Digital Commons Network^™

Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree

Faculty Publications

One of the grand challenges of amphiphilic self-assembly is the design of ordered structures whose morphology or shape can be explicitly and dynamically controlled by adjusting the properties of the amphiphiles or their surroundings. Such a capacity would enable researchers to create synthetic systems with functionality that meets or exceeds biological cells, and provide a robust platform for a broad range of engineering applications such as artificial tissues, drug delivery, and separation membranes. Despite significant progress, important fundamental questions remain unanswered, due in part to the limited resolution and the restricted parameter spaces that are readily accessible in experiments. Computational …

Data Literacy In The Social Sciences: Findings From A Local Study On Teaching With Quantitative Data In Undergraduate Courses, Patricia B. Condon, Eleta Exline, Louise Buckley

Faculty Publications

Objective – The University of New Hampshire (UNH) Library conducted an exploratory study of the pedagogical practices of social science instructors at UNH who teach using quantitative data in undergraduate courses. This study is connected to a suite of parallel studies at other higher education institutions that was designed and coordinated by Ithaka S+R.

The four aims of this study were to explore the ways in which instructors teach and engage undergraduates in the social sciences using quantitative data; understand the support needs of these instructors; develop actionable recommendations for campus stakeholders; and identify opportunities for the development of resources, …

Collection Due Process At Twenty-Five: A Still Important And Needed Check On Irs Collection, Leslie Book

Faculty Publications

No abstract provided.

Diurnal Time-Activity Budget And Habitat Use Of Whooping Cranes (Grus Americana) In The Reintroduced Louisiana Nonmigratory Population, Phillip L. Vasseur, Sammy L. King, Michael D. Kaller

Faculty Publications

Time-activity budget studies provide valuable insights for better understanding animal behavior relative to spatial and temporal habitat use. We examined a reintroduced, nonmigratory Whooping Crane (Grus americana) population to determine how time-activity budgets change relative to crane age, sex, habitat type, and season. Our study area encompassed natural marshes and working wetlands primarily in southwestern Louisiana. From June 2012 to January 2016, we conducted continuous focal sampling on individuals (n = 27) from the first 4 captive-reared cohorts released in the state. We classified age groups as juveniles, subadults, and adults, and identified 5 main habitat types utilized by cranes …

Strengthening The Ti/Tin Interface Against Shear Failure With Al Dopants: A Molecular Dynamics Study, Nisha Dhariwal, Abu Shama Mohammad Miraz, W. J. Meng, Collin D. Wick

Faculty Publications

The impact of Al doping on the stability and shear strength of the Ti/TiN interface was investigated using a newly developed modified embedded atom model interatomic potential. The model was parameterized to the interfacial properties of pure Al, TiAl and AlN binaries as well as TiAlN ternary system. The results of the new model are in reasonably good agreement with those obtained using Density Functional Theory and experimental data from the literature. A Ti/TiN system with a misfit dislocation network present on the Ti layer adjacent to the TiN interface was chosen for doping because of its low interfacial energy. …

The Mechanics Of Share Repurchases Or How I Stopped Worrying And Learned To Love Stock Buybacks, Richard A. Booth

Faculty Publications

Stock repurchases by issuing corporations have always been controversial. They have become even more so recently because of the perception that the excess funds used to finance them have come from tax cuts and other sources (such as government bailouts) that were intended to stimulate reinvestment or enhanced wages and benefits for workers. As a result, critics have proposed amendments to tax law that discourage buybacks (and possibly dividends as well). The theory is that the benefits of such distributions go mostly to executives (who are compensated in large part with equity) and to already wealthy stockholders. The controversy is …

Delineating The Effects Of Molecular And Colloidal Interactions Of Dissolved Organic Matter On Titania Photocatalysis, Mostafa Maghsoodi, Céline Jacquin, Benoit Teychené, Geoffroy Lesage, Samuel D. Snow

Faculty Publications

In the face of significant challenges to practical applications of photocatalysis for water treatment, recent reports revealed a potential route to overcome a problem posed by dissolved organic matter (DOM). These studies showed that inhibition of photocatalytic processes by DOM is driven largely by competition for active surface sites on TiO2 or other catalysts, and controlling the type of DOM present in solution could significantly mitigate DOM fouling. Whether or not control of solution parameters could achieve the same preventative action is not known. Here, a series of DOM isolates, including humic acid (HA) and transphilic (TPI), hydrophobic (HPO), or …

