gebhart/patrepeval huggingface dataset:
Electrochemical Flow Reactor for Selective Extraction of Lithium Chloride from Natural Brines (2020)

An electrochemical flow reactor for the extraction of lithium chloride from natural brines has been designed and tested. It comprises two 3D porous packed bed electrodes and an anion exchange membrane. The electrodes were filled with conducting petroleum coke particles covered with LiMn 2 O 4 (anode) in contact with dilute LiCl recovery solution and partly de-lithiated Li 1−x Mn 2 O 4 (cathode) in contact with natural brine. The electrolytes were circulated at constant flow rate through the porous packed bed electrodes and a constant current was passed at the lithium deficient Li 1−x Mn 2 O 4 (cathode) with Li + ion intercalation and de-intercalation at the LiMn 2 O 4 (anode), while a flow of chloride ions operated at the anion selective membrane to compensate charge. In a second step, the electrolytes were exchanged and LiCl was recovered from the lithiated Li 1−x Mn 2 O 4 , now acting as anode. A mathematical model for the flow reactor with the diffusion and migration described by the Nernst-Planck equation, the convective flow of electrolyte and the LiMn 2 O 4 battery intercalation model has been developed using the finite element method under the COMSOL environment.
Measurement of cement setting by impedance monitoring (2002)

Cement setting can be monitored by electrical impedance measurement in a broad frequency range by using different containers or sample probes. The present work describes two new measurement methods that do not require any special sample holder nor any sample preparation. One method measures cement paste conductivity during setting in the 1 kHz to 100 kHz frequency range. The other method measures cement paste permittivity from 10 MHz to 1 GHz. Both methods use an electrode configuration that allows in situ monitoring. The conductivity method is less error-prone and easier to implement, and allows us, for instance, to quantify the effect of superplasticizers.
Computational observer design techniques for linear systems with unknown inputs using the concept of transmission zeros (1993)

Computational observer design techniques for linear systems subject to unknown inputs are presented. Complete and intuitive geometric conditions for the solution of the problem which result in design matrix equations are provided. These design equations are solved in a computationally efficient way. The synthesis of the reduced-order observer takes full advantage of the concept of transmission zeros. In particular, the necessary and sufficient conditions obtained are given in terms of the transmission zeros of the triple (A,D,C).< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Molecular Properties of ClpAP Protease of <i>Escherichia coli</i>:  ATP-Dependent Association of ClpA and ClpP (1998)

The ClpAP protease from Escherichia coli consists of the ATP-binding regulatory component, ClpA (subunit Mr 84 165), and the proteolytic component, ClpP (subunit Mr 21 563). Our hydrodynamic studies demonstrate that the predominant forms of these proteins in solution correspond to those observed by electron microscopy. ClpP and proClpP(SA), which in electron micrographs appear to have subunits arranged in rings of seven subunits, were found by ultracentrifugation to have s20,w values of 12.2 and 13.2 S and molecular weights of 300 000 and 324 000 +/- 3000, respectively, indicating that the native form of each consists of two such rings. The two intact rings of ClpP were separated in the presence of >/= 0.1 M sulfate at low temperatures, suggesting that ring-ring contacts are polar in nature and more easily disrupted than subunit contacts within individual rings. Sedimentation equilibrium analysis indicated that ClpA purified without nucleotide exists as an equilibrium mixture of monomers and dimers with Ka = (1.0 +/- 0.2) x 10(5) M-1 and that, upon addition of MgATP or adenosine 5'-O-(3-thiotriphosphate), ClpA subunits associated to a form with Mr 505 000 +/- 5000, consistent with the hexameric structure seen by electron microscopy. Sedimentation velocity and gel-filtration analysis showed that the nucleotide-promoted hexamer of ClpA (s20,w = 17.2 S) binds tightly to ClpP producing species with s20,w values of 21 and 27 S (f/f0 = 1.5 and 1.8, respectively), consistent with electron micrographs of ClpAP that show a single tetradecamer of ClpP associated with either one or two ClpA hexamers [Kessel et al. (1995) J. Mol. Biol. 250, 587-594]. Under assay conditions in the presence of ATP and Mg2+, the apparent dissociation constant of hexameric ClpA and tetradecameric ClpP was approximately 4 +/- 2 nM. By the method of continuous variation, the optimal ratio of ClpA to ClpP in the active complex was 2:1. The specific activities of limiting ClpA and ClpP determined in the presence of an excess of the other component indicated that the second molecule of ClpA provides very little additional activation of ClpP.
Wind turbine blade production – new products keep pace as scale increases (2012)

