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Enhancing lutein productivity of Chlamydomonas sp. via high-intensity light exposure with corresponding carotenogenic genes expression profiles
摘要： The marine microalga Chlamydomonas sp. JSC4 is a potential lutein source with high light tolerance. In this study, light intensity was manipulated to enhance cell growth and lutein production of this microalga. High lutein productivity (5.08 mg/L/d) was achieved under high light irradiation of 625 μmol/m2/s. Further increase in light intensity to 750 μmol/m2/s enhanced the biomass productivity to 1821.51 mg/L/d, but led to a decrease in lutein content. Under high light conditions, most carotenoids and chlorophyll contents decreased, while zeaxanthin and antheraxanthin contents increased. Inspection of gene expression profile shows that the lut1 and zep genes, responsible for lutein synthesis and flow of zeaxanthin into violaxanthin, respectively, were downregulated, while zeaxanthin biosynthesis gene crtZ was upregulated when the microalga was exposed to a high light intensity. This is consistent with the decrease in lutein content and increase in zeaxanthin content under high light exposure.
关键词： Lutein productivity,high light,Chlamydomonas sp.,gene expression
更新于2025-09-23 15:23:52
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Work performance in relation to lighting environment in office buildings
摘要： The purpose of this study was to investigate the effect of lighting environment on the work performance. Orthogonal experiments with three-factor and three-level for each factor were designed and carried out in a laboratory aiming to reveal the relationship between lighting illuminance (ILL), uniformity of illuminance (U-ILL), correlated colour temperature (CCT) and workers’ productivity. Twenty-four participants’ work performance was evaluated by subjective questionnaires, objective physiological tests, accompanied with computerized neuro-behavioural tests assessing six kinds of neuro-behavioural functions. Results illustrate that when exposed to high ILL, U-ILL and CCT environment, participants reported highest satisfaction on productivity and attention, while lowest score on stress, difficulty of conducting work and fatigue. The range value and variance analysis from neuro-behavioural tests demonstrated the appropriate level of each factor and the optimal combination. However, they varied with the type of tests illustrating that lighting conditions could influence neuro-behavioural functions differentially. The improvements of perception, learning and memory function of participants were benefited from high ILL, high U-ILL and high/medium CCT. Low ILL, low U-ILL and moderate CCT were appropriate to increase participants’ thinking and executive performance. Moreover, high quality of tear film crystallization was related to higher illuminance. The present study suggests that it is necessary to design personalized illumination environment for particular workplace.
关键词： Subjective evaluation,Office building,Lighting environment,Neurobehavioral tests,Productivity
更新于2025-09-23 15:23:52
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Innovation capability, network embeddedness and economic performance: profiling solar power innovators in China
摘要： This paper discusses the technological upgrading of China in photovoltaics technology. It explores the patterns of innovation and network embeddedness and their impact on economic performance at the firm level. Identifying the main innovators over 1995–2014 with patent and market share indicators, the landscape of their activities is inspected through two hierarchical cluster analyses in parallel: first, against the quantity, quality and diversity of patents, and second, against global-integration, component-size and position in technological knowledge networks. The resulting clusters are cross-related to understand their interrelations with age, size, turnover and productivity of actors. The multivariate analysis of variance shows a significant relationship between turnover and productivity. Global-integration in small-world networks is significantly related with economic performance. Quality of innovation shows higher importance than quantity and diversity. While specialisation in high-tech fields has positive impact on turnover, production-oriented firms with low-tech focus have higher productivity.
关键词： patent profiles,MANOVA,productivity,cluster analysis,concurrency matrix,technological upgrading,China,emerging economy,innovation system,solar photovoltaics,economic performance,network embeddedness patterns
更新于2025-09-23 15:22:29
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Benefits, problems and challenges of plant factories with artificial lighting (PFALs): a short review
摘要： The benefits and problems to be solved and challenges for plant factories with artificial lighting (PFALs) are discussed. The benefits include high resource-use efficiency, high annual productivity per unit land area, and production of high-quality plants without using pesticides, regardless of weather. A major problem to be solved is high initial investment and operation costs. Challenges for the next-generation smart PFALs include the introduction of advanced technologies such as artificial intelligence with the use of big data, genomics and phenomics (or methodologies and protocols for noninvasive measurement of plant-specific traits related to plant structure and function).
