417932 research outputs found
Sort by
Discursive disruption, Populist Communication and Democracy: The cases of Hugo Chávez and Donald J. Trump (forthcoming)
No full textMetal-incorporated mesoporous oxides: synthesis and applications
No full textMesoporous oxides are outstanding metal nanoparticle catalyst supports owing to their well-defined porous structures. Such mesoporous architectures not only prevent the aggregation of metal nanoparticles but also enhance their catalytic performance. Metal/metal oxide heterojunctions exhibit unique chemical and physical properties because of the surface reconstruction around the junction and electron transfer/interaction across the interface. This article reviews the methods used for synthesizing metal-supported hybrid nanostructures and their applications as catalysts for environmental remediation and sensors for detecting hazardous materials
Improving the hydrostability of ZIF-8 membrane by biomolecule towards enhanced nanofiltration performance for dye removal
No full textZeolitic imidazolate frameworks-8 (ZIF-8)/polymer composite membranes have shown great promise in gas separation, catalysis and biotechnology due to their microporous nature. However, the structural instability against protonation limits the application of ZIF-8 materials in aqueous environments, e.g. water treatment membranes. In this study, a ZIF-8 nanocomposite membrane with satisfactory hydrostability was explored. More specifically, a series of composite ZIF-8 thin film containing DNA molecules were deposited on dopamine-modified polysulfone (PSF) substrates via an in situ growth under ambient conditions. The incorporation of DNA molecules significantly enhanced the hydrophilicity of the composite membrane (water contact angle reduced from 66.9° to 29.2°). Compared with the pure ZIF-8 counterpart, the DNA-containing ZIF-8 membrane exhibited higher water flux, accompanied with higher rejections for organic dyes and inorganic salt ions. More importantly, the DNA-containing ZIF-8 membrane showed significantly enhanced water stability and anti-fouling property during the filtration tests. The utilization of biomacromolecules to stabilize ZIF membrane enables potential applications for ZIF membranes for wider water-related applications
Global direct nitrous oxide emissions from the bioenergy crop sugarcane (Saccharum spp. inter-specific hybrids)
No full textSugarcane is the second largest bioenergy crop in the world and it accounts for 80% of global sugar production. Grown mostly in wet and warm tropics with relatively high nitrogen (N) fertiliser input and crop residue retention, sugarcane production is a significant source of nitrous oxide (NO) emission. Yet, a global evaluation of research on NO emission from sugarcane crop is lacking. Here, we conducted a meta-analysis using data from 141 measurements compiled from 15 sugarcane field studies reported from different countries to i) quantify NO emissions and emission factors (EFs) globally, and for tropics and sub-tropics, and ii) identify the key factors that promote NO emission. Our analysis shows that the global mean total NO emission from sugarcane production reached 2.26 (CI: 1.93–2.62) kg NO-N ha yr with an estimated EF of 1.21% (CI: 0.971–1.46%). NO emissions increased exponentially with increase in N fertiliser rate, questioning the adequacy of Intergovernmental Panel on Climate Change (IPCC) default EF value (1%) for sugarcane NO emission estimation. Mean total NO emissions and EFs in tropics and sub-tropics did not vary significantly. Supplementing synthetic N fertiliser (SN) with organic amendments (OA) significantly increased mean NO emission (~1.4-fold) and EF (~2.5-fold) compared to SN. A remarkable reduction in NO emission (38.6%) and EF (61.5%) was evident when enhanced efficiency fertilisers (EEF) replaced SN. In contrast, crop residue removal had little impact on NO emission and EF, but both parameters showed an upward trend with irrigation and increased rainfall. Soil carbon content and pH were emerged as key regulators of sugarcane NO emission and EF. It is concluded that global sugarcane NO emission could be significant and that there is considerable prospect for mitigating the emission through innovative nutrient formulations and precision agriculture that help meet crop nutrient demand without compromising environmental imperatives
Uranium-thorium dating of coral mortality and community shift in a highly disturbed inshore reef (Weizhou Island, northern South China Sea)
No full textInshore coral habitats are at high risk of loss due to a combination of climate warming and regional-scale human impacts. As a result, they have undergone significant declines. Direct evidence of acute and chronic disturbance on most inshore coral assemblages is limited. Long-term, periodical surveys and historical baseline data essential for effective management are lacking. Using high-precision uranium-thorium (U–Th) dating, we reconstruct a ~100-year-long history of extensive coral loss, changes in coral community structure, and a shifting baseline. The data were collected at Weizhou Island, northern South China Sea (SCS), which has highly disturbed inshore coral habitats that are typical globally. According to our U–Th dates, major coral mortalities around Weizhou Island have occurred since the 1950s, with increasing frequency and severity since the 1980s. The extensive loss of branching Acropora and collapse of coral communities with peaks around 1960, 1984, and 1998 are accompanied by a shift toward low coral cover and noncoral-dominated assemblages. Prior to this collapse, the local coral community structure sustained remarkable long-term stability over millennia. The timing of the Acropora loss and massive coral mortalities coincides with multiple acute and chronic, natural and anthropogenic disturbance events. We suggest that priority should be given to directly addressing the causes of degradation and effectively controlling chronic disturbances before attempting to restore reef ecosystems. This is probably the only way to solve the “wicked problem” of sustaining the key functions and ecosystem services of inshore coral habitats such as those of Weizhou Island, northern SCS
Chronic elevation of plasma cortisol causes differential expression of predominating glucocorticoid in plasma, saliva, fecal, and wool matrices in sheep
