646 research outputs found

    Introduction to the Virtual Element Method for 2D Elasticity

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    An introductory exposition of the virtual element method (VEM) is provided. The intent is to make this method more accessible to those unfamiliar with VEM. Familiarity with the finite element method for solving 2D linear elasticity problems is assumed. Derivations relevant to successful implementation are covered. Some theory is covered, but the focus here is on implementation and results. Examples are given that illustrate the utility of the method. Numerical results are provided to help researchers implement and verify their own results.Comment: 28 pages, 9 figures Corrections: Section 13: strain operator definition now refers to some equations in the paper for clarification on using the strain operator Section 13: Typo fixed regarding dimensions of capital Pi matri

    Defects in Self Assembled Colloidal Crystals

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    Colloidal self assembly is an efficient method for making 3-D ordered nanostructures suitable for materials such as photonic crystals and macroscopic solids for catalysis and sensor applications. Colloidal crystals grown by convective methods exhibit defects on two different scales. Macro defects such as cracks and void bands originate from the dynamics of meniscus motion during colloidal crystal growth while micro defects like vacancies, dislocation and stacking faults are indigenous to the colloidal crystalline structure. This paper analyses the crystallography and energetics of the microscopic defects from the point of view of classical thermodynamics and discusses the strategy for the control of the macroscopic defects through optimization of the liquid-vapor interface.Singapore-MIT Alliance (SMA

    The influence of substrate roughness, patterning, curvature, and compliance in peeling problems

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    NMP is supported by the European Commission under the Graphene FET Flagship (WP14 'Polymer composites' No. 604391) and FET Proactive 'Neurofibres' grant No. 732344. FB is supported by 'Neurofibres' grant No. 732344

    In utero exposure to cigarette smoking, environmental tobacco smoke and reproductive hormones in US girls approaching puberty

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    BACKGROUND/AIMS: Evidence is unclear whether prenatal smoking affects age at menarche and pubertal development, and its impact upon hormones has not been well studied. We aim to identify potential pathways through which prenatal smoking and environmental tobacco smoke (ETS) affect reproductive hormones in girls approaching puberty. METHODS: We examined the association between prenatal smoking, current ETS and luteinizing hormone (LH) and inhibin B (InB) in 6- to 11-year-old girls in the 3rd National Health and Nutrition Examination Survey, 1988-1994. Parents/guardians completed interviewer-assisted questionnaires on health and demographics at the time of physical examination. Residual blood samples were analyzed for reproductive hormones in 2008. RESULTS: Of 660 girls, 19 and 39% were exposed to prenatal smoke and current ETS, respectively. Accounting for multiple pathways in structural equation models, prenatally exposed girls had significantly lower LH (β = -0.205 log-mIU/ml, p < 0.0001) and InB (β = -0.162, log-pg/ml, p < 0.0001). Prenatal smoking also influenced LH positively and InB negatively indirectly through BMI-for-age. ETS was positively associated with LH, but not with InB. CONCLUSION: Exposure to maternal smoking may disrupt reproductive development manifesting in altered hormone levels near puberty

    Interrelationships and consequential effects among technological innovation, service consistency, customer satisfaction and loyalty in banking

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    The key to long-term success in banking is consistent improvement and delivering of quality product and or value-added service that conform to the expectations of customers. IT-innovative products/services and processes (technological innovation) facilitate these key elements of customer satisfaction and critical factors for retaining valued customers. The objective of this paper is to explore the effects of technological innovation on service consistency and the consequential effects on customer satisfaction and loyalty covering seven universal banks in Ghana. The results of the empirically tested model reveal new/improved product/process functionalities, service consistency and innovative product/process satisfaction contribute significantly to customer loyalty (p &lt; 0.001). Service consistency has a marginal higher impact (? = .373) on customer loyalty than the others. Product/process quality contributes significantly (with ? ranging from .345 to .742 and p &lt; 0.001) to each of the above three antecedents than all other items

    Evidence of extrinsic factors dominating intrinsic blood host preferences of major African malaria vectors.

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    One of the key determinants of a haematophagous vector's capacity to transmit pathogens is its selection of which host to secure a blood meal from. This choice is influenced by both intrinsic (genetic) and extrinsic (environmental) factors, but little is known of their relative contributions. Blood fed Anopheles mosquitoes were collected from a malaria endemic village in Ghana. Collections were conducted across a range of different host availabilities and from both indoor and outdoor locations. These environmental factors were shown to impact dramatically the host choice of caught malaria vectors: mosquitoes caught indoors were ten-fold more likely to have sourced their blood meal from humans; and a halving in odds of being human-fed was found for mosquitoes caught only 25 m from the centre of the village. For the first time, we demonstrate that anthropophagy was better explained by extrinsic factors (namely, local host availability and indoor/outdoor trapping location) than intrinsic factors (namely, the (sibling) species of the mosquito caught) (respective Akaike information criterion estimates: 243.0 versus 359.8). Instead of characterizing biting behaviour on a taxonomic level, we illustrate the importance of assessing local entomology. Accounting for this behavioural plasticity is important, both in terms of measuring effectiveness of control programmes and in informing optimal disease control strategies

