Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
347
result(s) for
"Palmer, Graham"
Sort by:
A Biophysical Perspective of IPCC Integrated Energy Modelling
The following article conducts an analysis of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5), specifically in relation to Integrated Assessment Models (IAMs). We focus on the key drivers of economic growth, how these are derived and whether IAMs properly reflect the underlying biophysical systems. Since baseline IAM scenarios project a three- to eight-fold increase in gross domestic product (GDP)-per-capita by 2100, but with consumption losses of only between 3–11%, strong mitigation seems compatible with economic growth. However, since long-term productivity and economic growth are uncertain, they are included as exogenous parameters in IAM scenarios. The biophysical economics perspective is that GDP and productivity growth are in fact emergent parameters from the economic-biophysical system. If future energy systems were to possess worse biophysical performance characteristics, we would expect lower productivity and economic growth, and therefore, the price of reaching emission targets may be significantly costlier than projected. Here, we show that IAMs insufficiently describe the energy-economy nexus and propose that those key parameters are integrated as feedbacks with the use of environmentally-extended input-output analysis (EEIOA). Further work is required to build a framework that can supplement and support IAM analysis to improve biophysical rigour.
Journal Article
Household Solar Photovoltaics: Supplier of Marginal Abatement, or Primary Source of Low-Emission Power?
With declining system costs and assuming a short energy payback period, photovoltaics (PV) should, at face value, be able to make a meaningful contribution to reducing the emission intensity of Australia’s electricity system. However, solar is an intermittent power source and households remain completely dependent on a “less than green” electricity grid for reliable electricity. Further, much of the energy impact of PV occurs outside of the conventional boundaries of PV life-cycle analyses (LCA). This paper examines these competing observations and explores the broader impacts of a high penetration of household PV using Melbourne, Victoria as a reference. It concludes that in a grid dominated by unsequestered coal and gas, PV provides a legitimate source of emission abatement at high, but declining costs, with the potential for network and peak demand support. It may be technically possible to integrate a high penetration of PV, but the economic and energy cost of accommodating high-penetration PV erodes much of the benefits. Future developments in PV, storage, and integration technologies may allow PV to take on a greater long term role, but in the time horizon usually discussed in climate policy, a large-scale expansion of household PV may hinder rather than assist deep cuts to the emission intensity of Australia’s electricity system.
Journal Article
Application of Raman Spectroscopy and Micro‐Indentation to Micro‐Map the Path and Boundary of NaOCI‐Induced Dentine Collagen Changes in an Ex‐Vivo Root Canal Irrigation Model
Objectives To apply Raman spectroscopy and micro‐indentation to micro‐map the path and boundary of NaOCl‐induced dentine collagen changes in an ex‐vivo root canal irrigation model. Material and Methods Root canals of extracted single‐rooted teeth were prepared and irrigated with NaOCl or saline. Four teeth (NaOCl = 3; saline = 1) embedded in epoxy resin and sectioned transversely into discs were Raman‐analyzed on coronal surfaces from inter‐ and intra‐tubular dentine in 4 quadrants over 12, 24, and 48 min‐acquisition times. Eight additional teeth stratified by root maturity, irrigated with NaOCl (n = 7) or saline (n = 1), sectioned transversely and then embedded, were Raman‐analyzed on apical surfaces at 18 equidistant (50 μm) points/quadrant for Amide bands. Micro‐indentation of the corresponding facing sectioned surface was correlated with Amide band changes. Generalized linear and non‐linear regression models were used for data analysis. Results Spectral quality at 24/48 min was similar and better than at 12 min. Inter‐tubular but not intra‐tubular spectra were masked by fluorescence. Spectral features near the canal lumen ( < 500 μm) showed more significant collagen alteration and varied by tooth/quadrant but decreasingly towards the cemento‐dentinal junction (CDJ) without a clear boundary. Significant (p < 0.0001) changes in Amide I/III bands up to 300 μm from the canal and were accompanied by deeper corresponding indentations upto 200 μm. Canal instrumentation had a significant (p < 0.0001) effect on both Amide‐I and Amide‐III bands. Conclusions NaOCl altered dentinal collagen and reduced microhardness but varied with quadrants/teeth, without a definable boundary; collagen changes were obvious within 300 μm of the canal and microhardness changes within 200 μm but evident to a decreasing extent up to the CDJ.
Journal Article
Renewables rise above fossil fuels
Fossil fuels have long been considered cheap compared to other energy sources, such as solar or wind. Researchers now show that with easy-to-access fossil fuels running out, the more productive renewables may be approaching and even exceeding oil and gas in net energy generation in many cases.
Journal Article
Mass Spectrometric Determination of Dioxygen Bond Splitting in the \Peroxy\ Intermediate of Cytochrome c Oxidase
The \"peroxy\" intermediate (P form) of bovine cytochrome c oxidase was prepared by reaction of the two-electron reduced mixed-valence CO complex with 18O2 after photolytic removal of CO. The water present in the reaction mixture was recovered and analyzed for 18O enrichment by mass spectrometry. It was found that approximately one oxygen atom (18O) per one equivalent of the P form was present in the bulk water. The data show that the oxygen-oxygen dioxygen bond is already broken in the P intermediate and that one oxygen atom can be readily released or exchanged with the oxygen of the solvent water.
