Michael Savage - Academia.edu (original) (raw)

Papers by Michael Savage

Research paper thumbnail of Stagnation–saddle points and flow patterns in Stokes flow between contra-rotating cylinders

Journal of Fluid Mechanics, 1998

The steady flow is considered of a Newtonian fluid, of viscosity μ, between contra-rotating cylin... more The steady flow is considered of a Newtonian fluid, of viscosity μ, between contra-rotating cylinders with peripheral speeds U1 and U2. The two-dimensional velocity field is determined correct to O(H0/2R)1/2, where 2H0 is the minimum separation of the cylinders and R an ‘averaged’ cylinder radius. For flooded/moderately starved inlets there are two stagnation–saddle points, located symmetrically about the nip, and separated by quasi-unidirectional flow. These stagnation–saddle points are shown to divide the gap in the ratio U1[ratio ]U2 and arise at [mid ]X[mid ]=A where the semi-gap thickness is H(A) and the streamwise pressure gradient is given by dP/dX =μ(U1+U2)/H2(A). Several additional results then follow.(i) The effect of non-dimensional flow rate, λ: A2=2RH0(3λ−1) and so the stagnation–saddle points are absent for λ<1/3, coincident for λ=1/3 and separated for λ>1/3.(ii) The effect of speed ratio, S=U1/U2: stagnation–saddle points are located on the boundary of recircula...

Research paper thumbnail of Evaporation measurement comparisons and advective influences using Bowen ratio, lysimetric and eddy correlation methods

Research paper thumbnail of Evaporation Measurement above Vegetated Surfaces Using Micrometeorological Techniques

Research paper thumbnail of Stent thrombosis incidence in a quaternary Australian centre

Heart, Lung and Circulation

Research paper thumbnail of Transcatheter aortic-valve replacement - is there a sex difference?

Heart, Lung and Circulation

Research paper thumbnail of Outcomes of patients with chronic lung disease receiving TAVR in a prospective database

Heart, Lung and Circulation

Research paper thumbnail of PostHarvest Vapour Heat Treatment of Hass and Fuerte Avocado for the 1997 Season

In an attempt to extend storage life, Hass and Fuerte avocado (Persea Americana Mill) fruit were ... more In an attempt to extend storage life, Hass and Fuerte avocado (Persea Americana Mill) fruit were exposed to post-harvest vapour heat treatments of varying duration and temperature. The vapour heat treatment temperature regimes were 36, 38, 40 and 42°C for durations of 1, 2, 4 and 8 hours each. On removal from cold storage fruit were evaluated for firmness, and ripened at room temperature. Ripe fruit were evaluated for heat/cold damage, days to ripening, weight loss and physiological disorders. These experiments were conducted during the 1996 and 1997 Fuerte and Hass avocado seasons.

Research paper thumbnail of Surface layer scintillometry for estimating the sensible heat flux component of the surface energy balance

Research paper thumbnail of The research outputs: catchment runoff and river flows

Research paper thumbnail of Optical coherence tomography findings in definite stent thrombosis

Heart, Lung and Circulation

Research paper thumbnail of Age is no barrier to transcather aortic-valve replacement

Heart, Lung and Circulation

Research paper thumbnail of Peripheral access site vascular complications in Transcatheter Aortic-Valve Replacement (TAVR)

Heart, Lung and Circulation

Research paper thumbnail of Description and sensitivity analysis of a model (SprayAid) for timing fungicide applications for maize grey leaf spot control

South African Journal of Plant and Soil

Research paper thumbnail of Theory and practice of evaporation measurement, with special focus on surface layer scintillometry as an operational tool for the estimation of spatially averaged evaporation

Report to the Water Research Commission on the project "Implementation of bichromatic scintillati... more Report to the Water Research Commission on the project "Implementation of bichromatic scintillation as an operational tool for the estimation of spatially averaged evaporation"

Research paper thumbnail of Ein Modell des Druckvorganges: Der rechnerische Ansatz

Research paper thumbnail of Testing Fog-Water Collection along the Eastern Escarpment of Eritrea

Fog is considered as an alternative water resource for fresh water in the eastern escarpment of E... more Fog is considered as an alternative water resource for fresh water in the eastern escarpment of Eritrea. This area is bestowed with high-altitude dense fog, which is formed during the uphill movement of adiabatically cooled humid air masses from the Red Sea. A pilot project was implemented in 2007 in the villages of Arborobue and Nefasit where the high fog-water yields were measured during the fog-period (from November to March), actually the dry season. In each village, ten Large Fog Collectors (LFC, each 40 m 2) were installed through the funds of Water Foundation (Germany), technical assistance from FogQuest (Canada) and with full engagement of the local implementing partners (Water Resources Department, Zonal Administrations, the beneficiary communities, and Vision Eritrea). 1. Background Eritrea is located in the horn of Africa and it has mostly arid and semi arid climate with about 70% of its land area classified as hot and arid receiving an average annual rainfall of less tha...

