gebhart/patrepeval huggingface dataset:
Karst rocky desertification in southwestern China: geomorphology, landuse, impact and rehabilitation (2004)

Abstract Karst rocky desertification is a process of land degradation involving serious soil erosion, extensive exposure of basement rocks, drastic decrease in soil productivity, and the appearance of a desert‐like landscape. It is caused by irrational, intensive land use on a fragile karst geo‐ecological environment. The process is expanding rapidly, and it is daily reducing the living space of residents and is the root of disasters and poverty in the karst areas of southwestern China. The tectonic, geomorphic and environmental background to karst rocky desertification is analysed. Population pressure and the intensive land use that have led to this serious land degradation are described. Although the problem concerns the Chinese Government and some profitable experience in the partial restoration or reconstruction of the ecological environment has been gained, effective remedial action has not been achieved on a large scale. Copyright © 2004 John Wiley & Sons, Ltd.
Expanding the Range of Impregnated Technology: New Performance Benchmark Set in Middle East (Et Al) (2002)

Abstract The range of application of new diamond impregnated drill bit technology continues to expand into lithologies normally drilled with roller cone bits. Historically, application of impregnated drill bits has been restricted to deep intervals that contain mainly hard and abrasive sandstone. Conversely, PDC bits perform best in relatively softer, non-abrasive rock. This left a very common sequence of formations, hard abrasive sandstone interbedded with soft shale, to be drilled with either roller cone or PDC bits. None of the two choices has delivered satisfactory performance in terms of penetration rate and bit life. Working with several operators, the bit company has conducted extensive laboratory and field development tests that have resulted in a new generation of aggressive diamond impregnated bits that offer unique advantages for drilling mixed formations more economically. The authors will outline the new impregnated technology in the context of its application and give examples on how to best apply it to achieve maximum performance. The following case studies will demonstrate significant performance improvement and illustrate an expanded range of applications for impregnated diamond bits. Oman: 8-3/8" impregnated bit set new cumulative footage record of 1130 meters drilling in two fields in central Oman. Algeria, Rhourde Nouss field: Set longest bit run through Grés de Oued Saret to Quartzites de Hamra, drilling 97 meters further than best offset and replaced 2-4 bit runs. Algeria Hassi Messaoud field: Broke country single run footage record (361 meters); doubled footage over conventional impregnated technology while achieving the best penetration rate through the interval. Venezuela: Replaced three roller cones bits relative to hole section in offset wells.
Structural elucidation of aibellin, a new peptide antibiotic with efficiency enhancing activity on rumen fermentation. (1994)

A new peptide antibiotic, aibellin, that had the efficiency enhancing activity on rumen fermentation, was isolated from the culture broth of the fungus, Verticimonosporium ellipticum D1528, and its primary structure was elucidated from spectrometric analysis and chemical degradation. Aibellin is a 20-residue peptaibol, and it has a unique structural feature in the novel C-terminal amino alcohol. Moreover, aibellin is the first peptaibol that possesses two acidic amino acids in the C-terminal region and a Phe residue in the middle of the sequence.
Motion and structure from point correspondences with error estimation: planar surfaces (1991)

The determination of motion and structure of a planar scene from monocular image sequences, is studied. A new and simpler linear algorithm, that gives closed-form solutions for motion and structure parameters using point correspondences between two images, assuming that the coplanar points undergo a rigid motion in 3-D space, is presented. A series of analytical results is established. From two perspective views of a planar scene which is undergoing a rigid motion, there are generally two (normalized) interpretations for motion parameters and the positions of the object plane. These two interpretations, one vertical and the other illusive, are both valid in the sense that they render the same pair of images. The authors identify all the special cases in which the number of interpretations is not two, and derive necessary and sufficient geometrical conditions for those special cases to occur. The approach to error estimation is based on the first-order perturbation. The estimated errors provide quantitative assessment for the accuracy of the solutions. They also indicate degenerate or nearly degenerate configurations in the presence of noise.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Genetic design for facilitated production and recovery of recombinant proteins in <i>Escherichia coli</i> (2002)

Genetic strategies have been used for more than two decades to improve bacterial bioprocesses and to simplify recovery procedures. Such strategies include the design of efficient expression vectors and the improvement of bacterial production strains in different ways, e.g. by deletion of protease genes or engineering for overexpression of rare-codon tRNAs, foldases or chaperones. Gene multimerization is another such principle that has proved beneficial to improve production yields. Genetic strategies have furthermore been exploited to facilitate recovery processes by adapting the product for a particular purification principle. In this area, affinity fusions have been commonly used, but other principles, such as modified isoelectric point (pI) or hydrophobic properties have also been successfully investigated. A recent drastic step forward in the use of gene technology to improve recovery processes for recombinant proteins is the introduction of combinatorial protein engineering to generate tailor-made product-specific affinity ligands. This strategy, which allows efficient recovery of a recombinant protein in its native form, is likely to be increasingly used also in industrial-scale bioprocesses, since novel protein ligands have been described that can be sanitized using common industrial cleaning-in-place procedures. The examples presented in this review make it evident that genetic strategies will be of utmost importance in the future for facilitating production and recovery of recombinant proteins.
Comparison of standards and power supply design options for limiting harmonic distortion in power systems (1993)

