260 research outputs found
Assessment of Seismic Damage of Buildings and Related Environmental Impacts
Sustainable development has only recently started examining the existing infrastructure, and a key aspect of this is hazard mitigation. To examine buildings under a sustainable perspective requires an understanding of a building\u27s life-cycle environmental costs, including the consideration of associated environmental impacts induced by earthquake damage. Damage repair costs lead to additional material and energy consumption, leading to harmful environmental impacts. Merging results obtained from a seismic evaluation and life-cycle analysis for buildings will give a novel outlook on sustainable design decisions. To evaluate the environmental impacts caused by buildings, long-term impacts accrued throughout a building\u27s lifetime and impacts associated with damage repair need to be quantified. A method and literature review for completing this examination has been developed and is discussed.
Using software Athena and HAZUS-MH, this study evaluated the performance of steel and concrete buildings considering their life-cycle assessments and earthquake resistance. It was determined that code design-level greatly effects a building repair and damage estimations. This study presented two case study buildings and found specific results that were obtained using several premade assumptions. Future research recommendations were provided to make this methodology more useful in real-world applications. Examining cost and environmental impacts that a building has through, a cradle-to-grave analysis and seismic damage assessment will help reduce material consumption and construction activities from taking place before and after an earthquake event happens
UnterdrĂĽckung von Bewegungsartefakten in PPG-Signalen mittels Adaptive-Noise-Canceling
In diesem Beitrag wird die Problematik der bewegungsbedingten Artefaktbehaftung von PPG-Siganlen im Kontext des Langzeitmonitorings untersucht. Dabei wird besonders das Potential einer Signalrekonstruktion basierend auf adaptiver Filterung mittels Beschleunigungssignalen anhand verschiedener Bewegungsmuster evaluiert und quantifiziert. Ziel ist es, die Anwendbarkeit für kontinuierliches Monitoring abzuschätze
Capacitive Left Hand Finger and Bow Sensors for Synchronization and Rhythmical Regularity Analysis in String Ensembles
(Abstract to follow
Field Investigation of Gearbox Vibration Due to Cracked Motor Rotor Bars
Case StudyApproximately one year after installing a new gearbox, vibration levels were gradually increasing. The tire plant requested that the gearbox manufacturer investigate under warranty. A field study was performed by an independent engineering company to measure the vibration of the motor, gearbox, and rubber mixer unit at the plant
Electromagnetic Effects On The Torsional Natural Frequencies Of An Induction Motor Driven Reciprocating Compressor With A Soft Coupling
LectureThe electromagnetic field in the air gap of an electric motor is responsible for producing torque between the rotor and stator. The analysis and design of motor-driven equipment trains can be improved by including this electromagnetic (EM) effect. Torsional vibration or unsteady conditions from a reciprocating compressor are superimposed over the steady-state operation of an induction motor. In the past, these phenomena were usually neglected as typical analytic methods were unavailable for the prediction of these special effects. In some cases, not accounting for EM influence leads to substantial errors in the torsional vibration analysis (TVA). Torsional vibration data were obtained on a motor driven reciprocating compressor system with a torsionally soft rubber coupling. This paper shows how the torsional stiffening effect of the electromagnetic field can affect the torsional natural frequencies (TNFs) of a compressor system that utilizes a torsionally soft coupling. The torsional measurements documented herein show that a shift in the first TNF occurred due to the effective torsional spring to ground related to EM. The torsional data confirmed that this effect is significant for a motor-driven reciprocating compressor system with a torsionally soft coupling. Comparisons of the field data are then made with theoretical predications of the TNFs with and without EM effects. A relatively simple methodology for calculating torsional stiffness and damping of EM is shown and yielded good correlation with the measured data. The accurate prediction of all dynamic characteristics of the system becomes more important when the motor is controlled by a variable frequency drive (VFD) over a large speed range so that dangerous torsional resonances can be avoided. As a result of the torsional measurements, the minimum operating speed of this compressor system was increased to provide a sufficient separation margin (SM) from the TNF as recommended by American Petroleum Institute, API 618 for reciprocating compressors [1]. This was accomplished by reprogramming the VFD in the field. To minimize dynamic torque in the rubber coupling, it was also recommended that operating the reciprocating compressor with single-acting cylinders be avoided since such operation produced higher dynamic torque at 1Ă— running speed and excited a torsional natural frequency of the system. In the future, the EM effect should be included in torsional analyses, especially for motor-driven reciprocating compressors with soft couplings
Prevalence Of Gastro-Intestinal Parasites In Relation To Availability Of Sanitary Facilities Among Schooling Children In Makurdi, Nigeria
The prevalence of gastro-intestinal parasites in school children in relation to availability of sanitaryfacilities was investigated. Stool samples from 580 pupils from nine schools in Makurdi were examined for intestinal parasites. Sanitary facilties available within the schools were also noted. The overall prevalence rate of parasitic infection was 5413%. Pupils in schools that had lower ratio of number of pupils per toilet had lower infection rates than those from schools with high ratio of number of pupils per toilet. This was however not statistically sgnificant (X 22.272, d = 2, P > 0.05). The following parasites were encountered, namely Ascaris lumbricoides (11.89%), Ancylostoma duodenale (18.62 %), Strongyloides steroralis (1.89%), Trichuris trichura (4.65%), Tapeworm (3.79 %), Entamoeba histolytica (7.06 %), Schistosoma mansoni (1.55 %) and Entemoeba coli (2.41 %). The implications of these results were discussed highlighting the need for provision of sanitary facilities: lke children friendly toiets portable water and fencing the school premises from trespassers as long-term intervention strategies. Occasional activities like mass school based chemotherapy and health education are recommended as immediate interventionstrategies to prevent and control intestinal parasite Keywords: Intestinal parasites, School children, Sanitary facilitiesAnimal Research International Vol. 3 (2) 2006 pp. 489-49
Investigation Of Engine Vibration For Natural Gas Gathering And Transmission
Case Studypg. 406-42
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A study of NO{sub x} reduction by fuel injection recirculation. Final report, January 1995--June 1996
Flue-gas recirculation (FGR) is a well-known method used to control oxides of nitrogen (NO{sub x}) in industrial burner applications. Recent small- and large-scale experiments in natural-gas fired boilers have shown that introducing the recirculated flue gases with the fuel results in a much greater reduction in NO{sub x}, per unit mass of gas recirculated, in comparison to introducing the flue gases with the combustion air. That fuel injection recirculation (FIR) is more effective than windbox FGR is quite remarkable. At present, however, there is no definitive understanding of why FIR is more effective than conventional FGR. The objective of the present investigation is to ascertain whether or not chemical and/or molecular transport effects alone can explain the differences in NO{sub x} reduction observed between FIR and FGR by studying laminar diffusion flames. The purpose of studying laminar flames is to isolate chemical effects from the effects of turbulent mixing and heat transfer, which are inherent in practical boilers. The results of both the numerical simulations and the experiments suggest that, although molecular transport and chemical kinetic phenomena are affected by the location of diluent addition depending on flow conditions, the greater effectiveness of FIR over FGR in practical applications may result from differences in turbulent mixing and heat transfer. Further research is required to understand how differences in diluent-addition location affect NO{sub x} production in turbulent flames. The present study, however, provides an underlying basis for understanding how flow conditions can affect flame chemistry. 51 figs., 7 tabs
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