Latent thermal energy storage was widely used in many thermal engineering, but the low thermal conductivity of Phase-Change Material (PCM) limited the thermal storage efficiency seriously. Filling ...metal foam has been an effective way to enhance the heat transfer due to its capability to improve the overall heat conduction effectively. To optimize the thermal performance of the paraffin-metal foam composite PCM, this study analyzed the influence laws of porosity and pore density of copper foam. A two-dimensional numerical model considering two-temperature non-equilibrium equation was built and validated by published results, while the four parameters including the liquid fraction, the temperature response rate, the heat flux, and heat storage capacity were evaluated. The results showed reducing the porosity could improve the thermal behavior of composite PCM especially between 92% and 98%, but it would reduce the heat storage capacity of about 22.3 kJ per the 2% increased porosity. The recommended porosity was 92%. Moreover, increasing pore density could also enhance the thermal behavior of the composite PCM, especially between 5PPI and 15PPI, and it had no influence on the heat storage capacity.
•The two-temperature model with the non-equilibrium state was used.•The sensitivity range of porosity and the pore density were analyzed.•The recommended porosity of copper foam was 94%.•The recommended pore density of copper foam was 15PPI.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Plants have the potential to reduce CO2 concentration, but their photosynthesis is directly influenced by the indoor lighting environment. As a result, the efficiency of indoor plants is limited by ...indoor lighting environment. In order to explore the effect of lighting environments on the reduction of indoor CO2 concentration by indoor plants, three representative lighting environments were constructed, including a natural lighting environment, a poor lighting environment and an all-day lighting environment, while five common plants were selected to be planted in five transparent sealed chambers. Experimental results show that the lighting environment affected the CO2 concentration largely in transparent sealed chambers. Compared to the transparent sealed chamber without plants, the highest and average CO2 concentrations were increased by from 47.9% to 160.9% and from 21.6% to 132.4% in the poor lighting environment, respectively, while they decreased by from 60.4% to 84.6% and from 71.4% to 89.7% in the all-day lighting environment. This indicated that plants did not purify the indoor air consistently. Among the selected plants, the most suitable houseplant was Scindapsus aureus, followed by Chlorophytum comosum and Bambusa multiplex.
Employing split air conditioners (SAC) for indoor heating is common, but the poor air quality usually occurs due to lack of fresh air and low relative humidity in winter. The indoor living wall (ILW) ...has become a reasonable option to refine the indoor heating environment through their purification and photosynthesis. To improve the heating environment, ILW were integrated with the SAC. The system integrating the ILW with the SAC (ILW-SAC) was installed in a common room with referring to the other identical room only having the SAC. The indoor thermal environment and CO2 concentration were tested, while the 72 participants were invited to demonstrate their feelings by using skin temperature measurements. The results showed that ILW-SAC significantly improved the indoor environment by increasing relative humidity by 10.8%, controlling air speed between 0.2 m/s and 0.3 m/s, and reducing CO2 concentration by 49 ppm. ILW-SAC lowered the mean skin temperature by 0.4 °C and let the mean skin temperature closer to the neutral value. ILW-SAC was found to improve the overall freshness sensation and thermal comfort level by about 1.32 and 1.10 respectively. By employing ILW-SAC, the indoor thermal environment and air quality are refined significantly in winter.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Indoor plants can improve indoor thermal environment, relieve the anxiety, and reduce the CO2 concentration especially in enclosed rooms with air-conditioning and heating. However, owing to the space ...limitation and the light requirement, it is very difficult to maintain traditional large-scale plantings indoors. To improve indoor planting efficiency and thermal environment, the living wall was introduced to be combined with air-conditioning. Two identical rooms were built to analyze the efficiency of combining a living wall with air-conditioning. One room contained a living wall and air-conditioning, while the other room only with air-conditioning was served as a reference. The indoor thermal environment and CO2 concentration were monitored, while the 64 participants were questioned to display their subjective feelings in two rooms. The results showed that combining the living wall lowered the relative humidity by 2.6%, maintained the indoor air speed at 0.20 m/s∼0.30 m/s and reduced the CO2 concentration by approximately 10%, while it increased the uniformity of these environmental parameters. The average skin temperature in the room with the living wall was 0.2 °C higher than that in the referred room and closer to the neutral mean skin temperature. The living wall significantly improved the subjective evaluation on indoor environment, especially in air movement and air freshness, with the thermal comfort level from 0.13 (Slightly higher than ''Neutral (0)'') to 0.73 (Slightly lower than ''Comfortable (+1)'').
