bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Residual Dentition on the Dynamic Adjustment of Wear Facet Morphology on a Mandibular First Molar Crown
Authors: Li Linlin , Chen Hu , Li Weiwei , Wang Yong , Sun Yuchun
Published: November 2020

Purpose

To evaluate the effect of different residual dentitions on the dynamic adjustment of wear facet morphology on a single mandibular first molar crown with a virtual articulator.

Materials and Methods

Gypsum casts (N = 12) of natural full dentitions were mounted on an articulator and scanned. The mandibular right first molar (#46) was prepared and a copy of the tooth before it was prepared and used to design the crown. The wear facets on the original #46 were selected and elevated by 0.3 mm in the occlusal direction to generate high points. The #46 with high points was segmented to create a digital wax pattern. Then different teeth were virtually removed to generate 4 types of residual dentitions: Type I (no teeth), Type II (adjacent teeth), Type III (ipsilateral posterior teeth and canine), and Type IV (all teeth). The crowns were adjusted dynamically with different residual teeth to guide mandibular movement of the virtual articulator. Three‐dimensional deviations, negative and positive volumes between crowns and wear facets on the original #46 were analyzed. The Kruskal‐Wallis test was used to analyze the results.

Results

The mean deviation values and positive volumes decreased with the decrease in residual teeth, and the negative volumes showed an opposite trend. The mean deviation values, root mean square, and positive volumes were not significantly different. The negative volume of the crowns of Type I was different from that of Type IV (p = 0.031).

Conclusions

Residual dentition affects the dynamic adjustment of wear facet morphology. When there are insufficient residual teeth, mandibular movements should be accurately measured.
Success rates of pediatric dental referrals made by public health dental hygiene practitioners
Authors: Burgette Jacqueline M. , Mestre Yanelis , Martin Brian , Ray Kristin N. , Stiles Amy , Hoberman Alejandro
Published: November 2020

Objectives

The purpose of this study was to evaluate whether Public Health Dental Hygiene Practitioner (PHDHP) referrals to pediatric dentists were more successful for children younger than 3 years old and those with dental caries.

Methods

We reviewed the electronic health records of 1,450 children, age 1 to 12 years, who completed a dental visit with a PHDHP in 2017 at UPMC Children's Hospital of Pittsburgh's (CHP) Primary Care Center. We tracked whether children who visited the onsite PHDHP accepted a referral to CHP pediatric dentists, and if so, whether they successfully completed the referral.

Results

Of the 1,450 children who visited the PHDHP, 67 percent (n = 973) accepted a referral to CHP pediatric dentists. Of these referrals, 32 percent (312/973) were successfully fulfilled. The proportions of accepted and fulfilled referrals were significantly higher for children older than 3 years old and those with dental caries. After controlling for child age, gender, and insurance status, children with dental caries had 5.7 times greater odds of successful referral from the PHDHP to the pediatric dentist compared to children without dental caries (95 percent CI 4.1–7.9).

Conclusions

PHDHPs were more successful referring children older than 3 years old and those with dental caries to pediatric dentists. PHDHPs are allied dental health professionals that can be effective at referring children to pediatric dentists when they have dental caries. Additional strategies are needed to enhance the success rate of dental referrals for young children under 3 years old.
Hippocampal modulation of auditory processing in epilepsy
Authors: Shigeto Hiroshi
Published: November 2020

The hippocampus is anatomically and functionally connected to other brain regions　tightly. Especially in the field of memory research, it has become clear that the connections between the cerebral cortex, thalamus, and hippocampus are regulated via slow‐wave rhythms and high‐frequency oscillation. In addition, the hippocampus, as a limbic system, is more excitable to inputs than the cerebral cortex and has a reverberant circuit structure, which induces long‐lasting neural activity. Because of such characteristics of the hippocampus, it is treated as a key structure in epilepsy. Auditory processing has been shown to be affected by hippocampal activity, and impaired auditory processing function in patients with medial temporal lobe epilepsy has been elucidated using techniques such as cognitive behavior tests and electrophysiological recordings. We recorded the auditory‐induced magnetoencephalography of patients with refractory medial temporal lobe epilepsy and examined which hemisphere was more affected. In contrast to previous language studies, we only used simple tone stimulation, by which we could obtain the laterality information regarding epileptic activity and left‐right difference. In this article, we reviewed the effects of hippocampal activity on brain function, including the findings of our auditory stimulus‐induced magnetic field recordings of medial temporal lobe epilepsy.
Instructed versus spontaneous entrainment of running cadence to music tempo
Authors: Van Dyck Edith , Buhmann Jeska , Lorenzoni Valerio
Published: November 2020

Matching exercise behavior to musical beats has been shown to favorably affect repetitive endurance tasks. In this study, our aim was to explore the role of spontaneous versus instructed entrainment, focusing on self‐paced exercise of healthy, recreational runners. For three 4‐min running tasks, 33 recreational participants were either running in silence or with music; when running with music, either no instructions were given to entrain to the music, or participants were instructed to match their running cadence with the tempo of the music. The results indicated that less entrainment occurred when no instruction to match the exercise with the musical tempo was provided. In addition, similar to the condition without music, lower speeds and shorter step lengths were observed when runners were instructed to match their running behavior to the musical tempo when compared with the condition without such instruction. Our findings demonstrate the impact of instruction on running performance and stress the importance of intention to entrain running behavior to musical beats.
Nursing strategies for environmental justice: A scoping review
Authors: LeClair Jessica , Watts Theresa , Zahner Susan
Published: November 2020

Objective

To describe types of strategic actions nurses take to promote environmental justice (EJ) through research, education, advocacy, and practice (REAP) reported in peer‐reviewed literature.

