Instrumentation

This paper describes the analysis of L-band radiometric measurement data gathered with the synthetic aperture radiometer HUT-2D during several ground-based and airborne measurement campaigns. The radiometric data are analyzed from the instrument's performance point of view, aiming to verify the theoretical performance of an instrument of this kind and to assess the performance of the HUT-2D radiometer system in particular. The data sets considered for the study consist of measurements of well-known natural targets, such as cosmic background radiation, and measurements of pure water scenes, the brightness temperature of which is possible to model based on in situ measurements. We define four figures of merit, which are applicable for synthetic aperture radiometers. These are radiometric resolution, image bias, pixel-to-pixel random error, and temporal stability. Then, we use the selected data sets to assess these in the case of HUT-2D. The experimental results are discussed and compared to the theoretical values, where applicable. Also, we discuss possibilities to improve the presented performance. The main results of this paper are the consolidated performance parameters of the HUT-2D instrument. We study and discuss the properties of the error components related to the technology in a general level, and study the scalability of the errors as a function of the measured targets. In particular, the stability of the direction-dependent error component is pointed out, and a mitigation guideline is proposed.

Self-Regulated Learning or SRL is an important academic performance for every student in completing a series of academic activities and realized by himself, especially in an online learning environment that is not supervised directly by the teacher. This research is an effort to develop a measuring instrument in the form of an SRL scale and called the SRLS based on three aspects according to the theory presented by Zimmerman. The purpose of this study is to produce a student SRL measurement tool in the online learning era in order to find patterns of student involvement in learning that can be applied by students to improve learning achievement. Respondents involved in this study amounted to 408 students of SMP/MTs grades VII to IX. Validation of items through an expert judgment process by experts in psychometry and psychology with the results of the content validity item (CVI) obtained is 0.68 to 1.00 and the reliability test results have a Cronbach alpha value of 0.893. The results of this research will provide benefits to identify patterns of student involvement in learning and generated guidelines for the use of the SSRL measuring instrument.

Çalgı eğitimi ve icrasında en önemli unsurlar arasında yer alan “ritmik yapının” önemi her daim
ön plana çıkmaktadır. Müzik denilen olgunun kısa tanımında yer alan “ses kaynağı” ve “ritim”
öğeleri de dikkate alındığında bilinmektedir ki temelde ritim sistematiğinin her müzisyende olması
temel bir şarttır. Bu temelde “ritmik yapı” denilen kavram ele alındığında karşımıza metronom
kullanımının önemi çıkmaktadır. Bu çalışmanın amacı; ritim duygusunun geliştirilmesi ve ud
çalgısına uyarlanması konusunda tespit edilen bazı problemleri ortaya koymaya çalışarak bu
problemlerin nasıl bertaraf edileceği konusunda gerekli teknik bilgilerin aktarılmasıdır.

The overall system performance with reference to sensitivity can be expressed by considering individual component sensitivities. The sensor RTD is connected to the transmitter through signal conditioner that converts the change in resistance resulted from RTD in to equivalent current signal ranging between 4-20 mA. The various other components considered here are, Actuator, final control element (control valve), sensor, transmitter and process.

A cryopreservation procedure using an aluminium cryo-plate was successfully developed using in vitro-grown Dalmatian chrysanthemum (Tanacetum cinerariifolium) shoot tips. Shoot cultures were cold-hardened at 5 degree C on MS medium containing 0.5 M sucrose over a period of 20 to 40 days. Shoot tips with basal plate (1.0-1.5 x 1.0 mm) were dissected from shoot cultures and precultured at 5 degree C for 2 days on MS medium containing 0.5 M sucrose. Precultured shoot tips were placed on aluminium cryo-plates (7 mm x 37 mm x 0.5 mm) with 10 wells (diameter 1.5 mm, depth 0.75 mm) and embedded in alginate gel. Osmoprotection was performed by immersing the cryo-plates for 30 or 60 min in 25 ml pipetting reservoirs filled with loading solution (2 M glycerol + 1.4 M sucrose). For dehydration, the loading solution was replaced with PVS 7M vitrification solution (30 percent glycerol, 19.5 percent ethylene glycol and 0.6 M sucrose in liquid MS basal medium), which was applied for 40 min. After ...

