Influences of the mixed LiCl-CaCl 2 liquid desiccant solution on a membrane-based dehumidification system: parametric analysis and mixing ratio selection

The membrane-based liquid desiccant dehumidification system has high energy efficiency without the traditional liquid system carry-over problem. The performance of such a system strongly depends on solution's temperature and concentration, which have direct relationship to the solution surface vapour pressure. Compared with the pure liquid desiccant solution, the mixed liquid desiccant solution has lower surface vapour pressure, better system performance and lower material cost. In this paper, the performance of a flat-plate membrane-based liquid desiccant dehumidification system with the mixed solution (LiCl and CaCl2) is investigated through theoretical and experimental approaches. A mathematical model is established to predict the system performance, while the electrolyte non-random two-liquid (NRTL) method is applied to calculate the mixed solution properties. The influences of the solution mixing ratio, temperature Tsol and concentration Csol are evaluated, and it is found that the regeneration heat Qreg can be dramatically reduced by either applying a high concentration solution or increasing CaCl2 content in the mixed solution. Compared with the pure LiCl solution system, the mixed solution system COP can be improved up to 30.23% by increasing CaCl2 content for a 30% concentration solution. The optimum mixing ratio varies with the solution concentration. For the mixed LiCl-CaCl2 solution, the system highest COPs appear at the mixing ratios of 3:1, 2:1 and 1:1 for 20%, 30% and 40% concentrations respectively

State-of-the-art review of 3DPV technology: structures and models

© 2019 Elsevier Ltd Increasing energy conversion efficiency from sunlight to power is one of the key solutions for the world's energy shortage and greenhouse gas reduction, but the conventional flat photovoltaic module without sun tracking mechanism has the low sunlight energy collection ability. This paper presents the state-of-the-art three-dimensional photovoltaic (3DPV) technology with high photovoltaic energy conversion efficiency, which is able to absorb off-peak sunlight and reflected light more effectively, thereby it can generate more power. At first, this paper is to catalogue and critique different 3DPV structures and models, as well as assess their characteristics. Afterwards, the main influence factors on the 3DPV structures and models including shape, height and spacing of the solar cells, latitude of the installation, optimal device design and shadow cast, are reviewed. Finally, the challenges and future technological developments of 3DPV structures and models are highlighted. This study demonstrated that the 3DPV technology can increase the captured sunlight approximately 15–30% in comparison with the conventional flat PV technology

WGCNA based identification of hub genes associated with cold response and development in Apis mellifera metamorphic pupae

Honeybee is a crucial pollinator in nature, and plays an indispensable role in both agricultural production and scientific research. In recent decades, honeybee was challenged with health problems by biotic and abiotic stresses. As a key ecological factor, temperature has been proved to have an impact on the survival and production efficiency of honeybees. Previous studies have demonstrated that low temperature stress can affect honeybee pupation and shorten adult longevity. However, the molecular mechanism underlying the effects of low temperatures on honeybee growth and development during their developmental period remain poorly understood. In this paper, the weighted gene co-expression analysis (WGCNA) was employed to explore the molecular mechanisms underpinnings of honeybees’ respond to low temperatures (20°C) during four distinct developmental stages: large-larvae, prepupae, early-pupae and mid-pupae. Through an extensive transcriptome analysis, thirteen gene co-expression modules were identified and analyzed in relation to honeybee development and stress responses. The darkorange module was found to be associated with low temperature stress, with its genes primarily involved in autophagy-animal, endocytosis and MAPK signaling pathways. Four hub genes were identified within this module, namely, loc726497, loc409791, loc410923, and loc550857, which may contribute to honeybee resistance to low temperature and provide insight into the underlying mechanism. The gene expression patterns of grey60 and black modules were found to correspond to the developmental stages of prepupae and early-pupae, respectively, with the hub genes loc409494, loc725756, loc552457, loc726158, Ip3k and Lcch3 in grey60 module likely involved in brain development, and the hub genes loc410555 in black module potentially related to exoskeleton development. The brown module genes exhibited a distinct pattern of overexpression in mid-pupae specimens, with genes primarily enriched in oxidative phosphorylation, citrate cycle and other pathways, which may be related to the formation of bee flying muscle. No related gene expression module was found for mature larvae stage. These findings provide valuable insights into the developmental process of honeybees at molecular level during the capped brood stage