Design and Sample

A scoping review of literature was conducted that described EJ nursing strategies and included nurses listed as authors, subjects, partners, or organizational members. The sample consisted of 35 articles, representing 24 primary research studies and 11 nonresearch articles. Data were separately analyzed by research and nonresearch articles for a clearer understanding of evidence‐based strategies within domains of REAP.

Results

Articles in the sample highlighted the importance of authentic community partnership and represented diversity of nursing strategies that addressed a range of environmental exposures and subsequent health and racial inequities. Climate justice, a concept that emerged from the EJ movement and intersects with planetary health, is a recent focus in professional nursing.

Conclusions

This scoping review establishes an understanding of the extent of nursing knowledge and research in EJ and lays the groundwork for further research on effective EJ nursing strategies. Community‐Based Participatory Research/Participatory Action Research methods are fundamental for EJ research, and further theoretical development is needed to guide evaluation of EJ nursing strategies for education, advocacy, and practice.
Healthcare in the new age of transparency
Authors: DesRoches Catherine M.
Published: November 2020

Debates around access to and ownership of an individual's digital information have taken center stage in health care. A decade ago, the idea of offering patients ready access to their clinical notes was a fringe idea. Today, information transparency in health care is a pressing legislative and regulatory issue in the United States and elsewhere. The 21st Century Cures Act of 2016 requires that clinicians and health care organizations give patients electronic access to the information in their electronic medical records. Rules to enact this legislative priority by the Office of the National Coordinator for Health Information Technology and the Centers for Medicare and Medicaid Services substantially expanded the types of information that must be easily accessible to patients and exchanged among clinicians in electronic form. A growing body of research supports the notion that sharing transparent medical records, including clinical notes with patients, can help to strengthen communication, trust in clinicians, and patient engagement. Patients receiving dialysis may receive particular benefits from this greater transparency due to their increased risk for fragmented care. In the paper, we review the decade of research focused on the effects of sharing clinical notes with patients and the implications for improved engagement and care.
The reliability and success of peritoneal dialysis during the COVID‐19 pandemic
Authors: Yeter Hasan H. , Gok Oguz Ebru , Akcay Omer F. , Karaer Refika , Yasar Emre , Duranay Murat , Ayli Mehmet D. , Guz Galip
Published: November 2020

We evaluated the symptoms, changes in laboratory findings during the novel coronavirus disease (COVID‐19) pandemic, and the effect of depression in patients with peritoneal dialysis (PD). This is an observational and cross‐sectional study. All patients were asked to fill the clinical assessment form and Beck depression and anxiety inventory. Also, the last two laboratory evaluations during this period were examined. A total of 123 patients performing PD were included. None of the patients were diagnosed with COVID‐19. In the total study population, parathyroid hormone (PTH), serum albumin, phosphorus and ferritin levels significantly elevated at the end of 97 ± 31 days. PTH and phosphorus levels remained stable in remote monitoring automated PD (RM‐APD) group (p = 0.4 and p = 0.5), they tended to increase in continuous ambulatory PD group and significantly increased in automated PD group (p = 0.09 and p = 0.01 for PTH and p = 0.06 and p = 0.001 for phosphorus, respectively). Moderate to severe depression was associated with dyspnoea, weight gain more than 5 kg, fatigue, palpitation and increased anxiety. PD is a reliable and successful form of dialysis and can be safely administered even if hospital access is restricted. Also, RM‐APD may be a better choice because of providing more stable bone‐mineral metabolism. Moreover, evaluating depression and anxiety is essential for the accurate clinical assessment.
Latin Dominant Participles: Dynamics of Derivation and Interpretation*
Authors: Jakielaszek Jarosław
Published: November 2020

The Latin dominant participle construction poses a challenge for syntactic and semantic analysis due to its exhibiting an apparent syntax–semantics mismatch. Its syntactic behaviour and distribution is determined by a nominal phrase fronted to its left periphery, yet interpretive properties indicate that it is a propositional structure subject to nominalization. With the Minimalist Program of Chomsky (1993, 1995) as the framework of analysis, it is argued that taking into account the dynamics of syntactic operations as envisaged in Chomsky (2013b, 2015) and related work is sufficient to provide an account of syntactic and semantic properties of the dominant participle construction without positing construction–specific rules or covert syntactic nominalizers.
Design and evaluation of advanced automatic control strategies in a total nitrogen removal activated sludge plant
Authors: Tejaswini E. S. S. , Uday Bhaskar Babu G. , Seshagiri Rao A.
Published: November 2020

