bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rate Dependent Reinforcement of Liquid Nanofoam on Thin-Walled Tubes
Authors: Li Mingzhe , He Bang , Barbat Saeed , Gu Sihao , Lu Weiyi 
Published: January 2018

Thin-walled metal tubes have been widely used as energy absorbers to mitigate adverse effects of impact and protect structures and facilities. However, once the initial buckling stress of the tube is reached, the post-buckling plateau of the tube has a much reduced average stress which determines the energy absorption efficiency of the empty tube. As a result, the real energy absorption efficiency of the thin-walled tube is much lower than the theoretical limit which is proportional to the value of initial buckling stress. We hypothesize that by filling thin-walled tubes with the novel liquid nanofoam (LN), (i) the energy absorption efficiency of the hybrid structure can reach the theoretical limit, and (ii) the main working mechanism is the effect of solid-liquid interaction on tube buckling.
To test these hypotheses, we have characterized the energy absorption efficiency of LN filled steel tubes by using quasi-static compression tests and dynamic impacts. The quasi-static behavior of LN filled tubes is characterized by an Instron 5982 universal tester. Results show that the gravimetric and volumetric energy absorption efficiencies of LN filled steel tubes are 20% and 220% higher than the values of empty tubes, respectively. This is due to the changed buckling mode and the promoted post-buckling stress of the hybrid structure by the highly compressible LN. The dynamic behavior of LN filled tubes is characterized by a dynamic impact test (∼3 m/s) with a lab-customized drop tower apparatus. It is found that both the gravimetric and volumetric energy absorption efficiencies of LN filled tubes are further increased by 16%. The strain rate dependent behavior of LN filled tubes must be attributed to the solid-liquid interaction between the LN and the steel tube wall, which is further verified by comparing the mechanical behaviors of LN filled tubes with solid foams filled tubes.
Our experimental results have demonstrated that the energy absorption efficiency of thin-walled tubes are significantly improved by the LN filler especially at higher strain rates. This hybrid structure may have a potential for future use in the design of light-weight and small scale cellular structures for vehicle safety and crashworthiness.
Structural Acoustic Physics Based Modeling of Curved Composite Shells
Authors: Hesse Rachel E. , Hulton Andrew W. 
Published: January 2018

Understanding sound wave propagation through a curved shell geometry is essential for a wide variety of underwater applications. The objective of this study was to use physics-based modeling (PBM) to investigate wave propagations through curved shells that are subjected to acoustic excitation. An improved understanding of the absorption and reflection properties of materials, such as fiber-reinforced polymer (FRP) composites, will enhance the design methods for a variety of Navy products such as acoustic sensors, acoustic windows, and unmanned underwater vehicles.
The research documented in this report investigates the reflection and transmission coefficients of both flat plates and curved shells for steel and composite materials. Results show that the finite element computational models accurately match analytical calculations, and that the composite material studied in this report has more desirable reflection and absorption properties than steel for typical Navy applications. This research also explores the use of coupled Eulerian-Lagrangian (CEL) and smoothed particle hydrodynamics (SPH) modeling approaches in place of the current, traditional Lagrangian approach. Unfortunately, these approaches were found to be unsuitable for the type of acoustic analyses performed throughout this research. However, results from the traditional Lagrangian approach confirmed the validity of current modeling techniques and allowed for the study of the acoustic properties of various geometries and materials. This can help drive future research on composite material applications and enhance design methods for future Navy products.
A Wearable Device for Assisting Persons With Vision Impairment
Authors: Trivedi Urvish , McDonnough Jonielle , Shamsi Muhaimen , Ochoa Andrez Izurieta , Braynen Alec , Krukauskas Cody , Alqasemi Redwan , Dubey Rajiv 
Published: January 2018

Detecting humans and objects during walking has been a very difficult problem for people with visual impairment. To safely avoid collision with any object or human and to navigate from one location to another, it is significant to know how far and what kind of obstacle the user is facing. In recent years, many researches have shown that providing different vibration stimulation can be very useful to convey important information to the user. In this paper, we present our stereovision system with high definition camera to detect and identify humans and obstacles in real time and compare it with a modified version of existing wearable haptic belt that uses high-performance Ultrasonic sensors. The aim of this paper is to present the practicability of stereovision system over cane and assistive technology such as vibrotactile belt.
The study is based on two assistive technologies. The first one consists of the vibrotactile belt connected to ultrasonic sensors and an accelerometer which returns user movement & speed information to the microcontroller. The microcontroller initiates expressive vibrotactile stimulation based on sensor data. Data gathered from this technology will be used as the baseline data for comparison with our stereovision system. Second, we present a novel approach to detect the type of obstacle using object recognition algorithm and the best approach to avoid it using the stereovision feedback. Data gathered from this technology with be comparted against the baseline data from the vibrotactile belt. In addition, we present the results of the comparative study which shows that stereovision system has plethora of advantages over vibrotactile belt.
Design of Intelligent Control for an Air Conditioning System Solar Using an Absorption Refrigeration Cycle
Authors: Cardona-Gil Jorge A. , Osorio Marisol 
Published: January 2018

