377 research outputs found

    Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics

    Get PDF
    Gas detectors for elementary particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This work studies properties of potential eco-friendly gas replacements by computing the physical and chemical parameters relevant for use as detector media, and suggests candidates to be considered for experimental investigation

    Can ratoon cropping improve resource use efficiencies and profitability of rice in central China?

    Get PDF
    Identifying cropping systems with small global warming potential (GWP) per unit of productivity is important to ensure food security while minimizing environmental footprint. During recent decades, double-season rice (DR) systems in central China have progressively shifted into single-crop, middle-season rice (MR) due to high costs and labor requirements of double-season rice. Ratoon rice (RR) has been proposed as an alternative system that reconciliates both high annual productivity and relatively low costs and labor requirements. Here we used onfarm data collected from 240 farmer fields planted with rice in 2016 to evaluate annual energy balance, environmental impact, and net profit of MR, DR, and RR cropping systems in central China. Energy factors, emission values, and commodity prices obtained from literature and official statistics were used to estimate energy balance, GWP, and economic profit. Average annual yield was 7.7, 15.3. and 13.2 Mg ha−1 for MR, DR, and RR systems, respectively. Average total annual energy input (36 GJ ha−1), GWP (9783 kg ha−1), and production cost (3057 ha−1)ofRRwere35–48 ha−1) of RR were 35–48% higher than those of MR. However, RR achieved 72–129% higher annual grain yield (13.2 Mg ha−1), net energy yield (159 GJ ha−1), and net economic return (2330 ha−1) than MR. Compared with DR, RR produced statistically similar net energy yield while doubling the net economic return, with 32–42% lower energy input, production costs, and GWP. Consequently, RR exhibited significantly higher net energy ratio and benefit-to-cost ratio, and substantially lower yield-scaled GWP than the other two cropping systems. In the context of DR being replaced by MR, our analysis indicated that RR can be a viable option to achieve both high annual productivity and large positive energy balance and profit, while reducing the environmental impact

    Can ratoon cropping improve resource use efficiencies and profitability of rice in central China?

    Get PDF
    Identifying cropping systems with small global warming potential (GWP) per unit of productivity is important to ensure food security while minimizing environmental footprint. During recent decades, double-season rice (DR) systems in central China have progressively shifted into single-crop, middle-season rice (MR) due to high costs and labor requirements of double-season rice. Ratoon rice (RR) has been proposed as an alternative system that reconciliates both high annual productivity and relatively low costs and labor requirements. Here we used onfarm data collected from 240 farmer fields planted with rice in 2016 to evaluate annual energy balance, environmental impact, and net profit of MR, DR, and RR cropping systems in central China. Energy factors, emission values, and commodity prices obtained from literature and official statistics were used to estimate energy balance, GWP, and economic profit. Average annual yield was 7.7, 15.3. and 13.2 Mg ha−1 for MR, DR, and RR systems, respectively. Average total annual energy input (36 GJ ha−1), GWP (9783 kg ha−1), and production cost (3057 ha−1)ofRRwere35–48 ha−1) of RR were 35–48% higher than those of MR. However, RR achieved 72–129% higher annual grain yield (13.2 Mg ha−1), net energy yield (159 GJ ha−1), and net economic return (2330 ha−1) than MR. Compared with DR, RR produced statistically similar net energy yield while doubling the net economic return, with 32–42% lower energy input, production costs, and GWP. Consequently, RR exhibited significantly higher net energy ratio and benefit-to-cost ratio, and substantially lower yield-scaled GWP than the other two cropping systems. In the context of DR being replaced by MR, our analysis indicated that RR can be a viable option to achieve both high annual productivity and large positive energy balance and profit, while reducing the environmental impact

    Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics

    Full text link
    Modern gas detectors for detection of particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This review studies properties of potential eco-friendly gas candidate replacements.Comment: 38 pages, 9 figures, 8 tables. To be submitted to Journal of Instrumentatio

    Candidate eco-friendly gas mixtures for MPGDs

    Get PDF
    Modern gas detectors for detection of particles require F-based gases for optimal performance.Recent regulations demand the use of environmentally unfriendly F-based gases t o be limited or banned. This review studies properties of potential eco-friendly gas candidate replacements

    Prospects for Increasing Sugarcane and Bioethanol Production on Existing Crop Area in Brazil

    Get PDF
    This article assesses sugarcane yield gaps (YG) in Brazil to determine the degree to which production can be increased without land expansion. In our scenario assessments, we evaluated how much of the projected sugarcane demand to 2024 (for both sugar and bioethanol) can be satisfied through YG closure. The current national average yield is 62% of yield potential estimated for rainfed conditions (i.e., a YG of 38%). Continuing the historical rate of yield gain is not sufficient to meet the projected demand without an area expansion by 5% and 45% for lowand high-demand scenarios, respectively. Closing the exploitable YG to 80% of potential yield would meet future sugarcane demand, with an 18% reduction in sugarcane area for the low-demand scenario or a 13% expansion for the high-demand scenario. A focus on accelerating yield gains to close current exploitable YG is a high priority for meeting future demand while minimizing pressure on additional land requirements

