66 research outputs found

    The renewable energy and energy efficiency potential of Waitakere City : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Technology in Energy Management at Massey University

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    Electricity restrictions and blackouts have occurred in Waitakere City in the past and are likely to occur again in the future unless the city can become more self reliant by meeting, at least in part, the increasing energy requirements for what is one of the fastest growing cities in New Zealand. In this study the potentials for energy conservation, energy efficiency and renewable energy resources have been broadly quantified and assessed using desktop analysis of publicly available data for stationary final use energy systems (i.e. excluding transportation) within the geographical area of Waitakere City and adjoining waters. It was found that energy efficiency and energy conservation measures can consistently and predictably achieve overall energy savings and reduce daily and seasonal peak demand. The best renewable energy resource potential exists with solar and geothermal for heating applications and wave, offshore and inshore wind and tidal currents for electricity generation. There is very limited potential for hydro and bioenergy systems beyond what already exists. PV solar and land based wind power generation are currently only feasible for limited off-grid applications. This scoping study confirms the achievability of the vision expressed in Waitakere City Council's "Long Term Council Community Plan" (LTCCP) that by 2020 " Waitakere City will be an energy cell, not an energy sink. Air quality supports good health". A range of flagship projects have been identified to progress the achievement of this vision. Waitakere City Council can use this report as part of the development of a comprehensive energy management plan

    Dynamic Contrast-enhanced MR Imaging of Carotid Atherosclerotic Plaque: Model Selection, Reproducibility, and Validation.

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    Purpose: compare four known pharmacokinetic models for their ability to describe dynamic contrast material-enhanced magnetic resonance (MR) imaging of carotid atherosclerotic plaques, to determine reproducibility, and to validate the results with histologic findings. Materials and Methods: The study was approved by the institutional medical ethics committee. Written informed consent was obtained from all patients. Forty-five patients with 30%-99% carotid stenosis underwent dynamic contrast-enhanced MR imaging. Plaque enhancement was measured at 16 time points at approximately 25-second image intervals by using a gadolinium-based contrast material. Pharmacokinetic parameters (volume transfer constant, Ktrans; extracellular extravascular volume fraction, v e; and blood plasma fraction, v p) were determined by fitting a two-compartment model to plaque and blood gadolinium concentration curves. The relative fit errors and parameter uncertainties were determined to find the most suitable model. Sixteen patients underwent imaging twice to determine reproducibility. Carotid endarterectomy specimens from 16 patients who were scheduled for surgery were collected for histologic validation. Parameter uncertainties were compared with the Wilcoxon signed rank test. Reproducibility was assessed by using the coefficient of variation. Correlation with histologic findings was evaluated with the Pearson correlation coefficient. Results: The mean relative fit uncertainty (+/- standard error) for Ktrans was 10% +/- 1 with the Patlak model, which was significantly lower than that with the Tofts (20% +/- 1), extended Tofts (33% +/- 3), and extended graphical (29% +/- 3) models (P <.001). The relative uncertainty for v p was 20% 6 2 with the Patlak model and was significantly higher with the extended Tofts (46% +/- 9) and extended graphical (35% +/- 5) models (P <.001). The reproducibility (coefficient of variation) for the Patlak model was 16% for Ktrans and 26% for v p. Significant positive correlations were found between Ktrans and the endothelial microvessel content determined on histologic slices (Pearson r = 0.72, P = .005). Conclusion: The Patlak model is most suited for describing carotid plaque enhancement. Correlation with histologic findings validated Ktrans as an indicator of plaque microvasculature, and the reproducibility of Ktrans was good. (C)RSNA, 201

    Gas mixing enhanced by power modulations in atmospheric pressure microwave plasma jet

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    Microwave plasma jet operating in atmospheric pressure argon was power modulated by audio frequency sine envelope in the 10^2 W power range. Its effluent was imaged using interference filters and ICCD camera for several different phases of the modulating signal. The combination of this fast imaging with spatially resolved optical emission spectroscopy provides useful insights into the plasmachemical processes involved. Phase-resolved schlieren photography was performed to visualize the gas dynamics. The results show that for higher modulation frequencies the plasma chemistry is strongly influenced by formation of transient flow perturbation resembling a vortex during each period. The perturbation formation and speed are strongly influenced by the frequency and power variations while they depend only weakly on the working gas flow rate. From application point of view, the perturbation presence significantly broadened lateral distribution of active species, effectively increasing cross-sectional area suitable for applications