lntrapulmonary percussive ventilation (IPV) is a novel form of chest physiotherapy delivered by a percussive pneumatic device (IPV, Percussionaire, Sand Point, ID). There are few published reports about the use of IPV for diseases other than cystic fibrosis. We report our experience with three pediatric patients and one adult patient with persistent pulmonary consolidation refractory to conventional therapies. Three of the four patients had neurornuscular disease; one patient had segmental atelectasis due to aspiration. Three of the four patients showed clinical and radiographic improvement within 48 hours of starting IPV. The fourth patient experienced brief episodes of third-degree atrioventricular block, hypoxemia, and bradycardia during two IPV treatments. IPV was safely restarted and he slowly improved. We conclude that while IPV requires further clinical evaluation, it appears to be a safe and effective therapy for selected patients. However, close observation is essential during and after IPV treatments, especially in patients who have difficulty mobilizing or expectorating sputum. Pediatr Pulmonol.

It is well known that certain fluids are birefringent and when flows are viewed in polarised light interference fringes are observed. The fringes are caused by a phase shift in the light passing through the fluid and are proportional to the integral of the maximum shear strains in the fluid. In order to understand what is happening within the flow and overcome the difficulties due to this integration of analysing three dimensional flows, additional computational or experimental information is needed. In this work, a commercially available computer code (Fluent) is used for the first time to model the flows. The flow data are then exported to a spreadsheet where the shear rates are integrated across the field and then banded for graphical output. The results from this are then compared to results generated from birefringent flow experiments and the agreement is found to be good since the modelled fringes show the same patterns as those in the experiment. This novel use of computational and experimental techniques together will allow quantitative analysis of three dimensional flows in the future. 2 Currently, there are still a lot of empirical variables involved in fitting the computational fringes to the experiment, but the results of this preliminary study show that this is a promising approach to this type of problem.

Musical genres are categorical labels created by humans to characterize pieces of music. A musical genre is characterized by the common characteristics shared by its members. These characteristics typically are related to the instrumentation, rhythmic structure, and harmonic content of the music. Genre hierarchies are commonly used to structure the large collections of music available on the Web. Currently musical genre annotation is performed manually. Automatic musical genre classification can assist or replace the human user in this process and would be a valuable addition to music information retrieval systems. In addition, automatic musical genre classification provides a framework for developing and evaluating features for any type of content-based analysis of musical signals.

The use of mass spectra generated at 70 eV in electron ionization (EI) as a universal standard for EI has helped in the generation of searchable library databases and had a profound influence on the analytical applications of gas chromatography/mass spectrometry (GC/MS), similarly for liquid chromatography tandem mass spectrometry (LC-MS/MS), suggesting a novel method to normalize the collisional energy for the universalization of fragmentation energy for the analysis of Chemical Weapon Convention (CWC)-related chemicals by atmospheric pressure ionization-tandem mass spectrometry (API-MS n ) using threedimensional (3D) ion trap instruments. For normalizing fragmentation energy a "fragmentation energy index" (FEI) is proposed which is an arbitrary scale based on the fact of specific MS/MS fragmentation obtained at different collisional energies for the reference chemicals which are not CWC scheduled compounds. FEI 6 for the generation of an MS n librarysearchable mass spectral database is recommended.

Thermal cameras are used in research laboratories to measure tissue temperature during laser irradiation. This study was an evaluation of the accuracy of a 3–5 μm thermal camera and two 8–12 μm cameras in detecting the maximum temperatures of small targets. The size of the targets was within the range of laser spot diameters which are used for vessel welding, angioplasty, and dermatology. The response to a sharp thermal edge was measured and analyzed for the three cameras, which had a scanning rate of 30 frames per second. The response of the 3–5 μm camera to reference black body targets of different sizes was also studied.It was found that the detector system required an average of 2.44 μs to reach 90% of maximum step response for the 8–12 μm system and 5.85 μs for the 3–5 μm system. With a 3×5 telescope and a 9.5 inch focal distance close-up lens, the 3–5 μm camera underestimated the temperature of targets smaller than 2.0 mm because of its slow detector response. Although the 8–12 μm camera provides more accurate measurements due to its faster detector response, it still underestimates the temperature of targets smaller than 900 μm, when similar magnification and focal distance are used.Methods to compensate for the inaccuracies are discussed, including empirical correction factors and the inverse filtering technique.

