gebhart/patrepeval huggingface dataset:
An intelligent stand-alone ultrasonic device for monitoring local structural damage: implementation and preliminary experiments (2010)

Continuous structural health monitoring has the potential to significantly improve the safety management of aged, in-service civil structures. In particular, monitoring of local damage growth at hot-spot areas can help to prevent disastrous structural failures. Although ultrasonic nondestructive evaluation (NDE) has proved to be effective in monitoring local damage growth, conventional equipment and devices are usually bulky and only suitable for scheduled human inspections. The objective of this research is to harness the latest developments in embedded hardware and wireless communication for developing a stand-alone, compact ultrasonic device. The device is directed at the continuous structural health monitoring of civil structures. Relying on battery power, the device possesses the functionalities of high-speed actuation, sensing, signal processing, and wireless communication. Integrated with contact ultrasonic transducers, the device can generate 1 MHz Rayleigh surface waves in a steel specimen and measure response waves. An envelope detection algorithm based on the Hilbert transform is presented for efficiently determining the peak values of the response signals, from which small surface cracks are successfully identified.
A flexible multiport RAM compiler for data path (1991)

A multiport RAM compiler with flexible layout and port organization has been developed using 1.0- mu m CMOS technology. A new memory cell with an additional column-enable gate yielded a controllability over the aspect ratio of the memory cell array. The targeted feature is the flexibility in both layout and port organization. Fast access time and fully static and asynchronous port operation are also goals. A wide bit-word organization range including 16 b*2048 words and 72 b*512 words was also obtained. This compiler generates up to 32 K three-port RAM and 16 K six-port RAM. In addition to READ and WRITE ports, READ/WRITE ports are also available. The operations of the ports are fully static and asynchronous to each other. The RAM requires no DC power consumption. The address access times of the generated three-port RAMs are, for example, 5.0 ns for 1 K and 11.0 ns for 32 K.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Electromigration in Pb-Free Solder Bumps with Cu Column as Flip-Chip Joints (2006)

The electromigration in flip chip joints of Cu column bump with two different kinds of solder bumps; eutectic SnPb or eutectic SnAg was studied. The Cu columns were 50 /spl mu/m thick and 50 /spl mu/m diameter for eutectic SnPb solders and 80 /spl mu/m thick and 85 /spl mu/m diameter for eutectic SnAg solders. We observed that these flip chip joints did not fail after 1 month at 100 /spl deg/C with a current density of 1/spl times/10/sup 4/ A/cm/sup 2/. In these flip chip joints of Cu column bumps with solder bumps, the current distribution in the solder region was uniform and they had strong resistance against electromigration induced failure. The effect of Cu column bump on current distribution in the solder joint has been confirmed by simulation. When we compared the difference in microstructural change between the Cu column with eutectic SnPb and the Cu column with eutectic SnAg, we found that electromigration enhanced the formation of Kirkendall voids at the Cu/Cu/sub 3/Sn interface in the eutectic SnPb case due to t he smaller amount of Sn in the solder bump. Therefore, the flip chip joints of Cu column bumps with eutectic SnPb solder bumps would be weakened at the interface after high current stressing.
Molecular imprinted photonic crystal for sensing of biomolecules (2016)

Abstract Molecularly imprinted polymers (MIPs) are highly cross-linked polymers with high binding capacity and selectivity to the target molecules. MIPs become increasingly important because of the potential applications in drug delivery, purification and separation. In spite of the tremendous progress that has been made in the molecular imprinting field, many challenges remain to be addressed, especially in transforming the binding event into a detectable optical signal. The combination of photonic crystal and molecular imprinting technique is becoming a popular research idea. Compared to the conventional MIPs, the molecularly imprinted photonic crystal sensors (MIPCB) have the advantage of directly convert the molecule recognition process into optical signal. This review comprehensively summarizes various MIPCB, including the principle of molecular imprinted photonic crystal sensors, recent development, some challenges and effective strategies for MIPCB.
Decomposition of N<sub>2</sub>O over Hexaaluminate Catalysts (2007)

