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Development of an anthraquinone-based cyanide colorimetric sensor with activated C–H group: Large absorption red shift and application in food and water samples 全文
2020
Zhu, Tingting | Li, Zheyao | Fu, Chao | Chen, Lu | Chen, Xi | Gao, Chen | Zhang, Shuhan | Liu, Chuanxiang
Development of colorimetric sensors has emerged as an attractive strategy for cyanide detection owing to their unique advantages, including simple visual detection and economical nature. In this work, anthraquinone derivatives (3a-d) have been easily prepared via nucleophilic substitution of 1-chloro anthraquinone with substituted phenylacetonitriles, with only nitro-substituted anthraquinone 3d displaying colorimetric sensor capabilities. The sensor showed good selectivity, reversibility and reusability toward cyanide detection, as well as efficient naked-eye color change from colorless to blue-purple in a neutral aqueous medium. The deprotonation mechanism of CH was investigated by NMR spectroscopy and supported by DFT calculations. Furthermore, the sensor 3d was successfully loaded onto test strips as a convenient and efficient solid-state sensor for cyanide detection. It was utilized for cyanide detection in cassava flour and bitter almonds food samples, as well as displaying excellent performance in real-world water samples.
显示更多 [+] 显示较少 [-]A stakeholder analysis for a water-energy-food nexus valuation in an Atlantic Forest area: implications for an integrated assessment and a participatory approach. 全文
2020
MELLONI, G. | BONATTI, M. | TURETTA, A. P. D. | SIEBER, S.
A water-energy-food (WEF) nexus assessment supports natural resource management by providing an integrated framework for evaluation and decision-making. The participation of a wide range of stakeholders is essential for achieving environmental, economic, and social sustainability in this framework. This analysis supports the decision-making process of the nexus assessment by facilitating dialogue between stakeholders in order to achieve long term efficiencies, especially in rural landscapes where most of the services connected to WEF securities are provided. We identify the most relevant stakeholders operating in the connection between agricultural practices and the WEF nexus to stimulate their engagement in the nexus governance. The study area was the Atlantic Forest Reserve of Ribeirão das Lajes, Brazil. A stakeholder analysis, generating qualitative data using snowball sampling interviews was applied and, after the identification of stakeholders, an analytical categorization disclosing potential conflicts among them was performed. We obtained a pool of stakeholders from different organizational types, including a large number of public entities at local and state levels. The main threat to the development of the project is considered to be the lack of communication between the parties. We note that the prior identification of this group of stakeholders facilitates this communication, enhancing social representation in the area. Outcomes of this study demonstrate the relevance of stakeholder analysis in nexus governance for integrated natural resource management.
显示更多 [+] 显示较少 [-]Binary and ternary sustainable composites of gellan gum, hydroxyethyl cellulose and lignin for food packaging applications: Biocompatibility, antioxidant activity, UV and water barrier properties 全文
2020
Rukmanikrishnan, Balasubramanian | Ramalingam, Srinivasan | Rajasekharan, Satish Kumar | Lee, Jintae | Lee, Jaewoong
Biopolymers of gellan gum (G), 2-hydroxyethyl cellulose (HEC), and lignin (L)-based binary and ternary sustainable composites were prepared for food packaging and biomedical application. The composite films were flexible and transparent or translucent with slight brown in color. The incorporation of lignin considerably improved the thermal and mechanical and hydrophobic properties of the composite films. The addition of 10 wt% of lignin to the composites increased the tensile strength by 54.3% and 59.2% respectively. The prepared lignin-based composite films showed high ultraviolet (UV) protection, with almost 100% protection against UVB (280–320 nm) and 90% against UVA (320–400 nm). The surface hydrophobicity of the composite films increased with the addition of lignin. The binary and ternary composites containing 1, 5, and 10 wt% lignin exhibited excellent radical scavenging activities. The gellan gum/HEC/lignin based composite films achieved the best biocompatibility. The obtained composites showed efficient antioxidant and non-cytotoxic activities, although there was no remarkable antimicrobial activity.
显示更多 [+] 显示较少 [-]Phallus impudicus loaded with γ-Fe2O3 as solid phase bioextractor for the preconcentrations of Zn(II) and Cr(III) from water and food samples 全文
2020
We investigated the application of fungus Phallus impudicus loaded γ-Fe₂O₃ nanoparticles as a biosorbent for magnetic solid phase extractions of trace levels of Zn(II) and Cr(III) ions from natural samples before their measurements by inductively coupled plasma optical emission spectrometry. The characterization of magnetized P. impudicus was performed using the scanning electron microscope, the energy dispersive X-ray and Fourier transform infrared spectroscopy. Important experimental factors were investigated. The experimental results fitted well to the Langmuir adsorption model and pseudo-second order kinetic model. Limit of detections of targeted ions by magnetic solid phase extraction method based on use of P. impudicus were found as 10.5 ngL⁻¹ and 12.6 ngL⁻¹ respectively for Cr(III) and Zn(II). The sorption capacities of the biosorbent were 22.8 mgg⁻¹ for Cr(III) and 25.6 mgg⁻¹ for Zn(II). The preconcentration factors were achieved as 100 for both of ions. RSDs for inter- and intraday precisions were found as lower than 2.0% and 2.1% respectively for both of targeted ions. The accuracy of the recommended process was tested by recovery measurements on the certificated reference materials and successfully applied for quantification recoveries of Cr(III) and Zn(II) ions from water and food samples.
