خيارات البحث
النتائج 261 - 270 من 272
Techno-economic potential of low-temperature, jacket-water heat recovery from stationary internal combustion engines with organic Rankine cycles: A cross-sector food-retail study النص الكامل
2020
Le Brun, Niccolo | Simpson, Michael | Acha, Salvador | Shah, Nilay | Markides, Christos N.
We examine the opportunities and challenges of deploying integrated organic Rankine cycle (ORC) engines to recover heat from low-temperature jacket-water cooling circuits of small-scale gas-fired internal combustion engines (ICEs), for the supply of combined heat and power (CHP) to supermarkets. Based on data for commercially-available ICE and ORC engines, a techno-economic model is developed and applied to simulate system performance in real buildings. Under current market trends and for the specific (low-temperature) ICE + ORC CHP configuration investigated here, results show that the ICE determines most economic savings, while the ORC engine does not significantly impact the integrated CHP system performance. The ORC engines have long payback times (4–9 years) in this application, because: (1) they do not displace high-value electricity, as the value of exporting electricity to the grid is low, and (2) it is more profitable to use the heat from the ICEs for space heating rather than for electricity conversion. Commercial ORC engines are most viable (payback ≈ 4 years) in buildings with high electrical demands and low heat-to-power ratios. The influence of factors such as the ORC engine efficiency, capital cost and energy prices is also evaluated, highlighting performance gaps and identifying promising areas for future research.
اظهر المزيد [+] اقل [-]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 النص الكامل
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.
اظهر المزيد [+] اقل [-]Compound-specific δ2H analysis highlights the relationship between direct assimilation and de novo synthesis of amino acids from food and water in a terrestrial mammalian omnivore النص الكامل
2020
Newsome, Seth D. | Nakamoto, Bobby J. | Curras, Mauriel Rodriguez | Fogel, Marilyn L.
Hydrogen isotope (δ²H) analysis has been routinely used as an ecological tracer for animal movement and migration, yet a biochemical understanding of how animals incorporate this element in the synthesis of tissues is poorly resolved. Here, we apply a new analytical tool, amino acid (AA) δ²H analysis, in a controlled setting to trace the influence of drinking water and dietary macromolecules on the hydrogen in muscle tissue. We varied the δ²H of drinking water and the proportions of dietary protein and carbohydrates with distinct hydrogen and carbon isotope compositions fed to house mice among nine treatments. Our results show that hydrogen in the non-essential (AANESS) and essential (AAESS) AAs of mouse muscle is not readily exchanged with body water, but rather patterns among these compounds can be described through consideration of the major biochemical pathway(s) used by organisms to synthesize or route them from available sources. Dietary carbohydrates contributed more hydrogen than drinking water to the synthesis of AANESS in muscle. While neither drinking water nor dietary carbohydrates directly contributed to muscle AAESS, we did find that a minor but measurable proportion (10–30%) of the AAESS in muscle was synthesized by the gut microbiome using hydrogen and carbon from dietary carbohydrates. δ²H patterns among individual AAs in mice muscle are similar to those we previously reported for bacteria, which provides additional support that this approach may allow for the simultaneous analysis of different AAs that are more influenced by drinking water (AANESS) versus dietary (AAESS) sources of hydrogen.
