1,008 research outputs found
Experimental study on a solar-powered thermochemical sorption refrigeration system using strontium chloride/EG-ammonia working pair
An experimental intermittent thermochemical refrigeration system using strontium chloride (SrCl2)–ammonia reaction is described, which mainly consists of an adsorption bed and an evaporator/condenser. The strontium chloride is used as solid absorbent and ammonia as refrigerant. A kind of consolidated composite material based on expanded graphite and strontium chloride is developed firstly, then the composite material is filled into the adsorption bed. The process of desorption or regeneration of strontium chloride is driven by solar energy, and the temperature range of the heating fluid is from 90 to 110℃, which can be heated by solar energy collected by low cost solar flat plate collectors. In the evaporation–absorption process, the evaporating temperature is between -10 and -35℃. The theoretical analysis shows that this refrigeration system is technical feasibility
Resource utilization: Preparation and Application of a sulfited Fat-liquor based on Waste beef tallow from Tannery
Content:
Leather industry is one of many traditional, characteristic and ascendant industries. During the development of Leather industry, the problem of a certain the waste of resources and environmental pollution has been yielded. The waste tallow is one of the problems should be solved quickly. Based on the problem of the waste of resources and environmental pollution form the waste tallow during the leather
industry, act waste beef tallow from tannery as raw material, detection of its physical and chemical properties, de-colorization, deodorization, amidation, esterification and sulfitation were done successively.
Results suggested that the acid value and the saponification value of the waste beef tallow is 45mgKOH/g, 207mgKOH/g respectively. When 6% activated clay was used after 10% hydrogen peroxide, it has the best effect in decolorization and deodorization. When catalyzed by 1% sodium formate, n(ethanolamine):n (waste beef tallow)is 4:1,the reaction temperature was 130~140oC and time was 2hrs, the acid value and hydroxyl value of the treated beef tallow is 15~30mgKOH/g, about 280mgKOH/g respectively. When the optimum dosage of sodium sulfite is 20%, the fatliquor obtained light yellow and good stability. The sheepskin garment leather fatliquored by this fatliquor is very soft.
Take-Away:
Modification of a sulfited fatliquor based on waste beef tallow.
Application of this sulfited fatliquor.
Other methods of modification of waste beef tallow
Kinematics and Collimation of the Two-Sided Jets in NGC 4261: VLBI Study on Sub-parsec Scales
We report multi-frequency VLBI studies of the sub-parsec scale structure of
the two-sided jet in the nearby radio galaxy NGC 4261. Our analyses include new
observations using the Source Frequency Phase Referencing technique with the
Very Long Baseline Array at 44 and 88 GHz, as well as archival data at 15 and
43 GHz. Our results show an extended double-sided structure at 43/44 GHz and
provide a clear image of the nuclear region at 88 GHz, showing a core size of
0.09 mas and a brightness temperature of K. Proper
motions are measured for the first time in the two-sided jet, with apparent
speeds ranging from to in the approaching jet
and in the receding jet. The jet-to-counter-jet brightness
ratio allows us to constrain the viewing angle to between and
and the intrinsic speed to between and . We
confirm the parabolic shape of the upstream jet on both sides of the central
engine, with a power-law index of . Notably, the jet collimation
is found to be already completed at sub-parsec scales, with a transition
location of about 0.61 pc, which is significantly smaller than the Bondi radius
of 99.2 pc. This behavior can be interpreted as the initial confinement of the
jet by external pressure from either the geometrically thick, optically thin
advection-dominated accretion flows (ADAF) or the disk wind launched from it.
