Bond–slip models for double strap joints strengthened by CFRP

This paper presents the results of a series of tension tests on CFRP bonded steel plate double strap joints. The main aim of this research is to provide detailed understanding of bond characteristics using experimental and numerical analysis of strengthened double strap joints under tension. A parametric study has been performed by numerical modelling with the variables of CFRP bond lengths, adhesive maximum strain and adhesive layer thicknesses. Finally, bond-slip models are proposed for three different types of adhesives within the range of the parametric study.

Lateral distortional buckling tests of a new hollow flange channel beam

The LiteSteel beam (LSB) is a new hollow flange channel section developed by OneSteel Australian Tube Mills using their patented dual electric resistance welding and automated continuous roll-forming process. It has a unique geometry consisting of torsionally rigid rectangular hollow flanges and a relatively slender web. The LSBs are commonly used as flexural members in buildings. However, the LSB flexural members are subjected to lateral distortional buckling, which reduces their member moment capacities. Unlike the commonly observed lateral torsional buckling of steel beams, the lateral distortional buckling of LSBs is characterised by simultaneous lateral deflection, twist, and cross sectional change due to web distortion. An experimental study including more than 50 lateral buckling tests was therefore conducted to investigate the behaviour and strength of LSB flexural members. It included the available 13 LSB sections with spans ranging from 1200 to 4000 mm. Lateral buckling tests based on a quarter point loading were conducted using a special test rig designed to simulate the required simply supported and loading conditions accurately. Experimental moment capacities were compared with the predictions from the design rules in the Australian cold-formed steel structures standard. The new design rules in the standard were able to predict the moment capacities more accurately than previous design rules. This paper presents the details of lateral distortional buckling tests, in particular the features of the lateral buckling test rig, the results and the comparisons. It also includes the results of detailed studies into the mechanical properties and residual stresses of LSBs.

Spectroscopic and structural characterization of pascoite

Pascoite mineral having yellow-orange colour of Colorado, USA origin has been characterized by EPR, optical and NIR spectroscopy. The colour dark red-orange to yellow-orange colour of the pascoite indicates that the mineral contain mixed valency of vanadium. The optical spectrum exhibits a number of electronic bands due to presence of VO(II) ions in the mineral. From EPR studies, the parameters of g, A are evaluated and the data confirm that the ion is in distorted octahedron. Optical absorption studies reveal that two sets of VO(II) is in distorted octahedron. The bands in NIR spectra are due to the overtones and combinations of water molecules.

Exploring the theoretical underpinnings of driving whilst influenced by illicit substances

An increasing number of studies are highlighting the alarming proportion of motorists that drive after having consumed illicit drugs. However presently, little attention has focused on the factors that may facilitate drug driving from a criminogenic paradigm. This study evaluated the contribution of deterrence, defiance, and deviance theories on intentions to drug drive to determine factors that might facilitate or reduce this behaviour. A total of 922 individuals completed a questionnaire that assessed frequency of drug use and a variety of perceptions on deterrence, defiance, and deviance constructs. The analysis showed that the defiance constructs (i.e., experiencing feelings of shame and believing in the legitimacy of sanctioning authority) and the deviance constructs (i.e., moral attachment to the norm and having a criminal conviction) were predictive of drug driving intentions. The facets of deterrence theory were not found to be significant predictors. Ultimately, this study illustrates that a range of behavioural and perceptual factors have the capacity to influence decisions to drug drive. As a result, there appears the need to extend the focus of research endeavours beyond legal sanctions to examine other factors that may be utilised to both understand the aetiology of drug driving as well as increase the possibility of compliance with the corresponding legislation.

