gebhart/patrepeval huggingface dataset:
Doped GaN grown by Phase Shift Epitaxy, fabrication and characterization of GaN:Eu LED (2013)

A novel growth and doping scheme in Molecular Beam Epitaxy (MBE) named Phase Shift Epitaxy (PSE) is developed and described in this thesis.PSE is a periodic and dynamic growth scheme which desynchronizes the host material growth and the dopant incorporation by adjusting delays between shutter operations.PSE frees the doping procedure from the limited growth conditions of the host material, making it a very effective technique for determining the optimum surface condition for a particular dopant.In order to demonstrate its advantages over traditional MBE growth, PSE techniques were applied to the doping of GaN (activated layer of GaN:Eu LED) and Mg doping of GaN (p-type).The optimum PSE condition for GaN:Eu with Eu doped in a Ga-rich surface condition, was shown to lead to over 50% enhancement of the photoluminescence efficiency of Eu ions compared with the optimum traditional MBE condition.Luminescence from a specific Eu location was significantly increased.With the PSE growth of p-type GaN:Mg, Mg self-compensation effect was significantly suppressed at high Mg concentration when Mg is doped in an N-rich condition.A high hole concentration (2.4E18cm -3 ) is achieved with the optimum PSE condition for Mg doping.Even with a relatively high compensation donor level and a relatively poor template quality, this hole concentration result is comparable to the highest concentration, thanks to the self-compensating effect of PSE.Phase Shift Epitaxy is thus demonstrated to be a very effective tool in the doping of GaN, as well as other compound semiconductors.
Sulfur dioxide transport through aqueous solutions: Part II. Experimental results and comparison with theory (1980)

Abstract Measurements were made of the steady state flux of sulfur dioxide through films of water and solutions of neutral and alkaline sodium salts (0.1 to 2.0 M sodium chloride, 10 −3 to 3.0M sodium hydroxide, NaHSO 3 or sodium sulfite) with sulfur dioxide partial pressures between 10 and 100Pa. In agreement with equilibrium theory (Part I), data from water and sodium chloride solutions show that HSO is responsible for 83 to 95% of the flux (facilitation factor F between 5 and 19). In alkaline solutions, HSO and other sulfur containing species cause F to be as large as 1 370. Equilibrium theory, however, overpredicts F by up to a factor of 7. The NEBLA (Part I) accounts for this deviation.
Temperature dependence in time-of-flight ion scattering spectra of LiTaO3 (0001) and surface charge compensation of pyroelectric changes (2002)

We used time-of-flight scattering and recoiling spectrometry to study the surface of a LiTaO3 (0001̄) single crystal as a function of temperature (22–200 °C). We found that the variations in surface voltage induced by pyroelectric changes of spontaneous polarization could be quantitatively estimated by computing the effects of surface voltage on the ion optics and scattering events, and measuring scattering and recoiling spectral peak shifts. Generally, when LiTaO3 (0001̄) in a steady state at room temperature was probed, its negative spontaneous polarization charge was compensated by an equivalent amount of positive surface charge and the surface voltage was virtually zero. Raising the sample temperature reduced the spontaneous polarization and indeed a rising positive surface voltage was recorded, which shows that the positive surface charge could not be drained out from the insulating surface instantaneously. However, above 160 °C, the surface voltage returned to around zero, which indicates the presence of a thermally induced surface charge compensation mechanism on LiTaO3 (0001̄) above 160 °C. Cooling the sample both closed this surface charge compensation channel and increased the negative spontaneous polarization charge. A rising negative surface voltage, which is a proper pyroelectric response, was experimentally recorded. However, the spectral changes in the cooling cycle were rather complex. First, peak shifts did not follow the theoretical pyroelectric changes, and second, unexpected additional peaks were observed. These spectral behaviors are attributed to the presence of enhanced ion induced electron and negative ion emission as additional surface charge compensation mechanisms which modified the pyroelectric changes of surface voltage on LiTaO3 (0001̄). In addition, these surface properties were found to be sensitive to surface treatments such as sputtering and proton exchange.
Neural Fingerprint Enhancement (2018)