    The Ser82 RAGE variant affects lung function and serum RAGE in smokers and sRAGE production in vitro

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    Introduction: Genome-Wide Association Studies have identified associations between lung function measures and Chronic Obstructive Pulmonary Disease (COPD) and chromosome region 6p21 containing the gene for the Advanced Glycation End Product Receptor (AGER, encoding RAGE). We aimed to (i) characterise RAGE expression in the lung, (ii) identify AGER transcripts, (iii) ascertain if SNP rs2070600 (Gly82Ser C/T) is associated with lung function and serum sRAGE levels and (iv) identify whether the Gly82Ser variant is functionally important in altering sRAGE levels in an airway epithelial cell model. Methods: Immunohistochemistry was used to identify RAGE protein expression in 26 human tissues and qPCR was used to quantify AGER mRNA in lung cells. Gene expression array data was used to identify AGER expression during lung development in 38 fetal lung samples. RNA-Seq was used to identify AGER transcripts in lung cells. sRAGE levels were assessed in cells and patient serum by ELISA. BEAS2B-R1 cells were transfected to overexpress RAGE protein with either the Gly82 or Ser82 variant and sRAGE levels identified. Results: Immunohistochemical assessment of 6 adult lung samples identified high RAGE expression in the alveoli of healthy adults and individuals with COPD. AGER/RAGE expression increased across developmental stages in human fetal lung at both the mRNA (38 samples) and protein levels (20 samples). Extensive AGER splicing was identified. The rs2070600T (Ser82) allele is associated with higher FEV1, FEV1/FVC and lower serum sRAGE levels in UK smokers. Using an airway epithelium model overexpressing the Gly82 or Ser82 variants we found that HMGB1 activation of the RAGE-Ser82 receptor results in lower sRAGE production. Conclusions: This study provides new information regarding the expression profile and potential role of RAGE in the human lung and shows a functional role of the Gly82Ser variant. These findings advance our understanding of the potential mechanisms underlying COPD particularly for carriers of this AGER polymorphism

    Proteomic identification and characterization of hepatic glyoxalase 1 dysregulation in non-alcoholic fatty liver disease

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    Background: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. However, its molecular pathogenesis is incompletely characterized and clinical biomarkers remain scarce. The aims of these experiments were to identify and characterize liver protein alterations in an animal model of early, diet-related, liver injury and to assess novel candidate biomarkers in NAFLD patients. Methods: Liver membrane and cytosolic protein fractions from high fat fed apolipoprotein E knockout (ApoE−/−) animals were analyzed by quantitative proteomics, utilizing isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Differential protein expression was confirmed independently by immunoblotting and immunohistochemistry in both murine tissue and biopsies from paediatric NAFLD patients. Candidate biomarkers were analyzed by enzyme-linked immunosorbent assay in serum from adult NAFLD patients. Results: Through proteomic profiling, we identified decreased expression of hepatic glyoxalase 1 (GLO1) in a murine model. GLO1 protein expression was also found altered in tissue biopsies from paediatric NAFLD patients. In vitro experiments demonstrated that, in response to lipid loading in hepatocytes, GLO1 is first hyperacetylated then ubiquitinated and degraded, leading to an increase in reactive methylglyoxal. In a cohort of 59 biopsy-confirmed adult NAFLD patients, increased serum levels of the primary methylglyoxal-derived advanced glycation endproduct, hydroimidazolone (MG-H1) were significantly correlated with body mass index (r = 0.520, p < 0.0001). Conclusion: Collectively these results demonstrate the dysregulation of GLO1 in NAFLD and implicate the acetylation-ubquitination degradation pathway as the functional mechanism. Further investigation of the role of GLO1 in the molecular pathogenesis of NAFLD is warranted. Keywords: Non-alcoholic fatty liver disease, Glyoxalase, Methylglyoxal, Proteomics, iTRA

    Plasma–liquid interactions: a review and roadmap

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    Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on non-equilibrium plasmas
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