Catalytic N2O decomposition has been studied over metal-substituted hexaaluminates with the general formula ABAl11O19, where A = La, Ba, and B = Mn, Fe, Ni. The materials were prepared by coprecipitation via the carbonate route followed by calcination at 1473 K for 10 h. Inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), transmission electron microscopy (TEM), and N2 adsorption techniques were used to characterize the catalysts. The activity in direct N20 decomposition was evaluated by means of temperature-programmed reaction and steady-state experiments. Fe- and Mn-containing hexaaluminates present the highest activities. The Ni-containing catalysts are significantly less active, comparable to the hexaaluminates without metal substitution. The catalytic activity was practically not influenced by the A cation (La or Ba) in the structure. The Fe- and Mn-substituted hexaaluminates exhibit high activity and stability for N2O decomposition in mixtures simulating the outlet of the Pt-Rh gauzes in ammonia oxidation reactors, containing N2O, NO, O2, and H2O. These materials are promising for high-temperature abatement of this powerful greenhouse gas in the chemical industry, particularly in nitric acid and caprolactam production.
The Components of the Bid-Ask Spread: A General Approach (1997)

A simple time-series market microstructure model is constructed within which existing models of spread components are reconciled. We show that existing models fail to decompose the spread into all its components. Two alternative extensions of the simple model are developed to identify all the components of the spread and to estimate the spread at which trades occur. The empirical results support the presence of a large order processing component and smaller, albeit significant, adverse selection and inventory components. The spread components differ significantly according to trade size and are also sensitive to assumptions about the relation between orders and trades.
Simultaneous extraction of phosphatidylcholine and phosphatidylethanolamine from soybean lecithin (2015)

A high composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was simultaneously extracted from soybean lecithin by using a mixed solvent consisting of ethanol and chloroform. The addition of chloroform in ethanol improved the total extraction yield to give high a composition of PC and PE. Thus, the best extraction yield (52%) of PC and PE was achieved at an ethanol/chloroform ratio of 6/4 (v/v). Molecular dynamics calculations of the amorphous cell bearing PC, PE, and solvent molecules were performed in order to understand the distribution of PC and PE molecules in specific solvent conditions. The extraction yield was also sensitive to extraction temperature, time and liquid to solid ratio. The extracted PC and PE mixture was successfully purified by flash chromatography using chloroform/methanol (8/2 v/v) as eluting solvent. The purified yields of PE and PC from lecithin extract were 16 and 35%, respectively. The structure of the extracted products was characterized by thin‐layer chromatography and 1 H, 13 C, 31 P NMR, FTIR and UV/vis spectroscopies, and elemental analysis. The purity of PE and PC was higher than 95%. Practical applications: Lecithin composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids is widely used in human food, animal feed, pharmaceuticals, paints, and other industrial applications. Lecithin can easily be extracted chemically using various solvents in order to obtain pure components. Due to the importance of phospholipids there have been a number of reports on the extraction of PC from lecithin; however, there have been few reports on the extraction of PE or the simultaneous extraction of PC and PE. Thus the simultaneous extraction of PC (35%) and PE (16%) from soybean lecithin by using a mixed solvent consisting of ethanol and chloroform can be a good example to obtain such components in high yields. The protocol employed here is quite straightforward so that pure PC and PE can be obtained economically and may attract interest on mixed solvent systems for the simultaneous extraction of lecithin components. Phosphatidylcholine and phosphatidylethanolamine were simultaneously extracted from soybean lecithin by using a mixed solvent consisting of ethanol and chloroform.
Downhole vibration sensing by vibration energy harvesting (2007)

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.
Steroid-protein interactions. Human corticosteroid binding globulin: some physicochemical properties and binding specificity (1981)