Biometrics fingerprint matching has been done with a heavily hand-tuned and designed process of classical computer vision techniques for several decades. This approach has lead to accurate solutions solving crimes today, and as such little effort has been placed on using deep learning in this domain. Given that convolutional neural networks have shown dominance for most other image based problems, we re-evaluate their potential for improving the fingerprint process. By leveraging synthetic data generators we show that one can train a neural fingerprint enhancer that improves matching accuracy on real fingerprint images. Our approach is both simple in design and for potential deployment and adoption in real world use.
Visible blind GaN p-i-n photodiodes (1998)

We present the growth and characterization of GaN p-i-n photodiodes with a very high degree of visible blindness. The thin films were grown by low-pressure metalorganic chemical vapor deposition. The room-temperature spectral response shows a high responsivity of 0.15 A/W up until 365 nm, above which the response decreases by six orders of magnitude. Current/voltage measurements supply us with a zero bias resistance of 1011 Ω. Lastly, the temporal response shows a rise and fall time of 2.5 μs measured at zero bias. This response time is limited by the measurement circuit.
Simple Demographics Often Identify People Uniquely (2018)

In this document, I report on experiments I conducted using 1990 U.S. Census summary data to determine how many individuals within geographically situated populations had combinations of demographic values that occurred infrequently. It was found that combinations of few characteristics often combine in populations to uniquely or nearly uniquely identify some individuals. Clearly, data released containing such information about these individuals should not be considered anonymous. Yet, health and other person-specific data are publicly available in this form. Here are some surprising results using only three fields of information, even though typical data releases contain many more fields. It was found that 87% (216 million of 248 million) of the population in the United States had reported characteristics that likely made them unique based only on {5-digit ZIP, gender, date of birth}. About half of the U.S. population (132 million of 248 million or 53%) are likely to be uniquely identified by only {place, gender, date of birth}, where place is basically the city, town, or municipality in which the person resides. And even at the county level, {county, gender, date of birth} are likely to uniquely identify 18% of the U.S. population. In general, few characteristics are needed to uniquely identify a person.
Universal Battery Performance and Degradation Model for Electric Aircraft (2020)

Development of Urban Air Mobility (UAM) concepts has been primarily focused on electric vertical takeoff and landing aircraft (eVTOLs), small aircraft which can land and takeoff vertically, and which are powered by rechargeable (typically lithium-ion) batteries. Design, analysis, and operation of eVTOLs requires fast and accurate prediction of Li-ion battery performance throughout the lifetime of the battery. eVTOL battery performance modeling must be particularly accurate at high discharge rates to ensure accurate simulation of the high power takeoff and landing portions of the flight. In this work, we generate a battery performance and thermal behavior dataset specific to eVTOL duty cycles. We use this dataset to develop a battery performance and degradation model (Cellfit) which employs physics-informed machine learning in the form of Universal Ordinary Differential Equations (U-ODE's) combined with an electrochemical cell model and degradation models which include solid electrolyte interphase (SEI) growth, lithium plating, and charge loss. We show that Cellfit with U-ODE's is better able to predict battery degradation than a mechanistic battery degradation model. We show that the improved accuracy of the degradation model improves the accuracy of the performance model. We believe that Cellfit will prove to be a valuable tool for eVTOL designers.
Physical and chemical changes during the extrusion process (1986)

