The present study reports for the first time the performance of silver phosphate (Ag3PO4) microcrystals as photocatalyst (degradation of Rodamine B-RhB) and antifungal agent (against Candida albicans–C. albicans) under visible-light irradiation (455 nm). Ag3PO4 microcrystals were synthesized by a simple co-precipitation (CP) method at room temperature. The structural and electronic properties of the as-synthetized Ag3PO4 have been investigated before and after 4 cycles of RhB degradation under visible light using X-ray diffraction (XRD), micro-Raman spectroscopy, UV–Vis spectrophotometer and field emission scanning electron microscopy (FE-SEM) images. The antifungal activity was analyzed in planktonic cells and 48h-biofilm of C. albicans by colony forming units (CFU) counting, confocal laser and FE-SE microscopies. Statistical analysis was carried out using SPSS software. Morphological and structural modifications of Ag3PO4 were observed upon recycling. After 4 recycles, the material maintained its photodegradation property; an eightfold increase in the efficiency of Ag3PO4 was observed in planktonic cells and a two fold increase in biofilm when irradiated under visible light. Thus, higher antifungal effectiveness against C. albicans was obtained when associated with visible-light irradiation. 相似文献
This research verified the ability of Lactobacillus rhamnosus encapsulated with inulin to tolerate the simulated digestive system and their viability in a soy blend. Probiotic encapsulated in alginate-chitosan matrix without inulin presented a better encapsulation efficiency (80.92%) than encapsulation with inulin (57.39%). On the 28th day, the count of probiotics decreased by 3.42 and 1.99 logarithmic cycles of free and encapsulated cells without inulin, respectively. In contrast, the microorganisms encapsulated with inulin showed an increase of 1.26 logs CFU g−1. During gastrointestinal simulation, cell counts decreased by 0.78, 1.55 and 1.95 CFU g−1 logs for encapsulated cells without inulin, free and encapsulated with inulin, respectively. Sensory panellists liked the fermented soy blend with encapsulated lactobacilli, and this result shows the possibility to create new probiotic foods of plant origin. Therefore, the alginate/chitosan matrix can be considered adequate for the encapsulation of L. rhamnosus. The inulin reduces the encapsulation efficiency and increases the cell loss in gastrointestinal simulation. Considering cellular losses, the best option for preparing a fermented soy blend is to use L. rhamnosus encapsulated without inulin. 相似文献
Carbon dioxide (CO2) gas is the main contributor to climate change. CO2 storage in underground brines and oil‐field brines by mineral trapping has been considered as a promising alternative in order to reduce CO2 emissions. However, permanent storage of CO2 in stable carbonate minerals is greatly dependent on brine pH, being favored over an alkaline pH. The effect of alkaline additives (NaOH, KOH, CaO) and buffer solutions (NaHCO3/NaOH, Na2HPO4/NaOH, NH4Cl/NH4OH) on the mineral trapping of CO2 under mild conditions using a synthetic brine is investigated. The results indicate that both NaOH+NH4Cl/NH4OH and KOH+NH4Cl/NH4OH mixtures promote precipitation mainly of calcium carbonate (CaCO3). 相似文献
Prepreg is a pre-impregnated composite fiber where a thermoset polymer matrix material is present. Before being used, these materials are kept at low temperatures and have a low-density polyethylene (LDPE) film for your protection. The increase in the use of structural composites based on prepregs causes an increase in the amount of protective LDPE film. This material is usually discarded or incinerated and can cause great damage to the environment. Thus, the present work aimed to study the feasibility of recycling up to 100% of protective LDPE (rLDPE) to develop blends-based nanocomposites with rLDPE/virgin LDPE (60/40, 70/30, 80/20, 90/10 and 100/0) with the addition of 5 wt% of compatibilizer agent (maleic anhydride grafted LDPE, LDPE-g-MA), and 1 wt% of bentonite (BNT) using a co-rotational twin-screw extruder, followed by hot pressing in a hydropneumatic press and die-cutting. Water absorption test, thermal aging resistance, morphological characterization by scanning electron microscopy, mechanical properties by Izod impact strength and tensile tests, and differential scanning calorimetry were performed. By the results, it was possible to verify the viability of 100% of the recycling of rLDPE. The results showed a good distribution of 1 wt% of BNT in the matrix, better mechanical properties when compared with virgin LDPE. Furthermore, the thermal properties, water absorption test, and thermal aging resistance showed no statistical differences between the samples. These results confirm the effectiveness and the environmental gain in the use of the recycled material. 相似文献
Amongst the different perovskites being investigated for application in solar cells, one of the most frequently scrutinized is methylammonium lead iodide CH3NH3PbI3 (or MAPbI3), which is usually obtained by the reaction of lead iodide (PbI2) with methylammonium iodide (MAI). Although this perovskite has been extensively studied and utilized in the manufacture of high-efficiency solar cells, its formation chemistry is still not well understood. Reliable experimental determination of the activation energy between PbI2 and MAI has been difficult due to the rapid reaction at room temperature. In this work, we determined the activation energy by adopting the Arrhenius equation. This was possible by controlling the reaction using MAI vapor, instead of liquid solution. This procedure allowed the reaction to be carried out at temperatures of up to 150 °C. The formation of MAPbI3 films was obtained by a two-step process: deposition of thin PbI2 film by thermal evaporation and subsequent conversion into perovskite by exposure to MAI vapor. The conversion of PbI2 to MAPbI3 as a function of temperature was probed by X-ray diffraction. An activation energy of 0.12?±?0.02 eV was obtained. This low value explains the ease of MAPbI3 formation at low temperatures, and partially explains its instability in environmental conditions.
This research assessed the economic impact and construction costs of buildings with solar chimneys in Thailand, called bioclimatic houses. A solar chimney uses a combination of air gaps between walls and roof, and effective ventilation to lower the indoor temperature and reduce the need for air conditioning. The study looked at small, medium, and large size houses and studied construction techniques, the materials used, and the time needed to build a residential structure. It also polled owners of bioclimatic houses about their satisfaction. The techniques employed in building bioclimatic houses take slightly longer and cost slightly more than those used in standard construction. However, the study found that bioclimatic houses use approximately 10–20% less electricity for air conditioning require less maintenance and have a payback period of 6–13 years, depending on the size. The lifespan of insulation material used in standard houses is about 20–25 years, while the lifespan of a solar chimney is about 40–50 years. The solar chimney concept can also be applied to standard houses with minimal renovation. The study found that this type of house was suitable for use in Thailand, and with increased consumer awareness, had a high probability for adoption. 相似文献
Dyes have been applied and are playing an increasingly important role in many industries, including the textile, printing, medical and energy industries. Their wide applications imply that specific dyes possessing given properties need to be effectively designed. The present review aims to survey information related to activity/property research of dyes that has been published in the past two decades. Emphasis is laid particularly on studies based on quantitative structure–activity/property relationships that have contributed to the theoretical design and application of dyes. Finally, the perspectives of quantitative structure‐activity/property relationship studies are set out in order to show how this method may be used to design new dyes and to evaluate their different properties. The challenges facing these studies are also outlined. 相似文献
The classification of traditional Minas cheese (TMC) from different regions is important to ensure authenticity. Different chemometric approaches were used to discriminate TMCs from three different regions (Serro, Canastra and Araxá) of Minas Gerais, Brazil. The data obtained from the literature were used to develop an artificial neural network and to obtain linear discriminant functions, which were able to classify 100% of cheeses from different regions as a function of physico‐chemical composition. Both chemometric methods can be very useful tools to discriminate TMC from different regions based on physico‐chemical data which are obtained in a very quick and simple way. 相似文献