gebhart/patrepeval huggingface dataset:
COHERENT THZ FREQUENCY RADIATION FROM SHOCK WAVES: A NEW ULTRAFAST STRAIN WAVE DETECTION MECHANISM (2007)

We discover that strain waves of THz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. By considering AlN/GaN heterostructures, we show that the radiation is of detectable amplitude and contains sufficient information to determine the time‐dependence of the strain wave with potentially unprecedented nearly atomic time and space resolution. We demonstrate this phenomenon within the context of high amplitude THz frequency strain waves that spontaneously form at the front of shock waves in GaN crystals. We have performed proof of principle experiments that demonstrate THz signals that correlate with strain wave propagation times across Al thin films.
A novel compensation method for the anode gain non-uniformity of multi-anode photomultiplier tubes (2011)

The position-sensitive multi-anode photomultiplier tube (MA-PMT) is widely used in high-resolution scintillation detectors. However, the anode gain nonuniformity of this device is a limiting factor that degrades the intrinsic performance of the detector module. The aim of this work was to develop a gain compensation method for the MA-PMT and evaluate the resulting enhancement in the performance of the detector. The method employs a circuit that is composed only of resistors and is placed between the MA-PMT and a resistive charge division network (RCN) used for position encoding. The goal of the circuit is to divide the output current from each anode, so the same current flows into the RCN regardless of the anode gain. The current division is controlled by the combination of a fixed-value series resistor with an output impedance that is much larger than the input impedance of the RCN, and a parallel resistor, which detours part of the current to ground. PSpice simulations of the compensation circuit and the RCN were performed to determine optimal values for the compensation resistors when used with Hamamatsu H8500 MAPMTs. The intrinsic characteristics of a detector module consisting of this MA-PMT and a lutetium-gadolinium-oxyorthosilicate (LGSO) crystal array were tested with and without the gain compensation method. In simulation, the average coefficient of variation and max/min ratio decreased from 15.7% to 2.7% and 2.0 to 1.2, respectively. In the flood map of the LGSO-H8500 detector, the uniformity of the photopeak position for individual crystals and the energy resolution were much improved. The feasibility of the method was shown by applying it to an octagonal prototype positron emission tomography scanner.
Design considerations of phoswich detectors for high resolution positron emission tomography (2007)

A way to improve the spatial resolution in positron emission tomography (PET) is to determine the depth-of- interaction (DOI) in the detector. A way to achieve this is to use the phoswich approach, a detector with two or more layers of different scintillators. The layer identification is done by using differences in scintillation decay time and pulse shape discrimination techniques. The advantages of the concept have been demonstrated in the HRRT high resolution PET system using a LSO/LYSO combination giving a high spatial resolution uniformity of around 2.5 mm within a larger part of the imaged volume. A phoswich combination that lately has received attention is LuAP/LSO or LuYAP/LSO. The suggestions come from the Crystal Clear Collaboration and there is a patent application for its use in PET. This particular combination of phoswich has, however, a complication since both LuAP and LuYAP emits in the excitation band of LSO, thus limiting the functionality. In the present paper we have looked into this and suggested different ways to overcome these drawbacks.
A multifunctional amphiphilic polymer as a platform for surface-functionalizing metallic and other inorganic nanostructures (2014)

We designed a new set of polymer ligands that combine multiple metal-coordinating groups and short polyethylene glycol (PEG) moieties in the same structure. The ligand design relies on the controlled grafting of a large number of amine-terminated histamines and PEG short chains onto a poly(isobutylene-alt-maleic anhydride) backbone, via a one-step nucleophilic addition reaction. This addition reaction is highly efficient, can be carried out in organic media and does not require additional reagents. We show that when imidazole groups are used the resulting polymer ligand can strongly ligate onto metal nanostructures such as nanoparticles (NPs) and nanorods (NRs) made of gold cores. The resulting polymer-coated NPs and NRs exhibit good colloidal stability to pH changes and added electrolytes. This constitutes a departure from the use of thiol-based ligands to coordinate on Au surfaces. The present chemical approach also opens up additional opportunities for designing hydrophilic and reactive platforms where the polymer coating can be adjusted to various metal and metal oxide surfaces by simply modifying or combining the addition reaction with other metal coordinating groups. These could include iron oxide NPs and semiconductor QDs. These polymer-capped NPs and NRs can be used to develop biologically-active platforms with potential use for drug delivery and sensing.
Quantitative analysis of three‐dimensional fluid flow in rotating bioreactors for tissue engineering (2004)