The wind energy industry is one of the fastest-growing consumers of fibre reinforced plastics in the world. Production challenges are compounded as the scale of wind turbines continues to climb. Blades, among the most complex parts to mould, now exceed 80 m in length and are getting longer. Freelance journalist Richard Stewart reports on new products and processes developed to meet the needs of utility-scale blade producers.
Optimal Aggregation Algorithms for Middleware (2002)

Let D be a database of N objects where each object has m fields. The objects are given in m sorted lists (where the ith list is sorted according to the ith field). Our goal is to find the top k objects according to a monotone aggregation function t, while minimizing access to the lists. The problem arises in several contexts. In particular Fagin (JCSS 1999) considered it for the purpose of aggregating information in a multimedia database system. We are interested in instance optimality, i.e. that our algorithm will be as good as any other (correct) algorithm on any instance. We provide and analyze several instance optimal algorithms for the task, with various access costs and models.
Dollar Commonwealth (1979)

For some international money investors, the late 1970s could have been described as the 'Great Deflation'. An Italian, whose favoured money was Swiss francs and whose monetary wealth was held predominately in francs, would have perceived a falling price for the Italian shopping basket. Possibly less than 100 miles distant, in Geneva, a less fortunate investor may have experienced the worst inflation of his lifetime. A Geneva resident whose favourite money was US dollars would have perceived a rocketing price for his shopping basket.KeywordsMoney MarketSmall BankFlexible Exchange RateFinancial CentreSwiss FrancThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Asynchronous and high-accuracy digital modulated signal detection by sensor networks (2011)

Adaptive modulation can be used to significantly enhance the spectrum utilization for both civilian applications, e.g., cognitive radio, and military ones. It requires a receiver to follow the modulation variation of a transmitter dynamically and automatically. Binary automatic modulation detection technology has been applied to detect the modulation scheme for adaptive modulation. Modulation classification was proposed for a multi-sensor scenario in our prior work using a distributed algorithm to enhance the detection accuracy. In this paper, the function of blind detection by the wireless sensor network (WSN) is further extended to support multiple modulation hypotheses. Besides providing spatial diversities, distributed sensors perform complicated calculations of likelihood functions and use the master node (radio) for data fusion and maximum likelihood testing. The proposed method requires no synchronization across the network and works well with low transmission bandwidth. Both analytical and numerical results are presented to validate its effectiveness.
Electrically Driven Supersonic Combustion (2018)

This manuscript reviews published works related to plasma assistance in supersonic combustion; focusing on mixing enhancement, ignition and flameholding. A special attention is paid for studies, which the author participated in person. The Introduction discusses general trends in plasma-assisted combustion and, specifically, work involving supersonic conditions. In Section 2, the emphasis is placed on different approaches to plasma application for fuel ignition and flame stabilization. Several schemes of plasma-based actuators for supersonic combustion have been tested for flameholding purposes at flow conditions where self-ignition of the fuel/air mixture is not realizable due to low air temperatures. Comparing schemes indicates an obvious benefit of plasma generation in-situ, in the mixing layer of air and fuel. In Section 3, the problem of mixing enhancement using a plasma-based technique is considered. The mechanisms of interaction are discussed from the viewpoint of triggering gasdynamic instabilities promoting the kinematic stretching of the fuel-air interface. Section 4 is related to the description of transitional processes and combustion instabilities observed in plasma-assisted high-speed combustion. The dynamics of ignition and flame extinction are explored. It is shown that the characteristic time for reignition can be as short as 10 ms. Two types of flame instability were described which are related to the evolution of a separation zone and thermoacoustic oscillations, with characteristic times 10 ms and 1 ms correspondingly.
Antibody Distance from the Cell Membrane Regulates Antibody Effector Mechanisms (2017)

