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11.
Preparation, Thermal Properties and Thermal Reliability of Form-Stable Paraffin/Polypropylene Composite for Thermal Energy Storage 总被引:1,自引:0,他引:1
This study is focused on the preparation, characterization, and determination of thermal properties and thermal reliability
of paraffin/polypropylene (PP) composite as a novel form-stable phase change material (PCM) for thermal energy storage applications.
In the composite, paraffin acts as a PCM when PP is operated as supporting material. The composites prepared at different
mass fractions of paraffin (50, 60, 70, 80, and 90 w/w%) by solution casting method were subjected to leakage test by heating
the composites over the melting temperature of the PCM. The paraffin/PP composite (70/30 w/w%) is found as the maximum paraffin
containing composite and was characterized using Fourier transform infrared spectroscopy, optic microscopy, differential scanning
calorimetry (DSC), and thermal gravimetric analysis (TGA) techniques. DSC analysis indicated that the form-stable paraffin/PP
composite melts at 44.77–45.52 °C and crystallizes at 53.55–54.80 °C. It has latent heats of 136.16 and −136.59 J/g for melting
and crystallization, respectively. These thermal properties make it potential PCM for latent heat thermal energy storage (LHTES)
purposes such as solar space heating applications. Accelerated thermal cycling tests indicated that the form-stable PCM had
good thermal reliability. TGA also showed that the form-stable PCM degrades in two distinguishable steps and had good chemical
stability. 相似文献
12.
The objective of this paper is to develop a general pricing model for Turkish Lignite, which is mainly sold to thermal plants. This model will contribute to the development of coal mining within the scope of privatization efforts of the Turkish energy market. The paper consists of two stages. First, data of 10 thermal plants have been evaluated by using hedonic pricing analysis to determine influential price parameters. The results of hedonic regression analysis indicate the effect and importance of calorific value and electricity price on lignite prices. Second, a general coal-pricing model has been developed by taking into account the results of hedonic analysis. Comparison of the coal prices estimated by the developed pricing model and the coal prices obtained from thermal plants indicates an acceptable relation. 相似文献
13.
Bleaching of chemithermomechanical pulp (CTMP) using environmentally friendly chemicals 总被引:1,自引:0,他引:1
Tutus A Usta M 《Journal of environmental biology / Academy of Environmental Biology, India》2004,25(2):141-145
Increasing environmental restrictions require a reduction in the use of chlorine-containing bleaching agents mainly chlorine gas. There are several approaches to this goal, including changes in the cooking process and the influent treatment. The aim of this study is to improve the physical and optical properties of chemithermomechanical pulp (CTMP) which has low brightness and strong tendency towards aging in chlorine-free bleaching sequences. For this reason, initially 7 different sets of single stage hydrogen peroxide bleaching operations were performed. After the analysis of the data obtained, the optimum bleaching conditions were as: H2O2 ratio on oven dry (o.d) raw material: 2%, NaOH ratio (on o.d raw material): 1.5%, MgSO4 ratio (on o.d raw material) : 0.5%, Na2SiO3 ratio (on o.d raw material) : 3%, EDTA ratio (on o.d raw material) : 0.5%, reaction time: 60 minutes, reaction temperature: 70 degrees C and concentration: 16%. Then, 11 different sets of two and multistage H2O2 (P), NaBH4 (B), and Na2S2O4 (S) bleaching operations were carried out. Optimum bleaching conditions were found in bleaching of BPSP with 4 stage sequences. As a result, CTMP brightness was observed to increase from 47% to 81.37% elrepho while yellowness of bleached pulps decreased from 321 per thousand to 164.01 per thousand elrepho. 相似文献
14.
Seat belt use habit has been investigated according to the education level of drivers. Copies of a questionnaire were distributed to 1000 participants of four different education levels. Factors such as seat belt usage habit, restricting factors and crash data have been investigated. Data have been analyzed with SPSS 15.0 software. Increased level of education leads to increased seat belt usage, lower numbers of crashes and crash severities. The factors restricting seat belt use are lack of habit, discomfort and short distance driving. The use of precaution signal and increases in comfort can increase seat belt usage. The primary and high school education on traffic safety and seat belt usage has been serving the purpose. 相似文献
15.
16.
