66 research outputs found
Bauschinger effect in thin metal films: Discrete dislocation dynamics study
No full textThe effects of dislocation climb on plastic deformation during loading and unloading are studied using a two-dimensional discrete dislocation dynamics model. Simulations are performed for polycrystalline thin films passivated on both surfaces. Dislocation climb lowers the overall level of the stress inside thin films and reduces the work hardening rate. Climb decreases the density of dislocations in pile-ups and reduces back stresses. These factors result in a smaller Bauschinger effect on unloading compared to simulations without climb. As dislocations continue to climb at the onset of unloading and the dislocation density continues to increase, the initial unloading slope increases with decreasing unloading rate. Because climb disperses dislocations, fewer dislocations are annihilated during unloading, leading to a higher dislocation density at the end of the unloading step.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Dislocation climb in two-dimensional discrete dislocation dynamics
No full textIn this paper, dislocation climb is incorporated in a two-dimensional discrete dislocation dynamics model. Calculations are carried out for polycrystalline thin films, passivated on one or both surfaces. Climb allows dislocations to escape from dislocation pile-ups and reduces the strain-hardening rate, especially for fully passivated films. Within the framework of this model, climb modifies the dislocation structures that develop during plastic deformation and results in the formation of pile-ups on slip planes that do not contain any dislocation sources.Materials Science and EngineeringMechanical, Maritime and Materials Engineerin
Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae
No full textAims: Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae was investigated in this study.
Materials and Methods: The efficacy of 30 ppb silver in 0.3% hydrogen peroxide solution for inactivation of selected Enterobacteriaceae, including Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae was assessed for 72 hours in a designated nutrient broth medium and steel surface. The bactericidal growth ability was determined for each bacterium genus by the conventional colony count method and turbidimetry via an optical density (OD) assay at 450 nm in a time interval of 24 hours.
Results: Suspensions of K.pneumoniae, and P.mirabilis showed a significant OD reduction at three 24-hour intervals (CI = 0.95; P < 0.05, for both), along with blocked growth in a designated broth medium during 24 to 48 hours of exposure. The disinfectant was also significantly efficient for inactivating of the mentioned bacteria on steel surfaces after a 15-minute time exposure (CI = 0.95; P < 0.05). For E.coli, the OD decreased slightly during the initial exposure time, but increased after 24 hours. Viable E.coli cells were proved by colonies grown on the plate. A qualitative surface decontamination test showed that three pathogenic bacteria were inactivated significantly after disinfectant exposure (CI = 0.95, P < 0.05).
Conclusions: In conclusion, a combination of hydrogen peroxide and silver ions was proposed as a strong disinfecting agent both in suspensions and on the surfaces against these three important human pathogens
Reinventing planning and planners: Ideological decontestations and rhetorical appeals
No full textThis article contributes to the debate about ideologically motivated planning reforms. It aims to advance the debate by exploring how change is legitimised through forms of rhetorical persuasion. It shows how political ideologies become embedded in planning policies and practices through strategies of legitimation aimed at justifying specific ideas, beliefs and values as self-evident and inevitable. These legitimation strategies rely on distinctive rhetorical appeals to steer planning discourses, policies and institutions. By using short illustrative examples of ‘ideology in action’ from Britain, Denmark and the Netherlands, the article shows that various combinations of rhetorical appeals to logos, ethos, pathos and doxa (logic, character, emotion and identity) are often simultaneously at work to naturalise contested planning reforms.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Spatial Planning and Strateg
Restoring Systemic Proximities: Towards the re-territorialization of the Dutch Rivierenland
