114 research outputs found

    Parameters Affecting Genetic Algorithm In Leak Detection By Inverse Transients Analysis

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    A CASE STUDY: INTELLIGENT SHADING RETROFIT TO EXISTING HOME-OFFICE USING MULTI-OBJECTIVE OPTIMIZATION

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    Improved energy performance and occupant comfort are driving building design decisions due to the increasing demand for sustainable and green buildings. However, despite the variety of technological developments in other fields, the range of solutions to improve building performance is limited. One of the main limitations for an early designer is a performance evaluation method to facilitate the design process. This paper offers a new shading performance optimization process that can help designers evaluate both daylighting and energy performance and generate optimized and flexible designs that can be further improved by implementing user-specific automation. The proposed performance optimization method utilizes parametric design, building simulation models, and Genetic Algorithms. Common shading design systems are explored through parametric design, and daylighting and energy modeling simulations are performed to evaluate shading device performance. Genetic Algorithms are used to identify design options with optimal energy and daylighting performance. A case study is conducted to verify the effectiveness of the overall process. Results are used to analyze the influence of design decisions among different shading designs. Finally, future directions in both shading design and energy optimization are presented

    Solvent-free electrospinning of liquid polybutadienes and their in-situ photocuring

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    A single-step approach to rapidly convert low molecular weight polybutadienes into fine rubber crosslinked fibers and nonwoven mats without using any heat or solvent was described. This environmentally friendly method consisted in the electrospinning at room temperature of liquid polybutadiene and polybutadiene-graft-maleic anhydride polymers without any solvent; the flying jet was irradiated to trigger the in-situ curing of the forming fibers at ambient conditions, obtaining a good control over the fibrous morphology and enhancing the performance of the membranes. The kinetics of the photo-crosslinking reaction was studied through FT-IR spectroscopy. Liquid polybutadiene-graft-maleic anhydride polymers demonstrated a faster rate of photocuring, compared to neat polybutadienes. In order to further speed up the reaction, a thiol-based crosslinker and a photoinitiator were introduced into the formulations. The photo-induced crosslinking was more efficient as different reactions concomitantly took place: besides the thiol-ene crosslinking involving the multifunctional thiol crosslinker, the oxidation of the polybutadiene chains and the esterification of the maleic anhydride moieties occurred. Moreover, a polar additive was used to control the electrospinning process by lowering the viscosity and increasing the electrical conductivity. The structural, thermal and surface properties of the fabricated polybutadiene-based electrospun membranes were assessed. The membranes exhibited an excellent morphology stability, high insolubility, good thermal properties and a pronounced hydrophobic character

    Formulation, characterisation and stabilisation of buccal films for paediatric drug delivery of omeprazole

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    This study aimed to develop films for potential delivery of omeprazole (OME) via the buccal mucosa of paediatric patients. Films were prepared using hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), sodium alginate (SA), carrageenan (CA) and metolose (MET) with polyethylene glycol (PEG 400) as plasticiser, OME (model drug) and L-arg (stabiliser). Gels (1% w/w) were prepared at 40°C using water and ethanol with PEG 400 (0–1% w/w) and dried in an oven (40°C). Optimised formulations containing OME and L-arg (1:1, 1:2 and 1:3) were prepared to investigate the stabilisation of the drug. Tensile properties (Texture analysis, TA), physical form (differential scanning calorimetry, DSC; X-ray diffraction, XRD; thermogravimetric analysis, TGA) and surface topography (scanning electron microscopy, SEM) were investigated. Based on the TA results, SA and MET films were chosen for OME loading and stabilisation studies as they showed a good balance between flexibility and toughness. Plasticised MET films were uniform and smooth whilst unplasticised films demonstrated rough lumpy surfaces. SA films prepared from aqueous gels showed some lumps on the surface, whereas SA films prepared from ethanolic gels were smooth and uniform. Drug-loaded gels showed that OME was unstable and therefore required addition of L-arg. The DSC and XRD suggested molecular dispersion of drug within the polymeric matrix. Plasticised (0.5% w/w PEG 400) MET films prepared from ethanolic (20% v/v) gels and containing OME: L-arg 1:2 showed the most ideal characteristics (transparency, ease of peeling and flexibility) and was selected for further investigation

    Ciprofloxacin-loaded calcium alginate wafers prepared by freeze-drying technique for potential healing of chronic diabetic foot ulcers

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    Calcium alginate (CA) wafer dressings were prepared by lyophilization of hydrogels to deliver ciprofloxacin (CIP) directly to the wound site of infected diabetic foot ulcers (DFUs). The dressings were physically characterized by scanning electron microscopy (SEM), texture analysis (for mechanical and in vitro adhesion properties), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Further, functional properties essential for wound healing, i.e., porosity, in vitro swelling index, water absorption (Aw), equilibrium water content (EWC), water vapor transmission rate (WVTR), evaporative water loss (EWL), moisture content, in vitro drug release and kinetics, antimicrobial activity, and cell viability (MTT assay) were investigated. The wafers were soft, of uniform texture and thickness, and pliable in nature. Wafers showed ideal wound dressing characteristics in terms of fluid handling properties due to high porosity (SEM). XRD confirmed crystalline nature of the dressings and FTIR showed hydrogen bond formation between CA and CIP. The dressings showed initial fast release followed by sustained drug release which can inhibit and prevent re-infection caused by both Gram-positive and Gram-negative bacteria. The dressings also showed biocompatibility (> 85% cell viability over 72 h) with human adult keratinocytes. Therefore, it will be a potential medicated dressing for patients with DFUs infected with drug-resistant bacteria
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