显示更多 [+] 显示较少 [-]Analysis of Nitrate Pollution Pathways on a Vulnerable Agricultural Plain in Slovenia: Taking the Local Approach to Balance Ecosystem Services of Food and Water 全文
2020
Miha Curk | Matjaž Glavan | Marina Pintar
Groundwater pollution with nitrate of agricultural origin is a major problem in many countries. A great deal of effort is focused on finding ways to reduce leaching from agricultural land. In this study, different land management scenarios were evaluated with the SWAT model in order to determine which are the most effective in reducing nitrate leaching on specific soil types in the Krška kotlina alluvial plain (Slovenia). The area is very important both for agriculture production and drinking water resources. The model was calibrated for three soil moisture field trial sites, each representing one major soil type of the area. Simulated soil moisture values were in good agreement with the observed values (PBIAS (percent bias) ±25%). Of the nine land management scenarios that were evaluated, vegetable rotation caused the most nitrate leaching on all soil types, but it fared better on Cambisol than on Fluvisol. Orchards on the other hand leached the least amount of nitrate, but also fared better on Cambisol. Presented studies should be considered as a preliminary stage in the study of nitrate pollution in the investigated area. Results show that nitrate leaching varies for different land management scenarios on different soil types. Further work should concentrate on field trials to evaluate the impacts of reduced fertilization on nitrate leaching and both crop yield and quality on different soil types.
显示更多 [+] 显示较少 [-]Gestión del agua en la industria alimentaria como estrategia empresarial para disminuir la huella hídrica generada en el desarrollo de su actividad económica 全文
2020
Galeano Orozco, Paula Andrea | Villegas Jiménez, Nora Elena
RESUMEN: La industria alimentaria es uno de los sectores más contaminantes a nivel del agua, sus cargas orgánicas generan consecuencias como la contaminación y eutrofización del medio acuático, afectando así los ecosistemas. Debido a ello, las industrias han adoptado planes para el uso eficiente del agua, conceptos de economía circular y estrategias de producción limpia, que han ayudado a disminuir la huella hídrica de dicho sector. En el presente estado del arte se explora la información referente al tema, en el cual se encontró que la gestión del recurso hídrico tiene como común denominador, estrategias como la estructuración de una adecuada área de gestión ambiental, la caracterización de los vertimientos, los principios de producción más limpia como reducción de pérdidas, reuso, recirculación del agua y el tratamiento final, la educación ambiental, capacitaciones al personal, planes de mejora continua, mantenimiento preventivo, cambio de tecnologías obsoletas, principios de economía circular, instalación de trampas de grasa, tecnologías limpias, plantas de tratamientos de aguas residuales, dispositivos ahorradores, hasta extenderse más allá e incluir entre sus metas, planes para comunidades, proyectos sociales y de innovación y desarrollo, protección de cuencas, humedales y agua en general. Así las empresas podrán adoptar medidas que les permitan alcanzar los objetivos y metas enmarcados en el desarrollo sostenible y fortalecer su área ambiental, reducir costos, ayudar al medio ambiente y ser más competitivas a nivel empresarial. | Pregrado | Ingeniera Ambiental
显示更多 [+] 显示较少 [-]Effects of food ration, water flow rate and bacteriological levels of broodstock on the reproductive conditioning of the European flat oyster (Ostrea edulis, Linnaeus 1758) 全文
2020
Verónica Maneiro | Ysabel Santos | Antonio J. Pazos | Arturo Silva | Yolanda Torres-Corral | José L. Sánchez | M. Luz Pérez-Parallé
The natural production of the native flat oyster Ostrea edulis and the production of seed in hatcheries are insufficient to meet demand. Several projects have recently been developed to optimise flat oyster production and to establish a reliable protocol for broodstock conditioning in hatcheries. In this sense, the positive effect of a gradient of temperature and a gradient of daylight on the gonadal development, spawning and larval production of O. edulis during winter and autumn conditioning was previously confirmed. No other study has yet been optimised the effect of other factors on flat oyster conditioning.This work examines the combined effect of two important factors on broodstock conditioning, namely the food ration and the water flow rate, for the first time. Furthermore, the bacteriological load of oyster broodstock and its influence on O. edulis conditioning had not been studied before. The results showed that the broodstock conditioned with a food ration of 3% produced the highest number of viable larvae. Oysters conditioned at a flow rate of 3 L h−1 oyster−1 had the highest mortality rate, coinciding with the highest levels of vibrio and heterotrophic bacteria in both meat and intervalvar fluid. The best larval production results were obtained when the 3% food ration was combined with a water flow rate of 2 L h−1 oyster−1.
