892 resultados para LOW-POWER-CONSUMPTION


Relevância:

80.00% 80.00%

Publicador:

Resumo:

The progress in wearable and implanted health monitoring technologies has strong potential to alter the future of healthcare services by enabling ubiquitous monitoring of patients. A typical health monitoring system consists of a network of wearable or implanted sensors that constantly monitor physiological parameters. Collected data are relayed using existing wireless communication protocols to the base station for additional processing. This article provides researchers with information to compare the existing low-power communication technologies that can potentially support the rapid development and deployment of WBAN systems, and mainly focuses on remote monitoring of elderly or chronically ill patients in residential environments.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The cleaning procedure consists of two-step-flashing: (i) cycles of low power flashes T similar to 1200 K) at an oxygen partial pressure of P(o2) = 6 x 10(-8) mbar, to remove the carbon from the surface, and (ii) a single high power flash (T similar to 2200 K), to remove the oxide layer. The removal of carbon from the surface through the chemical reaction with oxygen during low power flash cycles is monitored by thermal desorption spectroscopy. The exposure to O(2) leads to the oxidation of the W surface. Using a high power flash, the volatile W-oxides and the atomic oxygen are desorbed, leaving a clean crystal surface at the end of procedure. The method may also be used for cleaning other refractory metals like Mo, Re and It. (C) 2009 Elsevier B.V. All rights reserved.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The usual tests to compare variances and means (e. g. Bartlett`s test and F-test) assume that the sample comes from a normal distribution. In addition, the test for equality of means requires the assumption of homogeneity of variances. In some situation those assumptions are not satisfied, hence we may face problems like excessive size and low power. In this paper, we describe two tests, namely the Levene`s test for equality of variances, which is robust under nonnormality; and the Brown and Forsythe`s test for equality of means. We also present some modifications of the Levene`s test and Brown and Forsythe`s test, proposed by different authors. We analyzed and applied one modified form of Brown and Forsythe`s test to a real data set. This test is a robust alternative under nonnormality, heteroscedasticity and also when the data set has influential observations. The equality of variance can be well tested by Levene`s test with centering at the sample median.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This work presents the use of sequential injection analysis (SIA) and the response surface methodology as a tool for optimization of Fenton-based processes. Alizarin red S dye (C.I. 58005) was used as a model compound for the anthraquinones family. whose pigments have a large use in coatings industry. The following factors were considered: [H(2)O(2)]:[Alizarin] and [H(2)O(2)]:[FeSO(4)] ratios and pH. The SIA system was designed to add reagents to the reactor and to perform on-line sampling of the reaction medium, sending the samples to a flow-through spectrophotometer for monitoring the color reduction of the dye. The proposed system fed the statistical program with degradation data for fast construction of response surface plots. After optimization, 99.7% of the dye was degraded and the TOC content was reduced to 35% of the original value. Low reagents consumption and high sampling throughput were the remarkable features of the SIA system. (C) 2008 Published by Elsevier B.V.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Coupling a liquid core waveguide cell to a sequential injection chromatograph improved the detection limits for determination of triazine herbicides without compromising peak resolution. Separation of simazine, atrazine, and propazine was achieved in water samples by a 25mm long C18 monolithic column. Detection was made at 238nm using a type II LCW (silica capillary coated with Teflon (R) AF2400) cell with 100cm of optical path length. Detection limits for simazine, atrazine, and propazine were 2.3, 1.9, and 4.5 mu g L-1, respectively. Reduced analysis time and low solvent consumption are other remarkable features of the proposed method.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Pineapple leaf fiber (PALF) which is rich in cellulose, abundantly available, relatively inexpensive, low density, nonabrasive nature, high filling level possible, low energy consumption, high specific properties, biodegradability and has the potential for polymer reinforcement. The utilization of pineapple leaf fiber (PALF) as reinforcements in thermoplastic and thermosetting resins in micro and nano form for developing low cost and lightweight composites is an emerging field of research in polymer science and technology. In this paper we examines the industrial applicabiliy of PALF, mainly for production of composite materials and special papers, chemical feedstocks (bromelin enzyme) and fabrics.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In order to get a better understanding of the interaction between employees and their technical work tools one needs to know what factors influence the interaction. The purpose of this study was to examine if there is a correlation between the personality traits Extraversion (E) and Neuroticism (N), tested with Eysenck Personality Inventory (EPI), and experience of the new Intranet among employees at The Swedish National Transport Administration (SNTA), and also to gather information of employees’ opinions about the new Intranet. A survey, containing questions about the Intranet and a personality test (EPI), was posted on SNTA’s Intranet for eight workdays (N = 88, females = 53, males = 35). A Multiple Regression showed no significant correlations between personality traits (E/N) and experience of the new Intranet. Considering the study’s low Power (.34) one cannot draw any conclusions of the statistical tests. A majority of the participants did not think that the new Intranet is better than the old one, and thought it was difficult to find necessary information on the Intranet at first. However, they did not think this had a negative effect on the time it took to accomplish their work tasks. For upcoming studies more participants are required (preferable more than 200) and the survey should not only be available via computers in order to reach people who is not frequent users of computers.