Advanced control strategies are designed for an activated sludge‐based wastewater treatment plant (WWTP) consisting of two anoxic, three aerobic reactors and secondary settler by considering the influent data from an existing WWTP. Four different control strategies (PI/FPI/MPC/FLC) are designed and a systematic procedure is developed to implement these control strategies. The plant performance is evaluated using operational cost index (OCI) and effluent quality index (EQI) and the controller performance is assessed based on integral of squared error. The EQI and OCI for open loop are reported as 4469 and 12 743 respectively. Whereas, when advanced controllers are implemented, a significant decrease of 19.89% and 5.24% in EQI and OCI is observed for MPC and a decrease of 20.9% and 4.63% in EQI and OCI is observed for fuzzy controller. The outcomes of this research help the wastewater utilities to adopt advanced control strategies for enhanced operation and decision‐making.
Composite Proton Electrolyte Membranes C Poly Ether-Ether Ketone (SPEEK) at Various Amount of Mesoporous Phosphotungstic Acid (mPTA) for Hydrogen Fuel Cell Application
Authors: Mehanathan Shaymala , Mohamed Hilmi , Jaafar Juhana , Ilbeygi Hamid
Published: November 2020

Polymer electrolyte membrane fuel cells (PEMFC), also known as proton exchange membrane fuel cells utilise polymer electrolyte membranes (PEMs) to conduct protons for ion-exchange purposes. Nafion is a common polymeric material to be used as PEM for fuel cells. However, Nafion has major weaknesses such as low proton conductivity under anhydrous conditions at elevated temperatures due to water evaporation and continuous need for water management, low tolerance for fuel impurities and high cost. This study fabricates a newly composite PEM by blending SPEEK and mesoporous phosphotungstic acid (mPTA) at various loading in order to obtain the most favourable PEMFC power output. SP/2.0mPTA membrane has shown outstanding properties in terms of dense structure, 35.75% of water uptake and expected an elemental mapping of 76.20% Tungsten and 23.80% Phosphorus. Even with a lower proton conductivity of 3.502 mScm-1, this membrane has a higher power density of 154.4 mW/cm2 compared to the other four membranes. Owing to the unique characteristics of the as-synthesized mPTA such as high surface area, porous structure, good thermal and chemical resistance, SPEEK-mPTA membrane is one of the promising materials for PEMFC applications.
Improvements in Electrospun Nanofibrous Membranes and Their Applications in Water Treatments
Authors: Al-Husaini Issa Sulaiman , Sakthipandi K.
Published: November 2020

Nanofibrous structures/buildings offer many interesting features due to their large spacious surface area. This makes them promising through various applications, especially water management. This new generation of large-membered/poous membranes shows great hope that it can be used in a variety of partition systems due to its outstanding features such as surprisingly high porosity (≥ 90%) and connected 3D pore structure, as compared to standard techniques. This article reviews updates of electrospun nanofibrous layers (ENMs) with some highlights of recent achievements, issues, and future ideas for water treatment. To begin with, the basic principles of electrospinning were discussed. The use of ENMs in thin-film composite membranes (TFC) in pressure-driven procedures for water treatment is introduced. The new use of ENMs in the membrane distillation (MD) process is hotly discussed. Deductions, conclusions and opinions are expressed in terms of recent developments.
Optimization of PSF Membrane Transport Properties with the Use of Porogenic Additive
Authors: Dhume Supriya S. , Mahajan-Tatpate Pallavi , Chendake Yogesh J.
Published: November 2020

The porous membrane works upon sieving mechanism, where the separation and transport properties are dependent upon membrane morphology and porosity. This porosity and pore size are dependent upon membrane materials and formation parameters. Polysulfone (PSF) is one of the widely used membrane material due to its stability properties. Current work is targeted towards optimization of PSF based membranes by varying dope solution concentration and composition with the use of polyethylene glycol (PEG (MW6000)) as porogen in dope solution to enhance the transport rate and selectivity. An increase in PEG rejection with linear decrease in water flux and pore size was observed with the increase in dope solution concentration. Uniform membranes formation without any abnormal pore-size is observed from transport properties. The use of PEG as porogen leads to increased porosity due to leaching of Porogen during the phase inversion, which resulted in enhanced transport rate (85%). Further the formed membranes maintained pore size as seen from bubble point, rejection and pore size analysis. This resulted in maintenance of selectivity. Such increased transport with high selectivity is highly essential when applicability of membranes in industrial processes like process separation and waste treatment are considered. This would lead to large industrial benefits.
High-Performance Nanosilver Thin Film Nanocomposite Membranes Prepared on Carbon Nanotube-Based Supports
Authors: Gumbi N. N. , Mbuli B. S. , Daramola M. O. , Mhlanga S. D. , Mamba B. B. , Nxumalo E. N.
Published: November 2020

