نتایج جستجو برای: ballast
تعداد نتایج: 1836 فیلتر نتایج به سال:
Most electronic ballasts for fluorescent lamps provide a sinusoidal lamp current at the switching frequency. The high-frequency current flowing through the lamp can generate significant radiated noise, which is unacceptable in noise-sensitive applications, such as fluorescent lights in airplanes. Using shielded enclosures for the lamps may solve the problem, but it is expensive. A discontinuous...
∗ Corresponding author Abstract -This exploratory study examined the possibility of driving a fluorescent lamp at high frequency with no serially connected passive elements. The proposed driver is a full bridge stage controlled by the phase shifted PWM scheme. Current feedback was used to stabilize the average of the rectified lamp current to a set value. The experimental results of this resear...
The efficacy of chlorine dioxide (ClO2) in eliminating organisms present in estuarine ballast water of a containership was determined under actual operating conditions by comparing the survival of planktonic communities present in waters of treated and control ballast tanks. Sampling was via ballast-tank hatches. The treatment (5 mg L(-1)ClO2 without pre-filtration) delivered by a prototype ClO...
Ballast as a part of the railway system plays an important role in the operation of the railways and also has a great impact on repair and maintenance activities. Hence most of the repair and maintenance activities in traditional railway systems are due to the defections in the ballast layer and therefore most of the maintenance budget is spent on repairing these defects. These repair and maint...
Biological invasions through ships’ ballast water create threats to the environment and to the human health and thus, need to treat prior to the discharge. In this study, an innovative electro-disinfection reactor system is developed and optimized for disinfection of E. coli in ballast water to achieve the International Maritime Organization’s (IMO) guideline, 250 CFU/100ml. Optimized hydraulic...
As high speed rail is becoming increasingly popular around the globe, alignments are being forced onto marginal land due to land costs and the requirement for straight tracks. Rail foundations spread the applied wheel loads to prevent damage to the underlying in-situ soil upon which tracks are built. Designs which cannot sustain the resulting stresses will cause serviceability issues and will r...
Non-native species are spread around the globe by various means, including aquaculture and ship vectors, hull fouling and ballast water. The introduction of nonindigenous species may cause a serious harm to ecosystems, economy and human health. The ballast water is a primary source for the introduction of harmful species and pathogens, therefore, the detection of such organisms could prevent un...
To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Since International Maritime Organization (IMO) regulations are concerned with the unintended transportation of pathogenic bacteria through ballast water, empha...
Methods for verifying ballast water treatments in foreign vessels are needed to protect the Great Lakes from the discharge of live non-native organisms or pathogens. A prototype automated viability test system using fluorescein diacetate (FDA), a membrane permeable fluorogen, to differentiate live from dead bacteria and algae is described. The automated fluorescence intensity detection device (...
Electromagnetic interference (EMI) is one of the serious problems in most electrical and electronic appliances including fluorescent lamps. The electronic ballast used to regulate the power flow through the lamp is the major cause for EMI. The interference is because of the high frequency switching operation of the ballast. Formerly, some EMI mitigation techniques were in practice, but they wer...
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