Showing papers by "University of Wollongong published in 1993"

What is hegemonic masculinity

Abstract: A developing debate within the growing theoretical literature on men and masculinity concerns the relationship of gender systems to the social formation. Crucially at issue is the question of the autonomy of the gender order. Some, in particular Waters, are of the opinion that change in masculine gender systems historically has been caused exogenously and that, without those external factors, the systems would stably reproduce. 1 For Hochschild, the "motor" of this social change is the economy, particularly and currently, the decline in the purchasing power of the male wage, the decline in the number and proportion of "male" skilled and unskilled jobs, and the rise in "female" jobs in the growing services sector. 2 1 have argued that gender relations themselves are bisected by class relations and vice-versa, and that the salient moment for analysis is the relation between the two. 3

Anastomosis and the continuum of channel pattern

Abstract: Anastomosing rivers are characterized by multiple channels separated by islands excised from the floodplain. Their status relative to the continuum concept of channel pattern is assessed with channel pattern defined in terms of three variables—flow strength, bank erodibility and relative sediment supply. Using an ordinal scaling (L(ow)–M(oderate)–H(igh)), the traditional forms of straight, meandering and braided have respective representations of (L,L,L), (M,L/M,L/M) and (H,H,M/H) in terms of those variables. The anastomosing pattern is on average represented by (L,L,M/H) but not so definitively as other forms. Specification of the third element (sediment supply) is particularly hampered by the paucity of data but aggradation, a characteristic of many anastomosing rivers, can be thought of as symptomatic of a moderately high rate of supply relative to the ability for onward transport. A sufficiently high rate of supply to a channel with low flow strength and resistant banks would induce shoaling and/or lateral constriction that locally forces flow out of the main channel and ultimately leads to the cutting of anabranches. A flow regime characterized by concentrated floods of relatively large magnitude is also regarded as highly conducive to the formation of new channels where low bank erodibility constrains channel capacity. Anastomosis may in certain cases represent a transitional form of channel pattern but there is no denying the longevity of some anastomosing systems.

Microstructure, corrosion and tribological behaviour of plasma immersion ion-implanted austenitic stainless steel

Abstract: The surface modification of AISI 316 stainless steel by plasma immersion ion implantation (PI3) has been investigated over a range of treatment temperatures. Below 250°C the results are similar to those obtained by conventional ion beam implantation of nitrogen, but the depth of nitrogen penetration increases dramatically with temperature. Up to 450 °C a nitrogen-expanded austenite phase is formed which is shown to have improved corrosion performance over the untreated material. At 520 °C chromium nitride is precipated and the expanded austenite transforms to martensite, leading to a reduction in corrosion resistance. Pin-on-disc testing indicates improved wear resistance at all temperatures, with reduction in the wear volume by factors of several hundred at high loads. This can be attributed to the formation of an oxide layer which prevents the initiation of severe metallic wear.

Expectations and product performance as determinants of satisfaction for a high-involvement purchase

Abstract: Customer satisfaction is a central issue for organizations wishing to create a sustainable competitive advantage in the 1990s. Empirical work to date, concentrating on low-involvement, nondurable products, has concluded that both prior expectations and postpurchase experience interact to influence the level of customer satisfaction. Only a few studies have examined the purchase of high-involvement, nondurable products. The current study employs a multiattribute approach using pre- and postpurchase questionnaires to assess determinants of customer satisfaction for a high-involvement product. Causal path analysis shows perceived product performance to be the most powerful determinant. Prior expectations did interact with performance to affect disconfirmation, which translated into only a minor impact on satisfaction. © 1993 John Wiley & Sons, Inc.

Pervious and impervious runoff in urban catchments

Abstract: Rainfall and runoff depths were examined for 763 storms on 26 urban basins located in 12 countries For 17 of the basins, impervious surfaces were the major contributors to storm runoff These basins were generally smaller than 25 ha and had small to medium storms in the data set Nine basins had significant amounts of runoff from pervious as well as impervious surfaces Eight of these basins are located in Australia For all 26 basins, plots of rainfall and runoff depths were used to estimate the effective impervious area and the impervious area initial loss The data plotted close to a single straight line on all basins, indicating that the effective impervious area remained constant for all storm sizes The effective impervious fraction was related to total impervious area and the directly connected impervious fraction estimated from maps For the basins with pervious runoff, the depth of rain in the storm was the most important factor in determining pervious runoff for rainfalls less than 50

Application of Cognitive‐Behavioural Family Intervention for Schizophrenia in Multidisciplinary Teams: What Can the Matter Be?