“Teaching them a lesson?” : a qualitative exploration of underlying motivations for driver aggression

Aggressive driving is increasingly a concern for drivers in highly motorised countries. However, the role of driver intent in this behaviour is problematic and there is little research on driver cognitions in relation to aggressive driving incidents. In addition, while drivers who admit to behaving aggressively on the road also frequently report being recipients of similar behaviours, little is known about the relationship between perpetration and victimisation or about how road incidents escalate into the more serious events that feature in capture media attention. The current study used qualitative interviews to explore driver cognitions and underlying motivations for aggressive behaviours on the road. A total of 30 drivers aged 18-49 years were interviewed about their experiences with aggressive driving. A key theme identified in responses was driver aggression as an attempt to manage or modify the behaviour of other road users. Two subthemes were identified and appeared related to separate motivations for aggressive responses: ‘teaching them a lesson’ referred to situations where respondents intended to convey criticism or disapproval, usually of unintended behaviours by the other driver, and thus encourage self-correction; and ‘justified retaliation’ which referred to situations where respondents perceived deliberate intent on the part of the other driver and responded aggressively in return. Mildly aggressive driver behaviour appears to be common. Moreover such behaviour has a sufficiently negative impact on other drivers that it may be worth addressing because of its potential for triggering retaliation in kind or escalation of aggression, thus compromising safety.

A circuit-breaker restrike diagnostic algorithm using ATP and wavelet transforms

Circuit breaker restrikes are unwanted occurrence, which can ultimately lead to breaker. Before 2008, there was little evidence in the literature of monitoring techniques based on restrike measurement and interpretation produced during switching of capacitor banks and shunt reactor banks. In 2008 a non-intrusive radiometric restrike measurement method, as well a restrike hardware detection algorithm was developed. The limitations of the radiometric measurement method are a band limited frequency response as well as limitations in amplitude determination. Current detection methods and algorithms required the use of wide bandwidth current transformers and voltage dividers. A novel non-intrusive restrike diagnostic algorithm using ATP (Alternative Transient Program) and wavelet transforms is proposed. Wavelet transforms are the most common use in signal processing, which is divided into two tests, i.e. restrike detection and energy level based on deteriorated waveforms in different types of restrike. A ‘db5’ wavelet was selected in the tests as it gave a 97% correct diagnostic rate evaluated using a database of diagnostic signatures. This was also tested using restrike waveforms simulated under different network parameters which gave a 92% correct diagnostic responses. The diagnostic technique and methodology developed in this research can be applied to any power monitoring system with slight modification for restrike detection.

The evaluation of new and isotopically labeled isoindoline nitroxides and an azaphenalene nitroxide for EPR oximetry

Isoindoline nitroxides are potentially useful probes for viable biological systems, exhibiting low cytotoxicity, moderate rates of biological reduction and favorable Electron Paramagnetic Resonance (EPR) characteristics. We have evaluated the anionic (5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl; CTMIO), cationic (5-(N,N,N-trimethylammonio)-1,1,3,3-tetramethylisoindolin-2-yloxyl iodide, QATMIO) and neutral (1,1,3,3-tetramethylisoindolin-2-yloxyl; TMIO) nitroxides and their isotopically labeled analogs ((2)H(12)- and/or (2)H(12)-(15)N-labeled) as potential EPR oximetry probes. An active ester analogue of CTMIO, designed to localize intracellularly, and the azaphenalene nitroxide 1,1,3,3-tetramethyl-2,3-dihydro-2-azaphenalen-2-yloxyl (TMAO) were also studied. While the EPR spectra of the unlabeled nitroxides exhibit high sensitivity to O(2) concentration, deuteration resulted in a loss of superhyperfine features and a subsequent reduction in O(2) sensitivity. Labeling the nitroxides with (15)N increased the signal intensity and this may be useful in decreasing the detection limits for in vivo measurements. The active ester nitroxide showed approximately 6% intracellular localization and low cytotoxicity. The EPR spectra of TMAO nitroxide indicated an increased rigidity in the nitroxide ring, due to dibenzo-annulation.

Are the ‘cave’ minerals archerite (K,NH4)H2PO4 and biphosphammite (K,NH4)H2PO4 identical? A molecular structural study

The molecular structure of the mineral archerite ((K,NH4)H2PO4) has been determined and compared with that of biphosphammite ((NH4,K)H2PO4). Raman spectroscopy and infrared spectroscopy has been used to characterise these ‘cave’ minerals. Both minerals originated from the Murra-el-elevyn Cave, Eucla, Western Australia. The mineral is formed by the reaction of the chemicals in bat guano with calcite substrates. Raman and infrared bands are assigned to H2PO4-, OH and NH stretching vibrations. The Raman band at 981 cm-1 is assigned to the HOP stretching vibration. Bands in the 1200 to 1800 cm-1 region are associated with NH4+ bending modes. The molecular structure of the two minerals appear to be very similar, and it is therefore concluded that the two minerals are identical.