Among different strategies available technologically to reduce energy consumption and environmental impact in buildings, there is the use of new thermal-operated air conditioning systems. An available alternative is absorption refrigeration systems, which can operate with renewable energy sources such as solar energy, and use environmentally friendly refrigerant substances.
In Colombia, this type of systems has not been investigated thoroughly nor have carried out developments, because the field of solar energy is emphasized in the use of thermal energy, to be used on a refrigeration cycle that allows to condition an environment of a determined compound, and besides that, this air conditioning going to achieve through intelligent control, it has not been subject of considerable advances, neither in the part of applied research, nor its implementation. According to this, the idea is to use developments of these systems that have been simulated and implemented in other countries, including Spain, for the start in the UPB with research, development and implementation of those after making a literature review about the systems.
To develop the aforementioned system, a comprehensive literature review of the technologies has been made to be implemented in terms of automation and control. A simulation in the TRNSYS software of the system to be implemented in a building on the campus of the UPB, which requires air conditioning for the comfort of the people who inhabit, is eveloped. The system will be regulated by a controle system that receives information from various parts of the plant with temperature and flow sensors. To carry out the control of this system, classical control techniques are going to be used for some water systems that constitute the demonstrative installation, but for the part of chilled water and air conditioning, intelligent control techniques will be handled, which allows to meet the needs of the air conditioning system that is intended to be implement, as this part is quite complex for the management of different variables. This system will operate automatically acting on valves, pumps, fans, fan-coil and/or mats of water (they act as radiant walls) for correct operation by previously established set points [1].
Measuring Displacement Within a Transfemoral Socket Using Marker-Based Optical Tracking System: Static Tests
Authors: Salazar-Salgado Sara , Rendón-Vélez Elizabeth 
Published: January 2018

In lower limb amputees, the comfort and fit of the prosthesis determine whether the user wears or not the prosthesis, fact on which a successful rehabilitation depends. The prosthetic fit is highly related with the relative motion between the socket and the residual limb (i.e., displacement). Displacement has been measured in static and dynamic position and between several surfaces such as skin-socket, liner-socket, bone-socket using various instruments. Marker-based optical tracking system is one of the most recent instruments used for measuring displacement between the socket and the residual limb that solves many of the constraints faced by other measurement instruments. Two options have been reported on the literature for using this instrument: transparent test socket with 2D marker and definite socket with cavities and 3D marker, both facing different limitations. The objective of this study is to evaluate these two options using Marker-based optical tracking system in order to give recommendations and contribute to the use of this method on future research.
Two sockets were used for the study: a transparent socket and a definite socket with and without cavities. Six trials were performed using both sockets with three types of markers located inside the socket: 2D circular, 3D hemisphere and 3D sphere. VICON motion capture system was used to detect the visibility of the markers at knee flexion angles (0° to 30°).
The results showed that all markers were visible from 15° to 30° knee flexion in all trials. The 2D marker presented difficulty of detection on knee angles from 0° to 10°, especially on the final socket without cavities. 3D hemisphere marker was seen almost all along the knee angles. 3D-sphere marker was visible in all positions, but the relatively large size of these markers may not be adequate to measure displacement.
Using the definite socket with the 2D circular and 3D hemisphere markers could be a good option to measure displacement between the residual limb and socket. Using this socket will be closer to reality than doing it on the transparent one. Additionally, the size of the 3D-hemisphere is relatively small, it may not drastically change the behavior between surfaces and as it is a 3D marker it can be better seen by the cameras.
Further tests should be done with patients walking all along the path in order to assess if the markers visibility is the same on static and dynamic trials.
Creep Modeling of Polyvinyl Chloride Bolted Flange Joints
Authors: Zhao Zijian , Kanthabhabha Jeya Rahul Palaniappan , Bouzid Abdel-Hakim 
Published: January 2018