Harmonic distortion in power systems is growing due to the popularity of switch-mode power electronic equipment. This equipment has recognized advantages, such as reducing weight and improving control and efficiency in power converters and supplies. A disadvantage of switch-mode power converters is that their lowest-cost circuit may burden the power system with harmonic loading. Methods to reduce this distortion are recognized, but economic incentives are yet to be realized. Standardization is the most effective means to influence equipment design and to control distortion in power systems. The authors compare the major European and American standards, as well as some of the electronic equipment design changes that are supposed to limit harmonics.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Reversible switching between superhydrophobic states on a hierarchically structured surface (2012)

Nature offers exciting examples for functional wetting properties based on superhydrophobicity, such as the self-cleaning surfaces on plant leaves and trapped air on immersed insect surfaces allowing underwater breathing. They inspire biomimetic approaches in science and technology. Superhydrophobicity relies on the Cassie wetting state where air is trapped within the surface topography. Pressure can trigger an irreversible transition from the Cassie state to the Wenzel state with no trapped air--this transition is usually detrimental for nonwetting functionality and is to be avoided. Here we present a new type of reversible, localized and instantaneous transition between two Cassie wetting states, enabled by two-level (dual-scale) topography of a superhydrophobic surface, that allows writing, erasing, rewriting and storing of optically displayed information in plastrons related to different length scales.
Evaluation of A Passive Ultrasonic Log Application for Casing Integrity Assessment: A Case Study in A South Oman Field (2012)

Abstract The paper presents evaluation of passive ultrasonic logging tool deployed using E-line to assess casing integrity in 3 oil producing wells in South of Oman. In addition a comparison is offered between the ultrasound logging technology and a more conventional well integrity test using a hoist and multi-set plug that has been utilized to date. The ultrasonic log was run in a selection of oil producing wells, operated by beam pump. Those wells were confirmed as having well integrity issues from well surveillance data and were causing significant oil deferment (2.2% of total oil production). Those wells have a history of cementation challenges owning to heavy losses that occur within a water bearing zone located above the pay zone. This, combined with the presence of H2S and oxygenated water at this depth, has resulted in a number of corrosion related integrity issues across the field. The logging program was originally planned inside tubing with surface pressures of 1,800 psi but it was decided to log inside casing (without tubing) because leak was more severe than predicted (1 m3/min of leak rate). In wells A and B, leak points at 630 m and 225 m were identified and respectively verified. However, another leaking interval in well A was also identified from conventional WIT using hoist. In well C, no pressure held on surface causing lack of differential across leak which resulted in identification failure on first attempt (inside tubing). On second attempt (inside casing), unclear ultrasound reading was attained but seven leak points still can be identified after several log passes. The tool can save significant hoist time and will become viable alternative. In conclusion this paper illustrates examples of where the ultrasonic log has provided highly accurate leak detection, significant time saving and improvements in overall operating efficiency. The limits of the technology are also discussed with recommendations provided for the application of the service based on operational experience gained during the technical evaluation.
Average soliton dynamics and the operation of soliton systems with lumped amplifiers (1991)

It is shown that the dynamics of optical pulse propagation in lumped amplified systems is described by the lossless nonlinear Schrodinger equation under the condition that the amplifier spacing is short compared to the nonlinear evolution length scale. The errors involved in this description are quantified and are on the order of the square of the amplifier spacing. The authors also consider an alternative method of pulse preemphasis which has been proposed, and they show how it relates to the average soliton method presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Coding of image textures using wavelet decomposition and hierarchical multirate vector quantization (2003)

A preliminary investigation into the compression of texture images using wavelet decomposition and hierarchical multirate vector quantization (HMVQ) (of the high frequency subimages) is presented. The effect of using HMVQ on the first three multiresolution subimages of forty texture images is examined. When using unique codebooks for each image, even with the same codebook size the smoother images are decoded with higher quality results. The effects of using two different training sets to create codebooks is examined. It is found that the choice of the training set determines the effect of the coding on the texture images.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Stability of solitons in randomly varying birefringent fibers (1991)