Contribution of infrastructure to the township's sustainable development in Southwest China

Townships in Southwest China are usually located in mountainous regions, which are abundant in natural and cultural landscape resources. There are additional requirements for the township’s sustainable development in these areas. However, insufficient infrastructures, due to limited resources, constrain the sustainable development of these townships. Sustainable contribution of infrastructure (SCOI) in this study is defined as the performance of infrastructure as a contribution to the coordinated development among economic, social, and environmental dimensions of township’s sustainable development. It is necessary to assess these infrastructures according to SCOI and provide choices for investment to maximize resource utilization. Therefore, an assessing model of SCOI with 26 general indicators was developed, which covers five most urgently needed infrastructures of these townships in Southwest China, including road transport, sewage treatment, waste disposal, water supply, and gas. In this model, quantitative and qualitative methods are combined to acquire different SCOI of each infrastructure. The result of the SCOI would be an important reference for infrastructure investment. A case study of Jiansheng Town, that is located in the Dadukou district of Chongqing, demonstrates the applicability of the model. It shows the assessing model of SCOI is efficient to identify the most valuable infrastructure that is appropriate for investment with the goal of township’s sustainable development. This study can provide insights for infrastructure investment and management in townships or areas

Techno-economic assessment of the horizontal geothermal heat pump systems: a comprehensive review

Geothermal heat pump has been widely recognized as one of the promising technologies for building applications because of its high energy efficiency and low operating expense, however the high capital investment and installation costs discourage building owners to choose such a system. The horizontal geothermal heat pump system with reduced cost is a viable option that would be utilized widely, the aim of this paper is to catalogue and critique a range of effective approaches for the horizontal geothermal heat pump systems in different regions based on techno-economic assessment data. A ground heat exchanger is a vital component of the horizontal geothermal heat pump. The state-of-the-art analytical and numerical models of the linear-loop, slinky-coil and spiral-coil ground heat exchangers are generalized, in addition to their advantages and disadvantages. A large number of economic evaluation methods for analysing the financial performance of the horizontal geothermal heat pump system are presented. At the end, the standpoints, recommendations and potential future study on the horizontal geothermal heat pump system are deliberated

Steady-state performance evaluation and energy assessment of a complete membrane-based liquid desiccant dehumidification system

A complete membrane-based liquid desiccant dehumidification system is investigated under the steady operating condition, which mainly consists of a dehumidifier, a regenerator, three heat exchangers, a cold and a hot water supply units. A finite difference mathematical model is developed for the complete system to investigate the system dehumidification performance and energy requirement, and validated by experimental data. The dehumidification performance is evaluated by the system sensible and latent effectiveness and moisture flux rate, while its energy performance is assessed by the total cooling capacity and coefficient of performance. It is found that the number of heat transfer units in the dehumidifier side and solution to air mass flow rate ratio have the most considerable impact on the system performance, while the number of heat transfer units in the regenerator side and solution inlet concentration in the dehumidifier have comparatively weak influences. The system sensible and latent effectiveness can be improved by increasing the dehumidifier side number of heat transfer units before reaching its critical value of 6. However, the amount of moisture being absorbed, total cooling capacity and coefficient of performance decrease with the dehumidifier side number of heat transfer units at the low air flow rate. The critical value of solution to air mass flow rate ratio varies with number of heat transfer units, and it is preferable to keep the flow rate ratio at or below its critical value as further increasing solution flow rate would reduce the system coefficient of performance

Techno-economic assessment of the horizontal geothermal heat pump systems: A comprehensive review

