bluuebunny/crossref_metadata_2025_split huggingface dataset:
Muscle adaptation to exercise: New Saltin’s paradigms
Authors: Booth F. W. 
Published: November 2015

The title assigned for my lecture at the Saltin Symposium was “Muscle adaptation to exercise: new paradigms.” The title's topic made me remember that some of Saltin's paradigms for his development of a novel exercise model were either originated by him or modified by him from existing information. Therefore, I deemed it would be instructive for future generations to consider one facet of his 54‐year career – human exercise models. I arbitrarily selected to share five examples of new paradigm models initiated by Saltin. They are: bed rest; arms vs legs; one leg vs the other leg; myokine communication from skeletal muscle to other organs/tissues; and 42‐day cross‐country skiing expedition. I arbitrarily selected the above as examples of novel approaches that he used to the study humans during maximal endurance exercise. Noteworthy though is that Saltin's lifetime demeanor, itself, is a model for other scientists. In final analysis, the world is richer due to his passion to study humans to advance medical science by uncovering mechanisms as to how the human body is constructed to perform endurance types of exercise at maximal intensities and durations.
Rapid hepatic perfusion decellularization: technique and critique
Authors: Fathi Ibrahim , Elhammady Habashi , Sakr Mahmoud , Nabawi Ayman , Marei Mona 
Published: November 2015

AbstractBackgroundOrgan shortage facing the increasing success of liver transplantation has provoked research into the utilization of animal organs for clinical transplantation. The technique of whole‐organ decellularization aims at the removal of the antigenic cellular content, thus evading the immune rejection cascade and the production of complex three‐dimensional extracellular matrices of the entire organs with preservation of their intrinsic vascular networks rendering them transplantable. The aim of this study was the production of decellularized rabbit liver matrices by applying a simple, rapid perfusion decellularization technique and their characterization (both qualitatively and quantitatively).Materials and methodsDecellularization of the caudate hepatic lobes of New Zealand white rabbits (n = 22) was achieved through sequential perfusion of the portal venous system with deionized water, 0.8% Triton X‐100 and 0.8% sodium dodecyl sulphate (SDS). Decellularized specimens were characterized both qualitatively (histology, fluoroscopy, corrosion casting and scanning electron microscopy) and quantitatively (total collagen assay [colorimetric] and total DNA assay [Hoechst 33258]). A Student's t‐test was used to compare quantitative laboratory results before and after decellularization. A probability (P) value of <0.05 was considered significant.ResultsEffective decellularization was achieved as proven by histology and quantitative assessment (DNA remnants <1.5%, P = 0.0009), while preserving 68% of the total collagen content (P = 0.003). Portal vascular network integrity was confirmed by fluoroscopy and corrosion casting. Scanning electron microscopy also confirmed the preservation of the three‐dimensional architecture.ConclusionsLiver perfusion decellularization technique using both 0.8% Triton X‐100 and 0.8% SDS is a simple and rapid technique, yielding efficiently decellularized liver matrices preserving their vascular integrity, 3D architecture and 68% of total collagen content.
Key Technologies to Implement High Thermal Ambient Data Center
Authors: Zhang Shu , Han Yu , Ahuja Nishi , Liu Xiaohong , Ren Huahua , Guo Guangliang 
Published: November 2015