Alternatively, the shape transition may also be explained by the internal flow
transition from a magnetically dominated to a particle-dominated regime.Comment: 9 pages, 5 figures, 2 table
3-{[Bis(pyridin-2-ylmethyl)amino]methyl}-2-hydroxy-5-methylbenzaldehyde
In the title compound, C21H21N3O2, the pyridine rings and the benzene ring lie in a propeller arrangement around the central tertiary amine N atom. The dihedral angles formed by the benzene ring with the pyridine rings are 61.0 (3) and 49.6 (3)°, while the dihedral angle between the pyridine rings is 69.7 (3)°. The molecular conformation is stabilized by intramolecular bifurcated O—H⋯N hydrogen bonds. In the crystal, inversion dimers are formed via pairs of C—H⋯N hydrogen bonds
5 GHz TMRT observations of 71 pulsars
We present integrated pulse profiles at 5~GHz for 71 pulsars, including eight
millisecond pulsars (MSPs), obtained using the Shanghai Tian Ma Radio Telescope
(TMRT). Mean flux densities and pulse widths are measured. For 19 normal
pulsars and one MSP, these are the first detections at 5~GHz and for a further
19, including five MPSs, the profiles have a better signal-to-noise ratio than
previous observations. Mean flux density spectra between 400~MHz and 9~GHz are
presented for 27 pulsars and correlations of power-law spectral index are found
with characteristic age, radio pseudo-luminosity and spin-down luminosity. Mode
changing was detected in five pulsars. The separation between the main pulse
and interpulse is shown to be frequency independent for six pulsars but a
frequency dependence of the relative intensity of the main pulse and interpulse
is found. The frequency dependence of component separations is investigated for
20 pulsars and three groups are found: in seven cases the separation between
the outmost leading and trailing components decreases with frequency, roughly
in agreement with radius-to-frequency mapping; in eleven cases the separation
is nearly constant; in the remain two cases the separation between the outmost
components increases with frequency. We obtain the correlations of pulse widths
with pulsar period and estimate the core widths of 23 multi-component profiles
and conal widths of 17 multi-component profiles at 5.0~GHz using Gaussian
fitting and discuss the width-period relationship at 5~GHz compared with the
results at at 1.0~GHz and 8.6~GHz.Comment: 46 pages, 14 figures, 8 Tables, accepted by Ap
Effects of computer-based cognitive training combined with physical training for older adults with cognitive impairment: A four-arm randomized controlled trial
OBJECTIVE: Combined physical (PHY) and cognitive (COG) training in sequential (SEQ) and simultaneous (SIMUL) sessions may delay the progression of cognitive impairment. To date, no study has directly compared in older adults with cognitive impairment the effects of COG training, PHY training, SEQ motor-cognitive training and SIMUL motor-cognitve training on specific indices of cognitive performance and activities of daily living (ADL). The purpose of this study was to determine whether SEQ and SIMUL motor-cognitive training can improve treatment outcomes compared with PHY or COG training alone. We also aimed to compare the effects of SEQ versus SIMUL motor-cognitive training on cognitive functions and instrumental ADL (IADL) in older adults with cognitive impairment.
METHODS: A cluster randomized controlled trial was conducted. Eighty older adults with cognitive impairment were randomly assigned to COG, PHY, SEQ or SIMUL training groups. The intervention consisted of 90-min training sessions, totaling 36 sessions. Outcome measures were the Montreal Cognitive Assessment, three subtests of the Wechsler Memory Scale (WMS) and the Lawton IADL scale.
RESULTS: Significant interaction effects between group and time were found in WMS-spatial span (
CONCLUSIONS: Our study showed SEQ and SIMUL motor-cognitive training led to more pronounced improvements in visuospatial working memory or verbal memory compared with isolated COG or PHY training for community-based older adults with cognitive impairment. For enhancing effects on IADL, we suggest the use of sensitive measurement tools and context-enriched cognitive training involving real-life task demands
Testing and Data Reduction of the Chinese Small Telescope Array (CSTAR) for Dome A, Antarctica
The Chinese Small Telescope ARray (hereinafter CSTAR) is the first Chinese
astronomical instrument on the Antarctic ice cap. The low temperature and low
pressure testing of the data acquisition system was carried out in a laboratory
refrigerator and on the 4500m Pamirs high plateau, respectively. The results
from the final four nights of test observations demonstrated that CSTAR was
ready for operation at Dome A, Antarctica. In this paper we present a
description of CSTAR and the performance derived from the test observations.Comment: Accepted Research in Astronomy and Astrophysics (RAA) 1 Latex file
and 20 figure
- …