774 research outputs found

    The geoid in Kenya

    Get PDF
    The definition of geoidal undulations is given and after summarizing the methods of determination of the geoid, computed geoidal undulations by some of the methods for several points in Kenya are compared to the results obtained by the satellite gravimetric solutions. Results from astrogeodetic levelling and satellite altimetry show some reasonable agreement with the satellite gravimetric geoids while results by Doppler satellite positioning indicate that good agreement can be obtained if the orthometric heights for the points are adjusted to a uniform system

    Protective Alumina Coatings by Low Temperature Metalorganic Chemical Vapour Deposition

    Get PDF
    Alumina thin films were processed from aluminium tri-iso-propoxide in a horizontal, with N2 as a carrier gas, occasional addition of water in the gas phase, deposition temperature in the range 350-700°C, total pressure 0.67 kPa (2 kPa when water was used). The films do not diffract X-ray when prepared below 700°C. At 700°C, they start to crystallize as γ-alumina. EDS, EPMA, ERDA, RBS, FTIR and TGA revealed that films prepared in the range 350- 415°C, without water in the gas phase, have an overall composition Al2O3-x(OH)2x, with x tending to 0 with increasing temperature. Al2O3 is obtained above 415°C. When water is added in the vapour phase, the film composition is Al2O3, even below 415°C. Coatings deposited in these conditions show promising protection properties

    NIT COVID-19 at WNUT-2020 Task 2: Deep Learning Model RoBERTa for Identify Informative COVID-19 English Tweets

    Full text link
    This paper presents the model submitted by the NIT_COVID-19 team for identified informative COVID-19 English tweets at WNUT-2020 Task2. This shared task addresses the problem of automatically identifying whether an English tweet related to informative (novel coronavirus) or not. These informative tweets provide information about recovered, confirmed, suspected, and death cases as well as the location or travel history of the cases. The proposed approach includes pre-processing techniques and pre-trained RoBERTa with suitable hyperparameters for English coronavirus tweet classification. The performance achieved by the proposed model for shared task WNUT 2020 Task2 is 89.14% in the F1-score metric.Comment: 5 pages, one figures, conferenc

    The Effect of Electronic Cigarette User Modifications and E-liquid Adulteration on the Particle Size Profile of an Aerosolized Product

    Get PDF
    Electronic cigarettes (e-cigarettes) are an alternate nicotine delivery system that generate a condensation aerosol to be inhaled by the user. The size of the droplets formed in the aerosol can vary and contributes to drug deposition and ultimate bioavailability in the lung. The growing popularity of e-cigarette products has caused an increase in internet sources promoting the use of drugs other than nicotine (DOTNs) in e-cigarettes. The purpose of this study was to determine the effect of various e-cigarette and e-liquid modifications, such as coil resistance, battery voltage, and glycol and drug formulation, on the aerosol particle size. E-liquids containing 12 mg/mL nicotine prepared in glycol compositions of 100% propylene glycol (PG), 100% vegetable glycerin (VG), or 50:50 PG:VG were aerosolized at three voltages and three coil resistances. Methamphetamine and methadone e-liquids were prepared at 60 mg/mL in 50:50 PG:VG and all e-liquids were aerosolized onto a 10 stage Micro-Orifice Uniform Deposit Impactor. Glycol deposition correlated with drug deposition, and the majority of particles centered between 0.172–0.5 μm in diameter, representing pulmonary deposition. The 100% PG e-liquid produced the largest aerosol particles and the 100% VG and 50:50 PG:VG e-liquids produced ultra-fine particles \u3c0.3 μm. The presence of ultrafine particles indicates that drugs can be aerosolized and reach the pulmonary alveolar regions, highlighting a potential for abuse and risk of overdose with DOTNs aerosolized in an e-cigarette system

    Effectiveness of endotracheal suctioning with normal saline Versus without normal saline on airway clearance among intubated patients at Government Rajaji Hospital, Madurai