In recent years, the internet services industry has been developing rapidly. Accordingly, the demands for compute and storage capacity continue to increase and internet data centers are consuming more power than ever before to provide this capacity. Based on the Forest & Sullivan market survey, data centers across the globe now consume around 100GWh of power and this consumption is expected to increase 30% by 2016. With development expanding, IDC (Internet Data Center) owners realize that small improvements in efficiency, from architecture design to daily operations, will yield large cost reduction benefits over time.
Cooling energy is a significant part of the daily operational expense of an IDC. One trend in this industry is to raise the operational temperature of an IDC, which also means running IT equipment at HTA (Higher Ambient Temperature) environment. This might also include cooling improvements such as water-side or air-side economizers which can be used in place of traditional closed loop CRAC (Computer room air conditioner) systems. But just raising the ambient inlet air temperature cannot be done by itself without looking at more effective ways of managing cooling control and considering the thermal safety.
An important trend seen in industry today is customized design for IT (Information Technology) equipment and IDC infrastructure from the cloud service provider. This trend brings an opportunity to consider IT and IDC together when designing and IDC, from the early design phase to the daily operation phase, when facing the challenge of improving efficiency. This trend also provides a chance to get more potential benefit out of higher operational temperature. The advantages and key components that make up a customized rack server design include reduced power consumption, more thermal margin with less fan power, and accurate thermal monitoring, etc. Accordingly, the specific IDC infrastructure can be re-designed to meet high temperature operations.
To raise the supply air temperature always means less thermal headroom for IT equipment. IDC operators will have less responses time with large power variations or any IDC failures happen. This paper introduces a new solution called ODC (on-demand cooling) with PTAS (Power Thermal Aware Solution) technology to deal with these challenges. ODC solution use the real time thermal data of IT equipment as the key input data for the cooling controls versus traditional ceiling installed sensors. It helps to improve the cooling control accuracy, decrease the response time and reduce temperature variation. By establishing a smart thermal operation with characteristics like direct feedback, accurate control and quick response, HTA can safely be achieved with confidence. The results of real demo testing show that, with real time thermal information, temperature oscillation and response time can be reduced effectively.
The Influence of Nanoparticle Type on the Viscosity of Nanoenhanced Energy Storage Materials
Authors: Hess Kieran , Fleischer Amy S. 
Published: November 2015

The use of nanoparticles to improve the thermal properties of low thermal conductivity phase change materials is of significant interest. However, the addition of nanoparticles to a base fluid is known to result in an increase in viscosity. An increase in viscosity can suppress convective currents, reducing overall heat transfer thus it necessary to quantify the impact of nanoparticle addition on the viscosity of a PCM.
In this work nanoparticle enhanced phase change mateirals are synthesized using paraffin and three different types of nanoparticles: exfoliated graphite nanoplatelets (xGNP), multi-walled carbon nanotubes (MWCNT) and herringbone graphite nanofibers (HGNF). The particles are loaded at rates between 0.0024wt% to 0.1wt%. The viscosity is analyzed at temperatures between 60 and 100°C. The influence of temperature, nanoparticle type and nanoparticle loading level on viscosity are presented and discussed.
The results show that for xGNP and HGNF within the operating condition studied here that there is no impact of the nanoparticle addition on the viscosity of the base material. However, the addition of MWCNT is found to increase the viscosity of the base fluid with the impact increasing with loading level.
MD Evaluation of the IR Spectra of DNA Bases in the Process of Transport Through Graphene Nanopore
Authors: Kitani Takumu , Zolotoukhina Tatiana 
Published: November 2015

Development of the 1D and 2D IR spectroscopy of small organic molecules and clusters opens yet another way of possible identification of small organic molecules in the state of motion in the graphene nanopore scanning device. With the advantage of obtaining qualitative and at least semi-quantitative information of specimens real-time and non-invasively, vibrational spectroscopy techniques, infrared (IR) and Raman have become more and more important in the analysis of biomolecular samples. At present, the sensitivity and spatial resolution of these techniques stands at the challenge of the detection and analysis of biosamples at very low concentration (single molecule) and high spatial resolution (nanometer/sub-nanometer scale). Spectral analysis requires theoretical assignment of vibrational modes to each biomolecule.
We considered vibrational spectra of DNA nucleobase at the time when they are translocated through the graphene nanopore. The Fourier transform of the density of states (DOS) of each base was calculated and the spectra of the base molecules and C atoms of graphene pore edge were obtained. Translocation rate was fixed to have maximum interaction of the base with 1.5 nm pore and single orientation of nucleobases was evaluated relative to molecular plane. Whether interaction of nucleobase and nanopore is able to enhance the signal is still remains unanswered. But we have shown that the spectra of each nucleobase are different and can be considered the fingerprint of the particular molecule.
The interaction forces between pore and base are structure dependent and time-limited by translocation time. In such case, transient correlation functions were utilized for the DOSes of the individual bases and forces on each atom of the particular base were sorted by intensity. The spectra of individual atoms in the bases as well as of whole molecule were compared and frequencies of most intense peaks were related to particular atoms. Molecular dynamics method is used for the DNA base and graphene nanopore calculations with the MM2/MM3 potentials for the base and REBO graphene potential. Interaction potential between the bases can simultaneously give additional information for the electronic transport calculations with possible tra and graphene are of the MM2/MM3 part of the Van der Waals interaction only has been considered. Possibility of base identification by spectral signature is confirmed. Calculated spectra are compared with results of the existing IR measurements for nucleobases.
A Numerical Study of Pulsating Heat Pipe Performance
Authors: d’Entremont Brian P. , Thome John R. 
Published: November 2015