Geothermal heat pump has been widely recognized as one of the promising technologies for building applications because of its high energy efficiency and low operating expense, however the high capital investment and installation costs discourage building owners to choose such a system. The horizontal geothermal heat pump system with reduced cost is a viable option that would be utilized widely, the aim of this paper is to catalogue and critique a range of effective approaches for the horizontal geothermal heat pump systems in different regions based on techno-economic assessment data. A ground heat exchanger is a vital component of the horizontal geothermal heat pump. The state-of-the-art analytical and numerical models of the linear-loop, slinky-coil and spiral-coil ground heat exchangers are generalized, in addition to their advantages and disadvantages. A large number of economic evaluation methods for analysing the financial performance of the horizontal geothermal heat pump system are presented. At the end, the standpoints, recommendations and potential future study on the horizontal geothermal heat pump system are deliberated.N/

A laser-engraved wearable sensor for sensitive detection of uric acid and tyrosine in sweat

Wearable sweat sensors have the potential to provide continuous measurements of useful biomarkers. However, current sensors cannot accurately detect low analyte concentrations, lack multimodal sensing or are difficult to fabricate at large scale. We report an entirely laser-engraved sensor for simultaneous sweat sampling, chemical sensing and vital-sign monitoring. We demonstrate continuous detection of temperature, respiration rate and low concentrations of uric acid and tyrosine, analytes associated with diseases such as gout and metabolic disorders. We test the performance of the device in both physically trained and untrained subjects under exercise and after a protein-rich diet. We also evaluate its utility for gout monitoring in patients and healthy controls through a purine-rich meal challenge. Levels of uric acid in sweat were higher in patients with gout than in healthy individuals, and a similar trend was observed in serum

Podophyllotoxin Extracted from Juniperus sabina

This study aimed to investigate the antifertility effect of Juniperus sabina fruit on male rats and its possible mechanism, and hence it might be developed as a potential nonhormonal male contraceptive. Male rats were intragastrically fed for consecutive 8-week and 4-week recovery with the fruit of J. Sabina, and sperm maturation, serum testosterone level, and histopathology were analyzed. Epididymal epithelial cell culture was prepared for detection of podophyllotoxin activities. Furthermore, cell proliferation, transmission electron microscopy, Annexin V/Propidium iodide, TUNEL, RT-PCR, ELISA, and western blotting were examined. The results showed that rat sperm motility and fertility were remarkably declined after feeding the fruit. Moreover, the fruit targeted the epididymis rather than the testis. After 4-week recovery, more than half of the male rats resumed normal fertility. It was found that podophyllotoxin significantly inhibited epididymal epithelial cell proliferation, promoted cell apoptosis, and increased the mRNA and protein levels of TNF-α and the expression levels of cytochrome c, caspase-8, caspase-9, and caspase-3. Our findings suggest that the fruit of J. sabina could inhibit male rat sperm maturation and fertility. The potential mechanism might be related to podophyllotoxin, inducing epididymal epithelial cell apoptosis through TNF-α and caspase signaling pathway

Genetic Differentiation of Eastern Honey Bee (Apis cerana) Populations Across Qinghai-Tibet Plateau-Valley Landforms

Many species of high-altitude plateaus tend to be narrowly distributed along river valleys at lower elevations due to a limitation of suitable habitats. The eastern honeybee (Apis cerana) is such a species and this study explored the effects of long and narrow geographic distributions on honeybee populations. Genetic differentiation and diversity were assessed across populations of the southeastern Qinghai-Tibet Plateau. A total of 492 honeybee samples from eight sampling sites in four valleys were analyzed for the genetic differentiation and diversity of 31 microsatellite loci and mitochondrial tRNAleu-COII fragments. The following results were obtained: (1) Microsatellite genetic differentiation coefficients (FST) ranged from 0.06 to 0.16, and mitochondrial FST estimates ranged from 0.18 to 0.70 for different sampling sites in the same valley, indicating genetic differentiation. (2) Honeybees in adjacent valleys were also genetically differentiated. The FST of microsatellites and mitochondria were 0.04–0.29 and 0.06–0.76, respectively. (3) Likely a result of small population sizes, the observed genetic diversity was low. The observed impedance of honeybee gene flow among valleys increased both genetic differentiation and population numbers in the Qinghai-Tibet Plateau. This study contributes significantly to the current understanding of the mechanism underlying population genetic differentiation and highlights the potential effects of utilizing genetic resources that are subject to the ecological conditions of the long and narrow geographic distributions of plateau-valley landforms