The paper describes the design of a floating gate MOS sensor embedded in a readout CMOS element, used as a radiation monitor. A maximum sensitivity of 1 mV/rad is estimated within an absorbed dose range from 1 to 10 krad. The paper shows in particular the design of a microelectronic circuit that includes the floating gate sensor, an oscillator, a modulator, a transmitter and an integrated antenna. A prototype of the circuit has recently been simulated, fabricated and tested exploiting a commercial 180 nm, 4 metal CMOS technology. Some simulation results are presented along with a measurement of the readout circuit response to an input voltage swing. Given the small estimated area of the complete chip prototype, that is less than 1 mm 2 , the chip fits a large variety of applications, from spot radiation monitoring systems in medicine to punctual measurements or radiation level in High-Energy Physics experiments.

To provide guidelines for the development of two types of closed-set speech-perception tests that can be applied and interpreted in the same way across languages. The guidelines cover the digit triplet and the matrix sentence tests that are most commonly used to test speech recognition in noise. They were developed by a working group on Multilingual Speech Tests of the International Collegium of Rehabilitative Audiology (ICRA). The recommendations are based on reviews of existing evaluations of the digit triplet and matrix tests as well as on the research experience of members of the ICRA Working Group. They represent the results of a consensus process. The resulting recommendations deal with: Test design and word selection; Talker characteristics; Audio recording and stimulus preparation; Masking noise; Test administration; and Test validation. By following these guidelines for the development of any new test of this kind, clinicians and researchers working in any language will be ...

A : We present a simulation-based study using deep convolutional neural networks (DC-NNs) to identify neutrino interaction vertices in the MINERνA passive targets region, and illustrate the application of domain adversarial neural networks (DANNs) in this context. DANNs are designed to be trained in one domain (simulated data) but tested in a second domain (physics data) and utilize unlabeled data from the second domain so that during training only features which are unable to discriminate between the domains are promoted. MINERνA is a neutrino-nucleus scattering experiment using the NuMI beamline at Fermilab. A-dependent cross sections are an important part of the physics program, and these measurements require vertex finding in complicated events. To illustrate the impact of the DANN we used a modified set of simulation in place of physics data during the training of the DANN and then used the label of the modified simulation during the evaluation of the DANN. We find that deep learning based methods offer significant advantages over our prior track-based reconstruction for the task of vertex finding, and that DANNs are able to improve the performance of deep networks by leveraging available unlabeled data and by mitigating network performance degradation rooted in biases in the physics models used for training. K : neutrino, reconstruction, convolutional neural networks, deep learning, domain adversarial neural networks

1] We use a global hydrographic dataset to study the effect of instrument related biases on the estimates of longterm temperature changes in the global ocean since the 1950s. The largest discrepancies are found between the expendable bathythermographs (XBT) and bottle and CTD data, with XBT temperatures being positively biased by 0.2-0.4°C on average. Since the XBT data are the largest proportion of the dataset, this bias results in a significant World Ocean warming artefact when time periods before and after introduction of XBT are compared. Using biascorrected XBT data we argue reduces the ocean heat content change since the 1950s by a factor of 0.62. Our estimate of the ocean heat content increase (0-3000 m) between 1957 -66 and 1987-96 is 12.8Á10 22 J. Because of imperfect sampling this estimate has an uncertainty of at least 8Á10 22 J.

Polarization phenomena in a metal-semiconductor-metal (M-S-M) structure of metallic Schottky contacts deposited on CdZnTe radiation detectors were studied. We evaluate the distribution of the electric field along the biased M-S-M structure by Pockels measurements. The results show that almost all the electric field is developed across the depletion layer of the reverse-biased contact. The noise measurements of the CdZnTe detectors studied show that the dominant noise is 1/ f m noise. The 1/ f m noise, with the parameter m close to one, is present at frequencies below 100 Hz and its bandwidth decreases in the course of the polarization process. At higher frequencies, we observed an increase of the m parameter to 2, which indicates a strengthened effect of the generation-recombination processes. In the frequency band of dominating 1/ f m = 1 noise, the increase of magnitude of the noise spectral density was proportional to the power of 6, in relation to the current through the detector. This high value is explained as a result of a screening effect of the space charge buildup during the polarization.