Biofouling in membranes is a serious concern as it leads to a severe reduction in membrane performance by increasing the membranes’ resistance to permeate flow. This work describes a facile method for the production of high performance nanosilver polyamide thin-film nanocomposite (TFN) membranes on carbon nanotube-based supports for biofouling control. The TFN membranes were prepared by the interfacial polymerization of a thin polyamide layer over a polyethersulfone (PES) support layer. Nanosilver (nAg) particles were generated in-situ on the surface of the polyamide layer using a reduction reaction between a silver salt and sodium borohydride. The support layer of the TFN membrane contained nitrogen doped multi-walled carbon nanotubes (N-MWCNTs) at various dosages. The SEM/EDS microscopic analyses revealed that nAg particles were present on the polyamide layer and that they were evenly distributed throughout the TFN membrane. Furthermore, the TFN membrane showed an improved water permeability (from 16.74 L/m2.h to 22.86 L/m2.h at 150 Psi) without sever compromise in NaCl rejection (from 98.37% to 99.40%) compared to the bare TFC membrane. This was attributable to the combined hydrophilic effects imparted by the presence of nAg on the TFN polyamide layer and the oxidised CNTs in the support layer. Antibacterial tests conducted using Escherichia coli bacteria demonstrated that the TFN containing nAg particles membranes exude better antibacterial activity compared to the pristine TFC membrane as evidenced by a clear zone of inhibition, in the area surrounding the TFN membrane and the absence of bacterial colonies. The present study demonstrated that the presence of low dosages of CNTs in the support layer is essential in the improvement of mechanical strength and performance properties of the support layer, while nAg plays a crucial role in the enhancement of TFN membrane performance.
A Conceptual Model for Internet of Things Risk Assessment in Healthcare Domain with Deep Learning Approach
Authors: Zakaria Mohd Nizam , Abu Bakar Nur Azaliah , Abas Hafiza , Hassan Noor Hafizah
Published: November 2020

The Internet of Things (IoT) has become a prevalent technology in the IT industry. One of the industries that can benefit extensively in this technology is healthcare. However, the healthcare IoT is still under debate with several studies suggesting it is lack of interoperability, security, and too much complexity. Even more, the risk involved in deploying it is still enormous. Many traditional risk assessment models are unable to provide a specific IoT risk guideline and specification, especially in the healthcare area. Thus, it is essential to understand the full extent of the IoT risk and how to manage its risk in the healthcare area. The risk management models, such as NIST SP 800-30, ISO/IEC 27005, OCTAVE, CRAMM, and EBIOS, which are among the leading and widely used in many areas and healthcare fields, have also been described. Besides, this paper includes a review of three IoT risk assessment models that are based on ABA-IDS, Deep Learning, and AHP-SVM. Based on the review analysis, we proposed a new enhanced healthcare IoT risk assessment model, which aims to provide a real-time monitoring and mitigating risks that incorporate the NIST SP 800-30 framework, ABA-IDS, and CNN deep learning. This shall constitute a better classification of each risk identified to find the best risk mitigation plan.
Case Study and Cooperative Learning in Cryptography Course
Authors: Neu Jan Tan @ Atan Nazrin Amirul , Kadir Rashidah
Published: November 2020

Cryptography is one of the important components in data and telecommunications, it is important when communicating over any entrusted medium, which includes just about any network, particularly the Internet. It is also one of the important courses in Information Technology courses. For now, students seem to be hard to understands because they are lack of interest in learning this course. This problem is caused by their awareness towards the application and the usage of cryptography. In this study, a different approach will be used to open the students’ eyes towards the importance cryptography and the usage of cryptography application in their daily life to increase their interest in cryptography along with their understandings in cryptography. This study will focus on an approach that will improve the teaching interest and their understanding of the student by using case study and student-centered learning approach which is the cooperative learning approach. A case study is developed to carry out the tasks that will make the students realized the importance of cryptography. In order to make sure that the students’ get better understanding towards cryptography, the cooperative learning practice will be implemented. At the end of this study, the result from the implementation of the case study and cooperative learning will be analyzed and evaluated. The tasks of the cooperative learning practice will be identified in this study and the effectiveness of the practice will be measure based on the tasks given. Finally, the effectiveness will be evaluated after the given tasks is finished. This evaluation will be the final result of this study whether the implementation of case study and cooperative learning practice is effective than traditional teaching method or vice versa.
On the Accuracy of an Analytical Solution to Model Wave-Induced Loads on an Underwater Vehicle in Real-Time
Authors: Klamo Joseph T. , Turner Travis M. , Cool Colin Y. , Yeager Kathryn I. , Kwon Young W.
Published: November 2020

