2,545 research outputs found
Investigation of plastic deformation in prestressed concrete slabs from long time loading
It is the purpose of this research to investigate the creep in a thin concrete slab under a long-time prestress load with the compressive load being applied to the edge of the slab through a bearing plate of small dimensions.
Seven plain concrete slabs, 3\u27 x 4\u27 x 4 , approximately one year old, made of normal cement and approved aggregate were subjected to the following loading conditions: (1) Three slabs loaded at the center of the greater dimension with a prestress load or 20,000 pounds applied over an area of eight square inches, (2) Three slabs loaded symmetrically at six inches from each end with a prestress load of 20,000 pounds being applied over an area of eight square inches at each symmetrical point, and (3) An unloaded slab used to measure variations in strains due to temperature, humidity and shrinkage.
By the use of SR-4 electric strain gages placed at predetermined points in the vicinity of the applied loads the values of the strains due to the applied load and subsequent creep were determined. It is hoped that a more complete evaluation of creep can be compiled from the results of this investigation --Introduction, pages 3-4
Brake lights at the border: Going international twenty-two miles away (an international marketing/management case): Working paper series--02-13
Russ Clark is a successful NAPA Auto Parts franchisee in Yuma County, Arizona. He sees opportunity in the neighboring Mexican city of San Luis Rio Colorado. But crossing the border with an after-market auto parts store will require building relationships with others, lots of learning to overcome the significant barriers, and some savvy decision-making, in addition to the usual evaluation of business opportunities. Clark must cope with the barriers to doing business in Mexico, a completely foreign environment, even though the projected location of his new store is only 22 miles away from home. Further, his mistrust of lawyers has thoroughly turned him off to the common practice of hiring a lawyer to intercede for him with the Mexican authorities, and he must consider some alternate plan to make the important contacts that could have been easily facilitated by the lawyer. Clark must consider a location decision, product mix, human resource issues, and how to promote the new business in an uncertain context. Clearly, his current American business model will require a great degree of adaptation to make the venture a success. Note: Teaching Notes for this case can be requested from the authors. For contact information, see case
In-situ electronics and communications for intelligent energy storage
Lithium-ion batteries are increasingly common in high-power, safety–critical applications such as aerospace, spaceflight, automotive and grid storage. The voltage and power specifications of such applications usually require large numbers of individual cells combined in series and parallel to form a battery pack. It is then the role of the Battery Management System (BMS) to monitor these cells condition and ensure they remain within safe operating limits. To minimise cost and complexity, it is typical to monitor only a fraction of the cells in a battery pack. This creates potential safety and reliability issues and requires conservative limits imposed on the overall system to ensure safe operation. This is insufficient in high-power, safety–critical applications and thus alternative approaches to battery management are required. Here we demonstrate the development of novel miniature electronic devices for incorporation in-situ at a cell-level during manufacture. This approach enables local cell-to-cell and cell-to-BMS data communication of sensor data without the need for additional wiring infostructure within a battery module assembly. The electronics firmware and hardware integration within the cell’s electrode stack is demonstrated to function after triggering post cell formation and through cycling and electrochemical impedance analysis. This work shows that the proposed approach has a negligible impact on the cells’ performance and highlights a new technique for active monitoring of the cell’s in-situ conditions. This research will enable new methods of cells characterization and monitoring for optimum electrochemical and thermal performance while improving system safety
Chronicles of Oklahoma
Article describes the oil boom that began at Red Fork, Oklahoma, and the controversy over who discovered and had rights to the oil well there
System Design for an Online Social Networking App with a Notification and Recommender System to Build Social Capital in a University Setting
Social capital in higher education commuter institutions may be declining because fewer students remain on campus. Social capital is the network of relationships in a group. Higher social capital is derived from broader and more complex networks. Social networks can grow because members who belong to a particular group possess a sense of community. If students spend less time on campus, their sense of community may decrease, because they would be less likely to participate in the community. This puts Higher Ed commuter institutions at a disadvantage in terms of generating and maintaining social capital. We investigate the possibility to counter this disadvantage by actively promoting participating in an Online Social Network (OSN); specifically, with the use of a Notification and Recommender System (NARS) in an OSN via a mobile platform. Our results suggest that introducing a purposefully designed OSN has the potential to facilitate creation of structural and relational social capital, but that it might not have an effect on cognitive social capital
TASER International, Inc. - Grappling with growth: Working paper series--05-01