Research paper thumbnail of A grazing clock for measurement of time spent grazing by cattle

To date, time spent grazing has been measured most successfully using an electronic grazing clock... more To date, time spent grazing has been measured most successfully using an electronic grazing clock. Difficulties experienced with this clock however, were that temperature and stage in the life of the batteries affected the readings. Further, periods of grazing shorter than the units of time registered by the clock could not be recorded. This paper describes the construction, operation and testing of a grazing clock designed to overcome these problems. Uittreksel Tyd bestee aan beweiding is tot dusver mees suksesvol gemeet met ‘n elektroniese weidingshorlosie. Probleme is egter met hierdie horlosie teegekom. Lesings was nie konstant met verandering in temperatuur of met da/ing in batterykrag nie. Periodes van beweiding wat korter was as die eenhede geregistreerbaar deur die horlosie kon ook nie bepaal word nie. Hierdie referaat beskryf die konstruksie, gebruik en toetsing van ‘n weidingshorlosie ontwerp om hierdie probleme uit te skakel.

Research paper thumbnail of Comparison of sensible heat flux as measured by surface layer scintillometer and eddy covariance methods under different atmospheric stability conditions

Research paper thumbnail of Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Trans-catheter Aortic Valve Replacement

Heart, Lung and Circulation, 2015

Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury ... more Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality. Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed. Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity. Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

Research paper thumbnail of The effect of a trash blanket on the energy balance of a sugarcane crop: preliminary results

Although crop responses to plant residue layers (trash blanket) are well documented, mechanisms a... more Although crop responses to plant residue layers (trash blanket) are well documented, mechanisms are poorly understood. The partitioning of the available energy at the crop surface is important, as it affects the microclimate and drives processes such as crop water use and growth. This communication gives preliminary results of attempts to quantify the impact of a trash blanket on the energy balance and its effects on crop microclimate, water use and growth.

Research paper thumbnail of Stagnation–saddle points and flow patterns in Stokes flow between contra-rotating cylinders

Journal of Fluid Mechanics, 1998

The steady flow is considered of a Newtonian fluid, of viscosity μ, between contra-rotating cylin... more The steady flow is considered of a Newtonian fluid, of viscosity μ, between contra-rotating cylinders with peripheral speeds U1 and U2. The two-dimensional velocity field is determined correct to O(H0/2R)1/2, where 2H0 is the minimum separation of the cylinders and R an ‘averaged’ cylinder radius. For flooded/moderately starved inlets there are two stagnation–saddle points, located symmetrically about the nip, and separated by quasi-unidirectional flow. These stagnation–saddle points are shown to divide the gap in the ratio U1[ratio ]U2 and arise at [mid ]X[mid ]=A where the semi-gap thickness is H(A) and the streamwise pressure gradient is given by dP/dX =μ(U1+U2)/H2(A). Several additional results then follow.(i) The effect of non-dimensional flow rate, λ: A2=2RH0(3λ−1) and so the stagnation–saddle points are absent for λ<1/3, coincident for λ=1/3 and separated for λ>1/3.(ii) The effect of speed ratio, S=U1/U2: stagnation–saddle points are located on the boundary of recircula...

Research paper thumbnail of Evaporation measurement comparisons and advective influences using Bowen ratio, lysimetric and eddy correlation methods

Research paper thumbnail of Evaporation Measurement above Vegetated Surfaces Using Micrometeorological Techniques

Research paper thumbnail of Stent thrombosis incidence in a quaternary Australian centre

Heart, Lung and Circulation

Research paper thumbnail of Transcatheter aortic-valve replacement - is there a sex difference?

Heart, Lung and Circulation

Research paper thumbnail of Outcomes of patients with chronic lung disease receiving TAVR in a prospective database

Heart, Lung and Circulation

Research paper thumbnail of PostHarvest Vapour Heat Treatment of Hass and Fuerte Avocado for the 1997 Season

In an attempt to extend storage life, Hass and Fuerte avocado (Persea Americana Mill) fruit were ... more In an attempt to extend storage life, Hass and Fuerte avocado (Persea Americana Mill) fruit were exposed to post-harvest vapour heat treatments of varying duration and temperature. The vapour heat treatment temperature regimes were 36, 38, 40 and 42°C for durations of 1, 2, 4 and 8 hours each. On removal from cold storage fruit were evaluated for firmness, and ripened at room temperature. Ripe fruit were evaluated for heat/cold damage, days to ripening, weight loss and physiological disorders. These experiments were conducted during the 1996 and 1997 Fuerte and Hass avocado seasons.

