gebhart/patrepeval huggingface dataset:
The influence of the comonomer in the copolymerization of ethylene with α‐olefins using C<sub>2</sub>H<sub>4</sub>[ind]<sub>2</sub>ZrCl<sub>2</sub>/methylaluminoxane as catalyst system (1996)

Abstract Copolymers based on ethylene with different incorporations of 1‐hexene, 1‐octene and 1‐decene were obtained. There is not any marked variation of activity when different metallocenes were tested. The type and the concentration of the comonomer in the feed do not have a strong influence on the catalytic activity of the system, but the presence of the comonomer increases the activity compared with that in the absence of it. From 13 C NMR it was found that below 8% of comonomer incorporated the comonomer units appear isolated between polyethylene blocks, sequences of the type ethylene‐comonomer‐ethylene‐comonomer appear only above 8% of comonomer incorporated for all the systems studied. The reactivity of the comonomers for this particular system shows that the size of the lateral chain influences the percentage of comonomer incorporated, 1‐hexene being the highest one incorporated. The crystallinity of the copolymers exerts a linear relation with the amount of comonomer incorporated, and it is independent of lateral chain lengths. The molecular weight of the copolymers obtained was found to be dependent on the comonomer concentration in the feed, showing that there is a transfer reaction with the comonomer. The polydispersity ( M̄ w / M̄ n ) of the copolymers is rather narrow and dependent on the concentration of the comonomer incorporated.
Contact and metallization problems in GaAs integrated circuits (1986)

Despite the rapid maturing of GaAs as an integrated circuit technology, both for digital and analog applications, the rather empirical nature of our contact metallurgy betrays a lack of basic scientific understanding of the metal–semiconductor interface and its electrical properties. Schottky barrier heights to GaAs are considered to be fixed and determined by Fermi level pinning due to surface states. On the scale of the control of barrier height required for integrated circuits (tens of millivolts), this is not the case. We have no accepted model which allows us to predict barrier heights on ideal barriers, much less ones on processed real surfaces. Where film stress is present, such as with refractory silicides used for self‐aligned gate metal gate field‐effect transistors, run‐to‐run variations may amount to hundreds of millivolts. Schottky barrier heights of metal–AlGaAs barriers, used with modulation‐doped field‐effect transistors, are now known, but not to the desired accuracy. Ohmic contacts are required to both n‐ and p‐type material over a large doping range, including contact to the two‐dimensional gas in modulation‐doped devices. The widely used alloyed contact does not appear to be extendable to lower contact resistance, better area uniformity, or processing temperature sensitivity. Some novel alternatives will be discussed, and their potential accessed. The need for minimal contact resistance to p‐doped bases of heterojunction bipolar transistors has focused attention recently on contacts to p‐GaAs. There is a distinct trend toward the use of refractory metal contacts due to the elevated temperatures to which they are subjected during processing which cause severe degradation to the presently used gold‐based metallurgy.
A Simulation Study on the Topotactic Transformations from Aluminophosphate AlPO<sub>4</sub>-21 to AlPO<sub>4</sub>-25 (2001)

Aluminophosphate AlPO(4)-21 (AWO), formulated /(CH(3))(2)NH(2)/[Al(3)P(3)O(12)(OH)], has been synthesized solvothermally by using dimethylamine as the template. Single-crystal X-ray diffraction analysis shows that AlPO(4)-21 crystallizes in the monoclinic space group P2(1)/n with a = 8.687(2) A, b = 17.428(5) A, c = 9.159(2) A, beta = 109.60(2) degrees, V = 1306.3(5) A(3), and Z = 4. XRD analysis shows that AlPO(4)-21 transforms to AlPO(4)-25 (ATV) upon calcination at 500 degrees C. The molecular dynamics simulation approach was used to investigate the topotactic transformations from AlPO(4)-21. The simulation study suggests that AlPO(4)-21 is energetically favored to transform to AlPO(4)-25, as well as other hypothetical forms, by the changing of the UUDD chains to the UDUD chains.
Comparative study of spiculogenesis in demosponge and hexactinellid larvae (2003)

