829 resultados para light weight design


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Amorphous drug-polymer solid dispersions have the potential to enhance the dissolution performance and thus bioavailability of BCS class II drug compounds. The principle drawback of this approach is the limited physical stability of amorphous drug within the dispersion. Accurate determination of the solubility and miscibility of drug in the polymer matrix is the key to the successful design and development of such systems. In this paper, we propose a novel method, based on Flory-Huggins theory, to predict and compare the solubility and miscibility of drug in polymeric systems. The systems chosen for this study are (1) hydroxypropyl methylcellulose acetate succinate HF grade (HPMCAS-HF)-felodipine (FD) and (2) Soluplus (a graft copolymer of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol)-FD. Samples containing different drug compositions were mixed, ball milled, and then analyzed by differential scanning calorimetry (DSC). The value of the drug-polymer interaction parameter ? was calculated from the crystalline drug melting depression data and extrapolated to lower temperatures. The interaction parameter ? was also calculated at 25 °C for both systems using the van Krevelen solubility parameter method. The rank order of interaction parameters of the two systems obtained at this temperature was comparable. Diagrams of drug-polymer temperature-composition and free energy of mixing (?G mix) were constructed for both systems. The maximum crystalline drug solubility and amorphous drug miscibility may be predicted based on the phase diagrams. Hyper-DSC was used to assess the validity of constructed phase diagrams by annealing solid dispersions at specific drug loadings. Three different samples for each polymer were selected to represent different regions within the phase diagram

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Background:Research examining the relationship between adiponectin (AN) isoforms, body weight and cardiovascular (CV) risk factors is limited, particularly in younger populations. Objectives:To investigate the inter-relationships between AN isoforms and CV risk factors, and their dependence on body weight status, in adolescents. Design:Blood samples from 92 obese, 92 overweight and 92 normal weight age- and sex-matched adolescents were analysed for traditional cardiovascular disease (CVD) risk biomarkers and also total, high molecular weight (HMW), medium and low molecular weight (LMW) AN. Results:A significant inverse association was observed between total and HMW AN and waist-hip ratio (P=0.015, P=0.006, respectively), triglycerides (P=0.003, P=0.003, respectively) and systolic blood pressure (P=0.012, P=0.024, respectively) and a significant positive association with high-density lipoprotein (P<0.001, P<0.001, respectively) in multi-adjusted analyses. There was no evidence of a relationship between multimeric AN and high-sensitivity C-reactive protein. There was also little evidence of a relationship between LMW AN and CVD risk factors. There was a strong, body mass index (BMI)-independent, association between AN, CVD biomarkers and the hypertriglyceridemic waist phenotype. Conclusion:Prominent, BMI-independent associations between total and HMW AN, but not LMW AN, and CVD risk factors were already evident in this young population. This research in adolescents supports the contention that AN subfractions may have different biological actions. These associations in apparently healthy adolescents suggest an important role for AN and its subfractions in the pathogenesis of metabolic syndrome traits and indicate that the potential for total or HMW AN to act as early universal biomarkers of CV risk warrants further study.

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In a prospective study of 501 infants of low birth weight (LBW) who mostly weighed 2,041 g (4 1/2 lb) or less, and of 203 control infants of full birth weight (FBW > 2,500 g), 335 LBW and 139 FBW children were followed beyond the age of 6 years and 6 months. The incidence of neurological defects was negatively correlated with birth weight, and the mean "global" IQ of different birth weight groups retained a direct relationship. While the relationship of birth weight to IQ gradually became less marked, the effect of social class was increasingly evident from the age of 2 years and 6 months. The preterm children whose birth weight was appropriate for gestational age (AGA) attained a slightly higher mean IQ and significantly better grade placement in the third school year than the children who were unduly light for their gestational age. Details of the neurological and ophthalmological defects are given, and the predictive significance of neonatal variables is analyzed.

