453 research outputs found

    Commercial Common Sense in Contract Interpretation: Observations on the Court of Appeal in Technix v Fitzroy and The Malthouse v Rangatira

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    The contemporary principles of contract interpretation require courts to have regard to a number of factors to determine the meaning of a contract, including the plain meaning of the express contractual language, the contract's context, and commercial common sense. These principles superseded the narrower plain meaning rule, which directed courts to interpret contracts in a manner largely consistent with the plain and ordinary meaning of their express words. Since their manifestation some 20 years ago, these principles have undergone change, development and elaboration to the extent that some commentators now claim the approach to contract interpretation more closely resembles the former plain meaning rule, with courts giving "primacy" to the words of the contract in order to deliver "commercial certainty". This article argues that while courts must give primacy to the express contractual language, that does not mean courts should maintain an unwavering loyalty to the plain meaning of those words, even if their meaning is clear. Courts that adopt this approach, referred to by some as the "conservative approach", risk obscuring the true meaning of a contract that can only be obtained through the careful balancing of a contract's internal and external factors, including commercial common sense. This article demonstrates the problem with the "conservative approach" through the analysis of two Court of Appeal decisions, and argues that courts should not overstate the circumstances in which departure from the plain meaning of a contract should occur

    Qualitative and quantitative contaminants assessment in recycled pellets from post-consumer plastic waste by means of spectroscopic and thermal characterization

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    The complexity of any plastic recycling initiative lies in the heterogeneous nature of the post-consumer commingled plastic waste stream: recycling treatments are challenging without prior reliable sorting. A suitable identification system should be able to recognize different plastics and blends. Nowadays, the main technique used as quality control in plastic waste sorting centers is differential scanning calorimetry, whose result can be purely qualitative or semi-quantitative, since only the crystalline fraction is evaluated. Moreover, the time required for data acquisition is relatively long. Infrared spectroscopy is an alternative, faster technique extensively used in applied research, but not widely utilized in industry. In this work, the cross-use of infrared spectroscopy and calorimetry is tested in a real, practical case: the quality control of recycled pellets (namely composed of polyolefins only), which represent the output of a commingled plastic recycling plant and are used as secondary raw materials for different applications. Appropriate infrared spectroscopy calibration curves were built to allow the quantitative analysis with respect to the most common polymers found in the commingled plastic waste stream; the composition and contaminants in the recycled pellets were thereby determined and tracked through different production batches through the cross-use of the two techniques outlined above

    Innovative Thermal and Acoustic Insulation Foams from Recycled Fiberglass Waste

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    This study examines a lightweight thermal and acoustic insulation material, produced starting from a hydrogel-based mixture composed by renewable biopolymer and fiberglass waste powders. The gel 3D porous network is preserved after water removal by sublimation, resulting in a lightweight thermal and acoustic insulation material with good overall performance. Mechanical, thermal, and acoustic properties can be tuned as a function of biopolymer and additives concentration. This material addresses environmental concerns both in terms of secondary raw sources use and fiberglass waste disposal. Moreover, contrary to mineral wools currently on the market, it can overcome the problem of fiber release, with significant human health benefits. Thanks to its good properties and its fabrication process based on a circular economy approach, it can be appealing for thermal and acoustic insulating applications in building and industrial sectors and also in terms of environmental footprint

    Redox control of IL-6-mediated dental pulp stem cell differentiation on alginate/hydroxyapatite biocomposites for bone ingrowth

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    Composites and porous scaffolds produced with biodegradable natural polymers are very promising constructs which show high biocompatibility and suitable mechanical properties, with the possibility to be functionalized with growth factors involved in bone formation. For this purpose, alginate/hydroxyapatite (Alg/HAp) composite scaffolds using a novel production design were successfully developed and tested for their biocompatibility and osteoconductive properties in vitro. Redox homeostasis is crucial for dental pulp stem cell (DPSC) differentiation and mineralized matrix deposition, and interleukin-6 (IL-6) was found to be involved not only in immunomodulation but also in cell proliferation and differentiation. In the present study, we evaluated molecular pathways underlying the intracellular balance between redox homeostasis and extracellular matrix mineralization of DPSCs in the presence of composite scaffolds made of alginate and nano-hydroxyapatite (Alg/HAp). Prostaglandin-2 (PGE2) and IL-6 secretion was monitored by ELISA assays, and protein expression levels were quantified by Western blotting. This work aims to demonstrate a relationship between DPSC capacity to secrete a mineralized matrix in the presence of Alg/HAp scaffolds and their immunomodulatory properties. The variation of the molecular axis Nrf2 (nuclear factor erythroid 2-related factor 2)/PGE2/IL-6 suggests a tight intracellular balance between oxidative stress responses and DPSC differentiation in the presence of Alg/HAp scaffolds

    Ant-nest corrosion failure of heat exchangers copper pipes

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    This paper reports on the failure analysis carried out on leaking copper pipes from three different air conditioning systems. Pinhole leaks originating from localized corrosion morphology were reported. Microscopic interconnecting tunnels inside the pipe section were observed; these tunnels were filled with corrosion products. Experimental findings and similarity to previously reported cases pointed out a corrosion mechanism known as \u201cant-nest corrosion\u201d as failure cause. This type of corrosion could develop in heat exchanger components stored after assembly, during leakage tests or in the initial operational stages. It was shown that an ant-nest corrosion attack could start due to different reasons and propagate in different ways (from the inside or from the outside of the tube). In the first examined case, it was supposed that the hydrolysis of a halocarbon gas circulating in the pipe was the triggering cause of the corrosion event; in the other cases, we ascribed the starting corrosion event to the presence of residual organic contaminants on the external pipe surface