关键词： resource-use efficiency (RUE),cultivation system module (CSM),standardization,smart LED lighting system,annual productivity,artificial intelligence,phenotyping
更新于2025-09-23 15:22:29
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Use of Sun-Induced Chlorophyll Fluorescence Obtained by OCO-2 and GOME-2 for GPP Estimates of the Heihe River Basin, China
摘要： Sun-induced chlorophyll ?uorescence (SIF) provides a new method for monitoring vegetation photosynthesis from space and has been widely used to estimate gross primary productivity (GPP). However, the ability of SIF obtained from the Orbital Carbon Observatory 2 (OCO-2 SIF) and Global Ozone Monitoring Experiment-2 (GOME-2) to estimate GPP in the cold and arid region of Heihe River Basin remains unclear because previous comparisons were insuf?cient. Here, we choose maize and alpine meadow to evaluate the performance of SIF obtained by OCO-2 and GOME-2 in GPP estimations. The results of this study show that daily SIF757 had stronger correlations with daily tower GPP than daily SIF771, and the correlation between daily SIF757 and daily tower GPP was stronger than the correlation between 16-d averaged SIF740 and 16-d averaged tower GPP. The 16-d averaged absorbed photosynthetically active radiation (APAR) and reconstructed sun-induced ?uorescence (RSIF) had the strongest linear correlations with 16-d averaged tower GPP. GPP_VPM and GPP_RSIF exhibited the best performance in GPP estimation, closely followed by GPP_SIF757, then GPP_SIF771 and GPP_ SIF740. We also found that the robustness of the correlation coef?cients of OCO-2 SIF with GOME-2 SIF was highly dependent on the size of their spatial footprint overlaps, indicating that the spatial differences between OCO-2 and GOME-2 footprints contribute to the differences in GPP estimates between OCO-2 and GOME-2. In addition, the differences of viewing zenith angle (VZA), cloud contamination, scale effects, and environmental scalars (Tscalar × Wscalar) can result in differences between OCO-2 SIF and GOME-2 SIF.
关键词： vegetation photosynthesis model,eddy covariance,sun-induced ?uorescence,gross primary productivity,carbon cycle
更新于2025-09-23 15:22:29
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Experimental Work on the Effect of Saline Water Medium on the Performance of Solar Still with Tracked Parabolic Trough Collector (TPTC)
摘要： An experimental work is presented to study the effect of the saline water medium on the performance of double acting solar still combined with tracked parabolic trough collector (TPTC). Three saline water mediums are considered in the basin: pure saline water, steel wire mesh, and sand saturated with saline water. The effect of these mediums on the freshwater productivity of modified solar still (solar still with TPTC) and the conventional solar still was studied. The study was carried out during cold climate (winter) and hot climate (summer) times. Additionally, a comparison of the performance of the desalination system at different saline water mediums between winter and summer was conducted. Moreover, a cost analysis of the system was presented. The findings reveal that using wire mesh and sand raises the daily yield freshwater by about 3.1% and 13.7% respectively in winter and about 3.4% and 14.1% respectively in summer for the modified system. Furthermore, using wire mesh and sand with saline water of the modified system enhance the system efficiency by 3.3% and 15.3% respectively in summer and 3.9% and 13.8% respectively in winter. The cost of the accumulated liter of freshwater is reduced by using sand and wire mesh.
关键词： Freshwater Productivity,Solar Still,Sand,Wire Mesh,Tracked Parabolic Trough Collector (TPTC)
更新于2025-09-23 15:21:21
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A comprehensive study on the effect of light quality imparted by light-emitting diodes (LEDs) on the physiological and biochemical properties of the microalgal consortia of Chlorella variabilis and Scenedesmus obliquus cultivated in dairy wastewater
摘要： The effect of light wavelengths on the physiological, biochemical and lutein content of the microalgal consortia Chlorella variabilis and Scenedesmus obliquus was evaluated using different light sources. Among different light treatments, cool-white fluorescent light produced the highest biomass of 673 mg L?1 with a specific growth rate of 0.75 day?1 followed by blue (500 mg L?1; 0.73 day?1). The chlorophyll content was enhanced under blue light (10.7 mg L?1) followed by cool fluorescent light (9.3 mg L?1), whereas the lutein productivity was enhanced under cool fluorescent light (7.22 mg g?1). Protein content of the microalgal consortia was enhanced under all light treatments with the highest protein accumulation under cool-white fluorescent light (~56% of dry mass) closely followed by amber light (52% of dry mass), whereas the carbohydrate content was higher under amber light (~35% of dry mass). The results revealed that the consortia could grow well on diluted dairy wastewater thereby reducing the cost of algal production when compared with the use of inorganic media and a two-phase culture process utilizing cool fluorescent and amber light could be employed for maximizing algal biomass and nutrient composition with enhanced lutein production. The study also emphasizes on the economic efficiency of LED lights in terms of biomass produced based on the modest electricity consumed and the importance of using amber light for cultivating microalgae for its nutrient content which has seldom been studied.