A pulsating heat pipe (PHP), also known as an oscillating heat pipe (OHP), is a passive thermal transport device which consists of a single meandering microchannel making multiple passes each through an evaporator and condenser. With a sufficient number of such passes, intermittent boiling of liquid slugs within each evaporator pass perturbs flow in adjacent channels leaving the device in a perpetually unstable state of oscillation. A PHP is thus distinguished operationally from a loop thermosyphon by having a motive force other than buoyancy and the ability to operate in all gravitational orientations.
The most successful PHP models to date track liquid slug motion, sensible heating of the slugs, and mass transfer between liquid slugs and vapor plugs due to evaporation and condensation. However, the predictive capabilities of PHP models remain poor and the numbers assigned to evaporation and condensation heat transfer coefficients are generally not well justified by any realistic physical process. The current study applies methods consistent with state of the art prediction methods in microchannel boiling, to obtain results which predict the PHP’s heat transfer performance and the effect of gravitational orientation on performance.
Data Center Optimization Using Performance Metrics
Authors: Seymour Mark J. , Herrlin Magnus K. 
Published: November 2015

Data centers are rapidly growing in size and number and consume an increasing and also significant proportion of energy production. Yet, their mission critical nature means they are constructed and operated at almost any cost. The data center industry is becoming more aware of the need to manage energy alongside managing capacity and availability. A vital element — and one that cannot be ignored — is how well cooling is delivered to IT equipment. Monitoring allows you to understand how well you are currently operating and whether you are within acceptable bounds. Meanwhile, simulation of the airflow and heat transfer allows you to predict future performance and understand current and future cooling issues. The challenge with both approaches is that they provide large volumes of data and interpretation can become a challenging task. Consider two scenarios:
i. One configuration results in a lot of ‘hot spots’ in the data center, resulting in equipment permanently operating in the ASHRAE Allowable range for intake air temperature.
ii. A second configuration has one ‘hot spot’ where equipment is operating above the ASHRAE Allowable range, but the remainder is within the ASHRAE Recommended range.
Which is better? One solution is to use metrics to help understand the performance. However, existing metrics are not always well known and understood. The only metric that is currently in common use is Power Usage Effectiveness (PUE). While PUE is useful as a measure of data center cooling efficiency, it does not address the cool air delivery effectiveness within the IT space. However, high-level cooling delivery metrics such as Rack Cooling Index (RCI), Return Temperature Index (RTI), Supply Heat Index (SHI), and Return Heat Index (RHI) have been recognized for producing key information but are not as widely used as they could be. Other metrics have been developed that give more detailed understanding of delivery performance. Capture Index, or more specifically Cold Aisle Capture Index (CACI) and Hot Aisle Capture Index (HACI) provide a measure of whether cooling systems targeting specific equipment work effectively. Simulation also allows diagnostic performance ‘measurement’ with detailed indices such as Rack and Room Recirculation. Since data center airflow is complex, this paper uses case studies to show how using metrics provides a rapid insight into both performance and what might need to be addressed to improve and optimize performance.
Fabrication, Packaging, and Catheter Assembly of 2D CMUT Arrays for Endoscopic Ultrasound and Cardiac Imaging
Authors: Moini Azadeh , Nikoozadeh Amin , Choe Jung Woo , Khuri-Yakub Butrus T. , Chang Chienliu , Stephens Doug , Smith L. Scott , Sahn David 
Published: November 2015

Ultrasound is increasingly in demand as a medical imaging tool and can be particularly beneficial in the field of intracardiac echocardiography (ICE). However, many challenges remain in the development of a 3D ultrasound imaging system.
We have designed and fabricated a quad-ring capacitive micromachined ultrasound transducer (CMUT) for real-time, volumetric medical imaging. Each CMUT array is composed of four concentric, independent ring arrays, each operating at a different frequency, with 128 elements per ring. In this project, one ring will be used for imaging. A large (5mm diameter) lumen is available for delivering other devices, including high intensity focused ultrasound transducers for therapeutic applications or optical fibers for photoacoustic imaging.
We address several challenges in developing a 3D imaging system. Through wafer vias are incorporated in the fabrication process for producing 2D CMUT arrays. Device integration with electronics is achieved through solder bumping the arrays, designing a flexible PCB, and flip chip bonding CMUT and ASICs to the flexible substrate. Finally, we describe a method for integrating the flex assembly into a catheter shaft. The package, once assembled, will be used for in-vivo open chest experiments.
Measurement and Simulation of Moisture Induced Die Stresses in Flip Chip on Laminate Assemblies
Authors: Nguyen Quang , Roberts Jordan C. , Suhling Jeffrey C. , Jaeger Richard C. , Lall Pradeep 
Published: November 2015