Immunotherapy using mAbs, such as rituximab, is an established means of treating hematological malignancies. Abs can elicit a number of mechanisms to delete target cells, including complement-dependent cytotoxicity, Ab-dependent cellular cytotoxicity, and Ab-dependent cellular phagocytosis. The inherent properties of the target molecule help to define which of these mechanisms are more important for efficacy. However, it is often unclear why mAb binding to different epitopes within the same target elicits different levels of therapeutic activity. To specifically address whether distance from the target cell membrane influences the aforementioned effector mechanisms, a panel of fusion proteins consisting of a CD20 or CD52 epitope attached to various CD137 scaffold molecules was generated. The CD137 scaffold was modified through the removal or addition of cysteine-rich extracellular domains to produce a panel of chimeric molecules that held the target epitope at different distances along the protein. It was shown that complement-dependent cytotoxicity and Ab-dependent cellular cytotoxicity favored a membrane-proximal epitope, whereas Ab-dependent cellular phagocytosis favored an epitope positioned further away. These findings were confirmed using reagents targeting the membrane-proximal or -distal domains of CD137 itself before investigating these properties in vivo, where a clear difference in the splenic clearance of transfected tumor cells was observed. Together, this work demonstrates how altering the position of the Ab epitope is able to change the effector mechanisms engaged and facilitates the selection of mAbs designed to delete target cells through specific effector mechanisms and provide more effective therapeutic agents.
Fixed latency serial transceiver with single bit error correction on FPGA (2017)

Serial links are essential components for communication. High speed Serializer-Deserializer (SerDes) chips are typically designed for variable latency error correction associated with a set of data transferred at a time. Here, we propose a fixed latency serial transceiver with bit error correction. Fixed latency serial links operations requires dedicated circuitry and they are usually not needed for most communication operations. In this work, we present a link architecture based on the high speed SerDes with bit error correction embedded in Xilinx Spartan6 Field Programmable Gate Arrays (FPGAs).
Characterizing and Identifying Incipient Carious Lesions in Dental Enamel Using Micro-Raman Spectroscopy (2012)

Early detection of dental caries is vital if improved patient outcomes are to be achieved by reversal of the demineralization process. Current techniques used by dentists for identifying carious lesions are effective in identifying more advanced lesions, but do not have sufficient sensitivity and specificity to detect them at the earliest stages. This study focused on characterizing the growth of incipient carious lesions in vitro using micro-Raman spectroscopy. The incipient carious lesions were grown on the buccal faces of human molars by controlled exposure to lactic acid. Lesions were cross-sectioned to expose the subsurface body of the lesion and then examined using micro-Raman spectroscopy. The intensity of the phosphate peaks in the Raman spectra was found to differ significantly between healthy enamel and the demineralized region of the lesions. The sensitivity of the phosphate peaks to the degree of demineralization was observed by taking a series of spectra over the cross section of the lesions. This revealed that the body of the lesion is highly demineralized, but in a narrow surface region (up to 10 µm) there is little demineralization. All the phosphate peaks were found to be sensitive to the degree of demineralization; however, changes in the intensity of the pronounced phosphate peak at 961 cm(-1) offer the most promise for identifying lesions. The results indicate that micro-Raman spectroscopy has both the sensitivity and selectivity to identify incipient carious lesions, but the presence of a surface layer with a relatively high mineral content could complicate the analysis.
A UNIVERSIDADE: COMPROMISSO COM A EXCELÊNCIA E INSTRUMENTO DE TRANSFORMAÇÃO (2001)

