gebhart/patrepeval huggingface dataset:
Polyvinyl Chloride/Silica Nanoporous Composite Separator for All-Vanadium Redox Flow Battery Applications (2013)

We demonstrate application of a commercial nanoporous polyvinyl chloride (PVC)/silica separator in an all-vanadium redox flow battery (VRB) as a low-cost alternative to expensive Nafion membranes. This hydrophilic separator is composed of silica particles enmeshed in a PVC matrix that creates unique porous structures. These nano-scale pores with an average pore size of 45 nm and a porosity of 65% serve as ion transport channels that are critically important for flow battery operation. The VRB flow cell using the PVC/silica separator produces excellent electrochemical performance in a mixed-acid VRB system with average energy efficiency (EE) of 79% at the current density of 50 mA·cm−2. This separator affords the VRB flow cell with excellent rate capability with its EE higher than that of Nafion membrane at current densities above 100 mA·cm−2. With this separator, the EE of the VRB flow cell exhibits great tolerance to temperature fluctuations in the typical operational temperature range of the mixed-acid VRB system. More importantly, the flow cell using the separator demonstrates an excellent capacity retention over cycling, which enables the VRB system to operate in the long term with minimal electrolyte maintenance.
Electric Current Computed Tomography and Eigenvalues (1990)

In electric current computed tomography, patterns of currents or voltages are applied to electrodes on the surface of a body and the resulting voltages or currents are measured. A reconstruction and display of an approximation to the impedance inside the body is then made based on these external measurements. It is shown how the problems of choosing current patterns, electrode size and number can be studied in terms of the spectral properties of certain pseudodifferential operators. The proofs given here are simpler and more general than those in [ IEEE Trans. Medical Imaging, 5 (1986), pp. 91–95] and [Clin. Phys. Physiol. Meas. Suppl. A, (1987), pp. 39–46].
Porous silicon filters for mid- to far-IR range (2004)

We present in this paper the development of novel mid-to-far IR filters that are based on porous silicon structures. The diameters of the pores in such filters are by orders of magnitude less than the central wavelength of the transmission band, leading to effective averaging of the porous structure by the light waves. Such filters have a number of important advantages over multilayer interference filters. Since the filters are made from a single material by means of an electrochemical etching process (rather than through deposition), these filters do not exhibit delamination problems and are well suited for operation at extreme temperatures (for example, in the environment of space). Our fabrication technique permits the fabrication of filters up to 200 mm (8 inches) in diameter, suitable for any wavelength from below 1.1 μm to more than 45 μm. The results of experimental testing of such filters are shown to prove the main predictions.
A laser-based method of detecting underwater sound through an ice layer. (2009)

An aerial, remote sensor has been devised to detect underwater sound through an ice layer by optically measuring the resulting vibration velocity on the ice surface, using a laser Doppler vibrometer. The laser was focused on an ice block approximately 8 in. wide by 12 in. long and 3.5 in. thick floating in a tank of water 16 in. deep. A submerged transducer was used to generate underwater acoustic signals to provide ice surface vibrations for the sensor to detect. Although acoustic attenuation through the ice was not an issue for this test, laser alignment was crucial. Since sensor reliability depends on receiving laser reflections from the ice surface, the laser was steered nearly perpendicularly onto the ice surface that had both smooth and rough features. The broadband optical sensor provides a remote sensing capability for measuring ice surface vibrations in response to underwater acoustic signals such as from marine mammals, passive or active sonar, and from underwater acoustic communication systems. The results of this landmark experiment will be presented, which demonstrate the feasibility for detecting underwater sound through an ice layer by probing the ice surface with a laser vibrometer, paving the way for in-air sensing in arctic regions.
Hand-Based Gesture Recognition for Vehicular Applications Using IR-UWB Radar (2017)

Modern cars continue to offer more and more functionalities due to which they need a growing number of commands. As the driver tries to monitor the road and the graphic user interface simultaneously, his/her overall efficiency is reduced. In order to reduce the visual attention necessary for monitoring, a gesture-based user interface is very important. In this paper, gesture recognition for a vehicle through impulse radio ultra-wideband (IR-UWB) radar is discussed. The gestures can be used to control different electronic devices inside a vehicle. The gestures are based on human hand and finger motion. We have implemented a real-time version using only one radar sensor. Studies on gesture recognition using IR-UWB radar have rarely been carried out, and some studies are merely simple methods using the magnitude of the reflected signal or those whose performance deteriorates largely due to changes in distance or direction. In this study, we propose a new hand-based gesture recognition algorithm that works robustly against changes in distance or direction while responding only to defined gestures by ignoring meaningless motions. We used three independent features, i.e., variance of the probability density function (pdf) of the magnitude histogram, time of arrival (TOA) variation and the frequency of the reflected signal, to classify the gestures. A data fitting method is included to differentiate between gesture signals and unintended hand or body motions. We have used the clustering technique for the classification of the gestures. Moreover, the distance information is used as an additional input parameter to the clustering algorithm, such that the recognition technique will not be vulnerable to distance change. The hand-based gesture recognition proposed in this paper would be a key technology of future automobile user interfaces.
Geranylgeranyltransferase I inhibitors induce p27 accumulation and G1 arrest in human breast cancer cell lines independently of Rb status and expression levels of Erb1, 2, 3 and 4 (2004)