Root canal preparation has been considered one of the most important steps in root canal therapy, thus many techniques and instruments have been developed. The aim of this study was to evaluate the cleaning of the root canal through three different instrumentation techniques. Thirty mandibular incisors were selected and submitted to lingual access cavities. Afterwards, the canals were filled with India ink dye previously stored in carpules, which was inserted into the root canal by means of anesthetic syringe and anesthetic needles. After 48 hours, during which the dye was allowed to dry inside the root canal, the teeth were divided in three groups: G1- GT rotatory instrumentation; G2- manual instrumentation; G3- association of both. After instrumentation, the teeth were longitudinally sectioned. The cleaning process accomplished through the different instrumentation techniques was evidenced by dye removal at the cervical, middle and apical thirds of the root canal. The results of this study showed that were not statistically significant differences between these three instrumentation techniques for all three thirds of the root canal.

DarkSide-50 is a detector for dark matter candidates in the form of weakly interacting massive particles (WIMPs). It utilizes a liquid argon time projection chamber (LAr TPC) for the inner main detector. The TPC is surrounded by a liquid scintillator veto (LSV) and a water Cherenkov veto detector (WCV). The LSV and WCV, both instrumented with PMTs, act as the neutron and cosmogenic muon veto detectors for DarkSide-50. This paper describes the electronics and data acquisition system used for these two detectors.

A determination of the Avogadro constant from two selected silicon single-crystals with natural isotopic compositions is described. The density, molar mass, and lattice spacing of the two crystals were measured at NMIJ, PTB, IRMM, IMGC, and NIST. When all the data are combined, they lead to a value of the Avogadro constant of 6.022 1353 (18) 10 23 mol 1 with a relative combined standard uncertainty of 3.1 10 7 .

Selenium content of soils is an important issue due to the narrow range between the nutritious requirement and toxic effects upon Se exposure. However, its determination is challenging due to low concentrations within complex matrices that hamper the analysis in most spectroscopic techniques. In this study, we explored the possibilities of several analytical approaches combined with total reflection X-ray (TXRF) spectrometry for soil Se determinations. The direct analysis of a solid suspension using 20 mg of fine ground material (<50 µm) has a relatively high Se limit of detection (LOD) of 1 mg/kg (worldwide Se average in soils ) 0.4 mg/kg) and is therefore only suitable for seleniferous soils. Several fast and simple analytical strategies were developed to decrease matrix effects and improve the LOD for Se determination in soil digests. On one hand, the application of a liquid-liquid extraction procedure using ethyl ether and the introduction of a Cr absorbent in the instrument configuration were carried out to avoid the associated problems on TXRF analysis of soil extracts due to the high Fe concentrations (∼700 mg/L). On the other hand, a dispersive liquid-liquid microextraction procedure (DLL-ME) before the TXRF analysis of the soil digest was also developed. The effects of various experimental parameters such as sample volume, effect of major elements present in the soil matrix (Fe), and Se concentration in the sample were investigated. The LOD using this analytical methodology (0.05 mg/kg of Se) was comparable to or lower than those obtained in previous works using other popular spectrometric techniques such as GFAAS, ICPMS, and AFS. The calculated Se concentration for JSAC-0411 ([Se] ) 1.32 ( 0.27 mg/kg) using the combination of DLLME and TXRF ([Se] ) 1.40 ( 0.23 mg/kg) was in agreement with the certified value.

Current measurements from DIARAD/VIRGO, PMO6V/VIRGO and ACRIM3 radiometers are of the same order of magnitude, but differ from TIM/SORCE by about 4.5 W m À2 . This difference is higher than the sum of the claimed individual absolute uncertainties of the instruments. In this context, the SOLAR payload on the International Space Station embarks the SOVIM package. We give the results of the differential absolute radiometer DIARAD/SOVIM and discuss its associated uncertainties. Compared to DIARAD/ VIRGO, all possible efforts have been made to improve the absolute accuracy. Substantial progress has been made in the aperture area and electrical power measurements. The measured TSI value from the left channel of DIARAD/SOVIM during three days of June 2008 is 1364.50 ± 1.38 W m À2 (Total) or ±0.49 W m À2 (if we combine the individual contributions in quadrature). The right channel gives 1364.75 W m À2 with the same uncertainties. These values are about 1.2 W m À2 lower than DIARAD/VIRGO and about 4 W m À2 higher than TIM/SORCE. The difference between the left and right channels measurements is as low as 0.25 W m À2 which is within the improved uncertainty limits.