Developable Mechanisms On Regular Cylindrical Surfaces, Jacob R. Greenwood, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Developable mechanisms can provide high functionality and compact stowability. This paper presents engineering models to aid in the design of cylindrical developable mechanisms. These models take into account the added spatial restrictions imposed by the developable surface. Equations are provided for the kinematic analysis of cylindrical developable mechanisms. A new classification for developable mechanisms is also presented (intramobile, extramobile, and transmobile) and two graphical methods are provided for determining this clas sification for single-DOF planar cylindrical developable mechanisms. Characteristics specific to four-bar cylindrical developable mechanisms are also discussed.

Student Preferences For Active Learning And Their Beliefs, Experiences, And Knowledge, Tammy Shilling, Jerome Thayer, Anneris Coria-Navia, Heather Ferguson

Faculty Publications

Active teaching methods are believed to facilitate higher-order thinking skills and prepare allied health students for independent clinical decision-making. This quantitative, correlational study aimed to explain the relationships between student preferences for active over traditional methods and their beliefs, the frequency and positiveness of their experiences, and the extent of knowledge they have received regarding active and traditional teaching methods. Two hundred and thirty students completed a 53-item online survey. Students were enrolled in a Doctor of Physical Therapy, Masters in Speech-language Pathology, or Bachelor of Science Nursing program in one of seventeen participating institutions across a ten-state Midwest region. …

Large Deflection Analysis Of General Beams In Contact-Aided Compliant Mechanisms Using Chained Pseudo-Rigid-Body Model, Mohui Jin, Collin Ynchausti, Xianmin Zhang, Zhou Yang, Benliang Zhu, Larry L. Howell

Faculty Publications

The nonlinear analysis and design of contact-aided compliant mechanisms (CCMs) are challenging. This paper presents a nonlinear method for analyzing the deformation of general beams that contact rigid surfaces in CCMs. The large deflection of the general beam is modeled by using the chained pseudo-rigid-body model. A geometry constraint from the contact surface is developed to constrain the beam’s deformed configuration. The contact analysis problem is formulated based on the principle of minimum potential energy and solved using an optimization algorithm. Besides, a novel technique based on the principle of work and energy is proposed calculate the reaction force/moment of …

A Model For Multi-Input Mechanical Advantage In Origami-Based Mechanisms, Jared Butler, Adam Shrager, Timothy Simpson, Landen Bowen, Mary Frecker, Robert Lang, Eric Wilcox, Paris Von Lockette, Larry L. Howell, Spencer P. Magleby

Faculty Publications

Mechanical advantage is traditionally defined for single input and single-output rigid-body mechanisms. A generalized approach for identifying single-output mechanical advantage for a multiple-input compliant mechanism, such as many origami-based mechanisms, would prove useful in predicting complex mechanism behavior. While origami-based mechanisms are capable of offering unique solutions to engi neering problems, the design process of such mechanisms is complicated by the interaction of motion and forces. This paper presents a model of the mechanical advantage for multi input compliant mechanisms and explores how modifying the parameters of a model affects their behavior. The model is used to predict the force-deflection …

A Diversity, Equity, And Inclusion Audit Of The American Families Of Faith Project: Exploring Lifespan Spiritual Development In Religiously And Racially Diverse Families, David C. Dollahite, Justin J. Hendricks, Loren D. Marks

Faculty Publications

Social science and religious studies scholars should endeavor to broaden theories, methods, and samples to be more inclusive. Therefore, we have conducted an “equity audit” of the American Families of Faith (AFF) project. We evaluated the diversity, equity, and inclusion of the AFF project’s (a) research team, (b) products, and (c) samples. We then discuss the reasoning behind the decisions that resulted in the existing strengths and limitations of the project, the fruits of this and previous evaluations (including a presentation of some narrative accounts from parents and youths across several religious-ethnic communities across the US), opportunities for growth, and …

Uncovering The Optimal Molecular Characteristics Of Hydrophobe-Containing Polypeptoids To Induce Liposome Or Cell Membrane Fragmentation, Tianyi Yu, Marzhana Omarova, Meng Zhang, Istiak Hossain, Jianqiang Chen, Omead Darvish, Vijay T. John, Donghui Zhang

