gebhart/patrepeval huggingface dataset:
Virtual impactor-based label-free bio-aerosol detection using holography and deep learning (2022)

Exposure to bio-aerosols such as mold spores and pollen can lead to adverse health effects. There is a need for a portable and cost-effective device for long-term monitoring and quantification of various bio-aerosols. To address this need, we present a mobile and cost-effective label-free bio-aerosol sensor that takes holographic images of flowing particulate matter concentrated by a virtual impactor, which selectively slows down and guides particles larger than ~6 microns to fly through an imaging window. The flowing particles are illuminated by a pulsed laser diode, casting their inline holograms on a CMOS image sensor in a lens-free mobile imaging device. The illumination contains three short pulses with a negligible shift of the flowing particle within one pulse, and triplicate holograms of the same particle are recorded at a single frame before it exits the imaging field-of-view, revealing different perspectives of each particle. The particles within the virtual impactor are localized through a differential detection scheme, and a deep neural network classifies the aerosol type in a label-free manner, based on the acquired holographic images. We demonstrated the success of this mobile bio-aerosol detector with a virtual impactor using different types of pollen (i.e., bermuda, elm, oak, pine, sycamore, and wheat) and achieved a blind classification accuracy of 92.91%. This mobile and cost-effective device weighs ~700 g and can be used for label-free sensing and quantification of various bio-aerosols over extended periods since it is based on a cartridge-free virtual impactor that does not capture or immobilize particulate matter.
Mid-IR quantum cascade lasers and amplifiers: recent developments and applications (2004)

This talk will give an overview of the most recent results on the realization of new quantum cascade laser devices and the perspective of their innovative applications in the mid-infrared range of the spectrum.
Millimeter-Wave Reconfigurable Adaptive Hybrid Beamformers for MIMO Communication (2020)

Millimeter-wave multi-input-multi-output (MIMO) communication, based on beamforming, is a revolutionary new element in wireless systems including 5G/beyond-5G cellular, WiFi, radar etc. Highly integrated beamforming transceivers supporting basic directional communication through beam-steering, thereby improving the link-budget are reaching maturity. However, to further enhance the data rates and network capacity, advanced multi-antenna spatial signal processing techniques will be necessary in future wireless systems. This research introduces several systemic, architectural and circuit techniques that enable advanced spatial processing. Several millimeter-wave prototype chips implementing “hybrid beamforming” have been designed. Characterization of these prototypes conducted in lab and on-air settings showcase the mentioned techniques while achieving excellent system energy efficiency. This dissertation makes the following seven key contributions: 1) It introduces a “fully-connected” hybrid MIMO/beamforming architecture. Circuit architecturesand design techniques are introduced to implement RF-domain spatio-temporal signal processing, and in turn, facilitate a compact, energy-efficient and spectrally efficientembodiment. 2) The fully-connected hybrid architecture is extended to enable reconfiguration across multiple MIMO modes in disparate mm-wave frequency bands (e.g., 28/37 GHz), and an inter-band full-aperture carrier aggregation(CA) mode. 3) Beam adaptation techniques that enable adaptive beam and null formation in hybrid beamformers and RF phased arrays are introduced. Onchip implementations using a new time-multiplexed least mean square scheme are described. 4) A fundamental challenge in MIMO transmitter design due to the increase in peak-to-average-power-ratio is studied. The system energy efficiencies of several hybrid MIMO architectures across various power amplifier topologies are compared rigorously via analysis and experiment. 5) A new architecture is introduced that directly enables simultaneous transmit and receive (STAR) beamforming for multi-antenna frequency-division-duplexing (FDD) or full-duplex (FD) communicationwith a per-element self-interference cancellation scheme. 6) Hybrid MIMO architectures with multi-layer spatial signal processing that mitigate complexity versus spectral-efficiency tradeoffs of single-layer hybrid beamforming architectures are proposed; in addition, these architectures facilitate efficient upward scaling of the number of supported MIMO streams and users. 7) A compact, bidirectionaltransceiver architecture and constituent circuit techniques are proposed which enable dual-band transceiver operation. These techniques allow the transceiver to be reconfigurablebetween numerous transmit/receive configurations that combine MIMO, CA, TDD, FDD and FD functionalities.
Challenges & Physical Insights Into the Design of Fin-Based SCRs and a Novel Fin-SCR for Efficient On-Chip ESD Protection (2018)