Abstract: Cognitive-behavioural family interventions for schizophrenia have demonstrated utility in reducing relapse rates and improving functional status, but there is little information on the routine application of this work. In the current study therapists in standard health care settings were trained in delivering a cognitive-behavioural intervention to clients and families. Six months to 3 years after the family training, 45 therapists reported the number of families they had systematically treated, and the difficulties they had encountered. Sixty-nine per cent reported giving three sessions or more of the intervention to at least one family, but only 18% had used it with three or more families. Therapists reported particular difficulty integrating the family work with their other responsibilities and interests: Allowance of time to undertake the intervention, afterhours scheduling, and illness or holidays presented particular difficulties. Only 4% reported that their knowledge of behavioural techniq...

Porosity Calculation of Binary Mixtures of Nonspherical Particles

Abstract: An investigation has been made of the packing of binary mixtures of either spherical or nonspherical particles. It is shown that this binary packing system can satisfactorily be described by the Westman equation. By use of the concept of “equivalent packing diameter,” nonspherical particle packing may be related to spherical particle packing. The porosity of binary mixtures of nonspherical particles can then be predicted by means of a model developed for spherical particles. This approach is verified by the good agreement between the calculated and experimental results.

Formation of braided river floodplains, Waimakariri River, New Zealand

Abstract: Floodplains along the braided gravel-bed Waimakariri River are discontinuous although generally extensive landforms composed predominantly of gravel bars capped with vertically accreted fines In order of importance, three mechanisms lead to floodplain formation River bed abandonment by lateral migration of the braid-train initiates the formation of the largest floodpiains, which usually occur downstream of tributary fans and valley bedrock spurs In the headwater reaches, localized river bed aggradation during high magnitude events leads to floodplain formation by producing a surface resistant to erosion by lesser events due to either the coarse nature of the deposit, or by its elevation over the river bed, or both The least important mechanism initiating floodplain development is localized river or channel incision A six stage model is proposed for the sequential development of floodplains on the Waimakariri River from: (i) active river bed; (ii) stabilizing bar; (iii) incipient floodplain; (iv) established floodplain; (v) mature floodplain; and to (vi) terrace Two mechanisms, lateral migration by the braid-train and reactivation of abandoned channels within floodplains, operating separately or in combination, are responsible for floodplain reworking and their relatively young age (<250 years) Clearly, braided rivers can construct substantial areas of well developed floodplain

X-ray surface dose measurements using TLD extrapolation.

Abstract: Surface dosemeasurements in therapeutic x‐ray beams are of importance in determining the dose to the skin of patients undergoing radiotherapy.Measurements were performed in the 6‐MV beam of a medicallinear accelerator with LiF thermoluminescencedosimeters(TLD) using a solid water phantom. TLD chips (surface area 3.17×3.17 cm2) of three different thicknesses (0.230, 0.099, and 0.038 g/cm2) were used to extrapolate dose readings to an infinitesimally thin layer of LiF. This surface dose was measured for field sizes ranging from 1×1 cm2 to 40×40 cm2. The surface dose relative to maximum dose was found to be 10.0% for a field size of 5×5 cm2, 16.3% for 10×10 cm2, and 26.9% for 20×20 cm2. Using a 6‐mm Perspex block tray in the beam increased the surface dose in these fields to 10.7%, 17.7%, and 34.2% respectively. Due to the small size of the TLD chips, TLD extrapolation is applicable also for intracavity and exit dose determinations. The technique used for in vivodosimetry could provide clinicians information about the build up of dose up to 1‐mm depth in addition to an extrapolated surface dosemeasurement.

Ratings of perceived exertion and affect in hot and cool environments.

Abstract: The effects of hot and cool environments on perceptual and physiological responses during steady-state exercise were examined in men (n = 14) performing 30 min of constant exercise (cycle ergometry) at a perceived exertion of "somewhat hard" Subjects exercised at the same absolute exercise intensity in hot (40 degrees C), neutral (24 degrees C), and cool (8 degrees C) conditions Data were collected for differential ratings of perceived exertion (RPE), affect, thermal sensation, mean skin (Tsk) and rectal temperatures (Tre), and cardiac frequency (fc) The subjects completed the hot exposure with an average Tsk of 375 degrees C (SEM 011), while the neutral and cool conditions produced values of 338 (SEM 009) and 282 degrees C (SEM 030), respectively The Tsk was significantly higher in the hot than the neutral and cool conditions throughout exercise (P < 005) The fc was significantly lower in the cool than in the other conditions (P < 005), and the subjects completed the hot exposure with a mean fc more than 20 beatsmin-1 greater than observed in the other conditions The subjects felt worse (lower affect) in the heat throughout exercise (P < 005) Overall RPE was significantly lower in the cool than in the heat, while chest RPE scores for the cool and hot conditions were displaced vertically by approximately two points Subjects perceived work to be harder, felt worse, and experienced greater thermal sensation in the hot condition, compared with the neutral and cool conditions Changes in cutaneous vasomotor tone and heat-induced influences on the chest may have accounted for the RPE changes observed in the heat

Investigation of the tissue equivalence of gels used for NMR dosimetry.