Alike other polymer material, PolyVinyl Chloride (PVC) shows a clear creep behavior, the rate of which is influenced by temperature, load and time. Polyvinyl chloride bolted flange joints undergo relaxation under compression for which the material creep properties are different than those under tension. Since the sealing capacity of a flanged gasketed joint is impacted by the amount of relaxation that takes place, it is important to properly address and predict the relaxation behavior due to flange creep under compression and reduce the chances of leakage failure of PVC flange joints.
The main objective is study the creep behavior of PVC flanges under the influence of normal operating conditions. This is achieved by developing a PVC creep model based on creep test data under various compressive load, temperature and time. A simulation of a PVC flange relaxation behavior bot numerically and experimentally is conducted on an NPS 3 class 150 bolted flange joint of dissimilar materials one made of PVC material and the other one by steel SA105. The study also provides a clear picture on how the compression creep data on Ring specimen may be utilized for predicating the flange performance under various operating temperatures with time.
Thermal Stress Analysis and Determination of Stitching Pattern Effect on Aerodynamics of a Soccer Ball
Authors: Rahman Mosfequr , Salekeen Sirajus , Holland Asher , Nixon Todd , Kight Hunter , Stevens Jared , Altieri Matt , Adkins John 
Published: January 2018

Soccer is played all over the world in a wide range of temperature environments. One of the objectives of this numerical study is to determine whether temperature has an effect on the body and performance of a soccer ball. Another object is to aerodynamically determine the effect of stitching pattern of the ball on its flight.
The soccer ball was modeled in ANSYS Workbench and tested with thermal-stress analysis tool at nominal temperatures of 0°C, 20°C, and 40°C. The maximum deformation of a soccer ball at normal condition occurred at 40°C which was 1.0503 cm as compared to the 0.9587 cm at 0°C. This normal condition means when the ball is subjected to an internal pressure of 80 kPa which is the standard inflation pressure. When an external 2700 Pa pressure was applied to the soccer ball which is the average force of a kick, the maximum deformation again occurred at 40°C which was 5.2289 cm as compared to the 4.7599 cm at 0°C. Therefore, the stiffness of the ball materials decreased as the temperature increased. This reveals that the ball delivers a greater force at the surface of contact when the temperature drops.
The second part of this study as mentioned earlier was to study the aerodynamic effect on a soccer ball traveling through the air at a certain speed. Two types of soccer ball were analyzed for this reason to see which of the two flew better in the air. The two types were a regular FIFA soccer ball with stitching and a normal soccer ball without stitching. Two tests were performed on both types of the soccer ball. These tests were done using ANSYS FLUENT and the sought out output parameters were velocity, pressure, Reynolds Number and drag force. In the first test the soccer balls were rotating in the air and in the second test the soccer balls were not rotating in the air. For the first test, the ball without stitching had the higher velocity, Reynolds Number, and drag force, which were 126.2 m/s, 2.420 × 106, and 122.6 N respectively. This means the ball without stitching is experiencing a more random turbulent flow and is being pulled more into the direction of the drag force. This happens because the soccer ball without stitching will rotate faster and won’t have stitching patterns to create friction that will slow down the flow. For the second test, the ball with stitching had the higher velocity, Reynolds Number and drag force which were 42.22 m/s, 8.095 × 105, and 16.81 N respectively. This means the soccer ball with stitching is experiencing a random turbulent flow and is being pulled in the direction of the drag force because the stitching patterns are not in complete contact with the air to create friction.
Finite Element Numerical Analysis of Deflection Behavior in Photostrictive Actuators on Overhanging and Propped Cantilever Beam Models
Authors: Rahman Mosfequr , Taylor Hunter , Rahman Abdur , Molina Gustavo 
Published: January 2018