3864 Several peptidomimetics such as GGTI-2431 were designed based on the C-terminal CAAL tetrapeptide sequence of geranylgeranyltransferase I (GGTase I) substrates. GGTI-2431 inhibited GGTase I potently (IC50 = 20nM) and selectively over the closely related enzyme farnesyltransferase (FTase) (IC50 = 170μM). Enzyme kinetic studies demonstrated that GGTI-2431 inhibits GGTase I in a competitive manner to the CAAL tetrapeptide. The effects of GGTI-2431 on signaling pathways and cell cycle progression was determined in 6 human breast cancer cell lines over-expressing various levels of ErbB receptors: MDA-MB-231 (ErbB1 & 2), MDA-MB-468 (ErbB1), BT474 (ErbB2), MCF-7 (ErbB4), Sk-Br3 (ErbB2), MDA-MB-453 (ErbB2 &3). Regardless of the ErbB expression level status, GGTI-2431 induced G1 arrest in all cell lines except MDA-MB-453. Induction of Rb hypophosphorylation was not necessary for G1 arrest since GGTI-2431 did not induce Rb hypophosphorylation in all cell lines and in some cell lines Rb was not present. GGTI-2431 also increased p27 protein levels in all 6 cell lines. GGTI-2431 inhibited tyrosine phosphorylation levels of STAT3 and Akt only in MDA-MB-468. In contrast, P-ERK 1/2 levels were decreased in MDA-MB-231, MD-MB-468 and MCF-7. Thus, our results demonstrate that inhibition of protein geranylgeranylation in breast cancer cells induces G1 block and increases p27 in a manner independent of ErbB receptor overexpression, functional Rb status, and oncogenic signaling pathways such as P-STAT3, P-Akt and P-Erk1/2. (This work was partially supported by NCI grant CA67771.)
Direct patterning of nanometer-scale silicide structures by focused ion-beam implantation through a thin barrier layer (2001)

Recently several new approaches have been proposed to manufacture silicide structures using mask-less techniques. We have developed a new technique for direct patterning and formation of cobalt silicide structures using focused ion-beam (FIB) implantation. Utilizing the effects of ion-beam mixing and properties of thin barrier oxides, silicide lines with dimensions down to 170 nm were produced on (100) silicon substrates using the FIB. The process involves the ion implantation of 200 keV As++ through a cobalt thin film. A thin (∼2 nm) oxide (SiOx) at the Si/Co interface acts as a selective reaction barrier. Ion-beam mixing was instrumental in fracturing of the oxide layer, thereby allowing the silicidation reaction to proceed across the boundary during subsequent rapid thermal anneal treatments. Diffusion controlled reactions advanced rapidly in the implanted areas, while it is inhibited elsewhere. A threshold dose of 3×1015 cm−2 was required for process initiation. Four-terminal resistance test structures were formed for electrical measurements. Reported resistivity was in the range of 12 to 23±1 μΩ cm.
Enhanced Photoluminescence and Solar Cell Performance <i>via</i> Lewis Base Passivation of Organic–Inorganic Lead Halide Perovskites (2014)

Organic-inorganic metal halide perovskites have recently emerged as a top contender to be used as an absorber material in highly efficient, low-cost photovoltaic devices. Solution-processed semiconductors tend to have a high density of defect states and exhibit a large degree of electronic disorder. Perovskites appear to go against this trend, and despite relatively little knowledge of the impact of electronic defects, certified solar-to-electrical power conversion efficiencies of up to 17.9% have been achieved. Here, through treatment of the crystal surfaces with the Lewis bases thiophene and pyridine, we demonstrate significantly reduced nonradiative electron-hole recombination within the CH(3)NH(3)PbI(3-x)Cl(x) perovskite, achieving photoluminescence lifetimes which are enhanced by nearly an order of magnitude, up to 2 μs. We propose that this is due to the electronic passivation of under-coordinated Pb atoms within the crystal. Through this method of Lewis base passivation, we achieve power conversion efficiencies for solution-processed planar heterojunction solar cells enhanced from 13% for the untreated solar cells to 15.3% and 16.5% for the thiophene and pyridine-treated solar cells, respectively.
Low Cost Fiberoptic Gyroscope (1990)