Molecular Structure of the mineral woodhouseite CaAl3(PO4,SO4)2(OH)6

The mineral woodhouseite CaAl3(PO4,SO4)2(OH)6 is a hydroxy phosphate-sulphate mineral belonging to the beudantite subgroup of alunites, and has been characterised by Raman spectroscopy, complimented with infrared spectroscopy. Bands at various wavenumbers were assigned to the different vibrational modes of woodhouseite, which were then associated to the molecular structure of the mineral. Bands were primarily assigned to phosphate and sulphate stretching and bending modes. Two symmetric stretching modes for both phosphate and sulphate supported the concept of non-equivalent phosphate and sulphate units in the mineral structure. Bands in the OH stretching region enabled hydrogen bond distances to be calculated.

A vibrational spectroscopic study of the mineral hinsdalite (Pb,Sr)Al3(PO4)(SO4)(OH)6

The objective of this research is to determine the molecular structure of the mineral hinsdalite using vibrational spectroscopy. The mineral hinsdalite (Pb,Sr)Al3(PO4,SO4)2(OH)6 is a hydroxy phosphate-sulphate mineral belonging to the beudantite subgroup of alunites. The mineral is interesting because it contains two oxyanions, phosphate and sulphate, which is unusual. The formation of hinsdalite offers a mechanism for the removal of phosphate from the environment. The mineral has been characterised by Raman spectroscopy and infrared spectroscopy. The spectra are then related to the molecular structure of the mineral. Bands at various wavenumbers are assigned to the different vibrational modes of hinsdalite, which were then associated to the molecular structure of the mineral. Bands were primarily assigned to phosphate and sulphate stretching and bending modes. The Raman spectrum is characterised by an intense sharp band at 982 cm-1 with a component band at 997 cm-1 assigned to the ν1 (PO4)3- symmetric stretching modes. Two symmetric stretching modes for both phosphate and sulphate supported the concept of non-equivalent phosphate and sulphate units in the mineral structure. Bands in the OH stretching region enabled hydrogen bond distances to be calculated. Hinsdalite is characterised by disordered phosphate/sulphate tetrahedra and non-equivalent phosphate units are observed in the vibrational spectrum of hinsdalite.

Partial protection against chlamydial reproductive tract infection by a recombinant major outer membrane protein/CpG/cholera toxin intranasal vaccine in the guinea pig Chlamydia cavaie model

Chlamydia trachomatis is a major cause of sexually transmitted diseases worldwide. There currently is no vaccine to protect against chlamydial infection of the female reproductive tract. Vaccine development has predominantly involved using the murine model, however infection of female guinea pigs with Chlamydia caviae more closely resembles chlamydial infection of the human female reproductive tract, and presents a better model to assess potential human chlamydial vaccines. We immunised female guinea pigs intranasally with recombinant major outer membrane protein (r-MOMP) combined with CpG-10109 and cholera toxin adjuvants. Both systemic and mucosal immune responses were elicited in immunised animals. MOMP-specific IgG and IgA were present in the vaginal mucosae, and high levels of MOMP-specific IgG were detected in the serum of immunised animals. Antibodies from the vaginal mucosae were also shown to be capable of neutralising C. caviae in vitro. Following immunisation, animals were challenged intravaginally with a live C. caviae infection of 102 inclusion forming units. We observed a decrease in duration of infection and a significant (p<0.025) reduction in infection load in r-MOMP immunised animals, compared to animals immunised with adjuvant only. Importantly, we also observed a marked reduction in upper reproductive tract (URT) pathology in r-MOMP immunised animals. Intranasal immunisation of female guinea pigs with r-MOMP was able to provide partial protection against C. caviae infection, not only by reducing chlamydial burden but also URT pathology. This data demonstrates the value of using the guinea pig model to evaluate potential chlamydial vaccines for protection against infection and disease pathology caused by C. trachomatis in the female reproductive tract.

