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2020

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Articles 9991 - 10020 of 10640

Full-Text Articles in Engineering

A Multi-Constraint Predictive Control System With Auxiliary Emergency Controllerfor Autonomous Vehicles, Farhad Partovi Ebrahimpour Jan 2020

A Multi-Constraint Predictive Control System With Auxiliary Emergency Controllerfor Autonomous Vehicles, Farhad Partovi Ebrahimpour

Graduate Research Theses & Dissertations

In the last few years, several research groups and companies have worked on developing autonomous vehicles. Among the first automation layers, the safety layer plays a significant role in this field. However, considering safety should not diminish the importance of the efficiency of the vehicle in terms of path tracking with the desired speed. This thesis introduces a multi-constraint predictive control algorithm along with a safety layer to guarantee object avoidance in emergency situations. First, there is a quick review of autonomous cars and their functionalities. In the following, a controller switching mechanism is proposed and designed. It switches the …


Molecular Dynamic Simulations Of Mechanical Properties In Nb-Nbc Core-Shell Nanowires And Nodes, Austin Pauga Jan 2020

Molecular Dynamic Simulations Of Mechanical Properties In Nb-Nbc Core-Shell Nanowires And Nodes, Austin Pauga

Graduate Research Theses & Dissertations

Nanoporous materials have attracted attention recently because of their extensive range of possible applications. These nanoporous materials are comprised of nanowires and nodes. A node joins three or more nanowires of different orientations. Current research has focused on nanowires and nodes composed of metallic single crystals and core-shells. Nanoporous materials experience brittle failure from the rupture of the weakest feature, overloading the other remaining structural features. To alter the deformation behavior of the network nodes, a ceramic layer has been added around the metal. Coating the metallic ligaments with ceramic shell increases the buckling capacity of each ligament and further …


Improving The Efficiency Of Planar Goubau Line And Goubau-Line-Based Endfire Antenna, Sreelakshmi Radhakrishnan Jan 2020

Improving The Efficiency Of Planar Goubau Line And Goubau-Line-Based Endfire Antenna, Sreelakshmi Radhakrishnan

Graduate Research Theses & Dissertations

This thesis presents the use of two dielectric layers in a planar Goubau line (PGL) to improve its transmission efficiency compared to the existing single-layer models, which is less than 70% efficient at lower frequencies up to 5 GHz. Further, as an extension of the thesis, the possibility of obtaining directive radiation pattern with radiation efficiency greater than 89.6% using a Goubau-line-based antenna is studied. While none of the existing Goubau-line-based antennas are able to obtain an endfire pattern with radiation efficiency of above 80%, the proposed model utilizes stubs that are periodically attached to the main line of length …


Bimetallic Nanoparticles Integrated Membranes For Groundwater Remediation: Synthesis, Characterization And Applications, Hongyi Wan Jan 2020

Bimetallic Nanoparticles Integrated Membranes For Groundwater Remediation: Synthesis, Characterization And Applications, Hongyi Wan

Theses and Dissertations--Chemical and Materials Engineering

The detoxification of chlorinated organics from groundwater, such as trichloroethylene (TCE), tetrachloroethylene (PCE), polychlorinated biphenyl (PCB) and carbon tetrachloride (CTC), is a challenging area. Reductive dechlorination has been investigated using iron and iron-based nanoparticles, such as bare Fe, sulfidized Fe (S-Fe) and palladized Fe (Pd-Fe). However, issues including particle agglomeration, difficulties in recycling and particle leaching have been reported to hinder the application and wide usage of these techniques. The integration of nanoparticles and membranes can address these issues because of the large surface area, stability, and the potential for versatile functionalities. In this study, commercial polyvinylidene difluoride (PVDF) microfiltration …


Characterization And Electrochemical Performance Of Dopamine-Sensitized Titania Thin Films, Joshua Garay Jan 2020

Characterization And Electrochemical Performance Of Dopamine-Sensitized Titania Thin Films, Joshua Garay

