scholarly journals Scattering of VHF radio waves from within an ice sheet containing the vertical-girdle-type ice fabric and anisotropic reflection boundaries

2003 ◽  
Vol 37 ◽  
pp. 305-316 ◽  
Author(s):  
Shuji Fujita ◽  
Kenichi Matsuoka ◽  
Hideo Maeno ◽  
Teruo Furukawa
Keyword(s):  
Ice Sheet ◽  
Polarization Plane ◽  
Anisotropic Scattering ◽  
Physical Structure ◽  
Antenna System ◽  
Cross Polarization ◽  
Radio Waves ◽  
Experimental Conditions ◽  
Different Types ◽  
Remote Measurements

AbstractWe studied the scattering of radio waves off strata within the ice sheet at Mizuho station, Antarctica, to determine the most plausible scattering mechanisms at this location. We measured the effects of birefringence and anisotropic scattering boundaries on the return signal using the following set of experimental conditions: (1) co-polarization and cross-polarization antenna arrangements, (2) all orientations of the antenna system, (3) 60 and 179 MHz frequencies, and (4) pulse lengths of 150–1000 ns. Analyses of the propagated radio waves suggested that the signal is dominated by anisotropic scatter-ingboundaries at 179 MHz, but effects from birefringence also occurred. At depths of 250– 750 m, the scattering was stronger when the polarization plane was along the flowline. In contrast, at depths of about 900–1500 m, scattering was stronger when the polarization plane was perpendicular to the flowline. We suggest that the scattering below about 250 m is related to a layered ice stratum of crystal-orientation fabrics with different types or different cluster strengths. Although our study was at a single site, similar remote measurements over wider regions should provide valuable information about the physical structure of this vast ice sheet.

Early Spelling Acquisition: Does Writing Really Beat the Computer?

1992 ◽  
Vol 15 (3) ◽  
pp. 223-228 ◽  
Author(s):  
Sharon Vaughn ◽  
Jeanne Shay Schumm ◽  
Jane Gordon
Keyword(s):  
Learning Disabled ◽  
Primary Grade ◽  
Group Differences ◽  
Experimental Conditions ◽  
Spelling Acquisition ◽  
Instructional Activity ◽  
Study Results ◽  
Different Types ◽  
Computer Based ◽  
Based Instruction

This research evaluated the efficacy of handwriting, letter tiles, and computer-based instruction on the early spelling acquisition of normal achieving (NLD) and learning disabled (LD) elementary students. The study replicated and extended the Cunningham and Stanovich (1990) study. Forty-eight primary-grade students (24 non-learning disabled; 24 learning disabled) received spelling training under three experimental conditions that involved different types of instructional activity: writing, sorting letter tiles, or typing on the computer. Results indicated no significant differences between the LD and NLD groups on words spelled correctly for any of the three conditions. Since the number of spelling words learned was low across conditions and groups, the number of correctly learned bigrams was examined. No within-group differences emerged for condition (writing, tile, computer); however, significant differences between the groups were found on number of bigrams learned for writing, tile, and computer, with the NLD group outperforming the LD group on all three conditions. Statistically significant time effects for bigrams were also noted for all three conditions. Unlike the Cunningham and Stanovich (1990) study, results did not replicate the superiority of the handwriting condition for the NLD group, nor was the handwriting condition found to be significantly more effective for the LD group.

scholarly journals Combination of Autohydrolysis and Catalytic Hydrolysis of Biomass for the Production of Hemicellulose Oligosaccharides and Sugars

Reactions ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 30-46
Author(s):  
Léa Vilcocq ◽  
Agnès Crepet ◽  
Patrick Jame ◽  
Florbela Carvalheiro ◽  
Luis C. Duarte
Keyword(s):  
Agricultural Waste ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Energy Crop ◽  
Catalytic Hydrolysis ◽  
Experimental Conditions ◽  
Different Types ◽  
Hemicellulosic Sugars ◽  
Hydrolysis Of

Three different types of biomass sourced from forestry waste (eucalyptus residues), agricultural waste (wheat straw), and energy crop (miscanthus) were used as starting materials to produce hemicellulosic sugars, furans (furfural and hydroxymethylfurfural), and oligosaccharides. A two-step hybrid process was implemented; biomass was first autohydrolysed without any additive to extract hemicelluloses and dissolve it in water. Then, the hydrolysate was treated with a solid acid catalyst, TiO2-WOx, in order to achieve hydrolysis and produce monomeric sugars and furans. This article investigates the role of the biomass type, autohydrolysis experimental conditions, polymerisation degree and composition of hemicelluloses on the performance of the process coupling autohydrolysis and catalytic hydrolysis. The highest global yields of both oligosaccharides and monomeric sugars were obtained from Eucalyptus (37% and 18%, respectively).

