895 resultados para Civil and Environmental Engineering
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Call for papers
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Mobile technologies have yet to be widely adopted by the Architectural, Engineering, and Construction (AEC) industry despite being one of the major growth areas in computing in recent years. This lack of uptake in the AEC industry is likely due, in large part, to the combination of small screen size and inappropriate interaction demands of current mobile technologies. This paper discusses the scope for multimodal interaction design with a specific focus on speech-based interaction to enhance the suitability of mobile technology use within the AEC industry by broadening the field data input capabilities of such technologies. To investigate the appropriateness of using multimodal technology for field data collection in the AEC industry, we have developed a prototype Multimodal Field Data Entry (MFDE) application. This application, which allows concrete testing technicians to record quality control data in the field, has been designed to support two different modalities of data input speech-based data entry and stylus-based data entry. To compare the effectiveness or usability of, and user preference for, the different input options, we have designed a comprehensive lab-based evaluation of the application. To appropriately reflect the anticipated context of use within the study design, careful consideration had to be given to the key elements of a construction site that would potentially influence a test technician's ability to use the input techniques. These considerations and the resultant evaluation design are discussed in detail in this paper.
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ODTs have emerged as a novel oral dosage form with a potential to deliver a wide range of drug candidates to paediatric and geriatric patients. Compression of excipients offers a costeffective and translatable methodology for the manufacture of ODTs. Though, technical challenges prevail such as difficulty to achieve suitable tablet mechanical strength while ensuring rapid disintegration in the mouth, poor compressibility of preferred ODT diluent Dmannitol, and limited use for modified drug-release. The work investigates excipients’ functionality in ODTs and proposes new methodologies for enhancing material characteristics via process and particle engineering. It also aims to expand ODT applications for modified drug-release. Preformulation and formulation studies employed a plethora of techniques/tests including AFM, SEM, DSC, XRD, TGA, HSM, FTIR, hardness, disintegration time, friability, stress/strain and Heckel analysis. Tableting of D-mannitol and cellulosic excipients utilised various compression forces, material concentrations and grades. Engineered D-mannitol particles were made by spray drying mannitol with pore former NH4HCO3. Coated microparticles of model API omeprazole were prepared using water-based film forming polymers. The results of nanoscopic investigations elucidated the compression profiles of ODT excipients. Strong densification of MCC (Py is 625 MPa) occurs due to conglomeration of physicomechanical factors whereas D-mannitol fragments under pressure leading to poor compacts. Addition of cellulosic excipients (L-HPC and HPMC) and granular mannitol to powder mannitol was required to mechanically strengthen the dosage form (hardness >60 N, friability <1%) and to maintain rapid disintegration (<30 sec). Similarly, functionality was integrated into D-mannitol by fabrication of porous, yet, resilient particles which resulted in upto 150% increase in the hardness of compacts. The formulated particles provided resistance to fracture under pressure due to inherent elasticity while promoted tablet disintegration (50-77% reduction in disintegration time) due to porous nature. Additionally, coated microparticles provided an ODT-appropriate modified-release coating strategy by preventing drug (omeprazole) release.
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The principal aim of this chapter is to undertake a critical review of the social and environmental accountability of global business activities in developing countries. While global business activities have contributed to the economic development of developing countries they have many adverse social and environmental consequences which are often under-studied. I explore the role of accounting in making those consequences visible. The chapter, however, concludes that while social and environmental accounting has the potential to raise the visibility of social and environmental impacts of corporate activities it often fails to do so particularly under the current voluntary disclosure regime where corporations can choose what to report and how to report. This is even more pronounced in the developing countries because of their vulnerabilities arising from various social and environmental problems. The chapter argues for a case of ‘surrogate accountability’ as an alternative to the current corporate driven form of accountability.