Theses and Dissertations--Chemical and Materials Engineering

Sensitization of mesoporous titania films with dopamine and polydopamine for visible light photoelectrochemical activity is investigated. Sensitization effectiveness is compared with 8 mM dopamine solutions of varying pH (acidic, basic, and neutral), as well as with a basic polydopamine solution. Vibrational changes due to dopamine attachment are determined from detached powders by Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) is used to quantify organics attached. X-ray photoelectron spectroscopy (XPS) of intact films probes the chemically induced charge shift from dopamine attachment. Cyclic voltammetry identifies the irreversible dopamine oxidation and tin reduction voltages. Finally, chronoamperometric curves are used to compare …


Effect Of Silica Nanoconfinement Of Lipid Bilayers On Its Phase Transition And On The Colloidal Stability Of Silica Nanoparticles, Aniruddha Atul Shirodkar Jan 2020

Effect Of Silica Nanoconfinement Of Lipid Bilayers On Its Phase Transition And On The Colloidal Stability Of Silica Nanoparticles, Aniruddha Atul Shirodkar

Theses and Dissertations--Chemical and Materials Engineering

In this work, we incorporated 4-(N-Boc-aminometyl) phenylboronic acid (BA), at different concentrations, into 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (DPPC) bilayers confined within nanopores of two different mean pore diameters of 7.4 nm and 11.7 nm of micron sized silica particles. The confinement of DPPC into nanopores resulted in the depression in the main phase transition temperatures compared to the liposomal system. The addition of BA was found to induce disruptions in the acyl chains of the lipid molecules at all concentrations of the solute. The lipid bilayer cooperativity was found to be higher in the confined systems compared to the liposomal systems despite …


Silica Nanoporous Confinement Effects On Ionic Liquid Properties For Better Design Of Small Molecule Separation, Electrochemical Devices And Drug Delivery, Yuxin He Jan 2020

Silica Nanoporous Confinement Effects On Ionic Liquid Properties For Better Design Of Small Molecule Separation, Electrochemical Devices And Drug Delivery, Yuxin He

Theses and Dissertations--Chemical and Materials Engineering

Silica nanoconfinement provides a high level of control of ionic liquids (ILs) in localizing catalysts, creating distinct environment for tuning reactivity and controlling the partition of solvents, reactants and products. Silica thin films with two different pore sizes (2.5 nm and 8 nm) were synthesized to study the effect of nanopore confinement on ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), and 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]). Silica thin films with accessible 8 nm pore diameters were synthesized using evaporation-induced self-assembly (EISA) with Pluronic P123 as templating surfactant on a chemically neutral modified substrate. The silica films with similar orthogonal aligned mesostructured but …


Nanostructured Metal Thin Films As Components Of Composite Membranes For Separations And Catalysis, Michael J. Detisch Jan 2020

Nanostructured Metal Thin Films As Components Of Composite Membranes For Separations And Catalysis, Michael J. Detisch

Theses and Dissertations--Chemical and Materials Engineering

Novel metallic thin film composite membranes are synthesized and evaluated in this work for improved separations and catalysis capabilities. Advances in technology that allow for improved membrane performance in solvent separations are desirable for low molecular weight organic separation applications such as those in pharmaceutical industries. Additionally, the introduction of catalytic materials into membrane systems allow for optimization of complex processes in a single step. By adding a nanostructured metallic thin film to its surface, a polymer membrane may be modified to exhibit these improved properties. Using magnetron sputtering, thin metal films may be deposited on commercially available membranes to …


A Framework For Heterologous Biosynthesis Of Natural Products In Mammalian Cells Via Polymer-Mediated Transfections, Logan Warriner Jan 2020

A Framework For Heterologous Biosynthesis Of Natural Products In Mammalian Cells Via Polymer-Mediated Transfections, Logan Warriner

Theses and Dissertations--Chemical and Materials Engineering

With the promise to treat a multi-faceted list of serious inherited and acquired diseases, such as cancer, neurodegenerative and infectious diseases, and inherited genetic indications, gene therapy has continued to push the boundaries of traditional medicine since its earliest implementation. While much progress has been made, clinical success has largely remained elusive. Immunogenicity, difficulty producing commercially relevant quantities, and having a limited genetic payload still limits the ability of viruses to act as directed delivery agents for genetic material. As such, researchers have turned to cationic synthetic materials as a means of delivering nucleic acids, which can circumvent the immune …


