671 resultados para carbon footprint, contabilità ambientale, web calculator
Resumo:
In a pilot application based on web search engine calledWeb-based Relation Completion (WebRC), we propose to join two columns of entities linked by a predefined relation by mining knowledge from the web through a web search engine. To achieve this, a novel retrieval task Relation Query Expansion (RelQE) is modelled: given an entity (query), the task is to retrieve documents containing entities in predefined relation to the given one. Solving this problem entails expanding the query before submitting it to a web search engine to ensure that mostly documents containing the linked entity are returned in the top K search results. In this paper, we propose a novel Learning-based Relevance Feedback (LRF) approach to solve this retrieval task. Expansion terms are learned from training pairs of entities linked by the predefined relation and applied to new entity-queries to find entities linked by the same relation. After describing the approach, we present experimental results on real-world web data collections, which show that the LRF approach always improves the precision of top-ranked search results to up to 8.6 times the baseline. Using LRF, WebRC also shows performances way above the baseline.
Resumo:
The aims of the project were to scope and develop sustainable energy curriculum frameworks for Australian higher education Institutions that meet the needs of Australian and international student graduates and employers, both now and into the near future. The focus was on student centred learning and outcomes and to support graduates with the knowledge, skills and generic attributes required to work in the rapidly expanding sustainable energy industry in Australia and globally. The outputs of the project are designed to be relevant to specialist Sustainable Engineering and Energy Studies programs, as well as conventional engineering, science and humanities and social science programs that have a sustainable energy focus or major.
Resumo:
Glassy carbon (GC) electrode modified with a self-assembled monolayer (SAM) of 1,8,15,22-tetraaminophthalocyanatocobalt(II) (4α-CoIITAPc) was used for the selective and highly sensitive determination of nitric oxide (NO). The SAM of 4α-CoIITAPc was formed on GC electrode by spontaneous adsorption from DMF containing 1 mM 4α-CoIITAPc. The SAM showed two pairs of well-defined redox peaks corresponding to CoIII/CoII and CoIIIPc−1/CoIIIPc−2 in 0.2 M phosphate buffer (PB) solution (pH 2.5). The SAM modified electrode showed excellent electrocatalytic activity towards the oxidation of nitric oxide (NO) by enhancing its oxidation current with 310 mV less positive potential shift when compared to bare GC electrode. In amperometric measurements, the current response for NO oxidation was linearly increased in the concentration range of 3×10−9 to 30×10−9 M with a detection limit of 1.4×10−10 M (S/N=3). The proposed method showed a better recovery for NO in human blood serum samples.
Resumo:
Spontaneous adsorption of 1,8,15,22-tetraaminophthalocyanatocobalt(II) (4α-CoIITAPc) on glassy carbon (GC) electrode leads to the formation of a stable self-assembled monolayer (SAM). Since the SAM of 4α-CoIITAPc is redox active, its adsorption on GC electrode was followed by cyclic voltammetry. SAM of 4α-CoIITAPc on GC electrode shows two pairs of well-defined redox peaks corresponding to CoIII/CoII and CoIIIPc−1/CoIIIPc−2. The surface coverage (Γ) value, calculated by integrating the charge under CoII oxidation, was used to study the adsorption thermodynamics and kinetics of 4α-CoIITAPc on GC surface. Cyclic voltammetric studies show that the adsorption of 4α-CoIITAPc on GC electrode has reached the saturation coverage (Γs) within 3 h. The Γs value for the SAM of 4α-CoIITAPc on GC electrode was found to be 2.37 × 10−10 mol cm−2. Gibbs free energy (ΔGads) and adsorption rate constant (kad) for the adsorption of 4α-CoIITAPc on GC surface were found to be −16.76 kJ mol−1 and 7.1 M−1 s−1, respectively. The possible mechanism for the self-assembly of 4α-CoIITAPc on GC surface is through the addition of nucleophilic amines to the olefinic bond on the GC surface in addition to a meager contribution from π stacking. The contribution of π stacking was confirmed from the adsorption of unsubstituted phthalocyanatocobalt(II) (CoPc) on GC electrode. Raman spectra for the SAM of 4α-CoIITAPc on carbon surface shows strong stretching and breathing bands of Pc macrocycle, pyrrole ring and isoindole ring. Raman and CV studies suggest that 4α-CoIITAPc is adopting nearly a flat orientation or little bit tilted orientation.