Abstract: The transition of Fe2+ to Fe3+ in Fricke solution after irradiation results in a change of NMR proton relaxation times in agarose gels which can be used for the dosimetry of ionizing radiation. The main advantage of this system is the possibility of observing dose distributions in 3 dimensions in a medium which is supposed to be tissue equivalent. The aim of the study was to quantify parameters which determine the tissue equivalence of NMR dosimetry gels. Electron densities and effective atomic numbers were calculated for gels with varying iron, sulphur and agarose concentration. The Hounsfield CT numbers so derived agree well with the CT numbers measured on a clinical CT scanner (effective photon energy 70.7 keV).

Immunizing public key cryptosystems against chosen ciphertext attacks

Abstract: Three methods for strengthening public key cryptosystems in such a way that they become secure against adaptively chosen ciphertext attacks are presented. In an adaptively chosen ciphertext attack, an attacker can query the deciphering algorithm with any ciphertext except for the exact object ciphertext to be cryptanalyzed. The first strengthening method is based on the use of one-way hash functions, the second on the use of universal hash functions, and the third on the use of digital signature schemes. Each method is illustrated by an example of a public key cryptosystem based on the intractability of computing discrete logarithms in finite fields. Security of the three example cryptosystems is formally proved. Two other issues, namely, applications of the methods to public key cryptosystems based on other intractable problems and enhancement of information authentication capability to the cryptosystems, are also discussed. >

Dosimetry of 6‐MV x‐ray beam penumbra

Abstract: The measurement of x-ray beam dose profiles in the penumbral region, using silicon diode, ionization chamber, TLD, and film dosimetry, has been investigated for a 6-MV beam defined by independent collimators. Penumbral width (80%-20%) at dmax, as measured by diode, film, and TLD was found to be 3.6, 3.6, and 3.4 mm, respectively. These results reflect the relative sensitive widths of each of the measurement systems (2.5, 2.0, and 1.0 mm, respectively). An empirical forming function was used to relate the penumbral shape measured with a finite-sized detector to that which would be measured with a point detector, the width of the point detector penumbra calculated from the diode penumbra is 3.4 mm, indicating that the TLD rods are a good approximation to a point detector. An alternative method of determining the width of a point detector penumbra is to extrapolate the penumbral widths obtained using two or more detectors of sensitive width. With this method, using Farmer and RK ionization chambers, a point detector penumbra width of 3.1 mm is obtained. An EGS4 Monte Carlo simulation, where a point source was assumed, gave a penumbral width of 2.8 mm. Negligible differences between the penumbra of beams defined by symmetric and asymmetric collimators was observed.

Somatic hypermutation in 5′ flanking regions of heavy chain antibody variable regions

Abstract: The aim of this study has been to determine the distribution of somatic mutations in the 5' flanking regions of rearranged immunoglobulin heavy chain variable region genes (VDJ). We sequenced the 5' flanking region in 12 secondary immune response antibodies produced in C57BL/6j mice against the hapten (4-hydroxy-3-nitrophenyl)acetyl (NP) coupled to chicken-gamma-globulin. In these and previously published sequences, almost 97% of the mutations occurred in the transcribed region of the gene, and only a minority of genes (5/29) contained mutations upstream of the transcription start (cap) site. No potential germ-line donor was found for a cluster of five base changes previously found in a single heavy chain gene, 3B62. However, the uniqueness of this mutational cluster and its distance from the normally mutated region suggests that the nucleotide changes may not be due to the normal mutator mechanism. Thus, as this was the only instance of somatic mutations that far upstream of the promoter/cap site region, the reverse transcriptase model for somatic hypermutation is still a possibility. The data are consistent with a mutational mechanism that requires transcription of the rearranged target V(D)J gene which appears to result in the generation of a positively skewed asymmetrical distribution of somatic mutations. A single mode is centered near the V(D)J and a long tail extends into the 3' non-translated region of the J-C intron. Two classes of model could explain this mutation distribution pattern: those where transcription products (RNA, cDNA) are the direct mutational substrates, or those that postulate local unfolding of the chromatin around a V(D)J rearrangement directly exposing the DNA of the transcribed region to specific mutational enzymes.