2,178 research outputs found

    Performance Assessment of Flexible Pavements: Fuzzy Evidence Theory Approach

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    Pavement performance evaluation is one of the most important steps of the pavement management system. It consists of identifying pavement condition according to various distresses occurs in the pavement surface. Data collection in performance assessment of road is done in several ways. An attempt has been made to address the problem and a new formalism is proposed for performance assessment of flexible pavements. Vagueness in the perception of expert for performance assessment of pavement based on techno-scientific parameters in linguistic terms for the domain base usage coupled with impression in parametric data calls for the application of fuzzy modeling. For this study fuzzy evidence theory weightage method “Dempster’s Shafer’s (D-S)” is applied to determine the Pavement Condition Distress Index (PCDI) of flexible pavement. D-S theory provides a designed framework to overcome the risk of uncertainty and ignorance. For the assessment of pavements five major structural indicators like longitudinal cracks, transverse cracks etc. and eleven major functional indicators like potholes, rutting, patching etc. are considered. Expert opinion is taken from the experts who are involved in the field of transportation engineering. Questionnaire Survey methodology has been adopted for the collection of experts opinions. Five linguistic terms are used for the same, which are, ‘Very important’, ‘Important’, ‘Average’, ‘Less important’ and ‘Not Important’. Based on PCDI, Pavement Condition Index (PCI) is calculated. The rating of flexible pavements is also done based on PCI. For the application of the model, five road segments of MIDC Chakan, Pune area is considered. PCI of all the road segments is determined by using the stated index. Based on PCI value, road segment 1 rated 5 with less PCI value and road segment 4 rated 1 with high PCI value. The defined method is also compared with the rating system given in Indian Road Congress (IRC -82-2015)

    Novel Selective Maintenance Approach to Ensure Mission Reliability of Armored Vehicles Considering Multiple Deployment Roles in Distinct Operating Profiles

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    Given the gravity of the element of surprise in modern warfare, military forces worldwide are constantly attempting to achieve and maintain operational readiness of their critical military equipment. Selective Maintenance (SM) is considered an effective approach for achieving system operational readiness. Effective use of the SM approach for military equipment requires considering various military-specific factors such as multiple deployment roles, distinct operating profiles, human reliability, and the use of refurbished or non-OEM spares. This makes the SM approach for military systems very challenging. This paper presents an approach that formulates the SM problem intending to achieve and maintain the required level of operational readiness for predefined future missions from a military viewpoint. This approach employs a novel methodology that estimates the mission reliability of military equipment while modeling the combined impact of several important military-specific factors. This complex yet necessary integration of various military-specific factors makes the present approach accurate and apt to the exact modus operandi of the armed forces. The developed approach is demonstrated for the maintenance of armored vehicles deployed on distinct missions under different operating conditions. Numerical investigations illustrate the efficacy of the present approach and highlight its advantages over the conventional maintenance approach

    Focused action is required to protect ethnic minority populations from COVID-19 post-lockdown

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    Since the association between COVID-19 and ethnicity was first noted in April 2020,1 numerous large-scale national datasets have been analysed.2–6 The evidence is clear — ethnicity is a key risk factor for adverse COVID-19 outcome, alongside age, male sex, obesity, deprivation, and comorbidities.7 There are significant ethnic inequalities in the risk of admission to hospital and risk of death from COVID-19. Black and South Asian ethnic groups are at greatest risk, although most ethnic minorities have been shown to have increased risk when compared with white populations.7 Beyond admission to hospital and mortality risk, there is also concern over longer-term impacts, that is, post-acute COVID-19,8 which could significantly impact ethnic minority populations

    Magnetic Behavior of Manganese-Doped ZnSe Quantum Dots

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    Magnetic properties of manganese-doped ZnSe quantum dots with the size of approximately 3.6 nm are investigated. The amount of Mn in the ZnSe quantum dots has been varied from 0.10% to 1.33%. The doping level in the quantum dots is much less than that used in the precursor. The co-ordination of Mn in the ZnSe lattice has been determined by electron paramagnetic resonance (EPR). Two different hyperfine couplings 67.3×10−4 and 60.9×10−4 cm−1 observed in the EPR spectrum imply that Mn atoms occupy two distinct sites; one uncoordinated (near the surface) and other having a cubic symmetric environment (nanocrystal core), respectively. Photoluminescence measurements also confirm the incorporation of Mn in ZnSe quantum dots. From the Curie-Weiss behavior of the susceptibility, the effective Mn-Mn antiferromagnetic exchange constant (J1) has been evaluated. The spin-glass behavior is observed in 1.33% Mn-doped ZnSe quantum dots, at low temperature. Magnetic behavior at a low temperature is discussed

