Feasibility of Harvesting Power To Run A Domestic Water Meter Using Streaming Cell Technology

We investigate the possibility of using streaming cells as a means of harvesting energy from the town water supply. We measure the electrical power developed from streaming cells using tap water as a working fluid. We estimate the amount of energy available from a typical domestic household based on water usage data. We estimate the amount of energy required to operate a simple data logger and transmitter. From these estimates we calculate the required efficiency and physical form of a streaming cell energy converter. We comment on the feasibility of using streaming cell technology as a means of harvesting energy from a domestic water supply

Scaling of Electrode-Electrolyte Interface Model Parameters In Phosphate Buffered Saline

We report how the impedance presented by a platinum electrode scales with the concentration of phosphate buffered saline (PBS). We find that the constant phase element of the model scales with approximately the log of concentration, whereas the resistivity is inversely proportional. Using a novel DC measurement technique we show that the Faradaic response of a platinum electrode, and thus the safe exposure limit, does not scale with concentration below 900mV overpotential across a pair of electrodes. We compare objective measurements made in saline to those made in the spinal cavity of live sheep. We comment upon the appropriateness of using PBS as a substitute for living sheep

Design study of a thermocouple power sensor as a monolithic fin-line

Making traceable power measurements above 110 GHz using current measurement technologies is challenging. We investigate a design of power sensor consisting of a thermocouple-based integrated circuit (IC) mounted as a finline component in WR-6 waveguide. The design is original in that it contains an antenna, terminating resistor and thermocouples on-chip. We detail the design and report results from simulations and measurements made on a two-port 16:1 scale model. Our design of scale model provides both insertion and reflection loss measurements. Electromagnetic simulation and easily-calibrated model measurements confirm that the short antenna fins feasible on a monolithic microwave integrated circuit (MMIC) can achieve acceptable specifications. The design proves to be relatively insensitive to the value of the terminating resistance or the size of the antenna fins

The energy efficiency of 8-bit low-power microcontrollers

We have measured the energy cost of processing, sleeping, non-volatile memory writes and ADC measurements of six 8-bit microprocessors from three manufacturers. These measurements compare the chips directly to one another and reveal ideal operating points which can be used to reduce energy consumption

Odontoameloblastoma with extensive chondroid matrix deposition in a guinea pig

Odontoameloblastomas (previously incorporated within ameloblastic odontomas) are matrix-producing odontogenic mixed tumors and are closely related in histologic appearance to the 2 other types of matrix-producing odontogenic mixed tumors: odontomas and ameloblastic fibro-odontomas. The presence or absence of intralesional, induced non-neoplastic tissue must be accounted for in the diagnosis. Herein we describe a naturally occurring odontoameloblastoma with extensive chondroid cementum deposition in a guinea pig (Cavia porcellus). Microscopically, the mass featured palisading neoplastic odontogenic epithelium closely apposed to ribbons and rings of a pink dental matrix (dentinoid), alongside extensive sheets and aggregates of chondroid cementum. The final diagnosis was an odontoameloblastoma given the abundance of odontogenic epithelium in association with dentinoid but a paucity of pulp ectomesenchyme. Chondroid cementum is an expected anatomical feature of cavies, and its presence within the odontoameloblastoma was interpreted as a response of the ectomesenchyme of the dental follicle to the described neoplasm. Our case illustrates the inductive capabilities of odontoameloblastomas while highlighting species-specific anatomy that has resulted in a histologic appearance unique to cavies and provides imaging and histologic data to aid diagnosis of these challenging lesions

Choosing the right microcontroller: A comparison of 8-bit Atmel, Microchip and Freescale MCUs

When choosing a microcontroller there are many options, so which platform should you choose? There is little independent information available to help engineers decide which platform might best suit their needs and most designers tend to stick with the brand with which they are familiar. This is a difficult question to answer without bias if the people conducting the evaluations have had previous experience with MCU programming predominantly on one platform. This article draws on a case study. We built three “Smart” Sprinkler Taps, small, self-contained irrigation controllers, differing only in the microcontroller unit (MCU) on the inside. We compare cost, development software quality and hardware performance from the perspective of a new user to each of the platforms

Self-trapping and excited state absorption in fluorene homo-polymer and copolymers with benzothiadiazole and tri-phenylamine

