bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapidly Deployable Lightweight Shelters for Austere Environments
Authors: Jayson Eric M. , Mathy Gregory R. 
Published: April 2014

An innovative solution for a rapidly deployable shelter for use in austere environments is presented in this paper. The design incorporates a self-erecting dome structure and a compressible, high R-value thermal barrier to enable rapid in-theatre deployment of personnel in harsh environmental conditions.
The design concept presented in the paper was originally developed in response to the Army branch of the small business innovative research (SBIR) solicitation topic A11-099. The proposed 400 ft2 shelter meets the design goals of deployment by two people in 20 minutes, capability of withstanding 100 mph winds, and an R value of at least 15. These objectives have been proven via test, analysis, and mechanical demonstration of the key design components and systems.
The primary structure consists of eight composite tubes. The tubes are slip-fit into a central hub; each member is similar to a spoke extending outward radially from the hub. A tension cable is run around the outer perimeter of the radial spokes, passing through a fitting at the tip of each spoke, and a protective skin is draped over the structural members. The structure is then elastically deformed via buckling into a dome-shaped structure by tensioning the cable. This allows quick, easy shelter erection from a single location by one person using a winch. The protective skin is then tensioned to the shelter base with adjustable straps. Stakes are not required to support the structure. A scale model of the primary structure was built to demonstrate the controlled buckling of the members to form the main structural components, and the scale model successfully demonstrated deployment in minimal time.
A cellular fabric blanket, which uses entrapped air to provide a thermal barrier, is hung from the inside of the structure and is mechanically expanded to maintain the desired cell size. It can then be packed to 1/20th of its deployed volume for transportation. Simulations and tests were used to optimize the cell size and aspect ratio for weight, manufacturability, and R value. Analytical predictions and component-level testing have demonstrated that a system-level R value of 15 is achievable.
Objective Assessment of Minimally Invasive Surgical Skills
Authors: Keshavarz Panahi Ali , Cho Sohyung 
Published: April 2014

Minimally invasive surgery (MIS) is known to be a difficult procedure to master due to its complexity, compared to traditional open surgery. Therefore, an objective and quantitative assessment tool is highly required in MIS, which can be used for determining surgeon’s skills, evaluating educational programs and providing subjects with unbiased feedback. The goal of this paper is to review various assessment methods, summarize capabilities of the methods, and suggest future possible improvements. Specifically, this paper categorize existing methods into two groups: the first and the most well known group focuses on the analysis of surgical motions, and the other group uses force and torque as a key metric. Specifically, motion analysis includes tracking the body, tool, or hand motions of a surgeon, either from teleoperated robotic systems or surgical simulators using different sensors like wireless or electromagnetic motion tracking sensors, video-glove-based input devices, optical tracking system, or magnetic tracking technologies. Sometimes data explored form this method is synchronized with eye-gaze data (what a surgeon looks at while operating), or videographic data. Using motion analysis actually the number of movements, rate of movements, total path length, movement variability, time taken to complete the operation, average or peak velocity are considered for assessing surgical skills. On the other hand, the methods in the second group assess the skills based on force and toque data that surgeons apply through surgical instruments. More specifically, these methods use different kind of sensors placed on the grasper. Different force and torque measurement systems, hidden-Markov-model-based analysis, simulated models with criteria, and Virtual reality have been developed, allowing for the quantification of the performance of surgeons.
Although, each method has its own advantageous, and according to the kind of surgical task and evaluation, these methods can be used successfully to assess surgical skills, to provide predictive validity for each of these methods more study is needed. Also, future works should improve the efficiency of each method and move toward automated, low-cost and real time assessment methods.
Modeling and Simulation of Shoulder-Humerus Complex via Multibody Dynamics
Authors: Harrington Nicholas D. , Duan Shanzhong (Shawn) 
Published: April 2014

In this paper, a multibody dynamics model of the shoulder-upper arm complex is presented. Three major bones clavicle, scapula, and humerus in the shoulder-upper arm complex are represented by rigid bodies. The soft tissues such as tendons, ligaments, and muscles are modeled as springs and dampers respectively attached to the rigid bodies. The joints between the bones are expressed as ideal kinematic joints. Kane’s equations are then used to derive equations of motion of this multibody system.
Based on the model, a person’s stand-up motion, aided by shoulder-upper arm complex force for lifting his/her upper body weight is analyzed. Commercial computer software is used to create the multibody shoulder-upper arm complex computational model and then carry out simulation. The model may be utilized in motion analysis of elderly people and sports medicine to study fatigue mechanism and prevent injuries of the shoulder-upper arm complex.
A New Anchorage Device for Orthodontic Applications
Authors: Najari Mohamad , El-Rich Marwan , Adeeb Samer , Taha Bachar 
Published: April 2014

