Supercapacitor leakage in energy-harvesting sensor nodes: fact or fiction?

As interest in energy-harvesting sensor nodes continues to grow, the use of supercapacitors as energy stores or buffers is gaining popularity. The reasons for their use are numerous, and include their high power density, simple interfacing requirements, simpler measurement of state-of-charge, and a greater number of charging cycles than secondary batteries. However, supercapacitor energy densities are orders of magnitude lower. Furthermore, they have been reported to exhibit significant leakage, and this has been shown to increase exponentially with terminal voltage (and hence stored energy). This observation has resulted in a number of algorithms, designs and methods being proposed for effective operation of supercapacitor-based energy-harvesting sensor nodes. In this paper, it is argued that traditional ‘leakage’ is not as significant as has commonly been suggested. Instead, what is observed as leakage is in fact predominantly due to internal charge redistribution. As a result, it is suggested that different approaches are required in order to effectively utilize supercapacitors in energy-harvesting sensor nodes

Ultra low-power photovoltaic MPPT technique for indoor and outdoor wireless sensor nodes

Photovoltaic (PV) energy harvesting is commonly used to power wireless sensor nodes. To optimise harvesting efficiency, maximum power point tracking (MPPT) techniques are often used. Recently-reported techniques focus solely on outdoor applications, being too power-hungry for use under indoor lighting. Additionally, some techniques have required light sensors (or pilot cells) to control their operating point. This paper describes an ultra low-power MPPT technique which is based on a novel system design and sample-and-hold arrangement, which enables MPPT across the range of light intensities found indoors and outdoors and is capable of cold-starting. The proposed sample-and-hold based technique has been validated through a prototype system. Its performance compares favourably against state-of-the-art systems, and does not require an additional pilot cell or photodiode. This represents an important contribution, in particular for sensors which may be exposed to different types of lighting (such as body-worn or mobile sensors)

Observation requirements for unmanned planetary missions, part 2

Observation requirements for unmanned planetary mission

Statistical evaluation of proton radiation from solar flares Final technical report

Statistical evaluation of proton radiation from solar flare

Vocational Schools Are No Vacation: Determining Who Really Benefits from Student Labor

On April 28, 2011, in Solis v. Laurelbrook Sanitarium & School, Inc., the U.S. Court of Appeals for the Sixth Circuit held that students who worked as part of the curriculum at a religious-based boarding school were not employees under the Fair Labor Standards Act. In so holding, the Sixth Circuit expressly endorsed the “primary benefit” test for determining whether trainees are employees for purposes of the FLSA. The primary benefit test effectuates the purpose of the FLSA, provides courts with the flexibility to prevent employers from exploiting workers, and ultimately benefits employees and students like those at Laurelbrook. Nevertheless, the test does little to clarify Congress’s circular definitions of “employ” and “employee,” leaving employers and schools like Laurelbrook without much guidance

A Jury of Whose Peers?: Eliminating Racial Discrimination in Jury Selection Procedures

The jury system is intended to instill fairness and increase confidence in the American legal system as a whole. Despite this goal, widespread discrimination remains in jury selection procedures. In order to adequately protect both a defendant’s right to be tried by a jury of his peers and every citizen’s right to participate in the legal system, representativeness should be improved at each of three levels where juror exclusion takes place: (1) the assembly of the jury pool; (2) the issuance of exemptions and excusals from jury service; and (3) the use of peremptory challenges in empanelling the petit jury. States should institute a system like the one used in Massachusetts, which limits service to one day or one trial and eliminates all exemptions from jury service. In addition, the Supreme Court should reevaluate the current unfettered use of peremptory challenges

Come to A Night in the Chapel and The Mall with Jackie Blue

My collection of garments and accessories being sold at The Mall was conceived in Southern Italy. I visited the home of my ancestors in August of 2022 for the first time. Relatively early in my presenting feminine, I proved to be a spectacle for the places I visited and their inhabitants. Days filled with gawking, pointing, and yelling; the attention was not new to me, just in this case I couldn’t understand what my viewers were saying. Only at night, after the locals got drunk and the lights were dimmed did I sort of blend in with the other big-nosed wiry women roaming the streets of Calabria with me. It was an odd position to be in, for sure, but it allowed me to exist singularly and instinctually for a while. Traveling with my mom and sister, who did not receive these stares, I frequently went out on my own to explore. I found that I kept gravitating toward the same two places in these moments of discomfort. The places I found myself instinctively entering were 1. Churches and 2. Shopping malls. Thinking retrospectively about these intuitive ventures, I realized that I wasn\u27t ever being noticed in these settings. In the churches, Catholic frequenters were too focused on praying to notice me walking by. And in the malls, I found that because there were so many people, all enthralled by the mall’s visuals of consumption, I was not at the top of their lists to stare at either. Although I wasn’t being noticed by the locals in these places, I still couldn’t shake this feeling that I was being watched over. This surveillance was transformed only when I decided to stare back at its source. Physically, I learned that this stare was coming from the statues of Maria in the churches, and from the faces of mannequins in the malls. Metaphysically, I learned that this gaze was actually my own. When I stared back at one of these forms, I first only felt the impermeable nature of its ceramic or plastic make up. After about thirty seconds, my stare’s source became abstracted. Maria and the mannequin transitioned out of objectiveness and into reflectiveness. My visual consciousness became superimposed onto my subjects and I ultimately switched places with them. I became them. These humanoid forms acted as vessels for me to see myself through and in these moments, surrounded by binary Italy and its forces of isolation, I fell in love with what I saw. God’s image of a young Gaga basking in her potential. I couldn’t be luckier. A Night in the Chapel acts as a culminating moment for all of these metaphysical happenings of self and God to be created into a collection of physical objects for the masses to see and absorb. The Mall harps on the fact that I was never truly exposed to fine art as a kid but rather found inspiration for creativity when I frequented my local shopping mall with my mom weekly. The two in tandem tell a story of self

The Montana Travel Industry 2021

2021 summary of the Montana travel and recreation industry

A High School Economics Course Curriculum That Effectively Integrates Language and Content Instruction for English Learners

While secondary English learners face barriers to learning across all content areas, social studies courses are especially linguistically complex, and have a high level of expected prior knowledge. In the author\u27s experience as a high school EL teacher, economics is often a particularly challenging course for EL students. This prompted the research question: How can a high school economics curriculum be designed to help English learners gain a deep understanding of the course topics while improving their academic English proficiency? A review of the literature found that features of a sheltered instruction model will validate, engage, and benefit a diverse range of English learners as they simultaneously learn content and increase English proficiency. The project is a Sheltered Economics Course Plan, with a scope and sequence of five units for a semester-long economics course, and lesson plans to launch each of these units. The unit overview includes academic content benchmarks and English language development expectations, which provide the basis for lesson-level content and language objectives. A sheltered instruction (SIOP) lesson template was used to create the detailed lesson plans. The lesson plans each include key features of sheltered instruction, with an emphasis on developing academic vocabulary, using multimodal techniques that support comprehension, grouping students intentionally for interaction, and reviewing key vocabulary and content concepts at the end of each lesson