Among the family of pulse time modulation (PTM) techniques, square wave frequency modulation (SWFM) is particularly well suited to the transmission of high-quality wideband instrumentation and video signals such as MAC and high definition TV over optical fibres due to its attractive combination of performance and simplicity. This paper discusses aspects of SWFM and describes two experimental systems employing novel demodulators suitable for 5.5 MHz (PAL) and 12 MHz wide format MAC bandwidth systems respectively. &gt;

The results of several research eld studies were evaluated to estimate the precision and bias of various designated PM 2:5 Federal Reference Method (FRM) samplers. Precision was favorable in these carefully conducted research studies where all operational activities were strictly controlled, with an average coef cient of variation (CV) ranging from 2 to 6%. No signi cant bias was found between the method designations. Comparisons between the designated reference method samplers meet the EPA Equivalent Method Criteria for comparability except for one pair of samplers. In this instance, the y-intercept of the Andersen RAAS2.5-300 versus the Rupprecht & Patashnick Partisol-Plus 2025 was 1.07 ¹g/m 3 , slightly exceeding the y-intercept 1.0 ¹g/m 3 limit. Nondesignated PM 2:5 samplers demonstrated strong linear relationships when compared to reference method samplers; however, the comparisons presented in this analysis did not meet the EPA Subpart C criteria. These results indicate that the currently designated reference method samplers should allow precision and bias objectives to be achieved for the National PM 2:5 Network.

Background: Jejunal feeding is an attractive means for delivering nutrients to critically ill patients. Nasojejunal tubes may have different advantages and disadvantages that may have important clinical implications. Methods: To compare the suitability of 2 different nasojejunal feeding tubes (Tube A, Dobbhoff; Tube B, Freka-Trelumina) for use by endoscopists and nursing staff, a randomized, controlled, prospective trial was performed in 60 patients. The primary end point was time required for tube placement. Secondary end points were successful placement and nursing problems encountered during clinical use. Results of upper endoscopy were also recorded. Results: Placement took significantly longer with Tube A than Tube B (95% CI for median [11.5, 20.0] minutes vs. [5.5, 7.5] minutes; p < 0.001), and was less successful (73.3% vs. 90%; p = 0.18). Nursing problems occurred significantly more often with Tube A compared with Tube B (11 vs. 1; p < 0.001). Tube B stayed in place significantly longer than Tube A (37 days vs. 21 days; p = 0.034). In 45% of the cases, upper endoscopy provided a diagnosis of potential therapeutic relevance. Conclusions: Selection of a nasojejunal tube for endoscopic placement has significant implications with respect to time required for placement, duration of tube usage and the practicability for nursing staff. Diagnostic upper endoscopy performed concomitantly often reveals findings of clinical importance. (Gastrointest Endosc 2002;56:858-63.) Endoscopic placement of nasojejunal tubes: comparison of 2 different tubes

A GPS network has been installed to monitor vertical crustal movement in the Lambert Glacier region, East Antarctica. The program commenced in January 1998 with a solar-powered GPS system installed at Beaver Lake. Solar-powered observations were also made late in the Antarctic summer of 1999. In January 2000, two new solarpowered sites will be installed to expand the monitoring network. In addition, we will be installing a hydrogen fuel cell power system at Beaver Lake to enable the equipment to operate throughout the winter months when solar power is not available. In this paper we outline the equipment which has been developed in order to operate remote GPS equipment in Antarctica, provide predictions of the expected rate of rebound and comment on preliminary results from the data collected to date.

We present test results and characterization of a data transmission system based on a last generation FPGA and a commercial QSFP+ (Quad Small Form Pluggable +) module. QSFP+ standard defines a hot-pluggable transceiver available in copper or optical cable assemblies for an aggregated bandwidth of up to 40 Gbps. We implemented a complete testbench based on a commercial development card mounting an Altera Stratix IV FPGA with 24 serial transceivers at 8.5 Gbps, together with a custom mezzanine hosting three QSFP+ modules. We present test results and signal integrity measurements up to an aggregated bandwidth of 12 Gbps.