In this work, an investigation has been performed on hygrothermally induced die stresses in flip chip assemblies caused by moisture absorption by the underfill encapsulant. Silicon test chips were first applied to perform a variety of measurements of moisture and thermally induced die stresses in flip chip on laminate assemblies. The sample die stresses were first measured after underfill encapsulation and cure, and then subsequently after long term storage (10 years) at room temperature and ambient humidity. The assemblies were then exposed to and 85 °C and 85% RH high humidity harsh environment for various durations, and the die stresses were evaluated as a function of the exposure time. Finally, reversibility tests were conducted to see whether the effects of moisture uptake were permanent. After long term storage, the experimental measurements showed that the normal stresses in the flip chip die relaxed significantly, while the shear stresses exhibited only small variations. In addition, the 85/85 hygrothermal exposure had strong effects, generating tensile die normal stress changes of up to 30 MPa in the flip chip assemblies. Thus, the initial compressive die normal stresses due to flip chip assembly were found to relax significantly during the moisture exposure. Upon fully redrying, it was observed that the moisture-induced stress changes were fully recovered.
The results of the experimental measurements were subsequently correlated with predictions from finite element numerical simulations. When performing moisture diffusion modeling, the conventional method is to use a thermal analogy based on the similarity of governing equations of heat transfer and moisture diffusion. However, this method has some drawbacks including giving incorrect results when dealing with time- and temperature-dependent problems or discontinuities in the moisture concentrations at material boundaries. In this study, we have used a new feature in ANSYS v14 to perform coupled multi-physics simulations of the moisture diffusion process without the aforementioned limitations. The simulation results were found to show strong correlations with experimental measurements.
Characterization of Die Stresses in Plastic Packages Subjected to Moisture and Thermal Exposures
Authors: Nguyen Quang , Rahim M. Kaysar , Roberts Jordan C. , Suhling Jeffrey C. , Jaeger Richard C. 
Published: November 2015

Stress sensing test chips are a powerful tool for measuring in-situ stresses in electronic packages. In this study, we have applied (111) silicon test chips to perform a variety of measurements of die stresses in plastic packages. In particular, stresses were characterized in 240 pin Quad Flat Packs (QFPs) subjected to various thermal and moisture loadings. The utilized 10 × 10 mm sensor chips incorporated optimized eight-element piezoresistive rosettes that were capable of measuring the complete state of stress at the die surface (including the interfacial shear stresses).
The fabricated test chips were initially used to measure die stresses in the QFPs after molding and post mold bake. Measurement results were correlated with finite element simulations of the molding process. Subsequently, the effects of thermal cycling on the measured die stress distributions for selected packages were investigated. After these initial measurements, the samples were stored at room temperature and ambient humidity for 17 years. The samples were then re-measured after this long term storage to evaluate the degree of die stress relaxation that had occurred. Several packages were then exposed to a harsh high temperature and high humidity environment (85 C, 85% RH) for various time durations, and allowed to absorb moisture. The die stresses at several locations were characterized as a function of time during the hygrothermal exposure. The weight variations in each sample were also measured during the 85/85 exposure to gauge the moisture uptake, and reversibility tests were conducted to see whether the effects of moisture uptake were permanent. Using these measurements and numerical simulations, valuable insight has been gained on moisture induced failure phenomena in plastic packages.
Good agreement was found between the predicted and measured die normal stress distributions occurring after molding of the QFP. The magnitudes of the in-plane normal and shear stresses were found to have decreased by up to 30% after moderate levels of thermal cycling. After long term storage, the experimental measurements showed that the die normal stresses in the QFPs relaxed significantly (up to 40%), while the die shear stresses exhibited only small variations. In addition, the 85/85 hygrothermal exposures had strong effects, generating tensile die normal stress changes of up to 130 MPa. Upon fully redrying in reversibility tests, it was observed that the moisture-induced normal stress changes were not recovered. Good correlations were observed between the variations of sample weight (increases in moisture content) and the variations of the die normal and shear stress changes.