500 research outputs found

    Critique by Design:Tackling Urban Renewal in the Design Studio

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    Cataloged from PDF version of article.The dominant mode of urbanization in our contemporary world is marked by large scale urban renewal projects, which are deployed with little or no consideration given to the social predicaments. The urban design studio can serve as a domain in which critical reflections on urban issues can be incorporated into design works. In this article, we propose a methodology of 'critique by design', which does not seek to arrive at scientific knowledge but rather involves the development of urban design proposals critically engaging with the urban issues they address through conceptual approaches. We discuss our methodology through the case of an experimental studio work conducted in Ankara, Turkey at Bilkent University, Department of Urban Design and Landscape Architecture in 2011

    Printed Dot Quality in Response to Doctor Blade Angle in Gravure Printing

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    Doctor blade is one of the critical machine part of the gravure printing press that controls the amount of ink transfer on the substrate. The angle of the blade can be varied; however, an improper angle may cause major problems. In this study, the doctor blade angle was positioned at three different level to address its effect on the printed dot quality. Print trials were made on a web-fed gravure press at the speed of 650 ft./min. A high-resolution overhead camera was used to analyze the key dot attributes. The results showed that measuring only the density of printed dot –a traditional quality control method– is insufficient. Incorporating the camera was assisted capturing missing dots, as well as quantifying dot area, perimeter and circularity. Print trials showed that the image quality was undesirable, when the blade angle exceeded or fell behind the optimum position

    The effect of green biobased binder on structural, mechanical, liquid absorption and wetting properties of coated papers

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    Synthetic styrene-butadiene (SB) and styrene-acrylic (SA) latex binders used in paper coating formulations are common and based on unsustainable petroleum sources. Today\u27s papermaking industry turns towards sustainable substitutes that do not compromise quality, and reduce carbon emission, toxic substance release and waste disposal concerns related to fossil fuel sources. In this study, colloidal starch-based latex nanoparticles that do not require cooking were used for pigment coating and coated on the paper surfaces. The effects of these new biobased binders on the structural and mechanical strength properties, liquid absorption, wetting and surface topography of the paper were investigated and compared with the properties of coated paper that SB latex was used as a coating binder. The results demonstrated that the biobased latex decreases the grammage of paper while maintaining an identical thickness relative to the SB latex samples. The porosity, permeability and roughness of biobased latex are found higher than the SB latex. The biobased latex successfully replaced SB latex at 1:1 ratio and enabled an equivalent of bursting, tear, tensile strength and structural properties

    Controlling unequal surface energy results caused by test liquids: the case of UV/O3 Treated PET

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    Ultraviolet/ozone (UV/O3) treatment has been reported to be an effective method to modify properties such as wettability, adhesion or adsorption of plastic surfaces. The change in the surface is measured by contact angle analysis, which employs liquids and their surface tensions (ST) to estimate the surface energy (SE). We found two different practices in the scientific community: (1) the majority of researchers adopted the ST value of liquids from the literature, while (2) other researchers conducted real-time measurements in the lab under ambient conditions prior to SE estimation. To the best of our knowledge, there is no study that compares the difference between the two practices. One study was found to show different SE methods generating unequal SE values for the same substrate. However, there was no definitive conclusion backed by general thermodynamics rules. In this study, we presented (1) a statistical significance test that showed the literature and experimental ST values are significantly different, and studied (2) the effect of different liquid pairs on the SE estimation for UV/O3 treated poly(ethylene terephthalate) (PET) substrate. Modification techniques such as atmospheric pressure plasma or chemical modification were studied previously to examine PET’s wettability and the SE. The UV/O3 treatment was studied to improve adhesion and to modify its chemical properties for adsorption. In contrast, we studied (3) the effect of UV/O3 on wettability at different timeframes and addressed (4) how to control unequal SE based on a method that was refined on a rigorous thermodynamic three-phase system. It must be noted that this method can be generalized to other types of solid surfaces to estimate thermodynamically self-consistent SE values. This work also provides (5) a web-based calculator that complements computational findings available to the readership in the data availability section

    Reverse Engineering Gene Networks with ANN: Variability in Network Inference Algorithms

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    Motivation :Reconstructing the topology of a gene regulatory network is one of the key tasks in systems biology. Despite of the wide variety of proposed methods, very little work has been dedicated to the assessment of their stability properties. Here we present a methodical comparison of the performance of a novel method (RegnANN) for gene network inference based on multilayer perceptrons with three reference algorithms (ARACNE, CLR, KELLER), focussing our analysis on the prediction variability induced by both the network intrinsic structure and the available data. Results: The extensive evaluation on both synthetic data and a selection of gene modules of "Escherichia coli" indicates that all the algorithms suffer of instability and variability issues with regards to the reconstruction of the topology of the network. This instability makes objectively very hard the task of establishing which method performs best. Nevertheless, RegnANN shows MCC scores that compare very favorably with all the other inference methods tested. Availability: The software for the RegnANN inference algorithm is distributed under GPL3 and it is available at the corresponding author home page (http://mpba.fbk.eu/grimaldi/regnann-supmat