Abstract Chemical and physical processes are attracting increasing attention from plastics processors. The reasons for this are basically twofold. On the one hand, more and more processors are recognizing that the quality of their products is highly dependent upon physical processes (cooling, temperature control, blending, etc.) and, on the other hand, new methods of physical and chemical treatment are being developed which are bringing improvements in quality and hence, virtually inevitably, greater profitability in production. This technology has made its impact both on discontinuous processing (reaction injection molding), on cable and pipe extrusion, and on the direct polymerization of tapes and films. The formulations that can be applied here are monomer casting systems. A prerequisite for the industrial utilization of this system is a process analysis of the reaction molding compound processing in a parallel‐running twin screw extruder to allow the influence of the process parameters on product quality (e.g., molecular weight) to be clarified and the polymerization to be integrated into other processing sequences, such as panel extrusion. The modification of tried and tested plastics through blending with other polymers, however, can also change the properties of the material in such a way that cost‐intensive plastics can be replaced or even new fields of application can be opened up. The attainable properties are just as much a function of the individual components and their percentage content as they are of the blending technique, as investigalions on a corotating twin‐screw extruder have shown. The melting zone takes on primary significance, since it is here that both the homogenization and desired or undesired high shearing takes place. The crystallization of semicrystalline plastics also has a considerable influence on product quality. To date this has been influenced by the selective addition of nucleiproducing foreign substances. A new process substitutes electron‐irradiated granules for these nucleating agents, such that the drawbacks of the foreign particles (toxicity, notch effect, and optical impairment) are eliminated. The effectiveness of this measure is reflected in better mechanical characteristic values. These both allow a higher product quality and a shortening of cooling time and hence higher productivity. Modijication of material properties through subsequent crosslinking represents the state of the art in rubber and polyethylene extrusion for cables and pipes. Special peroxides and the application of microwave energy make it possible to crosslink extrudates (pipes, profiles) made of HDPE and EPDM. The kinetics of crosslinking are explained, taking the example of crosslinking with peroxides. It is seen that the process technologv has to be adapted to the compound in terms of residence time and temperature. Under these conditions the microwave energy crosslinking plant operates with considerably shorter plant lengths and hence with lower energy losses.
Enhanced opportunistic beamforming scheme for practical broadcast systems (2007)

Abstract In multiantenna systems the optimisation of linear spatial precoding is severely hampered by the amount of feedback. A practical solution consists in the opportunistic beamforming (OB), which randomly generates the beamforming and schedules the user with the largest signal‐to‐noise ratio (SNR). In this paper we investigate the benefits that can be provided by the knowledge of the users spatial covariance at the transmitter. We enhance the OB scheme by matching the beamforming generation to the users channels spatial patterns. We analytically assess the performance of the proposed scheme, referred to as Cluster‐Eigenbeamforming (Cluster‐EB), both in ideal (perfect feedback) and in practical scenario (imperfect feedback). Cluster‐EB is shown to outperform the conventional schemes and the performance gain increases in practical systems as Cluster‐EB capitalises on the spatial covariance knowledge to reduce the sensitivity with respect to the feedback imperfections. Copyright © 2007 John Wiley &amp; Sons, Ltd.
PS 16-05 ANGIOTENSIN II-INDUCED HYPERTENSION IS DEPENDENT ON THE BRAIN CYTOSOLIC PHOSPHOLIPASE A2Aα-GENERATED OXIDATIVE STRESS (2016)

Objective: Angiotensin (Ang) II by activating cytosolic phospholipase A2a (cPLA2a) releases arachidonic acid (AA), and the pro-hypertensive AA metabolites mediate Ang II-induced hypertension and associated pathogenesis. These findings and the demonstration that Ang II increases blood pressure via generation of oxidative stress in subfornical organ (SFO) in the brain, led us to hypothesize that these effects of Ang II are dependent on cPLA2a activation in SFO. Design and method: To test this hypothesis, we investigated the effect of Ang II infusion (700ng/kg/min, s.c.) for 14 days in wild type (cPLA2a+/+) and cPLA2a-/- mice transduced in SFO with enhanced cyan-fluorescence protein (Ad-ECFP)-cPLA2a DNA. Results: Ang II increased mean arterial pressure (MAP) measured by radio-telemetry in cPLA2a+/+ but not cPLA2a-/- mice (100 ± 2 to 161 ± 6 mmHg vs. 104 ± 3 to 112 ± 3 mmHg, respectively, P < 0.05). Ang II increased cPLA2 activity, measured by immunohistochemistry using anti-phospho-Ser505, in SFO of cPLA2a+/+ but not cPLA2a-/- mice. Ang II increased reactive oxygen species (ROS) production measured by dihydroethidium staining (5.09 ± 0.31 to 8.99 ± 0.33 AU, P < 0.05), in SFO of cPLA2a+/+ but not in cPLA2a-/- mice. Ad-ECFP-cPLA2a DNA (1x1012 pfu/0.5 μL) but not Ad-GFP DNA transduced in SFO of cPLA2a-/- mice, restored Ang II effect on MAP and ROS production (115 ± 4 to 149 ± 2 mmHg and 4.40 ± 0.31 to 7.66 ± 0.47 AU with Ad-ECFP-cPLA2a DNA vs. 109 ± 5 to 116 ± 4 mmHg, and 4.04 ± 0.35 to 4.56 ± 0.19 AU with Ad-GFP, respectively, P < 0.05). In contrast, Ad-cPLA2a shRNA, but not Ad-shRNA transduced in SFO of cPLA2a+/+ mice, inhibited cPLA2 expression and its activity, and abolished Ang II-induced increase in blood pressure. Conclusions: These observations suggest that AA released by cPLA2a via one or more of its metabolites increase oxidative stress in SFO that promotes development of hypertension.
Placental Evaluation (2014)