In orthodontic treatment, anchorage is the most important element that affects the treatment’s success. To improve the load bearing capacity of the anchorage there are several devices developed in recent decades such as midpalatal implants and onplants but they also have limitation on directions of applied load and their support position adjustability.
The purpose of this study was to investigate the efficiency of a new anchorage device by analyzing the load-bearing and stress distribution among the cortical and cancellous bones of the mandible as well as the anchorage system components using nonlinear 3D Finite Element (FE) method. The new device is composed of an adjustable stainless steel plate equipped with bracket and mounted with two titanium mini-screws into the mandible. The response of this new system was compared to an isolated mini-screw system under different loading scenarios.
A maximum of 500gr force was applied in different directions on the bracket and the isolated mini-screw head to simulate the orthodontic loading. Using the new anchorage device reduced von-Mises stress in the whole structure approximately by 50% comparing to the isolated mini-screw. In the cortical bone and depending on the direction of the applied force, von-Mises stress decreased from 6 to 3MPa under vertical shear force and from 6 to 1.5MPa under horizontal and inclined shear forces. In the cancellous bone the stress decreased similarly as in the cortical bone from 0.6 to ≈0.3MPa under horizontal and inclined shear. Under vertical shear force the decrease was less significant from 0.57MPa to 0.5MPa.
This new device while offering wide fields of orthodontic forces applications thanks to its bracket provides the same resistive force (500gr) as the isolated mini-screw with much lower stresses in the bone and anchorage implant as well. The next step is to investigate the efficiency of this new device in the teeth movement.
Heat Transfer in Cone Calorimeter Tests of Generic Wall Assemblies
Authors: Aire Charles T. , Torvi David A. , Weckman Elizabeth J. 
Published: April 2014

It is critical for the construction industry to ensure that new building designs and materials, including wall and floor assemblies (e.g., a studded wall with insulation and drywall) provide an acceptable level of fire safety. A key fire safety requirement that is specified in building codes is the minimum fire resistance rating, which is a measure of the ability of an assembly to limit fire spread within a building. A manufacturer of building materials (e.g., insulation or drywall) is required to perform full-scale fire resistance furnace tests to determine the fire resistance ratings of assemblies that use their products. Fire resistance test facilities are very limited and these tests are very expensive to perform. Therefore, it can be difficult to properly assess the impact of changes to individual components on the overall fire performance of an assembly during the design process.
As part of a project to develop methods of using small-scale fire test data to predict full-scale fire resistance test results, the heat transfer through scale models of common wall assembly designs was measured during cone calorimeter tests using an incident heat flux of 75 kW/m2. Wall assemblies consisting of single and double layers of 12.7 mm (1/2 in.) regular and lightweight gypsum board, and 15.9 mm (5/8 in.) type X gypsum board, along with mineral wool insulation and wood studs were tested. Temperature measurements made at various points within these assemblies are presented in this paper, and are discussed using results from thermal gravimetric analysis tests of the three types of gypsum board. Implications of this research to the development of heat transfer models and scaling relationships are also briefly discussed.
Combustion Analysis of Twisting-Blade Piston Diesel Engine Fuelled With Karanja Bio-Diesel
Authors: Rajashekar Chandrashekarapur Ramachandraih , Chandrasekhar Tumkur Krishnamurthy , Prasad Tejendra , Kemparaju Chelur Rangalppa , Shankar Chebiyyam Uma 
Published: April 2014

Bio-diesels have very poor atomization characteristics, due to decreased cone angle because of high viscosity and low volatility. Innovativeness is required to use the bio-diesel as efficient vehicular fuel.
This paper presents the effect of piston geometry on combustion and emission characteristics of Karanja bio-diesel fuelled C.I.Engine. The piston crown has been modified into twisting blade combustion chamber. Three blades are made to twist through an angle of 60o in the piston crown at the end of compression stroke to induce turbulence to improve the combustibility of combustible mixture. In the present work the combustion and emission characteristics of twisting blade piston fuelled with Karanja bio-diesel have been studied and compared with standard piston engine.
Design of a New Knee Orthosis Locking System
Authors: Moreira Pedro , Ramôa Pedro , Flores Paulo 
Published: April 2014

