The development of eco-friendly cosmetic such as those from microalgae for skin regeneration and collagen synthesis has gained a great interest worldwide. Accordingly, the potential of microalgae biomass as source of anti-aging cosmetic cream with high antioxidant activity has been investigated. Stabilities and sensory characteristics of cosmetic creams supplemented with Spirulina, Tetraselmis sp. and Dunaliella sp. at 0.5, 1.5 and 2.5%, respectively, revealed a conservation of physico-chemical and preliminary stability properties of formulations. To analyze physico-chemical and textural parameters, accelerated stability study was evaluated under two thermal conditions (25 and 40 °C) during 90 days. Results showed that pH values of all formulations were within the limits of normal skin pH range under storage time at 25 and 40 °C. During this period, the colored creams showed a significant changes of a* and b* indices, reflecting the instability of microalgae colors. Microalgae modified the textural characteristics of emulsions. The Tetraselmis sp. containing-cream had the lowest (P < 0.05)?values of hardness, springiness, and cohesiveness. The 0.5% Spirulina containing-cream had the best stable consistency and adhesiveness under time and temperature variations. It exhibited the best properties to be used for skin care products. Thanks to their high content in bioactive macromolecules, microalgae considerably improved the antioxidant activity of the new formulated skin creams.
The present paper addresses defining the extent of the mixing zones of effluents discharged into rivers, which is a problem that should be analyzed based on probabilistic terms, as it is governed by several random processes. A river’s flow regime is one of the main variables, and it has a high dependence on hydrological processes. Additionally, after calculating the extent of the mixing zone, it is necessary to determine if the resulting dimensions are admissible or not. Common practice includes the admissibility criteria associated with the geometry of the river. However, this practice does not consider the environmental characteristics of the river that make it capable of absorbing the impact of the effluent (the biological and hydromorphological status of the river and the presence of structures that can change the river flow conditions, ecologically sensitive area or threatened species). This paper presents work on two important topics: on the one hand, the development of a methodology to establish the admissible extent of the mixing zone as a function of the environmental vulnerability of the river to the discharged effluent and, on the other hand, the proposal of a procedure to perform the calculations of the effluent mixing considering the variability of the river’s flow regime. The proposed methodological approaches are illustrated with an application to a real case, including a numerical simulation of the hydrodynamic and effluent evolution of the river during a year, to test the proposed methodology’s suitability and demonstrate the important savings in computational effort that can be achieved. 相似文献
Life cycle assessment (LCA) of waste treatment processes is often associated with considerable uncertainties. The aim of this study is to estimate the total uncertainty in the modelled composting system and the influence of material and process parameters on the uncertainty. Four composting combinations with fresh (FC) and mature substrate compost (MSC) from partially enclosed (PEC) and open composting (OC) were investigated. Perturbation analysis was used to determine the effect of parameters on the result and Monte Carlo simulation was used to estimate the total uncertainty. This study showed that the production of MSC using PEC had the lowest overall impacts across all impact categories except ozone depletion. Results of the Monte Carlo simulation showed that comparing composting options was challenging. The sensitivity ratios obtained from the perturbation analysis showed that the process parameter percentage of carbon fraction degraded was the most influential for FC. In MSC, the moisture content in the input material and the substitution factor used for peat were the most influential. Monte Carlo simulations demonstrated the overall uncertainty of the model and its relevance when comparing results between combinations. The perturbation analysis identified the parameters that required more accurate data to reduce the uncertainty in the model.
Journal of Material Cycles and Waste Management - Lemon peel waste (LPW) were pyrolysed in a laboratory fixed-bed reactor at final temperature of 300 °C, 400 °C and... 相似文献
Environmental Science and Pollution Research - The diversity of marine biomasses is a set of exploitable and renewable resources with application in several sectors. In this context, a co-culture... 相似文献
Environmental Science and Pollution Research - Microplastics (MPs) are ubiquitous environmental contaminants; through their physicochemical properties, they can have potentially negative effects on... 相似文献
A central tenet of landscape ecology is that mobile species depend on complementary habitats, which are insufficient in isolation, but combine to support animals through the full annual cycle. However, incorporating the dynamic needs of mobile species into conservation strategies remains a challenge, particularly in the context of climate adaptation planning. For cold-water fishes, it is widely assumed that maximum temperatures are limiting and that summer data alone can predict refugia and population persistence. We tested these assumptions in populations of redband rainbow trout (Oncorhynchus mykiss newberrii) in an arid basin, where the dominance of hot, hyperproductive water in summer emulates threats of climate change predicted for cold-water fish in other basins. We used telemetry to reveal seasonal patterns of movement and habitat use. Then, we compared contributions of hot and cool water to growth with empirical indicators of diet and condition (gut contents, weight–length ratios, electric phase angle, and stable isotope signatures) and a bioenergetics model. During summer, trout occurred only in cool tributaries or springs (<20 °C) and avoided Upper Klamath Lake (>25 °C). During spring and fall, ≥65% of trout migrated to the lake (5–50 km) to forage. Spring and fall growth (mean [SD] 0.58% per day [0.80%] and 0.34 per day [0.55%], respectively) compensated for a net loss of energy in cool summer refuges (–0.56% per day [0.55%]). In winter, ≥90% of trout returned to tributaries (25–150 km) to spawn. Thus, although perennially cool tributaries supported thermal refuge and spawning, foraging opportunities in the seasonally hot lake ultimately fueled these behaviors. Current approaches to climate adaptation would prioritize the tributaries for conservation but would devalue critical foraging habitat because the lake is unsuitable and unoccupied during summer. Our results empirically demonstrate that warm water can fuel cold-water fisheries and challenge the common practice of identifying refugia based only on summer conditions. 相似文献