Current Source DC-DC Converter for Undersea Fiber Optic Sensors

Today, there are nearly 400 cable networks spanning roughly 750,000 miles to connect our world together. With thousands of miles of cable already lying on the ocean floor, with thousands more to come, many have recognized a unique opportunity in using this cable infrastructure as an attachment point for sensors to help study and monitor the ocean. Placing sensors onto a submarine cable is not a simple task; the sensors will require power that they receive from a transmission cable, from a battery, or from the submarine cable itself. Unfortunately, the existing power feed configuration for submarine cables typically only accounts for cable repeaters and their specified current requirement. Therefore, a converter will be required to properly power the sensors. Because only the current is a known value (as the voltage will be variable depending on the position along the cable), a current source DC-DC converter must be used. This project entails the design and construction of a current source DC-DC converter that is intended to meet the following specifications for the sensors: step down an input current of 0.9 amps to 0.625 amps, maintain an output voltage of 24 volts, and an output power of 15 watts. The goal of this project was to create a current-source DC-DC converter that stepped down a 0.9A input current to a 0.625A output current at 24V. The designed circuit successfully stepped down the input current to the proper output; however, further improvements will be needed to achieve the desired efficiency and output ripple specifications. Overall, the constructed circuit provides a proof of concept of the current source design that can be iterated upon for better results in the future

Correcting Misconceptions About Gamification of Assessment: More Than SJTs and Badges

Describing the current state of gamification, Chamorro-Premuzic, Winsborough, Sherman, and Hogan () provide a troubling contradiction: They offer examples of a broad spectrum of gamification interventions, but they then summarize the entirety of gamification as “the digital equivalent of situational judgment tests.” This mischaracterization grossly oversimplifies a rapidly growing area of research and practice both within and outside of industrial–organizational (I-O) psychology. We agree that situational judgment tests (SJTs) can be considered a type of gamified assessment, and gamification provides a toolkit to make SJTs even more gameful. However, the term gamification refers to a much broader and potentially more impactful set of tools than just SJTs, which are incremental, versatile, and especially valuable to practitioners in an era moving toward business-to-consumer (B2C) assessment models. In this commentary, we contend that gamification is commonly misunderstood and misapplied by I-O psychologists, and our goals are to remedy such misconceptions and to provide a research agenda designed to improve both the science and the practice surrounding gamification of human resource processes

Insights into the evolution of the Thomson Orogen from geochronology, geochemistry, and zircon isotopic studies of magmatic rocks

Zircon U–Pb ages, εHf(t), and δ18O isotopic data together with geochemistry and limited Sm–Nd results from magmatic rocks sampled in deep-basement drill cores from undercover parts of the Thomson Orogen provide strong temporal links with outcropping regions of the orogen and important clues to its evolution and relationship with the Lachlan Orogen. SHRIMP U–Pb zircon ages show that magmatism of Early Ordovician age is widespread across the central, undercover regions of the Thomson Orogen and occurred in a narrow time-window between 480 and 470 Ma. These rocks have evolved εHf(t)zrn (−12.18 to −6.26) and εNd (−11.3 to −7.1), and supracrustal δ18Ozrn (7.01–8.50‰), which is in stark contrast to Early Ordovician magmatic rocks in the Lachlan Orogen that are isotopically juvenile. Two samples have late Silurian ages (425–420 Ma), and four have Devonian ages (408–382 Ma). The late Silurian rocks have evolved εHf(t)zrn (−6.42 to −4.62) and supracrustal δ18Ozrn (9.26–10.29‰) values, while the younger Devonian rocks show a shift toward more juvenile εHf(t)zrn, a trend that is also seen in rocks of this age in the Lachlan Orogen. Interestingly, two early Late Devonian samples have juvenile εHf(t)zrn (0.01–1.92) but supracrustal δ18Ozrn (7.45–8.77‰) indicating rapid recycling of juvenile material. Two distinct Hf–O isotopic mixing trends are observed for magmatic rocks of the Thomson Orogen. One trend appears to have incorporated a more evolved supracrustal component and is defined by samples from the northern two-thirds of the Thomson Orogen, while the other trend is generally less evolved and from samples in the southern third of the Thomson Orogen and matches the isotopic character of rocks from the Lachlan Orogen. The spatial association of the Early Ordovician magmatism with the more evolved metasedimentary signature suggests that at least the northern part of the Thomson Orogen is underlain by older pre-Delamerian metasedimentary rocks

Percutaneous Approach to Pericardial Disease Management

Percutaneous access of the pericardial space is increasingly sought. This is not only due to growing prevalence of pericardial effusions and cardiac tamponade, but also the emerging diagnostic and therapeutic potential of the pericardial space for mapping and ablation of arrhythmogenic circuits, biopsy, and drug delivery. Although increasingly performed, percutaneous pericardiocentesis remains a technically challenging procedure with potentially life-threatening complications. Consequently, management of patients with pericardial disease is highly complex. In this chapter we outline a step-by-step approach to percutaneous pericardiocentesis and the required specialised management of pericardial disease patients. Procedural complications are discussed along with their alleviating therapeutic strategies. Furthermore, we describe approaches to the prevention and management of recurrent pericardial effusion including diagnostic and therapeutic procedures such as percutaneous balloon pericardiotomy and intra-pericardial delivery of chemotherapeutics and sclerosing agents