Tissue engineering has emerged as a viable alternative to the problem of organ and tissue shortage. Our laboratory has developed matrices for bone tissue engineering based on sintered spherical particles and, using bioreactor technology, has demonstrated the ability to produce highly mineralized matrices in vitro. In this study, porous microcapsule scaffolds were developed for bone tissue engineering in the high aspect ratio vessel rotating bioreactor. The motion of individual microcapsules as well as scaffolds in the bioreactor were studied by numerical simulation and in situ imaging analysis. Results show that spherical microcapsules with density less than the surrounding fluid exhibited two motions: (1) a periodic circular orbit with tangential speed equal to the free fall speed of the particle, and (2) an inward radial migration of the circular orbit toward the center of the bioreactor vessel. Lighter-than-water scaffolds were fabricated by sintering poly(lactic-co-glycolic acid) hollow microcarriers with diameter from 500 to 860 microm into a fixed three-dimensional geometry with approximately 30% pore volume and 180 to 190 microm median pore size. Scaffolds were fabricated with aggregate densities ranging from 0.65 g/mL and 0.99 g/mL by appropriate combinations of hollow and solid microcarriers within the scaffold. Scaffold velocity in the bioreactor for the above range of densities was accurately predicted by numerical simulation and ranged from 100 mm/s to 3 mm/s. Maximum shear stress estimation due to media flow over the exterior of the scaffold ranged from 0.3 N/m(2) to 0.006 N/m(2). Internal perfusion velocity through scaffolds also was calculated and ranged from 13 mm/s to 0.2 mm/s. Estimates of maximum interior shear stress ranged from 0.03 to 0.0007 N/m(2). These analytical methods provide an excellent vehicle for the study of bone tissue synthesis in three-dimensional culture with fluid flow.
Small-Pore Zeolites: Synthesis and Catalysis (2018)

In the past decade or so, small-pore zeolites have received greater attention than large- and medium-pore molecular sieves that have historically dominated the literature. This is primarily due to the commercialization of two major catalytic processes, NOx exhaust removal and methanol conversion to light olefins, that take advantage of the properties of these materials with smaller apertures. Small-pore zeolites possess pores that are constructed of eight tetrahedral atoms (Si<sup>4+</sup> and Al<sup>3+</sup>), each time linked by a shared oxygen These eight-member ring pores (8MR) provide small molecules access to the intracrystalline void space, e.g., to NOx during car exhaust cleaning (NOx removal) or to methanol en route to its conversion into light olefins, while restricting larger molecule entrance and departure that is critical to overall catalyst performance. In total, there are forty-four structurally different small-pore zeolites. Forty-one of these zeolites can be synthesized, and the first synthetic zeolite (KFI, 1948) was in fact a small-pore material. Although the field of 8MR zeolite chemistry has expanded in many directions, the progress in synthesis is framework-specific, leaving insights and generalizations difficult to realize. This review first focuses on the relevant synthesis details of all 8MR zeolites and provides some generalized findings and related insights. Next, catalytic applications where 8MR zeolites either have been commercialized or have dominated investigations are presented, with the aim of providing structure-activity relationships. The review ends with a summary that discusses (i) both synthetic and catalytic progress, (ii) a list of opportunities in the 8MR zeolite field, and (iii) a brief future outlook.
A novel gate boosting circuit for 2-phase high voltage CMOS charge pump (2009)