Journal Article
Does Energy Efficiency Reduce Emissions and Peak Demand? A Case Study of 50 Years of Space Heating in Melbourne
This paper examines the relationship between space heating energy efficiency and two related but distinct measures; greenhouse mitigation, and peak demand. The historic role of Melbourne’s space heating provides an opportunity to assess whether improvements in energy efficiency lead to sustained reductions in energy consumption or whether rebound factors “take back” efficiency gains in the long run. Despite significant and sustained improvements in appliance efficiency, and the thermal efficiency of new building fabrics, the per-capita heating energy consumption has remained remarkably stable over the past 50 years. Space heating efficiency is bound up with notions of comfort, sufficiency and lifestyle, and the short-run gains from efficiency become incorporated into a new set of norms. It is this evolution of cultural norms that reconciles the contradiction between the short-run gains from efficiency measures, with the efficiency rebound that becomes evident over the long-term. The related, but distinct peak demand measure can be influenced by efficiency measures, but energy efficiency measures will not alter the requirement for large-scale conventional energy to provide affordable and reliable winter heating.
Journal Article
The effects of lubrication on the static frictional resistance of orthodontic brackets
Difficulties are experienced with the collection and storage of freshly harvested human saliva to use as a lubricant for the laboratory testing of the frictional resistance of orthodontic brackets. In order to overcome these difficulties, researchers have suggested the use of saliva substitutes due to their ease of storage and consistency of properties throughout testing. Others have criticized the use of artificial saliva and prefer the dry state. The present study aimed to compare the effects of human saliva and an artificial saliva (Saliva Orthana®) with the dry state for the static frictional resistance testing of orthodontic brackets.
The static frictional resistance and the lubrication effect of human saliva, Saliva Orthana® and the dry state were investigated using upper central incisor stainless steel brackets and 0.019 x 0.025 inch stainless steel wires in an Instron® Universal Testing Machine. Static frictional resistance was measured 100 times for each lubrication state. The ‘wettability’ of each lubricant was determined by measuring the contact angle against a stainless steel surface using the CAM 200 Optical Contact Angle Meter. Distilled water acted as a control. The viscosity of each lubricant and their Newtonian or non-Newtonian fluid behaviour under stress was measured using a Brookfield Digital Rheometer Model DV-III+.
The differences in static frictional resistance between the three lubricants when examined as a group did not reach statistical significance (
= 0.059). The difference between human saliva and Saliva Orthana® was considered to be of weak statistical significance and clinical relevance (Means: 0.917 N; 0.819 N:
= 0.053). Human saliva and the dry state revealed very similar mean frictional values (Means: 0.917 N; 0.875 N:
= 0.932). The contact angle tests indicated a statistically significant difference between the lubricants with Saliva Orthana® having the smallest angle and therefore the highest ‘wettability’. Human saliva had the highest initial viscosity and behaved as a non-Newtonian fluid, contrasting with Saliva Orthana® and distilled water, both of which behaved as Newtonian fluids.
The current results indicate that artificial saliva is not an ideal alternative to human saliva for friction testing in the laboratory. The results therefore support the proposal that, when human saliva is not available, it may be preferable to test orthodontic frictional resistance in the dry state.
Journal Article
Novel sol–gel preparation of (P2O5)0.4–(CaO)0.25–(Na2O)X–(TiO2)(0.35−X) bioresorbable glasses (X = 0.05, 0.1, and 0.15)
Quaternary phosphate-based glasses in the P
2
O
5
–CaO–Na
2
O–TiO
2
system with a fixed P
2
O
5
and CaO content of 40 and 25 mol% respectively have been successfully synthesised via sol–gel method and bulk, transparent samples were obtained. The structure, elemental proportion, and thermal properties of stabilised sol–gel glasses have been characterised using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX),
31
P nuclear magnetic resonance (
31
P NMR), titanium K-edge X-ray absorption near-edge structure (XANES), fourier transform infrared (FTIR) spectroscopy, and differential thermal analysis (DTA). The XRD results confirmed the amorphous nature for all stabilized sol–gel derived glasses. The EDX result shows the relatively low loss of phosphorus during the sol–gel process and Ti K-edge XANES confirmed titanium in the glass structure is in mainly six-fold coordination environment. The
31
P NMR and FTIR results revealed that the glass structure consist of mainly Q
1
and Q
2
phosphate units and the Ti
4+
cation was acting as a cross-linking between phosphate units. In addition DTA results confirmed a decrease in the glass transition and crystallisation temperature with increasing Na
2
O content. Ion release studies also demonstrated a decrease in degradation rates with increasing TiO
2
content therefore supporting the use of these glasses for biomedical applications that require a degree of control over glass degradation. These sol–gel glasses also offer the potential to incorporate proactive molecules for drug delivery application due to the low synthesis temperature employed.
Journal Article