5 research outputs found

    Political E-Mail: Protected Speech or Unwelcome Spam?

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    Candidates for political office are using unsolicited bulk e-mails to reach the electorate. Commonly known as political spam, this campaign tactic is an inexpensive supplement to television, radio, and print ads. Advocates claim that campaigning via the internet reduces candidates\u27 dependence on fundraising, but critics detest political spam as the latest nuisance. This iBrief examines the legal basis for political spam, distinguishes political spam from analogous regulated speech, and argues that political spam serves an interest worth protecting

    Preparation for a Thermal Balance Test of the MIST student satellite

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    The MIST project was founded in 2014 at KTH and has been worked on by roughly 100 students since.Thermal engineering has been an important part of the project from start and a thermal model has beendeveloped to predict ight conditions. The thermal model created by previous students has to be correlatedby performing a thermal balance test. This test is going to take place in a thermal vacuum chamberat KTH Albanova during the period November 2019 to February 2020. This thesis describes the process ofpreparation for a Thermal Balance Test for MIST. Included in the preparation of the test are; developingthe test specications and denition of ground support equipment needed for the Thermal Balance Testin order to successfully correlate the thermal model.To perform the test some of the equipment has to be replaced with replacement components. The batteryand the solar panels are two expensive and crucial systems for the mission and has been chosen to bereplaced with mass dummies. These mass dummies are used in the thesis both to keep the correct thermalcapacity and approximate the conductive properties. The solar panel dummy plates can be drilled into, tomake sure the cables for thermocouples and heaters can get inside the satellite. Heaters will be mountedon the satellite, both to create gradients across the satellite to be able to measure them, and to useas safety heaters to prevent the temperature to get to low and damage components. The heaters will bemounted on the battery replacement board, the solar panel replacement plates and the bottom cover plate.The thermocouples to be used in the test are already installed in the vacuum chamber, which are of TypeT class 1 with a temperature accuracy of 0:5 C. The chamber has 50 thermocouples installed where24 are planned to be used to measure gradients across interfaces to be able to correlate them with thethermal model.In this thesis the thermal model is simulated in the new vacuum chamber environment to investigatewhat temperatures can be expected in the test and nd components and interfaces of interest to placethermocouples on. The test will start from ambient temperature of 20 C, then change the temperatureof the chamber to 0 C, with a temperature ramp of 1.5 C/min. The chamber will stay at 0 C until thetemperature of the satellite has stabilized within the chosen stability criteria of 0.5 C over two hours. Thisset point is chosen to take measurements for the hot case. When measurements are made, the chamberwill go to -50 C and stabilize at that temperature to take temperature measurements for the cold case.The temperature gradients measured in both the hot and cold case will be used to correlate the thermalmodel with the physical model.MIST projektet grundades 2014 pĂ„ KTH och har arbetats pĂ„ av drygt 100 studenter sedan projektet startade. Termisk kontroll har sedan projektets start varit av hög vikt och en termisk modell har tagits fram för att förutse temperaturer i omloppsbana. Den termiska modellen skapad av tidigare studenter mĂ„ste korreleras genom att utföra ett termiskt vakuumkammartest. Det testet kommer att genomföras i en vakuumkammare pĂ„ KTH Albanova under perioden November 2019 till Februari 2020. Den hĂ€r avhandlingen beskriver processen att ta fram ett termisk vakuumkammartest för att korrelera modellen.För att genomföra testet mĂ„ste vissa komponenter bytas ut till ersĂ€ttningskomponenter. Batteriet och solpanelerna Ă€r dyra och kritiska system för uppdraget och har valts att ersĂ€ttas med ersĂ€ttningskomponenter. Dessa ersĂ€ttningskomponenter anvĂ€nds i den hĂ€r rapporten för att bebhĂ„lla korrekt termisk massa och approximera de konduktiva egenskaperna. SolpanelsersĂ€ttningsplĂ„tarna kan borras i för att lĂ€ttare fĂ„ in sladdar för termiska sensorer och vĂ€rmare i satelliten. VĂ€rmare kommer att monteras pĂ„ satelliten, bĂ„de för att skapa en temperaturgradient över satelliten för att kunna mĂ€ta dessa, samt som sĂ€kerhetsvĂ€rmare för att undvika att temperaturen blir för lĂ„g och skada komponenter. VĂ€rmarna kommer att vara monterade pĂ„ batteriersĂ€ttnings komponenten, solpanelsplĂ„tarna och pĂ„ den undre tĂ€ckplattan.De termiska sensorerna valda för detta test Ă€r av Typ T klass 1 med en noggrannhet pĂ„ ±0.5 ◩C. Vakuumkammaren har 50 installerade termiska sensorer och 24 av dem Ă€r planerade att anvĂ€ndas i testet för att mĂ€ta temperaturskillnader mellan komponenter för att kunna korrelera kopplingen mellan dem i den termiska modellen.I den hĂ€r avhandlingen kommer den termiska modellen simuleras i den nya vakuumkammarmiljön för att undersöka vilka temperaturer som kan förvĂ€ntas och hitta komponenter av intresse för att korrelera och placera termiska sensorer pĂ„. Testet kommer att starta pĂ„ en rumstemperatur pĂ„ 20 ◩C, sedan Ă€ndra temperaturen pĂ„ kammaren till 0 ◩C, med en hastighet pĂ„ 1.5 ◩C/min. Kammaren kommer att stanna pĂ„ 0 ◩C tills att satelliten har stabiliserats med det valda stabilitets kriteriet att temperaturen inte fĂ„r Ă€ndras med mer Ă€n 0.5 ◩C över tvĂ„ timmar. Denna temperatur Ă€r vald för att ta mĂ€tningar för det varma fallet. NĂ€r mĂ€tningarna Ă€r gjorde kommer kammaren att gĂ„ ned till -50 ◩C och stabiliseras pĂ„ den temperaturen för att ta mĂ€tningar för det kalla fallet. Temperaturgradienterna mĂ€tta i bĂ„da fallen kommer att anvĂ€ndasför att korrelera den termiska modellen med den fysiska modellen