Faculty Publications

Cellular functions of membrane proteins are strongly coupled to their structures and aggregation states in the cellular membrane. Molecular agents that can induce the fragmentation of lipid membranes are highly sought after as they are potentially useful for extracting membrane proteins in their native lipid environment. Toward this goal, we investigated the fragmentation of synthetic liposome using hydrophobe-containing polypeptoids (HCPs), a class of facially amphiphilic pseudo-peptidic polymers. A series of HCPs with varying chain lengths and hydrophobicities have been designed and synthesized. The effects of polymer molecular characteristics on liposome fragmentation are systemically investigated by a combination of light scattering …

The Financial Impact Of Suspended Licenses In Illinois, Colleen Chien

Faculty Publications

No abstract provided.

Synthetic Strategies Of Supported Pd-Based Bimetallic Catalysts For Selective Semi-Hydrogenation Of Acetylene: A Review And Perspectives, Xinxiang Cao, Ben W.-L. Jang, Jiaxue Hu, Lei Wang

Faculty Publications

Selective semi-hydrogenation of acetylene is an extremely important reaction from both industrial and theoretical perspectives. Palladium, due to its unique chemical and physical properties, is the most active and currently irreplaceable metal for this reaction in industry, but the poor catalytic selectivity towards ethylene is also its inherent shortcoming. Introducing a secondary metal to tune a geometric and electronic structures of Pd nanoparticles and to create a synergistic effect is the most widely used strategy to effectively improve the overall catalytic performance of Pd-based catalysts. Thus, various supported Pd-based bimetallic catalysts for selective semi-hydrogenation of acetylene have been exploited in …

Practices And Perceptions Of Family-Centered Care: A Cross-Sectional Survey Of Secondary School Athletic Trainers, Zachary K. Winkelmann, Nancy A. Uriegas, James M. Mensch, Conner E. Montgomery, Toni M. Torres-Mcgehee

Faculty Publications

Family-centered care (FCC) includes collaboration between families and healthcare providers, the creation of flexible policies, and the family taking an active role in the delivery of care. Secondary school athletic trainers provide care for underage patients in school-based health systems, making them responsible for maintaining communication with parents, guardians, and/or caregivers. This cross-sectional survey investigated the extent to which athletic trainers (n = 205) include aspects of FCC in their daily secondary school clinical practice (current practices = CP) and whether they believe that aspect of care is necessary for FCC to be provided in athletic training (perceived necessary = …

Numerical Simulation Of Steady-State Thermal Blooming With Natural Convection, Jeremiah S. Lane, Justin Cook, Martin Richardson, Benjamin F. Akers

Faculty Publications

This work investigates steady-state thermal blooming of a high-energy laser in the presence of laser-driven convection. While thermal blooming has historically been simulated with prescribed fluid velocities, the model introduced here solves for the fluid dynamics along the propagation path using a Boussinesq approximation to the incompressible Navier–Stokes equations. The resultant temperature fluctuations were coupled to refractive index fluctuations, and the beam propagation was modeled using the paraxial wave equation. Fixed-point methods were used to solve the fluid equations as well as to couple the beam propagation to the steady-state flow. The simulated results are discussed relative to recent experimental …

Ranked Document Retrieval In External Memory, Rahul Shah, Cheng Sheng, Sharma Thankachan, Jeffrey Vitter

Faculty Publications

The ranked (or top-k) document retrieval problem is defined as follows: preprocess a collection {T1,T2,... ,Td} of d strings (called documents) of total length n into a data structure, such that for any given query (P,k), where P is a string (called pattern) of length p ≥ 1 and k ϵ [1,d] is an integer, the identifiers of those k documents that are most relevant to P can be reported, ideally in the sorted order of their relevance. The seminal work by Hon et al. [FOCS 2009 and Journal of the ACM 2014] presented an O(n)-space (in words) data structure …

Perspectives On Lifespan Religious And Spiritual Development From Scholars Across The Lifespan, Megan Gale, Justin J. Hendricks, David C. Dollahite, Loren D. Marks