    Evaluation and Validation of a Method for Determining Platelet Catecholamine in Patients with Obstructive Sleep Apnea and Arterial Hypertension

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    Background: Measurements of plasma and urinary catecholamine are susceptible to confounding factors that influence the results, complicating the interpretation of sympathetic nervous system (SNS) activity in the Obstructive sleep apnea (OSA) and arterial hypertension (HYP) conditions.Objective: in this study, we validated a test for platelet catecholamine and compared the catecholamine levels (adrenaline and noradrenaline) in urine, plasma and platelets in patients with OSA and HYP compared with controls.Methods: in the validation, 30 healthy, nonsmoking volunteers who were not currently undergoing treatment or medication were selected as the control group. One hundred fifty-four individuals (114 OSA, 40 non-OSA) were consecutively selected from the outpatient clinic of the Sleep Institute and underwent clinical, polysomnographic and laboratory evaluation, including the urinary, plasma and platelet levels of adrenaline (AD) and noradrenaline (NA). Patients were then allocated to groups according to the presence of OSA and/or hypertension.Results: A logistic regression model, controlled for age and BMI, showed that urinary AD and urinary NA were risk factors in the OSA+HYP group and the HYP group; however, the model showed higher levels of platelet NA for OSA without HYP. After 1 year of CPAP (continuous upper airway pressure) treatment, patients (n = 9) presented lower levels of urinary NA (p = 0.04) and platelet NA (p = 0.05).Conclusion: Urinary NA and AD levels were significantly associated with the condition of hypertension with and without OSA, whereas platelet NA with OSA without comorbidity. These findings suggest that platelet catecholamine levels might reflect nocturnal sympathetic activation in OSA patients without hypertension.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Associacao Fundo de Pesquisa a Psicobiologia (AFIP), BrazilConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Psychobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiol, São Paulo, BrazilAssoc Fundo Incent & Pesquisa, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psychobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiol, São Paulo, BrazilWeb of Scienc

    Use of nanoparticle binders for paper coatings: A review

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    Starch is a biopolymer that is used as a co-binder alongside synthetic petroleum based latex binders for paper coating applications, though it causes production downtimes due to the problems during cooking process, such as gelling; lack of full expansion of starch granules; increase in viscosity during cooling; bacteria growth in cooked starch and difficulties in viscosity control during storage. On the other hand, synthetic binders negatively affect paper recyclability and biodegradability. To overcome these problems, a new biopolymer binder has been introduced to the paper manufacturing, being used initially as a partial replacement for petroleum based synthetic latex polymers. This study reviews the recent developments of nanoparticle biopolymer binders, referred to as biolatex binders. These binders are shipped dry and can be dispersed in water without cooking requirement while improving paper quality and reducing costs of paper manufacturing. They also provide quality benefits, coater runnability improvements and new higher solids coating formulations for future product advancements

    Numerical Solution of the Time Dependent 3D Schrödinger Equation Describing Tunneling of Atoms from Anharmonic Traps

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    We present an efficient numerical method for the integration of the 3D Schrödinger equation. A tunneling problem of two interacting bosonic atoms confined in a 1D anharmonic trap has been successfully solved by means of this method. We demonstrate fast convergence of the final results with respect to spatial and temporal grid steps. The computational scheme is based on the operator-splitting technique with the implicit Crank-Nicolson algorithm on spatial sixth-order finite-differences. The computational time is proportional to the number of spatial grid points

    Angular momentum-Large-scale structure alignments in LCDM models and the SDSS

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    We study the alignments between the angular momentum of individual objects and the large-scale structure in cosmological numerical simulations and real data from the Sloan Digital Sky Survey, Data Release 6. To this end we measure anisotropies in the two point cross-correlation function around simulated halos and observed galaxies, studying separately the 1- and 2-halo regimes. The alignment of the angular momentum of dark-matter haloes in LCDM simulations is found to be dependent on scale and halo mass. At large distances (2-halo regime), the spins of high mass haloes are preferentially oriented in the direction perpendicular to the distribution of matter; lower mass systems show a weaker trend that may even reverse to show an angular momentum in the plane of the matter distribution. In the 1-halo term regime, the angular momentum is aligned in the direction perpendicular to the matter distribution; the effect is stronger than for the 1-halo term and increases for higher mass systems. On the observational side, we focus our study on galaxies in the Sloan Digital Sky Survey, Data Release 6 (SDSS-DR6) with elongated apparent shapes, and study alignments with respect to the major semi-axis. We find an excess of structure in the direction of the major semi-axis for all samples; the red sample shows the highest alignment (2.7+-0.08%) and indicates that the angular momentum of flattened spheroidals tends to be perpendicular to the large-scale structure. (Abridged)Comment: 10 pages, 6 figures, accepted for publication in MNRAS; the definitive version is available at www.blackwell-synergy.co
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