Sensor characterization for multisensor odor-discrimination system

In recent years, with the advent of new and cheaper sensors, the use of olfactory systems in homes, industries, and hospitals has a new start. Multisensor systems can improve the ability to distinguish between complex mixtures of volatile substances. To develop multisensor systems that are accurate and reliable, it is important to take into account the anomalies that may arise because of electronic instabilities, types of sensors, and air flow. In this approach, 32 metal oxide semiconductor sensors of 7 different types and operating at different temperatures have been used to develop a multisensor olfactory system. Each type of sensor has been characterized to select the most suitable temperature combinations. In addition, a prechamber has been designed to ensure a good air flow from the sample to the sensing area. The multisensor system has been tested with good results to perform multidimensional information detection of two fruits, based on obtaining sensor matrix data, extracting three features parameters from each sensor curve and using these parameters as the input to a pattern recognition system. (C) 2012 Elsevier B.V. All rights reserved.Cueto Belchí, AD.; Rothpfeffer, N.; Pelegrí Sebastiá, J.; Chilo, J.; García Rodríguez, D.; Sogorb Devesa, TC. (2013). Sensor characterization for multisensor odor-discrimination system. Sensors and Actuators A: Physical. 191:68-72. doi:10.1016/j.sna.2012.11.039S687219

From wood to waste and waste to wood

In this thesis the flow of elements from the forest to the pulp mill and the possibility to recycle nutrients in solid pulp-mill residues back to the forest have been studied. To get improved estimations of element removal at whole tree harvesting (WTH), the changing element concentrations with changing diameter of Picea abies stems were investigated. The results showed that element concentration for Ba, Cd and Pb in wood and Ba, Ca, Cd, Co, Mn, Sr and Zn for bark were significantly positively correlated with diameter whereas Cu, Fe, K, Mg and P in wood and Cr, Cu, Fe, K, Na, Ni and P in bark were negatively correlated. In order to test the recycling potential of different solid waste products a mass-balance study was made for three pulp mills in Sweden. Bark-ash had the best composition of plant nutrients but high concentrations of some heavy metals. GLD and lime mud contain less nutrients, except Ca and Mg. Mixing of bark-ash and GLD can be a way to improve nutrient composition and achive a high degree of recycling. Pelleting and heat treatment of ash and GLD was evaluated as a way to get stable pellets with long-lasting effect in the field. Pelleting decreased the reactivity of the pellets, resulting in less effect on pH and low leaching rates of elements. The heating of ash pellets gave a decreased surface area and decreased reactivity in the soil. Mixing bark-ash with GLD resulted in an increased leaching of DOC and DON. Heating of GLD pellets increased pH significantly in the leachate due to formation and subsequent dissolution of MgO. The pre-treatments did not decrease the rapid leaching of K and Na from the pellets. There was no tendency for increased N or C mineralisation in the mor layer for any pellet type. Thus, when pure ash pellets are used, the risk of high N losses from mor layers in podsolised spruce stands after ash application is small, even under disturbed conditions. However, more caution should be taken with mixtures containing GLD, which show a greater interaction with the mor. Heating of GLD pellets should be avoided

Leverantörsval för ett mekanikföretag

Problembakgrund: Val av leverantör är det som anses påverkar ett företags produktkvalitet mest. När man söker nya leverantörer är det viktigt att veta vilka typer av kvaliteter man önskar hos dessa och vilken relation man vill ha till dem. Att ha ett mindre antal leverantörer skapar logistiska fördelar. Syfte: Syftet med studien är att ta fram en mall för hantering av leverantörer för mindre konkurrenskraftiga mekanikföretag som ämnar öka sin leverantörssamverkan med fokus på bedömning och val.  Metod: För att uppnå syftet med studien kommer vi använda oss av en kvalitativ metod med abduktiv ansats. Fokus kommer ligga på en fallstudie som är uppdelad i tre delar. Resultat: Val av leverantör har skett med hjälp av insamlad data från intervjuer och enkäter. Ett steg i det planerade utförandet av fallstudien uteblev. Slutsats: Syftet med studien anses ha uppfyllts efter att val av leverantör har gjorts efter leverantörsbedömning i fallstudien. Studien har bidragit med en mall för mindre konkurrenskraftiga mekanikföretag som önskar se över sina leverantörsmöjligheter

Leverantörsval för ett mekanikföretag

Problembakgrund: Val av leverantör är det som anses påverkar ett företags produktkvalitet mest. När man söker nya leverantörer är det viktigt att veta vilka typer av kvaliteter man önskar hos dessa och vilken relation man vill ha till dem. Att ha ett mindre antal leverantörer skapar logistiska fördelar. Syfte: Syftet med studien är att ta fram en mall för hantering av leverantörer för mindre konkurrenskraftiga mekanikföretag som ämnar öka sin leverantörssamverkan med fokus på bedömning och val.  Metod: För att uppnå syftet med studien kommer vi använda oss av en kvalitativ metod med abduktiv ansats. Fokus kommer ligga på en fallstudie som är uppdelad i tre delar. Resultat: Val av leverantör har skett med hjälp av insamlad data från intervjuer och enkäter. Ett steg i det planerade utförandet av fallstudien uteblev. Slutsats: Syftet med studien anses ha uppfyllts efter att val av leverantör har gjorts efter leverantörsbedömning i fallstudien. Studien har bidragit med en mall för mindre konkurrenskraftiga mekanikföretag som önskar se över sina leverantörsmöjligheter

Biochar as a Fuel: 2. Significant Differences in Fuel Quality and Ash Properties of Biochars from Various Biomass Components of Mallee Trees

This study shows the significant differences in the fuel quality and ash properties of biochars produced from the slow pyrolysis of various biomass components (leaf, wood, and bark). The objective is to identify which component is likely to cause problems in subsequent utilization processes if biochar produced from various components of mallee trees is used as a fuel. It is found that the pyrolysis of different biomass components produced biochars with distinct characteristics, largely because of the differences in the biological structure of these components. Leaf biochar showed the poorest grindability, possibly because of the presence of abundant tough oil glands in leaf. Even for the biochar prepared from the pyrolysis of leaf at 800 °C, the oil gland enclosures remained largely intact after grinding. Biochars produced from leaf, bark, and wood components also have significant differences in ash properties. Even with low ash content, wood biochars have low Si/K and Ca/K ratios, suggesting that these biochars may have a high slagging propensity, in comparison to bark and leaf biochars. It appears that, in the utilization of biochar prepared from mallee biomass, the grindability is likely to be limited by the leaf fraction while ash-related problems could be due to the wood and bark components