This paper presents the detailed physical insights into the silicon-controlled rectifier (SCR) phenomena in planar equivalent Fin SCR devices. The complexity and roadblocks for SCR triggering in FinFET technology are explored. Implication of contact silicidation on Fin SCR turn-ON is discussed in detail. Device design approaches are discussed for efficient Fin-enabled SCRs. In this direction, a novel contact engineering scheme in Fin technology is disclosed for improved SCR action. Moreover, a novel Fin SCR is presented, which offers area-efficient electrostatic discharge current carrying capability.
Relaxing Substrate Specificity in Antibody-Catalyzed Reactions:  Enantioselective Hydrolysis of <i>N</i>-Cbz-Amino Acid Esters (1996)

For a catalytic antibody to be generally useful for organic synthetic chemistry, it must be able to accept a broad range of substrates, yet retain high selectivity. In this work, we propose a hapten design to endow antibody catalysts with two opposing qualities, such as high enantioselectivity and broad substrate specificity. Racemic hapten 2 induced two separate classes of catalytic antibodies to hydrolyze either the l- or d-isomers of N-Cbz-amino acid esters 1. In the kinetic resolution of racemic ester 9, antibodies 7G12 and 3G2 gave 96% ee of l-10 and 94% ee of d-10, respectively. In addition, antibody 7G12 displayed broad substrate specificity, hydrolyzing the l-esters of Ala (1a), Leu (1b), Norleu (1c), Met (1d), Phe (1e), Val (1f), and phenylglycine (1g) with high enantioselectivity. Antibody 3G2 also hydrolyzed the d-isomers of these esters without sacrificing the enantioselectivity. This observation suggests that the use of haptens that fit snugly into the antigen-combining site, and leave the linker moiety outside, is an effective approach for the generation of catalytic antibodies with high selectivity and broad substrate applicability.
Cut-demand based routing resource allocation and consolidation for routability enhancement (2011)

To successfully route a design, one essential requirement is to allocate sufficient routing resources. In this paper, we show that allocating routing resources based on horizontal and vertical (H/V) cut-demands can greatly improve routability especially for designs with thin areas. We then derive methods to predict the maximum H/V cut-demands and propose two cut-demand based approaches, one is to allocate routing resources considering the maximum H/V cut-demands and the other is to consolidate fragmented metal-1 routing resources for effective resource utilization. Experimental results demonstrate that the resource allocation method can precisely determine design areas and the resource consolidation method can significantly improve routability. With better routability, the routing time is about 5 times faster on average and the design area can be further reduced by 2--15%.
Monoclonal Antibodies Bind A SNP-Sensitive Epitope that is Present Uniquely in Mycobacterium avium Subspecies Paratuberculosis (2011)