Spicule deposition was studied by electron microscopy in fixed embryos and larvae of the haplosclerid sponge Reniera sp. and the hexactinellid Oopsacas minuta. Spicules form in centrally located vacuoles within cells and within syncytia, as in the adult sponges. In Reniera, scleroblasts differentiate from micromeres prior to gastrulation. At gastrulation the scleroblasts migrate to the periphery of the embryo and commence spicule deposition around a hexagonal axial filament. Sclerocytes have numerous pseudopodia and migrate to the posterior pole where they become aligned along the antero-posterior axis in the free-swimming larva. Reniera larvae possess some 40-50 oxeas, each 70-75 microm long and 1 microm wide. Mature Oopsacas larvae have up to 14 stauractin spicules, which are produced on a rectangular axial filament in tissues that lie under the smooth epithelium at the posterior pole of the larva. Young sclerocytes have many pseudopodia. The 4-rayed spicules elongate along both the antero-posterior and medial axes, until the longitudinal rays become anchored in a lipid-filled cytoplasm at the anterior of the larva and the lateral rays intersect around the midline. The length of the transverse rays of the stauractins in free-swimming larvae are 27-45 microm each, while the length of the two longitudinal rays is 40-80 microm. Although spicule deposition begins in cells with a similar morphology in both cellular and syncytial sponges, the elaboration and organization of the spicules differ markedly in cellular and syncytial sponges and appear to be an outcome of the very distinct cellular differentiation and larval morphogenesis that occur in each of these groups.
Large-scale 3D scene modeling by registration of laser range data with Google Maps images (2009)

This work presents a novel approach to registering multiple range images on top of a Google Maps image. The fundamental concept behind the method is matching completely different types of input with each other using classification as a middleman. Range images and Google Maps images are separated into classes, and the range image is also projected into a 2D top-down template image. The template image can then be matched against the Google Maps image to find its location and orientation on the map, which can be used for registering the range images. An experiment comparing this technique against using GPS to find position and orientation showed that it is effective at automatically constructing a reasonable large-scale 3D model whereas GPS would be completely ineffective.
On the performance of interference canceller based I/Q imbalance compensation (2002)

In quadrature receivers, unavoidable imbalances in the analog front-end between the I- and Q-branches result in finite and usually insufficient rejection of the image frequency band. This causes the image signal to appear as interference on top of the desired signal. Both analog and digital techniques to compensate the effects of I/Q imbalance have been presented in the literature. In this paper, we carry out a detailed performance analysis of the interference cancellation based imbalance compensation structure utilizing baseband digital signal processing. Also simulation results are provided for comparison. The results indicate that the interference canceller based solution can offer adequate performance for most communication applications.
Vascular Tree Segmentation in Medical Images Using Hessian-Based Multiscale Filtering and Level Set Method (2013)

Vascular segmentation plays an important role in medical image analysis. A novel technique for the automatic extraction of vascular trees from 2D medical images is presented, which combines Hessian-based multiscale filtering and a modified level set method. In the proposed algorithm, the morphological top-hat transformation is firstly adopted to attenuate background. Then Hessian-based multiscale filtering is used to enhance vascular structures by combining Hessian matrix with Gaussian convolution to tune the filtering response to the specific scales. Because Gaussian convolution tends to blur vessel boundaries, which makes scale selection inaccurate, an improved level set method is finally proposed to extract vascular structures by introducing an external constrained term related to the standard deviation of Gaussian function into the traditional level set. Our approach was tested on synthetic images with vascular-like structures and 2D slices extracted from real 3D abdomen magnetic resonance angiography (MRA) images along the coronal plane. The segmentation rates for synthetic images are above 95%. The results for MRA images demonstrate that the proposed method can extract most of the vascular structures successfully and accurately in visualization. Therefore, the proposed method is effective for the vascular tree extraction in medical images.
Use of Bismuth Subsalicylate for the Prevention of Travelers' Diarrhea (1990)