The fetal membranes, commonly called the placenta, are the connection between the developing fetus and the uterus of the mare. A healthy functional placenta is critical for fetal nutrition and gas exchange. Examination of the placenta after foaling can offer valuable insight into the in utero health of the newborn foal. Consequently, it is recommended that owners, farm managers, foaling attendants, or veterinarians perform an evaluation of each placenta. This chapter discusses step by step procedure for evaluating the placenta of the mare. It briefly discusses an alternative technique for evaluating the placenta. The chapter lists equipments and supplies needed to perform the evaluation of the placenta.
Spatialized Teleconferencing: Recording and `Squeezed' Rendering of Multiple Distributed Sites (2008)

Teleconferencing systems are becoming increasing realistic and pleasant for users to interact with geographically distant meeting participants. Video screens display a complete view of the remote participants, using technology such as wraparound or multiple video screens. However, the corresponding audio does not offer the same sophistication: often only a mono or stereo track is presented. This paper proposes a teleconferencing audio recording and playback paradigm that captures the spatial location of the geographically distributed participants for rendering of the remote soundfields at the users' end. Utilizing standard 5.1 surround sound playback, this paper proposes a surround rendering approach that `squeezes' the multiple recorded soundfields from remote teleconferencing sites to assist the user to disambiguate multiple speakers from different participating sites.
In vitro folding of methionine‐arginine human lyspro‐proinsulin S‐sulfonate—Disulfide formation pathways and factors controlling yield (2010)

We investigated the in vitro folding of an oxidized proinsulin (methionine-arginine human lyspro-proinsulin S-sulfonate), using cysteine as a reducing agent at 5°C and high pH (10.5-11). Folding intermediates were detected and characterized by means of matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), reversed-phase chromatography (RPC), size-exclusion chromatography, and gel electrophoresis. The folding kinetics and yield depended on the protein and cysteine concentrations. RPC coupled with MALDI-MS analyses indicated a sequential formation of intermediates with one, two, and three disulfide bonds. The MALDI-MS analysis of Glu-C digested, purified intermediates indicated that an intra-A-chain disulfide bond formed first among A6, A7, and A11. Various non-native intra-A (A20 with A6, A7, or A11), intra-B (between B7 and B19), and inter-A-B disulfide bonds were observed in the intermediates with two disulfide bonds. The intermediates with three disulfide bonds had mainly the non-native intra-A and intra-B bonds. At a cysteine-to-proinsulin-SH ratio of 3.5, all intermediates with the non-native disulfide bonds were converted to properly folded proinsulin via disulfide bond reshuffling, which was the slowest step. Aggregation via the formation of intermolecular disulfide bonds of early intermediates was the major cause of yield loss. At a higher cysteine-to-proinsulin-SH ratio, some intermediates and folded MR-KPB-hPI were reduced to proteins with thiolate anions, which caused unfolding and even more yield loss than what resulted from aggregation of the early intermediates. Reducing protein concentration, while keeping an optimal cysteine-to-protein ratio, can improve folding yield significantly.
Determination of human papillomavirus 16 physical status through E1/E6 and E2/E6 ratio analysis (2014)

