scholarly journals Comparison of Emission Measurement Methods for Electromagnetic Disturbances in the Frequency Range from 30 MHz to 300 MHz for LED Lamps According to EN 55015

2019 ◽  
Vol 63 (2) ◽  
pp. 106-111
Author(s):  
Kazimierz Kamuda ◽  
Dariusz Klepacki ◽  
Kazimierz Kuryło ◽  
Wiesław Sabat

The results of measurements of electromagnetic disturbances emitted by LED lamps, in the frequency range from 30 MHz to 300 MHz, which were made using two methods described in the EN 55015/2013 standard have been presented in the paper. In order to compare both methods, each tested lamp was first measured using the traditional method described in Section4.4.2 and then tested by an alternative, equivalent method described in Annex B of the above-mentioned standard. The comparison of results for both methods indicates that using first method, a given LED lamp emits disturbances below the acceptable limits, while the same LED lamp tested with the second method emits disturbances that are at the limit of admissible values. Additionally, used statistical tools in the form of calculated linear correlation coefficient show that the nature of the emission of disturbances measured for the same lamp is very comparable in both methods. The reference of these quasi-peak values to the permissible limits applicable in one or the other method may lead to different decisions.

2019 ◽  
Vol 29 (3) ◽  
pp. 778-796 ◽  
Author(s):  
Patrick Taffé

Recently, a new estimation procedure has been developed to assess bias and precision of a new measurement method, relative to a reference standard. However, the author did not develop confidence bands around the bias and standard deviation curves. Therefore, the goal in this paper is to extend this methodology in several important directions. First, by developing simultaneous confidence bands for the various parameters estimated to allow formal comparisons between different measurement methods. Second, by proposing a new index of agreement. Third, by providing a series of new graphs to help the investigator to assess bias, precision, and agreement between the two measurement methods. The methodology requires repeated measurements on each individual for at least one of the two measurement methods. It works very well to estimate the differential and proportional biases, even with as few as two to three measurements by one of the two methods and only one by the other. The repeated measurements need not come from the reference standard but from either measurement methods. This is a great advantage as it may sometimes be more feasible to gather repeated measurements with the new measurement method.


1977 ◽  
Vol 67 (5) ◽  
pp. 1249-1258
Author(s):  
Douglas C. Nyman ◽  
Harsh K. Gupta ◽  
Mark Landisman

abstract The well-known relationship between group velocity and phase velocity, 1/u = d/dω (ω/c), is adapted to the practical situation of discrete observations over a finite frequency range. The transformation of one quantity into the other is achieved in two steps: a low-order polynomial accounts for the dominant trends; the derivative/integral of the residual is evaluated by Fourier analysis. For observations of both group velocity and phase velocity, the requirement that they be mutually consistent can reduce observational errors. The method is also applicable to observations of eigenfrequency and group velocity as functions of normal-mode angular order.


Author(s):  
Amit Kauts ◽  
Monika

The present study intends to examine the effect of dramatization on speaking skills and academic achievement in English among primary students. The sample consisted of 240 fifth class students from four co-educational private schools of district Fazilka. The sample was divided into two groups randomly. One of the two groups was designated as Experimental Group and the other as Control Group. Experimental group was taught through Dramatization and the control group was taught through traditional method. The obtained data was analysed using two way Analysis of Variance. The results revealed that (i) Teaching through dramatization was found effective than traditional method with respect to achievement of students in English and gain scores in speaking skills (ii) Boys outperformed girls in case of achievement gain scores (iii) Girls outperformed boys in case of gain scores of speaking skills.