اظهر المزيد [+] اقل [-]Best of both worlds : Co-producing climate services that integrate scientific and indigenous weather and seasonal climate forecast for water management and food production in Ghana
2020
Nyadzi, Emmanuel
Best of both worlds : Co-producing climate services that integrate scientific and indigenous weather and seasonal climate forecast for water management and food production in Ghana النص الكامل
2020
Nyadzi, Emmanuel
Climate variability and its impacts on the agriculture system is clearly evident in Ghana. Weather and seasonal climate forecast information service has been in operation for some time in the country. However, farmers generally do not find the information useful for their farm-level decision making. Forecast accuracy, untimeliness, and mismatch of forecast information and needs are often reported constraints for farmers to use weather and climate information. Consequently, the majority of farmers rely on their indigenous ecological knowledge to predict weather and seasonal climate patterns. At the same time, current weather and seasonal climate forecast information systems in Ghana face serious constraints in how they are used (if at all because of the one directional assumption behind its development; where only science produces new knowledge and makes it accessible for end-users with no or limited involvement of the end-users. In this context, this study addresses the central question: How can climate information services be improved through the coproduction of farmers and scientist? It aims at improving the reliability and acceptability of forecast information by integrating indigenous and scientific forecast. In this dissertation, I used a multi-method research approach, consisting of social participatory methods, mental modelling methods, forecast verification methods, and the principle of citizen science for data gathering and analysis. Initial diagnostics revealed certain issues that limit the uptake of climate information services in Northern Ghana: (1) the mismatch between forecast information provided and the farmers' information need (2) poor quality of forecast information, (3) the disconnect between forecast providers (researchers) and farmers, (4) management of unrealistic expectations of farmers. In response, I proposed a framework for second generation climate services that have the potential to facilitate co-production of relevant and accurate weather and seasonal climate forecast information and manages user expectation while strengthening the collaboration between information providers and users. Results of our analysis show that farmers’ information needs are linked to the type and timing of farm-level decision making. Also, model-based seasonal forecasts have the potential to provide relevant information at farmers most preferred lead time. Findings also show that in addition to historical rainfall patterns, farmers also use observational changes in certain indigenous ecological indicators to predict the coming season. In particular, there is a cognitive relationship between the observational changes and the predicted rainfall event. I observed that farmers’ indigenous forecasting skills and techniques are not intuitive but rationally developed and improve with age and experience. Results also show that farmers and Ghana Meteorological agency are on average able to accurately forecast one out of every three daily rainfall events. Similar results were obtained at the seasonal timescale. Furthermore, I recognized that forecast reliability and usefulness can be improved if indigenous forecast data are quantitatively collected and integrated with the scientific forecast using the proposed integrated probability forecast method. Finally, this dissertation contributes to the calls for a more integrated, co-learning, and co-production approach to climate services that move away from the current focus on science-driven and user-informed climate services. The approach developed in this dissertation is relevant for managing the impact of climate variability and change, particularly because it includes the knowledge of indigenous peoples which is often overlooked.
اظهر المزيد [+] اقل [-]Development of oil-in-water emulsions based on rice bran oil and soybean meal as the basis of food products able to be included in ketogenic diets النص الكامل
2020
Benitez, Lucas Osvaldo | Castagnini, Juan Manuel | Añon, Maria Cristina | Salgado, Pablo Rodrigo
