracy.
Prediction of Functional Overreaching From Subjective Fatigue and Readiness to Train After Only 3 Days of Cycling
Authors: ten Haaf Twan , van Staveren Selma , Oudenhoven Erik , Piacentini Maria F. , Meeusen Romain , Roelands Bart , Koenderman Leo , Daanen Hein A.M. , Foster Carl , de Koning Jos J.
Published: November 2016

Purpose:

To investigate whether monitoring of easily measurable stressors and symptoms can be used to distinguish early between acute fatigue (AF) and functional overreaching (FOR).

Methods:

The study included 30 subjects (11 female, 19 male; age 40.8 ± 10.8 y, VO2max 51.8 ± 6.3 mL · kg–1 · min–1) who participated in an 8-d cycling event over 1300 km with 18,500 climbing meters. Performance was measured before and after the event using a maximal incremental test. Subjects with decreased performance after the event were classified as FOR, others as AF. Mental and physical well-being, internal training load, resting heart rate, temperature, and mood were measured daily during the event. Differences between AF and FOR were analyzed using mixed-model ANOVAs. Logistic regression was used to determine the best predictors of FOR after 3 and 6 d of cycling.

Results:

Fifteen subjects were classified as FOR and 14 as AF (1 excluded). Although total group changes were observed during the event, no differences between AF and FOR were found for individual monitoring parameters. The combination of questionnaire-based changes in fatigue and readiness to train after 3 d cycling correctly predicted 78% of the subjects as AF or FOR (sensitivity = 79%, specificity = 77%).

Conclusions:

Monitoring changes in fatigue and readiness to train, using simple visual analog scales, can be used to identify subjects likely to become FOR after only 3 d of cycling. Hence, we encourage athlete support staff to monitor not only fatigue but also the subjective integrated mental and physical readiness to perform.
Interscholastic Competitive Balance: An Examination of State Athletic Association Administrators
Authors: Johnson James E. , Giannoulakis Chrysostomos , Scott Beau F.
Published: November 2016

While competitive balance literature is robust when addressing professional sport from an economic perspective, little empirical work has focused on understanding what shapes interscholastic competitive balance policies. Using the theory of distributive justice as a framework, the purpose of this multiple case study was to examine the perceptions of top administrators regarding sociocultural influences on interscholastic competitive balance. Qualitative interview data collected from six state commissioners/executive directors revealed four predominant findings: (a) policy is driven by a philosophical approach that is aligned with the theory of distributive justice; (b) an overemphasis on winning strongly influences policy; (c) political influence through legal threats and state educational policy shapes committee decisions; and (d) the prevailing challenges of policy creation include school size, geography, public/nonpublic status, tradition, sport-specific characteristics, and lack of knowledge. Implications of these findings are discussed.
Patient Outcomes Utilizing the Mulligan Concept of Mobilization With Movement to Treat Intercollegiate Patients Diagnosed With Lateral Ankle Sprain: An a Priori Case Series
Authors: May James M. , Nasypany Alan , Paolino Julie , Baker Russell , Seegmiller Jeffrey
Published: November 2016

Context:

While the incidence and reinjury rates of lateral ankle sprain (LAS) continue to persist at high rates across many sporting activities, further exploration of assessment and treatment beyond the traditional ligamentous and strength/proprioceptive model is warranted. Further, assessing and treating both arthrokinematic and osteokinematic changes associated with LAS can provide insight into a more diverse approach to treating ankle pathology.

Objective:

To examine the clinical use of the Mulligan Concept mobilization with movement (MWM) while treating patients diagnosed with an acute grade I or II LAS through authentic patient care.

Design:

An a priori case series.

Setting:

Intercollegiate athletic training clinic.

Patients:

Intercollegiate patients diagnosed with an acute grade I or II LAS.

Intervention:

The Mulligan Concept distal fibular anterior to posterior MWM.

Main Outcome Measures:

Pain-Intensity Numeric Rating Scale (NRS) with Non-Weight Bearing (NRS-NWB) and Weight Bearing (NRS-WB), Disablement of the Physically Active Scale (DPAscale), Foot and Ankle Ability Measure (FAAM) with Activity of Daily living (FAMM-ADL) and Sport (FAAM-Sport), Client Specific Impairment Measure (CSIM), Y-Balance Composite (YBC), and Weight Bearing Measure for Dorsiflexion (WBDF).

Results:

Patients who are diagnosed with an acute grade I or II LAS and are treated with the Mulligan Concept report immediate and long-lasting minimal clinically important differences in patient outcome measures.