No full textUncertainty posed by Climate Change brings control approaches to environmental processes and dynamics into question. In the Netherlands and particularly in the Dutch River area (Rivierenland in Dutch) narratives have already shifted towards an adaptive planning (Davoudi, 2013). However, there is still a need to go beyond the physical cultural and programmatic separation between rivers -active areas in flood management- and the urbanized territory -passive areas in flood management-. The definition of these dualities in the Dutch territory not only feeds a model based on vulnerability, but it also leaves the problem of a fragmented landscape unsolved. Aiming at the enhancement of adaptive territories and the embracement of uncertainty, the thesis proposes the operationalization of an approach based on enhanced connectivity throughout the territory, where every part of the urbanized territory takes a role in the active management of floods and ecosystem restoration. An approach aiming at restoring systemic proximities between culture and nature and between local land management and territorial water safety. The main design outcome of the thesis is a transformation pathway towards the hybridization of the territory by increasing ecological densities and buffer capacities per land management unit. A pathway where synergistic coupling of functions are activated locally, triggering processes of innovation and cultural appropriation of the proposal, as opportunities for emerging ecosystem-based production models. The graduation research is positioned within an emerging urban paradigm, one that re-defines the act of urbanization as an act of re-territorialization (Deleuze and Guatari, 2000), where land uses are associated to evolutionary land roles that different occupation patterns perform in the establishment of a more symbiotic relation with the ecology in which these are embedded. Sources: Davoudi, S., Brooks, E., & Mehmood, A. (2013). Evolutionary resilience and strategies for climate adaptation. Planning Practice & Research, 28(3), 307-322. Guattari, F., & Deleuze, G. (2000). A thousand plateaus: capitalism and schizophrenia. London: Athlone Press.Architecture, Urbanism and Building Science
Comparative study of cationic and anionic dye removal from aqueous solutions using sawdust‐based adsorbent
No full textThe Relationship between EFL Learners’ Extensive Reading and English Language Proficiency
No full textThe present study aims at investigating the effects of extensive reading (ER) on language proficiency of Iranian intermediate EFL learners. A Preliminary English Test (PET) was administered to 106 male and female university students. The participants were selected as intermediate learners and were divided into three groups (one control and two experimental groups). During the ten sessions of the treatment, ten short stories (authentic and simplified) were provided to the two homogenous groups (two experimental groups). The first experimental group received authentic reading texts and the second experimental group received simplified reading texts, while the participants of the control group followed the ordinary reading course at the university. All three groups received post-tests administered after the treatment. The results of the t-tests revealed that there is no significant difference in reading scores across the posttest between two experimental groups. The results of ANOVA also revealed that there is a significant difference between the scores of the control group and experimental groups’ participants. Based on the interview result after the post-test, all of the participants (100%) agreed that they had positive attitude toward extensive reading after participating in the treatment sessions. The study suggests, however, students’ curriculum courses should include extensive reading texts in order to develop EFL language proficiency
Comparison of anxiety and depression symptoms between male daily smokers and nondaily smokers resident in Kashan city during 2016-2017
No full textBackground: Several studies have shown the dangers of cigarette smoking among daily smokers. However, another group that has recently been investigated is a nondaily smoking group. The nondaily smokers experience the adverse health effects of smoking more than nonsmokers. This study aimed to evaluate the prevalence of depression and anxiety among daily and nondaily smokers.
Materials and Methods: In this cross-sectional study with snowball sampling, 385 male residents of Kashan were selected and divided into three groups of daily smokers (118), nondaily smokers (114) and nonsmokers (135). Depression and anxiety were measured by the Beck depression inventory and beck anxiety inventory.
Results: The results of the current study showed no significant difference in the prevalence of depression and anxiety in both daily and nondaily smokers (P<0.05). Also, depression and anxiety levels in daily smokers and nondaily smokers were significantly higher than nonsmokers (P<0.05).
Conclusion: The prevalence of depression and anxiety among nondaily smokers is the same as the daily smokers. Thus, in both groups, in addition to smoking, special attention should be paid to anxiety and depression disorders
Optimum Pumping Well Placement and Capacity Design for a Groundwater Lowering System in Urban Areas with the Minimum Cost Objective
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