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Resultados 171-180 de 408
Functionalization of polymers and nanomaterials for water treatment, food packaging, textile and biomedical applications: a review Texto completo
2021
Makvandi, Pooyan | Iftekhar, Sidra | Pizzetti, Fabio | Zarepour, Atefeh | Zare, Ehsan Nazarzadeh | Ashrafizadeh, Milad | Agarwal, Tarun | Padil, Vinod V. T. | Mohammadinejad, Reza | Sillanpaa, Mika | Maiti, Tapas Kumar | Perale, Giuseppe | Z̤arrābī, ʻAlī | Rossi, Filippo
The inert nature of most commercial polymers and nanomaterials results in limitations of applications in various industrial fields. This can be solved by surface modifications to improve physicochemical and biological properties, such as adhesion, printability, wetting and biocompatibility. Polymer functionalization allows to graft specific moieties and conjugate molecules that improve material performances. In the last decades, several approaches have been designed in the industry and academia to graft functional groups on surfaces. Here, we review surface decoration of polymers and nanomaterials, with focus on major industrial applications in the medical field, textile industry, water treatment and food packaging. We discuss the advantages and challenges of polymer functionalization. More knowledge is needed on the biology behind cell–polymer interactions, nanosafety and manufacturing at the industrial scale.
Mostrar más [+] Menos [-]New water-soluble chitin derivative with high antibacterial properties for potential application in active food coatings Texto completo
2021
Kritchenkov, Andreii S. | Kletskov, Alexey V. | Egorov, Anton R. | Tskhovrebov, Alexander G. | Kurliuk, Aleh V. | Zhaliazniak, Natallia V. | Shakola, Tatsiana V. | Khrustalev, Victor N.
The synthesis of new chitin derivatives through ultrasound-assisted treatment of the chitin with 1-azido-3-chloropropan-2-ol under Green Chemistry conditions is described. This is the first example of ultrasound-assisted polymer analogues transformation of chitin unaccompanied by noticeable backbone degradation or deacetylation. The obtained water-soluble azido chitin derivatives are characterized by high antibacterial activity, which is comparable with that of commercial antibiotics ampicillin and gentamicin. At the same time, they were demonstrated almost identical in vitro toxicity as unmodified chitin and chitosan. The antibacterial activity of the obtained polymers is mainly provided by azido moiety in their macromolecules. The conjugation of azido moiety to chitin backbone strongly diminishes the toxicity of the azido pharmacophore, but preserves its antibacterial properties. The most potent chitin derivative was used for the film coating of Ricotta cheese samples. This food coating proved to be efficient for the prolongation of shelf life of Ricotta cheese.
Mostrar más [+] Menos [-]Critical reflections on Water-Energy-Food Nexus in Computable General Equilibrium models: A systematic literature review Texto completo
2021
Bardazzi, Elisa | Bosello, Francesco
The paper analyses how the Water-Energy-Food Nexus is treated in Computable General Equilibrium (CGE) models, discussing their design, importance and possible ways of improvement. The analysis of their structure is critical for evaluating their potential efficiency in understanding the Nexus, which will be particularly effective for gauging the importance of the topic, the reciprocal dependency of its elements and the expected macroeconomic, demographic and climatic pressures that will act on its components. General equilibrium models can be useful devices to this end, as they are specifically built to track interdependencies and transmission effects across sectors and countries. Nevertheless, the review showed that most CGEs in the literature struggle to represent the competing water uses across sectors and, in particular, those concerning the energy sector. Therefore, it highlights the need to resolve this issue as a necessary step toward improving future research.
Mostrar más [+] Menos [-]Floods, soil and food – Interactions between water management and rice production within An Giang province, Vietnam Texto completo
2021
Livsey, John | Thi Da, Chau | Scaini, Anna | Lan, Thai Huynh Phuong | Long, Tran Xuan | Berg, Håkan | Manzoni, Stefano
Rapid intensification of Vietnamese rice production has had a positive effect on the nation's food production and economy. However, the sustainability of intensive rice production is increasingly being questioned within Vietnam, particularly in major agricultural provinces such as An Giang. The construction of high dykes within this province, which allow for complete regulation of water onto rice fields, has enabled farmers to grow up to three rice crops per year. However, the profitability of producing three crops is rapidly decreasing as farmers increase their use of chemical fertilizer inputs and pesticides. Increased fertilizer inputs are partly used to replace natural flood-borne, nutrient-rich sediment inputs that have been inhibited by the dykes, but farmers believe that despite this, soil health within the dyke system is degrading. However, the effects of the dykes on soil properties have not been tested. Therefore, a sampling campaign was conducted to assess differences in soil properties caused by the construction of dykes. The results show that, under present fertilization practices, although dykes may inhibit flood-borne sediments, this does not lead to a systematic reduction in nutrients that typically limit rice growth within areas producing three crops per year. Concentrations of total nitrogen, available phosphorous, and both total and available potassium, and pH were higher in the surface layer of soils of three crop areas when compared to two crop areas. This suggests that yield declines may be caused by other factors related to the construction of dykes and the use of chemical inputs, and that care should be taken when attempting to maintain crop yields. Attempting to compensate for yield declines by increasing fertilizer inputs may ultimately have negative effects on yields.