The aim of this work was to develop rice bran oil-in-water emulsions stabilized with proteins and polysaccharides from soybean meal as the basis of food products able to be included in ketogenic diet. The effect of the formulation (ketogenic ratios and oil mass fractions) and the high-pressure homogenization conditions (number of homogenization cycles) on the properties of the resulting O/W emulsions was evaluated. All freshly prepared emulsions showed multimodal particle size distributions and shear-thinning behaviour. At a fixed ketogenic ratio, all emulsions had the same oil to emulsifiers + stabilizers proportion, but increasing their oil mass fraction resulted in systems composed by smaller particles with greater interfacial area, and apparent viscosity. The same effect was observed by increasing the number of homogenization cycles. Meanwhile, increasing the ketogenic ratio (at a fixed oil mass fraction) diminished its apparent viscosity. Most of the studied emulsions were stable for seven days of quiescent refrigerated storage, although some changes in its particle size distributions were observed. Only, the stored emulsions with the highest ketogenic ratio and the lowest oil mass fraction presented gravitational separation but no phase separation. Emulsions prepared after five homogenization cycles presented greater stability to the coalescence than those prepared in one cycle. | Fil: Benitez, Lucas Osvaldo. Universidad Nacional de Entre Ríos. Facultad de Ciencias de la Alimentación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina | Fil: Castagnini, Juan Manuel. Universidad Nacional de Entre Ríos. Facultad de Ciencias de la Alimentación; Argentina | Fil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina | Fil: Salgado, Pablo Rodrigo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina
اظهر المزيد [+] اقل [-]Challenges and opportunities in the operationalization of the Water-Environment-Energy-Food (WE2F) Nexus: Case study of the upper Niger basin and inner Niger delta, West Africa النص الكامل
2020
Seidou, Ousmane; Maiga, Fatoumata; Ringler, Claudia; Kalcic, Spela; Ferrini, Luca | http://orcid.org/0000-0002-8266-0488 Ringler, Claudia
The ever-increasing demand for water, food, and energy is putting unsustainable pressure on natural resources worldwide, often leading to environmental degradation that, in turn, affect water, food, and energy security. The recognition of the complex interlinkages between multiple sectors has led to the creation of various holistic approaches to environmental decision making such as Integrated Natural Resources Management (INRM), Integrated Water Resources Management (IWRM), Virtual Water (VW), Water Footprint (WF) and lately the Food-EnergyEnvironment-Water nexus (WE2F). All these approaches aim to increase resource use efficiency and promote sustainability by increasing the cooperation between traditionally disjoint sectors, and mainly differ by the number and relative weights of the sectors included in their framework. They also suffer from the same face and the same barriers for implementation, some of which may never be fully overcome. The paper discusses the benefits of adopting a WE2F nexus approach in the Upper Niger Basin (UNB) and the Inner Niger Delta (IND), but also the multiple difficulties associated with its practical implementation. IWRM/WE2F initiatives in the UNB/IND such as the BAMGIRE project piloted by Wetlands International and funded by the Dutch Embassy in Mali to secure livelihoods and biodiversity in a changing environment, is taken as an example of partial success in the use of a nexus approach to watershed management. It was shown there are multiple barriers to the operational implementation of the WE2F. However, while a full understanding of all interlinkage between sectors may never be possible, data collection, scientific research and model development can improve our ability to understand the complex system in which we live, and hence take better decisions. | Non-PR | IFPRI5; CRP5; 1 Fostering Climate-Resilient and Sustainable Food Supply; Capacity Strengthening | EPTD | CGIAR Research Program on Water, Land and Ecosystems (WLE)
اظهر المزيد [+] اقل [-]Challenges and opportunities in the operationalization of the Water-Environment-Energy-Food (WE2F) Nexus: Case study of the upper Niger basin and inner Niger delta, West Africa النص الكامل
2020
Seidou, O. | Maiga, F. | Ringler, Claudia | Kalcic, S. | Ferrini, L.
The ever-increasing demand for water, food, and energy is putting unsustainable pressure on natural resources worldwide, often leading to environmental degradation that, in turn, affect water, food, and energy security. The recognition of the complex interlinkages between multiple sectors has led to the creation of various holistic approaches to environmental decision making such as Integrated Natural Resources Management (INRM), Integrated Water Resources Management (IWRM), Virtual Water (VW), Water Footprint (WF) and lately the Food-EnergyEnvironment-Water nexus (WE2F). All these approaches aim to increase resource use efficiency and promote sustainability by increasing the cooperation between traditionally disjoint sectors, and mainly differ by the number and relative weights of the sectors included in their framework. They also suffer from the same face and the same barriers for implementation, some of which may never be fully overcome. The paper discusses the benefits of adopting a WE2F nexus approach in the Upper Niger Basin (UNB) and the Inner Niger Delta (IND), but also the multiple difficulties associated with its practical implementation. IWRM/WE2F initiatives in the UNB/IND such as the BAMGIRE project piloted by Wetlands International and funded by the Dutch Embassy in Mali to secure livelihoods and biodiversity in a changing environment, is taken as an example of partial success in the use of a nexus approach to watershed management. It was shown there are multiple barriers to the operational implementation of the WE2F. However, while a full understanding of all interlinkage between sectors may never be possible, data collection, scientific research and model development can improve our ability to understand the complex system in which we live, and hence take better decisions