Microfiltration Membrane Pore Functionalization Approaches For Chloro-Organic Remediation To Heavy Metal Sorption, Mohammad Saiful Islam Jan 2020

Microfiltration Membrane Pore Functionalization Approaches For Chloro-Organic Remediation To Heavy Metal Sorption, Mohammad Saiful Islam

Theses and Dissertations--Chemical and Materials Engineering

Microfiltration polyvinylidene fluoride (PVDF) membranes have distinct advantage for open structure in terms of high internal surface area and ease of access in the pore domain. Functionalization of PVDF membranes with different functional groups (-COOH, -OH, -SH) enables responsive (pH, temperature) properties to membrane, tuning of effective pore size, controlling permeate flux. PVDF microfiltration membrane functionalization with suitable responsive polymer such as poly acrylic acid (PAA) to incorporate carboxyl (-COOH) group enables further modification of functionalized PAA-PVDF membranes for different application ranging from catalysis, bio reactor to heavy metal sorption platform. As a catalytic reactor bed, this PAA-PVDF membranes are …


The Development Of Temperature And Ph Responsive Hydrogels And Membranes For Selective Sorption Of Perfluoroorganics And Nanoparticle Integrated Catalytic Degradation Of Pcb, Anthony Saad Jan 2020

The Development Of Temperature And Ph Responsive Hydrogels And Membranes For Selective Sorption Of Perfluoroorganics And Nanoparticle Integrated Catalytic Degradation Of Pcb, Anthony Saad

Theses and Dissertations--Chemical and Materials Engineering

The functionalization and use of responsive and catalytic polymeric membranes and materials were explored for contaminant capture and degradation. While membranes have a wide variety of uses across multiple industries, the inclusion of materials that are temperature and pH responsive in the membrane pore domain yields a wide range of applications and possibilities for water treatment. Temperature and pH responsive polymers, as well as controlled nanostructured materials, were synthesized in membrane pores for advanced adsorption-desorption and catalytic treatment of emerging organic contaminants in water. In this study, supported by the NIEHS, poly-N-isopropylacrylamide (PNIPAm) was used as a model thermo-responsive polymer, …


Understanding And Mitigating The Electrochemical-Mechanical Degradation Of High Capacity Battery Electrodes, Dingying Dang Jan 2020

Understanding And Mitigating The Electrochemical-Mechanical Degradation Of High Capacity Battery Electrodes, Dingying Dang

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries (LIBs) with high energy density and cycling stability play a critical role in developing electric vehicle (EV) and grid energy storage techniques. The electrochemical performance of LIBs can be improved by using high capacity positive (e.g., LiNi1/3Mn1/3Co1/3O2, i.e., NMC111) and negative (e.g., silicon) electrodes; both, however, experience severe electrochemical-mechanical degradation caused by the lithiation/delithiation induced volume changes. Understanding mechanical degradation mechanisms and their relationships with the capacity fading of electrodes is important for improving the cycling stability of electrodes as well as optimizing the design of electrodes with high capacity …


A Thermodynamic And Feasibility Study Of Green Solvents For The Fabrication Of Water Treatment Membranes, Xiaobo Dong Jan 2020

A Thermodynamic And Feasibility Study Of Green Solvents For The Fabrication Of Water Treatment Membranes, Xiaobo Dong

Theses and Dissertations--Chemical and Materials Engineering

Nonsolvent induced phase separation (NIPS) has been widely used to fabricate polymeric membranes. In NIPS, a polymer is dissolved in a solvent to form a dope solution, which is then cast on a substrate and immersed in a nonsolvent bath, where phase inversion occurs. Petroleum-derived organic solvents, such as N-Methyl-2-Pyrrolidone (NMP) and Dimethylacetamide (DMAc), have been traditionally used to fabricate polymeric membranes via NIPS. However, these solvents may have negative impacts on environmental and human health; therefore, using greener and less toxic solvents, preferably derived from biomass, is of great interest to make membrane fabrication sustainable. In this dissertation, two …