The accuracy of an existing analytical solution for modeling the linear, first-order wave-induced loads on a fully submerged body is investigated. The accuracy is assessed for the situation where the underlying theoretical assumptions are met, and the sensitivity of the accuracy to these assumptions is also explored. The accuracy was quantified by comparing the analytical solutions to experimental measurements from a tow tank with wave generation capability. The assessment showed that when all the assumptions are met, the heave and surge forces are predicted quite accurately but the pitch moment is overpredicted. The results also showed that the deeply submerged assumption is met as long as the body does not cause a disruption of the passing wave on the free surface. The slenderness and end face curvature assumptions are also quite relaxed and the curvature assumption only affects the pitch moment accuracy. The most stringent assumption appears to be the body-of-revolution assumption which can cause all three loads to be predicted poorly. The analytical solution appears to be accurate over a large parameter space and could be incorporated as a wave disturbance model into a virtual environment used to develop control and autonomy of unmanned underwater vehicles.
Design Guidelines for Axial Turbines Operating With Non-Ideal Compressible Flows
Authors: Giuffre' Andrea , Pini Matteo
Published: November 2020

The impact of non-ideal compressible flows on the fluid-dynamic design of axial turbine stages is examined. First, the classical similarity equation (CSE) is revised and extended to account for the effect of flow non-ideality. Then, the influence of the most relevant design parameters is investigated through the application of a dimensionless turbine stage model embedding a first-principles loss model. The results show that compressibility effects induced by the fluid molecular complexity and the stage volumetric flow ratio produce an offset in the efficiency trends and in the optimal stage layout. Furthermore, flow non-ideality can lead to either an increase or a decrease of stage efficiency up to 3–4% relative to turbines designed to operate in dilute gas state. This effect can be predicted at preliminary design phase through the evaluation of the isentropic pressure–volume exponent. Three-dimensional (3D) RANS simulations of selected test cases corroborate the trends predicted with the reduced-order turbine stage model. URANS computations provide equivalent trends, except for case study niMM1, featuring a non-monotonic variation of the generalized isentropic exponent. For such turbine stage, the efficiency is predicted to be higher than the one computed with any steady-state model based on the control volume approach.
The Influence of Strut Waviness on the Tensile Response of Lattice Materials
Authors: Seiler Philipp E. , Li Kan , Deshpande Vikram S. , Fleck Norman A.
Published: November 2020

Recent advances in additive manufacturing methods make it possible, for the first time, to manufacture complex micro-architectured solids that achieve desired stress versus strain responses. Here, we report experimental measurements and associated finite element (FE) calculations on the effect of strut shape upon the tensile response of two-dimensional (2D) lattices made from low-carbon steel sheets. Two lattice topologies are considered: (i) a stretching-dominated triangular lattice and (ii) a bending-dominated hexagonal lattice. It is found that strut waviness can enhance the ductility of each lattice, particularly for bending-dominated hexagonal lattices. Manufacturing imperfections such as undercuts have a small effect on the ductility of the lattices but can significantly reduce the ultimate tensile strength. FE simulations provide additional insight into these observations and are used to construct design maps to aid the design of lattices with specified strength and ductility.
Moving Morphable Inclusion Approach: An Explicit Framework to Solve Inverse Problem in Elasticity
Authors: Mei Yue , Du Zongliang , Zhao Dongmei , Zhang Weisheng , Liu Chang , Guo Xu
Published: November 2020

In this work, we present a novel inverse approach to characterize the nonhomogeneous mechanical behavior of linear elastic solids. In this approach, we optimize the geometric parameters and shear modulus values of the predefined moving morphable inclusions (MMIs) to solve the inverse problem. Thereby, the total number of the optimization parameters is remarkably reduced compared with the conventional iterative inverse algorithms to identify the nonhomogeneous shear modulus distribution of solids. The proposed inverse approach is tested by multiple numerical examples, and we observe that this approach is capable of preserving the shape and the shear moduli of the inclusions well. In particular, this inverse approach performs well even without any regularization when the noise level is not very high. Overall, the proposed approach provides a new paradigm to solve the inverse problem in elasticity and has potential of addressing the issue of computational inefficacy existing in the conventional inverse approaches.
Pressurization Analysis for Heating of a Screw Top Utility Can Loaded With Plutonium Oxide Powder by a 1273 K Fire
Authors: Laurinat James E. , Kesterson Matthew R. , Hensel Steve J.
Published: November 2020

The documented safety analysis for the Savannah River National Laboratory (SRNL) evaluates the consequences of a postulated 1273 K fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage containers. The oxide storage configuration selected for analysis is can/bag/can, comprised of oxide powder inside an 8.38 × 10−6 m3 stainless steel B vial inside 0.006 kg of polyethylene bagging inside a one-quart screw top utility can of the type commonly used to package solvents or rubber cements. To enable evaluation of the dose consequences, temperature and pressure transients have been calculated for exposure of a typical set of storage containers to the fire. The pressurization analysis credits venting to and from the B vial but does not credit venting or leakage from the can. Due to the low rate of venting from the B vial into the can gas space, the can pressure is nearly independent of the B vial pressure. Calculated maximum pressures are compared to the utility can burst pressure. In lieu of a structural analysis of the utility cans, burst pressures and leakage rates were measured using compressed nitrogen gas. The measured gauge burst pressure was 0.250 ± 0.043 MPa. The measured burst pressures are lower than the calculated maximum pressure due to fire exposure, indicating that the utility cans could burst during exposure to a 1273 K fire.
Assessment and Performance Evaluation of Water Hammer in Hydroelectric Plants With Hydropneumatic Tank and Pressure Regulating Valve
Authors: Romuald Bagaragaza , Jian Zhang , Dong Yu Xiao , Claire Dusabemariya
Published: November 2020