Reducing agents (dithiothreitol and beta-mercaptoethanol) significantly decrease the affinity constants of the human corticosteroid-binding globulin (CBG)-cortisol complex in proportion to their concentration; the resulting Ka values are more consistent than those obtained in the absence of the reductants. The effect is reversible. The equilibrium association constants of the CBG complexes with cortisol and progesterone show a relatively broad pH maximum between pH 8 and 11. In this pH range, cortisol was found to be bound more strongly than progesterone; this relationship is reversed around pH 6. The van't Hoff plot of the temperature effect on Ka of the CBG-cortisol complex (4-41 degrees C) exhibits a nonlinear, possibly biphasic temperature dependency. The shape of the van't Hoff plot was similar in the presence of mercaptoethanol. The association of cortisol and progesterone to human CBG at 4 and 37 degrees C is enthalpy driven, compensating for the unfavorable change in entropy. Studies with 47 steroids served to elucidate the influence on binding affinity of polar and nonpolar groups and other structural alterations. The contribution of specific structural changes in the steroid molecule to the free energy of binding can be calculated from the results. Important structures for optimal binding are the 20-oxo group, a 10 beta-methyl group, and a double bond at the 4 position. A complementary image of the binding site with respect to the nature of binding at various locations is proposed.
Role of the crystallization substrate on the photoluminescence properties of organo-lead mixed halides perovskites (2014)

We have fabricated CH3NH3PbI3−xClx perovskite thin films crystallized in situ on substrates of different natures (e.g., porosity, wettability) and investigated their photoluminescence properties. We observe that the crystallization time and thin film structure are strongly influenced by the chemical nature and porosity of the substrate. Moreover, we find that the mesoporous scaffold can tune the emissive properties of the semiconducting compound both in terms of spectral region and dynamics. In particular, perovskite crystallites grown in the nanometre size porous scaffold present a shorter-living and blue-shifted emission with respect to the perovskite crystals which are free to grow without any constraints.
Direct Fabrication of a Hybrid Cell/Hydrogel Construct by a Double-nozzle Assembling Technology (2009)

Assembling multitype cells and biomimic extracellular matrix materials in a single construct is a promising method to regenerate complex tissues/organs in vitro. A new double-nozzle assembling technique was used to fabricate a hybrid cell/hydrogel construct with a vascular-like network to perform as a mass exchange conduit. Using a digital model to mimic an anatomical liver structure, adipose-derived stromal cells (ADSC) were combined within a gelatin/alginate/fibrinogen hydrogel to form a vascular-like network and hepatocytes combined gelatin/alginate/chitosan were placed around it. The construct was stabilized in a thrombin/CaCl 2 /Na 5 P 3 O 10 solution after assembly. The ADSC were induced to differentiate into endothelial-like cells with endothelial growth factor. The albumin secretion level of the embedded hepatocytes increased during the 2 weeks culture, while the levels of urea and alanine transaminase were decreased after an increasing profile. These preliminary results indicate that this double-nozzle assembling technique could be a powerful tool for fabricating complex constructs with special intrinsic/ extrinsic structures. This technology has the potential to be widely used in medical regeneration and drug screening.
Wafer-Level Packaging With Soldered Stress-Engineered Micro-Springs (2009)

Micro-springs for integrated circuit test and packaging are demonstrated as soldered flip chip interconnects in a direct die to printed circuit board package. The spring interconnects are fabricated with thin film metallization as the last step in a wafer-scale process. The z-compliance of the interconnects can be used to test and/or burn-in parts in wafer form. After the parts are diced from the wafer, the springs then become the first-level (and often the last-level) interconnect between the chip and the board. The xy-compliance of the interconnect enables considerably large die to be soldered to an organic printed circuit board without underfill using a surface mount compatible process. To demonstrate this concept, daisy chain test vehicles were fabricated on die measuring 11.5 mm times 6.5 mm with 48 spring contacts on a 0.8 mm times 0.65 mm grid array, each spring measuring 400 mum times 100 mum. The parts were placed onto organic boards with screen printed solder paste using a pick and place machine. The parts were reflowed to complete the solder connection to each spring using eutectic and lead-free solder. Assembled parts have undergone >20 000 hot plate thermal cycles and >1000 oven thermal cycles without failure.
The Chemistry of CH Bond Activation on Diamond (2010)

