29 research outputs found
Final phase-resolving Boussinesq-type models (D42)
No full textThe design of structures to be built in the nearshore region generally involves the evaluation of different possible layouts, under the effects of local wave and cunents conditions, with the aim of minimizing costs and maximizing the desired results. In particular the design of lowcrested structures involves optimisation of several parameters, which influence both the position, and the shape of the structures. The possible layout of the structures to be designed can be tested experimentally in wave tanks and wave flumes using adequate scale models. An alternative and attractive procedure is to employ suitable numerical and mathematical models. In principle, a very advanced numerical model, able to conectly simulate all the nearshore phenomena (turbulence, waves, currents, sediment transport, etc.) could be equivalent or even superior to a physical model. In practice, the numerical models currently employed in engineering activities, use several assumptions and simplifications: the phenomena that can be simulated strictly depend on the governing equations solved by the model. Indeed, the great advantage of numerical and mathematica! models is that their application is usually much less expensive than physical ones: it is certainly more economie to modify a computer file describing the bathymetry of the area under investigation than rebuild a physical model layout. This report is structured into two discrete sections, the first one contributed by AUTh and the second one by UR3. In the first section a 2DH higher-order Boussinesq-type model combined with a porous flow model, developed tor simulating flow around porous submerged structures is presented. On the other hand, in the second section enhancements on the applicability of Boussinesq-type equations (BTE) into the surf and swash zone are described.Delo
Dry port network model: Best practices in the EU with notes from the USA
No full textThe modern distribution of goods is highly complex, as it supports a closely linked globalized world. In the development of port terminals, competition is no longer only at the level of services. The increase in maritime transport and demand/supply in the hinterlands, with ensuing problems of capacity, distribution and movement, have called for renewed attention on adequate structures and infrastructures. This evolution, enabled by technology, commercial interests and public policies, can be considered as a stage in the ongoing development of containerization and intermodal transport. At this stage, it is important to consider port terminals and maritime navigation networks as a system, together with terrestrial goods transport. Increasingly, regions are developing so-called dry or inland ports, to better serve the demand. We set out to define a sustainable model for dry ports, beginning with a review of relevant literature focused on Italian, Dutch and selected USA examples. We first define dry port, in the context of intermodal transport, ports in general and inland ports. Our investigation led to the identification of management tools and best practices. We report on visits and interviews to selected inland ports and identify key dry port activities, applications of innovative technologies and implications for different modes of transport. For the three countries studied, we identify strengths and weaknesses related to infrastructure, structures, internal organization of yard, types of imported and exported goods, transport methods and related travel times and costs. In regards to resilience and sustainability, vulnerabilities such as congestion, climate issues and cyber-attacks are considered. Finally, a maturity model for assessing dry ports is proposed.Transport and Logistic
Development of a novel biocompatible drug delivery platform for ophthalmic conditions
No full textGlaucoma is a chronic optic neuropathy that affects an estimated 70 million people worldwide of which 7 million are blind. It is the number one cause of irreversible blindness and the only proven modifiable risk factor is raised intra-ocular pressure (IOP). Glaucoma treatment aims to reduce IOP and can be in the form of eye drops, laser or surgery. Surgery aims to increase outflow mechanism for drainage of aqueous humour from the anterior chamber. This can be in the form of glaucoma filtration surgery (GFS) or insertion of a glaucoma drainage device (GDD). GFS is complicated by scarring in the post-operative period and GDD surgery insertion is complicated by the development of a fibrous encapsulation around the device. This encapsulation initially acts as a flow control mechanism but subsequently results in device failure. Factors that may influence this include: the material surface quality, the shape of the device and the device material. 2-methacryloyloxyethyl (MPC) is used as a synthetic polymer based coating that has been demonstrated to prevent the occurrence of coronary artery stenosis. The aim of this investigation was to assess the in vitro biocompatibility of 3D printed and PC based materials compared to materials used in current ophthalmic devices. Sterility testing was performed using ethanol and autoclaving processes, commonly used techniques for the development of ophthalmic devices. Adhesion of monocytes, macrophages and fibroblasts to material surfaces was assessed using live stain, Alamar Blue and CyQUANT assays and fluorescent microscopy. Adsorption of albumin and fibrinogen was assessed using SDS Page Gel Electrophoresis, UV Photospectrometry, Fluorescein Isothiocyanate Labelled Bovine Serum Albumin (FITC-BSA) and Micro Bicinchoninic Acid (BCA) techniques. PC based materials (containing 5 and 15% MPC) were compared to Polytetrafluoroethylene (PTFE), Polyethylene Terephthalate (PET), Polymethyl Methacrylate (PMMA), Silicone, 2-hydroxyethyl methacrylate (HEMA) and a contact lens that contains 15% MPC. It was observed that PC based materials demonstrated less cellular and protein adhesion than materials used in current ophthalmic devices but more than a contact lens of similar composition. This suggests that the manufacturing process may play a role in the biocompatibility response and these studies were therefore repeated with different contact lenses based on the Food & Drug Administration (FDA) grouping of contact lenses. PC is a potential material that can be used to improve biocompatibility of ophthalmic devices. Future work will be performed to develop a novel drug delivery platform that can be used in the treatment of ophthalmic conditions
Molecular yardsticks.
