Fetma och övervikt är ett hälsoproblem som drabbar mer än var tionde person och antalet individer med BMI >30 ökar ständigt. Som en följd av detta kommer allt fler patienter som genomgår anestesi att ha ett högt BMI. Förändringar i respiration, luftvägsanatomi och ett flertal andra fysiologiska förändringar i kroppen gör generell anestesi för patienter med fetma till en anestesiologisk utmaning. Syftet var att beskriva vilka omvårdnadsåtgärder anestesisjuksköterskan kan använda för att bibehålla god ventilation hos feta patienter vid generell anestesi. Studien genomfördes som en litteraturstudie där 12 vetenskapliga artiklar analyserades. Resultatet av de granskade artiklarna gav följande teman; val av ventilations strategier, val av hjälpmedel och val av patientläge. Litteraturstudiens resultat visar att anestesisjuksköterskan på ett patientsäkert sätt kan söva en fet patient om hon har kunskap om de förändringar som kräver särskild uppmärksamhet och lägger ner tid på förberedelse. Resultatet kan vara till gagn för anestesisjuksköterskor som vårdar dessa patienter inom all operationsverksamhet, då det kan bidra till en ökad vårdkvalitet och patientsäkerhet. Möjligheter och utmaningar i operationsvården kring dessa patienter är återkommande i fokus och kommer troligen att fortsätta vara så även i framtiden, därför behövs vidare forskning inom ämnet anestesiologisk omvårdnad vid fetma.

No description available.

In this thesis, heat powered ejector cooling systems was investigated in two ways: to store the cold energy with energy storage system and to utilize low grade energy to provide both electricity and cooling effect. A basic ejector prototype was constructed and tested in the laboratory. Water was selected as the working fluid due to its suitable physical properties, environmental friendly and economically available features. The computer simulations based on a 1-0 ejector model was carried out to investigate the effects of various working conditions on the ejector performance. The coefficients of performance from experimental results were above 0.25 for generator temperature of lI5°C-130 °C, showing good agreements with theoretical analysis. Experimental investigations on the operating characteristics of PCM cold storage system integrated with ejector cooling system were conducted. The experimental results demonstrated that the PCM cold storage combined with ejector cooling system was practically applicable. The effectiveness-NTU method was applied for characterizing the tube-in-container PCM storage system. The correlation of effectiveness as the function of mass flow rate was derived from experimental data, and was used as a design parameter for the PCM cold storage system. In order to explore the possibility of providing cooling effect and electricity simultaneously, various configurations of combined power and ejector cooling system were studied experimentally and theoretically. The thermal performance of the combined system in the range of 0.15-0.25 and the turbine output between 1200W -1400W were obtained under various heat source temperatures, turbine expansion ratios and condenser temperatures. Such combined system was further simulated with solar energy as driving force under Shanghai climates, achieving a predicted maximum thermal efficiency of 0.2. By using the methods of Life Saving Analysis, the optimized solar collector area was 30m2 and 90m2 respectively for the system without and with power generation. The environmental impacts and the carbon reductions of these two systems were discussed.