关键词： Biomass productivity,Economic efficiency,Amber,Lutein,Nutrient content
更新于2025-09-23 15:21:01
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Role of light emitting diode (LED) wavelengths on increase of protein productivity and free amino acid profile of Spirulina sp. cultures
摘要： LEDs have specific wavelengths that can positively influence the production of microalga biomass and biomolecules of interest. Filling the gaps in the literature, this study evaluated the effect of different LED wavelengths and photoperiods on protein productivities and free amino acid (FAA) profile of Spirulina sp. LEB 18 cultures. The best protein productivity results were obtained in red and green LED cultures using integral and partial photoperiods, respectively. In these experiments, protein productivities increased 2 and 1.6 times, respectively, compared to the control culture using fluorescent light. Green LEDs in partial photoperiod provided also the highest concentrations of essential and non-essential FAA, about 1.8 and 2.3 times higher, respectively, than control cultures. LEDs showed to be a promising sustainable light source for increasing protein productivity and FAA concentration in Spirulina sp. LEB 18 cultures.
关键词： Photoperiod,Microalgae,Protein productivity,Cyanobacteria,Light source
更新于2025-09-23 15:21:01
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Efficient preparation of polymer nanofibers by needle roller electrospinning with low threshold voltage
摘要： A novel electrospinning system with needle roller as spinneret for efficient preparation of nanofibers was proposed. The results of finite element simulation indicate that the electric field is more concentrated at the tip of needle piece compared with that for disc and coil spinnerets, which can effectively reduce the threshold voltage of electrospinning. Using polyvinyl alcohol (PVA) as model polymer, the effects of spacing between needle pieces and concentration of spinning solution on fiber diameter and productivity of nanofibers were investigated. The results indicate that the average diameter decreases and the uniformity of diameter increases when increasing the spacing between needle pieces. When the spacing between the needle pieces is 14 mm, the average and standard deviation (SD) of fiber diameter is as small as 190 and 72 nm, respectively. The productivity of nanofibers slightly increases with the concentration of spinning solution, and it is as high as 12.8 g/h when the PVA concentration was 11 wt% for a needle piece spacing of 10 mm, which is much higher than the productivities of reported electrospinning systems. The proposed system has the potential for the preparation of uniform nanofibers with increased throughput and reduced cost.
关键词： electrospinning,productivity,nanofibers,needle roller,threshold voltage
更新于2025-09-23 15:21:01
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Use of principal components of UAV-acquired narrow-band multispectral imagery to map the diverse low stature vegetation fAPAR
摘要： The fraction of absorbed photosynthetically active radiation (fAPAR) is an important plant physiological index that is used to assess the ability of vegetation to absorb PAR, which is utilized to sequester carbon in the atmosphere. This index is also important for monitoring plant health and productivity, which has been widely used to monitor low stature crops and is a crucial metric for food security assessment. The fAPAR has been commonly correlated with a greenness index derived from spaceborne optical imagery, but the relatively coarse spatial or temporal resolution may prohibit its application on complex land surfaces. In addition, the relationships between fAPAR and remotely sensed greenness data may be influenced by the heterogeneity of canopies. Multispectral and hyperspectral unmanned aerial vehicle (UAV) imaging systems, conversely, can provide several spectral bands at sub-meter resolutions, permitting precise estimation of fAPAR using chemometrics. However, the data pre-processing procedures are cumbersome, which makes large-scale mapping challenging. In this study, we applied a set of well-verified image processing protocols and a chemometric model to a lightweight, frame-based and narrow-band (10 nm) UAV imaging system to estimate the fAPAR over a relatively large cultivated land area with a variety of low stature vegetation of tropical crops along with native and non-native grasses. A principal component regression was applied to 12 bands of spectral reflectance data to minimize the collinearity issue and compress the data variation. Stepwise regression was employed to reduce the data dimensionality, and the first, third and fifth components were selected to estimate the fAPAR. Our results indicate that 77% of the fAPAR variation was explained by the model. All bands that are sensitive to foliar pigment concentrations, canopy structure and/or leaf water content may contribute to the estimation, especially those located close to (720 nm) or within (750 nm and 780 nm) the near-infrared spectral region. This study demonstrates that this narrow-band frame-based UAV system would be useful for vegetation monitoring. With proper pre-flight planning and hardware improvement, the mapping of a narrow-band multispectral UAV system could be comparable to that of a manned aircraft system.
关键词： MiniMCA,precision agriculture,leaf area index,productivity,Chemometrics
更新于2025-09-23 15:21:01