Thermometry using OH laser-induced fluorescence excitation spectra: A feasibility study

In this thesis, rotational spectra, acquired through laser-induced fluorescence (LIF) on the OH-radical, were used to evaluate temperatures in different combustion environments. By comparing experimental spectra with theoretical ones of known temperature, the temperature can be determined. A MATLAB-code has been developed that evaluates temperature by comparing experimental spectra with a library of theoretical spectra, using a least-square algorithm. The theoretical spectra database was generated with the software LIFBASE. The code was used to evaluate temperature from OH-spectra acquired from already existing excitation scans recorded in an HCCI-engine, using photofragmentation LIF (PF-LIF). The LIF-signal was detected with ICCD-cameras. The measurements are thus spatially resolved in two dimensions. This spatial resolution was utilized to get spatially resolved, quantitative temperature measurements. Some reference excitation scans were performed during this project using both LIF and PF-LIF. These were acquired in premixed, laminar flames and in a free flow of hydrogen peroxide-vapor at ambient conditons

From Fauna to Flames : Remote Sensing with Scheimpflug Lidar

This thesis presents applications of the Scheimpflug Lidar (S-Lidar) method. The technique has been applied to combustion diagnostics on a scale of several meters as well as fauna detection and monitoring over distances of kilometers. Lidar or laser radar is a remote sensing technique where backscattering of laser light is detected with range resolution along the direction of the laser beam. It is an established method in e.g. atmospheric sensing where it is used to map and monitor gases and aerosols. In contrast to conventional Lidar, which uses a time-of-flight approach, Scheimpflug Lidar uses imaging to achieve range resolution. The laser beam transmitted from the Lidar system is sharply imaged onto a detector, resulting in range resolution along the sensor. This is done by placing the laser beam, the collection optics and the detector according to two trigonometrical conditions called the Scheimpflug and hinge rules. This kind of Lidar technique enables the use of small, continuous-wave diode lasers and line-array detectors with kHz sampling rates. A general description of the equations governing the achievable measurement range and resolution of S-Lidar are presented. The way the equations relate to the conventional Lidar equation is also discussed as well as the impact of the beam width. The instrumentation and experimental considerations for far range S-Lidar for aerial fauna monitoring are described and some temporally and spatially resolved data from field campaigns in Africa, China and Sweden are presented. A method used to reduce and analyze the large amount of collected data is also described. For the short-range applications, down-scaled versions of the system were developed. These systems are described as well as their applications. The short range system has mostly been used to investigate the potential of the technique to be applied for combustion diagnostics, and results from measurements in flames using both elastic and inelastic optical techniques, such as Rayleigh scattering and two-line atomic fluorescence are presented. A hyperspectral Lidar system aimed at aquatic applications is also presented

Scheimpflug Lidar for combustion diagnostics

A portable Lidar system developed for large-scale (~1-20 m) combustion diagnostics is described and demonstrated. The system is able to perform remote backscattering measurements with range and temporal resolution. The range resolution is obtained by sharply imaging a part of the laser beam onto a CMOS-array or ICCD detector. The large focal depth required to do this is attained by placing the laser beam, the collection optics and the detector in a so-called Scheimpflug configuration. Results from simulations of the range capabilities and range resolution of the system are presented and its temporal resolution is also discussed. Various applications, important for combustion diagnostics, are also demonstrated, including Rayleigh scattering thermometry, aerosol detection and laser-induced fluorescence measurements. These measurements have been carried out using various continuous-wave GaN diode lasers, emitting in the violet-blue (405 – 450 nm) wavelength regime. It is anticipated that Scheimpflug Lidar will provide a useful and versatile diagnostic tool for combustion research, not only for fundamental studies, but in particular for applications at industrial sites

Lidar reveals activity anomaly of malaria vectors during pan-African eclipse

Yearly, a quarter billion people are infected and a half a million killed by the mosquito-borne disease malaria. Lack of real-time observational tools for continuously assessing the unperturbed mosquito flight activity in situ limits progress toward improved vector control. We deployed a high-resolution entomological lidar to monitor a half-kilometer static transect adjacent to a Tanzanian village. We evaluated one-third million insect observations during five nights, four days, and one annular solar eclipse. We demonstrate in situ lidar classification of several insect families and their sexes based on their modulation signatures. We were able to compare the fine-scale spatiotemporal activity patterns of malaria vectors during ordinary days and an eclipse to disentangle phototactic activity patterns from the circadian mechanism. We observed an increased insect activity during the eclipse attributable to mosquitoes. These unprecedented findings demonstrate how lidar-based monitoring of distinct mosquito activities could advance our understanding of vector ecology

Applications of KHZ-CW Lidar in Ecological Entomology

The benefits of kHz lidar in ecological entomology are explained. Results from kHz-measurements on insects, carried out with a CW-lidar system, employing the Scheimpflug principle to obtain range resolution, are presented. A method to extract insect events and analyze the large amount of lidar data is also described

Byggnadens klimatpåverkan kan minska med en genomtänkt projekteringsprocess

Idag står byggprocessen av nybyggda hus för lika mycket eller rentav större klimatpåverkan än byggnaders drift under 50 år. Trots det är det ytterst få byggprojekt som arbetar med att minimera byggprocessens energianvändning och klimatpåverkan från hela livscykeln. Det finns inte heller några krav i Boverkets byggregler som styr mot låg klimatpåverkan från byggandet. Men det finns en rad olika möjligheter till förbättring, inte minst för arkitekter.QC 20170123Integrering av livscykeltänkande I bygg- och fastighetssektorn genom beräkning av “inbyggd” energi och klimatpåverka

Byggnadens klimatpåverkan kan minska med en genomtänkt projekteringsprocess

Idag står byggprocessen av nybyggda hus för lika mycket eller rentav större klimatpåverkan än byggnaders drift under 50 år. Trots det är det ytterst få byggprojekt som arbetar med att minimera byggprocessens energianvändning och klimatpåverkan från hela livscykeln. Det finns inte heller några krav i Boverkets byggregler som styr mot låg klimatpåverkan från byggandet. Men det finns en rad olika möjligheter till förbättring, inte minst för arkitekter.QC 20170123Integrering av livscykeltänkande I bygg- och fastighetssektorn genom beräkning av “inbyggd” energi och klimatpåverka

CW Laser radar for combustion diagnostics

A CW-laser radar system developed for combustion diagnostics is described. The system is based on triangulation to attain range information. A portable system has been constructed and here we show some result from measurements in various flames, for example Rayleigh scattering thermometry and monitoring of particle distributions with high temporal and spatial resolution. The concept can equally well be based on pulsed lasers, allowing suppression of background emission through gated detection