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The impact of Acoustic and Sound Quality caused by location of impeller rib in blowerLee, Chen-hsi 10 August 2010 (has links)
Abstract
The advances of modern technology , creating a CPU and
hardware speed greatly enhance the relative increase in number of work- ing temperature , so as not to make parts for high temperature, shortened life expectancy , we must take active cooling can be resolved , is gener-
ated by the use of forced convection fan the heat away , but the fan noise when running , although not damage the hearing , have the potential to affect users of emotions ; as people increasingly rely on the computer, the fan gradually pay attention to the noise problem , so fans of R & D in recent years , in addition to increasing thermal efficiency , the increasing demands for noise.
This article will examine the main centrifugal fan to AIO computer system for the experiment; AIO computer is the host and screen into one of the computer system, characterized by the internal space is small, heat is not easy, so the general would choose as the main centrifugal fan cooling fan, but the disadvantage of centrifugal fan noise is high, so this will do for the improvement of centrifugal fan noise research; to change the location of support ribs as the experimental setting, experimental method consists of three steps; first: Analog and down air inlet differences in velocity distribution, the second: the actual measurement centrifugal fan, is divided into single and measurement noise into the system and the sound quality of the judge, the third: performance testing; study showed that support rib in the middle of the design, the noise about 10% area reduction, sound quality also improved the effectiveness of nearly 50%, performance is also about 10% of the upgrade, the support rib in the middle of the design for double inlet centrifugal fans, for
the better design.
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Análisis y medición del nivel de infiltración de aire y puentes térmicos en espacios de oficinaMacari Urra, Barbara Ximena January 2013 (has links)
Ingeniero Civil / En la presente memoria se hace un estudio de comparación de una casa oficina ubicada en el primer piso de una casa versus el caso con aislación continua en la envolvente térmica y mejoras constructivas.
Para las pruebas se utiliza el Blower Door, el cual consiste de un ventilador que se coloca en la puerta principal y produce un cambio de presiones entre el interior y el exterior y sirve para medir el grado de estanqueidad de la casa.
Se analizarán los puentes térmicos que se puedan encontrar en la envolvente, como también el nivel de infiltración de la casa. Se compararán luego estos resultados con lo obtenido mediante un software llamado THERM para el caso de puentes térmicos y con la infiltración máxima para una oficina.
Luego se calcularán los gastos energéticos que se obtengan debido a las características antes mencionadas para compararlas y verificar que se cumpla con el requisito máximo.
Se logra concluir que los resultados esperados eran los correctos, es decir, que el diseño base de la edificación tiene pérdidas superiores al caso propuesto con aislación térmica exterior de 50 mm, cambio a ventanas eficientes, y el intercambio de hora de 5 veces. La diferencia entre ambos casos es de 56% kilowatts por hora en un año.
Al analizar únicamente la envolvente exterior de la edificación se obtiene una diferencia de 26% watts, dentro de estas pérdidas se consideran las pérdidas debido a los puentes térmicos los cuales influyen en un 15% en el resultado final.
Se recomienda el uso del aislante EIFS en las edificaciones para poder así disminuir los gastos y que las construcciones sean más eficientes.
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The Impact of Contextual Variables on Internal Auditors' Propensity to Communicate UpwardlyTolleson, Thomas D. (Thomas Dale) 12 1900 (has links)
The author examined whether contextual variables impact internal auditors' self-assessed likelihood of whistleblowing. The author synthesized a theoretical framework and developed research hypotheses that predict relationships between the self-assessed likelihood of whistleblowing and (1) magnitude of the consequences (2) channels of communication and (3) type of wrongdoing. To test these hypotheses, the author provided internal auditors (n=123) with a scenario and asked them to self-assess the likelihood of reporting evidence of a malfacation to their internal audit director even though their audit manager told them to ignore the wrongdoing.