Resumo:
Electropolymerized film of 3,3′,3″,3‴-tetraaminophthalocyanatonickel(II) (p-NiIITAPc) on glassy carbon (GC) electrode was used for the selective and stable determination of 3,4-dihydroxy-l-phenylalanine (l-dopa) in acetate buffer (pH 4.0) solution. Bare GC electrode fails to determine the concentration of l-dopa accurately in acetate buffer solution due to the cyclization reaction of dopaquinone to cyclodopa in solution. On the other hand, p-NiIITAPc electrode successfully determines the concentration of l-dopa accurately because the cyclization reaction was prevented at this electrode. It was found that the electrochemical reaction of l-dopa at the modified electrode is faster than that at the bare GC electrode. This was confirmed from the higher heterogeneous electron transfer rate constant (k0) of l-dopa at p-NiIITAPc electrode (3.35 × 10−2 cm s−1) when compared to that at the bare GC electrode (5.18 × 10−3 cm s−1). Further, it was found that p-NiIITAPc electrode separates the signals of ascorbic acid (AA) and l-dopa in a mixture with a peak separation of 220 mV. Lowest detection limit of 100 nM was achieved at the modified electrode using amperometric method. Common physiological interferents like uric acid, glucose and urea does not show any interference within the potential window of l-dopa oxidation. The present electrode system was also successfully applied to estimate the concentration of l-dopa in the commercially available tablets.
Resumo:
We fabricated high performance supercapacitors by using all carbon electrodes, with volume energy in the order of 10−3 Whcm−3, comparable to Li-ion batteries, and power densities in the range of 10 Wcm−3, better than laser-scribed-graphene supercapacitors. All-carbon supercapacitor electrodes are made by solution processing and filtering electrochemically-exfoliated graphene sheets mixed with clusters of spontaneously entangled multiwall carbon nanotubes. We maximize the capacitance by using a 1:1 weight ratio of graphene to multi-wall carbon nanotubes and by controlling their packing in the electrode film so as to maximize accessible surface and further enhance the charge collection. This electrode is transferred onto a plastic-paper-supported double-wall carbon nanotube film used as current collector. These all-carbon thin films are combined with plastic paper and gelled electrolyte to produce solid-state bendable thin film supercapacitors. We assembled supercapacitor cells in series in a planar configuration to increase the operating voltage and find that the shape of our supercapacitor film strongly affects its capacitance. An in-line superposition of rectangular sheets is superior to a cross superposition in maintaining high capacitance when subject to fast charge/discharge cycles. The effect is explained by addressing the mechanism of ion diffusion into stacked graphene sheets.
Resumo:
The use of circular hollow steel members has attracted a great deal of attention during past few years because of having excellent structural properties, aesthetic appearance, corrosion and fire protection capability. However, no one can deny the structural deficiency of such structures due to reduction of strength when they are exposed to severe environmental conditions such as marine environment, cold and hot weather. Hence strengthening and retrofitting of structural steel members is now very imperative. This paper presents the findings of a research program that was conducted to study the bond durability of carbon fibre-reinforced polymer (CFRP) strengthened steel tubular members under cold weather and tested under four-point bending. Six number of CFRP-strengthened specimens and one unstrengthened specimen were considered in this program. The three specimens having sand blasted surface to be strengthened was pre-treated with MBrace primer and other three were remained untreated and then cured under ambient temperature at least four weeks and cold weather (3 C) for three and six months period of time. Quasi-static tests were then performed on beams to failure under four-point bending. The structural response of each specimen was predicted in terms of failure load, mid-span deflection, composite beam behaviour and failure mode. The research outcomes show that the cold weather immersion had an adverse effect on durability of CFRP-strengthened steel structures. Moreover, the epoxy based adhesion promoter was found to enhance the bond durability in plastic range. The analytical models presented in this study were found to be in good agreement in terms of predicting ultimate load and deflection. Finally, design factors are proposed to address the short-terms durability performance under cold weather.