Sumário: 1. Saudação; 2. O sistema educacional brasileiro e a evolução do ensino superior no país; 3. A postura do educador e do universitário; 4. Os objetivos da Universidade; 5. A missão e os compromissos da Universidade no mundo contemporâneo; 6. Notas; 7. Abstract.
Experimental implementation of coded aperture coherent scatter spectral imaging of cancerous and healthy breast tissue samples (2015)

A fast and accurate scatter imaging technique to differentiate cancerous and healthy breast tissue is introduced in this work. Such a technique would have wide-ranging clinical applications from intra-operative margin assessment to breast cancer screening. Coherent Scatter Computed Tomography (CSCT) has been shown to differentiate cancerous from healthy tissue, but the need to raster scan a pencil beam at a series of angles and slices in order to reconstruct 3D images makes it prohibitively time consuming. In this work we apply the coded aperture coherent scatter spectral imaging technique to reconstruct 3D images of breast tissue samples from experimental data taken without the rotation usually required in CSCT. We present our experimental implementation of coded aperture scatter imaging, the reconstructed images of the breast tissue samples and segmentations of the 3D images in order to identify the cancerous and healthy tissue inside of the samples. We find that coded aperture scatter imaging is able to reconstruct images of the samples and identify the distribution of cancerous and healthy tissues (i.e., fibroglandular, adipose, or a mix of the two) inside of them. Coded aperture scatter imaging has the potential to provide scatter images that automatically differentiate cancerous and healthy tissue inside of ex vivo samples within a time on the order of a minute.
Automatic segmentation and quantification of the cardiac structures from non-contrast-enhanced cardiac CT scans (2017)

Early structural changes to the heart, including the chambers and the coronary arteries, provide important information on pre-clinical heart disease like cardiac failure. Currently, contrast-enhanced cardiac computed tomography angiography (CCTA) is the preferred modality for the visualization of the cardiac chambers and the coronaries. In clinical practice not every patient undergoes a CCTA scan; many patients receive only a non-contrast-enhanced calcium scoring CT scan (CTCS), which has less radiation dose and does not require the administration of contrast agent. Quantifying cardiac structures in such images is challenging, as they lack the contrast present in CCTA scans. Such quantification would however be relevant, as it enables population based studies with only a CTCS scan. The purpose of this work is therefore to investigate the feasibility of automatic segmentation and quantification of cardiac structures viz whole heart, left atrium, left ventricle, right atrium, right ventricle and aortic root from CTCS scans. A fully automatic multi-atlas-based segmentation approach is used to segment the cardiac structures. Results show that the segmentation overlap between the automatic method and that of the reference standard have a Dice similarity coefficient of 0.91 on average for the cardiac chambers. The mean surface-to-surface distance error over all the cardiac structures is [Formula: see text] mm. The automatically obtained cardiac chamber volumes using the CTCS scans have an excellent correlation when compared to the volumes in corresponding CCTA scans, a Pearson correlation coefficient (R) of 0.95 is obtained. Our fully automatic method enables large-scale assessment of cardiac structures on non-contrast-enhanced CT scans.
Characterization of an Interleaved F-DAS MIMO indoor propagation channel (2010)

A key point in the deployment of new wireless services is the cost-effective extension and enhancement of the network's radio coverage in indoor environments. Distributed Antenna Systems using Fiber-optics distribution (F-DAS) represent a suitable method of extending multiple-operator radio coverage into indoor premises, tunnels, etc. Another key point is the adoption of MIMO (Multiple Input-Multiple Output) transmission techniques which can exploit the multipath nature of the radio link to ensure reliable, high-speed wireless communication in hostile environments. In this paper novel indoor deployment solutions based on Radio over Fiber (RoF) and distributed-antenna MIMO techniques are presented and discussed, highlighting their potential in different cases.
Vertical cavity surface emitting laser packaging with auto power control (2002)

We will discuss a discrete VCSEL packaging method using a monitoring photodiode for auto power control. We have demonstrated a VCSEL package with an output power variation within /spl plusmn/1% over a temperature range from 0 to 65/spl deg/C.
Public Versus Secret Reserve Prices in eBay Auctions: Results from a Pokemon Field Experiment (2001)

