gebhart/patrepeval huggingface dataset:
Experimental performance of the buried-channel acoustic charge transport device (1983)

High-speed electron transport is accomplished in a new type of buried-channel charge transfer device which is based on the nonlinear acoustoelectric interaction between large amplitude surface acoustic waves (SAW) and electrons in GaAs. The performance of the acoustic charge transport (ACT) device is enhanced by design improvements which provide precise channel definition and charge injection structures. A transfer efficiency in excess of 0.996 has been measured in an experimental device operating at the SAW clock frequency of 358 MHz.
P5F-2 Improved Fiber Optic Hydrophone Sensors (2007)

Broadband fiber optic hydrophones are an attractive solution for characterization and measurement of high intensity acoustic fields which are encountered in clinical ultrasound applications upto 100 MHz. A small sensing area avoids spatial acoustic field averaging and provides sub-millimeter resolution required for enhanced imaging in diagnostic applications. In this paper we present analytical and experimental performance results of broadband down-tapered fiber optical hydrophone sensors based on reflection type sensing and intensity detection scheme. Both uncoated as well as gold coated down-tapered fibers have been fabricated. Experimental results employing these fiber sensors for a 1.6 MHz acoustic signal, at 1 MPa pressure have corroborated the analytical predictions that thin metal coating can improve the sensitivity by almost 15 dB over that of uncoated tapered fiber. Such improvement in sensitivity is due to enhanced reflectance from the thin metal layer that senses the incident acoustic pressure.
Effects of incorporating nanosized calcium phosphate particles on properties of whisker‐reinforced dental composites (2006)

Clinical data indicate that secondary caries and restoration fracture are the most common problems facing tooth restorations. Our ultimate goal was to develop mechanically-strong and caries-inhibiting dental composites. The specific goal of this pilot study was to understand the relationships between composite properties and the ratio of reinforcement filler/releasing filler. Nanoparticles of monocalcium phosphate monohydrate (MCPM) were synthesized and incorporated into a dental resin for the first time. Silicon carbide whiskers were fused with silica nanoparticles and mixed with the MCPM particles at MCPM/whisker mass ratios of 1:0, 2:1, 1:1, 1:2, and 0:1. The composites were immersed for 1-56 days to measure Ca and PO4 release. When the MCPM/whisker ratio was changed from 0:1 to 1:2, the composite flexural strength (mean +/- SD; n = 5) decreased from 174 +/- 26 MPa to 138 +/- 9 MPa (p < 0.05). A commercial nonreleasing composite had a strength of 112 +/- 14 MPa. When the MCPM/whisker ratio was changed from 1:2 to 1:1, the Ca concentration at 56 days increased from 0.77 +/- 0.04 mmol/L to 1.74 +/- 0.06 mmol/L (p < 0.05). The corresponding PO4 concentration increased from 3.88 +/- 0.21 mmol/L to 9.95 +/- 0.69 mmol/L (p < 0.05). Relationships were established between the amount of release and the MCPM volume fraction v(MCPM) in the resin: [Ca]= 42.9 v(MCPM) (2.7), and [PO4] = 48.7 v(MCPM) (1.4). In summary, the method of combining nanosized releasing fillers with reinforcing fillers yielded Ca- and PO4-releasing composites with mechanical properties matching or exceeding a commercial stress-bearing, nonreleasing composite. This method may be applicable to the use of other Ca-PO4 fillers in developing composites with high stress-bearing and caries-preventing capabilities, a combination not yet available in any dental materials.
Interrelationship Between Hardness and Resistivity of Metal Alloy Films as Contact Materials in MEMS Switches (2006)

