bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Cutting Path on Custom 3D-Printed Surgical Guides for Bone-Tumor Resection
Authors: Helguero Carlos G. , Castro Juan , Ochoa César , Maldonado Fausto , Ramírez Emilio A. , Amaya Jorge L. 
Published: January 2020

Abstract
Custom three-dimensional (3D) printed guides are being used in the operative room as an aid to surgeons for increasing the accuracy of their cutting and resection techniques. In terms of bone-tumor resection, the cutting path printed in the custom jig is significantly important for two main purposes: first, the required fit for the implant that will replace the resected bone section and, second, the interaction between the remaining, healthy bone and the new implant in terms of forces, stresses and deformation.
Bone tumor resection has posed a challenge in orthopedic oncology, specifically due to a high level of difficulty in performing a limb-sparing surgery with negative margins on the remaining bone. A straight cutting path is usually used in clinical procedures due to the type of tooling available inside the operative room. 3D printed cutting path guides offer the possibility to evolve from a straight to a different path, e.g. a tapered path, and overcome fitting problems during surgery.
This work investigates the current straight cutting path used for typical bone tumor resection and compares it to a proposed tapered cutting path in terms of both implant fitting and stress analysis. Finite element analysis software is used to simulate a compression force exerted over the femur bone. Different taper cut angles are studied and results are reported to obtain an ideal angle for resection. Results are presented to evidence the need to evolve from the current resection technique in order to minimize the number of revision surgeries and for a better quality of life of patients under this type of surgical procedure.
Analysis of a Vertical-Axis Spherical Turbine for Energy Harvesting in Urban Water Supply Systems
Authors: Valencia Adriana S. , Jativa Cervantes Hugo , Castillo Eduardo , Garavitto Oguier A. , Soriano Guillermo E. , Castro Livingston D. 
Published: January 2020

Abstract
Fast-growing cities are a challenge for its current energy demand, especially in developing countries. Replacement of micro-turbines instead of dropping pressure valves in urban-water pipelines may assist in supplying energy to the electrical grid. The understanding of turbine design and its operational characteristics can help for efficient energy harvesting in these cities. The aim of this work is to design a cheap and versatile hydrokinetic vertical axis spherical turbine for extracting energy from water pipelines of 800 mm in diameter. The turbine runner is based on a NACA0018 airfoil. Performance prediction is obtained by implementing a double multiple stream tube (DMST) based model. Computational fluid dynamics (CFD) and finite element analysis are used for performance and design improvements. Based on the analysis, the turbine can generate an output power of approximately 1.71 kW with a dropping pressure head of 0.4 m and an internal flow velocity of 2.07 m/s with an efficiency of approximately 42.7%. The proposed method allows determining the available energy of 390 kW in the city of Guayaquil, Ecuador.
The Role of Higher Education Institutions Regarding Climate Change: The Case of Escuela Superior Politécnica del Litoral and its Carbon Footprint in Ecuador
Authors: Criollo Nancy P. , Ramirez Angel D. , Salas Daniel A. , Andrade Rafael 
Published: January 2020

Abstract
A case study of a university campus in a tropical area has been analyzed. Escuela Superior Politécnica del Litoral (ESPOL), one of the leading public polytechnic higher education institutions in Ecuador, is located in Guayaquil in the Guayas province. ESPOL has around 12300 students and 1740 faculty members and administrative staff. The climatic conditions are defined as dry tropical forest and have two main seasons, one with rain and high humidity and one that is dry. Average day temperature is 28°C. Air conditioning is required throughout the whole year. The carbon footprint (CF) has been calculated for the university campus as prescribed by the ISO 14064 International Standard for greenhouse gases (GHG) Emission and the Greenhouse Gas Protocol by the World Business Council for Sustainable Development (WBCSD) and World Resources Institute (WRI). Results indicate that the major contributor to the CF of the ESPOL campus is electricity generation off–campus with 66%. The CF per student is 0.406 tons CO2e which in comparison with information of other higher education institutions (HEIs) campuses is low. This is mostly associated with the CF of the electricity generated in Ecuador which is above 80% renewable. Additionally, a comparison of HEI cases based on their CF has been done. Further mitigation of GHG emissions is possible by energy efficiency measures at the building and transportation level.
Experimental Evaluation of Microclimate Cooling Garments Under Controlled Ambient Conditions
Authors: Baghirzade Mammadbaghir , Burns Samuel , Sun Hongwei , Sobkowicz-Kline Margaret , Johnston Stephen , Mack J. Hunter 
Published: January 2020