    Preparation for a Thermal Balance Test of the MIST student satellite

    No full text
    The MIST project was founded in 2014 at KTH and has been worked on by roughly 100 students since.Thermal engineering has been an important part of the project from start and a thermal model has beendeveloped to predict ight conditions. The thermal model created by previous students has to be correlatedby performing a thermal balance test. This test is going to take place in a thermal vacuum chamberat KTH Albanova during the period November 2019 to February 2020. This thesis describes the process ofpreparation for a Thermal Balance Test for MIST. Included in the preparation of the test are; developingthe test specications and denition of ground support equipment needed for the Thermal Balance Testin order to successfully correlate the thermal model.To perform the test some of the equipment has to be replaced with replacement components. The batteryand the solar panels are two expensive and crucial systems for the mission and has been chosen to bereplaced with mass dummies. These mass dummies are used in the thesis both to keep the correct thermalcapacity and approximate the conductive properties. The solar panel dummy plates can be drilled into, tomake sure the cables for thermocouples and heaters can get inside the satellite. Heaters will be mountedon the satellite, both to create gradients across the satellite to be able to measure them, and to useas safety heaters to prevent the temperature to get to low and damage components. The heaters will bemounted on the battery replacement board, the solar panel replacement plates and the bottom cover plate.The thermocouples to be used in the test are already installed in the vacuum chamber, which are of TypeT class 1 with a temperature accuracy of 0:5 C. The chamber has 50 thermocouples installed where24 are planned to be used to measure gradients across interfaces to be able to correlate them with thethermal model.In this thesis the thermal model is simulated in the new vacuum chamber environment to investigatewhat temperatures can be expected in the test and nd components and interfaces of interest to placethermocouples on. The test will start from ambient temperature of 20 C, then change the temperatureof the chamber to 0 C, with a temperature ramp of 1.5 C/min. The chamber will stay at 0 C until thetemperature of the satellite has stabilized within the chosen stability criteria of 0.5 C over two hours. Thisset point is chosen to take measurements for the hot case. When measurements are made, the chamberwill go to -50 C and stabilize at that temperature to take temperature measurements for the cold case.The temperature gradients measured in both the hot and cold case will be used to correlate the thermalmodel with the physical model.MIST projektet grundades 2014 pĂ„ KTH och har arbetats pĂ„ av drygt 100 studenter sedan projektet startade. Termisk kontroll har sedan projektets start varit av hög vikt och en termisk modell har tagits fram för att förutse temperaturer i omloppsbana. Den termiska modellen skapad av tidigare studenter mĂ„ste korreleras genom att utföra ett termiskt vakuumkammartest. Det testet kommer att genomföras i en vakuumkammare pĂ„ KTH Albanova under perioden November 2019 till Februari 2020. Den hĂ€r avhandlingen beskriver processen att ta fram ett termisk vakuumkammartest för att korrelera modellen.För att genomföra testet mĂ„ste vissa komponenter bytas ut till ersĂ€ttningskomponenter. Batteriet och solpanelerna Ă€r dyra och kritiska system för uppdraget och har valts att ersĂ€ttas med ersĂ€ttningskomponenter. Dessa ersĂ€ttningskomponenter anvĂ€nds i den hĂ€r rapporten för att bebhĂ„lla korrekt termisk massa och approximera de konduktiva egenskaperna. SolpanelsersĂ€ttningsplĂ„tarna kan borras i för att lĂ€ttare fĂ„ in sladdar för termiska sensorer och vĂ€rmare i satelliten. VĂ€rmare kommer att monteras pĂ„ satelliten, bĂ„de