Sample records for e layer

  1. Multi-Layer E-Textile Circuits (United States)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory


    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  2. Sporadic E-Layers and Meteor Activity (United States)

    Alimov, Obid


    In average width it is difficult to explain variety of particularities of the behavior sporadic layer Es ionospheres without attraction long-lived metallic ion of the meteoric origin. Mass spectrometric measurements of ion composition using rockets indicate the presence of metal ions Fe+, Mg+, Si+, Na+, Ca+, K+, Al+ and others in the E-region of the ionosphere. The most common are the ions Fe+, Mg+, Si+, which are primarily concentrated in the narrow sporadic layers of the ionosphere at altitudes of 90-130 km. The entry of meteoric matter into the Earth's atmosphere is a source of meteor atoms (M) and ions (M +) that later, together with wind shear, produce midlatitude sporadic Es layer of the ionosphere. To establish the link between sporadic Es layer and meteoroid streams, we proceeded from the dependence of the ionization coefficient of meteors b on the velocity of meteor particles in different meteoroid streams. We investigated the dependence of the critical frequency f0Es of sporadic E on the particle velocity V of meteor streams and associations. It was established that the average values of f0Es are directly proportional to the velocity V of meteor streams and associations, with the correlation coefficient of 0.53 ions M+ of meteoric origin.

  3. Parameters of Sporadic E Layers and Transparency For Radio Waves (United States)

    Bencze, P.

    Two frequency parameters of sporadic E layers are included into the scaling of verti- cal incidence ionograms, foEs and fbEs. They are called critical and blanketing fre- quency, respectively. On the basis of results of incoherent scatter measurements at mid-latitudes referring to the structure of sporadic E layers, the critical frequency is considered representing the mean electron density of patches imbedded in the back- ground electron density. The blanketing frequency would correspond to the back- ground electron density. Thus, the difference between critical and blanketing frequen- cies foEs-fbEs could indicate the transparency of sporadic E layers. Comparison of temporal and spatial variations of the transparency with corresponding variations of the vertical shear of the horizontal wind shows that the transparancy can be due to the wind-shear and patches would indicate eddies in the layer.

  4. 20 March 2015 solar eclipse influence on sporadic E layer (United States)

    Pezzopane, M.; Pietrella, M.; Pignalberi, A.; Tozzi, R.


    This paper shows how the solar eclipse occurred on 20 March 2015 influenced the sporadic E (Es) layer as recorded by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. In these locations, the solar eclipse was only partial, with the maximum area of the solar disk obscured by the Moon equal to ∼54% at Rome and ∼45% at Gibilmanna. Nevertheless, it is shown that the strong thermal gradients that usually accompany a solar eclipse, have significantly influenced the Es phenomenology. Specifically, the solar eclipse did not affect the Es layer in terms of its maximum intensity, which is comparable with that of the previous and next day, but rather in terms of its persistence. In fact, both at Rome and Gibilmanna, contrary to what typically happens in March, the Es layer around the solar eclipse time is always present. On the other hand, this persistence is also confirmed by the application of the height-time-intensity (HTI) technique. A detailed analysis of isoheight ionogram plots suggests that traveling ionospheric disturbances (TIDs) likely caused by gravity wave (GW) propagation have played a significant role in causing the persistence of the Es layer.

  5. Energetics and structure of the lower E region associated with sporadic E layer

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    K.-I. Oyama


    Full Text Available The electron temperature (Te, electron density (Ne, and two components of the electric field were measured from the height of 90 km to 150 km by one of the sounding rockets launched during the SEEK-2 campaign. The rocket went through sporadic E layer (Es at the height of 102 km–109 km during ascent and 99 km–108 km during decent, respectively. The energy density of thermal electrons calculated from Ne and Te shows the broad maximum in the height range of 100–110 km, and it decreases towards the lower and higher altitudes, which implies that a heat source exists in the height region of 100 km–110 km. A 3-D picture of Es, that was drawn by using Te, Ne, and the electric field data, corresponded to the computer simulation; the main structure of Es is projected to a higher altitude along the magnetic line of force, thus producing irregular structures of Te, Ne and electric field in higher altitude.

  6. Avian Hepatitis E Virus Infection in Organic Layers. (United States)

    Crespo, Rocio; Opriessnig, Tanja; Uzal, Francisco; Gerber, Priscilla F


    Between 2012 and 2014, 141 chickens from 10 organic layer flocks with a history of severe drop in egg production (up to 40%) and slight increased mortality (up to 1% per week) were submitted to the Avian Health and Food Safety Laboratory (Puyallup, WA). At necropsy, the most common finding was pinpoint white foci on the liver and regressed ova without any other remarkable lesions. Histologically, there was multifocal mild-to-severe acute necrotizing hepatitis present. No significant bacteria were recovered from liver samples, and tests for mycotoxins were negative. Twenty-six serum samples from four affected flocks tested were positive for avian hepatitis E virus (HEV) immunoglobulin Y antibodies. Avian HEV RNA was detected in 10 livers of chickens from two different affected flocks. The avian HEV was characterized by sequencing and determined to belong to genotype 2. The diagnosis of a clinical manifest HEV was based solely on the demonstration of specific viral RNA and the absence of other causative agents in samples from flocks, as the clinical sings and pathologic lesions were atypical.

  7. Securing the Application Layer in eCommerce

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    Bala Musa S


    Full Text Available As e-commerce transaction is evolving, security is becoming a paramount issue since a great deal of credit cards, fund transfer, web shopping and public retirements are involved. Therefore, an appropriate development process is necessary for such security critical application. Also, handling security issues at early stage of software development is paramount to avoiding vulnerabilities from scaling through production environment unnoticed. This paper proposes a comprehensive security requirements and security design within the development phase of an e-commerce application as a security control to identify security flaws at early stage of web application development which might prevent re-architecture when discovered at a later stage.

  8. Case study of simultaneous observations of sporadic sodium layer, E-region field-aligned irregularities and sporadic E layer at low latitude of China (United States)

    Xie, H. Y.; Ning, B. Q.; Zhao, X. K.; Hu, L. H.


    Using the Na lidar at Haikou (20.0°N, 110.3°E), the VHF coherent radar and the digital ionosonde both at Sanya (18.4°N, 109.6°E), cases of simultaneous observations of sporadic sodium layer (SSL), E-region field-aligned irregularities (FAI) and sporadic E layer (Es) in the mesosphere and lower thermosphere (MLT) region at low latitude of China are studied. It is found that SSL occurs simultaneously or follows the enhancement of Es and FAI. The Es, FAI and SSL descend slowly with time which is mostly controlled by the diurnal tide (DT). Besides, the interaction of gravity wave (GW) with tides can cause oscillations in FAI and SSL. Our observations support the neutralization of ions for SSL formation: when the metallic ions layer descents to the altitudes where models predict, the sodium ions convert rapidly to atomic Na that may form an SSL event. Moreover, the SSL peak density will increase (decrease) in the convergence (divergence) vertical shear region of zonal wind.

  9. Automatic layer segmentation of H&E microscopic images of mice skin (United States)

    Hussein, Saif; Selway, Joanne; Jassim, Sabah; Al-Assam, Hisham


    Mammalian skin is a complex organ composed of a variety of cells and tissue types. The automatic detection and quantification of changes in skin structures has a wide range of applications for biological research. To accurately segment and quantify nuclei, sebaceous gland, hair follicles, and other skin structures, there is a need for a reliable segmentation of different skin layers. This paper presents an efficient segmentation algorithm to segment the three main layers of mice skin, namely epidermis, dermis, and subcutaneous layers. It also segments the epidermis layer into two sub layers, basal and cornified layers. The proposed algorithm uses adaptive colour deconvolution technique on H&E stain images to separate different tissue structures, inter-modes and Otsu thresholding techniques were effectively combined to segment the layers. It then uses a set of morphological and logical operations on each layer to removing unwanted objects. A dataset of 7000 H&E microscopic images of mutant and wild type mice were used to evaluate the effectiveness of the algorithm. Experimental results examined by domain experts have confirmed the viability of the proposed algorithms.

  10. Seasonal variability and descent of mid-latitude sporadic E layers at Arecibo

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    N. Christakis


    Full Text Available Sporadic E layers (Es follow regular daily patterns in variability and altitude descent, which are determined primarily by the vertical tidal wind shears in the lower thermosphere. In the present study a large set of sporadic E layer incoherent scatter radar (ISR measurements are analyzed. These were made at Arecibo (Geog. Lat. ~18° N; Magnetic Dip ~50° over many years with ISR runs lasting from several hours to several days, covering evenly all seasons. A new methodology is applied, in which both weak and strong layers are clearly traced by using the vertical electron density gradient as a function of altitude and time. Taking a time base equal to the 24-h local day, statistics were obtained on the seasonal behavior of the diurnal and semidiurnal tidal variability and altitude descent patterns of sporadic E at Arecibo. The diurnal tide, most likely the S(1,1 tide with a vertical wavelength around 25 km, controls fully the formation and descent of the metallic Es layers at low altitudes below 110 km. At higher altitudes, there are two prevailing layers formed presumably by vertical wind shears associated mainly with semidiurnal tides. These include: 1 a daytime layer starting at ~130 km around midday and descending down to 105 km by local midnight, and 2 a less frequent and weaker nighttime layer which starts prior to midnight at ~130 km, descending downwards at somewhat faster rate to reach 110 km by sunrise. The diurnal and semidiurnal-like pattern prevails, with some differences, in all seasons. The differences in occurrence, strength and descending speeds between the daytime and nighttime upper layers are not well understood from the present data alone and require further study.

  11. A Three-Layered Cyclic Model of E-Learning Development and Evaluation (United States)

    Lam, Paul; McNaught, Carmel


    Evaluation is often depicted as being in a cyclic relationship, together with the planning, development, and implementation aspects of e-learning in higher education. This article supports this view and elaborates the multiple roles evaluation can have. We present a three-layered cyclic model developed during an e-learning support project:…

  12. Effect of layered nanostructures on the linewidth of forbidden E2 transitions (United States)

    Guzatov, D. V.; Klimov, V. V.


    In the framework of classical electrodynamics, analytical expressions are derived and investigated for the linewidth of forbidden E2 transitions in an atom (molecule) located near layered metal – dielectric nanostructures. It is shown that the radiation intensity at the forbidden transition during detection in the halfspace behind a layered nanostructure can significantly exceed the intensity during detection in the half-space where an atom (molecule) is located.

  13. Performance Analysis of IEEE 802.16e Wimax Physical Layer

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    Dr. Vineeta Saxena Nigam *,


    Full Text Available WiMAX (worldwide inter-operability for microwave access is an emerging technology for global broadband wireless system offering high speed access to mobile and broadband services. It is based on IEEE 802.16e standard. This standard only deals with MAC and PHY layer specification of network architecture. Considerable research has been done on performance analysis of PHY layer model of WiMAX system over AWGN channel model. This paper attempts performance analysis of IEEE 802.16e PHY layer model over AWGN as well as SUI channel models as SUI channel models are more realistic models based on empirical results. Different modulation schemes, coding rates, and different values of cyclic prefix are considered for comparison using BER (Bit error rate ratio and SNR (Signal to Noise ratio as performance parameters.

  14. Permeability and charge-dependent adsorption properties of the S-layer lattice from Bacillus coagulans E38-66.


    Sára, M; Pum, D; Sleytr, U B


    We investigated the permeability properties of the oblique S-layer lattice from Bacillus coagulans E38-66 after depositing cell wall fragments on a microfiltration membrane, cross-linking the S-layer protein with glutaraldehyde, and degrading the peptidoglycan with lysozyme. Comparative permeability studies on such multilayered S-layer membranes and suspended S-layer vesicles from thermophilic members of the family Bacillaceae with use of the space technique (M. Sára and U. B. Sleytr, J. Bact...


    Directory of Open Access Journals (Sweden)

    Sen-Tarng Lai


    Full Text Available E-commerce is an important information system in the network and digital age. However, the network intrusion, malicious users, virus attack and system security vulnerabilities have continued to threaten the operation of the e-commerce, making e-commerce security encounter serious test. How to improve ecommerce security has become a topic worthy of further exploration. Combining routine security test and security event detection procedures, this paper proposes the Two-Layer Secure Prevention Mechanism (TLSPM. Applying TLSPM, routine security test procedure can identify security vulnerability and defect, and develop repair operations. Security event detection procedure can timely detect security event, and assist follow repair. TLSPM can enhance the e-commerce security and effectively reduce the security risk of e-commerce critical data and asset.

  16. Caracterização por espectroscopia vibracional de filmes Layer-by-Layer contendo ftalocianina, polímeros condutores e gomas naturais


    Kitagawa, Igor Lebedenco [UNESP


    Esta dissertação apresenta o estudo do crescimento (em escala nanométrica) e morfológica (em escala micrométrica) de filmes finos fabricados segundo a técnica Layer-by-Layer (LbL) contendo ftalocianina tetrasulfonada de níquel, polímeros condutores, o polímero poli(alilamina hidroclorada) (PAH), e gomas naturais. Três sistemas foram investigados: i) filmes LbL de NiTsPc e PAH; ii) filme LbL de NiTsPc, PAH e gomas naturais e iii) filmes LbL dos polímeros condutores polianilina (PANI) e poli(o-...

  17. More evidence for a planetary wave link with midlatitude E region coherent backscatter and sporadic E layers

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    K. Schlegel

    Full Text Available Measurements of midlatitude E region coherent backscatter obtained during four summers with SESCAT, a 50 MHz Doppler system operating in Crete, Greece, and concurrent ionosonde recordings from the same ionospheric volume obtained with a CADI for one of these summers, are used to analyse the long-term variability in echo and Es occurrence. Echo and Es layer occurrences, computed in percent of time over a 12-h nighttime interval, take the form of time sequences. Linear power spectrum analysis shows that there are dominant spectral peaks in the range of 2–9 days, the most commonly observed periods appearing in two preferential bands, of 2–3 days and 4–7 days. No connection with geomagnetic activity was found. The characteristics of these periodicities compare well with similar properties of planetary waves, which suggests the possibility that planetary waves are responsible for the observed long-term periodicities. These findings indicate also a likely close relation between planetary wave (PW activity and the well known but not well understood seasonal Es dependence. To test the PW postulation, we used simultaneous neutral wind data from the mesopause region around 95 km, measured from Collm, Germany. Direct comparison of the long-term periodicities in echo and Es layer occurrence with those in the neutral wind show some reasonable agreement. This new evidence, although not fully conclusive, is the first direct indication in favour of a planetary wave role on the unstable midlatitude E region ionosphere. Our results suggest that planetary waves observation is a viable option and a new element into the physics of midlatitude Es layers that needs to be considered and investigated.Key words: Ionosphere (ionosphere irregularities; mid-latitude ionosphere – Meteorology and atmospheric dynamics (waves and tides

  18. New Boundary Layer Facility at Andøya, 69N 16E (United States)

    Gausa, M. A.; Reuder, J.; Blindheim, S.


    The present presentation introduces an inative for a new boundary layer research facility on the island of Andøya (69N,16E) in Norway. The facility will appreciate international cooperation and contributions.Most boundary layer observatories (as e.g. the Lindenberg Observatory in Germany, the Cabauw facility in the Netherlands, or the Boulder Atmospheric Observatory in the US) are located in mid latitudes. Arctic or sub-arctic stations are rare or not representative due to their location in valleys (e.g. Ny Ålesund). In addition, most of the existing sites are representative for a continental boundary layer and do not allow to observe coupling processes to the free troposphere and the upper atmosphere. The island of Andøya has a unique location at 69N. To the West, Andøya is open to the Norwegian Sea. Its orology maintains an almost undisturbed marine boundary on the foreseen location under SW and W wind weather conditions. Due to rugged mountains, other wind directions provide a more transformed PBL. The understanding of the Planetary Boundary Layer (PBL), in particular with respect to turbulence and turbulent exchange processes, is crucial for a wide range of science fields and environmental monitoring tasks: To name a few: basic atmospheric science, monitoring of pollutants, weather forecast, and climate projection. The PBL is consequently research focus for several research groups, which investigate the empirical and theoretical description of this complex height region. In particular, in high latitudes this lowermost layer of the atmosphere the understanding is poor. The following research topics of the new facility are foreseen: present climate projections show their largest bias in polar regions; this is mostly attributed to inappropriate parameterization of PBL processes in the numerical models forecasts of extreme weather events at high latitudes, e.g. of Polar lows with their potential of hazards for infrastructure and traffic, are still poor for the

  19. Influence of tides and planetary waves on E sporadic layer at mid latitudes (United States)

    Pezzopane, Michael; Pignalberi, Alessio; Zuccheretti, Enrico

    This paper describes the influence that tides and planetary waves have on the variability shown by the main characteristics of the E sporadic (Es) layer, that is the top frequency (ftEs) and the lowest virtual height (h’Es). The study is based on ionograms recorded during the summertime of 2013, a year falling in the maximum of solar activity of cycle 24, and precisely in June, July, August and September, by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. We applied the height-time-intensity (HTI) methodology proposed by Haldoupis et al. (2006) to investigate how tides control the Es dynamics. As a whole, the HTI analysis showed that a well-defined semidiurnal periodicity characterizes the Es layer descent and occurrence for all the considered months, although in September some cases which showed a prevailing diurnal periodicity were recorded. Through the application of the wavelet analysis it was also found that the tidal oscillations shown by ftEs and h’Es are affected by a strong amplitude modulation with periods of several days but with important differences between the two parameters. This amplitude modulation is a proof that Es layers are indirectly affected by planetary waves through their nonlinear interaction with tides at lower altitudes; this nonlinear interaction produces the presence of secondary waves with frequencies that are the sum and difference of the primary waves frequencies involved in the interaction as proposed by Teitelbaum and Vial [1991]. This work adds to those that were already done by Haldoupis et al. (2004, 2006), and confirms that ionosonde data, especially those registered in summertime, can be used as a powerful tool for studying tidal and planetary waves properties, as well as their climatology, in the mesosphere-low-termosphere region.

  20. A comparison algorithm to check LTSA Layer 1 and SCORM compliance in e-Learning sites

    CERN Document Server

    Sengupta, Souvik; Banerjee, Nilanjan


    The success of e-Learning is largely dependent on the impact of its multimedia aided learning content on the learner over the hyper media. The e-Learning portals with different proportion of multimedia elements have different impact on the learner, as there is lack of standardization. The Learning Technology System Architecture (LTSA) Layer 1 deals with the effect of environment on the learner. From an information technology perspective it specifies learner interaction from the environment to the learner via multimedia content. Sharable Content Object Reference Model (SCROM) is a collection of standards and specifications for content of web-based e-learning and specifies how JavaScript API can be used to integrate content development. In this paper an examination is made on the design features of interactive multimedia components of the learning packages by creating an algorithm which will give a comparative study of multimedia component used by different learning packages. The resultant graph as output helps...

  1. The formation of sporadic E layers by a vortical perturbation excited in a horizontal wind shear flow

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    G. G. Didebulidze


    Full Text Available The formation of the mid-latitude sporadic E layers (Es layers by an atmospheric vortical perturbation excited in a horizontal shear flow (horizontal wind with a horizontal linear shear is investigated. A three-dimensional atmospheric vortical perturbation (atmospheric shear waves, whose velocity vector is in the horizontal plane and has a vertical wavenumber kz≠0, can provide a vertical shear of the horizontal wind. The shear waves influence the vertical transport of heavy metallic ions and their convergence into thin and dense horizontal layers. The proposed mechanism takes into account the dynamical influence of the shear wave velocity in the horizontal wind on the vertical drift velocity of the ions. It also can explain the multi-layer structure of Es layers. The pattern of the multi-layer structure depends on the value of the shear-wave vertical wavelength, the ion-neutral collision frequency and the direction of the background horizontal wind. The modelling of formation of sporadic E layers with a single and a double peak is presented. Also, the importance of shear wave coupling with short-period atmospheric gravity waves (AGWs on the variations of sporadic E layer ion density is examined and discussed.

  2. Ultra-low material pixel layers for the Mu3e experiment

    CERN Document Server

    Berger, N; Henkelmann, L; Herkert, A; Aeschbacher, F Meier; Ng, Y W; Noehte, L O S; Schöning, A; Wiedner, D


    The upcoming Mu3e experiment will search for the charged lepton flavour violating decay of a muon at rest into three electrons. The maximal energy of the electrons is 53 MeV, hence a low material budget is a key performance requirement for the tracking detector. In this paper we summarize our approach to meet the requirement of about 0.1 % of a radiation length per pixel detector layer. This includes the choice of thinned active monolithic pixel sensors in HV-CMOS technology, ultra-thin flexible printed circuits, and helium gas cooling.

  3. Midnight variations of spreading of ionospheric sporadic E-layers before earthquakes

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    Dieter H.H. Hoffmann


    Full Text Available

    In the present study, ionospheric phenomena caused by earthquakes of magnitudes M >4.0 were investigated. Night-time observations of the spreading of sporadic E-layers (Es-spread performed every 15 min by the Dushanbe and Petropavlovsk-Kamchatsky (middle Asia vertical sounding stations were studied. The mean relative occurrence frequency of Esspread at different values of the blanketing frequency fbEs was considered, and the dependence of Es-spread on the season as well as on the year through an 11-yr solar activity cycle were studied. The fbEs characterizes the maximum plasma density of the Es-layer. The analysis shows that 1- 3 days before seismic shocks in the Earth crust at depths of h <80 km, the occurrence frequency of the Es-spread increases a few hours before midnight. This effect is characteristic of a strengthening of the turbulization of the E-layer plasma. On the basis that the radius of the earthquake preparation region (RD is estimated by the Dobrovolsky formula RD ≈ exp(M km, it was found that Es-spread is observed more often when the distance between the epicenter and the radar station is not greater than RD + 150 km. In cases of earthquakes at greater distances and depths, no midnight effect was found. The authors act on the assumption that the Es-spread might be caused by acoustic waves with periods of 20 s to 5 min. When such acoustic disturbances propagate from the Earth surface they will have maximum amplitudes if they move nearly vertically to greater altitudes.

  4. Sporadic E layer at mid-latitudes: average properties and influence of atmospheric tides (United States)

    Pignalberi, A.; Pezzopane, M.; Zuccheretti, E.


    This paper describes a study of the daily variability shown by the main characteristics of the sporadic E (Es) layer, that is the top frequency (ftEs) and the lowest virtual height (h'Es). The study is based on ionograms recorded by the Advanced Ionospheric Sounder by the Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed in the ionospheric stations at Rome (41.8° N, 12.5° E) and Gibilmanna (37.9° N, 14.0° E), Italy, during the summer (June, July, August and September) of 2013, a year falling in the ascending phase of solar cycle 24. The ftEs presents a diurnal variation characterized by two maxima, the first around noon is very well defined and the second in the evening/night is much less defined; the amplitude of both maxima decreases from June to September accompanied by a general decrease of the ftEs values which is more pronounced in the daytime than in the nighttime. h'Es also presents a diurnal variation characterized by two maxima but, unlike ftEs, these present the same amplitude which is independent from the considered month. Assuming that both ftEs and h'Es trends are influenced by the atmospheric tides, the height-time-intensity (HTI) technique was applied to deeply investigate how these waves control the Es dynamics. The HTI study, along with a fast Fourier transform analysis, show that a well-defined semidiurnal periodicity characterizes the Es layer dynamics most accurately in June and July, while in August and September the daytime semidiurnal periodicity becomes weaker and the role of the diurnal periodicity is consequently highlighted.

  5. Pathological Effects of Aflatoxin and Their Amelioration by Vitamin E in White Leghorn Layers

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    Wajid A Khan, M Zargham Khan*, Ahrar Khan and Iftikhar Hussain1


    Full Text Available White Leghorn layer breeder hens, 30 weeks of age, were divided into 12 groups (A-L. Group A was kept on basal feed and served as control, while group B was offered feed supplemented with vitamin E (100 mg/Kg. Groups C-G were offered feed containing 100, 500, 2,500, 5,000 and 10,000 µg/Kg aflatoxin B1 (AFB1, respectively, whereas groups H-L were offered same dietary levels of AFB1 along with vitamin E (100 mg/Kg. The experimental feeds were offered for three weeks and afterward all the groups were switched over to basal feed for next two weeks. Body weight, absolute and relative weights of liver and kidneys of AF fed birds were significantly higher than control group. Pathological lesions in aflatoxin (AF fed birds included enlarged, pale and friable liver, swollen kidneys and hemorrhages on different organs. Histopathological lesions in liver included fatty change, congestion and hemorrhages, while in kidneys tubular necrosis, cellular infiltration, congestion and hemorrhages were found in groups fed AFB1 at 500 μg/Kg and higher doses. In AF fed hens, no significant ameliorative effects of vitamin E could be observed upon AF induced decrease in feed intake, gross pathology and histopathological alterations and organ weight except body weights. It was concluded that the vitamin E ameliorated the AFB1 induced toxic effects in some of parameters studied.

  6. Measured Instantaneous Viscous Boundary Layer in Turbulent Rayleigh-B\\'{e}nard Convection

    CERN Document Server

    Zhou, Quan


    We report measurements of the instantaneous viscous boundary layer (BL) thickness $\\delta_v(t)$ in turbulent Rayleigh-B\\'{e}nard convection. It is found that $\\delta_v(t)$ obtained from the measured instantaneous two-dimensional velocity field exhibits intermittent fluctuations. For small values, $\\delta_v(t)$ obeys a lognormal distribution, whereas for large values the distribution of $\\delta_v(t)$ exhibits an exponential tail. The variation of $\\delta_v(t)$ with time is found to be driven by the fluctuations of the large-scale mean flow velocity, as expected, and the local horizontal velocities close to the plate can be used as an instant measure of this variation. It is further found that the mean velocity profile measured in the laboratory frame can now be brought into coincidence with the theoretical Blasius laminar BL profile, if it is resampled relative to the time-dependent frame of $\\delta_v(t)$.

  7. Formation of palladium nanofilms using electrochemical atomic layer deposition (E-ALD) with chloride complexation. (United States)

    Sheridan, Leah B; Gebregziabiher, Daniel K; Stickney, John L; Robinson, David B


    Pd thin films were formed by electrochemical atomic layer deposition (E-ALD) using surface-limited redox replacement (SLRR) of Cu underpotential deposits (UPD) on polycrystalline Au substrates. An automated electrochemical flow deposition system was used to deposit Pd atomic layers using a sequence of steps referred to as a cycle. The initial step was Cu UPD, followed by its exchange for Pd ions at open circuit, and finishing with a blank rinse to complete the cycle. Deposits were formed with up to 75 cycles and displayed proportional deposit thicknesses. Previous reports by this group indicated excess Pd deposition at the flow cell ingress, from electron probe microanalysis (EPMA). Those results suggested that the SLRR mechanism did not involve direct transfer between a Cu(UPD) atom and a Pd(2+) ion that would take its position. Instead, it was proposed that electrons are transferred through the metallic surface to reduce Pd(2+) ions near the surface where their activity is highest. It was proposed that if the cell was filled completely before a significant fraction of the Cu(UPD) atoms had been oxidized then the deposit would be homogeneous. Previous work with EDTA indicated that the hypothesis had merit, but it proved to be very sensitive to the EDTA concentration. In the present study, chloride was used to complex Pd(2+) ions, forming PdCl(4)(2-), to slow the exchange rate. Both complexing agents led to a decrease in the rate of replacement, producing more homogeneous films. Although the use of EDTA improved the homogeneity, it also decreased the deposit thickness by a factor of 3 compared to the thickness obtained via the use of chloride.

  8. The reliability of the improved eN method for the transition prediction of boundary layers on a flat plate

    Institute of Scientific and Technical Information of China (English)

    SU CaiHong


    The transition criterion in the improved eN method is that transition would occur whenever the velocity amplitude of disturbance reaches 1%-2% of the free stream velocity,while in the conventional eN method,the N factor is an empirical factor.In this paper the reliability of this key assumption in the improved eN method is checked by results of transition prediction by using the Parabolized Stability Equations (PSE).Transition locations of an incompressible boundary layer and a hypersonic boundary layer at Mach number 6 on a flat plate are predicted by both the improved eN method and the PSE method.Results from both methods agree fairly well with each other,implying that the transition criterion proposed in the improved eN method is reliable.

  9. Competition between winds and electric fields in the formation of blanketing sporadic E layers at equatorial regions (United States)

    Resende, Laysa Cristina Araújo; Batista, Inez Staciarini; Denardini, Clezio Marcos; Carrasco, Alexander José; de Fátima Andrioli, Vânia; Moro, Juliano; Batista, Paulo Prado; Chen, Sony Su


    In the present work, we analyze the competition between tidal winds and electric fields in the formation of blanketing sporadic E layers (Esb) over São Luís, Brazil (2° 31' S, 44° 16' W), a quasi-equatorial station. To investigate this competition, we have used an ionospheric E region model (MIRE) that is able to model the Esb layers taking into account the E region winds and electric fields. The model calculates the densities for the main molecular and metallic ions by solving the continuity and momentum equations for each of the species. Thus, the main purpose of this analysis is to verify the electric fields role in the occurrence or disruption of Esb layers through simulations. The first results of the simulations show that the Esb layer is usually present when only the tidal winds were considered. In addition, when the zonal component of the electric field is introduced in the simulation, the Esb layers do not show significant changes. However, the simulations show the disruption of the Esb layers when the vertical electric field is included. In this study, we present two specific cases in which Esb layers appear during some hours over São Luís. We can see that these layers appear when the vertical electric field was weak, which means that the tidal components were more effective during these hours. Therefore, the vertical component of the electric field is the main agent responsible for the Esb layer disruption. [Figure not available: see fulltext. Caption: Ionograms from São Luís on January 5, 2005, show a clear case of the competition between electric fields and wind effects in the Es layer formation. In ionograms, the Esq trace is clearly seen and identified by a blue arrow. Besides the Esq, we can identify another Es trace at 1415 UT (identified by a black arrow) that persists until 1600 UT. This layer becomes stronger in each ionogram, as can be seen by its effect on partially blocking the reflection from the low-frequency end of F region above

  10. First report of sporadic K layers and comparison with sporadic Na layers at Beijing, China (40.6°N, 116.2°E) (United States)

    Jiao, Jing; Yang, Guotao; Wang, Jihong; Cheng, Xuewu; Li, Faquan; Yang, Yong; Gong, Wei; Wang, Zelong; Du, Lifang; Yan, Chunxiao; Gong, Shunsheng


    A double-laser beam lidar was successfully developed to simultaneously measure K and Na layers at Beijing (40.6°N, 116.2°E) in 2010. Statistical analysis of the parameters of sporadic K (Ks) and sporadic Na (Nas) layers was performed over 2 years of lidar data, and different characteristics of them were found. The average Ks occurrence (2.9%) was lower than that of Nas (5.9%); the Nas occurrence had a maximum (19.3%) in May-June months and a minimum (1.6%) in January-February months, while the Ks occurrence had a maximum (4.9%) in January-February months and a minimum (1.0%) in September-October months; most Ks peaks tended to occur around 93 km, which was ~2 km lower than that of Nas (~95 km); the Ks peak density was often at least 1 order of magnitude lower than that of Nas; notably, two Ks with high peak densities (>1000 cm-3) were observed, which were much higher than K density (15-300 cm-3) reported before. The ascending time of Ks was often longer than its descending time, but an opposite trend occurred for Nas. During the 152 cases of joint observation for the K and Na layers, 21% (32/152) were cases in which Ks and Nas events simultaneously occurred, while 79% (120/152) were cases in which only one layer (K or Na) exhibited a strong Ks or Nas.

  11. Co-observation of sporadic K layer and sporadic Na layer at Beijing, China (40.6°N, 116.2°E) (United States)

    Jiao, Jing


    A double-laser beam lidar was successfully developed to simultaneously measure K and Na layers at Beijing (40.6°N, 116.2°E) in 2010. Statistical analysis of the parameters of sporadic K (Ks) and sporadic Na (Nas) layers was performed over two years of lidar data, and different characteristics of them were found. The average Ks occurrence (2.9 %) was lower than that of Nas (5.9 %); the Nas occurrence had a maximum (19.3 %) in May-June months and a minimum (1.6 %) in January-February months, while the Ks occurrence had a maximum (4.9 %) in January-February months and a minimum (1.0 %) in September-Octerbor months; most Ks peaks tended to occur around 93 km, which was ~ 2 km lower than that of Nas (~ 95 km); the Ks peak density was often at least one order of magnitude lower than that of Nas; notably, two Ks with high peak densities (> 1000 cm-3) were observed, which was much higher than K density (15-300 cm-3) reported before. The ascending time of Ks was often longer than its descending time, but an opposite trend occurred for Nas. During the 152 cases of joint observation for the K and Na layers, 21 % (32/152) were cases in which Ks and Nas events simultaneously occurred, while 79% (120/152) were cases in which only one layer (K or Na) exhibited a strong Ks or Nas.

  12. Occurrence of Sporadic -E layer during the Low Solar Activity over the Anomaly Crest Region Bhopal, India (United States)

    Bhawre, Purushottam


    Ionospheric anomaly crest regions are most challenging for scientific community to understand its mechanism and investigation, for this purpose we are investigating some inospheric result for this region. The study is based on the ionogram data recorded by IPS-71 Digital Ionosonde installed over anomaly crust region Bhopal (Geo.Lat.23.2° N, Geo. Long77.4° E, Dip latitude18.4°) over a four year period from January 2007 to December 2010, covering the ending phase of 23rd Solar Cycle and starting phase of 24th solar cycle. This particular period is felt to be very suitable for examining the sunspot number and it encompasses periods of low solar activities. Quarterly ionograms are analyzed for 24 hours during these study years and have been carefully examined to note down the presence of sporadic- E. We also note down the space weather activities along with the study. The studies are divided in mainly four parts with space and geomagnetic activities during these periods. The occurrence probability of this layer is highest in summer solstice, moderate during equinox and low during winter solstice. Remarkable occurrence peaks appear from June to July in summer and from December to January in winter. The layer occurrence showed a double peak variation with distinct layer groups, in the morning (0200 LT) and the other during evening (1800 LT).The morning layer descent was associated with layer density increase indicating the strengthening of the layer while it decreased during the evening layer descent. The result indicates the presence of semi-diurnal tide over the location while the higher descent velocities could be due to the modulation of the ionization by gravity waves along with the tides. The irregularities associated with the gradient-drift instability disappear during the counter electrojet and the current flow is reversed in westward.

  13. Electron density and plasma waves in mid-latitude sporadic-E layer observed during the SEEK-2 campaign

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    H. Mori


    Full Text Available The SEEK-2 campaign was carried out over Kyushu Island in Japan on 3 August 2002, by using the two sounding rockets of S310-31 and S310-32. This campaign was planned to elucidate generation mechanisms of Quasi-Periodic Echoes (QPEs associated with mid-latitude sporadic-E (Es layers. Electron number densities were successfully measured in the Es layers by using the impedance probe on board two rockets. The plasma waves in the VLF and ELF ranges were also observed on board the S310-32 rocket. Results of electron density measurement showed that there were one or two major peaks in the Es layers along the rockets' trajectories near the altitude of about 10km. There were some smaller peaks associated with the main Es layers in the altitude range from 90 to 120 km. These density peaks were distributed in a very large extent during the SEEK-2 campaign. The Es layer structure is also measured by using the Fixed Bias Probe (FBP, which has a high spatial resolution of several meters (the impedance probe has an altitude resolution of about 400 m. The comparison with the total electron content (TEC measured by the Dual Band Beacon revealed that the Es layer was also modulated in the horizontal direction with the scale size of 30–40 km. It was shown that the QP echoes observed by the ground-based coherent radar come from the major density peak of the Es layer. The plasma wave instrument detected the enhancement of VLF and ELF plasma waves associated with the operation of the TMA release, and also with the passage of the Es layers. Keywords. Ionosphere (Ionospheric irregularities; Midlatitude ionosphere; Plasma temeperature and density

  14. Electrophoretic Carb on Nanotub e Field Emission Layer for Plasma Display Panels

    Institute of Scientific and Technical Information of China (English)

    Qifa Liu; Zhuoqing Yang; Yan Wang; Guifu Ding∗


    A carbon-nanotube (CNT) electrophoretic deposition (EPD) process has been developed to pre-pare a field emission layer in plasma display panels (PDP) for discharge voltage reduction. The CNT layer as a source of discharge priming electrons has been fabricated on the PDP front panel. The balling grinding, mix-acid treatment and EPD parameters have been investigated in order to obtain good uniformity and ex-cellent field emission capability of CNT layer, in order to meet the specifications of CNTs in PDP cell. The measured turn-on field was around 1.1 V/µm in the field emission testing while the minimum sustaining voltage was decreased by 30∼40 V with the use of CNT layer in the discharge testing.

  15. Impact of Sodium Layer variations on the performance of the E-ELT MCAO module

    CERN Document Server

    Schreiber, L; Arcidiacono, C; Pfrommer, T; Holzlöhner, R; Lombini, M; Hickson, P


    Multi-Conjugate Adaptive Optics systems based on sodium Laser Guide Stars may exploit Natural Guide Stars to solve intrinsic limitations of artificial beacons (tip-tilt indetermination and anisoplanatism) and to mitigate the impact of the sodium layer structure and variability. The sodium layer may also have transverse structures leading to differential effects among Laser Guide Stars. Starting from the analysis of the input perturbations related to the Sodium Layer variability, modeled directly on measured sodium layer profiles, we analyze, through a simplified end-to-end simulation code, the impact of the low/medium orders induced on global performance of the European Extremely Large Telescope Multi-Conjugate Adaptive Optics module MAORY.

  16. Electric field measurements of DC and long wavelength structures associated with sporadic-E layers and QP radar echoes

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    S. Ohtsuki


    Full Text Available Electric field and plasma density data gathered on a sounding rocket launched from Uchinoura Space Center, Japan, reveal a complex electrodynamics associated with sporadic-E layers and simultaneous observations of quasi-periodic radar echoes. The electrodynamics are characterized by spatial and temporal variations that differed considerably between the rocket's upleg and downleg traversals of the lower ionosphere. Within the main sporadic-E layer (95–110 km on the upleg, the electric fields were variable, with amplitudes of 2–4 mV/m that changed considerably within altitude intervals of 1–3 km. The identification of polarization electric fields coinciding with plasma density enhancements and/or depletions is not readily apparent. Within this region on the downleg, however, the direction of the electric field revealed a marked change that coincided precisely with the peak of a single, narrow sporadic-E plasma density layer near 102.5 km. This shear was presumably associated with the neutral wind shear responsible for the layer formation. The electric field data above the sporadic-E layer on the upleg, from 110 km to the rocket apogee of 152 km, revealed a continuous train of distinct, large scale, quasi-periodic structures with wavelengths of 10–15 km and wavevectors oriented between the NE-SW quadrants. The electric field structures had typical amplitudes of 3–5 mV/m with one excursion to 9 mV/m, and in a very general sense, were associated with perturbations in the plasma density. The electric field waveforms showed evidence for steepening and/or convergence effects and presumably had mapped upwards along the magnetic field from the sporadic-E region below. Candidate mechanisms to explain the origin of these structures include the Kelvin-Helmholtz instability and the Es-layer instability. In both cases, the same shear that formed the sporadic-E layer would provide the energy to generate the km-scale structures. Other possibilities

  17. Formation mechanisms for low-altitude E{sub S} and their relationship with neutral Fe layers: Results from the METAL campaign

    Energy Technology Data Exchange (ETDEWEB)

    Kirkwood, S.; Von Zahn, U.


    This paper presents results from the METAL campaign, which was a study of sporadic E layers, and metal layers, in the lower altitude ionosphere, at high-latitude locations. Data was collected by a variety of instrumentation, including EISCAT UHF incoherent scatter radar, ionosondes, lidar, and rockets. A number of sporadic E layers were observed, and their origins were consistent with model results. These layers were observed to rapidly drop in altitude in many cases. When Fe layers were observed, they were not observed at exactly the same altitude, nor did they exhibit the same drift in altitude with time.

  18. Layer-by-layer assembly of peptide based bioorganic–inorganic hybrid scaffolds and their interactions with osteoblastic MC3T3-E1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Romanelli, Steven M. [Fordham University Department of Chemistry, 441 East Fordham Road, Bronx, NY 10458 (United States); Fath, Karl R. [The City University of New York, Queens College, Department of Biology, 65-30 Kissena Blvd, Flushing, NY 11367 (United States); The Graduate Center, The City University of New York, 365 Fifth Avenue, NY 10016 (United States); Phekoo, Aruna P. [The City University of New York, Queens College, Department of Biology, 65-30 Kissena Blvd, Flushing, NY 11367 (United States); Knoll, Grant A. [Fordham University Department of Chemistry, 441 East Fordham Road, Bronx, NY 10458 (United States); Banerjee, Ipsita A., E-mail: [Fordham University Department of Chemistry, 441 East Fordham Road, Bronx, NY 10458 (United States)


    In this work we have developed a new family of biocomposite scaffolds for bone tissue regeneration by utilizing self-assembled fluorenylmethyloxycarbonyl protected Valyl-cetylamide (FVC) nanoassemblies as templates. To tailor the assemblies for enhanced osteoblast attachment and proliferation, we incorporated (a) Type I collagen, (b) a hydroxyapatite binding peptide sequence (EDPHNEVDGDK) derived from dentin sialophosphoprotein and (c) the osteoinductive bone morphogenetic protein-4 (BMP-4) to the templates by layer-by-layer assembly. The assemblies were then incubated with hydroxyapatite nanocrystals blended with varying mass percentages of TiO{sub 2} nanoparticles and coated with alginate to form three dimensional scaffolds for potential applications in bone tissue regeneration. The morphology was examined by TEM and SEM and the binding interactions were probed by FITR spectroscopy. The scaffolds were found to be non-cytotoxic, adhered to mouse preosteoblast MC3T3-E1 cells and promoted osteogenic differentiation as indicated by the results obtained by alkaline phosphatase assay. Furthermore, they were found to be biodegradable and possessed inherent antibacterial capability. Thus, we have developed a new family of tissue-engineered biocomposite scaffolds with potential applications in bone regeneration. - Highlights: • Fmoc-val-cetylamide assemblies were used as templates. • Collagen, a short dentin sialophosphoprotein derived sequence and BMP-4 were incorporated. • Hydroxyapatite–TiO{sub 2} nanocomposite blends and alginate were incorporated. • The 3D scaffold biocomposites adhered to preosteoblasts and promoted osteoblast differentiation. • The biocomposites also displayed antimicrobial activity.

  19. E6/E7 oncogenes in epithelial suprabasal layers and estradiol promote cervical growth and ear regeneration. (United States)

    García, C; Hernández-García, D; Valencia, C; Rojo-León, V; Pérez-Estrada, J-R; Werner, M; Covarrubias, L


    Tissue growth is a common characteristic of carcinogenesis and regeneration. Here we show that suprabasal expression of human papillomavirus (HPV)16 E6/E7 oncogenes in Tg(K6b-E6/E7) mice, similar to that observed in HPV-infected human tissue, and estradiol increased cervical epithelium growth and ear-hole closure efficiency. Oncogenes in combination with estradiol had a significant contribution to the proliferation of suprabasal cells of cervical epithelium that correlated with an increased expression of keratin genes. Remarkably, long-term treatments with estradiol resulted in evident cellular and tissue abnormalities indicative of a precancerous phenotype. Regenerating ear epithelium of transgenic mice also showed increased suprabasal cell proliferation and expression of keratin genes. Unexpectedly, we observed higher ear regeneration efficiency in adult than in young female mice, which was further increased by E6/E7 oncogenes. Supporting a role of estradiol in this phenomenon, ovariectomy and treatment with an estrogen receptor inhibitor caused a significant reduction in regenerative capacity. Our data suggest that Tg(K6b-E6/E7) mice are unique to mimic the initial stages of HPV-mediated cervical carcinogenesis, and ear regeneration could facilitate the elucidation of mechanisms involved.

  20. High resolution observations of sporadic-E layers within the polar cap ionosphere using a new incoherent scatter radar experiment

    Directory of Open Access Journals (Sweden)

    B. Damtie

    Full Text Available High resolution observations of sporadic-E layers using a new experiment with the EISCAT (European Incoherent SCATter Svalbard radar (ESR are presented. The observations were made by means of a new type of hardware, which was connected in parallel with the standard receiver. The radar beam was aligned with the geomagnetic field. The experiment applies a new modulation principle. Two phase codes, one with 22 bits and the other with 5 bits, were transmitted at separate frequencies. Each bit was further modulated by a 5-bit Barker code. The basic bit length of both transmissions was 6 µs. Instead of storing the lagged products of the ionospheric echoes in the traditional way, samples of both the transmitted pulses and the ionospheric echoes were taken at intervals of 1 µs and stored on hard disk. The lagged products were calculated later in an off-line analysis. In the analysis a sidelobe-free Barker decoding technique was used. The experiment produces range ambiguities, which were removed by mathematical inversion. Sporadic-E layers were observed at 105–115 km altitudes, and they are displayed with a 150-m range resolution and a 10-s time resolution. The layers show sometimes complex shapes, including triple peaked structures. The thickness of these sublayers is of the order of 1–2 km and they may be separated by 5 km in range. While drifting downwards, the sublayers merge together to form a single layer. The plasma inside a layer is found to have a longer correlation length than that of the surrounding plasma. This may be an indication of heavy ions inside the layer. The field-aligned ion velocity is also calculated. It reveals shears in the meridional wind, which suggests that shears probably also exist in the zonal wind. Hence the wind shear mechanism is a possible generation mechanism of the layer. However, observations from the coherent SuperDARN radar indicate the presence of an ionospheric electric field pointing in the sector between

  1. Fluorescence energy transfer in the bi-fluorescent S-layer tandem fusion protein ECFP-SgsE-YFP. (United States)

    Kainz, Birgit; Steiner, Kerstin; Sleytr, Uwe B; Pum, Dietmar; Toca-Herrera, José L


    This work reports for the first time on the fabrication of a bi-functional S-layer tandem fusion protein which is able to self-assemble on solid supports without losing its functionality. Two variants of the green fluorescent protein (GFP) were genetically combined with a self-assembly system having the remarkable opportunity to interact with each other and act as functional nanopatterning biocoating. The S-layer protein SgsE of Geobacillus stearothermophilus NRS 2004/3a was fused with the cyan ECFP donor protein at the SgsE N-terminus and with the yellow YFP acceptor protein at the C-terminus. The fluorescence energy transfer was studied with spectrofluorimetry, confocal microscopy and flow cytometry, whilst protein self-assembly (on silicon dioxide particles) and structural investigations were carried out with atomic force microscopy (AFM). The fluorescence resonance energy transfer efficiency of reassembled SgsE tandem protein was 20.0 ± 6.1% which is almost the same transfer efficiency shown in solution (19.6 ± 0.1%). This work shows that bi-fluorescent S-layer fusion proteins self-assemble on silica particles retaining their fluorescent properties.

  2. Physical Layer Multi-Core Prototyping A Dataflow-Based Approach for LTE eNodeB

    CERN Document Server

    Pelcat, Maxime; Piat, Jonathan; Nezan, Jean-François


    Base stations developed according to the 3GPP Long Term Evolution (LTE) standard require unprecedented processing power. 3GPP LTE enables data rates beyond hundreds of Mbits/s by using advanced technologies, necessitating a highly complex LTE physical layer. The operating power of base stations is a significant cost for operators, and is currently optimized using state-of-the-art hardware solutions, such as heterogeneous distributed systems. The traditional system design method of porting algorithms to heterogeneous distributed systems based on test-and-refine methods is a manual, thus time-expensive, task.   Physical Layer Multi-Core Prototyping: A Dataflow-Based Approach for LTE eNodeB provides a clear introduction to the 3GPP LTE physical layer and to dataflow-based prototyping and programming. The difficulties in the process of 3GPP LTE physical layer porting are outlined, with particular focus on automatic partitioning and scheduling, load balancing and computation latency reduction, specifically in sys...

  3. The variations of ionosphere critical frequency of E layer over the equatorial geomagnetic region in Southeast Asia (United States)

    Kenpankho, Prasert; Ishii, Mamoru; Supnithi, Pornchai


    We investigate the values of the critical frequency of the ionospheric E layer, foE, obtained at Chumphon ionospheric observatory station, Thailand. For a declining phase of the solar cycle 23 during the year 2005-2008 and an inclining phase of the solar cycle 24 during the year 2009-2013, the foE data have been used to investigate the foE variations over the equatorial geomagnetic region in Southeast Asia. A comparison between the observation data and International Reference Ionosphere (IRI) 2012 model has also been investigated and studied. The results show that the foE obtained from IRI 2012 model underestimates foE from Chumphon station especially during the period of 7-11 am and after 6 pm for each day and all seasons. As the results combining with the previous investigations, we suggest that the underestimation of ionospheric foE by IRI 2012 model is helpful for the correction and improvement of IRI model in an equatorial Asia region.

  4. The role of soil layers in preventing ground water pollution with 17ß-estradiol hormone (E 2

    Directory of Open Access Journals (Sweden)

    A’zam Golzari


    Full Text Available Background: Estrogens include estoril (E3, estradiol and estrone (E1. These chemicals are produced in human and animal bodies as well as in synthetic chemicals (drugs. Estrogens can enter water sources in different ways. When these chemicals enter the human body through water and wastewater, they have the ability to mimic or disrupt the normal estrogen activities in humans and animals. Estrogens in wastewater are able to pass soil layers and contaminate groundwater. Therefore, in this study, the removal of the hormone 17ß-estradiol (E2 as a representative of estrogens in three types of soils was studied. The selection was chosen in respect to the importance of entering the hormone into groundwater through the soil. Methods: This study was an experimental study in which the removal of the hormone E2 from different depths of three types of soils was experimented. The soils were consisted of two different textures, the silty sandy clay and the silty sand with gravel. The hormone E2 was diluted and injected into the drilled holes. Soils were characterized in the soil mechanics laboratory. Hormone extraction from the soils was performed using a centrifuge and analyzed with the Elecsys device. The results were analyzed using the IBM SPSS version 22 software. Results: The results showed that the removal rates of hormone E2 in the three types of soils were higher than 99.5%, and the removal rate in the silty sand was more than the others. In all three soil samples, the removal rates in the first layer were high. The average injected hormone in the soil decreased from 3500 to 3112 ng/l. The results showed that the adhesion and plasticity of the soil had also affected the removal rates. Conclusion: Results showed that the soil plays a significant role in the removal of E2 hormone and this hormone was reduced or eliminated in the first layers of the soils. Thus, the risk of groundwater contamination is low.

  5. Propagação do 'Boysenberry' por estaquia e mergulhia 'Boysenberry' propagation by cutting and layering

    Directory of Open Access Journals (Sweden)

    Andrei Spaziani Tiberti


    Full Text Available Visando a estudar a propagação por estaquia e mergulhia do 'Boysenberry' (híbrido entre 'Marionberry' e framboesa, o objetivo do presente trabalho foi quantificar o potencial rizogênico de estacas caulinares armazenadas a frio-úmido e tratadas com ácido indolbutírico e da mergulhia desse híbrido. No primeiro experimento, estacas caulinares de 15cm foram tratadas com diferentes concentrações de ácido indolbutírico (AIB: 1000, 2000, 3000 e 4000mg L-1 por 10seg., além do controle composto somente por água. No segundo experimento, as estacas foram armazenadas a frio-úmido por 10, 20, 30, 40, 50 e 60 dias, além do controle sem armazenamento. Em ambos os experimentos, as estacas caulinares foram enterradas 2/3 de seu comprimento na posição vertical, utilizando a vermiculita de grânulos finos como substrato, em telado com sombreamento de 50%. Após 60 dias, foram analisadas as porcentagens de enraizamento, brotação e o número médio de raízes. No terceiro experimento, as mergulhias de ponta foram realizadas na porção apical dos ramos, aplicando-se, na extremidade do ramo, diferentes concentrações de AIB (0, 1000, 2000, 3000 e 4000mg L-1. Os ramos foram enterrados em caixas de plástico contendo o substrato casca de pinus umedecido. Passados 45 dias, foram removidos para a mensuração. Concluiu-se que as estacas caulinares devem ser armazenadas a frio-úmido por 20 dias e não serem tratadas com AIB; a mergulhia de ponta promoveu maior emissão de raízes quando tratadas com 4000mg L-1.In order to study the propagation by cutting and layering by 'Boysenberry' (hybrid between 'Marionberry'e framboesa, the objective of the present study was to quantify the rizogenic potential of stems cuttings storage at cold temperature and treated with indolbutyric acid and the point layering of this hybrid. In the first experiment, the stems cuttings of 15cm of length were treated with different concentrations of indolbutyric acid (IBA: 1000

  6. First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki

    Directory of Open Access Journals (Sweden)

    S. Sridharan


    Full Text Available Simultaneous observations of atmospheric sodium (Na made by a resonance lidar and E-region field-aligned-irregularities (FAI made by the Indian MST radar, both located at Gadanki (13.5° N, 79.2° E and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5° N, 77° E are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~95 km Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes.

  7. A Fast MAC-Layer Handover for an IEEE 802.16e-Based WMAN (United States)

    Ray, Sayan K.; Pawlikowski, Krzysztof; Sirisena, Harsha

    We propose a modification of the IEEE 802.16e hard handover (HHO) procedure, which significantly reduces the handover latency constraint of the original HHO procedure in IEEE 802.16e networks. It allows a better handling of the delay-sensitive traffic by avoiding unnecessary time-consuming scanning and synchronization activity as well as simplifies the network re-entry procedure. With the help of the backhaul network, it reduces the number of control messages in the original handover policy, making the handover latency acceptable also for real-time streaming traffic. Preliminary performance evaluation studies show that the modified handover procedure is able to reduce the total handover latency by about 50%.

  8. Effects of scattering on the partial transparency of sporadic-E layers, 1; Neglecting the earth's magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Takefu, M. (Kyushu Univ., Fukuoka (Japan))


    The effects of the scattering of HF radio waves by wavelike irregularities on the partial transparency of sporadic-E layers are studied using the full wave method. Reflection and transmission coefficients and theoretical ionograms are calculated for some sporadic-E layer models including wavelike irregularities when the Earth's magnetic field is neglected. The main result obtained is that if the weak irregularities in a sporadic-E layer contain 'wavelike' electron density fluctuations with amplitudes of only a few percent of the background electron density and with wavelengths of 10-100 m, resonant scattering may take place, and the effects of scattering by these irregularities are significant enough to give satisfactory explanations for the partial transparency of sporadic-E layers. (author).

  9. E2CAV, Pavement layer thickness estimation system based on image texture operators

    Directory of Open Access Journals (Sweden)

    Brayan Barrios Arcila


    Full Text Available Context: Public roads are an essential part of economic progress in any country; they are fundamental for increasing the efficiency on transportation of goods and are a remarkable source of employment. For its part, Colombia has few statistics on the condition of its roads; according with INVIAS the state of the roads in Colombia can be classified as “Very Good” (21.1%, “Good” (34.7%, and “Regular” or “Bad” (43.46%. Thus, from the point of view of pavement rehabilitation, it is worth securing the quality of those roads classified as “Regular” or “Bad”. Objective: In this paper we propose a system to estimate the thickness of the pavement layer using image segmentation methods. The pavement thickness is currently estimated using radars of terrestrial penetration, extraction of cores or making pips; and it is part of structural parameters in the systems of evaluation of pavement. Method: The proposed system is composed of a vertical movement control unit, which introduces a video scope into a small hole in the pavement, then the images are obtained and unified in a laptop. Finally, this mosaic is processed through texture operators to estimate the thickness of the pavement. Users can select between the Otsu method and Gabor filters to process the image data. Results: The results include laboratory and field tests; these tests show errors of 5.03% and 11.3%, respectively, in the thickness of the pavement. Conclusion: The proposed system is an attractive option for local estimation of pavement thickness, with minimal structural damage and less impact on mobility and number of operators.

  10. Morphological study of the field-aligned E-layer irregularities observed by the Gadanki VHF radar

    Directory of Open Access Journals (Sweden)

    C. J. Pan


    Full Text Available We report on the field-aligned irregularities observed in the low-latitude sporadic E-layer (Es with the Gadanki (13.5° N, 79.2° E; geomagnetic latitude 6.3° N VHF radar. The radar was operated intermittently for 15 days during the summer months in 1998 and 1999, for both daytime and nighttime observation. The total observation periods are 161h for the nighttime and 68h for the daytime. The observations were used to study the percentage of occurrence of the E-region echoes for both daytime and nighttime. The statistical characteristics of the mean radial velocity and spectral width are presented for three cases based on the echo occurrence characteristics and the altitude of observations (from 90 to 140km ranges, namely, the lower E-region daytime (90-110km, the lower E-region nighttime (90-105km and the upper E-region nighttime (105-140km echoes. The results are compared with that of Piura, a low-latitude station located at about the same geomagnetic latitude, but to the south of the equator. By comparing the behaviors of the lower E-region radar echoes of the summer months between Gadanki and Piura, we find that the lower altitude echoes below about 100km are rarely reported in Piura but commonly seen in Gadanki. Features of the nighttime echoes observed by these two radars are quite similar but daytime FAI echoes are again seldom detected by Piura.

  11. Simultaneous ionospheric E- and F-layer perturbations caused by some major earthquakes in India

    Directory of Open Access Journals (Sweden)

    O. P. Singh


    Full Text Available The variation in nighttime ionospheric E- and F-region critical frequencies (foEs and foF2 is examined for the months of August 1988, September 1993 and May 1997 in which major earthquakes (6E. The percent deviations of foF2 and foEs from their monthly median are determined for pre-midnight (18:00-00:00 h LT and post-midnight (00:00- 06:00 h LT periods and studied over a span of 20 days before the occurrence of earthquakes. The results show that foF2 are reduced in both the time sectors prior to the occurrence of main shocks. In pre-midnight sector the reduction is between 24 and 30%, 0 to 4 days before the main shocks and in the post-midnight sector it is between 18 and 26%, 1 to 15 days before the main shocks. The foEs show enhancements by 100 to 155% during the same periods. The effects of magnetic storms (Kp and Dst variations on the data are identified clearly but they do not vitiate the effects of earthquakes. The earthquake related anomalies are interpreted in terms of electromagnetic coupling between the lithosphere and ionosphere during earthquakes preparation processes.

  12. Large Scale Circulation and boundary layer structure in a rough Rayleigh-B{\\'e}nard cell filled with water

    CERN Document Server

    Liot, Olivier; Rusaouën, Elonore; Coudarchet, Thibaut; Salort, Julien; Chillà, Francesca


    We report Particle Image Velocimetry of the Large Scale Circulation and the viscous boundary layer in turbulent thermal convection. We use two parallelepipedic Rayleigh-B{\\'e}nard cells with a top smooth plate. The first one has a rough bottom plate and the second one has a smooth one so we compare the rough-smooth and the smooth-smooth configurations. The dimensions of the cell allow to consider a bi-dimensional mean flow. Lots of previous heat flux measurements have shown a Nusselt--Rayleigh regime transition corresponding to an increase of the heat flux in presence of roughness which is higher than the surface increase. Our velocity measurements show that if the mean velocity field is not clearly affected by the roughness, the velocity fluctuations rise dramatically. It is accompanied by a change of the longitudinal velocity structure functions scaling. Moreover, we show that the boundary layer becomes turbulent close to roughness, as it was observed recently in the air [Liot et al., JFM, vol. 786, pp. 275...

  13. Adaptive QoS provision for IEEE 802.16e BWA networks based on cross-layer design

    Directory of Open Access Journals (Sweden)

    Kuo GS


    Full Text Available Abstract This article proposes an integrated framework for adaptive QoS provision in IEEE 802.16e broadband wireless access networks based on cross-layer design. On one hand, an efficient admission control (AC algorithm is proposed along with a semi-reservation scheme to guarantee the connection-level QoS. First, to guarantee the service continuity for handoff connections and resource efficiency, our semi-reservation scheme considers both users' handoff probability and average resource consumption together, which effectively avoids resource over-reservation and insufficient reservation. For AC, a new/handoff connection is accepted only when the target cell has enough resource to afford both instantaneous and average resource consumption to meet the average source rate request. On the other hand, a joint resource allocation and packet scheduling scheme is designed to provide packet-level QoS guarantee in term of "QoS rate", which can ensure fairness for the services with identical priority level in case of bandwidth shortage. Particularly, an enhanced bandwidth request scheme is designed to reduce unnecessary BR delay and redundant signaling overhead caused by the existing one in IEEE 802.16e, which further improves the packet-level QoS performance and resource efficiency for uplink transmission. Simulation results show that the proposed approach not only balances the tradeoff among connection blocking rate, connection dropping rate, and connection failure rate, but also achieves low mean packet dropping rate (PDR, small deviation of PDR, and low QoS outage rate. Moreover, high resource efficiency is ensured.

  14. Occurrence of Sporadic -E layer during the Ending Phase of Solar Cycle 23rd and Rising Phase of Solar Cycle 24th over the Anomaly Crest Region Bhopal (United States)

    Bhawre, Purushottam; Gwal, Ashok Kumar; Tripathi, Sharad Chandra; Mansoori, Azad Ahmad; Aslam A., M.; Khan, Parvaiz A.; Purohit, Pramod K.; Waheed, Malik Abdul; Khatarkar, Prakash

    Ionospheric anomaly crest regions are most challenging for scientific community to understand its mechanism and investigation, for this purpose we are investigating some inospheric result for this region. The study is based on the ionogram data recorded by IPS-71 Digital Ionosonde installed over anomaly crust region Bhopal (Geo.Lat.23.2° N, Geo. Long77.4° E, Dip latitude18.4°) over a four year period from January 2007 to December 2010, covering the ending phase of 23rd Solar Cycle and starting phase of 24th solar cycle. This particular period is felt to be very suitable for examining the sunspot number and it encompasses periods of low solar activities. Quarterly ionograms are analyzed for 24 hours during these study years and have been carefully examined to note down the presence of sporadic- E. We also note down the space weather activities along with the study. The studies are divided in mainly four parts with space and geomagnetic activities during these periods. The occurrence probability of this layer is highest in summer solstice, moderate during equinox and low during winter solstice. Remarkable occurrence peaks appear from June to July in summer and from December to January in winter. The layer occurrence showed a double peak variation with distinct layer groups, in the morning (0200 LT) and the other during evening (1800 LT).The morning layer descent was associated with layer density increase indicating the strengthening of the layer while it decreased during the evening layer descent. The result indicates the presence of semi-diurnal tide over the location while the higher descent velocities could be due to the modulation of the ionization by gravity waves along with the tides. The irregularities associated with the gradient-drift instability disappear during the counter electrojet and the current flow is reversed in westward. Keyword: ionosphere, solar cycle, sporadic - E

  15. Effect of moisture and chitosan layered silicate on morphology and properties of chitosan/layered silicates films; Efeito do teor de quitosana e do silicato em camadas na morfologia e propriedades dos filmes quitosana/silicatos em camadas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.R.M.B. da; Santos, B.F.F. dos; Leite, I.F., E-mail: [Universidade Federal da Paraiba (UFPB), PB (Brazil). Centro de Tecnologia. Departamento de Engenharia de Materiais


    Thin chitosan films have been for some time an object of practical assessments. However, to obtain biopolymers capable of competing with common polymers a significant improvement in their properties is required. Currently, the technology of obtaining polymer/layered silicates nanocomposites has proven to be a good alternative. This work aims to evaluate the effect of chitosan content (CS) and layered silicates (AN) on the morphology and properties of chitosan/ layered silicate films. CS/AN bionanocomposites were prepared by the intercalation by solution in the proportion 1:1 and 5:1. Then were characterized by infrared spectroscopy (FTIR), diffraction (XRD) and X-ray thermogravimetry (TG). It is expected from the acquisition of films, based on different levels of chitosan and layered silicates, choose the best composition to serve as a matrix for packaging drugs and thus be used for future research. (author)

  16. Natural Infection with Avian Hepatitis E Virus and Marek's Disease Virus in Brown Layer Chickens in China. (United States)

    Yang, Shuqing; Wang, Liyuan; Sun, Shuhong


    In the present study, avian hepatitis E virus (HEV) and serotype-1 strains of Marek's disease virus (MDV-1) were detected from a flock of 27-wk-old brown layer hens in China, accompanied by an average daily mortality of 0.44%. Postmortem examination of 25 sick hens and five apparently healthy hens selected randomly from the flock showed significant pathologic changes consistent with hepatitis-splenomegaly syndrome (HSS), including hepatomegaly, peritoneal fluid, and hepatic subcapsular hemorrhages. Microscopic examination of these livers showed multifocal necrotizing hepatitis and mild lymphocytic infiltration. These liver samples were investigated for HEV by reverse-transcription PCR. The overall detection rate of HEV RNA in samples of sick chickens was about 56% (14/25), while in samples from apparently healthy hens, it was 80% (4/5). Sequencing analysis of three 242-base-pair fragments of the helicase gene revealed 95.5% to 97.9% nucleotide identity compared with published avian HEV genotype 3, whereas identities demonstrated only 77.3% to 86.0% similarity when compared with genotypes 1, 2, and 4. Unexpectedly, the MDV meq gene was detected in livers from both apparently healthy chickens (2/5) and sick chickens (12/25) by PCR analysis. The meq gene (396 base pairs) was determined to belong to MDV-1 by further sequencing. The co-infection rate of avian HEV and MDV in this flock was 30% (9/30). This is the first report of dual infection of a nonenvelope RNA virus (HEV) with a herpesvirus (MDV) in chickens in China.