A comparison of the effects of a chlamydial vaccine administered during or after a C. muridarum urogenital infection of female mice

There are approximately 92 million new chlamydial infections of the genital tract in humans diagnosed each year, costing health care systems billions of dollars in treatment not only of acute infections, but also of associated inflammatory sequelae, such as pelvic inflammatory disease (PID) and ectopic pregnancy. These numbers are increasing at a steady rate and, due to the asymptomatic nature of infections, the incidence may be underestimated and the costs of treatment therefore higher. Over the previous few decades there has been a large amount of research into the development of an efficacious vaccine against genital tract chlamydial infections. The majority of this research has focused on females, due to the high rate of development of associated diseases, including PID, which can lead to ectopic pregnancy and infertility. In light of the increasing infection rates that have occurred despite the availability of antibiotics, and the asymptomatic nature of chlamydial infections, it is imperative that an efficacious vaccine that protects against infection and associated pathology be developed.

Effect of external high pressures on the clay mineral sodium montmorillonite intercalated with methylated octadecylammonium bromide surfactants

Raman microprobe spectra of the clay mineral Wyoming SWy-2-sodium montmorillonite intercalated with the surfactants, methyltrioctadecylammonium bromide (TOMA) dimethyldiotadecylammonium bromide (DODMA) and octadecyl-trimethylammonium bromide (ODTMA), have been measured in the CH2 stretching region at external pressures up to ~40 kbar with the aid of a diamond-anvil cell. In the case of the intercalated clays containing TOMA and DODMA, the Raman data afford evidence for gauche to trans conformational changes in the orientation of the CH2 chains in the surfactants with increasing pressure. These conformational changes are reversed completely upon the release of pressure.

FGFR2 mutations are rare across histologic subtypes of ovarian cancer

OBJECTIVE: Ovarian cancer is the leading cause of death from gynecologic malignancies in the Western world. Fibroblast growth factor receptor (FGFR) signaling has been implicated to play a role in ovarian tumorigenesis. Mutational activation of one member of this receptor family, FGFR2, is a frequent event in endometrioid endometrial cancer. Given the similarities in the histologic and molecular genetics of ovarian and endometrial cancers, we hypothesized that activating FGFR2 mutations may occur in a subset of endometrioid ovarian tumors, and possibly other histotypes. METHODS: Six FGFR2 exons were sequenced in 120 primary ovarian tumors representing the major histologic subtypes. RESULTS: FGFR2 mutation was detected at low frequency in endometrioid (1/46, 2.2%) and serous (1/41, 2.4%) ovarian cancer. No mutations were detected in clear cell, mucinous, or mixed histology tumors or in the ovarian cancer cell lines tested. Functional characterization of the FGFR2 mutations confirmed that the mutations detected in ovarian cancer result in receptor activation. CONCLUSIONS: Despite the low incidence of FGFR2 mutations in ovarian cancer, the two FGFR2 mutations identified in ovarian tumors (S252W, Y376C) overlap with the oncogenic mutations previously identified in endometrial tumors, suggesting activated FGFR2 may contribute to ovarian cancer pathogenesis in a small subset of ovarian tumors.

Experimental and finite element analysis of a double strap joint between steel plates and normal modulus CFRP

Strengthening of steel structures using externally-bonded carbon fibre reinforced polymers ‘CFRP’ is a rapidly developing technique. This paper describes the behaviour of axially loaded flat steel plates strengthened using carbon fibre reinforced polymer sheets. Two steel plates were joined together with adhesive and followed by the application of carbon fibre sheet double strap joint with different bond lengths. The behaviour of the specimens was further investigated by using nonlinear finite element analysis to predict the failure modes and load capacity. In this study, bond failure is the dominant failure mode for normal modulus (240 GPa) CFRP bonding which closely matched the results of finite elements. The predicted ultimate loads from the FE analysis are found to be in good agreement with experimental values.