497 research outputs found

    Transport of cross helicity and radial evolution of alfvenicity in the solar wind

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    A transport theory including cross helicity, magnetohydrodynamic(MHD) turbulence, and driving by shear and pickup ions, is applied to the radial evolution of the solar wind. The radial decrease of cross helicity observed in the solar wind can be accounted for when sufficient driving is included to overcome the inherent tendency for MHD turbulence to produce Alfvenic states

    Radial evolution of cross helicity at low and high latitudes in the solar wind

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    We employ a turbulence transport theory to the radial evolution of the solar wind at both low and high latitudes. The theory includes cross helicity, magnetohydrodynamic (MHD) turbulence, and driving by shear and pickup ions. The radial decrease of cross helicity, observed in both low and high latitudes, can be accounted for by including sufficient shear driving to overcome the tendency of MHD turbulence to produce Alfvénic states. The shear driving is weaker at high latitudes leading to a slower evolution. Model results are compared with observations from Ulysses and Voyager

    Optimal Stack Layout in a Sea Container Terminal with Automated Lifting Vehicles

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    Container terminal performance is largely determined by its design decisions, which include the number and type of quay cranes (QCs), stack cranes (SCs), transport vehicles, vehicle travel path, and stack layout. The terminal design process is complex because it is affected by factors such as topological constraints, stochastic interactions among the quayside, vehicle transport and stackside operations. Further, the orientation of the stack layout (parallel or perpendicular to the quayside) plays an important role in the throughput time performance of the terminals. Previous studies in this area typically use deterministic optimization or probabilistic travel time models to analyze the effect of stack layout on terminal throughput times, and ignore the stochastic interactions among the resou

    Stabilization of expansive soils using alkali activated fly ash

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    This research work presents the efficacy of sodium based alkaline activators and class F fly ash as an additive in improving the engineering characteristics of expansive Black cotton soils. Sodium hydroxide concentrations of 10, 12.5 and 15 molal along with 1 Molar solution of sodium silicate were used as activators. The activator to ash ratios was kept between between 1 and 2.5 and ash percentages of 20, 30 and 40 %, relatively to the total solids. The effectiveness of this binder is tested by conducting the Unconfined compressive strength (UCS) at curing periods of 3,7 and 28 days and is compared with that of a common fly ash based binder, also the most effective mixtures were analysed for mineralogy with XRD. Suitability of alkaline activated fly ash mix as a grouting material is also ascertained by studying the rheological properties of the grout such as, setting time, density and viscosity and is compared with that of common cement grouts. Results shows that the fluidity of the grouts correlate very well with UCS, with an increase in the former resulting in a decrease in the latter

    Evaluating the transparency capability of smart manufacturing systems

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    Transparency encompasses the potential to monitor operations instantaneously so that required corrective actions can be taken as needed. Transparency entails the ability to track processes in real-time, enhance the visibility of the operations, and require a seamless network for improved communication for smart manufacturing systems. However, there is a lack of proper metrics to assess the transparency of smart manufacturing environments. This paper contributes to the assessment of transparency by proposing a metric for its evaluation. In doing so, we found that the assessment of transparency takes the quantification of traceability into account. Hence, a step-in assessment is conducted by initially developing a mathematical model for traceability, followed by a model for transparency. The model is validated by analysing the sensitivity and applicability through simulation-based experimentation. The results demonstrate the level of traceability followed by transparency with the implementation of smart manufacturing systems. A point of inflexion that determines the variability in the offerings of traceability at a given set of inputs was found. This is one of the few works that focus on the development of a metric for quantifying transparency through the traceability of smart manufacturing systems. Furthermore, it investigates the behaviour by analyzing the sensitivity of the model through simulation-based approaches, which is a unique addition to the realm of the smart manufacturing literature. Managers can refer to this study's findings to design the deployment of smart manufacturing systems with informative trade-offs to maintain their required traceability and transparency capabilities

    New FTY720-docetaxel nanoparticle therapy overcomes FTY720-induced lymphopenia and inhibits metastatic breast tumour growth

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    Purpose: Combining molecular therapies with chemotherapy may offer an improved clinical outcome for chemoresistant tumours. Sphingosine-1-phosphate (S1P) receptor antagonist and sphingosine kinase 1 (SK1) inhibitor FTY720 (FTY) has promising anticancer properties, however, it causes systemic lymphopenia which impairs its use in cancer patients. In this study, we developed a nanoparticle (NP) combining docetaxel (DTX) and FTY for enhanced anticancer effect, targeted tumour delivery and reduced systemic toxicity. Methods: Docetaxel, FTY and glucosamine were covalently conjugated to poly(lactic-co-glycolic acid) (PLGA). NPs were characterised by dynamic light scattering and electron microscopy. The cellular uptake, cytotoxicity and in vivo antitumor efficacy of CNPs were evaluated. Results: We show for the first time that in triple negative breast cancer cells FTY provides chemosensitisation to DTX, allowing a four-fold reduction in the effective dose. We have encapsulated both drugs in PLGA complex NPs (CNPs), with narrow size distribution of ~ 100 nm and excellent cancer cell uptake providing sequential, sustained release of FTY and DTX. In triple negative breast cancer cells and mouse breast cancer models, CNPs had similar efficacy to systemic free therapies, but allowed an effective drug dose reduction. Application of CNPs has significantly reversed chemotherapy side effects such as weight loss, liver toxicity and, most notably, lymphopenia. Conclusions: We show for the first time the DTX chemosensitising effects of FTY in triple negative breast cancer. We further demonstrate that encapsulation of free drugs in CNPs can improve targeting, provide low off-target toxicity and most importantly reduce FTY-induced lymphopenia, offering potential therapeutic use of FTY in clinical cancer treatment

