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1694 Uppsatser om Natural frequency - Sida 20 av 113

Omkonstruktion av friskluftsventil

Genom konstruktion och tillverkning av prototyper samt med hjälp av ljud- och flödesmätningar av dessa, tillsammans med standardmodellen, har vi lyckats förbättra flödet genom ventilen Al-db 450, producerad av Fresh AB i Gemla. För ljudmätningar har en testrigg konstruerats och tillverkats..

Kvalitetskontroll av utskrifter från Kodak Approval XP4

When using the digital halftone proofing systems, a closer print match can be achieved compared to what earlier couldbe done with the analogue proofing systems. These proofing systems possibilities to produce accurate print match canas well lead to producing bad print matches as several print related parameters can be adjusted manually in the systemby the user. Therefore, more advanced knowledge in graphic arts technology is required by the user of the system.The prepress company Colorcraft AB wishes to control that their color proofs always have the right quality. This projectwas started with the purpose to find a quality control metod for Colorcraft´s digital halftone proofing system(Kodak Approval XP4).Using a software who supports spectral measuring combined with a spectrophotometer and a control bar, a qualitycontrol system was assembled. This system detects variations that lies out of the proofing system´s natural deviation.The prerequisite for this quality control system is that the tolerances are defined with consideration taken to the proofingsystems natural deviations.

På personlig frekvens - En studie av svenska B2C-företags inställning till RFID inom lojalitetsprogram

Kundrelationerna i svenska B2C-företag är inte lika goda som de var för 60 år sedan och de är inte lika goda som företagen skulle önska att de var. Forskningsfrågan och syftet med uppsatsen var därför att förklara vad som påverkar svenska B2C-företags beslut att utnyttja Radio Frequency Identification (RFID) som identifieringsteknik för att personliggöra kundrelationer inom sina lojalitetsprogram. Studien utfördes som en fallstudie då vi undersökte hur två stora svenska B2C-företag, IKEA Family och ICA, arbetade med lojalitetsprogram, identifieringstekniker och hur de ställde sig till alternativa identifieringstekniker gestaltat genom RFID. Studien utfördes med deduktiv ansats genom inledande teoriinsamling och därefter genom intervjuer med en intervjuperson på vardera företag. De slutsatser som sedermera kunde dras var att tillräcklig kunskap saknas kring RFID och dess potential, att det är en ekonomisk fråga och en stor investering för företag som inte brukar vara först att ta till sig ny teknik som dessutom inte är standardiserad samt att det skulle kunna kränka kundernas integritet och därmed ha motsatt effekt till lojalitetsprogrammens syfte..

Naturligtvis : en studie om naturens betydelse för ungdomars hälsa

The aim of this study was to investigate the importance of nature for the health and well-being of young adults. A qualitative method was used and data was collected through semi-structured interviews with eleven people from the ages of 15-20. The interviews were transcribed with the results of the study revealing that nearly everyone felt calm and relaxed while they were in a natural environment. The most common motivation to be outdoors was socializing with friends, performing any kind of sport and/or taking walks. Reasons to stay indoors were rainy, cold weather, lack of time, and in some cases circumstances related to their surroundings, such as where they live.

En oscillatorbank till en lågfrekvensradar : LORA/VHF

The goal of this thesis work is to enable an existing UHF radar to operate in the VHF band instead. In order to achieve this, new coherent local oscillators are required. Different options are suggested and one of them is implemented and analyzed..

Frekvensomriktare i hydraulhissdrift

Hydroware Elevation Technology AB sells control and regulation equipment for hydraulic elevators. The company now wants to investigate the possibility of changing their present softstarters to frequency inverters to supply power to their pump engines. They also want to investigate the possibility of future use in so called ?intelligent? houses.The purpose of this report is to investigate these possibilities..

Kommunikationseffektivitet och kommunikationsstrategier för L1- och L2-talare i referentiella problemlösningsuppgifter

This thesis examines and measures differences in effciency between L1- and L2 language use for solving referential problems. Quantitative measures used in the study were time and error frequency. Qualitative measures, such as how the tasks and the participants own performance were experienced, were measured by an post interview and two questionaires. Two different tasks, a sorting task and a construction task, in which each informant was given the role as a constructor or instructor, were used for data gathering. A total of 20 dyads, divided in two language groups (English and Swedish) participated in the study.