Mostrar más [+] Menos [-]Pesticide residues in foods and water in Qatar and their impact on food exposure risk assessment Texto completo
2021
Elobeid, Tahra | Ganji, Vijay | Al-Saeedi, Sara | Mohamed, Alaa Abdelmonem | Dahir, Hana Mohamed | Hassan, Hassan | Karam, Layal | Attieh, Grace
Purpose: The purposes of this study were to analyze fruits, vegetables, water and soil for organochlorine pesticide (OCP) residues and to assess the food exposure of these pesticides in Qatar. Design/methodology/approach: Pesticides were quantified in dates, leafy vegetables, fruiting vegetables, water and soil samples using a gas chromatography-electron capture detector and gas chromatography-mass spectrometry. These pesticides were α-benzene hexachloride (BHC), ß-BHC, heptachlor, aldrin, g-chlordane, endosulfan I, α-chlordane, dieldrin, endrin and methoxychlor. Additionally, food exposure risk assessment was performed by estimating daily intakes of OCP. Findings: Most analyzed samples contained at least one OCP residue. Endosulfan was the only pesticide that was not detected. The concentrations of OCP in samples were below the maximum residue level (MRL) except endosulfan. Among all the samples analyzed, ˜18% of those exceeded the MRL with respect to the concentrations of methoxychlor and heptachlor. Only intake of methoxychlor (0.018 mg/day) exceeded the MRL (0.01 mg/day). Dates and fruiting vegetables were likely to pose a higher risk than leafy vegetables because they contained heptachlor, endrin and methoxychlor. Leafy vegetables might pose a greater risk than dates and fruiting vegetables because of the presence of β-BHC and dieldrin. Originality/value: Eight out of ten OCPs that were measured were found to be below the MRL. These pesticides should be eliminated from the food supply based on the Qatar National Implementation Plan of the Stockholm Convention in 2010. Based on the intake risk assessment, overall, the intake of OCP may not pose a major risk to human health as the concentrations of OCP were below MRL, except methoxychlor. Water and soil are the potential sources of contamination of OCP in foods that were tested in Qatar. To limit the health risks associated with OCPs, there is a need for close monitoring of food and agricultural practices and the types of pesticides imported into Qatar.
Mostrar más [+] Menos [-]Evaluating the Potential of a Water-Energy-Food Nexus Approach toward the Sustainable Development of Bangladesh Texto completo
2021
Mohammad Nahidul Karim | Bassel Daher
In pursuit of continuous economic development, Bangladesh has undertaken long-term plans to boost its productivity in the agriculture, energy, and industrial sectors and to align with the United Nations Sustainable Development Goals (SDGs). Unless these strong interconnections and cross sectoral impacts are recognized, achievement of the future policy goals and national priorities of the concerned ministries regarding food self-sufficiency, cleaner energy sources, and water availability will be compromised. This study focuses on evaluating the impacts of cross-sectoral policy decisions on the interconnected resource systems at a national scale in Bangladesh. A quantitative analysis is performed to identify resource requirements, synergies, and trade-offs related to a set of future strategies. The analysis concludes by showing that land is the most limiting resource for future expansion and that fresh water will become a critical resource if alternative sources of water are not explored, and, that energy generation, if coal and other fossil fuels are favored over alternative energy sources, will significantly add to the total carbon emissions. Given the limitations of land available for agricultural expansion, of renewable water resources, and the challenges in meeting increasing water, energy, and food demands, the strong interdependencies among the interconnected resource systems must be accounted for. The SDG and national priority indicators are found to improve under scenarios for which resources are conserved via alternative sources.
Mostrar más [+] Menos [-]Review: Trends in point-of-care diagnosis for Escherichia coli O157:H7 in food and water Texto completo
2021
Rani, Alka | Ravindran, Vivek B. | Surapaneni, Aravind | Mantri, Nitin | Ball, A. S.
Escherichia coli O157:H7, a Shiga-producing E. coli is a major pathogenic E. coli strain which since the early 1980s has become a crucial food and water-borne pathogen. Several management strategies can be applied to control the spread of infection; however early diagnosis represents the optimum preventive strategy to minimize the infection. Therefore, it is crucial to detect this pathogen in a fast and efficient manner in order to reduce the morbidity and mortality. Currently used gold standard tests rely on culture and pre-enrichment of E. coli O157:H7 from the contaminated source; they are time consuming and laborious. Molecular methods such as polymerase chain reaction are sensitive; however, they require expensive instrumentation. Therefore, there is a requirement for Accurate, Sensitive, Specific, User friendly, Rapid, Equipment free and Deliverable (ASSURED) detection methods for use in the laboratory and in the field. Emerging technologies such as isothermal amplification methods, biosensors, surface enhanced Raman Spectroscopy, paper-based diagnostics and smartphone-based digital methods are recognized as new approaches in the field of E. coli O157:H7 diagnostics and are discussed in this review. Mobile PCR and CRISPR-Cas diagnostic platforms have been identified as new tools in E. coli O157:H7 POC diagnostics with the potential for implementation by industry. This review describes advances and progress in the field of E. coli O157:H7 diagnosis in the context of food and water industry. The focus is on emerging high throughput point-of-care (POC) E. coli O157:H7 diagnostics and the requirement for the transformation to service routine diagnostics in the food and water industry.