A fiber gyro concept different from the standard concept is presented. First me-asurements at constant temperature show a bias uncertainty <8°/h and a scale factor accuracy < 0.1%. Due to the inherent properties of the 3 x 3 coupler used, this concept offers the potential for low cost fiberoptic gyros with low to medium performance.
Accelerating magnetic resonance fingerprinting (MRF) using t-blipped simultaneous multislice (SMS) acquisition (2015)

The MB=2 t-Blipped SMS-MRF acquisition/reconstruction method has been demonstrated and validated to provide more rapid parameter mapping in the MRF framework.
Last mile problem in overlay design (2005)

Performance of overlay networks is dependent on last-mile connections, since they require that data traverse these last-mile bottlenecks at each forwarding step. This requires several times more upstream bandwidth than downstream, further exaggerating the asymmetry between down-stream and upstream bandwidth in last-mile technologies. This imbalance can cause packet queuing at the outgoing network interface of forwarding nodes, increasing latency and causing packet losses. We describe a model of a last-mile constrained overlay network and formulate and use it to solve a simplified latency- and bandwidth-bounded overlay construction problem. We observe that queueing delay may be a significant component of the end-to-end delay and approaches ignoring this may potentially result in an overlay network violating the delay and/or loss bounds. We observe that allowing a small amount of loss, it is possible to support a significantly large number of nodes. For a given end to end delay and loss bound we identify feasible degree (fan out) of each nodes. Our study sheds insights which provide engineering guidelines for designing overlays accounting for last mile problem in the Internet.
The Force Awakens: Illuminating the Role of Kynurenine in Cancer Progression and Treatment (2020)

Abstract Cancer is the second leading cause of death in the United States, with an estimated 40% of all Americans expected to be diagnosed with cancer in their lifetime. Despite progress in treatment options, major obstacles in current therapies must be overcome to limit their harmful side effects on patients. To evade immune clearance, many cancers elevate tryptophan (Trp) catabolism in the tumor microenvironment (TME) by upregulating the enzyme indoleamine 2,3-dioxygenase (IDO). As a result, cancer cells (1) monopolize extracellular tryptophan and (2) release L-kynurenine into the TME, an independent immune signal. This change in metabolism generates immune suppression in the TME, but whether the cause arises from Trp depletion or the accumulation of the IDO product kynurenine (L-Kyn) remains highly controversial. Kynurenine is known to induce immunosuppressive phenotypes through aryl hydrocarbon receptor (AhR) activation. However, the functional role of this binding is still poorly understood, despite an explosion of interest and information in the field. Our strategy uses the enzyme kynureninase (KynU) to degrade kynurenine into non-toxic products, thereby restoring anti-tumor immunity without harming the tryptophan metabolism of healthy cells. Moreover, this work aims to determine kynurenine’s molecular effect on T cells to better understand why its depletion successfully relieves tumor burden.
<i>meso</i>-aryl expanded porphyrins: synthesis, structures, and coordination chemistry (2004)

meso-aryl expanded porphyrins, that can be regarded as real homologues of meso-tetraaryl porphyrins, were prepared by our synthetic protocol under the modified Rothemund-Lindsey conditions. This new class of molecules exhibits interesting spectral, electrochemical, and coordination properties. These promising features are emphasized, with a particular attention on the annulenic properties.
Comparison of cell search methods for asynchronous wideband CDMA cellular system (2002)

Cell search within a CDMA system consists of the tasks carried out by a mobile station in order to find, identify, and synchronize to a new cell. We distinguish between initial cell search, where the mobile station after power on searches for the cell to which it has the lowest path loss, and cell search carried out for maintaining connection to the network in idle mode and to find handover candidates in active mode. In this paper, we focus on initial cell search. In cellular systems employing asynchronous base stations, no common time reference exists. Consequently, base stations cannot be identified by their relative time offset. One way to facilitate cell search in an asynchronous system is to have each cell transmitting a unique downlink scrambling code. The disadvantage is that the mobile station must now search for a large number of different scrambling codes, which leads to significantly higher complexity compared to the case of a synchronized system. One approach to cell search in an asynchronous system has been proposed for ETSI WCDMA. In this case, each cell uses a unique downlink scrambling code of length 10 ms. The set of scrambling codes is divided into groups with a limited number of codes in each group. In addition, each cell periodically transmits two special orthogonal code words, known as the primary and secondary synchronization codes, PSC and SSC respectively. In ETSI WCDMA, as well as in our work, orthogonal Gold codes are used for the PSC and SSC codes.
A new and simple method of resolution. Preparation of 3-fluoro-D-alanine-2-d (1977)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA new and simple method of resolution. Preparation of 3-fluoro-D-alanine-2-dGeorge Gal, John M. Chemerda, Donald F. Reinhold, and Robert M. PurickCite this: J. Org. Chem. 1977, 42, 1, 142–143Publication Date (Print):January 1, 1977Publication History Published online1 May 2002Published inissue 1 January 1977https://doi.org/10.1021/jo00421a029RIGHTS & PERMISSIONSArticle Views121Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (282 KB) Get e-Alerts Get e-Alerts
BehavioCog: An Observation Resistant Authentication Scheme (2016)