The effects of randomly varying birefringence on solitons are studied. It is shown analytically that the evolution equation can be reduced to the nonlinear Schrödinger equation if the variation length is much shorter than the soliton period. The soliton does not split at high values of the average birefringence, but it does undergo spreading and loss of polarization. A soliton with a temporally constant initial state of polarization is still largely polarized after 40z(0) if the normalized birefringence is delta </= 1.3.
Quantitative AES and LEED Study of Alkali Metal Overlayers on W(100) (1973)

Experimental Auger calibration curves have been obtained for Cs, Rb, K, and Na adsorbed on a W(100) substrate, by monitoring the ratio of the adsorbate-substrate Auger peak-to-peak heights with coverage. A comparative study is made on such curves obtained in the four-grid LEED system and the cylindrical mirror analyzer. The adsorbate on a W substrate has an enhanced Auger yield over that on a Mo substrate due to the increase in the backscattering factor. The attenuation of the substrate Auger electrons is dependent on the atomic number of the alkali adsorbates. The first well-defined LEED pattern during the alkali adsorption revealed a C(2×2) structure. At higher coverages a two-domain hcp structure was observed with no change in the C(2×2) structure.
Detecting Protein‐Protein Interactions In Vivo with FRET using Multiphoton Fluorescence Lifetime Imaging Microscopy (FLIM) (2007)

Protein interactions are critical for many processes in mammalian cells. Such interactions include the stable association of proteins within multi-subunit complexes and the transient association of regulatory proteins. Information about protein interactions in cells has previously come from either in vitro analyses using recombinant expressed proteins, or from yeast 2-hybrid studies. A limitation of this approach is that the protein interaction is studied in isolation, without regard to the many competing protein interactions that can occur within cells. This unit presents a light microscopy approach for detecting protein-protein interactions in vivo based on the measurement of FRET using the multiphoton fluorescence lifetime imaging microscopy (FLIM) technique. By using the FLIM-FRET technique, the spatial organization and quantification of such interactions in a living cell can be characterized. A detailed protocol describing the complete microscope procedure and the choice of the appropriate experimental controls as well as the FRET calculations is also included.
Control as a key technology for a radical innovation in wind energy generation (2010)

This paper is concerned with an innovative technology, denoted as Kitenergy, for the conversion of high-altitude wind energy into electricity. The research activities carried out in the last five years, including theoretical analyses, numerical simulations and experimental tests, indicate that Kitenergy could bring forth a revolution in wind energy generation, providing renewable energy in large quantities at lower cost than fossil energy. After an overview of the main features of the technology, this work investigates three important aspects: the evaluation of the performance achieved by the employed control law, the optimization of the generator operating cycle and the possibility to generate continuously a constant and maximal power output. These issues are tackled through the combined use of advanced modeling, control and optimization methods, which results to be key technologies for a significant breakthrough in renewable energy generation.
BASIC—ALIMENTARY TRACT A Mouse Model of Clostridium difficile-Associated Disease (2008)

Background & Aims: Infection with Clostridium difficile causes nosocomial antibiotic–associated diarrhea and colitis. Hamsters historically have been used to investigate disease pathogenesis and treatment, but are not ideal models because of the lack of hamsterspecific reagents and genetically modified animals, and because they develop fulminant disease. The aim of this study was to establish a mouse model of antibiotic-induced C difficile–associated disease (CDAD) that more closely resembles human disease. Methods: C57BL/6 mice were exposed to a mixture of antibiotics (kanamycin, gentamicin, colistin, metronidazole, and vancomycin) for 3 days. Two days later, they were given injections of clindamycin and then challenged 1 day later with different doses of C difficile. Results: Mice that were exposed to antibiotics and then challenged with C difficile developed diarrhea and lost weight. Disease severity varied from fulminant to minimal in accordance with the challenge dose. Typical histologic features of CDAD were evident. Oral vancomycin prevented CDAD in all mice, but 68% died from colitis after treatment was discontinued. All animals that survived an initial episode of CDAD showed no evidence of diarrhea or colitis after subsequent rechallenge with C difficile. Different strains of C difficile tested in the model showed different levels of virulence in mice. Conclusions: We have developed a mouse model of CDAD that closely represents the human disease. In light of the recent substantial increases in CDAD incidence and severity, this model will be valuable in testing new treatments, examining disease pathogenesis, and elucidating mechanisms of protective immunity.
Temperature dependence of the absorption coefficient of GaAs and ZnSe at 10.6 μm (1974)