No full textThe synthesis and chemistry of a family of Equilibrium Transfer Alkylating Crosslink (ETAC) reagents with extended conjugation were developed. These cross-functionalized reagents were designed for protein cross-link studies. The exchange chemistry of the three carbon bridge 2,2-bis(4-tolylsulfonylmethyl)-m-nitroacetophenone with sulfur and nitrogen nucleophiles was studied where it was determined that: (1) the m-nitrobenzoyl group is a sufficient activating function; (2) the sulfonyl function is a suitable leaving group for undergoing an elimination necessary for the ETAC process. The extended reagents were then prepared. These substituted diene, triene, and tetraene-1-one ETAC reagents were synthesized by a titanium tetrachloride-diisopropylethylamine aldol/dehydration sequence. The exchange chemistry of the extended ETAC reagents with mercaptans was a function of the length and substitution of the extended reagents. Thus, 2-(2-hydroxyethylsulfonylmethyl)-m-nitro-2(Z),4-pentadienophenone undergoes reaction with two equivalents of ethanethiol to form the dithiolether, while 2-(2-hydroxyethylsulfonylmethyl)-5-(p-nitrophenyl)-m-nitro-2(Z),4(E)-pentadienophenone remained unchanged under the same reaction conditions. The exchange chemistry with dimercaptans is a more accurate model of a protein system. The reactions with dimercaptans gave macrocyclic structures. The isolation of crystalline macrocycles containing trans double bonds in 50-55% yields was possible with several of the extended ETAC reagents. The architecture of the adding bis-mercaptan was also important; the adding bis-mercaptan must be long enough to bridge the extended ETAC reagent. The ETAC reagents were successful in the cross-linking of proteins. The aldol/dehydration reaction mediated by titanium tetrachloride was extensively studied. It was possible to prepare: (1) a water soluble extended ETAC reagent, 2-(2-trimethylammoniumethylthiomethyl)-m-nitro-2(Z),4-pentadienophenone; (2) an aliphatic extended ETAC reagent, 3-(2-hydroxyethylsulfonylmethyl)hexa-3(Z),5-diene-2-one; and (3) an extended double-armed ETAC reagent, 2- (3-(2-hydroxyethylsulfonyl)-1-propenyl) -m-nitro-2(E),4-hexadienophenone. These ETAC reagents underwent the corresponding exchange reactions with mono and bis-mercaptans.PhDBiochemistryHealth and Environmental SciencesImmunologyOrganic chemistryPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/128490/2/9023523.pd
The threshold of motion of coarse sediment particles by regular non-breaking waves
No full textCivil Engineering and Geoscience
Advances in fluid mechanics for offshore engineering: A modelling perspective
No full textpublishedVersion© 2014 The Author(s) Published by the Royal Society. All rights reserved
Noncovalent complexation of amphotericin-B with Poly(α-glutamic acid).
No full textA noncovalent complex of amphotericin B (AmB) and poly(α-glutamic acid) (PGA) was prepared to develop a safe and stable formulation for the treatment of leishmaniasis. The loading of AmB in the complex was in the range of ∼20-50%. AmB was in a highly aggregated state with an aggregation ratio often above 2.0. This complex (AmB-PGA) was shown to be stable and to have reduced toxicity to human red blood cells and KB cells compared to the parent compound; cell viability was not affected at an AmB concentration as high as 50 and 200 μg/mL respectively. This AmB-PGA complex retained AmB activity against intracellular Leishmania major amastigotes in the differentiated THP-1 cells with an EC50 of 0.07 ± 0.03-0.08 ± 0.01 μg/mL, which is similar to Fungizone (EC50 of 0.06 ± 0.01 μg/mL). The in vitro antileishmanial activity of the complex against Leishmania donovani was retained after storage at 37 °C for 7 days in the form of a solution (EC50 of 0.27 ± 0.03 to 0.35 ± 0.04 μg/mL) and for 30 days as a solid (EC50 of 0.41 ± 0.07 to 0.63 ± 0.25 μg/mL). These encouraging results indicate that the AmB-PGA complex has the potential for further development
Author response: Ab interno versus ab externo surgical approach on outflow resistance of a subconjunctival drainage device
No full text