Human papillomavirus (HPV) 16 genome integration into the host chromosome is a crucial event during the life cycle of the virus and a major step towards carcinogenesis. The integration of HPV16 DNA promotes a constitutive high expression level of E6 and E7 oncoproteins, resulting in the extensive proliferation of the infected epithelial cells. In the present report the physical status of the HPV16 genome was studied, through determination of E1/E6 and E2/E6 DNA copy number ratios in 61 cervical samples of low- and high-grade malignancy and 8 cervical cancer samples, all of them associated with HPV16 infection. The selection of E1, E2 and E6 amplification target regions was performed according to the most prevalent deleted/disrupted sites of E1 and E2 genes. For this target selection we also considered the most conserved regions of E1, E2 and E6 genes among the same HPV16 isolates that were recently reported by our group. The analysis of HPV16 DNA form revealed a significant association among the mixed DNA forms in low-grade and high-grade malignancies, (χ(2), P<0.01). The comparative analysis of E1/E6 and E2/E6 in the same cervical samples provides an accurate picture of HPV16 DNA form and may reveal whether different HPV16 DNA integrants coexist in the same cervical sample or not. This study proposes that E1/E6 and E2/E6 ratios determine with accuracy the HPV16 DNA integration pattern and may predict multiple integration events in the examined sample, thus providing significant information about the progression of cervical dysplasia.
Study progress in cancer stem cells (2007)

OBJECTIVE:The study on stem cells as seed cells is very important for the study of tumorigenesis and clinical treatment.In this paper,the progress in the study of stem cell recently was summarized,and the concept,characteristics and application of stem cell was reviewed.DATA SOURCES:A computer-based online search of Medline was undertaken for the related English articles dated from January 1980 to December 2006 with the of cancer stem cell.STUDY SELECTION:The data were selected firstly,and the quotation of each article was looked over.Articles about the progress and clinical value of stem cells were selected,and the repetitive studies were excluded.DATA EXTRACTION:Totally 106 related articles were collected,76 repetitive or similar studies were excluded,and 30 met the inclusive criteria were included,which involved in the concept,sources,study progress,and clinical values of stem cells.DATA SYNTHESIS:Cancer stem cells have capabilities of division proliferation,self-renewal and multi-differentiation.At present,cancer stem cells have been found in leukemia,breast cancer,brain cancer,tumor of prostate and other tumor tissues.Most current therapies for tumor are to treat the divided tumor cells,but not stem cells,which are only temporary solutions but not radical ones.The relapse,metabasis and drug tolerance of tumor may be related with stem cells,so stem cells might contribute significantly to the therapeutic management of malignant tumors.Meanwhile,the normal stem cells should not be damaged.But because their cell phenotypes are nearly identical,the specific targets must be found. CONCLUSION:Cancer stem cells have been successfully isolated from malignant tumors of hematological system.Moreover,they are found in majority of solid tumors.One of the drug tolerance mechanisms is the expression of one or various drug transporter,which has provide more thoughts and direction for the occurrence and treatment of tumor.
Dirhodium tetraacetate catalyzed carbon-hydrogen insertion reaction in N-substituted .alpha.-carbomethoxy-.alpha.-diazoacetanilides and structural analogs. Substituent and conformational effects (1992)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirhodium tetraacetate catalyzed carbon-hydrogen insertion reaction in N-substituted .alpha.-carbomethoxy-.alpha.-diazoacetanilides and structural analogs. Substituent and conformational effectsAndrew G. H. Wee, Baosheng Liu, and Lin ZhangCite this: J. Org. Chem. 1992, 57, 16, 4404–4414Publication Date (Print):July 1, 1992Publication History Published online1 May 2002Published inissue 1 July 1992https://pubs.acs.org/doi/10.1021/jo00042a018https://doi.org/10.1021/jo00042a018research-articleACS PublicationsRequest reuse permissionsArticle Views1158Altmetric-Citations92LEARN 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-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts