title: Comparative tests of joint surface roughness of rocks from the McMurdo Sound area, Antarctica

authors: Doolin, William Richard

subjects: Antarctica

abstract: Barton and co-workers (Barton, 1973, 1976; Barton and Choubey, 1977; Barton and Bandis, 1980; Bandis et al., 1981) have developed an empirical relationship to estimate the peak frictional resistance of a joint, which considers both the joint wall compressive strength and a joint surface roughness coefficient (JRC). Estimation of JRC can be achieved by comparing joint surface profiles with standard profiles of known JRC values. Alternatively, Barton proposes two simple index tests, tilt and pull (or push) tests, suitable for use in the field, from which JRC values can be back-calculated.
Results from tests using these methods, conducted on 67 joints from six Antarctic lithologies, were statistically compared to results obtained from a numerical characterisation technique, involving computer digitisation, developed by Tse and Cruden (1979). While tilt and pull tests correlate well together, neither performs as reliably against the numerical technique as the profile comparison method.
The Schmidt test hammer can be used to estimate compressive strength by quantitative relationships established with point load strength or uniaxial compressive strength. Its usefulness lies in its ability to test the narrow zone of influence of a joint wall. Basic friction angles can be simply estimated by a modified method of Stimpson (1981), involving the tilting of three cylindrical cores arranged as an elongated pyramid.
Time series analysis of 125 joint surface profiles, using autocorrelation and spectral density functions, suggests that a majority of joint surfaces from all tested lithologies show a high amplitude periodic roughness with a wavelength of between 100 and 150 mm, upon which is superimposed one or more secondary, lower amplitude, periodic roughnesses, with a wavelength dependent on the degree of joint roughness, but most often around 12 mm.

text: Comparative tests of joint surface roughness of rocks from the McMurdo Sound area, Antarctica Barton and co-workers (Barton, 1973, 1976; Barton and Choubey, 1977; Barton and Bandis, 1980; Bandis et al., 1981) have developed an empirical relationship to estimate the peak frictional resistance of a joint, which considers both the joint wall compressive strength and a joint surface roughness coefficient (JRC). Estimation of JRC can be achieved by comparing joint surface profiles with standard profiles of known JRC values. Alternatively, Barton proposes two simple index tests, tilt and pull (or push) tests, suitable for use in the field, from which JRC values can be back-calculated.
Results from tests using these methods, conducted on 67 joints from six Antarctic lithologies, were statistically compared to results obtained from a numerical characterisation technique, involving computer digitisation, developed by Tse and Cruden (1979). While tilt and pull tests correlate well together, neither performs as reliably against the numerical technique as the profile comparison method.
The Schmidt test hammer can be used to estimate compressive strength by quantitative relationships established with point load strength or uniaxial compressive strength. Its usefulness lies in its ability to test the narrow zone of influence of a joint wall. Basic friction angles can be simply estimated by a modified method of Stimpson (1981), involving the tilting of three cylindrical cores arranged as an elongated pyramid.
Time series analysis of 125 joint surface profiles, using autocorrelation and spectral density functions, suggests that a majority of joint surfaces from all tested lithologies show a high amplitude periodic roughness with a wavelength of between 100 and 150 mm, upon which is superimposed one or more secondary, lower amplitude, periodic roughnesses, with a wavelength dependent on the degree of joint roughness, but most often around 12 mm.

year: 1986

title: Ferrocenyl hydroxymethylphosphines (η⁵-C₅H₅)Fe[η⁵⁻C₅H₄P(CH₂OH)₂] and 1,1′-[Fe{η⁵-C₅H₄P(CH₂OH)₂}₂] and their chalcogenide derivatives

authors: Henderson, William

subjects: chemistry

abstract: The ferrocenyl hydroxymethylphosphines FcP(CH₂OH)₂ [Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄)] and 1,1′-Fc′[P(CH₂OH)₂]₂ [Fc′=Fe(η⁵⁻C₅H₄)₂] were prepared by reactions of the corresponding primary phosphines FcPH₂ and 1,1′-Fc′(PH₂)₂ with excess aqueous formaldehyde. The crystal structure of FcP(CH₂OH)₂ was determined and compared with the known ferrocenyl hydroxymethylphosphine FcCH₂P(CH₂OH)₂. The chalcogenide derivatives FcP(E)(CH₂OH)₂ and 1,1′-Fc′[P(E)(CH₂OH)₂]₂ (E=O, S, Se) were prepared and fully characterised. Crystal structure determinations on FcP(O)(CH₂OH)₂ and FcP(S)(CH₂OH)₂ were performed, and the hydrogen-bonding patterns are compared with related compounds. The sulfide shows no hydrogen-bonding involving the phosphine sulfide group, in contrast to other reported ferrocenyl hydroxymethylphosphine sulfides. The platinum complex cis-[PtCl₂{FcP(CH₂OH)₂}₂] was prepared by reaction of 2 mol equivalents of FcP(CH₂OH)₂ with [PtCl₂(1,5-cyclo-octadiene)], and was characterised by 31P-NMR spectroscopy and negative ion electrospray mass spectrometry, which gave a strong [M+Cl]⁻ ion.