A novel gate boosting circuit is proposed for general switched-capacitor charge pump. The proposed circuit only requires two small transistors to generate the necessary driving signal from a clock signal that swings between 0V to V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DD</sub> for closing and opening the charge transfer switches in the charge pump. As a result, the proposed gate boosting circuit reduces the design complexity and silicon area. Moreover, the regular structure eases the layout and increases the reliability of the implemented charge pump. A 3× Makowski charge pump implemented by the proposed gate boosting element is simulated. An output voltage closed to the ideal one shows that the proposed gate boosting circuit is suitable to be used in designing high efficiency charge pumps.
Sertoli cell ablation and replacement of the spermatogonial niche in mouse (2020)

Spermatogonia, which produce sperm throughout the male lifetime, are regulated inside a niche composed of Sertoli cells, and other testis cell types. Defects in Sertoli cells often lead to infertility, but replacement of defective cells has been limited by the inability to deplete the existing population. Here, we use an FDA-approved non-toxic drug, benzalkonium chloride (BC), to deplete testis cell types in vivo. Four days after BC administration, Sertoli cells are preferentially depleted, and can be replaced to promote spermatogenesis from surviving (host) spermatogonia. Seven days after BC treatment, multiple cell types can be engrafted from fresh or cryopreserved testicular cells, leading to complete spermatogenesis from donor cells. These methods will be valuable for investigation of niche-supporting cell interactions, have the potential to lead to a therapy for idiopathic male infertility in the clinic, and could open the door to production of sperm from other species in the mouse.
Ultrasmall Sub-10 nm Near-Infrared Fluorescent Mesoporous Silica Nanoparticles (2012)

Ultrasmall sub-10 nm nanoprobes and carriers are of significant interest due to their favorable biodistribution characteristics in in vivo experiments. Here we describe the one-pot synthesis of PEGylated mesoporous silica nanoparticles with a single pore, tunable sizes around 9 nm and narrow size distributions that can be labeled with near-infrared dye Cy5.5. Particles are characterized by a combination of transmission electron microscopy, dynamic light scattering, fluorescence correlation spectroscopy, optical spectroscopy, nuclear magnetic resonance spectroscopy, and nitrogen sorption/desorption measurements. The possibility to distinguish an "inside" and "outside" may render these particles an interesting subject for further studies in sensing, drug delivery, and theranostics applications.
Enhancing human color vision by breaking binocular redundancy (2017)

To see color, the human visual system combines the response of three types of cone cells in the retina--a compressive process that discards a significant amount of spectral information. Here, we present an approach to enhance human color vision by breaking its inherent binocular redundancy, providing different spectral content to each eye. We fabricated a set of optical filters that "splits" the response of the short-wavelength cone between the two eyes in individuals with typical trichromatic vision, simulating the presence of approximately four distinct cone types ("tetrachromacy"). Such an increase in the number of effective cone types can reduce the prevalence of metamers--pairs of distinct spectra that resolve to the same tristimulus values. This technique may result in an enhancement of spectral perception, with applications ranging from camouflage detection and anti-counterfeiting to new types of artwork and data visualization.
Terahertz-wave generation in periodically-inverted GaAs (2005)

Efficient generation of narrow-band terahertz-wave pulses tunable in the 2-3 THz frequency range was achieved in periodically-inverted GaAs; structures pumped by 100-fs pulses tunable between 2 and 4 microns, via mechanism of quasi-phase-matched optical rectification.
Investigation of the stability of polyelectrolyte multilayer coatings in open‐tubular capillary electrochromatography using laser scanning confocal microscopy (2005)