Photostriction is best defined as the generation of strain in a material via light irradiation. In essence the photostrictive effect is a result of the combination of the photovoltaic and converse-piezoelectric effects. When light comes into contact with the surface of a photostrictive material, the photovoltaic effect causes the generation of a large amount of voltage. The converse-piezoelectric effect in turn converts the produced voltage into mechanical motion, which induces strain in the material. Photostrictive ceramics are considered excellent materials for use in advanced actuation technologies. This is due to their ability to be activated through irradiation of light, which provides advantages over conventional actuators, which include remote control capability, freedom from physical actuation, and reduced electromagnetic (EM) interference. Conversely conventional actuators require hard wired connections to transmit control signals that can produce EM interference, creating signal noise. Photostrictive ceramics have also found use in the manufacturing of micro electromechanical systems, also known as MEMS technology, mostly due to their wireless capabilities.
Photostrictive materials are ferroelectric ceramics that exhibit the photostrictive effect. PLZT, (Pb, La)(Zr, Ti) O3 ceramics doped with WO3, exhibit large photostriction deflection under uniform illumination of light, and have potential uses in numerous micro-electro-mechanical systems as a result of this property. The objective of this research is to numerically investigate the effect of light intensity on transverse deflection of an overhanging beam model, and to assess the effect actuator size has on deflection for a propped cantilever beam model using finite element analysis technique. The current research results is then compared with the validated results of other studies on PLZT using other model types.
From this numerical investigation it has been observed that for an overhanging beam model, the transverse deflection of PLZT actuators has a direct relationship to the intensity of the light applied in order to induce photostriction. It has also been observed that this relationship applies over a large range of light intensity upwards of 4000 mW/cm2, boosting maximum deflection into the micron range (1E−6 – 1E−7 m). With regard to the propped cantilever beam model, it has been observed that incomplete PLZT coverage of the cantilever beam portion of the model caused upwards transverse deflection. However, as the amount of PLZT actuator was increased, the deflection behavior exponentially approached negative values. By comparing these results with similar studies on alternate model types, it was confirmed that for beams deposited with PLZT actuator, light intensity and actuator size and surface coverage will affect the transverse deflection of the beam in the same manner regardless of the beam model.
A Proposal of a New Product Development Methodology: The CS-TG Method “Causality Search T-Method With Graphical Modeling”
Authors: Hosokawa Tetsuo , Matsushita Makoto 
Published: January 2018

In 2015, our team proposed a new development methodology, which we named the Causality Search T-Method (CS-T Method). This method makes it possible to solve the intrinsic limitation of target characteristics-based Parameter Design. Specifically, target characteristics-based Parameter Design is in essence a black-box method, which makes it difficult to obtain information on the mechanisms of quality improvement. The first aim of the CS-T Method is to determine the causal relationships between the target characteristics and multiple candidate “Effective-Explanation Factors” (EEF) such as physical properties, sensing data. The second aim is to improve the efficiency. Through a case study, our team demonstrated that it is possible to determine the causal relationships with significantly fewer experiments.
We propose an extension of the CS-T Method, one which incorporates Graphical Modeling (GM), which we have named the CS-TG Method. Unlike conventional GM, which performs the analysis on the entire pool of candidate EEFs, CS-TG method allows the GM analysis to focus on the limited set of factors that were identified by the original CS-T as having a causal relationship with the target characteristics. In doing so, the new method is able to establish the causal relationships between each of the individual EEFs with fewer experiments.
Enhancing prescribing of guideline-recommended medications for ischaemic heart diseases: a systematic review and meta-analysis of interventions targeted at healthcare professionals
Authors: Nguyen Thang , Nguyen Hoa Q , Widyakusuma Niken N , Nguyen Thao H , Pham Tam T , Taxis Katja 
Published: January 2018

ObjectivesIschaemic heart diseases (IHDs) are a leading cause of death worldwide. Although prescribing according to guidelines improves health outcomes, it remains suboptimal. We determined whether interventions targeted at healthcare professionals are effective to enhance prescribing and health outcomes in patients with IHDs.MethodsWe systematically searched PubMed and EMBASE for studies published between 1 January 2000 and 31 August 2017. We included original studies of interventions targeted at healthcare professionals to enhance prescribing guideline-recommended medications for IHDs. We only included randomised controlled trials (RCTs). Main outcomes were the proportion of eligible patients receiving guideline-recommended medications, the proportion of patients achieving target blood pressure and target low-density lipoprotein-cholesterol (LDL-C)/cholesterol level and mortality rate. Meta-analyses were performed using the inverse-variance method and the random effects model. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach.ResultsWe included 13 studies, 4 RCTs (1869 patients) and 9 cluster RCTs (15 224 patients). 11 out of 13 studies were performed in North America and Europe. Interventions were of organisational or professional nature. The interventions significantly enhanced prescribing of statins/lipid-lowering agents (OR 1.23; 95% CI 1.07 to 1.42, P=0.004), but not other medications (aspirin/antiplatelet agents, beta-blockers, ACE inhibitors/angiotensin II receptor blockers and the composite of medications). There was no significant association between the interventions and improved health outcomes (target LDL-C and mortality) except for target blood pressure (OR 1.46; 95% CI 1.11 to 1.93; P=0.008). The evidence was of moderate or high quality for all outcomes.ConclusionsOrganisational and professional interventions improved prescribing of statins/lipid-lowering agents and target blood pressure in patients with IHDs but there was little evidence of change in other outcomes.PROSPERO registration numberCRD42016039188.