A microcontrolled, portable and inexpensive photometer is proposed. It uses a near infrared light emitting diode (NIR LED) as radiation source, a PbSe photoresistor as infrared detector and a programmable interrupt controller (PIC) microcontroller as control unit. The detector system presents a thermoresistor and a thermoelectric cooling to control the detector temperature and keep the noise at low levels. The microcontroller incorporated total autonomy on the proposed photometer. As its components are inexpensive and of easy acquisition, the proposed NIR LED-photometer is an economical alternative for chemical analyses in small routine, research and/or teaching laboratories. By being portable and microcontrolled, it also allows carrying out field chemical analyses. The instrument was successfully applied on the screening analysis to verify adulteration in gasoline samples.

The effects of Seal-In X5 and Dermo liner (Össur) on suspension and patient's comfort in lower limb amputees are unclear. In this report, we consider the case of a 51-yr-old woman with bilateral transtibial amputation whose lower limbs were amputated because of peripheral vascular disease. The subject had bony and painful residual limbs, especially at the distal ends. Two prostheses that used Seal-In X5 liners and a pair of prostheses with Dermo liners were fabricated, and the subject wore each for a period of 2 wks. Once the 2 wks had passed, the pistoning within the socket was assessed and the patient was questioned as to her satisfaction with both liners. This study revealed that Seal-In X5 liner decreased the residual limb pain experienced by the patient and that 1-2 mm less pistoning occurred within the socket compared with the Dermo liner. However, the patient needed to put in extra effort for donning and doffing the prosthesis. Despite this, it is clear that the Seal-In X5 liner offers a viable alternative for individuals with transtibial amputations who do not have enough soft tissue around the bone, especially at the end of the residual limb. Copyright © 2012 by Lippincott Williams & Wilkins.

https://graphics.tx.ovid.com/ovftpdfs/FPDDNCLBPCEOKH00/fs047/ovft/live/gv024/00002060/00002060-201210000-00011.pdf 
https://www.ncbi.nlm.nih.gov/pubmed/22173083

Real-time holographic interferometry and shadowgraph visualization are used to study convection in the fluid between two concentric spheres when two distinct buoyancy forces are applied to the fluid. The heated inner sphere has a constant temperature that is greater than the constant temperature of the outer sphere by ΔT. In addition to the usual gravitational buoyancy from temperature induced density differences, another radial buoyancy is imposed by applying an a.c. voltage difference, ΔV between the inner and outer spheres. The resulting electric field gradient in this spherical capacitor produces a central polarization force. The temperature dependence of the dielectric constant results in the second buoyancy force that is especially large near the inner sphere. The normal buoyancy is always present and, within the parameter range explored in our experiment, always results in a large-scale cell that is axisymmetric about the vertical. We have found that this flow becomes unstabl...

The characteristics of tonal noise and the variations of flow structure around NACA0018 airfoil in a uniform flow are studied by means of simultaneous measurement of noise and velocity field by particle-image velocimetry to understand the generation mechanism of tonal noise. Measurements are made on the noise characteristics, the phase-averaged velocity field with respect to the noise signal, and the cross-correlation contour of velocity fluctuations and noise signal. These experimental results indicate that the tonal noise is generated from the periodic vortex structure on the pressure surface of the airfoil near the trailing edge of the airfoil. It is found that the vortex structure is highly correlated with the noise signal, which indicates the presence of noise-source distribution on the pressure surface. The vorticity distribution on the pressure surface breaks down near the trailing edge of the airfoil and forms a staggered vortex street in the wake of the airfoil.

The Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) was developed and provided to the National Aeronautics and Space Administration's EOS Aqua satellite by the National Space Development Agency of Japan, as one of the indispensable instruments for Aqua's mission. AMSR-E is a modified version of AMSR that was launched December 2002 aboard the Advanced Earth Observing Satellite-II (ADEOS-II). It is a six-frequency dual-polarized total-power passive microwave radiometer that observes water-related geophysical parameters supporting global change science and monitoring efforts. The hardware improvements over existing spaceborne microwave radiometers for earth imaging include the largest main reflector of its kind and addition of 6.925-GHz channels. These improvements provide finer spatial resolution and the capability to retrieve sea surface temperature and soil moisture information on a global basis. This paper provides an overview of the instrument characteristics, mission objectives, and data products.