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The UK Government and large employers have recognised the skills gap between learners leaving the education system and the requirements of employers. The current system is seen to be failing significant numbers of learners and has been accused of schooling but not educating our young people. University-led technical colleges are one part of the solution being developed to provide outstanding engineering education. This paper focusses on the learning experience that the Aston University Engineering Academy, the first University-led University Technical College (UTC), has created for entrants to the Engineering Academy in September 2012, when it opens in brand new buildings next to the University. The overall aim is to produce technically literate young people that have business and enterprise skills as well as insight into the diverse range of opportunities in Engineering and Technical disciplines. The project has brought University staff and students together with employers and Academy staff to optimise the engineering education that they will receive. The innovative model presented has drawn on research from across the world in the implementation of this new type of school, as well as educational practices from the USA and the Scandinavian countries. The resulting curriculum is authentic and exciting and expands the University model of problem-based learning and placements into the secondary school environment. The benefits of this close partnership for University staff and students, the employers and the Academy staff are expanded on and the paper concludes with a prediction of progression routes from the Academy.
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Microporous polycaprolactone (PCL) matrices loaded with hydrophobic steroidal drugs or a hydrophilic drug - pilocarpine hydrochloride - were produced by precipitation casting using solutions of PCL in acetone. The efficiency of steroid incorporation in the final matrix (progesterone (56 %) testosterone (46 %) dexamethasone (80 %)) depended on the nature of the drug initially co-dissolved in the PCL solution. Approximately 90 % w/w of the initial load of progesterone, 85 % testosterone and 50 % dexamethasone was released from the matrices in PBS at 37°C over 8 days. Pilocarpine hydrochloride (PH)-loaded PCL matrices, prepared by dispersion of powder in PCL solution, released 70-90 % of the PH content over 12 days in PBS. Application of the Higuchi model revealed that the kinetics of steroid and PH release were consistent with a Fickian diffusion mechanism with corresponding diffusion coefficients of 5.8 × 10-9 (progesterone), 3.9 × 10 -9 (testosterone), 7.1 × 10-10 (dexamethasone) and 22 × 10-8 cm2/s (pilocarpine hydrochloride). The formulation techniques described are expected to be useful for production of implantable, insertable and topical devices for sustained delivery of a range of bioactive molecules of interest in drug delivery and tissue engineering.
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In recent years there has been growing concern about the emission trade balances of countries. This is due to the fact that countries with an open economy are active players in international trade. Trade is not only a major factor in forging a country’s economic structure, but contributes to the movement of embodied emissions beyond country borders. This issue is especially relevant from the carbon accounting policy and domestic production perspective, as it is known that the production-based principle is employed in the Kyoto agreement. The research described herein was designed to reveal the interdependence of countries on international trade and the corresponding embodied emissions both on national and on sectoral level and to illustrate the significance of the consumption-based emission accounting. It is presented here to what extent a consumption-based accounting would change the present system based on production-based accounting and allocation. The relationship of CO2 emission embodied in exports and embodied in imports is analysed here. International trade can blur the responsibility for the ecological effects of production and consumption and it can lengthen the link between consumption and its consequences. Input-output models are used in the methodology as they provide an appropriate framework for climate change accounting. The analysis comprises an international comparative study of four European countries (Germany, the United Kingdom, the Netherlands, and Hungary) with extended trading activities and carbon emissions. Moving from a production-based approach in climate policy to a consumption-based principle and allocation approach would help to increase the efficiency of emission reductions and would force countries to rethink their trading activities in order to decrease the environmental load of production activities. The results of this study show that it is important to distinguish between the two emission accounting approaches, both on the global and the local level.