A simple polyelectrolyte multilayer (PEM) coating procedure was used for the development of stable modified capillaries. PEM coatings were constructed in fused-silica capillaries using alternating rinses of cationic and anionic polyelectrolytes. The multilayer coatings investigated in this study consisted of two and twenty layer pairs, or bilayers. A bilayer is one layer of a cationic polymer and one layer of an anionic polymer. Poly(diallyldimethylammonium chloride) was used as the cationic polymer, and the polymeric surfactant poly(sodium N-undecanoyl-L-leucylvalinate) was used as the anionic polymer. Previous studies for both chiral and achiral separations have shown that PEM-coated capillaries have excellent reproducibilities, remarkable endurance, and strong stabilities against extreme pH values when used in open-tubular capillary electrochromatography (OT-CEC). In this study, the stability of the coatings was further investigated after exposure to 0.1 M and 1.0 M NaOH. Structural changes of these coatings were monitored using laser scanning confocal microscopy (LSCM) after flushing the capillaries with NaOH. This technique allowed observation of the degradation of the coatings. Observations are discussed in terms of separations using OT-CEC. Electropherograms obtained from the chiral separation of 1,1'-binaphthyl-2,2'-dihydrogenphosphate in OT-CEC showed a decrease in selectivity and an increase in electroosmotic mobility after long exposure to NaOH. The ability to recover the capillaries by exposure to NaOH was also demonstrated. Measurements of electroosmotic mobility and selectivity showed that 2-bilayer and 20-bilayer PEM coatings could be completely removed from the capillary surface after approximately 3.5 and 9.5 h, respectively, of continuous exposure to 1 M NaOH.
Physical reconfiguration of an origami-inspired deployable microstrip patch antenna array (2017)

The physical reconfiguration and deployment of a 2×2 corporate-fed microstrip patch antenna array is investigated. The origami-inspired antenna array reconfigures structurally using a Miura-ori fold pattern to deploy to/from a compact folded state from/to a flat state. The impact of folding on the electromagnetic performance is evaluated across a range of physical states to study the impact of physical reconfiguration. In particular, the input impedance and beamforming capabilities are used to characterize the performance as a function of the primary folding parameter. These performance metrics are impacted by a feed network that extends across the folds and the beamforming capabilities that are impacted by the changing element spacing and orientation. Results from simulation and a fabricated structure are provided for a 2.4 GHz design.
<title>Design and fabrication of optical MEMS using a four-level planarized surface-micromachined polycrystalline silicon process</title> (1998)

This paper describes the design and fabrication of optical microelectromechanical systems devices using the Sandia Ultra-planar Multi-level MEMS Technology fabrication process. This state-of-the-art process, offered by Sandia National Laboratories, provides unique and very advantageous features which make it ideal for optical devices such as micromirrors. This enabling process permits the development of micromirror devices with near-ideal characteristics which have previously been unrealizable in standard polysilicon processes. This paper describes many of these characteristics such as elevated address electrodes, various address wiring techniques, planarized mirror surfaces using Chemical Mechanical Polishing, unique post-process metallization, and the best active surface area to date.
Secure migration of IPTV services from a STB to mobile devices for pay per view video (2010)

Recently with rapid development of broadband network and IT technology, consumers are capable of wirelessly connecting to the internet through Access Point (AP) or 3G to conveniently browse the Internet or even receive a digital multimedia. The advancing of this technology is providing consumer with an easy access to Internet anywhere to receive services. One of the services that is attracting user in these days is IPTV services. IPTV is known as Internet Protocol TV that is capable of delivering a high quality of multimedia such as data, voice, and video to consumer homes through wired set-top box (STB). But with the advancing of mobile devices technology, users would want to receive their services through mobile devices at home or outside. However, the use of wireless environment has many risks and weaknesses when you compared it to existing wire networks. For instant, in wireless environment, mobile devices have vulnerabilities such as denial-of-service attack (DoS attack), man-in-middle attack, replay attack, and so on. Therefore consumer security and privacy are essential security issue as well as protecting digital content when users connect to wireless environment. Therefore, a secure migration of IPTV services from a set-top box (STB) to mobile devices at home or outside for pay per view video mechanism is proposed in this paper.
Monodispersed and size-controlled multibranched gold nanoparticles with nanoscale tuning of surface morphology (2011)

A novel seed-mediated synthetic route to produce multibranched gold nanoparticles is reported, in which it is possible to precisely tune both their size and nanostructuration, while maintaining an accurate level of monodispersion. The nanoscale control of surface nanoroughness/branching, ranging from small bud-like features to elongated spikes, allows to obtain fine tuning of the nanoparticle optical properties, up to the red and near-IR region of the spectrum. Such anisotropic nanostructures were demonstrated to be excellent candidates for SERS applications, showing significantly higher signals with respect to the standard spherical nanoparticles.
SLACID - sparse linear algebra in a column-oriented in-memory database system (2014)