Heart Tissue Reconstruction By Light-Controlled Cell Adhesion, Patterning And Alignment On Decellularized Scaffolds, Cong Li Jan 2020

Heart Tissue Reconstruction By Light-Controlled Cell Adhesion, Patterning And Alignment On Decellularized Scaffolds, Cong Li

Theses and Dissertations--Chemical and Materials Engineering

There is an urgent demand for engineered tissues and organs because of extremely limited donor tissues available for transplant. The challenge of tissue rejection has motivated many researchers to try to remove all of the cells from a heart and then add back in patient matched cells. These recellularized hearts are a promising avenue towards a functional bioartifical heart that is less likely to be rejected. Decellularized extracellular matrix (ECM) scaffolds generated from animal hearts do not have the cellular components that elicit immune rejection in patient, and they also preserve the native heart tissue structure. While decellularization techniques are …


Effects Of Hole Transporting Layers And Surface Ligands On Interface Energetics And Photovoltaic Performance Of Methylammonium Lead Iodide Perovskites, So Min Park Jan 2020

Effects Of Hole Transporting Layers And Surface Ligands On Interface Energetics And Photovoltaic Performance Of Methylammonium Lead Iodide Perovskites, So Min Park

Theses and Dissertations--Chemical and Materials Engineering

Organic metal halide perovskites are promising materials for various optoelectronic device applications such as light emitting diodes (LED) and photovoltaic (PV) cells. Perovskite solar cells (PSCs) have shown dramatic increases in power conversion efficiency over the previous ten years, far exceeding the rate of improvement of all other PV technologies. PSCs have attracted significant attention due to their strong absorbance throughout the visible region, high charge carrier mobilities, color tunability, and ability to make ultralight weight devices. However, organic metal halide perovskites still face several challenges. For example, their environmental stability issue must be overcome to enable widespread commercialization. Meeting …


Polymeric Nanocomposite Membranes With Phosphorene Based Pore Fillers For Fouling Control, Joyner Eke Jan 2020

Polymeric Nanocomposite Membranes With Phosphorene Based Pore Fillers For Fouling Control, Joyner Eke

Theses and Dissertations--Chemical and Materials Engineering

Phosphorene is a two-dimensional material exfoliated from bulk phosphorus. Specifically, relevant to the field of membrane science, the band gap of phosphorene provides it with potential photocatalytic properties, which could be explored in making reactive membranes able to control the accumulation of compounds on the surface during filtration, or fouling. Another reason phosphorene is a promising candidate as a membrane material additive is due to its catalytic properties which can potentially destroy foulants on the membrane surface.

The first goal of this study was to develop an innovative and robust membrane able to control and reverse fouling with minimal changes …


Applications Of Drones In Atmospheric Chemistry, Travis J. Schuyler Jan 2020

Applications Of Drones In Atmospheric Chemistry, Travis J. Schuyler

Theses and Dissertations--Chemistry

The emission of greenhouse gases (GHGs) has changed the composition of the atmosphere during the Anthropocene. A major technical and scientific challenge is quantifying the resulting fugitive trace gas fluxes under variable meteorological conditions. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating contributions of different processes to radiative forcing. Therefore, the adverse environmental and health effects of undetected gas leaks motivates new methods of detecting, characterizing, and quantifying plumes of fugitive trace gases. Currently, there is no mobile platform able to quantify trace gases at altitudes(UASs), or drones, can be deployed on-site in …


Synthesis Of Metal Oxide Surface And Interface Arrays By A Combined Solid-Liquid- Vapor/Vapor-Liquid-Solid Approach, Alexandra J. Riddle Jan 2020

Synthesis Of Metal Oxide Surface And Interface Arrays By A Combined Solid-Liquid- Vapor/Vapor-Liquid-Solid Approach, Alexandra J. Riddle