  17. Study on the Efficiency of Grape Seed Meals Used as Antioxidants in Layer Diets Enriched with Polyunsaturated Fatty Acids Compared with Vitamin E

    Directory of Open Access Journals (Sweden)

    M Olteanu

    Full Text Available ABSTRACT The 4-week study was conducted with 180 Lohmann Brown layers (52 weeks of age. The layers were assigned to three groups (C, E1 and E2. The basal diet (group C consisted mainly of corn, soybean meal and corn gluten, and contained 19% crude protein and 11.58 MJ/kg metabolizable energy. The diets for groups E1 and E2 differed from group C by the inclusion of 5% flax meal and of dietary antioxidants. The concentration of α-linolenic acid in the fat of E1 and E2 diets was almost 10 times higher than in group C. E1 diet was supplemented with vitamin E (100 mg/kg feed, DM, while E2 diet was supplemented with 2% grape seed meal (polyphenols: 630.890 µg gallic acid equivalents/g sample; flavonoids: 5.065 µg rutin equivalents/g sample; antioxidant capacity: 28.468 mM trolox equivalents/g sample. The antioxidant capacity of E2 was higher than in C, but lower than in E1. Haugh units of the eggs (18 eggs/group harvested during the last experimental week were not significantly different among groups. The ω-6/ω-3 polyunsaturated fatty acids (PUFAs ratio in the fat from the eggs was 4.46 ± 0.11 (E1 and 4.52 ± 0.21 (E2, three times lower (p<0.05 than the control group (14.70 ± 0.43. In group E1 in particular, but also in group E2, the concentration of total polyphenols in the egg yolk was higher (p<0.05 than in group C.

  18. Synthesis and properties of layered synthetic microstructure (LSM) dispersion elements for 62 eV (200A) to 1. 24 keV (10A) radiation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, T.W. Jr.


    The opportunities offered by engineered synthetic multilayer dispersion elements for x-rays have been recognized since the earliest days of x-ray diffraction analysis. In this paper, application of sputter deposition technology to the synthesis of Layered Synthetic Microstructure (LSMs) of sufficient quality for use as x-ray dispersion elements is discussed. It will be shown that high efficiency, controllable bandwidth dispersion elements, with d spacings varying from 15 A to 180 A, may be synthesized onto both mechanically stiff and flexible substrates. Multilayer component materials include tungsten, niobium, molybdenum, titanium, vanadium, and silicon layers separated by carbon layers. Experimental observations of peak reflectivity in first order, integrated reflectivity in first order, and diffraction performance at selected photon energies in the range, 100 to 15,000 eV, will be reported and compared to theory.

  19. Echinococcus multilocularis laminated-layer components and the E14t 14-3-3 recombinant protein decrease NO production by activated rat macrophages in vitro. (United States)

    Andrade, M Amparo; Siles-Lucas, Mar; Espinoza, Elsa; Pérez Arellano, José Luis; Gottstein, Bruno; Muro, Antonio


    Echinococcus multilocularis and Echinococcus granulosus cause alveolar and cystic (unilocular) echinococcosis, respectively, in humans and animals. It is known that these parasites can affect, among other molecules, nitric oxide (NO) production by periparasitic host cells. Nevertheless, detailed dissection of parasite components specifically affecting cell NO production has not been done to date. We compare the effect of E. granulosus and E. multilocularis defined metacestode structural (laminated-layer associated) and metabolic (14-3-3 protein, potentially related with E. multilocularis metacestode tumor-like growth) components on the NO production by rat alveolar macrophages in vitro. Our results showed that none of these antigens could stimulate macrophage NO production in vitro. However, a reversed effect of some Echinococcus antigens on NO in vitro production was found when cells were previously exposed to LPS stimulation. This inhibitory effect was found when E. multilocularis laminated-layer (LL) or cyst wall (CW) soluble components from both species were used. Pre-stimulation of cells with LPS also resulted in a strong, dose-dependent reduction of NO and iNOS mRNA production after incubation of cells with the E14t protein. Thus, the E. multilocularis 14-3-3 protein appears to be one of the components accounting for the suppressive effect of the CW and LL metacestode extracts.

  20. Mechanical and thermal properties of polypropylene and layered double hydroxides nanocomposites; Propriedades mecanicas e termicas de nanocompositos de polipropileno e hidroxidos duplos lamelares

    Energy Technology Data Exchange (ETDEWEB)

    Duarte de Farias, A.M.; Fraga, M.A.; Oliveira, R.B.; Oliveira, M.G., E-mail: [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil)


    The recent interest in polymer nanocomposites involving layered double hydroxides (LDH) is due to improved thermal stability, flame resistance, mechanical and barrier properties. The LDHs are structurally described as the stacking of layers with positively charged hydrated anions intercalated between these lamellae. In this paper, polypropylene nanocomposites with Mg / Al-HDL unmodified and modified with sodium dodecyl sulfate (DS) were prepared in the internal mixing chamber equipped with roller rotors and heated to 190 deg C. The nanocomposites were injected molded and then morphology, mechanical and thermal properties were evaluated by X-ray diffraction, tensile tests and DSC, respectively. The results revealed that both LDH and LDH-DS reached a good degree of dispersion in the PP matrix, resulting in increased stiffness, but reduced capacity for deformation and toughness of nanocomposites. The crystallinity of the nanocomposites was higher compared to the PP matrix. (author)

  1. Identification of AglE, a Second Glycosyltransferase Involved in N Glycosylation of the Haloferax volcanii S-Layer Glycoprotein▿


    Abu-Qarn, Mehtap; Giordano, Assunta; Battaglia, Francesca; Trauner, Andrej; Hitchen, Paul G.; Morris, Howard R.; Dell, Anne; Eichler, Jerry


    Archaea, like Eukarya and Bacteria, are able to N glycosylate select protein targets. However, in contrast to relatively advanced understanding of the eukaryal N glycosylation process and the information being amassed on the bacterial process, little is known of this posttranslational modification in Archaea. Toward remedying this situation, the present report continues ongoing efforts to identify components involved in the N glycosylation of the Haloferax volcanii S-layer glycoprotein. By co...

  2. Numerical Simulations of the Lunar Penetrating Radar and Investigations of the Geological Structures of the Lunar Regolith Layer at the Chang’E 3 Landing Site

    Directory of Open Access Journals (Sweden)

    Chunyu Ding


    Full Text Available In the process of lunar exploration, and specifically when studying lunar surface structure and thickness, the established lunar regolith model is usually a uniform and ideal structural model, which is not well-suited to describe the real structure of the lunar regolith layer. The present study aims to explain the geological structural information contained in the channel 2 LPR (lunar penetrating radar data. In this paper, the random medium theory and Apollo drilling core data are used to construct a modeling method based on discrete heterogeneous random media, and the simulation data are processed and collected by the electromagnetic numerical method FDTD (finite-difference time domain. When comparing the LPR data with the simulated data, the heterogeneous random medium model is more consistent with the actual distribution of the media in the lunar regolith layer. It is indicated that the interior structure of the lunar regolith layer at the landing site is not a pure lunar regolith medium but rather a regolith-rock mixture, with rocks of different sizes and shapes. Finally, several reasons are given to explain the formation of the geological structures of the lunar regolith layer at the Chang’E 3 landing site, as well as the possible geological stratification structure.

  3. The StcE metalloprotease of enterohaemorrhagic Escherichia coli reduces the inner mucus layer and promotes adherence to human colonic epithelium ex vivo. (United States)

    Hews, Claire L; Tran, Seav-Ly; Wegmann, Udo; Brett, Bernard; Walsham, Alistair D S; Kavanaugh, Devon; Ward, Nicole J; Juge, Nathalie; Schüller, Stephanie


    Enterohaemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen and tightly adheres to human colonic epithelium by forming attaching/effacing lesions. To reach the epithelial surface, EHEC must penetrate the thick mucus layer protecting the colonic epithelium. In this study, we investigated how EHEC interacts with the intestinal mucus layer using mucin-producing LS174T colon carcinoma cells and human colonic mucosal biopsies. The level of EHEC binding and attaching/effacing lesion formation in LS174T cells was higher compared to mucin-deficient colon carcinoma cell lines, and initial adherence was independent of the presence of flagellin, Escherichia coli common pilus, or long polar fimbriae. Although EHEC infection did not affect gene expression of secreted mucins, it resulted in reduced MUC2 glycoprotein levels. This effect was dependent on the catalytic activity of the secreted metalloprotease StcE, which reduced the inner mucus layer and thereby promoted EHEC access and binding to the epithelium in vitro and ex vivo. Given the lack of efficient therapies against EHEC infection, StcE may represent a suitable target for future treatment and prevention strategies.

  4. Characterization and obtainment of thin films based on N,N,N-trimethyl chitosan and heparin through the technical layer-by-layer; Caracterizacao e obtencao de filmes finos de N,N,N-trimetil quitosana e heparina atraves da tecnica layer-by-layer

    Energy Technology Data Exchange (ETDEWEB)



    Thin films of Heparin (HP) and N,N,N-trimethyl chitosan (TMC) with a high degree of quaternization (DQ) were obtained at pH 7.4 through the layer-by-layer (LbL) technique. Polystyrene (PS) was oxidized with aqueous solution of sodium persulfate and subsequently employed as substrate. The characterization of TMC and the respective determination of DQ were performed through {sup 1}H NMR spectroscopy. The thin films de TMC/HP were characterized by FTIR-ATR and AFM. Both techniques confirmed the adsorption of TMC and HP in surface of the PS. The increasing of the bilayers provides a decrease of the projections and/or roughness, further of minimizing the depressions at the surface of the films. Studies of thin films the base of TMC/HP prepared from the LbL technique has not been reported in the literature. It is expected that the thin films of TMC/HP present anti-adhesive and antimicrobial properties. (author)

  5. A fusion tag to fold on: the S-layer protein SgsE confers improved folding kinetics to translationally fused enhanced green fluorescent protein. (United States)

    Ristl, Robin; Kainz, Birgit; Stadlmayr, Gerhard; Schuster, Heinrich; Pum, Dietmar; Messner, Paul; Obinger, Christian; Schaffer, Christina


    Genetic fusion of two proteins frequently induces beneficial effects to the proteins, such as increased solubility, besides the combination of two protein functions. Here, we study the effects of the bacterial surface layer protein SgsE from Geobacillus stearothermophilus NRS 2004/3a on the folding of a C-terminally fused enhanced green fluorescent protein (EGFP) moiety. Although GFPs are generally unable to adopt a functional confirmation in the bacterial periplasm of Escherichia coli cells, we observed periplasmic fluorescence from a chimera of a 150-amino-acid N-terminal truncation of SgsE and EGFP. Based on this finding, unfolding and refolding kinetics of different S-layer-EGFP chimeras, a maltose binding protein-EGFP chimera, and sole EGFP were monitored using green fluorescence as indicator for the folded protein state. Calculated apparent rate constants for unfolding and refolding indicated different folding pathways for EGFP depending on the fusion partner used, and a clearly stabilizing effect was observed for the SgsE_C fusion moiety. Thermal stability, as determined by differential scanning calorimetry, and unfolding equilibria were found to be independent of the fused partner. We conclude that the stabilizing effect SgsE_C exerts on EGFP is due to a reduction of degrees of freedom for folding of EGFP in the fused state.

  6. Inferring hydroxyl layer peak heights from ground-based measurements of OH(6-2 band integrated emission rate at Longyearbyen (78° N, 16° E

    Directory of Open Access Journals (Sweden)

    F. Sigernes


    Full Text Available Measurements of hydroxyl nightglow emissions over Longyearbyen (78° N, 16° E recorded simultaneously by the SABER instrument onboard the TIMED satellite and a ground-based Ebert-Fastie spectrometer have been used to derive an empirical formula for the height of the OH layer as a function of the integrated emission rate (IER. Altitude profiles of the OH volume emission rate (VER derived from SABER observations over a period of more than six years provided a relation between the height of the OH layer peak and the integrated emission rate following the procedure described by Liu and Shepherd (2006. An extended period of overlap of SABER and ground-based spectrometer measurements of OH(6-2 IER during the 2003–2004 winter season allowed us to express ground-based IER values in terms of their satellite equivalents. The combination of these two formulae provided a method for inferring an altitude of the OH emission layer over Longyearbyen from ground-based measurements alone. Such a method is required when SABER is in a southward looking yaw cycle. In the SABER data for the period 2002–2008, the peak altitude of the OH layer ranged from a minimum near 76 km to a maximum near 90 km. The uncertainty in the inferred altitude of the peak emission, which includes a contribution for atmospheric extinction, was estimated to be ±2.7 km and is comparable with the ±2.6 km value quoted for the nominal altitude (87 km of the OH layer. Longer periods of overlap of satellite and ground-based measurements together with simultaneous on-site measurements of atmospheric extinction could reduce the uncertainty to approximately 2 km.

  7. Observed variability in the upper layers at the Equator, 90°E in the Indian Ocean during 2001-2008, 1: zonal currents (United States)

    Rao, R. R.; Horii, T.; Masumoto, Y.; Mizuno, K.


    The observed variability of zonal currents (ZC) at the Equator, 90°E shows a strong seasonal cycle in the near-surface 40-350 m water column with periodic east-west reversals most pronounced at semiannual frequency. Superposed on this, a strong intraseasonal variability of 30-90 day periodicity is also prominently seen in the near-surface layer (40-80 m) almost throughout the year with the only exception of February-March. An eastward flowing equatorial undercurrent (EUC) is present in the depth range of 80-160 m during March-April and October-November. The observed intraseasonal variability in the near-surface layer is primarily determined by the equatorial zonal westerly wind bursts (WWBs) through local frictional coupling between the zonal flow in the surface layer and surface zonal winds and shows large interannual variability. The eastward flowing EUC maintained by the ZPG set up by the east-west slope of the thermocline remotely controlled by the zonal wind (ZW) and zonally propagating wave fields also shows significant interannual variability. This observed variability on interannual time scales appears to be controlled by the corresponding variability in the alongshore winds off the Somalia coast during the preceding boreal winter, the ZW field along the equator, and the associated zonally propagating Kelvin and Rossby waves. The salinity induced vertical stratification observed in the near-surface layer through barrier layer thickness (BLT) effects also shows a significant influence on the ZC field on intraseasonal time scale. Interestingly, among all the 8 years (2001-2008), relatively weaker annual cycle is seen in both ZC in the 40-350 m water column and boreal spring sea surface temperature (SST) only during 2001 and 2008 along the equator caused through propagating wave dynamics.

  8. Effect of single layer centrifugation using Androcoll-E-Large on the sperm quality parameters of cooled-stored donkey semen doses. (United States)

    Ortiz, I; Dorado, J; Ramírez, L; Morrell, J M; Acha, D; Urbano, M; Gálvez, M J; Carrasco, J J; Gómez-Arrones, V; Calero-Carretero, R; Hidalgo, M


    The aim of this study was to determine the effect of single layer centrifugation (SLC) using Androcoll-E-Large on donkey sperm quality parameters after 24 h of cool-storage. Ejaculates were collected from Andalusian donkeys and then cooled at 5°C. SLC was carried out after 24 h of cool-storage using Androcoll-E-Large. In the first experiment, all sperm parameters assessed (total and progressive sperm motility, viability, sperm morphology and sperm kinematics VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were statistically compared between semen samples processed or not with Androcoll-E-Large. Significant differences (Pdonkeys, increasing the sperm quality of cooled-stored donkey semen doses after 24 h of cool storage.

  9. Effects of scattering on the partial transparency of sporadic-E layers, 2; Including the earth's magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Takefu, M. (Kyushu Univ., Fukuoka (Japan))


    The present discussion concerns the study of the partial transparency of sporadic-E layers in terms of the scattering of HF radio waves by wavelike irregularities. The method used is basically the same as that of Part I of this study, but the Earth's magnetic field is included in this paper. The main effects of the Earth's magnetic field are the difference in the reflection frequencies of the o- and x-modes and the mode coupling between these two modes. Numerical results are compared with the results obtained by rocket and radio measurements. Finally, the partially transparent Es traces on ionograms are tentatively classified into 6 types on the basis of the physical processes involved. It is shown that weak 'wavelike' sporadic-E irregularities, if they exist, with amplitudes of only a few percent of the background electron density and with wavelengths of 10 - 100 m, are efficient enough to produce appreciable scattered echoes to give satisfactory explanations for the partial transparency of sporadic-E layers. (author).

  10. A spectral study of the mid-latitude sporadic E layer characteristic oscillations comparable to those of the tidal and the planetary waves (United States)

    Pignalberi, A.; Pezzopane, M.; Zuccheretti, E.


    In this paper different spectral analyses are employed to investigate the tidal and planetary wave periodicities imprinted in the following two main characteristics of the sporadic E (Es) layer: the top frequency (ftEs) and the lowest virtual height (h‧Es). The study is based on ionograms recorded during the summertime of 2013, and precisely in June, July, August and September, by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. It was confirmed that the diurnal and semidiurnal atmospheric tides play a fundamental role in the formation of the mid-latitude Es layers, acting through their vertical wind-shear forcing of the long-living metallic ions in the lower thermosphere, and at the same time it was found that the planetary atmospheric waves might affect the Es layers acting through their horizontal wind-shear forcing with periods close to the normal Rossby modes, that is 2, 5, 10 and 16 days. The wavelet analysis shows also that the ftEs and h‧Es tidal oscillations undergo a strong amplitude modulation with periods of several days and with important differences between the two parameters. This amplitude modulation, characterizing markedly the first thirty days of the ftEs spectrogram, suggests that Es layers are affected indirectly by planetary waves through their nonlinear interaction with the atmospheric tides at lower altitudes. This study wants to be a continuation of the Haldoupis et al. (2004) work in order to verify their results for the foEs characteristic and on the other hand to extend the study also to the h‧Es characteristic not yet shown so far. Anyhow, the study confirms that ionosonde data, especially those registered in summertime, represent a powerful tool for studying tidal and planetary waves properties and their climatology in the mesosphere-low-thermosphere region.

  11. Fontes de lipídios na dieta de poedeiras: desempenho produtivo e qualidade dos ovos Lipids sources on layer hen diet: performance and egg quality

    Directory of Open Access Journals (Sweden)

    D.D. Oliveira


    Full Text Available Os efeitos de fontes de lipídios na dieta de poedeiras sobre o desempenho produtivo e a qualidade do ovo foram verificados em dois experimentos. Foram utilizados quatro tratamentos, definidos de acordo com a fonte lipídica adicionada nas rações: óleo de soja, óleo de girassol, óleo de linhaça e ração controle (sem adição de óleo. Os experimentos foram realizados com poedeiras de 20 e 54 semanas de idade, respectivamente, com duração de oito semanas. Avaliaram-se os parâmetros produtivos - consumo de ração, conversão alimentar, produção e peso dos ovos - e de qualidade do ovo - porcentagens de gema, albúmen e casca, sólidos da gema, unidades Haugh, pH do albúmen, e cor da gema. Somente o peso do ovo de poedeiras jovens foi afetado pela inclusão de óleos vegetais na ração. Esses ovos apresentaram maior peso e maior porcentagem de gema que os produzidos pelas poedeiras jovens alimentadas com ração-controle. Concluiu-se que a utilização de diferentes fontes de lipídios na ração de poedeiras não altera o desempenho produtivo e a qualidade interna dos ovos, com exceção do peso do ovo de poedeiras novas, que aumenta com a utilização de óleos vegetais.The effects of different sources of fat in the diet of layer hens on performance and egg quality were recorded in two experiments. Four treatments were defined by the lipid source added to the diets: soybean oil, sunflower oil, linseed oil and control diet (without oil added. The experiments were carried out with layers from 20 to 54 weeks of age, respectively, for eight weeks. Production parameters (feed intake, feed conversion, egg production, and egg weight and quality of eggs (percentages of yolk, albumen, and shell; total solids of yolk; Haugh units; pH of albumen; and yolk color were evaluated. Among the parameters of production and quality of the eggs, only the weight of eggs and percentage of yolk of young hens were affected by the inclusion of vegetable

  12. Estimation of Guggulsterone E and Z in the Guggul-based Commercial Formulations Using High-performance Thin-layer Chromatography. (United States)

    Sairkar, Pramod Kumar; Sharma, Anjana; Shukla, N P


    Guggulsterone (GS) is a plant steroid and bioactive compound present in gum Guggul of Commiphora wightii. An Indian herbal medicine system "Ayurveda" has a long history of use of gum Guggul and plant extract of C. wightii as medicine for the treatment of various illnesses. Complex nature, low availability, and inconsistency of phytoconstituents make its analysis of difficult tasks. In this work, six different Guggul-based herbal formulations were examined for estimation of GS and their isomers (E and Z) through high-performance thin-layer chromatography technique. For that various concentrations of standard E-GS and Z-GS (50 ng-250 ng/spot) with samples (20 μg/spot) were applied on silica gel coated aluminum plate and developed with the mobile phase of toluene: ethyl acetate: formic acid: methanol (6:2:1:0.5). The scanning was performed at 254 nm wavelength and the absorbance (scan) spectrum of E-GS and Z-GS peak was generated at 200 nm-400 nm wavelength range. Rf value and scan spectrum pattern of the samples reveal that they contain either one form of GS (E-GS, Z-GS) or both. The quantity of E-GS and Z-GS within the samples was ranged from 0.230 ± 0.0040-0.926 ± 0.0168% to 0.537 ± 0.0026-0.723 ± 0.0177%, respectively.

  13. Transition prediction of a hypersonic boundary layer over a cone at small angle of attack——with the improvement of e~N method

    Institute of Scientific and Technical Information of China (English)


    The problem of transition prediction for hypersonic boundary layers over a sharp cone has been studied in this work. The Mach number of the oncoming flow is 6, the cone half-angle is 5o,and the angle of attack is 1o. The conventional eN method is used, but the transition location so obtained is obviously incorrect. The reason is that in the conventional method, only the amplifying waves are taken into account, while in fact, for different meridians the decay processes of the disturbances before they begin to grow are different. Based on our own previous work, new interpretation and essential improvement for the eN method are proposed. Not only the amplification process but also the decay process is considered. The location, where by linear stability theory, the amplitude of disturbance wave is amplified from its initial small value to 1%, is considered to be the transition location. The new result for transition prediction thus obtained is found to be fairly satisfactory. It is also indicated that for the calculation of base flow, boundary layer equations can be used for a small angle of attack. Its computational cost is much smaller than those for DNS.

  14. Transition prediction of a hypersonic boundary layer over a cone at small angle of attack--with the improvement of eN method

    Institute of Scientific and Technical Information of China (English)

    SU CaiHong; ZHOU Heng


    The problem of transition prediction for hypersonic boundary layers over a sharp cone has been stud-ied in this work. The Mach number of the oncoming flow is 6, the cone half-angle is 5Ω, and the angle of attack is 1Ω. The conventional eN method is used, but the transition location so obtained is obviously incorrect. The reason is that in the conventional method, only the amplifying waves are taken into ac-count, while in fact, for different meridians the decay processes of the disturbances before they begin to grow are different. Based on our own previous work, new interpretation and essential improvement for the eN method are proposed. Not only the amplification process but also the decay process is con-sidered. The location, where by linear stability theory, the amplitude of disturbance wave is amplified from its initial small value to 1%, is considered to be the transition location. The new result for transi-tion prediction thus obtained is found to be fairly satisfactory. It is also indicated that for the calculation of base flow, boundary layer equations can be used for a small angle of attack. Its computational cost is much smaller than those for DNS.

  15. The topside behavior in the mesospheric sodium layer observed by lidar at Yanqing (40.46°N, 115.98°E) and at Haikou (20.01°N, 110.32°E) (United States)

    Liu, Yingjie; Clemesha, Barclay Robert; Wang, Jihong


    Due to meteoric ablation, large amounts of metal atoms deposit in the mesopause region, forming the metal layers that can be observed by ground-based lidars. It is widely acknowledged that the meteoric metal layers are normally confined to altitudes of 75-115 km. In fact, the observable upper limit of the topside layer depends largely on the performance of the instruments, the integration time and the observation conditions. With the support of the Chinese Meridional project in the eastern hemisphere, two brand new sodium fluorescence lidars with the same configuration were respectively set up at Yanqing (40.46°N, 115.98°E) and at Haikou (20.01°N, 110.32°E) in April, 2010. They displayed powerful detection capabilities which allow us to study the topside behavior of the mesospheric sodium layer. Based on the observations made at Yanqing between April 2010 and June 2012 and those at Haikou between April 2010 and December 2012, seasonal variations of sodium densities were studied. Comparison between these two sites (~2300 km apart) reveals a strong correlation in the topside sodium layer. Independently of their seasonal characteristics at lower altitudes, they both show an extension to 120 km and above, predominantly during summer. 90 nights of simultaneous observations at these two sites shows that the variation trends of sodium densities above 102 km are remarkably similar in contrast to their different seasonal characteristics below 98 km. At 105 km the correlation coefficient reaches up to 0.71, and almost all of the major peaks can be found one by one with their relative strengths reproduced to a large degree. It indicates that the topside extension effect is global in the mesospheric sodium layer, combined with the observations at other latitudes. Comparison with known meteor showers shows that most of these extensions correspond well to one or more meteor showers, although not one by one. Meteor showers with velocities less than 35 km/s appear to have more

  16. Identification of a surface layer structure and analysis of humidity data in two weather situations at Jodhpur (26° 18′N, 73° 04′E), India, during MONTBLEX 1990

    Indian Academy of Sciences (India)

    N Das; M Bose; U K De


    The Monsoon Trough Boundary Layer Experiment held in 1990 was a multi-institutional effort to probe the atmospheric boundary layer over the monsoon trough over northern India. For this experiment, four micrometeorological towers were set up at four different locations along the normal position of the trough. One such tower of 30m height was located at Jodhpur (26° 18′N, 73° 04′E), Rajasthan. The fast and slow response data available during the experiment have been used in the present study to determine a suitable layer-structure of the surface layer for evaluation of sensible heat flux using the multilayer hypothesis of Kramm (1989).

  17. Prospects of e-beam evaporated molybdenum oxide as a hole transport layer for perovskite solar cells (United States)

    Ali, F.; Khoshsirat, N.; Duffin, J. L.; Wang, H.; Ostrikov, K.; Bell, J. M.; Tesfamichael, T.


    Perovskite solar cells have emerged as one of the most efficient and low cost technologies for delivering of solar electricity due to their exceptional optical and electrical properties. Commercialization of the perovskite solar cells is, however, limited because of the higher cost and environmentally sensitive organic hole transport materials such as spiro-OMETAD and PEDOT:PSS. In this study, an empirical simulation was performed using the Solar Cell Capacitance Simulator software to explore the MoOx thin film as an alternative hole transport material for perovskite solar cells. In the simulation, properties of MoOx thin films deposited by the electron beam evaporation technique from high purity (99.99%) MoO3 pellets at different substrate temperatures (room temperature, 100 °C and 200 °C) were used as input parameters. The films were highly transparent (>80%) and have low surface roughness (≤2 nm) with bandgap energy ranging between 3.75 eV and 3.45 eV. Device simulation has shown that the MoOx deposited at room temperature can work in both the regular and inverted structures of the perovskite solar cell with a promising efficiency of 18.25%. Manufacturing of the full device is planned in order to utilize the MoOx as an alternative hole transport material for improved performance, good stability, and low cost of the perovskite solar cell.

  18. The Equatorial Ekman Layer

    CERN Document Server

    Marcotte, Florence; Soward, Andrew


    The steady incompressible viscous flow in the wide gap between spheres rotating about a common axis at slightly different rates (small Ekman number E) has a long and celebrated history. The problem is relevant to the dynamics of geophysical and planetary core flows, for which, in the case of electrically conducting fluids, the possible operation of a dynamo is of considerable interest. A comprehensive asymptotic study, in the limit E<<1, was undertaken by Stewartson (J. Fluid Mech. 1966, vol. 26, pp. 131-144). The mainstream flow, exterior to the E^{1/2} Ekman layers on the inner/outer boundaries and the shear layer on the inner sphere tangent cylinder C, is geostrophic. Stewartson identified a complicated nested layer structure on C, which comprises relatively thick quasi-geostrophic E^{2/7} (inside C) and E^{1/4} (outside C) layers. They embed a thinner E^{1/3} ageostrophic shear layer (on C), which merges with the inner sphere Ekman layer to form the E^{2/5} Equatorial Ekman layer of axial length E^{...

  19. Short chain nitrocompounds as a treatment of layer hen manure and litter; effects on in vitro survivability of Salmonella, generic E. coli and nitrogen metabolism. (United States)

    Ruiz-Barrera, Oscar; Anderson, Robin C; Hume, Michael E; Corrales-Millan, Jonatan; Castillo-Castillo, Yamicela; Corral-Luna, Agustin; Guevara-Valdez, Jose Luis; Salinas-Chavira, Jaime; Rodriguez-Muela, Carlos; Arzola-Alvarez, Claudio


    The current study was conducted to assess the bactericidal effectiveness of several nitrocompounds against pathogens in layer hen manure and litter. Evidence from an initial study indicated that treatment of layer hen manure with 12 mM nitroethane decreased populations of generic E. coli and total coliforms by 0.7 and 2.2 log10 colony forming units (CFU) g(-1), respectively, after 24 h aerobic incubation at ambient temperature when compared to untreated populations. Salmonella concentrations were unaffected by nitroethane in this study. In a follow-up experiment, treatment of 6-month-old layer hen litter (mixed with 0.4 mL water g(-1)) with 44 mM 2-nitroethanol, 2-nitropropanol or ethyl nitroacetate decreased an inoculated Salmonella typhimurium strain from its initial concentration (3 log10 CFU g(-1)) by 0.7 to 1.7 log10 CFU g(-1) after 6 h incubation at 37°C in covered containers. After 24 h incubation, populations of the inoculated S. Typhmiurium in litter treated with 44 mM 2-nitroethanol, 2-nitropropanol, ethyl nitroacetate or nitroethane were decreased more than 3.2 log10 CFU g(-1) compared to populations in untreated control litter. Treatment of litter with 44 mM 2-nitroethanol, 2-nitropropanol, ethyl nitroacetate decreased rates of ammonia accumulation more than 70% compared to untreated controls (0.167 µmol mL(-1) h(-1)) and loses of uric acid (litter treated with 44 mM 2-nitropropanol, indicating that some of these nitrocompounds may help prevent loss of nitrogen in treated litter. Results warrant further research to determine if these nitrocompounds can be developed into an environmentally sustainable and safe strategy to eliminate pathogens from poultry litter, while preserving its nitrogen content as a nutritionally valuable crude protein source for ruminants.

  20. 初中体育课实施分层教学的实验研究%Layered teaching in P. E. teaching of junior high school

    Institute of Scientific and Technical Information of China (English)



    针对体育课堂教学中学生的个体差异和不同需求,在初中体育课中实施"分层教学",确保让每一个学生受益.结果表明,分层教学是一种有效的教学方法,能够激发学生参与体育运动兴趣,使之变被动为主动学习,切实提高课堂教学的实效性;有利于身体素质好的学生掌握和提高运动的技术技能,也有利于身体素质差的学生增强体质.%According to the school sports teaching needs and individual differences, layered teaching is implemented in the P. E. teaching of junior high schools. The research shows that layered teaching is an effective teaching method which can stimulate students' interest in sports, improve the effectiveness of teaching, improve the body quality and students' mastering the skill.

  1. Avian hepatitis E virus in an outbreak of hepatitis--splenomegaly syndrome and fatty liver haemorrhage syndrome in two flaxseed-fed layer flocks in Ontario. (United States)

    Agunos, A C; Yoo, D; Youssef, S A; Ran, D; Binnington, B; Hunter, D B


    Two commercial layer chicken flocks that were fed a flax-based diet beginning at 28 weeks of age for the production of omega-3 fatty-acid-enriched eggs experienced increased mortality when the birds reached 37 weeks. The average weekly mortality was 0.34% over a 20-week period, with peak mortality of 0.9% for 1 week. Reduced feed consumption, reduced body weight gain and poor peak production were noticed prior to the onset of increased mortality. A total of 245 birds were necropsied and 78% of these had lesions in the liver and spleen, with 44% of those necropsied having changes consistent with hepatitis-splenomegaly syndrome, with lesions ranging from acute periportal lymphoplasmacytic hepatitis to chronic severe cholangiohepatitis with haemorrhage, vasculitis and amyloidosis. A total of 11% of the birds had lesions typical of fatty liver haemorrhagic syndrome, and 22% had lesions found in both hepatitis-splenomegaly syndrome and fatty liver haemorrhagic syndrome. No significant bacteria or viruses were recovered from samples of the liver/bile or spleen but 11 of 21 bile samples contained avian hepatitis E virus RNA detectable with a reverse transcriptase-polymerase chain reaction assay. Comparative sequence analysis found identities of 82 to 92% and 78 to 80% between the helicase and capsid protein genes, respectively, of the virus detected in this outbreak and those of other avian hepatitis E virus isolates, suggesting extensive genetic heterogeneity in avian hepatitis E viruses in Ontario flocks.

  2. Performance Analysis of IEEE 802.11e (EDCF) and IEEE 802.11(DCF) WLAN Incorporating Different Physical Layer Standards (United States)

    Sharma, V.; Singh, H.; Malhotra, J.


    Medium access coordination function basically implements the distributed coordination function (DCF) which provides support to best effort services but limited to QoS services. Subsequently, a new standard, namely enhanced distributed channel access (EDCA) is reported. The IEEE 802.11e (EDCA) defines MAC procedures to support QoS requirements which specifies distributed contention based access scheme to access the shared wireless media. This paper evaluates the performance of EDCA based IEEE 802.11 WLAN for various access categories (ACs) using OPNET™ Modeller 14.5. Further, the computed results are compared with DCF protocols in terms of QoS parameters. Furthermore, the simulative observation is reported at data rate of 54 Mbps using different physical layer protocols such as IEEE 802.11a/b/g to stumble on the best one to be implemented with EDCF to achieve improved QoS.

  3. Generation of zonal flow and magnetic field by coupled internal-gravity and alfvén waves in the ionospheric E-layer (United States)

    Kaladze, Tamaz; Kahlon, Laila

    Nonlinear dynamics of coupled internal-gravity (IG) and alfven electromagnetic planetary waves in the weakly ionized ionospheric E-layer is investigated. Under such coupling new type of alfven waves is revealed. It is shown that such short wavelength turbulence of IG and alfvén waves is unstable with respect to the excitation of low-frequency and large-scale perturbations of the zonal flow and magnetic field. A set of coupled equations describing the nonlinear interaction of coupled IG and alfven waves with zonal flows is derived. The nonlinear mechanism of the instability is driven by the advection of vorticity and is based on the parametric excitation of convective cells by finite-amplitude coupled IG and alfven waves leading to the inverse energy cascade toward the longer wavelength. The growth rates of the corresponding instability and the conditions for driving them are determined. The possibility of generation of the intense mean magnetic field is shown.

  4. Estimation of guggulsterone E and Z in the Guggul-based commercial formulations using high-performance thin-layer chromatography

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Sairkar


    Full Text Available Background: Guggulsterone (GS is a plant steroid and bioactive compound present in gum Guggul of Commiphora wightii. An Indian herbal medicine system “Ayurveda” has a long history of use of gum Guggul and plant extract of C. wightii as medicine for the treatment of various illnesses. Complex nature, low availability, and inconsistency of phytoconstituents make its analysis of difficult tasks. Aims: In this work, six different Guggul-based herbal formulations were examined for estimation of GS and their isomers (E and Z through high-performance thin-layer chromatography technique. Materials and Methods: For that various concentrations of standard E-GS and Z-GS (50 ng–250 ng/spot with samples (20 μg/spot were applied on silica gel coated aluminum plate and developed with the mobile phase of toluene: ethyl acetate: formic acid: methanol (6:2:1:0.5. The scanning was performed at 254 nm wavelength and the absorbance (scan spectrum of E-GS and Z-GS peak was generated at 200 nm–400 nm wavelength range. Results and Conclusions: Rf value and scan spectrum pattern of the samples reveal that they contain either one form of GS (E-GS, Z-GS or both. The quantity of E-GS and Z-GS within the samples was ranged from 0.230 ± 0.0040–0.926 ± 0.0168% to 0.537 ± 0.0026–0.723 ± 0.0177%, respectively.

  5. Estimation of Guggulsterone E and Z in the Guggul-based Commercial Formulations Using High-performance Thin-layer Chromatography (United States)

    Sairkar, Pramod Kumar; Sharma, Anjana; Shukla, N. P.


    Background: Guggulsterone (GS) is a plant steroid and bioactive compound present in gum Guggul of Commiphora wightii. An Indian herbal medicine system “Ayurveda” has a long history of use of gum Guggul and plant extract of C. wightii as medicine for the treatment of various illnesses. Complex nature, low availability, and inconsistency of phytoconstituents make its analysis of difficult tasks. Aims: In this work, six different Guggul-based herbal formulations were examined for estimation of GS and their isomers (E and Z) through high-performance thin-layer chromatography technique. Materials and Methods: For that various concentrations of standard E-GS and Z-GS (50 ng–250 ng/spot) with samples (20 μg/spot) were applied on silica gel coated aluminum plate and developed with the mobile phase of toluene: ethyl acetate: formic acid: methanol (6:2:1:0.5). The scanning was performed at 254 nm wavelength and the absorbance (scan) spectrum of E-GS and Z-GS peak was generated at 200 nm–400 nm wavelength range. Results and Conclusions: Rf value and scan spectrum pattern of the samples reveal that they contain either one form of GS (E-GS, Z-GS) or both. The quantity of E-GS and Z-GS within the samples was ranged from 0.230 ± 0.0040–0.926 ± 0.0168% to 0.537 ± 0.0026–0.723 ± 0.0177%, respectively. PMID:28584486

  6. 饰瓷对磨牙e.max双层全瓷冠断裂类型的影响%Influence of Veneering on Failure Behavior of e. max Bi- layered All- ceramic Molar Crowns. P

    Institute of Scientific and Technical Information of China (English)

    潘娱; Michael V Swain; 马骁; 张新平; 赵克


    目的:通过抗折破坏实验研究饰瓷对磨牙e.max双层全瓷冠断裂强度和断裂类型的影响,为减少临床双层全瓷修复体崩瓷提供实验依据.方法:制作单层全瓷冠(IPS e.max Press)和双层全瓷冠(IPS e.max Press/Ceram)共40个(每组20个),粘接于树脂代型后进行抗折破坏实验并记录断裂强度值;体视显微镜和扫描电子显微镜下观察断裂类型;能谱分析饰瓷-核瓷界面化学元素构成.结果:单层全瓷冠断裂强度值[(2665.4±759.2)N]与双层全瓷冠[(1431.1±404.3)N]间差异有统计学意义(P=0.000).饰瓷内部及饰瓷-核瓷界面缺陷催生裂纹造成饰瓷崩裂是双层全瓷冠断裂的主要模式.结论:饰瓷对磨牙e.max双层全瓷冠断裂强度和断裂类型均有影响;饰瓷内部及饰瓷-核瓷界面缺陷是全瓷冠断裂的主要原因,提高饰瓷断裂强度及减少界面缺陷可减少因崩瓷造成的修复体失败.%Objective: To evaluate the effect of veneering on fracture strength and failure mode of e. max bi-layered all-ceramic molar crowns, so as to provide an experimental basis for reducing veneer chipping and delamination in clinical situations. Methods: Forty all-ceramic molar crowns (IPSe. max Press) were fabricated in two groups (with and without veneering) and each group consists of twenty identical crowns. The crowns were seated on composite resin dies by adhesion and then the specimens were loaded to failure by using a universal mechanical testing machine under compressive load. Fractographic morphology and fracture mode of the failed specimens were observed by a stereomicroscope and a scanning electron microscope (SEM), and the compositions of the veneer-core interface were analyzed by energy dispersive spectroscopy (EDS). Result: Statistical analysis results indicated a significant difference of the mean fracture strength between mono-layered group (2665.4±759.2 N) and bi-layered group (1431.1±404.3 N, P=0.000). The bi-layered crowns

  7. Yield and fruit quality of peach scion by using rootstocks propagated by air layering and seed Produtividade e qualidade de fruto de pessegueiro utilizando porta-enxertos propagados por alporquia aérea e semente

    Directory of Open Access Journals (Sweden)

    Luciano Picolotto


    Full Text Available In rootstock propagation, several methods can be used; however few practices are adopted due to the lack of information about the behavior of stionic combinations at field. The work aimed to compare the propagation method by air layering with the traditional propagation system by seeds using the scion peach [Prunus persica (L. Batsch] cultivar Granada. The following variables were measured: yield, fruit weight and size, skin color, flesh firmness, total soluble solids content (TSS and titatrable acidity (TA, TSS/TA ratio, total phenols, trunk diameter and pruning mass. Yield, total phenols and titatrable acidity were higher when using the air layering propagation. There was no difference between propagation methods regarding color and diameter of fruit, flesh firmness and total soluble solid and TSS/TA ratio. Depending on propagation method, the fruit weight did not differ, nevertheless using the seed propagated Capdeboscq rootstock fruit weight was heavier. Plant behavior in each propagation method depended on the rootstock used. Scion cultivar (cv. Granada on air layering rootstock-derived keeps similar or superior yield and same attributes of fruit quality, better than using rootstocks derived from seeds.Na propagação de porta-enxertos vários métodos podem ser usados, no entanto alguns são pouco utilizados devido à falta de informação sobre o comportamento das plantas a campo. Avaliou-se o método de propagação de porta-enxertos por alporquia comparado ao sistema tradicional de propagação por meio de sementes no pêssego [Prunus persica (L. Batsch] cv. copa Granada. Avaliaram-se as seguintes variáveis: produtividade, peso de fruto, coloração da epiderme, firmeza de polpa, teor de sólidos solúveis totais (SST e acidez titulável (AT, relação SST/AT, tamanho de fruto, fenóis totais, diâmetro de tronco, e peso de poda. A produtividade, fenóis totais e acidez titulável foram maiores quando utilizado o método de propaga

  8. Two years observations on the diurnal evolution of coastal atmospheric boundary layer features over Thiruvananthapuram (8.5∘ N, 76.9∘ E), India (United States)

    Anurose, T. J.; Subrahamanyam, D. Bala; Sunilkumar, S. V.


    The atmospheric boundary layer (ABL) over a given coastal station is influenced by the presence of mesoscale sea breeze circulation, together with the local and synoptic weather, which directly or indirectly modulate the vertical thickness of ABL (z ABL). Despite its importance in the characterization of lower tropospheric processes and atmospheric modeling studies, a reliable climatology on the temporal evolution of z ABL is not available over the tropics. Here, we investigate the challenges involved in determination of the ABL heights, and discuss an objective method to define the vertical structure of coastal ABL. The study presents a two year morphology on the diurnal evolution of the vertical thickness of sea breeze flow (z SBF) and z ABL in association with the altitudes of lifting condensation level (z LCL) over Thiruvananthapuram (8.5∘ N, 76.9∘ E), a representative coastal station on the western coastline of the Indian sub-continent. We make use of about 516 balloon-borne GPS sonde measurements in the present study, which were carried out as part of the tropical tropopause dynamics field experiment under the climate and weather of the sun-earth system (CAWSES)-India program. Results obtained from the present study reveal major differences in the temporal evolution of the ABL features in relation to the strength of sea breeze circulation and monsoonal wind flow during the winter and summer monsoon respectively. The diurnal evolution in z ABL is very prominent in the winter monsoon as against the summer monsoon, which is attributed to the impact of large-scale monsoonal flow over the surface layer meteorology. For a majority of the database, the z LCL altitudes are found to be higher than that of the z ABL, indicating a possible decoupling of the ABL with the low-level clouds.

  9. Short chain nitrocompounds as a treatment of layer hen manure and litter; effects on in vitro survivability of Salmonella, generic E. coli, and nitrogen metabolism (United States)

    Layer hen manure and litter contain appreciable amounts of uric acid, which makes these good crude protein sources for ruminants. Rumen microbial populations can upgrade the nitrogen in uric acid into high quality microbial protein of nutritional value to the host. Layer hen manure and litter can ...

  10. Carbon thin films deposited by the magnetron sputtering technique using cobalt, copper and nickel as buffer-layers; Filmes finos de carbono depositados por meio da tecnica de magnetron sputtering usando cobalto, cobre e niquel como buffer-layers

    Energy Technology Data Exchange (ETDEWEB)

    Costa e Silva, Danilo Lopes


    In this work, carbon thin films were produced by the magnetron sputtering technique using single crystal substrates of alumina c-plane (0001) and Si (111) and Si (100) substrates, employing Co, Ni and Cu as intermediate films (buffer-layers). The depositions were conducted in three stages, first with cobalt buffer-layers where only after the production of a large number of samples, the depositions using cooper buffer-layers were carried out on Si substrates. Then, depositions were performed with nickel buffer layers using single-crystal alumina substrates. The crystallinity of the carbon films was evaluated by using the technique of Raman spectroscopy and, then, by X-ray diffraction (XRD). The morphological characterization of the films was performed by scanning electron microscopy (SEM and FEG-SEM) and high-resolution transmission electron microscopy (HRTEM). The XRD peaks related to the carbon films were observed only in the results of the samples with cobalt and nickel buffer-layers. The Raman spectroscopy showed that the carbon films with the best degree of crystallinity were the ones produced with Si (111) substrates, for the Cu buffers, and sapphire substrates for the Ni and Co buffers, where the latter resulted in a sample with the best crystallinity of all the ones produced in this work. It was observed that the cobalt has low recovering over the alumina substrates when compared to the nickel. Sorption tests of Ce ions by the carbon films were conducted in two samples and it was observed that the sorption did not occur probably because of the low crystallinity of the carbon films in both samples. (author)

  11. Electronic structure and magnetic properties of magnetically dead layers in epitaxial CoF e2O4/A l2O3/Si (111 ) films studied by x-ray magnetic circular dichroism (United States)

    Wakabayashi, Yuki K.; Nonaka, Yosuke; Takeda, Yukiharu; Sakamoto, Shoya; Ikeda, Keisuke; Chi, Zhendong; Shibata, Goro; Tanaka, Arata; Saitoh, Yuji; Yamagami, Hiroshi; Tanaka, Masaaki; Fujimori, Atsushi; Nakane, Ryosho


    Epitaxial CoF e2O4/A l2O3 bilayers are expected to be highly efficient spin injectors into Si owing to the spin filter effect of CoF e2O4 . To exploit the full potential of this system, understanding the microscopic origin of magnetically dead layers at the CoF e2O4/A l2O3 interface is necessary. In this paper, we study the cation distribution, electronic structures, and the magnetic properties of CoF e2O4(111 ) layers with various thicknesses (thickness d =1.4 , 2.3, 4, and 11 nm) in the epitaxial CoF e2O4(111 ) /A l2O3(111 ) /Si (111 ) structures using soft x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) combined with cluster-model calculation. The magnetization of CoF e2O4 measured by XMCD gradually decreases with decreasing thickness d , and finally, a magnetically dead layer is clearly detected at d =1.4 nm . The magnetically dead layer has frustration of magnetic interactions, which is revealed from comparison between the magnetizations at 300 and 6 K. From analysis using configuration-interaction cluster-model calculation, the decrease of d leads to a decrease in the inverse-to-normal spinel structure ratio and also a decrease in the average valence of Fe at the octahedral sites. These results strongly indicate that the magnetically dead layer at the CoF e2O4/A l2O3 interface originates from various complex networks of superexchange interactions through the change in the cation distribution and electronic structure. Furthermore, from comparison of the magnetic properties between d =1.4 and 2.3 nm, it is found that the ferrimagnetic order of the magnetically dead layer at the CoF e2O4/A l2O3 interface is partially restored by increasing the thickness from d =1.4 to 2.3 nm.

  12. Nonmixing layers (United States)

    Gaillard, Pierre; Giovangigli, Vincent; Matuszewski, Lionel


    We investigate the impact of nonideal diffusion on the structure of supercritical cryogenic binary mixing layers. This situation is typical of liquid fuel injection in high-pressure rocket engines. Nonideal diffusion has a dramatic impact in the neighborhood of chemical thermodynamic stability limits where the components become quasi-immiscible and ultimately form a nonmixing layer. Numerical simulations are performed for mixing layers of H2 and N2 at a pressure of 100 atm and temperature around 120-150 K near chemical thermodynamic stability limits.

  13. Initial evaluation and comparison of plasma damage to atomic layer carbon materials using conventional and low T{sub e} plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Jagtiani, Ashish V.; Miyazoe, Hiroyuki; Chang, Josephine; Farmer, Damon B.; Engel, Michael; Neumayer, Deborah; Han, Shu-Jen; Engelmann, Sebastian U., E-mail:; Joseph, Eric A. [IBM, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Boris, David R.; Hernández, Sandra C.; Walton, Scott G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lock, Evgeniya H. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)


    The ability to achieve atomic layer precision is the utmost goal in the implementation of atomic layer etch technology. Carbon-based materials such as carbon nanotubes (CNTs) and graphene are single atomic layers of carbon with unique properties and, as such, represent the ultimate candidates to study the ability to process with atomic layer precision and assess impact of plasma damage to atomic layer materials. In this work, the authors use these materials to evaluate the atomic layer processing capabilities of electron beam generated plasmas. First, the authors evaluate damage to semiconducting CNTs when exposed to beam-generated plasmas and compare these results against the results using typical plasma used in semiconductor processing. The authors find that the beam generated plasma resulted in significantly lower current degradation in comparison to typical plasmas. Next, the authors evaluated the use of electron beam generated plasmas to process graphene-based devices by functionalizing graphene with fluorine, nitrogen, or oxygen to facilitate atomic layer deposition (ALD). The authors found that all adsorbed species resulted in successful ALD with varying impact on the transconductance of the graphene. Furthermore, the authors compare the ability of both beam generated plasma as well as a conventional low ion energy inductively coupled plasma (ICP) to remove silicon nitride (SiN) deposited on top of the graphene films. Our results indicate that, while both systems can remove SiN, an increase in the D/G ratio from 0.08 for unprocessed graphene to 0.22 to 0.26 for the beam generated plasma, while the ICP yielded values from 0.52 to 1.78. Generally, while some plasma-induced damage was seen for both plasma sources, a much wider process window as well as far less damage to CNTs and graphene was observed when using electron beam generated plasmas.

  14. A climatology of the F-layer equivalent winds derived from ionosonde measurements over two decades along the 120°-150°E sector

    Directory of Open Access Journals (Sweden)

    X. Luan


    Full Text Available The vertical equivalent winds (VEWs at the F-layer are analyzed along the 120°-150°E longitude sector with an emphasis on their latitudinal dependence. The VEWs are derived from the monthly median data of fourteen ionosonde stations over two decades. The results show that the VEWs have considerable dependences on the magnetic latitude with an approximate symmetry about the magnetic equator. They are mostly controlled by the electric field drifts in the magnetic equatorial region, and shift to be mostly contributed by neutral winds at mid-latitudes. The relative contribution of the two dynamic factors is regulated by the magnetic dip in addition to their own magnitudes. The VEWs generally have opposite directions and different magnitudes between lower and higher latitudes. At solar minimum, the magnitudes of VEWs are only between -20 and 20m/s at lower latitudes, while at higher latitudes they tend to increase with latitudes, typically having magnitudes between 20-40m/s. At solar maximum, the VEWs are reduced by about 10-20m/s in magnitudes during some local times at higher latitudes. A tidal analysis reveals that the relative importance of major tidal components is also different between lower and higher latitudes.

    The VEWs also depend on local time, season and solar activity. At higher latitudes, the nighttime VEWs have larger magnitude during post-midnight hours and so do the daytime ones before midday. The VEWs tend to have an inverse relationship with solar activity not only at night, but also by day, which is different from the meridional winds predicted by the HWM93 model. The latitudinal dependence of VEWs has two prevailing trends: one is a maximum at the highest latitudes (as far as the latitudes concerned in the present work; the other is a mid-latitude maximum. These two latitudinal trends are mostly dependent on season, while they depend relatively weakly on local time and solar activity. The

  15. Variability of sporadic E-layer semi transparency (foEs-fbEswith magnitude and distance from earthquake epicenters to vertical sounding stations

    Directory of Open Access Journals (Sweden)

    E. V. Liperovskaya


    Full Text Available Variations of the Es-layer semi transparency co-efficient were analyzed for more than 100 earthquakes with magnitudes M > 4 and depths h Es-layer X = (foEs – fbEs/fbEs can characterize, for thin layers, the presence of small scale plasma turbulence. It is shown that the turbulence level decreases by ~ 10% during three days before earthquakes probably due to the heating of the atmosphere. On the contrary, the turbulence level increases by the same value from one to three days after the shocks. For earthquakes with magnitudes M > 5 the effect exists at distances up to 300 km from the epicenters. The effect could also exist for weak (M ~ 4 and shallow (depth < 50 km earthquakes at a distance smaller than 200 km from the epicenters.

  16. Characterization and improvement gas diffusion layer of low temperature fuel cell; Caracterizacao e aprimoramento da camada difusora de celulas a combustivel de funcionamento a baixa temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C.Z.; Dantas, R.; Oliveira, I.S. de; Azevedo, C.M.N.; Pires, M. [Pontificia Univ. Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Quimica; Canalli, V. [Pontificia Univ. Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Engenharia


    In low temperature fuel cells the main part is the membrane electrode assembly (MEA). The gas diffusion layer is a component of the MEA, being a composite material constituted by carbon powder and polytetrafluoroethylene, used to increases hydrofobicity, fundamental characteristic in water transport into system. In this work methods were adapted with the aim to a better characterization of the diffusion layer by the measuring the following parameter: contact angle and hysteresis; morphology, thickness and porosity. From these characterization results optimized MEAS will be produced to better fuel cell performance. (author)

  17. Retrieval of atmospheric boundary layer height by CSIR NLC mobile LIDAR, Pretoria (25.5° S; 28.2° E), South Africa

    CSIR Research Space (South Africa)

    Sivakumar, V


    Full Text Available that the earth?s surface heats up due to solar radiation and this results in various thermodynamic chemical reactions causing turbulence in the PBL. The boundary layer height is therefore expected to vary more during the day and to 4116 stabilize after sun... of planetary (nocturnal) boundary layer (PBL). The PBL is found to be around 2 km and found to vary with time. During the night it is found to be more stable and vary largely during the day time. We have used the above datasets to study the diurnal...

  18. Strain relaxation during solid-phase epitaxial crystallisation of Ge{sub x}Si{sub 1-x} alloy layers with depth dependent G{sub e} compositions

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Wahchung; Elliman, R.G.; Kringhoj, P. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences


    The solid-phase epitaxial crystallisation of depth dependent Ge{sub x}Si{sub lx} alloy layers produced by implanting Ge into Si substrates was studied. In-situ monitoring was done using time-resolved reflectivity (TRR) whilst post-anneal defect structures were characterised by Rutherford backscattering and channeling spectrometry (RBS-C) and transmission electron microscopy (TEM). Particular attention was directed at Ge concentrations above the critical concentration for the growth of fully strained layers. Strain relief is shown to be correlated with a sudden reduction in crystallisation velocity caused by roughening of the crystalline/amorphous interface. 11 refs., 1 tab., 2 figs.

  19. Alimentação de Codornas com Milho Moído e Ração de Postura no Período Pós-jejum Durante a Muda Forçada e Seus Efeitos Sobre o Desempenho Performance of Layer Quail Fed Corn Meal or Layer Diet During a Post Molt Period

    Directory of Open Access Journals (Sweden)

    EA Garcia


    Full Text Available O experimento foi realizado com o objetivo de avaliar o desempenho de codornas poedeiras alimentadas por diferentes períodos com milho moído ou ração de postura durante sete dias após três dias de jejum, método de muda utilizado. Após esse período, as aves foram alimentadas com ração de postura durante as 20 semanas do período experimental. Utilizou-se um delineamento inteiramente ao acaso com três tratamentos (ração de postura por sete dias, ração de postura por três dias e milho moído por quatro dias e milho moído por sete dias, e quatro repetições de 24 aves por parcela. Os resultados mostraram que aves alimentadas apenas com ração de postura nos sete primeiros dias após o jejum apresentaram maior produção de ovos nas seis primeiras semanas do período de produção pós-muda. Porém, não foi constatado efeito de tratamento sobre a produção de ovos, peso dos ovos, consumo de ração e conversão alimentar durante as 20 semanas do período experimental.The experiment was conducted to evaluate layer quails performance fed in different periods with corn meal or laying diet during a 7-day post-molt period. Following this, birds were fed laying diet during the experimental period of 20 weeks. The experiment followed a completely randomized design with three treatments (laying diet during 7 days; laying diet ration during 3 days + corn meal during 4 days or corn meal during 7 days and three replications of 24 birds per pen. The results showed that quails fed laying diet during 7 days post-molt presented larger egg production during the first six weeks of production period than the others receiving corn meal. However there was no effect of treatments on egg production, egg weight, feed consumption and feed conversion during the experimental period of 20 weeks.

  20. Effectiveness of EDTA and EDTA-T brushingm on the removal of root surface smear layer Efeito do EDTA e EDTA-T aplicado de forma ativa na remoção de "smear layer" de superfícies radiculares

    Directory of Open Access Journals (Sweden)

    José Eduardo Cezar Sampaio


    Full Text Available The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon gel in different concentrations (5%, 10%, 15%, 20% and 24%, using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control application of saline solution (n = 20; Group II - EDTA gel (pH 7.0 was applied in the following concentrations: 5%, 10%, 15%, 20% and 24% (n = 100; Group III - EDTA-T gel (pH 7.0 applied in the same concentrations described above (n = 100. The photomicrographs were evaluated by one calibrated examiner using a smear layer removal index and following statistical analysis (Kruskal-Wallis test. The results demonstrated that the specimens treated with EDTA and EDTA-T gel presented a better smear layer removal than the control group (p 0.05. Within the limits of this study, it can be concluded that all treatment modalities effectively removed the smear layer from the root surface. The addition of texapon into the EDTA gel formulation did not increase its effectiveness.O objetivo do presente estudo foi comparar, através de microscopia eletrônica de varredura, o efeito da aplicação de gel de EDTA e de EDTA-T (texapon em diferentes concentrações (5%, 10%, 15%, 20% e 24% na remoção de "smear layer" de superfícies radiculares previamente raspadas com instrumentos manuais. Duzentos e vinte espécimes de superfícies radiculares submetidas à raspagem foram divididos em 3 grupos. Grupo I - (controle solução salina (n = 20; Grupo II - gel de EDTA (pH 7,0 nas concentrações de 5%, 10%, 15%, 20% e 24% (n = 100; Grupo III - gel de EDTA-T (pH 7,0 nas concentrações acima descritas (n = 100. As fotomicrografias obtidas foram avaliadas por um examinador calibrado através da aplicação de um índice de remoção de "smear layer", e os dados foram analisados através de análise estat

  1. Polymethyl methacrylate and polystyrene with layered double hydroxide nano composites: In situ synthesis, morphology and thermal properties; Nanocompositos de polimetacrilato de metila e poliestireno com hidroxido duplo lamelar: sintese in situ, morfologia e propriedades termicas

    Energy Technology Data Exchange (ETDEWEB)



    Over the past decade, polymer nanocomposites have attracted interest, both in industry and in academia, because they often exhibit remarkable improvement in their properties when compared with pure polymer or conventional micro and macro-composites using low levels of reinforcements. In this work polymethyl methacrylate and polystyrene reinforced with layered double hydroxide, which was intercalated with sodium dodecyl sulfate were synthesized by in situ bulk polymerization. The nanocomposites were characterized and compared by X-ray diffraction, thermogravimetric analysis and flammability test. The X-ray diffraction demonstrated that synthesized nanocomposites showed a high global dispersion of layered double hydroxide, suggesting exfoliated morphology. The result of thermogravimetric analysis and flammability test for synthesized polystyrene/ layered double hydroxide nanocomposite presented a significant improvement in thermal stability and flammability property when compared with pure polymer. (author)

  2. In situ synthesis and study of morphology and thermal properties of polyamide 6 nanocomposites reinforced with different layered compounds; Sintese in situ e estudo da morfologia e propriedades termicas de nanocompositos de poliamida 6 reforcados com diferentes compostos lamelares

    Energy Technology Data Exchange (ETDEWEB)

    Botan, Rodrigo; Sartor, Sabrina de B.; Moraes, Samara B. de; Lona, Liliane M.F., E-mail: [Universidade Estadual de Campinas (FEQ/UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Quimica


    Presently the research and development of new polymer nanocomposites is a field of large interest and importance to the scientific and technological community. For the development and improvement in synthesis and properties of new nanocomposites, different reinforcement types have been explored. Thus, this work studies the in situ synthesis and, morphological and thermal characterization of new polyamide 6 (PA6) nanocomposites reinforced with two different types of layered compounds: layered double hydroxide (LDH) and layered hydroxide salt (LHS). These new synthesized nanocomposites were characterized by x-ray diffraction (XRD), infrared spectroscopy by Fourier transform (FTIR) and thermogravimetric analysis (TGA). The results demonstrate that the new nanocomposites showed strong evidence of exfoliated morphology with improvement in their thermal properties compared with the neat PA6. (author)

  3. Thickness and photocatalytic activity relation in TiO$_2$:N films grown by atomic layer deposition with methylene-blue and E. coli bacteria

    Indian Academy of Sciences (India)



    This study presents an analysis of the photocatalytic efficiency in TiO$_2$:N thin films grown by atomic layer deposition related to the film thickness. The nitriding process was carried out with nitrogen plasma by molecular nitrogen decomposition after TiO$_2$ deposition. The study was performed using the time-dependent degradation of colour units for methylene-blue solutions and inactivation percentages for Escherichia coli bacteria, for potential applications in sewage purification. To determine the optoelectronic properties of the films, the optical, structural, surface and thickness characterizations were carried out by photoluminescence, Raman spectroscopy, atomic force microscopy and scanning electron microscopy, respectively.

  4. Expanded austenite in nitrided layers deposited on austenitic and super austenitic stainless steel grades; Analise da austenita expandida em camadas nitretadas em acos inoxidaveis austeniticos e superaustenitico

    Energy Technology Data Exchange (ETDEWEB)

    Casteletti, L.C.; Fernandes, F.A.P.; Heck, S.C. [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Engenharia de Materais, Aeronautica e Automobilistica; Oliveira, A.M. [Instituto de Educacao, Ciencia e Tecnologia do Maranhao (IFMA), Sao Luis, MA (Brazil); Gallego, J., E-mail: gallego@dem.feis.unesp.b [UNESP, Ilha Solteira, SP (Brazil). Dept. Engenharia Mecanica


    In this work nitrided layers deposited on austenitic and super austenitic stainless steels were analyzed through optical microscopy and X-rays diffraction analysis (XRD). It was observed that the formation of N supersaturated phase, called expanded austenite, has promoted significant increment of hardness (> 1000HV). XRD results have indicated the anomalous displacement of the diffracted peaks, in comparison with the normal austenite. This behavior, combined with peaks broadening, it was analyzed in different nitriding temperatures which results showed good agreement with the literature. (author)

  5. Layer-by-Layer Assembly of Enzymes on Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun; Liu, Guodong; Lin, Yuehe


    The use of Layer-by-layer techniques for immobilizing several types of enzymes, e.g. glucose oxidase (GOx), horse radish oxidases(HRP), and choline oxidase(CHO) on carbon nanotubes and their applications for biosenseing are presented. The enzyme is immobilized on the negatively charged CNT surface by alternatively assembling a cationic polydiallyldimethyl-ammonium chloride (PDDA) layer and a enzyme layer. The sandwich-like layer structure (PDDA/enzyme/PDDA/CNT) formed by electrostatic assembling provides a favorable microenvironment to keep the bioactivity of enzyme and to prevent enzyme molecule leakage. The morphologies and electrocatalytic acitivity of the resulted enzyme film were characterized using TEM and electrochemical techniques, respectively. It was found that these enzyme-based biosensors are very sensitive, selective for detection of biomolecules, e.g. glucose, choline.

  6. Morfofisiologia de Andropogon gayanus Kunth sob adubação mineral e orgânica em três estratos verticais Morphophysiology of Andropogon gayanus Kunth with organic and mineral fertilization in three vertical layers

    Directory of Open Access Journals (Sweden)

    Maria Socorro de Souza Carneiro


    Full Text Available Neste experimento foram avaliadas algumas características morfofisiológicas do capim-andropogon, Andropogon gayanus Kunth cv. Planaltina (Poaceae, submetido a quatro tratamentos de adubação (0, 25, 50 kg N/ha/corte e 20t esterco bovino aplicado após o corte de uniformização, dois intervalos entre cortes (28 e 42 dias, em duas épocas de avaliação (84 e 168 dias e amostrado em três estratos (20-40 cm; 40-60 cm; >60 cm do solo. O delineamento experimental utilizado foi o de blocos casualizados em parcelas subsubdivididas. Os maiores valores de massa seca total e de colmos foram registrados no estrato inferior (20-40 cm, enquanto que os estratos superiores apresentaram maior massa seca de folhas (40-60 e > 60 cm e relação folha/colmo. A adubação não influenciou significativamente (P > 0,05 as características do capim-andropogon estudadas nesta pesquisa.The morphophysiological characteristics of the andropogon grass, Andropogon gayanus Kunth cv. Planaltina (Poaceae with four manure treatments (control; 25 kg N/ha/cutting date; 50 kg N/ha/cutting date and 20 t/ha of cattle manure applied after each cut, were evaluated. There were 28 and 42-day cut intervals within two evaluation periods (84 and 168 days, sampled in three layers (0.20-0.40 m; 0.40-0.60 m; > 0.60 m. Complete randomized block design in a split-split-plot arrangement has been used. Highest values of total dry mass and dry mass of stem were reported in the lowest layer (0.20-0.40 m. The upper layers had higher leaf dry mass (0.40-0.60 m and > 0.60 m, higher leaf area and consequently higher leaf/stem ratio. The four fertilization treatments were not significantly influential on the characteristics of the grass analyzed in this research.

  7. Estudo comparativo entre as técnicas de sutura total e serosubmucosa em anastomoses colônicas na presença de um protetor intraluminar em cães Comparative study of all-layers suture and extramucosal single layer suture with an intraluminal protector in dogs

    Directory of Open Access Journals (Sweden)

    Cíntia Lourenço Santos


    Full Text Available OBJETIVO: Avaliar a cicatrização comparando as técnicas de sutura total e parcial em anastomoses colônicas término-terminais na presença de um protetor intraluminar confeccionado a partir de um dreno de Penrose. MÉTODOS: Foram realizadas anastomoses colônicas em 10 cães nos quais foi suturado a mucosa / submucosa um protetor intraluminar por meio da eversão do segmento intestinal proximal em 10 cm. Os animais foram distribuidos em dois grupos experimentais: Grupo 1 - sutura total e Grupo 2 - sutura serosubmucosa. Os animais foram reoperados com sete dias de pós-operatório para coleta de material e subseqüente análise histopatológica. RESULTADOS: Observamos no exame histopatológico das anastomoses realizadas com sutura serosubmucosa (Grupo 2 uma melhor cicatrização caracterizada por um menor infiltrado inflamatório e por uma maior integridade das camadas intestinais quando comparadas com o Grupo 1. CONCLUSÃO: O uso da técnica de sutura parcial mostrou-se superior a de sutura total nas anastomoses colônicas na presença de protetor intraluminar.BACKGROUND: This study aims to evaluate the colonic anastomotic healing testing of all layers suture and single layer suture using an intraluminal protector. The intraluminal protector was shaped from a Penrose drain and then fixed 10 cm from the superior end of the anastomotic site. METHODS: Colonic anastomoses were done in 10 dogs, which were sutured, in the proximal segment with an intraluminal protector made of Penrose n.3 drain, using interrupted mucosal / submucosal suture. In the subsequent anastomoses, the animals were subdivided in two experimental groups: 1 - in all layers and 2 - extramucosal. In the seventh postoperative day, a tissue fragment was collected for histopathological analysis. RESULTS: Group 2 histopathological examinations had a better scar (extramucosal suture, characterized by a lesser inflammatory process than in animals in which all layers suture was used

  8. A case study of atmospheric boundary layer features during winter over a tropical inland station – Kharagpur (22.32°N, 87.32°E)

    Indian Academy of Sciences (India)

    Denny P Alappattu; P K Kunhikrishnan; Marina Aloysius; M Mohan


    The local weather and air quality over a region are greatly influenced by the atmospheric boundary layer (ABL) structure and dynamics. ABL characteristics were measured using a tethered balloon-sonde system over Kharagpur (22.32°N, 87.32°E, 40m above MSL), India, for the period 7 December 2004 to 30 December 2004, as a part of the Indian Space Research Organization– Geosphere Biosphere Program (ISRO–GBP) Aerosol Land Campaign II. High-resolution data of pressure, temperature, humidity, wind speed and wind direction were archived along with surface layer measurements using an automatic weather station. This paper presents the features of ABL, like ABL depth and nocturnal boundary layer (NBL) depth. The sea surface winds from Quikscat over the oceanic regions near the experiment site were analyzed along with the NCEP/NCAR reanalysis winds over Kharagpur to estimate the convergence of wind, moisture and vorticity to understand the observed variations in wind speed and relative humidity, and also the increased aerosol concentrations. The variation of ventilation coefficient (VC), a factor determining the air pollution potential over a region, is also discussed in detail.

  9. Boundary-layer theory

    CERN Document Server

    Schlichting (Deceased), Hermann


    This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.

  10. E-Government in Lithuania – Local Self-Government Layer Elektroninė valdžia Lietuvoje: savivaldos pjūvis

    Directory of Open Access Journals (Sweden)

    Elena Raginytė


    Full Text Available

    Lithuanian public e-services at the level of municipalities are lagging behind the level of the central authorities. This is due to many factors, which leads to a slight lack of good position. A large proportion of the municipal authorities do not have e-service development strategies, or governing documents by the activities of the virtual space. It should be noted that this situation is in the part of central authorities too. This leads to the situation that the strategy aims are not fully realized. Although individual government institutions have been successful and effectively developing e-services, e.g. the State Tax Inspectorate is at the fifth level of public service. In order to improve the needs of society and citizens, a public service list was formed, whose services should be transferred as soon as possible to the virtual space, and provided with the levels of public e-services. The implementation of established goals can expect significant improvement in this area. Important, but still weak-moved to the virtual space of the public service areas is the environmental area. There has been no public e-service concept of environmental area in Lithuania yet. The article describes models of public e-services in the field of waste management.

    Keywords: E-government, self-government, e-services, environmental area.

    Elektroninės valdžios (e. valdžios plėtra Lietuvoje aktuali kaip ir visoje Europoje


    Directory of Open Access Journals (Sweden)

    Rafael Vivian


    Full Text Available

    Nesta pesquisa objetivou-se quantificar características físicas, químicas e biológicas, bem como a qualidade de um Argissolo vermelho-amarelo com vegetação natural e cultivado com pastagens e culturas. Foram coletadas amostras de solo, na profundidade de 0 a 10 cm, nos seguintes ambientes: mata nativa (I; pastagem de Brachiaria brizantha, formada pelo consórcio com milho (II; pastagem de B. brizantha com dez anos de uso (III; área cultivada com milho em plantio direto (IV; e área de pastagem de B. brizantha, formada após o cultivo de soja em plantio direto (V. As seguintes características foram avaliadas: físicas (densidade do solo, porosidade total, diâmetro médio geométrico de agregados, umidade gravimétrica, textura, capacidade de retenção de água e o grau de floculação; químicas (pH em água, P e K disponíveis, P-remanescente, Ca, Mg e Al, H+Al, carbono orgânico, soma e saturação por bases, CTC, Zn e Cu; e microbiológicas (carbono da biomassa microbiana, respiração basal, quociente microbiano e metabólico e atividade das enzimas fosfatases ácida e alcalina e ?-glicosidade. Comparado ao sistema de referência (I, o ordenamento dos ambientes para a qualidade de solo foi V, II, IV e III, sendo a pastagem exclusiva o ambiente de pior qualidade. Logo, onde houve interação entre agricultura e cultivo forrageiro, a qualidade do ambiente edáfico foi superior ao de monocultivo, quer seja com milho ou pastagem exclusiva. E, conforme o manejo, essa qualidade pode se aproximar do ambiente de referência.

    PALAVRAS-CHAVE: Integração lavoura-pecuária; plantio direto; milho; soja; sustentabilidade.

  1. Multi-layered proton-conducting electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae H.; Dorris, Stephen E.; Balachandran, Uthamalingam


    The present invention provides a multilayer anode/electrolyte assembly comprising a porous anode substrate and a layered solid electrolyte in contact therewith. The layered solid electrolyte includes a first dense layer of yttrium-doped barium zirconate (BZY), optionally including another metal besides Y, Ba, and Zr (e.g., a lanthanide metal such as Pr) on one surface thereof, a second dense layer of yttrium-doped barium cerate (BCY), and an interfacial layer between and contacting the BZY and BCY layers. The interfacial layer comprises a solid solution of the BZY and BCY electrolytes. The porous anode substrate comprises at least one porous ceramic material that is stable to carbon dioxide and water (e.g., porous BZY), as well as an electrically conductive metal and/or metal oxide (e.g., Ni, NiO, and the like).

  2. Coordinated investigation of summer time mid-latitude descending E layer (Es) perturbations using Na lidar, ionosonde, and meteor wind radar observations over Logan, Utah (41.7°N, 111.8°W) (United States)

    Yuan, Tao; Fish, C.; Sojka, J.; Rice, D.; Taylor, M. J.; Mitchell, N. J.


    It is well known that there is a strong correlation between the formation of a descending sporadic E layer (Es) and the occurrence of large upper atmospheric zonal wind shears, most likely driven by solar thermal tides and/or gravity waves. We present new results of Es perturbation events captured between 13 and 17 July 2011 (UT days 194-198) as part of a coordinated campaign using a wind/temperature Na lidar at Utah State University [41.7ºN, 111.8°W], and a Canadian Advanced Digital Ionosonde (CADI; Scientific Instrumentation Ltd., Saskatoon, Saskatchewan, Canada) and SkiYMet meteor wind radar, both located at nearby Bear Lake Observatory [41.9°N, 111.4°W]. During this period, the CADI detected strong descending Es on 2 days (195 and 197) when large modulations of the top-side mesospheric Na layer occurred in synchronism with strong oscillations in the ionosonde E region echoes. A weakening in the descending E layer echoes was observed on the other 2 days (196 and 198) coincident with a large reduction in the zonal diurnal and semidiurnal amplitudes above 95 km. Both tidal components were found to have comparable contributions to the total zonal wind shear that was critical for Es formation and its downward propagation. Further investigation indicates that the weakening tidal amplitudes and the occurrence of the Es events were also influenced by a strong quasi-two-day period modulation, suggesting significant quasi-two-day wave (QTDW) interactions with the tides. Indeed, a nonlinear, wave-wave interaction-induced 16-hour period child wave was also detected, with amplitude comparable to that of the prevailing tides. These interaction processes and their associated effects are consistent with earlier Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model studies of nonlinear interactions between the migrating tidal waves and the QTDW and were probably responsible for the observed damping of the tidal amplitudes resulting in the disruption

  3. Evaluation of peak voltage, irradiation time, output and half value layer in computed tomography equipment;Avaliacao da tensao de pico, tempo de irradiacao, rendimento e camada semi-redutora em equipamentos de tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Nersissian, Denise Y.; Santos, Lucas R. dos; Saito, Ricardo H. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia; Silva, Marcia C. [Hospital Albert Einstein (HAE), Sao Paulo, SP (Brazil)


    In this work, the voltage peak, the irradiation time, output and half value layer were evaluated in two multislice computed tomography equipment. These evaluations are commonly done in conventional, fluoroscopic and mammographic equipment, but not in computed tomography. The results have depicted that accuracy and reproducibility meet the 10% limit established by Portaria SVS MS 453/1998 and by Guia de Radiodiagnostico - RE 1016/2005. The half value layer is between (6.55 +- 0.31) mmAl and (7.70 +- 0.39) mmAl for 120 kVp on three bow tie filter positions. The output obtained for the isocenter position was 0.097, 0.158, 0.227 and 0.286 mGy/mAs for 80, 100, 120 e 135 kVp, respectively; being similar between two tomography equipment. Such evaluations have only been possible due to the intervention on the CT equipment, stopping the rotation of the X-ray tube inside the gantry. (author)

  4. Detection of Avian Hepatitis E Virus in Hailan Brown Layer Chickens%用RT-PCR检测海兰褐蛋鸡禽戊型肝炎病毒

    Institute of Scientific and Technical Information of China (English)

    杨树青; 孙嘉; 孔祥伟; 贠鲁祥; 孙淑红


    为证实我国蛋鸡群中存在禽戊型肝炎病毒(hepatitis E virus,HEV),从患有大肝大脾病的某海兰褐蛋鸡群采集粪便样品40份、血浆样品10份.提取RNA后,进行禽HEV ORF2基因片段的RT-PCR(reverse transcription PCR)检测,阳性样品进行克隆测序.同时采集疑似HEV感染鸡的肝,在两周龄SPF鸡进行了人工接种试验.结果表明,来自海兰褐蛋鸡群的40份粪便和10份血浆样品中,27份粪便样品和4份血浆样品为禽HEV RNA阳性.随机选取两个阳性样品的序列进行分析,其与国内外参考序列相似性为78.1%~98.3%.进化树分析显示与中国、欧洲参考株在同一分支,属于禽HEV基因3型.人工接种试验结果显示,接种后14 d的SPF鸡肝中均鉴定出HEV RNA阳性(4/4).我国蛋鸡群存在基因3型禽HEV.本研究首次发现并报道国内蛋鸡存在禽HEV,这为进一步了解禽HEV在我国鸡群的流行状况及其危害提供了依据.

  5. Identification and characterization of avian hepatitis E virus in 2013 outbreaks of hepatitis-splenomegaly syndrome in two US layer operations. (United States)

    Gerber, Priscilla F; Trampel, Darrell W; Opriessnig, Tanja


    Two commercial Midwestern egg-type chicken flocks experienced significant increases in mortality rates in April 2013 with clinical signs appearing in 17-week-old pullets on Farm A and in 46-week-old hens on Farm B. Average weekly mortality was 0.44% over a 4-week period on Farm A and 0.17% over an 8-week period on Farm B. On Farm A, flocks in the affected house had a 45% decrease in daily egg production from weeks 19 to 27 when compared with standard egg production curves (P hepatitis-splenomegaly syndrome, including hepatomegaly with serosanguineous fluid in the coelomic cavity and hepatic subcapsular haemorrhages. Microscopic lesions were characterized by multifocal necrotizing hepatitis and intrahepatic haemorrhage. No significant bacteria were recovered from liver samples, but 72 to 100% of the liver samples from affected chickens on Farm A (8/11) and Farm B (7/7) contained detectable amounts of avian hepatitis E virus (aHEV) RNA as determined by polymerase chain reaction. Sequencing and phylogenetic analysis of a 361-base-pair fragment of the helicase gene demonstrated 98.6 to 100% nucleotide identity between the aHEV genomes from Farm A and Farm B, whereas identities ranged from 74.6 to 90.5% when compared with other representative sequences. Sequences from this study clustered within aHEV genotype 2 previously recognized in the USA. In contrast to other reported aHEV outbreaks that occurred in 30-week-old to 80-week-old chickens, in the present investigation clinical aHEV was identified in 17-week-old chickens on one of the farms.

  6. Boundary layer transition studies (United States)

    Watmuff, Jonathan H.


    A small-scale wind tunnel previously used for turbulent boundary layer experiments was modified for two sets of boundary layer transition studies. The first study concerns a laminar separation/turbulent reattachment. The pressure gradient and unit Reynolds number are the same as the fully turbulent flow of Spalart and Watmuff. Without the trip wire, a laminar layer asymptotes to a Falkner & Skan similarity solution in the FPG. Application of the APG causes the layer to separate and a highly turbulent and approximately 2D mean flow reattachment occurs downstream. In an effort to gain some physical insight into the flow processes a small impulsive disturbance was introduced at the C(sub p) minimum. The facility is totally automated and phase-averaged data are measured on a point-by-point basis using unprecedently large grids. The evolution of the disturbance has been tracked all the way into the reattachment region and beyond into the fully turbulent boundary layer. At first, the amplitude decays exponentially with streamwise distance in the APG region, where the layer remains attached, i.e. the layer is viscously stable. After separation, the rate of decay slows, and a point of minimum amplitude is reached where the contours of the wave packet exhibit dispersive characteristics. From this point, exponential growth of the amplitude of the disturbance is observed in the detached shear layer, i.e. the dominant instability mechanism is inviscid. A group of large-scale 3D vortex loops emerges in the vicinity of the reattachment. Remarkably, the second loop retains its identify far downstream in the turbulent boundary layer. The results provide a level of detail usually associated with CFD. Substantial modifications were made to the facility for the second study concerning disturbances generated by Suction Holes for laminar flow Control (LFC). The test section incorporates suction through interchangeable porous test surfaces. Detailed studies have been made using isolated

  7. Boundary layer transition studies (United States)

    Watmuff, Jonathan H.


    A small-scale wind tunnel previously used for turbulent boundary layer experiments was modified for two sets of boundary layer transition studies. The first study concerns a laminar separation/turbulent reattachment. The pressure gradient and unit Reynolds number are the same as the fully turbulent flow of Spalart and Watmuff. Without the trip wire, a laminar layer asymptotes to a Falkner & Skan similarity solution in the FPG. Application of the APG causes the layer to separate and a highly turbulent and approximately 2D mean flow reattachment occurs downstream. In an effort to gain some physical insight into the flow processes a small impulsive disturbance was introduced at the C(sub p) minimum. The facility is totally automated and phase-averaged data are measured on a point-by-point basis using unprecedently large grids. The evolution of the disturbance has been tracked all the way into the reattachment region and beyond into the fully turbulent boundary layer. At first, the amplitude decays exponentially with streamwise distance in the APG region, where the layer remains attached, i.e. the layer is viscously stable. After separation, the rate of decay slows, and a point of minimum amplitude is reached where the contours of the wave packet exhibit dispersive characteristics. From this point, exponential growth of the amplitude of the disturbance is observed in the detached shear layer, i.e. the dominant instability mechanism is inviscid. A group of large-scale 3D vortex loops emerges in the vicinity of the reattachment. Remarkably, the second loop retains its identify far downstream in the turbulent boundary layer. The results provide a level of detail usually associated with CFD. Substantial modifications were made to the facility for the second study concerning disturbances generated by Suction Holes for laminar flow Control (LFC). The test section incorporates suction through interchangeable porous test surfaces. Detailed studies have been made using isolated

  8. Cromatografia em camada delgada para o diagnóstico da intoxicação por aldicarb ("chumbinho" em cães e gatos Thin-layer chromatography for aldicarb poisoning diagnosis in dogs and cats

    Directory of Open Access Journals (Sweden)

    F.G. Xavier


    Full Text Available Avaliou-se a cromatografia em camada delgada (CCD como método de diagnóstico toxicológico para os casos de intoxicação por aldicarb em cães e gatos, utilizando-se 50 amostras de conteúdo gástrico obtidas durante a necropsia e 50 amostras de alimentos utilizados como iscas para intoxicar criminalmente os animais. Todas as amostras resultaram positivas para o aldicarb, mostrando ser a CCD uma técnica qualitativa eficiente, rápida e de baixo custo, com uso potencial na toxicologia veterinária forense.The present study concerns about the identification of aldicarb residues using thin-layer chromatography (TLC in 50 samples of gastric content obtained from the necropsy of dogs and cats and 50 samples of foods suspected of being used as baits. All samples resulted positive for aldicarb showing that the TLC is an efficient, fast and not expensive qualitative method for the detection of aldicarb, being useful for this purpose in the forensic veterinary toxicology.

  9. Cooperating systems: Layered MAS (United States)

    Rochowiak, Daniel


    Distributed intelligent systems can be distinguished by the models that they use. The model developed focuses on layered multiagent system conceived of as a bureaucracy in which a distributed data base serves as a central means of communication. The various generic bureaus of such a system is described and a basic vocabulary for such systems is presented. In presenting the bureaus and vocabularies, special attention is given to the sorts of reasonings that are appropriate. A bureaucratic model has a hierarchy of master system and work group that organizes E agents and B agents. The master system provides the administrative services and support facilities for the work groups.

  10. Comparative study of smear layer removal by different etching modalities and Er:YAG laser irradiation on the root surface: a scanning electron microscopy study; Estudo comparativo, atraves de microscopia eletronica de varredura, da acao de diferentes substancias quimicas e do laser de Er:YAG, na remocao de smear layer, em superficies radiculares submetidas a raspagem e aplainamento

    Energy Technology Data Exchange (ETDEWEB)

    Theodoro, Leticia Helena


    The aim of this study was to compare the effects of citric acid, EDTA, citric acid with tetracycline, and Er:YAG laser to smear layer removal on the root surface after scaling with manual instruments by SEM. Thirty specimens (n=30) of root surface before scaling were divided into 6 groups (n=5). The Control Group (G1) was not treated; Group 2 (G2) was conditioned with citric acid gel 24%, pH1, during 2 minutes; Group 3 (G3) was conditioned with EDTA gel 24%, pH 7, during 2 minutes; Group 4 (G4) was conditioned with citric acid and tetracycline gel 50%, pH1 during 2 minutes; Group 5 (G5) was irradiated with Er:YAG laser (2.94 {mu}m), 47 mJ/10 Hz, focused, under water spray during 15 seconds and fluence of 0.58 J/cm{sup 2}; Group 6 (G6) was irradiated with Er:YAG laser (2.94{mu}m), 83 mJ/10 Hz, focused, under water spray during 15 seconds and fluence of 1.03 J/cm{sup 2}. The micrographic were analyzed by scores and following the statistical analysis with Kruskal Wallis (p<0.05) H=20,31. The G1 was significantly different of all groups (28.0); the G2 (13.4), G3 (11.7), and G4 (13.6) showed no difference in relation to G5 (20.3) and G6 (6.0), but the G6 was significantly different from G5. From the results, it can be conclude that: 1) there was intensity smear layer after scaling and root planing; 2) all treatments were effective to smear layer remove with significantly difference to G2, G3, G4, G5 and G6; G2, G3 and G4 were not statistically different from G5 and G6; 3) G6 was more effective in the smear layer remotion in relation to G5 and both presented irregular root surface. (author)

  11. Correlação e correspondência topográfica entre espessura da camada de fibras nervosas da retina e campo visual no glaucoma primário de ângulo aberto Correlation and topographic match between nerve fiber layer thickness and visual field in primary open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Paula Boturão de Almeida


    classificados como discretos: SF e SN. Nos olhos classificados como moderados: SF e SI. Nos olhos classificados como graves: MD e SN; MD e EM; MD e S; CPSD e EM. 4- DN t e TD t; DN s e TD ni; DN i e TD ns. 5- Encontramos correspondência positiva (+ em 36 olhos (51,43% dos casos e correspondência negativa (- em 34 olhos (48,57% dos casos. Conclusões: Concluiu-se que houve poucas correlações significantes entre esses dois exames, e que as existentes foram muito fracas. Conclui-se, também, que houve correspondência topográfica, na análise dos setores mais comprometidos, em 51,43% dos casos.Purpose: To determine the relationship between nerve fiber layer thickness detected by scanning laser polarimetry (GDx and visual field function measured by automated conventional white-on-white perimetry. Methods: 82 eyes of 48 open angle glaucoma patients were studied. The following correlations were inves-tigated: 1- Correlation between mean sensitivity of 4 quadrants plus the fixation point, in dBs, and the mean of the nerve fiber layer thickness of the correspondent retina, in micra. 2- Correlation between mean sensitivity of 4 quadrants plus the fixation point, in dBs, and the mean of the nerve fiber layer thickness of the correspondent retina, in micra, in the patients classified according to the amount of visual field loss. 3- Correlation between the global indices of visual field and the numeric indices of GDx. 4- Correlation between the mean of "total deviation" of visual field and the "deviation from normal" of GDx. 5- Topographic match between visual field and retinal nerve fiber layer thickness changes. Statistical analysis was performed using the Spearmann coeficient correlation test. Results: We observed a very poor correlation regarding: 1- total GDx and VF total; superior GDx and nasal inferior VF; inferior GDx and nasal superior VF; nasal GDx and temporal VF; superior GDx and inferior VF; inferior GDx and superior VF. 2- inferior GDx and nasal superior VF (severe eyes

  12. Reflective article having a sacrificial cathodic layer

    Energy Technology Data Exchange (ETDEWEB)

    Kabagambe, Benjamin; Buchanan, Michael J.; Scott, Matthew S.; Rearick, Brian K.; Medwick, Paul A.; McCamy, James W.


    The present invention relates to reflective articles, such as solar mirrors, that include a sacrificial cathodic layer. The reflective article, more particularly includes a substrate, such as glass, having a multi-layered coating thereon that includes a lead-free sacrificial cathodic layer. The sacrificial cathodic layer includes at least one transition metal, such as a particulate transition metal, which can be in the form of flakes (e.g., zinc flakes). The sacrificial cathodic layer can include an inorganic matrix formed from one or more organo-titanates. Alternatively, the sacrificial cathodic layer can include an organic polymer matrix (e.g., a crosslinked organic polymer matrix formed from an organic polymer and an aminoplast crosslinking agent). The reflective article also includes an outer organic polymer coating, that can be electrodeposited over the sacrificial cathodic layer.

  13. Ácidos graxos da gema e composição do ovo de poedeiras alimentadas com rações com farelo de coco Yolk fatty acids and egg components from layers fed diets with coconut meal

    Directory of Open Access Journals (Sweden)

    Suely Carvalho Santiago Barreto


    Full Text Available O objetivo deste trabalho foi avaliar o efeito da inclusão do farelo de coco (FC na ração e do tempo de alimentação de poedeiras comerciais, sobre os ácidos graxos da gema e os componentes do ovo. O delineamento foi em esquema fatorial 5x2, com cinco níveis de inclusão do FC (0, 5, 10, 15 e 20% e dois tempos de alimentação (14 e 28 dias. Foram avaliados o peso e as porcentagens de albúmen, gema e casca dos ovos, bem como os sólidos e lipídios totais e o perfil de ácidos graxos das gemas. A inclusão do FC e o tempo de alimentação influenciaram apenas a proporção de ácido mirístico na gema, que aumentou com a inclusão do FC aos 28 dias de alimentação. Os ácidos esteárico e oléico variaram somente com o tempo de alimentação, e as maiores concentrações foram obtidas aos 28 dias. A relação de ácidos graxos poliinsaturados para ácidos graxos saturados da gema diminuiu a partir de 10% de inclusão e aumentou com o tempo de alimentação das aves. O uso de farelo de coco, na ração de poedeiras comerciais, não influencia a proporção dos componentes do ovo, apenas altera a concentração do ácido mirístico da gema.The objective of this work was to evaluate the effects of coconut meal (CM inclusion in commercial layer diets and feeding time, on egg components and yolk fatty acid composition. The experiment followed a factorial design 5x2, with five levels of CM inclusion (0, 5, 10, 15 and 20% and two feeding time (14 and 28 days. Parameters evaluated included: egg weight, and albumen, yolk and shell percentages, as well as solids, lipids and fatty acid profile of the yolk. The inclusion of CM and feeding time affected the yolk content of myristic acid which increased with CM level and with feeding time. The levels of stearic and oleic acids in the yolk varied with feeding time and were higher in the eggs after 28 days. Polyunsaturated to saturated fatty acid ratio in yolk decreased, when dietary CM levels were

  14. Modelos de dupla camada difusa de Gouy-Chapman e Stern aplicados a latossolos ácricos paulistas Gouy-chapman and Stern diffuse double layer models applied to acric oxisols from the state São Paulo - Brazil

    Directory of Open Access Journals (Sweden)

    L.R.F. Alleoni


    Full Text Available Modelos teóricos da dupla camada difusa de Gouy-Chapman e de Stern foram aplicados a um latossolo variação Una ácrico, de Guaira e a dois latossolos roxos ácricos, localizados em Ribeirão Preto e Guaíra, cidades ao norte do Estado de São Paulo, onde solos com caráter ácrico ocupam vasta área nas quais são cultivadas várias culturas de interesse econômico. Na concentração mais elevada do eletrólito suporte (KCl 0,1N, os dados obtidos em laboratório adaptaram-se melhor ao modelo de Stern. Entretanto, nas menores concentrações (KCl 0,01 e 0,001N, correspondentes a valores mais comuns encontrados em solos altamente intemperizados, o modelo de Gouy-Chapman representou melhor a variação da densidade superficial de carga com o potencial elétrico das amostras estudadas.Theoretical models of Gouy-Chapman and Stern, referred to diffuse double layer, were applied to three acric Oxisols, two named dusky red latosol and one Una variant latosol, from the São Paulo State - Brazil. Samples were collected in Ribeirão Preto and Guaira, regions of large occurrence of these soils, supporting many economic crops. In the highest concentration of the electrolyte (KC1 0.1N, the obtained values were better related to the Stern model. On the other hand, in more dilluted solutions (KC1 0.01 and 0.001N, corresponding to more usual ionic strenght of highly weathered soils, the variation of surface charge density of the samples with electric potential was in better agreement with the Gouy-Chapman theory.

  15. Effect of the sodium hypochlorite and citric acid association on smear layer removal of primary molars Efeito da associação de hipoclorito de sódio e ácido cítrico na remoção de "smear layer" de molares decíduos

    Directory of Open Access Journals (Sweden)

    Gabriela da Rosa Götze


    Full Text Available This study aimed to assess the capacity of a sodium hypochlorite and citric acid (CA association (the latter at different concentrations in removing coronal smear layer (SL of primary teeth. For this purpose, the pulp chamber roof and floor of 28 primary molars were removed to obtain enamel and dentine disks. SL was produced on the internal walls of the disks using high-speed drills. The disks were irrigated with 1% sodium hypochlorite and citric acid at different concentrations (CA-4%, CA-6%, CA-8% and CA-10%, and with 0.9% sodium chloride. The samples were split and observed under SEM. Scores were attributed to the obtained photomicrographs, according to the amount of SL present. It was noted that all the tested concentrations of citric acid used after the sodium hypochlorite were capable of removing SL. The results were analyzed by the Kruskal-Wallis test, and there was no significant statistical difference among the scores of the groups tested. However, it was observed that CA-8% and CA-10% caused peritubular dentine destruction, and that CA-4% presented a larger number of samples with dense SL. Based on these results, 6.0% citric acid in association with 1% sodium hypochlorite is suggested as auxiliary chemical substances for primary teeth irrigation.O objetivo deste estudo foi avaliar a capacidade da associação entre hipoclorito de sódio e ácido cítrico em diferentes concentrações para remover "smear layer" (SL coronária de dentes decíduos. Para isso, foram utilizados 28 molares decíduos, nos quais se realizou a remoção do teto e do assoalho da câmara pulpar, obtendo-se discos de esmalte e dentina. Produziu-se SL nas paredes internas dos discos utilizando-se brocas em alta rotação e eles foram irrigados com hipoclorito de sódio a 1%, ácido cítrico em diferentes concentrações (AC- 4%, AC- 6%, AC-8% e AC-10% e cloreto de sódio a 0,9%. As amostras foram esplitadas e observadas no MEV. Foram atribuídos escores

  16. Method for producing substrates for superconducting layers

    DEFF Research Database (Denmark)


    There is provided a method for producing a substrate (600) suitable for supporting an elongated superconducting element, wherein, e.g., a deformation process is utilized in order to form disruptive strips in a layered solid element, and where etching is used to form undercut volumes (330, 332......) between an upper layer (316) and a lower layer (303) of the layered solid element. Such relatively simple steps enable providing a substrate which may be turned into a superconducting structure, such as a superconducting tape, having reduced AC losses, since the undercut volumes (330, 332) may be useful...... for separating layers of material. In a further embodiment, there is placed a superconducting layer on top of the upper layer (316) and/or lower layer (303), so as to provide a superconducting structure with reduced AC losses....

  17. TiO2纳米管对MC3T3-E1前成骨细胞骨功能基因表达变化的影响%MC3T3-E1 Preosteobalst Osteogenic Gene Expression on Titanium with the Nanotube Layer.

    Institute of Scientific and Technical Information of China (English)

    于卫强; 徐玲; 张富强


    目的:研究阳极氧化TiO2纳米管对MC3T3-E1前成骨细胞骨功能基因表达变化的影响.方法:采用阳极氧化法在钛基底表面制备TiO2纳米管,扫描电镜观察其表面微结构,肌动蛋白染色研究细胞在材料表面的粘附生长情况,Real-time PCR技术系统分析材料对细胞骨功能基因表达的影响规律.结果:MC3T3-E1前成骨细胞在TiO2纳米管表面比光滑钛有更大的伸展面积,培养1周后,TiO2纳米管提高了细胞骨功能基因碱性磷酸酶、骨桥蛋白和骨钙蛋白的表达水平(P<0.05),培养2周后,骨功能基因表达水平与对照组之间没统计学差异.结论:TiO2纳米管可以促进MC3T3-E1前成骨细胞肌动蛋白组装,同时可以提高细胞骨功能基因的早期表达水平.%Objective: To evaluate the MC3T3-E1 preosteobalst osteogenic gene expression on the TiO2 nanotube layer in vitro. Methods: The TiO2 nanotube layer was grown by anodization. SEM experiment method has been employed to characterize the nanotubes. The action cytoskeletons of cells were visualized by a confocal laser scanning microscopy. Real-time PCR has been used to evalute bone gene expression of preosteoblast. Results.. The area of preosteoblast cultured on TiO2 nanotube layer was larger than that on smooth titanium. The nanotubes could promote the ALP, OPN, and OCN gene expression after one week of cultivation by analysing real-time PCR results (P<0. 05), but not after two weeks of cultivation. Conclution: Actin cytoskeleton of cells cultured on the nanotubes shows more arrangement than the smooth Ti. The TiO2 nanotube layer can promote bone gene expression at earlier period.

  18. 1eV吸收带边GaInAs/GaNAs超晶格太阳能电池的阱层设计%Well layer design for 1eV absorption band edge of GaInAs/GaNAs super-lattice solar cell

    Institute of Scientific and Technical Information of China (English)

    王海啸; 郑新和; 吴渊渊; 甘兴源; 王乃明; 杨辉


    使用In, N分离的GaInAs/GaNAs超晶格作为有源区是实现高质量1eV带隙GaInNAs基太阳能电池的重要方案之一。为在实验上生长出高质量相应吸收带边的超晶格结构,本文采用计算超晶格电子态常用的Kronig-Penney模型比较了不同阱层材料选择下,吸收带边为1 eV的GaInAs/GaNAs超晶格相关参数的对应关系以及超晶格应变状态。结果表明:GaNAs与GaInAs作为超晶格阱层材料在实现1 eV的吸收带边时具有不同的考虑和要求;在固定1 eV的吸收带边时, GaNAs材料作为阱层可获得较好的超晶格应变补偿,将有利于生长高质量且充分吸收的太阳能电池有源区。%The GaInAs/GaNAs super-lattice with a feature of space separation of In and N constituents as an active region, is one of the most important ways to achieve 1 eV GaInNAs-based solar cells. To experimentally realize the high-quality super-lattice structure with the required band-gap, Kronig-Penney model is used to obtain the barrier thickness dependence on the well thickness and its composition. Meanwhile, the strain state of GaInAs/GaNAs SLs with various well choices is also discussed. Results show that when both the GaNAs and GaInAs act as the well layers the super-lattice can achieve 1 eV band-gap, and when the GaN0.04As0.96 is considered to act as the well layer, the entire GaInAs/GaNAs SLs have smaller strain accumulations as compared with the case of Ga0.7In0.3As as the well layer in the super-lattice structure.

  19. Innovation in Layer-by-Layer Assembly. (United States)

    Richardson, Joseph J; Cui, Jiwei; Björnmalm, Mattias; Braunger, Julia A; Ejima, Hirotaka; Caruso, Frank


    Methods for depositing thin films are important in generating functional materials for diverse applications in a wide variety of fields. Over the last half-century, the layer-by-layer assembly of nanoscale films has received intense and growing interest. This has been fueled by innovation in the available materials and assembly technologies, as well as the film-characterization techniques. In this Review, we explore, discuss, and detail innovation in layer-by-layer assembly in terms of past and present developments, and we highlight how these might guide future advances. A particular focus is on conventional and early developments that have only recently regained interest in the layer-by-layer assembly field. We then review unconventional assemblies and approaches that have been gaining popularity, which include inorganic/organic hybrid materials, cells and tissues, and the use of stereocomplexation, patterning, and dip-pen lithography, to name a few. A relatively recent development is the use of layer-by-layer assembly materials and techniques to assemble films in a single continuous step. We name this "quasi"-layer-by-layer assembly and discuss the impacts and innovations surrounding this approach. Finally, the application of characterization methods to monitor and evaluate layer-by-layer assembly is discussed, as innovation in this area is often overlooked but is essential for development of the field. While we intend for this Review to be easily accessible and act as a guide to researchers new to layer-by-layer assembly, we also believe it will provide insight to current researchers in the field and help guide future developments and innovation.

  20. Aceitação sensorial de reestruturados empanados elaborados com filé de peito de galinhas matrizes de corte e poedeiras comerciais Sensory acceptance of nuggets prepared with broiler breeder and spent layer hens breast meat

    Directory of Open Access Journals (Sweden)

    Tatiana Pacheco Nunes


    Full Text Available Em 2005, no Brasil, o alojamento de galinhas poedeiras comerciais e de matrizes de corte somados foi de 109 milhões de cabeças, sendo que um número próximo a este deve ter sido descartado no mesmo período. Este grande número de galinhas descartadas contrasta com a falta de mercado consumidor e o baixo valor comercial alcançado por estas aves. A utilização da carne de galinhas na elaboração de produtos de conveniência poderia agregar valor e ampliar o consumo desta matéria-prima. Diante do exposto, o objetivo deste trabalho foi elaborar produtos empanados tipo nuggets, utilizando carne de galinhas de descarte (matrizes de corte e poedeiras comercias brancas e avaliar a aceitação pelo consumidor destes produtos, em comparação com nuggets elaborados com carne de frango. Os produtos desenvolvidos foram avaliados por análise sensorial, utilizando testes de aceitação e de intenção de compra em localização central (400 provadores. Não foram encontradas diferenças (p > 0,05 na aceitação sensorial nem na intenção de compra entre os três diferentes produtos avaliados. Concluiu-se que a elaboração de produtos empanados pode representar uma boa alternativa para a utilização de filés de peito de galinhas, agregando maior valor a estas aves ao final do ciclo de postura.In Brazil, the flock size of layer and broiler breeder hens housed in 2005 was 109 million. A similar number of hens might be spent in this period. This great number of spent hens contrasts with the absence of consumer market and the low commercial value reached by these birds. The manufacture of convenience products using spent hens meat could add value and elevate the consumption of this raw material. Thus, the purpose of this study was to develop nuggets made with spent hens (white layers and broiler breeders meat and evaluate the consumer acceptance of these products in comparison to nuggets elaborated with broiler meat. Sensory evaluation of acceptance

  1. Equivalente esférico e valores da espessura da camada de fibras nervosas obtidas com o GDX TM Scanning Laser System® Spherical equivalent and nerve fiber layer thickness assessed with GDX TM Scanning Laser System®

    Directory of Open Access Journals (Sweden)

    Lênio Souza Alvarenga


    Full Text Available Objetivo: Estudar a influência do equivalente esférico nos valores obtidos pelo GDX TM Scanning Laser System®. Métodos: Foram avaliados 41 olhos de 41 voluntários sem doenças oculares e com campo visual sem alterações. Foi realizada a polarimetria de varredura a laser com o GDX TM Scanning Laser System® de acordo com as instruções contidas no manual do aparelho. Foram comparados os valores obtidos nesse exame em um grupo de pacientes com equivalente esférico positivo e em um outro com este valor nulo ou negativo, pelo teste de Mann-Whitney. Resultados: Não se verificou diferença estatística entre os valores obtidos nos olhos de pacientes do grupo I e os do grupo II. Não foi encontrada correlação entre o equivalente esférico e os valores obtidos com o GDX TM Scanning Laser System®. Conclusões: Na amostra estudada não houve diferença estatística entre os valores obtidos em um grupo de olhos com equivalente esférico positivo e outro com este valor negativo ou nulo, usando-se o GDX TM Scanning Laser System®.Purpose: To evaluate the effect of spherical equivalent on the acquisition of nerve fiber layer (NFL thickness with GDX TM Scanning Laser System®. Methods: Forty-one eyes of 41 volunteers were enrolled in this study. All of them presented with no ocular disease and no visual field defect. The NFL thickness was measured with GDX TM Scanning Laser System® as described in its manual. The values obtained in a group of volunteers with negative spherical equivalent (group I were compared to those from a group with a positive spherical equivalent (group II by the Mann-Whitney test. Results: There was no statistical difference between mea-surements in eyes of group I and those in group II. The NFL thickness measurements were not correlated with the sphe-rical equivalent. Conclusions: In the studied group there was no statistical difference in the GDX TM Scanning Laser System® parameters related to spherical equivalent.

  2. Stability of Boundary Layer Flow. (United States)


    and Teske (1975). We can conclude (as in the case of ducting) that theoretical models of boundary layer structure and associated radar structure...FI33 (Secret). Hitney, (1978) "Surface Duct Effects," Naval Ocean Systems Center, San Diego, Calif., Report No. TD144. Lewellen, W. S., and M. E. Teske

  3. Physical Layer Ethernet Clock Synchronization (United States)



  4. Avaliação da espessura da camada de fibras nervosas da retina e mácula em pacientes com ambliopia Thickness of the retinal nerve fiber layer, macular thickness, in patients with amblyopia

    Directory of Open Access Journals (Sweden)

    Juliana Mitre


    Full Text Available OBJETIVO: Avaliar a espessura da camada de fibras nervosas da retina em olhos amblíopes e comparar com olhos normais e certificar se há correlação com a redução da acuidade visual. Além disso, este estudo se propõe avaliar a eficácia e eficiência em uma série de casos do protótipo de um equipamento nacional de magnificação para leitura. MÉTODOS: Participaram deste estudo 30 pacientes na faixa etária entre 9 e 80 anos (17 do sexo masculino. Foi desenvolvido um aparelho portátil, patenteado pela Unifesp (PI#020050145260, com um sistema de captura de imagens acoplado a um monitor de 5,6 polegadas proporcionando um aumento de 15 x. Foram analisadas a eficácia da acuidade visual e a eficiência de leitura após a utilização do protótipo proposto. RESULTADOS: Seis pacientes (20% apresentaram AV 8M, 12 pacientes (40% apresentaram AV 6M, 7 pacientes (23,3% apresentaram 5 M, 5 pacientes (16,7% apresentaram 4M. A média de acuidade visual antes da utilização do SLP medida pela tabela LHNV-1 logMAR foi de 5,75M e após a utilização 100% dos pacientes atingiram a eficácia de AV J1. CONCLUSÃO: O protótipo do SLP mostrou-se um recurso alternativo no processo de inclusão social das pessoas com baixa visão com diferentes níveis de resíduo visual. Também pode proporcionar incentivo psicológico, permitir conforto, mobilidade e independência àqueles que necessitam de uma leitura mais prolongada e maior distância de trabalho.OBJECTIVE: To compare the thickness of the retinal nerve fiber layer (RNFLand the macular thickness of the amblyopic eye with those of the non-amblyopic eye in patients with unilateral amblyopia using optical coherence tomography (OCT. METHODS: OCT was performed for13 patients with unilateral amblyopia who had no neurologic disease. Nine male andfour female patients, whose ages ranged from 23 to 63 years, were enrolled in the study. The RNFL thickness average analysis program was used to evaluate mean

  5. Protecting the ozone layer. (United States)

    Munasinghe, M; King, K


    Stratospheric ozone layer depletion has been recognized as a problem by the Vienna Convention for the Protection of the Ozone Layer and the 1987 Montreal Protocol (MP). The ozone layer shields the earth from harmful ultraviolet radiation (UV-B), which is more pronounced at the poles and around the equator. Industrialized countries have contributed significantly to the problem by releasing chlorofluorocarbons (CFCs) and halons into the atmosphere. The effect of these chemicals, which were known for their inertness, nonflammability, and nontoxicity, was discovered in 1874. Action to deal with the effects of CFCs and halons was initiated in 1985 in a 49-nation UN meeting. 21 nations signed a protocol limiting ozone depleting substances (ODS): CFCs and halons. Schedules were set based on each country's use in 1986; the target phaseout was set for the year 2000. The MP restricts trade in ODSs and weights the impact of substances to reflect the extent of damage; i.e., halons are 10 times more damaging than CFCs. ODS requirements for developing countries were eased to accommodate scarce resources and the small fraction of ODS emissions. An Interim Multilateral Fund under the Montreal Protocol (IMFMP) was established to provide loans to finance the costs to developing countries in meeting global environmental requirements. The IMFMP is administered by the World Bank, the UN Environmental Program, and the UN Development Program. Financing is available to eligible countries who use .3 kg of ODS/person/year. Rapid phaseout in developed countries has occurred due to strong support from industry and a lower than expected cost. Although there are clear advantages to rapid phaseout, there were no incentives included in the MP for rapid phaseout. Some of the difficulties occur because the schedules set minimum targets at the lowest possible cost. Also, costs cannot be minimized by a country-specific and ODS-specific process. The ways to improve implementation in scheduling and

  6. Layer-structured LiNi0.8Co0.2O2: A new triple (H+/O2-/e-) conducting cathode for low temperature proton conducting solid oxide fuel cells (United States)

    Fan, Liangdong; Su, Pei-Chen


    Solid oxide fuel cells with proton conducting electrolytes (H-SOFCs) show great potential for more efficient energy conversion over their oxygen ionic conducting counterparts at temperatures below 650 °C, providing a comparably high performance cathode material can be available. A brief review of current development of cathode materials shows that materials with triple (oxygen ionic, protonic, and electronic) conducting properties are most promising for H-SOFCs. In this work, a triple-conducting LiNi0.8Co0.2O2 (LNCO) with layered structure, allowing simultaneous conduction of intrinsic oxygen ion and electron as well as the extrinsic proton, is proposed as a cathode material for H-SOFC. The electrochemical impedance spectroscopy analysis of LNCO shows the good oxygen reduction reaction (ORR) activity with a considerably low activation energy of 0.88 eV, and an evident water uptake capability those facilitate the cathode reaction process. Fuel cells using LNCO cathode on a BaZr0.1Ce0.7Y0.2O3 proton-conducting electrolyte render a peak power density of 410 mW cm-2 at 650 °C under H2/air condition, which is higher than most of the typical cathode materials reported with similar cell configurations. This work also demonstrated a new series of simple and low cost cathode materials simultaneously possessing interesting triple-conduction and good ORR activities for low temperature H-SOFCs.

  7. Gênero, geração e classe: uma discussão sobre as mulheres das camadas médias e populares do Rio de Janeiro Gender, generation and social class: a debate about women in middle and popular layers in Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Maria das Dores Campos Machado


    Full Text Available Este artigo apresenta a comparação dos dados de duas pesquisas realizadas com o objetivo de verificar as continuidades e descontinuidades nas representações de gênero em diferentes gerações de famílias das camadas médias e populares do estado do Rio de Janeiro: das avós, das mães e das suas filhas. Privilegiamos aqui as percepções do lugar social da mulher no contexto das transformações em curso na sociedade brasileira. Considerando o crescimento da participação feminina no mercado de trabalho e o aumento no nível de escolaridade das mulheres, interessa-nos, particularmente, conhecer as representações e as práticas das integrantes dessas três gerações em torno da família, da religião e da profissionalização feminina.This article presents a comparison of data from two researches which aim at verifying the continuities and discontinuities in the gender representations in different generations of middle and popular-layer families in Rio de Janeiro State: that of grandmothers, of mothers and their daughters. Here we privileged the perceptions of the woman's social place in the context of the transformations in course in Brazilian society. Taking into account the growth of female participation in the labor market as well as the heightening of the women's schooling level, we are particularly interested in getting to know the representations and the practices of the members of these three generations abound family, religion and female professionalization.

  8. Síntese e caracterização de hidróxidos duplos a partir da lama vermelha Synthesis and characterization of layered double hydroxides from red mud

    Directory of Open Access Journals (Sweden)

    M. V. P. O. Cunha


    Full Text Available O resíduo do refino da bauxita, comumente conhecido como lama vermelha, tem mostrado ser capaz de ligar metais traços tais como o cobre, cádmio, zinco, cromo, níquel e chumbo sob condições apropriadas. A neutralização da lama vermelha é necessária porque essa lama é tipicamente cáustica, com pH em torno de 13. Muitas pesquisas têm sido desenvolvidas envolvendo a utilização da lama vermelha, porque contem uma série de elementos valiosos. Assim a utilização da lama vermelha como material de construção e como adsorvente é atrativa porque ela é utilizada em grande quantidade. Nada pode ser feito sem descartar componentes valiosos como titânio, zircônio e principalmente ferro. A síntese de hidrotalcita conectada com a reciclagem de soluções alcalinas representa uma maneira efetiva de uso dessa solução considerando a forte demanda por proteção ambiental no mundo. Os compostos tipo hidrotalcita, precipitados durante a neutralização da lama, também removem oxi-ânions de metais de transição através da combinação de intercalações e adsorção de espécies aniônicas na sua superfície externa. Os hidróxidos duplos lamelares (HDL vêm sendo investigados à muitos anos como materiais hospedeiros para uma variedade de reações de intercalação de anions. A estrutura lamelar dos HDLs pode ser usada para controlar a adição ou remoção de uma variedade de espécies químicas, tanto orgânicas quanto inorgânicas. Isto é alcançado através de sua habilidade de adaptar a separação das lamelas de hidróxidos, e da reatividade da região interlamelar. O material resultante adsorve anions quando colocado em soluções e reverte a estrutura da hidrotalcita. Avanços significativos têm sido alcançados recentemente na caracterização desses materiais, incluindo estudos estruturais sobre o mecanismo de intercalação. O objetivo desse trabalho foi a síntese e caracterização de HDLs a partir da lama vermelha, e

  9. Generalized approach to design multi-layer stacks for enhanced optical detectability of ultrathin layers (United States)

    Hutzler, A.; Matthus, C. D.; Rommel, M.; Frey, L.


    The optical detectability of ultrathin conductive films (down to one atomic layer) can be enhanced by choosing distinct layer-stacks. A simple analytical approach using the transfer matrix method is applied for calculating the reflectance of arbitrary multi-layer stack systems with and without the ultrathin layer of interest on top in a wide wavelength range, including both the visible spectrum and the ultraviolet spectrum. Then, the detectability defined by the Michelson contrast was calculated. Performing these calculations for thickness variations of the individual layers in the stack allows determining optimum layer thicknesses, e.g., maximum overall contrast or maximum contrast for a given wavelength. To demonstrate the validity of the methodology, two thin film stacks were investigated, which use p-type silicon as a substrate material and partially covered by a single-layer graphene as a top layer. For each stack, two samples with different layer thicknesses were fabricated and their experimentally determined reflectance was compared to the calculated values. The first system consists of a single SiO2 layer with a thickness of 147 nm and 304 nm, respectively, and the second is a double layer stack consisting of a Si3N4 layer with a thickness of 54 nm and 195 nm, respectively, on top of an 11 nm SiO2 film. The Michelson contrast of single-layer graphene flakes on the latter layer stacks becomes very high (absolute value of more than 0.3) in the visible wavelength range. Additionally, in the UV-B range a large difference in the reflection of selected SiO2 layer thicknesses on silicon substrates with and without single-layer graphene on top is found with a decrease in the measured reflectance of up to 33%. The measured and calculated values showed a high conformity suggesting this approach usable for the calculation of reflectance and transmittance properties of arbitrary layer stack systems including thin conductive layers.

  10. VSWI Wetlands Advisory Layer (United States)

    Vermont Center for Geographic Information — This dataset represents the DEC Wetlands Program's Advisory layer. This layer makes the most up-to-date, non-jurisdictional, wetlands mapping avaiable to the public...

  11. Basic Ozone Layer Science (United States)

    Learn about the ozone layer and how human activities deplete it. This page provides information on the chemical processes that lead to ozone layer depletion, and scientists' efforts to understand them.

  12. Ozone Layer Protection (United States)

    ... Search Search Ozone Layer Protection Share Facebook Twitter Google+ Pinterest Contact Us Ozone Layer Protection Welcome to ... Managing Refrigerant Emissions Stationary Refrigeration and Air Conditioning Car and Other Mobile Air Conditioning GreenChill Partnership Responsible ...

  13. Produção e qualidade de massa de forragem nos estratos da cultivar coastcross-1 consorciada com Arachis pintoi com e sem adubação nitrogenada = Forage mass production and quality in coastcross-1 pasture layers, mixed with Arachis pintoi with or without nitrogen fertilization

    Directory of Open Access Journals (Sweden)


    Full Text Available Neste trabalho, objetivou-se avaliar a massa de forragem nas frações lâminas foliares (LF, bainha + colmo verde (BCV, material morto (MM e seus teores de proteína bruta (PB e fibra em detergente neutro (FDN nos estratos de 0 a 7 cm, 7 a 14 cm e acima de 14 cm de altura da cultivar Coastcross-1 e planta inteira de Arachis pintoi (AP em pastejo, de março de 2003 a março de 2004. Estudaram-se os efeitos dos tratamentos CA0 = Coastcross-1 + Arachis sem N; CA100 = Coastcross-1 + Arachis com 100 kg de N; CA200 = Coastcross-1 + Arachis com 200 kg de N e C200 = Coastcross-1 com 200 kg deN, em um delineamento em blocos ao acaso, com duas repetições. O método de pastejo foi contínuo e a taxa de lotação, variável. As proporções de LF da gramínea Coastcross-1 aumentaram e de BCV, MM e AP diminuíram com o aumento da altura. Não foram observadas diferenças entre os tratamentos. A planta inteira da leguminosa Arachis teve pouca influência na composição da pastagem pela sua baixa disponibilidade. Os maiores (p This trial was carried out to evaluate forage mass in fraction leaf blade (LB, sheath + green stem (SGS, dead material (DE, and crude protein (CP percentage and neutral detergent fiber (NDF in thelayers of 0 to 7 cm, 7 to 14 cm and over 14 cm high. Coastcross-1 grass and the whole plant of Arachis pintoi (WPA were evaluated under grazing, from March 2003 to March 2004. The treatments evaluated were CA0 = Coastcross-1 + Arachis without N; CA100= Coastcross-1 + Arachis with 100 kg of N; CA200 = Coastcross-1 + Arachis with 200 kg of N; and C200 = Coastcross-1 with 200 kg of N, in a random block design, with two repetitions. The proportion of LB and SGS increased, while DE and WPA decreased with the increase of clipping height. No difference was observed among treatments. Arachis had little influence on pasture composition because of its low availability. The highest values (p < 0.05 for CP and the lowest values for NDF were observed in

  14. Piezoelectric Resonator with Two Layers (United States)

    Stephanou, Philip J. (Inventor); Black, Justin P. (Inventor)


    A piezoelectric resonator device includes: a top electrode layer with a patterned structure, a top piezoelectric layer adjacent to the top layer, a middle metal layer adjacent to the top piezoelectric layer opposite the top layer, a bottom piezoelectric layer adjacent to the middle layer opposite the top piezoelectric layer, and a bottom electrode layer with a patterned structure and adjacent to the bottom piezoelectric layer opposite the middle layer. The top layer includes a first plurality of electrodes inter-digitated with a second plurality of electrodes. A first one of the electrodes in the top layer and a first one of the electrodes in the bottom layer are coupled to a first contact, and a second one of the electrodes in the top layer and a second one of the electrodes in the bottom layer are coupled to a second contact.

  15. Building biomedical materials layer-by-layer

    Directory of Open Access Journals (Sweden)

    Paula T. Hammond


    Full Text Available In this materials perspective, the promise of water based layer-by-layer (LbL assembly as a means of generating drug-releasing surfaces for biomedical applications, from small molecule therapeutics to biologic drugs and nucleic acids, is examined. Specific advantages of the use of LbL assembly versus traditional polymeric blend encapsulation are discussed. Examples are provided to present potential new directions. Translational opportunities are discussed to examine the impact and potential for true biomedical translation using rapid assembly methods, and applications are discussed with high need and medical return.

  16. Efeito de cascas de café e de arroz dispostas nas camadas do solo sobre a germinação e o crescimento inicial do caruru-de-mancha Allelopathic effect of coffee and rice husks arranged in soil layers on the germination and initial growth of Amaranthus viridis

    Directory of Open Access Journals (Sweden)

    J.C.F. Santos


    Full Text Available Estudos dos efeitos dos resíduos de plantas pela utilização de coberturas mortas no controle das plantas daninhas têm apresentado dificuldade de determinar a diferenciação entre alelopatia e competição. Atualmente, muitas pesquisas têm se referido a critérios que propõem evidência à alelopatia. Este trabalho em casa de vegetação visou determinar os efeitos alelopáticos proporcionados pelas cascas de café e de arroz sobre o caruru-de-mancha, por meio das disposições desses resíduos nas camadas do solo. O delineamento experimental foi o de blocos casualizados, com os tratamentos em quatro repetições e organizados num esquema fatorial (3x3, sendo cascas de café e de arroz e vermiculita expandida como um fator e suas disposições, com resíduos depositados no topo, incorporados na superfície e incorporados no fundo, como segundo fator. Como testemunha foi usado um tratamento adicional sem cobertura. De modo geral, resíduos de cascas proporcionaram inibição da germinação e estímulo ao crescimento do caruru-de-mancha. A casca de arroz proporcionou menor índice de velocidade de emergência e germinação de sementes do que a casca de café. A casca de café depositada no topo proporcionou maior crescimento e maior peso da matéria seca do caruru-de-mancha, seguido pela mesma casca incorporada na superfície do solo.Studies of plant residue effects involving mulches to control weeds in perennial crops are difficult to carry out due to the need to differentiate between allelopathy and competition. Many researches, nowadays, refer to criteria proving allelopathy. This work was established under greenhouse conditions to determine the allelopathic effects of coffee and rice husks on Amaranthus viridis through their arrangements in soil layers. The experimental design was a randomized block with four replications, arranged in a 3 x 3 factorial scheme, with coffee and rice husks and expanded vermiculite being one factor and

  17. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar


    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  18. Effect of layered silicate content on the morphology and thermal properties of Poly(vinyl alcohol) films; Efeito do teor de silicato em camadas na morfologia e propriedades termicas de filmes de poli(alcool vinilico)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jessica R.M.B. da; Santos, Barbara F.F. dos; Leite, Itamara F., E-mail: [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Centro de Tecnologia. Departamento de Engenharia de Materiais


    This study aims to evaluate the effect of layered silicate content on the morphology and thermal properties of PVA films. The PVA/layered silicate (AN) films were prepared by intercalation solution, using 1 to 2% of bentonite with respect to the PVA total weight. Then the films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). Results of the FTIR revealed interaction between the functional groups of the PVA and the layered silicate. The XRD analysis showed that nanocomposites with intercalated and partially exfoliated morphology were obtained. The results of TG showed that the nanocomposite PVA/2%AN showed higher thermal stability compared to PVA/1%AN. The DSC results showed that the addition of AN to the PVA did not affect crystallization rate, as well as promoted a reduction in glass transition temperature and melting of the PVA. (author)

  19. Method for manufacturing carrier containing e.g. proteins for human during oral drug delivery operation for food and drug administration application in pharmaceutical industry, involves providing active ingredient to core layer

    DEFF Research Database (Denmark)


    or plastically deformable layer to increase stiction of the release layer. The method enables manufacturing the micro-container including an outer diameter of 200-500 pm and a height of 2-70 pm such that wall thickness is larger than 5 m to increase geometrical stability and reduce buckling. The method enables......), polymethacrylate (PMMA), Eudragits Poly-methacylic acid-co-methyl methacrylate, ethyl cellulose (EC), polyvinyl alcohol (PVA), polyvinylpyrollidone (PVP), polyethylene glycol (PEG), polyethylene glycol methacrylate (PEGMA), polyethylene glycol dimethacrylate (PEGDMA), poly-lactic-co-glycolic acid (PGLA...

  20. Influence of Core Permeability on Accropode Armour Layer Stability

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Christensen, M.; Jensen, T.


    Hedar and van der Meer studied the influence of core permeability on the stability of two layer rock armour. In both cases a significant influence was found. However, it is to be expected that for single layer armour there will be an even larger influence on the core permeability. This is because...... the dissipation of wave energy in single layer armour will e smaller than in double layer armour, thus giving room for larger flow velocities in and over armour layer On this background a laboratory stud of single layer Accropode stability was undertaken at Aalborg University in 1995. The test results as well...


    Directory of Open Access Journals (Sweden)



    Full Text Available Information availability in exact time is one of keys for correct decision making. One of thesolutions is by developing a Data Warehouse for supporting decision making. In general DataWarehouse contains Dependent Data Mart (DDM, Integration Layer(IL, and Extract-Transform-Load (ETL. Integration Layer is a database that contains data that already integrated,stored in aid for one or more decision support system. For its data source, integration layerrequire Extract-Transform-Load (ETL as supplier for clean and integrated data. IntegrationLayer volume would be much larger than any on dependent data mart that its support, so thefocus aspect in developing Integration Layer as core part of Data Warehouse is how to handle ahuge amount of data in considerable performance. Beside that, interfacing aspect is alsoimportant, e.g. how Integration Layer interact with ETL Process and supporting dependent data.

  2. Comparação das anastomoses esôfago-gástricas término-terminais em plano único e por invaginação de submucosa e mucosa, em ratos End-to-end esophagogastric anastomosis comparative study, between a single layer and submucosa-mucosa invagination technics: in rats

    Directory of Open Access Journals (Sweden)

    Décio Iandoli Júnior


    Full Text Available A cirurgia do esôfago ainda representa um grande desafio técnico-cirúrgico, devido a alta incidência de fístulas e estenoses. A anastomose esôfago-gástrica por telescopagem de um tubo cranial de submucosa e mucosa, desponta como grande esperança na melhoria dos resultados. Comparamos, em ratos, a anastomose extra-mucosa em plano único com telescopagem de tubo de submucosa e mucosa, com a realizada sem o tubo, procurando confirmar a eficácia desta anastomose na proteção da sutura contra a ocorrência de fístulas, e verificar se em um prazo maior de observação, esta técnica não aumentaria a ocorrência de estenoses. Utilizamos 40 ratos Wistar distribuídos em 2 grupos com 20 animais, sendo que, 10 foram observados por 7 dias e 10 por 14 dias. A avaliação dos resultados foi feita através de parâmetros medidos nas duas operações, como a variação ponderal, variação do diâmetro externo do esôfago, e o índice de estenose; além da análise à microscopia ótica. Foi feita análise estatística de todos os resultados. Os animais com a anastomose por invaginação de submucosa e mucosa, tiveram menor incidência de complicações, confirmando a segurança deste tipo de anastomose e suas vantagens em relação à anastomose convencional.The surgery of the esophagus represents, still today, a technician-surgical challenge, to its high incidence of complications as leakage and estenosis. The esophagus-gastric anastomosis for invagination of a craneal tube of submucosa and mucosa shows up as a great hope of obtaining better results. In this study, we compared, in rats, the extra-mucous anastomosis in single layer with a submucosa and mucosa tube, with accomplished it in the same way without the tube, trying to confirm the effectiveness of that anastomosis type in the protection of the suture edges against the leakage occurrence, as well, to verify if, this technique would not increase the estenosis occurrence. We stabilished a

  3. An ensemble perspective on multi-layer networks

    CERN Document Server

    Wider, Nicolas; Scholtes, Ingo; Schweitzer, Frank


    We study properties of multi-layered, interconnected networks from an ensemble perspective, i.e. we analyze ensembles of multi-layer networks that share similar aggregate characteristics. Using a diffusive process that evolves on a multi-layer network, we analyze how the speed of diffusion depends on the aggregate characteristics of both intra- and inter-layer connectivity. Through a block-matrix model representing the distinct layers, we construct transition matrices of random walkers on multi-layer networks, and estimate expected properties of multi-layer networks using a mean-field approach. In addition, we quantify and explore conditions on the link topology that allow to estimate the ensemble average by only considering aggregate statistics of the layers. Our approach can be used when only partial information is available, like it is usually the case for real-world multi-layer complex systems.