Balancing employee needs, project requirements and organisational priorities in team deployment

The 'people and performance' model asserts that performance is a sum of employee ability, motivation and opportunity (AMO). Despite extensive evidence of this people-performance link within manufacturing and many service sectors, studies within the construction industry are limited. Thus, a recent research project set out to explore the team deployment strategies of a large construction company with the view of establishing how a balance could be achieved between organisational strategic priorities, operational project requirements and individual employee needs and preferences. The findings suggested that project priorities often took precedence over the delivery of the strategic intentions of the organisation in meeting employees' individual needs. This approach is not sustainable in the long term because of the negative implications that such a policy had in relation to employee stress and staff turnover. It is suggested that a resourcing structure that takes into account the multiple facets of AMO may provide a more effective approach for balancing organisational strategic priorities, operational project requirements and individual employee needs and preferences more appropriately in the future

What if houses were powered by milk?

© 2017 Elsevier B.V. Living architectures and green energy are hot topics of the applied sciences. They aim to develop buildings that co-live with their environment and co-habit with people they house. An ultimate goal would be to make every block in a building capable of producing energy. We present results of scoping, and somewhat illustrative, experiments on generating electrical energy in modified aerated concrete blocks. These blocks are commonly used in modern building industry and therefore make an ideal candidate for ‘inbuilt’ microbial bio-reactors. We fill the blocks with milk to evaluate electro-generation potential of a pasteurised milk and to study power generating potential of the medium nutrient rich for micro-organisms. We assess the practicality of using bio-reactors which become colonised by local micro-flora

Understanding employee resourcing in construction organizations

In recent years the literature on employee resourcing has consistently advocated the importance of adopting a holistic, strategic approach to employee deployment decision making rather than adopting a reactive needs-based approach. This is particularly problematic in construction where the multi-project environment leads to constantly changing resource requirements and to changing demands over a project's life cycle. This can lead to inappropriate decisions, which fail to meet the longer-term needs of both construction organizations and their employees. A structured and comprehensive understanding of the current project team deployment practices within large construction organizations was developed. Project deployment practices were examined within seven case study contracting firms. The emergent themes that shaped the decision-making processes were grouped into five broad clusters comprising human resource planning, performance/career management, team deployment, employee involvement and training and development. The research confirms that a reactive and ad hoc approach to the function prevails within the firms investigated. This suggests a weak relationship between the deployment process and human resource planning, team deployment, performance management, employee involvement and training and development activities. It is suggested that strategic HR-business partnering could engender more transparent and productive relationships in this crucial area

Duration of Protection and Age-Dependence of the Effects of the SPf66 Malaria Vaccine in African Children Exposed to Intense Transmission of Plasmodium falciparum

The SPf66 synthetic vaccine is safe and partly efficacious against Plasmodium falciparum malaria among children 1-5 years old. The estimated vaccine efficacy [VE] for all clinical episodes over a period of 18 months after the third dose is 25% (95% confidence interval [CI], 1%-44%; P = .044). The observed temporal variations in efficacy could have been due to chance (likelihood ratio χ2 = 13.8,8 df; P = .086). Efficacy against clinical malaria did not vary significantly with age χ2 = 1.07, 4 df; P = .90). Overall parasite density was 21% lower in vaccine recipients than in the placebo group (95% CI, 0%-38%; P = .044). Further development of SPf66 may require trials to evaluate safety, immunogenicity, and efficacy when administered in the first year of life, together with other vaccines contained in the Expanded Programme of Tmmunization schedul

Mapping our Universe in 3D with MITEoR

Mapping our universe in 3D by imaging the redshifted 21 cm line from neutral hydrogen has the potential to overtake the cosmic microwave background as our most powerful cosmological probe, because it can map a much larger volume of our Universe, shedding new light on the epoch of reionization, inflation, dark matter, dark energy, and neutrino masses. We report on MITEoR, a pathfinder low-frequency radio interferometer whose goal is to test technologies that greatly reduce the cost of such 3D mapping for a given sensitivity. MITEoR accomplishes this by using massive baseline redundancy both to enable automated precision calibration and to cut the correlator cost scaling from N^2 to NlogN, where N is the number of antennas. The success of MITEoR with its 64 dual-polarization elements bodes well for the more ambitious HERA project, which would incorporate many identical or similar technologies using an order of magnitude more antennas, each with dramatically larger collecting area.Comment: To be published in proceedings of 2013 IEEE International Symposium on Phased Array Systems & Technolog