Due to a close genetic relatedness, there is no known antibody that detects Mycobacterium avium subspecies paratuberculosis (MAP), which causes Johne's disease in cattle and sheep, and does not cross-react with other M. avium subspecies. In the present study, a monoclonal antibody (MAb; 17A12) was identified from mice immunized with a cell membrane fraction of MAP strain K-10. This antibody is 100% specific as it detected a 25-kDa protein in all 29 MAP whole cell lysates, but did not bind to any of the 29 non-paratuberculosis strains tested in immunoblot assays. However, the antibody revealed variable reactivity levels in MAP strains as it detected higher levels in bovine isolates but comparably lower levels in ovine isolates of MAP. In order to identify the target binding protein for 17A12, a lambda phage expression library of MAP genomic fragments was screened with the MAb. Four reactive clones were identified, sequenced and all shown to be overlapping. Further analysis revealed all four clones expressed an unknown protein encoded by a sequence that is not annotated in the K-10 genome and overlapped with MAP3422c on the opposing DNA strand. The epitope of 17A12 was precisely defined to seven amino acids and was used to query the K-10 genome. Similarity searches revealed another protein, encoded by MAP1025, possessed a similar epitope (one-amino acid mismatch) that also reacted strongly to the antibody. A single nucleotide polymorphism (SNP) in MAP1025 was then identified by comparative sequence analysis, which results in a Pro28His change at residue 28, the first amino acid within the 17A12 epitope. This SNP is present in all MAP strains but absent in all non-MAP strains and accounts for the specificity of the 17A12 antibody. This new antibody is the first ever isolated that binds only to the paratuberculosis subspecies of M. avium and opens new possibilities for the specific detection of this significant ruminant pathogen.
Ultrabright Laser-Compton Light Sources and Novel Applications (2018)

The development, optimization and applications of compact, high-peak and high-average brilliance laser-Compton x-ray and gamma-ray sources is reviewed. Potential applications range from nuclear photonics to precision medical imaging and theranostics.
Functionalized Polymers and Surfaces via Ring-Opening Metathesis Polymerization (2005)

The research presented in this thesis focuses on the preparation of functionalized polymers using olefin metathesis polymerization methods. A portion of this research is also devoted to the development of applications for metathesis-derived polymers. Three distinct types of olefin metathesis polymerizations can be recognized within this work. Ring-opening metathesis polymerization (ROMP) is the most prevalent type, followed by acyclic diene metathesis (ADMET) polymerization and a hybrid of the ROMP and ADMET mechanisms known as ring-opening-insertion metathesis polymerization (ROIMP). Many of the concepts that appear throughout this thesis are introduced in Chapter 1. Olefin metathesis occupies a central role in each of the subsequent chapters; detailed descriptions of the mechanism and important olefin metathesis catalysts are provided. The chapter also includes background information regarding polymers, polymer properties and the application of ROMP in the construction of electronic devices. Although the utility of ADMET does not yet seem to match that of ROMP, valuable information can be obtained from ADMET polymerizations. In an effort to elucidate catalytic activity, Chapter 2 details a comparison of the ADMET polymerizations of terminal and non-terminal dienes. Experimental investigations involving ROIMP, a novel method for the production of A,B-alternating copolymers, is presented in Appendix A. The mechanism of ROIMP is conceptually very different from the mechanisms of either step growth or chain growth polymerizations. Efforts toward understanding the mechanism of ROIMP using a mathematical model are discussed in Chapter 3. Polymeric chain transfer agents (PCTAs) suitable for ROMP reactions are polymers that contain a single, metathesis-active olefin. These polymers are the focus of Chapter 4 and can be used in the preparation of novel block copolymers. As an example, Appendix B presents the preparation of block copolymers consisting of polyacetylene and various commodity polymers. Finally, the development of applications for surface-initiated ROMP (SI-ROMP) is discussed in Chapter 5 and Appendix C. Polymer films prepared using SI-ROMP are shown to be viable dielectric layers in thin-film transistors, and research is presented involving microcontact printing and dip pen nanolithography as methods for forming patterned SI-ROMP polymer films.
Identification, Characterization, and Formulation of a Novel Carbapenemase Intended to Prevent Antibiotic-Mediated Gut Dysbiosis (2019)