  4. Potencial poluidor de rejeitos carboníferos: II- efeitos da recuperação com camadas de solo sobre as plantas e a população microbiana Pollutant potencial of coal rejects: II- recuperation effects with soil layers in plants and microbial population

    Directory of Open Access Journals (Sweden)

    Larisa Ho Bech Gaivizzo


    Full Text Available A minimização do impacto sobre o ambiente advindo da mineração do carvão pode ser obtida pela recomposição topográfica da área minerada, seguida da cobertura dos rejeitos com uma camada de solo e de práticas de revegetação. Em vista disso, desenvolveu-se o presente trabalho com o objetivo de avaliar o efeito da adição de camadas de solo com diferentes espessuras aplicadas na superfície do rejeito carbonífero (RC, em posições de subsuperfície e do solo misturado ao rejeito sobre a produção de matéria seca das plantas de trevo-branco, milho e aveia-preta, e sobre a população microbiana. A utilização de uma camada de solo de 10cm na superfície do RC mostrou-se a mínima necessária ao estabelecimento de trevo e aveia. As culturas não apresentaram concentrações tóxicas de metais pesados. A elevada acidez do RC reduziu a densidade populacional de bactérias, actinomicetos e fungos, principalmente nas camadas de solo de subsuperfície.The landscape recomposition with soil layer and the introduction of plants have been used as an alternative to minimize the environmental impact caused by coal mining. The main concern for this practice is the low avaibility of soil from surface horizons and economic viability, consequently it is basic to determine the minimum soil layer thickness to be disposed on the reject. An experiment was carried out with addition of soil (Paleudult layers with different thickness disposed on the surface of coal rejects, and in subsurface positions, and soil mixed with rejects, concerning effects on biomass yield of white clover (Trifolium repens L., corn (Zea mays L., and oat (Avena strigosa L. as well as on soil microbial abundance. It was established that a soil layer of 10cm thickness was the minimum necessary for clover and oat growth. Toxic concentrations of heavy metals in plants were not detected. However, soil microbial population represented by bacteria, fungi and actinomyces showed a lower

  5. Stable water layers on solid surfaces. (United States)

    Hong, Ying-Jhan; Tai, Lin-Ai; Chen, Hung-Jen; Chang, Pin; Yang, Chung-Shi; Yew, Tri-Rung


    Liquid layers adhered to solid surfaces and that are in equilibrium with the vapor phase are common in printing, coating, and washing processes as well as in alveoli in lungs and in stomata in leaves. For such a liquid layer in equilibrium with the vapor it faces, it has been generally believed that, aside from liquid lumps, only a very thin layer of the liquid, i.e., with a thickness of only a few nanometers, is held onto the surface of the solid, and that this adhesion is due to van der Waals forces. A similar layer of water can remain on the surface of a wall of a microchannel after evaporation of bulk water creates a void in the channel, but the thickness of such a water layer has not yet been well characterized. Herein we showed such a water layer adhered to a microchannel wall to be 100 to 170 nm thick and stable against surface tension. The water layer thickness was measured using electron energy loss spectroscopy (EELS), and the water layer structure was characterized by using a quantitative nanoparticle counting technique. This thickness was found for channel gap heights ranging from 1 to 5 μm. Once formed, the water layers in the microchannel, when sealed, were stable for at least one week without any special care. Our results indicate that the water layer forms naturally and is closely associated only with the surface to which it adheres. Our study of naturally formed, stable water layers may shed light on topics from gas exchange in alveoli in biology to the post-wet-process control in the semiconductor industry. We anticipate our report to be a starting point for more detailed research and understanding of the microfluidics, mechanisms and applications of gas-liquid-solid systems.

  6. Genotypic characterization of microsatellite markers in broiler and layer selected chicken lines and their reciprocal F1s Caracterização genotípica de linhagens selecionadas de galinha de corte e postura e seus F1s recíprocos usando marcadores microssatélites

    Directory of Open Access Journals (Sweden)

    Millor Fernandes do Rosário


    Full Text Available Chicken experimental populations have been developed worldwide for QTL mapping, but their genotypic characterizations are not usually discussed. The objective of this study was to characterize genotypically two F1 reciprocal generations and their parental lines based on the estimation of genotypic parameters. These F1 generations originated two Brazilian reference populations to map QTL. The evaluated parameters were polymorphic information content (PIC, observed and expected heterozygosities and number of alleles at microsatellite loci on chromosomes 1, 3 and 4. All parental and F1 chickens from both populations were used totalling of 83 chickens: 14 from a broiler (TT and 14 from a layer line (CC and 55 from their reciprocal F1 generations. The chicken lines and the resource populations were developed at the National Research Center for Swine and Poultry (EMBRAPA, Brazil. Genotypes from all animals were obtained from 34 loci on chromosomes 1 (13, 3 (12 and 4 (9. Based on the sampling, we found that the two lines exhibited a total of 163 different alleles, of which 31 (31.1% and 44 (33.0% alleles were unique in CC and TT lines, respectively, with allelic frequencies ranging from 0.03 to 0.82. The observed heterozygosity was higher (0.68-0.71 in both F1 generations than in their founder lines due to linkage disequilibrium. Finally, the two chicken lines used as founders created two F1 reciprocal generations with high levels of PIC (0.50-0.52 and observed heterozygosity, as well as satisfactory number of alleles per locus (4.06-4.32. Our results will allow to compare and select families with highly informative microsatellite markers for QTL studies, reducing genotyping costs.Populações experimentais de frangos tem sido desenvolvidas pelo mundo para mapeamento de QTLs, mas a caracterização genotípica delas não é normalmente apresentada. O objetivo deste estudo foi caracterizar genotipicamente duas gerações F1 recíprocas e suas linhagens

  7. Avaliação das soluções irrigadoras da \\"smear layer\\" nos diversos níveis do conduto radicular com e sem o uso do ultra-som: estudo em microscopia eletrônica de varredura


    Clarissa Teles Rodrigues


    Este estudo teve como objetivo avaliar a capacidade de remoção da smear layer das paredes de canais radiculares instrumentados pelas soluções de soro fisiológico, EDTA a 17%, vinagre de maçã e SmearClear®, nos três níveis radiculares, associadas ou não ao ultra-som. Para tal propósito, foram utilizados 70 dentes caninos humanos superiores e inferiores extraídos os quais tiveram suas coroas removidas. O comprimento de trabalho foi determinado pela visualização da ponta de uma lima tipo K com d...

  8. Behaviour of layered sandstone under Brazilian test conditions:Layer orientation and shape effects

    Institute of Scientific and Technical Information of China (English)

    Abbass Tavallali; André Vervoort


    The experimental study in this paper focuses on the effects of the layer orientation and sample shape on failure strength and fracture pattern of samples tested under Brazilian test conditions (i.e. diametrical loading of cylindrical discs) for one particular layered sandstone which is from Modave in the south of Belgium. The variations of the strength in combination with the failure patterns are examined as a function of the inclination angle between the layer plane and the loading direction. The experimental, results clearly show that the induced fracture patterns are a combination of tensile and/or shear fractures. In shape effect experiments the layer thickness and the number of layer boundaries are investigated. Different blocks of Modave sandstone are used to prepare samples. The layer thickness is different among the various blocks, but the layer thickness in each studied rock block can be considered to be constant;hence, the number of layer boundaries changes according to the sample diameter for samples of the same block. The experimental study shows that the layer thickness plays a more important role than the number of layer boundaries per sample.

  9. The correlation between materials, processes and final properties in the pipeline coating system with polyethylene in triple layer; A correlacao entre materiais, processos e propriedades finais no sistema de revestimento de tubos com polietileno em tripla camada

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luiz C.; Campos, Paulo H. [Confab Industrial S.A., Pindamonhangaba, SP (Brazil); Silva, Christian E.; Santos, Paulo T. [Soco-Ril do Brasil S.A., Pindamonhangaba, SP (Brazil)


    The use of anticorrosion coating is a common practice in industrial pipeline applications. Among the several coatings types to buried and submerged pipelines, over all, the Fusion Bonded Epoxy and Three Layer Polyethylene coating systems have been large employed. They have showed an excellent performance protecting the pipe metal from external corrosive environment, considerably decreasing the designed cathodic protection requirements, basically in the first years of pipeline operation. Coating system success depends on not only of a suitable design or of the materials technology, but also depends on the process parameters and the raw material characteristics exhibited during the application. In this paper will be presented in a theoretical approach how the process parameters and the raw materials characteristics may affect the three layer polyethylene anticorrosion coating final properties. (author)

  10. The Application of Layer Theory to Design: The Control Layer (United States)

    Gibbons, Andrew S.; Langton, Matthew B.


    A theory of design layers proposed by Gibbons ("An Architectural Approach to Instructional Design." Routledge, New York, 2014) asserts that each layer of an instructional design is related to a body of theory closely associated with the concerns of that particular layer. This study focuses on one layer, the control layer, examining…

  11. 普通高校体育课实施分层教学的现状与发展对策研究%Research on the Status-quo and Development Countermeasures for the Layered P.E.Teaching of Higher Education Institutes

    Institute of Scientific and Technical Information of China (English)



    By researching the P.E.teaching outline of 36 higher education institutes(HEIs),it finds that the P.E.teaching management model of HEIs is diversified.And layered teaching has not been applied widely.By the method of literature review,questionnaire,expert interview,it makes an in-depth analysis on the status-quo of the layered teaching in the P.E.course in HEIs and finds that in the practice,there are some problems such as limited application scope,lack of layered methods,incomplete test measures,negative impact on the student self-esteem and shortage of education resources.For the existing problems,it proposes development strategy and suggestions in order to promote the implementation of layered education in the P.E.course in HEIs.It suggests that HEIs shall take layered teaching as the focus and premise,combine their own education features,and properly use teaching resources and reform P.E teaching according to their own condition.%通过对36所普通高校体育课教学大纲的调查研究,发现普通高校体育课教学管理模式呈多元化状态,分层教学尚未大范围实施。运用文献资料、问卷调查和专家访谈等方法,对当前普通高校体育课实施分层教学的现状进行深入研究,发现分层教学实施过程中存在实施范围不广泛、分层方法欠佳、考核方法不完善、学生心理有负面影响、教学资源不足等方面的问题,进而针对存在的问题,提出相应的发展对策及建议,以期推动普通高校体育课实施分层教学的进程。建议:普通高校要以分层教学为中心前提,结合学校自身办学特点,合理利用教学资源,因地制宜地开展体育课教学改革。

  12. Multi-layer coatings

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Abrams, Ze' ev R.; Gonsalves, Peter R.


    Disclosed herein are coating materials and methods for applying a top-layer coating that is durable, abrasion resistant, highly transparent, hydrophobic, low-friction, moisture-sealing, anti-soiling, and self-cleaning to an existing conventional high temperature anti-reflective coating. The top coat imparts superior durability performance and new properties to the under-laying conventional high temperature anti-reflective coating without reducing the anti-reflectiveness of the coating. Methods and data for optimizing the relative thickness of the under-layer high temperature anti-reflective coating and the top-layer thickness for optimizing optical performance are also disclosed.

  13. Intercalation of Layered Silicates, Layered Double Hydroxides, and Lead Iodide: Synthesis, Characterization and Properties. (United States)

    Mehrotra, Vivek

    Layered silicates, layered double hydroxides, and lead iodide are lamellar solids that can incorporate guest species into the galleries between their layers. Various intercalated forms of these layered materials have been synthesized and their properties studied. The dielectric behavior of pristine fluorohectorite, a typical layered silicate, and Zn-Al layered double hydroxide is explained by considering the structural ordering and mobility of the intercalated water molecules, as well as models invoking fractal time processes and fractal structure. Intercalative polymerization of aniline and pyrrole into fluorohectorite leads to a multilayered structure consisting of single polymer chains alternately stacked with the 9.6 A thick silicate layers. The polymer chains are confined to the quasi two-dimensional interlayer space between the rigid host layers. The hybrid films exhibit highly anisotropic properties. The optical, electrical and mechanical behavior is discussed in terms of the molecular confinement of the polymer chains. Ethylenediamine functionalized C _{60} clusters have also been intercalated into fluorohectorite via an ion-exchange procedure. Intercalation results in an improved thermal stability of the functionalized C_{60} clusters. Rutherford backscattering spectrometry has been used to elucidate the mechanism of intercalative ion exchange of silver in muscovite mica, a layered silicate with a layer charge density of 2e per unit cell. It is proposed that ion-exchange progresses by intercalating successive galleries through the edges of the mica layers. Guest-host interactions have been studied in the system aniline-PbI_2. The optical and structural effects of aniline intercalation in lead iodide thin films is discussed. Intercalation leads to a large shift in the optical band gap of PbI_2. The observed change in band gap is not only due to the increased separation between the PbI_2 layers but also because of an electrostatic interaction between the

  14. Addressing Ozone Layer Depletion (United States)

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  15. Structured luminescence conversion layer (United States)

    Berben, Dirk; Antoniadis, Homer; Jermann, Frank; Krummacher, Benjamin Claus; Von Malm, Norwin; Zachau, Martin


    An apparatus device such as a light source is disclosed which has an OLED device and a structured luminescence conversion layer deposited on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The structured luminescence conversion layer contains regions such as color-changing and non-color-changing regions with particular shapes arranged in a particular pattern.

  16. Layered circle packings

    Directory of Open Access Journals (Sweden)

    David Dennis


    Full Text Available Given a bounded sequence of integers {d0,d1,d2,…}, 6≤dn≤M, there is an associated abstract triangulation created by building up layers of vertices so that vertices on the nth layer have degree dn. This triangulation can be realized via a circle packing which fills either the Euclidean or the hyperbolic plane. We give necessary and sufficient conditions to determine the type of the packing given the defining sequence {dn}.

  17. Exigência nutricional de lisina para galinhas poedeiras de ovos brancos e ovos marrons, no segundo ciclo de produção: 2. características produtivas Nutritional requirements for lysine in white-egg and brwon-egg layers in second production cycle: 2. productive traits

    Directory of Open Access Journals (Sweden)

    Breno Augusto Campolina Barbosa


    Full Text Available O objetivo deste trabalho foi estabelecer as exigências de lisina para galinhas poedeiras de ovos brancos (Lohmann Selected Leghorn [LSL] e ovos marrons (Lohmann Brown [LB], no segundo ciclo de produção, da 83ª à 98ª semana de idade. Foi usado delineamento experimental inteiramente casualizado, com seis repetições e oito aves por unidade experimental. Os tratamentos foram constituídos de um fatorial 2 x 6 (duas linhagens x seis níveis de lisina. As aves foram alimentadas com rações contendo 2860 kcal EMkg de ração, 14,37% PB e 0,50% lisina e suplementadas com seis níveis de L-lisina HCl 98% (0,00; 0,08; 0,16; 0,24; 0,32; e 0,40%. Foram avaliados consumo de ração (g/ave.dia, produção de ovos (%, massa de ovo (g/ave.dia, peso de ovo (g e conversão alimentar. As poedeiras LSL apresentaram maior produção de ovos e as LB, maior peso médio dos ovos. Produção de ovos, peso de ovo, massa de ovo, conversão alimentar (g/g e kg/dz foram influenciados pelos níveis de lisina. As exigências nutricionais de lisina para poedeiras LSL e LB foram estimadas, por meio do modelo quadrático, em 0,76 e 0,80%, respectivamente, correspondendo a um consumo de 836 e 880 mg de lisina por ave/dia.This work aimed to establish lysine requirements for white-egg (Lohmann Selected Leghorn and brown-egg (Lohmann Brown layers hens in the second producing cycle, from 83 to 98 weeks of age. A completely randomized design with six replicates and eight birds per experimental unit was used. The treatments consisted in a 2 x 6 factorial involving two commercial lines and six lysine levels. The birds were fed diets containing 2860 kcal of ME/kg, 14.37% CP, and .50% lysine, supplemented with six levels of L-lysine HCl 98% (0, .00, .08, .16, .24, .32, and .40%. Feed intake (g/bird/day, egg production (%, egg mass (g/, egg weight (g, and feed:egg ratio were evaluated. The white-egg layer hens presented high egg production however and the brown-egg layer

  18. An Enhanced Leakage-Based Precoding Scheme for Multi-User Multi-Layer MIMO Systems


    Yang, Chunliang


    In this paper, we propose an enhanced leakage-based precoding scheme, i.e., layer signal to leakage plus noise ratio (layer SLNR) scheme, for multi-user multi-layer MIMO systems. Specifically, the layer SLNR scheme incorporates the MIMO receiver structure into the precoder design procedure, which makes the formulation of signal power and interference / leakage power more accurate. Besides, the layer SLNR scheme not only takes into account the inter-layer interference from different users, but...

  19. Determinação de fármacos diuréticos em associação por cromatografia em camada delgada e espectrofotometria Determination of diuretic drugs by thin layer chromatography and spectrophotometry

    Directory of Open Access Journals (Sweden)

    Dênia Mendes de Sousa Valladão


    Full Text Available A rapid, sensitive and reliable thin-layer chromatography/spectrophotometry screening procedure was developed for quantitative determination of diuretics associated in pharmaceutical dosage forms. The chromatographic method employed microcrystalline cellulose and butanol : acetic acid : water (4:1:1 or amilic alcohol : ammonium hydroxide 25% (9:1 as mobile phases and detection by U.V. light. The drugs were extracted using a simple procedure and were quantified by U.V. spectrophotometry. Results varied from 97.5 to 102.5% and are similar to those obtained by conventional methods. This method of quantification of diuretics is promising for quality control of drugs.

  20. NDAS Hardware Translation Layer Development (United States)

    Nazaretian, Ryan N.; Holladay, Wendy T.


    The NASA Data Acquisition System (NDAS) project is aimed to replace all DAS software for NASA s Rocket Testing Facilities. There must be a software-hardware translation layer so the software can properly talk to the hardware. Since the hardware from each test stand varies, drivers for each stand have to be made. These drivers will act more like plugins for the software. If the software is being used in E3, then the software should point to the E3 driver package. If the software is being used at B2, then the software should point to the B2 driver package. The driver packages should also be filled with hardware drivers that are universal to the DAS system. For example, since A1, A2, and B2 all use the Preston 8300AU signal conditioners, then the driver for those three stands should be the same and updated collectively.

  1. Model castings with composite surface layer - application

    Directory of Open Access Journals (Sweden)

    J. Szajnar


    Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in foundingprocess a composite surface layer on the basis of Fe-Cr-C alloy. Technology of composite surface layer guarantee mainly increase inhardness and aberasive wear resistance of cast steel castings on machine elements. This technology can be competition for generallyapplied welding technology (surfacing by welding and thermal spraying. In range of studies was made cast steel test castings withcomposite surface layer, which usability for industrial applications was estimated by criterion of hardness and aberasive wear resistance of type metal-mineral and quality of joint cast steel – (Fe-Cr-C. Based on conducted studies a thesis, that composite surface layer arise from liquid state, was formulated. Moreover, possible is control of composite layer thickness and its hardness by suitable selection of parameters i.e. thickness of insert, pouring temperature and solidification modulus of casting. Possibility of technology application of composite surface layer in manufacture of cast steel slide bush for combined cutter loader is presented.

  2. Enabling Realistic Cross-Layer Analysis based on Satellite Physical Layer Traces

    CERN Document Server

    Kuhn, Nicolas; Lacan, Jerome; Boreli, Roksana; Bes, Caroline; Clarac, Laurence


    We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager Tool (TMT) produces the corresponding link layer output, which is then used within the ns-2 network simulator via the additionally developed ns-2 interface module. We first present the analytical models for the link layer with bursty erasure packets and for the link layer reliability mechanisms with bursty erasures. Then, we present details of the TMT tool and our validation methodology, demonstrating that the selected performance metrics (recovery delay and throughput efficiency) exhibit a good match between the theoretical results and those obtained with TMT. Finally, we present results showing the impact of di...


    Directory of Open Access Journals (Sweden)

    Fabiane Pereira Gentilini


    Full Text Available This study aimed to relate the egg production with health status, expressed as cecal bacteria contamination, as well as to investigate the effect of total plasma proteins with egg quality of layers fed different diets reformulated to different metabolizable energy levels using an enzyme complex, obtained by solid state fermentation.  A total of  384 26-week old Hisex Brown layers were fed experimental diets during 280 days (10 periods of 28 days each. A total of 4 birds were allocated per cage, in a total of 64 birds/treatment. Treatments consisted in reformulating diets to different metablizable energy levels using an enzyme complex (EC obtained by  solid state fermentation:   T1 – basal diet (control; T2 –  basal diet  + EC (reformulated to  120 kcal ME/kg; T3 – basal diet + EC (reformulated to 90 kcal ME/kg; T4 – basal diet + EC (reformulated to 60 kcal ME/kg; T5 – basal diet + EC (reformulated to 30 kcal ME/kg and T6 – basal diet + EC ( on top. Egg production, egg weight, Haugh units, albumen weight, total plasma proteins and cecal bacteria count were evaluated.  Egg weight and albumen weight and cecal bacteria count, but not egg production, Haugh units and total plasma proteins,   were adversely affected when the EC was added on top of a diet containing a regular commercial premix. This study indicates that the health status of the gut can be improved by adding the SSF enzyme complex on top of a regular diet.

    KEY WORDS: Exogenous enzymes, Haugh units, sanitary status.
    Objetivou-se relacionar a produção de ovos com o status sanitário das aves, expresso pelo nível de contaminação bacteriana cecal, bem como os níveis plasmáticos de proteínas totais com a qualidade dos ovos de aves que receberam dietas com complexo enzimático (CE com diferentes níveis de valorização da energia metabolizável. Utilizaram-se 384 poedeiras Hisex Brown por um período de 280 dias, divididos em dez ciclos de 28

  4. Determination of half-value layers and tenth-value layer to barite as shielding against X radiation in radiological protection; Determinacao de camadas semi-redutoras e deci-redutoras para barita como blindagem contra radiacao x em protecao radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, G.A.; Aragao Filho, G.L., E-mail:, E-mail: [Instituto Federal de Pernambuco (IFPE), Recife, PE (Brazil); Almeida Junior, A.T., E-mail: [Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho (FUNDACENTRO), Belo Horizonte, MG (Brazil); Santos, M.A.P., E-mail: [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Araujo, F.G.S., E-mail: [Universidade Federal de Ouro Preto (UFOP /REDEMAT), MG (Brazil); Nogueira, M.S., E-mail: [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)


    The barium mortar has been widely used as radiation shielding material for X and gamma radiations in Brazil, by presenting some advantages as the high rate of efficiency in radiation shielding, the easy handling and application, the facility to be found in the national market and low cost. The determination of the half-value layers (HVL) and tenth-value layer (TVL) of different types of barite becomes the major factor to characterize the attenuation of these materials, in order to ensure the efficiency and quality of projects shielding, by ensuring the safety of workers occupationally exposed to radiation and of individuals to the public. Thus, plates of different thickness of mortar of barite were made for determination of their HVL and TVL. The plates were irradiated with X-ray qualities for radiological protection according to standard ISO 4037. A system of CdTe spectrometry was used to acquire spectra transmitted, in the presence of each plate, and their combinations. The areas of the spectra obtained, depending on the total thickness of the plates used in the arrangement were used to determine the attenuation curves. From these curves obtained in this work was to establish the HVL and TVL.

  5. Feeding different levels of vitamin E and selenium has no effect on serum immunoglobulin Y (IgY production by layers vaccinated against Escherichia coli and avian encephalomyelitis virus Alimentação com diferentes níveis de vitamina E e selênio não influencia a produção de imunoglobulina Y (IgY no soro de poedeiras leves vacinadas contra Escherichia coli e encefalomielite aviária

    Directory of Open Access Journals (Sweden)

    Giselle Kindlein


    Full Text Available The effects of vitamin E and selenium (Se supplementation on the immunity of hens vaccinated against a mixture of six swine-pathogenic Escherichia coli (EC and avian encephalomyelitis virus (AEV were studied. Antibody production (AbP was evaluated in ninety 49 to 57-week-old H&N Nick Chick hens fed diets containing 14IU Vitamin E kg-1 (basal diet, 27, 59, 111, or 111IU vitamin E kg-1 + 0.56ppm Se supplementation. At 51 wks of age, half of the hens were vaccinated against EC, and all birds were vaccinated against AEV. At 53-weeks of age, the birds received a second dose of EC vaccine. Blood samples were collected weekly and serum was analyzed by ELISA for anti-EC IgY and was expressed as optical density (OD. Vaccinated hens had higher serum OD than the non-vaccinated hens (P£0.05. Vaccinated hens fed 27 and 59IU of vitamin E/kg had a higher (POs efeitos da suplementação de vitamina E e Selênio (Se na imunidade de galinhas vacinadas contra uma mistura de 6 sorotipos patogênicos de Escherichia coli (EC e o vírus da encefalomielite aviária (VEA foram estudados. A produção de anticorpos foi avaliada em galinhas H&N Nick Chick durante a 49a e 57a semanas de vida. As aves foram alimentadas com dietas contendo 14UI de Vitamina E kg-1 (dieta basal, 27, 59, 111 e 111UI de Vitamina E kg-1 + 0,56ppm Se suplementar. Às 51 semanas de idade, metade das galinhas foi vacinada contra EC, e todas as aves foram vacinadas contra VEA. Às 53 semanas, as aves receberam a segunda vacina contra EC. Amostras de sangue foram coletadas semanalmente e o soro foi analisado por ELISA para anti-EC IgY e expresso como densidade óptica (DO. Galinhas vacinadas tiveram maior DO do que as não-vacinadas (P<0,05. Aves vacinadas que receberam 27 e 59 UI de vitamina E/kg tiveram maior DO do soro (P<0,05 do que as alimentadas com 111 UI + Se. Os antígenos utilizados mostraram não ser modelos satisfatórios para estudar a influência de micronutrientes na resposta imune de

  6. Densidade e qualidade dos estratos de forragem do capim Tanzânia (Panicum maximum Jacq. Cv. Tanzânia-1 manejado em diferentes alturas, sob pastejo Density bulk and quality of Tanzania grass layers (Panicum maximum Tanzania-1, at different heights in grazing

    Directory of Open Access Journals (Sweden)

    Geraldo Tadeu dos Santos


    Full Text Available O objetivo do trabalho foi avaliar o efeito de diferentes alturas (24; 26; 43; 45; 52; 62; 73 e 78 cm do pasto sobre a qualidade de forragem e estrutura do perfil do capim-Tanzânia, (Panicum maximum Jacq. cv. Tanzânia – 1 (Poaceae. Foram utilizados novilhos da raça Nelore sob pastejo com carga animal variável, por meio da técnica put and take. O delineamento experimental utilizado foi inteiramente casualizado, com duas repetições. A densidade de matéria seca total (DMT aumentou com o avanço no período experimental, enquanto a densidade de matéria seca de lâminas (DML não foi influenciada pelo período e pela altura do pasto. O estrato superior da pastagem foi a porção de maior qualidade, apresentando maior DML e maior teor de PB. Os estratos inferiores apresentaram menor qualidade, devido à maior DMT e menor DML, acarretando em maiores valores de FDA e FDN e menores teores de PB. O conteúdo de minerais das lâminas foi superior aos colmos, mantendo-se inalterado com relação aos estratos da pastagem.The effect of different sward heights (24; 26; 43; 45; 52; 62; 73 and 78 cm on forage quality and profile structure Tanzania grass, Panicum maximum Jacq. cv. Tanzania – 1 (Poaceae is provided. Nelore steers were used in grazing at variable stocking rates with put and take technique. The experimental design was completely randomized, with two replications. Total dry matter bulk densitity (TDMD increased during experimental period, while the leaf blade dry matter bulk density (LDMD was not influenced by period on by sward height. The upper layers had the best quality with higher LDMD and CP levels. Lower layers had the worst quality, due the higher TDMD and lower LDMD. This fact caused higher ADF and NDF levels and lower CP levels. Leaf blade mineral content was higher than that of stem, and remained unaltered in relation to the different layers.

  7. Superfluid Boundary Layer (United States)

    Stagg, G. W.; Parker, N. G.; Barenghi, C. F.


    We model the superfluid flow of liquid helium over the rough surface of a wire (used to experimentally generate turbulence) profiled by atomic force microscopy. Numerical simulations of the Gross-Pitaevskii equation reveal that the sharpest features in the surface induce vortex nucleation both intrinsically (due to the raised local fluid velocity) and extrinsically (providing pinning sites to vortex lines aligned with the flow). Vortex interactions and reconnections contribute to form a dense turbulent layer of vortices with a nonclassical average velocity profile which continually sheds small vortex rings into the bulk. We characterize this layer for various imposed flows. As boundary layers conventionally arise from viscous forces, this result opens up new insight into the nature of superflows.

  8. Layered Systems Engineering Engines (United States)

    Breidenthal, Julian C.; Overman, Marvin J.


    A notation is described for depicting the relationships between multiple, contemporaneous systems engineering efforts undertaken within a multi-layer system-of-systems hierarchy. We combined the concepts of remoteness of activity from the end customer, depiction of activity on a timeline, and data flow to create a new kind of diagram which we call a "Layered Vee Diagram." This notation is an advance over previous notations because it is able to be simultaneously precise about activity, level of granularity, product exchanges, and timing; these advances provide systems engineering managers a significantly improved ability to express and understand the relationships between many systems engineering efforts. Using the new notation, we obtain a key insight into the relationship between project duration and the strategy selected for chaining the systems engineering effort between layers, as well as insights into the costs, opportunities, and risks associated with alternate chaining strategies.

  9. Bi-layer functionally gradient thick film semiconducting methane sensors

    Indian Academy of Sciences (India)

    A Banerjee; A K Haldar; J Mondal; A Sen; H S Maiti


    Gas sensors based on metal oxide semiconductors like tin dioxide are widely used for the detection of toxic and combustible gases like carbon monoxide, methane and LPG. One of the problems of such sensors is their lack of sensitivity, which to some extent, can be circumvented by using different catalysts. However, highly reactive volatile organic compounds (VOC) coming from different industrial and domestic products (e.g. paints, lacquers, varnishes etc) can play havoc on such sensors and can give rise to false alarms. Any attempt to adsorb such VOCs (e.g. by using activated charcoal) results in sorption of the detecting gases (e.g. methane) too. To get round the problem, bi-layer sensors have been developed. Such tin oxide based functionally gradient bi-layer sensors have different compositions at the top and bottom layers. Here, instead of adsorbing the VOCs, they are allowed to interact and are consumed on the top layer of the sensors and a combustible gas like methane being less reactive, penetrates the top layer and interacts with the bottom layer. By modifying the chemical compositions of the top and bottom layers and by designing the electrode-lead wire arrangement properly, the top layer can be kept electrically shunted from the bottom layer and the electrical signal generated at the bottom layer from the combustible gas is collected. Such functionally gradient sensors, being very reliable, can find applications in domestic, industrial and strategic sectors.

  10. Reinforcing the mineral layer

    Energy Technology Data Exchange (ETDEWEB)

    Pishchulin, V.V.; Kuntsevich, V.I.; Seryy, A.M.; Shirokov, A.P.


    A way of reinforcing the mineral layer includes drilling holes and putting in anchors that are longer than the width of the layer strip being extracted. It also includes shortening the anchors as the strip is mined and reinforcing the remaining part of the anchor in the mouth of the hole. To increase the productivity and safety of the work, the anchors are shortened by cutting them as the strip is mined and are reinforced through wedging. The device for doing this has auxilliary lengthwise grooves in the shaft located along its length at an interval equal to the width of the band being extracted.

  11. X-ray study of the charge-density-wave transition in single-layer TiSe2

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xin-Yue; Hong, Hawoong; Chen, Peng; Chiang, T. -C.


    Synchrotron x-ray studies of single-layer TiSe2 reveal displacements of the Ti and Se atoms as a function of temperature. The measurements, with a high sensitivity of 0.001 Å, show a (2x2) charge density wave (CDW) structure at temperatures below a critical temperature of TC1 = 233 K. The temperature dependence follows a BCS-like second-order mean-field behavior. A fivelayer TiSe2 film also exhibits a CDW transition of the same character but at a lower transition temperature of TC5 = 204 K, which is the same as that for bulk TiSe2. The results demonstrate that lattice distortion is an integral part of the CDW transition that must also involve renormalization of the electronic structure.

  12. Nanocomposites of polystyrene-layered double hydroxide (ZnCr) modified with laurate/palmitate: characterization and synthesis in situ; Nanocompositos de poliestireno - hidroxido duplo lamelar (ZnCr) modificados com laurato/palmitato: sintese in situ e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Sartor, Sabrina de B.; Botan, Rodrigo; Lona, Liliane F., E-mail: [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Quimica


    Polymer nanocomposites have attracted great interest in the scientific community and industry, due to the fact that they show significant improvement in their mechanical and thermal properties. These improvements are attributed to the presence of nano reinforcement added to these materials. In this work nanocomposites of polystyrene (PS) and layered double hydroxide (LDH) of Zinc-Chrome modified with laurate and palmitate anions were synthesized via in situ polymerization. The characterization techniques employed were: Fourier transform infrared spectroscopy (FTIR), X ray diffraction analysis (XRD) and thermogravimetric analysis (TGA). The results obtained by XRD technique show that nanocomposites produced are strongly correlated to the presence of exfoliated morphology in its structure, while the TGA results show that these materials exhibit greater thermal stability when compared to neat PS. (author)

  13. Satellite to measure equatorial ozone layer (United States)


    The Atmosphere Explorer E (Explorer 55) Satellite is described. The satellite will gather information on the earth's upper atmosphere, particularly regarding the condition of the protective ozone layer. The satellite will also provide information concerning the earth's heat balance, and heat flow characteristics, and energy conversion mechanisms.

  14. Improved insulator layer for MIS devices (United States)

    Miller, W. E.


    Insulating layer of supersonic conductor such as LaF sub 3 has been shown able to impart improved electrical properties to photoconductive detectors and promises to improve other metal/insulator/semiconductor (MIS) devices, e.g., MOSFET and integrated circuits.

  15. Authors' reply to Discussion by E. Siebrits and S. L. Crouch regarding the paper "A two-dimensional linear variation displacement discontinuity method for three-layered elastic media", International Journal of Rock Mechanics and Mining Sciences, Vol. 36, No. 6, pp. 719-729, 1999

    CSIR Research Space (South Africa)

    Shou, KJ


    Full Text Available to Discussion by E. Siebrits and S. L. Crouch regarding the paper ``A two-dimensional linear variation displacement discontinuity method for three-layered elastic media'', International Journal of Rock Mechanics and Mining Sciences, Vol. 36, No. 6, pp. 719... of judging the accuracy of their ``highly accurate semi-analytic simulator'' which is International Journal of Rock Mechanics and Mining Sciences 37 (2000) 877±878 1365-1609/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved. PII: S...

  16. Layer-by-layer assembled carbon nanotube-acetylcholinesterase/biopolymer renewable interfaces: SPR and electrochemical characterization. (United States)

    Zhang, Yuanyuan; Arugula, Mary A; Kirsch, Jeffrey S; Yang, Xiaoyun; Olsen, Eric; Simonian, Aleksandr L


    Developing simple, reliable, and cost-effective methods of renewing an inhibited biocatalyst (e.g., enzymatic interfaces) on biosensors is needed to advance multiuse, reusable sensor applications. We report a method for the renewal of layer-by-layer (LbL) self-assembled inhibition-based enzymatic interfaces in multiwalled carbon nanotube (MWCNT) armored acetylcholinesterase (AChE) biosensors. The self-assembly process of MWCNT dispersed enzymes/biopolymers was investigated using surface plasmon resonance (SPR). The LbL fabrication consisted of alternating cushion layers of positively charged CNT-polyethylenimine (CNT-PEI) and negatively charged CNT-deoxyribonucleic acid (CNT-DNA) and a functional interface consisting of alternating layers of CNT-PEI and negatively charged CNT-acetylcholine esterase (CNT-AChE, pH 7.4). The observed SPR response signal increased while assembling the different layers, indicating the buildup of multiple layers on the Au surface. A partial desorption of the top enzymatic layer in the LbL structure was observed with a desorption strategy employing alkaline treatment. This indicates that the strong interaction of CNT-biopolymer conjugates with the Au surface was a result of both electrostatic interactions between biopolymers and the surface binding energy from CNTs: the closer the layers are to the Au surface, the stronger the interactions. In contrast, a similar LbL assembly of soluble enzyme/polyelectrolytes resulted in stronger desorption on the surface after the alkaline treatment; this led to the investigation of AChE layer removal, permanently inhibited after pesticide exposure on glassy carbon (GC) electrodes, while keeping the cushion layers intact. The desorption strategy permitted the SPR and electrochemical electrode surfaces to be regenerated multiple times by the subsequent self-assembly of fresh PEI/AChE layers. Flow-mode electrochemical amperometric analysis demonstrated good stability toward the determination of

  17. Estrutura e composição do estrato de regeneração em um fragmento florestal urbano: implicações para a dinâmica e a conservação da comunidade arbórea Structure and composition of the regeneration layer in an urban forest fragment: implications for the dynamics and conservation of the tree community

    Directory of Open Access Journals (Sweden)

    Jania Cabrelli Salles


    Full Text Available Este estudo foi realizado em um fragmento de floresta estacional semidecídua, sujeito a longo histórico de perturbação antrópica, localizado no perímetro urbano de Uberlândia, MG. Teve como objetivo avaliar a composição e a estrutura do estrato regenerativo e comparar com a comunidade adulta do dossel, de forma a revelar informações importantes sobre o funcionamento do ambiente e a dinâmica dessa formação vegetal. Para o levantamento do estrato regenerativo, utilizaram-se 30 parcelas de 10×10 m, onde todos os indivíduos com altura igual ou superior a um metro tiveram medidos a altura e o diâmetro ao nível do solo. A presença de espécies tardias de grande porte no estrato adulto, sem a correspondência de abundância no estrato regenerativo, sugere que as perturbações atingem diretamente o estrato inferior. O dossel da floresta estacional do Parque do Sabiá é composto de árvores que, provavelmente, possuem dezenas de anos e a formação de clareiras, naturais ou antrópicas, estimula o estabelecimento de espécies pioneiras. De forma geral, as espécies importantes do estrato regenerativo sugerem que a comunidade está sofrendo mudanças na sua composição florística, em um processo de sucessão caracterizado pela presença de grande número de indivíduos regenerantes, de espécies pertencentes aos primeiros estágios sucessionais.This study was carried out in a semideciduous seasonal forest fragment with a long history of manmade disturbance, located in urban Uberlândia, Minas Gerais. The aim was to compare the composition and structure of the regeneration layer with that of the adult canopy layer in order to obtain information on environmental functioning and the dynamics of this plant formation. In 30 plots of 10×10 m, plants equal to or taller than one meter were surveyed, recording height and stem diameter at soil level. The presence of large trees of secondary species in the canopy layer, without corresponding

  18. Potencial de utilização do estrato superior do solo laterítico da cidade de Londrina, Estado do Paraná, como material e apoio de aterros sanitários = Utilization potential of the soil layer in the city of Londrina, Parana State, as material and support for landfill solid wastes

    Directory of Open Access Journals (Sweden)

    Raquel Souza Teixeira


    Full Text Available Este trabalho apresenta uma avaliação do potencial de utilização da camada de solo laterítico, do perfil característico, da cidade de Londrina, Estado do Paraná, para o uso como material e apoio de aterros sanitários. Neste sentido fez-se necessária uma brevediscussão conceitual sobre resíduos sólidos, tipos de aterros e interação solo-contaminante. Em seguida foi feita uma descrição da localização da área de estudo e das características da camada do solo investigada. A avaliação do solo foi baseada em critérios geotécnicos a partir das características físicas, químicas e mineralógicas do solo, obtidas em ensaio de laboratório e em resultados publicados, em artigos técnicos, tomando-se por base uma pontuação e uma classificação, feitas a partir de atributos sugeridos por Zuquette (1993. A avaliação final, a respeito da utilização da camada de solo laterítico, para a implantação de um aterro sanitário, foi positiva.This paper shows an evaluation of the utilization potential of laterite soil layer, characteristic of the city of Londrina, Paraná State, as material and support for landfill solid wastes. At first, weprovided a brief definition of the solid residue, types of embankments, soil-contaminating interaction and contaminating processes. Then, we described the study area location and the layer characteristics of the soil under investigation. The soil evaluation was based on geotechnical criteria regarding physical, chemical and mineralogical characteristics of the soil, which were obtained from a laboratory experiment and from results published in technical articles. Grading and classification were done according to the attributes suggested by Zuquette (1993. The final evaluation on the use of the layer of laterite soil for the implantation of the sanitary bank was positive.

  19. Layer-controlled band alignment, work function and optical properties of few-layer GeSe (United States)

    Song, Xiufeng; Zhou, Wenhan; Liu, Xuhai; Gu, Yu; Zhang, Shengli


    The electronic properties, such as the layer-dependent behavior of the band structure, band gap, work function alignment and dielectric properties of the few-layer GeSe are systematically investigated via gradient-corrected density functional theory computations, inspired by the experimentally observation of two-dimension materials such as graphene, phosphorene, MoS2 and BN. The results indicate that the few-layer GeSe presents a robust direct band gap, which decreases with increasing the thickness from bilayer (1.15 eV) to six-layer (1.00 eV) around the X point. Furthermore, the work function increases rapidly from monolayer (4.44 eV) to trilayer (4.95 eV). The robust direct band gap characteristics and the layer-dependent band gap suggest that the few-layer GeSe is a promising material for efficient solar energy harvesting applications. The layer dependence of the GeSe work function offers a practical route to tune the Schottky barrier in GeSe based electronic devices. Our results provide new insights on utilizing the layer-controlled band gap of the atomic layers of GeSe.

  20. Improved electron transport layer

    DEFF Research Database (Denmark)


    The present invention provides: a method of preparing a coating ink for forming a zinc oxide electron transport layer, comprising mixing zinc acetate and a wetting agent in water or methanol; a coating ink comprising zinc acetate and a wetting agent in aqueous solution or methanolic solution...

  1. Physical layer network coding

    DEFF Research Database (Denmark)

    Fukui, Hironori; Popovski, Petar; Yomo, Hiroyuki


    Physical layer network coding (PLNC) has been proposed to improve throughput of the two-way relay channel, where two nodes communicate with each other, being assisted by a relay node. Most of the works related to PLNC are focused on a simple three-node model and they do not take into account...

  2. Layer-Cake Earth (United States)

    Tedford, Rebecca; Warny, Sophie


    In this article, the authors offer a safe, fun, effective way to introduce geology concepts to elementary school children of all ages: "coring" layer cakes. This activity introduces the concepts and challenges that geologists face and at the same time strengthens students' inferential, observational, and problem-solving skills. It also addresses…

  3. EHD lubricating layer

    Energy Technology Data Exchange (ETDEWEB)

    Shvarts, I.A.


    The simplest model of an EHD lubricating layer consists of a unipolarly charged nonconducting viscous fluid between two parallel or slightly inclined nonconducting plates. The performance of such a layer is analyzed here on the basis of the fundamental EHD equations, with a plane-parallel approximation of the flow of a thin layer under a variable upper boundary. The results of the solution indicate that the bearing capacity of such a layer between parallel plates does not depend on the viscosity of the fluid, but is proportional to the energy density of the electric field in vacuum. With the plates not parallel, the bearing capacity depends on the mobility and the diffusion of the charged fluid particles. In either case the energy of the electric field can be made to compensate for the energy dissipation due to viscous friction, and in this case or with overcompensation such as EHD bearing becomes an EHD generator. Most valuable for practical applications are fluids with a high dielectric permittivity, such as ammonia and hydrogen chloride at cryogenic temperatures. 5 references, 1 figure.

  4. The Functioning of a Cortex without Layers

    Directory of Open Access Journals (Sweden)

    Julien Guy


    Full Text Available A major hallmark of cortical organization is the existence of a variable number of layers, i.e., sheets of neurons stacked on top of each other, in which neurons have certain commonalities. However, even for the neocortex, variable numbers of layers have been described and it is just a convention to distinguish six layers from each other. Whether cortical layers are a structural epiphenomenon caused by developmental dynamics or represent a functionally important modularization of cortical computation is still unknown. Here we present our insights from the reeler mutant mouse, a model for a developmental, “molecular lesion”-induced loss of cortical layering that could serve as ground truth of what an intact layering adds to the cortex in terms of functionality. We could demonstrate that the reeler neocortex shows no inversion of cortical layers but rather a severe disorganization that in the primary somatosensory cortex leads to the complete loss of layers. Nevertheless, the somatosensory system is well organized. When exploring an enriched environment with specific sets of whiskers, activity-dependent gene expression takes place in the corresponding modules. Precise whisker stimuli lead to the functional activation of somatotopically organized barrel columns as visualized by intrinsic signal optical imaging. Similar results were obtained in the reeler visual system. When analyzing pathways that could be responsible for preservation of tactile perception, lemniscal thalamic projections were found to be largely intact, despite the smearing of target neurons across the cortical mantle. However, with optogenetic experiments we found evidence for a mild dispersion of thalamic synapse targeting on layer IV-spiny stellate cells, together with a general weakening in thalamocortical input strength. This weakening of thalamic inputs was compensated by intracortical mechanisms involving increased recurrent excitation and/or reduced feedforward

  5. Bimetallic layered castings alloy steel – carbon cast steel

    Directory of Open Access Journals (Sweden)

    T. Wróbel


    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast processso-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic carbon cast steel, whereas working part (layer is plate of austenitic alloy steel sort X10CrNi 18-8. The ratio of thickness between bearing and working part is 8:1. The quality of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  6. Examples of material solutions in bimetallic layered castings

    Directory of Open Access Journals (Sweden)

    S. Tenerowicz


    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. pearlitic grey cast iron, whereas working part (layer is depending on accepted variant plates of alloy steels sort X6Cr13, X12Cr13, X10CrNi18-8 and X2CrNiMoN22-5-3. The ratio of thickness between bearing and working part is 8:1. The verification of the bimetallic layered castings was evaluated on the basis of ultrasonic NDT (non-destructive testing, structure and macro- and microhardness researches.

  7. MITRE sensor layer prototype (United States)

    Duff, Francis; McGarry, Donald; Zasada, David; Foote, Scott


    The MITRE Sensor Layer Prototype is an initial design effort to enable every sensor to help create new capabilities through collaborative data sharing. By making both upstream (raw) and downstream (processed) sensor data visible, users can access the specific level, type, and quantities of data needed to create new data products that were never anticipated by the original designers of the individual sensors. The major characteristic that sets sensor data services apart from typical enterprise services is the volume (on the order of multiple terabytes) of raw data that can be generated by most sensors. Traditional tightly coupled processing approaches extract pre-determined information from the incoming raw sensor data, format it, and send it to predetermined users. The community is rapidly reaching the conclusion that tightly coupled sensor processing loses too much potentially critical information.1 Hence upstream (raw and partially processed) data must be extracted, rapidly archived, and advertised to the enterprise for unanticipated uses. The authors believe layered sensing net-centric integration can be achieved through a standardize-encapsulate-syndicateaggregate- manipulate-process paradigm. The Sensor Layer Prototype's technical approach focuses on implementing this proof of concept framework to make sensor data visible, accessible and useful to the enterprise. To achieve this, a "raw" data tap between physical transducers associated with sensor arrays and the embedded sensor signal processing hardware and software has been exploited. Second, we encapsulate and expose both raw and partially processed data to the enterprise within the context of a service-oriented architecture. Third, we advertise the presence of multiple types, and multiple layers of data through geographic-enabled Really Simple Syndication (GeoRSS) services. These GeoRSS feeds are aggregated, manipulated, and filtered by a feed aggregator. After filtering these feeds to bring just the type

  8. Cecorraphy in single layer using polypropylene and poliglecaprone 25 threads: comparative study in rats Cecorrafia em plano único com fios de polipropileno e poliglecaprone 25: estudo comparativo em ratos

    Directory of Open Access Journals (Sweden)

    Fernando Issamu Tabushi


    Full Text Available PURPOSE: To compare sutures with polypropylene and poliglecaprone 25 after partial cecotomy in rats. METHODS: Thirty six rats divided into two groups, A and B, of 18 animals; each group was also divided into three subgroups of six animals sacrificed at 4th, 7th and 14th days after surgery. Were studied the mortality, morbidity, complications attributable to sutures, macroscopy, optical microscopy and measurement of hydroxyproline at the level of the suture. RESULTS: There were no deaths or wound complications such as hematoma, seroma, abscess, evisceration or eventration. On microscopic evaluation reepithelization, coaptation and inflammation in both groups did not differ significantly. The average rate of tissue hydroxyproline found in the samples on the 4th day after surgery, was 21.38 mg/g tissue for group A and 16.68 mg/g for group B; on day 7 after surgery, the average was 15.64 mg/g tissue for group A and 26.53 mg/g for group B; on day 14, the average was 8.09 mg/g tissue for group A and 25.07 mg/g for group B. CONCLUSION: There were no differences on clinical evolution, macroscopic aspect, microscopic data and hydroxyproline concentration on both sutures.OBJETIVO: Comparar a sutura com fio de polipropileno e poliglecaprone 25 após cecotomia parcial em ratos. MÉTODOS: Trinta e seis ratos foram distribuídos em dois grupos A e B de 18 animais, e cada grupo foi dividido em três subgrupos de seis, sacrificados no 4º, 7º e 14º dias do pós-operatório. Estudou-se a mortalidade, morbidade, complicações atribuíveis às suturas, macroscopia, microscopia ótica e dosagem de hidroxiprolina no nível da sutura. RESULTADOS: Não houve mortalidade ou complicações da ferida operatória como hematoma, seroma, abscesso, evisceração ou eventração. Na avaliação microscópica os critérios de re-epitelização, coaptação e processo inflamatório ambos os grupos não apresentaram diferença significativa. A taxa tecidual média da

  9. Fermi level de-pinning of aluminium contacts to n-type germanium using thin atomic layer deposited layers

    Energy Technology Data Exchange (ETDEWEB)

    Gajula, D. R., E-mail:; Baine, P.; Armstrong, B. M.; McNeill, D. W. [School of Electronics, Electrical Engineering and Computer Science, Queen' s University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH (United Kingdom); Modreanu, M.; Hurley, P. K. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)


    Fermi-level pinning of aluminium on n-type germanium (n-Ge) was reduced by insertion of a thin interfacial dielectric by atomic layer deposition. The barrier height for aluminium contacts on n-Ge was reduced from 0.7 eV to a value of 0.28 eV for a thin Al{sub 2}O{sub 3} interfacial layer (∼2.8 nm). For diodes with an Al{sub 2}O{sub 3} interfacial layer, the contact resistance started to increase for layer thicknesses above 2.8 nm. For diodes with a HfO{sub 2} interfacial layer, the barrier height was also reduced but the contact resistance increased dramatically for layer thicknesses above 1.5 nm.

  10. Peeling Back the Layers (United States)


    NASA's Mars Exploration Rover Spirit took this panoramic camera image of the rock target named 'Mazatzal' on sol 77 (March 22, 2004). It is a close-up look at the rock face and the targets that will be brushed and ground by the rock abrasion tool in upcoming sols. Mazatzal, like most rocks on Earth and Mars, has layers of material near its surface that provide clues about the history of the rock. Scientists believe that the top layer of Mazatzal is actually a coating of dust and possibly even salts. Under this light coating may be a more solid portion of the rock that has been chemically altered by weathering. Past this layer is the unaltered rock, which may give scientists the best information about how Mazatzal was formed. Because each layer reveals information about the formation and subsequent history of Mazatzal, it is important that scientists get a look at each of them. For this reason, they have developed a multi-part strategy to use the rock abrasion tool to systematically peel back Mazatzal's layers and analyze what's underneath with the rover's microscopic imager, and its Moessbauer and alpha particle X-ray spectrometers. The strategy began on sol 77 when scientists used the microscopic imager to get a closer look at targets on Mazatzal named 'New York,' 'Illinois' and 'Arizona.' These rock areas were targeted because they posed the best opportunity for successfully using the rock abrasion tool; Arizona also allowed for a close-up look at a range of tones. On sol 78, Spirit's rock abrasion tool will do a light brushing on the Illinois target to preserve some of the surface layers. Then, a brushing of the New York target should remove the top coating of any dust and salts and perhaps reveal the chemically altered rock underneath. Finally, on sol 79, the rock abrasion tool will be commanded to grind into the New York target, which will give scientists the best chance of observing Mazatzal's interior. The Mazatzal targets were named after the home states of

  11. Níveis de fósforo disponível e tamanho de partícula do fosfato bicálcico na dieta de poedeiras comerciais de 24 a 58 semanas de idade Levels of the available phosphorus and particle size of dicalcium phosphate in brown egg layer hens diet from 24 to 58 weeks of age

    Directory of Open Access Journals (Sweden)

    Lúcio Francelino Araújo


    Full Text Available Um experimento foi conduzido para verificar o efeito de níveis de fósforo e do tamanho de partícula do fosfato bicálcico na dieta de poedeiras comerciais na fase de produção. Utilizou-se um delineamento experimental inteiramente casualizado, em esquema fatorial 2 × 3 com dois tamanhos de partícula do fosfato (fino e granulado e três níveis de fósforo disponível (0,28; 0,38 e 0,48%, totalizando seis tratamentos, cada um com cinco repetições de oito aves. As dietas experimentais foram isoproteicas, isocalóricas e isocálcicas. O consumo de ração, a produção de ovos, a massa de ovos, a conversão alimentar, a porcentagem de casca, a gravidade específica e os teores de cinzas, cálcio, fósforo e magnésio nos ossos não foram afetados pelas dietas. Dietas contendo fosfato bicálcico (fino ou granulado e 0,28% de fósforo disponível atendem às exigências de fósforo de galinhas poedeiras semipesadas de 24 a 58 semanas de idade.An experiment was carried out to verify the effect of levels of phosphorus and the particle size of dicalcium phosphate on diets for brown egg layer hens during production phase. A complete randomized experimental design as a 2 × 3 factorial arrangement, with two sizes of particles of phosphate (fine and granulate and three levels of available phosphorus (0.28, 0.38 and 0.48%, totalizing six treatements with five replications of eight birds each, was used. The experimental diets were isoproteic, isocaloric, and isocalcium. Feed intake, egg production, egg mass, feed conversion, shell percentage, egg specific gravity, ash, calcium, phosphorus and magnesium levels in the bones were not affected by the diets. Diets with dicalcium phosphate (fine or granulated and 0.28% available phosphorus level meet the phosphorus requirements in brown egg layer hens from 24 to 58 weeks of age.

  12. Fusion Utility in the Knudsen Layer

    Energy Technology Data Exchange (ETDEWEB)

    Davidovits, Seth [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Fisch, Nathaniel J. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)


    In inertial confi nement fusion, the loss of fast ions from the edge of the fusing hot-spot region reduces the reactivity below its Maxwellian value. The loss of fast ions may be pronounced because of the long mean free paths of fast ions, compared to those of thermal ions. We introduce a fusion utility function to demonstrate essential features of this Knudsen layer e ffect, in both magnetized and unmagnetized cases. The fusion utility concept is also used to evaluate restoring the reactivity in the Knudsen layer by manipulating fast ions in phase space using waves.

  13. Analytic prediction for planar turbulent boundary layers

    CERN Document Server

    Chen, Xi


    Analytic predictions of mean velocity profile (MVP) and streamwise ($x$) development of related integral quantities are presented for flows in channel and turbulent boundary layer (TBL), based on a symmetry analysis of eddy length and total stress. Specific predictions are the friction velocity $u_\\tau$: ${ U_e/u_\\tau }\\approx 2.22\\ln Re_x+2.86-3.83\\ln(\\ln Re_x)$; the boundary layer thickness $\\delta_e$: $x/\\delta_e \\approx 7.27\\ln Re_x-5.18-12.52\\ln(\\ln Re_x)$; the momentum thickness Reynolds number: $Re_x/Re_\\theta=4.94[{(\\ln {{\\mathop{\\rm Re}\


    Directory of Open Access Journals (Sweden)



    Full Text Available El queso de capa es un queso de pasta filata producido artesanalmente en Colombia. Se describió el proceso de producción artesanal y de tecnificación, así como también se realizaron análisis fisicoquímicos y microbiológicos. Los resultados microbiológicos mostraron que la carga de hongos del queso artesanal está por encima de los valores recomendados por las normas colombianas. El queso de capa tecnificado presentó un mayores porcentaje de sólidos totales y rendimiento que el artesanal, además presenta mejor calidad y propiedades organolépticas.A camada de queijo é um queijo produzido por mão na filata Colômbia. Ele descreveu o processo da produção artesanal de produtos químicos e tecnológicos, bem como condução e análisis microbiológica. Os resultados microbiológicos mostraram que a carga fúngica de queijo artesanal está ácima dos valores recomendados pelas normas da Colômbia. A camada de queijo-tecnificado apresentaram maior percentual de sólidos totais e retorno da nave também tem melhor qualidade e propriedades organolépticas.Layer Cheese is an artisanal-made typical Colombian "pasta filata" variety of cheese. This article describes the process of craft production and manufacturing. It was performed physicochemical and microbiological analysis. Results shown that the fungal load ofartisanal cheese is above the valúes recommended by Colombian standards. Manufacturated Layer cheese presented a higher percentage of total solids and the yield of artisanal cheese has better quality and organoleptic properties.

  15. Crack layer theory (United States)

    Chudnovsky, A.


    A damage parameter is introduced in addition to conventional parameters of continuum mechanics and consider a crack surrounded by an array of microdefects within the continuum mechanics framework. A system consisting of the main crack and surrounding damage is called crack layer (CL). Crack layer propagation is an irreversible process. The general framework of the thermodynamics of irreversible processes are employed to identify the driving forces (causes) and to derive the constitutive equation of CL propagation, that is, the relationship between the rates of the crack growth and damage dissemination from one side and the conjugated thermodynamic forces from another. The proposed law of CL propagation is in good agreement with the experimental data on fatigue CL propagation in various materials. The theory also elaborates material toughness characterization.

  16. Layered bismuth vanadate ferroelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Osipyan, V.G.; Savchenko, L.M.; Elbakyan, V.L.; Avakyan, P.B.


    The authors synthesize new layered bismuth vanadate ferroelectrics. The x-ray diffraction characteristics of Bi/sub 2/VO/sub 5.5/ are shown. Thermal expansion of ceramics with various compositions are presented, as are the temperature dependences of the dielectric constant of the ceramic with various compositions. Unit-cell parameters, Curie temperature, electrical conductivity and the dielectric characteristics of the compositions studied are shown.


    NARCIS (Netherlands)



    Misfit layer chalcogenides (MX)(1+x)(TX(2))(m) (M=Sn, Pb, Sb, Bi, rare earth; T=Ti, V, Cr, Nb, Ta; X=S, Se; 0.08

  18. Physical Layer Network Coding

    DEFF Research Database (Denmark)

    Fukui, Hironori; Yomo, Hironori; Popovski, Petar


    Physical layer network coding (PLNC) has the potential to improve throughput of multi-hop networks. However, most of the works are focused on the simple, three-node model with two-way relaying, not taking into account the fact that there can be other neighboring nodes that can cause/receive inter......Physical layer network coding (PLNC) has the potential to improve throughput of multi-hop networks. However, most of the works are focused on the simple, three-node model with two-way relaying, not taking into account the fact that there can be other neighboring nodes that can cause....../receive interference. The way to deal with this problem in distributed wireless networks is usage of MAC-layer mechanisms that make a spatial reservation of the shared wireless medium, similar to the well-known RTS/CTS in IEEE 802.11 wireless networks. In this paper, we investigate two-way relaying in presence...

  19. Multifunctional layered magnetic composites

    Directory of Open Access Journals (Sweden)

    Maria Siglreitmeier


    Full Text Available A fabrication method of a multifunctional hybrid material is achieved by using the insoluble organic nacre matrix of the Haliotis laevigata shell infiltrated with gelatin as a confined reaction environment. Inside this organic scaffold magnetite nanoparticles (MNPs are synthesized. The amount of MNPs can be controlled through the synthesis protocol therefore mineral loadings starting from 15 wt % up to 65 wt % can be realized. The demineralized organic nacre matrix is characterized by small-angle and very-small-angle neutron scattering (SANS and VSANS showing an unchanged organic matrix structure after demineralization compared to the original mineralized nacre reference. Light microscopy and confocal laser scanning microscopy studies of stained samples show the presence of insoluble proteins at the chitin surface but not between the chitin layers. Successful and homogeneous gelatin infiltration in between the chitin layers can be shown. The hybrid material is characterized by TEM and shows a layered structure filled with MNPs with a size of around 10 nm. Magnetic analysis of the material demonstrates superparamagnetic behavior as characteristic for the particle size. Simulation studies show the potential of collagen and chitin to act as nucleators, where there is a slight preference of chitin over collagen as a nucleator for magnetite. Colloidal-probe AFM measurements demonstrate that introduction of a ferrogel into the chitin matrix leads to a certain increase in the stiffness of the composite material.

  20. Behaviour of the Sm-Nd and Rb-Sr systems of the mafic-ultramafic layered sequence from Ribeirao dos Motas (Archaean), meridional craton Sao Francisco: evidences of mantle source enrichment and isotopic fractionation; Comportamento dos sistemas Sm-Nd e Rb-Sr da sequencia acamadada mafico-ultramafico Ribeirao dos Motas (Arqueano), craton Sao Francisco Meridional: evidencias de enriquecimento mantelico e fracionamento isotopico

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Mauricio Antonio; Carvalho Junior, Irneu Mendes de; Oliveira, Arildo Henrique de [Ouro Preto Univ., (UFOP), MG (Brazil). Dept. de Geologia]. E-mail:; Teixeira, Wilson [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias. Dept. de Mineralogia e Geotectonica; Pimentel, Marcio Martins [Brasilia Univ., DF (Brazil). Inst. de Geociencias. Lab. de Geocronologia


    The Ribeirao dos Motas layered sequence (SARM) crops out in the southern part of the Sao Francisco Craton, Brazil. This sequence comprises phaneritic meta ultramafic and metamafic rocks, which, although slightly deformed and metamorphosed, retain primary igneous layers. Porphyritic rocks with idiomorphic pyroxene crystals and heteradcumulate and adcumulate textures are also present. Eighteen isotopic analyses were performed in the SARM, comprising rocks with primary (relict) textures, as well as rocks in amphibolite facies and retro-metamorphosed to green-schist facies. Seven samples yield a Sm/Nd isochron age of 2.79 +- 0.30 Ga (MSWD=1.2 e epsilon {sub Ndt}=+0.48), constraining the accretion time of the SARM rocks. The positive epsilon {sub Ndt} value coupled with the Rb/Sr evidence is consistent with mantle source relatively enriched in Nd and Sr isotopes. Nevertheless, some SARM samples display isotopic fractionation and disturbance, which can be ascribed to the following processes or their combinations: a) mobilization of the incompatible elements due to regional high grade metamorphism; b) isotopic changes during upper amphibolite facies overprint; c) isotopic resetting by low-grade fluids associated to the Claudio Shear zone, which is located nearby the SARM. (author)

  1. S-layers as patterning structures and supporting layers for biomimetic membranes (United States)

    Pum, Dietmar; Wetzer, Barbara; Schuster, Bernhard; Sleytr, Uwe B.


    A new approach in nanostructure technology particularly in the functionalization of surfaces has been developed on the basis of crystalline bacterial cell surface layers (S- layers). S-layers are composed of monomolecular arrays of identical (glyco)proteins showing high molecular order, defined mass distribution and isoporosity, and a high binding capacity for functional macromolecules. The possibility for recrystallizing isolated S-layer subunits into large isoporous, coherent lattices at solid supports, at the air/water interface or on lipid films and for handling such layers by standard Langmuir-Blodgett techniques opens a broad spectrum of applications in basic and applied membrane research. S-layer supported functional phospholipid bilayers or tetraether lipid films mimic the molecular architecture of those archaebacterial cell envelopes that are exclusively composed of an S-layer and a plasma membrane. This novel concept could lead to new techniques for exploiting large scale structural and functional principles of membrane associated and integrated molecules (e.g. ion channels, proton pumps, receptors).

  2. Intercalation compounds involving inorganic layered structures

    Directory of Open Access Journals (Sweden)



    Full Text Available Two-dimensional inorganic networks can shown intracrystalline reactivity, i.e., simple ions, large species as Keggin ions, organic species, coordination compounds or organometallics can be incorporated in the interlayer region. The host-guest interaction usually causes changes in their chemical, catalytic, electronic and optical properties. The isolation of materials with interesting properties and making use of soft chemistry routes have given rise the possibility of industrial and technological applications of these compounds. We have been using several synthetic approaches to intercalate porphyrins and phthalocyanines into inorganic materials: smectite clays, layered double hydroxides and layered niobates. The isolated materials have been characterized by elemental and thermal analysis, X-ray diffraction, surface area measurements, scanning electronic microscopy, electronic and resonance Raman spectroscopies and EPR. The degree of layer stacking and the charge density of the matrices as well their acid-base nature were considered in our studies on the interaction between the macrocycles and inorganic hosts.

  3. Polyethylene oxide hydration in grafted layers (United States)

    Dormidontova, Elena; Wang, Zilu

    Hydration of water soluble polymers is one of the key-factors defining their conformation and properties, similar to biopolymers. Polyethylene oxide (PEO) is one of the most important biomedical-applications polymers and is known for its reverse temperature solubility due to hydrogen bonding with water. As in many practical applications PEO chains are grafted to surfaces, e.g. of nanoparticles or planar surfaces, it is important to understand PEO hydration in such grafted layers. Using atomistic molecular dynamic simulations we investigate the details of molecular conformation and hydration of PEO end-grafted to gold surfaces. We analyze polymer and water density distribution as a function of distance from the surface for different grafting densities. Based on a detailed analysis of hydrogen bonding between polymer and water in grafted PEO layers, we will discuss the extent of PEO hydration and its implication for polymer conformation, mobility and layer properties. This research is supported by NSF (DMR-1410928).

  4. Robust multiculturality emerges from layered social influence

    CERN Document Server

    Battiston, Federico; Latora, Vito; Miguel, Maxi San


    Why is our society multicultural? Based on the two mechanisms of homophily and social influence, the classical model for the dissemination of cultures proposed by Axelrod predicts the existence of a fragmented regime where different cultures can coexist in a social network. However, in such model the multicultural regime is achievable only when a high number of cultural traits is present, and is not robust against cultural drift, i.e. the spontaneous mutations of agents' traits. In real systems, social influence is inherently organised in layers, meaning that individuals tend to diversify their connections according to the topic on which they interact. In this work we show that the observed persistence of multiculturality in real-world social systems is a natural consequence of the layered organisation of social influence. We find that the critical number of cultural traits that separates the monocultural and the multicultural regimes depends on the redundancy of pairwise connections across layers. Surprising...

  5. Stochastic seismic response of multi-layered soil with random layer heights (United States)

    Badaoui, M.; Berrah, M. K.; Mébarki, A.


