Boiler Combustion Optimization of Vegetal Crop Residues from Greenhouses

This work presents an alternative for adding value to greenhouse crop residues, used for (1) heating and (2) as a CO2 source. Both options are focused on greenhouse agricultural production, but could be applied to other applications. The influence of factors, such as the air/fuel rate and turbulence inside the combustion chamber, is studied. Our results show that for pine pellets, olive pits, tomato-crop residues, and a blend of the latter mixed with almond prunings (75–25%), the thermal losses ranged from 19.5–53.1, 20.5–58.9, 39.9–95%, and 29.4–75.5%, respectively, while the NOX emissions were 30–247, 411–1792, and 361–2333 mg/Nm3, respectively. The above-mentioned blend was identified as the best set-up. The thermal losses were 39.2%, and the CO, NOX, and SO2 concentrations were 11,690, 906, and 1134 mg/Nm3, respectively (the gas concentration values were recalculated for 0% O2). Currently, no other work exists in the literature include a similar analysis performed using a boiler with a comparable thermal output (160.46 kW). The optimal configurations comply with the relevant local legislation. This optimization is important for future emission control strategies relating to using crop residues as a CO2 source. The work also highlights the importance of ensuring a proper boiler set-up for each case considered.

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The application of compound proportional resonant control strategy in multiple PV inverters system

Modern Physics Letters B ◽

10.1142/s0217984918400985 ◽

2018 ◽

Vol 32 (34n36) ◽

pp. 1840098

Author(s):

Yuan Li ◽

Huifang Shen ◽

Chao Xiong ◽

Yaofei Han ◽

Guofeng He

Keyword(s):

Control Strategy ◽

Closed Loop ◽

Control Strategies ◽

Integrated Control ◽

Reference Signal ◽

Loop Model ◽

Harmonic Compensation ◽

Feed Forward ◽

Feed Forward Control ◽

Set Up

In order to eliminate the effect on the grid current caused by the background harmonic voltage and the reference signal on the grid connected multi-inverter, this paper adopts the double closed-loop feed-forward control strategy. This strategy is based on the inductor voltage and the grid-connected current, and the integrated control strategy of quasi-proportional resonance loop parallel to a specific harmonic compensation loop. Based on the closed-loop model of multiple inverters, the change curves of the transfer function of the two control strategies are compared with the feed-forward control and the composite proportional resonance. The two corresponding control methods are used to analyze the current quality of the multi-inverter impact. Finally, the MATLAB/Simulink simulation model is set up to verify the proposed control strategies. The simulation results show that the proposed method can achieve better tracking of the sinusoidal command signal at the fundamental frequency, and enhance the anti-interference ability of the system at the 3rd, 5th, and 7th harmonic frequency.

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Whole Genome Sequencing of SARS-CoV-2: Adapting Illumina Protocols for Quick and Accurate Outbreak Investigation during a Pandemic

Genes ◽

10.3390/genes11080949 ◽

2020 ◽

Vol 11 (8) ◽

pp. 949 ◽

Cited By ~ 5

Author(s):

Sureshnee Pillay ◽

Jennifer Giandhari ◽

Houriiyah Tegally ◽

Eduan Wilkinson ◽

Benjamin Chimukangara ◽

...

Keyword(s):

South Africa ◽

Real Time ◽

Control Strategies ◽

Outbreak Investigation ◽

Infection Prevention And Control ◽

Library Preparation ◽

Large Hospital ◽

Preparation Methods ◽

Hospital Outbreak ◽

Set Up

The COVID-19 pandemic has spread very fast around the world. A few days after the first detected case in South Africa, an infection started in a large hospital outbreak in Durban, KwaZulu-Natal (KZN). Phylogenetic analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes can be used to trace the path of transmission within a hospital. It can also identify the source of the outbreak and provide lessons to improve infection prevention and control strategies. This manuscript outlines the obstacles encountered in order to genotype SARS-CoV-2 in near-real time during an urgent outbreak investigation. This included problems with the length of the original genotyping protocol, unavailability of reagents, and sample degradation and storage. Despite this, three different library preparation methods for Illumina sequencing were set up, and the hands-on library preparation time was decreased from twelve to three hours, which enabled the outbreak investigation to be completed in just a few weeks. Furthermore, the new protocols increased the success rate of sequencing whole viral genomes. A simple bioinformatics workflow for the assembly of high-quality genomes in near-real time was also fine-tuned. In order to allow other laboratories to learn from our experience, all of the library preparation and bioinformatics protocols are publicly available at protocols.io and distributed to other laboratories of the Network for Genomics Surveillance in South Africa (NGS-SA) consortium.