text: Ferrocenyl hydroxymethylphosphines (η⁵-C₅H₅)Fe[η⁵⁻C₅H₄P(CH₂OH)₂] and 1,1′-[Fe{η⁵-C₅H₄P(CH₂OH)₂}₂] and their chalcogenide derivatives The ferrocenyl hydroxymethylphosphines FcP(CH₂OH)₂ [Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄)] and 1,1′-Fc′[P(CH₂OH)₂]₂ [Fc′=Fe(η⁵⁻C₅H₄)₂] were prepared by reactions of the corresponding primary phosphines FcPH₂ and 1,1′-Fc′(PH₂)₂ with excess aqueous formaldehyde. The crystal structure of FcP(CH₂OH)₂ was determined and compared with the known ferrocenyl hydroxymethylphosphine FcCH₂P(CH₂OH)₂. The chalcogenide derivatives FcP(E)(CH₂OH)₂ and 1,1′-Fc′[P(E)(CH₂OH)₂]₂ (E=O, S, Se) were prepared and fully characterised. Crystal structure determinations on FcP(O)(CH₂OH)₂ and FcP(S)(CH₂OH)₂ were performed, and the hydrogen-bonding patterns are compared with related compounds. The sulfide shows no hydrogen-bonding involving the phosphine sulfide group, in contrast to other reported ferrocenyl hydroxymethylphosphine sulfides. The platinum complex cis-[PtCl₂{FcP(CH₂OH)₂}₂] was prepared by reaction of 2 mol equivalents of FcP(CH₂OH)₂ with [PtCl₂(1,5-cyclo-octadiene)], and was characterised by 31P-NMR spectroscopy and negative ion electrospray mass spectrometry, which gave a strong [M+Cl]⁻ ion.

year: 2002

title: Equity of travel required to access first definitive surgery for liver or stomach cancer in New Zealand

authors: Gurney, Jason

subjects: Humans

abstract: In New Zealand, there are known disparities between the Indigenous Māori and the majority non-Indigenous European populations in access to cancer treatment, with resulting disparities in cancer survival. There is international evidence of ethnic disparities in the distance travelled to access cancer treatment; and as such, the aim of this paper was to examine the distance and time travelled to access surgical care between Māori and European liver and stomach cancer patients. We used national-level data and Geographic Information Systems (GIS) analysis to describe the distance travelled by patients to receive their first primary surgery for liver or stomach cancer, as well as the estimated time to travel this distance by road, and the surgical volume of hospitals performing these procedures. All cases of liver (ICD-10-AM 3rd edition code: C22) and stomach (C16) cancer that occurred in New Zealand (2007-2019) were drawn from the New Zealand Cancer Registry (liver cancer: 866 Māori, 2,460 European; stomach cancer: 953 Māori, 3,192 European), and linked to national inpatient hospitalisation records to examine access to surgery. We found that Māori on average travel 120km for liver cancer surgery, compared to around 60km for Europeans, while a substantial minority of both Māori and European liver cancer patients must travel more than 200km for their first primary liver surgery, and this situation appears worse for Māori (36% vs 29%; adj. OR 1.48, 95% CI 1.09-2.01). No such disparities were observed for stomach cancer. This contrast between cancers is likely driven by the centralisation of liver cancer surgery relative to stomach cancer. In order to support Māori to access liver cancer care, we recommend that additional support is provided to Māori patients (including prospective financial support), and that efforts are made to remotely provide those clinical services that can be decentralised.

text: Equity of travel required to access first definitive surgery for liver or stomach cancer in New Zealand In New Zealand, there are known disparities between the Indigenous Māori and the majority non-Indigenous European populations in access to cancer treatment, with resulting disparities in cancer survival. There is international evidence of ethnic disparities in the distance travelled to access cancer treatment; and as such, the aim of this paper was to examine the distance and time travelled to access surgical care between Māori and European liver and stomach cancer patients. We used national-level data and Geographic Information Systems (GIS) analysis to describe the distance travelled by patients to receive their first primary surgery for liver or stomach cancer, as well as the estimated time to travel this distance by road, and the surgical volume of hospitals performing these procedures. All cases of liver (ICD-10-AM 3rd edition code: C22) and stomach (C16) cancer that occurred in New Zealand (2007-2019) were drawn from the New Zealand Cancer Registry (liver cancer: 866 Māori, 2,460 European; stomach cancer: 953 Māori, 3,192 European), and linked to national inpatient hospitalisation records to examine access to surgery. We found that Māori on average travel 120km for liver cancer surgery, compared to around 60km for Europeans, while a substantial minority of both Māori and European liver cancer patients must travel more than 200km for their first primary liver surgery, and this situation appears worse for Māori (36% vs 29%; adj. OR 1.48, 95% CI 1.09-2.01). No such disparities were observed for stomach cancer. This contrast between cancers is likely driven by the centralisation of liver cancer surgery relative to stomach cancer. In order to support Māori to access liver cancer care, we recommend that additional support is provided to Māori patients (including prospective financial support), and that efforts are made to remotely provide those clinical services that can be decentralised.

year: 2022