The influence of some physical characteristics of the milking machine on the rate of new mastitis infections

1973 ◽  
Vol 40 (1) ◽  
pp. 117-129 ◽  
Author(s):  
C. C. Thiel ◽  
Carol L. Cousins ◽  
D. R. Westgarth ◽  
F. K. Neave
Keyword(s):  
Short Duration ◽  
Streptococcus Agalactiae ◽  
The Other ◽  
Vacuum Fluctuations ◽  
Infection Rates ◽  
Experimental Conditions ◽  
Different Types ◽  
Before And After ◽  
Milking Machine ◽  
Do So

SummaryLarge differences in new infection rates occurred with half-udder milking machines in which one half of the cluster operated substantially free from vacuum fluctuations while the other half was subjected to various combinations of different types of fluctuation in vacuum. To increase the rate of new infection all teats were contaminated before and after each milking by immersion in a suspension of Streptococcus agalactiae and Str. dysgalactiae. A series of short-duration trials indicated that neither irregular nor cyclic fluctuations in vacuum acting alone were able to increase new infection rate. However, either the Nyhan and Cowhig irregular fluctuation, or a variant of it in combination with cyclic fluctuations in vacuum, was able to do so under the particular experimental conditions used.

scholarly journals Aspect Entropy Extraction Using Circular SAR Data and Scattering Anisotropy Analysis

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 346 ◽  
Author(s):  
Fei Teng ◽  
Wen Hong ◽  
Yun Lin
Keyword(s):  
Anisotropic Scattering ◽  
Synthetic Aperture ◽  
Viewing Angle ◽  
Denoising Method ◽  
Discrimination Capability ◽  
X Band ◽  
Different Types ◽  
Degree Of Anisotropy ◽  
Sar Data ◽  
Scattering Anisotropy

In conventional synthetic aperture radar (SAR) working modes, targets are assumed isotropic because the viewing angle is small. However, most man-made targets are anisotropic. Therefore, anisotropy should be considered when the viewing angle is large. From another perspective, anisotropy is also a useful feature. Circular SAR (CSAR) can detect the scattering variation under different azimuthal look angles by a 360-degree observation. Different targets usually have varying degrees of anisotropy, which aids in target discrimination. However, there is no effective method to quantify the degree of anisotropy. In this paper, aspect entropy is presented as a descriptor of the scattering anisotropy. The range of aspect entropy is from 0 to 1, which corresponds to anisotropic to isotropic. First, the method proposed extracts aspect entropy at the pixel level. Since the aspect entropy of pixels can discriminate isotropic and anisotropic scattering, the method prescreens the target from the isotropic clutters. Next, the method extracts aspect entropy at the target level. The aspect entropy of targets can discriminate between different types of targets. Then, the effect of noise on aspect entropy extraction is analyzed and a denoising method is proposed. The Gotcha public release dataset, an X-band circular SAR data, is used to validate the method and the discrimination capability of aspect entropy.

Biocapteurs ampérométriques à cholinestérases pour la détermination des pesticides organophosphorés

2002 ◽  
Vol 80 (3) ◽  
pp. 315-331 ◽  
Author(s):  
Graziella Turdean ◽  
Ionel Catalin Popescu ◽  
Liviu Oniciu
Keyword(s):  
Structure And Properties ◽  
Organophosphorous Pesticides ◽  
Amperometric Biosensors ◽  
Experimental Conditions ◽  
Gas And Liquid Chromatography ◽  
Different Types ◽  
Bibliographical Information ◽  
Kinetic Inhibition ◽  
Kinetic Treatment

The purpose of this study is a comparative presentation of the different types of the amperometric biosensors based on cholinesterases for the determination of organophosphorous pesticides using the bibliographical information of the last 20 years. The study contains the presentation of the structure and properties of the cholinesterases, the main reactions implied in the functioning of the amperometric biosensors, their applications and factors influencing the detection or (and) the inhibition process. The detection limit of the mono- or bi-enzymatic amperometric biosensors are relatively higher than those corresponding with the immunobiosensors or with gas and liquid chromatography, which are still considered as the reference methods. As shown, for many other amperometric biosensors, the Michaelis–Menten's kinetic treatment used for reactions catalyzed by free enzymes can be extended to describe the response of amperometric biosensors based on immobilized cholinesterases. The positive compromise between advantages and drawbacks, as well as the "soft" experimental conditions, point to the amperometric monoenzymatic bioelectrode, as an attractive analytical tool for the detection of organophosphorous pesticides.Key words: amperometric biosensor, acetylcholinesterase, organophosphorous pesticides, kinetic, inhibition.

