A simplified strategy based on the house of quality to prioritize farming practices under variable weather conditions

2021 ◽  
pp. 1-17
Author(s):  
Angélica Robayo-Avendaño ◽  
Dorian Prato-Garcia
Author(s):  
S. Purohit ◽  
P. Chauhan

<p><strong>Abstract.</strong> Visibility is clarity with which the distant objects are perceived in the atmosphere with the naked eye. Visibility monitoring is an important concern in health, environment and transport safety context. Quantitative measures of visibility are increasingly becoming important in various areas as they are representative of the particles present in the environment that causes degradation of the visibility. Existing techniques of visibility estimation employ human observers, optical instruments, chemical sensors or combination of some of them. These techniques suffer from poor spatial and temporal resolution, high cost of installation and maintenance, need of specialized personnel, continuous power supply requirement and difficulty in portability. We propose a smart phone-based visibility monitoring system which estimates air visibility/quality in terms of a quantitative measure: Turbidity. In principle, the application calculates turbidity as difference of intensity of captured sky image and analytical value of sky luminance obtained by implementing Perez model. The estimated turbidity tagged with date, time, location, solar position and luminance is sent to the backend server generating consolidated database for mapping of turbidity and generating various analytical reports. The application can easily be deployed to be used by large number of people facilitating citizen science. The results from application were validated against the observations from SAFAR INDIA application at different stations in Ahmedabad, dates and under variable weather conditions.</p>


2020 ◽  
pp. 1264-1274
Author(s):  
P.H. Zaidi ◽  
Thanh Nguyen ◽  
Dang N. Ha ◽  
Suriphat Thaitad ◽  
Salahuddin Ahmed ◽  
...  

Most parts of the Asian tropics are hotspots of climate change effects and associated weather variabilities. One of the major challenges with climate change is the uncertainty and inter-annual variability in weather conditions as crops are frequently exposed to different weather extremes within the same season. Therefore, agricultural research must strive to develop new crop varieties with inbuilt resilience towards variable weather conditions rather than merely tolerance to individual stresses in a specific situation and/or at a specific crop stage. C4 crops are known for their wider adaptation to range of climatic conditions. However, recent climatic trends and associated variabilities seem to be challenging the threshold limit of wider adaptability of even C4 crops like maize. In collaboration with national programs and private sector partners in the region, CIMMYT-Asia maize program initiated research for development (R4D) projects largely focusing on saving achievable yields across range of variable environments by incorporating reasonable levels of tolerance/resistance to major abiotic and biotic stresses without compromising on grain yields under optimal growing conditions. By integrating novel breeding tools like - genomics, double haploid (DH) technology, precision phenotyping and reducing genotype × environment interaction effects, a new generation of maize germplasm with multiple stress tolerance that can grow well across variable weather conditions were developed. The new maize germplasm were targeted for stress-prone environments where maize is invariability exposed to a range of sub-optimal growing conditions, such as drought, heat, waterlogging and various virulent diseases. The overarching goal of the stress-resilient maize program has been to achieve yield potential with a downside risk reduction.


2020 ◽  
Vol 12 (18) ◽  
pp. 7750 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Guillermo Martínez-Lucas ◽  
Ángel Molina-García ◽  
Jose-Ignacio Sarasua

Over the last two decades, variable renewable energy technologies (i.e., variable-speed wind turbines (VSWTs) and photovoltaic (PV) power plants) have gradually replaced conventional generation units. However, these renewable generators are connected to the grid through power converters decoupled from the grid and do not provide any rotational inertia, subsequently decreasing the overall power system’s inertia. Moreover, the variable and stochastic nature of wind speed and solar irradiation may lead to large frequency deviations, especially in isolated power systems. This paper proposes a hybrid wind–PV frequency control strategy for isolated power systems with high renewable energy source integration under variable weather conditions. A new PV controller monitoring the VSWTs’ rotational speed deviation is presented in order to modify the PV-generated power accordingly and improve the rotational speed deviations of VSWTs. The power systems modeled include thermal, hydro-power, VSWT, and PV power plants, with generation mixes in line with future European scenarios. The hybrid wind–PV strategy is compared to three other frequency strategies already presented in the specific literature, and gets better results in terms of frequency deviation (reducing the mean squared error between 20% and 95%). Additionally, the rotational speed deviation of VSWTs is also reduced with the proposed approach, providing the same mean squared error as the case in which VSWTs do not participate in frequency control. However, this hybrid strategy requires up to a 30% reduction in the PV-generated energy. Extensive detailing of results and discussion can be also found in the paper.


1990 ◽  
Vol 112 (4) ◽  
pp. 257-267 ◽  
Author(s):  
B. J. Huang ◽  
S. W. Hsieh

The steady-state performance test of solar collectors using ANSI/ASHRAE 93-1986 Standard was revised and an automation for the testing was carried out in the present study in order that the test can be easily performed outdoors in areas with variable weather conditions. It was shown that the 95 percent settling time of the collector τ95 can be adopted as the time basis in the selection of steady-state period for the test. To make the best use of the time available for the testing, the steady-state period defined by ANSI/ASHRAE 93-1986 Standard was changed to the τ95 plus five minutes, or ten minutes, whichever is larger. To reduce scatter uncertainty in the test results, the test period for the efficiency calculation was chosen as the segment of the last five minutes in the steady-state period and a steadiness condition defined statistically was adopted. To shorten the time for each test run a PC-based expert testing system, which is completely automatic and requires no operator, was developed in the present study. Using this expert system associated with the modified ANSI/ASHRAE 93-1986 Standard, we can effectively carry out the collector test at variable weather conditions with small scatter uncertainty and can substantially shorten the duration of a test.


2007 ◽  
Vol 242 (2-3) ◽  
pp. 800-804 ◽  
Author(s):  
Alain Paquette ◽  
André Bouchard ◽  
Alain Cogliastro

2021 ◽  
Vol 13 (16) ◽  
pp. 9449
Author(s):  
Alfredo de Toro ◽  
Carina Gunnarsson ◽  
Nils Jonsson ◽  
Martin Sundberg

All harvestable cereal straw cannot be collected every year in regions where wet periods are probable during the baling season, so some Swedish studies have used 'recovery coefficients’ to estimate potential harvestable amounts. Current Swedish recovery coefficients were first formulated by researchers in the early 1990s, after discussions with crop advisors, but there are no recent Swedish publications on available baling times and recovery proportions. Therefore, this study evaluated baling operations over a series of years for representative virtual farms and machine systems in four Swedish regions, to determine the available time for baling, baled straw ratio and annual variation in both. The hourly grain moisture content of pre-harvested cereals and swathed straw was estimated using moisture models and real weather data for 22/23 years, and the results were used as input to a model for simulating harvesting and baling operations. Expected available baling time during August and September was estimated to be 39–49%, depending on region, with large annual variation (standard deviation 22%). The average baling coefficient was estimated to be 80–86%, with 1400 t·year−1 harvestable straw and 15 t·h−1 baling capacity, and the annual variation was also considerable (s.d. 20%).


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