för att skapa en temperaturgradient över satelliten för att kunna mĂ€ta dessa, samt som sĂ€kerhetsvĂ€rmare för att undvika att temperaturen blir för lĂ„g och skada komponenter. VĂ€rmarna kommer att vara monterade pĂ„ batteriersĂ€ttnings komponenten, solpanelsplĂ„tarna och pĂ„ den undre tĂ€ckplattan.De termiska sensorerna valda för detta test Ă€r av Typ T klass 1 med en noggrannhet pĂ„ ±0.5 ◩C. Vakuumkammaren har 50 installerade termiska sensorer och 24 av dem Ă€r planerade att anvĂ€ndas i testet för att mĂ€ta temperaturskillnader mellan komponenter för att kunna korrelera kopplingen mellan dem i den termiska modellen.I den hĂ€r avhandlingen kommer den termiska modellen simuleras i den nya vakuumkammarmiljön för att undersöka vilka temperaturer som kan förvĂ€ntas och hitta komponenter av intresse för att korrelera och placera termiska sensorer pĂ„. Testet kommer att starta pĂ„ en rumstemperatur pĂ„ 20 ◩C, sedan Ă€ndra temperaturen pĂ„ kammaren till 0 ◩C, med en hastighet pĂ„ 1.5 ◩C/min. Kammaren kommer att stanna pĂ„ 0 ◩C tills att satelliten har stabiliserats med det valda stabilitets kriteriet att temperaturen inte fĂ„r Ă€ndras med mer Ă€n 0.5 ◩C över tvĂ„ timmar. Denna temperatur Ă€r vald för att ta mĂ€tningar för det varma fallet. NĂ€r mĂ€tningarna Ă€r gjorde kommer kammaren att gĂ„ ned till -50 ◩C och stabiliseras pĂ„ den temperaturen för att ta mĂ€tningar för det kalla fallet. Temperaturgradienterna mĂ€tta i bĂ„da fallen kommer att anvĂ€ndasför att korrelera den termiska modellen med den fysiska modellen

    Flight Testing of the Piper PA-28 Cherokee Archer II Aircraft

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    It is sometimes easily assumed that an experimental measurement will closely mimic the results from an associated theoretical model. The purpose of this project is to determine how close to a theoretical model - involving the component buildup method and the quadratic drag polar assumption - a Piper Archer II will perform in an actual test flight. During the test flight, the Archer II showed a similar correlation between air speed and performance as the model. The actual performance numbers were, however, consistently lower than their theoretical counterpart

    Associations between social and general health factors and symptoms related to temporomandibular disorders and bruxism in a population of 50 year-old subjects

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    The aim of this epidemiological study was to examine associations between temporomandibular (TMD)-related problems and variables from three domains: (1) socio-economic attributes, (2) general health and health-related lifestyle, and (3) dental attitudes and behaviors. The overall response rate to a questionnaire mailed to the total population of 50-year-old subjects in two Swedish counties (8,888 individuals) was 71 %. Among the 53 questions in the questionnaire, those related to social, general health, and health-related factors were used as independent variables in logistic regression models. Three TMD-related symptoms and reported bruxism were used as dependent variables. Impaired general health was the strongest risk factor for reported TMD symptoms. Along with female gender and dissatisfaction with dental care, impaired general health was significantly associated with all three TMD symptoms. A few more factors were associated with pain from the TMJ only. In comparison, reported bruxism showed more significant associations with the independent variables. In addition to the variables associated with TMD symptoms, being single, college/university education, and daily tobacco use were also significantly correlated with bruxism. Besides female gender, impaired general health, dissatisfaction with dental care, and a few social and health-related factors demonstrated significant associations with TMD symptoms and reported bruxism
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