4,043 research outputs found
Plasma heating due to X-B mode conversion in a cylindrical ECR plasma system
Extra Ordinary (X) mode conversion to Bernstein wave near Upper Hybrid
Resonance (UHR) layer plays an important role in plasma heating through
cyclotron resonance. Wave generation at UHR and parametric decay at high power
has been observed during Electron Cyclotron Resonance (ECR) heating experiments
in toroidal magnetic fusion devices. A small linear system with ECR and UHR
layer within the system has been used to conduct experiments on X-B conversion
and parametric decay process as a function of system parameters. Direct probing
{\em in situ} is conducted and plasma heating is evidenced by soft x-ray
emission measurement. Experiments are performed with hydrogen plasma produced
with 160-800 W microwave power at 2.45 GHz of operating frequency at
mbar pressure. The axial magnetic field required for ECR is such that the
resonant surface (B = 875 G) is situated at the geometrical axis of the plasma
system. Experimental results will be presented in the paper.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
In silico validation of personalized safe intervals for carbohydrate counting errors
For patients with Type 1 diabetes mellitus (T1DM), accurate carbohydrate counting (CC) is
essential for successful blood glucose regulation. Unfortunately, mistakes are common and may lead
to an incorrect dosage of prandial insulin. In this work, we aim to demonstrate that each person has
their own limits for CC errors, which can be computed using patient-specific data. To validate the
proposed method, we tested it using several scenarios to investigate the effect of different CC errors
on postprandial blood glucose. Virtual subjects from the T1DM Simulator were used in a clinical
trial involving 450 meals over 90 days, all following the same daily meal plan but with different
intervals for CC errors near, below, and above the limit computed for each patient. The results show
that CC errors within personalized limits led to acceptable postprandial glycemic fluctuations. In
contrast, experiments where 50% and 97.5% of the meals present a CC error outside the computed
safe interval revealed a pronounced degradation of the time in range. Given these results, we consider
the proposed method for obtaining personalized limits for CC errors an excellent starting point for
an initial assessment of patients? capabilities in CC and to provide appropriate ongoing education.511F-603F-4B30 | Francisco MirandaN/
Analysis of Deterioration in a Plasma Focus Device
Indexación: Scopus.The Plasma Focus (PF) is a kind of dense transient plasmas in with high-pulsed voltage. To produce devices for eld application it is necessary to obtain PF equipment able to operate for a long period of time. Thus, a reliability analysis is indispensable. In this work a reliability analysis program for plasma focus devices is presented. The program considers a criticality analysis using Failure Modes and Effects Criticality Analysis (FMECA) to identify the most important failure modes of the system. Said failure modes are studied operating the Plasma Focus for many cycles, obtaining from them the characteristic curves of V(t) and İ(t). Feature Extraction (FE) techniques are applied to obtain a list of parameters that correlate to the degrading process. Furthermore, Machine Learning tools are used to learn from the obtained data, linking the changes in these parameters during its life cycle to the decay of the system in hope for future implementation of a predictive maintenance system and a reference for data analysis and prediction in PFs. The study was applied to a portable plasma focus device operated at 2 joules of stored energy. © Published under licence by IOP Publishing Ltd.The work is supported by IAEA CRP contract 20370 and by grant ACT-1115, CONICYT, Chile.https://iopscience.iop.org/article/10.1088/1742-6596/1043/1/01204
Hundred joules plasma focus device as a potential pulsed source for in vitro cancer cell irradiation
Indexación: Web of Science; Scopus.Plasma focus devices may arise as useful source to perform experiments aimed to study the effects of pulsed radiation on human cells in vitro. In the present work, a table top hundred joules plasma focus device, namely "PF-400J", was adapted to irradiate colorectal cancer cell line, DLD-1. For pulsed x-rays, the doses (energy absorbed per unit mass, measured in Gy) were measured using thermoluminescence detectors (TLD-100 dosimeters). The neutron fluence and the average energy were used to estimate the pulsed neutron doses. Fifty pulses of x-rays (0.12 Gy) and fifty pulses of neutrons (3.5 μGy) were used to irradiate the cancer cells. Irradiation-induced DNA damage and cell death were assessed at different time points after irradiation. Cell death was observed using pulsed neutron irradiation, at ultralow doses. Our results indicate that the PF-400J can be used for in vitro assessment of the effect of pulsed radiation in cancer cell research.http://recursosbiblioteca.unab.cl:2296/doi/pdf/10.1063/1.499465
Načini upravljanja procesom fermentacije u siliranim hranivima
The control of fermentation process in ensilaged livestock feed is based on the knowledge of biomasses. The important aspects are the suitability for ensilaging (the content of fermentative carbohydrates and buffer capacity of the biomass), providing of the correct level of dry matter and anaerobic environment, wilting, using the chemical additives such as organic acids and their salts, using of biologic additives (inoculants), adsorption of mycotoxins, etc. In purpose of making the process of ensilaging of grasses, legumes and grass-legume mixes, the silages are prepared as bales or silo-tubes.Kontrola procesa fementacije bazira se na poznavanju biomasa u pogledu pogodnosti za siliranje, odnosno obezbeđivanju povoljnog odnosa šećera i pufernog kapaciteta. Biomase višegodišnjih leguminoza i trava neophodno je provenjavati, odnosno povećati sadržaj suve materije u silomasi na najmanje 300-400 g kg-1. Za teško silirajuće biomase (višegodišnje i jednogodišnje leguminoze) koristiti ugljenohidratna hraniva (kukuruzna prekrupa, prekrupa ostalih žitarica, suvi rezanci šećerne repe, melasa, i dr.). Korišćenje hemijskih sredstava iz reda organskih kiselina i njihovih soli. Upotreba bioloških dodataka, inokulanata u smeši sa enzimima (amilaze, celulaze, hemicelulaze i dr.) obezbeđuje dobijanje dobre i stabilne silaže, kao i silaže veće hranljive vrednosti. Korišćenje inokulanata sa homo i heterotrofnim mikroorganizmima u cilju obezbeđivanja aerobne stabilnosti silaža, posebno lakosilirajućih biomasa (kukuruza, sirka, sudanske trave, italijanskog ljulja i dr.)