This study presents a basic step towards the selection methodology of electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This involves the interrelationship between the two important parameters, resistivity and hardness, since they provide the guidelines and assessment of the contact resistance, wear, deformation, and adhesion characteristics of MEMS switches. For this purpose, thin film alloys of three noble metals; platinum (Pt), rhodium (Rh) and ruthenium (Ru) with gold (Au) were investigated. The interrelationship between resistivity and hardness was established for three amounts of alloying of these metals with gold. Thin films of gold (Au), platinum (Pt), ruthenium (Rh), and rhodium (Ru) were also characterized to obtain their baseline data for comparison. All films were deposited on silicon substrates. When Ru, Rh, and Pt are alloyed with Au, their hardness generally decreases but resistivity increases. This decrease or increase was, in general, dependent upon the amount of alloying.
Molecular Imprinting for the Recognition of N-Terminal Histidine Peptides in Aqueous Solution (2002)

A new procedure for creating macromolecular receptors for peptides using molecular imprinting has been developed. The polymeric receptor exhibits selective uptake of specific N-terminal histidine containing sequences of simple dipeptides. The polymerization and binding are carried out in water. The approach utilizes a strong Ni(II)−His binding to attract the N-terminus histidine of the dipeptide to the polymer surface and secondary interactions between peptide and polymer to discriminate between the peptide sequence. These developments are enabled by utilizing an aqueous based monomer formulation that includes N,N‘-ethylenebis(acrylamide) as a water-soluble cross-linking monomer and a polymerizable NTA ligand, which can be used to incorporate nickel and other metals into these polyacrylamides. The Ni−NTA complex provides a strong histidine binding site that draws the dipeptide to the polymer surface. Mild polymerization conditions that utilize low concentrations of water-soluble initiator and low-temperature result in quantitative polymer yields. Variation of monomer composition reveals an optimum cross-linking for achieving maximum selectivity for these polymers.
Development of an intelligent system for cooling rate and fill control in GMAW. [Gas Metal Arc Welding (GMAW)] (1992)

A control strategy for gas metal arc welding (GMAW) is developed in which the welding system detects certain existing conditions and adjusts the process in accordance to pre-specified rules. This strategy is used to control the reinforcement and weld bead centerline cooling rate during welding. Relationships between heat and mass transfer rates to the base metal and the required electrode speed and welding speed for specific open circuit voltages are taught to a artificial neural network. Control rules are programmed into a fuzzy logic system. TRADITOINAL CONTROL OF THE GMAW PROCESS is based on the use of explicit welding procedures detailing allowable parameter ranges on a pass by pass basis for a given weld. The present work is an exploration of a completely different approach to welding control. In this work the objectives are to produce welds having desired weld bead reinforcements while maintaining the weld bead centerline cooling rate at preselected values. The need for this specific control is related to fabrication requirements for specific types of pressure vessels. The control strategy involves measuring weld joint transverse cross-sectional area ahead of the welding torch and the weld bead centerline cooling rate behind the weld pool, both by means of video (2), calculating the required process parameters necessary to obtain the needed heat and mass transfer rates (in appropriate dimensions) by means of an artificial neural network, and controlling the heat transfer rate by means of a fuzzy logic controller (3). The result is a welding machine that senses the welding conditions and responds to those conditions on the basis of logical rules, as opposed to producing a weld based on a specific procedure.
Chemical probes to potently and selectively inhibit endocannabinoid cellular reuptake (2017)

Significance Suitable chemical tools have been instrumental in the discovery and characterization of the endocannabinoid system. However, the lack of potent and selective inhibitors for endocannabinoid transport has prevented the molecular characterization of this process. Current uptake inhibitors are poorly bioavailable to the central nervous system (CNS) and weakly selective because they also inhibit fatty acid amide hydrolase (FAAH), the major anandamide-degrading enzyme. Few studies have addressed the uptake inhibition of 2-arachidonoyl glycerol (2-AG), which is the major endocannabinoid. Here, we report a highly potent and selective endocannabinoid reuptake inhibitor. Our data indicate that endocannabinoid transport across the membrane can be targeted, leading to general antiinflammatory and anxiolytic effects in mice.
Differential logging: a commutative and associative logging scheme for highly parallel main memory database (2002)