2017 ◽  
Author(s):  
Carolyn Judge ◽  
Bill Beaver ◽  
John Zseleczk

The resistance of a planing hull is known to be highly dependent on trim angle. For several reasons, trim is difficult to measure to the level of accuracy normally attained with other towing tank measurements such as resistance or speed. In a recent study intended to validate CFD methods for planing hulls, 4’ and 8’ long geosim models of the Generic Prismatic Planing Hull (GPPH) were built and tested at USNA. Significant differences were found between the trim of the two models so a separate test program was conducted which focused specifically on the trim measurement of these two models in calm water. Five different trim measurement methods were used simultaneously on one model and then used again on the other model. Trim angles were compared between measurement methods and between models. Trim measurements with the same model agreed well and are the basis for an evaluation of measurement methods. The trim measured on the two different size models did not agree well even though the same instruments were used in most cases. The paper discusses reasons for the confirmed differences in calm water running trim of the two models and suggests ways to take advantage of this knowledge to make the best use of towing tank tests for planing boat performance prediction.


2021 ◽  
Author(s):  
V. Khokhlov ◽  
J. Meyer ◽  
D. Ritzmann ◽  
S. Lodetti ◽  
P. S. Wright ◽  
...  

2015 ◽  
Vol 50 (2) ◽  
pp. 153-162 ◽  
Author(s):  
EI Adeyeye ◽  
AJ Adesina

The levels of fatty acids, phospholipids and sterols were determined in the brains of she-goat and castrated goat found in Ekiti State, Nigeria by gas chromatography. Results showed that the crude fat levels were 9.98 and 10.2 % in the brains of she-goat and castrated goat respectively. The fatty acid composition of she-goat and castrated goat brain shows that the SFA was 40.6 and 42.7 %, MUFA was 37.1 and 38.7 % and PUFA was 20.9 and 22.3% respectively. The other parameters of she-goat and castrated goat brain were found: PUFA/SFA, 0.490 and 0.548; MUFA/SFA, 0.869 and 0.953; n-6/n-3, 0.775 and 11.7; LA/ALA, 0.876 and 28.0; AA/DGLA, 6.05 and 17.4; EPA/DHA, 1.00 and 5.89 and EPSI (PUFA/MUFA), 0.564 and 0.575 respectively. Phospholipids were present in she-goat and castrated goat with a value range of 2365 and 3047 mg/100g respectively. Among the sterols, only cholesterol was of any significant level with values of 1353 mg/100g (she-goat brain) and 1355 mg/100g (castrated goat brain). Linear correlation at ? = 0.05, df: n-1 showed that no significant difference exists between the crude fats, phospholipids and sterols except in the fatty acids parameters.Bangladesh J. Sci. Ind. Res. 50(2), 153-162, 2015


Author(s):  
P. Indraja ◽  
M. Madhava ◽  
S. Satyam ◽  
P. R. Chandra ◽  
S. Joy Prince

Mushroom cultivation is one of the most important steps in diversification of agriculture. Milky mushroom (Calocybeindica) is a tropical edible mushroom, popular because of its good nutritive value and it can be cultivated commercially on large scale. Generally, by creating controlled environment in rooms mushroom cultivation is taken up, In traditional method  it is typical to manage the atmospheric temperature and humidity in desired range, which can be maintained easily in greenhouse by automatic control system.Cultivation of milky mushroom in greenhouse was taken up in controlled environment under three different conditions of controlled temperature and relative humidity (RH). The experimental conditions are 28°C and 79% RH, 24°C and 84% RH and 32°C and 72%RH. The yield obtained was found maximum at 24°C temperature and 84% relative humidity when compared with the other two greenhouse environment conditions. The yield from the mushroom cultivation under controlled environmental conditions in greenhouse was found to be high when compared with the conventional practice. It was concluded that, the mushroom cultivation yields high under controlled greenhouse conditions and also economical compared to the conventional method.


2016 ◽  
Vol 9 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Martin Michalík ◽  
Vladimír Lukeš

AbstractThe validation of octanol-water partition coefficients (logP) quantum chemical calculations is presented for 27 alkane alcohols. The chemical accuracy of predicted logPvalues was estimated for six DFT functionals (B3LYP, PBE0, M06-2X, ωB97X-D, B97-D3, M11) and three implicit solvent models. Triple-zeta basis set 6-311++G(d,p) was employed. The best linear correlation with the experimental logPvalues was achieved for the B3LYP and B97-D3 functionals combined with the SMD model. On the other hand, no linearity was found when IEF-PCM or C-PCM implicit models were employed.


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