Abstract
A testing chamber was designed to evaluate the performance of microclimate cooling systems, which are used to extend human performance duration in heat stress environments by flowing fluids through flexible tubing in a conforming garment, carrying excess heat away from the wearer. The flexible experimental system accommodates changes in materials and garment design. In this study, one side of a chamber was able to output heat at a rate equivalent with that of human; a second, opposed chamber controls ambient conditions experienced by the garment. Temperature changes in both the interior and exterior sides of the chamber were measured. The cooling garment was tested at different conditions, transient and non-transient styles, with and without flowing fluid, and at various wattage densities (367.3 W/m2 and 576.8 W/m2). The designed testing chamber was validated for proper functionality. It was observed that, having a flowing fluid through the garment was more effective at higher body temperatures (∼45 °C) carrying away the excess amount of heat from the body.
Activity Coefficient of Different Salt Solutions for Reverse Electrodialysis Application
Authors: Emdadi Arash , Emdadi Simin , Zenouzi Mansour , Kowalski Gregory 
Published: January 2020

Abstract
Renewable energy sources and related conversion technologies are considered as the main solution for resolving the current issues related to global warming and environmental protection. Salinity gradient energy (SGE) is a source of renewable energy which can be defined as the Gibbs Energy of mixing when two solutions with different salinities mix together. The difference in the salinity of salt solutions is the main driving force of energy production by the SGE conversion technologies. One of the main conversion technologies of SGE is reverse electrodialysis (RED). In this technology the gradient between the concentrated and diluted salt solutions, the ions with a negative charge (anion) and positive charge (cation) pass through selective ion exchange membranes known as anion exchange membrane and cation exchange membrane. The driving force for diffusion of the ions is a function of the concentration gradient. The chemical potential of the salt solution is a function of the concentration of the salt solution and plays an important role in the Gibbs energy of mixing. The chemical potential of the salt solution is a thermodynamic property which is a function of the concentration and activity coefficient of the salt solution. The activity coefficient of the salt solution is a unique parameter which depends on the ionic strength of the solution and the type of ions in the salt solution. The salts with higher activity coefficient have a higher potential to be used in the SGE conversion process due to higher released Gibbs Energy during the mixing process. In this paper the thermodynamic model presented by Bromley [1], is used to calculate activity coefficient of 20 salts at different concentrations (0.01–6 molal). Two dimensionless parameters, Φ and Ψ, are defined as the ratio of activity coefficient and concentration between the concentrated and diluted solutions in 6 and 0.5 molal respectively. Using the dimensionless parameters, the theoretical open circuit voltage (OCV) of salt solutions in a RED cell is calculated. The salts are screened and ranked based on the activity coefficients and the theoretical open circuit voltage (OCV). The best salts are selected for use in a RED cell based on the activity coefficients and theoretical OCV. These alts could have potential for developing SGE storage systems in combination with renewable energy devices.
A Biphasic Viscoelastic Constitutive Model for Brain Tissue
Authors: Hosseini Farid Mohammad , Ramzanpour Mohammadreza , Ziejewski Mariusz , Karami Ghodrat 
Published: January 2020