    This paper deals with the effect of layer height randomness on the seismic response of a layered soil. These parameters are assumed to be lognormal random variables. The analysis is carried out via Monte Carlo simulations coupled with the stiffness matrix method. A parametric study is conducted to derive the stochastic behavior of the peak ground acceleration and its response spectrum, the transfer function and the amplification factors. The input soil characteristics correspond to a site in Mexico City and the input seismic accelerations correspond to the Loma Prieta earthquake. It is found that the layer height heterogeneity causes a widening of the frequency content and a slight increase in the fundamental frequency of the soil profile, indicating that the resonance phenomenon is a concern for a large number of structures. Variation of the layer height randomness acts as a variation of the incident angle, i.e., a decrease of the amplitude and a shift of the resonant frequencies.

  6. Bandgap Restructuring of the Layered Semiconductor Gallium Telluride in Air. (United States)

    Fonseca, Jose J; Tongay, Sefaattin; Topsakal, Mehmet; Chew, Annabel R; Lin, Alan J; Ko, Changhyun; Luce, Alexander V; Salleo, Alberto; Wu, Junqiao; Dubon, Oscar D


    A giant bandgap reduction in layered GaTe is demonstrated. Chemisorption of oxygen to the Te-terminated surfaces produces significant restructuring of the conduction band resulting in a bandgap below 0.8 eV, compared to 1.65 eV for pristine GaTe. Localized partial recovery of the pristine gap is achieved by thermal annealing, demonstrating that reversible band engineering in layered semiconductors is accessible through their surfaces.

  7. Modern Thin-Layer Chromatography. (United States)

    Poole, Colin F.; Poole, Salwa K.


    Some of the important modern developments of thin-layer chromatography are introduced. Discussed are the theory and instrumentation of thin-layer chromatography including multidimensional and multimodal techniques. Lists 53 references. (CW)

  8. Modern Thin-Layer Chromatography. (United States)

    Poole, Colin F.; Poole, Salwa K.


    Some of the important modern developments of thin-layer chromatography are introduced. Discussed are the theory and instrumentation of thin-layer chromatography including multidimensional and multimodal techniques. Lists 53 references. (CW)

  9. Diversity in S-layers. (United States)

    Zhu, Chaohua; Guo, Gang; Ma, Qiqi; Zhang, Fengjuan; Ma, Funing; Liu, Jianping; Xiao, Dao; Yang, Xiaolin; Sun, Ming


    Surface layers, referred simply as S-layers, are the two-dimensional crystalline arrays of protein or glycoprotein subunits on cell surface. They are one of the most common outermost envelope components observed in prokaryotic organisms (Archaea and Bacteria). Over the past decades, S-layers have become an issue of increasing interest due to their ubiquitousness, special features and functions. Substantial work in this field provides evidences of an enormous diversity in S-layers. This paper reviews and illustrates the diversity from several different aspects, involving the S-layer-carrying strains, the structure of S-layers, the S-layer proteins and genes, as well as the functions of S-layers.

  10. Single ferromagnetic layer magnetic random access memory (United States)

    Xing, M.-J.; Jalil, M. B. A.; Ghee Tan, Seng; Jiang, Y.


    We propose a magnetic random access memory (MRAM) device in which both the writing and reading processes are realized within a single ferromagnetic (FM) layer. The FM layer is sandwiched between layers of heavy element and oxide to enhance the Rashba spin-orbit coupling (RSOC). When the in-plane FM moments are oriented at some intermediate angle to the current direction, the RSOC effect induces a spin accumulation in the FM layer, which in turn generates a Rashba spin torque field via the s-d exchange interaction. This field acts as the writing field of the memory device. The RSOC also induces a charge accumulation in the transverse direction via the inverse spin Hall effect (ISHE), which can be used to realize the memory read-out. The writing and read-out processes of the proposed memory are modeled numerically via the non-equilibrium Green's function technique. Besides the advantages of Rashba spin torque writing, i.e., no spin injection and symmetrical data-writing process, this single FM layer MRAM design does away with having a giant magnetoresistive or magnetic tunnel junction multilayer structure by utilizing the ISHE for the read-out process.

  11. Basis reduction for layered lattices

    NARCIS (Netherlands)

    Torreão Dassen, Erwin


    We develop the theory of layered Euclidean spaces and layered lattices. We present algorithms to compute both Gram-Schmidt and reduced bases in this generalized setting. A layered lattice can be seen as lattices where certain directions have infinite weight. It can also be interpre

  12. S-Layer-Based Nanocomposites for Industrial Applications. (United States)

    Raff, Johannes; Matys, Sabine; Suhr, Matthias; Vogel, Manja; Günther, Tobias; Pollmann, Katrin

    This chapter covers the fundamental aspects of bacterial S-layers: what are S-layers, what is known about them, and what are their main features that makes them so interesting for the production of nanostructures. After a detailed introduction of the paracrystalline protein lattices formed by S-layer systems in nature the chapter explores the engineering of S-layer-based materials. How can S-layers be used to produce "industry-ready" nanoscale bio-composite materials, and which kinds of nanomaterials are possible (e.g., nanoparticle synthesis, nanoparticle immobilization, and multifunctional coatings)? What are the advantages and disadvantages of S-layer-based composite materials? Finally, the chapter highlights the potential of these innovative bacterial biomolecules for future technologies in the fields of metal filtration, catalysis, and bio-functionalization.

  13. A method for the densification of ceramic layers, especially ceramic layers within solid oxide cell (SOC) technology, and products obtained by the method

    DEFF Research Database (Denmark)


    A ceramic layer, especially for use in solid oxide cell (SOC) technology, is densified in a method comprising (a) providing a multilayer system by depositing the porous ceramic layer, which is to be densified, onto the selected system of ceramic layers on a support, (b) pre-sintering the resulting......(s) in the porous layer surface and (e) performing a thermal treatment at a temperature T2, where T2 > ?1, to obtain densification of and grain growth in the porous layer formed in step (b). The method makes it possible to obtain dense ceramic layers at temperatures, which are compatible with the other materials...... present in a ceramic multilayer system....

  14. The Boundary Layer Radiometer (United States)

    Irshad, Ranah; Bowles, N. E.; Calcutt, S. B.; Hurley, J.


    The Boundary Layer Radiometer is a small, low mass (<1kg) radiometer with only a single moving part - a scan/calibration mirror. The instrument consists of a three mirror telescope system incorporating an intermediate focus for use with miniature infrared and visible filters. It also has an integrated low power blackbody calibration target to provide long-term calibration stability The instrument may be used as an upward looking boundary layer radiometer for both the terrestrial and Martian atmospheres with appropriate filters for the mid-infrared carbon dioxide band, as well as a visible channel for the detection of aerosol components such as dust. The scan mirror may be used to step through different positions from the local horizon to the zenith, allowing the vertical temperature profile of the atmosphere to be retrieved. The radiometer uses miniature infrared filter assemblies developed for previous space-based instruments by Oxford, Cardiff and Reading Universities. The intermediate focus allows for the use of upstream blocking filters and baffles, which not only simplifies the design of the filters and focal plane assembly, but also reduces the risk of problems due to stray light. Combined with the calibration target this means it has significant advantages over previous generations of small radiometers.

  15. Thin layer chromatography. (United States)

    Santiago, Marina; Strobel, Scott


    In many experiments, it is important to be able to separate a mixture into its chemical components in order to isolate one compound or to assess the purity of the mixture. Thin layer chromatography (TLC) is one of the easiest and most versatile methods of doing this because of its low cost, simplicity, quick development time, high sensitivity, and good reproducibility. TLC is used by many industries and fields of research, including pharmaceutical production, clinical analysis, industrial chemistry, environmental toxicology, food chemistry, water, inorganic, and pesticide analysis, dye purity, cosmetics, plant materials, and herbal analysis. In its simplest form, glass plates are coated with a uniform layer of silica gel (SiO2). The dissolved sample is placed on the plate, and the plate is inserted into a screw-top jar containing the developing solvent and a piece of filter paper. When the solvent has risen to near the top of the plate, the plate is removed, dried, and visualized using UV light. Variations on this protocol are used for different purposes, including pretreating the sample, changing the sorbent, plate material, the solvent system, the development techniques, and method of detection and visualization or by coupling TLC to other techniques. © 2013 Elsevier Inc. All rights reserved.

  16. Multiresonant layered plasmonic films

    Energy Technology Data Exchange (ETDEWEB)

    DeVetter, Brent M. [Pacific Northwest National Laboratory, Richland, Washington, United States; Bernacki, Bruce E. [Pacific Northwest National Laboratory, Richland, Washington, United States; Bennett, Wendy D. [Pacific Northwest National Laboratory, Richland, Washington, United States; Schemer-Kohrn, Alan [Pacific Northwest National Laboratory, Richland, Washington, United States; Alvine, Kyle J. [Pacific Northwest National Laboratory, Richland, Washington, United States


    Multi-resonant nanoplasmonic films have numerous applications in areas such as nonlinear optics, sensing, and tamper indication. While techniques such as focused ion beam milling and electron beam lithography can produce high-quality multi-resonant films, these techniques are expensive, serial processes that are difficult to scale at the manufacturing level. Here, we present the fabrication of multi-resonant nanoplasmonic films using a layered stacking technique. Periodically-spaced gold nanocup substrates were fabricated using self-assembled polystyrene nanospheres followed by oxygen plasma etching and metal deposition via magnetron sputter coating. By adjusting etch parameters and initial nanosphere size, it was possible to achieve an optical response ranging from the visible to the near-infrared. Singly resonant, flexible films were first made by performing peel-off using an adhesive-coated polyolefin film. Through stacking layers of the nanofilm, we demonstrate fabrication of multi-resonant films at a fraction of the cost and effort as compared to top-down lithographic techniques.

  17. Layered kagome spin ice (United States)

    Hamp, James; Dutton, Sian; Mourigal, Martin; Mukherjee, Paromita; Paddison, Joseph; Ong, Harapan; Castelnovo, Claudio

    Spin ice materials provide a rare instance of emergent gauge symmetry and fractionalisation in three dimensions: the effective degrees of freedom of the system are emergent magnetic monopoles, and the extensively many `ice rule' ground states are those devoid of monopole excitations. Two-dimensional (kagome) analogues of spin ice have also been shown to display a similarly rich behaviour. In kagome ice however the ground-state `ice rule' condition implies the presence everywhere of magnetic charges. As temperature is lowered, an Ising transition occurs to a charge-ordered state, which can be mapped to a dimer covering of the dual honeycomb lattice. A second transition, of Kosterlitz-Thouless or three-state Potts type, occurs to a spin-ordered state at yet lower temperatures, due to small residual energy differences between charge-ordered states. Inspired by recent experimental capabilities in growing spin ice samples with selective (layered) substitution of non-magnetic ions, in this work we investigate the fate of the two ordering transitions when individual kagome layers are brought together to form a three-dimensional pyrochlore structure coupled by long range dipolar interactions. We also consider the response to substitutional disorder and applied magnetic fields.

  18. Characterization and use of crystalline bacterial cell surface layers (United States)

    Sleytr, Uwe B.; Sára, Margit; Pum, Dietmar; Schuster, Bernhard


    Crystalline bacterial cell surface layers (S-layers) are one of the most common outermost cell envelope components of prokaryotic organisms (archaea and bacteria). S-layers are monomolecular arrays composed of a single protein or glycoprotein species and represent the simplest biological membranes developed during evolution. S-layers as the most abundant of prokaryotic cellular proteins are appealing model systems for studying the structure, synthesis, genetics, assembly and function of proteinaceous supramolecular structures. The wealth of information existing on the general principle of S-layers have revealed a broad application potential. The most relevant features exploited in applied S-layer research are: (i) pores passing through S-layers show identical size and morphology and are in the range of ultrafiltration membranes; (ii) functional groups on the surface and in the pores are aligned in well-defined positions and orientations and accessible for chemical modifications and binding functional molecules in very precise fashion; (iii) isolated S-layer subunits from a variety of organisms are capable of recrystallizing as closed monolayers onto solid supports (e.g., metals, polymers, silicon wafers) at the air-water interface, on lipid films or onto the surface of liposomes; (iv) functional domains can be incorporated in S-layer proteins by genetic engineering. Thus, S-layer technologies particularly provide new approaches for biotechnology, biomimetics, molecular nanotechnology, nanopatterning of surfaces and formation of ordered arrays of metal clusters or nanoparticles as required for nanoelectronics.

  19. Analysis of turbulent boundary layers

    CERN Document Server

    Cebeci, Tuncer


    Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculati

  20. The Adobe Photoshop layers book

    CERN Document Server

    Lynch, Richard


    Layers are the building blocks for working in Photoshop. With the correct use of the Layers Tool, you can edit individual components of your images nondestructively to ensure that your end result is a combination of the best parts of your work. Despite how important it is for successful Photoshop work, the Layers Tool is one of the most often misused and misunderstood features within this powerful software program. This book will show you absolutely everything you need to know to work with layers, including how to use masks, blending, modes and layer management. You'll learn professional tech

  1. Metal deposition using seed layers (United States)

    Feng, Hsein-Ping; Chen, Gang; Bo, Yu; Ren, Zhifeng; Chen, Shuo; Poudel, Bed


    Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

  2. Comparação das técnicas de cromatografia em camada delgada e ELISA na quantificação de aflatoxinas em amostras de milho Comparison of thin layer chromatography and ELISA techniques in the quantification of aflatoxins in corn samples

    Directory of Open Access Journals (Sweden)

    Marize Silva OLIVEIRA


    Full Text Available A comparação das técnicas de Enzyme Linked Immunosorbent Assay (ELISA e cromatografia em camada delgada (CCD por quantificação visual e densitométrica foi utilizada na determinação de aflatoxina total, em amostras de milho naturalmente contaminadas. Os teores de aflatoxina total encontrados pelas técnicas de CCD e ELISA, apresentaram maior freqüência na faixa de 0-30 mig/kg e acima de 300 mig/kg. Os resultados das amostras apresentaram coeficiente de variação concentrados abaixo de 20, 30 e 40% para a técnica de ELISA e CCD com quantificação densitométrica e visual, respectivamente. Os coeficientes de correlação foram altamente significativos para as relações entre as quantificações visual e densitométrica (r = 0,9219; t = 26,36; p Two methods, enzyme linked immunosorbent assay (ELISA and thin layer chromatography (TLC by visual and densitometric, were compared for determination of aflatoxins in corn samples. The highest incidence of total aflatoxin detected by those methods were ranged from 0-30 mug/kg and above 300 mug/kg. For aflatoxins B2, G1, G2 the levels were ranged from 0-30mug/kg. The samples results showed variation coefficient below of 20, 30 and 40% for ELISA and CCD with densitometric and visual quantification, respectively. The correlation coefficients were highly significative for the relation between visual quantification and densitometric (r = 0,9219; t = 28,36; p<0,001, ELISA and visual quantification (r =0,8277; t = 17,58; p< 0,001, ELISA e quantification densitometric (r = 0,7373; t=13,01; p< 0,001, in the total aflatoxin detemination of all corn samples. confirming the equivalence of the studied methods.

  3. 2007 Program of Study: Boundary Layers (United States)


    PM Coalescence of charged water droplets Andrew Belmonte, Pennsylvania State University August 9 - 10:30 AM Multiscale analysis of strongly...Properties of Helium Near the Liquid-Vapor Critical Point. J. low Temp. Phys. 46, 115-135. [15] Polezhaev, V. I. and Soboleva, E. B. 2004 Rayleigh...through which potassium permanganate was added in most of the experiments in order to detect a possible appearance of boundary layer separation and

  4. 用于皮肤组织抗氧化的维生素E醇质体的研制与表征%Study on Preparation and Characterization of Vitamine E Ethosomes for Antioxidant Protection of Deeper Layers of Skin

    Institute of Scientific and Technical Information of China (English)

    刘利萍; 唐春红


    目的 制备能渗透到皮肤深层的维生素E(VE)醇质体制剂.方法 VE含量测定采用高效液相色谱法;VE醇质体制备采用注入法并结合L9(34)正交实验优化处方参数;用挤压法和Franz扩散法分别测定醇质体的变形性和在大鼠皮内的滞留量.结果 以Sinochrom ODS-BP(4.6 mm ×200 mm,5μm)为色之谱柱、甲醇-乙醚溶液(7:3)为流动相、流速1.0 mL·min-1、检测波长284nm、进样量20μL,辅料不干抚VE测定,VE在2.584~192.2μg·mL-1线性关系良好;VE醇质体的优化处方为:卵磷脂1.5%、乙醇30%、药/磷脂比1:10,得到VE包封率为(96.25±0.07)%、平均粒径167.58nm、跨距0.4的VE醇质体;VE醇质体在不同压力下的变形性是对应脂质体的3.5~6.4倍,渗透到真皮层中的含量是脂质体的11.95倍.结论 醇质体载体能有效地促进VE在真皮层中的分布,更好地保护皮肤.%OBJECTIVE To study the preparation of vitamin E (VE) ethosomes which can penetrate into deep skin. METHODS The amount of VE was assayed by HPLC. Sinochrom ODS-BP column(4.6 mm ×200 mm,5 μm)was used. VE was eluted using methanol-ether (7: 3) as mobile phase at a flow rate of 1.0 mL · min -1. The detection was carried out at 284 nm. To study the effect of variables on the encapsulation efficiency of ethosome, different batches of samples were prepared using injection method with L9 (3)4 orthogonal design. The deformability of ethosomes was determined by extrusion method. The deposition in skin was investigated on excised rat's skin with Franz diffusion cells. RESULTS The standard curve was linear over the range of 2. 584 - 192. 2 μg·mL-1. The optimized formula was as follows:lecithin 1.5%, drug/lecithin 1/10(mass/mass) and ethanol 30%. The encapsulation efficiency was (96. 25 ± 0. 071 ) %, and the mean size was 167. 58 nm with span of O. 4. The deformability of ethosomes was 3. 5 -6.4 times higher than that of liposomes under different extruding pressures. And the dermal

  5. The multiple layer solar collector (United States)

    Kenna, J. P.


    An analytical model is developed for obtaining numerical solutions for differential equations describing the performance of separate layers in a multiple layer solar collector. The configurations comprises heat transfer fluid entering at the top of the collector and travelling down through several layers. A black absorber plate prevents reemission of thermal radiation. The overall performance is shown to depend on the number of layers, the heat transfer coefficient across each layer, and the absorption properties of the working fluid. It is found that the multiple layer system has a performance inferior to that of flat plate selective surface collectors. Air gaps insulating adjacent layers do not raise the efficiency enough to overcome the relative deficiency.

  6. Dureza e resistência ao desgaste da camada de ZrN formada por nitretação a plasma sobre zircônia parcialmente estabilizada com ítria Hardness and wear resistance of the ZrN layer made by plasma nitriding of yttria partially-stabilized zirconia

    Directory of Open Access Journals (Sweden)

    R. Milani


    Full Text Available Corpos-de-prova de zircônia parcialmente estabilizada com ítria foram moldados por prensagem uniaxial, sinterizados e nitretados em plasma de micro-ondas à pressão atmosférica. A camada de ZrN sobre zircônia formou-se a uma taxa de 4 µm.min-1, podendo atingir uma espessura de 500 µm. As amostras foram caracterizadas por meio de medidas de dureza e resistência ao desgaste. A superfície nitretada apresentou dureza superior e resistência ao desgaste similar ao substrato de zircônia.Samples of yttria partially-stabilized zirconia were molded by uniaxial pressing, sintered and nitrided in an atmospheric pressure microwave plasma. This procedure leads to the formation of a ZrN layer whose growth rate and thickness reached 4 µm.min-1 and 500 µm, respectively. The samples were characterized by means of hardness and wear resistance tests. The nitrided surface exhibits superior hardness and wear resistance similar to that of the zirconia substrate.

  7. The Application of"Four-layer and Six-step"Segmented Recycling Method in Information-based Teaching:Take the Course of POR/E as an Example%"四层六步"分段循环式翻转教学法在信息化教学中的应用——以《POR/E》课程为例

    Institute of Scientific and Technical Information of China (English)



    Information-based teaching is a new type of teaching method developed rapidly in recent years. This paper carries out information-based teaching design for the course of POR/E to optimize the course content and improve teaching efficiency. The "four-layer and six-step" segmented recycling flipped teaching method has some referential significance for the information-based teaching of other courses.%信息化教学是近几年快速发展的新型教学方式.本文通过对《POR/E》课程进行信息化教学设计,以优化课程内容,提高教学效率,课程中采用的"四层六步"分段循环式翻转教学法对其他课程的信息化教学也有一定的借鉴作用.

  8. Alterações morfométricas da musculatura dos músculos longitudinal e circular de ratos submetidos à criação de piloros no intestino delgado Morfometric alterations of the longitudinal and circular muscle layers in rats who underwent pylorus construction in the small bowel

    Directory of Open Access Journals (Sweden)

    Cícero de Lima Rena


    Full Text Available OBJETIVO: Realizar um estudo morfométrico comparativo da musculatura longitudinal e circular do intestino delgado de ratos submetidos à construção cirúrgica de um e de dois piloros no intestino delgado utilizando-se da técnica de criação de piloros proposta por Rena et al. MÉTODO: Foram utilizados 52 ratos Wistar machos divididos em três grupos. O Grupo A, destacado como controle, composto de 10 animas, cada um forneceu 20mm de segmento de intestino para o estudo. Os animais do Grupo B, composto de 32 animais, foram submetidos à construção de dois piloros, um a 100mm e outro a 150mm da válvula ileocecal e os animais do grupo C, composto de 10 animais, foram submetidos à construção de um piloro a 100mm da mesma. A eutanásia ocorreu no décimo dia. A morfometria das camadas musculares longitudinal e circular acima e abaixo dos piloros foi estudada com utilização do microscópico modelo "Axiostar plus" conectado à câmera "Axioncam Version 5.05.10" com objetiva X5 / 0,12 no o programa "AxioVision". RESULTADOS: As alças apresentaram aumento da espessura da camada muscular acima e abaixo do ponto da operação. O estudo morfométrico comparativo das camadas musculares longitudinal e circular mostrou aumento significativo em comparação ao controle, não demonstrando significância entre os grupos B e C. CONCLUSÃO: Os resultados deste estudo revelaram importante aumento de espessura das camadas musculares, porém, menos acentuados que aqueles descritos na literatura quando foram realizados em animais submetidos à estenose fixa. Esses dados indicam que a construção operatória de piloros pela técnica utilizada promove alterações musculares de menor monta, possivelmente, pela função valvular do piloro.BACKGROUND AND PURPOSE: To undertake a morphometric comparative study of the longitudinal and circular layers of the small bowel muscularis propria in rats, whom underwent surgical construction of one and two pylorus

  9. Finely tailored performance of inverted organic photovoltaics through layer-by-layer interfacial engineering. (United States)

    Chen, Qun; Worfolk, Brian J; Hauger, Tate C; Al-Atar, Usama; Harris, Kenneth D; Buriak, Jillian M


    Control over interfacial properties in organic photovoltaics (OPVs) is critical for many aspects of their performance. Functionalization of the transparent conducting electrode, in this case, indium tin oxide (ITO), through an electrostatic layer by layer (eLbL) approach with cationic N,N'-bis[2-(trimethylammonium)ethylene] perylene-3,4,9,10-tetracarboxyldiimide (PTCDI(+)) and anionic poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate) (PEDOT:PSS(-)), led to high control over the surface properties. The films were studied through a variety of surface and spectroscopic techniques, including X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy, atomic force microscopy (AFM), and ellipsometry. The work function of modified ITO was measured by UV photoelectron spectroscopy (UPS) and showed oscillating values with respect to odd-even layer numbers; the strong odd-even effect is due to the differing electronic characteristics of the top layer, either PTCDI(+) or PEDOT:PSS(-). The modified ITO electrodes were then used as the cathode in a series of inverted organic photovoltaic architectures. The performance of inverted OPVs was, in parallel to the UPS results, found to be highly dependent on the layer number of coated films and showed an obvious oscillation based on layer number. Inverted OPVs were retested after 128 days of storage in air, and almost all devices maintained over 70% of original power conversion efficiency (PCE). © 2011 American Chemical Society

  10. Gravitational instability of thin gas layer between two thick liquid layers (United States)

    Pimenova, A. V.; Goldobin, D. S.


    We consider the problem of gravitational instability (Rayleigh-Taylor instability) of a horizontal thin gas layer between two liquid half-spaces (or thick layers), where the light liquid overlies the heavy one. This study is motivated by the phenomenon of boiling at the surface of direct contact between two immiscible liquids, where the rate of the "break-away" of the vapor layer growing at the contact interface due to development of the Rayleigh-Taylor instability on the upper liquid-gas interface is of interest. The problem is solved analytically under the assumptions of inviscid liquids and viscous weightless vapor. These assumptions correspond well to the processes in real systems, e.g., they are relevant for the case of interfacial boiling in the system water- n-heptane. In order to verify the results, the limiting cases of infinitely thin and infinitely thick gas layers were considered, for which the results can be obviously deduced from the classical problem of the Rayleigh-Taylor instability. These limiting cases are completely identical to the well-studied cases of gravity waves at the liquidliquid and liquid-gas interfaces. When the horizontal extent of the system is long enough, the wavenumber of perturbations is not limited from below, and the system is always unstable. The wavelength of the most dangerous perturbations and the rate of their exponential growth are derived as a function of the layer thickness. The dependence of the exponential growth rate on the gas layer thickness is cubic.

  11. Hidróxidos duplos lamelares: nanopartículas inorgânicas para armazenamento e liberação de espécies de interesse biológico e terapêutico Layered double hydroxides: inorganic nanoparticles for storage and release of species of biological and therapeutic interest

    Directory of Open Access Journals (Sweden)

    Vanessa R. R. Cunha


    Full Text Available Studies about the inorganic nanoparticles applying for non-viral release of biological and therapeutic species have been intensified nowadays. This work reviews the preparation strategies and application of layered double hydroxides (LDH as carriers for storing, carrying and control delivery of intercalated species as drugs and DNA for gene therapy. LDH show low toxicity, biocompatibility, high anion exchange capacity, surface sites for functionalization, and a suitable equilibrium between chemical stability and biodegradability. LDH can increase the intercalated species stability and promote its sub-cellular uptake for biomedical purposes. Concerning the healthy field, LDH have been evaluated for clinical diagnosis as a biosensor component.

  12. Determinação de aflatoxina B1 em pimenta (Piper nigrum L. e orégano (Origanum vulgare L. por cromatografia em camada delgada e densitometria Determination of aflatoxin B1 (Piper nigrum L. and oregano (Origanum vulgare L. by thin-layer chromatography and densitometry

    Directory of Open Access Journals (Sweden)

    Guilherme Prado


    Full Text Available An analytical study based on extraction with methanol-water, immunoaffinity cleanup and separation, identification and quantification of aflatoxin B1 by thin-layer chromatography,in ground black and white pepper and oregano was carried out. Validation of the applied methodology was done through accuracy and precision studies. Recoveries of aflatoxin B1 and relative standard deviations, from spice samples spiked at levels from 4.86 to 97.70 µg/kg, were, respectively, higher than 72% and lower than 20%. Application to spice samples available in Minas Gerais state, purchased at popular markets, showed no contamination with aflatoxin B1.

  13. Aeolian transport layer. (United States)

    Almeida, Murilo P; Andrade, José S; Herrmann, Hans J


    We investigate the airborne transport of particles on a granular surface by the saltation mechanism through numerical simulation of particle motion coupled with turbulent flow. We determine the saturated flux q(s) and show that its behavior is consistent with classical empirical relations obtained from wind tunnel measurements. Our results also allow one to propose and explain a new relation valid for small fluxes, namely, q(s) = a(u*-u(t))alpha, where u* and u(t) are the shear and threshold velocities of the wind, respectively, and the scaling exponent is alpha approximately 2. We obtain an expression for the velocity profile of the wind distorted by the particle motion due to the feedback and discover a novel dynamical scaling relation. We also find a new expression for the dependence of the height of the saltation layer as a function of the wind velocity.

  14. The layers of subtitling

    Directory of Open Access Journals (Sweden)

    Elena Di Giovanni


    Full Text Available The study of subtitling, although widely practiced over the past 20 years, has generally been confined to comparative studies focusing on the product of subtitle translation, with little or no consideration of the conditions of creation and reception. Focusing on the process of subtitle production, occasional studies have touched upon the cognitive processes accompanying it, but no study so far has related these processes, and the resulting products, to various degrees of translators’ competence. This is precisely what this essay does, focusing on the different layers of subtitle translation provided for two different films and in two different contexts. By analysing the first and second versions of subtitle translations, we shall reflect on the acquisition, and application, of different subtitling competences.

  15. Transparent layer constancy. (United States)

    Faul, Franz; Ekroll, Vebjørn


    In transparency perception the visual system assigns transmission-related attributes to transparent layers. Based on a filter model of perceptual transparency we investigate to what extent these attributes remain constant across changes of background and illumination. On a computational level, we used computer simulations to test how constant the parameters of the filter model remain under realistic changes in background reflectances and illumination and found almost complete constancy. This contrasts with systematic deviations from constancy found in cross-context matches of transparent filters. We show that these deviations are of a very regular nature and can be understood as a compromise between a proximal match of the mean stimulus color and complete constancy as predicted by the filter model.

  16. Wireless physical layer security (United States)

    Poor, H. Vincent; Schaefer, Rafael F.


    Security in wireless networks has traditionally been considered to be an issue to be addressed separately from the physical radio transmission aspects of wireless systems. However, with the emergence of new networking architectures that are not amenable to traditional methods of secure communication such as data encryption, there has been an increase in interest in the potential of the physical properties of the radio channel itself to provide communications security. Information theory provides a natural framework for the study of this issue, and there has been considerable recent research devoted to using this framework to develop a greater understanding of the fundamental ability of the so-called physical layer to provide security in wireless networks. Moreover, this approach is also suggestive in many cases of coding techniques that can approach fundamental limits in practice and of techniques for other security tasks such as authentication. This paper provides an overview of these developments.

  17. Templated quasicrystalline molecular layers (United States)

    Smerdon, Joe; Young, Kirsty; Lowe, Michael; Hars, Sanger; Yadav, Thakur; Hesp, David; Dhanak, Vinod; Tsai, An-Pang; Sharma, Hem Raj; McGrath, Ronan


    Quasicrystals are materials with long range ordering but no periodicity. We report scanning tunneling microscopy (STM) observations of quasicrystalline molecular layers on five-fold quasicrystal surfaces. The molecules adopt positions and orientations on the surface consistent with the quasicrystalline ordering of the substrate. Carbon-60 adsorbs atop sufficiently-separated Fe atoms on icosahedral Al-Cu-Fe to form a unique quasicrystalline lattice whereas further C60 molecules decorate remaining surface Fe atoms in a quasi-degenerate fashion. Pentacene (Pn) adsorbs at tenfold-symmetric points around surface-bisected rhombic triacontahedral clusters in icosahedral Ag-In-Yb. These systems constitute the first demonstrations of quasicrystalline molecular ordering on a template. EPSRC EP/D05253X/1, EP/D071828/1, UK BIS.

  18. Ferroelectrics based absorbing layers (United States)

    Hao, Jianping; Sadaune, Véronique; Burgnies, Ludovic; Lippens, Didier


    We show that ferroelectrics-based periodic structure made of BaSrTiO3 (BST) cubes, arrayed onto a metal plate with a thin dielectric spacer film exhibit a dramatic enhancement of absorbance with value close to unity. The enhancement is found around the Mie magnetic resonance of the Ferroelectrics cubes with the backside metal layer stopping any transmitted waves. It also involves quasi-perfect impedance matching resulting in reflection suppression via simultaneous magnetic and electrical activities. In addition, it was shown numerically the existence of a periodicity optimum, which is explained from surface waves analysis along with trade-off between the resonance damping and the intrinsic loss of ferroelectrics cubes. An experimental verification in a hollow waveguide configuration with a good comparison with full-wave numerical modelling is at last reported by measuring the scattering parameters of single and dual BST cubes schemes pointing out coupling effects for densely packed structures.

  19. Ozone Layer Observations (United States)

    McPeters, Richard; Bhartia, P. K. (Technical Monitor)


    The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV and SAGE (Stratospheric Aerosol and Gas Experiment) instruments for example, show that the largest changes are occurring in the lower stratosphere and upper troposphere. The goal of ozone measurement in the next decades will be to document the predicted recovery of the ozone layer as CFC (chlorofluorocarbon) levels decline. This will require a continuation of global measurements of total column ozone on a global basis, but using data from successor instruments to TOMS. Hyperspectral instruments capable of measuring in the UV will be needed for this purpose. Establishing the relative roles of chemistry and dynamics will require instruments to measure ozone in the troposphere and in the stratosphere with good vertical resolution. Instruments that can measure other chemicals important to ozone formation and destruction will also be needed.

  20. The Plasmasphere Boundary Layer

    Directory of Open Access Journals (Sweden)

    D. L. Carpenter


    Full Text Available As an inner magnetospheric phenomenon the plasmapause region is of interest for a number of reasons, one being the occurrence there of geophysically important interactions between the plasmas of the hot plasma sheet and of the cool plasmasphere. There is a need for a conceptual framework within which to examine and discuss these interactions and their consequences, and we therefore suggest that the plasmapause region be called the Plasmasphere Boundary Layer, or PBL. Such a term has been slow to emerge because of the complexity and variability of the plasma populations that can exist near the plasmapause and because of the variety of criteria used to identify the plasmapause in experimental data. Furthermore, and quite importantly in our view, a substantial obstacle to the consideration of the plasmapause region as a boundary layer has been the longstanding tendency of textbooks on space physics to limit introductory material on the plasmapause phenomenon to zeroth order descriptions in terms of ideal MHD theory, thus implying that the plasmasphere is relatively well understood. A textbook may introduce the concept of shielding of the inner magnetosphere from perturbing convection electric fields, but attention is not usually paid to the variety of physical processes reported to occur in the PBL, such as heating, instabilities, and fast longitudinal flows, processes which must play roles in plasmasphere dynamics in concert with the flow regimes associated with the major dynamo sources of electric fields. We believe that through the use of the PBL concept in future textbook discussions of the plasmasphere and in scientific communications, much progress can be made on longstanding questions about the physics involved in the formation of the plasmapause and in the cycles of erosion and recovery of the plasmasphere.

    Key words. Magnetospheric physics (plasmasphere; plasma convection; MHD waves and instabilities

  1. VT E911 Road Centerlines (United States)

    Vermont Center for Geographic Information — (Link to Metadata) EmergencyE911_RDS was originally derived from RDSnn (now called TransRoad_RDS). "Zero-length ranges" in the ROADS layer pertain to grand-fathered...

  2. Counting graphene layers with very slow electrons

    Energy Technology Data Exchange (ETDEWEB)

    Frank, Ludĕk; Mikmeková, Eliška; Müllerová, Ilona [Institute of Scientific Instruments AS CR, v.v.i., Královopolská 147, 61264 Brno (Czech Republic); Lejeune, Michaël [Laboratoire de Physique de la Matière Condensée, Faculté des Sciences d' Amiens, Universite de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens Cedex 2 (France)


    The study aimed at collection of data regarding the transmissivity of freestanding graphene for electrons across their full energy scale down to the lowest energies. Here, we show that the electron transmissivity of graphene drops with the decreasing energy of the electrons and remains below 10% for energies below 30 eV, and that the slow electron transmissivity value is suitable for reliable determination of the number of graphene layers. Moreover, electrons incident below 50 eV release adsorbed hydrocarbon molecules and effectively clean graphene in contrast to faster electrons that decompose these molecules and create carbonaceous contamination.

  3. Building blocks of e-commerce

    Indian Academy of Sciences (India)

    V Rajaraman


    This article examines the architecture of e-commerce as a set of layers, each supporting the one above it. The layers have clean interfaces, that is, they can be designed independently. We present an architecture with six layers. The lowest layer consists of a physical communication network such as local area network or public switched telephone networks. The next higher layer is the logical layer which describes the protocol used to interconnect communication systems to create internet, intranet and extranet. The services provided over the internet infrastructure, namely, e-mail, world wide web etc., are described in what is called network services layer. It is essential to ensure security of messages, documents etc., which are transmitted using network services. The messaging layer is thus concerned with encryption methods, both private and public key encryption and their applications. We call the layer above this the middleman service, which is concerned with valueadded services offered by intermediaries to enable payment for services received, certify digital signatures, safely transmit documents and provide information on behalf of companies. The topmost layer is the application layer which users see. The major applications are customer-to-business (C2B) e-commerce, business-tobusiness (B2B) e-commerce, customer-to-consumer (C2C) e-commerce etc. We briefly explain these modes.

  4. Processes for multi-layer devices utilizing layer transfer

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, Gregory N; Sanchez, Carlos Anthony; Tauke-Pedretti, Anna; Kim, Bongsang; Cederberg, Jeffrey; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J


    A method includes forming a release layer over a donor substrate. A plurality of devices made of a first semiconductor material are formed over the release layer. A first dielectric layer is formed over the plurality of devices such that all exposed surfaces of the plurality of devices are covered by the first dielectric layer. The plurality of devices are chemically attached to a receiving device made of a second semiconductor material different than the first semiconductor material, the receiving device having a receiving substrate attached to a surface of the receiving device opposite the plurality of devices. The release layer is etched to release the donor substrate from the plurality of devices. A second dielectric layer is applied over the plurality of devices and the receiving device to mechanically attach the plurality of devices to the receiving device.

  5. Processes for multi-layer devices utilizing layer transfer (United States)

    Nielson, Gregory N; Sanchez, Carlos Anthony; Tauke-Pedretti, Anna; Kim, Bongsang; Cederberg, Jeffrey; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J


    A method includes forming a release layer over a donor substrate. A plurality of devices made of a first semiconductor material are formed over the release layer. A first dielectric layer is formed over the plurality of devices such that all exposed surfaces of the plurality of devices are covered by the first dielectric layer. The plurality of devices are chemically attached to a receiving device made of a second semiconductor material different than the first semiconductor material, the receiving device having a receiving substrate attached to a surface of the receiving device opposite the plurality of devices. The release layer is etched to release the donor substrate from the plurality of devices. A second dielectric layer is applied over the plurality of devices and the receiving device to mechanically attach the plurality of devices to the receiving device.

  6. Nanomanufacturing : nano-structured materials made layer-by-layer.

    Energy Technology Data Exchange (ETDEWEB)

    Cox, James V.; Cheng, Shengfeng; Grest, Gary Stephen; Tjiptowidjojo, Kristianto (University of New Mexico); Reedy, Earl David, Jr.; Fan, Hongyou; Schunk, Peter Randall; Chandross, Michael Evan; Roberts, Scott A.


    Large-scale, high-throughput production of nano-structured materials (i.e. nanomanufacturing) is a strategic area in manufacturing, with markets projected to exceed $1T by 2015. Nanomanufacturing is still in its infancy; process/product developments are costly and only touch on potential opportunities enabled by growing nanoscience discoveries. The greatest promise for high-volume manufacturing lies in age-old coating and imprinting operations. For materials with tailored nm-scale structure, imprinting/embossing must be achieved at high speeds (roll-to-roll) and/or over large areas (batch operation) with feature sizes less than 100 nm. Dispersion coatings with nanoparticles can also tailor structure through self- or directed-assembly. Layering films structured with these processes have tremendous potential for efficient manufacturing of microelectronics, photovoltaics and other topical nano-structured devices. This project is designed to perform the requisite R and D to bring Sandia's technology base in computational mechanics to bear on this scale-up problem. Project focus is enforced by addressing a promising imprinting process currently being commercialized.

  7. Photovoltaic device comprising compositionally graded intrinsic photoactive layer (United States)

    Hoffbauer, Mark A; Williamson, Todd L


    Photovoltaic devices and methods of making photovoltaic devices comprising at least one compositionally graded photoactive layer, said method comprising providing a substrate; growing onto the substrate a uniform intrinsic photoactive layer having one surface disposed upon the substrate and an opposing second surface, said intrinsic photoactive layer consisting essentially of In.sub.1-xA.sub.xN,; wherein: i. 0.ltoreq.x.ltoreq.1; ii. A is gallium, aluminum, or combinations thereof; and iii. x is at least 0 on one surface of the intrinsic photoactive layer and is compositionally graded throughout the layer to reach a value of 1 or less on the opposing second surface of the layer; wherein said intrinsic photoactive layer is isothermally grown by means of energetic neutral atom beam lithography and epitaxy at a temperature of C. or less using neutral nitrogen atoms having a kinetic energy of from about 1.0 eV to about 5.0 eV, and wherein the intrinsic photoactive layer is grown at a rate of from about 5 nm/min to about 100 nm/min.

  8. Prediction of Silicon-Based Layered Structures for Optoelectronic Applications (United States)

    Luo, Wei; Ma, Yanming; Gong, Xingao; Xiang, Hongjun; CCMG Team


    A method based on the particle swarm optimization (PSO) algorithm is presented to design quasi-two-dimensional (Q2D) materials. With this development, various single-layer and bi-layer materials in C, Si, Ge, Sn, and Pb were predicted. A new Si bi-layer structure is found to have a much-favored energy than the previously widely accepted configuration. Both single-layer and bi-layer Si materials have small band gaps, limiting their usages in optoelectronic applications. Hydrogenation has therefore been used to tune the electronic and optical properties of Si layers. We discover two hydrogenated materials of layered Si8H2andSi6H2 possessing quasi-direct band gaps of 0.75 eV and 1.59 eV, respectively. Their potential applications for light emitting diode and photovoltaics are proposed and discussed. Our study opened up the possibility of hydrogenated Si layered materials as next-generation optoelectronic devices.

  9. Inter-layer synchronization in multiplex networks of identical layers

    Energy Technology Data Exchange (ETDEWEB)

    Sevilla-Escoboza, R. [Centro Universitario de los Lagos, Universidad de Guadalajara, Jalisco 47460 (Mexico); Sendiña-Nadal, I.; Leyva, I.; Buldú, J. M. [Complex Systems Group & GISC, Universidad Rey Juan Carlos, 28933 Móstoles, Madrid (Spain); Center for Biomedical Technology, Universidad Politécnica de Madrid, 28223 Pozuelo de Alarcón, Madrid (Spain); Gutiérrez, R. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Boccaletti, S. [CNR-Institute of Complex Systems, Via Madonna del Piano, 10, 50019 Sesto Fiorentino, Florence (Italy); The Italian Embassy in Israel, 25 Hamered st., 68125 Tel Aviv (Israel)


    Inter-layer synchronization is a distinctive process of multiplex networks whereby each node in a given layer evolves synchronously with all its replicas in other layers, irrespective of whether or not it is synchronized with the other units of the same layer. We analytically derive the necessary conditions for the existence and stability of such a state, and verify numerically the analytical predictions in several cases where such a state emerges. We further inspect its robustness against a progressive de-multiplexing of the network, and provide experimental evidence by means of multiplexes of nonlinear electronic circuits affected by intrinsic noise and parameter mismatch.

  10. Methods for improved growth of group III nitride buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro


    Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphology of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).

  11. Methods for improved growth of group III nitride buffer layers (United States)

    Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro


    Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphology of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).

  12. Características da camada limite atmosférica tropical (CLAT na região de Serpong-Indonésia durante as estações seca e chuvosa Tropical atmospheric boundary layer (BLAT characteristic in Serpong-Indonesia region, during drought and rainy seasons

    Directory of Open Access Journals (Sweden)

    José Francisco de Oliveira Júnior


    Full Text Available Através dos dados de superfície, radiossondagem e radar Doppler banda - L, em Serpong - Indonésia (6° 24’ S - 106° 42’ E, durante a estação seca (1993 e chuvosa (1994 foram estudadas as características da CLAT. Os dados de radar foram validados através da radiossondagem por métodos estatísticos (índice de correlação, média e desvio padrão. A estrutura da CLAT foi interpretada através do eco de radar (vento, observado continuamente para todos os dias do período de estudo. As características mais evidentes da CLAT nesta região foram à presença de uma CM (Camada de Mistura diurna que atingia a 0,3 km pela manhã e outra camada entre 3-5 km à tarde, observando-se um ciclo diurno de crescimento e estacionariedade, devido ao aquecimento e resfriamento da superfície. A principal característica entre as estações foi que no horário de 0300 TL (Tempo Local, ambas apresentavam o mesmo comportamento (intensidade e direção do vento, mas para o restante do dia existiu uma grande diferença entre elas. Na estação seca a intensidade e a direção do vento foi mais variável do que na chuvosa, resultado observado na altura da CLAT. As informações obtidas através do BLR (Boundary Layer Radar, mostram a existência de pronunciadas variações diurnas na CLAT em dias claros. Verificou-se que a variação diurna da CLAT teve uma influencia marcante, devido à existência da circulação de brisa marítima, confirmada pelo BLR no dia 12/10/93. A validação dos dados do radar apresentou resultados significativos, onde na estação seca, os coeficientes de regressão variaram entre 0,83 e 0,94, tanto na direção como na intensidade, e na chuvosa variou de 0,77 a 0,88 (intensidade e na direção da ordem de 0,3. Comprovou-se que as medidas de radar são equivalentes ao de radiossondagem, com o benefício de poder ter dados contínuos, provando-se que as observações, a partir da sua utilização deve desempenhar um papel

  13. Ocorrência de aflatoxinas em arroz consumido por militares do Exército Brasileiro por cromatografia em camada delgada e cromatografia líquida de alta eficiência Incidence of aflatoxins in rice to be consumed by militaries in the brazilian army by thin layer chromatography and high performance liquid chromatography methods

    Directory of Open Access Journals (Sweden)

    Jader Oliveira da Silva


    Full Text Available Fungos do gênero Aspergillus como A. flavus e A. parasiticus são capazes de produzir metabólitos secundários tóxicos denominados aflatoxinas. Estas espécies podem se desenvolver rapidamente em cereais sob condições favoráveis. A partir do conhecimento dos riscos à saúde decorrentes da presença de aflatoxinas em alimentos, foi realizado um levantamento para avaliar a presença de aflatoxinas em arroz beneficiado polido tipo I, destinado ao consumo dos militares do Exército Brasileiro. As amostras foram coletadas no armazém do 5º Batalhão de Suprimento do Exército Brasileiro, Curitiba-PR no período de novembro de 2003 a fevereiro de 2004 e avaliada a ocorrência de aflatoxinas B1, B2, G1 e G2, utilizando-se as técnicas de Cromatografia em Camada Delgada (CCD e Cromatografia Líquida de Alta Eficiência (CLAE. Objetivou-se, neste trabalho, contribuir com o controle de qualidade dos alimentos consumidos pelos militares da 5º Região Militar do Exército Brasileiro, no que se refere ao controle dos níveis de aflatoxinas e comparar as técnicas de CCD e CLAE. Do total de 30 amostras analisadas por cromatografia em camada delgada, não foi verificada em nenhuma a presença de aflatoxinas. De 26 amostras analisadas por cromatografia líquida de alta eficiência, seis (23,07% apresentaram positividade para aflatoxina B1 (AFB1, com níveis entre 0,54 e 2,04µg/kg e uma (3,84% apresentou presença de aflatoxina B2 (AFB2 com 1,84µg/kg.Aspergillus are fungal species like a A flavus and A parasiticus and they are able to develop secondary metabolites called mycotoxins. They grow quickly under ideal conditions. From the moment one discovered its danger for health resulted from the presence of aflatoxins in foods, an achievement was carried out to evaluate the presence of a mycotoxins lifiting in benefited polished rice type 1, used by Brazilian army. The samples were collected at " 5º Batalhão de Suprimento" (army departament from

  14. Síntese de hidróxidos duplos lamelares do sistema Cu, Zn, Al-CO3: propriedades morfológicas, estruturais e comportamento térmico Synthesis of layered double hydroxides of the Cu, Zn, Al-CO3 system: morphological and structural properties and thermal behavior

    Directory of Open Access Journals (Sweden)

    S. S. dos Santos


    Full Text Available Hidrotalcitas são argilas aniônicas, também conhecidas como Hidróxidos Duplos Lamelares (HDLs e possuem estrutura semelhante ao mineral brucita. Os HDLs do sistema Cu, Zn, Al-CO3 foram sintetizados em condições que favorecem a formação de cristais pequenos e de elevada área superficial. A caracterização foi feita por difração de raios X, análise termogravimétrica, espectroscopia na região do infravermelho e microscopia eletrônica de varredura. A síntese foi feita pelo método de coprecipitação em pH variável, utilizando sulfatos de cobre e zinco, soluções de alumínio e solução de hidróxido sódio. Os difratogramas de raios X mostram que os compostos sintetizados possuem alta cristalinidade; a intensidade e a largura dos picos comprovam que os materiais se apresentam bem organizados e com empilhamento das lamelas. Os espectros de infravermelho apresentaram bandas associadas ao ânion carbonato presente na região interlamelar dos HDLs.Hydrotalcite-like compounds are anionic clays, also known as layered double hydroxides (LDH, which have structure similar to brucite mineral. The LDHs of the system Cu, Zn, Al-CO3 were synthesized under conditions to promote the formation of small crystals with high surface area. The characterization was done by X-ray diffraction, thermogravimetric analysis, FTIR spectroscopy, and scanning electron microscopy. The synthesis were based on the co-precipitation method, under different conditions (hydrothermal bath, titration time using copper and zinc sulfate, aluminum and sodium hydroxide solutions. The X-ray diffraction patterns show that synthesized compounds have high crystallinity, the peak intensities show that they are well organized and stacked with the lamellae. The infrared spectrum shows bands associated with carbonate anion in the interlayer region.

  15. Neocortical layer 6, a review

    Directory of Open Access Journals (Sweden)

    Alex M Thomson


    Full Text Available This review attempts to summarise some of the major areas of neocortical research as it pertains to layer 6. After a brief summary of the development of this intriguing layer, the major pyramidal cell classes to be found in layer 6 are described and compared. The connections made and received by these different classes of neurones are then discussed and the possible functions of these connections, with particular reference to the shaping of responses in visual cortex and thalamus. Inhibition in layer 6 is discussed where appropriate, but not in great detail. Many types of interneurones are to be found in each cortical layer and layer 6 is no exception, but the functions of each type remain to be elucidated.

  16. Nanostructure Neutron Converter Layer Development (United States)

    Park, Cheol (Inventor); Sauti, Godfrey (Inventor); Kang, Jin Ho (Inventor); Lowther, Sharon E. (Inventor); Thibeault, Sheila A. (Inventor); Bryant, Robert G. (Inventor)


    Methods for making a neutron converter layer are provided. The various embodiment methods enable the formation of a single layer neutron converter material. The single layer neutron converter material formed according to the various embodiments may have a high neutron absorption cross section, tailored resistivity providing a good electric field penetration with submicron particles, and a high secondary electron emission coefficient. In an embodiment method a neutron converter layer may be formed by sequential supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In another embodiment method a neutron converter layer may be formed by simultaneous supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In a further embodiment method a neutron converter layer may be formed by in-situ metalized aerogel nanostructure development.

  17. Magnetism in layered Ruthenates

    Energy Technology Data Exchange (ETDEWEB)

    Steffens, Paul C.


    In this thesis, the magnetism of the layered Ruthenates has been studied by means of different neutron scattering techniques. Magnetic correlations in the single-layer Ruthenates of the series Ca{sub 2-x}Sr{sub x}RuO{sub 4} have been investigated as function of Sr-concentration (x=0.2 and 0.62), temperature and magnetic field. These inelastic neutron scattering studies demonstrate the coexistence of ferromagnetic paramagnon scattering with antiferromagnetic fluctuations at incommensurate wave vectors. The temperature dependence of the amplitudes and energies of both types of excitations indicate the proximity to magnetic instabilities; their competition seems to determine the complex behavior of these materials. In Ca{sub 1.8}Sr{sub 0.2}RuO{sub 4}, which shows a metamagnetic transition, the ferromagnetic fluctuations are strongly suppressed at low temperature, but appear at higher temperature or application of a magnetic field. In the high-field phase of Ca{sub 1.8}Sr{sub 0.2}RuO{sub 4} above the metamagnetic transition, a ferromagnetic magnon dominates the excitation spectrum. Polarized neutron scattering revealed the existence of a very broad signal around the zone centre, in addition to the well-known incommensurate excitations at Q=(0.3,0.3,0) in the unconventional superconductor Sr{sub 2}RuO{sub 4}. With this additional contribution, it is possible to set up a general model for the Q-dependent magnetic susceptibility, which is well consistent with the results of other measurement methods that do not resolve the Q-dependence. Upon doping with Ti, the incommensurate fluctuations are enhanced, in particular near the critical concentration for the onset of magnetic order, but no divergence down to very low temperature is observed. In the bilayer Ti-doped Ca{sub 3}Ru{sub 2}O{sub 7}, the existence of magnetic order with a propagation vector of about ((1)/(4),(1)/(4),0) has been discovered and characterized in detail. Above and below T{sub N}, excitations at this

  18. Boundary-Layer & health (United States)

    Costigliola, V.


    It has long been known that specific atmospheric processes, such as weather and longer-term climatic fluctuations, affect human health. The biometeorological literature refers to this relationship as meteorotropism, defined as a change in an organism that is correlated with a change in atmospheric conditions. Plenty of (patho)physiological functions are affected by those conditions - like the respiratory diseases - and currently it is difficult to put any limits for pathologies developed in reply. Nowadays the importance of atmospheric boundary layer and health is increasingly recognised. A number of epidemiologic studies have reported associations between ambient concentrations of air pollution, specifically particulate pollution, and adverse health effects, even at the relatively low concentrations of pollution found. Since 1995 there have been over twenty-one studies from four continents that have explicitly examined the association between ambient air pollutant mixes and daily mortality. Statistically significant and positive associations have been reported in data from various locations around the world, all with varying air pollutant concentrations, weather conditions, population characteristics and public health policies. Particular role has been given to atmospheric boundary layer processes, the impact of which for specific patient-cohort is, however, not well understood till now. Assessing and monitoring air quality are thus fundamental to improve Europe's welfare. One of current projects run by the "European Medical Association" - PASODOBLE will develop and demonstrate user-driven downstream information services for the regional and local air quality sectors by combining space-based and in-situ data with models in 4 thematic service lines: - Health community support for hospitals, pharmacies, doctors and people at risk - Public information for regions, cities, tourist industry and sporting event organizers - Compliance monitoring support on particulate

  19. Anisotropic Optical Properties of Layered Germanium Sulfide

    CERN Document Server

    Tan, Dezhi; Wang, Feijiu; Mohamed, Nur Baizura; Mouri, Shinichiro; Sandhaya, Koirala; Zhang, Wenjing; Miyauchi, Yuhei; Ohfuchi, Mari; Matsuda, Kazunari


    Two-dimensional (2D) layered materials, transition metal dichalcogenides and black phosphorus, have attracted much interest from the viewpoints of fundamental physics and device applications. The establishment of new functionalities in anisotropic layered 2D materials is a challenging but rewarding frontier, owing to their remarkable optical properties and prospects for new devices. Here, we report the anisotropic optical properties of layered 2D monochalcogenide of germanium sulfide (GeS). Three Raman scattering peaks corresponding to the B3g, A1g, and A2g modes with strong polarization dependence are demonstrated in the GeS flakes, which validates polarized Raman spectroscopy as an effective method for identifying the crystal orientation of anisotropic layered GeS. Photoluminescence (PL) is observed with a peak at around 1.66 eV that originates from the direct optical transition in GeS at room temperature. Moreover, determination of the polarization dependent characteristics of the PL and absorption reveals...

  20. Graded Recombination Layers for Multijunction Photovoltaics

    KAUST Repository

    Koleilat, Ghada I.


    Multijunction devices consist of a stack of semiconductor junctions having bandgaps tuned across a broad spectrum. In solar cells this concept is used to increase the efficiency of photovoltaic harvesting, while light emitters and detectors use it to achieve multicolor and spectrally tunable behavior. In series-connected current-matched multijunction devices, the recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron current from the next cell. We recently reported a tandem solar cell in which the recombination layer was implemented using a progression of n-type oxides whose doping densities and work functions serve to connect, with negligible resistive loss at solar current densities, the constituent cells. Here we present the generalized conditions for design of efficient graded recombination layer solar devices. We report the number of interlayers and the requirements on work function and doping of each interlayer, to bridge an work function difference as high as 1.6 eV. We also find solutions that minimize the doping required of the interlayers in order to minimize optical absorption due to free carriers in the graded recombination layer (GRL). We demonstrate a family of new GRL designs experimentally and highlight the benefits of the progression of dopings and work functions in the interlayers. © 2012 American Chemical Society.

  1. Determination of crystallization as a function of Mo layer thickness in Mo/Si multilayers

    DEFF Research Database (Denmark)

    Abdali, Salim; Gerward, Leif; Yakshin, A.E.;


    Mo/Si multilayer samples with different Mo layer thickness were deposited by electron beam evaporation, while Kr+ ions (300 eV) were used for polishing the Si layers. Crystallization as a function of the Mo layer thickness deposited was investigated by grazing incidence X-ray diffraction, giving...

  2. Oxygen-reducing catalyst layer

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Dennis P. (Maplewood, MN); Schmoeckel, Alison K. (Stillwater, MN); Vernstrom, George D. (Cottage Grove, MN); Atanasoski, Radoslav (Edina, MN); Wood, Thomas E. (Stillwater, MN); Yang, Ruizhi (Halifax, CA); Easton, E. Bradley (Halifax, CA); Dahn, Jeffrey R. (Hubley, CA); O' Neill, David G. (Lake Elmo, MN)


    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  3. Polymer-Layer Silicate Nanocomposites

    DEFF Research Database (Denmark)

    Potarniche, Catalina-Gabriela

    Nowadays, some of the material challenges arise from a performance point of view as well as from recycling and biodegradability. Concerning these aspects, the development of polymer layered silicate nanocomposites can provide possible solutions. This study investigates how to obtain polymer layered...... silicate nanocomposites and their structure-properties relationship. In the first part of the thesis, thermoplastic layered silicates were obtained by extrusion. Different modification methods were tested to observe the intercalation treatment effect on the silicate-modifier interactions. The silicate...

  4. Caracterização química e espectroscópica de ácidos húmicos e fúlvicos isolados da camada superficial de latossolos brasileiros Chemical and spectroscopic characterization of humic and fulvic acids isolated from the surface layer of Brazilian oxisols

    Directory of Open Access Journals (Sweden)

    Leonardo Barros Dobbss


    Full Text Available A determinação de características estruturais das substâncias húmicas (SH é essencial para o entendimento do comportamento da química de superfície dos solos altamente intemperizados. Ácidos húmicos (AH e fúlvicos (AF obtidos no horizonte superficial de sete Latossolos de diferentes regiões do Brasil foram caracterizados mediante a análise da composição elementar, da acidez total e carboxílica, da capacidade de oxidação e por métodos espectroscópicos. As substâncias húmicas apresentaram elevado grau de oxidação, acidez e massa molecular relativamente baixas, caracterizando a matéria orgânica alcalina solúvel como bastante reativa. Os AF apresentaram menor teor de C e maior de O do que os AH. Foram observados valores elevados da relação entre absorvância em 465 e 665 nm (E4/E6 e a massa molar média foi estimada em 1.106 e 618 g mol-1 para AH e AF, respectivamente. A menor massa molar estimada para os AF foi compatível com sua menor complexidade química revelada pelos espectros de IV-TF, que apresentaram menor número de bandas de absorção bem definidas. A ressonância magnética nuclear (RMN ¹H mostrou a presença de H mais hidrofóbico nos AH e de H ligado a átomos de O em maior quantidade nos AF, compatível com sua maior acidez e, portanto, solubilidade em qualquer valor de pH. Apesar da mesma funcionalidade química encontrada tanto nos AH como nos AF, a análise estatística permitiu separar a maioria desses ácidos, indicando a presença de frações humificadas de natureza química individual.The determination of structural characteristics of humic substances (HS is essential to understand the behavior of surface chemistry of highly weathered soils. Humic acids (HA and fulvic acids (FA isolated from the surface horizon of seven Oxisols of different locations of Brazil were characterized by analyses of elemental composition, total and carboxylic acidity, oxidation capacity and spectroscopic techniques

  5. Sub-Transport Layer Coding

    DEFF Research Database (Denmark)

    Hansen, Jonas; Krigslund, Jeppe; Roetter, Daniel Enrique Lucani


    Packet losses in wireless networks dramatically curbs the performance of TCP. This paper introduces a simple coding shim that aids IP-layer traffic in lossy environments while being transparent to transport layer protocols. The proposed coding approach enables erasure correction while being...... oblivious to the congestion control algorithms of the utilised transport layer protocol. Although our coding shim is indifferent towards the transport layer protocol, we focus on the performance of TCP when ran on top of our proposed coding mechanism due to its widespread use. The coding shim provides gains...


    Energy Technology Data Exchange (ETDEWEB)

    Swisdak, M.; Drake, J. F. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742 (United States); Opher, M., E-mail:, E-mail:, E-mail: [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)


    The picture of the heliopause (HP)-the boundary between the domains of the Sun and the local interstellar medium (LISM)-as a pristine interface with a large rotation in the magnetic field fails to describe recent Voyager 1 (V1) data. Magnetohydrodynamic (MHD) simulations of the global heliosphere reveal that the rotation angle of the magnetic field across the HP at V1 is small. Particle-in-cell simulations, based on cuts through the MHD model at V1's location, suggest that the sectored region of the heliosheath (HS) produces large-scale magnetic islands that reconnect with the interstellar magnetic field while mixing LISM and HS plasma. Cuts across the simulation reveal multiple, anti-correlated jumps in the number densities of LISM and HS particles, similar to those observed, at the magnetic separatrices. A model is presented, based on both the observations and simulations, of the HP as a porous, multi-layered structure threaded by magnetic fields. This model further suggests that contrary to the conclusions of recent papers, V1 has already crossed the HP.

  7. Atributos físicos do solo e distribuição do sistema radicular de citros como indicadores de horizontes coesos em dois solos de tabuleiros costeiros do estado da Bahia Soil physical attributes and citrus root system distribution as indicators of cohesive layers in soils of coastal table lands in the state of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Marlete Bastos Santana


    Full Text Available Em 2001, foram realizadas a caracterização física e a avaliação do sistema radicular de citros em dois solos típicos de Tabuleiros Costeiros (Latossolo Amarelo-LA e Argissolo Acinzentado-PAC do Estado da Bahia, visando estabelecer atributos que melhor identifiquem horizontes coesos. Em cada um dos solos, foram coletadas amostras nos primeiros quatro horizontes, para determinar granulometria, densidade do solo, porosidade total, macroporosidade, microporosidade e condutividade hidráulica saturada. Também foram determinadas a resistência do solo à penetração e a umidade crítica de resistência à penetração. Amostras de raízes de citros foram coletadas nos mesmos horizontes. Foi brusca a diminuição da densidade de raízes de citros nos horizontes AB, Bw1, BA e Bt1, associada ao aspecto coeso, sendo um indicador direto de horizonte coeso; no entanto, pela dificuldade de medição, buscou-se identificar atributos do solo mais bem relacionados com a densidade de raízes. A resistência do solo à penetração foi o atributo que melhor identificou a presença de horizonte coeso, devendo ser avaliada em umidade abaixo daquela considerada crítica para expressar a coesão. A condutividade hidráulica saturada também se revelou adequada para identificar horizonte coeso, podendo ser substituída pela macroporosidade, atributo igualmente importante para tal finalidade e com menor variabilidade e de mais fácil medição que aquele. A densidade do solo pode ser considerada um atributo para indicar a presença de horizontes coesos, tendo como principal limitação a interferência da granulometria na manifestação dos seus valores. Os indicadores recomendados permitem detectar a presença de horizontes coesos, orientando intervenções de manejo para superar os problemas de aprofundamento do sistema radicular que tais solos apresentam.The physical characterization of two typical Coastal Tableland soils (Yellow Latosol-YL and Gray Argisol


    NARCIS (Netherlands)



    Electron donation from MX double layers to TX(2) sandwiches, the interlayer bonding and the localization of conduction electrons in misfit layer compounds (MX)(p)(TX(2))(n) (M=Sn, Pb, Sb, Bi, rare earth metals; T=Ti, V, Cr, Nb, Ta; X=S, Se; 1.08

  9. Layer-by-Layer Proteomic Analysis of Mytilus galloprovincialis Shell.

    Directory of Open Access Journals (Sweden)

    Peng Gao

    Full Text Available Bivalve shell is a biomineralized tissue with various layers/microstructures and excellent mechanical properties. Shell matrix proteins (SMPs pervade and envelop the mineral crystals and play essential roles in biomineralization. Despite that Mytilus is an economically important bivalve, only few proteomic studies have been performed for the shell, and current knowledge of the SMP set responsible for different shell layers of Mytilus remains largely patchy. In this study, we observed that Mytilus galloprovincialis shell contained three layers, including nacre, fibrous prism, and myostracum that is involved in shell-muscle attachment. A parallel proteomic analysis was performed for these three layers. By combining LC-MS/MS analysis with Mytilus EST database interrogations, a whole set of 113 proteins was identified, and the distribution of these proteins in different shell layers followed a mosaic pattern. For each layer, about a half of identified proteins are unique and the others are shared by two or all of three layers. This is the first description of the protein set exclusive to nacre, myostracum, and fibrous prism in Mytilus shell. Moreover, most of identified proteins in the present study are novel SMPs, which greatly extended biomineralization-related protein data of Mytilus. These results are useful, on one hand, for understanding the roles of SMPs in the deposition of different shell layers. On the other hand, the identified protein set of myostracum provides candidates for further exploring the mechanism of adductor muscle-shell attachment.