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Whistle blowing, ethics and the law: an ethical evaluation of the Protected Disclosures Act 26 of 2000 using Hans Jonas’s theory of responsibilityOctober, Lydia Joy January 2015 (has links)
Magister Theologiae - MTh / South Africa has progressed towards the realisation of an expressive culture of disclosure. Significant implementation and enforcement of the Protected Disclosures Act (26 of 2000 – hereafter referred to as “the Act” or “the PDA”) of South Africa has assisted to enforce the practices and protections provided in terms of the enabling laws and a societal culture which is receptive to and respectful of whistle blowers. This thesis seeks to make a contribution to the discourse on whistle blowing and the PDA from an ethical perspective, by means of using ethical concepts and analysing and discussing ethical dilemmas to provide a greater understanding of the real cases of whistle blowing that has occurred. Various aspects of whistle blowing are defined and reviewed with reference to Hans Jonas’s theory of an ethics of responsibility. One such aspect is the idea of collective responsibility as understood by Hans Jonas. Hans Jonas describes responsibility; in terms of the future responsibility present individuals have as a collective in order to ensure that the future human being are able to actively engage in the world with the same familiarities as is experienced today. This thesis
will investigate, more specifically, the contribution made by Hans Jonas’s theory of
responsibility in understanding the PDA in terms of an ethics of responsibility. The research question is posed and attempts to discuss and analyse whether Hans Jonas’s theory of an ethics of responsibility may help to identify, analyse and assess ethical issues embedded in the Protected Disclosures Act 26 of 2000.
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Lufttätheten hos Aquavillor : lösningar, åtgärdsförslag med hjälp utav trycktäthetsprovningHillberg Åkerblom, Johan, Håll, Andreas January 2011 (has links)
De flytande hus som producerades av Aquavilla AB i början av sekelskiftet har problem med otätheter i konstruktionen. Detta har gjort att boende i Aquavillorna i förekommande fall har klagat över drag och att värmen inte går att få upp ordentligt i husen. Frågeställningen för detta examensarbete blir således: Hur ska man göra för att få en erforderlig täthet i nästa generation Aquavillor och hur får man in en kontroll av tätheten i produktionen? Metoden som användes var trycktäthetsprovning på tre Aquavillor för att få en uppfattning om hur pass otäta de är och med en värmekamera ta reda på var otätheterna finns. Utöver detta utfördes även en litteraturstudie och diskussioner med personer erfarna inom lufttätning fördes för att kunna föreslå förbättringar i konstruktionen för att förhindra luftläckage. I en byggnad med FTX-system som är otät kommer inte ventilationssystemet kunna utnyttjas som det ska, då frånluften istället för att värma upp den inkommande kalla uteluften, kommer att passera genom otätheter i klimatskalet. Detta medför stora energikostnader som kan undvikas med ett tätare hus. Utrymmen vari det läcker in luft blir kalla och påverkar den termiska komforten negativt. Aquavillornas klimatskärm är baserad på Casabonasystemet, en konstruktion av stålreglar och hård, bärande värmeisolering. Den okonventionella metoden för väggarnas uppbyggnad har varit nödvändig för att hålla vikten nere, men också bidragit till att göra byggnaden otät. Utförandet av tätning kring spotlights, lampknappar/eldosor och fönster verkar vara obefintligt eller slarvigt gjort. Att lokalisera otätheter görs bäst med en trycksatt byggnad, för att sedan gå igenom den med en värmekamera, anemometer eller spårgas. Metoderna har olika fördelar som enkelhet och låg kostnad.
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A Study on the Impeller Strength of Mini BlowerChung, Yuen-hsun 07 August 2010 (has links)
The interaction between the operating speed and the creep behavior of mini plastic fan has investigated in this study. The thermal-elastic-creep coupling model in Marc finite element method package are employed to simulate the stress distribution and creep deformation of a plastic fan operated in different operating temperature are simulated in this study. Results indicate that operating temperature affect the creep deformation significantly for a plastic fan or impeller. A comparison between the simulated data and measured data of PA66+ GF30 plastic fan was provided. A good agreement has been observed in this study. A comparison between the creep deformation of PET+GF30 and PBT+GF30 fan sets has also presented. Results indicate that PA66+GF30 plastic fan has a much better creep resistance a high temperature operating.
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Stanovení kvality technologických prostupů s využitím Blower Door testuKocfelda, Tomáš January 2014 (has links)
This work deals with the determination of the quality of implementation measures airtightening main airtightening layer wooden building. Diagnostics of air tightness of the building envelope was conducted thermography measurement thermal imager Flir S65 in artificially induced pressure inside the space defined by the main airtightening layer. Further measuring was performed air tightness of the building envelope using Blower door test. The results of the test determine intensity of air exchange, which is compared with the requirement to assessment the energy performance of buildings. The paper also outlines the influence of the quality airtightening measures to the air exchange rate and the life of wooden buildings.
