6,678 research outputs found
Validating performance of automotive materials at high strain rate for improved crash design
This paper investigates sources of performance variability in high velocity testing of automotive crash structures. Sources of variability, or so called noise factors, present in a testing environment, arise from uncertainty in structural properties, joints, boundary conditions and measurement system. A box structure, which is representative of a crash component, is designed and fabricated from a high strength Dual Phase sheet steel. Crush tests are conducted at low and high speed. Such tests intend to validate a component model and material strain rate sensitivity data determined from high speed tensile testing. To support experimental investigations, stochastic modeling is used to investigate the effect of noise factors on crash structure performance variability, and to identify suitable performance measures to validate a component model and material strain rate sensitivity data. The results of the project will enable the measurement of more reliable strain rate sensitivity data for improved crashworthiness predictions of automotive structures
Electron tunnel sensor technology
Researchers designed and constructed a novel electron tunnel sensor which takes advantage of the mechanical properties of micro-machined silicon. For the first time, electrostatic forces are used to control the tunnel electrode separation, thereby avoiding the thermal drift and noise problems associated with piezoelectric actuators. The entire structure is composed of micro-machined silicon single crystals, including a folded cantilever spring and a tip. The application of this sensor to the development of a sensitive accelerometer is described
Intelligent and adaptive tutoring for active learning and training environments
Active learning facilitated through interactive and adaptive learning environments differs substantially from traditional instructor-oriented, classroom-based teaching. We present a Web-based e-learning environment that integrates knowledge learning and skills training. How these tools are used most effectively is still an open question. We propose knowledge-level interaction and adaptive feedback and guidance as central features. We discuss these features and evaluate the effectiveness of this Web-based environment, focusing on different aspects of learning behaviour and tool usage. Motivation, acceptance of the approach, learning organisation and actual tool usage are aspects of behaviour that require different evaluation techniques to be used
Validating material information for stochastic crash simulation
This paper describes the steps in validating material information for stochastic simulation using a quasi static tensile test experiment Sources of physical noise usually present in a testing environment such as variation in material properties, geometry and boundary conditions are included as inputs to finite element models
Plant Oils and Products of Their Hydrolysis as Substrates for Polyhydroxyalkanoate Synthesis
Plant oils could provide a sustainable source of carbon for polyhydroxyalkanoate production as they are both renewable and inexpensive. No study to our knowledge has undertaken a comparative study of the use of major European and global commodity plants oils and products of their hydrolysis as substrates for medium chain length polyhydroxyalkanoate (mcl-PHA) production. There have been several studies which have investigated the use of plant oils and their hydrolysis products for short chain length PHA (scl-PHA) production, therefore, in this study, we have focused specifically on mcl-PHA-producing organisms. A comparison between direct growth on oils and the products of their hydrolysis is described here for several mcl-PHA-producing Pseudomonas strains. Pseudomonas putida KT2440, CA-3, GO16, Pseudomonas chlororaphis 555 were screened for their ability to utilize a range of common plant oils (olive, sunflower, rapeseed, and palm) and their hydrolysis products as sole sources of carbon and energy for growth and PHA accumulation. When the oils were supplied in shaken flask experiments, P. putida CA-3 and P. putida KT2440 showed little or no growth, while P. putida GO16 reached a cell dry weight of between 0.33 and 0.56 g Lā1, and accumulated mcl-PHA to between 12 and 25 % of CDW, P. chlororaphis 555 reached a cell dry weight of between 0.67 and 0.86 g Lā1, and accumulated mcl-PHA to between 27 and 34 % CDW in 48 h. In contrast, when the hydrolyzed fatty acid mixtures were supplied, all 4 strains tested grew and accumulated mcl-PHA. P. putida CA-3 and GO16 achieved the highest biomass (1.02 ā 1.06 g Lā1) with the majority of the hydrolyzed plant oil fatty acids, however P. chlororaphis 555 accumulated similar levels of PHA as these two strains. Despite being the strain of choice for mcl-PHA accumulation, for the majority of studies, P. putida KT2440 achieved less biomass and accumulated less PHA than other strains tested with the majority of oil-derived fatty acids. It is important to note that both biomass and PHA levels varied significantly across strain and hydrolyzed oil type. Due to the fact that P. chlororaphis 555 was able to grow and accumulate PHA from both plant oils and hydrolyzed oil fatty acids, it was selected for bioreactor trials to try to achieve high cell density and high PHA productivity using rapeseed oil and hydrolyzed rapeseed oil fatty acids. Rapeseed oil (RO) and its hydrolysis product (HROFA) were chosen for these experiments because P. chlororaphis 555 accumulated approximately 30 % mcl-PHA from both substrates, and as this oil can be produced globally, it would offer less barriers to scale-up than Palm oil. The mcl-PHA volumetric productivity with RO as the substrate was 0.53 g Lā1 hā1 after 25 h with a yield of 0.22 g PHA gā1 oil, while the volumetric productivity with HROFA as the substrate was 0.54 g Lā1 hā1 after 25 h with again a lower yield of 0.15 g PHA gā1 HROFA. Thus, under the fermentation conditions tested, HROFA was an inferior substrate for PHA production when compared to RO