•A new method was proposed to improve indoor environment.•Living wall reduced indoor CO2 concentration by about 10%.•Living wall also could reduce indoor relative humidity.•Living wall could improve indoor thermal comfort.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With the urban development, indoor air quality (IAQ) is of growing public health concern due to that fact people spend 80%–90% of their time indoors, which has prompted the use of plants to reduce ...the air pollution through the phytoremediation from interior spaces, especially in the enclosed rooms with air-conditioning and heating. Indoor plants have been proved to improve the indoor environment, relieve anxiety, and reduce CO2 concentration. However, the comprehensive review has not been published to summarize the development status and potential deficiencies of indoor green plants after 2018. The 50 published articles related to indoor green plants were selected by the primary retrieval system and the later manual screening. This review mainly focused on the effects of green plants on the indoor thermal environment and indoor pollutants including volatile organic compounds (VOCs), and CO2 concentration, while the application efficiency of green plants was described on learning or productivity efficiency, patients' post-operative recovery and emotion comprehensively.
•A detailed illustration was provided on indoor green plants.•Effects of indoor plants on indoor environment were comprehensive evaluated.•Indoor plants showed a great potential in the psychological aspect.•Future directions were discussed on the possible studies and applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
•Adding copper fame had a stronger influence in solidification process.•The partial filling of copper fame was studied.•The recommended volume fraction was 50%.•The contribution of unit volume ...fraction of copper fame was analyzed.
The copper foam is widely applied to improve the heat transfer performance of Phase-Change Material (PCM) used in Latent Thermal Energy Storage (LTES) system, but it will occupy the certain PCM place, resulting in the heat storage density reduction. To justify the contribution of copper foam and then explore the suitable volume fraction, a rectangular enclosure filled with PCM was built with 8 kinds of filling ratios of copper foam for comparison. A two-dimensional numerical simulation considering the two-temperature equation was built and validated by experimental results with the commonly employed evaluation parameters including the liquid fraction, temperature response rate, heat flux and heat storage capacity. Results showed the higher the volume fraction, the larger the improved thermal performance. The copper foam had a larger influence in the solidification process than in the melting process. Melting and solidification times were reduced by 93.32% and 97.63% for the volume fractions of 4.783% and 10.00%, respectively, compared to pure PCM. And the contribution efficiency of unit volume fraction was analyzed on melting and solidification time, temperature response rate, average heat flux and heat storage capacity under different volume fractions for the application reference.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
Indoor plants have great benefits to humans, including physical health, cognition and emotion through their repair and purification capabilities, but most of these positiv e effects have not ...been quantified and valued. In this study, the Corona Virus Disease 2019 (COVID-19), when people must be self-isolated at home and avoid outdoor activities in China, was utilized adequately and the influence of indoor plants was analyzed via the 2031 valid questionnaires, in which indoor plant status, interest degree, interaction frequency and anxiety alleviation were surveyed. Results showed that indoor plants were widely cultivated especially in the living room. Compared to before the COVID-19, the interest degree with indoor plants increased by ~33% and their overall interaction frequency increased by ~78% during the COVID-19. More than 70% of the surveyed people exhibited anxiety during the COVID-19, and the overall anxiety level was 1.17 (between ‘Slight anxiety’ and ‘Anxiety’). And ~61% of the surveyed people supported that indoor plants could alleviate self-isolation anxiety, and the anxiety alleviation degree was 0.79 (tend to ‘Releasing the certain anxiety’), which showed that indoor plants had also shown to have an indirect psychological effect on anxiety alleviation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The thermal energy storage plays a