    Relation of dietary fat intake perception to nutritional status and psychosocial factors

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    Excess dietary fat intake is associated with many chronic diseases. This cross-sectional study determines the differences in nutritional status and diet-related psychosocial factors by accuracy levels of dietary fat intake perceptions among adults. A total of 202 Universiti Putra Malaysia staff (20-55 years old) volunteered to participate in the study. Dietary fat accuracy levels (under-estimate, accurate and over-estimate) were determined by assessing actual fat intake through 24-hour diet recall and self-rated fat intake. Diet-related psychosocial factors assessed were perceived risks, intention to change, outcome expectancies and perceived barriers. About half (49.5%) of the respondents were classified as accurate estimators, while 35.6% and 14.9% were under-estimators and over-estimators, respectively. Dietary fat intake differed significantly between the dietary fat accuracy groups with under-estimators having the highest amount of dietary fat intake (F=17.10; p<0.001) and percentage of fat calories (F=103.99 ± 0.533%, p<0.001). Over-estimators had the highest mean BMI (F=3.11, p<0.05) compared to other groups. Among the fat accuracy groups, under-estimators reported the least barriers to eating low fat foods (F= 3.671, p<0.05). There were no significant differences in waist circumference, energy intake, perceived disease risks, intention to change and outcome expectancies among the dietary fat accuracy groups. These findings suggest that inaccurate perceptions of dietary fat intake should not be overlooked as one of the cognitive barriers to dietary change and factors that influence nutritional status among adults

    Bioavailability and biochemical effects of diclofenac sodium 0.1% ophthalmic solution in the domestic chicken (Gallus gallus domesticus)

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    Objective To determine if topical ophthalmic diclofenac sodium 0.1% solution alters renal parameters in the domestic chicken, and to determine if the drug is detectable in plasma after topical ophthalmic administration. Animals Thirty healthy domestic chickens Procedures Over seven days, 6 birds were treated unilaterally with 1 drop of artificial tear solution (group 1), 12 birds were treated unilaterally (group 2) and 12 bilaterally (group 3) with diclofenac sodium 0.1% ophthalmic solution. Treatments were provided for 7 days, every 12 hours in all groups. Pre- and post-treatment plasma samples from all birds were evaluated for changes in albumin, total protein, and uric acid. Post-treatment samples of all birds were also analyzed by HPLC-MS for detection of diclofenac sodium. Results Changes in pre- and post-treatment plasma albumin were significant (P \u3c 0.05) in groups 2 and 3, but not for group 1. Pre- and post-treatment changes in total protein and uric acid pre- and post-treatment were not significant for any group. Diclofenac sodium was not detectable (limit of detection = 0.10 ng/mL) in plasma samples from birds in group 1. Concentration of drug in group 3 was statistically greater than group 2 (P = 0.0008). Conclusions and Clinical Relevance Topical ophthalmic diclofenac sodium 0.1% administered every 12 hours in one or both eyes for 7 days is detectable in systemic circulation in the domestic chicken at 15 minutes post-administration, but did not cause overt changes in parameters used to monitor renal physiology

    Economic feasibility assessment of one and two stages dry fractionation of palm kernel oil.

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    Palm kernel oil can be fractionated into stearin and olein fractions. Traditionally, industrial players only fractionate the softer stearin fraction and harden it through complete hydrogenation. One stage dry fractionation yielded 37% of softer or 24% of harder stearin fraction. Two stages dry fractionation yielded 24% harder and 11% softer stearin fractions. Even though two stages dry fractionation salvaged up to 14% of the softer stearin fraction from the normally discounted palm kernel olein fraction, the double fractionation process was not always commercially feasible. Deciphering actual price statistics revealed that on a per metric tonne basis, the refining premium ranged from MYR90 to 250. Palm kernel olein discount was as high as 9% but could command premium over crude PKO by up to 2.5%. Due to the intrinsic relationship, the corresponding palm kernel stearin breakeven value could range from discount of MYR90 to premium of MYR1260 over crude PKO. The actual 60 months average market premium for palm kernel stearin stood at MYR870, promising an average MYR430 returns to refiners and processors. By incorporating two stages dry fractionation when the PKL discount was greater than 2.43%, refiners and processors could boost their net margins. When the PKL discount was 9%, the net margin could be boosted by up to 16%
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