With a GByte of memory priced at less than $2000, main-memory DBMSs (MMDBMSs) are emerging as an economically viable alternative to disk-resident DBMSs (DRDBMSs) in many problem domains. The MMDBMS can show significantly higher performance than the DRDBMS by reducing disk accesses to the sequential form of log writing and occasional checkpointing. Upon a system crash, the recovery process begins by accessing the disk-resident log and checkpoint data to restore a consistent state. With increasing CPU speed, however, such disk access is still the dominant bottleneck in MMDBMSs. To overcome this bottleneck, this paper explores alternatives of parallel logging and recovery. The major contribution of this paper is the so-called differential logging scheme that permits unrestricted parallelism in logging and recovery. Using the bit-wise XOR operation both to compute the differential log between the before and after images and to recover the consistent database state, this scheme offers the room for significant performance improvement in the MMDBMS. First, with logging done on the difference, the log volume is reduced to almost half compared with the conventional physical logging. Second, the commutativity and associativity of XOR enables processing of log records in an arbitrary order. This means that we can freely distribute log records to multiple disks to improve the logging performance. During the recovery time, we can do a parallel restart independently for each log disk. This paper shows the superior performance of the differential logging compared to the physical logging in a shared-memory multiprocessor environment.
Glucose determination in human aqueous humor with Raman spectroscopy (2005)

It has been suggested that spectroscopic analysis of the aqueous humor of the eye could be used to indirectly predict blood glucose levels in diabetics noninvasively. We have been investigating this potential using Raman spectroscopy in combination with partial least squares (PLS) analysis. We have determined that glucose at clinically relevant concentrations can be accurately predicted in human aqueous humor in vitro using a PLS model based on artificial aqueous humor. We have further determined that with proper instrument design, the light energy necessary to achieve clinically acceptable prediction of glucose does not damage the retinas of rabbits and can be delivered at powers below internationally acceptable safety limits. Herein we summarize our current results and address our strategies to improve instrument design.
Experiments with combined analysis for pointer aliasing (1998)

We present initial empirical experiments with combined analysis, a scalabk analysis technique that uses a program decomposition to apply different aliasing algorithms to independent program segments. The effectiveness of the solution strategy is validated through application to side-effect and reference analysis of C programs.
Context-specific information distribution using the Web 3L Model (2011)

This paper describes the use of social, semantic networks in business applications. Our approach - the Web 3L model - reinterprets the idea of the Web 3.0 as a 3-layer structure of networks. It combines relations from social and semantic networks in order to use them for context specific search and distribution of information. As an example the distribution of urgent requests in an internal knowledge management application is described. In addition, a social semantic search with a sophisticated user interface is shown.
Optical Parametric Amplification of Weak Signals for Imaging of Scattering Biological Tissue (2012)

Optical amplification of weak signals coming from scattering biological tissue is demonstrated by using the optical parametric amplification technology. Up to one thousand fold amplification of back-scattered signals enables fast imaging of biological samples.
Mechanosensitivity of Human Oligodendrocytes (2020)