اظهر المزيد [+] اقل [-]Influence of fruit food additives on the forms of water binding in wheat flour dough | Влияние фруктовых пищевых добавок на формы связи воды в тесте из пшеничной муки
2020
Viktorova, E.P. | Fedoseeva, O.V. | Shakhraj, T.A. | Kornen, N.N., Krasnodar Research and Development Inst. of Storage and Processing of Agricultural Produce (Russian Federation)
Summaries (En, Ru) | 2 ill. | The influence of fruit food additives "Yabochnaya" and "Grushevaya" obtained from secondary resources of fruit processing, on the forms of water connection in the wheat flour dough was evaluated. The additives are added to the test samples from wheat flour of the 1st grade in the amount of 6, 8 and 10% by weight of flour. Measurement of the nuclear magnetic relaxation characteristics of dough samples was performed using an NMR-analyzer AMV-1006M at a temperature of 23 deg C. It was found that the introduction additives "Yabochnaya" and "Grushevaya" to the dough samples in an amount of 10% by weight of flour allows increasing the content of strongly bound water in the dough by 6.5 or 4.9% respectively, which is explained by the higher content in the additive "Yabochnaya" compared to the additive "Grushevaya"of pectin (3.7% vs. 2.1%), largely showing water-retaining ability. The results, obtained using the NMR method, correspond to the data obtained in the study of the effect of these food additives on the water absorption capacity of the dough. Increasing in the dough the content of water, which is in a strongly bound state, will allow for further baking of dough blanks to reduce baking loss and, consequently, increase yield of products. | 6 ref. | Оценено влияние фруктовых пищевых добавок "Яблочная" и "Грушевая", полученных из вторичных ресурсов переработки фруктов, на формы связи воды в тесте из пшеничной муки. Добавки вносили в образцы теста из пшеничной муки 1-го сорта в количестве 6, 8 и 10% к массе муки. Измерение ядерно-магнитных релаксационных характеристик образцов теста осуществляли на ЯМР-анализаторе АМВ-1006М при температуре 23 град. С. Установлено, что внесение в образцы теста добавки "Яблочная" или "Грушевая" в количестве 10% к массе муки позволяет повысить содержание прочносвязанной воды в тесте на 6,5 или 4,9% соответственно, что объясняется более высоким содержанием в добавке "Яблочная" по сравнению с добавкой "Грушевая" пектина (3,7% против 2,1%), в значительной степени проявляющего водоудерживающую способность. Результаты, полученные с применением метода ЯМР, согласуются с данными, полученными при исследовании влияния указанных пищевых добавок на водопоглотительную способность теста. Повышение в тесте содержания воды, находящейся в прочносвязанном состоянии, позволит при дальнейшей выпечке тестовых заготовок снизить упек хлебобулочного изделия и, следовательно, увеличить его выход.
اظهر المزيد [+] اقل [-]Spherical mesoporous covalent organic framework as a solid-phase extraction adsorbent for the ultrasensitive determination of sulfonamides in food and water samples by liquid chromatography-tandem mass spectrometry النص الكامل
2020
Wen, Lian | Liu, Lu | Wang, Xia | Wang, Ming-Lin | Lin, Jin-Ming | Zhao, Ru-Song
Efficient extraction of polar sulfonamides antibiotics from aqueous samples and food is very challenging, because they are hydrophilic, their concentration is very low, and the matrix is complex. Covalent organic frameworks (COFs), a novel porous organic material, have attracted great attention. In this work, the spherical triphenylbenzene-dimethoxyterephthaldehyde-COFs (TPB-DMTP-COFs) were synthesized by a simple room temperature method, and due to their attractive properties, such as high outstanding acid-base stability, large specific surface area, low skeletal density, inherent porosity and high crystallinity, so TPB-DMTP-COFs as ideal solid phase extraction adsorbents showed excellent adsorption performance for trace polar sulfonamides in food and water. TPB-DMTP-COFs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, and so on. The important parameters were optimized to improve the extraction efficiency of TPB-DMTP-COFs toward sulfonamides. Analysis of sulfonamides was performed by liquid chromatography–tandem mass spectrometry. The developed method based on TPB-DMTP-COFs material achieved low limits of detection (0.5–1.0 ng L⁻¹), wide linearity (5–1000 ng L⁻¹), and good repeatability (2.5%–8.7%). The possible extraction mechanism was also discussed. Finally, the method was successfully applied to the enrichment and detection of sulfonamides in environmental water samples and food samples. The present study indicated that TPB-DMTP-COFs had splendid prospects in highly sensitive analysis of other pollutants in complex matrix.
اظهر المزيد [+] اقل [-]