The simulation approach of pipeline systems, pressure regulating valve (PRV), and hydropneumatic tank (HPT) in hydropower plants (HPP) is performed. The article used suitable protection devices such as hydropneumatic tank and pressure regulating valves to protect the hydro-electric system against water hammer negative effects. The method of characteristics solves hydraulic transient in the HPP system. This article simulates transient phenomena in a hydro-electric power system using FORTRAN language. The aim was to find out and diminish the water hammer at the entrance of the spiral case as well as the pipeline system. The paper has four major philosophies: simulation with no protection, simulation with hydropneumatic tank, simulation with pressure regulating valve, and the combination of hydropneumatic tank with the pressure regulating valve. The results show that a combination of the pressure regulating valve and the hydropneumatic tank is adequate appliances to lessen the effect of water hammer/transient flow in a hydropower plant system. However, in the transient process of the water diversion system, the gas' kinetic characteristic in the hydropneumatic tank has certain complexity when there is high fluctuation in the surge chamber. The study proved that the wicket gate's stepwise could cut down the impact of the water hammer automatically than applying the linear closure law on the network. The automated pressure regulating valve with a high opening stepwise can decrease the negative impact of water hammer significantly. The results from this research paper show that pipeline diameter has crucial factors that influence hydraulic transient in hydropower plant systems.
A Product Architecture-Based Tool for Bioinspired Function-Sharing
Authors: Bhasin Devesh , McAdams Daniel A. , Layton Astrid
Published: November 2020

In this work, we show that bioinspired function-sharing can be effectively leveraged in engineering design by abstracting and emulating the product architecture of biological systems that exhibit function-sharing. Systems that leverage function-sharing enable multiple functions to be performed by a single structure. Billions of years of evolution have led to the development of function-sharing adaptations in biological systems. Currently, engineers leverage biological function-sharing by imitating serendipitously encountered biological structures. As a result, utilizing bioinspired function-sharing remains limited to some specific engineering problems. To overcome this limitation, we propose the reduced function-means tree as a tool to simultaneously abstract both biological adaptations and their associated product architecture. The tool uses information from an existing bioinspired design abstraction tool and an existing product architecture representation tool. A demonstration study illustrates the tool's ability to abstract the product architectural interactions of function-sharing biological systems. The abstracted product architectural interactions are then shown to facilitate problem-driven bioinspiration of function-sharing. The availability of a problem-driven approach may reduce the need to imitate biological structures to leverage biological function-sharing in engineering design. This work is a step forward in analyzing biological product architectures to inspire engineering design. The future work will focus on validating the proposed tool by performing user studies.
An Advanced Comprehensive Approach to Accurately Modeling the Face-Milled Generated Spiral Bevel Gears
Authors: Wang Shenghui , Zhou Yuansheng , Liu Xinru , Liu Shengjun , Tang Jinyuan
Published: November 2020

The modeling of a spiral bevel gear (SBG) is a fundamental work to its design, analysis, and manufacturing. The essential work of modeling SBGs is the generation of tooth surface points that meet the strict accuracy requirement of the SBG industry. Specially, if those points are evenly distributed, the 3D models can be efficiently generated by developing automatic programs, or else the tedious manual modeling process is usually applied with 3D commercial software. Hence, it is very beneficial to accurately generating those evenly distributed points with an approach that can stably and efficiently solve the highly nonlinear equations related to the complicated tooth surface geometry. This work proposed such an approach to the SBG produced by face-milled generated (FMG) method. First, two representations of the geometric meshing theory (GMT) are introduced to calculate tooth surfaces of different cases as closed-form (explicit) results rather than implicit results. Subsequently, a new strategy is employed to accurately and efficiently obtain the tooth surface points that are approximately even-distributed. Furthermore, an advanced geometric iterative optimization algorithm (GIOA) is developed to solve the nonlinear equations in a stable way. With the calculated tooth surface points, a special automatic program is developed to accomplish the 3D modeling of SBGs. Examples are discussed to show the validity of this work.
A Study to Compare the Efficacy of a Biodegradable Dynamic Fixation System With Titanium Devices in Posterior Spinal Fusion Between Articular Processes in a Canine Model
Authors: Yu Tailong , Zheng Leyu , Chen Guanghua , Wang Nanxiang , Wang Xiaoyan , Song Chengchao , Yan Jinglong , Xi Chunyang
Published: November 2020