Analys av massapumps- och mixerarbete vid Metsä Board Sverige AB, Husums Fabriker : Energibesparingsåtgärder vid blekeri 4 & 5 med jämförelse mot ny utrustning

Husums plant has a selection of different pulp pumps at bleaching plant 4 and 5. The displacement- (HC-pump, Sund Defibrator PTD-60) and centrifugalpumps (MC-pump, MCA 42-200, MCP 30/20) are of interest in this report. The centrifugal pumps are controlled by throttle valves, which result in an energy loss. Chemical mixers are used to mix ClO2 into the pulp before proceeding into a holding tower where the bleaching process occurs.The energy demand of the different positions has been measured or calculated to be used in comparisons against new equipment. Quotations were requested and delivered from Valmet and Sulzer.

Åsktransienter och överspänningar : En spänningsfylld simulering av elkraftsystemet vid Forsmark 3

A power system will inevitably be subjected to transient overvoltages, most often produced by switching operations and lightning strikes. These transient overvoltages may harm sensitive equipment without sufficient protection, but it is not an easy task to predict what transients may occur or how they affect the system. A fault occurred in a low voltage system at Forsmark 2012 and overvoltages from lightning were concluded as the probable cause. The three aims with this thesis are to develop and test a model of the power system at Forsmark 3, analyse the transient behaviour of the system when subjected to lightning surges and identify critical parameters, and lastly to provide a tool for investigating the protection of the system. The modelling and simulations were performed in the freely available simulation program LT Spice.

Undersökning av vissa beläggningars påverkan på antenners effektivitet i tågmiljö

For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.

Stadsnära hav : en intervju/enkät om upplevelsen

The environment that surrounds us affects us all. Research has shown that we feel physically and emotionally best in natural environments with greenery or water elements. Urban environments are likely to be more stressing then natural environments. How we experience specific elements, as water, of an environment is not as much investigated. There is a need of further knowledge for us to fully understand the interplay between our senses and the environment. Human beings have always been depending on water and the search for it has characterized our deeds and doings through out evolution.

Aktiv bullerdämpning i ventilationssystem

Active headsets have been on the market for years and now it is time for something else to enter the stage. The technology of active noise reduction can for exmple also be used in ventilation systems for reducing ventilation noise. An active control system principally consists of four important components, namely the downstream error microphone, the upstream detection or reference microphone, the digital signal processor (DSP) and a loudspeaker. The upstream reference microphone listen to the primary ventilation noise and sends it to the DSP which makes a phase shift to the signal and sends it to the loudspeaker. The loudspeaker sends out the opposite waveform of the incoming one and reduce the primary ventilation noise.

Analys av skillnader mellan internationell och svensk rapportering av inträffade händelser på kärnkraftverk

Report of diploma work conducted at the Swedish Radiation Safety Authority (SSM) as part of the bachelors program in Nuclear Engineering at Uppsala University.All nuclear power plants in Sweden are obliged to report any deficiency in their barriers or the defense in depth in obedience to SSM?s regulations concerning safety in nuclear facilities. In addition, there is an international system for reporting such events. The purpose of this thesis is to study the Swedish report system and to analyze the differences between Swedish and international event reporting.In the Swedish system, SSM?s regulations are effectuated by means of event reports classified as category 1-3, designed individually at each Swedish facility.

Effekt av ras och säsong på nötkreaturs avbetningsgrad av konkurrenskraftiga betesmarksväxter :

Grasslands which have been actively managed for a long time and which in modern times have not been subject to cultivation such as fertilization are called semi-natural grasslands. These rare and species-rich areas hold an ecological, biological and historical value and if the management stops these areas will likely diminish. More effective agricultural systems and a declining number of grazing animals have in Sweden, among other countries, made semi-natural grasslands less valuable as foraging areas. Shrubs and fast growing plants rapidly colonize abandoned semi-natural grasslands, threatening biodiversity. The objective of this experiment was to determine the effects of breed and season on diet composition, with special reference to four competitive species found in wet areas ? in cattle grazing heterogeneous semi-natural grasslands ? and thereby contribute to improved management of these areas.

Mätningar och analys av elnätet hos FHP, Basproduktion

This report is a degree project performed at Freudenberg Household Products AB, (FHP). The degree project comprises measurement and analysis of the power net at FHP Basproduction. The content is divided between one theory-part, one document- part with measurements and also conclusions and a list of measures to be taken. During the project the purpose and restriction change from a quality investigation to only concentrate on harmonics and finding the reason why they exist, and also to find a solution to the problem with harmonics. The measurements shows that the power net contains harmonics of different order and intensity.

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