1,392 research outputs found

    Techno-economic analysis and physicochemical properties of Ceiba pentandra as second-generation biodiesel based on ASTM D6751 and EN 14214

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    © 2019 by the authors. Processing biodiesel from non-edible sources of feedstock seems to be thriving in recent years. It also has also gathered more attention than in the past, mainly because the biodiesel product is renewable and emits lower pollution compared to fossil fuels. Researchers have started their work on various kinds of biodiesel product, especially from a non-edible feedstock. Non-edible feedstocks such as Ceiba pentandra show great potential in the production of biodiesel, especially in the Southeast Asia region because the plants seem to be abundant in that region. Ceiba pentandra, also known as the Kapok tree, produces hundreds of pods with a length of 15 cm (5.9 in) and diameter 2-5 cm (1-2 in). The pods consist of seeds and fluffin the surrounding areas inside the pod, which itself contains yellowish fibre, a mixture of cellulose and lignin. The seeds of Ceiba pentandra can be used as feedstock for biodiesel production. The study for Ceiba pentandra will involve techno-economic, as well as a sensitivity analysis. Moreover, the study also shows that the techno-economic analysis of a biodiesel processing plant for 50 ktons Ceiba pentandra with a life span of 20 years is around 701millionwith3.7yearsofthepaybackperiod.Besidesthat,thisstudyalsoshowsthedifferencesinoperatingcostandoilconversionyield,whichhastheleastimpactonrunningcost.Byimprovingtheconversionprocessescontinuouslyandbyincreasingtheoperationaleffciency,thecostofproductionwilldecrease.Inaddition,thestudyalsoexplainsthedifferencesoffinalpricebiodieselanddieselfossilfuel,bothshowingdissimilarscenariossubsidyandtaxation.Biodieselhasasubsidyof701 million with 3.7 years of the payback period. Besides that, this study also shows the differences in operating cost and oil conversion yield, which has the least impact on running cost. By improving the conversion processes continuously and by increasing the operational effciency, the cost of production will decrease. In addition, the study also explains the differences of final price biodiesel and diesel fossil fuel, both showing dissimilar scenarios subsidy and taxation. Biodiesel has a subsidy of 0.10/L and $0.18/L with a total tax exemption of 15%. The value was obtained from the latest subsidy cost and diesel in Malaysia. Finally, further research is needed in order to fully utilize the use of Ceiba pentandra as one of the non-edible sources of biodiesel

    Recent Developments of Carboxymethyl Cellulose.

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    Carboxymethyl cellulose (CMC) is one of the most promising cellulose derivatives. Due to its characteristic surface properties, mechanical strength, tunable hydrophilicity, viscous properties, availability and abundance of raw materials, low-cost synthesis process, and likewise many contrasting aspects, it is now widely used in various advanced application fields, for example, food, paper, textile, and pharmaceutical industries, biomedical engineering, wastewater treatment, energy production, and storage energy production, and storage and so on. Many research articles have been reported on CMC, depending on their sources and application fields. Thus, a comprehensive and well-organized review is in great demand that can provide an up-to-date and in-depth review on CMC. Herein, this review aims to provide compact information of the synthesis to the advanced applications of this material in various fields. Finally, this article covers the insights of future CMC research that could guide researchers working in this prominent field

    Kinetic control of the coverage of oil droplets by DNA-functionalized colloids

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    We report a study of reversible adsorption of DNA-coated colloids on complementary functionalized oil droplets. We show that it is possible to control the surface coverage of oil droplets using colloidal particles by exploiting the fact that, during slow adsorption, compositional arrest takes place well before structural arrest occurs. As a consequence, we can prepare colloid-coated oil droplets with a "frozen" degree of loading but with fully ergodic colloidal dynamics on the droplets. We illustrate the equilibrium nature of the adsorbed colloidal phase by exploring the quasi-two-dimensional phase behavior of the adsorbed colloids under the influence of depletion interactions and present simulations of a simple model that illustrates the nature of the compositional arrest and the structural ergodicity.A.C. acknowledges support from the ETN-COLLDENSE (H2020-MCSA-ITN-2014, grant no. 642774). E.E. and J. Burelbach thank the Winton Programme for the Physics of Sustainability for the Pump Prime Grant and the scholarship award, respectively. D.J. thanks the Udayan Care-VCare grant, the Nehru Trust for Cambridge University, the Schlumberger Foundation’s Faculty for the Future Program, and Hughes Hall Santander Bursary Scholarship. Z.X. thanks the National University of Defense Technology Scholarship at Cambridge. A.S.N., D.E.P.P., and N.A.M.A. acknowledge financial support from the Portuguese Foundation for Science and Technology (FCT) (grants EXCL/FIS-NAN/ 0083/2012, UID/FIS/00618/2013, and IF/00255/2013). J. Brujic thanks the Materials Research Science and Engineering Center program of the National Science Foundation under Award DMR-1420073 and L. L. Pontani

    Ordering of binary colloidal crystals by random potentials

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    Structural defects are ubiquitous in condensed matter, and not always a nuisance. For example, they underlie phenomena such as Anderson localization and hyperuniformity, and they are now being exploited to engineer novel materials. Here, we show experimentally that the density of structural defects in a 2D binary colloidal crystal can be engineered with a random potential. We generate the random potential using an optical speckle pattern, whose induced forces act strongly on one species of particles (strong particles) and weakly on the other (weak particles). Thus, the strong particles are more attracted to the randomly distributed local minima of the optical potential, leaving a trail of defects in the crystalline structure of the colloidal crystal. While, as expected, the crystalline ordering initially decreases with an increasing fraction of strong particles, the crystalline order is surprisingly recovered for sufficiently large fractions. We confirm our experimental results with particle-based simulations, which permit us to elucidate how this non-monotonic behavior results from the competition between the particle-potential and particle-particle interactions

