Fraunhofer Chalmers Research Centre for Industrial Mathematics
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Insekter för humankonsumtion NÄRINGSVÄRDET I INSEKTER TILLGÄNGLIGA PÅ DEN EUROPEISKA MARKNADEN
No full textInsects for human consumption
The nutritional quality of novel food entering European markets
The rising global demand for meat puts a significant tension on the ecosystem and more sustainable alternative protein sources, which can substitute meat, are warranted. Insects have been suggested to serve as an alternative source to meat that could lead to diminished greenhouse gas emission produced by livestock. Before utilizing insects for food purpose, it is important to know their nutrient content. However, information about the composition of nutrients including macronutrients, vitamins and minerals are lacking for many insects. In the present study, the aim was to increase the knowledge regarding nutritional components in a selection of diverse edible insects. The analyzed components were phytic acid, vitamin E (α- and γ-tocopherol), amino acids, iron, zinc, copper and manganese. These nutrients were analyzed by different techniques including: High-Performance Liquid Chromatography (HPLC), Liquid Chromatography Mass Spectrometry (LCMS) and Atomic Absorption Spectroscopy (AAS). The insects analyzed were termite, buffalo worm, grasshopper, giant water bug, flying termite and yellow mealworm, in a total of eleven different samples. In all samples, the content of phytic acid was below the detection limit of the method (0.1 ppm). The content of α- and γ-tocopherol varied between the different insect species, with the highest content of α-tocopherol (0.556 mg/100g) found in grasshoppers whereas none were found in giant water bugs. In total 18 amino acids were quantified in all the samples and the content of amino acids varied within and between insects. Variations in copper concentration were found in the samples (0.5 - 2.7 mg/100g) as well as in iron concentration (1.9 - 19.6 mg/100g). The samples showed less variation in zinc concentration (3.5 - 4.6 mg/100g) apart from grasshoppers which had significantly higher content (7.6 mg/100 g). For manganese, the concentration found in different species of termites was significantly higher than expected (78 - 268 mg/100g). With exception of termites, based on the identified nutritional components suggest that the insects presented in this study can indeed be recommended as food or be served as a complement to a daily diet. Since the nutritional values varied significantly between several species the obtained data cannot support a general conclusion about nutritional contents in other insect species
Evaluating design alternatives for a complete street in Gothenburg, Sweden, using microscopic simulation
No full textTrain vibrations and site effect estimation Using ambient vibration measurement to estimate amplification of vibrations from trains
No full textTrain induced vibrations are known to cause annoyance and sleeping disorders among people living close to rail roads. This and other problems arising around train vibrations are brought up to date as the current government as well as previous ones suggest building of high speed train routes. The methods, commonly used in Sweden, for predicting levels of train induced vibrations are semi-empirical meaning that a formula is used in which site specific constants require measurements at the site to determine their value.
This thesis aims to study amplification of vibrations whose source are trainpassages. Specifically the fundamental frequency, having a wavelength corresponding to four times the soil depth is subject for the analysis. A method frequently used by seismologists to estimate amplification of earth quakes at certain sites is used. By measuring ambient vibrations with a three-axial accelerometer or geophone and dividing the mean of the two spectra of the horisontal components by that of the vertical,the fundamental frequency, f0, will be indicated by a peak in the resulting spectrum, called the H/V ratio. The method can also, to some extent, estimate the amplification factor at f0.
The effect of f0 on train vibration is studied in three steps. In the first step, measurement results from previous studies are studied with regard to f0, derived from soil depth maps and estimated deformation parameters. For the next step, FEM calculations are carried out studying transfer functions at the surface of a soil deposit with soil depth as parameter. Material parameters are chosen so that the fundamental frequency should appear within the studied frequency range. Also,measurements are performed using the H/V-ratio technique. At a meadow adjacent to a rail road, ambient vibrations are measured as well as vibrations from trains passing by close to and further away from the rail in order to obtain a transfer function. The spectra obtained from the train passages at each point, as well as the transfer functions, are compared with the corresponding H/V-ratio to see if there is amplification at f0.
The results from the literature study indicate that f0 does play a role in that sense that wave propagation below that frequency cannot occur,theoretically. The study of previously made measurements confirms this as sites with a high estimated f0 are not subject to high vibration levels. The FEM calculations also show a dependency of transmitted wave energy on soil depth in that sense that there is a frequency below which there is very weak wave propagation. The response spectra at 10 m and 40 m as well as the transfer function from the source to the field point also inherit a peak at this frequency which is one third octave lower than the expected fundamental frequency, concerning the vertical component.
As for the measurements, no conclusions can be made as the measurement equipment used was not sensitive enough to capture ambience. Nevertheless, the peaks in the H/V-ratio, although weak, appear at the same frequencies as those at which amplification occur in the measurement of train passages. It cannot be concluded, but also not excluded, that the difference in the measured spectra at the different points depend on f0
Evaluation of usage of plasma torches in cement production
No full textThis work developed and evaluated a heat transfer model for the cement production process,
focusing on the rotary kiln but also including the cyclone tower. The purpose of the
model is to evaluate the implementation of new heat sources, in this case plasma torches.
The rotary kiln model is discretised in angular, axial and radial directions and describes
the heat transfer characteristics of the gas, walls, and material in the kiln. The heat
transfer includes a description of the radiation, convection, and conduction between the
cells. The model also includes the flow of gas and material as well as the mixing within
the bed due to the rotation of the kiln. The heat transfer in the cyclone tower is assumed
efficient and the units are described by simple heat and mass balances.
The model is validated against two distinctive cases of operational conditions of production
line 8 at Cementa in Slite. An important part of the work was to define and collect
data for the model validation. The model shows good agreement with the measured wall
temperatures, considering the outside cooling is not included in the model. The results,
such as product temperature and heat absorbed by the bed, are consistent with gathered
data using a reasonable gas temperature profile and found equilibrium data.
The requirements of the material to reach the desired quality is key to the process and
emphasis is put on how to incorporate these requirements into the heat transfer model.
The work concluded that a detailed description of the reaction kinetics and heat of reaction
is difficult to include in the model due to its complexity and the maturity of the
field. Instead this work recommends that seven heating zones are defined through the
kiln where the required residence time and heat is determined externally by experiments
or detailed modelling of the cement chemistry. In this way the heat transfer model and
bed model could in concert and in an iterative manner decide the required temperature
profiles and conditions (e.g. gas concentrations or particle loads) of the gas as well as the
dimensions of the kiln to achieve the desired product temperature.
The model was applied to evaluate the implementation of a plasma torch in the cement
kiln. Compared to today’s combustion of coal and other fuels, the plasma torch will
decrease the particle load and change the gas composition. The result shows that significantly
(400°C) higher gas temperatures are required in the kiln with plasma torch
operation, to reach the desired bed temperatures. Furthermore, the example highlights
the importance of being able the predict the development of the gas temperature profile
through the kiln. Here the work recommend future work with measuring or detailed
modelling (CFD) of the gas phase temperature