The main goal of this work is to present the design of a new locking system for a Stance Control Knee Ankle Foot Orthosis (SCKAFO). The purpose of this solution is to support patients with gait disorders, namely patients with muscular weakness and dystrophy in quadriceps femoris muscle group.
The proposed system is able to perform two distinct functions. The first one deals with the locking situation of the orthosis during the stance phase of human gait, in which contact between the foot and the ground occurs. The second function is associated with unlocking situation of the orthosis during the swing phase, in order to allow for the flexion motion of the knee. Thus, in the context of the present work sensors, are used to detect the key phases that characterize the human gait, allowing for the correct system performance. These sensors are placed into anatomical relevant locations and allow the evaluation of the joint angles and accelerations during human gait. Subsequently, the information collected by these sensors is interpreted by a microcontroller that controls the actuation system in order to lock or unlock the knee orthosis locking mechanism.
Finally, a physical prototype was built and tested in a traditional knee orthosis, which will allow for its validation. From the preliminary results, it can be stated that the model proposed here differs from the available commercial solutions in the measure that it is dynamic and does not require foot sensors to determine the human gait phases to define the lock/unlock.
Effect of Swelling Behavior on Elastomeric Materials: Experimental and Numerical Investigation
Authors: Qamar Sayyad Zahid , Akhtar Maaz , Al-Kharusi Moosa S. M. 
Published: April 2014

In the last ten years, a new type of advanced polymer known as swelling elastomer has been extensively used as sealing element in the oil and gas industry. These elastomers have been instrumental in various new applications such as water shutoff, zonal isolation, sidetracking, etc. Though swell packers can significantly reduce costs and increase productivity, their failure can lead to serious losses. Integrity and reliability of swelling-elastomer seals under different field conditions is therefore a major concern. Investigation of changes in material behavior over a specified swelling period is a necessary first step for performance evaluation of elastomer seals. Current study is based on experimental and numerical analysis of changes in compressive and bulk behavior of an elastomeric material due to swelling. Tests and simulations were carried out before and after various stages of swelling. Specimens were placed in saline water (0.6% and 12% concentration) at a temperature of 50°C, total swelling period being one month. Both compression and bulk tests were conducted using disc samples. A small test rig had to be designed and constructed for determination of bulk modulus. Young’s modulus (under compression) and bulk modulus were determined for specimens subjected to different swelling periods. Shear modulus and Poisson’s ratio were calculated using isotropic relations. Experiments were also simulated using the commercial finite element software ABAQUS. Different hyperelastic material models were examined. As Ogden model with second strain energy potential gave the closest results, it has been used for all simulations.
The elastomer was a fast-swell type. There were drastic changes in material properties within one day of swelling, under both low and high salinity water. Values of elastic and shear modulus dropped by more than 90% in the first few days, and then remained almost constant during the rest of the one-month period. Poisson’s ratio, as expected, showed a mirror behavior of a sharp increase in the first few days. Bulk modulus exhibited a fluctuating pattern; rapid initial decrease, then a slightly slower increase, followed by a much slower decrease. Salinity shows some notable effect in the first 5 or 6 days, but has almost no influence in the later days. Very interestingly, Poisson’s ratio approaches the limiting value of 0.5 within the first 10 days of swelling, justifying the assumption of incompressibility used in most analytical and numerical models. In general, simulations results are in good agreement with experimental ones.
Power Plant Heat Rejection System Modeling and Comparison
Authors: Carter Thomas P. , Furlong James W. , Bushart Sean P. , Shi Jessica 
Published: April 2014

As noted in a Summer 2007 EPRI Journal article entitled Running Dry At The Power Plant, “Securing sufficient supplies of fresh water for societal, industrial, and agricultural uses while protecting the natural environment is becoming increasingly difficult in many parts of the United States. Climate variability and change may exacerbate the situation through hotter weather and disrupted precipitation patterns that promote regional drought.” [1] Currently, in the United States, thermoelectric power production accounts for approximately 41% of freshwater withdrawals [2] and 3% of overall fresh water consumption. [3]
The Electric Power Research Institute, EPRI, as part of its Technology Innovation (TI) program, is collaborating with Johnson Controls to conduct a feasibility study comparing the performance of a water saving Thermosyphon Cooling Hybrid System (TCHS) with other heat rejection systems for power plant applications. The TCHS employs a sensible heat rejection device, a thermosyphon cooler (TSC) in conjunction with an evaporative heat rejection device, an open cooling tower, to satisfy the annual cooling requirements of a given power plant. By reducing the evaporative heat load, the TCHS can significantly reduce the annual water consumed for cooling while still maintaining peak power plant output on the hottest summer days.
Details of the interactive simulation program developed to compare various power plant heat rejection systems on an annual 8,760 hourly basis are discussed. Examples of the types of results and comparisons that can be made from the data obtained from the simulation program are presented.
Adsorption Cooling With Multi-Stage Desiccant Processes
Authors: Huang Chen-Kang 
Published: April 2014