The signal processing firmware that has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA) is described. The firmware is implemented on a dual FPGA board, that is capable of processing the streams from 16 dual polarization antennas. Data processing includes channelization of the sampled data for each antenna, correction for instrumental response and for geometric delays and formation of one or more beams by combining the aligned streams. The channelizer uses an oversampling polyphase filterbank architecture, allowing a frequency continuous processing of the input signal without discontinuities between spectral channels. Each board processes the streams from 16 antennas, as part of larger beamforming system, linked by standard Ethernet interconnections. These are envisaged to be 8192 of these signal processing platforms in the first phase of the SKA so particular attention has been devoted to ensure the design is low cost and low power.

The reaction of trichloroethylene (C2HCI3) with water vapor or molecular hydrogen has been studied in a low-pressure [ca. 5 Torr (0.67 kPa)] microwave plasma tubular flow reactor. The experimental apparatus included feed introduction systems, a microwave plasma reactor, and full product analysis by flame ionization and thermal-conductivity gas chromatography, mass spectrometry, and specific ion or pH detection for hydrogen chloride [HCI]. Conversions of CeHC13 in the range 50 to almost 100% are achieved. Product analyses indicate conversion to HCI, some light hydrocarbons, nonparent chlorocarbons, and soot C(s). For the H20 case, carbon monoxide and trace carbon dioxide were produced in place of some light hydrocarbons and Cc~). At least 85 mole % of chlorine (CI) from the converted parent C2HCl s forms thermodynamically stable HCI at parent conversions of 80% or more. The remaining chlorine was present as nonparent chlorocarbons. Preliminary kinetic analyses were performed. The global reaction in the plasma was found to follow one-half-order kinetic dependence on each of C2HCl 3 and H20 or H 2. Elementary plasma reaction mechanisms are presented to account for CeHCI 3 conversion and the observed product distribution.

Current methods for analyzing bioaerosols are based on maintaining organism viability and quantifying culturability; this can result in underestimation of concentrations. A feasibility study investigated a new analytical technique that only requires intact cellular DNA to identify organisms. This technique uses the polymerase chain reaction (PCR) to amplify specific DNA sequences from an organism, and hybridization of PCR product with DNA probes, to detect and quantify organisms. LegioneUa pneumophila solutions were aerosolized in a chamber, and air samples were collected u~ing impingers and membrane filters. Samples were analyzed using the PCR-gene probe technique and gel electrophoresis. Results were compared with traditional plate counting and direct microscopic counts of cells stained with acridine orange. Results indicated that the PCR-gene probe technique provides a new way to identify and quantify bioaerosols that does not rely on viability and culturability. Therefore, the method would provide a more reliable estimate of airborne bacterial concentrations compared to traditional plate counts.

An experimental investigation on natural convection in air in vertical convergent channels with wall uniform heat flux is presented. Wall temperatures show that by increasing the spacing the effect of the convergence angle decreases. For the lowest spacing, a significant decrease of maximum wall temperature occurs passing from the parallel vertical plate configurations to convergence angles h P 2 .

Montréal. Il a pour mission la promotion et la valorisation de la recherche. Érudit offre des services d'édition numérique de documents scientifiques depuis 1998. Note : les règles d'écriture des références bibliographiques peuvent varier selon les différents domaines du savoir.

Les forêtstropicales rendentdes services environnementaux àlaplanètee ntière,mais dépendent d'Étatss ouverains,quil es utilisentavantt out comme des ressources économiques etcomme réserves foncières. L'exploitation non régulée dubois d'oeuvre estplusr entable pourl es exploitantsq uecelle pratiquée dans le cadre d'unaménagementetd'une gestion certifiée. La conversion des terres forestières en pâturages ouen espaces artificialisés estplusi ntéressante financièrementquel 'exploitation durable,et afortiori quel ac onservation,c omptetenudes systèmes dep rixetder émunération existants. Dans les avancéesdifficiles vers lac onstitution d'unh ypothétique" régime international" del 'environnement,laquestion des forêtsr eprésente unp ointdef riction Nord-Sudoùconvergentpratiquementt ousl es problèmes dudéveloppement durable :tensions entre lac roissanceé conomiquee tlapréservation del ab iodiversité,tension entre le temps long del arégénération des écosystèmes etles horizons financiers,incertitudes ur les droitsdep ropriété,incertitudes etpolémiques surl econtenumême del anotion dedura-bilité… Ainsi,l'absenced'autorités upranationale reconnuecompliquel 'ambition dep arvenir à une gestion internationale susceptible dem aintenir des services environnementaux globaux que rendentles écosystèmes forestiers. Dufaitducaractère globaldel eurs fonctions etservices,les forêtss ontsouventqualifiées de" patrimoine commun" del 'humanitéo u,d em anière plus savante,d e" bien publicmondial" (BPM). Considérer les forêtsm ondiales comme relevantdel a catégorie des BPM ne seraitpass ans conséquences url ep landes relations internationales. Cela constituerait,notamment,unargumenten faveurd'une convention internationale spécifique.