    CARATTERIZZAZIONE DI PROTEINE NUCLEARI INTERAGENTI CON IL DNA RIPETITIVO TELOMERICO DEI VERTEBRATI

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    1999/2000XII Ciclo1971Versione digitalizzata della tesi di dottorato cartacea

    Antibacterial and bioactive multilayer electrospun wound dressings based on hyaluronic acid and lactose-modified chitosan

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    Antibacterial multilayer electrospun matrices based on hyaluronic acid (HA) and a lactose-modified chitosan (CTL) were synthetized (i) by combining electrospun polycaprolactone (PCL) and polysaccharidic matrices in a bilayer device and (ii) by sequentially coating the PCL mat with CTL and HA. In both cases, the antibacterial activity was provided by loading rifampicin within the PCL support. All matrices disclosed suitable morphology and physicochemical properties to be employed as wound dressings. Indeed, both the bilayer and coated fibers showed an optimal swelling capacity (3426 ± 492 % and 1435 ± 251 % after 7 days, respectively) and water vapor permeability (160 ± 0.78 g/m2h and 170 ± 12 g/m2h at 7 days, respectively). On the other hand, the polysaccharidic dressings were completely wettable in the presence of various types of fluids. Depending on the preparation method, a different release of both polysaccharides and rifampicin was detected, and the immediate polysaccharide dissolution from the bilayer structure impacted the antibiotic release (42 ± 4 % from the bilayer structure against 25 ± 2 % from the coated fibers in 4 h). All the multilayer matrices, regardless of their production strategy and composition, revealed optimal biocompatibility and bioactivity with human dermal fibroblasts, as the released bioactive polysaccharides induced a faster wound closure in the cell monolayer (100 % in 24 h) compared to the controls (78 ± 8 % for untreated cells and 89 ± 5 % for cells treated with PCL alone, after 24 h). The inhibitory and bactericidal effects of the rifampicin loaded matrices were assessed on S. aureus, S. epidermidis, E. coli, and P. aeruginosa. The antibacterial matrices were found to be highly effective except for E. coli, which was more resistant even at higher amounts of rifampicin, with a bacterial concentration of 6.4 ± 0.4 log CFU/mL and 6.8 ± 0.3 log CFU/mL after 4 h in the presence of the rifampicin-loaded bilayer and coated matrices, respectively

    Alginate membranes loaded with hyaluronic acid and silver nanoparticles to foster tissue healing and to control bacterial contamination of non-healing wounds

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    Chronic non-healing wounds are a clinically important problem in terms of number of patients and costs. Wound dressings such as hydrogels, hydrocolloids, polyurethane films and foams are commonly used to manage these wounds since they tend to maintain a moist environment which is shown to accelerate re-epithelialization. The use of antibacterial compounds is important in the management of wound infections. A novel wound-dressing material based on a blended matrix of the polysaccharides alginate, hyaluronic acid and Chitlac-silver nanoparticles is here proposed and its application for wound healing is examined. The manufacturing approach to obtain membranes is based on gelling, foaming and freeze-casting of alginate, hyaluronic acid and Chitlac-silver nanoparticles mixtures using calcium ions as the cross-linking agent. Comprehensive evaluations of the morphology, swelling kinetics, permeability, mechanical characteristics, cytotoxicity, capability to inhibit metalloproteinases and of antibacterial property were conducted. Biological in vitro studies demonstrated that hyaluronic acid released by the membrane is able to stimulate the wound healing meanwhile the metal silver exploits an efficient antibacterial activity against both planktonic bacteria and biofilms. Overall, the experimental data evidence that the studied material could be used as antibacterial wound dressing for wound healing promotion

    Recycling alginate composites for thermal insulation

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    We present a new method for the total functional recycling of alginate-based composite materials made via ionotropic gelation. The original material, an alginate/fiberglass foam with thermal insulation characteristics, was produced following a patented process in which fiberglass waste is embedded into the polyanionic gel matrix, and the resulting compound is then freeze-dried. The functional recycling is carried out by disassembling the ionic matrix \u2013 which is initially formed by the interaction between a cation (e.g. calcium) and the negatively charged alginate backbone \u2013 with the use of a chelator (Ethylenediaminetetraacetic acid disodium salt) with a high affinity for the cations, thus obtaining a homogeneous solution. An ionotropic gel can then be re-formed upon deactivation of the chelating activity under mild acid conditions. We managed to maintain or improve the thermal, mechanical and acoustic performances of the original material and we successfully tested the possibility of multiple recycling cycles

    A hydrogel system based on a lactose-modified chitosan for viscosupplementation in osteoarthritis

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    Osteoarthritis (OA) is a chronic disease affecting joint functionality and often managed with hyaluronic acid (HA) administration. In this study, a hydrogel based on a lactose-modified chitosan (CTL) reticulated with boric acid has been developed as a viscosupplement for OA treatment. The rheological characterization allowed to identify a composition whose properties were in line with those of commercial products (in the order of tens of Pascal). The selected CTL-hydrogel showed biocompatibility and antioxidant activity in vitro, and it did not influence cytokines release by macrophages. Degradation studies carried out over 24 h pointed out its higher resistance to chemical degradation with respect to HA samples. Overall, this study underlines the advantages of the CTL-hydrogel to address the treatment of OA and shed light on an innovative application of CTL polymer, which is one of the main component of the proposed hydrogel system and not used in mixture with other molecules
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