Theses and Dissertations--Chemistry

This project was motivated by an in situ heating experiment in the transmission electron microscope (TEM) in which gold (Au) nanoparticles were observed to dissolve tin dioxide (SnO2) nanowires (NWs) under vacuum. The explanation for this observation was that the high-temperature and low-pressure environment of the TEM caused the reverse reaction of the well-known vapor-liquid-solid (VLS) method commonly used to grow NWs. In the VLS process, a metal catalyst absorbs reactant vapor until it becomes supersaturated. The precipitation of the NW occurs at the liquid-solid interface, which ceases when there is no longer reactant vapor, and the diameter of the …


Shape Tuning Of Silicon Nano-Tip Arrays Through Reactive Ion Etching For Cold Field Emission, Giridhar Tulasi Ram Sankabathula Jan 2020

Shape Tuning Of Silicon Nano-Tip Arrays Through Reactive Ion Etching For Cold Field Emission, Giridhar Tulasi Ram Sankabathula

Graduate Research Theses & Dissertations

Large area silicon nano-tip arrays have been predominantly used as cold cathode electron sources in the wide range of field emission applications. Various fabrication methodologies have been developed over the decades to obtain sharp-pointed field emitters. In this thesis, we mainly emphasized on reproducing high aspect ratio field emitters and to study their surface topographical changes encountered through reactive ion etching. A discrete set of high-density field emitters have been fabricated over the large area surfaces through a three-step nanofabrication process. The surface curvatures of the obtained emitter tips are finely tuned with multiple oxidation cycles to achieve a tip’s …


Optimizing Cluster Sets For The Scan Statistic Using Local Search, James Shulgan Jan 2020

Optimizing Cluster Sets For The Scan Statistic Using Local Search, James Shulgan

Graduate Research Theses & Dissertations

In recent years, scattering sensors to produce wireless sensor networks (WSN) has been proposed for detecting localized events in large areas. Because sensor measurements are noisy, the WSN needs to use statistical methods such as the scan statistic. The scan statistic groups measurements into various clusters, computes a cluster statistic for each cluster, and decides that an event has happened if any of the statistics exceeds a threshold. Previous researchers have investigated the performance of the scan statistic to detect events; however, little attention was given to the optimization of which clusters the scan statistic should use. Using the scan …


In-Situ Optoelectronic Powder Flow Measurement Analysis For Directed Energy Deposition Applications, Mark Sliwka Jan 2020

In-Situ Optoelectronic Powder Flow Measurement Analysis For Directed Energy Deposition Applications, Mark Sliwka

Graduate Research Theses & Dissertations

Directed energy deposition (DED) is a metal additive manufacturing method of creating parts by using a high-power laser to fuse powdered metals into fully dense three-dimensional structures. To ensure the geometric and mechanical integrity of the completed part, the powder flow rate of the DED system must be accurate and repeatable for manufacturability. Due to its opacity and reflectivity, one method of measuring powder flow is by utilizing an optoelectronic sensor. The sensor consists of a diode laser with a line generator that emits a thin defocused light sheet, a photodiode, and a set of lenses. The corresponding lens collimates …


Thermal / Structural Analysis Of The Hb 650 Thermal Shield, Gerald J. Smith Jan 2020

Thermal / Structural Analysis Of The Hb 650 Thermal Shield, Gerald J. Smith

Graduate Research Theses & Dissertations

Fermilab’s PIP-II project’s superconducting linear accelerator (Linac) will drive the next generation of particle accelerators through a revolution in beam intensity. Key to beam intensification are the high efficiencies of niobium-tin superconducting radiofrequency (SRF) cavities operating at cryogenic temperatures near 5 Kelvin. A multifaceted approach is employed to achieve and maintain the extreme temperature. Vacuum provides the first barrier to thermal convection. Physical thermal intercept zones further isolate the exterior shell vacuum vessel at 300 Kelvin from the supercooled beamline. The first thermal intercept lies just inside the exterior vacuum vessel forming the 40 Kelvin zone. This 40K thermal shield …


Interfaces In Lead-Free Tin Perovskite Photovoltaics: An Investigation Of Energetics, Ion Mobility, Surface Modification, And Performance, Alex Boehm Jan 2020