Faculty Publications

The purpose of the article is to share our perspectives on the key influences of lifespan religious and spiritual development as scholars from across the lifespan (i.e., the four authors are from different generations, including Baby Boomers, Generation X, Millennials, and Gen Z). Our perspectives are heavily influenced by our combined 60+ years of research experience in examining the connections between religion and family life. Our discussion is organized around Bronfenbrenner’s bioecological framework and the process-person-context-time model. Within this framework, the key factors we discuss that influence religious/spiritual development include (a) process (i.e., person-religion mismatch and family processes), (b) person …

On The Modeling Of A Contact-Aided Cross-Axis Flexural Pivot, Pietro Bilancia, Giovanni Berselli, Spencer P. Magleby, Larry L. Howell

Faculty Publications

This paper reports the study of a planar Cross-Axis Flexural Pivot (CAFP) comprising an additional contact pair. The proposed device turns useful for applications requiring a revolute joint that behaves differently when deflecting clockwise/anti-clockwise. The presence of the contact pair reduces the free length of one flexures, resulting in a considerable increment of the overall joint stiffness. The pivot behaviour is investigated, for different load cases, via the ChainedBeam-Constraint Model (CBCM), namely an accurate method to be applied in large deflection problems. A framework comprising Matlab and ANSYS is developed for testing the CAFP performances in terms of rotational stiffness, …

Kinetostatic And Dynamic Modeling Of Flexure-Based Compliant Mechanisms: A Survey, Mingxiang Ling, Larry L. Howell, Junyi Cao, Guimin Chen

Faculty Publications

Flexure-based compliant mechanisms are becoming increasingly promising in precision engineering, robotics and other applications due to the excellent advantages of no friction, no backlash, no wear, and minimal requirement of assembly. Because compliant mechanisms have inherent coupling of kinematic- mechanical behaviors with large deflections and/or complex serial-parallel configurations, the kinetostatic and dynamic analyses are challenging in comparison to their rigid-body counterparts. To address these challenges, a variety of techniques have been reported in a growing stream of publications. This paper surveys and compares the conceptual ideas, key advances, applicable scopes and open problems of the state-of-the-art kinetostatic and dynamic modeling …

An Origami-Based Medical Support System To Mitigate Flexible Shaft Buckling, Brandon Sargent, Jared Butler, Kendall Seymour, David Bailey, Brian D. Jensen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

This paper presents the development of an origami-inspired support system (the OriGuide) that enables the insertion of flexible instruments using medical robots. Varying parameters of a triangulated cylindrical origami pattern were combined to create an effective highly-compressible anti-buckling system that maintains a constant inner diameter for supporting an instrument and a constant outer diameter throughout actuation. The proposed origami pattern is composed of two repeated patterns: a bistable pattern to create support points to mitigate flexible shaft buckling and a monostable pattern to enable axial extension and compression of the support system. The origami-based portion of the device is combined …

Developable Mechanisms On Right Conical Surfaces, Lance P. Hyatt, Spencer P. Magleby, Larry L. Howell

Faculty Publications

An approach for designing developable mechanisms on a conical surface is presented. By aligning the joint axes of spherical mechanisms to the ruling lines, the links can be created in a way that the mechanism conforms to a conical surface. Terminology is defined for mechanisms mapped onto a right cone. Models are developed to describe the motion of the mechanism with respect to the apex of the cone, and connections are made to cylindrical developable mechanisms using projected angles. The Loop Sum Method is presented as an approach to determine the geometry of the cone to which a given spherical …

A Design Approach To Fully Compliant Multistable Mechanisms Employing A Single Bistable Mechanism, Yanjie Gou, Guimin Chen, Larry L. Howell

Faculty Publications

A fully compliant multistable mechanism is a monolithic structure that is capable of staying at multiple positions without power input, and has many applications including switches, valves, positioners. However, it is difficult to design such a mechanism because of the complexities of the multistable behavior, the practical stress limits and the buckling constraints. This paper discusses the design approach for fully compliant multistable mechanisms which employs a single bistable mechanism and several end-effectors connected in series. The force-displacement characteristics of the end-effectors are derived using the pseudo-rigid-body model. The design approach to the fully compliant multistable mechanism is provided to …

“Are These People Real?”: Designing And Playtesting An Alternative Reality, Educational Simulation, Jason K. Mcdonald, Jonathan Balzotti, Melissa Franklin, Jessica Haws, Jamin Rowan