Oligodendrocytes produce and repair myelin, which is critical for the integrity and function of the central nervous system (CNS). Oligodendrocyte and oligodendrocyte progenitor cell (OPC) biology is modulated <i>in vitro</i> by mechanical cues within the magnitudes observed <i>in vivo</i>. In some cases, these cues are sufficient to accelerate or inhibit terminal differentiation of murine oligodendrocyte progenitors. However, our understanding of oligodendrocyte lineage mechanobiology has been restricted primarily to animal models to date, due to the inaccessibility and challenges of human oligodendrocyte cell culture. Here, we probe the mechanosensitivity of human oligodendrocyte lineage cells derived from human induced pluripotent stem cells. We target phenotypically distinct stages of the human oligodendrocyte lineage and quantify the effect of substratum stiffness on cell migration and differentiation, within the range documented <i>in vivo</i>. We find that human oligodendrocyte lineage cells exhibit mechanosensitive migration and differentiation. Further, we identify two patterns of human donor line-dependent mechanosensitive differentiation. Our findings illustrate the variation among human oligodendrocyte responses, otherwise not captured by animal models, that are important for translational research. Moreover, these findings highlight the importance of studying glia under conditions that better approximate <i>in vivo</i> mechanical cues. Despite significant progress in human oligodendrocyte derivation methodology, the extended duration, low yield, and low selectivity of human-induced pluripotent stem cell-derived oligodendrocyte protocols significantly limit the scale-up and implementation of these cells and protocols for <i>in vivo</i> and <i>in vitro</i> applications. We propose that mechanical modulation, in combination with traditional soluble and insoluble factors, provides a key avenue to address these challenges in cell production and <i>in vitro</i> analysis.
Developments on Imaging and Velocimetry of Dynamic Two-Phase Flows with Electrical Capacitance Tomography Sensors (2022)

Electrical capacitance tomography (ECT) based imaging and velocimetry methods are demonstrated for two-phase dynamical flows involving gas-oil and air-water mixtures. We consider two extended ECT modalities in particular. Electrical capacitance volume tomography (ECVT) is applied for electrically non-conducting flows such as gas-oil, whereas displacement-current phase tomography (DCPT) is applied for conducting flows such as air-water. In addition, gas flow rates are calculated from the reconstructed image and velocity profile, and compared to the actual gas flow rate.
Optimization of reflective bistable twisted nematic displays with retardation compensation (2000)

The contrast ratios of reflective bistable twisted nematic liquid crystal displays with a rear quarter-wave film are optimized by means of a parameter space approach. By plotting the contrast ratio as a function of the twist angle and thickness-birefringence product (dΔn) of the display, the regions where the displays show the best contrast ratio are clearly shown. Both the absolute reflectance and the wavelength dispersion of two bistable twisted states are investigated. It is confirmed that superhigh contrast ratio (infinite in principle), reflectance about 95% with polarized-light input, a large dΔn value (0.63 μm), and low dispersion are possible for such reflective bistable liquid crystal display.
Generalized hybrid feedforward control of pulse width modulated switching converters (2016)

This paper presents general considerations for synthesis of hybrid feedforward control architectures for pulsewidth modulated (PWM) switching converters, where selected converter variables are sensed and utilized to determine the duty cycle to achieve a control objective based on the converter open-loop characteristics. Compared to standard feedback control techniques, advantages may include simpler controller implementation, more convenient sensing, and improved static and dynamic regulation. The approach is illustrated first through previously known examples, including feedforward control of boost PWM converters operating in continuous conduction mode (CCM), and hybrid feedforward control of boost power factor correction (PFC) rectifiers operating in discontinuous conduction mode (DCM). The synthesis principles are then used to realize new hybrid feedforward control architectures for a battery charger application, which comprises a four-switch non-inverting buck-boost converter to implement PFC functionality, followed by a buck converter to regulate battery charging power. Experimental results are provided for the considered hybrid feedforward controlled converters.
Finite-Alphabet Wiener Filter Precoding for mmWave Massive MU-MIMO Systems (2020)

Power consumption of multi-user (MU) precoding is a major concern in all-digital massive MU multiple-input multiple-output (MIMO) base-stations with hundreds of antenna elements operating at millimeter-wave (mmWave) frequencies. We propose to replace part of the linear Wiener filter (WF) precoding matrix by a finite-alphabet WF precoding (FAWP) matrix, which enables the use of low-precision hardware that consumes low power and area. To minimize the performance loss of our approach, we present methods that efficiently compute FAWP matrices that best mimic the WF precoder. Our results show that FAWP matrices approach infinite-precision error-rate and error-vector magnitude performance with only 3-bit precoding weights, even when operating in realistic mmWave channels. Hence, FAWP is a promising approach to substantially reduce power consumption and silicon area in all-digital mmWave massive MU-MIMO systems.
Ensemble learning for speech enhancement (2013)