Conclusion:

Clinicians who examine and use the Mulligan Concept MWM to treat acute LAS can expect immediate positive results that are progressively retained over time specific to patient-centered outcome measures as well as functional clinicianbased measures. Based on the immediate and positive results, clinicians should examine associated osteokinematic and arthrokinematic changes beyond that of the traditional ligamentous model.
Spinal Cord Injury and Seated Postural Control: A Test of the Rambling and Trembling Hypothesis
Authors: Shin Sunghoon , Sosnoff Jacob J.
Published: November 2016

Rambling–trembling analysis separates the center of pressure into two components: the rambling component (RM: supraspinal) and trembling component (TM: muscle stiffness/reflex). We hypothesized that persons with spinal cord injury (SCI) would demonstrate decreased RM resulting from altered supraspinal processing and increased TM resulting from increased muscle stiffness. We also anticipated that the TM component would be greater in SCI patients with Harrington rods than in those without them. The seated postural control was assessed in 18 persons with SCI, comprising 12 with and six without Harrington rods, and 18 age-matched controls. The SCI group had greater center of pressure sway, RM, and TM components than the controls, with no difference in the postural sway between the SCI subgroups, suggesting that the impairment of seated postural control in individuals with SCI results from disturbed supraspinal and peripheral mechanisms, but that the control itself is unaffected by internal fixation with Harrington rods. These were not entirely consistent with our hypothesis.
Red squirrels in the British Isles are infected with leprosy bacilli
Authors: Avanzi Charlotte , del-Pozo Jorge , Benjak Andrej , Stevenson Karen , Simpson Victor R. , Busso Philippe , McLuckie Joyce , Loiseau Chloé , Lawton Colin , Schoening Janne , Shaw Darren J. , Piton Jérémie , Vera-Cabrera Lucio , Velarde-Felix Jesùs S. , McDermott Fergal , Gordon Stephen V. , Cole Stewart T. , Meredith Anna L.
Published: November 2016

British squirrels infected with leprosy

With the exception of armadillos in the Americas, leprosy infections are considered almost exclusively restricted to humans. Avanzi
et al.
examined warty growths on the faces and extremities of red squirrels in the British Isles and found that two species of leprosy-causing organisms were to blame (see the Perspective by Stinear and Brosch).
Mycobacterium leprae
in the southern population of Brownsea Island squirrels originated from a medieval human strain.
M. lepromatosis
was found in red squirrels from elsewhere in the United Kingdom and Ireland. Human leprosy is proving hard to eradicate, despite available drugs. Perhaps other wildlife species are also reservoirs for this stubborn disease.

Science
, this issue p.
744
; see also p.
702
De novo design of a biologically active amyloid
Authors: Gallardo Rodrigo , Ramakers Meine , De Smet Frederik , Claes Filip , Khodaparast Ladan , Khodaparast Laleh , Couceiro José R. , Langenberg Tobias , Siemons Maxime , Nyström Sofie , Young Laurence J. , Laine Romain F. , Young Lydia , Radaelli Enrico , Benilova Iryna , Kumar Manoj , Staes An , Desager Matyas , Beerens Manu , Vandervoort Petra , Luttun Aernout , Gevaert Kris , Bormans Guy , Dewerchin Mieke , Van Eldere Johan , Carmeliet Peter , Vande Velde Greetje , Verfaillie Catherine , Kaminski Clemens F. , De Strooper Bart , Hammarström Per , Nilsson K. Peter R. , Serpell Louise , Schymkowitz Joost , Rousseau Frederic
Published: November 2016

Aggregation by design

Amyloid aggregation is driven by short sequences within proteins that self-assemble into characteristic amyloid structures. About 30 human proteins are implicated in amyloid-associated diseases, but many more contain short sequences that are potentially amyloidogenic. Gallardo
et al.
designed a peptide based on an amyloidogenic sequence in the vascular endothelial growth factor receptor VEGFR2. The peptide induced VEGFR2 to form aggregates with features characteristic of amyloids. Amyloids were toxic only in cells that required VEGFR2 activity, suggesting that the toxicity was due to loss of function of VEGFR2, rather than to inherent toxicity of the aggregates. The peptide inhibited VEGFR2-dependent tumor growth in a mouse tumor model.

Science
, this issue p.
10.1126/science.aah4949
Neural correlates of ticklishness in the rat somatosensory cortex
Authors: Ishiyama S. , Brecht M.
Published: November 2016

Resolving a ticklish problem

What is the neural correlate of ticklishness? When Ishiyama and Brecht tickled rats, the animals produced noises and other joyful responses. During the tickling, the authors observed nerve cell activity in deep layers of the somatosensory cortex corresponding to the animals' trunks. Furthermore, microstimulation of this brain region evoked the same behavior. Just as in humans, mood could modulate this neuronal activity. Anxiety-inducing situations suppressed the cells' firing, and the animal could no longer be tickled.