    Closing yield gaps for rice self-sufficiency in China

    Get PDF
    China produces 28% of global rice supply and is currently self-sufficient despite a massive rural-to-urban demographic transition that drives intense competition for land and water resources. At issue is whether it will remain self-sufficient, which depends on the potential to raise yields on existing rice land. Here we report a detailed spatial analysis of rice production potential in China and evaluate scenarios to 2030. We find that China is likely to remain self-sufficient in rice assuming current yield and consumption trajectories and no reduction in production area. A focus on increasing yields of double-rice systems on general, and in three single-rice provinces where yield gaps are relatively large, would provide greatest return on investments in research and development to remain self-sufficient. Discrepancies between results from our detailed bottom-up yield-gap analysis and those derived following a topdown methodology show that the two approaches would result in very different research and development priorities

    High-yield irrigated maize in the Western U.S. Corn Belt: II. Irrigation management and crop water productivity

    Get PDF
    Appropriate benchmarks for water productivity (WP), defined here as the amount of grain yield produced per unit of water supply, are needed to help identify and diagnose inefficiencies in crop production and water management in irrigated systems. Such analysis is lacking for maize in the Western U.S. Corn Belt where irrigated production represents 58% of total maize output. The objective of this paper was to quantify WP and identify opportunities to increase it in irrigated maize systems of central Nebraska. In the present study, a benchmark for maize WP was (i) developed from relationships between simulated yield and seasonal water supply (stored soil water and sowing-to-maturity rainfall plus irrigation) documented in a previous study; (ii) validated against actual data from crops grown with good management over a wide range of environments and water supply regimes (n = 123); and (iii) used to evaluate WP of farmer’s fields in central Nebraska using a 3-y database (2005–2007) that included field-specific values for yield and applied irrigation (n = 777). The database was also used to quantify applied irrigation, irrigation water-use efficiency (IWUE; amount of yield produced per unit of applied irrigation), and the impact of agronomic practices on both parameters. Opportunities to improve irrigation management were evaluated using a maize simulation model in combination with actual weather records and detailed data on soil properties and crop management collected from a subset of fields (n = 123). The linear function derived from the relationship between simulated grain yield and seasonal water supply, namely the mean WP function (slope = 19.3 kg ha−1 mm−1; x-intercept = 100 mm), proved to be a robust benchmark for maize WP when compared with actual yield and water supply data. Average farmer’s WP in central Nebraska was ~73% of the WP derived from the slope of the mean WP function. A substantial number of fields (55% of total) had water supply in excess of that required to achieve yield potential (900 mm). Pivot irrigation (instead of surface irrigation) and conservation tillage in fields under soybean–maize rotation had the greatest IWUE and yield. Applied irrigation was 41 and 20% less under pivot and conservation tillage than under surface irrigation and conventional tillage, respectively. Simulation analysis showed that up to 32% of the annual water volume allocated to irrigated maize in the region could be saved with little yield penalty, by switching current surface systems to pivot, improving irrigation schedules to be more synchronous with crop water requirements and, as a fine-tune option, adopting limited irrigation

    MA-XRF measurement for corrosion assessment on bronze artefacts

    Get PDF
    In this study, an innovative portable macro X-Ray Fluorescence (MA-XRF) scanner prototype has been employed in order to gain information on composition and distribution of corrosion products artificially grown on Cu-based coupons. First results have shown the importance of using artificially corroded reference samples before any assessment on archaeological artefacts. Moreover, the prototype used demonstrated to be a powerful tool for understanding complex corrosion processes which might occur on Cu-based alloys. The scanner was able to detect light elements as S and Cl, essential for studying the distribution of specific corrosion compounds. Using imaging techniques, it was possible to observe a gradient in Cu elemental maps intensity caused by the overlapping of a thicker corrosion product layer

    Improvement of functional bloating by an enterovaccine: a preliminary study

    Get PDF
    Background: bloating is a fastidious symptom reported by many patients who also have other gastrointestinal functional dis orders. Bloating is more common in women, and it is often asso ciated with meals and improves or disappears overnight. No spe cific treatments are to date available for this disturbing symptom. Aims: to evaluate the effects of an oral enterovaccine (Colifag ina ® ) on bloating and other abdominal symptoms in patients with prevalent complaints of functional bloating. Patients and methods: one hundred and forty-eight patients with functional bloating according to Rome III criteria were re cruited. Questionnaires and a VAS scale on their symptoms were administered at baseline and after four weeks of therapy with Colifagina ® . Results: after treatment, a significant amelioration of bloating (p < 0.0001), abdominal pain (p < 0.0001) and flatus (p < 0.0001) was observed; nausea and vomiting scores were not sig nificantly different at the end of the treatment. Subjective wellbe ing was also generally improved (p < 0.001) in treated patients. Conclusion: treatment with an enterovaccine may help im prove symptoms in patients with functional bloating
    • …
    corecore