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Hodnocení průvzdušnosti obytných dřevostaveb metodou Blower-door test / Airtightness estimation of wood based residential houses using Blower-door testSrba, Jaromír January 2016 (has links)
This dissertation analyses airtightness of residential buildings which in many ways influences their energy performance and therefore also their costs of use. Properly conducted airtightening layer can significantly extend the lifespan of the construction. The main objective of the dissertation is to evaluate the construction of newly built buildings in the Czech Republic and to assess the most important parameters which affect airtightness.
The Blower-door test was used to assess air leakage. This method belongs among the most widely used and conclusive methods of analysis. Its advantage is mainly the fact that it can detect construction defects of the airtightening layer in important stages of construction (and possibly enable these defects to be corrected before completion). The core of this method is to create a pressure difference of deltap 50 Pa between the exterior and the interior of the building and at the same time discover the faulty places which are different for positive and negative pressure.
The air leakage was assessed in 345 residential buildings constructed between 2006 and 2016, especially in conventional wood frame buildings or with buildings made from wood panels such as cross-laminated timber. The development of values of air change rate through the building envelope was evaluated according to the Czech standard ČSN 73 0540-2 and the results were compared to previous outcomes of other authors. Analysis and photo documentation of the most frequently detected leakage points are also part of the dissertation. A significant decrease in values of the air change rate was discovered, on average by 40.49% in 2016 compared to 2006, while for passive houses the air change rate values were almost steady. For buildings with wood frame construction, it was the way of ventilation which was determined as the most significant parameter affecting air leakage. For wooden buildings with natural or combined ventilation, the average value of air change rate at the pressure difference of 50 Pa was 1,29 h-1, for buildings with mechanical ventilation and heat recovery it was 1,18 h-1 and for buildings with very low energy consumption for heating with mechanical ventilation and heat recovery it was 0,44 h-1. Other parameters affecting the values of air leakage include the construction company, the presence of a chimney, the place and method of construction of the wood frame construction.
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Winter Weather Hazards: Injuries and Fatalities Associated with Snow RemovalHaney, Christa Robyn 06 May 2017 (has links)
An analysis of snow removal injury data from the National Electronic Injury Surveillance System (NEISS) revealed a persistent gender gap in injuries and deaths during snow clearing activities. In general, men, those who identified as White and those aged 60-79 represented the vast majority of injuries and deaths sustained during automated snow removal. Injuries and deaths from manual snow clearing had greater representation across gender lines, as well as across various age groups and race categories. This indicates that a greater cross-section of society relies on the standard shovel in comparison to the snow blower for snow removal. The most likely injuries sustained during shoveling were to the neck and back, while hand and finger injuries were far more common during the use of a snow blower. Similar percentages of cardiac (30%) and non-cardiac chest injuries (70%) were found for both manual and automated modes of snow removal. While the majority of cardiac chest injuries were in those aged 40-59 for shoveling and 60-79 for snow blowing, the majority of cardiac fatalities were in those aged 60-79 for both methods of snow removal. Daily all-cause mortality and daily deaths from acute heart attacks showed a weak but inverse relationship to daily maximum, minimum and average temperatures. Mortality related to temperatures had significant lag effects for two days. Daily all-cause and heart attack mortality were also significantly related to the depth of the existing snowpack. Snow to liquid ratios indicating differences between heavy, wet snow and dry, powdery snow were not significant. However, the water equivalent of the existing snowpack was significantly related to daily mortality. Comparisons between all age and elderly mortality showed weaker and opposite relationships for the elderly group suggesting the use of protective behaviors such as cold and snow avoidance.
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Teplovzdušné vytápění / Warm air heatingRohlíková, Věra January 2013 (has links)
The subject of this master's thesis is warm air heating system. The task is to apply this heating method to a specified building and to design technical solutions. The degree of completion of the extended project is appropriate for the requirements of building permit documentation. Proposed solutions were evaluated in the viewpoint of inner environment, space requirements, operation economy and environmental impact. Warm air heating system made by Atrea is used for building heating. The text part of the thesis deals with building air permeability and the experimental part describes performance of blower door test in a family house and evaluation of experiment data
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