A numerical study on the design trade-offs of a thin-film thermoelectric generator for large-area applications

Thin-film thermoelectric generators with a novel folding scheme are proposed for large-area, low energy-density applications. Both the electrical current and heat transfer are in the plane of the thermoelectric thin-film, yet the heat transfer is across the plane of the module - similar to conventional bulk thermoelectric modules. With such designs, the heat leakage through the module itself can be minimized and the available temperature gradient maximized. Different from the previously reported corrugated thermoelectric generators, the proposed folding scheme enables high packing densities without compromising the thermal contact area to the heat source and sink. The significance of various thermal transport, or leakage, mechanisms in relation to power production is demonstrated for different packing densities and thicknesses of the module under heat sink-limited conditions. It is shown that the power factor is more important than ZT for predicting the power output of such thin-film devices. As very thin thermoelectric films are employed with modest temperature gradients, high aspect-ratio elements are needed to meet the - usually ignored - requirements of practical applications for the current. With the design trade-offs considered, the proposed devices may enable the exploitation of thermoelectric energy harvesting in new - large-area - applications at reasonable cost.Comment: 26 pages,5 figures, post-peer-review, pre-copyedit version of an article published in Renewable Energ

Exploitation of Transparent Conductive Oxides in the Implementation of a Window-Integrated Wireless Sensor Node

Exploitation of transparent conductive oxides (TCO) to implement an energy-autonomous sensor node for a wireless sensor network (WSN) is studied and a practical solution presented. In the practical implementations, flexible and rigid substrates that is polyimide and glass, are coated with TCO, namely aluminum doped zinc oxide (AZO). AZO-coated flexible substrates are used to form thermoelectric generators (TEG) that produce electricity for the sensor electronics of the node from thermal gradients on a window. As the second solution to utilize AZO, its conductive properties are exploited to implement transparent antennas for the sensor node. Antennas for a UHF RFID transponder and the Bluetooth radio of the node are implemented. A prototype of a flexible transparent TEG, with the area of 67 cm2 when folded, was measured to produce power of 1.6 uW with a temperature difference of 43 K. A radiation efficiency of -9.1 dB was measured for the transparent RFID antenna prototype with the center frequency of 900 MHz. Radiation efficiencies between -3.8 dB and -0.4 dB, depending on the substrate, were obtained for the 2.45 GHz Bluetooth antenna.Comment: 10 pages, 14 figures, last author version accepted for publication in IEEE Sensors Journa

Spectrum, Volume 13, Number 3

Highlights include: WWPT will soon be transmitting a low power, on campus only, radio wave which can run continuously for 24 hours. WWPT currently broadcasts on 90.3. The new frequency is likely to be 91.5 pending further testing --Opening soon in former room SI 10, next to the radio station, is The Marche, which will offer a variety of grill and fast food items --The GE Scholar Program consists of students from a wide variety of ethnic backgrounds, many of whom are commuter students. Each scholar is awarded $2,000 per year and each participant in turn, contributes to the community --After seeing limited time in the Pioneer back field last season behind four-year starter Ron Stopkoski, Brian Ihlefeld has arrived as a strong and elusive runner this season as well as a big play maker for the SHU gridders --The varsity crews have their first competition this Sunday in Mystic, CT, where they will compete in the Great Pawcktuck Paddle or Row Race --The men’s soccer team is on a tear after winning 4 in a row --Women’s field hockey team has increased the win column to 4-1 with their recent victories over Manhattenville, Albany and Keene State