The objective of this study was to apply a biodegradable dynamic fixation system (BDFS) for lumbar fusion between articular processes and compare the fusion results and biomechanical changes with those of conventional rigid fixation. Twenty-four mongrel dogs were randomly assigned to 2 groups and subjected to either posterior lumbar fusion surgery with a BDFS or titanium rods (TRs) at the L5–L6 segments. Six animals in each group were sacrificed at 8 or 16 weeks. Fusion conditions were evaluated by computed tomography (CT), manual palpation, biomechanical tests, and histological analysis. Biomechanical tests were performed at the L4–7 (for range of motion (ROM)) and L5–6 (for fusion stiffness) segments. Histological examination was performed on organs, surrounding tissues, and the fused area. The magnesium alloy components maintained their initial shape 8 weeks after the operation, but the meshing teeth were almost completely degraded at 16 weeks. The biomechanical analysis revealed an increased lateral bending ROM at 8 weeks and axial torsion ROM at 16 weeks. The L4–5 extension–flexion ROMs in the BDFS group were 2.29 ± 0.86 deg and 3.17 ± 1.08 deg at 16 weeks, respectively, compared with 3.22 ± 0.56 deg and 5.55 ± 1.84 deg in TR group. However, both groups showed similar fusion results. The BDFS design is suitable, and its degradation in vivo is safe. The BDFS can be applied for posterior lumbar fusion between articular processes to complete the fusion well. Additionally, the BDFS can reduce the decline in lateral motion and hypermotion of the cranial adjacent segment in flexion–extension motion.
Individual-Specific Modeling of Rat Optic Nerve Head Biomechanics in Glaucoma
Authors: Schwaner Stephen A. , Perry Robert N. , Kight Alison M. , Winder Emily , Yang Hongli , Morrison John C. , Burgoyne Claude F. , Ross Ethier C.
Published: November 2020

Glaucoma is the second leading cause of blindness worldwide and is characterized by the death of retinal ganglion cells (RGCs), the cells that send vision information to the brain. Their axons exit the eye at the optic nerve head (ONH), the main site of damage in glaucoma. The importance of biomechanics in glaucoma is indicated by the fact that elevated intraocular pressure (IOP) is a causative risk factor for the disease. However, exactly how biomechanical insult leads to RGC death is not understood. Although rat models are widely used to study glaucoma, their ONH biomechanics have not been characterized in depth. Therefore, we aimed to do so through finite element (FE) modeling. Utilizing our previously described method, we constructed and analyzed ONH models with individual-specific geometry in which the sclera was modeled as a matrix reinforced with collagen fibers. We developed eight sets of scleral material parameters based on results from our previous inverse FE study and used them to simulate the effects of elevated IOP in eight model variants of each of seven rat ONHs. Within the optic nerve, highest strains were seen inferiorly, a pattern that was consistent across model geometries and model variants. In addition, changing the collagen fiber direction to be circumferential within the peripapillary sclera resulted in more pronounced decreases in strain than changing scleral stiffness. The results from this study can be used to interpret data from rat glaucoma studies to learn more about how biomechanics affects RGC pathogenesis in glaucoma.
Identification of Postural Controllers in Human Standing Balance
Authors: Wang Huawei , van den Bogert Antonie J.
Published: November 2020

Standing balance is a simple motion task for healthy humans but the actions of the central nervous system (CNS) have not been described by generalized and sufficiently sophisticated control laws. While system identification approaches have been used to extracted models of the CNS, they either focus on short balance motions, leading to task-specific control laws, or assume that the standing balance system is linear. To obtain comprehensive control laws for human standing balance, complex balance motions, long duration tests, and nonlinear controller models are all needed. In this paper, we demonstrate that trajectory optimization with the direct collocation method can achieve these goals to identify complex CNS models for the human standing balance task. We first examined this identification method using synthetic motion data and showed that correct control parameters can be extracted. Then, six types of controllers, from simple linear to complex nonlinear, were identified from 100 s of motion data from randomly perturbed standing. Results showed that multiple time-delay paths and nonlinear properties are both needed in order to fully explain human feedback control of standing balance.
A Thorax Marker Set Model to Analyse the Kinematics of Walking Without the Need to Place Markers on the Back
Authors: Orantes-Gonzalez Eva , Heredia-Jimenez Jose , Chohan Ambreen , Richards Jim D.
Published: November 2020

Background: Previous thorax models have been proposed for gait analysis, however these require markers to be placed on the back. This presents a limitation in the kinematic analysis of the thorax under load carriage conditions. Research question: This study evaluated the validity and reliability of a thorax marker set that does not require markers to be placed on the back (HubemaLab model) when compared to 3 previously published marker set models. Methods: 17 young adults were evaluated while walking at their self-selected speed. A 12 camera motion capture system was used to acquire the marker position data which was then processed using the respective models using Visual-3D. The level of agreement for the flexion/extension peak, right/left lateral peak and right/left rotation peak of the thorax angle and angular velocity; together with the range of motion and thorax angular velocities in the three planes was found between each thorax marker set, while the reliability was measured using the intraclass correlation coefficient. Results: The ICC results for the thorax angle ROM and the range of thorax angular velocity between the HubemaLab model and the other models showed excellent to good reliability in all three planes. While the ICCs for the peak flexion/extension, peak right/left lateral flexion and peak right/left rotation showed excellent to moderate reliability in all three planes. Conclusion: The new model could be potentially valuable for kinematic gait analysis under load carriage conditions which obscure markers placed on the back.
Fabrication and Characterization of Highly Deformable Artificial Muscle Fibers Based on Liquid Crystal Elastomers
Authors: Lu Haiqing , Zou Zhanan , Wu Xingli , Shi Chuanqian , Xiao Jianliang
Published: November 2020

