Harmonic emission before and after changing to LED lamps — Field measurements for an urban area

Author(s):  
Sarah K. Ronnberg ◽  
Mats Wahlberg ◽  
Math H.J. Bollen
Transport ◽  
2016 ◽  
Vol 31 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Mario De Luca ◽  
Francesco Abbondati ◽  
Thomas J. Yager ◽  
Gianluca Dell’Acqua

Surfaces of airport pavements are subject to contamination that can be very dangerous for the movement of aircraft particularly on the runway. A recurrent problem is represented by the deposits of vulcanized rubber of aircraft tires in the touchdown area during landings and lesser during take-offs. This causes a loss of grip that compromises the safety of aircraft movements in take-off and landing operations. This study deals with the surface characteristics decay phenomenon related to contamination from rubber deposits. The experiment was conducted by correlating the pavement surface characteristics, as detected by Grip Tester, to air traffic before and after de-rubberizing operation and two models were constructed for the assessment of functional capacity of the runway before and after the operations de-rubberizing.


Author(s):  
Hossein Khalili Shayan ◽  
Javad Farhoudi ◽  
Alireza Vatankhah

Abstract Radial gates are common structures in irrigation projects. This paper presents some theoretical-based equations for explicit estimation of the discharge from the radial gate under free and submerged flow conditions using Energy and Momentum (E-M) principles. The proposed equations were calibrated using extensive experimental data collected from the literature and this study for three types of radial gates under free and submerged flow conditions. The submergence threshold of radial gates is concluded, based on the concepts of hydraulic jump and the intersection of free and submerged head-discharge curves. The results indicated that the error in estimating the discharge increases under transition ( − 2.5 ≤ Sr% ≤ + 2.5), gate lip (1 < y0/w ≤ 2), and high submerged (yt/y0 ≥ 0.95) flow conditions. However, in these flow limit conditions, the discharge error can be considerably decreased by adjusting the tailwater depth to flow depth just after the gate and using the energy equation for the sections before and after the gate. The efficiency of the proposed methods was evaluated based on the data series from field measurements of radial gates in 29 check structures at irrigation canals in the United States and Iran. The results showed that the discharge could be estimated using the proposed equations in field conditions with acceptable accuracy.


2014 ◽  
Vol 1 (2) ◽  
pp. 109
Author(s):  
Dodi Irwan Siregar ◽  
Thamrin Thamrin ◽  
Muhammad Edisar

One of the environmental problems caused by the increasing growth of the industry.Industrial waste generated that goes into the soil can alter soil properties. This studyreviewing the nature of the soil as a result of the distribution of residual waste CPO (CrudePalm Oil) industry mills. This study uses the characteristics of resistivity and soil nutrientproperties. Soil resistivity properties were tested by making a model before and after thedistribution of waste residue does CPO. Then validated against field measurements, fieldmeasurements comparing the data with the model. To see the changes in nutrient content ofsoil Laboratory Testing properties of soil nutrient changes. The results showed that theresistivity properties change and nutrient content of the soil before and after the distributionof waste residue subjected CPO. Soil resistivity values that have mixed by CPO residualwaste is higher than the value of soil resistivity is not mixed waste palm oil residues, while thecontent of soil nutrients among other properties, increasing soil pH, Include content C-Organic (%) / Inceneration, P-Available (ppm) / Bray-1, N-Total (%) / Kjedahl decreaseddramatically. 


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nils Reidar B. Olsen ◽  
Stefan Haun

AbstractSoil slides can occur when the water level in a lake or a reservoir is lowered. This may take place in situations when a reservoir is flushed to remove sediments. The current study describes a three-dimensional numerical model used for the simulation of reservoir flushing that includes the slide movements. The geotechnical failure algorithms start with modelling the groundwater levels at the banks of the reservoir. A limit equilibrium approach is further used to find the location of the slides. The actual movement of the sediments is computed by assuming the soil to be a viscous liquid and by solving the Navier–Stokes equations. The resulting bed elevation changes from the slides are computed in adaptive grids that change as a function of water level, bed erosion and slide movements. The numerical model is tested on the Bodendorf reservoir in Austria, where field measurements are available of the bank elevations before and after a flushing operation. The results from the numerical simulations are compared with these observations. A parameter test shows that the results are very sensitive to the cohesion and less sensitive to the E and G modules of the soil.


2017 ◽  
Vol 62 (2) ◽  
pp. 236
Author(s):  
Safet Dogjani ◽  
Ylber Muceku ◽  
Pranvera Lazo

In this paper, we shortly are treating the results of the radon concentration in soil gas, which are obtained by a detailed study that was carried out during 2000-2005 years in the urban area of Tirana, Capital City of Albania. The field measurements were done by using Luk-4 equipment (Lucas method) and based on technique (Neznal et al. 1992, Neznal et al. 1994a, Neznal et al. 1994b, Neznal et al. 1996, Neznal et al. 2002b). From the analysis of the data taken by this research, was concluded that the level of the radon concentration in soil gas of Tirana urban area depends on the soil type. So, the highest level of radon gas (130.0 kBqm‐3) was observed in the inorganic clays and very fine sands with beige-red color (soils type 1), which is extended on the second terrace of Tirana River. This paper gives conclusions of soil gas radon concentration, where its value range from 0.9-1.54 kBqm‐3 up to 92.03-130.0 kBqm‐3. The results indicate that more than 50% of Tirana urban area is made of soils, which are characterized by high soil gas radon concentration, which constitutes a real risk for the Tirana’s residents.  


1997 ◽  
Vol 467 ◽  
Author(s):  
Qi Wang ◽  
Richard S. Crandall ◽  
Daxing Han

ABSTRACTWe study the effects of hydrogen dilution on the open circuit voltage of a-Si:H pin solar cells fabricated by rf glow discharge growth. We keep the p and n layers the same and only vary the i layer properties. A normal a-Si:H i layer, an H-diluted i layer, and a thin H-diluted layer inserted between p and normal i layer are selected for this study. We measure the JV characteristics and the internal electric field distribution using a transient-null-current technique both in annealed and light soaked states. We find that hydrogen dilution does stabilize the Voc either in a bulk H-diluted i layer or in a thin layer between p and normal i layer after 100 hours AMI sun light soaking. From dark IV measurement, both H-diluted cells show little change in current at voltage near Voc before and after light soaking; while the normal a-Si:H cell does show a noticeable change. Also the internal field measurements find a stronger electric field starting from p and i interface for both H-diluted cells compared to the normal a-Si:H cell. Furthermore, there are no measurable changes in the field profiles after 100 hour AMI light-soaking for both H-diluted and normal a-Si cells. All these suggest that hydrogen dilution increases the field strength near p and i interface, which is the key that leads to a more stable Voc of H-diluted cells.


Author(s):  
J. M. Stallings ◽  
T. E. Cousins ◽  
T. E. Stafford

Many multigirder steel bridges built before the 1980s are experiencing distortion-induced fatigue cracking at diaphragm-girder connections. A means of eliminating the cyclic stresses that cause those fatigue problems is to remove the interior diaphragms (diaphragms not at the girder supports). The effects of removing all interior channel diaphragms from an existing simple-span bridge with rolled-steel girders were evaluated based on field measurements of girder stresses and deflections made before and after the diaphragms were taken out. Results from tests with trucks of known weight indicate that removing the diaphragms resulted in increases between 6 and 15 percent in the maximum bottom flange stresses experienced by the most heavily loaded girder. Results for loading by trucks of unknown weight in normal traffic indicate that the most heavily loaded girder may carry up to 17 percent more load as a result of removing the diaphragms.


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