Interfaces In Lead-Free Tin Perovskite Photovoltaics: An Investigation Of Energetics, Ion Mobility, Surface Modification, And Performance, Alex Boehm

Theses and Dissertations--Chemistry

Halide perovskites have generated tremendous interest as low-cost semiconductors for optoelectronics, such as photovoltaics, lasers, and light emitting diodes due to their extraordinary optical and transport properties. Perovskite photovoltaics in particular have demonstrated a meteoric rise in power conversion efficiencies and drawn considerable interest as a next-generation solar energy technology. The rapid development has centered around lead-based derivatives, and concerns regarding the toxicity of lead has sparked interest in low toxicity and more environmentally friendly perovskite derivatives. In this regime tin (Sn) is regarded as a prominent alternative owing to the ideal bandgap and reduced toxicity exhibited by Sn-halide perovskites. …


Sequence-Coded Coherent Laser Ranging With High Detection Sensitivity, Keren Shemer, Gil Bashan, H Hagai Diamandi, Yosef London, Tzur Raanan, Yochai Israelashvili, Alon Charny, Itzik Cohen, Arik Bergman, Nadav Levanon, Avi Zadok Jan 2020

Sequence-Coded Coherent Laser Ranging With High Detection Sensitivity, Keren Shemer, Gil Bashan, H Hagai Diamandi, Yosef London, Tzur Raanan, Yochai Israelashvili, Alon Charny, Itzik Cohen, Arik Bergman, Nadav Levanon, Avi Zadok

Advanced Science Research Center

The compression of extended, coded sequences allows for laser ranging measurements with low peak power levels. Previous realizations of this approach were restricted by additive noise of direct, incoherent detection. In this work we bring together pulse sequence coding and optical coherent detection to achieve very high sensitivity. Collected sequences with an overall energy equivalent to only 800 photons are successfully compressed. The observed sensitivity agrees with analytic predictions. Compared with incoherent detection, measurement durations are reduced by four orders of magnitude. The protocol is suitable for laser ranging over tens of kilometers, depending on atmospheric conditions.


Magnetoquasistatic Resonances Of Small Dielectric Objects, Carlo Forestiere, Giovanni Miano, Guglielmo Rubinacci, Mariano Pascale, Antonello Tamburrino, Antonello Tamburrino, Roberto Tricarico, Salvatore Ventre Jan 2020

Magnetoquasistatic Resonances Of Small Dielectric Objects, Carlo Forestiere, Giovanni Miano, Guglielmo Rubinacci, Mariano Pascale, Antonello Tamburrino, Antonello Tamburrino, Roberto Tricarico, Salvatore Ventre

Advanced Science Research Center

A small dielectric object with positive permittivity may resonate when the free-space wavelength is large in comparison with the object dimensions if the permittivity is sufficiently high. We show that these resonances are described by the magnetoquasistatic approximation of the Maxwell's equations in which the normal component of the displacement current density field vanishes on the surface of the particle. They are associated to values of permittivities and frequencies for which source-free quasistatic magnetic fields exist, which are connected to the eigenvalues of a magnetostatic integral operator. We present the general physical properties of magnetoquasistatic resonances in dielectrics with arbitrary …


Demonstration Of A Quantized Acoustic Octupole Topological Insulator, Xiang Ni, Mengyao Li, Matthew Weiner, Andrea Alù, Alexander B. Khanikaev Jan 2020

Demonstration Of A Quantized Acoustic Octupole Topological Insulator, Xiang Ni, Mengyao Li, Matthew Weiner, Andrea Alù, Alexander B. Khanikaev

Advanced Science Research Center

Recently introduced quantized multipole topological insulators (QMTIs) reveal new types of gapped boundary states, which themselves represent lower-dimensional topological phases and host symmetry protected zero-dimensional corner states. Inspired by these predictions, tremendous efforts have been devoted to the experimental observation of quantized quadrupole topological phase. However, due to stringent requirements of anti-commuting reflection symmetries, it is challenging to achieve higher-order quantized multipole moments, such as octupole moments, in a three-dimensional structure. Here, we overcome this challenge, and experimentally realize the acoustic analogue of a quantized octupole topological insulator using negatively coupled resonators. We confirm by first-principle studies that our design …