The surface of hydrogen-terminated diamond resembles a solid hydrocarbon substrate. Interestingly, the C-H bonds on the diamond surface are not as unreactive as that of saturated hydrocarbon molecules owing to its unique surface electronic properties. The invention of C-H bond activation and C-C coupling reactions on the diamond surface allows chemists to develop powerful chemical transistors, biosensors, and photovoltaic cells on the diamond platform.
Leg Cramps and Restless Legs Syndrome During Pregnancy (2009)

Sleep disturbance during pregnancy can result in excessive daytime sleepiness, diminished daytime performance, inability to concentrate, irritability, and the potential for an increased length of labor and increased risk of operative birth. Sleep disturbance may be the result of a sleep disorder, such as leg cramps, a common yet benign disorder, or restless legs syndrome, a sensorimotor disorder. Both disrupt sleep, are distressing to the pregnant woman, and mimic one another and other serious disorders. During pregnancy, up to 30% of women can be affected by leg cramps, and up to 26% can be affected by restless legs syndrome.
Performance analysis of dynamic network coding scheme with opportunistic relay (2013)

In this paper, we consider a dynamic network coding scheme with opportunistic relay (DNC-OR) for multiple sources multiple relays networks. In DNC-OR, all of the source transmit one's own data one by one. The selected relay dynamically applies network coding according to whether the source-destination channel from suffers an outage and sends the network-coded data to the destinations. Assume that (denoted as F) the data received from other resources by each destination are reliable, under assumption F and in case the assumption F does not exist, theoretical and numerical results show that DNC-OR can provide superior system outage performance to the network-coded cooperation scheme with dynamic coding mechanism (DC-NCC) proposed by Cong Peng and yields a full diversity order of N + 1 , where N is the number of relay nodes. When the assumption F does not exist, we propose a dynamic network coding (DNC) scheme. The relay takes different actions according to different feedback message. For a network consist of a relay and two source-destination pairs, it is shown that DNC achieves superior diversity-multiplexing tradeoff to conventional cooperation(CC) by theoretical analysis and numerical results. Moreover, DNC-OR can significantly decrease system outage probability.
The role of NF-kappaB activation in lipopolysaccharide induced keratitis in rats. (2005)

The activation of NF-kappaB was increased in LPS treated corneas and was elevated in LPS induced keratitis by promoting overexpression of TNF-alpha mRNA. NF-kappaB may play an important role in the pathogenesis of LPS-associated keratitis in rats.
Separation of Volatile Organic Compounds from Nitrogen by Hollow Fiber Composite Membranes (2003)

Many industrial processes handling organic solvents produce volatile organic compounds (VOCs). These VOCs not only cause environmental pollution, but also represent an economic loss. VOC removal and recovery have become a big issue that needs to be addressed. Traditional techniques for VOCs removal include carbon adsorption, condensation, and absorption, and none is efficient enough to meet every need. Membrane separation has emerged as an excellent alternative or complementary technology for VOC separation. Separation of VOCs from nitrogen by composite hollow fiber membranes is studied in this thesis. Microporous hollow fiber membranes were spun from polyvinylidene fluoride (PVDF) using the phase inversion method, and the hollow fibers were coated with a thin layer of poly(ether block amide) (PEBA), thereby forming composite membranes. PVDF was chosen as the substrate material because of its excellent thermal and chemical stabilities and good mechanical strength, and PEBA was selected as the active separating layer because of its good permselectivity and film forming properties. In PEBA polymer, the hard polyamide blocks provide high mechanical strength, and the soft polyether blocks provide flexibility and elasticity. This study is focused on the preparation and characterization of PEBA/PVDF composite hollow fiber membranes. The membranes were tested for the removal of representative VOCs including hexane, heptane and cyclohexane, which are the main components of gasoline, and dimethyl carbonate (DMC), ethanol, methanol, and methyl t-butyl ether (MTBE) that are the oxygenates and octane number enhancers of gasoline. The separation of gasoline vapor from nitrogen was also investigated. It was found that the PEBA/PVDF composite hollow fiber membranes are effective for the separation of hydrocarbon vapors from nitrogen. The effects of hollow fiber membrane preparation conditions on the membrane performance were studied, and the separation performance of the composite hollow fiber membranes at various operating conditions (e. g. feed concentration, operating temperature) was evaluated.
THE DEVELOPMENT OF A PROSTHETIC HEART VALVE UTILIZING A RIGID HOUSING AND A FLEXIBLE BUTTERFLY-WING LEAFLET (1962)