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This paper reports on a design study assessing the impact of laminate manufacturing constraints on the structural performance and weight of composite stiffened panels. The study demonstrates that maximizing ply continuity results in weight penalties, while various geometric constraints related to manufacture and repair can be accommodated without significant weight penalties, potentially generating robust flexible designs.

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The Irish Pavilion at the Venice Architecture Biennale 2012 charts a position for Irish architecture in a global culture where the modes of production of architecture are radically altered. Ireland is one of the most globalised countries in the world, yet it has developed a national culture of architecture derived from local place as a material construct. We now have to evolve our understanding in the light of the globalised nature of economic processes and architectural production which is largely dependent on internationally networked flows of products, data, and knowledge. We have just begun to represent this situation to ourselves and others. How should a global architecture be grounded culturally and philosophically? How does it position itself outside of shared national reference points?
heneghan peng architects were selected as participants because they are working across three continents on a range of competition-winning projects. Several of these are in sensitive and/or symbolic sites that include three UNESCO World Heritage sites, including the Grand Egyptian Museum in Cairo, the Giants Causeway Visitor Centre in Northern Ireland, and the new Rhine Bridge near Lorelei.
Our dialogue led us to discussing the universal languages of projective geometry and number are been shared by architects and related professionals. In the work of heneghan peng, the specific embodiment of these geometries is carefully calibrated by the choice of materials and the detailed design of their physical performance on site. The stone facade of the Giant’s Causeway Visitor Centre takes precise measure of the properties of the volcanic basalt seams from which it is hewn. The extraction of the stone is the subject of the pavilion wall drawings which record the cutting of stones to create the façade of the causeway centre.
We also identified water as an element which is shared across the different sites. Venice is a perfect place to take measure of this element which suggests links to another site – the Nile Valley which was enriched by the annual flooding of the River Nile. An ancient Egyptian rod for measuring the water level of the Nile inspired the design of the Nilometre - a responsive oscillating bench that invites visitors to balance their respective weights. This action embodies the ways of thinking that are evolving to operate in the globalised world, where the autonomous architectural object is dissolving into an expanded field of conceptual rules and systems. The bench constitutes a shifting ground located in the unstable field of Venice. It is about measurement and calibration of the weight of the body in relation to other bodies; in relation to the site of the installation; and in relation to water. The exhibit is located in the Artiglierie section of the Arsenale. Its level is calibrated against the mark of the acqua alta in the adjacent brickwork of the building which embodies a liminal moment in the fluctuating level of the lagoon.
The weights of bodies, the level of water, changes over time, are constant aspects of design across cultures and collectively they constitute a common ground for architecture - a ground shared with other design professionals. The movement of the bench required complex engineering design and active collaboration between the architects, engineers and fabricators. It is a kind of prototype – a physical object produced from digital data that explores the mathematics at play – the see-saw motion invites the observer to become a participant, to give it a test drive. It shows how a simple principle can generate complex effects that are difficult to predict and invites visitors to experiment and play with them.

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The design of hot-rolled steel portal frames can be sensitive to serviceability deflection limits. In such cases, in order to reduce frame deflections, practitioners increase the size of the eaves haunch and / or the sizes of the steel sections used for the column and rafter members of the frame. This paper investigates the effect of such deflection limits using a real-coded niching genetic algorithm (RC-NGA) that optimizes frame weight, taking into account both ultimate as well as serviceability limit states. The results show that the proposed GA is efficient and reliable. Two different sets of serviceability deflection limits are then considered: deflection limits recommended by the Steel Construction Institute (SCI), which is based on control of differential deflections, and other deflection limits based on suggestions by industry. Parametric studies are carried out on frames with spans ranging between 15 m to 50 m and column heights between 5 m to 10 m. It is demonstrated that for a 50 m span frame, use of the SCI recommended deflection limits can lead to frame weights that are around twice as heavy as compared to designs without these limits.