Abstract
In this study, a rate-dependent biphasic model will be introduced to account for phenomenological behavior of brain tissue. For this purpose, a poro-hyper viscoelastic constitutive model is developed. The tissue is treated as a fluid-saturated porous medium, modeled as biphasic matter constituting of a solid matrix and interstitial liquids fill the porous spaces. The interactions between the two phases are assumed to be governed by Darcy’s law. This suggested model is calibrated with the experimental results of the bovine brain tissue, tested under high deformation rates (10, 100, 1000 mm/sec). The model will successfully take care of the detailed mechanical responses for solid and fluid phases, and their contributions to morphological behavior of this biological tissue. The material parameters of the model have been examined to agree well (R2 ≥ 0.96, where R is the coefficient of determination) with various deformation rates. In addition to representing the complete mechanical response and deformation of the solid phase, this biphasic model demonstrates the flow and diffusion of the liquid through the tissue networks.
Achieving Climate Control With Renewable Energy
Authors: Bower D. , Bielski M. , Mangan E. , Schell D. , Ghahremani K. , Gee D. 
Published: January 2020

Abstract
The purpose of this project was to explore the feasibility of powering a climate control system solely from a renewable energy source. The off-the-shelf cooling system components were taken from a ca. 1986 R-12 residential refrigerator and then reassembled onto a custom enclosure which was constructed to serve as the climate-controlled compartment. The enclosure design was purposefully simple: a rectangular shaped box constructed out of plywood and mounted on wheels together with a plexiglass door which was substituted for the front face. The overall design provided for enhanced mobility while also allowing for easy observation of the interior temperature via an interior-mounted, digital, commercial residential thermostat integrated into the control system. The system, nominally, is triggered by incident solar radiation; the initial set-point temperature was 21 °C. Compressor power was derived solely from renewable energy. Specifically, a pair of 100W 12V monocrystalline silicon photovoltaic solar panels was used to generate electricity which was subsequently stored in a deep-cycle battery. Under steady-state AC operation, the compressor draws approximately 2.1A. Due to system inefficiencies, the corresponding DC current draw is necessarily higher and approaches 22.3A. For a compressor duty cycle ranging from 50–100%, the current draw over a model 9 hr day would range from between 100.1–200.3 A-H. The lower limit is within the energy storage capacity for the fully-charged system, as currently designed.
Dynamic Behavior of Discretely Bonded Cross Tube With Functionally Graded Cellular Structure
Authors: Jenson Sean , Ohioma Eboreime , Ali Muhammad , Alam Khairul 
Published: January 2020

Abstract
Thin walled members are commonly used in vehicle’s frontal chassis to provide protection and damage attenuation to the passenger cabin in the case of an impact loading. These structural members undergo progressive deformation under axial loading. The type of deformation mode is critical as it defines the overall configuration of force-displacement curve. There are different types of deformation modes for cross tubes under axial loading. Likewise, the cellular structures exhibit distinct deformation modes under in-plane loading. The work presented here investigates the effects of bonding of cellular core structure on deformation modes of cross tubes under axial loading. The results show that partial, or discrete bonding of cellular core with the tube has significant effect on progressive deformation of tubes and therefore, presents an opportunity to re-configure force-displacement curve for improved protection of automobile structures under impact loading.
3D Flow Simulations of Fan Enclosure Concepts for a Novel Heat and Moisture Exchanger
Authors: Costa-Greger Justin , Wang Hailei 
Published: January 2020

Abstract
As the single most energy-intensive system in buildings, heating, ventilation, and air conditioning (HVAC) units consume on average 40 percent of total building energy in the United States. For regions with hot and humid climates, building loads due to HVAC systems increase significantly as a large portion of the electric load is used to condense moisture in the air. To improve building energy efficiency, energy recovery ventilators (ERV) have played an increasingly important role. They essentially rely on a membrane-based heat and moisture exchanger (HME) to reduce the latent heat load. A novel energy recovery ventilator was recently developed to improve ERV performance and advance building design. It combines a HME, two impeller fans and air enclosures into a single unit. In this work, two enclosure concepts were investigated, both of which have each fan placed in the enclosure of the HME inlet. Computational fluid dynamics (CFD) was used to model air flow inside the enclosure. The simulation results provided important information on the distribution of air flow across the inlets of the HME, which is expected to improve the enclosure design to meet the ERV performance target. A grid refinement study was conducted which showed that the medium grid refinement produced results within 3% of the asymptotic solution and had significantly less computation time compared to the fine grid. The first concept had a velocity uniformity of 86% at the HME inlet, while the second concept showed undesirable, reversed flow in the upper channels. The study indicates placing the fan at the outlet of the HME, rather than the inlet, would lead to more uniform air flow into the HME.
Period-1 Motions to Chaos With Varying Excitation Frequency in a Parametrically Driven Pendulum
Authors: Guo Yu , Luo Albert C. J. 
Published: January 2020