    NARCIS (Netherlands)



    Electron donation from MX double layers to TX(2) sandwiches, the interlayer bonding and the localization of conduction electrons in misfit layer compounds (MX)(p)(TX(2))(n) (M=Sn, Pb, Sb, Bi, rare earth metals; T=Ti, V, Cr, Nb, Ta; X=S, Se; 1.08

  11. Layer-by-Layer Proteomic Analysis of Mytilus galloprovincialis Shell (United States)

    Wang, Xin-xing; Bao, Lin-fei; Fan, Mei-hua; Li, Xiao-min; Wu, Chang-wen; Xia, Shu-wei


    Bivalve shell is a biomineralized tissue with various layers/microstructures and excellent mechanical properties. Shell matrix proteins (SMPs) pervade and envelop the mineral crystals and play essential roles in biomineralization. Despite that Mytilus is an economically important bivalve, only few proteomic studies have been performed for the shell, and current knowledge of the SMP set responsible for different shell layers of Mytilus remains largely patchy. In this study, we observed that Mytilus galloprovincialis shell contained three layers, including nacre, fibrous prism, and myostracum that is involved in shell-muscle attachment. A parallel proteomic analysis was performed for these three layers. By combining LC-MS/MS analysis with Mytilus EST database interrogations, a whole set of 113 proteins was identified, and the distribution of these proteins in different shell layers followed a mosaic pattern. For each layer, about a half of identified proteins are unique and the others are shared by two or all of three layers. This is the first description of the protein set exclusive to nacre, myostracum, and fibrous prism in Mytilus shell. Moreover, most of identified proteins in the present study are novel SMPs, which greatly extended biomineralization-related protein data of Mytilus. These results are useful, on one hand, for understanding the roles of SMPs in the deposition of different shell layers. On the other hand, the identified protein set of myostracum provides candidates for further exploring the mechanism of adductor muscle-shell attachment. PMID:26218932

  12. Layer-by-Layer Proteomic Analysis of Mytilus galloprovincialis Shell. (United States)

    Gao, Peng; Liao, Zhi; Wang, Xin-Xing; Bao, Lin-Fei; Fan, Mei-Hua; Li, Xiao-Min; Wu, Chang-Wen; Xia, Shu-Wei


    Bivalve shell is a biomineralized tissue with various layers/microstructures and excellent mechanical properties. Shell matrix proteins (SMPs) pervade and envelop the mineral crystals and play essential roles in biomineralization. Despite that Mytilus is an economically important bivalve, only few proteomic studies have been performed for the shell, and current knowledge of the SMP set responsible for different shell layers of Mytilus remains largely patchy. In this study, we observed that Mytilus galloprovincialis shell contained three layers, including nacre, fibrous prism, and myostracum that is involved in shell-muscle attachment. A parallel proteomic analysis was performed for these three layers. By combining LC-MS/MS analysis with Mytilus EST database interrogations, a whole set of 113 proteins was identified, and the distribution of these proteins in different shell layers followed a mosaic pattern. For each layer, about a half of identified proteins are unique and the others are shared by two or all of three layers. This is the first description of the protein set exclusive to nacre, myostracum, and fibrous prism in Mytilus shell. Moreover, most of identified proteins in the present study are novel SMPs, which greatly extended biomineralization-related protein data of Mytilus. These results are useful, on one hand, for understanding the roles of SMPs in the deposition of different shell layers. On the other hand, the identified protein set of myostracum provides candidates for further exploring the mechanism of adductor muscle-shell attachment.

  13. Natural melanin composites by layer-by-layer assembly (United States)

    Eom, Taesik; Shim, Bong Sub


    Melanin is an electrically conductive and biocompatible material, because their conjugated backbone structures provide conducting pathways from human skin, eyes, brain, and beyond. So there is a potential of using as materials for the neural interfaces and the implantable devices. Extracted from Sepia officinalis ink, our natural melanin was uniformly dispersed in mostly polar solvents such as water and alcohols. Then, the dispersed melanin was further fabricated to nano-thin layered composites by the layer-by-layer (LBL) assembly technique. Combined with polyvinyl alcohol (PVA), the melanin nanoparticles behave as an LBL counterpart to from finely tuned nanostructured films. The LBL process can adjust the smart performances of the composites by varying the layering conditions and sandwich thickness. We further demonstrated the melanin loading degree of stacked layers, combination nanostructures, electrical properties, and biocompatibility of the resulting composites by UV-vis spectrophotometer, scanning electron microscope (SEM), multimeter, and in-vitro cell test of PC12, respectively.

  14. Layer-layer competition in multiplex complex networks

    CERN Document Server

    Gómez-Gardeñes, Jesús; Gutiérrez, Gerardo; Arenas, Alex; Gómez, Sergio


    The coexistence of multiple types of interactions within social, technological and biological networks has moved the focus of the physics of complex systems towards a multiplex description of the interactions between their constituents. This novel approach has unveiled that the multiplex nature of complex systems has strong influence in the emergence of collective states and their critical properties. Here we address an important issue that is intrinsic to the coexistence of multiple means of interactions within a network: their competition. To this aim, we study a two-layer multiplex in which the activity of users can be localized in each of the layer or shared between them, favoring that neighboring nodes within a layer focus their activity on the same layer. This framework mimics the coexistence and competition of multiple communication channels, in a way that the prevalence of a particular communication platform emerges as a result of the localization of users activity in one single interaction layer. Our...

  15. A Framework of Information Service Platform in E-Government

    Institute of Scientific and Technical Information of China (English)

    GAN Renchu; DU Ding


    For exchanging and sharing information and services in e-government, a framework of information service platform (ISP) is presented. The multi-layer architecture of the ISP is introduced They are: user's requirement layer, business service layer, business process layer, business function layer and data layer. The lower layers are based on the architecture of web services and the upper layers are related to the institutional and organizational issues. In order to deal with the variation of user's requirements and changing environment, the matching and mapping processes with adaptive mechanism are illustrated.

  16. Síntese e caracterização de Nanocompósitos Esfoliados de Poliestireno: Hidróxido Duplo Lamelar via polimerização in situ Synthesis and characterization of Exfoliated Polystyrene: Layered Double Hydroxide Nanocomposites via in situ polymerization

    Directory of Open Access Journals (Sweden)

    Rodrigo Botan


    Full Text Available Nanocompósitos Esfoliados de Poliestireno (PS e Hidróxido Duplo Lamelar (HDL composto por zinco, alumínio e dodecil sulfato de sódio, como ânion interlamelar, foram sintetizados via polimerização in situ. O efeito de diferentes composições de HDL (0,5, 1, 3 e 5% em massa foi avaliado. Os nanocompósitos obtidos foram caracterizados através de ensaios de Difração de Raios X (DRX, Espectroscopia no Infravermelho por Transformada de Fourier (FTIR, Microscopia Eletrônica de Transmissão (MET e Análise Termogravimétrica (TGA. Os resultados obtidos através das análises de DRX e MET mostraram que todos os nanocompósitos produzidos apresentaram morfologia esfoliada. Os resultados das TGA, quando se utilizam 50% de perda de peso como ponto para comparação, apresentaram ganhos significativos de estabilidade térmica para todas as composições dos nanocompósitos em comparação ao poliestireno puro. Este comportamento possibilita uma vasta gama de aplicação destes novos materiais em diversos campos da indústria e pesquisa.Exfoliated nanocomposites of polystyrene (PS and layered double hydroxide (LDH compound of zinc, aluminium and sodium dodecyl sulfate, as interlayer anion, have been synthesized via in situ polymerization. The effect from the LDH compositions (0.5, 1, 3, 5% weight was studied. The nanocomposites were characterized by X-ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FTIR, Transmission Electron Microscopy (TEM and Thermogravimetric Analysis (TGA. The XRD and TEM results showed an exfoliated morphology for the nanocomposites in all compositions. With the 50% weight loss taken as a reference, the TGA results indicated significant improvement in thermal stability for all compositions of the nanocomposites, in comparison to pure polystyrene. This is promising for the application of these new materials in many fields of industry and research.

  17. Annual layering in the NGRIP ice core during the Eemian

    DEFF Research Database (Denmark)

    Svensson, Anders; Bigler, Matthias; Kettner, Ernesto


    The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core, annual layers can be identified from impurity...... records and visual stratigraphy, and stratigraphic layer counting has been performed back to 60 ka. In the deepest part of the core, however, the ice is close to the pressure melting point, the visual stratigraphy is dominated by crystal boundaries, and annual layering is not visible to the naked eye...... migration in the deep and warm NGRIP ice. Based on annual layer counting of the new records, we determine a mean annual layer thickness close to 11mm for all three sections, which, to first order, confirms the modeled NGRIP time scale (ss09sea). The counting does, however, suggest a longer duration...

  18. Characterization of dielectric layers grown at low temperature by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gieraltowska, Sylwia, E-mail: [Institute of Physics Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Wachnicki, Lukasz; Witkowski, Bartlomiej S. [Institute of Physics Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Mroczynski, Robert [Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Koszykowa 75, 00-662 Warsaw (Poland); Dluzewski, Piotr [Institute of Physics Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Godlewski, Marek [Institute of Physics Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Department of Mathematics and Natural Sciences, College of Science, Cardinal S. Wyszyński University, Dewajtis 5, 01-815 Warsaw (Poland)


    Dielectric films, such as hafnium dioxide (HfO{sub 2}), aluminum oxide (Al{sub 2}O{sub 3}), zirconium dioxide (ZrO{sub 2}), titanium dioxide (TiO{sub 2}) and their composite layers are deposited on polycrystalline and amorphous substrates by the atomic layer deposition (ALD) method. We demonstrate that the use of this technology guarantees a uniform and controlled surface coverage in the nanometer scale at low temperatures (in our case, below 100 °C). Modification of the composition of oxide layers allows the deposition of materials with quite different absorption coefficients, refractive indexes and dielectric constants. In particular, we demonstrate structural, electrical and optical properties of dielectric layers and test metal-oxide-semiconductor structures with these oxide materials. Our good quality dielectric layers, obtained at low-temperature ALD, are characterized by a high dielectric constant (above 10), very smooth surface, wide energy gap (above 3 eV), low leakage current (in the range of 10{sup −8} A/cm{sup 2} at 1 V), high dielectric strength (even 6 MV/cm) and high refractive indexes (above 1.5 in the visible spectral range). - Highlights: • We demonstrate the use of atomic layer deposition (ALD) at low temperatures (LT). • LT ALD guarantees a uniform and controlled surface coverage of dielectrics. • In our case, the dielectric films were deposited at very LT, below 100 °C. • Dielectrics (HfO{sub 2}, Al{sub 2}O{sub 3}, ZrO{sub 2}, TiO{sub 2} and composite layers) are obtained by ALD. • Our results also indicate high-quality dielectric films.

  19. Nomogram for the height of the daytime mixed layer

    Energy Technology Data Exchange (ETDEWEB)

    Nyren, K. [Ericsson EriSoft AB, Umeaa (Sweden); Gryning, S.E. [Risoe National Lab., Roskilde (Denmark)


    We present a nomogram that provide information about the general behaviour of the mixed layer at a given location. The nomogram is meant to be a practical and easy to use tool to determine the height of the mixed layer for i.e. weather forecaster, air pollution studies and planning of meteorological experiments. Use of the nomogram is restricted to flat, relatively homogeneous terrain. Inhomogeneous terrain with patch scales of 10 km or more might create organised circulation like i.e. lake breezes. The data represented in the nomogram is computed using a meteorological preprocessor and climatological temperature data for the location. The nomogram is simplified but retain main physical processes that control the evolution of the mixed layer and can be easily constructed for any chosen location on land. Nomogram of the mixed layer behavior at the location of Cabauw, the Netherlands is shown and discussed. (au)

  20. Multi-layered, chemically bonded lithium-ion and lithium/air batteries

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R


    Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

  1. Multi-layered, chemically bonded lithium-ion and lithium/air batteries (United States)

    Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R


    Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

  2. Intoxicação em cães e gatos: diagnóstico toxicológico empregando cromatografia em camada delgada e cromatografia líquida de alta pressão com detecção ultravioleta em amostras estomacais Intoxication in dogs and cats: toxicological diagnosis using thin layer chromatography and high pressure liquid chromatography with ultraviolet detection in stomach samples

    Directory of Open Access Journals (Sweden)

    Rachel Picada Bulcão


    Full Text Available Agrotóxicos e raticidas são responsáveis por inúmeras intoxicações humanas e animais. Dados preliminares sugerem que o uso ilegal desses compostos com a finalidade de intoxicação fatal em pequenos animais é uma prática comum na região central do Estado do Rio Grande do Sul. O Laboratório de Toxicologia (LATOX recebe amostras de casos em que a principal suspeita é a intoxicação por agrotóxicos ou raticidas (lícitos e ilícitos. O presente estudo teve como objetivo apresentar um levantamento das intoxicações de pequenos animais, analisadas pelo LATOX no período de 2004 a 2008, sendo identificados os xenobióticos por meio de métodos analíticos otimizados pelo laboratório, incluindo screening por cromatografia em camada delgada (CCD e possível confirmação por cromatografia líquida de alta eficiência (CLAE-UV. No período, foram analisadas 68 amostras oriundas de intoxicações em cães e gatos. As amostras biológicas analisadas foram o estômago e o conteúdo estomacal, das quais a CCD permitiu a identificação de carbamatos, warfarina e estricnina. Esta mostrou ser uma técnica qualitativa eficiente e adequada para esse propósito, além de ser relativamente rápida, de baixo custo e de sofrer pouca interferência de componentes da matriz. Também foi realizado um screening toxicológico por CLAE-UV para os carbamatos n-metilados: aldicarb, carbaril, carbofuran e propoxur. O resultado das análises indicou que o principal agente tóxico encontrado foi o aldicarb (chumbinho, responsável por 39,7% das intoxicações (27 casos, seguido por estricnina (seis casos, warfarina (três casos e monofluoracetato de sódio (um caso. Sendo assim, o "chumbinho" foi o principal agente envolvido em intoxicações de cães e gatos na região central do Estado no período avaliado, e os métodos analíticos CCD e CLAE-UV podem ser utilizados de forma eficiente na rotina laboratorial para identificação e confirmação dos xenobi

  3. Using Protection Layers for a 2-Photon Water Splitting Device

    DEFF Research Database (Denmark)

    Seger, Brian; Mei, Bastian Timo; Frydendal, Rasmus;


    conditions.(2) I will follow this up by discussing how protection layers bypass the corrosion issue by creating a buffer layer.(3) Finally I will show how we integrated a photocatalyst/protection layer/(co-catalyst) scheme to produce highly efficient H2 evolution photocathodes and O2 evolution photoanodes.(3....... Vesborg, O. Hansen and I. Chorkendorff, Journal of the American Chemical Society, 135, 1057 (2013). 4. B. Mei, A. A. Permyakova, R. Frydendal, D. Bae, T. Pedersen, P. Malacrida, O. Hansen, I. E. L. Stephens, P. C. K. Vesborg, B. Seger and I. Chorkendorff, The Journal of Physical Chemistry Letters, 5, 3456...

  4. Markov Logic An Interface Layer for Artificial Intelligence

    CERN Document Server

    Domingos, Pedro


    Most subfields of computer science have an interface layer via which applications communicate with the infrastructure, and this is key to their success (e.g., the Internet in networking, the relational model in databases, etc.). So far this interface layer has been missing in AI. First-order logic and probabilistic graphical models each have some of the necessary features, but a viable interface layer requires combining both. Markov logic is a powerful new language that accomplishes this by attaching weights to first-order formulas and treating them as templates for features of Markov random f

  5. Secure physical layer using dynamic permutations in cognitive OFDMA systems

    DEFF Research Database (Denmark)

    Meucci, F.; Wardana, Satya Ardhy; Prasad, Neeli R.


    This paper proposes a novel lightweight mechanism for a secure Physical (PHY) layer in Cognitive Radio Network (CRN) using Orthogonal Frequency Division Multiplexing (OFDM). User's data symbols are mapped over the physical subcarriers with a permutation formula. The PHY layer is secured...... of the permutations are analyzed for several DSA patterns. Simulations are performed according to the parameters of the IEEE 802.16e system model. The securing mechanism proposed provides intrinsic PHY layer security and it can be easily implemented in the current IEEE 802.16 standard applying almost negligible...

  6. The layer by layer selective laser synthesis of ruby

    Directory of Open Access Journals (Sweden)

    Vlasova M.


    Full Text Available In the work, features of the layer-by-layer selective laser synthesis (SLS of ruby from an Al2O3-Cr2O3 mixture are considered depending on the irradiation power, the laser beam traverse speed, the height and amount of the backfill of powder layers. It has been established that, under irradiation, a track consisting of polycrystalline textured ruby forms. The morphology of the surface of the track and its crystalline structure are determined by the irradiation conditions.

  7. Layer-by-layer magnetometry of polarizing supermirrors

    CERN Document Server

    Ruecker, U; Toperverg, B; Brueckel, T; Ott, F


    We investigate the remagnetization behaviour of remanent polarizing supermirrors by polarized neutron reflectometry. Such a mirror can be remagnetized in a magnetic field of 30 mT. It is shown, that at lower fields, the mirror is not completely remagnetized, but the magnetization of the thinner layers can be flipped more easily than the magnetization of the thicker layers. With polarized neutron reflectometry, we are able to find out exactly how many layers are magnetized parallel and how many are magnetized antiparallel to the external field. Furthermore, information about structural and magnetic imperfections (roughness, domain formation) is available. (orig.)

  8. Nanobiotechnology with S-layer proteins as building blocks. (United States)

    Sleytr, Uwe B; Schuster, Bernhard; Egelseer, Eva M; Pum, Dietmar; Horejs, Christine M; Tscheliessnig, Rupert; Ilk, Nicola


    One of the key challenges in nanobiotechnology is the utilization of self- assembly systems, wherein molecules spontaneously associate into reproducible aggregates and supramolecular structures. In this contribution, we describe the basic principles of crystalline bacterial surface layers (S-layers) and their use as patterning elements. The broad application potential of S-layers in nanobiotechnology is based on the specific intrinsic features of the monomolecular arrays composed of identical protein or glycoprotein subunits. Most important, physicochemical properties and functional groups on the protein lattice are arranged in well-defined positions and orientations. Many applications of S-layers depend on the capability of isolated subunits to recrystallize into monomolecular arrays in suspension or on suitable surfaces (e.g., polymers, metals, silicon wafers) or interfaces (e.g., lipid films, liposomes, emulsomes). S-layers also represent a unique structural basis and patterning element for generating more complex supramolecular structures involving all major classes of biological molecules (e.g., proteins, lipids, glycans, nucleic acids, or combinations of these). Thus, S-layers fulfill key requirements as building blocks for the production of new supramolecular materials and nanoscale devices as required in molecular nanotechnology, nanobiotechnology, biomimetics, and synthetic biology.

  9. D0 layer 0 innermost layer of silicon microstrip tracker

    Energy Technology Data Exchange (ETDEWEB)

    Hanagaki, K.; /Fermilab


    A new inner layer silicon strip detector has been built and will be installed in the existing silicon microstrip tracker in D0. They report on the motivation, design, and performance of this new detector.

  10. Determinação de daidzeína, genisteína e gliciteína em cápsulas de isoflavonas por cromatografia em camada delgada (CCD e cromatografia líquida de alta eficiência (CLAE Determination of daidzein, genistein and glycitein in isoflavone capsules by thin layer chromatography (TLC and high performance liquid chromatography (HPLC

    Directory of Open Access Journals (Sweden)

    Isabela da Costa César


    Full Text Available A utilização de produtos naturais e suplementos contendo extratos secos de isoflavonas aumentou na última década, devido, principalmente, aos efeitos benéficos atribuídos a estes compostos no alívio dos sintomas da menopausa. Genisteína, daidzeína e gliciteína são as agliconas mais abundantes nos extratos de soja, ocorrendo também como glicosídeos. Tendo em vista seus usos, não existe ainda na literatura uma definição da quantidade mínima de cada uma das agliconas que os extratos ou cápsulas de isoflavonas devem ter, e também não existe um método oficial para o controle de qualidade dos mesmos. O presente trabalho apresenta um método por CCD para análise qualitativa das três agliconas e de seus glicosídeos em extratos e cápsulas de isoflavonas, antes e após hidrólise ácida. A análise quantitativa das cápsulas de isoflavonas, realizada por cromatografia líquida de alta eficiência (CLAE, revelou grandes variações nos teores das três agliconas, após hidrólise ácida. Os teores variaram da seguinte forma, nos 18 lotes de cápsulas avaliados: daidzeína (13,34 a 76,20 mg/cápsula, genisteína (0,61 a 27,18 mg/cápsula e gliciteína (0,49 a 8,80 mg/cápsula.The use of herbal products and supplements based on isoflavone dry extracts has increased considerably in the last decade, mainly due to beneficial effects to relief of the menopausal symptoms credited to those compounds. Genistein, daidzein and glycitein are the most abundant isoflavone aglycones found in soy extract, where they also occur as glycosides. Concerning their uses, there is neither standardization regarding the minimum content of each aglycone in the extracts or capsules, nor an official method to the quality control of these products. The present work presents a TLC method for qualitative analysis of the three aglycones and their glycosides in extracts and capsules of isoflavones, before and after acid hydrolysis. The quantitative analysis of the

  11. Band Gap Engineering and Layer-by-Layer Band Gap Mapping of Selenium-doped Molybdenum Disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yongji [Rice University; Liu, Zheng [Rice University; Lupini, Andrew R [ORNL; Lin, Junhao [ORNL; Pantelides, Sokrates T [ORNL; Pennycook, Stephen J [ORNL; Zhou, Wu [ORNL; Ajayan, Pullikel M [Rice University


    Ternary two-dimensional dichalcogenide alloys exhibit compositionally modulated electronic structure and hence, control of dopant concentration within each layer of these layered compounds provides a powerful way to modify their properties. The challenge then becomes quantifying and locating the dopant atoms within each layer in order to better understand and fine-tune the desired properties. Here we report the synthesis of selenium substitutionally doped molybdenum disulfide atomic layers, with a broad range of selenium concentrations, resulting in band gap modulations of over 0.2 eV. Atomic scale chemical analysis using Z-contrast imaging provides direct maps of the dopant atom distribution in individual MoS2 layers and hence a measure of the local band gaps. Furthermore, in a bilayer structure, the dopant distribution of each layer is imaged independently. We demonstrate that each layer in the bilayer contains similar doping levels, randomly distributed, providing new insights into the growth mechanism and alloying behavior in two-dimensional dichalcogenide atomic layers. The results show that growth of uniform, ternary, two-dimensional dichalcogenide alloy films with tunable electronic properties is feasible.

  12. Boundary layers in stochastic thermodynamics. (United States)

    Aurell, Erik; Mejía-Monasterio, Carlos; Muratore-Ginanneschi, Paolo


    We study the problem of optimizing released heat or dissipated work in stochastic thermodynamics. In the overdamped limit these functionals have singular solutions, previously interpreted as protocol jumps. We show that a regularization, penalizing a properly defined acceleration, changes the jumps into boundary layers of finite width. We show that in the limit of vanishing boundary layer width no heat is dissipated in the boundary layer, while work can be done. We further give an alternative interpretation of the fact that the optimal protocols in the overdamped limit are given by optimal deterministic transport (Burgers equation).

  13. Bandgap tunability at single-layer molybdenum disulphide grain boundaries

    KAUST Repository

    Huang, Yu Li


    Two-dimensional transition metal dichalcogenides have emerged as a new class of semiconductor materials with novel electronic and optical properties of interest to future nanoelectronics technology. Single-layer molybdenum disulphide, which represents a prototype two-dimensional transition metal dichalcogenide, has an electronic bandgap that increases with decreasing layer thickness. Using high-resolution scanning tunnelling microscopy and spectroscopy, we measure the apparent quasiparticle energy gap to be 2.40±0.05 eV for single-layer, 2.10±0.05 eV for bilayer and 1.75±0.05 eV for trilayer molybdenum disulphide, which were directly grown on a graphite substrate by chemical vapour deposition method. More interestingly, we report an unexpected bandgap tunability (as large as 0.85±0.05 eV) with distance from the grain boundary in single-layer molybdenum disulphide, which also depends on the grain misorientation angle. This work opens up new possibilities for flexible electronic and optoelectronic devices with tunable bandgaps that utilize both the control of two-dimensional layer thickness and the grain boundary engineering.

  14. The inner core thermodynamics of the tropical cyclone boundary layer (United States)

    Williams, Gabriel J.


    Although considerable progress has been made in understanding the inner-core dynamics of the tropical cyclone boundary layer (TCBL), our knowledge of the inner-core thermodynamics of the TCBL remains limited. In this study, the inner-core budgets of potential temperature (θ), specific humidity ( q), and reversible equivalent potential temperature (θ _e) are examined using a high-resolution multilevel boundary layer model. The potential temperature budgets show that the heat energy is dominated by latent heat release in the eyewall, evaporative cooling along the outer edge of the eyewall, and upward surface fluxes of sensible and latent heat from the underlying warm ocean. It is shown that the vertical θ advection overcompensates the sum of radial advective warming from the boundary layer outflow jet and latent heating for the development of cooling in the eyewall within the TCBL. The moisture budgets show the dominant upward transport of moisture in the eyewall updrafts, partly by the boundary-layer outflow jet from the bottom eye region, so that the eyewall remains nearly saturated. The θ _e budgets reveal that the TCBL is maintained thermodynamically by the upward surface flux of higher-θ _e air from the underlying warm ocean, the radial transport of low-θ _e air from the outer regions of the TCBL, and the dry adiabatic cooling associated by eyewall updrafts. These results underscore the significance of vertical motion and the location of the boundary layer outflow jet in maintaining the inner core thermal structure of the TCBL.

  15. Organic photovoltaic devices with a single layer geometry (Conference Presentation) (United States)

    Kolesov, Vladimir A.; Fuentes-Hernandez, Canek; Aizawa, Naoya; Larrain, Felipe A.; Chou, Wen-Fang; Perrotta, Alberto; Graham, Samuel; Kippelen, Bernard


    Organic photovoltaics (OPV) can lead to a low cost and short energy payback time alternative to existing photovoltaic technologies. However, to fulfill this promise, power conversion efficiencies must be improved and simultaneously the architecture of the devices and their processing steps need to be further simplified. In the most efficient devices to date, the functions of photocurrent generation, and hole/electron collection are achieved in different layers adding complexity to the device fabrication. In this talk, we present a novel approach that yields devices in which all these functions are combined in a single layer. Specifically, we report on bulk heterojunction devices in which amine-containing polymers are first mixed in the solution together with the donor and acceptor materials that form the active layer. A single-layer coating yields a self-forming bottom electron-collection layer comprised of the amine-containing polymer (e.g. PEIE). Hole-collection is achieved by subsequent immersion of this single layer in a solution of a polyoxometalate (e.g. phosphomolybdic acid (PMA)) leading to an electrically p-doped region formed by the diffusion of the dopant molecules into the bulk. The depth of this doped region can be controlled with values up to tens of nm by varying the immersion time. Devices with a single 500 nm-thick active layer of P3HT:ICBA processed using this method yield power conversion efficiency (PCE) values of 4.8 ± 0.3% at 1 sun and demonstrate a performance level superior to that of benchmark three-layer devices with separate layers of PEIE/P3HT:ICBA/MoOx (4.1 ± 0.4%). Devices remain stable after shelf lifetime experiments carried-out at 60 °C over 280 h.

  16. Hepatite E Hepatitis E

    Directory of Open Access Journals (Sweden)

    Raymundo Paraná


    Full Text Available O vírus da hepatite E (VHE é o segundo vírus de transmissão fecal-oral com hepatotropismo confirmado, após o vírus da hepatite A. As grandes epidemias de hepatite das décadas de 50 e 60 na Índia foram causadas pelo VHE. Observaram-se surtos da infecção na África Central, América Latina, Oriente Médio e Repúblicas independentes da ex-União Soviética. O quadro clínico da doença assemelha-se ao de outras hepatites virais. Não há casos descritos de hepatite E crônicas. Cerca de 20% das mulheres que adquirem a doença durante a gravidez desenvolvem formas graves, com insuficiência hepática fulminante. Confirma-se o diagnóstico quando se encontra no soro anticorpos (método de ELISA das classes IgM (fase aguda e/ou IgG (curados. O imunoblot e o PCR-RNA podem ser usados quando necessário. Não há tratamento específico. O uso de imunoglobulina hiperimune tem sido aconselhado por alguns autores. A prevenção se faz pelos cuidados higiênicos e dietéticos habituais. Não há vacina eficaz contra a doença.Hepatitis E virus (HEV is the second most frequent hepatotropic virus transmitted via fecal-oral route, following closely behind hepatitis A virus. The great epidemics of hepatitis described during the 50s and 60s, in India, were caused by this virus. Epidemic bursts have also been described in Central Africa, Latin America, Middle East and in the independent Republics of the ex-Soviet Union. The clinical features of the disease do not differ from those reported for other viral hepatitides. There have been no cases of chronic hepatitis E reported. Around 20% of women infected during pregnancy develop a severe form of hepatitis which courses to liver failure. Diagnosis of hepatitis is confirmed when antibodies (using ELISA of the IgM class (acute phase and/or IgG (infected and cured are found in the serum. Immunoblot and PCR-RNA may be used as necessary. There is no specific treatment for hepatitis E. Hyperimmune serum has

  17. Layered double oxide (LDO) particle containing photoreactive hybrid layers with tunable superhydrophobic and photocatalytic properties (United States)

    Deák, Ágota; Janovák, László; Csapó, Edit; Ungor, Ditta; Pálinkó, István; Puskás, Sándor; Ördög, Tibor; Ricza, Tamás; Dékány, Imre


    Inorganic/organic hybrid layers have been prepared having superhydrophobic as well as photoreactive properties. The hybrid thin films with micro- and nanosized dual-scale surface roughness consist of ∼25 μm layered double oxide (LDO) photocatalyst particles and low surface energy poly(perfluorodecyl acrylate) [p(PFDAc)] fluoropolymer binder material. The application of [p(PFDAc)] resulted in the decrease in the surface free energy of the hydrophilic LDO. The structured surface LDO with ∼12% ZnO phase content were synthesized from layer double hydroxide (LDH) spheres. The determined excitation wavelength and the calculated band gap energy values were 386 nm and 3.23 eV, respectively. The hybrid thin films were prepared by a simple spray-coating method, which is a low-cost, fast and scalable film-forming technique. The surface roughness and also the wetting properties of the two-component hybrid layers proved to be finely adjustable by the LDO:fluoropolymer ratio. It was found that at 80-90 wt% LDO content, the thin films with a surface free energy value of ∼12 mJ/m2 displayed superhydrophobic behaviour (Θ > 150°) with satisfactory photocatalytic properties. This means special photoreactive surfaces with superhydrophobic properties instead of the conventional superhydropilic photocatalyst layers. According to the benzoic acid photodegradation test experiments of benzoic acid, the hybrid layers with 80-90 wt% LDO content photooxidized 22-24% of the initial test molecule concentration (0.17 g/L) under UV-A (λmax = 365 nm) illumination.

  18. On Backus average for generally anisotropic layers

    CERN Document Server

    Bos, Len; Slawinski, Michael A; Stanoev, Theodore


    In this paper, following the Backus (1962) approach, we examine expressions for elasticity parameters of a homogeneous generally anisotropic medium that is long-wave-equivalent to a stack of thin generally anisotropic layers. These expressions reduce to the results of Backus (1962) for the case of isotropic and transversely isotropic layers. In over half-a-century since the publications of Backus (1962) there have been numerous publications applying and extending that formulation. However, neither George Backus nor the authors of the present paper are aware of further examinations of mathematical underpinnings of the original formulation; hence, this paper. We prove that---within the long-wave approximation---if the thin layers obey stability conditions then so does the equivalent medium. We examine---within the Backus-average context---the approximation of the average of a product as the product of averages, and express it as a proposition in terms of an upper bound. In the presented examination we use the e...

  19. Layer-by-Layer Insight into Electrostatic Charge Distribution of Few-Layer Graphene (United States)

    Rokni, Hossein; Lu, Wei


    In few-layer graphene (FLG) systems on a dielectric substrate such as SiO2, the addition of each extra layer of graphene can drastically alter their electronic and structural properties. Here, we map the charge distribution among the individual layers of finite-size FLG systems using a novel spatial discrete model that describes both electrostatic interlayer screening and fringe field effects. Our results reveal that the charge density in the region very close to the edges is screened out an order of magnitude more weakly than that across the central region of the layers. Our discrete model suggests that the interlayer charge screening length in 1–8 layer thick graphene systems depends mostly on the overall gate/molecular doping level rather than on temperature, in particular at an induced charge density >5 × 1012 cm−2, and can reliably be determined to be larger than half the interlayer spacing but shorter than the bilayer thickness. Our model can be used for designing FLG-based devices, and offers a simple rule regarding the charge distribution in FLG: approximately 70%, 20%, 6% and 3% (99% overall) of the total induced charge density reside within the four innermost layers, implying that the gate-induced electric field is not definitely felt by >4th layer. PMID:28220816

  20. Layer-by-Layer Insight into Electrostatic Charge Distribution of Few-Layer Graphene (United States)

    Rokni, Hossein; Lu, Wei


    In few-layer graphene (FLG) systems on a dielectric substrate such as SiO2, the addition of each extra layer of graphene can drastically alter their electronic and structural properties. Here, we map the charge distribution among the individual layers of finite-size FLG systems using a novel spatial discrete model that describes both electrostatic interlayer screening and fringe field effects. Our results reveal that the charge density in the region very close to the edges is screened out an order of magnitude more weakly than that across the central region of the layers. Our discrete model suggests that the interlayer charge screening length in 1–8 layer thick graphene systems depends mostly on the overall gate/molecular doping level rather than on temperature, in particular at an induced charge density >5 × 1012 cm‑2, and can reliably be determined to be larger than half the interlayer spacing but shorter than the bilayer thickness. Our model can be used for designing FLG-based devices, and offers a simple rule regarding the charge distribution in FLG: approximately 70%, 20%, 6% and 3% (99% overall) of the total induced charge density reside within the four innermost layers, implying that the gate-induced electric field is not definitely felt by >4th layer.

  1. Atomic layer deposition for semiconductors

    CERN Document Server

    Hwang, Cheol Seong


    This edited volume discusses atomic layer deposition (ALD) for all modern semiconductor devices, moving from the basic chemistry of ALD and modeling of ALD processes to sections on ALD for memories, logic devices, and machines.

  2. Magnetic microscopy of layered structures

    CERN Document Server

    Kuch, Wolfgang; Fischer, Peter; Hillebrecht, Franz Ulrich


    This book presents the important analytical technique of magnetic microscopy. This method is applied to analyze layered structures with high resolution. This book presents a number of layer-resolving magnetic imaging techniques that have evolved recently. Many exciting new developments in magnetism rely on the ability to independently control the magnetization in two or more magnetic layers in micro- or nanostructures. This in turn requires techniques with the appropriate spatial resolution and magnetic sensitivity. The book begins with an introductory overview, explains then the principles of the various techniques and gives guidance to their use. Selected examples demonstrate the specific strengths of each method. Thus the book is a valuable resource for all scientists and practitioners investigating and applying magnetic layered structures.

  3. National Flood Hazard Layer (NFHL) (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The National Flood Hazard Layer (NFHL) is a compilation of GIS data that comprises a nationwide digital Flood Insurance Rate Map. The GIS data and services are...

  4. Hurricane Boundary-Layer Theory (United States)


    2501. Kundu PK. 1990. Fluid Mechanics . Academic Press: San Diego, USA. Kuo HL. 1982. Vortex boundary layer under quadratic surface stress. Boundary...identification of two mechanisms for the spin-up of the mean tangential circulation of a hurricane. The first involves convergence of absolute angular...momentum above the boundary layer, where this quantity is approximately conserved. This mechanism acts to spin up the outer circulation at radii

  5. Photocurrent generation in organic photodetectors with tailor-made active layers fabricated by layer-by-layer deposition. (United States)

    Vonhoeren, Benjamin; Dalgleish, Simon; Hu, Laigui; Matsushita, Michio M; Awaga, Kunio; Ravoo, Bart Jan


    Photodetectors supply an electric response when illuminated. The detectors in this study consist of an active layer and a polyvinylidene fluoride (PVDF) blocking layer, which are sandwiched by an aluminum and an indium tin oxide (ITO) electrode. The active layer was prepared of Zn porphyrins and assembled by covalent layer-by-layer (LbL) deposition. Layer growth was monitored by UV-vis absorbance, ellipsometry, and X-ray photoelectron spectroscopy. Upon exposure to chopped light, the detectors show an alternating transient photocurrent, which is limited by the accumulation of space charges at the blocking layer/active layer interface. We could show that the number of photoactive layers has a significant impact on device performance. The fastest response was achieved with fewer layers. The highest photocurrents were measured for detectors with an intermediate number of layers, beyond which, more layers did not lead to an increase in the photocurrent despite containing more active material.

  6. S-layer proteins as basic building blocks in a biomolecular construction kit (United States)

    Pum, Dietmar; Neubauer, Angela; Györvary, Erika; Sára, Margit; Sleytr, Uwe B.


    Crystalline bacterial cell surface layer (S-layer) proteins have been optimized during billions of years of biological evolution as constituent elements of one of the simplest self-assembly systems. Isolated S-layer proteins possess the intrinsic property of being able to recrystallize into two-dimensional arrays at a broad spectrum of surfaces (e.g. silicon) and interfaces (e.g. air-water interface or planar lipid films). The well-defined arrangement of functional groups on S-layer lattices allows the binding of molecules and particles in defined regular arrays. S-layers recrystallized on solid supports can be patterned in the submicrometre range using standard optical lithography. S-layers also represent templates for the formation of inorganic nanocrystal superlattices (e.g. CdS, Au, Ni, Pt, or Pd) as required for molecular electronics and nonlinear optics.

  7. Development of Novel Two-dimensional Layers, Alloys and Heterostructures (United States)

    Liu, Zheng


    The one-atom-think graphene has fantastic properties and attracted tremendous interests in these years, which opens a window towards various two-dimensional (2D) atomic layers. However, making large-size and high-quality 2D layers is still a great challenge. Using chemical vapor deposition (CVD) method, we have successfully synthesized a wide varieties of highly crystalline and large scale 2D atomic layers, including h-BN, metal dichalcogenides e.g. MoS2, WS2, CdS, GaSe and MoSe2 which belong to the family of binary 2D materials. Ternary 2D alloys including BCN and MoS2xSe2 (1 - x) are also prepared and characterized. In addition, synthesis of 2D heterostructures such as vertical and lateral graphene/h-BN, vertical and lateral TMDs are also demonstrated. Complementary to CVD grown 2D layers, 2D single-crystal (bulk) such as Phosphorene (P), WTe2, SnSe2, PtS2, PtSe2, PdSe2, WSe2xTe2 (1 - x), Ta2NiS5andTa2NiSe5 are also prepared by solid reactions. There work provide a better understanding of the atomic layered materials in terms of the synthesis, atomic structure, alloying and their physical properties. Potential applications of these 2D layers e.g. optoelectronic devices, energy device and smart coating have been explored.

  8. Layer-by-Layer Assembly of Biopolyelectrolytes onto Thermo/pH-Responsive Micro/Nano-Gels


    Díez-Pascual, Ana M.; Peter S. Shuttleworth


    This review deals with the layer-by-layer (LbL) assembly of polyelectrolyte multilayers of biopolymers, polypeptides (i.e., poly-l-lysine/poly-l-glutamic acid) and polysaccharides (i.e., chitosan/dextran sulphate/sodium alginate), onto thermo- and/or pH-responsive micro- and nano-gels such as those based on synthetic poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAA) or biodegradable hyaluronic acid (HA) and dextran-hydroxyethyl methacrylate (DEX-HEMA). The synthesis of the ...

  9. Mixed mosaic membranes prepared by layer-by-layer assembly for ionic separations. (United States)

    Rajesh, Sahadevan; Yan, Yu; Chang, Hsueh-Chia; Gao, Haifeng; Phillip, William A


    Charge mosaic membranes, which possess distinct cationic and anionic domains that traverse the membrane thickness, are capable of selectively separating dissolved salts from similarly sized neutral solutes. Here, the generation of charge mosaic membranes using facile layer-by-layer assembly methodologies is reported. Polymeric nanotubes with pore walls lined by positively charged polyethylenimine moieties or negatively charged poly(styrenesulfonate) moieties were prepared via layer-by-layer assembly using track-etched membranes as sacrificial templates. Subsequently, both types of nanotubes were deposited on a porous support in order to produce mixed mosaic membranes. Scanning electron microscopy demonstrates that the facile deposition techniques implemented result in nanotubes that are vertically aligned without overlap between adjacent elements. Furthermore, the nanotubes span the thickness of the mixed mosaic membranes. The effects of this unique nanostructure are reflected in the transport characteristics of the mixed mosaic membranes. The hydraulic permeability of the mixed mosaic membranes in piezodialysis operations was 8 L m(-2) h(-1) bar(-1). Importantly, solute rejection experiments demonstrate that the mixed mosaic membranes are more permeable to ionic solutes than similarly sized neutral molecules. In particular, negative rejection of sodium chloride is observed (i.e., the concentration of NaCl in the solution that permeates through a mixed mosaic membrane is higher than in the initial feed solution). These properties illustrate the ability of mixed mosaic membranes to permeate dissolved ions selectively without violating electroneutrality and suggest their utility in ionic separations.

  10. The near-global mesospheric potassium layer: Observations and modeling (United States)

    Dawkins, E. C. M.; Plane, J. M. C.; Chipperfield, M. P.; Feng, W.


    The meteoric metal layers act as unique tracers of chemistry and dynamics in the upper atmosphere. Existing lidar studies from a few locations show that K exhibits a semiannual seasonality (winter and summer maxima), quite unlike the annual seasonality (winter maximum and summer minimum) seen with Na and Fe. This work uses spaceborne observations made with the Optical Spectrograph and InfraRed Imager System instrument on the Odin satellite to retrieve the near-global K layer for the first time. The satellite data (2004 to mid-2013) are used to validate the implementation of a recently proposed potassium chemistry scheme in a whole atmosphere chemistry climate model, which provides a chemical basis for this semiannual seasonal behavior. The satellite and model data show that this semiannual seasonality is near global in extent, with the strongest variation at middle and high latitudes. The column abundance, centroid layer height, and root-mean-square width of the K layer are consistent with the limited available lidar record. The K data set is then used to investigate the impact of polar mesospheric clouds on the metal layers at high latitudes during summer. Finally, the occurrence frequency of sporadic K layers and their possible link to sporadic E layers are examined.

  11. The near‐global mesospheric potassium layer: Observations and modeling (United States)

    Dawkins, E. C. M.; Chipperfield, M. P.; Feng, W.


    Abstract The meteoric metal layers act as unique tracers of chemistry and dynamics in the upper atmosphere. Existing lidar studies from a few locations show that K exhibits a semiannual seasonality (winter and summer maxima), quite unlike the annual seasonality (winter maximum and summer minimum) seen with Na and Fe. This work uses spaceborne observations made with the Optical Spectrograph and InfraRed Imager System instrument on the Odin satellite to retrieve the near‐global K layer for the first time. The satellite data (2004 to mid‐2013) are used to validate the implementation of a recently proposed potassium chemistry scheme in a whole atmosphere chemistry climate model, which provides a chemical basis for this semiannual seasonal behavior. The satellite and model data show that this semiannual seasonality is near global in extent, with the strongest variation at middle and high latitudes. The column abundance, centroid layer height, and root‐mean‐square width of the K layer are consistent with the limited available lidar record. The K data set is then used to investigate the impact of polar mesospheric clouds on the metal layers at high latitudes during summer. Finally, the occurrence frequency of sporadic K layers and their possible link to sporadic E layers are examined. PMID:27478716

  12. Sensitivity analysis of bi-layered ceramic dental restorations. (United States)

    Zhang, Zhongpu; Zhou, Shiwei; Li, Qing; Li, Wei; Swain, Michael V


    The reliability and longevity of ceramic prostheses have become a major concern. The existing studies have focused on some critical issues from clinical perspectives, but more researches are needed to address fundamental sciences and fabrication issues to ensure the longevity and durability of ceramic prostheses. The aim of this paper was to explore how "sensitive" the thermal and mechanical responses, in terms of changes in temperature and thermal residual stress of the bi-layered ceramic systems and crown models will be with respect to the perturbation of the design variables chosen (e.g. layer thickness and heat transfer coefficient) in a quantitative way. In this study, three bi-layered ceramic models with different geometries are considered: (i) a simple bi-layered plate, (ii) a simple bi-layer triangle, and (iii) an axisymmetric bi-layered crown. The layer thickness and convective heat transfer coefficient (or cooling rate) seem to be more sensitive for the porcelain fused on zirconia substrate models. The resultant sensitivities indicate a critical importance of the heat transfer coefficient and thickness ratio of core to veneer on the temperature distributions and residual stresses in each model. The findings provide a quantitative basis for assessing the effects of fabrication uncertainties and optimizing the design of ceramic prostheses. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Hybrid window layer for photovoltaic cells (United States)

    Deng, Xunming


    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  14. Bacterial S-layer protein coupling to lipids

    DEFF Research Database (Denmark)

    Weygand, M.; Wetzer, B.; Pum, D.


    The coupling of bacterial surface (S)-layer proteins to lipid membranes is studied in molecular detail for proteins from Bacillus sphaericus CCM2177 and B. coagulans E38-66 recrystallized at dipalmitoylphosphatidylethanolamine (DPPE) monolayers on aqueous buffer. A comparison of the monolayer...... that the phosphatidylethanolamine headgroups must reorient toward the surface normal to accommodate such changes. In terms of the protein structure (which is as yet unknown in three dimensions), the electron density profile reveals a thickness I(z) approximate to 90 Angstrom of the recrystallized S-layer and shows water......-filled cavities near its center. The protein volume fraction reaches maxima of >60% in two horizontal sections of the S-layer, close to the lipid monolayer and close to the free subphase. In between it drops to similar to 20%. Four S-layer protein monomers are located within the unit cell of a square lattice...

  15. DNS Study on Physics of Late Boundary Layer Transition

    CERN Document Server

    Liu, Chaoqun


    This paper serves as a review of our recent new DNS study on physics of late boundary layer transition. This includes mechanism of the large coherent vortex structure formation, small length scale generation and flow randomization. The widely spread concept vortex breakdown to turbulence,which was considered as the last stage of flow transition, is not observed and is found theoretically incorrect. The classical theory on boundary layer transition is challenged and we proposed a new theory with five steps, i.e. receptivity, linear instability, large vortex formation, small length scale generation, loss of symmetry and randomization to turbulence. We have also proposed a new theory about turbulence generation. The new theory shows that all small length scales (turbulence) are generated by shear layer instability which is produced by large vortex structure with multiple level vortex rings, multiple level sweeps and ejections, and multiple level negative and positive spikes near the laminar sub-layers.Therefore,...

  16. Nonlocal thermal transport across embedded few-layer graphene sheets. (United States)

    Liu, Ying; Huxtable, Scott T; Yang, Bao; Sumpter, Bobby G; Qiao, Rui


    Thermal transport across the interfaces between few-layer graphene sheets and soft materials exhibits intriguing anomalies when interpreted using the classical Kapitza model, e.g. the conductance of the same interface differs greatly for different modes of interfacial thermal transport. Using atomistic simulations, we show that such thermal transport follows a nonlocal flux-temperature drop constitutive law and is characterized jointly by a quasi-local conductance and a nonlocal conductance instead of the classical Kapitza conductance. The nonlocal model enables rationalization of many anomalies of the thermal transport across embedded few-layer graphene sheets and should be used in studies of interfacial thermal transport involving few-layer graphene sheets or other ultra-thin layered materials.

  17. Investigation of turbulent plane mixing layer using generalized differential quadrature

    Energy Technology Data Exchange (ETDEWEB)

    Basirat Tabrizi, H.; Rezaei Niya, S.M.; Fariborz, S.J. [Amirkabir Univ. of Tech., Mechanical Engineering Dept., Tehran (Iran, Islamic Republic of)]. E-mail:;


    There is considerable interest in two-dimensional turbulent mixing layer, to name a few e.g. nature, combustion chamber, premixers of gas turbine combustor and many other technological applications. There features are the presence of large vortical structure, free turbulent characteristics, asymptotic behavior, faster growth rate. Some of the parameters that are known to affect the mixing layer behavior are investigated through the numerical models and experimental analysis during these past decades. A suitable solution for turbulent plane mixing layer requires the use of variable mesh size and an appropriate discretization scheme. The Generalized Differential Quadrature (GDQ) method is utilized to solve the problem. It can be a tool for evaluating the equations obtained for plane mixing layer. The present approach works well by refining mesh size, simplifying the calculation algorithms and less time for calculation anticipated. The numerical simulation is compared with the reported numerical and experimental results of others. (author)

  18. Photosensitivity of layered semiconductor propolis heterocontact (United States)

    Drapak, Stepan I.; Orletskii, Volodymyr B.; Bahtinov, Anatolii P.; Kovalyuk, Zakhar D.; Fotiy, Vasyl D.


    Room temperature photosensitivity and its spectral distribution are investigated for a hetercontact between a layered semiconductor (p-InSe) and a biological entity (propolis). The obtained heterocontacts has a maximum photosensitivity >= 10^4 V/W. It is shown that the form of spectral sensitivity curve depends on the way of the heterocontact preparation. The long-wave edge of relative quantum efficiency varies from hν =1.2 eV (the energy gap for InSe at T=300 K) to 1.6 eV depending on a state of aggregation of propolis. The maximum photosensitivity in the long-wave spectral range takes place when the propolis layer is under illumination. The obtained peculiarities of the photoelectrical properties cannot be explained in the framework of the classical description of photosensitivity spectral description (the window effect) what follows from the optical absorption measurements for InSe and propolis in the range hν propolis, a product from honey bee, must be taken into account.

  19. Plasmon analysis and homogenization in plane layered photonic crystals and hyperbolic metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Davidovich, M. V., E-mail: [Saratov State University (Russian Federation)


    Dispersion equations are obtained and analysis and homogenization are carried out in periodic and quasiperiodic plane layered structures consisting of alternating dielectric layers, metal and dielectric layers, as well as graphene sheets and dielectric (SiO{sub 2}) layers. Situations are considered when these structures acquire the properties of hyperbolic metamaterials (HMMs), i.e., materials the real parts of whose effective permittivity tensor have opposite signs. It is shown that the application of solely dielectric layers is more promising in the context of reducing losses.

  20. Plasmon analysis and homogenization in plane layered photonic crystals and hyperbolic metamaterials (United States)

    Davidovich, M. V.


    Dispersion equations are obtained and analysis and homogenization are carried out in periodic and quasiperiodic plane layered structures consisting of alternating dielectric layers, metal and dielectric layers, as well as graphene sheets and dielectric (SiO2) layers. Situations are considered when these structures acquire the properties of hyperbolic metamaterials (HMMs), i.e., materials the real parts of whose effective permittivity tensor have opposite signs. It is shown that the application of solely dielectric layers is more promising in the context of reducing losses.

  1. Analysis of plasmons and homogenization in a flat-layered photonic crystals and hyperbolic metamaterials (United States)

    Davidovich, Mikhael V.


    The dispersion equation and the analysis and homogenization in periodic and quasiperiodic plane layered structures with alternating dielectric layers of metal and dielectric layers, as well as a graphene sheet and SiO2 layers have been investigated. The cases are considered when these patterns become the properties of hyperbolic metamaterials, i.e., having different signs of the real parts of the tensor components of the effective dielectric constant. It is shown that usage only dielectric layers is perspective in reducing losses.

  2. Layer-by-layer films for biomedical applications

    CERN Document Server

    Picart, Catherine; Voegel, Jean-Claude


    The layer-by-layer (LbL) deposition technique is a versatile approach for preparing nanoscale multimaterial films: the fabrication of multicomposite films by the LbL procedure allows the combination of literally hundreds of different materials with nanometer thickness in a single device to obtain novel or superior performance. In the last 15 years the LbL technique has seen considerable developments and has now reached a point where it is beginning to find applications in bioengineering and biomedical engineering. The book gives a thorough overview of applications of the LbL technique in the c

  3. DAR Assisted Layer-by-Layer Assembly of Aromatic Compounds

    Institute of Scientific and Technical Information of China (English)

    姜思光; 陈晓东; 张莉; 刘鸣华


    A facile DAR (diphenylamine-4-diazonium-formaldehyde resin)assisted layer-by-layer (LbL) assembly of uitrathin organic film of aromatic compounds has been investigated. The muitilayer of pyrene or anthracene was fabricated through simple dipping of the glass slide into the mixed solution of DAR with the target compounds. In this method, DAR acted as an assistant compound to help the assembling of the aromatic compounds. Such a convenient deposition method not only reserves the advantages of the traditional LbL technique but also simplifies the technique and extends the effectiveness of LbL technique to small molecules without any charge.

  4. Annual layering in the NGRIP ice core during the Eemian

    Directory of Open Access Journals (Sweden)

    A. Svensson


    Full Text Available The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core annual layers can be identified from impurity records and visual stratigraphy, and stratigraphic layer counting has been performed back to 60 ka. In the deepest part of the core, however, the ice is close to the pressure melting point, the visual stratigraphy is dominated by crystal boundaries, and annual layering is not visible to the naked eye. In this study, we apply a newly developed setup for high-resolution ice core impurity analysis to produce continuous records of dust, sodium and ammonium concentrations as well as conductivity of melt water. We analyzed three 2.2 m sections of ice from the Eemian and the glacial inception. In all of the analyzed ice, annual layers can clearly be recognized, most prominently in the dust and conductivity profiles. Part of the samples is, however, contaminated in dust, most likely from drill liquid. It is interesting that the annual layering is preserved despite a very active crystal growth and grain boundary migration in the deep and warm NGRIP ice. Based on annual layer counting of the new records, we determine a mean annual layer thickness close to 11 mm for all three sections, which, to first order, confirms the modeled NGRIP time scale (ss09sea. The counting does, however, suggest a longer duration of the climatically warmest part of the NGRIP record (MIS5e of up to 1 ka as compared to the model estimate. Our results suggest that stratigraphic layer counting is possible basically throughout the entire NGRIP ice core provided sufficiently highly-resolved profiles become available.

  5. Annual layering in the NGRIP ice core during the Eemian

    Directory of Open Access Journals (Sweden)

    A. Svensson


    Full Text Available The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core, annual layers can be identified from impurity records and visual stratigraphy, and stratigraphic layer counting has been performed back to 60 ka. In the deepest part of the core, however, the ice is close to the pressure melting point, the visual stratigraphy is dominated by crystal boundaries, and annual layering is not visible to the naked eye. In this study, we apply a newly developed setup for high-resolution ice core impurity analysis to produce continuous records of dust, sodium and ammonium concentrations as well as conductivity of melt water. We analyzed three 2.2 m sections of ice from the Eemian and the glacial inception. In all of the analyzed ice, annual layers can clearly be recognized, most prominently in the dust and conductivity profiles. Part of the samples is, however, contaminated in dust, most likely from drill liquid. It is interesting that the annual layering is preserved despite a very active crystal growth and grain boundary migration in the deep and warm NGRIP ice. Based on annual layer counting of the new records, we determine a mean annual layer thickness close to 11 mm for all three sections, which, to first order, confirms the modeled NGRIP time scale (ss09sea. The counting does, however, suggest a longer duration of the climatically warmest part of the NGRIP record (MIS5e of up to 1 ka as compared to the model estimate. Our results suggest that stratigraphic layer counting is possible basically throughout the entire NGRIP ice core, provided sufficiently highly-resolved profiles become available.

  6. Atmospheric spatial atomic layer deposition of Zn(O,S) buffer layer for Cu(In,Ga)Se2 solar cells

    NARCIS (Netherlands)

    Frijters, C.H.; Poodt, P.; Illeberi, A.


    Zinc oxysulfide has been grown by spatial atomic layer deposition (S-ALD) and successfully applied as buffer layer in Cu(In, Ga)Se2 (CIGS) solar cells. S-ALD combines high deposition rates (up to nm/s) with the advantages of conventional ALD, i.e. excellent control of film composition and superior u

  7. Role of Cl on Diffusion of Cu in In2S3 Layers Prepared by Ion Layer Gas Reaction Method

    Directory of Open Access Journals (Sweden)

    Henry Wafula


    Full Text Available Ion layer gas reaction (ILGAR method allows for deposition of Cl-containing and Cl-free In2S3 layers from InCl3 and In(OCCH3CHOCCH33 precursor salts, respectively. A comparative study was performed to investigate the role of Cl on the diffusion of Cu from CuSCN source layer into ILGAR deposited In2S3 layers. The Cl concentration was varied between 7 and 14 at.% by varying deposition parameters. The activation energies and exponential pre-factors for Cu diffusion in Cl-containing samples were between 0.70 to 0.78 eV and between 6.0 × 10−6 and 3.2 × 10−5 cm2/s. The activation energy in Cl-free ILGAR In2S3 layers was about three times less compared to the Cl-containing In2S3, and the pre-exponential constant six orders of magnitude lower. These values were comparable to those obtained from thermally evaporated In2S3 layers. The residual Cl-occupies S sites in the In2S3 structure leading to non-stoichiometry and hence different diffusion mechanism for Cu compared to stoichiometric Cl-free layers.


    NARCIS (Netherlands)


    It is shown that if a disk of finite radius and the surrounding medium rotate coaxially with slightly different angular velocities, an axial layer in the form of a cylindrical shell exists at the edge of the disk. This shell of thickness O(E1/3) has length O(E-1) in axial direction, where E is the E

  9. Self-consistent unstirred layers in osmotically driven flows (United States)

    Bruus, Henrik; Hartvig Jensen, Kåre; Bohr, Tomas


    It has long been recognized, that the osmotic transport characteristics of membranes may be strongly influenced by the presence of unstirred concentration boundary layers adjacent to the membrane. Previous experimental as well as theoretical works have mainly focused on the case where the solutions on both sides of the membrane remain well-mixed due to an external stirring mechanism. We investigate the effects of concentration boundary layers on the efficiency of osmotic pumping processes in the absence of external stirring i.e. when all advection is provided by the osmosis itself. This case is relevant in the study of intracellular flows, e.g. in plants. For such systems, we show that no well-defined boundary layer thickness exists and that the reduction in concentration can be estimated by a surprisingly simple mathematical relation across a wide range of geometries and P'eclet numbers. This work is accepted for publication in Journal of Fluid Mechanics.

  10. Catalysts, Protection Layers, and Semiconductors

    DEFF Research Database (Denmark)

    Chorkendorff, Ib


    Hydrogen is the simplest solar fuel to produce and in this presentation we shall give a short overview of the pros and cons of various tandem devices [1]. The large band gap semiconductor needs to be in front, but apart from that we can chose to have either the anode in front or back using either...... acid or alkaline conditions. Since most relevant semiconductors are very prone to corrosion the advantage of using buried junctions and using protection layers offering shall be discussed [2-4]. Next we shall discuss the availability of various catalysts for being coupled to these protections layers...... and how their stability may be evaluated [5, 6]. Examples of half-cell reaction using protection layers for both cathode and anode will be discussed though some of recent examples under both alkaline and acidic conditions. Si is a very good low band gap semiconductor and by using TiO2 as a protection...

  11. Boundary layer control for airships (United States)

    Pake, F. A.; Pipitone, S. J.


    An investigation is summarized of the aerodynamic principle of boundary layer control for nonrigid LTA craft. The project included a wind tunnel test on a BLC body of revolution at zero angle of attack. Theoretical analysis is shown to be in excellent agreement with the test data. Methods are evolved for predicting the boundary layer development on a body of revolution and the suction pumping and propulsive power requirements. These methods are used to predict the performance characteristics of a full-scale airship. The analysis indicates that propulsive power reductions of 15 to 25 percent and endurance improvements of 20 to 40 percent may be realized in employing boundary-layer control to nonrigid airships.

  12. Supermolecular layered dou- ble hydroxides

    Institute of Scientific and Technical Information of China (English)


    Research progresses in the layered double hydroxides ·mH2O intercalated with metal coordinate ions or oxometalates in the last ten years are reviewed. These layered double hydroxides are mainly intercalated with polyoxometalate (POM) ions, a LiAl-LDH photochemical assembly containing TiO2 and CH3(CH2)12COO- anions, together with Zn(TPPC) (porphy-rin derivate) and macrocyclic ligand-containing porphyrin derivate anions. Emphasis is put on the synthesis methods for intercalation of the anions into the interlayer regions, the characterization techniques and structures for the layered compounds and the newest research progress in the fields such as catalysis. The review also forecasts the prospects of the field.

  13. The aqueous thermal boundary layer (United States)

    Katsaros, Kristina B.


    This article reviews the available data, measurement techniques, and present understanding of the millimeter thick aqueous thermal boundary layer. A temperature difference between the surface and lower strata, δT, of the order of a few tenths to -1 °C have been observed. Techniques ranging from miniature mercury thermometers and electrical point sensors to optical interferometry and infrared radiometry have been employed. Many processes influence the temperature structure in this thin boundary layer. Among them are: the net upward heat flux due to evaporation and sensible heat transfer; infrared and solar radiation; and the turbulence near the interface due to wind mixing, wave breaking and current shear. Presence of solute and surface-active materials stimulate or dampen these mixing processes thereby influencing boundary-layer thickness and temperature structure.

  14. Asymptotic analysis and boundary layers

    CERN Document Server

    Cousteix, Jean


    This book presents a new method of asymptotic analysis of boundary-layer problems, the Successive Complementary Expansion Method (SCEM). The first part is devoted to a general comprehensive presentation of the tools of asymptotic analysis. It gives the keys to understand a boundary-layer problem and explains the methods to construct an approximation. The second part is devoted to SCEM and its applications in fluid mechanics, including external and internal flows. The advantages of SCEM are discussed in comparison with the standard Method of Matched Asymptotic Expansions. In particular, for the first time, the theory of Interactive Boundary Layer is fully justified. With its chapter summaries, detailed derivations of results, discussed examples and fully worked out problems and solutions, the book is self-contained. It is written on a mathematical level accessible to graduate and post-graduate students of engineering and physics with a good knowledge in fluid mechanics. Researchers and practitioners will estee...

  15. Lamb waves in a thin isotropic layer between two anisotropic layers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Haiyan; ZHOU Quan; L(U) Donghui


    Attenuative Lamb wave propagation in adhesively bonded anisotropic composite plates is introduced. The isotropic adhesive exhibits viscous behavior to stimulate the poor curing of the middle layer. Viscosity is assumed to vary linearly with frequency, implying that attenuation per wavelength is constant. Attenuation can be implemented in the analysis through modification of elastic properties of isotropic adhesive. The new properties become complex, but cause no further complications in the analysis. The characteristic equation is the same as that used for the elastic plate case, except that both real and imaginary parts of the wave number (i.e., the attenuation) must be computed. Based on the Lowe's solution in finding the complex roots of characteristic equation, the effect of longitudinal and shear attenuation coefficients of the middle adhesive layer on phase velocity dispersion curves and attenuation dispersion curves of Lamb waves propagating in bonded anisotropic composites is visualized numerically.