Over the years, countless algorithms have been proposed to solve the problem of speech enhancement from a noisy mixture. Many have succeeded in improving at least parts of the signal, while often deteriorating others. Based on the assumption that different algorithms are likely to enjoy different qualities and suffer from different flaws, we investigate the possibility of combining the strengths of multiple speech enhancement algorithms, formulating the problem in an ensemble learning framework. As a first example of such a system, we consider the prediction of a time-frequency mask obtained from the clean speech, based on the outputs of various algorithms applied on the noisy mixture. We consider several approaches involving various notions of context and various machine learning algorithms for classification, in the case of binary masks, and regression, in the case of continuous masks. We show that combining several algorithms in this way can lead to an improvement in enhancement performance, while simple averaging or voting techniques fail to do so.
Facile synthesis of highly thermally stable TiO<sub>2</sub> photocatalysts (2017)

Synthesis of titanium dioxide (TiO<sub>2</sub>) nanoparticles by a new one-pot solvothermal process.
Low-stress leadframe design for plastic IC packages (2002)

This paper describes a method of leadframe design which reduces thermal deformation and stress in the chip, and improves moldability of leadframe-based plastic encapsulated IC packages. The design works by splitting the die-pad into several sections joined together by flexible expansion joints. The split die-pad allows relative motion between the sections of the pad and breaks down the total die-pad length that is rigidly attached to the chip into smaller segments. These two factors reduce the magnitude of coefficient-of-thermal-expansion (CTE) mismatch and out-of-plane deformation of the assembly, resulting in reduced chip stress and improved moldability.
Joint domain localized processing using measured spatial steering vectors (2002)

The joint domain localized (JDL) adaptive processing algorithm mitigates interference in a localized processing region in the angle-Doppler domain. Spatial and temporal steering vectors transform the data collected in the space-time domain to the angle-Doppler domain. However, the JDL algorithm depends on the assumption that the spatial and temporal steering vectors form an orthogonal set. In practice, due to the mutual coupling between antenna elements, the spatial steering vectors do not form an orthogonal set. This paper presents a modification of the JDL algorithm to account for the non-orthogonality of these steering vectors. Examples from the multichannel airborne radar measurement (MCARM) database demonstrate the improvement in detection capability.
Confuser rejection modeling (2008)

In this paper we present a method of estimating the performance of a classifier system based on a reported confusion matrix. We develop a method of fitting parameters to observed confusion matrices, such that the expected performance of non-forced decision detection versus the probability of not-in-library reports can be estimated based on the forced decision confusion matrix. The approach also lends itself to a general methodology for modeling classes of confusers in a statistical manner, and can in principle also be extended to modeling clutter severity.
Novel Device and Strategy for Growing Large, High-Quality Protein Crystals by Controlling Crystallization Conditions (2021)

Neutron diffraction experiments are informative for determining the locations of hydrogen atoms in protein molecules; however, much larger crystals are needed than those required for X-ray diffraction. Thus, additional techniques are required to grow larger crystals. Here, a unique crystallization device and strategy for growing large protein crystals are introduced. The device uses two micropumps to control crystal growth by altering the precipitant concentration and regulating the pinpoint injection of dry air flow to the crystallization cell. Furthermore, the crystal growth can be observed in real time. Preliminary microbatch crystallization experiments at various concentration ranges of polyethylene glycol (PEG) 4000 and sodium chloride were first performed to elucidate optimized crystallization conditions. Based on these results, a device to precisely control the sodium chloride and PEG concentrations and the supply of dry air to the crystallization cell was used, and 1.8 mm lysozyme and 1.5 mm alpha-amylase crystals with good reproducibility were obtained. X-ray data sets of both crystals were collected at room temperature at BL2S1 of the Aichi Synchrotron Radiation Center and confirmed that these crystals were of high quality. Therefore, this crystallization device and strategy were effective for growing large, high-quality protein crystals.