Resumo:
Carbon nanoscrolls (CNSs) are one of the carbon-based nanomaterials similar to carbon nanotubes (CNTs) but are not widely studied in spite of their great potential applications. Their practical applications are hindered by the challenging fabrication of the CNSs. A physical approach has been proposed recently to fabricate the CNS by rolling up a monolayer graphene nanoribbon (GNR) around a CNT driven by the interaction energy between them. In this study, we perform extensive molecular dynamics (MD) simulations to investigate the various factors that impact the formation of the CNS from GNR. Our simulation results show that the formation of the CNS is sensitive to the length of the CNT and temperature. When the GNR is functionalized with hydrogen, the formation of the CNS is determined by the density and distribution of the hydrogen atoms. Graphyne, the allotrope of graphene, is inferior to graphene in the formation of the CNS due to the weaker bonds and the associated smaller atom density. The mechanism behind the rolling of GNR into CNS lies in the balance between the GNR–CNT van der Waals (vdW) interactions and the strain energy of GNR. The present work reveals new important insights and provides useful guidelines for the fabrication of the CNS.
Resumo:
This phenomenographic research investigated variation in web professionals' understanding of information literacy. The outcome is of value for the education of practitioners both in the areas of information literacy, and web design and development. Analysis of 23 in-depth interviews with web workers from different stages of web design and development process revealed that they experience information literacy as staying informed, building a successful website, solving a problem or participating in a community of practice. The present research advances the existing understanding of the concept of information literacy, especially in an occupational context. Additionally, using the web professionals' world as the context of the study, the research also contributes to the field of website design and development by shedding light on less-researched experiences of people involved in this industry.
Resumo:
This paper reports on a current initiative at Queensland University of Technology to provide timely, flexible and sustainable training and support to academic staff in blended learning and associated techno-pedagogies via a web-conferencing classroom and collaboration tool, Elluminate Live!. This technology was first introduced to QUT in 2008 as part of the university‘s ongoing commitment to meeting the learning needs of diverse student cohorts. The centralised Learning Design team, in collaboration with the university‘s department of eLearning Services, was given the task of providing training and support to academic staff in the effective use of the technology for teaching and learning, as part of the team‘s ongoing brief to support and enhance the provision of blended learning throughout the university. The resulting program, ―Learning Design Live‖ (LDL) is informed by Rogers‘ theory of innovation and diffusion (2003) and structured according to Wilson‘s framework for faculty development (2007). This paper discusses the program‘s design and structure, considers the program‘s impact on academic capacity in blended learning within the institution, and reflects on future directions for the program and emerging insights into blended learning and participant engagement for both staff and students.
Resumo:
The estimated one million Australians with type 2 diabetes face significant risks of morbidity and premature mortality. Inadequate diabetes self-management is associated with poor glycaemic control, which is further impaired by comorbid dysphoria. Regular access to ongoing self-management and psychological support is limited, especially in rural and regional locations. Web-based interventions can provide complementary support to patients’ usual care. Semi-structured interviews were undertaken with two samples that comprised (a) 13 people with type 2 diabetes and (b) 12 general practitioners (GPs). Interviews explored enablers and barriers to self-care, emotional challenges, needs for support, and potential web-based programme components. Patients were asked about the potential utility of a web-based support programme, and GPs were asked about likely circumstances of patient referral to it. Thematic analysis was used to summarise responses. Most perceived facilitators and barriers to self-management were similar across the groups. Both groups highlighted the centrality of dietary self-management, valued shared decision-making with health professionals, and endorsed the idea of web-based support. Some emotional issues commonly identified by patients varied to those perceived by GPs, resulting in different attributions for impaired self-care. A web-based programme that supported self-management and psychological/emotional needs appears likely to hold promise in yielding high acceptability and perceived utility.