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Pregnancy and the postpartum period is a time of increased vulnerability for retention of excess body fat in women. Breastfeeding (BF) has been shown to have many health benefits for both mother and baby; however, its role in postpartum weight management is unclear. Our aim was to systematically review and critically appraise the literature published to date in relation to the impact of BF on postpartum weight change, weight retention and maternal body composition. Electronic literature searches were carried out using MEDLINE, EMBASE, PubMed, Web of Science, BIOSIS, CINAHL and British Nursing Index. The search covered publications up to 12 June 2012 and included observational studies (prospective and retrospective) carried out in BF mothers (either exclusively or as a subgroup), who were 2 years postpartum and with a body mass index (BMI) >18.5 kg m(-2), with an outcome measure of change in weight (including weight retention) and/or body composition. Thirty-seven prospective studies and eight retrospective studies were identified that met the selection criteria; studies were stratified according to study design and outcome measure. Overall, studies were heterogeneous, particularly in relation to sample size, measurement time points and in the classification of BF and postpartum weight change. The majority of studies reported little or no association between BF and weight change (n=27, 63%) or change in body composition (n=16, 89%), although this seemed to depend on the measurement time points and BF intensity. However, of the five studies that were considered to be of high methodological quality, four studies demonstrated a positive association between BF and weight change. This systematic review highlights the difficulties of examining the association between BF and weight management in observational research. Although the available evidence challenges the widely held belief that BF promotes weight loss, more robust studies are needed to reliably assess the impact of BF on postpartum weight management.International Journal of Obesity advance online publication, 20 August 2013; doi:10.1038/ijo.2013.132.

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Considering the development of aerospace composite components, designing for reduced manufacturing layup cost and structural complexity is increasingly important. While the advantage of composite materials is the ability to tailor designs to various structural loads for minimum mass, the challenge is obtaining a design that is manufacturable and minimizes local ply incompatibility. The focus of the presented research is understanding how the relationships between mass, manufacturability and design complexity, under realistic loads and design requirements, can be affected by enforcing ply continuity in the design process. Presented are a series of sizing case studies on an upper wing cover, designed using conventional analyses and the tabular laminate design process. Introducing skin ply continuity constraints can generate skin designs with minimal ply discontinuities, fewer ply drops and larger ply areas than designs not constrained for continuity. However, the reduced design freedom associated with the addition of these constraints results in a weight penalty over the total wing cover. Perhaps more interestingly, when considering manual hand layup the reduced design complexity is not translated into a reduced recurring manufacturing cost. In contrast, heavier wing cover designs appear to take more time to layup regardless of the laminate design complexity. © 2012 AIAA.

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Implications Provision of environmental enrichment in line with that required by welfare-based quality assurance schemesdoes not always appear to lead to clear improvements in broiler chicken welfare. This research perhaps serves to highlightthe deficit in information regarding the ‘real world’ implications of enrichment with perches, string and straw bales.

Introduction Earlier work showed that provision of natural light and straw bales improved leg health in commercial broilerchickens (Bailie et al., 2013). This research aimed to determine if additional welfare benefits were shown in windowedhouses by increasing straw bale provision (Study 1), or by providing perches and string in addition to straw bales (Study 2).