TASER International, Inc. is one of the world's leading less-lethal weapons manufacturers and distributors. The case begins with a dramatic moment, as the brothers who run the company become aware of a highly critical article in Barron's which questions the legitimacy of their high stock price and casts doubt on their continued ability to grow. The case presents the company's counterarguments to the critical Barron's article. (Note that both the Barron's article in its entirety and the response document from the company's website are included with the case as appendices.) Students are shown TASER's powerful and effective marketing strategy to police and military, and then asked to consider whether and how to approach the potentially huge, lucrative consumer market. The case resulted from lengthy in-person, email, and phone interviews with TASER's President, Tom Smith. In addition, the company and its products have been well publicized in the national business press and in the local newspapers. Further, product details and other information on TASERs and other less-lethal weapons have been published in numerous police and military sources. Finally, TASER International's website has been a rich source of supplemental information to support the writing of the case
NASA GIBS and Worldview: Visualizing NASA's Earth Science Data for All to Explore
For more than 20 years, the NASA Earth Observing System (EOS) has operated dozens of remote sensing satellites collecting nearly 15 Petabytes of data that span thousands of science parameters. Within these observations are keys the Earth Scientists have used to unlock many discoveries that we now understand about our planet. Also contained within these observations are a myriad of opportunities for learning and education. The challenge is making them accessible to educators and students in intuitive and simple ways so that effort can be spent on lesson enrichment and not overcoming technical hurdles.The NASA Global Imagery Browse Services (GIBS) system and NASA Worldview interactive mapping site provide a unique view into EOS data through daily full resolution visualizations of hundreds of Earth science parameters. For many of these parameters, visualizations are available within hours of acquisition from the satellite. For others, visualizations are available for the entire mission of the satellite. Accompanying the visualizations are visual aids such as color legends, place names, and orbit tracks. By using these visualizations, educators and students can observe natural phenomena that enrich a scientific education.This presentation will provide an overview of the visualizations available in NASA GIBS and Worldview and how they are accessed. Specific attention will be given to the newer capabilities and accomplishments, including: Support for geostationary sub-daily visualizations, Enhanced support for vector-based visualizations, Improved Worldview tour and snapshot capabilities, New imagery products across a growing set of scientific areas
Improving resilience to hot weather in the UK: The role of communication, behaviour and social insights in policy interventions
At present, there is little guidance on how to communicate the dangers relating to hot weather events and on how to better prepare for them. Social responses to hot weather risks need to be a priority as populations around the world become more exposed to these under a changing climate. In this commentary, we argue that policy interventions focused on improving resilience to hot weather need to be more closely aligned with broader sustainability challenges and more effectively incorporate communication, behaviour, and social insights. With a particular focus on the UK, we highlight the risks of not taking these into account and outline ways in which policy-making on hot weather events could be improved, by drawing on international best practice and supporting decision-making within a range of relevant institutions across the health, transport and housing sectors
Pace Versus Prediction: Is the Age of the Runner Associated With Marathon Success?
INTRODUCTION: During closed-loop exercise, such as marathon running, the athlete adopts a pacing strategy to optimise performance. Exercise intensity (speed) is modulated in response to afferent signals from biological and psychological systems, which relay the responses of the exercise to the brain where efferent, homeostatic-orientated responses are issued. Thus a conscious perception of effort is continuously compared to a sub-conscious template which is derived from previous exposure to the sensations of pain and fatigue and expected exercise duration. The purpose of this study was to explore the association between pacing strategy/race outcome and biological age of the athlete. METHODS: Following local institutional ethical approval n = 777 runners who were competing in the 2015 London Marathon volunteered and agreed to participate. Age, gender and experience of the participants were ascertained using an online survey and opportunistic questionnaire surveying at the pre-marathon registration event. Age was stratified according to the following classifications: 18-39 yrs, 40-49 yrs, 50-59 yrs and >60 yrs. Additionally, participants were asked to predict their marathon finish time (PT) serving as a proxy for end-point and compared to actual finish time (FT). All participating runners 5km splits and FT were downloaded from the race website, converted to speed and then normalised (%) to the final split time/speed (m∙s-1). RESULTS: Significant differences were observed for all age groups (p 60 yrs (p = 0.153). Non-significant differences observed between age groups across all 5km splits (p > 0.05), but within group differences observed between 10-15km for all age groups (p 60yrs at 30-35km (ES = 0.53). CONCLUSIONS: These data suggest that the biological age of the athlete is associated with the implementation of a successful pacing strategy and may be a function of the accrued training volume and/or emotional-event development. Athletes are encouraged to pace themselves with older (>60yrs) athletes with similar PT’
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