Sellers in eBay auctions have the opportunity to choose both a public minimum bid amount and a secret reserve price. We ask, empirically, whether the seller is made better or worse off by setting a secret reserve above a low minimum bid, versus the option of making the reserve public by using it as the minimum bid level. In a field experiment, we auction 50 matched pairs of Pokémon cards on eBay, half with secret reserves and half with equivalently high public minimum bids. We find that secret reserve prices make us worse off as sellers, by reducing the probability of the auction resulting in a sale, deterring serious bidders from entering the auction, and lowering the expected transaction price of the auction.
Effects of superovulation, embryo recovery, culture system and embryo transfer on development of rabbit embryos <i>in vivo</i> and <i>in vitro</i> (1990)

Uninterrupted development of rabbit embryos in vivo was studied in 7 superovulated and 7 normally ovulating (GnRH-treated) does, while another 7 does were superovulated and 1-cell embryos were collected from them at 19 h after LH to compare development in vivo and in vitro. Embryos from the last group were either cultured in the presence or absence of rabbit oviduct epithelial cells for 65 h in Medium 199, or were immediately transferred to recipients. At 84 h after LH or GnRH, blastomere number, embryo volume and stage of development were assessed for all embryos. Intrazonal embryo volumes were significantly reduced in embryos recovered from superovulated donors. Superovulation also had a negative effect on embryo cell numbers. However, this reduction was more severe in embryos remaining in vivo in superovulated donors until 84 h after LH than it was in embryos transferred to nonsuperovulated recipients at the 1-cell stage (19 h after LH). The embryo recovery procedure apparently caused little harm to the embryos, except that the mucin layer on flushed and immediately transferred embryos was significantly thinner than that of embryos residing continuously in vivo. Co-culture with rabbit oviduct epithelial cells resulted in improved development in vitro, but this development was still significantly retarded compared with embryos developing in vivo.
Nanoplastic in the North Atlantic Subtropical Gyre (2017)

Plastics can be found in all ecosystems across the globe. This type of environmental pollution is important, even if its impact is not fully understood. The presence of small plastic particles at the micro- and nanoscales is of growing concern, but nanoplastic has not yet been observed in natural samples. In this study, we examined four size fractions (meso-, large micro-, small micro-, and nanoplastics) of debris collected in the North Atlantic subtropical gyre. To obtain the nanoplastic portion, we isolated the colloidal fraction of seawater. After ultrafiltration, the occurrence of nanoscale particles was demonstrated using dynamic light scattering experiments. The chemical fingerprint of the colloids was obtained by pyrolysis coupled with gas chromatography-mass spectrometry. We demonstrated that the signal was anthropogenic and attributed to a combination of plastics. The polymer composition varied among the size classes. At the micro- and nanoscales, polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene were observed. We also observed changes in the pyrolytic signals of polyethylene with decreasing debris size, which could be related to the structural modification of this plastic as a consequence of weathering.
Increasing of the EUV resist's sensitivity (2010)

In this article there are considered two methods of increasing of the sensitivity for polymer resists. These resists are used in the process of extreme UV (EUV) lithography. The both discussed methods can be used independently of one another or in turn. The first method supposes usage specific polymers as EUV resists. The increase of the coefficient of absorption in relation to EUV waves is characteristic for these polymers. The second method is applicable only for particular positive polymer resists. This method assumes an additional irradiation of the substrate's plane by the UV light appropriate to the certain spectral range. These waves are affecting exclusively on the earlier formed polymer macro-radicals. So the number of macromolecular ruptures increases in several times only in the areas preliminary exposed by EUV radiation. Moreover the degradation of the linear resolution due to this procedure is small.
ChemInform Abstract: Novel 2′‐Deoxy Pyrazine C‐Nucleosides Synthesized via Palladium‐Catalyzed Cross‐Couplings. (1998)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.