In the last century, there has been a rapid growth and development in economy and modern technology around the world. This phenomenon helped improving wealth and living standard but also brought pollutions to the society and the environment. Among various kinds of pollution, air pollution takes a larger proportion. Therefore, there is increasing concern about the ventilation and pollution removal behavior in the urban environment. Among different academic studies performed, the use of computational fluid dynamics (CFD) had become more popular. Since wind tunnel experiments serve as validations for CFD results, this thesis developed the technique required for wind tunnels experiments and to investigate the pollutant removal related to urban geometry, as well as the technique for gas sampling to examine the distribution of pollutants in urban boundary layer over idealized two-dimensional (2D) street canyons. Three specific tasks are archived to accomplish the above objectives. The first task was to extend the wind tunnel in the Department of Mechanical Engineering, the University of Hong Kong. An extension duct was designed to increase the length of the test section in which the reduced-scale model could be installed. The dimensions of the test section were specified according to the required length for fully developed flow inside the test section, the environment in the laboratory and the original wind tunnel conditions. The extension duct was then constructed and mounted, with the wind profile inside the test section obtained afterwards. After construction of the extended test section for experimental purposes, the second task was to examine the pollutant transport behaviors from the ground level of idealized 2D urban street canyons to the urban atmospheric boundary layer (ABL) using both laboratory wind tunnel measurements and CFD. Movable rectangular aluminum blocks were placed in the wind tunnel in cross-flow to construct street canyons of different building-height-to-street-width (aspect) ratios. Wetted filter papers were applied on the surface of the blocks inside the street region, modeling the source of pollutant emission inside the street canyons. The wind tunnel and CFD results complemented each other to elucidate the pollutant removal mechanism that is in line with other results available in literature. From the experimental results obtained, scaling effect was observed in the mass transfer behaviors even the flows had fulfilled kinematic similarity. A new indicator, the scaled overall pollutant removal coefficient, was formulated for the comparison of pollutant removal performance. The improved agreement in the comparison with the CFD results showed that the scaled overall pollutant removal coefficient could be used to account for the scaling effects occurred in laboratory experiments at finite Reynolds number (〖10〗^(3 ) to 〖10〗^(5 ) in this study) for comparison of pollutant removal performance. The behavior of pollutants inside the street canyons was studied; however, the pollutant concentration inside a street could be affected by the pollutant source in another street, even there were several streets away from it. The pollutant escaped from the source street could act as air entrainment into other streets, affecting the air quality. The concentration profile correlated to the street geometry was thus studied. The last task of this dissertation was to study the effect of urban geometry on the concentration profile of the urban ABL by means of gas dispersion experiments. Experiments were carried out in the wind tunnels of the Department of Mechanical Engineering and Department of Civil Engineering with different sets of experimental models used. A special gas emission source was constructed in order to simulate the linear source due to busy traffic in the street regions. The required gas sampling techniques were also studied throughout the measurement. Trial experiments were carried out and preliminary results had been obtained. Furthermore, the pollutant concentration profiles downstream from a linear pollutant source in an idealized 2D street canyon were also measured. Throughout the experiments, different designs of line source were tested and factors affecting the experimental results were considered. One of the line source designs was adopted and the pollutant concentrations in street canyons of different aspect ratios were observed. The concentration decreases rapidly with increasing distance from the roof but then increases to steady value. The average pollutant concentration over the concentration profile was different at different aspect ratios. It is believed that its performance depends on the pollutant removal behavior from street regions. / published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

Denna rapport behandlar ett produktutvecklingsprojekt i kursen Examensarbete för högskoleingenjörsprogrammet innovationsteknik och design, MSGC12, vid fakulteten för hälsa, natur- och teknikvetenskap vid Karlstads universitet våren 2015. Handledare för projektet har varit universitetsadjunkt Lennart Wihk och examinator för projektet har varit professor Leo de Vin. Arbetet gjordes i uppdrag av Carl-Ola Danielsson för Swegon i Arvika. Uppdraget har haft som mål att effektivisera underplåten för en av Swegons komfortmoduler både konstruktion- och utseendemässigt. Detta gjordes för att användarvänligheten och säkerheten vid underhållsarbeten ska öka samt för att skapa ett mervärde hos produkten. Arbetet resulterade i ett flertal koncept för hur låsningsanordningen till komfortmodulernas underplåt kan utformas. En utvärdering av dessa koncept resulterade sedan i ett grundläggande koncept för hur låsningsanordningen bör utformas. Genom layoutkonstruktionen utvecklades det grundläggande konceptet och resulterade i totalt tre slutkoncept. Slutkoncepten är alla en typ av snabblåsning mellan underplåten och komfortmodulen. På grund av den minskade tid som slutkoncepten medför vid öppning och stängning av underplåten minskar den statiska belastningen på användaren. Slutkoncepten möjliggör öppning och stängning av underplåten med ett enhandsgrepp, vilket minskar risken för olyckor vid underhållsarbeten av komfortmodulerna. Det finns utrymme för vidarutveckling av slutkoncepten i form av konstruktionsförbättringar, materialval samt fastmonteringsanordning i underplåt och komfortmodul. / This report covers a product development project within the course Degree of Bachelor of Science thesis for innovation and design engineer program, MSGC12, at the Faculty of Health, Nature and Engineering Science at Karlstad University in the spring of 2015. Lennart Wihk has been the supervisor of the project and Professor Leo de Vin acted as examiner for the project. The work was commissioned by Carl-Ola Danielsson for the company Swegon in Arvika, Sweden. The project aimed at improving the face plate for one of Swegon’s comfort modules in both construction and appearance. This was done to improve the usability and safety during maintenance work and to create an added value in the product. The work resulted in a number of concepts for how the locking device to the comfort modules face plate can be designed. An evaluation of these concepts later on resulted in a basic concept for how the locking device should be designed. By a further development of the basic concept, a total of three final concepts were developed. All of the final concepts are a type of quick locking positioned between the face plate and the comfort module. Because of the reduced time required in opening and closing the face plate, the static load is reduced on the user. The final concepts enable opening and closing of the face plate with one hand, reducing the risk of accidents during maintenance work of the comfort modules. There is room for further development of the final concepts in terms of design improvements, material choice and the mounting arrangement of the face plate and the comfort module.

