title: Milk Powder Deposition in Cross-Flow Heat Exchangers

authors: Englebrecht, R.

abstract: The lack of heat recovery implementation in spray dryer exhausts can be ascribed to difficulties associated with particulate fouling that reduce the thermal performance of these units. The aim of this work is to experimentally characterise the deposition of two brands of skim milk powder (A and B) on a bare tube bank in cross-flow. Results show that the tube powder deposition for powder A reached a maximum at the second row of tubes while for powder B the maximum was at the third row. Analysing the mid diameter of tube deposited particles for powder A showed a separation of particles based on tube row where increasing tube row number into the heat exchanger the deposited particle size was reduced.

text: Milk Powder Deposition in Cross-Flow Heat Exchangers The lack of heat recovery implementation in spray dryer exhausts can be ascribed to difficulties associated with particulate fouling that reduce the thermal performance of these units. The aim of this work is to experimentally characterise the deposition of two brands of skim milk powder (A and B) on a bare tube bank in cross-flow. Results show that the tube powder deposition for powder A reached a maximum at the second row of tubes while for powder B the maximum was at the third row. Analysing the mid diameter of tube deposited particles for powder A showed a separation of particles based on tube row where increasing tube row number into the heat exchanger the deposited particle size was reduced.

year: 2013

title: Metagenome analysis of an extreme microbial symbiosis reveals eurythermal adaptation and metabolic flexibility

authors: Grzymski, Joseph J.

subjects: Epsilonproteobacteria

abstract: Hydrothermal vent ecosystems support diverse life forms, many of which rely on symbiotic associations to perform functions integral to survival in these extreme physicochemical environments. Epsilonproteobacteria, found free-living and in intimate associations with vent invertebrates, are the predominant vent-associated microorganisms. The vent-associated polychaete worm, Alvinella pompejana, is host to a visibly dense fleece of episymbionts on its dorsal surface. The episymbionts are a multispecies consortium of Epsilonproteobacteria present as a biofilm. We unraveled details of these enigmatic, uncultivated episymbionts using environmental genome sequencing. They harbor wide-ranging adaptive traits that include high levels of strain variability analogous to Epsilonproteobacteria pathogens such as Helicobacter pylori, metabolic diversity of free-living bacteria, and numerous orthologs of proteins that we hypothesize are each optimally adapted to specific temperature ranges within the 10–65 °C fluctuations characteristic of the A. pompejana habitat. This strategic combination enables the consortium to thrive under diverse thermal and chemical regimes. The episymbionts are metabolically tuned for growth in hydrothermal vent ecosystems with genes encoding the complete rTCA cycle, sulfur oxidation, and denitrification; in addition, the episymbiont metagenome also encodes capacity for heterotrophic and aerobic metabolisms. Analysis of the environmental genome suggests that A. pompejana may benefit from the episymbionts serving as a stable source of food and vitamins. The success of Epsilonproteobacteria as episymbionts in hydrothermal vent ecosystems is a product of adaptive capabilities, broad metabolic capacity, strain variance, and virulent traits in common with pathogens.

text: Metagenome analysis of an extreme microbial symbiosis reveals eurythermal adaptation and metabolic flexibility Hydrothermal vent ecosystems support diverse life forms, many of which rely on symbiotic associations to perform functions integral to survival in these extreme physicochemical environments. Epsilonproteobacteria, found free-living and in intimate associations with vent invertebrates, are the predominant vent-associated microorganisms. The vent-associated polychaete worm, Alvinella pompejana, is host to a visibly dense fleece of episymbionts on its dorsal surface. The episymbionts are a multispecies consortium of Epsilonproteobacteria present as a biofilm. We unraveled details of these enigmatic, uncultivated episymbionts using environmental genome sequencing. They harbor wide-ranging adaptive traits that include high levels of strain variability analogous to Epsilonproteobacteria pathogens such as Helicobacter pylori, metabolic diversity of free-living bacteria, and numerous orthologs of proteins that we hypothesize are each optimally adapted to specific temperature ranges within the 10–65 °C fluctuations characteristic of the A. pompejana habitat. This strategic combination enables the consortium to thrive under diverse thermal and chemical regimes. The episymbionts are metabolically tuned for growth in hydrothermal vent ecosystems with genes encoding the complete rTCA cycle, sulfur oxidation, and denitrification; in addition, the episymbiont metagenome also encodes capacity for heterotrophic and aerobic metabolisms. Analysis of the environmental genome suggests that A. pompejana may benefit from the episymbionts serving as a stable source of food and vitamins. The success of Epsilonproteobacteria as episymbionts in hydrothermal vent ecosystems is a product of adaptive capabilities, broad metabolic capacity, strain variance, and virulent traits in common with pathogens.

year: 2008

title: He huringa āhuarangi, he huringa ao: A changing climate, a changing world

authors: Awatere, S

subjects: climate change adaptation

abstract: Iwi/hapū (tribe/subtribe) governance institutions are increasingly asserting their rangatiratanga (autonomy) to manage climate change risks and meet the well-being of whānau (family)/ hapū/iwi. Howevere, there is a shortange of specific guidance for whānau/hapū/iwi with respect to climate change adaptation and mitigation. We provide a commentary about risk and uncertainty, knowledge gaps, and options for climate change mitigation and adaptation for whānau/hapū/iwi.

text: He huringa āhuarangi, he huringa ao: A changing climate, a changing world Iwi/hapū (tribe/subtribe) governance institutions are increasingly asserting their rangatiratanga (autonomy) to manage climate change risks and meet the well-being of whānau (family)/ hapū/iwi. Howevere, there is a shortange of specific guidance for whānau/hapū/iwi with respect to climate change adaptation and mitigation. We provide a commentary about risk and uncertainty, knowledge gaps, and options for climate change mitigation and adaptation for whānau/hapū/iwi.

year: 2021-10