We thank the EPSRC [EP/J009318/1 and EP/J009016/1] for funding. MJP thanks the European Research Council (ERC) for funding under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant No. 258990.Excited state absorption (ESA) is studied using time-dependent density functional theory and compared with experiments performed in dilute solutions. The molecules investigated are a fluorene pentamer, polyfluorene F8, the alternating F8 copolymer with benzothiadiazole F8BT, and two blue-emitting random copolymers F8PFB and F8TFB. Calculated and measured spectra show qualitatively comparable results. The ESA cross-section of co-polymers at its maximum is about three times lower than that of F8. The ESA spectra are found to change little upon structural relaxation of the excited state, or change in the order of sub-units in a co-polymer, for all studied molecules. In all these molecules, the strongest ESA transition is found to arise from the same electronic process, exhibiting a reversal of the charge parity. In addition, F8PFB and F8TFB are found to possess almost identical electronic behaviour.Publisher PDFPeer reviewe

Prevalence and Determinants of Obesity among Primary School Children in Dar es Salaam, Tanzania.

Childhood obesity has increased dramatically and has become a public health concern worldwide. Childhood obesity is likely to persist through adulthood and may lead to early onset of NCDs. However, there is paucity of data on obesity among primary school children in Tanzania. This study assessed the prevalence and determinants of obesity among primary school children in Dar es Salaam. A cross sectional study was conducted among school age children in randomly selected schools in Dar es Salaam. Anthropometric and blood pressure measurements were taken using standard procedures. Body Mass Index (BMI) was calculated as weight in kilograms divided by the square of height in meters (kg/m2). Child obesity was defined as BMI at or above 95th percentile for age and sex. Socio-demographic characteristics of children were determined using a structured questionnaire. Logistic regression was used to determine association between independent variables with obesity among primary school children in Dar es Salaam. A total of 446 children were included in the analysis. The mean age of the participants was 11.1±2.0 years and 53.1% were girls. The mean BMI, SBP and DBP were 16.6±4.0 kg/m2, 103.9±10.3mmHg and 65.6±8.2mmHg respectively. The overall prevalence of child obesity was 5.2% and was higher among girls (6.3%) compared to boys (3.8%). Obese children had significantly higher mean values for age (p=0.042), systolic and diastolic blood pressures (all p<0.001). Most obese children were from households with fewer children (p=0.019) and residing in urban areas (p=0.002). Controlling for other variables, age above 10 years (AOR=3.3, 95% CI=1.5-7.2), female sex (AOR=2.6, 95% CI=1.4-4.9), urban residence (AOR=2.5, 95% CI=1.2-5.3) and having money to spend at school (AOR=2.6, 95% CI=1.4-4.8) were significantly associated with child obesity. The prevalence of childhood obesity in this population was found to be low. However, children from urban schools and girls were proportionately more obese compared to their counterparts. Primary preventive measures for childhood obesity should start early in childhood and address socioeconomic factors of parents contributing to childhood obesity

Fermi Surface as the Driving Mechanism for Helical Antiferromagnetic Ordering in Gd-Y Alloys

The first direct experimental evidence for the Fermi surface (FS) driving the helical antiferromagnetic ordering in a gadolinium-yttrium alloy is reported. The presence of a FS sheet capable of nesting is revealed, and the nesting vector associated with the sheet is found to be in excellent agreement with the periodicity of the helical ordering.Comment: 4 pages, 4 figure

Nonparametric Estimation of the Case Fatality Ratio with Competing Risks Data: An Application to Severe Acute Respiratory Syndome (SARS)

For diseases with some level of associated mortality, the case fatality ratio measures the proportion of diseased individuals who die from the disease. In principle, it is straightforward to estimate this quantity from individual follow-up data that provides times from onset to death or recovery. In particular, in a competing risks context, the case fatality ratio is defined by the limiting value of the sub-distribution function, associated with death, at infinity. When censoring is present, however, estimation of this quantity is complicated by the possibility of little information in the right tail of of the sub-distribution function, requiring use of estimators evaluated at large or the largest observed death times. With right censoring, the variability of such estimators is large in the tail, suggesting the possibility of using estimators evaluated at smaller death times where bias may be increased but overall mean squared error be smaller. These issues are investigated here for nonparametric estimators of the sub-distribution functions for both death and recovery. The ideas are illustrated on case fatality data for individuals infected with severe acute respiratory syndrome (SARS) in Hong Kong in 2003