Rural Women Artists: A Visual Analysis of the Mural Art Forms of Santhal Pargana, Jharkhand, India
Women are the pioneers of traditional mural art practices in rural India. Warli art, Gond art, and Madhubani paintings are examples of their artworks. The women belonging to the Santhal region in eastern India, are highly skilled in rich rural vernacular art. Murals are generally created by them during local festivals and marriage ceremonies. The women of six districts that comprise the Santhal Pargana (Dumka, Godda, Deoghar, Jamtara, Pakur and Sahibganj), decorate their mud houses during these occasions with visual borders and motifs.
A pilot study was carried out with the women artists to research these murals. The framework for the visual analysis is based on distinct symmetry operations such as translation, rotation, reflection, and glide reflection. This paper examines the various artistic expressions of the rural women of Santhal Pargana
Student Anxiety and Their Speaking Performance: Teaching EFL to Indonesian Student
This study aims at finding out whether or not there's an impact on students' anxiety on their speaking performance. In addition, it also has an aim to identify factors relate to students' reluctance that can hinder their oral performance. Observation, interview, and questionnaire have been used to collect the data which has then been analyzed in a qualitative way. 25 students of the second semester of English Department Universitas Nusa Cendana Indonesia have been selected as the subject of this research. Based on the findings and analysis, it can be revealed that students' anxiety definitely has an impact on their speaking performance and this becomes one of the reasons why they find it difficult to express themselves in English. Many factors have been identified but only those which have been considered as the main ones are presented in this writing to answer the question of why the students have been reluctant in their oral performance. Knowing that their oral performance was severely hampered by the above-mentioned factors, several solutions have been recommended to make them easy to cope with their anxiety
Effect of sheared flows on classical and neoclassical tearing modes
The influence of toroidal sheared equilibrium flows on the nonlinear evolution of classical and neoclassical tearing modes is studied through numerical solutions of a set of reduced generalized MHD equations that include viscous force effects based on neoclassical closures. In general, differential flow is found to have a strong stabilizing influence leading to lower saturated island widths for the classical tearing mode and reduced growth rates for the neoclassical mode. Velocity shear, on the other hand, is seen to make a destabilizing contribution
Temperature dependence of the resistance of metallic nanowires (diameter 15 nm): Applicability of Bloch-Gr\"{u}neisen theorem
We have measured the resistances (and resistivities) of Ag and Cu nanowires
of diameters ranging from 15nm to 200nm in the temperature range 4.2K-300K with
the specific aim to assess the applicability of the Bloch-Gr\"{u}neisen formula
for electron phonon resistivity in these nanowires. The wires were grown within
polymeric templates by electrodeposition. We find that in all the samples the
resistance reaches a residual value at T=4.2K and the temperature dependence of
resistance can be fitted to the Bloch-Gr\"{u}neisen formula in the entire
temperature range with a well defined transport Debye temperature
(). The value of Debye temperature obtained from the fits lie
within 8% of the bulk value for Ag wires of diameter 15nm while for Cu
nanowires of the same diameter the Debye temperature is significantly lesser
than the bulk value. The electron-phonon coupling constants (measured by
or ) in the nanowires were found to have the same
value as that of the bulk. The resistivities of the wires were seen to increase
as the wire diameter was decreased. This increase in the resistivity of the
wires may be attributed to surface scattering of conduction electrons. The
specularity p was estimated to be about 0.5. The observed results allow us to
obtain the resistivities exactly from the resistance and gives us a method of
obtaining the exact numbers of wires within the measured array (grown within
the template).Comment: 9 pages, 10 figure
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