    Get PDF
    AIM OF THE STUDY: To evaluate the Effectiveness of endotracheal suctioning with normal saline versus without normal saline on airway clearance among intubated patients at Government Rajaji hospital, Madurai. OBJECTIVES: To assess the level of airway clearance among the intubated patients on mechanical ventilator in both group 1 and group11 and to associate the level of airway clearance among GroupI and Group II intubated patients with their selected socio demographic and clinical variable. HYPOTHESES: There is a significant difference between Group I and Group II after endotracheal suctioning on airway clearance among intubated patients. There is a significant difference between the pretest and post test scores of airway clearance in both group1 and in group II after endotracheal suctioning. There is a significant association between the level of airway clearance among intubated patients with their selected socio demographic data and clinical variables.. METHODOLOGY: A True experimental design was used. 60 subjects were selected by consecutive sampling method. Intervention Endotracheal suctioning without normal saline was given to the group1 and endotracheal suctioning with normal saline was given to the group 11 every second hourly and also on demand basis from 7am to 7pm. Pretest before endotracheal suctioning and post test 10 minutes after the last suctioning at 7pm were done with structured observational check list. FINDINGS: There was a significant reduction score 5.9% in group I patients and 29.2% of reduction score in group II. There was significant association between pretest level of airway clearance score and Younger, females and with less duration of admission in hospital were having more reduced air clearance score than others

    Intracavity Gain And Absorption Dynamics Of Hybrid Modelocked Semiconductor Lasers Using Multiple Quantum Well Saturable Absorbers

    Get PDF
    Time resolved intracavity gain, saturable absorption dynamics, intracavity intensity pulse profiles, and their corresponding spectrograms, were measured in an external cavity hybrid mode-locked semiconductor diode laser. These measurements were performed to obtain fundamental information of the mode-locking dynamics and to determine their role in the pulse shaping and chirping dynamics. The results of these experiments show that the integrating nonlinearity associated with gain depletion, coupled with group velocity dispersion, leads to asymmetric intensity pulse profiles with predominantly cubic temporal phase, while saturable absorption coupled with group velocity dispersion tends to linearize the chirp. Exploitation of these dynamics may allow researchers to generate optical pulses with higher peak intensities than previously reported

    Activity of natural radionuclides and their contribution to the absorbed dose in the fish cubera snapper (lutjanus cyanopterus, cuvier, 1828) on the coast of Ceara, Brazil

    Get PDF
    Visando a radioproteção ambiental, baseada no conceito de limite de taxa de dose absorvida, foi desenvolvida uma metodologia de conversão da concentração de atividade de radionuclídeos (Bq kg-1) em taxa de dose absorvida (Gy a-1). O modelo considera apenas a taxa de dose absorvida interna. Essa metodologia foi aplicada ao peixe vermelho-caranho (Lutjanus cyanopterus, Cuvier, 1828) capturado na costa do Ceará e aos radionuclídeos naturais: urânio-238, rádio-226, chumbo-210, tório-232 e rádio-228. As taxas de dose absorvidas foram calculadas por radionuclídeo e por tipo de radiação emitida. A taxa de dose média devida a esses radionuclídeos foi de 5.36 µGy a-1, valor seis ordens de grandeza menor que o valor de limite de taxa de dose absorvida utilizada no presente trabalho (3.65 10³ mGy a-1), e similar ao encontrado na literatura para peixes bentônicos. Ra-226 e U-238 contribuíram com 67% e 22% da taxa de dose absorvida, seguidos de Th-232 com 10%. Já Ra-228 e Pb-210 respondem por menos de 1% da taxa de dose absorvida. Essa distribuição é um pouco diferente do relatado na literatura, onde Ra-226 responde por 86% da taxa de dose absorvida.A methodology was developed for converting the activity concentration of radionuclides (Bq kg-1) into absorbed dose rate (Gy y-1), aiming an approach to environmental radioprotection based on the concept of standard dose limit. The model considers only the internal absorbed dose rate. This methodology was applied to the cubera snapper fish (Lutjanus cyanopterus, Cuvier, 1828) caught off the coast of Ceará. The natural radionuclides considered were uranium-238, radium-226, lead-210, thorium-232 and radium-228. The absorbed dose rates were calculated for individual radionuclides and the type of emitted radiation. The average dose rate due to these radionuclides was 5.36 µGy y-1, a value six orders of magnitude smaller than the threshold value of absorbed dose rate used in this study (3.65 10³ mGy y-1), and similar to that found in the literature for benthic fish. Ra-226 and U-238 contributed 67% and 22% of the absorbed dose rate, followed by Th-232 with 10%. Ra-228 and Pb-210, in turn, accounted for less than 1% of the absorbed dose rate. This distribution is somewhat different from that reported in the literature, where the Ra-226 accounts for 86% of the absorbed dose rate
    • …
    corecore