Viola Seravalli Eric B. Jelin Jena L. Miller Aylin Tekes Luca Vricella Ahmet A. Baschat 《黑龙江环境通报》2017,37(10):1046-1049
Fetoscopic endotracheal occlusion (FETO) is a prenatal treatment that may increase survival in severe congenital diaphragmatic hernia (CDH). In the USA, FETO is offered for isolated severe left-sided CDH in the context of an FDA-approved feasibility study. FETO in non-isolated cases of severe CDH is only performed with a compassionate use exemption from US regulatory bodies. Anomalies frequently associated with CDH include congenital cystic lesions of the lung and cardiac defects. We describe two cases of non-isolated severe left-sided CDH that underwent prenatal FETO, survived after birth and underwent postnatal surgical repair. The potential benefit of FETO in this setting is discussed. © 2017 John Wiley & Sons, Ltd. 相似文献
17.
E. Joanne Verweij Martine C. de Vries Esther J. Oldekamp Alex J. Eggink Dick Oepkes Femke Slaghekke Jochem K. H. Spoor Jan A. Deprest Jena L. Miller Ahmet A. Baschat Philip L. J. DeKoninck 《黑龙江环境通报》2021,41(8):949-956
Since the completion of the Management of Myelomeningocoele Study, maternal-fetal surgery for spina bifida has become a valid option for expecting parents. More recently, multiple groups are exploring a minimally invasive approach and recent outcomes have addressed many of the initial concerns with this approach. Based on a previously published framework, we attempt to delineate the developmental stage of the surgical techniques. Furthermore, we discuss the barriers of performing randomized controlled trials comparing two surgical interventions and suggest that data collection through registries is an alternative method to gather high-grade evidence. 相似文献
18.
Scott Beaver Ahmet Palazoglu Angadh Singh Su-Tzai Soong Saffet Tanrikulu 《Atmospheric environment (Oxford, England : 1994)》2010,44(14):1761-1771
Methods are presented to extract intra-seasonal meteorological patterns at three scales to explain 24-h fine particulate matter (PM2.5) pollution events: evolving large-scale meteorological scenarios, synoptic regimes driving diurnal variability near the surface, and localized meteorological triggers. The methods were applied to understand how winter weather conditions impacted PM2.5 around the San Francisco Bay Area (SFBA). Analyzing data across 12 winters (November–March) ensured robust characterization of the SFBA conditions. SFBA 24-h PM2.5 exceedances (35 μg m?3) required several simultaneous characteristics: a ridge of aloft high pressure moving over SFBA, providing weak surface pressure gradients over Central California; persistent easterly flows through SFBA extending vertically to around the 925-hPa pressure level; orographically channeled winds resulting from stability; enhanced nocturnal cooling under clear-sky conditions providing for enhanced drainage flows off the Central California slopes; and at least two consecutive days of these conditions. 相似文献
19.
Şeyda Fikirdeşici Ergen Esra Üçüncü Tunca Alper Devrim Ozkan Tolga Tarkan Ölmez Emrah Acaröz Ahmet Altındağ 《Chemistry and Ecology》2013,29(5):455-465
The accumulations of Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn in the exoskeleton, gills, hepatopancreas and abdominal muscles of crayfish Astacus leptodactylus (Eschscholtz, 1823) were determined. The strongest correlation observed was between Cr and Ni in the gills (r?=?0.904); moderate to strong correlations between Al, Cr, Fe, Ni and Cu were also observed in gill tissue. Disregarding the gills, the strongest correlation was found between Cu and Zn in the hepatopancreas (r?=?0.808); the correlation between these two metals might have been a result of metallothionein activity. The accumulation of Pb was found to correlate with that of Cd in the exoskeleton, Cd and Zn in the gills, Zn and Cu in the hepatopancreas and Cu in the abdominal muscle. None of these correlations were present in lakewater and sediment samples, suggesting that the crayfish metabolism may be responsible for the co-accumulation of metal–metal pairs. As all correlations in non-gill tissues are observed between divalent metals, a shared transporter such as divalent metal transporter 1 might be involved in the accumulation of these metals. 相似文献
20.
Erdal Yabalak Özkan Görmez Ahmet Murat Gizir 《Journal of environmental science and health. Part. B》2018,53(5):334-339
This study was conducted to investigate the degradation of propham, which is a compound that pollutes water and seriously threatens human health, by subcritical water oxidation and using H2O2 as an oxidising agent. The maximum total organic carbon removal rate of propham was obtained as 73.65% at 40 min of treatment time and 60 mM of H2O2 concentration and 373 K of temperature. In addition, response surface method based on the Box-Behnken design was applied to design the degradation experiments of propham for determination of the combined effects of process variables, namely temperature, concentration of oxidising agent and treatment time. The proposed quadratic model of propham degradation, which was examined with the analysis of variance, was used for navigating the design space. The R2 and adjusted R2 values of the model were determined as 0.9921 and 0.9819 respectively. It was shown that propham was effectively degraded, thus could be removed from the water by using an environmentally friendly method. 相似文献