显示更多 [+] 显示较少 [-]The influence of water temperature, salinity and food availability on nacre deposition rates in shells and pearls of Japanese and hybrid pearl oyster, Pinctada fucata () 全文
2020
Muhammad, Gunawan | Atsumi, Takashi | Komaru, Akira
The objectives of this study were to 1) determine the influence of environmental factors (water temperature, food availability [chlorophyll-a], salinity) on nacre deposition rate and tablet thickness at different positions in shells of two strains of pearl oyster, Pinctada fucata (Gould, 1850)—one from Japan, and one a Hybrid between this Japanese strain and another from China; 2) compare nacre deposition rates and tablet thickness in different shell positions within and between these two pearl oyster strains; and 3) determine relationships between shell nacre deposition rate and tablet thickness in host oysters of these two strains with those of their pearls. Nacre and tablet thickness were measured at three positions along the mantle pallial line (anterior, middle, and posterior), and one position close to the hinge, on the left valve of each oyster. Water temperature and chlorophyll-a were positively correlated (p < .001, Spearman's rho >0.75) and salinity was negatively correlated (p < .001, Spearman's rho < −0.7) with nacre deposition rate at all shell positions in both pearl oyster strains. Only water temperature below 13 °C influenced nacre tablet thinning. Significant differences in total nacre deposition occurred between the four sampling positions on the shell in both strains (p < .001), with deposition at the hinge area the slowest for both Hybrid (373.212 μm) and Japanese (569.248 μm) oysters. Nacre tablet thickness in the middle position on the shell increased most steadily over time, and was thinnest in the coolest months (0.151 μm and 0.167 μm for Hybrid and Japanese oysters, respectively). No significant difference (p > .05) in nacre tablet thickness was apparent between strains. Correlation analysis of nacre deposition rate between the shell and pearls showed that all shell positions were highly correlated with their respective pearls (p < .001, Spearman's Rho >0.75). Environmental factors influence shell nacre deposition and thickness, and because shell nacre deposition is related to pearl nacre, pearl growth also. This influence varies in different shell positions, with nacre deposition in the posterior position on the shell the fastest, and the middle position showing the most stable and thin nacre tablet. Japanese pearl oysters exhibit better nacre deposition than Hybrid oysters and would be more appropriate as host oysters in Ago Bay, Japan, should culture occur in environmental conditions comparable to those in this study.
显示更多 [+] 显示较少 [-]The role of soil water monitoring tools and agricultural innovation platforms in improving food security and income of farmers in smallholder irrigation schemes in Tanzania 全文
2020
Mdemu, M. | Kissoly, L. | Bjornlund, H. | Kimaro, E. | Christen, E. W. | Van Rooyen, A. | Stirzaker, R. | Ramshaw, P.
Smallholder irrigation is an important pathway towards better livelihoods and food security in sub-Saharan Africa. This article assesses the contribution of farmer-friendly soil and water monitoring tools, and agricultural innovation platforms, towards household income and food security in two small-scale irrigation schemes in Tanzania. Quantitative and qualitative data from farmer’s field books, household surveys and focus groups were used to assess the impacts of the two interventions. The two interventions together contributed to enhancing smallholders’ food security and household income in the two schemes, as did the agricultural innovation platform on its own.
显示更多 [+] 显示较少 [-]Effects of trehalose and corn starch on the mechanical glass transition temperature and texture properties of deep-fried food with varying water and oil contents 全文
2020
Jothi, Jakia Sultana | Le, Trinh Ngoc Dang | Kawai, Kiyoshi
The effects of trehalose and corn starch on the mechanical glass transition temperature (Tg) and texture properties of a deep-fried sample (particles of deep-fried batter) with varying water and oil contents were investigated. Tg decreased linearly with increases in both water and oil contents, attributable to their plasticizing effects. Tg was elevated by the addition of trehalose, likely due to its anti-plasticizing effect. Corn starch had a negligible effect on Tg. The critical water content and water activity (water content and water activity at Tg = 25 °C) were determined by extrapolation, and obtained values were validated by isothermal mechanical relaxation. The texture of the samples changed from brittle to ductile near the critical water content and water activity. The trehalose-added sample maintained a brittle texture at a higher water content than the non-additive and corn starch-added samples, as trehalose elevated the critical water content of the deep-fried samples.
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