Gott, Vincent L.; Daggett, Ronald L.; Botham, Richard J.; Koepke, Donald E.; Zarnstorff, William C.; Young, William P. Author Information
THE CHEMISTRY OF VITAMIN E. IV. THE SYNTHESIS OF TOCOPHEROLS<sup>1, *</sup> (1939)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTHE CHEMISTRY OF VITAMIN E. IV. THE SYNTHESIS OF TOCOPHEROLS1, *LEE IRVIN SMITH and HERBERT E. UNGNADECite this: J. Org. Chem. 1939, 04, 3, 298–304Publication Date (Print):July 1, 1939Publication History Published online1 May 2002Published inissue 1 July 1939https://pubs.acs.org/doi/10.1021/jo01215a012https://doi.org/10.1021/jo01215a012research-articleACS PublicationsRequest reuse permissionsArticle Views406Altmetric-Citations9LEARN 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 optionsGet e-Alertsclose Get e-Alerts
Thermo-driven light controller by using thermal modulation of diffraction wavelength in holographic polymer dispersed liquid crystal grating (2014)

A microperiodic structure composed of polymer and liquid crystal (LC) phases, called holographic polymer dispersed liquid crystal (HPDLC), was fabricated based on a photo-induced phase separation technique by laser interferometric exposure. The diffraction wavelength of HPDLC gratings formed by different LC composites and grating structures was experimentally investigated by spectroscopic measurements as a function of temperature at around 30 °C. The HPDLC gratings composed of nematic LC having low nematic to isotropic temperature (T<sub>NI</sub>) and film thickness of 25 μm showed the switch of diffraction wavelength between visible and infrared lights by the change of temperature. The optical characteristics achieved in HPDLC gratings are expected to be applicable for the basis of diffractive type of thermodriven light controller which can supply visibility constantly for solar-ray control windows.
Measuring cell proliferation by relative movement. I. Introduction and in vitro studies (1991)

This paper presents two new ways of analysing data which may be obtained from pulse labelling a population of cells with bromodeoxyuridine and analysing that population as a function of time with bivariate flow cytometry. The progression of cells is measured by the change in position in the cell cycle, as shown by a change in the mean DNA content of the labelled and unlabelled cells. The particular measures of the mean DNA content used are extensions of the relative movement of the labelled undivided cells, RMlu(t), which was introduced by Begg and co-workers to measure the DNA synthesis time, TS. In general, the relative movement is defined as the mean DNA fluorescence of a population of cells less the DNA fluorescence of the cells in G1 and divided by the difference in DNA fluorescence of the cells in G2 + M and G1. In this paper we examine the relative movements of all the labelled cells and all of the unlabelled cells, denoted RML(t) and RMU(t) respectively. It is found that RML(t) and RMU(t) exhibit clear cyclic behaviour and distinguishable characteristics which depend directly on the transit times (T) of the cell cycle phases, i.e. TG1, TS and TG2 + M. Furthermore, the peak heights of the RMU(t) curve are shown to depend strongly on the growth fraction of the population under consideration. A theoretical treatment of the curves so obtained is presented, and is shown to yield values in close agreement with those from other methods for measuring these transit times and a lower limit to values for the growth fraction of Chinese hamster ovary cells grown in vitro.