For traditional adsorption cooling systems using silica-gel-like desiccant wheels, the moisture is removed from the air and stored in the desiccant wheels. The subsequent reactivation process is to dry the wheel by blowing hot air. The moisture is added to the dried air to take the advantage of evaporative cooling. Currently, the two processes are performed on the different sections of a wheel. However, the temperature of the reactivated part will be higher, and the residual heat will be dissipated into the air-conditioning space. Some researchers have reported to add another section to cool down the regenerative part. Unfortunately, the addition of cooling section decreases the working durations of other two sections.
In this study, a novel desiccant-evaporative cooling process is proposed. The wheel is now stationary. Fans and air doors were designed to adjust various air flows to pass through the wheel to perform the dehumidifying, reactivation, and cooling inside the wheel. Most importantly, for each period, the desiccant wheel was used only to dehumidify, reactivate, or cool down. The air to cool the desiccant wheel was released outside, so no residual heat went to the air-conditioning space. The outdoor air was acquired to be heated and reactivate the desiccant wheel. The indoor was used to cool the wheel to achieve better cooling effects.
An experimental prototype was designed and established. The air could be directed through the desiccant wheel. A controller was installed. The duration of the dehumidifying, reactivation, and cooling process could be set on the panel. The evaporative cooling process was performed by ten ultrasonic humidifiers. The hot air was from a liquid-to-air heat exchanger, and the hot water can be from a solar heater or any waste heat sources.
Optimized sets of period durations were suggested. The criteria to end each process have been proposed for future automation. It is shown that the novel design is able to deliver cooler air. Although the cool air output is currently intermittent, a solution has been figured out and will be improved soon.
A Distributed Source, Finite Absorption Model of a Pulsed Laser Diffusivity Measurement System
Authors: Hall James B. , Jones Matthew R. , LeFevre Jeremy , Terrill Trevor J. 
Published: April 2014

Thermal diffusivity is a thermophysical property that quantifies the ratio of the rate at which heat is conducted through a material to the amount of energy stored in a material. The pulsed laser diffusion (PLD) method is a widely used technique for measuring thermal diffusivities of materials. This technique is based on the fact that the diffusivity of a sample may be inferred from measurement of the time-dependent temperature profile at a point on the surface of a sample that has been exposed to a pulse of radiant energy from a laser or flash lamp. The standard approach to PLD is based on a simple model that produces an explicit relationship between the diffusivity and the time required for the temperature of the sample surface to reach a specified fraction of the peak temperature. However, the standard approach is based on idealizations that are difficult to achieve in practice, so models that represent a PLD measurement system with greater fidelity are desired.
Assessment of the impact of the approximations made in the development of the standard approach showed that neglect of the spatial and temporal variations of the input power leads to significant errors in measurement of the thermal diffusivity. The objective of this paper is to present the Distributed Source Finite Absorption model which represents the spatial and temporal variations in the pulse with greater fidelity.
The cost of the increased fidelity is an increase in the complexity of the algorithm used to determine values of the thermal diffusivity. A simple relationship between an easily determined characteristic of the measured temperature profile and the thermal diffusivity does not exist. Therefore, a new method of extracting values from measured time dependent-temperature profiles based on a genetic algorithm and on reduced order modeling has been developed. This paper also presents a numerical verification of this proposed new method for measuring the thermal diffusivity.
Optimization Methodology for an Automotive Composite Hood
Authors: Lazzarini Alberto , Valgimigli Alessandro , Baldini Andrea , Dolcini Enrico , Sangermano Stefano 
Published: April 2014

The current emissions regulations lead car manufacturers to look carefully for weight reduction. In the automotive industry the classic trial-and-error approach to design is becoming inadequate and techniques based on optimization are necessary to improve the design process. In this study a methodology to design a sport-car front hood is proposed. The process carried out could also be extended to car components characterised by a similar configuration.
Starting from the geometry of the actual part, a design volume has been defined. The first step consists of a topology optimization performed considering the material as isotropic (aluminium properties): the output is a rough structure which accomplishes all the imposed targets. The interpretation of the topology results brings to a re-design phase aimed at realising a feasible component.
The subsequent optimization step is dedicated to composite material structures and acts on the component plybook, varying thickness and orientation of each ply to find the best solution complying with targets. Finally, the component has to be reviewed from a technological point of view in order to be virtually delivered and to proceed with the prototype phase.