Puheterapeutit alle kolmevuotiaiden lasten arvioinnissa ja kuntoutuksessa

Tavoiteet: Varhaiskuntoutuksen on osoitettu olevan tehokasta ja vaikuttavan laaja-alaisesti lapsen kasvuun ja kehitykseen aivojen plastisuuden kautta. Käsitteenä varhaiskuntoutus on kuitenkin vakiintumaton, eikä sille ole yhtenäistä linjaa terveydenhuoltojärjestelmässämme. Tutkimuksen tarkoituksena oli kartoittaa suomalaisten puheterapeuttien kokemuksia ja näkemyksiä alle kolmevuotiaiden lasten puheterapeuttisesta arviosta ja kuntoutuksesta, sekä puheterapeuttien valmiuksista työskennellä kyseisen ikäluokan kanssa. Lisäksi tutkimuksessa selvitetiin tekijöitä, joiden vuoksi pienet lapset ohjautuvat puheterapeutin luokse. Menetelmät: Tutkimus toteutettiin kyselytutkimuksena internetissä Helsingin yliopiston E-lomakkeella huhti-toukokuussa 2016. Vastauspyyntö saatteineen välitettiin suomalaisille puheterapeuteille Suomen Puheterapeuttiliiton sekä neljän puheterapeutteja työllistävän yrityksen kautta. Saadut vastaukset analysoitiin tilastollisesti IBM SPSS Statistics 24 -ohjelmalla käyttäen nonparametrisia tilastollisia testejä sekä laadullisesti ryhmittelemällä. Tulokset: Kyselyyn vastasi yhteensä 194 suomalaista puheterapeuttia, joista 111 työskenteli säännöllisesti ja 73 vaihtelevasti alle kolmevuotiaiden lasten kanssa. Puheterapeuttien osaaminen pienten lasten osalta rakentui suurimmaksi osaksi työkokemuksen kautta ja varsinkin säännöllisen työskentelyn koettiin lisäävän taitoja alle kolmevuotiaiden lasten kanssa työskentelyyn. Ammatillista osaamista ylläpidettiin ja kasvatettiin lisäksi täydennyskoulutuksilla sekä kirjallisuudella. Logopedian peruskoulutuksen koettiin antavan ikäryhmän kanssa työskentelyyn vain vähän valmiuksia. Tulosten perusteella puheterapeuteille ohjaudutaan varhaisessa vaiheessa eniten erilaisten sairauksien ja vammojen sekä puheen viiveen vuoksi. Lasten arvioinnissa käytettiin eniten standardoituja testejä, havainnointia ja vanhempien haastattelua. Kuntoutuksessa korostuivat AAC-menetelmien sekä leikin käyttö. Käytänteet alle kolmevuotiaiden lasten puheterapiaan ohjautumisessa ja puheterapeuttisessa kuntoutuksessa osoittautuivat vaihteleviksi ja liittyivät käytössä oleviin resursseihin. Suuri osa puheterapeuteista koki, että muut terveydenalan ammattihenkilöt eivät ole tarpeeksi tietoisia heidän työnkuvastaan ja tämän vuoksi heidän varhaisen vaikuttamisen osaamistaan ei osata hyödyntää tarpeeksi.Aim: Due to the plasticity of the brain of a child under three years old early intervention can be very effective and affect the growth and development of the child extensively. As a concept early intervention is as yet unestablished within our healthcare system. The purpose of this study was to find out what kind of experiences Finnish speech-language therapists (SLTs) have about the assessment and the rehabilitation of children under three years old and the readiness of SLTs to work with these small children. The study also aimed to find out the reasons why small children are being sent to speech-language therapists. Methods: This study was done by a questionnaire and the material was gathered using an electrical survey with the E-lomake -program of the University of Helsinki between April and May 2016. The questionnaire was delivered to Finnish SLTs via the Finnish Assocation of Speech Therapists and four corporations that employ SLTs. The data was analysed with the IBM SPSS Statistics 24 -program using nonparameterized statistical tests and qualitative grouping. Results and conclusions: The questionnaire was answered by 194 SLTs out of which 111 worked regulary and 73 occasionally with children under three. The SLTs’ know-how about working with small children was mostly based on work experience. The professional capabilities were maintained and developed by additional trainings and literature. A degree in logopedics was considered to provide only minor capabilities toward working with small children. The results indicate that small children are sent to SLTs mostly because of disabilities and delayed speech development. The most popular assessment methods were tests, free observation and interviewing the child’s parents. AAC methods and playing were popular methods of rehabilitation. The practices in rehabilitating small children were varying and based on the available resources. According to the SLTs other healthcare professionals are not aware of what an SLT does and therefore their know-how is not utilized to it’s full extent

Occupational Safety and Health and Temporary Agency Work in Multiemployer Restaurants

Peer reviewe

Nano-thermoelectric infrared bolometers

Infrared (IR) radiation detectors are used in numerous applications from thermal imaging to spectroscopic gas sensing. Obtaining high speed and sensitivity, low-power operation and cost-effectiveness with a single technology remains to be a challenge in the field of IR sensors. By combining nano-thermoelectric transduction and nanomembrane photonic absorbers, we demonstrate uncooled IR bolometer technology that is material-compatible with large-scale CMOS fabrication and provides fast and high sensitivity response to long-wavelength IR (LWIR) around 10 $\mu$m. The fast operation speed stems from the low heat capacity metal layer grid absorber connecting the sub-100 nm-thick n- and p-type Si nano-thermoelectric support beams, which convert the radiation induced temperature rise into voltage. The nano-thermoelectric transducer-support approach benefits from enhanced phonon surface scattering in the beams leading to reduction in thermal conductivity, which enhances the sensitivity. We demonstrate different size nano-thermoelectric bolometric photodetector pixels with LWIR responsitivities, specific detectivities and time constants in the ranges 179-2930 V/W, 0.15-3.1$\cdot10^{8}$ cmHz$^{1/2}$/W and 66-3600 $\mu$s, respectively. We benchmark the technology against different LWIR detector solutions and show how nano-thermoelectric detector technology can reach the fundamental sensitivity limits posed by phonon and photon thermal fluctuation noise.Comment: 20 pages, 4 figures, 1 tabl