Larger-Scale Ocean-Atmospheric Patterns Drive Synergistic Variability And World-Wide Volatility Of Wheat Yields, Ehsan Najafi, Indrani Pal, Reza Khanbilvardi Jan 2020

Larger-Scale Ocean-Atmospheric Patterns Drive Synergistic Variability And World-Wide Volatility Of Wheat Yields, Ehsan Najafi, Indrani Pal, Reza Khanbilvardi

Advanced Science Research Center

Diagnosing potential predictability of global crop yields in the near term is of utmost importance for ensuring food supply and preventing socio-economic consequences. Previous studies suggest that a substantial proportion of global wheat yield variability depends on local climate and larger-scale ocean-atmospheric patterns. The science is however at its infancy to address whether synergistic variability and volatility (major departure from the normal) of multi-national crop yields can be potentially predicted by larger-scale climate drivers. Here, using observed data on wheat yields for 85 producing countries and climate variability from 1961–2013, we diagnose that wheat yields vary synergistically across key producing …


Demonstration Of A Third-Order Hierarchy Of Topological States In A Three-Dimensional Acoustic Metamaterial, Matthew Weiner, Xiang Ni, Mengyao Li, Andrea Alù, Alexander B. Khanikaev Jan 2020

Demonstration Of A Third-Order Hierarchy Of Topological States In A Three-Dimensional Acoustic Metamaterial, Matthew Weiner, Xiang Ni, Mengyao Li, Andrea Alù, Alexander B. Khanikaev

Advanced Science Research Center

Classical wave systems have constituted an excellent platform for emulating complex quantum phenomena, such as demonstrating topological phenomena in photonics and acoustics. Recently, a new class of topological states localized in more than one dimension of a D-dimensional system, referred to as higher-order topological (HOT) states, has been reported, offering an even more versatile platform to confine and control classical radiation and mechanical motion. Here, we design and experimentally study a 3D topological acoustic metamaterial supporting third-order (0D) topological corner states along with second-order (1D) edge states and first-order (2D) surface states within the same topological bandgap, thus establishing …


University-Community Partnership For Water Technology Deployment And Co-Innovation: A Decade Of Engagement, Paul M. Cabacungan, Gregory L. Tangonan, Nerissa G. Cabacungan Jan 2020

University-Community Partnership For Water Technology Deployment And Co-Innovation: A Decade Of Engagement, Paul M. Cabacungan, Gregory L. Tangonan, Nerissa G. Cabacungan

Ateneo Innovation Center

The Ateneo de Manila University (Philippines), through its Ateneo Innovation Center (AIC), integrated existing simple technologies into one system – the Water-Electricity-Lighting System (WELS) – to respond to the need for potable water, lighting and communication. WELS is a portable clean water system with provision for lighting and cellular phone charging. It can be connected to a rainwater harvesting facility. Ten years of WELS deployments revealed its flexibility for customization in order to address varied water needs, especially for disaster response. Review of documentations done on past installation experiences highlights the value of engagement between university-based technology providers and community-recipients. …


Adaptive Filtration Of The Uav Movement Parameters Based On The Aoa-Measurement Sensor Networks, Igor Tovkach, Serhii Zhuk Jan 2020

Adaptive Filtration Of The Uav Movement Parameters Based On The Aoa-Measurement Sensor Networks, Igor Tovkach, Serhii Zhuk

International Journal of Aviation, Aeronautics, and Aerospace

Currently, the urgent task is to assess the small-sized maneuvering UAVs movement parameters. The location of an unknown UAV as a radio source can be determined using AoA measurements of the wireless sensor network. To describe the movement of a maneuvering UAV, a model is used in the form of a dynamic system with switching in discrete time. The values of switching variable determine type of UAV movement. To synthesize trajectory filtering algorithms, the Markov property of the extended process is used, which includes a vector of UAV movement parameters and a switching variable. The optimal trajectory filtering algorithm describes …