No full textThere is increasing interest in using nonblood measures of glucocorticoids to assess the physiological response to chronic stress conditions. In sheep, cortisol has been measured in various matrices including saliva, feces, and wool, but comprehensive studies of the relationship between plasma concentrations of cortisol and concentrations in these nonblood matrices are lacking. Therefore, we tested the hypothesis that administration of cortisol to sheep would result in elevated concentrations of cortisol in blood, saliva, feces, and wool. Merino ewes were administered with saline or 2 mg/kg BW/d hydrocortisone acetate (HCA) by intramuscular (i.m.) injection for 28 d. This treatment was imposed to mimic circulating cortisol concentrations experienced during periods of chronic stress. Cortisol and cortisone were directly measured in plasma, saliva, and wool before, during, and after treatment with saline or HCA. A 14-d pre-treatment and a 14-d post-treatment period were used to measure time taken for glucocorticoid concentrations in each of the matrices to return to baseline levels. Cortisol was also measured in feces before, during, and after treatment. Wool growth was also measured. Before treatment, there was no difference in the concentration of cortisol or cortisone in plasma, saliva, feces, or wool in animals treated with saline or HCA. In contrast, treatment with HCA increased (P < 0.05) concentrations of both cortisol and cortisone in plasma, saliva, and wool and of cortisol in feces. In plasma, cortisol concentrations were higher than cortisone (P < 0.05), whereas saliva cortisol and cortisone concentrations did not differ significantly. In wool, the concentration of cortisone was about 19-fold higher than that of cortisol during treatment and post-treatment periods. Treatment with HCA inhibited wool growth. These results demonstrate that an increase in glucocorticoids in the blood of sheep is reflected in increases in saliva (after 7 d of treatment), feces (21 d), and wool (14 d). Therefore, measures of glucocorticoids in these matrices may provide a measure of activation of the adrenal glands over time in sheep, thereby providing a retrospective indicator of chronic stress. With respect to wool, it appears that cortisol is predominantly metabolized to cortisone in the skin or wool follicle and is stored as cortisone. Therefore wool cortisone may also provide an important measure in quantifiying chronic stress in sheep
Lust, love and curiosity: the emotional threads in the Dutch encounter with an exotic east
No full textThis chapter examines the manifestation and representations of emotion in the encounter of East and West that took place between Dutch and Japanese individuals during the period of Japan’s seclusion. It focuses, firstly, on representative Japanese artistic and associated literary images of the West as a primary source for reading emotion in this East-West encounter. Lust, love and curiosity are all emotions that are potentially attributable to scenes of sexual intimacy that took place in Dejima, which were portrayed in a Japanese art form, shunga. The chapter contextualizes these visual representations of purported emotion by examining their Dutch and Japanese cultural settings, and the artistic traditions of this genre. It then extends to briefly consider other emotional threads – love and curiosity – that are discernible as arising from this narrow ‘node of contact’ that contributed to the two-way flows of mutually desired information
Extremely efficient flexible organic solar cells with a graphene transparent anode: Dependence on number of layers and doping of graphene
No full textGraphene has shown tremendous potential as a transparent conductive electrode (TCE) for flexible organic solar cells (OSCs). However, the trade-off between electrical conductance and transparency as well as surface roughness of the graphene TCE with increasing layer number limits power conversion efficiency (PCE) enhancement and its use for large-area OSCs. Here, we use a 300 nm-thick poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c]-[1,2,5]thiadiazole)]:[6,6]-phenyl-C-butyric acid methyl ester blend as the photoactive layer and a benzimidazole (BI)-doped graphene as the transparent anode to demonstrate efficient OSCs with good flexibility. It is found that 3 layer (L) graphene had the best balance between sheet resistance, optical transmittance and surface roughness for optimized cell design. A 0.2 cm cell with a 3L BI-doped graphene anode had a PCE of 6.85%, which is one of the highest PCE values reported so far for flexible graphene anode-based OSCs. The flexible cells were mechanically robust, showing only a small performance degradation during up to 250 flexing cycles. Moreover, the combination of the thick photoactive layer with the optimized 3L BI-doped graphene TCE enabled production of 1.6 cm flexible OSCs with a PCE of 1.8%. Our work illustrates the importance of graphene TCE development for flexible OSCs as well as other wearable optoelectronic devices
Lower-limb work during high- and low-impact activities in hip-related pain: associations with sex and symptom severity
No full textBackground:Hip-related pain (HRP) is described as a movement-related disorder. However, little attention is given to the way people with HRP move, especially in populations still participating in sport. Thus, limiting our understanding of movementbased impairments in HRP and their potential relationships with pain/symptoms. Research Question: (1) What are the differences in absolute and relative amounts of positive and negative lower-limb joint work during walking and the single-leg drop jump (SLDJ) in football players with and without HRP? (2) What are the relationships between lower-limb joint work and HRP burden? Methods:88 football players with HRP and 30 control football players were recruited. Positive and negative work done by the hip, knee, and ankle (and each joint's relative contribution to total work done) were calculated. The effect of sex on the relationship between HRP and work done, as well as the association between work done and International Hip Outcome Tool (iHOT33) scores, were assessed using linear and beta regressions models. Results:Walking: No joint work variables were significantly different between groups, nor were any relationships with iHOT33 scores evident. SLDJ: The knee's relative contribution to total lower-limb negative work done was 37.7 % and 42.4 % for women with and without HRP, respectively (P = 0.04). The iHOT33 was significantly associated with positive (P = 0.03 t
Data sources:
Access Repository Dashboard
Do you manage University of Queensland eSpace? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!