Cross Polarized 2x2 LTE MIMO System for Automotive Shark Fin Application

2020 ◽  
Vol 35 (10) ◽  
pp. 1207-1216
Author(s):  
Djordje Preradov ◽  
Daniel Aloi
Keyword(s):  
Mimo System ◽  
Antenna System ◽  
Small Distance ◽  
Design Parameters ◽  
Cross Polarization ◽  
Physical Constraints ◽  
Mimo Antenna ◽  
Planar Monopole Antenna ◽  
Fin Design ◽  
Better Than

In this research we propose two orthogonally placed FR4 printed planar monopole antenna elements for use in the automobile roof top shark fin antenna for LTE MIMO applications. The discussed MIMO antenna system is designed to cover the worldwide LTE frequency band from 698MHz to 2700MHz. The goal of this research is to achieve satisfactory MIMO performance across the whole band while staying within physical constraints of the shark fin style antenna. The target reflection coefficient (S11) of each element is -6dB. Because of physical constraints of the automotive shark fin design antenna MIMO decorrelation is achieved by cross polarization and small distance separation. Correlation better than -12dB is targeted and achieved in higher bands, while in lower frequency bands antennas would not benefit from MIMO performance. Numerical simulation of the MIMO antenna system is performed using FEKO in order to verify the design parameters. Simulation findings are confirmed by manufacturing antennas and testing in the lab.

scholarly journals The MGED Ontology: A Framework for Describing Functional Genomics Experiments

2003 ◽  
Vol 4 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Christian J. Stoeckert ◽  
Helen Parkinson
Keyword(s):  
Functional Genomics ◽  
Microarray Gene Expression Data ◽  
Experimental Information ◽  
Experimental Sample ◽  
Experimental Conditions ◽  
Microarray Gene Expression ◽  
Microarray Experiments ◽  
Different Types ◽  
Species Specific ◽  
Initial Focus

The Microarray Gene Expression Data (MGED) society was formed with an initial focus on experiments involving microarray technology. Despite the diversity of applications, there are common concepts used and a common need to capture experimental information in a standardized manner. In building the MGED ontology, it was recognized that it would be impractical to cover all the different types of experiments on all the different types of organisms by listing and defining all the types of organisms and their properties. Our solution was to create a framework for describing microarray experiments with an initial focus on the biological sample and its manipulation. For concepts that are common for many species, we could provide a manageable listing of controlled terms. For concepts that are species-specific or whose values cannot be readily listed, we created an ‘OntologyEntry’ concept that referenced an external resource. The MGED ontology is a work in progress that needs additional instances and particularly needs constraints to be added. The ontology currently covers the experimental sample and design, and we have begun capturing aspects of the microarrays themselves as well. The primary application of the ontology will be to develop forms for entering information into databases, and consequently allowing queries, taking advantage of the structure provided by the ontology. The application of an ontology of experimental conditions extends beyond microarray experiments and, as the scope of MGED includes other aspects of functional genomics, so too will the MGED ontology.

Presence Related Formal Aspects of Hedonic Valence in Mood Management: An Investigation of the Impact of Mediated Experiences on Induced Aggressive Mood

2009 ◽  
Vol 18 (3) ◽  
pp. 222-231
Author(s):  
Karin Schweizer
Keyword(s):  
Sensory Information ◽  
Current Paper ◽  
Exposure Condition ◽  
Experimental Conditions ◽  
Mood Management ◽  
Hedonic Value ◽  
Experimental Induction ◽  
Television Exposure ◽  
Different Types ◽  
The Impact