Faculty Publications

In this design case, we report our design and playtest of a form of alternative reality, educational simulation that we call a playable case study (PCS). One of the features that make our simulations unique is how they are designed to implement a principle called This Is Not a Game, or TINAG, meaning that the affordances we design into the simulation suggest to students that the experience they are having is real, in contrast to the way the artificial nature of the experience is highlighted in many computer games. In this case, we describe some challenges we encountered in designing …

Fast-, Light-Cured Scintillating Plastic For 3d-Printing Applications, Brian G. Frandsen, Michael Febbraro, Thomas Ruland, Theodore W. Stephens, Paul A. Hausladen, Juan J. Manfredi, James E. Bevins

Faculty Publications

Additive manufacturing techniques enable a wide range of possibilities for novel radiation detectors spanning simple to highly complex geometries, multi-material composites, and metamaterials that are either impossible or cost prohibitive to produce using conventional methods. The present work identifies a set of promising formulations of photocurable scintillator resins capable of neutron-gamma pulse shape discrimination (PSD) to support the additive manufacturing of fast neutron detectors. The development of these resins utilizes a step-by-step, trial-and-error approach to identify different monomer and cross-linker combinations that meet the requirements for 3D printing followed by a 2-level factorial parameter study to optimize the radiation detection …

Rigidly Foldable Thick Origami Using Designed-Offset Linkages, Robert J. Lang, Nathan Brown, Brian Ignaut, Spencer P. Magleby, Larry L. Howell

Faculty Publications

We present new families of thick origami mechanisms that achieve rigid foldability and parallel stacking of panels in the flat-folded state using linkages for some or all of the hinges between panels. A degree-four vertex results in a multi-loop eight-bar spatial mechanism that can be analyzed as separate linkages. The individual linkages are designed so that they introduce offsets perpendicular to the panels that are mutually compatible around each vertex. This family of mechanisms offers the unique combination of a planar unfolded state, parallel-stacked panels in the flat folded state, and kinematic single-degree-of-freedom motion from the flat- unfolded to the …

Heat Set Creases In Polyethylene Terephthalate (Pet) Sheets To Enable Origami-Based Applications, Brandon Sargent, Nathan Brown, Brian D. Jensen, Spencer P. Magleby, William G. Pitt, Larry L. Howell

Faculty Publications

Polyethylene terephthalate (PET) sheets show promise for application in origami-based engineering design. Origami-based engineering provides advantages that are not readily available in traditional engineering design methods. Several processing methods were examined to identify trends and determine the effect of processing of PET sheets on the crease properties of origami mechanisms in PET. Various annealing times, temperatures, and cooling rates were evaluated and data collected for over 1000 samples. It was determined that annealing temperature plays the largest role in crease response. An increase in the crystallinity of a PET sheet while in the folded state likely increases the force response …

A Cprbm-Based Method For Large-Deflection Analysis Of Contact-Aided Compliant Mechanisms Considering Beam-To-Beam Contacts, Mohui Jin, Benliang Zhu, Jiasi Mo, Zhou Yang, Xianmin Zhang, Larry L. Howell

Faculty Publications

Contact-aided compliant mechanisms (CCMs) utilize contact to achieve enhanced functionality. The contact phenomenon of CCMs increases the difficulties of their analysis and design, especially when they exhibit beam-to-beam contact. Considering the particularity of CCMs analysis, which is more about the mechanisms’ deformation, this paper presents a numerical method to analyze the large deflection and stress of the CCMs considering beam-to-beam contacts. Based on our previous work on beam-to-rigid contact, the large deformation of general beams in CCMs is modeled by using the chained pseudo-rigid-body model (CPRBM). An approximation based on the geometric information of CPRBM is proposed in this paper …

Deployable Convex Generalized Cylindrical Surfaces Using Torsional Joints, Todd G. Nelson, Jared T. Burton, Curtis G. Nelson, Luis M. Baldelomar Pinto, Zhicheng Deng, Larry L. Howell

Faculty Publications

The ability to deploy a planar surface to a desired convex profile with a simple actuation can enhance foldable or morphing airfoils, deployable antennae and reflectors, and other applications where a specific profile geometry is desired from a planar sheet. A model using a system of rigid links joined by torsional springs of tailorable stiffness is employed to create an approximate curved surface when two opposing tip loads are applied. A system of equations describing the shape of the surface during deployment is developed. The physical implementation of the model uses compliant torsion bars as the torsion springs. A multidimensional …