Mostrar más [+] Menos [-]Biodiesel sustainability: The global impact of potential biodiesel production on the energy–water–food (EWF) nexus Texto completo
2021
Chong, Cheng Tung | Loe, Ting Yu | Wong, Kang Yao | Ashokkumar, Veeramuthu | Lam, Su Shiung | Chong, Wen Tong | Borrion, Aiduan | Tian, Bo | Ng, Jo-Han
A data-driven model is used to analyse the global effects of biodiesel on the energy–water–food (EWF) nexus, and to understand the complex environmental correlation. Several criteria to measure the sustainability of biodiesel and four main limiting factors for biodiesel production are discussed in this paper. The limiting factors includes water stress, food stress, feedstock quantity and crude oil price. The 155-country model covers crude oil prices ranging from USD10/bbl to USD160/bbl, biodiesel refinery costs ranging from -USD0.30/L to USD0.30/L and 45 multi-generation biodiesel feedstocks. The model is capable of ascertaining changes arising from biodiesel adoption in terms of light-duty diesel engine emissions (NO, CO, UHC and smoke opacity), water stress index (WSI), dietary energy supply (DES), Herfindahl–Hirschman index (HHI) and short-term energy security. With the addition of potential biodiesel production, the renewable energy sector of global primary energy profile can increase by 0.43%, with maximum increment up to 10.97% for Malaysia. At current crude oil price of USD75/bbl and refinery cost of USD0.1/L, only Benin, Ireland and Togo can produce biodiesel profitably. The model also shows that water requirement varies non-linearly with multi-feedstock biodiesel production as blending ratio increases. Out of the 155 countries, biodiesel production is limited by feedstock quantity for 82 countries, 47 are limited by crude oil price, 20 by water stress and 6 by food stress. The results provide insights for governments to set up environmental policy guidelines, in implementing biodiesel technology as a cleaner alternative to diesel.
Mostrar más [+] Menos [-]Alternative pathways for sustainable energy development and implications for water and food security in the Philippines Texto completo
2018 | 2021 | 2016
International Food Policy Research Institute (IFPRI)
The Philippines currently relies largely on fossil-fuel based power generation (about 77 percent) and is expected to increase power generation from coal-based (fossil) plants to meet future energy demand, which would negatively affect environmental outcomes. Primary energy supply is expected to double between 2011 and 2030. The renewable energy potential is relatively high in the Philippines and could contribute to supply modern reliable energy services and improve energy security. The government’s energy reform agenda highlights the importance of access to more reliable energy using indigenous energy resources while minimizing imported fossil-fuel use in an optimal and cost-effective way. The feasibility of this type of diversification from fossil-fuel to renewable energy based power generation can be assessed by applying energy optimization models, such as MARKAL1/TIMES2. Application of a bottom-up energy optimization model can provide important insights into the implications of prospective conversion technologies that can be pursued by the Philippine government in a cost-efficient and effective way to ensure energy security and develop a low-carbon society. | Non-PR | CRP5; Phil-EWF; IFPRI2 | EPTD | CGIAR Research Program on Water, Land and Ecosystems (WLE)
Mostrar más [+] Menos [-]Causal relations of upscaled urban aquaponics and the food-water-energy nexus—A Berlin case study Texto completo
2021
Baganz, Gösta F.M. | Schrenk, Manfred | Körner, Oliver | Baganz, Daniela | Keesman, Karel J. | Goddek, Simon | Siscan, Zorina | Baganz, Elias | Doernberg, Alexandra | Monsees, Hendrik | Nehls, Thomas | Kloas, Werner | Lohrberg, Frank
Aquaponics, the water-reusing production of fish and crops, is taken as an example to investigate the consequences of upscaling a nature-based solution in a circular city. We developed an upscaled-aquaponic scenario for the German metropolis of Berlin, analysed the impacts, and studied the system dynamics. To meet the annual fish, tomato, and lettuce demand of Berlin’s 3.77 million residents would require approximately 370 aquaponic facilities covering a total area of 224 hectares and the use of different combinations of fish and crops: catfish/tomato (56%), catfish/lettuce (13%), and tilapia/tomato (31%). As a predominant effect, in terms of water, aquaponic production would save about 2.0 million m3 of water compared to the baseline. On the supply-side, we identified significant causal link chains concerning the Food-Water-Energy nexus at the aquaponic facility level as well as causal relations of a production relocation to Berlin. On the demand-side, a ‘freshwater pescatarian diet’ is discussed. The new and comprehensive findings at different system levels require further investigations on this topic. Upscaled aquaponics can produce a relevant contribution to Berlin’s sustainability and to implement it, research is needed to find suitable sites for local aquaponics in Berlin, possibly inside buildings, on urban roofscape, or in peri-urban areas.
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