Research paper thumbnail of Surface layer scintillometry for estimating the sensible heat flux component of the surface energy balance

Research paper thumbnail of The research outputs: catchment runoff and river flows

Research paper thumbnail of Optical coherence tomography findings in definite stent thrombosis

Heart, Lung and Circulation

Research paper thumbnail of Age is no barrier to transcather aortic-valve replacement

Heart, Lung and Circulation

Research paper thumbnail of Peripheral access site vascular complications in Transcatheter Aortic-Valve Replacement (TAVR)

Heart, Lung and Circulation

Research paper thumbnail of Description and sensitivity analysis of a model (SprayAid) for timing fungicide applications for maize grey leaf spot control

South African Journal of Plant and Soil

Research paper thumbnail of Theory and practice of evaporation measurement, with special focus on surface layer scintillometry as an operational tool for the estimation of spatially averaged evaporation

Report to the Water Research Commission on the project "Implementation of bichromatic scintillati... more Report to the Water Research Commission on the project "Implementation of bichromatic scintillation as an operational tool for the estimation of spatially averaged evaporation"

Research paper thumbnail of Ein Modell des Druckvorganges: Der rechnerische Ansatz

Research paper thumbnail of Testing Fog-Water Collection along the Eastern Escarpment of Eritrea

Fog is considered as an alternative water resource for fresh water in the eastern escarpment of E... more Fog is considered as an alternative water resource for fresh water in the eastern escarpment of Eritrea. This area is bestowed with high-altitude dense fog, which is formed during the uphill movement of adiabatically cooled humid air masses from the Red Sea. A pilot project was implemented in 2007 in the villages of Arborobue and Nefasit where the high fog-water yields were measured during the fog-period (from November to March), actually the dry season. In each village, ten Large Fog Collectors (LFC, each 40 m 2) were installed through the funds of Water Foundation (Germany), technical assistance from FogQuest (Canada) and with full engagement of the local implementing partners (Water Resources Department, Zonal Administrations, the beneficiary communities, and Vision Eritrea). 1. Background Eritrea is located in the horn of Africa and it has mostly arid and semi arid climate with about 70% of its land area classified as hot and arid receiving an average annual rainfall of less tha...

Research paper thumbnail of A grazing clock for measurement of time spent grazing by cattle

To date, time spent grazing has been measured most successfully using an electronic grazing clock... more To date, time spent grazing has been measured most successfully using an electronic grazing clock. Difficulties experienced with this clock however, were that temperature and stage in the life of the batteries affected the readings. Further, periods of grazing shorter than the units of time registered by the clock could not be recorded. This paper describes the construction, operation and testing of a grazing clock designed to overcome these problems. Uittreksel Tyd bestee aan beweiding is tot dusver mees suksesvol gemeet met ‘n elektroniese weidingshorlosie. Probleme is egter met hierdie horlosie teegekom. Lesings was nie konstant met verandering in temperatuur of met da/ing in batterykrag nie. Periodes van beweiding wat korter was as die eenhede geregistreerbaar deur die horlosie kon ook nie bepaal word nie. Hierdie referaat beskryf die konstruksie, gebruik en toetsing van ‘n weidingshorlosie ontwerp om hierdie probleme uit te skakel.

Research paper thumbnail of Comparison of sensible heat flux as measured by surface layer scintillometer and eddy covariance methods under different atmospheric stability conditions

Research paper thumbnail of Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Trans-catheter Aortic Valve Replacement

Heart, Lung and Circulation, 2015

Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury ... more Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality. Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed. Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity. Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

Research paper thumbnail of The effect of a trash blanket on the energy balance of a sugarcane crop: preliminary results

Although crop responses to plant residue layers (trash blanket) are well documented, mechanisms a... more Although crop responses to plant residue layers (trash blanket) are well documented, mechanisms are poorly understood. The partitioning of the available energy at the crop surface is important, as it affects the microclimate and drives processes such as crop water use and growth. This communication gives preliminary results of attempts to quantify the impact of a trash blanket on the energy balance and its effects on crop microclimate, water use and growth.