Material and methods Commercial windowed houses in Northern Ireland containing ~23,000 broiler chickens (placed inhouses as hatched) were used in this research which took place in 2011. In Study 1 two houses on a single farm wereassigned to one of two treatments: (1) 30 straw bales per house (1 bale/44m2), or (2) 45 straw bales per house (1bale/29m2). Bales of wheat straw, each measuring 80cm x 40cm x 40cm were provided from day 10 of the rearing cycle,as in Bailie et al. (2013). Treatments were replicated over 6 production cycles (using 276,000 Ross 308 and Cobb birds),and were swapped between houses in each replicate. In Study 2, four houses on a single farm were assigned to 1 of 4treatments in a 2 x 2 factorial design. Treatments involved 2 levels of access to perches (present (24/house), or absent), and2 levels of access to string (present (24/house), or absent), and both types of enrichment were provided from the start of thecycle. Each perch consisted of a horizontal, wooden beam (300 cm x 5 cm x 5cm) with a rounded upper edge resting on 2supports (15 cm high). In the string treatment, 6 pieces of white nylon string (60 cm x 10 mm) were tied at their mid-pointto the wire above each of 4 feeder lines. Thirty straw bales were also provided per house from day 10. This study wasreplicated over 4 production cycles using 368,000 Ross 308 birds. In both studies behaviour was observed between 0900and 1800 hours in weeks 3-5 of the cycle. In Study 1, 8 focal birds were selected in each house each week, and generalactivity, exploratory and social behaviours recorded directly for 10 minutes. In Study 2, 10 minute video recordings weremade of 6 different areas (that did not contain enrichment) of each house each week. The percentage of birds engaged inlocomotion or standing was determined through scan sampling these recordings at 120 second intervals. Four perches andfour pieces of string were filmed for 25 mins in each house that contained these enrichments on one day per week. The totalnumber of times the perch or string was used was recorded, along with the duration of each bout. In both studies, gaitscores (0 (perfect) to 5 (unable to walk)) and latency to lie (measured in seconds from when a bird had been encouraged tostand) were recorded in 25 birds in each house each week. Farm and abattoir records were also used in both studies todetermine the number of birds culled for leg and other problems, mortality levels, slaughter weights, and levels of pododermatitis and hock burn. Data were analysed using SPSS (version 20.0) and treatment and age effects on behaviouralparameters were determined in normally distributed data using ANOVA (‘Straw bale density*week’, or‘string*perches*week’ as appropriate), and in non-normally distributed data using Kuskall-Wallace tests (P<0.05 forsignificance) . Treatment (but not age) effects on performance and health data were determined using the same testsdepending on normality of data.

Results Average slaughter weight, and levels of mortality, culling, hock burn and pododermatitis were not affected bytreatment in either study (P<0.05). In Study 1 straw bale (SB) density had no significant effect on the frequency orduration of behaviours including standing, walking, ground pecking, dust bathing, pecking at bales or aggression, or onaverage gait score (P>0.05). However, the average latency to lie was greater when fewer SB were provided (30SB 23.38s,45SB 18.62s, P<0.01). In Study 2 there was an interaction between perches (Pe) and age in lying behaviour, with higherpercentages of birds observed lying in the Pe treatment during weeks 4 and 5 (week 3 +Pe 77.0 -Pe 80.9, week 4 +Pe 79.5 -Pe 75.2, week 5 +Pe 78.4 -Pe 76.2, P<0.02). There was also a significant interaction between string (S) and age inlocomotory behaviour, with higher percentages of birds observed in locomotion in the string treatment during week 3 butnot weeks 4 and 5 (week 3 +S 4.9 -S 3.9, week 4 +S 3.3 -S 3.7, week 5 +S 2.6 -S 2.8, P<0.04). There was also aninteraction between S and age in average gait scores, with lower gait scores in the string treatment in weeks 3 and 5 (week3: +S 0.7, -S 0.9, week 4: +S 1.5, -S 1.4, week 5: +S 1.9, -S 2.0, P<0.05). On average per 25 min observation there were15.1 (±13.6) bouts of perching and 19.2 (±14.08) bouts of string pecking, lasting 117.4 (±92.7) and 4.2 (±2.0) s for perchesand string, respectively.

Conclusion Increasing straw bale levels from 1 bale/44m2 to 1 bale/29m2 floor space does not appear to lead to significantimprovements in the welfare of broilers in windowed houses. The frequent use of perches and string suggests that thesestimuli have the potential to improve welfare. Provision of string also appeared to positively influence walking ability.However, this effect was numerically small, was only shown in certain weeks and was not reflected in the latency to lie.Further research on optimum design and level of provision of enrichment items for broiler chickens is warranted. Thisshould include measures of overall levels of activity (both in the vicinity of, and away from, enrichment items).