Antibiotics can damage the gut microbiome leading to opportunistic infections and the emergence of antibiotic resistance. Microbiome protection via antibiotic inactivation in the gastrointestinal (GI) tract represents a strategy to limit antibiotic exposure of the colonic microbiota. Proof of concept for this approach was achieved with an orally-administered beta-lactamase enzyme, SYN-004 (ribaxamase), that was demonstrated to degrade ceftriaxone excreted into the GI tract and protect the gut microbiome from antibiotic-mediated dysbiosis. Ribaxamase efficiently degrades penicillin and cephalosporin beta-lactam antibiotics, but is not active against carbapenems. To expand this microbiome protection strategy to include all classes of beta-lactams, three distinct carbapenemases were evaluated for manufacturability, antibiotic degradation spectrum, and stability in human intestinal fluid. <i>E. coli</i> production strains were generated for P2A, a novel metallo-enzyme isolated from <i>B. cereus</i>, New Delhi metallo-beta-lactamase (NDM), and <i>Klebsiella pneumoniae</i> carbapenemase (KPC). While all three enzymes effectively inactivated a broad range of antibiotics, including penicillins, most cephalosporins, and carbapenems in vitro, only P2A retained biological activity when incubated with human chyme. As functional stability in the intestinal tract is a key requirement for an orally-delivered enzyme, P2A was chosen as a potential clinical candidate. An enteric formulation of P2A was developed, called SYN-006, that was inert under high acid conditions, with enzyme dissolution occurring at pH > 5.5. SYN-006 has the potential to expand microbiome protection via antibiotic inactivation to include all classes of beta-lactam antibiotics.
Design Considerations for Robust Noise Rejection in Otoacoustic Emissions Measured In-Field Using Adaptive Filtering (2017)

Otoacoustic emission (OAE) measurement is a sensitive and effective technique to monitor changes in the inner ear potentially induced by noise exposure. However, outside a controlled testing environment, measurements are challenging since the level of ambient noise might be higher than the low-level OAE response. Therefore, an OAE system was designed, suitable to measure OAEs repeatedly on an individual worker in noisy test conditions. This system features a left and right earpiece, each equipped with a pair of miniature loudspeakers, an external and an internal microphone. In addition to the passive attenuation of the earpiece, adaptive filtering on the distortion product OAE (DPOAE) signals is used to further enhance the ratio between the measured OAE signal and interfering noise. The adaptive filtering technique uses the sound captured by the ipsilateral external and internal microphones as well as from the contralateral internal and external microphones. In this paper, the accuracy of DPOAE signals are studied using different combinations of the four microphones in single and dual adaptive filter topologies, as well as the benefits of adding a fixed transfer function in the adaptive filtering algorithm topology to estimate the acoustic path. Side-by-side comparison shows that a dual-stage adaptive filtering algorithm, using a combination of the contralateral internal microphone with the ipsilateral external microphone, is the most promising approach to denoise the DPOAE signal.
Complementary planar terahertz metamaterials (2007)

Planar electric split ring resonator (eSRR) metamaterials and their corresponding inverse structures are designed and characterized computationally and experimentally utilizing finite element modeling and THz time domain spectroscopy. A complementary response is observed in transmission. Specifically, for the eSRRs a decrease in transmission is observed at resonance whereas the inverse structures display an increase in transmission. The frequency dependent effective complex dielectric functions are extracted from the experimental data and, in combination with simulations to determine the surface current density and local electric field, provide considerable insight into the electromagnetic response of our planar metamaterials. These structures may find applications in the construction of various THz filters, transparent THz windows, or THz grid structures ideal for constructing THz switching/modulation devices.
Hierarchical video caching in wireless cloud: Approaches and algorithms (2012)

We had introduced video caching techniques in the Radio Access Network (RAN) in [1] as a way to reduce the need to bring requested videos from Internet CDNs, thus reducing overall backhaul traffic, improving video quality of experience and increasing network capacity to support more simultaneous video requests. In this paper, we investigate supplementing the resulting wireless cloud with a hierarchical caching scheme, where the gateways in the Core Network (CN) also have video caches. The hierarchical caching approach further improves network capacity by enabling multiple cell sites to share caches at higher levels of the hierarchy, thereby improving overall cache hit ratio, without increasing the total cache size used. In addition, we exploit hierarchical caching to better accommodate mobility, so that when a user with an active video session moves from one cell to a neighboring cell, it is likely that the video currently being downloaded is already in a cache within the RAN or CN network associated with the new cell. To achieve the goal of improving capacity and supporting mobility, we extend our User Preference Profile (UPP) based caching policies [1] to accommodate the hierarchical caching structure introduced in this paper. For all the videos that miss the cache in any layer of hierarchy, we propose a scheduling approach to allocate RAN and CN backhaul resources judiciously so as to maximize the capacity of the wireless network. We extend our discrete event statistical simulation framework developed in [1] to study the performance of the proposed hierarchical caching approach. Our simulation results show that using hierarchical caching can enhance cache hit ratio by 24% and network capacity by up to 45% compared to caching only in the RAN. Significant capacity gains are also observed when additionally considering user mobility.
Sensitive, On-Line Turn-to-Turn Fault Detection in AC Motors (2000)

