100 research outputs found

    Who governs and what is governed in port governance: a review study

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    Based on an intensive literature review, this paper investigates and presents generalized answers to the two basic questions of port governance, namely who governs and what is governed. There are totally 77 studies selected as the core literature sample according to a five-step approach. The results from literature review show evidences in favor of the important roles played by governmental organizations and port organizations as the main governing bodies of port governance. Furthermore, our analysis shows first, that multilevel governance has become a notable feature of port governance. Second, there are increasing involvements by national or regional levels of government in some countries such as the USA, Brazil, China. Third, port authorities at local level are generally holding the centre-stage position with further autonomy in managing port operations. Fourth, not-for-profit organizations related to port activities play the role of coordinators in port governance. Finally, different governance regimes with different specific governing actors for different port classifications can be identified for many nations. This study shows that fundamentally institutional arrangements and specific port activities are the two basic categories of what is governed. The institutional arrangements determine the port governance configuration and allocation of responsibilities of port activities. There are 12 groups of specific port activities within five categories identified in port governance

    Proposal for an ecofriendly and economic strategy for efficient radioiodination of coumarin derivatives

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    Combination of the calculation of reactivity descriptors and the cold iodine test for some coumarin derivatives was used in order to optimize the radioiodination reaction. The strongly nucleophilic predicted coumarins were subjected to the action of cold iodine. With two coumarins substituted at 3 by the 2-hydroxybenzoyl group, iodination did not occur but a product of intramolecular heterocyclization was obtained. This strategy is useful for economic and environmentally friendly radioiodination.publishe

    Shear band dynamics from a mesoscopic modeling of plasticity

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    The ubiquitous appearance of regions of localized deformation (shear bands) in different kinds of disordered materials under shear is studied in the context of a mesoscopic model of plasticity. The model may or may not include relaxational (aging) effects. In the absence of relaxational effects the model displays a monotonously increasing dependence of stress on strain-rate, and stationary shear bands do not occur. However, in start up experiments transient (although long lived) shear bands occur, that widen without bound in time. I investigate this transient effect in detail, reproducing and explaining a t^1/2 law for the thickness increase of the shear band that has been obtained in atomistic numerical simulations. Relaxation produces a negative sloped region in the stress vs. strain-rate curve that stabilizes the formation of shear bands of a well defined width, which is a function of strain-rate. Simulations at very low strain-rates reveal a non-trivial stick-slip dynamics of very thin shear bands that has relevance in the study of seismic phenomena. In addition, other non-stationary processes, such as stop-and-go, or strain-rate inversion situations display a phenomenology that matches very well the results of recent experimental studies.Comment: 10 pages, 10 figure

    Monotherapy with pixantrone in histologically confirmed relapsed or refractory aggressive B-cell non-Hodgkin lymphoma: post-hoc analyses from a phase III trial.

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    This post hoc analysis of a phase 3 trial explored the effect of pixantrone in patients (50 pixantrone, 47 comparator) with relapsed or refractory aggressive B-cell non-Hodgkin lymphoma (NHL) confirmed by centralized histological review. Patients received 28-d cycles of 85 mg/m(2) pixantrone dimaleate (equivalent to 50 mg/m(2) in the approved formulation) on days 1, 8 and 15, or comparator. The population was subdivided according to previous rituximab use and whether they received the study treatment as 3rd or 4th line. Median number of cycles was 4 (range, 2-6) with pixantrone and 3 (2-6) with comparator. In 3rd or 4th line, pixantrone was associated with higher complete response (CR) (23·1% vs. 5·1% comparator, P = 0·047) and overall response rate (ORR, 43·6% vs. 12·8%, P = 0·005). In 3rd or 4th line with previous rituximab (20 pixantrone, 18 comparator), pixantrone produced better ORR (45·0% vs. 11·1%, P = 0·033), CR (30·0% vs. 5·6%, P = 0·093) and progression-free survival (median 5·4 vs. 2·8 months, hazard ratio 0·52, 95% confidence interval 0·26-1·04) than the comparator. Similar results were found in patients without previous rituximab. There were no unexpected safety issues. Pixantrone monotherapy is more effective than comparator in relapsed or refractory aggressive B-cell NHL in the 3rd or 4th line setting, independently of previous rituximab

    Comparison of thermo-hydraulic performance among different 3D printed periodic open cellular structures

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    As additive manufacturing of periodic open cellular structures (POCS) is gaining interest in structured catalytic reactor research, this work seeks to thermohydraulically compare the well-known Kelvin lattice structure with the lesser-researched BCC and gyroid lattice structures. Using a combined CFD (Computational Fluid Dynamic) and experimental approach, the selected POCS are fabricated through Laser Powder Bed Fusion (LPBF), characterized, and subsequently subjected to numerical analysis. From the manufacturability point of view, the 3D printed samples closely matched their CAD designs, showing a maximum porosity deviation of 15% below design values. A CFD model, validated through pressure drop experiment, was employed to compare the POCS designs on shared geometric attributes such as specific surface area and porosity. While all structures exhibited comparable performance in term of heat and momentum transfer, our findings suggest that the Gyroid lattice may provide the optimal balance between momentum and heat transfer rates in low-velocity region. Conversely, the BCC configuration may be more favourable at higher velocity. An Ergun-like correlation was also developed and validated for each lattice type, with a Mean Absolute Percentage Error (MAPE) below 10%. Our pressure drop results align quite well with existing literature correlations, showing a MAPE under 20%. Concerning heat transfer, the values forecasted in this research show a reasonable alignment with literature's results, though they tend to be on the lower spectrum.</p

    Helosciadium crassipes Koch (Apiaceae) extracts as natural sunscreen and preservative additives

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    Recently, ingredients derived from natural sources have gained increasing interest in the cosmetic field due to their low toxicity. Therefore, this study was designed to explore the cosmetic potential of Helosciadium crassipes Koch (Apiaceae) species growing in Algeria as a promising natural preservative and broad-spectrum UV protection additive. In our study, the in-vitro antioxidant effect was assessed via DPPH radical scavenging and total antioxidant capacity by phosphomolybdenum method (TAC), while the protection against UVB radiation was evaluated according to the sun protection factor (SPF) by using UV spectroscopic technic at wavelengths ranging from 290 to 320 nm and Mansur’s equation, for the photoprotective effect against long-wavelength UVA, UVA/UVB and critical wavelength (λc) parameters were evaluated. The outcomes showed that among the tested extracts, the methanolic extract (MeOH) contains high levels of phenolics and flavonoids, and possesses a significant antioxidant effect, particularly in DPPH radical scavenging assay. Similarly, this last one exhibited high photoprotective activity in UVB and UVA ranges. The gathered results reveal the possibility of using this extract as a good natural additive to be incorporated into cosmetic formulations as a broad-spectrum UV protection candidate and as a preservative agent

    Phenomenology and physical origin of shear-localization and shear-banding in complex fluids

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    We review and compare the phenomenological aspects and physical origin of shear-localization and shear-banding in various material types, namely emulsions, suspensions, colloids, granular materials and micellar systems. It appears that shear-banding, which must be distinguished from the simple effect of coexisting static-flowing regions in yield stress fluids, occurs in the form of a progressive evolution of the local viscosity towards two significantly different values in two adjoining regions of the fluids in which the stress takes slightly different values. This suggests that from a global point of view shear-banding in these systems has a common physical origin: two physical phenomena (for example, in colloids, destructuration due to flow and restructuration due to aging) are in competition and, depending on the flow conditions, one of them becomes dominant and makes the system evolve in a specific direction.Comment: The original publication is available at http://www.springerlink.co
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