The temperature (T) dependence of the absorption coefficient β at 10.6 μm of Czochralski-grown high-resistivity GaAs and chemical vapor deposited (CVD) ZnSe is measured by laser calorimetry. Experimental data are compared with theoretical curves for intrinsic multiphonon absorption. The temperature dependence of β for GaAs is found to possibly exhibit multiphononlike behavior below ∼450°K, but deviates rapidly from theoretical predictions above ∼500°K. The latter effect may be attributed to an increase in free-carrier density via thermal ionization from a level near 0.37 eV. The absorption coefficient of CVD ZnSe is found to be independent of T over the temperature range investigated, and therefore this material appears to be impurity or surface loss dominated.
Nucleosides LIII Syntheses and Reactions of 6,7-Dipyridyllumazine and 2' -Deoxylumazine N-1 Nucleosides (1993)

Summary The chemical syntheses of 6,7-(α-pyridyl)-1-(2,3,5-tri-O-benzoy-β-D-ribofuranosyl)-lumazine (6) and the corresponding free nucleoside 7 are described. Thiation of 6 with P 4 S 10 gave a salt type adduct derivative of 4-thiolumazine 8 which afforded the free nucleoside 9 on deblocking. Treatment of 8 with methanolic NH 3 gave the isopterin-N-1 nucleoside 10. 2,2' -Anhydro compound 13 was obtained by the diphenyl carbonate technique and characterised as the diacetate 14. Acid hydrolysis of 14 gave the arabino-nucleoside 15. which was isolated also from hydrolysis of 14 with hydroxide ion. Reaction of 7 with acetyl bromide gave the 2'-bromo-2'-deoxy derivative 11 as minor product together with triacetate 12 as the main analogue. Reduction of the bromo function in 11 into the expected 2'-deoxy analogue during the treatment with tri-n-butyltin hydride has failed and the 2.2' -anhydro compound 15 was the only product isolated. Alternatively. the 6,7-bis-(α-pyridyl)-1-(2-deoxy-3.5-di-O-toloulyl-α and β-D-ribofuranosyl)-Iumazine (17) and (19) were synthesized from direct condensation of sugar 16 and the silylated base 4. Debolcking of 17 and 19 with sodium methoxide gave the free analogues 18 and 20 respectively.
Relationship between the weight of hatching eggs and subsequent early performance of broiler chicks (1991)

1. The effect of egg weight on the subsequent performance of individual growing chicks was studied. Eggs from commercial broiler breeder hens were collected at 52, 55 and 57 weeks of age and incubated. The chicks were reared for 18 d. 2. Egg weight and hatched chick weight were not affected by the age of the hens during the 52 to 57-week period, but there was a close correlation between egg weight and hatching weight, irrespective of the age of the hens (r = 0.89). Chick:egg weight ratio at hatching was about 0.71 and independent of hen age. One d after hatching, chick weights had decreased by about 1.5 g. 3. The initial high correlation between egg weight and chick weight decreased markedly during post-hatching growth, becoming insignificant 5 d after hatching. At 18 d of age, however, chicks from eggs of older hens tended to be heavier than those from younger birds. The greater 18-d weights appeared to be associated more with higher food intake during that period, than with greater egg weight. 4. It was concluded that, in individual broiler chicks, the advantage of the initially higher weight attributable to a larger egg diminishes rapidly after hatching, and the main factor affecting final body weight is food intake.
ESR and ENDOR investigations of spin exchange in mixed galvinoxyl/nitroxide biradicals. Syntheses (1982)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTESR and ENDOR investigations of spin exchange in mixed galvinoxyl/nitroxide biradicals. SynthesesB. Kirste, A. Krueger, and H. KurreckCite this: J. Am. Chem. Soc. 1982, 104, 14, 3850–3858Publication Date (Print):July 1, 1982Publication History Published online1 May 2002Published inissue 1 July 1982https://pubs.acs.org/doi/10.1021/ja00378a013https://doi.org/10.1021/ja00378a013research-articleACS PublicationsRequest reuse permissionsArticle Views393Altmetric-Citations40LEARN 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
On the potential for artificial bandwidth extension of bone and tissue conducted speech: a mutual information study (2015)

To enhance the communication experience of workers equipped with hearing protection devices and radio communication in noisy environments, alternative methods of speech capture have been utilized. One such approach uses speech captured by a microphone in an occluded ear canal. Although high in signal-to-noise ratio, bone and tissue conducted speech has a limited bandwidth with a high frequency roll-off at 2 kHz. In this paper, the potential of using various bandwidth extension techniques is investigated by studying the mutual information between the signals of three uniquely placed microphones: inside an occluded ear, outside the ear and in front of the mouth. Using a Gaussian mixture model approach, the mutual information of the low and high-band frequency ranges of the three microphone signals at varied levels of signal-tonoise ratio is measured. Results show that a speech signal with extended bandwidth and high signal-to-noise ratio may be achieved using the available microphone signals.