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This paper considers the optimal design of fabricated steel beams for long-span portal frames. The design optimisation takes into account ultimate as well as serviceability limit states, adopting deflection limits recommended by the Steel Construction Institute (SCI). Results for three benchmark frames demonstrate the efficiency of the optimisation methodology. A genetic algorithm (GA) was used to optimise the dimensions of the plates used for the columns, rafters and haunches. Discrete decision variables were adopted for the thickness of the steel plates and continuous variables for the breadth and depth of the plates. Strategies were developed to enhance the performance of the GA including solution space reduction and a hybrid initial population half of which is derived using Latin hypercube sampling. The results show that the proposed GA-based optimisation model generates optimal and near-optimal solutions consistently. A parametric study is then conducted on frames of different spans. A significant variation in weight between fabricated and conventional hot-rolled steel portal frames is shown; for a 50 m span frame, a 14–19% saving in weight was achieved. Furthermore, since Universal Beam sections in the UK come from a discrete section library, the results could also provide overall dimensions of other beams that could be more efficient for portal frames. Eurocode 3 was used for illustrative purposes; any alternative code of practice may be used.

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BACKGROUND: Web-based programs are a potential medium for supporting weight loss because of their accessibility and wide reach. Research is warranted to determine the shorter- and longer-term effects of these programs in relation to weight loss and other health outcomes.

OBJECTIVE: The aim was to evaluate the effects of a Web-based component of a weight loss service (Imperative Health) in an overweight/obese population at risk of cardiovascular disease (CVD) using a randomized controlled design and a true control group.

METHODS: A total of 65 overweight/obese adults at high risk of CVD were randomly allocated to 1 of 2 groups. Group 1 (n=32) was provided with the Web-based program, which supported positive dietary and physical activity changes and assisted in managing weight. Group 2 continued with their usual self-care (n=33). Assessments were conducted face-to-face. The primary outcome was between-group change in weight at 3 months. Secondary outcomes included between-group change in anthropometric measurements, blood pressure, lipid measurements, physical activity, and energy intake at 3, 6, and 12 months. Interviews were conducted to explore participants' views of the Web-based program.

RESULTS: Retention rates for the intervention and control groups at 3 months were 78% (25/32) vs 97% (32/33), at 6 months were 66% (21/32) vs 94% (31/33), and at 12 months were 53% (17/32) vs 88% (29/33). Intention-to-treat analysis, using baseline observation carried forward imputation method, revealed that the intervention group lost more weight relative to the control group at 3 months (mean -3.41, 95% CI -4.70 to -2.13 kg vs mean -0.52, 95% CI -1.55 to 0.52 kg, P<.001), at 6 months (mean -3.47, 95% CI -4.95 to -1.98 kg vs mean -0.81, 95% CI -2.23 to 0.61 kg, P=.02), but not at 12 months (mean -2.38, 95% CI -3.48 to -0.97 kg vs mean -1.80, 95% CI -3.15 to -0.44 kg, P=.77). More intervention group participants lost ≥5% of their baseline body weight at 3 months (34%, 11/32 vs 3%, 1/33, P<.001) and 6 months (41%, 13/32 vs 18%, 6/33, P=.047), but not at 12 months (22%, 7/32 vs 21%, 7/33, P=.95) versus control group. The intervention group showed improvements in total cholesterol, triglycerides, and adopted more positive dietary and physical activity behaviors for up to 3 months verus control; however, these improvements were not sustained.

CONCLUSIONS: Although the intervention group had high attrition levels, this study provides evidence that this Web-based program can be used to initiate clinically relevant weight loss and lower CVD risk up to 3-6 months based on the proportion of intervention group participants losing ≥5% of their body weight versus control group. It also highlights a need for augmenting Web-based programs with further interventions, such as in-person support to enhance engagement and maintain these changes.