    Tai Chi for Disease Activity and Flexibility in Patients with Ankylosing Spondylitis—A Controlled Clinical Trial

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    We investigated the effects of tai chi on disease activity, flexibility and depression in patients with ankylosing spondylitis (AS). We allocated 40 patients to either a tai chi treatment group or a no-treatment control group. The tai chi group performed 60 min of tai chi twice weekly for eight consecutive weeks and 8 weeks of home-based tai chi, after which the group showed significant improvement in disease activity and flexibility compared to the control group. All outcome measures were significantly lower in the tai chi group than they were during pre-treatment, while they did not change in the control group. These findings suggest that tai chi can improve disease activity and flexibility for patients with AS. Tai chi is an easily accessible therapy for patients and, as such, may be an effective intervention for AS. However, we cannot completely discount the possibility that the placebo effect was responsible for the improvement

    Simple estimators of the intensity of seasonal occurrence

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    <p>Abstract</p> <p>Background</p> <p>Edwards's method is a widely used approach for fitting a sine curve to a time-series of monthly frequencies. From this fitted curve, estimates of the seasonal intensity of occurrence (i.e., peak-to-low ratio of the fitted curve) can be generated.</p> <p>Methods</p> <p>We discuss various approaches to the estimation of seasonal intensity assuming Edwards's periodic model, including maximum likelihood estimation (MLE), least squares, weighted least squares, and a new closed-form estimator based on a second-order moment statistic and non-transformed data. Through an extensive Monte Carlo simulation study, we compare the finite sample performance characteristics of the estimators discussed in this paper. Finally, all estimators and confidence interval procedures discussed are compared in a re-analysis of data on the seasonality of monocytic leukemia.</p> <p>Results</p> <p>We find that Edwards's estimator is substantially biased, particularly for small numbers of events and very large or small amounts of seasonality. For the common setting of rare events and moderate seasonality, the new estimator proposed in this paper yields less finite sample bias and better mean squared error than either the MLE or weighted least squares. For large studies and strong seasonality, MLE or weighted least squares appears to be the optimal analytic method among those considered.</p> <p>Conclusion</p> <p>Edwards's estimator of the seasonal relative risk can exhibit substantial finite sample bias. The alternative estimators considered in this paper should be preferred.</p

    Notch Ankyrin Repeat Domain Variation Influences Leukemogenesis and Myc Transactivation

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    , cell-based and structural analyses to compare the abilities of activated Notch1-4 to support T cell development, induce T cell acute lymphoblastic leukemia/lymphoma (T-ALL), and maintain T-ALL cell growth and survival., a direct Notch target that has an important role in Notch-associated T-ALL.We conclude that the leukemogenic potentials of Notch receptors vary, and that this functional difference stems in part from divergence among the highly conserved ankyrin repeats, which influence the transactivation of specific target genes involved in leukemogenesis

    Origin of Capacity Fading in Nano-Sized Co3O4Electrodes: Electrochemical Impedance Spectroscopy Study

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    Transition metal oxides have been suggested as innovative, high-energy electrode materials for lithium-ion batteries because their electrochemical conversion reactions can transfer two to six electrons. However, nano-sized transition metal oxides, especially Co3O4, exhibit drastic capacity decay during discharge/charge cycling, which hinders their practical use in lithium-ion batteries. Herein, we prepared nano-sized Co3O4with high crystallinity using a simple citrate-gel method and used electrochemical impedance spectroscopy method to examine the origin for the drastic capacity fading observed in the nano-sized Co3O4anode system. During cycling, AC impedance responses were collected at the first discharged state and at every subsequent tenth discharged state until the 100th cycle. By examining the separable relaxation time of each electrochemical reaction and the goodness-of-fit results, a direct relation between the charge transfer process and cycling performance was clearly observed

    Prognostic scores in brain metastases from breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Prognostic scores might be useful tools both in clinical practice and clinical trials, where they can be used as stratification parameter. The available scores for patients with brain metastases have never been tested specifically in patients with primary breast cancer. It is therefore unknown which score is most appropriate for these patients.</p> <p>Methods</p> <p>Five previously published prognostic scores were evaluated in a group of 83 patients with brain metastases from breast cancer. All patients had been treated with whole-brain radiotherapy with or without radiosurgery or surgical resection. In addition, it was tested whether the parameters that form the basis of these scores actually have a prognostic impact in this biologically distinct group of brain metastases patients.</p> <p>Results</p> <p>The scores that performed best were the recursive partitioning analysis (RPA) classes and the score index for radiosurgery (SIR). However, disagreement between the parameters that form the basis of these scores and those that determine survival in the present group of patients and many reported data from the literature on brain metastases from breast cancer was found. With the four statistically significant prognostic factors identified here, a 3-tiered score can be created that performs slightly better than RPA and SIR. In addition, a 4-tiered score is also possible, which performs better than the three previous 4-tiered scores, incl. graded prognostic assessment (GPA) score and basic score for brain metastases (BSBM).</p> <p>Conclusion</p> <p>A variety of prognostic models describe the survival of patients with brain metastases from breast cancer to a more or less satisfactory degree. However, the standard brain metastases scores might not fully appreciate the unique biology and time course of this disease, e.g., compared to lung cancer. It appears possible that inclusion of emerging prognostic factors will improve the results and allow for development and validation of a consensus score for broad clinical application. The model that is based on the authors own patient group, which is not large enough to fully evaluate a large number of potential prognostic factors, is meant to illustrate this point rather than to provide the definitive score.</p
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