Denna rapport kommer att undersöka elanvändningen på ventilationsaggregaten i R-huset på Mälardalens högskola och även undersöka om byte av fläkt och motor i ventilationsaggregat vid eventuellt hög elanvändning är ekonomisk lönsamt. R-husets byggår är 1993 och har de mest uråldriga ventilationsaggregaten av skolans fastigheter. Ett ventilationsaggregats livslängd kan uppskattas mellan 20-30 år. Enligt undersökningar finns det stora möjligheter till energieffektiviseringsåtgärder i sektorn bostäder och service där ventilationsaggregat med föråldrad teknik och komponenter kan vara miljöbovar med hög elanvändning. En avgränsning i arbetet är att ventilationsaggregatet med högst specifik fläkt effekt (SFP) ska undersökas noggrant i form av energieffektivisering. Energieffektiviseringen kommer att begränsas till luftbehandlingsaggregatets fläktar och motorer. Kartläggning genomfördes med tryckmätningar på ventilationsaggregaten i R-huset och även el mätningar. El mätningarna behövdes för att beräkna den aktuella elanvändningen för fläktarna. Resultatet av den beräknade elanvändningen för vardera fläkt visade sig vara hög. Tryck mätningarna utfördes för att få fram tryckuppsättningen för fläktarna i aggregaten och vid beräkning av till- och frånluftsflöde. Tryckuppsättningen och flöde över fläktar behövdes vid val av ny fläkt och motor. Resultatet av kartläggningen visar att det totala SFP-värdet som står för den specifika fläkteffekten är höga i jämförelse vid nyproduktion där boverkets byggregler har krav på SFP-värde under 2,0 kW/(m3,s). Högsta SFP-värdet ligger på 4,4 kW/(m3/s) och en livscykelkostnad (LCC) utfördes för detta ventilationsaggregat. LCC-kalkylen baseras på en kalkylperiod på 10 år då på befintliga fläktar och motorer bedöms ha den livslängden. Kalkylräntan är satt till 9 %, energiprisökningen 5 % och detta ger en real kalkylränta på 4 %. Elpriset är valt till det aktuella på 0,80 kr/kWh. LCC-kalkylen visar att det inte är lönsamt att byta till nya fläktar och motorer. Payback metoden gav 12 års återbetalningstid vilket är länge i jämförelse med studerad litteraturstudie. En känslighetsanalys utfördes med ett fördubblat elpris och då blev det ekonomiskt lönsamt att byta befintliga fläktar och motorer till nya. / This report will examine the electricity consumption of the ventilation units in the R building at Mälardalen University and also investigate whether replacing the fan and motor in the ventilation unit with new combined fan and engine units in the event of high electricity consumption is economic profitable. The building was built in 1993 and has the oldest ventilation units of all properties at the university. A ventilation unit’s life can be estimated to last for 20-30 years. According to studies, there are major opportunities for energy efficiency measures in the residential and service sector, where ventilation systems with outdated technology and components can be energy wasters with high electricity consumption. A limitation of this work is that the ventilation unit with the highest Specific Fan Power (SFP) should be examined carefully in terms of energy efficiency. Energy efficiency will be limited to the air handling fans and motors. Mapping was conducted with pressure measurements in the ventilation units and also electrical measurements were done. Electricity measurements are needed to calculate the current electricity consumption of the fans. The result of the estimated power consumption of each fan was found to be high. Pressure measurements were performed to obtain the pressure of the fans in the units and to calculate supply and exhaust air flow. The pressure rise and flow of the fans are needed in order to select a new fan and motor. The result of the survey shows that the total SFP value is high in comparison with the new construction where Boverkets regulations requirements for SFP value is below 2.0. The highest SFP-value is 4.4 kW / (m3 / s) and a Life Cycle Cost (LCC) calculation was performed for that ventilation unit. The LCC calculation is based on a calculation time period of 10 years, where the existing fans and motors are predicted to last for 10 years. The discount rate is set at 9%, energy with a price increase of 5% and this gives a total discount rate of 4%. Electricity prices are up to date and are 0.80 SEK / kWh. LCC calculation shows that it is not profitable to switch to new fans and motors and as payback method gave a 12-year repayment period. A sensitivity analysis was performed with a redoubled electricity price and it then became economically viable to replace existing fans and motors with new ones.