Pengaruh Pemberian Ekstrak Jamur Psilocybe Cubensis Dosis Bertingkat Terhadap Rasa Ingin Tahu Mencit Swiss Webster Yang Diukur Dengan Manual Hole Board
Background : Psilocybin mushrooms are one of the hallucinatory effect that Psilocybe cubensis. Compounds contained in it may provide psychological effects, effects on the nervous edge mapun behavior. Psychological and behavioral effects can be seen from the level of curiosity. Curiosity is an emotion related to the curious behavior such as exploration, investigation, and learning.Objectives : To determine and analyze the effect of Psilocybe cubensis mushroom extract at a dose rate of curiosity on the rise in male miceMethod : experimental study, simple random sampling methodInterventions : The samples used were male Swiss Webster mice amounted to 20 fish with specific inclusion criteria were divided into 4, the control group (P0), the low-dose group (P1) is given Psilocybe cubensis extract at a dose of 0.75 g / kg, medium-dose group (P2) at a dose of 1.5 g / kg, and high-dose groups (P3) at a dose of 3 g / kg. Each extract in mice dropped as much as 1 times before the study began. After that, test Manual Hole Board for 5 minutes to determine the level of curiosity. Differences in the level of curiosity in the treatment group compared with the control group were analyzed by t test indepent.Results : The average score Manual Hole Board in the control group is equal to 29.80; later in the low-dose group decreased an average score being 24.60; moderate dose group experienced a decline in score of 18.20, while in the high-dose group also score decreased to 7.20. The higher the dose given to the mice will lower the score Manual Hole Board significantly (P <0.05), further down the level of curiosity in mice.Conclusion : Giving Psilocybe cubensis with multilevel dose may decrease the level of curiosity in male Swiss Webster mic
Critical Thinking Activities and the Enhancement of Ethical Awareness: An application of a āRhetoric of Disruptionā to the undergraduate general education classroom
This article explores how critical thinking activities and assignments can function to enhance studentsā ethical awareness and sense of civic responsibility. Employing Levinasās Othercentered theory of ethics, Burkeās notion of āthe paradox of substanceā, and Murrayās concept of āa rhetoric of disruptionā, this article explores the nature of critical thinking activities designed to have students question their (often taken-for-granted) moral assumptions and interrogate their (often unexamined) moral identities. This article argues that such critical thinking activities can trigger a metacognitive destabilization of subjectivity, understood as a dialectical prerequisite (along with exposure to otherness) for increased ethical awareness. This theoretical model is illustrated through a discussion of three sample classroom activities designed to destabilize moral assumptions and identity, thereby clearing the way for a heightened acknowledgment of otherness. In so doing, this article provides an alternative (and dialectically inverted) strategy for addressing one of the central goals of many General Education curricula: the development of ethical awareness and civic responsibility. Rather than introducing students to alternative perspectives and divergent cultures with the expectation that heightened moral awareness will follow, this article suggests classroom activities and course assignments aimed at disrupting moral subjectivity and creating an opening in which otherness can be more fully acknowledged and the diversity of our world more fully appreciated
Goal Difficulty and Openness to Interpersonal Goal Support
When people pursue important goals, they are often surrounded by close others who could provide help and support for the achievement of these goals. The present work investigated whether people are more likely to be open to such interpersonal goal support from a romantic partner when they perceive their goals as being easy versus difficult. Using a multiple methods approach, three studies revealed that, compared with the pursuit of easy goals, when people pursue difficult goals, they are less likely to seek out and be open to support from their romantic partner. Studies 2 and 3 revealed that the effect of goal difficulty on openness to support was partially mediated by loss in self-efficacy. Finally, Study 3 revealed that lack of openness to support can have detrimental long-term consequences for the relationship, as it undermines relationship well-being
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