    The Digital Life of Walkable Streets

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    Walkability has many health, environmental, and economic benefits. That is why web and mobile services have been offering ways of computing walkability scores of individual street segments. Those scores are generally computed from survey data and manual counting (of even trees). However, that is costly, owing to the high time, effort, and financial costs. To partly automate the computation of those scores, we explore the possibility of using the social media data of Flickr and Foursquare to automatically identify safe and walkable streets. We find that unsafe streets tend to be photographed during the day, while walkable streets are tagged with walkability-related keywords. These results open up practical opportunities (for, e.g., room booking services, urban route recommenders, and real-estate sites) and have theoretical implications for researchers who might resort to the use social media data to tackle previously unanswered questions in the area of walkability.Comment: 10 pages, 7 figures, Proceedings of International World Wide Web Conference (WWW 2015

    The structure of the ternary Eg5–ADP–ispinesib complex

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    The human kinesin Eg5 is responsible for bipolar spindle formation during early mitosis. Inhibition of Eg5 triggers the formation of monoastral spindles, leading to mitotic arrest that eventually causes apoptosis. There is increasing evidence that Eg5 constitutes a potential drug target for the development of cancer chemotherapeutics. The most advanced Eg5-targeting agent is ispinesib, which exhibits potent antitumour activity and is currently in multiple phase II clinical trials. In this study, the crystal structure of the Eg5 motor domain in complex with ispinesib, supported by kinetic and thermodynamic binding data, is reported. Ispinesib occupies the same induced-fit pocket in Eg5 as other allosteric inhibitors, making extensive hydrophobic interactions with the protein. The data for the Eg5-ADP-ispinesib complex suffered from pseudo-merohedral twinning and revealed translational noncrystallographic symmetry, leading to challenges in data processing, space-group assignment and structure solution as well as in refinement. These complications may explain the lack of available structural information for this important agent and its analogues. The present structure represents the best interpretation of these data based on extensive data-reduction, structure-solution and refinement trials

    Yttrium Enhanced Glass-Forming Ability of Zr-Based Metallic Glasses

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    Thermodynamic behavior of Zr56-xCo28Al16Yx (0, 2, 7, 10) bulk metallic glass-forming alloys has been studied using an analytical approach where some of the key thermodynamic quantities such as ΔH, ΔS and ΔG has been estimated using a hyperbolic temperature dependence of specific heat difference ΔCp in the supercooled liquid region. The study is focused on understanding the effect of Yttrium-doping on the thermodynamics of the alloys in the supercooled region and on the glass-forming ability of these alloys. The analytical approach has been found to give estimates of ΔG in a wide supercooled liquid region in excellent agreement with the experimental results. Estimated ΔG values are found to be minimum for Y concentration of 7 and 10% which is consistent with the observed high GFA for these compositions. Fundamental elemental properties such as atomic size, electronegativity, the heat of mixing have been found to play an important role in governing the thermodynamics of the alloys in the supercooled liquid region

    Yttrium Enhanced Glass-Forming Ability of Zr-Based Metallic Glasses

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    803-810Thermodynamic behavior of Zr56-xCo28Al16Yx (x = 0, 2, 7, 10 at. %) bulk metallic glass-forming alloys has been studied using an analytical approach where some of the key thermodynamic quantities such as ΔH, ΔS and ΔG have been estimated using a hyperbolic temperature dependence of specific heat difference ΔCp in the supercooled liquid region. The study is focused on understanding the effect of yttrium (Y) doping on the thermodynamics of the alloys in the supercooled region and on the glass-forming ability (GFA) of these alloys. The analytical approach has been found to give estimates of ΔG in a wide supercooled liquid region which is in excellent agreement with the experimental results. Estimated ΔG values are found to be minimum for Y concentration of 7% and 10% which is consistent with the observed high GFA for these compositions. Fundamental elemental properties such as atomic size, electronegativity, the heat of mixing have been found to play an important role in governing the thermodynamics of the alloys in the supercooled liquid region
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