Abstract
In this paper, with varying excitation frequency, period-1 motions to chaos in a parametrically driven pendulum are presented through period-1 to period-4 motions. Using the implicit discrete maps of the corresponding differential equations, discrete mapping structures are developed for different periodic motions, and the corresponding nonlinear algebraic equations of such mapping structures are solved for analytical predictions of bifurcation trees of periodic motions. Both period-1 static points to period-2 motions and period-1 motions to period-4 motions are illustrated. The corresponding stability and bifurcations are studied. Finally, numerical illustrations of various periodic motions on the bifurcation trees are presented in verification of the analytical prediction.
Effects of Axial Compression Load, Borehole Clearance, and Contact Force Using Axial-Lateral Fluid Coupled Drill String Vibration Model
Authors: Chodankar Abhijeet D. , Seibi Abdennour 
Published: January 2020

Abstract
Drill string vibrations have resulted in an increase in non-productive time, drilling cost, and a need for drill string system optimization in the oil and gas industry. Higher vibrations can lead to washout, blow-out phenomena, and a rapid wear and tear of drill string components. An in-depth understanding of the root causes of the drill string vibrations is of utmost importance. The effects of mass imbalance, bottom hole assembly (BHA) design, weight on bit, hole angle, hole size, RPM, drilling fluid viscosity, bit and formation type on drill string vibrations have been studied in the past. The main objective of this paper is to propose a novel drill string vibration model taking into consideration the effects of axial compression load, borehole clearance, and contact force in conjunction with Euler-Bernoulli, Rayleigh, and Shear beam theories. The proposed model studies the effects of axial compression load, borehole clearance, and stiffness on the natural frequency and frequency response of drill string. The drill string is considered as a cantilever beam with a circular cross-sectional area in a horizontal drilling condition, while the fluid (water) around it is considered as a spring and dashpot model. Drill string vibrations are modeled based on a distributed system approach. The forces acting on the cantilever beam element are axial compression load, shear forces, bending moment, fluid stiffness and damping forces. A fourth order partial differential equation is derived and the solution is obtained based on the assumed modes approach to obtain the characteristic equation and mode shapes. Natural frequency is determined using the eigen values obtained from the characteristic equation. The orthogonality conditions are further derived to decouple the derived equation. The drill string is initially assumed unbounded, hence the amount of contact force required to restrict the drill string within the borehole is determined. An iterative process is employed to restrict the drill string deflection within the borehole with a corresponding increase in the stiffness of the drill string system. This will help in determining the experienced down hole contact forces and the stiffness requirements of the bottom hole assembly. Dominant frequencies are identified, compared with field results, further guiding the operator to avoid rotating the drill string at particular frequencies. A detailed study of the effects of contact forces, borehole clearances, and axial compression load will provide comprehensive guidelines in BHA design of drill string assembly. To conclude, this paper proposed an accurate model to identify dominant frequencies and provides a thorough BHA design guidelines for the drill string design manufacturers and field operators leading to a reduction in drilling cost and unproductive time, and environmentally friendly drilling operations.
A Magnetic and Shape Memory Alloy Actuated Gripper for Surgical Applications
Authors: Cooke Ian , DeClerck Brendon , Hallett Jesse , Miller Tyler , Mitchell Alexis , Rashidi Reza 
Published: January 2020