During the months of July 1977 and July 1985, students from the United States participated in a double-blind, placebo-controlled trial examining the effectiveness of liquid bismuth subsalicylate (BSS) (1977) and two dosages of the tablet formulation of BSS (1985) in preventing diarrhea while in Guadalajara, Mexico. In the first study, 62 subjects received BSS for 3 weeks at a dosage of 60 mL four times daily (4.2 g of BSS/d) compared with 66 students receiving an oral placebo at a similar dosage schedule. In the second study, 51 students took two tablets four times daily (2.1 g of BSS/d), 63 took one tablet four times daily (1.05 g of BSS/d), and 58 took a placebo (two tablets taken four times daily), each for 3 weeks. In the initial study, 14 (23%) BSS-treated subjects developed diarrhea compared with 40 (61%) placebo-tested persons (P less than .0001). In the second trial, seven (14%) subjects taking two tablets of BSS four times daily, 15 (24%) taking one tablet of BSS four times daily, and 23 (40%) receiving placebo tablets experienced diarrhea (P less than .001 for the higher dose). The percent protection provided by BSS was 62% for the group that received 4.2 g/d, 65% for 2.1 g/d, and 40% for 1.05 g/d, when compared with the corresponding placebo group. In cases in which stools were analyzed, seven (24%) of 29 BSS-treated subjects who had diarrhea had a detectable enteric pathogen, compared with 35 (59%) of 59 of those randomized to receive a placebo. BSS was well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)
Mini-column silicon field-emitter arrays (1995)

We report emission data of silicon field emitter arrays fabricated with the ultimate goal of their integration within a planar lens structure for beam focusing experiments. The field emitters have been fabricated as linear arrays (with 20 μm separation between tips), square arrays (with 12 μm tip-to-tip separation), and single tips. The emitters themselves are formed on columns approximately 0.7 μm in height and 0.4 μm in diameter, and have gate aperture diameters as small as 1.1 μm. Two types of field emitter tips have been fabricated: One has been formed via isotropic etching of silicon in an SF6 plasma, the second using an orientation-dependent silicon wet etching procedure. Both have been sharpened with an oxidation process, and tip radii as small as 4 nm have been obtained. During testing, 14.4 μA of anode current was obtained from a single tip. From a 100 tip array, 3 mA of current was measured at a gate voltage of 85 V. From a 10 000 tip array, 14.5 mA was obtained.
A 3D Finite Element Model for History Matching Hydraulic Fracturing in Unconsolidated Sands Formation (2010)

Abstract Field hydraulic fracturing tests data provide valuable information regarding the mechanical and hydraulic behaviours of the reservoir formation. By history matching the field bottomhole pressure vs. time curve from hydraulic fracturing tests, a set of field-calibrated geomechanical models can be obtained, which is an important asset for any further works on utilizing geomechanics to enhance the injection and production performance. This paper presents a 3D finite element model for history matching the complete bottomhole pressure vs. time curve generated during hydraulic fracturing tests, considering the injection rate as input. To simulate the hydraulic fracturing process in unconsolidated sands formation, a poro-elasto-plastic constitutive model, together with a strain-induced anisotropic full permeability model, are formulated and implemented into a 3D finite element geomechanical simulator. Unlike the conventional simulation of hydraulic fracturing in hard rock, hydraulic fracturing in an unconsolidated sands reservoir is simulated as a large area of shear dilated plastic zone, inside of which the effective stresses are low and hydraulic conductivities are high. It is shown that the proposed numerical model can capture the hydraulic fracture initiation and propagation in unconsolidated sands formation and matches the field pressure vs. time curve.
Lafora disease E3 ubiquitin ligase malin is recruited to the processing bodies and regulates the microRNA-mediated gene silencing process via the decapping enzyme Dcp1a (2012)

Intracellular transport, processing and stability of mRNA play critical roles in the functional physiology of the cell and defects in these processes are thought to underlie the pathogenesis in a number of neurodegenerative disorders. One of the cellular sites that regulate the mRNA half-life is the processing bodies, the dynamic cytoplasmic structures that represent the non-translating mRNA and the ribonucleoprotein complex that also control the decapping and translation of mRNA. In the present study we explored the possible role of malin E3 ubiquitin ligase in the mRNA decay pathway via the processing bodies. Defects in malin are associated with Lafora disease (LD)-a neurodegenerative disorder characterized by myoclonus seizures. We show here that malin is recruited to the processing bodies and that malin regulates the recruitment of mRNA decapping enzyme Dcp1a by promoting its degradation via the ubiquitin proteasome system. Depletion of malin results in elevated levels of Dcp1a and an altered microRNA-mediated gene silencing activity. Our study suggests that malin is one of the critical regulators of processing bodies and that defects in the mRNA processing might underlie some of the disease symptoms in LD.
Improving customer shopping experience using an Android bar-code reader application (2018)

A Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Mobile Telecommunications and Innovation (MSc. MTI)
Design strategy of two-dimensional material field-effect transistors: Engineering the number of layers in phosphorene FETs (2016)

Thickness or the number of layers in 2D semiconductors is a key parameter to determine the material's electronic properties and the overall device performance of 2D material electronics. Here, we discuss the engineering practice of optimizing material and device parameters of phosphorene field-effect transistors (FETs) by means of self-consistent atomistic quantum transport simulations, where the impacts of different numbers of phosphorene layers on various device characteristics are explored in particular, considering two specific target applications of high-performance and low-power devices. Our results suggest that, for high-performance applications, monolayer phosphorene should be utilized in a conventional FET structure since it can provide the equally large on current as other multilayer phosphorenes (Ion &gt; 1 mA/μm) without showing a penalty of relatively lower density of states, along with favorableness for steep switching and large immunity to gate-induced drain leakage. On the other hand, more comprehensive approach is required for low-power applications, where operating voltage, doping concentration, and channel length should be carefully engineered along with the thickness of phosphorene in tunnel FET (TFET) structure to achieve ultra-low leakage current without sacrificing on current significantly. Our extensive simulation results revealed that either bilayer or trilayer phosphorene can provide the best performance in TFET with the maximum Ion/Ioff of ∼2 × 1011 and the subthreshold swing as low as 13 mV/dec. In addition, our comparative study of phosphorene-based conventional FET and TFET clearly shows the feasibility and the limitation of each device for different target applications, providing irreplaceable insights into the design strategy of phosphorene FETs that can be also extended to other similar layered material electronic devices.
Hollow-waveguide integrated optic system with an integrated laser source (2000)

The paper describes recent work on the development of hollow waveguide integrated optic systems with integrated laser sources. Both monolithic and hybrid laser integration concepts have been considered. The hybrid approach has been carried through into the design, manufacture and demonstration of a homodyne system. Details of design, manufacturing and assessment issues, and the demonstration of the system as a Doppler anemometer, will be discussed.
A High Power Density Power Factor Correction Converter with a Multilevel Boost Front-End and a Series-Stacked Energy Decoupling Buffer (2018)

High efficiency and high power density Power Factor Correction (PFC) converters are desirable in many ac-dc applications such as data center power delivery and electric vehicle on-board chargers. In conventional boost converter based PFC designs, two of the major limitations to achieve high power density are the size of the input filter inductor of the boost converter and the twice-line frequency energy buffering capacitor bank. In this work, a 1.5 kW universal ac (95 to 265 Vac) input, 400 V dc output PFC converter with a flying capacitor multilevel (FCML) boost front-end and a series-stacked buffer (SSB) is implemented to improve the overall system power density and efficiency. The unique challenges in both hardware and digital controller designs to achieve the co-operation of PFC, FCML and SSB are addressed, and corresponding solutions are presented in detail.
Evolution of Temperature Profiles during Stress-Induced Transformation in NiTi Thin Films (2013)

This paper presents a time-resolved investigation of tensile loading induced temperature profiles in pseudoelastic NiTi thin film specimens. A finite element model for coupled mechanical and time dependent thermal analysis is presented that accounts for the different effects of local generation of latent heat and heat transfer. For strain rates larger than 0.24/s, the maximum temperature increases from room temperature to above 50 °C. Subsequent stress relaxation after temperature compensation results in a temperature decrease from room temperature down to -20 °C. The observed evolution of temperature profiles is in qualitative agreement with infrared thermography experiments on NiTi films fabricated by magnetron sputtering.
An All-lrtran Doublet Objective (1965)

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Allen E. Murray, "An All-lrtran Doublet Objective," Appl. Opt. 4, 254-255 (1965) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article
Control of primary angiitis of the CNS associated with cerebral amyloid angiopathy by cyclophosphamide alone (1999)