The overall aim of the research reported here was the development of a simple, low-cost passive solar heating system for operation in the Portuguese climate. The performance of this device is critically dependent on the rate of convective heat exchange across the cavity behind the heater plate. Both computational and experimental studies of the heat transfer characteristics of this new storage device, have been conducted. An experimental installation in full scale was designed and constructed to enable the measurement of local heat transfer rates. Computer simulations of the laminar flow under solar-driven conditions were made using an existing steady, threedimensional computational fluid dynamics (CFD) code based on the finite-volume method (PHOENICS Code shareware version 1.S). A boundary-fitted co-ordinate system was developed to fit the non-rectangular geometry of the cavity, that represented the water store, which provided the computational grid for the CFD code. The experimental data from the test rig was used to validate the CFD model. A solar water heating system was built to test the design under realistic weather conditions. The experimental thermal performance was evaluated in 48% while the theoretical was estimated in 51 %.

No description available.

The main aim of the project is the creation of a CFD model for a plant in the Falun Hospital in Sweden. CFD is a new area of engineering that appears because of the great improvement in the computers last years. Creating a CFD model is a difficult process but the model is capable to give a great amount of data and also the model allows predicting the results when parameters of the system are changed so the model lets to save money and time and becomes an interesting tool to choose the optimal solution for the system. In this case the system studied is the air distributed by the ventilation system inside a plant of the Falun Hospital. The model have to predict the characteristics of the airflows inside the plant, how the air moves through the different areas of the plant and how these airflows affects in the distribution of temperature inside the plant. Also the model has to become a use tool to analyze possible changes in the ventilation system to improve it. And a tool to get boundary conditions to study specific areas of this zone in future studies. The project its part of a bigger project performed by the department of energy technology from Gävle university “Consequences in comfort and inside environment at energy optimization within the health care sector”. The project it is a study of the use of energy in health care buildings in Sweden after the analysis of the energy usage a study to optimize the use of the energy and how these changes affects the patient and workers climate comfort in these buildings. The CFD model have to be a tool that helps in the study of the ventilation system and the relation with the comfort in the Falun Hospital and also a tool to choose an optimal solution for the ventilation system after changes to improve the energy usage in the building avoiding the use of experimental changes in the hospital.

No description available.