Abstract
This paper presents the development of a novel shape memory alloy (SMA) actuated gripper for use in the biomedical applications. The use of SMA in surgical forceps can allow a surgical robot to accurately and repeatedly apply a force and grip small objects or perform minor surgeries that are less invasive and allow for quicker recovery times. Current designs of thermally actuated grippers use SMAs as the gripping parts, which limits their application due to the transfer of heat to the object being gripped. The design of the gripper illustrated in this paper isolates the SMA coil from the gripping jaws to maintain a constant surface temperature at the gripping end and prevent thermal contamination of soft tissues. Isolating the SMA from the grippers also simplifies automated surgical robots by centralizing all heating elements. A magnetic field exerted between a pair of permanent magnets is used to restore the SMA coil upon cooling. The gripper housing and jaws were fabricated using a 3-D printer to allow for modeling of small features with little down time. A Nitinol SMA wire with a transition temperature of 45°C was wrapped into a 2.5mm diameter coil and heat treated to set the predefined shape. The SMA coil and other parts were assembled to form the gripper. The gripper was successfully tested using an Interlink Electronics Force Sensor and data acquisition card (DAQ), and the forces between the gripper jaws as well as the response time to close and open the jaws were recorded. The gripper produced a force of 0.9N when reaching the transition temperature. The response time for the gripper to close and open the jaws was measured to be approximately 0.16 s and 0.12 s, respectively. It was found that the magnetic field had a faster actuation on the coil than the shape memory alloy force during opening and closing jaws.
Fast Colored Point Feature Histograms Global Registration
Authors: Liu Xingjie , Wang Guolei , Zhang Simin , Chen Ken 
Published: January 2020

Abstract
We present an algorithm for fast global registration on colored dense point clouds. We combine CIELAB color information with fast point feature histograms for better correspondence and use color difference score to delete wrong pairs. The optimization is based on a method from Intel Labs that does not update correspondence or query closest-point during optimization. Experiments are taken on real partial overlapped data obtained from Kinect V2. The algorithm achieves a precise alignment with no initialization and cost little time. It can be extended to real-time robotics application for further study.
Research on Dynamic Characteristics of Complex Gap Combined Rotor of Large Generator
Authors: Li Yuan , Li Chen , Li Hui , Qi Shemiao , Liu Yi , Liu Heng 
Published: January 2020

Abstract
In this paper, a large generator rotor with complex clearance is taken as the research object, and the dynamic analysis model of this rotor is established. This study focuses on the prediction of the contact stiffness of its widely distributed contact interface and the cross-scale interstitial stiffness of the rotor. Furthermore, the dynamic characteristics of torsional under typical rotor state are studied, and the combined rotor of large generator is tested and verified. Through theoretical analysis and experimental study, the influence mechanism of clearance on dynamic characteristics of large generator rotor is revealed.
Mutual Information-Based Sensing Optimization for In-Process Quality Inspection of Multi-Station Assembly Processes
Authors: Liu Yinhua , Hu Xiaolei , Yue Xiaowei 
Published: January 2020

Abstract
To increase productivity and satisfy diverse customer demands, many assembly processes have been converted from single-model lines to flexible assembly lines. Conventional fixed-location sensing approaches cannot be used to inspect a broad mixture of different quality features for multiple product models effectively. The in-process dimensional quality inspection systems with robot-mounted optical gauging have been becoming increasingly popular for flexible multi-station assembly processes. These new systems enable more powerful quality inspection for various designs and provide more flexibility for dimensional monitoring and diagnosis. Meanwhile, they bring new challenges to sensing efficacy and efficiency because in-process cycle time for quality inspection is limited in dozens of seconds. This paper focuses on sensing optimization problem for multi-station assembly processes. We propose a novel data-driven sensing optimization approach based on in situ quality inspection data, for the purpose of improving variation detection of subsequent assemblies. Based on the dimensional inspection datasets, a mutual information-based model is proposed to measure the correlation relationships among components, intermediate subassemblies and final products. An objective function considering the maximum relevance and the minimum redundancy is developed, and then an optimization algorithm is applied to obtain the optimal sensors. A case study in auto body assembly process is used to show the performance of the proposed method.