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Modelling temporal dynamics of Culicoides Latreille (Diptera: Ceratopogonidae) populations on Reunion Island (Indian Ocean), vectors of viruses of veterinary importance

Parasites & Vectors ◽

10.1186/s13071-019-3812-1 ◽

2019 ◽

Vol 12 (1) ◽

Cited By ~ 2

Author(s):

Yannick Grimaud ◽

Hélène Guis ◽

Frédéric Chiroleu ◽

Floriane Boucher ◽

Annelise Tran ◽

...

Keyword(s):

Vegetation Index ◽

Temporal Dynamics ◽

Control Strategies ◽

Host Density ◽

Environmental Drivers ◽

Hurdle Model ◽

Reunion Island ◽

Annual Variations ◽

Réunion Island ◽

Set Up

Abstract Background Reunion Island regularly faces outbreaks of epizootic haemorrhagic disease (EHD) and bluetongue (BT), two viral diseases transmitted by haematophagous midges of the genus Culicoides (Diptera: Ceratopogonidae) to ruminants. To date, five species of Culicoides are recorded in Reunion Island in which the first two are proven vector species: Culicoides bolitinos, C. imicola, C. enderleini, C. grahamii and C. kibatiensis. Meteorological and environmental factors can severely constrain Culicoides populations and activities and thereby affect dispersion and intensity of transmission of Culicoides-borne viruses. The aim of this study was to describe and predict the temporal dynamics of all Culicoides species present in Reunion Island. Methods Between 2016 and 2018, 55 biweekly Culicoides catches using Onderstepoort Veterinary Institute traps were set up in 11 sites. A hurdle model (i.e. a presence/absence model combined with an abundance model) was developed for each species in order to determine meteorological and environmental drivers of presence and abundance of Culicoides. Results Abundance displayed very strong heterogeneity between sites. Average Culicoides catch per site per night ranged from 4 to 45,875 individuals. Culicoides imicola was dominant at low altitude and C. kibatiensis at high altitude. A marked seasonality was observed for the three other species with annual variations. Twelve groups of variables were tested. It was found that presence and/or abundance of all five Culicoides species were driven by common parameters: rain, temperature, vegetation index, forested environment and host density. Other parameters such as wind speed and farm building opening size governed abundance level of some species. In addition, Culicoides populations were also affected by meteorological parameters and/or vegetation index with different lags of time, suggesting an impact on immature stages. Taking into account all the parameters for the final hurdle model, the error rate by Normalized Root mean Square Error ranged from 4.4 to 8.5%. Conclusions To our knowledge, this is the first study to model Culicoides population dynamics in Reunion Island. In the absence of vaccination and vector control strategies, determining periods of high abundance of Culicoides is a crucial first step towards identifying periods at high risk of transmission for the two economically important viruses they transmit.

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Advanced Planar Oxygen Sensors for Future Emission Control Strategies

10.4271/970459 ◽

1997 ◽

Cited By ~ 11

Author(s):

Harald Neumann ◽

Gerhard Hötzel ◽

Gert Lindemann

Keyword(s):

Control Strategies ◽

Emission Control ◽

Oxygen Sensors ◽

Future Emission

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Use of tomato crop residues into soil for control of bacterial wilt caused by Ralstonia solanacearum

Crop Protection ◽

10.1016/j.cropro.2011.03.025 ◽

2011 ◽

Vol 30 (9) ◽

pp. 1138-1143 ◽

Cited By ~ 10

Author(s):

M.J. Zanón ◽

M.I. Font ◽

C. Jordá

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Crop Residues ◽

Tomato Crop

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Percolation-Based Risk Index for Pathogen Invasion: Application to Soilborne Disease in Propagation Systems

Phytopathology ◽

10.1094/phyto-02-13-0033-r ◽

2013 ◽

Vol 103 (10) ◽

pp. 1012-1019 ◽

Cited By ~ 5

Author(s):

S. Poggi ◽

F. M. Neri ◽

V. Deytieux ◽

A. Bates ◽

W. Otten ◽

...

Keyword(s):

Plant Pathogens ◽

Control Strategies ◽

Risk Index ◽

Host Density ◽

Transmission Probability ◽

Pathogen Transmission ◽

Soilborne Disease ◽

Pathogen Invasion ◽

Fungal Plant Pathogens ◽

Set Up

Propagation systems for seedling growth play a major role in agriculture, and in notable cases (such as organic systems), are under constant threat from soil and seedborne fungal plant pathogens such as Rhizoctonia solani or Pythium spp. Yet, to date little is known that links the risk of disease invasion to the host density, which is an agronomic characteristic that can be readily controlled. We introduce here, for the first time in an agronomic system, a percolation framework to analyze the link. We set up an experiment to study the spread of the ubiquitous fungus R. solani in replicated propagation systems with different planting densities, and fit a percolation-based epidemiological model to the data using Bayesian inference methods. The estimated probability of pathogen transmission between infected and susceptible plants is used to calculate the risk of invasion. By comparing the transmission probability and the risk values obtained for different planting densities, we are able to give evidence of a nonlinear relationship between disease invasion and the inter-plant spacing, hence to demonstrate the existence of a spatial threshold for epidemic invasion. The implications and potential use of our methods for the evaluation of disease control strategies are discussed.