fundamental role in improving the efficiency and reliability of solar energy applied in the building engineering and its conventional techniques are Latent and ...Sensible Heat Thermal Energy Storage (LHTES and SHTES). To analyze the thermal performance of LHTES-Tank and SHTES-Tank with paraffin RT55 and water as thermal storage mediums respectively, a contrastive experiment was done. The experiment included 5 thermal charging and discharging cycles by changing Heat Transfer Fluid (HTF) temperatures between 20 °C and 80 °C. Results show the thermal discharging was more difficult than thermal charging in LHTES-Tank. Most paraffin could melt entirely but cannot solidify completely, while around 19.36% of paraffin in LHTES-Tank was always solid or liquid, and thereby acted as a dead mass. Paraffin had the higher thermal storage capacity than water only in the phase-change temperature range, so water may play the thermal storage potential more efficiently than paraffin under the large HTF temperature difference. Also based on this reason, LHTES-Tank had only a little advantage in thermal and exergy efficiency compared to SHTES-Tank under the HTF temperature of 20°C–80 °C, but its optimization potential was showed to be very large. Finally, the main existing problems were summarized according to thermal behavior of LHTES-Tank.
•A contrastive experiment was done to analyze thermal performance of LHTES-Tank and SHTES-Tank.•Thermal and exergy analysis was employed to evaluate LHTES-Tank and SHTES-Tank.•Thermal discharging is more difficult than thermal charging in LHTES-Tank.•The main existing problems are summarized on LHTES-Tank.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Sensitive detection of cancer biomarker microRNAs （miRNAs） is of vital importance for cancer diagnosis and treatment. Nonetheless, the detection sensitivity in the existing miRNA bioassays is ...severely limited by the structural characteristics of miRNA （including small length and high sequence homology） because most of these methods are based on target amplification. Herein, we report a novel approach to sensitive and specific detection of low-abundance miRNA via a unique strategy of nanoprobe dissolution-enhanced fluorescence amplification, in which a capture probe featuring molecular beacon structure is designed. By means of this strategy, miRNA-21 was detected in a linear range from 10 fM to 100 pM with a detection limit as low as 1.38 fM. High selectivity of the newly developed biosensor was demonstrated by the good discrimination against a target with a single-base mismatch. Furthermore, this assay was used for the detection of miRNA-21 added into fetal bovine serum samples with the recovery in the range of 90.2%--108% and coefficients of variation below 10.1%, indicating its promising applications to RNA immunoassays and early cancer diagnosis.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
An experiment was performed to examine the effect of dietary copper supplementation on weight gain, neuropeptide Y (NPY) concentration and NPY mRNA expression level in the hypothalamus of pigs. ...Forty-five crossbred pigs were randomly assigned to three groups of 15 pigs, each comprising five replicates of 3 animals. Pigs were allocated to diets that contained 10
mg/kg (as a control), 125 and 250
mg/kg copper as CuSO
4. Live weight gain and feed conversion efficiency was determined at the end of the experiment and five pigs, selected at random from each group, were slaughtered and the hypothalami collected for determination of NPY concentration and NPY mRNA expression level. The results showed that average daily gain (ADG) and average daily feed intake (ADFI) were higher and feed:gain (F:G) ratio was lower in pigs fed the diets with 125 and 250
mg/kg copper (
P<0.05), respectively, than in pigs fed a diet with 10
mg/kg copper, but that there was no statistically significant difference in growth performance between animals of the 125
mg/kg and the 250
mg/kg copper groups. Furthermore, pigs fed diets with 125 and 250
mg/kg copper had higher NPY concentrations and NPY mRNA expression levels in their hypothalamus than control animals. The data indicated that 125 and 250
mg/kg copper gave similar responses in terms of weight gain, whilst high dietary copper could enhance NPY concentration and NPY mRNA expression level in the hypothalamus of pigs. High dietary copper appears to increase feed intake and promote weight gain by enhancing NPY concentration and NPY mRNA expression level in the hypothalamus of pigs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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