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Background: Traffic light labelling of foods—a system that incorporates a colour-coded assessment of the level of total fat, saturated fat, sugar and salt on the front of packaged foods—has been recommended by the UK Government and is currently in use or being phased in by many UK manufacturers and retailers. This paper describes a protocol for a pilot randomised controlled trial of an intervention designed to increase the use of traffic light labelling during real-life food purchase decisions.

Methods/design: The objectives of this two-arm randomised controlled pilot trial are to assess recruitment, retention and data completion rates, to generate potential effect size estimates to inform sample size calculations for the main trial and to assess the feasibility of conducting such a trial. Participants will be recruited by email from a loyalty card database of a UK supermarket chain. Eligible participants will be over 18 and regular shoppers who frequently purchase ready meals or pizzas. The intervention is informed by a review of previous interventions encouraging the use of nutrition labelling and the broader behaviour change literature. It is designed to impact on mechanisms affecting belief and behavioural intention formation as well as those associated with planning and goal setting and the adoption and maintenance of the behaviour of interest, namely traffic light label use during purchases of ready meals and pizzas. Data will be collected using electronic sales data via supermarket loyalty cards and web-based questionnaires and will be used to estimate the effect of the intervention on the nutrition profile of purchased ready meals and pizzas and the behavioural mechanisms associated with label use. Data collection will take place over 48 weeks. A process evaluation including semi-structured interviews and web analytics will be conducted to assess feasibility of a full trial.

Discussion: The design of the pilot trial allows for efficient recruitment and data collection. The intervention could be generalised to a wider population if shown to be feasible in the main trial.

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In this paper, a novel nanolens with super resolution, based on the photon nanojet effect through dielectric nanostructures in visible wavelengths, is proposed. The nanolens is made from plastic SU-8, consisting of parallel semi-cylinders in an array. This paper focuses on the lens designed by numerical simulation with the finite-difference time domain method and nanofabrication of the lens by grayscale electron beam lithography combined with a casting/bonding/lift-off transfer process. Monte Carlo simulation for injected charge distribution and development modeling was applied to define the resultant 3D profile in PMMA as the template for the lens shape. After the casting/bonding/lift-off process, the fabricated nanolens in SU-8 has the desired lens shape, very close to that of PMMA, indicating that the pattern transfer process developed in this work can be reliably applied not only for the fabrication of the lens but also for other 3D nanopatterns in general. The light distribution through the lens near its surface was initially characterized by a scanning near-field optical microscope, showing a well defined focusing image of designed grating lines. Such focusing function supports the great prospects of developing a novel nanolithography based on the photon nanojet effect.

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Objectives: To explore children's accounts of their experiences of the UK‘s largest childhood obesity programme, MEND (Mind, Exercise, Nutrition…Do it!) (See www.mendprogramme.org). Design: Semi-structured interviews were conducted with children who had completed the MEND obesity programme. Interviews were transcribed verbatim and analysed using Interpretative Phenomenological Analysis (IPA). Method Fourteen children spanning diverse areas of London comprised this study (eight male, six female), aged between 11 and 14 years and in secondary school. Participants were interviewed a year after completing one of the London-based MEND obesity programmes. Results: This article focuses on the most common and striking theme to emerge from the original dataset (The complete analysis may be found in L. Watson, Unpublished doctoral thesis): Fun. Subthemes were: ‘going with the flow’; active participation in activities that led to new experiences (‘actually doing it’ – seeing the fun side); the importance of others in the experience of fun (‘you do games in unity’ – ‘it's not as fun on your own’). Conclusion: Children have fun when engaged in interactive and varied activities with opportunity for individual feedback and improvement. When designing childhood obesity programmes, conditions that optimise children's experience of fun should be emphasised over didactic and risk-heavy information pertaining to childhood obesity.