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Real-Time Simulation of an Experimental Rig With Pressurized SOFC

Volume 4: Cycle Innovations; Fans and Blowers; Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Marine; Oil and Gas Applications ◽

10.1115/gt2011-45527 ◽

2011 ◽

Cited By ~ 1

Author(s):

Paolo Pezzini ◽

Francesco Caratozzolo ◽

Alberto Traverso

Keyword(s):

Experimental Data ◽

Real Time ◽

Control Strategies ◽

Simulation Models ◽

Electrical Current ◽

Cell System ◽

Time Model ◽

Transient Behaviour ◽

Set Up ◽

Time Required

The availability of reliable simulation models can reduce the time required for commissioning test rigs as well as preventing components from suffering serious damage during testing. The aim of this study is to set up and validate, against experimental data, a real-time model referring to the Rolls-Royce Fuel Cell System Limited (RRFCS) hybrid system concept, based on SOFCs. The dynamic model of the SOFC “block” has been developed, run in real-time, and successfully validated against experiments. Initially, the dynamic evolution of the model is considered under constant inputs at steady-state and is compared against experimental data; secondly, transient behaviour is also considered. Step variations of the main air flow, main fuel flow, syngas flow and electrical current were performed. The model can now be employed to carry out the following: performance analysis, design verification, development of control strategies, on-line analysis and integration with Human Machine Interface.

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The Modeling and Control Study of VSC-MTDC System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.516-517.1453 ◽

2012 ◽

Vol 516-517 ◽

pp. 1453-1458 ◽

Cited By ~ 1

Author(s):

Peng Ye ◽

Lin Yuan ◽

Duo Jiao Guan ◽

Xing Wei Xu ◽

Kai Yuan Hou

Keyword(s):

Reactive Power ◽

Control Strategies ◽

Local Mode ◽

Modeling And Control ◽

Voltage Controller ◽

Control Scheme ◽

Dc Voltage Control ◽

Set Up ◽

And Control ◽

The Mathematical Model

VSC-Multi-Terminal Direct Current(VSC-MTDC) system is much more controllable and economic. In this paper, the mathematical model for the VSC-MTDC system is set up. Base on this model, the multi-terminal constant DC voltage control scheme with an offset component was developed for MTDC system in the distribute network. Decoupling linear PI controllers are applied for the independent control of active and reactive power. Constant DC and AC voltage controller is implemented respectively for source side and loads side for the high quality power supply. Simulation results show that the control scheme is very effective. With the proposed control strategies, dynamic process of the system can be controlled effectively. What is more, the control law is not complex and it is in the local mode. All of these merits make the control strategy very practical.

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The release of macronutrients from second crop corn straw and their behaviour in a red-yellow latosol

Australian Journal of Crop Science ◽

10.21475/ajcs.19.13.11.p1863 ◽

2019 ◽

pp. 1833-1838

Author(s):

Edilson Cavalli ◽

Anderson Lange ◽

Cassiano Cavalli ◽

Mirelly Mioranza ◽

Onã da Silva Freddi ◽

...

Keyword(s):

Soil Profile ◽

Crop Residues ◽

Ground Cover ◽

Soil Characteristics ◽

Agricultural Systems ◽

Corn Straw ◽

Litter Bags ◽

Soil Function ◽

Rainy Period ◽

Set Up

Crop residues left on the soil function as a nutrient reservoir and as a ground cover in agricultural systems. The aim of the present study is to assess the chemical alterations in the soil after the decomposition of different amounts of straw from corn as second crop. The climate of the region is classified as hot tropical and the soil is categorized as Red-Yellow Latosol (Typic hapludox) in the cerrado-amazon ecotone. The experiment was set up in randomized blocks in September 2013 after harvesting the second crop corn, comprised of corn straw rates (0, 14.18 and 42.54 t ha-1) with six repetitions. The content of macronutrients, H+Al, pH and base saturation in the soil profile were assessed. The straw rates were added to litter bags and stored on the soil, where they were kept for 154 days throughout the rainy period. Subsequently, the soil characteristics were assessed in layers 0 to 0.05, 0.05 to 0.10, 0.10 to 0.15, 0.15 to 0.20 and 0.20 to 0.40 m. The Ca+2 and Mg+2 elements were only released by the straw on the first 0.05 m of soil. However, K circulated in the soil profile reaching depth of 0.40 m. There was reduction in K+ saturation in treatments without straw. No alterations were observed in the other nutrients and studied attributes. According to the results, it is important to distribute the cultural remains of maize homogeneously in the area during harvesting to avoid the appreciation of soil fertility spots, especially of K.

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