Resumo:
Background: The prevalence of type 2 diabetes is rising with the majority of patients practicing inadequate disease self-management. Depression, anxiety, and diabetes-specific distress present motivational challenges to adequate self-care. Health systems globally struggle to deliver routine services that are accessible to the entire population, in particular in rural areas. Web-based diabetes self-management interventions can provide frequent, accessible support regardless of time and location Objective: This paper describes the protocol of an Australian national randomized controlled trial (RCT) of the OnTrack Diabetes program, an automated, interactive, self-guided Web program aimed to improve glycemic control, diabetes self-care, and dysphoria symptoms in type 2 diabetes patients. Methods: A small pilot trial is conducted that primarily tests program functionality, efficacy, and user acceptability and satisfaction. This is followed by the main RCT, which compares 3 treatments: (1) delayed program access: usual diabetes care for 3 months postbaseline followed by access to the full OnTrack Diabetes program; (2) immediate program: full access to the self-guided program from baseline onward; and (3) immediate program plus therapist support via Functional Imagery Training (FIT). Measures are administered at baseline and at 3, 6, and 12 months postbaseline. Primary outcomes are diabetes self-care behaviors (physical activity participation, diet, medication adherence, and blood glucose monitoring), glycated hemoglobin A1c (HbA1c) level, and diabetes-specific distress. Secondary outcomes are depression, anxiety, self-efficacy and adherence, and quality of life. Exposure data in terms of program uptake, use, time on each page, and program completion, as well as implementation feasibility will be conducted. Results: This trial is currently underway with funding support from the Wesley Research Institute in Brisbane, Australia. Conclusions: This is the first known trial of an automated, self-guided, Web-based support program that uses a holistic approach in targeting both type 2 diabetes self-management and dysphoria. Findings will inform the feasibility of implementing such a program on an ongoing basis, including in rural and regional locations.
Resumo:
In recent years, there has been a significant trend toward land acquisition in developing countries, establishing forestry plantations for offsetting carbon pollution generated in the Global North. Badged as “green economic development,” global carbon markets are often championed not only as solutions to climate change, but as drivers of positive development outcomes for local communities. But there is mounting evidence that these corporate land acquisitions for climate change mitigation—including forestry plantations—severely compromise not only local ecologies but also the livelihoods of the some of the world’s most vulnerable people living at subsistence level in rural areas in developing countries.
Resumo:
This paper presents a new approach to web browsing in situ- ations where the user can only provide the device with a sin- gle input command device (switch). Switches have been de- veloped for example for people with locked-in syndrome and are used in combination with scanning to navigate virtual keyboards and desktop interfaces. Our proposed approach leverages the hierarchical structure of webpages to operate a multi-level scan of actionable elements of webpages (links or form elements). As there are a few methods already exist- ing to facilitate browsing under these conditions, we present a theoretical usability evaluation of our approach in com- parison to the existing ones, which takes into account the average time taken to reach any part of a web page (such as a link or a form) but also the number of clicks necessary to reach the goal. We argue that these factors contribute together to usability. In addition, we propose that our ap- proach presents additional usability benefits.
Resumo:
Steel hollow sections used in structures such as bridges, buildings and space structures involve different strengthening techniques according to their structural purpose and shape of the structural member. One such technique is external bonding of CFRP sheets to steel tubes. The performance of CFRP strengthening for steel structures has been proven under static loading while limited studies have been conducted on their behaviour under impact loading. In this study, a comprehensive numerical investigation is carried out to evaluate the response of CFRP strengthened steel tubes under dynamic axial impact loading. Impact force, axial deformation impact velocities are studied. The results of the numerical investigations are validated by experimental results. Based on the developed finite element (FE) model several output parameters are discussed. The results show that CFRP wrapping is an effective strengthening technique to increase the axial dynamic load bearing capacity by increasing the stiffness of the steel tube.