Artificial muscles have important applications in areas ranging from robotics to prosthetics and medical devices. In this study, highly deformable artificial muscle fibers that utilize superior actuating properties of liquid crystal elastomers and liquid-like deformability of liquid metal are reported. An effective and low-cost fabrication approach using screen printing technique is developed. The actuating properties of the artificial muscle fibers, including the dependence of temperature, contraction strain, and pulling force of the artificial muscle fiber on electric heating current and heating time, are characterized. The results could provide important guidance to design and for development of soft systems that utilize the actuating mechanisms of liquid crystal elastomers.
Mechanosensing of a Graphene Flake on a Bent Beam
Authors: Hu Yue , Leng Jiantao , Chang Tienchong
Published: November 2020

The ability of mechanosensing is essential for intelligent systems. Here we show by molecular dynamics (MD) simulations that a graphene flake on a bent beam exhibits amazing mechanosensing behavior, termed flexotaxis. The graphene flake can perceive the beam bending gradient which indeed leads to a gradient of atomic density that produces a driving force on the flake toward the direction of increasing density. An analytical model is developed to further confirm the mechanism, and the simulation results can be well reproduced by the model. Our findings may have general implications not only for the potential applications of graphene as sensing elements in nanoscale intelligent devices but also for the exploration of mechanosensing capability of other two-dimensional materials.
Sizing Optimization of Pneumatic Actuation Systems Through Operating Point Analysis
Authors: Vigolo Vinícius , De Negri Victor Juliano
Published: November 2020

This paper reports a study on the static and dynamic behavior of pneumatic actuation systems, resulting in a comprehensive view of the influence of the system parameters on the energy efficiency and dynamic performance. The operating point approach based on the steady-state analysis of a pneumatic actuation system is used for developing analytical expressions to describe the relationship between the piston diameter and the system performance, including displacement time, stroke end velocity, and energy efficiency. The validity of the proposed equations is demonstrated by comparison with results from a test rig. Sensitivity analysis using a nonlinear dynamic simulation model indicated that a specific operating region exists, where good energy efficiency and the maximum dynamic performance are achieved. Moreover, the results show that an oversized system becomes more inefficient in both energetic and dynamic aspects. The results obtained provide a very consistent foundation for developing a method for pneumatic system sizing.
Magnetron sputtering
Authors: Rossnagel Stephen M.
Published: November 2020

Magnetron sputtering developed rapidly in the 1980s for semiconductor, hard coating, and architectural glass applications. While the general operating principles were well known, subtle issues relating to cathode material, operating parameters, and deposition processes were only empirically understood. A sequence of magnetron measurements is described, which helps develop a more general understanding. The plasma is mostly conventional but is strongly perturbed by the large fluxes of energetic, neutral atoms sputtered from the cathode, which alter the gas dynamics as well as the discharge impedance. These studies have led to practical innovations, such as collimation and ionization of the sputtered atoms, which have been widely used for semiconductor manufacturing applications.
Modified atomic layer deposition of MoS2 thin films
Authors: Zeng Li , Richey Nathaniel E. , Palm David W. , Oh Il-Kwon , Shi Jingwei , Maclsaac Callisto , Jaramillo Thomas , Bent Stacey F.
Published: November 2020

As one of the most attractive transition metal dichalcogenides (TMDs), the growth of molybdenum disulfide (MoS2) with industrial compatibility is of great importance. Atomic layer deposition (ALD) has been shown to be a promising method to achieve the growth of high-quality TMD materials. However, MoS2 films deposited by ALD often are amorphous with nonideal stoichiometry and require high-temperature post-deposition annealing. In this study, we introduce a modified ALD recipe using Mo(CO)6 and H2S, resulting in controllable linear growth behavior, a S-to-Mo ratio of 2:1, and crystalline films at a temperature as low as 190 °C. The growth mechanisms and key factors leading to this improvement are proposed and complemented by kinetics calculations. This newly developed methodology relies on aligning the process time with the reaction kinetics of carbonyl disassociation. The MoS2 films prepared herein were shown to be active hydrogen evolution reaction catalysts.
3D printing an external-cavity diode laser housing
Authors: Brekke E. , Bennett T. , Rook H. , Hazlett E. L.
Published: November 2020

The ability to control the frequency of an external-cavity diode laser (ECDL) is an essential component for undergraduate laboratories and atomic physics research. Typically, the housing for the ECDL's diffraction grating and piezoelectric transducer is either purchased commercially or machined from metal. Here, we present an alternative to these commonly used options that utilizes 3D printing, a tool available in many physics departments. We characterize the performance of our ECDL system using atomic spectroscopy and self-heterodyne interferometry and show that it is sufficient for use in undergraduate spectroscopy experiments and a number of research applications, where extremely narrow laser linewidths are not necessary. The performance and affordability of 3D-printed designs make them an appealing option for future use.