Corticosteroids combined with cyclophosphamide are currently recommended for primary angiitis of the CNS. The authors report a 71-year-old man with primary angiitis of the CNS and amyloid angiopathy who responded to cyclophosphamide without steroids, suggesting that corticosteroids may not be needed in all cases of primary angiitis of the CNS.
Upgrading of Postconsumer Absorbent Hygiene Products for Bioethanol Production (2018)

Postconsumer absorbent hygiene products (AHPs), one of the most intractable municipal solid waste (MSW) streams, are generally subjected to landfills, causing urban waste management difficulties and environmental pollution. This study investigated the viability of recycling the cellulose component from postconsumer AHPs, demonstrated the fermentability of obtained cellulosic sugars for bioethanol production, and evaluated the technical feasibility of the process through scale-up. A set of integrated unit operations was developed to effectively upcycle the recovered AHPs into bioproducts. The processes were further optimized and scaled up 50-fold. Up to 83.5% glucose and 46.0% xylose yields were achieved during enzymatic saccharification. The sugars were readily fermentable through separate hydrolysis and fermentation (SHF) as well as simultaneous saccharification and fermentation (SSF) with maximum 89.9% ethanol theoretical yield.
Electrical characteristics of plasma deposited SiO/sub 2/ films produced in an ECR reactor from silane/O/sub 2/ or TEOS/O/sub 2/ gas mixtures (1995)

Summary form only given. One method of low-temperature deposition of SiO/sub 2/ films is plasma deposition using a Si containing source gas. Previous work has investigated the properties of the plasma generated with silane (SiH/sub 4/)/O/sub 2/ and tetraethoxysilane (TEOS)/O/sub 2/ gas mixtures in an electron cyclotron resonant (ECR) plasma reactor. It was found that the SiO concentration in the SiH/sub 4//O/sub 2/ plasma was about 2/spl times/10/sup 11/ cm/sup -3/, while that in the TEOS/O/sub 2/ plasma was about 2/spl times/10/sup 9/ cm/sup -3/. That work also examined the SiO/sub 2/ deposition rate, etch rate of the SiO/sub 2/ film in a CHF/sub 3//O/sub 2/ plasma, and compared the refractive index of the films produced by the two source gas mixtures. These characteristics were all found to be a function of the gas mixture, and the power and pressure of the ECR plasma. This work examines the dependence of the ac electrical properties of ECR deposited SiO/sub 2/ films on the source gas mixture (SiH/sub 4//O/sub 2/ or TEOS/O/sub 2/) and the plasma power and pressure. This is motivated by the need to assess the applicability of these films to electrical applications, and to determine the sensitivity of the electrical properties to process variations. The films are deposited onto a silicon wafer which has been passivated with a thermal oxide layer, and on which an interdigitated electrode pattern has been fabricated.
Determination of Metal Dispersion of Pt/CeO<sub>2</sub> Catalyst by CO-pulse Method (2005)

In order to establish a CO adsorption method for rapid measurement of metal dispersion of catalysts containing CeO2 that disturbs the measurement due to the adsorption of H2 or CO, the effect of reduction conditions on CO adsorption over Pt/CeO2 catalyst was examined on the basis of the standardized manual of CO-pulse method established by the Committee on Reference Catalyst, the Catalysis Society of Japan. Reduction of the catalysts under the standardized condition (673 K, 15 min) showed that Pt catalysts supported on low surface area CeO2 (12.6 m2·g−1) gave reasonable ratios of adsorbed CO to total Pt. However, the CO/Pt ratio exceeded unity on high surface area CeO2 support (66.7 m2·g−1), suggesting adsorption of CO on the CeO2 surface. Reduction of the catalyst under milder conditions at 373 to 573 K for 15 min to 5 h gave constant CO/Pt ratio of 0.40 within a reasonable experimental error. The mean particle diameter estimated from this CO/Pt ratio on the assumption of spherical particles closely agreed with a volume-area mean diameter measured by TEM. It was concluded that the dispersion of Pt supported on CeO2 can be measured by lowering the reduction temperature to suppress the effect of the CeO2 support.