ABSTRACT
The successful use of solar energy for cooking requires the systems adopted not only to have technical attributes that conveniently address specific cooking requirements but also are socially and economically acceptable to its end-users. When displacing cooking fuels used in developing countries, solar cooking can lead to (i) improved health in children and women, (ii) less local forest degradation, (iii) less local pollution, and (iv) lower contributions to global greenhouse gas emissions. The diverse range of thermal and photovoltaic solar cooking systems available, or under development, in different regions of the world is discussed in the present work. Particular attention is given to the social, cultural, and economic factors that have limited adoption of solar cookers. Technical developments that address these limitations are shown to only be effective when they facilitate traditional ways of cooking particular foods in and at desired times in specific climates.
Subject(s)
Air Pollution, Indoor , Household Articles , Solar Energy , Air Pollution, Indoor/analysis , Child , Cooking , Female , HumansABSTRACT
In order to enable greater accuracy in the determination of the mass discharge of gas and water-gas ratios (WGR) in groundwater from springs, we have developed a field-deployable instrument using commercially available components to independently measure the gas and water mass flow rates in springs with bubbling mixed-phase flow. Collecting and measuring the free gas phase will allow for further compositional analysis that may be useful in improving gas-derived parameters such as recharge temperature and age, as well as quantification of methanogenesis and flux of crustal/mantle gasses. By installing a phase separator at the spring discharge, a thermal mass flow sensor is utilized to measure the gas flow rate (ebullition + flux) generated from a spring. The water flow rate is determined by a standard weir. Field performance of the device was tested on a spring discharging from the Arbuckle-Simpson aquifer near the town of Connerville in south-central Oklahoma, USA.
Subject(s)
Groundwater , Natural Springs , Cities , GasesABSTRACT
BACKGROUND: In this study, we investigated the agreement between measurements made on ultrasound and those made on magnetic resonance imaging (MRI) in the assessment of glenohumeral dysplasia resulting from brachial plexus birth palsy. METHODS: Thirty-nine patients (14 male and 25 female) with brachial plexus birth palsy were evaluated at 2 tertiary care centers. All patients underwent ultrasonography and MRI for suspected glenohumeral dysplasia. Studies were obtained at an average of 2 months apart (range, 0 to 6 months). The average patient age at the time of the initial imaging study was 20 months (range, 4 to 54 months). Four blinded independent evaluators measured the alpha angle, the posterior humeral head displacement (PHHD), and glenoid version on both the ultrasound and MRI study for each patient. The percentage of the humeral head anterior to the scapular axis (PHHA) was determined on MRI only. Measurements were obtained on OsiriX software (Pixmeo). Intraclass correlation coefficients (ICCs) were used to assess the intrarater and interrater reliability, and Bland-Altman plots were used to compare MRI and ultrasound measurement agreement. RESULTS: We found excellent interrater reliability for measurements of the alpha angle on MRI, glenoid version on MRI, and the alpha angle on ultrasound (ICC: 0.83, 0.75, and 0.78, respectively). The interrater reliability for the PHHD on both MRI and ultrasound was good (ICC: 0.70 and 0.68, respectively), and the interrater reliability for the PHHA on MRI was fair (ICC: 0.57). However, the interrater reliability for glenoid version on ultrasound was poor (ICC: 0.30). Relative to MRI measurements, ultrasound measurements were found to underestimate the alpha angle and glenoid version by an average of 13° ± 23° and 6° ± 17°, respectively, and overestimate the PHHD by an average of 4% ± 20%. Increasing patient age corresponded with a significant increase in the MRI-ultrasound measurement difference for the alpha angle (p < 0.01) and a marginally significant increase in the difference for the PHHD (p < 0.06). CONCLUSIONS: Measurements on MRI and ultrasound were reliable, with measured bias. The poor agreement between measurements on MRI and ultrasound calls into question the validity of using ultrasonography as a stand-alone modality in the evaluation of glenohumeral dysplasia. MRI remains the gold standard for fully evaluating the glenohumeral joint. The clinical role of ultrasonography may be that of a screening tool or a way of evaluating joint reduction in real time. LEVEL OF EVIDENCE: Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.