Estimation of energy-saving potential and indoor thermal comfort by the central control of the heating curve in old apartment buildings

In this research, an existing building calibrated simulation model from 1981 was built based on measured energy and indoor temperature data. The model was used to study the central control's energy-saving potential. With parametric simulations, DHW circulation internal heat gain and ventilation airflow rate was determined as 85% and 0.29 l/s/m², respectively. DHW circulation heat loss has been found almost as high as DHW use. Dropping the heating curve from 70/40 °C to 65/35 °C resulted in a saving of 0.6 kWh/m²a (0.8% of space heating energy) on the cost of thermal comfort as yearly hours of the mean air temperature below 21 °C rose from 2.7% to 9.0%. It was necessary to reduce the heating curve to 55/25 °C in a hypothetical scenario with fully open thermostats, indicating heat redistribution from warmer to colder rooms, leading to higher heating energy. The findings indicate no energy saving potential due to compromising thermal comfort even by 5 °C heating curve reduction. It was revealed that the building average indoor temperature is not a factor to estimate energy-saving potential because of too low temperature in the coldest apartments.

PREOPERATIVE HALO-GRAVITY TRACTION WITH AND WITHOUT ANTERIOR RELEASE FOR SEVERE SCOLIOSIS

ABSTRACT Objective: This study aims to compare the use of halo-gravity traction (HGT) with and without previous anterior release, in terms of curve reduction, for the treatment of pediatric severe spinal deformity. Methods: From 2010 to 2016, all patients treated with HGT prior to instrumentation for scoliosis and kyphoscoliosis were reviewed. They were assessed by deformity etiology, previous anterior release, instrumentation procedure used, traction protocol, major Cobb angle before traction, after the protocol, and after the instrumentation procedure. Twelve patients met these criteria and constituted the sample groups: Group I (n=7) with anterior release and Group II (n=5) without anterior release. Results: The average pre-traction major curve Cobb angles were 114.9o and 108.4º for Group I and II, respectively (P>0.05). After HGT, both groups achieved a significant reduction in curve angle (P<0.05). Group I presented an average Cobb angle of 95.0o after HGT, representing a 17.3% (19.8o) curve reduction. Group II presented a Cobb angle of 80.1o, representing a 25.2% (28.4o) curve reduction. The difference between the two groups in relation to the reduction of major curve after HGT was not statistically significant (P=0.073). After the surgical procedure, the correction achieved was significantly improved (P<0.05), without statistically significant difference between the two groups (P>0.05). No major HGT related complications were reported. Conclusions: Anterior release prior to HGT did not increase major curve correction after posterior surgery for severe pediatric idiopathic and syndromic scoliosis. HGT is an effective and safe technique, though it frequently presents minor and transitory complications. Level of Evidence III; Retrospective Comparative Study.

XQUED: The Next Generation of Wet Light Curve Reduction and Analysis Software

For many years, the Whole Earth Telescope has used the QED software package, created by R. E. Nather, to reduce the data gathered from the WET standard, PMT based photometers. While essential for reducing this data, QED alone is not a sufficient package for reducing CCD photometry data, which is becoming a larger fraction of WET data. In addition, QED requires DOS, while many astronomers, and WET HQ, do everything in a different environment (usually Unix based). A new version of the data reduction software will allow the WET to continue to operate with future CCD photometers and systems, and to reduce archival photometry data with new computer systems. Here a software package is described which will satisfy these new needs.

Atmospheric Extinction Corrections for WET Observations

Account of the extinction in the Earth’s atmosphere is an important part of the WET light curve reduction procedures. Usually, WET observations are not corrected for the second order extinction effects: the dependence of the extinction coefficient on spectral type and on air mass (the Forbes effect). The ignorance of these effects does not change seriously the derived pulsation amplitudes at the frequencies higher than 200 μHz but the increase of the noise at lower frequencies takes place. For obtaining the true extra-atmospheric magnitudes of stars, a modification of the extinction correction procedure is proposed. For photometry with the R647 phototube we recommend to use a filter cutting out the region below 310 nm, in order to decrease and stabilize the extinction coefficient. A method for estimation of spectral type of the comparison star from WET observations is proposed.

Investigation of Variation in Fatigue Life Calculated Using Damage Fraction

This paper identifies the leading causes for large variations in the calculated fatigue lives of the hypothetical pitch link experiment of the American Helicopter Society, conducted in cooperation with all U.S. manufacturers of military helicopters. Multivariate Analysis of Variance (MANOVA) is used to show that approximately 85 percent of the variations can be attributed to only two of the five analytical steps involved and the interactions between them. These steps are the method of cycle counting and the amount of S/N curve reduction.

Effects of Spacing on Cassava (Manihot Esculenta)

SUMMARYThree varieties in one cassava trial and five in another were planted in a systematic density experiment which showed that optimum plant density for root yield changes with plant age. Some varieties showed a pronounced optimum plant population, whilst others showed a flattopped response curve. Reduction in yield above the optimum is due to a reduced harvest index. Yields of over 50 t–ha were obtained with varieties that respond to close spacing.