  16. Histological, biochemical and pharmacologycal characterization of the gastric muscular layer in Chagas disease Caracterização histológica, bioquímica e farmacológica da musculatura gástrica na doença de Chagas

    Directory of Open Access Journals (Sweden)

    Wagner Carlucci


    Full Text Available PURPOSE: To assess in vitro the correlation between the number of neurons and the sensitivity to cholinergic drugs and acetylcholinesterase activity in chagasic patients. METHODS: A 3x1 cm strip of the muscle layer of the anterior part of the stomach, always close to the angular incisure, was removed from 10 chronic chagasic patients (6 men submitted to megaesophagus or megacolon surgery and from 10 non-chagasic patients (4 men submitted to other types of surgery (control group, aged on average 52.3 and 50.1 years, respectively, for histological and pharmacological studies. The action of cholinergic drugs was investigated in isolated preparations according to the superfusion method of Ferreira and Costa, and acetylcholinesterase activity was determined by the method of Ellman. For neuron count, the strips were cut into 8 µm sections according to the method standardized by Alcântara. RESULTS: There was a difference in number of neurons between the chagasic (5,6 and control (7,3 groups. Acetylcholinesterase activity, in moles of hydrolyzed substrate per minute per gram tissue, was reduced in chagasic patients (4,32 compared to the controls (7,30. No hypersensitivity of the gastric musculature to cholinergic drugs was detected, with a reduced maximum response to carbachol and betanechol in the chagasic group. CONCLUSIONS: The reduction of neurons in the myenteric plexus of the stomach of chronic chagasic patients can be demonstrated even in the absence of clinical chagasic gastropathy. The hypersensitivity of the gastric musculature to cholinergic drugs probably depends on intense denervation. The reduced acetylcholinesterase activity demonstrates the involvement of the cholinergic innervation in the stomach of chronic chagasic patients. There was no correlation between number of neurons, sensitivity to cholinergic drugs and acetylcholinesterase activity in the gastric musculature of chagasic and non-chagasic patients.OBJETIVO: Avaliar in vitro a

  17. The Lowest Atmosphere: Atmospheric Boundary Layer Including Atmospheric Surface Layer. (United States)


    of motion of the atmosphere— "second order closure"—to such applications as the SCIPUFF -PC code for tracer dispersion (see Sykes, 1994). Now, for...Turbulence, Methuen, London, 2nd Ed., 1955. Sykes, R.I., "The SCIPUFF -PC Code," ARAP Draft Report, 1994. Tennekes, H., "The Atmospheric Boundary Layer

  18. Electrostatic layer-by-layer construction of fibrous TMV biofilms. (United States)

    Tiu, Brylee David B; Kernan, Daniel L; Tiu, Sicily B; Wen, Amy M; Zheng, Yi; Pokorski, Jonathan K; Advincula, Rigoberto C; Steinmetz, Nicole F


    As nature's choice in designing complex architectures, the bottom-up assembly of nanoscale building blocks offers unique solutions in achieving more complex and smaller morphologies with wide-ranging applications in medicine, energy, and materials science as compared to top-down manufacturing. In this work, we employ charged tobacco mosaic virus (TMV-wt and TMV-lys) nanoparticles in constructing multilayered fibrous networks via electrostatic layer-by-layer (LbL) deposition. In neutral aqueous media, TMV-wt assumes an anionic surface charge. TMV-wt was paired with a genetically engineered TMV-lys variant that displays a corona of lysine side chains on its solvent-exposed surface. The electrostatic interaction between TMV-wt and TMV-lys nanoparticles became the driving force in the highly controlled buildup of the multilayer TMV constructs. Since the resulting morphology closely resembles the 3-dimensional fibrous network of an extracellular matrix (ECM), the capability of the TMV assemblies to support the adhesion of NIH-3T3 fibroblast cells was investigated, demonstrating potential utility in regenerative medicine. Lastly, the layer-by-layer deposition was extended to release the TMV scaffolds as free-standing biomembranes. To demonstrate potential application in drug delivery or vaccine technology, cargo-functionalized TMV biofilms were programmed.

  19. Nonparallel stability of boundary layers (United States)

    Nayfeh, Ali H.


    The asymptotic formulations of the nonparallel linear stability of incompressible growing boundary layers are critically reviewed. These formulations can be divided into two approaches. The first approach combines a numerical method with either the method of multiple scales, or the method of averaging, of the Wentzel-Kramers-Brillouin (WKB) approximation; all these methods yield the same result. The second approach combined a multi-structure theory with the method of multiple scales. The first approach yields results that are in excellent agreement with all available experimental data, including the growth rates as well as the neutral stability curve. The derivation of the linear stability of the incompressible growing boundary layers is explained.

  20. Operating System Abstraction Layer (OSAL) (United States)

    Yanchik, Nicholas J.


    This viewgraph presentation reviews the concept of the Operating System Abstraction Layer (OSAL) and its benefits. The OSAL is A small layer of software that allows programs to run on many different operating systems and hardware platforms It runs independent of the underlying OS & hardware and it is self-contained. The benefits of OSAL are that it removes dependencies from any one operating system, promotes portable, reusable flight software. It allows for Core Flight software (FSW) to be built for multiple processors and operating systems. The presentation discusses the functionality, the various OSAL releases, and describes the specifications.

  1. Spatial atmospheric ALD of functional layers for CIGS Solar Cells

    NARCIS (Netherlands)

    Illiberi, A.; Frijters, C.; Balder, J.E.; Poodt, P.W.G.; Roozeboom, F.


    Spatial Atmosperic Atomic Layer Depositon combines the advantages of temporal ALD, i.e. excellent control of film composition and uniformity over large area substrates, with high growth rages (up tot nm/s). In this paper we present a short overview of our research acctivity carried out on S-ALD of f

  2. Self-consistent unstirred layers in osmotically driven flows

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Bohr, Tomas; Bruus, Henrik


    on both sides of the membrane remain well mixed due to an external stirring mechanism. We investigate the effects of concentration boundary layers on the efficiency of osmotic pumping processes in the absence of external stirring, i.e. when all advection is provided by the osmosis itself. This case...

  3. Lidar Scanning of Momentum Flux in the Marine Boundary Layer

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Mann, Jakob; Courtney, Michael

    required for wind engineering. Estimations of friction velocity over the sea can be performed by combining wind speed measurements, a sea roughness length formulation and the surface-layer wind profile, i.e. a bulk-derived method. This method was tested in Peña et al. (2008) by comparison with direct...

  4. Extreme ultraviolet induced defects on few-layer graphene

    NARCIS (Netherlands)

    Gao, A.; Rizo, P. J.; Zoethout, E.; Scaccabarozzi, L.; Lee, C. J.; Banine, V.; F. Bijkerk,


    We use Raman spectroscopy to show that exposing few-layer graphene to extreme ultraviolet (EUV, 13.5 nm) radiation, i.e., relatively low photon energy, results in an increasing density of defects. Furthermore, exposure to EUV radiation in a H2 background increases the graphene dosage sensitivity, du

  5. Boundary Layer Simulation and Control in Wind Tunnels (United States)


    Vol. 1, No. 4, April 1963, pp. 931-933. AIAA 11. Maybe, Dennis G.: Some Remarks on Dynamic Aeroelastic Model Tests in Cryogenic Wind Tunnels...distribution). 42. Lindhout, J.P.F, Moek , C., Boer, E. de and Berg, B. van den: A Method for the Calculation of 3D Boundary Layers on Practical Wing

  6. Two Phases of Coherent Structure Motions in Turbulent Boundary Layer

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Hua; JIANG Nan


    Two phases of coherent structure motion are acquired after obtaining conditional phase-averaged waveforms for longitudinal velocity of coherent structures in turbulent boundary layer based on Harr wavelet transfer. The correspondences of the two phases to the two processes (i.e. ejection and sweep) during a burst are determined.

  7. Consolidation of flaw-tolerant layered structures by the insertion of reactive layers

    Directory of Open Access Journals (Sweden)

    Baudín, C.


    Full Text Available The processing parameters to obtain a laminate consisting of very thin alumina-aluminium titanate crack deflecting layered structures sandwiched between relatively thick load bearing alumina layers are described. The optimum processing conditions for the insertion of reactive layers to improve joining during sintering have been established. Pre-sintered alumina tapes were used as the load bearing components while the internal structures were shaped by a combination of electrophoretic deposition (EPD and dipping. The dipped layers acted as reactive layers during sintering. The thickness of the dipped layers has to be controlled in order to avoid the disappearance of the EPD structure during sintering as well as the cracking of the coating during drying or handling. The specimens were mechanically tested in three points bending with the applied load perpendicular to the layers and the fracture surfaces were observed by scanning electron microscopy. The obtained structure presents crack deflection at the microstructural scale during fracture which confers it flaw tolerance.

    Se describen los parámetros de procesamiento mas adecuados para obtener laminados constituidos por capas finas de alúmina-titanato de aluminio deflectoras de grietas alternadas con capas gruesas de alúmina resistentes a las cargas. Estas últimas se han fabricado a partir de láminas obtenidas por colaje en cinta y presintetizadas. Las estructuras con capacidad para la deflexión de las grietas se conformaron mediante una combinación de deposición electroforética e inmersión. Se han establecido las condiciones óptimas para que las capas obtenidas por inmersión actúen como capas reactivas durante la sinterización, sin que desaparezca la estructura EPD durante la sinterización ni se produzca el agrietamiento durante el secado y la manipulación de la estructura. El comportamiento mecánico de las estructuras laminadas obtenidas se analizó mediante

  8. Expression and cytosolic assembly of the S-layer fusion protein mSbsC-EGFP in eukaryotic cells

    NARCIS (Netherlands)

    Blecha, Andreas; Zarschler, Kristof; Sjollema, Klaas A.; Veenhuis, Marten; Rödel, Gerhard; Rodel, G.


    Background: Native as well as recombinant bacterial cell surface layer (S-layer) protein of Geobacillus (G.) stearothermophilus ATCC 12980 assembles to supramolecular structures with an oblique symmetry. Upon expression in E. coli, S-layer self assembly products are formed in the cytosol. We tested

  9. Performing Multicut on Walkable Environments : Obtaining a Minimally Connected Multi-Layered Environment from a Walkable Environment

    NARCIS (Netherlands)

    Hillebrand, A.; van den Akker, J.M.; Geraerts, R.J.; Hoogeveen, J.A.


    A multi-layered environment is a representation of the walkable space in a 3D virtual environment that comprises a set of two-dimensional layers together with the locations where the different layers touch, which are called connections. This representation can be used for crowd simulations, e.g. to

  10. Prediction of turbulent shear layers in turbomachines (United States)

    Bradshaw, P.


    The characteristics of turbulent shear layers in turbomachines are compared with the turbulent boundary layers on airfoils. Seven different aspects are examined. The limits of boundary layer theory are investigated. Boundary layer prediction methods are applied to analysis of the flow in turbomachines.

  11. Improving modeling with layered UML diagrams

    DEFF Research Database (Denmark)

    Störrle, Harald


    Layered diagrams are diagrams whose elements are organized into sets of layers. Layered diagrams are routinely used in many branches of engineering, except Software Engineering. In this paper, we propose to add layered diagrams to UML modeling tools, and elaborate the concept by exploring usage...

  12. Adhesion Between Poly(dimethylsiloxane) Layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    Different adhesion methods of poly(dimethylsiloxane) (PDMS) layers were studied with respect to adhesional force and the resulting rheology of the two-layered PDMS films were investigated. The role of adhesion between PDMS layers on the performances of two-layer structures was studied with peel...

  13. Doped LZO buffer layers for laminated conductors (United States)

    Paranthaman, Mariappan Parans [Knoxville, TN; Schoop, Urs [Westborough, MA; Goyal, Amit [Knoxville, TN; Thieme, Cornelis Leo Hans [Westborough, MA; Verebelyi, Darren T [Oxford, MA; Rupich, Martin W [Framingham, MA


    A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the substrate, the biaxially textured buffer layer comprising LZO and a dopant for mitigating metal diffusion through the LZO, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.

  14. High Performance Thin Layer Chromatography. (United States)

    Costanzo, Samuel J.


    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  15. Shockwave-boundary layer interactions

    NARCIS (Netherlands)

    Glepman, R.


    Shock wave-boundary layer interactions are a very common feature in both transonic and supersonic flows. They can be encountered on compressor and turbine blades, in supersonic jet inlets, on transonic wings, on the stabilization fins of missiles and in many more situations. Because of their major i

  16. the Martian atmospheric boundary layer

    DEFF Research Database (Denmark)

    Petrosyan, A.; Galperin, B.; Larsen, Søren Ejling


    The planetary boundary layer (PBL) represents the part of the atmosphere that is strongly influenced by the presence of the underlying surface and mediates the key interactions between the atmosphere and the surface. On Mars, this represents the lowest 10 km of the atmosphere during the daytime...

  17. High Performance Thin Layer Chromatography. (United States)

    Costanzo, Samuel J.


    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  18. Properties Research of Ceramic Layer

    Directory of Open Access Journals (Sweden)

    Z. Żółkiewicz


    Full Text Available In the method of full mould the polystyrene model, which fills the mould cavity in the course of filling by the liquid metal is subjected tothe influence of high temperature and passes from the solid, through the liquid, to the gaseous state. During this process solid and gaseousproducts of thermal decomposition of polystyrene patterns occur. The kinetics of this process is significantly influenced by the gasificationtemperature, density and mass of the polystyrene patterns. One of the basic parameters is the amount and rate of gas from the polystyrenemodel during its thermal decomposition. Specific properties of ceramic layer used for lost foam castings are required. To ensure optimalprocess flow of metal in the form proper permeability of the ceramic layer is needed.To ensure optimal conditions for technological casting method EPS patterns are tested and determined are the technological parametersand physical-chemical process in: material properties of the pattern, properties of the ceramic layer applied to the pattern, pattern gasification kinetics pouring processIn the course of the research the characteristics of polystyrene and ceramic layer were determined.

  19. Origin and evolution of asthenospheric layers (United States)

    Czechowski, Leszek; Grad, Marek


    The lithosphere is underlain by the asthenosphere. Traditionally, the boundary between the lithosphere and the asthenosphere (LAB) is defined by a difference in response to stress: the lithosphere remains elastic or brittle, while the asthenosphere deforms viscously and accommodates strain through plastic deformation. The reology of rocks depends on many factors: temperature, pressure, chemical composition, size of grains, etc. However, the basic differences of lithosphere and asthenosphere properties could be explained as a result of the temperature and pressure. The effective viscosity of mantle is proportional to C exp(A q), where q is the ratio (melting temperature/temperature), C and A are positive constants. The mantle is not molten, so q>1. If the temperature is close to the melting temperature then q is close to 1 and effective viscosity is low (e.g. 1018 Pa s). This situation is observed in asthenosphere. The lithosphere is a thermal boundary layer for the convection in the mantle. The temperature of the upper part is low (q is high) but the temperature gradient in the lithosphere is high and temperature is increasing fast. In the mantle below the lithosphere, the temperature gradient is low (could be close to the adiabatic one). The melting temperature is increasing with depth faster than true temperature. Hence, q and the viscosity reach minimum value just below LAB and are increasing with depth in the mantle below. It is a typical situation. The tectonic processes in subduction zones could change this picture. The one lithospheric plate could be placed in the mantle below another plate. Distribution q in such a case could have two minima, so two asthenospheric layers could be formed. Another important factor determining rheological properties is a stress tensor T. Generally viscosity is proportional to the power of the invariant of the stress tensor: I(T)^(1-n). For n=1 the viscosity does not depend on stress (i.e. Newtonian rheology), for true mantle n

  20. Decomposition Principles and Online Learning in Cross-Layer Optimization for Delay-Sensitive Applications

    CERN Document Server

    Fu, Fangwen


    In this paper, we propose a general cross-layer optimization framework in which we explicitly consider both the heterogeneous and dynamically changing characteristics of delay-sensitive applications and the underlying time-varying network conditions. We consider both the independently decodable data units (DUs, e.g. packets) and the interdependent DUs whose dependencies are captured by a directed acyclic graph (DAG). We first formulate the cross-layer design as a non-linear constrained optimization problem by assuming complete knowledge of the application characteristics and the underlying network conditions. The constrained cross-layer optimization is decomposed into several cross-layer optimization subproblems for each DU and two master problems. The proposed decomposition method determines the necessary message exchanges between layers for achieving the optimal cross-layer solution. However, the attributes (e.g. distortion impact, delay deadline etc) of future DUs as well as the network conditions are ofte...

  1. The quality of the joint between alloy steel and unalloyed cast steel in bimetallic layered castings

    Directory of Open Access Journals (Sweden)

    T. Wróbel


    Full Text Available In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer. The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic unalloyed cast steel, whereas working part (layer is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.

  2. 911 Call Center (PSAP) Service Areas, Master coverage of "atom" features used as a source to generate several derivative layers for the Sheriff RMS and E-911 map rolls. Cover is painstakingly maintained interactively by GIS staff. All atom boundaries are snapped to the road centerline cover, Published in 2008, 1:1200 (1in=100ft) scale, Sedgwick County Government. (United States)

    NSGIC Local Govt | GIS Inventory — 911 Call Center (PSAP) Service Areas dataset current as of 2008. Master coverage of "atom" features used as a source to generate several derivative layers for the...

  3. Organic photovoltaic cells utilizing ultrathin sensitizing layer (United States)

    Rand, Barry P.; Forrest, Stephen R.


    A photosensitive device includes a series of organic photoactive layers disposed between two electrodes. Each layer in the series is in direct contact with a next layer in the series. The series is arranged to form at least one donor-acceptor heterojunction, and includes a first organic photoactive layer comprising a first host material serving as a donor, a thin second organic photoactive layer comprising a second host material disposed between the first and a third organic photoactive layer, and the third organic photoactive layer comprising a third host material serving as an acceptor. The first, second, and third host materials are different. The thin second layer serves as an acceptor relative to the first layer or as a donor relative to the third layer.

  4. Cyclone with boundary layer displacement

    Energy Technology Data Exchange (ETDEWEB)

    Gorton-Huelgerth, A.; Hoffmann, D.; Staudinger, G. [Technische Universitaet Graz, Graz (Austria). Inst. fuer Verfahrenstechnik, Abt. fuer Apparatebau und Mechanische Verfahrenstechnik


    In a cyclone the boundary layers at the cover plate and outside of the vortex finder are considered to affect the separation efficiency of a cyclone. To improve separation efficiency, the boundary layers at and the space between vortex finder and cover plate were investigated. Two identical cyclones, 400 mm diameter and 990 mm long were manufactured with high precision from stainless steel. One was equipped with openings for insertion of velocity probes; the opening could be closed with glass windows to allow Laser Doppler Anemometry. The other cyclone was used for testing separation efficiency. Velocity measurements by both conventional pressure probes and Laser Doppler Anemometry revealed that only a minor part of the boundary layer at the outside of the vortex finder reaches the lower end of it, because the axial velocity is slowed down drastically. Light sheet visualization showed that there exists a heavily particle loaded boundary layer at the cover plate. There are no particles at the lower part of the vortex finder. This can be explained by the radial mass exchange. The effect of vortex finder length on separation efficiency was investigated by varying the length of the vortex finder and measuring the separation efficiency using a limestone powder as test material. It was found that the separation efficiency is not sensitive to the length of the vortex finder. Particle slip increases only where the vortex finder is definitely shorter than its diameter. It was tried to improve the separation efficiency by introducing an air curtain along the vortex finder. The positive effect on separation efficiency and particle cut size is minimal. Results from velocity measurements with cylinder pressure probes in the boundary layer do not fit the results from other measurement techniques. Many older measurements were made with these probes. The conclusions drawn and the design rules deduced are to be questioned. 17 refs., 21 figs., 2 tabs.

  5. Incorporating Cyber Layer Failures in Composite Power System Reliability Evaluations

    Directory of Open Access Journals (Sweden)

    Yuqi Han


    Full Text Available This paper proposes a novel approach to analyze the impacts of cyber layer failures (i.e., protection failures and monitoring failures on the reliability evaluation of composite power systems. The reliability and availability of the cyber layer and its protection and monitoring functions with various topologies are derived based on a reliability block diagram method. The availability of the physical layer components are modified via a multi-state Markov chain model, in which the component protection and monitoring strategies, as well as the cyber layer topology, are simultaneously considered. Reliability indices of composite power systems are calculated through non-sequential Monte-Carlo simulation. Case studies demonstrate that operational reliability downgrades in cyber layer function failure situations. Moreover, protection function failures have more significant impact on the downgraded reliability than monitoring function failures do, and the reliability indices are especially sensitive to the change of the cyber layer function availability in the range from 0.95 to 1.

  6. Photoluminescence of phosphorus atomic layer doped Ge grown on Si (United States)

    Yamamoto, Yuji; Nien, Li-Wei; Capellini, Giovanni; Virgilio, Michele; Costina, Ioan; Schubert, Markus Andreas; Seifert, Winfried; Srinivasan, Ashwyn; Loo, Roger; Scappucci, Giordano; Sabbagh, Diego; Hesse, Anne; Murota, Junichi; Schroeder, Thomas; Tillack, Bernd


    Improvement of the photoluminescence (PL) of Phosphorus (P) doped Ge by P atomic layer doping (ALD) is investigated. Fifty P delta layers of 8 × 1013 cm‑2 separated by 4 nm Ge spacer are selectively deposited at 300 °C on a 700 nm thick P-doped Ge buffer layer of 1.4 × 1019 cm‑3 on SiO2 structured Si (100) substrate. A high P concentration region of 1.6 × 1020 cm‑3 with abrupt P delta profiles is formed by the P-ALD process. Compared to the P-doped Ge buffer layer, a reduced PL intensity is observed, which might be caused by a higher density of point defects in the P delta doped Ge layer. The peak position is shifted by ∼0.1 eV towards lower energy, indicating an increased active carrier concentration in the P-delta doped Ge layer. By introducing annealing at 400 °C to 500 °C after each Ge spacer deposition, P desorption and diffusion is observed resulting in relatively uniform P profiles of ∼2 × 1019 cm‑3. Increased PL intensity and red shift of the PL peak are observed due to improved crystallinity and higher active P concentration.

  7. Thermally stable magnetic media based on antiferromagnetically coupled layers (United States)

    Fullerton, Eric E.


    The combination of signal-to-noise requirements, write field limitations, and thermal activation of small particles is thought to limit the potential areal density of longitudinal media and is commonly referred to as the "superparamagnetic limit". Recording media composed of antiferromagnetically coupled (AFC) magnetic recording layers is a promising approach to extend areal densities of longitudinal media beyond these perceived limits [1,2]. The recording medium is made up of two ferromagnetic recording layer separated by a nonmagnetic layer whose thickness is tuned to couple the layers antiferromagnetically. For such a structure, the effective areal moment density (Mrt) of the composite structure is given by the difference between the ferromagnetic layers allowing the effective magnetic thickness to scale independently of the physical thickness of the media. The resulting media appears magnetically thin while being physically thick and, thus, allows AFC media to maintain thermal stability even for low Mrt values. Experimental realization of this concept using CoPtCrB alloy layers that demonstrates thermally stable low-Mrt media suitable for high-density recording will be discussed. This work is done in collaboration with D. T. Margulies, M. E. Schabes,M. Doerner, M. Carey, B. Gurney, A. Moser, M. Best, G. Zeltzer, K. Rubin, and H. Rosen. [1]. Fullerton et al., Appl. Phys. Lett. 77, 3806 (2000). [2]. Abarra et al., Appl. Phys. Lett. 77, 2581 (2000).

  8. Interior of Titan: 2-Layer or 3-Layer and Does It Matter? (United States)

    McKinnon, W. B.; Bland, M. T.


    melting and catastrophic differentiation should ensue.) More critically, a low-density rock core is unlikely to resist dehydration and densification as it heats radiogenically. Even assuming such favorable conditions as late core formation at 500 m.y. after accretion (e.g., carapace infall) and leaching of appreciable 40K (say, 30%) to the ice (ocean) layer, antigorite dehydration begins at 2 b.y. for realistic thermal properties, and is complete for the majority of the core by 4.5 b.y. (the outer portion of such a core always remains cool). Under a variety of thermal evolution scenarios, only extreme assumptions permit Titan's core to remain cool and undehydrated. Thus, thermochemically realistic, solar-composition-rock-bearing, interior models of Titan that satisfy its density and MOI must contain 3 (or more) layers, specifically, a mixed ice-rock layer of some sort must exist between the complex "ice" layer and a rock core. This structure (and the atmosphere) offer constraints on conditions during accretion (rate, timing, rock "particle" size distribution) and the role (if any) of a Late Heavy Bombardment in the outer solar system. It remains to be seen how such a structure could evolve to be Ganymede-like (plausibly driven by tidal heating) and form an metallic core without either iron metal or magnetite.

  9. Rapid Prototyping Of Layered Composite Parts (United States)

    Wolff, Edwin D.


    Numerically controlled cutting accelerates fabrication of layers. Proposed method derived from stereoscopic lithography. CATIA or CAEDS computer program used to generate three-dimensional mathematical model of prototype part. In model, geometry of part specified in layers, as in stereoscopic lithography. Model data for each layer fed to computer-numerically-controlled ultrasonic cutting machine. Sheet of prepreg (uncured composite material) of specified layer thickness placed in machine and cut, under control of model data, to specified shape of layer.

  10. A computer generator for randomly layered structures

    Institute of Scientific and Technical Information of China (English)

    YU Jia-shun; HE Zhen-hua


    An algorithm is introduced in this paper for the synthesis of randomly layered earth models. Under the assumption that the layering and the physical parameters for a layer are random variables with truncated normal distributions, random numbers sampled from the distributions can be used to construct the layered structure and determine physical parameters for the layers. To demonstrate its application, random models were synthesized for the modelling of seismic ground motion amplification of a site with uncertainties in its model parameters.

  11. Buffer layer for thin film structures (United States)

    Foltyn, Stephen R.; Jia, Quanxi; Arendt, Paul N.; Wang, Haiyan


    A composite structure including a base substrate and a layer of a mixture of strontium titanate and strontium ruthenate is provided. A superconducting article can include a composite structure including an outermost layer of magnesium oxide, a buffer layer of strontium titanate or a mixture of strontium titanate and strontium ruthenate and a top-layer of a superconducting material such as YBCO upon the buffer layer.

  12. [A comment on chiral thin layer chromatography]. (United States)

    Chen, Xuexian; Yuan, Liming


    In recent eight years, authors' group has repeated a lot of experiments of chiral thin layer chromatography coming from literature. From the practical opinion, we summarized that there are nine characteristics for chiral thin layer chromatography. Some progresses of chiral thin layer chromatography are reviewed, and the enantioselectivity of a commercial chiral thin layer plate is introduced. The study of vancomycin as the chiral selector in thin layer chromatography is also reported.

  13. Tetradymite layer assisted heteroepitaxial growth and applications

    Energy Technology Data Exchange (ETDEWEB)

    Stoica, Vladimir A.; Endicott, Lynn; Clarke, Roy; Uher, Ctirad


    A multilayer stack including a substrate, an active layer, and a tetradymite buffer layer positioned between the substrate and the active layer is disclosed. A method for fabricating a multilayer stack including a substrate, a tetradymite buffer layer and an active layer is also disclosed. Use of such stacks may be in photovoltaics, solar cells, light emitting diodes, and night vision arrays, among other applications.

  14. Chemical solution seed layer for rabits tapes (United States)

    Goyal, Amit; Paranthaman, Mariappan; Wee, Sung-Hun


    A method for making a superconducting article includes the steps of providing a biaxially textured substrate. A seed layer is then deposited. The seed layer includes a double perovskite of the formula A.sub.2B'B''O.sub.6, where A is rare earth or alkaline earth metal and B' and B'' are different rare earth or transition metal cations. A superconductor layer is grown epitaxially such that the superconductor layer is supported by the seed layer.

  15. Spraying asymmetry into functional membranes layer-by-layer (United States)

    Krogman, Kevin C.; Lowery, Joseph L.; Zacharia, Nicole S.; Rutledge, Gregory C.; Hammond, Paula T.


    As engineers strive to mimic the form and function of naturally occurring materials with synthetic alternatives, the challenges and costs of processing often limit creative innovation. Here we describe a powerful yet economical technique for developing multiple coatings of different morphologies and functions within a single textile membrane, enabling scientists to engineer the properties of a material from the nanoscopic level in commercially viable quantities. By simply varying the flow rate of charged species passing through an electrospun material during spray-assisted layer-by-layer deposition, individual fibres within the matrix can be conformally functionalized for ultrahigh-surface-area catalysis, or bridged to form a networked sublayer with complimentary properties. Exemplified here by the creation of selectively reactive gas purification membranes, the myriad applications of this technology also include self-cleaning fabrics, water purification and protein functionalization of scaffolds for tissue engineering.

  16. Perturbation of a Multiple Eigenvalue in the Benard Problem for Two Fluid Layers. (United States)


    EIGENVAWUE IN THlE BENARtD PROBLEM FOR TWO FLUID LAYERS Ca O~ Yuriko Renardy and Michael Renardy MUathematics Research Center University of Wisconsin...OF WISCONSIN - MADISON MATHEMATICS RESEARCH CENTER PERTUBBATION OF A MULTIPLE EIGENVALUE IN THE BENARD PROBLEM FOR TWO FLUID LAYERS Yuriko Renardy and...PROBLEM FOR TWO FLUID LAYERS Yuriko Renardy and Michael Renardy 1. INTRODUCTION In the B6nard problem for one fluid, "exchange of stabilities" holds


    Directory of Open Access Journals (Sweden)

    M. Numan, M. Siddique and M. S. Yousaf1


    Full Text Available A serological survey for detection of antibodies against avian influenza virus (AIV subtype H9 in vaccinated layer flocks was carried out. Serum samples were divided into age groups A, B, C, D (commercial layers and E, F, G, H (layer breeders. Haemagglutination inhibition (HI test was performed to determine serum antibodies against AIV-H9 subtype. Geometric mean titer (GMT values were calculated. Results showed the level of protection of vaccinated birds was satisfactory.

  18. Folder: a MATLAB-based tool for modelling deformation in layered media subject to layer parallel shortening or extension (United States)

    Adamuszek, Marta; Dabrowski, Marcin; Schmid, Daniel W.


    We present Folder, a numerical tool to simulate and analyse the structure development in mechanically layered media during the layer parallel shortening or extension. Folder includes a graphical user interface that allows for easy designing of complex geometrical models, defining material parameters (including linear and non-linear rheology), and specifying type and amount of deformation. It also includes a range of features that facilitate the visualization and examination of various relevant quantities e.g. velocities, stress, rate of deformation, pressure, and finite strain. Folder contains a separate application, which illustrates analytical solutions of growth rate spectra for layer parallel shortening and extension of a single viscous layer. In the study, we also demonstrate a Folder application, where the role of confinement on the growth rate spectrum and the fold shape evolution during the deformation of a single layer subject to the layer parallel shortening is presented. In the case of the linear viscous materials used for the layer and matrix, the close wall proximity leads to a decrease of the growth rate values. The decrease is more pronounced for the larger wavelengths than for the smaller wavelengths. The growth rate reduction is greater when the walls are set closer to the layer. The presence of the close confinement can also affect the wavelength selection process and significantly shift the position of the dominant wavelength. The influence of the wall proximity on the growth rate spectrum for the case of non-linear viscous materials used for the layer and/or matrix is very different as compared to the linear viscous case. We observe a multiple maxima in the growth rate spectrum. The number of the growth rate maxima, their value and the position strongly depend on the closeness of the confinement. The maximum growth rate value for a selected range of layer-wall distances is much larger than in the case when the confinement effect is not taken

  19. Leaky waves in boundary layer flow (United States)

    Pralits, Jan


    Linear stability analysis of boundary layer flow is traditionally performed by solving the Orr-Sommerfeld equation (OSE), either in a temporal or a spatial framework. The mode structure of the OSE is in both cases composed of a finite number of discrete modes which decay at infinity in the wall- normal direction y, and a continuous spectrum of propagating modes behaving as (±ik y) when y->∞, with real k. A peculiarity of this structure is that the number of discrete modes changes with the Reynolds number, Re. They indeed seem to disappear behind the continuous spectrum at certain Re. This phenomenon is here investigated by studying the response of the Blasius boundary layer forced instantaneously in space and time. Since the solution of the forced and homogeneous Laplace-transformed problem both depend on the free-stream boundary conditions, it is shown here that a suitable change of variables can remove the branch cut in the Laplace plane. As a result, integration of the inverse Laplace transform along the two sides of the branch cut, which gives rise to the continuous spectrum, can be replaced by a sum of residues corresponding to an additional set of discrete eigenvalues. These new modes grow at infinity in the y direction, and are analogous to the leaky waves found in the theory of optical waveguides, i.e. optical fibers, which are attenuated in the direction of the waveguide but grow unbounded in the direction perpendicular to it.

  20. Surface roughness scattering in multisubband accumulation layers (United States)

    Fu, Han; Reich, K. V.; Shklovskii, B. I.


    Accumulation layers with very large concentrations of electrons where many subbands are filled became recently available due to ionic liquid and other new methods of gating. The low-temperature mobility in such layers is limited by the surface roughness scattering. However, theories of roughness scattering so far dealt only with the small-density single subband two-dimensional electron gas (2DEG). Here we develop a theory of roughness-scattering limited mobility for the multisubband large concentration case. We show that with growing 2D electron concentration n the surface dimensionless conductivity σ /(2 e2/h ) first decreases as ∝n-6 /5 and then saturates as ˜(d aB/Δ2)≫1 , where d and Δ are the characteristic length and height of the surface roughness and aB is the effective Bohr radius. This means that in spite of the shrinkage of the 2DEG thickness and the related increase of the scattering rate the 2DEG remains a good metal.

  1. Electron accumulation layer in ultrastrong magnetic field (United States)

    Sammon, M.; Fu, Han; Shklovskii, B. I.


    When a three-dimensional electron gas is subjected to a very strong magnetic field, it can reach a quasi-onedimensional state in which all electrons occupy the lowest Landau level. This state is referred to as the extreme quantum limit ( EQL ) and has been studied in the physics of pulsars and bulk semiconductors. Here we present a theory of the EQL phase in electron accumulation layers created by an external electric field E at the surface of a semiconductor with a large Bohr radius such as InSb , PbTe , SrTiO 3 ( STO ) , and particularly in the LaA 1 O 3 / SrTiO 3 ( LAO / STO ) heterostructure. The phase diagram of the electron gas in the plane of the magnetic field strength and the electron surface concentration is found for different orientations of the magnetic field. We find that in addition to the quasi-classical metallic phase ( M ), there is a metallic EQL phase, as well as an insulating Wigner crystal state ( WC ). Within the EQL phase, the Thomas-Fermi approximation is used to find the electron density and the electrostatic potential profiles of the accumulation layer. Additionally, the quantum capacitance for each phase is calculated as a tool for experimental study of these phase diagrams.

  2. Polyelectrolyte Layer-by-Layer Assembly on Organic Electrochemical Transistors. (United States)

    Pappa, Anna-Maria; Inal, Sahika; Roy, Kirsty; Zhang, Yi; Pitsalidis, Charalampos; Hama, Adel; Pas, Jolien; Malliaras, George G; Owens, Roisin M


    Oppositely charged polyelectrolyte multilayers (PEMs) were built up in a layer-by-layer (LbL) assembly on top of the conducting polymer channel of an organic electrochemical transistor (OECT), aiming to combine the advantages of well-established PEMs with a high performance electronic transducer. The multilayered film is a model system to investigate the impact of biofunctionalization on the operation of OECTs comprising a poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) film as the electrically active layer. Understanding the mechanism of ion injection into the channel that is in direct contact with charged polymer films provides useful insights for novel biosensing applications such as nucleic acid sensing. Moreover, LbL is demonstrated to be a versatile electrode modification tool enabling tailored surface features in terms of thickness, softness, roughness, and charge. LbL assemblies built up on top of conducting polymers will aid the design of new bioelectronic platforms for drug delivery, tissue engineering, and medical diagnostics.

  3. Polyelectrolyte Layer-by-Layer Assembly on Organic Electrochemical Transistors

    KAUST Repository

    Pappa, Anna-Maria


    Oppositely charged polyelectrolyte multilayers (PEMs) were built up in a layer-by-layer (LbL) assembly on top of the conducting polymer channel of an organic electrochemical transistor (OECT), aiming to combine the advantages of well-established PEMs with a high performance electronic transducer. The multilayered film is a model system to investigate the impact of biofunctionalization on the operation of OECTs comprising a poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) film as the electrically active layer. Understanding the mechanism of ion injection into the channel that is in direct contact with charged polymer films provides useful insights for novel biosensing applications such as nucleic acid sensing. Moreover, LbL is demonstrated to be a versatile electrode modification tool enabling tailored surface features in terms of thickness, softness, roughness, and charge. LbL assemblies built up on top of conducting polymers will aid the design of new bioelectronic platforms for drug delivery, tissue engineering, and medical diagnostics.

  4. Layer-by-layer microcapsules templated on erythrocyte ghost carriers. (United States)

    Shaillender, Mutukumaraswamy; Luo, Rongcong; Venkatraman, Subbu S; Neu, Björn


    This work reports the fabrication of layer-by-layer (LbL) microcapsules that provide a simple mean for controlling the burst and subsequent release of bioactive agents. Red blood cell (RBC) ghosts were loaded with fluorescently labeled dextran and lysozyme as model compounds via hypotonic dialysis with an encapsulation efficiency of 27-31%. It is demonstrated that these vesicles maintain their shape and integrity and that a uniform distribution of the encapsulated agents within these carriers is achieved. The loaded vesicles were then successfully coated with the biocompatible polyelectrolytes, poly-L-arginine hydrochloride and dextran sulfate. It is demonstrated that the release profiles of the encapsulated molecules can be regulated over a wide range by adjusting the number of polyelectrolyte layers. In addition, the LbL shell also protects the RBC ghost from decomposition thereby potentially preserving the bioactivity of encapsulated drugs or proteins. These microcapsules, consisting of an RBC ghost coated with a polyelectrolyte multilayer, provide a simple mean for the preparation of loaded LbL microcapsules eliminating the core dissolution and post-loading of bioactive agents, which are required for conventional LbL microcapsules.

  5. Fluidized bed layer-by-layer microcapsule formation. (United States)

    Richardson, Joseph J; Teng, Darwin; Björnmalm, Mattias; Gunawan, Sylvia T; Guo, Junling; Cui, Jiwei; Franks, George V; Caruso, Frank


    Polymer microcapsules can be used as bioreactors and artificial cells; however, preparation methods for cell-like microcapsules are typically time-consuming, low yielding, and/or involve custom microfluidics. Here, we introduce a rapid (∼30 min per batch, eight layers), scalable (up to 500 mg of templates), and efficient (98% yield) microcapsule preparation technique utilizing a fluidized bed for the layer-by-layer (LbL) assembly of polymers, and we investigate the parameters that govern the formation of robust capsules. Fluidization in water was possible for particles of comparable diameter to mammalian cells (>5 μm), with the experimental flow rates necessary for fluidization matching well with the theoretical values. Important variables for polymer film deposition and capsule formation were the concentration of polymer solution and the molecular weight of the polymer, while the volume of the polymer solution had a negligible impact. In combination, increasing the polymer molecular weight and polymer solution concentration resulted in improved film deposition and the formation of robust microcapsules. The resultant polymer microcapsules had a thickness of ∼5.5 nm per bilayer, which is in close agreement with conventionally prepared (quiescent (nonflow) adsorption/centrifugation/wash) LbL capsules. The technique reported herein provides a new way to rapidly generate microcapsules (approximately 8 times quicker than the conventional means), while being also amenable to scale-up and mass production.

  6. A Comparative Analysis of Series And Finite Element Solutions For Flow In Multi-layer Aquifers With Contiguous Layers (United States)

    Wong, S.; Craig, J. R.


    Recently, Wong S. & J.R. Craig [Computational Methods in Water Resources XVII International Conference, 2008] have developed a semi-analytic series (SAS) solution method for simulating 2D steady-state groundwater flow in multi-layer aquifers with natural unconformity. The advantages of the approach include the capability to predict groundwater flow in aquifer systems with a geometrically complex structure, i.e., layers that are contiguous but vary (sometimes dramatically) in thickness across the modelled domain. The SAS approach is unorthodox compared to numerical scheme such as finite element (FE) method when handling an aquifer basin with contiguous layers. This research attempts to compare the robustness of the SAS solution with that of the FE solution under variety of different geometric conditions, including the increasing of system aspect ratios and the inclusion of pinching layers. It was found that the SAS approach is a useful benchmarking tool and that for contiguous layers, both FE methods continue to be highly accurate at even large aspect ratios. Based on the benchmarking experiments, some rules of thumb for mesh generation in FE models of regional aquifer systems with both contiguous and discontiguous layering are identified.

  7. Nonlinear Instability of Liquid Layers. (United States)

    Newhouse, Lori Ann

    The nonlinear instability of two superposed viscous liquid layers in planar and axisymmetric configurations is investigated. In the planar configuration, the light layer fluid is bounded below by a wall and above by a heavy semiinfinite fluid. Gravity drives the instability. In the first axisymmetric configuration, the layer is confined between a cylindrical wall and a core of another fluid. In the second, a thread is suspended in an infinite fluid. Surface tension forces drive the instability in the axisymmetric configurations. The nonlinear evolution of the fluid-fluid interface is computed for layers of arbitrary thickness when their dynamics are fully coupled to those of the second fluid. Under the assumption of creeping flow, the flow field is represented by an interfacial distribution of Green's functions. A Fredholm integral equation of the second kind for the strength of the distribution is derived and then solved using an iterative technique. The Green's functions produce flow fields which are periodic in the direction parallel to the wall and have zero velocity on the wall. For small and moderate surface tension, planar layers evolve into a periodic array of viscous plumes which penetrate into the overlying fluid. The morphology of the plumes depends on the surface tension and the ratio of the fluid viscosities. As the viscosity of the layer increases, the plumes change from a well defined drop on top of a narrow stem to a compact column of rising fluid. The capillary instability of cylindrical interfaces and interfaces in which the core thickness varies in the axial direction are investigated. In both the unbounded and wall bounded configurations, the core evolves into a periodic array of elongated fluid drops connected by thin, almost cylindrical fluid links. The characteristics of the drop-link structure depend on the core thickness, the ratio of the core radius to the wall radius, and the ratio of the fluid viscosities. The factors controlling the

  8. Microbial quality of culled chicken layers in Penang, Malaysia

    Directory of Open Access Journals (Sweden)

    Ong Pek Geck


    Full Text Available Aim: To determine the microbial quality of culled chicken layers in Penang, Malaysia. Materials and Methods: Samples were obtained from three layer farms (designated as Farm A, Farm B and Farm C. A total of 67 culled chicken layer samples consisting of egg wash water, chicken carcass rinse, drinking water, cloaca swab, feed and faeces were examined for enterobacteriaceae, total and faecal coliforms, and Escherichia coli using the procedures in the bacteriological analytical manual. Results: The total plate count for bacteria ranged from 2.7 x 103 cfuml-1 to 1.8 x 107 cfug-1 (Farm A, 1100.0 Most probable number (MPNml-1/ MPNg-1 for Farm A, B and C. Similarly, E. coli count for all the three farms ranged from 1100.0 MPNml-1/MPNg-1. E. coli counts were very low for most of the samples examined except chicken carcass and faeces. Conclusion: In general, Farm A had higher bacterial count, followed by Farm C and Farm B. This work gives an indication that pathogenic foodborne pathogens such as E. coli, Salmonella, Citrobacter, Enterobacter, Klebsiella, Shigella and Yersinia spp. may be present in culled chicken layers and consequently pose the risk of causing food poisoning or outbreaks.

  9. Interface phenomena in double-layer organic photoreceptors (United States)

    Sasvari, G.; Juhasz, C.; Hirsch, J.


    Single photogeneration layers of a phthalocyanine pigment dispersed in a polyvinyl butyral binder, and double layers consisting of the photogeneration layer coated with hole transport layers of TPTA, DEH and BD molecularly dispersed in polycarbonate were exposed to single-shot light excitation. The charge collected was measured as a function of temperature, electric field, exposure intensity and duration. The resulting mean transport level of TPTA was found to be 0.17 eV, and that of DEH 0.11 eV, below the valence band of the pigment, but that of BD was found to be 0.09 eV above it. The injection efficiencies were independent of field and amounted to 0953-8984/9/30/015/img1 for TPTA and 0.02 for DEH, at room temperature, but that for BD was 0.1 independently of temperature. Models for the injection efficiencies in these cases are also discussed in this work for the first time.

  10. Single-layer graphene on silicon nitride micromembrane resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Bagci, Tolga; Zeuthen, Emil


    for exciting new devices, such as optoelectromechanical transducers. Here, we add a single-layer graphene on SiN micromembranes and compare electromechanical coupling and mechanical properties to bare dielectric membranes and to membranes metallized with an aluminium layer. The electrostatic coupling...... of graphene covered membranes is found to be equal to a perfectly conductive membrane, without significantly adding mass, decreasing the superior mechanical quality factor or affecting the optical properties of pure SiN micromembranes. The concept of graphene-SiN resonators allows a broad range of new...... experiments both in applied physics and fundamental basic research, e.g., for the mechanical, electrical, or optical characterization of graphene....

  11. Pareto distance for multi-layer network analysis

    DEFF Research Database (Denmark)

    Magnani, Matteo; Rossi, Luca


    services, e.g., Facebook, Twitter, LinkedIn and Foursquare. As a result, the analysis of on-line social networks requires a wider scope and, more technically speaking, models for the representation of this fragmented scenario. The recent introduction of more realistic layered models has however determined...... on the nature of the connections required by the Pareto distance may in theory result in a large number of potential shortest paths between pairs of nodes. However, an experimental computation of distances on multi-layer networks of increasing size shows an interesting and non-trivial stable behavior....

  12. A numerical study of the turbulent Ekman layer (United States)

    Coleman, G. N.; Ferziger, J. H.; Spalart, P. R.


    The three-dimensional time-dependent turbulent flow in a neutrally stratified Ekman layer over a smooth flat surface was numerically simulated by directly solving the Navier-Stokes equations. Issues addressed using the direct numerical simulation (DNS) fields include the presence or absence of large-scale coherent structures ('longitudinal' or 'roll' vortices) in neutrally stratified Ekman-layer turbulence, the effects of the horizontal component of the angular velocity vector (i.e., latitude), and implications for models of the PBL. Experimental and DNS profiles are compared.

  13. A Smart Layer For Remote Laboratories

    Directory of Open Access Journals (Sweden)

    Ricardo J. Costa


    Full Text Available Commonly, when a weblab is developed tosupport remote experiments in sciences and engineeringcourses, a particular hardware/software architecture isimplemented. However, the existence of severaltechnological solutions to implement those architecturesdifficults the emergence of a standard, both at hardwareand software levels. While particular solutions are adoptedassuming that only qualified people may implement aweblab, the control of the physical space and the powerconsumption are often forgotten. Since controlling these twoprevious aspects may increase the quality of the weblabhosting the remote experiments, this paper proposes the useof a new layer implemented by a domotic system bus withseveral devices (e.g. lights, power sockets, temperaturesensors, and others able to be controlled through theInternet. We also provide a brief proof-of-concept in theform of a weblab equipped with a simple domotic systemusually implemented in smart houses. The added value tothe remote experiment hosted at the weblab is also identifiedin terms of power savings and environment conditions.

  14. Layering-induced Superlubricity: Gold on Graphite (United States)

    Vanossi, Andrea; Guerra, Roberto; Tosatti, Erio; Nanofriction Group Sissa Team


    By means of realistic MD simulations, we explore the static friction trend as a function of the true contact area and the model dimensionality for 2D gold nanoislands and 3D gold nanoclusters deposited on graphite, interesting tribological systems whose slow and fast dynamics have been previously investigated. For increasing island size, because of the relative gold-graphite lattice mismatch, the interface stress energy has the chance to pile up by forming frustrated unmatched (i.e., incommensurate) regions and to develop a continuous solitonic pathway, foreshadowing a possible condition for the occurrence of ultra-low friction regimes. The significant reduction of the depinning threshold, towards superlubricity, with the system dimensionality can be ascribed to a layering-induced effective stiffness of the interface contact, favoring the natural Au-C lattice incommensurability. Partly sponsored under SNSF Sinergia Grant CRSII2 136287/1, EU ERC Grant No. 320796 MODPHYSFRICT, EU COST Action MP1303.

  15. Ultraviolet laser deposition of graphene thin films without catalytic layers

    KAUST Repository

    Sarath Kumar, S. R.


    In this letter, the formation of nanostructured graphene by ultraviolet laser ablation of a highly ordered pyrolytic graphite target under optimized conditions is demonstrated, without a catalytic layer, and a model for the growth process is proposed. Previously, graphene film deposition by low-energy laser (2.3 eV) was explained by photo-thermal models, which implied that graphene films cannot be deposited by laser energies higher than the C-C bond energy in highly ordered pyrolytic graphite (3.7 eV). Here, we show that nanostructured graphene films can in fact be deposited using ultraviolet laser (5 eV) directly over different substrates, without a catalytic layer. The formation of graphene is explained by bond-breaking assisted by photoelectronic excitation leading to formation of carbon clusters at the target and annealing out of defects at the substrate.

  16. Development of a cell line from Echinococcus granulosus germinal layer. (United States)

    Albani, Clara María; Cumino, Andrea Carina; Elissondo, María Celina; Denegri, Guillermo María


    In vitro culture of parasitic helminths provides an important tool to study cell regeneration and physiology, as well as for molecular biology and genetic engineering studies. In the present study, we established in vitro propagation of cells from Echinococcus granulosus germinal cyst layer. E. granulosus germinal cells grew beyond 100 passages and showed no signs of reduced proliferation capacity. Microscopic analysis revealed that cells grew both attached to the substrate and in suspension, forming three-dimensional structures like mammalian stem cell aggregates. Examination of the chromosome number of attached germinal cells showed a high degree of heteroploidy, suggesting the occurrence of transformation during culture. Monolayer cells survived cryopreservation and were able to proliferate after thawing. Based on the characteristics displayed by E. granulosus germinal cells, we establish a cell line from the E. granulosus germinal layer. Furthermore, we propose that this cell line could be useful for drug screening and for obtaining parasite material.

  17. Characterization of hafnium oxide resistive memory layers deposited on copper by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, B.D.; Bishop, S.M. [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States); Leedy, K.D. [Air Force Research Laboratory, 2241 Avionics Circle, Wright Patterson Air Force Base, Dayton, OH 45433 (United States); Cady, N.C., E-mail: [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States)


    Hafnium oxide-based resistive memory devices have been fabricated on copper bottom electrodes. The HfO{sub x} active layers in these devices were deposited by atomic layer deposition (ALD) at 250 °C with tetrakis(dimethylamido)hafnium(IV) as the metal precursor and an O{sub 2} plasma as the reactant. Depth profiles of the HfO{sub x} by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a copper concentration on the order of five atomic percent throughout the HfO{sub x} film. In addition to the Cu doped HfO{sub x}, a thin layer (20 nm) of Cu{sub x}O is present at the surface. This surface layer is believed to have formed during the ALD process, and greatly complicates the analysis of the switching mechanism. The resistive memory structures fabricated from the ALD HfO{sub x} exhibited non-polar resistive switching, independent of the top metal electrode (Ni, Pt, Al, Au). Resistive switching current voltage (I–V) curves were analyzed using Schottky emission and ionic hopping models to gain insight into the physical mechanisms underpinning the device behavior. During the forming process it was determined that, at voltages in excess of 2.5 V, an ionic hopping model is in good agreement with the I–V data. The extracted ion hopping distance ∼ 4 Å was within the range of interatomic spacing of HfO{sub 2} during the forming process consistent with ionic motion of Cu{sup 2+} ions. Lastly the on state I–V data was dominated at larger voltages by Schottky emission with an estimated barrier height of ∼ 0.5 eV and a refractive index of 2.59. The consequence of the Schottky emission analysis indicates the on state resistance to be a product of a Pt/Cu{sub 2}O/Cu filament(s)/Cu{sub 2}O/Cu structure. - Highlights: • HfO{sub 2} was grown via atomic layer deposition at 250 and 100 °C on Cu substrates. • A Cu{sub 2}O surface layer and Cu doping were observed in post-deposition of HfO{sub 2}. • Resistive memory devices were fabricated and

  18. Study of the elementary composition and stratigraphy layers of pigments in statues of polychromed wood using a portable system of EDXRF; Estudo da composicao elementar e estratigrafia das camadas de pigmentos em estatuas de madeira policromada usando um sistema portatil de EDXRF

    Energy Technology Data Exchange (ETDEWEB)

    Blonski, Maria Selia


    The energy dispersive X-ray fluorescence (EDXRF) is a non-destructive analytical technique, which permits the determination of the chemical elements present in art works. EDXRF is a non destructive and very interesting methodology for the study of objects of cultural and historical interest, due to the simplicity of the technique, which does not need a previous preparation of the sample, to the multi elemental analysis character and the possibility of the use of portable equipment, which allows in situ analysis. In this work a portable equipment of X-ray fluorescence was used for measurements of pigments in sculptures of polychromed woods belonging to the Laboratory of Conservation and Restoration of the Museum of Archaeology and Ethnology of the University of Sao Paulo (MAE-USP), and sculptures and decorated wood of the Church of the Paroquia Imaculada Conceicao, in Sao Paulo-SP. The portable EDXRF system is constituted of a X -ray tube with Ag anode (operated at 17 kV and 2 {mu}A for the Church measurements and at 17 kV and 3 {mu}A for the sculptures of the museum measurements), a Si-PIN detector (FWHM = 221 eV for the {sup 55}Fe(Mn) 5.9 keV line), standard nuclear electronic chain for X-ray spectrometry, a 8K multichannel analyser, a HP200LX palm top and a mechanical system for the positioning of detector and X-ray tube, which permits two degrees of freedom for the excitation-detection system movement. The excitation-detection time was 500 s for each measurement. In the sculptures of the Church, the analysis of the regions of the brown clothes for both sculptures showed the presence of Fe and Mn indicating to be the pigment brown umbria, due to the strong presence of the respective elements. In the decoration of the column of the altar, gold region, was verified the presence of the elements Ti, Cr, Fe, Cu, Zn and Au. In the pulpit (gold region), it was verified the elements K, Ca, Ti, Fe and Au. In a stain of that gilding region of the pulpit, that was

  19. Stability of compressible boundary layers (United States)

    Nayfeh, Ali H.


    The stability of compressible 2-D and 3-D boundary layers is reviewed. The stability of 2-D compressible flows differs from that of incompressible flows in two important features: There is more than one mode of instability contributing to the growth of disturbances in supersonic laminar boundary layers and the most unstable first mode wave is 3-D. Whereas viscosity has a destabilizing effect on incompressible flows, it is stabilizing for high supersonic Mach numbers. Whereas cooling stabilizes first mode waves, it destabilizes second mode waves. However, second order waves can be stabilized by suction and favorable pressure gradients. The influence of the nonparallelism on the spatial growth rate of disturbances is evaluated. The growth rate depends on the flow variable as well as the distance from the body. Floquet theory is used to investigate the subharmonic secondary instability.

  20. Photon transport through layered media

    CERN Document Server

    Masood, W


    The objective of this project is to study photon transport in layered media. In this regard the properties of the photon have been studied. The interactions that it makes with matter have been studied as well. ANISN code has been run for the sample problems regarding neutron and photon transport. As the project pertains to the transport of photons the layered media, therefore, photon energy spectrum was calculated using isotopes inventory calculation code ORIKAN which is run using 12 energy groups. The photon cross-section library used has a 21 group structure. The 12 group structure was expanded into 21 groups by using the method of histogram splitting. Calculations were made to find values of the energy transmitted at the outermost surface of the shield and then plotted for varying thicknesses of the shield. Finally, the results obtained have been discussed.

  1. Parameterization of entrainment in a sheared convective boundary layer using a first-order jump model

    NARCIS (Netherlands)

    Kim, S.W.; Park, S.U.; Pino, D.; Vilà-Guerau de Arellano, J.


    Basic entrainment equations applicable to the sheared convective boundary layer (CBL) are derived by assuming an inversion layer with a finite depth, i.e., the first-order jump model. Large-eddy simulation data are used to determine the constants involved in the parameterizations of the entrainment

  2. Magnetic head having a wear-resistant layer, and method of manufacturing such a magnetic head

    NARCIS (Netherlands)

    Dirne, F.W.A.; Zieren, V.; Broese van Groenou, A.; Oorschot, L.F.M. van; Lasinski, P.; Jongh, M. de; Roozeboom, F.


    Magnetic head having a head face (5) and comprising a head structure composed of thin layers and provided with a transducing element (E11), in which different materials occurring in different areas are present in the head face. The head face is provided with a first layer (31) of a material which is

  3. Effect of dopants on the transparency and stability of the conductivity of plasma polymerised thiophene layers

    NARCIS (Netherlands)

    Groenewoud, L.M.H.; Weinbeck, A.E.; Engbers, G.H.M.; Feijen, J.


    Iodine is frequently used as dopant for plasma polymerised thiophene (PPT) layers, but suffers from several drawbacks such as the rapidly decaying conductivity upon exposure to air, and the absorption of light by iodine species that are present in the doped PPT layer (i.e., I2, I3− , and I5−). This

  4. Temperature distribution of single layer (United States)

    Tang, Xuefei; Fan, Zhengxiu; Wang, ZhiJiang


    Temperature distributions of Ti02 single layer irradiated by iOns, 1. 06 m wavelength laser pulse were calculated with thermal transfer equation. Following conclusions were obtained: To improve thermal parameters of coating can reduce the peak temperature obviously; The thermal parameters of substrate have little effect on temperature response of coating; Temperature distribution of thin film depends on the electrical field distribution, The peak temperature of quarter -wavelength coatings is lower than that of half-wavelength coatings.

  5. Transition in hypersonic boundary layers (United States)

    Zhang, Chuanhong; Zhu, Yiding; Chen, Xi; Yuan, Huijing; Wu, Jiezhi; Chen, Shiyi; Lee, Cunbiao; Gad-el-Hak, Mohamed


    Transition and turbulence production in a hypersonic boundary layer is investigated in a Mach 6 wind tunnel using Rayleigh-scattering visualization, fast-response pressure measurements, and particle image velocimetry. It is found that the second-mode instability is a key modulator of the transition process. Although the second-mode is primarily an acoustic wave, it causes the formation of high-frequency vortical waves, which triggers a fast transition to turbulence.

  6. Transition in hypersonic boundary layers

    Directory of Open Access Journals (Sweden)

    Chuanhong Zhang


    Full Text Available Transition and turbulence production in a hypersonic boundary layer is investigated in a Mach 6 wind tunnel using Rayleigh-scattering visualization, fast-response pressure measurements, and particle image velocimetry. It is found that the second-mode instability is a key modulator of the transition process. Although the second-mode is primarily an acoustic wave, it causes the formation of high-frequency vortical waves, which triggers a fast transition to turbulence.

  7. RBS analysis of electrochromic layers

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.C.; Bell, J.M. [University of Technology, Sydney, NSW (Australia); Kenny, M.J.; Wielunski, L.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics


    Tungsten oxide thin films produced by dip-coating from tungsten alkoxide solutions are of interest for their application in large area switchable windows. The application consists of a layer of electrochromic tungsten oxide (W0{sub 3}) on indium tin oxide (ITO) coated glass in contact with a complementary structure. Electrochromic devices are switchable between states of high and low transparency by the application of a small voltage. The mechanism relies on the dual injection of ions and electrons into the W0{sub 3} layer from adjacent layers in the device. Electrochromic tungsten oxide can be deposited using standard techniques (eg. sputtering and evaporation) but also using sol-gel deposition. Sol-gel processing has an advantage over conventional preparation techniques because of the simplicity of the equipment. The scaling up to large area coatings is also feasible. RBS and forward recoil has been used to obtain profiles for individual elements in the structure of electrochromic films. 3 refs., 3 figs.

  8. Dust-ion-acoustic Gardner double layers in a dusty plasma with two-temperature electrons

    Indian Academy of Sciences (India)

    M M Masud; I Tasnim; A A Mamun


    The properties of dust-ion-acoustic Gardner double layers (DIA GDLs) in an unmagnetized dusty plasma, whose constituents are negatively-charged stationary dust, inertial ions, and Boltzmann electrons of two distinct temperatures, are rigorously investigated by employing the reductive perturbation method: Gardner approach. The standard Gardner equation is derived, and its double layer (DL) solution is obtained. It has been shown that the properties of the DIA GDLs are significantly modified by some plasma parameters (viz. = e1/e2, e1 = e10/i0, and e2 = e20/i0, where e1 (e2) is the cold (hot) electron temperature, e10 (e20) is the cold (hot) electron number density at equilibrium, and i0 is the ion number density at equilibrium). The implications of our investigation in understanding the basic features of nonlinear electrostatic perturbations observed in many space plasma systems and laboratory devices are briefly discussed.

  9. eCIP, eBook, and eLibrary%eCIP,eBook与eLibrary

    Institute of Scientific and Technical Information of China (English)



    @@一 eCIP,eBook与eLibrary表示了文献工作数字化的三个层面.eCIP(electronic Catalog-ing in Publication)表示文献书目数字化(自动编目),eBook表示文献自身数字化(电子书),eLibrary表示文献收藏、利用方式的数字化(数字图书馆).

  10. Influência da redução medicamentosa da pressão intra-ocular na medida da espessura da camada de fibras nervosas da retina de olhos hipertensos e glaucomatosos pela polarimetria de varredura a laser The influence of intraocular pressure reduction with medication on retinal nerve fiber layer thickness measurements obtained with scanning laser polarimetry in glaucomatous and hypertensive eyes

    Directory of Open Access Journals (Sweden)

    Rodrigo Rezende Gomes Avelino


    Full Text Available OBJETIVO: Avaliar o efeito da redução da pressão intra-ocular (PIO obtido com o uso de terapia medicamentosa na espessura da camada de fibras nervosas da retina medida pela polarimetria de varredura a laser (PVL em pacientes glaucomatosos ou hipertensos oculares. MÉTODOS: Trinta e sete olhos de 37 pacientes foram prospectivamente incluídos no estudo e avaliados com a PVL sem uso de medicação ocular hipotensora e num período entre 15 e 30 dias após a instituição de medicação ocular hipotensora, que resultou em redução da PIO de pelo menos 25%. Os parâmetros medidos pela PVL antes e após a redução da PIO foram comparados com o teste t de Student pareado. RESULTADOS: A PIO média dos 37 pacientes diminuiu significativamente de 26,57±4,23 mmHg para 16,54±2,92 mmHg (p0,05. CONCLUSÃO: A redução da PIO com o uso de medicação ocular hipotensora não altera a medida da espessura da camada de fibras nervosas da retina pela PVL em pacientes com glaucoma ou hipertensão ocular.PURPOSE: To evaluate changes in retinal nerve fiber layer thickness as measured by scanning laser polarimetry (SLP after the use of medication to reduce intraocular pressure (IOP in glaucomatous or ocular hypertensive patients. METHODS: The authors prospectively enrolled 37 eyes of 37 patients in whom IOP was reduced by more than 25% after the use of medication. The images were obtained before and 15 to 30 days after the introduction of medication. The SLP parameters measured before and after the use of medication were compared using paired Student's t Test. RESULTS: The mean IOP was significantly reduced from 26.57±4.23 mmHg to 16.54 ±2.92 mmHg after the use of medication (p0.05. CONCLUSION: The retinal nerve fiber layer thickness, as measured by SLP, is not affected by the reduction of IOP with medication in patients with glaucoma or ocular hypertension.

  11. Cross-layer design in optical networks

    CERN Document Server

    Brandt-Pearce, Maïté; Demeester, Piet; Saradhi, Chava


    Optical networks have become an integral part of the communications infrastructure needed to support society’s demand for high-speed connectivity.  Cross-Layer Design in Optical Networks addresses topics in optical network design and analysis with a focus on physical-layer impairment awareness and network layer service requirements, essential for the implementation and management of robust scalable networks.  The cross-layer treatment includes bottom-up impacts of the physical and lambda layers, such as dispersion, noise, nonlinearity, crosstalk, dense wavelength packing, and wavelength line rates, as well as top-down approaches to handle physical-layer impairments and service requirements.

  12. Tunable multiple layered Dirac cones in optical lattices. (United States)

    Lan, Z; Celi, A; Lu, W; Öhberg, P; Lewenstein, M


    We show that multiple layered Dirac cones can emerge in the band structure of properly addressed multicomponent cold fermionic gases in optical lattices. The layered Dirac cones contain multiple copies of massless spin-1/2 Dirac fermions at the same location in momentum space, whose different Fermi velocity can be tuned at will. On-site microwave Raman transitions can further be used to mix the different Dirac species, resulting in either splitting of or preserving the Dirac point (depending on the symmetry of the on-site term). The tunability of the multiple layered Dirac cones allows us to simulate a number of fundamental phenomena in modern physics, such as neutrino oscillations and exotic particle dispersions with E~p(N) for arbitrary integer N.

  13. Introducing convex layers to the Traveling Salesman Problem

    CERN Document Server

    Liew, Sing


    In this paper, we will propose convex layers to the Traveling Salesman Problem (TSP). Firstly, we will focus on human performance on the TSP. Experimental data shows that untrained humans appear to have the ability to perform well in the TSP. On the other hand, experimental data also supports the hypothesis of convex hull i.e. human relies on convex hull to search for the optimal tour for the TSP. Secondly, from the paper published by Bonabeau, Dorigo and Theraulaz, social insect behavior would be able to help in some of the optimizing problems, especially the TSP. Thus, we propose convex layers to the TSP based on the argument that, by the analogy to the social insect behavior, untrained humans' cognition should be able to help in the TSP. Lastly, we will use Tour Improvement algorithms on convex layers to search for an optimal tour for a 13-cities problem to demonstrate the idea.

  14. Investigation of plasma hydrogenation and trapping mechanism for layer transfer (United States)

    Chen, Peng; Chu, Paul K.; Höchbauer, T.; Lee, J.-K.; Nastasi, M.; Buca, D.; Mantl, S.; Loo, R.; Caymax, M.; Alford, T.; Mayer, J. W.; Theodore, N. David; Cai, M.; Schmidt, B.; Lau, S. S.


    Hydrogen ion implantation is conventionally used to initiate the transfer of Si thin layers onto Si wafers coated with thermal oxide. In this work, we studied the feasibility of using plasma hydrogenation to replace high dose H implantation for layer transfer. Boron ion implantation was used to introduce H-trapping centers into Si wafers to illustrate the idea. Instead of the widely recognized interactions between boron and hydrogen atoms, this study showed that lattice damage, i.e., dangling bonds, traps H atoms and can lead to surface blistering during hydrogenation or upon postannealing at higher temperature. The B implantation and subsequent processes control the uniformity of H trapping and the trap depths. While the trap centers were introduced by B implantation in this study, there are many other means to do the same without implantation. Our results suggest an innovative way to achieve high quality transfer of Si layers without H implantation at high energies and high doses.