    Analyzing Behavioural Health Interventions and Their Impact on Occupational Safety

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    Behavioural health treatments are very important for improving workplace safety because they deal with the mental and behavioural issues that cause risks in the workplace. Integrating mental health tactics into safety measures has become more important as workplaces get more complicated. This essay looks into different mental health treatments and how they can help make workplaces safer. The main goal is to find out how different methods, like stress management, mindfulness, resilience training, and cognitive-behavioral treatment, can help workers avoid crashes, injuries, and long-term health problems at work. This research uses a variety of methods, mixing both personal and quantitative data from a wide range of fields, such as healthcare, transportation, building, and manufacturing. A study was done to see the differences between organisations that have used behavioural health treatments and those that have not. Particularly those resulting from human error, the findings reveal a clear correlation between mental health initiatives and less accidents at workplace. These programs helped participants manage their emotions, deal with stress, and approach problems as they arose. These elements taken together make the workplace safer. Companies who applied these techniques also reported that their employees were generally more content, more involved, and more efficient. This emphasises even more the need of adding mental health into safety precautions at employment. This paper also addresses the issues that arise when attempting to implement these sorts of initiatives, including insufficient funds, management and employees not following through, and the requirement of long-term commitment to training and resources. The study emphasises the importance of implementing unique adjustments according to the demands of every company. Remember that safety at work is complex even as businesses keep giving health and safety first priority. Physical and psychological elements must be considered concurrently if one is to create a safe, healthy workplace environment

    Topological Structure of Manufacturing Industry Supply Chain Networks

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    Empirical analyses of supply chain networks (SCNs) in extant literature have been rare due to scarcity of data. As a result, theoretical research have relied on arbitrary growth models to generate network topologies supposedly representative of real-world SCNs. Our study is aimed at filling the above gap by systematically analysing a set of manufacturing sector SCNs to establish their topological characteristics. In particular, we compare the differences in topologies of undirected contractual relationships (UCR) and directed material flow (DMF) SCNs. The DMF SCNs are different from the typical UCR SCNs since they are characterised by a strictly tiered and an acyclic structure which does not permit clustering. Additionally, we investigate the SCNs for any self-organized topological features. We find that most SCNs indicate disassortative mixing and power law distribution in terms of interfirm connections. Furthermore, compared to randomised ensembles, self-organized topological features were evident in some SCNs in the form of either overrepresented regimes of moderate betweenness firms or underrepresented regimes of low betweenness firms. Finally, we introduce a simple and intuitive method for estimating the robustness of DMF SCNs, considering the loss of demand due to firm disruptions. Our work could be used as a benchmark for any future analyses of SCNs

    Extraction of Scandium (III) from acidic solutions using organo-phosphoric acid reagents: A comparative study

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    Comparative and synergistic solvent extraction of Sc(III) using two phosphoric acidic reagents such as di-(2-ethyhexyl) phosphoric acid and 2,4,4,tri-methyl,pentyl-phosphinic acid was investigated. Slope analysis method suggests a cation exchange reaction of Sc(III) with both extractants at a molar ratio of extractant: Sc(III) = 2.5:1 at equilibrium pH< 1.5. The plot of log D vs. log [Extractant] yield the slope (n) value as low as 1.2-1.3 and as high as n=7 at low and high extrcatant concentration level, respectively. Extraction isotherm study predicted the need of 2 stages at A: O=1:4 and A: O=1:3 using 0.1 M D2EHPA and 0.1 M Cyanex 272, respectively. Stripping of Sc (III) was carried out at varied NaOH concentration to ascertain the optimum stripping condition for effective enrichment of metal. The predicted stripping condition (2)-stages with A: O=1:3 and 1:4 for D2EHPA and Cyanex 272, respectively) obtained from Mc-Cabe Thiele plot was further validated by 6-cycles CCS study. An actual leach solution of Mg-Sc alloy bearing 1.0 g/L of Sc (III), 2.5 g/L of Mg and 0.2 M HCl was subjected for selective separation of Sc at the optimum condition. The counter current simulation (CCS) study for both extraction and stripping of actual solution resulted quantitative separation of Sc with ∼12 fold enrichment. The organic phase before and after loading of Sc (III) along with the diluents was characterized by FTIR to ascertain the phase transportation of Sc (III)

    Interplay of Ferromagnetism and Static Band Jahn-Teller Distortion in La1-xSrxMnO3

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