Scientific computations and analytical business applications are often based on linear algebra operations on large, sparse matrices. With the hardware shift of the primary storage from disc into memory it is now feasible to execute linear algebra queries directly in the database engine. This paper presents and compares different approaches of storing sparse matrices in an in-memory column-oriented database system. We show that a system layout derived from the compressed sparse row representation integrates well with a columnar database design and that the resulting architecture is moreover amenable to a wide range of non-numerical use cases when dictionary encoding is used. Dynamic matrix manipulation operations, like online insertion or deletion of elements, are not covered by most linear algebra frameworks. Therefore, we present a hybrid architecture that consists of a read-optimized main and a write-optimized delta structure and evaluate the performance for dynamic sparse matrix workloads by applying workflows of nuclear science and network graphs.
Fixing multi-client oscillations in HTTP-based adaptive streaming: A control theoretic approach (2013)

In recent years, the technology for video delivery over the Internet is shifting towards a new paradigm: HTTP-based adaptive streaming (HAS). An HAS client receives video contents on a segment by segment basis via standard HTTP GET requests. It can dynamically change the rate and quality of the video in the presence of time-varying bandwidth changes. When multiple clients compete over a common bottleneck link, however, they often fail to converge to their respecitive fair share of bandwidth. This leads to constant oscillations in the received video quality. In this paper, we uncover the cause of such oscillations based on observations from large-scale test bed experiments. We then propose a novel client rate adaptation algorithm, which strives to stabilize the playout buffer at a reference level via a proportional-integral controller (PIC). Test bed evaluation results confirm the effectiveness of the proposed PIC scheme and its superior performance over Microsoft Smooth Streaming.
Compact dielectric resonator antenna for WLAN applications (2003)

A new dielectric resonator antenna (DRA) with reduced size for WLAN applications is presented. The proposed antenna consists of a rectangular dielectric resonator with partial vertical and horizontal metallisations which is coupled to a microstrip line through a rectangular aperture in the ground plane. A 9.6 reduction coefficient is obtained compared to the volume of an equivalent isolated DRA. An experimental 12% bandwidth is also achieved in spite of the compact size.
Stokes shift emission spectroscopy of human tissue and key biomolecules (2003)

The Stokes-shifted emission spectra were measured for various photoactive biomolecules in aqueous solution and tissue such as tryptophan, collagen, nicotinamide adenine dinucleotide, and flavin. Information is obtained on the molecular activity in the tissue. This new approach allows for the extraction of some new information not obtained from excitation and/or fluorescence spectroscopy for a single spectral scan.
A novel antimicrobial peptide from the loach, <i>Misgurnus anguillicaudatus</i> (1997)

A novel antimicrobial peptide, named misgurin, was isolated and characterized from the loach (mudfish), Misgurnus anguillicaudatus. The 21-amino-acid peptide with a molecular mass of 2502 Da was purified to homogeneity using a heparin-affinity column and C18 reverse-phase and gel-permeation high-performance liquid chromatography. The complete amino acid sequence of misgurin, which was determined by an automated amino acid sequencer, was Arg-Gln-Arg-Val-Glu-Glu-Leu-Ser-Lys-Phe-Ser-Lys-Lys-Gly-Ala-Ala-Ala-Arg- Arg-Arg-Lys. Misgurin is a strongly basic peptide which has 5 arginine and 4 lysine residues. Comparison of the amino acid sequence with those of other known antimicrobial peptides revealed that misgurin was a novel antimicrobial peptide. Misgurin showed a strong antimicrobial activity in vitro against a broad spectrum of microorganisms without significant hemolytic activity and was about 6 times more potent than magainin 2. Scanning electron microscopy confirmed that the peptide caused damage to the cell membrane by a pore-forming mechanism similar to that of magainin 2. This damage occurred at the minimal inhibition concentration (MIC), but at higher concentration than MIC it lysed the cell.