  15. Vertical pressure gradient and particle motions in wave boundary layers

    DEFF Research Database (Denmark)

    Jensen, Karsten Lindegård

    The present study covers both a numerical and experimental investigation of the processes in the oscillatory boundary layer. In the first part a direct numerical simulation (DNS) is conducted to study the vertical pressure gradient, and its role in relation to laminar to turbulent transition...... and its role in the fully turbulent boundary layer. The pressure in the flow is obtained from the flow fields of the oscillatory boundary layer. What differs, the vertical pressure gradient, from other turbulent quantities, like e.g. velocity fluctuations is that it can detect newly generated turbulence....... This is in contrast to velocity fluctuations that are diffusive, so they can also contain residual turbulence from the previous half cycle until they are dissipated. Furthermore, the magnitude of the mean value of conditionally averaged vertical pressure gradient (for −∂p∗/∂x∗ 2 > 0) is compared to the submerged...

  16. Unexpected semiconducting properties in few-layer arsenene

    CERN Document Server

    Zhang, Z Y; Xue, D S; Si, M S; Zhang, G P


    We demonstrate few-layer arsenene similar to phosphorene, which are derived from the or- thorhombic bulk arsenic but are thermally stable, semiconducting and of high carrier mobility. Although its monolayer is an indirect bandgap semiconductor, which is dominated by the mutual competition between the intarlayer bond parameters R1 and R2, the indirect-direct bandgap tran- sition is proposed from the analysis of wavefunction. Once any more layer is added, multilayer arsenene are always direct bandgap semiconductors with bandgap in the order of 1 eV. Even more remarkable is that the intrinsic carrier mobility can reach as high as several thousand square cen- timeters per volt-second. All these make few-layer arsenene intriguing for devices applications in semiconducting industry.

  17. Annual layering in the NGRIP ice core during the Eemian

    DEFF Research Database (Denmark)

    Svensson, Anders; Bigler, Matthias; Kettner, Ernesto


    records and visual stratigraphy, and stratigraphic layer counting has been performed back to 60 ka. In the deepest part of the core, however, the ice is close to the pressure melting point, the visual stratigraphy is dominated by crystal boundaries, and annual layering is not visible to the naked eye....... In this study, we apply a newly developed setup for high-resolution ice core impurity analysis to produce continuous records of dust, sodium and ammonium concentrations as well as conductivity of melt water. We analyzed three 2.2m sections of ice from the Eemian and the glacial inception. In all of the analyzed......The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core, annual layers can be identified from impurity...

  18. Layers over layer-by-layer assemblies: silanization of polyelectrolyte multilayers. (United States)

    Dirani, Ali; Fernandes, Antony E; Wong, Diana Ramirez; Lipnik, Pascale; Poleunis, Claude; Nysten, Bernard; Glinel, Karine; Jonas, Alain M


    The functionalization of poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA) polyelectrolyte multilayers by silanes reacted from the gas phase is studied depending on reaction time and temperature, pH of multilayer assembly, and nature of the reacting silane group. Whereas monochlorosilanes only diffuse in the multilayer and graft in limited amount, trichloro- and triethoxysilanes form rapidly a continuous gel layer on the surface of the multilayer, with a thickness of ca. 10-20 nm. The reactivity is lower in the strongly paired regime of the multilayers (neutral assembly conditions) but otherwise is not affected by the pH of multilayer assembly. Silanization considerably broadens the range of possible functionalities for (PAH/PAA) multilayers: hydrophobicity, surface-initiated polymerization, and grafting of fluorescent probes by the formation of disulfide bridges are demonstrated. Conversely, our results also broaden the range of substrates that can be functionalized by silanes, using (PAH/PAA) multilayers as ubiquitous anchoring layers.

  19. Nature, theory and modelling of geophysical convective planetary boundary layers (United States)

    Zilitinkevich, Sergej


    horizontal branches of organised structures. This mechanism (Zilitinkevich et al., 2006), was overlooked in conventional local theories, such as the Monin-Obukhov similarity theory, and convective heat/mass transfer law: Nu~Ra1/3, where Nu and Ra are the Nusselt number and Raleigh numbers. References Hellsten A., Zilitinkevich S., 2013: Role of convective structures and background turbulence in the dry convective boundary layer. Boundary-Layer Meteorol. 149, 323-353. Zilitinkevich, S.S., 1973: Shear convection. Boundary-Layer Meteorol. 3, 416-423. Zilitinkevich, S.S., 1991: Turbulent Penetrative Convection, Avebury Technical, Aldershot, 180 pp. Zilitinkevich S.S., 2012: The Height of the Atmospheric Planetary Boundary layer: State of the Art and New Development - Chapter 13 in 'National Security and Human Health Implications of Climate Change', edited by H.J.S. Fernando, Z. Klaić, J.L. McKulley, NATO Science for Peace and Security Series - C: Environmental Security (ISBN 978-94-007-2429-7), Springer, 147-161. Zilitinkevich S.S., 2013: Atmospheric Turbulence and Planetary Boundary Layers. Fizmatlit, Moscow, 248 pp. Zilitinkevich, S.S., Hunt, J.C.R., Grachev, A.A., Esau, I.N., Lalas, D.P., Akylas, E., Tombrou, M., Fairall, C.W., Fernando, H.J.S., Baklanov, and A., Joffre, S.M., 2006: The influence of large convective eddies on the surface layer turbulence. Quart. J. Roy. Met. Soc. 132, 1423-1456. Zilitinkevich S.S., Tyuryakov S.A., Troitskaya Yu. I., Mareev E., 2012: Theoretical models of the height of the atmospheric planetary boundary layer and turbulent entrainment at its upper boundary. Izvestija RAN, FAO, 48, No.1, 150-160 Zilitinkevich, S.S., Elperin, T., Kleeorin, N., Rogachevskii, I., Esau, I.N., 2013: A hierarchy of energy- and flux-budget (EFB) turbulence closure models for stably stratified geophysical flows. Boundary-Layer Meteorol. 146, 341-373.

  20. Sparse coding for layered neural networks (United States)

    Katayama, Katsuki; Sakata, Yasuo; Horiguchi, Tsuyoshi


    We investigate storage capacity of two types of fully connected layered neural networks with sparse coding when binary patterns are embedded into the networks by a Hebbian learning rule. One of them is a layered network, in which a transfer function of even layers is different from that of odd layers. The other is a layered network with intra-layer connections, in which the transfer function of inter-layer is different from that of intra-layer, and inter-layered neurons and intra-layered neurons are updated alternately. We derive recursion relations for order parameters by means of the signal-to-noise ratio method, and then apply the self-control threshold method proposed by Dominguez and Bollé to both layered networks with monotonic transfer functions. We find that a critical value αC of storage capacity is about 0.11|a ln a| -1 ( a≪1) for both layered networks, where a is a neuronal activity. It turns out that the basin of attraction is larger for both layered networks when the self-control threshold method is applied.

  1. Effect of Mo-doping concentration on the physical behaviour of sprayed ZnO layers (United States)

    Reddy, T. Sreenivasulu; Reddy, M. Vasudeva; Reddy, K. T. Ramakrishna


    Mo-doped zinc oxide layers (MZO) have been prepared on cleaned glass substrates by chemical spray pyrolysis technique by varying Mo-doping concentration in the range, 0 - 5 at. %. The X-ray diffraction studies revealed that all the as prepared layers were polycrystalline in nature and exhibited wurtzite structure. The layers prepared with lower Mo-doping concentration (2 at. %), the films showed the (002) plane as the dominant peak. The optical analysis indicated that all the layers had an average optical transmittance of 80% in the visible region and the evaluated band gap varied in the range, 3.28 - 3.50 eV.

  2. Reflection of Electromagnetic Waves by a Nonuniform Plasma Layer Covering a Metal Surface

    Institute of Scientific and Technical Information of China (English)

    GAO Hong-Mei; FA Peng-Ting


    Reflection coefficients of electromagnetic waves in a nonuniform plasma layer with electrons, positive ions and negative ions, covering a metal surface are investigated by using the finite-difference-time-domain method. It is shown that the reflection coefficients are influenced greatly by the density gradient on the layer edge, layer thickness and electron proportion, i.e., the effect of the negative ions. It is also found that low reflection or high attenuation can be reached by properly choosing high electron proportion, thick plasma layer, and smooth density gradient in the low frequency regime, but sharp density gradient in the high frequency regime.

  3. Vitamin E (United States)

    Vitamins are substances that your body needs to grow and develop normally. Vitamin E is an antioxidant. It plays a role ... immune system and metabolic processes. Good sources of vitamin E include Vegetable oils Margarine Nuts and seeds ...

  4. Vitamin E (United States)

    ... vitamin E combined with other antioxidants, zinc, and copper showed promise for slowing down the rate of ... several years had an increased risk of prostate cancer. Are there any interactions with vitamin E that ...

  5. Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers

    DEFF Research Database (Denmark)

    Christensen, M.; Burcharth, H. F.


    A new design for Dolos breakwater armour layers is presented: Dolos armour units are placed in a selected geometric pattern in a single layer. A series of model tests have been performed in order to determine the stability of such single-layer Dolos armour layers. The test results are presented...... and compared to the stability formula for the traditional double-layer, randomly placed Dolos armour layer design presented by Burcharth (1992). The results of a series of stability tests performed with Accropode® armour layers is presented and compared to the test results obtained with single-layer Dolos...

  6. Layer-by-layer assemblies for antibacterial applications. (United States)

    Zhu, Xiaoying; Jun Loh, Xian


    The adhesion and proliferation of bacteria on various artificial surfaces affects the functionality of these specific interfaces. To overcome the problems caused by bacterial growth on these surfaces, various antibacterial coatings were developed. In this review, we summarized most of the antibacterial surfaces prepared by the Layer-by-Layer (LbL) assembly approach and classified these LbL films based on their antibacterial mechanisms. In the first group, the bactericidal LbL assemblies which incorporate various biocides including heavy metals, antibiotics, cationic molecules, antimicrobial peptides and enzymes are able to kill surrounding or contacted bacteria. In the second group, we focused on the physical aspects of film surfaces. Bacterial adhesion resistant LbL films have been fabricated to adjust the substrate surface properties such as surface free energy (or wettability), roughness, and surface charge which may affect the adhesion of bacteria. Furthermore, as an enhancement in the antibacterial efficiency, multifunctional LbL assemblies combining both bactericidal and adhesion resistant functionalities were discussed. The advantages and limitations of these antibacterial LbL assemblies were summarized and subsequently directions for future development were proposed.

  7. Dendrimers in Layer-by-Layer Assemblies: Synthesis and Applications

    Directory of Open Access Journals (Sweden)

    Katsuhiko Sato


    Full Text Available We review the synthesis of dendrimer-containing layer-by-layer (LbL assemblies and their applications, including biosensing, controlled drug release, and bio-imaging. Dendrimers can be built into LbL films and microcapsules by alternating deposition of dendrimers and counter polymers on the surface of flat substrates and colloidal microparticles through electrostatic bonding, hydrogen bonding, covalent bonding, and biological affinity. Dendrimer-containing LbL assemblies have been used to construct biosensors, in which electron transfer mediators and metal nanoparticles are often coupled with dendrimers. Enzymes have been successfully immobilized on the surface of electrochemical and optical transducers by forming enzyme/dendrimer LbL multilayers. In this way, high-performance enzyme sensors are fabricated. In addition, dendrimer LbL films and microcapsules are useful for constructing drug delivery systems because dendrimers bind drugs to form inclusion complexes or the dendrimer surface is covalently modified with drugs. Magnetic resonance imaging of cancer cells by iron oxide nanoparticles coated with dendrimer LbL film is also discussed.

  8. Neurons of the dentate molecular layer in the rabbit hippocampus.

    Directory of Open Access Journals (Sweden)

    Francisco J Sancho-Bielsa

    Full Text Available The molecular layer of the dentate gyrus appears as the main entrance gate for information into the hippocampus, i.e., where the perforant path axons from the entorhinal cortex synapse onto the spines and dendrites of granule cells. A few dispersed neuronal somata appear intermingled in between and probably control the flow of information in this area. In rabbits, the number of neurons in the molecular layer increases in the first week of postnatal life and then stabilizes to appear permanent and heterogeneous over the individuals' life span, including old animals. By means of Golgi impregnations, NADPH histochemistry, immunocytochemical stainings and intracellular labelings (lucifer yellow and biocytin injections, eight neuronal morphological types have been detected in the molecular layer of developing adult and old rabbits. Six of them appear as interneurons displaying smooth dendrites and GABA immunoreactivity: those here called as globoid, vertical, small horizontal, large horizontal, inverted pyramidal and polymorphic. Additionally there are two GABA negative types: the sarmentous and ectopic granular neurons. The distribution of the somata and dendritic trees of these neurons shows preferences for a definite sublayer of the molecular layer: small horizontal, sarmentous and inverted pyramidal neurons are preferably found in the outer third of the molecular layer; vertical, globoid and polymorph neurons locate the intermediate third, while large horizontal and ectopic granular neurons occupy the inner third or the juxtagranular molecular layer. Our results reveal substantial differences in the morphology and electrophysiological behaviour between each neuronal archetype in the dentate molecular layer, allowing us to propose a new classification for this neural population.

  9. Black layers on historical architecture. (United States)

    Toniolo, Lucia; Zerbi, Carlotta M; Bugini, Roberto


    The external surface of any building in urban polluted environment is unavoidably destined to be covered with layers that assume a grey to black colour and are generally called 'black crusts'. These, according to standard protocols and glossary, are deteriorated surface layers of stone material; they can have variable thickness, are hard and fragile and can detach spontaneously from the substrate, which, in general, is quite decayed. Plain visual examination may lead to consider 'black crusts' all similar, whilst only a careful diagnostic investigation can distinguish 'black crusts' and the consequences of their formation on stone substrates. In this paper, various black layers on marble are studied and compared and the morphological and compositional characteristics discussed according to the related mechanisms of formation. Differences between old (hundred years) and recent crusts (30 years) are investigated and pointed out. Samples of black crusts collected from the Milan Cathedral façade (Candoglia Marble) have been studied and compared with the careful and synergic employ of traditional techniques: optical (transmission and reflected VIS light) and electron microscopy, X-ray spectrometry and micro-Fourier transform infrared spectroscopy. Visual examination of loose fragments does not allow to point out outstanding differences amongst the various samples; black layers have similar main mineral components, gypsum and airborne particles, with different spatial distribution. The microscopic studies allowed to point out the porosity differences, the gypsum crystallisation habit, different amount of embedded particles, level and progress of marble decay. The observations lead to define three main types of black crusts: black crust deriving from marble sulphation, compact deposit and encrustation due to exogenic materials deposition. Black crusts show evidence of sulphation in progress, without a clear continuity solution between crust and marble; the lack of

  10. Large-eddy simulation of the very stable boundary layer (United States)

    Chinita, M. J.; Matheou, G.


    The stable boundary layer is ubiquitous and typically forms at night when the ground radiatively cools and in polar regions throughout the day. Stable stratification and the associated reduction in the energetic scales in combination with the large anisotropy of turbulent motions challenge numerical models. This modeling difficulty also affects large-eddy simulation (LES) methods leading to scarce LES results for very stable conditions. In contrast, the NWP of convective flows has greatly benefited from the ample availability of high quality LES data. In order to overcome these limitations, a novel LES model setup is developed to enable the modeling of very stable boundary layers. A series of Ekman layer-type boundary layers at various surface cooling rates, geotropic winds and latitudes (rotation rates) is presented. A temperature surface condition is applied in the LES. The surface heat flux is dynamically computed byresolving the surface layer since the often-used Monin-Obukhov similarity theory cannot represent very stable conditions. Depending on the conditions, the LES gracefully transitions to a direct numerical simulation (DNS) where the flow becomes fully resolved. Two stability regimes can be discerned based on vertical profiles of the Richardson number. Overall, the model predicts that turbulence is very resilient with respect to stability. Temperature and velocity fluctuations persist even at high Richardson numbers. The nature of the fluctuations, i.e., due to turbulence/overturning or waves, is discussed. Scaling relations and spectra are also presented and discussed.

  11. Infrared fingerprints of few-layer black phosphorus (United States)

    Zhang, Guowei; Huang, Shenyang; Chaves, Andrey; Song, Chaoyu; Özçelik, V. Ongun; Low, Tony; Yan, Hugen


    Black phosphorus is an infrared layered material. Its bandgap complements other widely studied two-dimensional materials: zero-gap graphene and visible/near-infrared gap transition metal dichalcogenides. Although highly desirable, a comprehensive infrared characterization is still lacking. Here we report a systematic infrared study of mechanically exfoliated few-layer black phosphorus, with thickness ranging from 2 to 15 layers and photon energy spanning from 0.25 to 1.36 eV. Each few-layer black phosphorus exhibits a thickness-dependent unique infrared spectrum with a series of absorption resonances, which reveals the underlying electronic structure evolution and serves as its infrared fingerprints. Surprisingly, unexpected absorption features, which are associated with the forbidden optical transitions, have been observed. Furthermore, we unambiguously demonstrate that controllable uniaxial strain can be used as a convenient and effective approach to tune the electronic structure of few-layer black phosphorus. Our study paves the way for black phosphorus applications in infrared photonics and optoelectronics.

  12. Ultraefficient reduced model for countercurrent two-layer flows (United States)

    Lavalle, Gianluca; Vila, Jean-Paul; Lucquiaud, Mathieu; Valluri, Prashant


    We investigate the dynamics of two superposed layers with density contrast flowing countercurrent inside a channel, when the lower layer is much thinner than the wavelength of interfacial waves. We apply a low-dimensional film model to the bottom (heavier) layer and introduce a fast and efficient method to predict the onset of flow reversal in this phase. We study three vertical scenarios with different applied pressure gradients and compare the temporal growth rates of linear and weakly nonlinear waves to the Orr-Sommerfeld problem and to the weakly nonlinear theory, respectively. At the loading point, i.e., when a large wave hump stands at the interface, our spatiotemporal analysis shows that the system is absolutely unstable. We then present profiles of nonlinear saturated waves, pressure field, and streamline distribution in agreement with direct numerical simulation. The reduced model presented here allows us to explore the effect of the upper-layer speed on the wave pattern, showing that the wave profile is very sensitive when the mean film thickness, rather than the liquid flow rate, is maintained constant in the simulation. In addition, we show the strong effect of surface tension on both the maximum wave hump and the crest steepness before the loading point. Finally, we reveal how the nonlinear wave speed affects the vortex distribution within the lower layer by analyzing the stream function under different scenarios.

  13. Infrared fingerprints of few-layer black phosphorus. (United States)

    Zhang, Guowei; Huang, Shenyang; Chaves, Andrey; Song, Chaoyu; Özçelik, V Ongun; Low, Tony; Yan, Hugen


    Black phosphorus is an infrared layered material. Its bandgap complements other widely studied two-dimensional materials: zero-gap graphene and visible/near-infrared gap transition metal dichalcogenides. Although highly desirable, a comprehensive infrared characterization is still lacking. Here we report a systematic infrared study of mechanically exfoliated few-layer black phosphorus, with thickness ranging from 2 to 15 layers and photon energy spanning from 0.25 to 1.36 eV. Each few-layer black phosphorus exhibits a thickness-dependent unique infrared spectrum with a series of absorption resonances, which reveals the underlying electronic structure evolution and serves as its infrared fingerprints. Surprisingly, unexpected absorption features, which are associated with the forbidden optical transitions, have been observed. Furthermore, we unambiguously demonstrate that controllable uniaxial strain can be used as a convenient and effective approach to tune the electronic structure of few-layer black phosphorus. Our study paves the way for black phosphorus applications in infrared photonics and optoelectronics.

  14. From front contact to back contact in cadmium telluride/cadmium sulfide solar cells: Buffer layer and interfacial layer (United States)

    Roussillon, Yann

    Cadmium telluride (CdTe) polycrystalline thin film solar cells, with their near optimum direct band-gap of 1.4 eV matching almost perfectly the sun radiation spectrum, are a strong contender as a less expensive alternative, among photovoltaic materials, than the more commonly used silicon-based cells. Polycrystalline solar cells are usually deposited over large areas. Such devices often exhibit strong fluctuations (nonuniformities) in electronic properties, which originate from deposition and post-deposition processes, and are detrimental to the device performance. Therefore their effects need to be constrained. A new approach in this work was, when a CdS/CdTe solar cell is exposed to light and immersed in a proper electrolyte, fluctuations in surface potential can drive electrochemical reactions which result in a nonuniform interfacial layer that could balance the original nonuniformity. This approach improved the device efficiency for CdS/CdTe photovoltaic devices from 1--3% to 11--12%. Cadmium sulfide (CdS), used as a window layer and heterojunction partner to CdTe, is electrically inactive and absorb light energies above its band-gap of 2.4 eV. Therefore, to maximize the device efficiency, a thin US layer needs to be used. However, more defects, such as pinholes, are likely to be present in the film, leading to shunts. A resistive transparent layer, called buffer layer, is therefore deposited before CdS. A key observation was that the open-circuit voltage (Voc) for cells made using a buffer layer was high, around 800 mV, similar to cells without buffer layer after Cu doping. The standard p-n junction theory cannot explain this phenomena, therefore an alternative junction mechanism, similar to metal-insulator-semiconductor devices, was developed. Furthermore, alternative Cu-free back-contacts were used in conjunction with a buffer layer. The Voc of the devices was found to be dependent of the back contact used. This change occurs as the back-contact junction

  15. Reverse engineering of multi-layer films


    Effendi Widjaja; Marc Garland


    This contribution introduces the combined application of Raman microscopy and band-target entropy minimization (BTEM) in order to successfully reverse-engineer a multi-layer packaging material. Three layers are identified, namely, polyethylene, a paper and talc layer (with two distinct cellulose forms), and a poly-styrene co-polymer composite containing anatase and calcite. This rapid and non-destructive approach provides a unique opportunity for the assessment of multi-layer composites, incl...

  16. Assembly of 1D nanofibers into a 2D bi-layered composite nanofibrous film with different functionalities at the two layers via layer-by-layer electrospinning. (United States)

    Wang, Zijiao; Ma, Qianli; Dong, Xiangting; Li, Dan; Xi, Xue; Yu, Wensheng; Wang, Jinxian; Liu, Guixia


    A two-dimensional (2D) bi-layered composite nanofibrous film assembled by one-dimensional (1D) nanofibers with trifunctionality of electrical conduction, magnetism and photoluminescence has been successfully fabricated by layer-by-layer electrospinning. The composite film consists of a polyaniline (PANI)/Fe3O4 nanoparticle (NP)/polyacrylonitrile (PAN) tuned electrical-magnetic bifunctional layer on one side and a Tb(TTA)3(TPPO)2/polyvinylpyrrolidone (PVP) photoluminescent layer on the other side, and the two layers are tightly combined face-to-face together into the novel bi-layered composite film of trifunctionality. The brand-new film has totally different characteristics at the double layers. The electrical conductivity and magnetism of the electrical-magnetic bifunctional layer can be, respectively, tunable via modulating the PANI and Fe3O4 NP contents, and the highest electrical conductivity can reach up to the order of 10(-2) S cm(-1), and predominant intense green emission at 545 nm is obviously observed in the photoluminescent layer under the excitation of 357 nm single-wavelength ultraviolet light. More importantly, the luminescence intensity of the photoluminescent layer remains almost unaffected by the electrical-magnetic bifunctional layer because the photoluminescent materials have been successfully isolated from dark-colored PANI and Fe3O4 NPs. By comparing with the counterpart single-layered composite nanofibrous film, it is found that the bi-layered composite nanofibrous film has better performance. The novel bi-layered composite nanofibrous film with trifunctionality has potential in the fields of nanodevices, molecular electronics and biomedicine. Furthermore, the design conception and fabrication technique for the bi-layered multifunctional film provide a new and facile strategy towards other films of multifunctionality.

  17. S-layer nanoglycobiology of bacteria


    Messner, Paul; Steiner, Kerstin; Zarschler, Kristof; Schäffer, Christina


    Cell surface layers (S-layers) are common structures of the bacterial cell envelope with a lattice-like appearance that are formed by a self-assembly process. Frequently, the constituting S-layer proteins are modified with covalently linked glycan chains facing the extracellular environment. S-layer glycoproteins from organisms of the Bacillaceae family possess long, O-glycosidically linked glycans that are composed of a great variety of sugar constituents. The observed variations already exc...

  18. Multiple-Dynode-Layer Microchannel Plate (United States)

    Woodgate, Bruce E.


    Improved microchannel-plate electron image amplifier made of stack of discrete microchannel-plate layers. New plates easier to manufacture because no need to etch long, narrow holes, to draw and bundle thin glass tubes, or to shear plates to give microchannels curvatures necessary for reduction of undesired emission of ions. Discrete dynode layers stacked with slight offset from layer to layer to form microchannel plate with curved channels. Provides for relatively fast recharging of microchannel dynodes, with consequent enhancement of performance.

  19. Behavior of macromolecules in adsorbed layers

    Institute of Scientific and Technical Information of China (English)

    牟伯中[1; 姚恒申[2; 罗平亚[3


    A model for describing the behavior ot macromoiecuies in aosoroea layers is developed by introducing a concept of distribution density of layer thickness U based on stochastic process and probabilistic statistics. The molecular behavior of layers adsorbed on clay particle surfaces is discussed; the random distribution and its statistics of the layer thickness are given by incorporating experimental results with an ionic polyelectrolyte with the molecular weight of 1.08×106and chain charged density of 0.254.

  20. Behavior of macromolecules in adsorbed layers

    Institute of Scientific and Technical Information of China (English)


    A model for describing the behavior of macromolecules in adsorbed layers is developed by introducing a concept of distribution density of layer thickness U based on stochastic process and probabilistic statistics. The molecular behavior of layers adsorbed on clay particle surfaces is discussed; the random distribution and its statistics of the layer thickness are given by incorporating experimental results with an ionic polyelectrolyte with the molecular weight of 1.08×106 and chain charged density of 0.254.

  1. Multi-Layer Traffic Steering

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Gimenez, Lucas Chavarria


    This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle...... users can be steered towards higher priority carriers whenever coverage allows it. However, such an approach may overload the prioritized layers. For that purpose, an enhanced scheme is proposed, where priorities are adjusted on a user basis and are provided to the terminal via the connection release...

  2. Novel layered two-dimensional semiconductors as the building blocks for nano-electronic/photonic systems (United States)

    Su, Guoxiong; De, Debtanu; Hadjiev, Viktor G.; Peng, Haibing


    Layered two-dimensional (2D) semiconductors beyond graphene have been emerging as potential building blocks for the next-generation electronic/photonic applications. Representative metal chalcogenides, including the widely studied MoS2, possess similar layered crystal structures with weak interaction between adjacent layers, thus allowing the formation of stable thin-layer crystals with thickness down to a few or even single atomic layer. Other important chalcogenides, involving earth-abundant and environment-friendly materials desirable for sustainable applications, include SnS2 (band gap: 2.1 eV) and SnS (band gap: 1.1 eV). So far, commonly adopted for research purpose are mechanical and liquid exfoliation methods for creating thin layers of such 2D semiconductors. Most recently, chemical vapor deposition (CVD) was attracting significant attention as a practical method for producing thin films or crystal grains of MoS2. However, critical yet still absent is an effective experimental approach for controlling the positions of thin crystal grains of layered 2D semiconductors during the CVD process. Here we report the controlled CVD synthesis of thin crystal arrays of representative layered semiconductors (including SnS2 and SnS) at designed locations on chip, promising large-scale optoelectronic applications. Our work opens a window for future practical applications of layered 2D semiconductors in integrated nano-electronic/photonic systems.

  3. Boundary layer structure in turbulent Rayleigh-Benard convection

    CERN Document Server

    Shi, Nan; Schumacher, Joerg


    The structure of the boundary layers in turbulent Rayleigh-Benard convection is studied by means of three-dimensional direct numerical simulations. We consider convection in a cylindrical cell at an aspect ratio one for Rayleigh numbers of Ra=3e+9 and 3e+10 at fixed Prandtl number Pr=0.7. Similar to the experimental results in the same setup and for the same Prandtl number, the structure of the laminar boundary layers of the velocity and temperature fields is found to deviate from the prediction of the Prandtl-Blasius-Pohlhausen theory. Deviations decrease when a dynamical rescaling of the data with an instantaneously defined boundary layer thickness is performed and the analysis plane is aligned with the instantaneous direction of the large-scale circulation in the closed cell. Our numerical results demonstrate that important assumptions which enter existing classical laminar boundary layer theories for forced and natural convection are violated, such as the strict two-dimensionality of the dynamics or the s...

  4. Cultivation and irradiation of human fibroblasts in a medium enriched with platelet lysate for obtaining feeder layer in epidermal cell culture; Cultivo e irradiacao de fibroblastos humanos em meio enriquecido com lisado de plaquetas para obtencao de camada de sustentacao em culturas de celulas da epiderme

    Energy Technology Data Exchange (ETDEWEB)

    Yoshito, Daniele


    For over 30 years, the use of culture medium, enriched with bovine serum, and murines fibroblasts, with the rate of proliferation controlled by irradiation or by share anticarcinogenic drugs, has been playing successfully its role in assisting in the development of keratinocytes in culture, for clinical purposes. However, currently there is a growing concern about the possibility of transmitting prions and animals viruses to transplanted patients. Taking into account this concern, the present work aims to cultivate human fibroblasts in a medium enriched with human platelets lysate and determine the irradiation dose of these cells, for obtaining feeder layer in epidermal cell culture. For carrying out the proposed objective, platelets lysis has standardized, this lysate was used for human fibroblasts cultivation and the irradiation dose enough to inhibit its duplication was evaluated. Human keratinocytes were cultivated in these feeder layers, in culture medium enriched with the lysate. With these results we conclude that the 10% platelets lysate promoted a better adhesion and proliferation of human fibroblasts and in all dose levels tested (60 to 300 Gy), these had their mitotic activity inactivated by ionizing irradiation, being that the feeder layers obtained with doses from 70 to 150 Gy were those that provided the best development of keratinocytes in medium containing 2.5% of human platelet lysate. Therefore, it was possible to standardize both the cultivation of human fibroblasts as its inactivation for use as feeder layer in culture of keratinocytes, so as to eliminate xenobiotics components. (author)

  5. Can the chemistry save the crisis of the mankind in the twenty-first century? To the gentle chemistry in environment from the ozone layer depletion; Kagaku wa 21 seiki no jinrui no kiki wo sukueruka? Ozonso kahai kara kankyo ni yasashii kagaku e

    Energy Technology Data Exchange (ETDEWEB)

    Tominaga, T. [The Univ. of Tokyo, Tokyo (Japan)


    The representative result as the global environmental problems caused by chemical substance is the ozone layer depletion of the stratosphere by chlorofluorocarbon (CFC). The regulation of the CFC began in 1989 based on 'Vienna Convention for the Ozone layer protection' (1985) and 'Montreal Protocol on Substances that Deplete the Ozone Layer' (1987). Production and consumption of CFC, tetrachloromethane, methylchloroform and halon have already been aborted, and the regulation of HCFC and bromomethane were also began to turn to the abolition. The increase of atmosphere average concentration such as CFC and methylchloroform has already blunted in such the international regulation. The chloride concentration of stratosphere from substance of the ozone layer depletion would reach a peak soon, and was prospected to be reduced after then. It is expected to drop to previous level before the South Pole ozone hole appeared after the middle in the twenty-first century. Finally, the future prospect of the gentle chemistry in the environment is described. (NEDO)

  6. Layer resolved spectroscopy of potassium adsorbed on a Ru(001) surface: Photoemission and thermal desorption study

    Energy Technology Data Exchange (ETDEWEB)

    Hrbek, J. (Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (US)); Shek, M. (Department of Physics, Hunter College of CUNY, New York, New York 10021); Sham, T.K. (Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7, Canada); Xu, G. (Chemistry Department, Brookhaven National Laboratory, Upton, New York, 11973)


    High-resolution photoemission spectroscopy and thermal desorption were used to study the coverage dependence of the K 3{ital p}{sub 3/2,1/2} core levels of K overlayers on Ru(001). Three doublets were observed to evolve sequentially and to shift to higher binding energy with increasing coverage of potassium. The doublets were assigned to photoemission from the interface (first layer), bulk'' (second layer), and surface (third layer). Spin--orbit splitting was observed for the first time in the condensed potassium phase by photoemission. The results are discussed in terms of the equivalent core approximation using a Born--Haber cycle. In the thermal desorption data three coverage regimes can be distinguished: a first layer desorbing with first-order kinetics and a strongly decreasing heat of adsorption ({ital E}{sub {ital A}} =2.80--0.87 eV); a second layer with zero-order desorption kinetics and {ital E}{sub {ital A}} =0.78 eV; a third layer and multilayers with the same kinetic order but with {ital E}{sub {ital A}} increasing from 0.78 to 0.93 eV, which is close to the heat of sublimation of potassium.

  7. Computer Program Re-layers Engineering Drawings (United States)

    Crosby, Dewey C., III


    RULCHK computer program aids in structuring layers of information pertaining to part or assembly designed with software described in article "Software for Drawing Design Details Concurrently" (MFS-28444). Checks and optionally updates structure of layers for part. Enables designer to construct model and annotate its documentation without burden of manually layering part to conform to standards at design time.

  8. The Hole in the Ozone Layer. (United States)

    Hamers, Jeanne S.; Jacob, Anthony T.

    This document contains information on the hole in the ozone layer. Topics discussed include properties of ozone, ozone in the atmosphere, chlorofluorocarbons, stratospheric ozone depletion, effects of ozone depletion on life, regulation of substances that deplete the ozone layer, alternatives to CFCs and Halons, and the future of the ozone layer.…

  9. An Electromagnetic GL Double Layered Cloak

    CERN Document Server

    Xie, Ganquan; Xie, Feng; Xie, Lee


    In this paper, we propose a new electromagnetic (EM) GL double layered cloak. The GL double layered cloak is consist of two sphere annular layers, $R_1 \\le r \\le R_2$ and $R_2 \\le r \\le R_3$. Two type cloak materials are proposed and installed in the each layer, respectively. The outer layer cloak of the GL double layered cloak has the invisible function, the inner layer cloak has fully absorption function. The GL double layered metamaterials are weak degenerative and weak dispersive. When the source is located outside of the GL double layered cloak, the excited EM wave field propagation outside of the double layered cloak is as same as in free space and never be disturbed by the cloak; also, the exterior EM wave can not penetrate into the inner layer and concealment. When local sources are located inside of the GL double cloaked concealment with the normal EM materials, the excited EM wave is propagating under Maxwell equation governing, it is complete absorbed by the inner layer cloak of GL double cloak and...

  10. Development of inverted organic solar cells with TiO₂ interface layer by using low-temperature atomic layer deposition. (United States)

    Lin, Zhenhua; Jiang, Changyun; Zhu, Chunxiang; Zhang, Jie


    Organic solar cells (OSCs) with inverted structure have attracted much attention in recent years because of their improved device air stability due to the use of stable materials for electrodes and interface layers. In this work, TiO(2) films, fabricated using low temperature (e.g., 130-170 °C) atomic layer deposition (ALD) on ITO substrates, are used as electron selective interface layers to investigate inverted OSCs. It is found that though the as-deposited TiO(2) films are high resistive due to the presence of oxygen defects, the defects can be significantly reduced by light soaking. PV cells with 15-nm-thick amorphous-TiO(2) layers fabricated at low temperature show better performance than those with poly crystal TiO(2) with same thickness deposited at 250 °C. The low temperature ALD-grown TiO(2) films are dense, stable and robust with capability of conformal coating on nanostructural surfaces, showing a promising interface layer for achieving air-stable plastic OSCs with roll-to-roll mass production potential.

  11. Desenvolvimento e aplicação de metodologia por cromatografia em camada delgada para determinação do perfil de alcalóides oxindólicos pentacíclicos nas espécies sul-americanas do gênero Uncaria Development and application of a thin layer chromatographic method for the determination of the pentacyclic oxindole alkaloid profile in South-American species of the genus Uncaria

    Directory of Open Access Journals (Sweden)

    Ligia M.M. Valente


    Full Text Available O gênero Uncaria (Rubiaceae é representado na América do Sul e Central por duas espécies: U. tomentosa (Willd. DC. e U. guianensis (Aubl. Gmel., conhecidas popularmente como unha-de-gato. Ambas são trepadeiras perenes, sendo empregadas na prevenção e cura de várias doenças. Nessas plantas são encontrados alcalóides oxindólicos e indólicos, triterpenos glicosilados, taninos e flavonóides. Seis alcalóides oxindólicos pentacíclicos, considerados seus marcadores: especiofilina, mitrafilina, uncarina F, isomitrafilina, pteropodina e isopteropodina, são usados na padronização do material vegetal e fitoterápicos derivados. O presente trabalho descreve o desenvolvimento de metodologia analítica qualitativa utilizando cromatografia em camada delgada (CCD para determinação do perfil dos seis alcalóides oxindólicos pentacíclicos marcadores das espécies. O desenvolvimento do método incluiu a comparação entre o uso do extrato metanólico bruto, e de frações enriquecidas obtidas por partição ácido-base clássica ou pelo uso de resina básica Poliamida 6. Utilizou-se gel de sílica como fase estacionária, e variaram-se alguns parâmetros como: eluentes, concentração da amostra, espaço de eluição e tipos de reveladores. O método desenvolvido em CCD mostrou-se confiável, reprodutível e seletivo para os alcalóides alvos, sendo aplicado na análise de amostras de folhas e caule das duas espécies e também de fitoterápicos comerciais à base de U. tomentosa.The species Uncaria tomentosa (Willd. DC. and U. guianensis Gmel. (Rubiaceae, known as cat's claw, are large woody vines occurring in the Amazon rain forest and other tropical areas of South and Central America. It has been used medicinally by indigenous peoples for at least 2,000 years for several diseases. Tetra- and pentacyclic oxindole alkaloids, triterpenoid glycosides, sterols and flavonoids are found in these plants. Among these metabolites, six pentacyclic

  12. Dispersal, settling and layer formation. (United States)

    Caffrey, James R; Hughes, Barry D; Landman, Kerry A


    Motivated by examples in developmental biology and ecology, we develop a model for convection-dominated invasion of a spatial region by initially motile agents which are able to settle permanently. The motion of the motile agents and their rate of settling are affected by the local concentration of settled agents. The model can be formulated as a nonlinear partial differential equation for the time-integrated local concentration of the motile agents, from which the instantaneous density of settled agents and its long-time limit can be extracted. In the limit of zero diffusivity, the partial differential equation is of first order; for application-relevant initial and boundary-value problems, shocks arise in the time-integrated motile agent density, leading to delta-function components in the motile agent density. Furthermore, there are simple solutions for a model of successive layer formation. In addition some analytic results for a one-dimensional system with non-zero diffusivity can also be obtained. A case study, both with and without diffusion, is examined numerically. Some important predictions of the model are insensitive to the specific settling law used and the model offers insight into biological processes involving layered growth or overlapping generations of colonization.

  13. Layered Working-Set Trees

    CERN Document Server

    Bose, Prosenjit; Dujmović, Vida; Howat, John


    The working-set bound [Sleator and Tarjan, J. ACM, 1985] roughly states that searching for an element is fast if the element was accessed recently. Binary search trees, such as splay trees, can achieve this property in the amortized sense, while data structures that are not binary search trees are known to have this property in the worst case. We close this gap and present a binary search tree called a layered working-set tree that guarantees the working-set property in the worst case. The unified bound [Badoiu et al., TCS, 2007] roughly states that searching for an element is fast if it is near (in terms of rank distance) to a recently accessed element. We show how layered working-set trees can be used to achieve the unified bound to within a small additive term in the amortized sense while maintaining in the worst case an access time that is both logarithmic and within a small multiplicative factor of the working-set bound.

  14. Optical stability of silicon nitride MIS inversion layer solar cells (United States)

    Jaeger, K.; Hezel, R.


    For MIS inversion layer solar cells with silicon nitride as an AR coating, accelerated optical stress tests were performed. Degradation of the cell characteristics occurred which was found to be caused by photons with energies equal to or greater than 3.7 eV (wavelength of 335 nm or less). Generation of interface states at the silicon-insulator interface by UV light is shown to be the mechanism responsible. The original cell data could be completely restored by heat treatment (activation energy 0.5 eV) and partially by illumination with short-wavelength light. As the most striking result, however, it is demonstrated that the UV light-induced instability can be drastically improved by incorporation of cesium ions into the silicon nitride layer. An interpretation is given for this effect.

  15. Pareto distance for multi-layer network analysis

    DEFF Research Database (Denmark)

    Magnani, Matteo; Rossi, Luca


    Social Network Analysis has been historically applied to single networks, e.g., interaction networks between co-workers. However, the advent of on-line social network sites has emphasized the stratified structure of our social experience. Individuals usually spread their identities over multiple...... services, e.g., Facebook, Twitter, LinkedIn and Foursquare. As a result, the analysis of on-line social networks requires a wider scope and, more technically speaking, models for the representation of this fragmented scenario. The recent introduction of more realistic layered models has however determined...... new research problems related to the extension of traditional single-layer network measures. In this paper we take a step forward over existing approaches by defining a new concept of geodesic distance that includes heterogeneous networks and connections with very limited assumptions regarding...

  16. Some measurements in synthetic turbulent boundary layers (United States)

    Savas, O.


    Synthetic turbulent boundary layers are examined which were constructed on a flat plate by generating systematic moving patterns of turbulent spots in a laminar flow. The experiments were carried out in a wind tunnel at a Reynolds number based on plate length of 1,700,000. Spots were generated periodically in space and time near the leading edge to form a regular hexagonal pattern. The disturbance mechanism was a camshaft which displaced small pins momentarily into the laminar flow at frequencies up to 80 Hz. The main instrumentation was a rake of 24 hot wires placed across the flow in a line parallel to the surface. The main measured variable was local intermittency; i.e., the probability of observing turbulent flow at a particular point in space and time. The results are reported in x-t diagrams showing the evolution of various synthetic flows along the plate. The dimensionless celerity or phase velocity of the large eddies is found to be 0.88, independent of eddy scale. All patterns with sufficiently small scales eventually showed loss of coherence as they moved downstream. A novel phenomenon called eddy transposition was observed in several flows which contained appreciable laminar regions. The large eddies shifted in formation to new positions, intermediate to their original ones, while preserving their hexagonal pattern. The present results, together with some empirical properties of a turbulent spot, are used to estimate the best choice of scales for constructing a synthetic boundary layer suitable for detailed study. The values recommended are: spanwise scale/thickness = 2.5, streamwise scale/thickness = 8.

  17. Experimental investigation on coupling flows between liquid and liquid metal layers (United States)

    Yano, Kanako; Tasaka, Yuji; Murai, Yuichi; Takeda, Yasushi; Yanagisawa, Takatoshi


    This study aims to clarify coupling of flows between liquid metal and other usual liquids, e.g. water or oil, in fluid dynamical systems. In past studies for two-layer Rayleigh-Bénard system where the immiscible two liquids are layered, two types of coupling were observed; these are called as ``mechanical coupling'' and ``thermal coupling.'' As a typical character of low Pr fluid, large-scale structure in the liquid metal layer has oscillating motion. In this study we investigate ``thermal coupling'' especially how the oscillation of cells in the liquid metal layer propagates to the upper liquid layer and vice versa by changing a ratio of the height of the layers and viscosity of the upper layer fluid. Visualization of the liquid metal motion was conducted by means of ultrasonic velocity profiling, and then the oscillating motion is expressed on the space-time velocity map. PIV measurement of the upper, transparent fluid layer shows the modulation of the convective motion due to the oscillation in the liquid metal layer. Point-wise measurement of temperature at several positions in the fluid layer represents the modulation quantitatively.

  18. Textured strontium titanate layers on platinum by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Blomberg, T., E-mail: [ASM Microchemistry Ltd., Vaeinoe Auerin katu 12 A, 00560 Helsinki (Finland); Anttila, J.; Haukka, S.; Tuominen, M. [ASM Microchemistry Ltd., Vaeinoe Auerin katu 12 A, 00560 Helsinki (Finland); Lukosius, M.; Wenger, Ch. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Saukkonen, T. [Aalto University, Puumiehenkuja 3, 02150 Espoo (Finland)


    Formation of textured strontium titanate (STO) layers with large lateral grain size (0.2-1 {mu}m) and low X-ray reflectivity roughness ({approx} 1.36 nm) on Pt electrodes by industry proven atomic layer deposition (ALD) method is demonstrated. Sr(t-Bu{sub 3}Cp){sub 2}, Ti(OMe){sub 4} and O{sub 3} precursors at 250 Degree-Sign C were used to deposit Sr rich STO on Pt/Ti/SiO{sub 2}/Si Empty-Set 200 mm substrates. After crystallization post deposition annealing at 600 Degree-Sign C in air, most of the STO grains showed a preferential orientation of the {l_brace}001{r_brace} plane parallel to the substrate surface, although other orientations were also present. Cross sectional and plan view transmission electron microscopy and electron diffraction analysis revealed more than an order of magnitude larger lateral grain sizes for the STO compared to the underlying multicrystalline {l_brace}111{r_brace} oriented platinum electrode. The combination of platinum bottom electrodes with ALD STO(O{sub 3}) shows a promising path towards the formation of single oriented STO film. - Highlights: Black-Right-Pointing-Pointer Amorphous strontium titanate (STO) on platinum formed a textured film after annealing. Black-Right-Pointing-Pointer Single crystal domains in 60 nm STO film were 0.2-1 {mu}m wide. Black-Right-Pointing-Pointer Most STO grains were {l_brace}001{r_brace} oriented.

  19. Aligned Layers of Silver Nano-Fibers

    Directory of Open Access Journals (Sweden)

    Andrii B. Golovin


    Full Text Available We describe a new dichroic polarizers made by ordering silver nano-fibers to aligned layers. The aligned layers consist of nano-fibers and self-assembled molecular aggregates of lyotropic liquid crystals. Unidirectional alignment of the layers is achieved by means of mechanical shearing. Aligned layers of silver nano-fibers are partially transparent to a linearly polarized electromagnetic radiation. The unidirectional alignment and density of the silver nano-fibers determine degree of polarization of transmitted light. The aligned layers of silver nano-fibers might be used in optics, microwave applications, and organic electronics.

  20. Dense, layered membranes for hydrogen separation (United States)

    Roark, Shane E.; MacKay, Richard; Mundschau, Michael V.


    This invention provides hydrogen-permeable membranes for separation of hydrogen from hydrogen-containing gases. The membranes are multi-layer having a central hydrogen-permeable layer with one or more catalyst layers, barrier layers, and/or protective layers. The invention also relates to membrane reactors employing the hydrogen-permeable membranes of the invention and to methods for separation of hydrogen from a hydrogen-containing gas using the membranes and reactors. The reactors of this invention can be combined with additional reactor systems for direct use of the separated hydrogen.

  1. Dynamics of liquid solidification thermal resistance of contact layer

    CERN Document Server

    Lipnicki, Zygmunt


    This monograph comprehensively describes phenomena of heat flow during phase change as well as the dynamics of liquid solidification, i.e. the development of a solidified layer. The book provides the reader with basic knowledge for practical designs, as well as with equations which describe processes of energy transformation. The target audience primarily comprises researchers and experts in the field of heat flow, but the book may also be beneficial for both practicing engineers and graduate students.

  2. Optical Detection Using Four-Layer Semiconductor Structures (United States)


    analog considers the thyristor, specifically in this case a Shockley diode, as two Bipolar Junction Transistors (BJTs), one npn and one pnp, con- 15...appropriate BJT layer: emitter (E), base (B) and collector (C). The subscript pnp or npn is used to distinguish between the two transistors . It must be...both transistors in the active mode. The holes gathering in the pnp collector (P2) and the electrons in npn collector (N1) have no external escape

  3. Methods for Estimating the Ultimate Bearing Capacity of Layered Foundations

    Institute of Scientific and Technical Information of China (English)

    袁凡凡; 闫澍旺


    The Meyerhof and Hanna′s(M-H) method to estimate the ultimate bearing capacity of layered foundations was improved. The experimental results of the load tests in Tianjin New Harbor were compared with predictions with the method recommended by the code for the foundations of harbor engineering, i.e. Hansen′s method and the improved M-H method. The results of the comparisons implied that the code and the improved M-H method could give a better prediction.

  4. Collective plasmonic properties in few-layer gold nanorod supercrystals


    Hamon, Cyrille; Novikov, Sergey M.; Scarabelli, Leonardo; Solis, Diego M.; Altantzis, Thomas; Bals, Sara; Taboada, Jose M.; Obelleiro, Fernando; Liz-Marzán, Luis M.


    Abstract: Gold nanorod supercrystals have been widely employed for the detection of relevant bioanalytes with detection limits ranging from nano- to picomolar levels, confirming the promising nature of these structures for biosensing. Even though a relationship between the height of the supercrystal (i.e., the number of stacked nanorod layers) and the enhancement factor has been proposed, no systematic study has been reported. In order to tackle this problem, we prepared gold nanorod supercry...

  5. The role of harzburgite layers in the morphology of subducting plates and the behavior of oceanic crustal layers (United States)

    Yoshida, Masaki


    Previous numerical studies of mantle convection focusing on subduction dynamics have indicated that the viscosity contrast between the subducting plate and the surrounding mantle have a primary effect on the behavior of subducting plates. The seismically observed plate stagnation at the base of the mantle transition zone (MTZ) under the Western Pacific and Eastern Eurasia is considered to mainly result from a viscosity increase at the ringwoodite to perovskite + magnesiowüstite (Rw→Pv+Mw) phase decomposition boundary, i.e., the boundary between the upper and lower mantle. The harzburgite layer, which is sandwiched between basaltic crust and depleted peridotite (lherzolite) layers, is a key component of highly viscous, cold oceanic plates. However, the possible sensitivity of the effective viscosity of harzburgite layers in the morphology of subducting plates that are flattened in the MTZ and/or penetrated in the lower mantle has not been examined systematically in previous three-dimensional (3D) numerical modeling studies that consider the viscosity increase at the boundary between the upper and lower mantle. In this study, in order to investigate the role of harzburgite layers in the morphology of subducting plates and the behavior of oceanic crustal layers, I performed a series of numerical simulations of mantle convection with semi-dynamic plate subduction in 3D regional spherical-shell geometry. The results show that a buckled crustal layer is observed under the "heel" of the stagnant slab that begins to penetrate into the lower mantle, regardless of the magnitude of the viscosity contrast between the harzburgite layer and the underlying mantle, when the factor of viscosity increase at the boundary of the upper and lower mantle is larger than 60-100. As the viscosity contrast between the harzburgite layer and the underlying mantle increases, the curvature of buckling is larger. When the viscosity increase at the boundary of the upper and lower mantle and the

  6. Five layers in a turbulent pipe flow (United States)

    Lee, Jinyoung; Ahn, Junsun; Sung, Hyung Jin


    The scaling laws governing the five layers of the mean velocity distribution of a turbulent pipe flow were characterized using the available DNS data (Reτ = 544 , 934, 3008). Excluding the very near-wall and core regions, the buffer, meso- and log layers were identified by examining the streamwise mean momentum equation and the net force spectra. The (outer) log layer was located in the overlap region where the viscous force was negligible. Another (inner) log layer was observed in the buffer layer, in which the viscous force was directly counterbalanced by the turbulent inertia. A meso-layer between the buffer and outer log layers was found to feature viscous effects. The acceleration force of the large-scale motions (LSMs) penetrated the outer log layer at higher Reynolds numbers, as observed in the net force spectra. The acceleration force of the LSMs became strong and was counterbalanced by the deceleration force of the small-scale motions (SSMs), indicating that the inner and outer length scales contributed equally to the meso-layer. The outer log layer was established by forming an extended connection link between the meso- and outer layers. This work was supported by the Creative Research Initiatives (No. 2016-004749) program of the National Research Foundation of Korea (MSIP) and partially supported by KISTI under the Strategic Supercomputing Support Program.

  7. Experimental research on the stability of armour and secondary layer in a single layered Tetrapod breakwater

    NARCIS (Netherlands)

    De Jong, W.; Verhagen, H.J.; Olthof, J.


    Physical model tests were done on an armour of Tetrapods, placed in a single layer. The objective of the investigations was to study the stability of the secondary layer, and to see if the material of this secondary layer could be washed out through the single layer of Tetrapods. It was concluded

  8. Combined technique for estimating the quality of joining the layers in three-layer pipes (United States)

    Nikulin, S. A.; Rozhnov, A. B.; Nechaikina, T. A.; Rogachev, S. O.; Votinov, S. N.; Zavodchikov, S. Yu.


    The prospects of estimating the quality of joining the layers of a three-layer pipe for the fuel claddings of a fast reactor from the results of a combined investigation, which includes computer-assisted quantitative metallography, microindentation, electron-probe microanalysis, and layer-by-layer atomic emission spectroscopy, are discussed.

  9. S-layer protein self-assembly. (United States)

    Pum, Dietmar; Toca-Herrera, Jose Luis; Sleytr, Uwe B


    Crystalline S(urface)-layers are the most commonly observed cell surface structures in prokaryotic organisms (bacteria and archaea). S-layers are highly porous protein meshworks with unit cell sizes in the range of 3 to 30 nm, and thicknesses of ~10 nm. One of the key features of S-layer proteins is their intrinsic capability to form self-assembled mono- or double layers in solution, and at interfaces. Basic research on S-layer proteins laid foundation to make use of the unique self-assembly properties of native and, in particular, genetically functionalized S-layer protein lattices, in a broad range of applications in the life and non-life sciences. This contribution briefly summarizes the knowledge about structure, genetics, chemistry, morphogenesis, and function of S-layer proteins and pays particular attention to the self-assembly in solution, and at differently functionalized solid supports.

  10. Network Composition from Multi-layer Data

    CERN Document Server

    Lerman, Kristina; Yan, Xiaoran


    It is common for people to access multiple social networks, for example, using phone, email, and social media. Together, the multi-layer social interactions form a "integrated social network." How can we extend well developed knowledge about single-layer networks, including vertex centrality and community structure, to such heterogeneous structures? In this paper, we approach these challenges by proposing a principled framework of network composition based on a unified dynamical process. Mathematically, we consider the following abstract problem: Given multi-layer network data and additional parameters for intra and inter-layer dynamics, construct a (single) weighted network that best integrates the joint process. We use transformations of dynamics to unify heterogeneous layers under a common dynamics. For inter-layer compositions, we will consider several cases as the inter-layer dynamics plays different roles in various social or technological networks. Empirically, we provide examples to highlight the usef...

  11. Radiation induced topotactic [2 + 2] dimerisation of acrylate derivatives among the layers of a CaFe layered double hydroxide followed by IR spectroscopy (United States)

    Srankó, D. F.; Canton, S.; Enghdahl, A.; Muráth, Sz.; Kukovecz, Á.; Kónya, Z.; Sipiczki, M.; Sipos, P.; Pálinkó, I.


    Various acrylates [E-phenylpropenoate, E-3(4‧-nitrophenyl)propenoate, E-3(2‧,5‧-difluorphenyl)propenoate, E-3(2‧-thienyl)propenoate, E-3(4‧-imidazolyl)propenoate or E-2,3-dimethylpropenoate] were successfully intercalated into Ca(II)Fe(III) layered double hydroxide (CaFe-LDH) verified by a range of instrumental methods. The possible arrangements for the organic anions were suggested on the basis of basal spacing data, layer thickness and the dimensions of the quantum chemically optimised structures of the acrylate ions. Using the acrylate-CaFe-LDHs as reactant-filled nanoreactors, photoinitiated topotactic [2 + 2] cyclisation reactions followed by IR spectroscopy could be performed with many representatives [E-phenylpropenoate-, E-3(4‧-nitrophenyl)propenoate-, E-3(2‧,5‧-difluorphenyl)propenoate- or E-3(2‧-thienyl)propenoate-CaFe-LDHs] resulting in cyclobutane derivatives within the layers of the host material indicating that there were domains where the intercalated anions were in close proximity to each other and in proper arrangement for the reaction to occur.

  12. EKHARA Monte Carlo generator for e+e- to e+e-pi0 and e+e- to e+e- pi+pi- processes


    Czyz, Henryk; Ivashyn, Sergiy


    We present EKHARA Monte Carlo event generator of reactions e+e- to e+e- pi0 and e+e- to e+e- pi+pi-. The newly added channel (e+e- to e+e-pi0) is important for gamma*gamma* physics and can be used for the pion transition form factor studies at meson factories.

  13. Electrochemistry of ATP-capped silver nanoparticles in layer-by-layer multilayer films (United States)

    Singh, Poonam; Solomon, Virgil C.; Buttry, Daniel A.


    Colloidal silver nanoparticles (Ag NPs) capped with adenosine triphosphate (ATP) were prepared using borohydride reduction of Ag+ in the presence of ATP. Subsequent characterization was done using transmission electron microscopy/high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and non-contact atomic force microscopy (NcAFM) confirming the size and composition of the Ag NPs. This report focuses on two topics: (1) the change in NP size and properties as a function of molar ratios of Ag+ to ATP capping ligand to BH4 - reductant, and (2) the electrochemical behavior of the NPs in layer-by-layer (LbL) multilayer films. On the basis of electrostatic interaction between negatively charged phosphate groups on Ag NPs and positively charged poly(diallyldimethylammonium) hydrochloride, NPs were immobilized on 3-mercaptopropionic acid (MCP)-functionalized gold electrodes using LbL assembly method followed by characterization of the film using NcAFM. Furthermore, the redox chemistry for phase transformations of immobilized Ag NPs to AgCl or Ag2O in multilayer films was examined using cyclic voltammetry (CV) in NaOH and NaCl solutions. A non-linear increase of charge with an increase in the number of bilayers in the film was observed up to five layers. Underpotential deposition of Pb on multilayer film of Ag NPs confirmed the presence of Ag in multilayer films. The stability of the LbL film toward electrochemical cycling to higher potentials (i.e., +0.8 V) in NaOH solutions was evaluated.

  14. A new layered iron fluorophosphate

    Indian Academy of Sciences (India)

    Amitava Choudhury


    A new iron fluorophosphate of the composition, [C6N4H21] [Fe2F2(HPO4)3][H2PO4]·2H2O, I has been prepared by the hydrothermal route. This compound contains iron fluorophosphate layers and the H2PO$_{4}^{-}$ anions are present in the interlayer space along with the protonated amine and water molecules. The compound crystallizes in the monoclinic space group 21/. ( = 13.4422(10) Å, = 9.7320(10) Å, = 18.3123(3) Å, = 92.1480 °, = 2393.92(5) Å3, = 4, = 719.92, calc = 1.997 g cm-3, 1 = 0.03 and 2 = 0.09).

  15. Smear layer--materials surface. (United States)

    Eick, J D


    SEM and TEM photomicrographs were presented of the smear layer and several dentin-adhesive interfaces. It was shown that as the wetting and penetration of the dentin adhesive increased, the shear bond strength also increased. Three categories of dentin adhesives were presented. Category one included Scotchbond, Dentin Adhesit and Gluma, with shear bond strength values between 5 and 7 MPa; the second category, dentin adhesives based on Dr. Bowen's research, included Tenure and Mirage Bond, with shear bond strengths between 8 and 14 MPa; the third category included Superbond and Scotchbond 2, with shear bond strength values up to 20 MPa. Failures occurred at the interface or in the resin adhesive for materials in categories one and two; failures occurred through the dentin or composite for materials in category three.

  16. films using atomic layer deposition (United States)

    Chervinskii, Semen; Matikainen, Antti; Dergachev, Alexey; Lipovskii, Andrey A.; Honkanen, Seppo


    We fabricated self-assembled silver nanoisland films using a recently developed technique based on out-diffusion of silver from an ion-exchanged glass substrate in reducing atmosphere. We demonstrate that the position of the surface plasmon resonance of the films depends on the conditions of the film growth. The resonance can be gradually shifted up to 100 nm towards longer wavelengths by using atomic layer deposition of titania, from 3 to 100 nm in thickness, upon the film. Examination of the nanoisland films in surface-enhanced Raman spectrometry showed that, in spite of a drop of the surface-enhanced Raman spectroscopy (SERS) signal after the titania spacer deposition, the Raman signal can be observed with spacers up to 7 nm in thickness. Denser nanoisland films show slower decay of the SERS signal with the increase in spacer thickness.

  17. Superconductivity in Layered Organic Metals

    Directory of Open Access Journals (Sweden)

    Jochen Wosnitza


    Full Text Available In this short review, I will give an overview on the current understanding of the superconductivity in quasi-two-dimensional organic metals. Thereby, I will focus on charge-transfer salts based on bis(ethylenedithiotetrathiafulvalene (BEDT-TTF or ET for short. In these materials, strong electronic correlations are clearly evident, resulting in unique phase diagrams. The layered crystallographic structure leads to highly anisotropic electronic as well as superconducting properties. The corresponding very high orbital critical field for in-plane magnetic-field alignment allows for the occurrence of the Fulde–Ferrell– Larkin–Ovchinnikov state as evidenced by thermodynamic measurements. The experimental picture on the nature of the superconducting state is still controversial with evidence both for unconventional as well as for BCS-like superconductivity.

  18. Tracer diffusion inside fibrinogen layers (United States)

    Cieśla, Michał; Gudowska-Nowak, Ewa; Sagués, Francesc; Sokolov, Igor M.


    We investigate the obstructed motion of tracer (test) particles in crowded environments by carrying simulations of two-dimensional Gaussian random walk in model fibrinogen monolayers of different orientational ordering. The fibrinogen molecules are significantly anisotropic and therefore they can form structures where orientational ordering, similar to the one observed in nematic liquid crystals, appears. The work focuses on the dependence between level of the orientational order (degree of environmental crowding) of fibrinogen molecules inside a layer and non-Fickian character of the diffusion process of spherical tracer particles moving within the domain. It is shown that in general particles motion is subdiffusive and strongly anisotropic, and its characteristic features significantly change with the orientational order parameter, concentration of fibrinogens, and radius of a diffusing probe.

  19. Tracer diffusion inside fibrinogen layers

    CERN Document Server

    Cieśla, Michał; Sagués, Francesc; Sokolov, Igor M


    We investigate the motion of tracer (test) particles in crowded environments by carrying simulations of two-dimensional Gaussian random walk in model fibrinogen monolayers of different orientational ordering. The fibrinogen molecules are significantly anisotropic and therefore they can form structures where orientational ordering, similar to the one observed in nematic liquid crystals, appears. The work focuses on the dependence between level of the orientational order (degree of environmental crowding) of fibrinogen molecules inside a layer and non-Fickian character of the diffusion process of spherical tracer particles moving within the domain. It is shown that in general particles motion is subdiffusive and strongly anisotropic, and its characteristic features significantly change with the orientational order parameter, concentration of fibrinogens and radius of a diffusing probe.

  20. Layered amphibolite sequence in NE Sardinia, Italy: remnant of a pre-Variscan mafic silicic layered intrusion? (United States)

    Franceschelli, Marcello; Puxeddu, Mariano; Cruciani, Gabriele; Dini, Andrea; Loi, Marilisa


    A banded amphibolite sequence of alternating ultramafic, mafic (amphibolite) and silicic layers, tectonically enclosed within Variscan migmatites, outcrops at Monte Plebi (NE Sardinia) and shows similarities with leptyno-amphibolite complexes. The ultramafic layers consist of amphibole (75-98%), garnet (0-20%), opaque minerals (1-5%) and biotite (0-3%). The mafic rocks are made up of amphibole (65-80%), plagioclase (15-30%), quartz (0-15%), opaque minerals (2-3%) and biotite (0-2%). The silicic layers consist of plagioclase (60-75%), amphibole (15-30%) and quartz (10-15%). Alteration, metasomatic, metamorphic and hydrothermal processes did not significantly modify the original protolith chemistry, as proved by a lack of K2O-enrichment, Rb-enrichment, CaO-depletion, MgO-depletion and by no shift in the rare earth element (REE) patterns. Field, geochemical and isotopic data suggest that ultramafic, mafic and silicic layers represent repeated sequences of cumulates, basic and acidic rocks similar to macrorhythmic units of mafic silicic layered intrusions. The ultramafic layers recall the evolved cumulates of Skaergaard and Pleasant Bay mafic silicic layered intrusions. Mafic layers resemble Thingmuli tholeiites and chilled Pleasant Bay mafic rocks. Silicic layers with Na2O: 4-6 wt%, SiO2: 67-71 wt% were likely oligoclase-rich adcumulates common in many mafic silicic layered intrusions. Some amphibolite showing a strong Ti-, P-depletion and REE-depletion are interpreted as early cumulates nearly devoid of ilmenite and phosphates. All Monte Plebi rocks have extremely low Nb, Ta, Zr, Hf content and high LILE/HFSE ratios, a feature inherited from the original mantle sources. The mafic and ultramafic layers show slight and strong LREE enrichment respectively. Most mafic layer samples plot in the field of continental tholeiites in the TiO2-K2O-P2O5 diagram and are completely different from N-MORB, E-MORB and T-MORB as regards REE patterns and Nd, Sr isotope ratios but show