We propose that by integrating behavioural biometric gestures---such as drawing figures on a touch screen---with challenge-response based cognitive authentication schemes, we can benefit from the properties of both. On the one hand, we can improve the usability of existing cognitive schemes by significantly reducing the number of challenge-response rounds by (partially) relying on the hardness of mimicking carefully designed behavioural biometric gestures. On the other hand, the observation resistant property of cognitive schemes provides an extra layer of protection for behavioural biometrics; an attacker is unsure if a failed impersonation is due to a biometric failure or a wrong response to the challenge. We design and develop an instantiation of such a "hybrid" scheme, and call it BehavioCog. To provide security close to a 4-digit PIN---one in 10,000 chance to impersonate---we only need two challenge-response rounds, which can be completed in less than 38 seconds on average (as estimated in our user study), with the advantage that unlike PINs or passwords, the scheme is secure under observation.
Polyurethane waste recycling. 2. Polyol recovery and purification (1984)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyurethane waste recycling. 2. Polyol recovery and purificationJacob Braslaw and John L. GerlockCite this: Ind. Eng. Chem. Process Des. Dev. 1984, 23, 3, 552–557Publication Date (Print):July 1, 1984Publication History Published online1 May 2002Published inissue 1 July 1984https://pubs.acs.org/doi/10.1021/i200026a024https://doi.org/10.1021/i200026a024research-articleACS PublicationsRequest reuse permissionsArticle Views751Altmetric-Citations26LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
Optical and acoustic monitoring of bubble cloud dynamics at a tissue-fluid interface in ultrasound tissue erosion (2007)

Short, high-intensity ultrasound pulses have the ability to achieve localized, clearly demarcated erosion in soft tissue at a tissue-fluid interface. The primary mechanism for ultrasound tissue erosion is believed to be acoustic cavitation. To monitor the cavitating bubble cloud generated at a tissue-fluid interface, an optical attenuation method was used to record the intensity loss of transmitted light through bubbles. Optical attenuation was only detected when a bubble cloud was seen using high speed imaging. The light attenuation signals correlated well with a temporally changing acoustic backscatter which is an excellent indicator for tissue erosion. This correlation provides additional evidence that the cavitating bubble cloud is essential for ultrasound tissue erosion. The bubble cloud collapse cycle and bubble dissolution time were studied using the optical attenuation signals. The collapse cycle of the bubble cloud generated by a high intensity ultrasound pulse of 4-14 micros was approximately 40-300 micros depending on the acoustic parameters. The dissolution time of the residual bubbles was tens of ms long. This study of bubble dynamics may provide further insight into previous ultrasound tissue erosion results.
Searchable Encryption to Reduce Encryption Degradation in Adjustably Encrypted Databases (2017)

Processing queries on encrypted data protects sensitive data stored in cloud databases. CryptDB has introduced the approach of adjustable encryption for such processing. A database column is adjusted to the necessary level of encryption, e.g. order-preserving, for the set of executed queries, but never reversed. This has the drawback that long running cloud databases will eventually transform into only order-preserving encrypted databases. In this paper we propose searchable encryption as an alternative in order to reduce this encryption degradation. It maintains security while only marginally impacting performance when applied only to infrequently used queries for searching. We present a budget-based encryption selection algorithm as part of query planning for making the appropriate choice between searchable and deterministic or order-preserving encryption. We evaluate our algorithm on a long-tail distributed TPC-C benchmark on an experimental implementation of encrypted queries in an in-memory database. In one choice of parameters our algorithm incurs only a $$1.5\%$$ performance penalty, but one of 15 columns is not decrypted to order-preserving or deterministic encryption. Our selection algorithm is configurable, such that higher security gains are possible at the cost of performance.
Coupling of large number of vias in electronic packaging structures and differential signaling (2003)

A method is presented for modeling the multi-interaction among large numbers of vertical vias in densely packaged integrated circuits. The analysis of the interior problem is based upon a cylindrical wave expansion of the magnetic field Green's function and the foldy-lax multiple scattering formula. The exterior problem of bent traces is analyzed using the MOM approach. A system matrix equation is obtained by combining the exterior and interior problem, the solution of which gives the propagation characteristics of the entire structure. Using an iterative solver, results are illustrated for problems of several thousand vias with moderate CPU and memory requirements. Also illustrated are the results for common and differential modes in differential signaling, including the effects of surrounding idle vias and shorting vias.