909 research outputs found
Passive solar-energy air-heating wall panels
The development of products which enable passive solar-energy
air-heating to be integrated into the heating strategies of public,
commercial and industrial buildings is described. These buildings
are, in general, only occupied significantly during the day;
consequently the bulk of heating demand coincides with the period of
solar gain. In these circumstances collected solar heat should be
delivered with the minimum of delay.
The design and operation of units which are capable of supplying solar
heated air in this manner is outlined. These are passive, naturalcirculation
air-heating collectors, also known as natural-convection
air-heaters, or thermosyphoning air panels.
Four methods of retrofitting such solar collectors to non-domestic
buildings have been identified, one of which, the overcladding
collector, has not been proposed previously. Problems associated with
the successful installation and operation of these units have also
been considered.
The relative merits of a number of methods of testing passive solarenergy
air-heating collectors have been investigated. A method of
determining instantaneous collector efficiency based on the
measurement of glazing temperature, inlet and outlet air temperature,
ambient temperature and insolation has been developed.
Three novel design proposals have been presented: i) a collector
constructed with the insulation fitted outside, rather than inside, so
that the metal body of the collector may provide more symmetrical
heating of the air flow than the conventional arrangement, ii) an
absorber which consisted of parallel ducts to increase the rate of
heat transfer to the air, heating it symmetrically, (iii) a hinged
air-deflector for conversion from the heating to the ventilation mode
Correlating PressureâInduced Emission Modulation with Linker Rotation in a Photoluminescent MOF
Conformational changes of linker units in metalâorganic frameworks (MOFs) are often responsible for gateâopening phenomena in selective gas adsorption and stimuliâresponsive optical and electrical sensing behaviour. Herein, we show that pressureâinduced bathochromic shifts in both fluorescence emission and UVâVis absorption spectra of a twoâfold interpenetrated Hf MOF, linked by 1,4âphenyleneâbis(4âethynylbenzoate) ligands ( Hfâpeb ), are induced by rotation of the central phenyl ring of the linker, from a coplanar arrangement to a twisted, previously unseen conformer. Singleâcrystal Xâray diffraction, alongside in situ fluorescence and UVâVis absorption spectroscopies, measured up to 2.1 GPa in a diamond anvil cell on single crystals, are in excellent agreement, correlating linker rotation with modulation of emission. Topologically isolating the 1,4âphenyleneâbis(4âethynylbenzoate) units within a MOF facilitates concurrent structural and spectroscopic study in the absence of intermolecular perturbation, allowing characterisation of the luminescence properties of a highâenergy, twisted conformation of the previously wellâstudied chromophore. We expect the unique environment provided by network solids, and the capability of combining crystallographic and spectroscopic analysis, will greatly enhance understanding of luminescent molecules and lead to the development of novel sensors and adsorbents
Hidden negative linear compressibility in lithium L-tartrateâ
Development of artificial muscles, next-generation pressure sensors and precision optics relies on advances in materials with anomalous mechanical properties. Negative linear compressibility, NLC, is one such rare, counterintuitive phenomenon, in which a material expands along one axis under hydrostatic pressure. Both classical and recent NLC materials face a pay-off between the active pressure range and magnitude of NLC, and in the vast majority of cases the NLC effect decreases with pressure. By decoupling the mechanical behaviour of building units for the first time in a winerack framework containing two different strut types, we show that lithium L-tartrate exhibits NLC with a maximum value, Kmax = -21 TPa^-1, and an overall NLC capacity, ĎNLC = 5.1 %, that are comparable to the most exceptional materials to date. Furthermore, the contributions from molecular strut compression and angle opening interplay to give rise to so-called âhiddenâ negative linear compressibility, in which NLC is absent at ambient pressure, switched on at 2 GPa and sustained up to the limit of our experiment, 5.5 GPa. Analysis of the changes in crystal structure using variable-pressure synchrotron X-ray diffraction reveals new chemical and geometrical design rules to assist the discovery of other materials with exciting hidden anomalous mechanical properties
An Assessment of How Australian Fisheries Management Plans Account for Climate Change Impacts
For Australian fisheries to remain productive and sustainable (environmentally and commercially), there is a need to incorporate climate change considerations into management and planning, and to implement planned climate adaptation options. Here, we determine the extent to which Australian state fisheries management documents consider issues relating to climate change, as well as how frequently climate change is considered a research funding priority within fisheries research in Australia. We conduct a content analysis of fisheries management documents investigating categories and themes relating to Australian state fisheries, climate, and environmental change. We also reviewed recent Research Priorities from the major fisheries research funding body for reference to climate change related themes, and the number of subsequently funded projects which considered climate change or related topics. Results show that commercial state fisheries management documents consider climate only to a limited degree in comparison to other topics, with less than one-quarter of all fisheries management documents having content relating to climate. However, we find that the south-east and south-west regions of the Australian coastline have the highest incorporation of âclimateâ and âenvironmental protection considerationsâ in their fisheries management documents, and that fisheries are more likely to have more âclimate-related mentionsâ within their related management documents, if they (i) primarily target species with higher economic commercial catch values, (ii) commercial catch weights, or (iii) a greater number of commercial fish stocks existing. Only a small number of recently funded fisheries research projects considered climate change, representing only a small proportion of fisheries research investment. Given the extensive climate-driven impacts recently documented among key Australian fisheries species and associated ecosystems, we conclude that there is a clear need for fisheries management in Australia to consider longer-term climate adaptation strategies for Australian commercial state fisheries to remain sustainable into the future. We suggest that without additional climate-related fisheries research and funding, many Australian agencies and fisheries may not be prepared for the impacts and subsequent adaptation efforts required for sustainable fisheries under climate chang
Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors
Background Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. Methods We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (177Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. Results At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. Conclusions Treatment with 177Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the 177Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11
Seabird and marine mammal management options in the face of climate change
Climate change is already impacting Australia’s oceans. Responses by marine life to both climate variability and change have been documented for low trophic levels, however, responses for Australia’s iconic higher trophic level marine taxa are poorly understood, including for many conservation-dependent seabirds and marine mammals. We report initial results from a national study evaluating impacts an adaptation options. Individual time series and combined analyses show consistent responses to historical climate signals, however, improved monitoring protocols are needed to maximize detection of any climate-related demographic signals. Despite difference in sampling , the development of regional multi-species-indices of environmental change provides robust climate indicators over large regions
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