Science
, this issue p.
757
First flu is forever
Authors: Viboud Cécile , Epstein Suzanne L.
Published: November 2016

A change in the properties of influenza virus in 1968 has left a profound mark on population immunity
Lipid Mediators in Inflammation
Authors: Bennett Melanie , Gilroy Derek W.
Published: November 2016

Lipids are potent signaling molecules that regulate a multitude of cellular responses, including cell growth and death and inflammation/infection, via receptor-mediated pathways. Derived from polyunsaturated fatty acids (PUFAs), such as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), each lipid displays unique properties, thus making their role in inflammation distinct from that of other lipids derived from the same PUFA. This diversity arises from their synthesis, which occurs via discrete enzymatic pathways and because they elicit responses via different receptors. This review will collate the bioactive lipid research to date and summarize the major pathways involved in their biosynthesis and role in inflammation. Specifically, lipids derived from AA (prostanoids, leukotrienes, 5-oxo-6,8,11,14-eicosatetraenoic acid, lipoxins, and epoxyeicosatrienoic acids), EPA (E-series resolvins), and DHA (D-series resolvins, protectins, and maresins) will be discussed herein.
Second harmonic generation of femtosecond pulses using ZnO nanorods grown by chemical bath deposition with drop casted seed layer
Authors: Panda R. , Bhattacharya S. , Samal R. , Singh A. , Sahoo P. K. , Datta P. K. , Das S. K.
Published: November 2016

We report efficient second harmonic generation (SHG) of femtosecond (fs) pulses using ZnO nanorods grown by chemical bath deposition (CBD) method with drop-casted seed layer. The SHG behavior of the nanorods are tested using an amplified Ti:sapphire fs laser of pulse duration of 100[Formula: see text]fs at 800[Formula: see text]nm. The SHG signal from the ZnO nanorods is found to be of very high intensity as detected by a low cost, compact spectrometer. In a comparative study, the SHG signal from ZnO nanorods grown over seed layer is found to be 12 times higher than the SHG signal observed from the ZnO nanorods grown on substrate without any seed layer. The efficient SHG in former case is due to the growth of high density, well oriented nanorods whereas the lower signal in the later case is due to growth of low density, randomly oriented nanorods. The polarization dependence behavior of the SHG signal is studied both experimentally and theoretically.
Taming Multirelations
Authors: Furusawa Hitoshi , Struth Georg
Published: November 2016

Binary multirelations generalise binary relations by associating elements of a set to its subsets. We study the structure and algebra of multirelations under the operations of union, intersection, sequential, and parallel composition, as well as finite and infinite iteration. Starting from a set-theoretic investigation, we propose axiom systems for multirelations in contexts ranging from bi-monoids to bi-quantales.
Automated view and path planning for scalable multi-object 3D scanning
Authors: Fan Xinyi , Zhang Linguang , Brown Benedict , Rusinkiewicz Szymon
Published: November 2016

Demand for high-volume 3D scanning of real objects is rapidly growing in a wide range of applications, including online retailing, quality-control for manufacturing, stop motion capture for 3D animation, and archaeological documentation and reconstruction. Although mature technologies exist for high-fidelity 3D model acquisition, deploying them at scale continues to require non-trivial manual labor. We describe a system that allows non-expert users to scan large numbers of physical objects within a reasonable amount of time, and with greater ease. Our system uses novel view- and path-planning algorithms to control a structured-light scanner mounted on a calibrated motorized positioning system. We demonstrate the ability of our prototype to safely, robustly, and automatically acquire 3D models for large collections of small objects.
Downsampling scattering parameters for rendering anisotropic media
Authors: Zhao Shuang , Wu Lifan , Durand Frédo , Ramamoorthi Ravi
Published: November 2016

Volumetric micro-appearance models have provided remarkably high-quality renderings, but are highly data intensive and usually require tens of gigabytes in storage. When an object is viewed from a distance, the highest level of detail offered by these models is usually unnecessary, but traditional linear downsampling weakens the object's intrinsic shadowing structures and can yield poor accuracy. We introduce a joint optimization of single-scattering albedos and phase functions to accurately downsample heterogeneous and anisotropic media. Our method is built upon
scaled phase functions
, a new representation combining abledos and (standard) phase functions. We also show that modularity can be exploited to greatly reduce the amortized optimization overhead by allowing multiple synthesized models to share one set of down-sampled parameters. Our optimized parameters generalize well to novel lighting and viewing configurations, and the resulting data sets offer several orders of magnitude storage savings.
Computing inversion-free mappings by simplex assembly
Authors: Fu Xiao-Ming , Liu Yang
Published: November 2016

We present a novel method, called
Simplex Assembly
, to compute inversion-free mappings with low or bounded distortion on simplicial meshes. Our method involves two steps: simplex disassembly and simplex assembly. Given a simplicial mesh and its initial piecewise affine mapping, we project the affine transformation associated with each simplex into the inversion-free and distortion-bounded space. The projection disassembles the input mesh into disjoint simplices. The disjoint simplices are then assembled to recover the original connectivity by minimizing the mapping distortion and the difference of the disjoint vertices with respect to the piecewise affine transformations, while the piecewise affine mapping is restricted inside the feasible space. Due to the use of affine transformations as variables, our method explicitly guarantees that no inverted simplex occurs, and that the mapping distortion is below the bound during the optimization. Compared with existing methods, our method is robust to an initialization with many inverted elements and positional constraints. We demonstrate the efficiency and robustness of our method through a variety of geometric processing tasks.