Abstract Turn-to-turn fault detection is based on the principle that symmetrical (unfaulted) motors powered by symmetrical multiphase voltage sources will have no negative sequence currents flowing in the leads. A turn-to-turn fault will break that symmetry and give rise to a negative sequence current which may then be used as a measure of fault severity or to initiate protective action, such as a circuit breaker trip. A new way of looking at the effects of turn faults has been developed that improves sensitivity andspeedwhile reducing the probability of misdetection, taking into account voltage balance, load or voltage variation, and instrument errors. The method has been implemented on a PC and tested, in real time, with controllable faults in a small motor. Reliable detection of one shorted turn out of 648 turns per phase (in a Y-connected motor) was demonstrated with the fault indicator becoming fully developed in two cycles of line frequency after initiation of the fault.
Novel Specimen Design for Measurement of In-Plane Fracture Toughness of Metals (2019)

Abstract Standard-compliant measurement of the in-plane fracture toughness of metals is often challenging due to insufficient material in the through-thickness direction to extract a full single edge bending (SEB) or compact tension (CT) fracture specimen. In the present work, we propose a new specimen design methodology to overcome this challenge. A W-shaped SEB specimen (called W-SEB) was developed, and its topology was optimized using finite element simulations. The new specimen design was validated numerically and experimentally on a case study showing excellent agreement with standard ASTM E1820 actual SEB specimen geometry. In view assessing the anisotropy of the fracture toughness (KQ and crack tip opening displacement (CTOD)) of pipeline steels susceptible to hydrogen-induced cracking (HIC), the W-SEB specimen was tested on X65 and X42 pipeline steel samples taken from the field. Experimental results show an increase in the maximum CTOD along the in-plane direction as compared to the transverse direction for both steel grades. Such experimental results could lead to important considerations with respect to accurate fitness for service assessment of HIC-damaged assets.
Aliphatic propargylamines: potent, selective, irreversible monoamine oxidase B inhibitors (1992)

A series of aliphatic propargylamine derivatives has been synthesized. Some of them possess highly potent, irreversible, selective, inhibitory activity toward monoamine oxidase B (MAO-B). The potency of the inhibitors is related to chain length and substitution of a hydrogen on the terminal carbon of the aliphatic chain. MAO inhibitory activity as assessed in vitro increased as the aliphatic carbon chain length increased. Substitution of a hydrogen by hydroxyl, carboxyl, or carbethoxyl groups at the aliphatic chain terminal or replacement of the methyl group on the nitrogen atom by an ethyl group considerably reduced the inhibitory activity. Stereospecific effects were observed with the R-(-)-enantiomer being 20-fold more active than the S-(+)-enantiomer. Inhibitors with relatively short carbon chain lengths (i.e. four to six carbons) were found to be more potent than those with longer chains in inhibiting brain MAO-B activity in vivo especially after oral administration. Chronic administration of low doses of the aliphatic propargylamines caused a slight cumulative inhibition of MAO-A activity in the mouse brain. These MAO-B inhibitors appear to be nontoxic, and they do not possess an amphetamine-like moiety in their structure as is the case for deprenyl. We expect that these aliphatic propargylamines may be useful in the treatment in certain neuropsychiatric disorders.