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Egyre többen ismerik fel, hogy az élelmiszer-fogyasztás egészségügyi és környezeti hatása is jelentős. A különböző életstílusú társadalmi csoportok fogyasztási szerkezete eltérő lehet. Jelen tanulmány ezerfős, országos reprezentatív minta alapján vizsgálja az élelmiszer-fogyasztási szerkezet eltéréseit a nemek és különböző iskolázottságú fogyasztók körében. Jellemző fogyasztási klasztereket tár fel a fogyasztás szerkezete alapján. A fogyasztás szerkezeti és mennyiségi értékein túlmenően az ökológiai lábnyom indikátorával a fogyasztás környezetterhelését is számszerűsíti. _____ Concern about both health and environmental impacts of food consumption is increasing. Social groups with various lifestyles can have different food consumption structure. The present study analyses the differences in the food consumption structure among genders and educational groups based on a national, representative survey of 1000 adults. Food consumption clusters are identified based on food consumption structure. Beyond the analysis of food consumption and its structure, its environmental impact is quantified by the ecological footprint indicator.
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Studies have shown that the environmental conditions of the home are important predictors of health, especially in low-income communities. Understanding the relationship between the environment and health is crucial in the management of certain diseases. One health outcome related to the home environment among urban, minority, and low-income children is childhood lead poisoning. The most common sources of lead exposure for children are lead paint in older, dilapidated housing and contaminated dust and soil produced by accumulated residue of leaded gasoline. Blood lead levels (BLL) as low as 10 μg/dL in children are associated with impaired cognitive function, behavior difficulties, and reduced intelligence. Recently, it is suggested that the standard for intervention be lowered to BLL of 5 μg /dl. The objectives of our report were to assess the prevalence of lead poisoning among children under six years of age and to quantify and test the correlations between BLL in children and lead exposure levels in their environment. This cross-sectional analysis was restricted to 75 children under six years of age who lived in 6 zip code areas of inner city Miami. These locations exhibited unacceptably high levels of lead dust and soil in areas where children live and play. Using the 5 μg/dL as the cutoff point, the prevalence of lead poisoning among the study sample was 13.33%. The study revealed that lead levels in floor dust and window sill samples were positively and significantly correlated with BLL among children (p < 0.05). However, the correlations between BLL and the soil, air, and water samples were not significant. Based on this pilot study, a more comprehensive environmental study in surrounding inner city areas is warranted. Parental education on proper housecleaning techniques may also benefit those living in the high lead-exposed communities of inner city Miami.
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This research examines evolving issues in applied computer science and applies economic and business analyses as well. There are two main areas. The first is internetwork communications as embodied by the Internet. The goal of the research is to devise an efficient pricing, prioritization, and incentivization plan that could be realistically implemented on the existing infrastructure. Criteria include practical and economic efficiency, and proper incentives for both users and providers. Background information on the evolution and functional operation of the Internet is given, and relevant literature is surveyed and analyzed. Economic analysis is performed on the incentive implications of the current pricing structure and organization. The problems are identified, and minimally disruptive solutions are proposed for all levels of implementation to the lowest level protocol. Practical issues are considered and performance analyses are done. The second area of research is mass market software engineering, and how this differs from classical software engineering. Software life-cycle revenues are analyzed and software pricing and timing implications are derived. A profit maximizing methodology is developed to select or defer the development of software features for inclusion in a given release. An iterative model of the stages of the software development process is developed, taking into account new communications capabilities as well as profitability. ^
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The purpose of this study is to characterize the degradation products of Irgarol 1051(2-methylthio-4-tertbutylamino-6-cyclopropylamino- s-triazine), a compound recently developed for use as an antifouling agent on boat hulls. The photolytic fate of this compound in different natural waters will be used in the development of a monitoring program designed to survey the occurrence of this compound and its degradation products in South Florida marinas, the Miami River and surrounding coastal areas. ^ The transformation of Irgarol 1051 and degradation rate constants were characterized in a photo-reactor under simulated natural conditions. The degradation pathway in the UVB-UVA region (300nm to 350nm) closely resembled the transformations under natural conditions in the pond, showing that both direct photolysis and the presence of natural sensitizers play an important role in the abiotic transformation of this compound. Irgarol 1051 has an average environmental half-life of 10 days in surface waters. Average concentrations from samples around Biscayne Bay and the Miami River increased from 1–5 ng/L during 1999 and increased to between 28 and 38 ng/L in 2001, respectively. Irgarol concentrations showed a strong correlation with concentrations of its major transformation product, M1, from samples collected as part of the study ([M1]/[Irgarol] = 0.247, R2 = 0.9165, n = 125). ^
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Coral reefs are experiencing declines worldwide and recently coral diseases have been identified as significant contributors to coral mortality. However, little is known regarding the factors that drive coral disease distributions and dynamics. Current knowledge of the organisms that cause coral diseases is also limited, with pathogens having been identified for only 5 of the 21 described coral diseases. The study presented here describes coral disease dynamics in terms of occurrence, prevalence, spatial distribution, and host species susceptibility from 2002--2004 on reefs of the Northern Florida Keys (NFK) and Lee Stocking Island (LSI) in the Bahamas' Exuma chain. In addition, this research investigated the influence of temperature, sediment, and nutrient availability on coral disease prevalence and severity. Finally, microbial communities associated with a polymicrobial disease, black band, were examined to address spatial and temporal variability. ^ Four scleractinian diseases were observed in repeated surveys conducted during June-August of each year: black band disease (BBD), white plague type 2 (WP), dark spots syndrome (DSS), and yellow band disease-(YBD). Coral disease prevalence was generally low in both the NFK and LSI as compared to epizootic levels reported previously in the NFK and other regions of the Caribbean. Disease prevalence and species susceptibility varied spatially and temporally. Massive framework species, including Siderastrea siderea, Colpophyllia natans, and Montastraea annularis, along with relatively smaller colonies of Meandrina meandrites and Dichocoenia stokesi, were most susceptible to disease. Temperature, sedimentation, and dissolved inorganic nitrogen were positively correlated with BBD infections. Furthermore, experimental nutrient enrichment exacerbated coral tissue loss to BBD both in situ and in vivo. Profiling of BBD microbial communities using length heterogeneity PCR revealed variation over space and time, with significantly distinct bacterial assemblages in the NFK, LSI, and US Virgin Islands. ^ This study contributes to knowledge of the relationship between coral diseases and the environment, and facilitates predictions regarding potential changes in coral reef communities under differing environmental conditions. Additionally, this research provides further understanding of coral disease dynamics at both the host and microbial pathogen levels.^
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The balance between the costs and benefits of conspicuous signals ensures that the expression of those signals is related to the quality of the bearer. Plastic signals could enable males to maximize conspicuous traits to impress mates and competitors, but reduce the expression of those traits to minimize signaling costs, potentially compromising the information conveyed by the signals. ^ I investigated the effect of signal enhancement on the information coded by the biphasic electric signal pulse of the gymnotiform fish Brachyhypopomus gauderio. Increases in population density drive males to enhance the amplitude of their signals. I found that signal amplitude enhancement improves the information about the signaler's size. Furthermore, I found that the elongation of the signal's second phase conveys information about androgen levels in both sexes, gonad size in males and estrogen levels in females. Androgens link the duration of the signal's second phase to other androgen-mediated traits making the signal an honest indicator of reproductive state and aggressive motivation. ^ Signal amplitude enhancement facilitates the assessment of the signaler's resource holding potential, important for male-male interactions, while signal duration provides information about aggressive motivation to same-sex competitors and reproductive state to the opposite sex. Moreover, I found that female signals also change in accordance to the social environment. Females also increase the amplitude of their signal when population density increases and elongate the duration of their signal's second phase when the sex ratio becomes female-biased. Indicating that some degree of sexual selection operates in females. ^ I studied whether male B. gauderio use signal plasticity to reduce the cost of reproductive signaling when energy is limited. Surprisingly, I found that food limitation promotes the investment in reproduction manifested as signal enhancement and elevated androgen levels. The short lifespan and single breeding season of B. gauderio diminishes the advantage of energy savings and gives priority to sustaining reproduction. I conclude that the electric signal of B. gauderio provides reliable information about the signaler, the quality of this information is reinforced rather than degraded with signal enhancement.^