In this paper, we present the implementation of a new class of optical pressure sensors in a robotic tactile-sensing system based on polydimethylsiloxane (PDMS). The sensor consists of a tapered optical fiber, where an optical signal goes across, embedded into a PDMS-gold nanocomposite material (GNM). By applying different pressure forces onto the PDMS-based nanocomposite, changes in the optical transmittivity of the fiber can be detected in real time due to the coupling between the GNM and the tapered fiber region. The intensity reduction of a transmitted light is correlated to the pressure force magnitude. Light intensity is converted into an electric signal by a system suitable for robotic implementation. High sensitivity using forces by applying weights of a few grams is proved. Sensitivity on the order of 5 g is checked. A detailed algorithm for the detection of roughness and shapes by means of a robotic finger is proposed.

The Microgravity technique consists of measuring minute variations in the gravitational pull of the Earth and interpreting the presence of voids/cavities from these readings. Gravity variations arising from such features are virtually undetectable by conventional gravity investigation methods as their resultant anomalies are superimposed upon much larger variations generated by changes in height, latitude and the regional geological environment.

The atomic force microscope (AFM) has a unique capability of allowing the high-resolution imaging of biological samples on substratum surfaces in physiological solutions. Recent technological progress of AFM in biological research has resulted in remarkable improvements in both the imaging rate and the tip force acting on the sample. These improvements have enabled the direct visualization of dynamic structural changes and dynamic interactions occurring in individual biological macromolecules, which is currently not possible with other techniques. Therefore, high-speed AFM is expected to have a revolutionary impact on biological sciences. In addition, the recently achieved atomic-resolution in liquids will further expand the usefulness of AFM in biological research. In this article, we first describe the various capabilities required of AFM in biological sciences, which is followed by a detailed description of various devices and techniques developed for high-speed AFM and atomic-resolution in-liquid AFM. We then describe various imaging studies performed using our cutting-edge microscopes and their current capabilities as well as their limitations, and conclude by discussing the future prospects of AFM as an imaging tool in biological research.

Meso-scale characteristics of disturbances that bring about atmospheric disasters in pre-and mature monsoon seasons in Bangladesh are analyzed. Several types of meteorological instruments capable of observations with high temporal and spatial resolutions were introduced for the first time in this area to capture the meso-scale structure of rainfall systems. We installed an automatic weather station (AWS) and several automatic raingauges (ARGs) and utilized the weather radar of Bangladesh Meteorological Department (BMD). From the radar image in the summer of 2001 (16-18 July), a striking feature of the systematic diurnal variation in this area was elucidated. In these 3 days, the diurnal evolutions of convective activity were remarkably similar to each other, implying that this pattern can be understood as a typical response of local cloud systems to the diurnal variation of insolation under some summer monsoon situations. The ARG data show the difference in characteristics of rainfall between pre-and mature monsoon seasons. The short intense downpour tends to occur more frequently in the pre-monsoon season than in the mature monsoon season. The pre-monsoon rainfall also has clear diurnal variation with a peak that is more strongly concentrated in time. In the northern part the rainfall peak is found in between midnight and early morning, while it is observed in the daytime in central to western parts of the country. Two disaster cases caused

The paper outlines the practical realization and characteristics of a small, totally autonomous passive frequency standard based on the coherent population trapping (CPT) phenomenon. The frequency standard, including physical characteristics, block diagrams of the optical control CPT resonance system and of the digital control electronics, is described. The characteristics of the frequency standard relative to general functionality and frequency stability are given, as measured on several units. he was responsible for the design and production testing of the Kernco GPS VCXO program. In addition to these programs, he has contributed to the design, testing, and qualification under several successful NASA and DOD programs producing military and space qualified hardware. He is currently working on the development of frequency standards based on coherent population trapping technology.