This paper lays out presence related formal aspects of media offerings suited to evoke mood management (Zillmann, 1988). Zillmann proposes that apart from other dimensions, the mood-impacting characteristics of media stimuli vary with the hedonic valence referring to the content (see also Knobloch-Westerwick, 2006). In this contribution, it is claimed that not only does the hedonic value vary with content, but also with formal characteristics of stimuli that refer to different types of media. In contrast to other investigations on mood management, these investigations focus on the reduction of aversive moods when exposed to certain media offerings. The investigations do not focus on the measurement of selected stimuli arrangements in terms of time and intensity. To test this hypothesis, the current paper presents the results of two studies in which 66 participants were presented with film sequences in order to induce aggressive moods. In the first experiment, which served as a treatment check, it was shown that aggressive moods could be reduced more with televised exposures than with a waiting period. In a second experiment, participants having partaken in the experimental induction of aggressive moods were allocated to different experimental conditions that are classified according to formal aspects of hedonic valence: a television exposure condition, an internet surfing condition, and a chat condition. These activities can be numerically classified according to three axes, (i) the amount of sensory information, (ii) the extent of possible interactions, and (iii) the synchrony between sender and recipient. The resulting categorizations of certain media offerings (television exposure: 3, internet surfing: 9–11, and chatting: 8) simultaneously represent certain aspects of the concept of presence. Results show that the induced aggressive moods can be mostly reduced by the treatment (media offerings) with the highest number allocated (internet surfing). Moreover, the findings show an overall decrease of aggressive moods according to the increasing number from television to internet.

Xps and Sem Studies on the Corrosion of UO2 Cointaining Plutonium in Demineralized and Carbonated Water.

2002 ◽  
Vol 757 ◽  
Author(s):  
J. Cobos ◽  
T. Wiss ◽  
T. Gouder ◽  
V. V. Rondinella
Keyword(s):  
Radiation Field ◽  
Surface Oxidation ◽  
Photoemission Spectroscopy ◽  
Spent Fuel ◽  
Experimental Conditions ◽  
Different Types ◽  
Leaching Experiments ◽  
Carbonated Water ◽  
Storage Times

ABSTRACTAn oxidation and dissolution study has been performed on UO2 pellets containing ∼10 and ∼0.1 wt. % 238Pu, ∼10 wt. % 239Pu and on undoped UO2 to investigate the effects of radiolysis and composition on the corrosion behavior of spent fuel. The so-called alpha-doped UO2 is used to simulate the alpha-radiation field of different types of commercial LWR spent fuel after different storage times. Leaching experiments in demineralized and carbonated water at room temperature under oxidizing conditions showed that relatively high amounts of 238Pu were released. The leached surfaces were examined with X-ray Photoemission Spectroscopy (XPS), and the progressive surface oxidation was monitored. The oxidation of the U(IV) during the leaching experiments, in the materials doped with 238Pu resulted in precipitation of U(VI) phases: enhanced formation of studtite for the strongest radiation field and shoepite at low radiation field was observed on the surface of the pellet. Essentially no precipitation of Pu-rich phases was directly observed. Leaching in carbonated water and characterization of UO2 containing 239Pu under the same experimental conditions were performed and the results compared to those for alpha-doped UO2. The chemistry effects due to the presence of Pu in addition to alpha-radiolysis were investigated.

scholarly journals Polarization lidar: An extended three-signal calibration approach

2018 ◽  
Author(s):  
Cristofer Jimenez ◽  
Albert Ansmann ◽  
Moritz Haarig ◽  
Ronny Engelmann ◽  
Jörg Schmidt ◽  
...  
Keyword(s):  
Polarization Plane ◽  
Laser Pulses ◽  
Experimental Conditions ◽  
New Formalism ◽  
Long Term Stability ◽  
Receiver Unit ◽  
Water Cloud ◽  
Elliptically Polarized

Abstract. We present a new formalism to calibrate a three-signal polarization lidar and to measure highly accurate height profiles of the volume linear depolarization ratios under realistic experimental conditions. The methodology considers elliptically polarized laser light, angular misalignment of the receiver unit with respect to the main polarization plane of the laser pulses, and cross-talk between the receiver channels. A case study of a liquid-water cloud observation demonstrates the potential of the new technique. Long-term observations of the calibration parameters corroborate the robustness of the method and the long-term stability of the three-signal polarization lidar. A comparison with another polarization lidar shows excellent agreement regarding the derived volume linear polarization ratio of biomass burning smoke throughout the troposphere and the lower stratosphere up to 16 km height.

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