3,798 research outputs found
Environmentally friendly technologies to maintain stored paddy rice quality
Exports of processed rice have been increasing every year, as well as legislative restrictions and consumer demand for certified chemical free rice, pressing the rice processing industry to new challenges. The objective of this work was the implementation of a Rice Quality Certification Program. The package includes the association of a rigorous sanitation program and safe environmentally friendly control measures. It was accomplished in a large paddy rice facility with 40 silos during the 2008/09 rice crop. Silo sanitation was done by washing with pressurized water the conveyor belt structure above the silo roof, around the externals walls and thorough aspiration of the aeration system. During silo filling, the lower and top portions of the rice grain were treated with a mixture of diatomaceous earth (DE) and powder deltamethrin. Artificial chilling was applied as soon as the top layer of the grain mass was leveled by insufflating cool air (6 to 8ºC) with a large cooling machine through the aeration system. The grain mass temperature stabilized at about 12-14ºC, and kept this range of temperature for about 60 d. As the temperature of the grain mass increased, mainly on the top layer, aeration was performed with natural air from the cold fronts during the winter months. After 8 months on storage the rice was free of external insects, as proved by the grain sampling just before processing. For the 2009/10 crop season, the rice quality program will be repeated on 60 silos with few adjustments.Keywords: Chilled aeration, Inert dust, Physical insect control, Rice quality maintenance
Potential Response of Soil-Borne Fungal Pathogens Affecting Crops to a Scenario of Climate Change in Europe
A study was carried out on the potential response of soil-borne pathogens causing crop yield losses under a climate change scenario in Europe. A controlled chamber set of experiments was carried out to quantify pathogen response to temperature using pure colonies of three soil-borne fungi, representative of low (Fusarium nivale), medium-high (Athelia rolfsii) and high (Macrophomina phaseolina) temperature requirements. A generic model to simulate fungal growth response to temperature based on these experiments was developed and linked to a soil temperature model component, and to components to simulate soil water content accounting for crop water uptake of potential hosts. Pathogens relative growth was simulated over Europe using the IPCC A1B emission scenario as realization of the Hadley-CM3 global climate model, available from the European Commission and processed for use with biophysical models. The simulations resulting from using the time span centred on 2030 were compared to the baseline, centred on the year 2000, using a sample of 30 years of daily weather. The general trend of soil-borne pathogens response to the scenario of climate change is a relative increase in growth in colder areas of Europe, as a function of their temperature requirements. Projections of F. nivale in the future indicate a relative increase of this winter pathogen of wheat in Northern European countries. A. rolfsii and M. phaseolina, two soil-borne pathogens typical of warmer agricultural areas, could find more favourable conditions in areas of the Central Europe, but they differentiated in Southern Europe where A. rolfsii resulted affected by summer soil temperatures above optimum
Spatial distribution of stored grain insects in a rice storage and processing facility in Brazil
This study describes the spatial distribution of stored product insects captured biweekly using foodbaited cage traps in a large rice storage and processing facility, in the state of Rio Grande do Sul, Brazil. Monitoring started in August 2009 and will be carried out for 1 year, the first 5 months of sampling being presented in this study. From end of August 2009 until the end of December 2009, a total of 9893 insects were captured in the 99 cage traps. The most abundant species were: Carpophilus spp. (76%), Typhaea stercorea (8.6%), Ahasverus advena (5.5%), Tribolium castaneum (2.3%), Sitophilus oryzae (2%), Sitophilus zeamais (1.5%), Ephestia spp. (1.2 %), Cryptolestes ferrugineus (1%), Rhyzopertha dominica (0.64%), Oryzaephilus surinamensis (0.6%), Anthicus floralis (0.4%), Lasioderma serricorne (0.25%). The first two species, which make up for 84.6% of the insects collected, are not considered pests in stored grain, rather are attracted by moldy material present in residues or even in the bait material. The other insects, including primary and secondary species, comprised about 15% of the total trapped. The spatial distribution of the most important species infesting rice grain and of the total insect number was analyzed using Surfer 6.04 (Golden software, Golden, CO, USA) and contour maps were constructed to target areas for sanitation. Except for trap 66, located by the rice hulk storage box, the spatial distribution we observed using the contour maps showed that the greatest number of insects was mostly captured in cages placed in the receiving area, around the dryers, as well as outside of the structure where grain residues frequently accumulate. As indicated on the maps for total number of insects, a few isolated infested spots were detected. The parboiled rice area had the least amount of insects, except for trap 61, placed outside the structure. The population of primary and the most important secondary insect species, as well as the overall number of insects, decreased after sanitation and physical control measures were applied. Our observations confirm that insect monitoring is an essential tool for targeting and evaluating the control measures adopted in the quality program of rice storage and processing facilities. Keywords: Insect monitoring; Spatial distribution; Stored grain pests; Stored ric
Stability of a buoyant Oldroyd-B flow saturating a vertical porous layer with open boundaries
The performance of several engineering applications are strictly connected to the rheology of the working fluids and the Oldroyd-B model is widely employed to describe a linear viscoelastic behaviour. In the present paper, a buoyant Oldroyd-B flow in a vertical porous layer with permeable and isothermal boundaries is investigated. Seepage flow is modelled through an extended version of Darcy’s law which accounts for the Oldroyd-B rheology. The basic stationary flow is parallel to the vertical axis and describes a single-cell pattern where the cell has an infinite height. A linear stability analysis of such a basic flow is carried out to determine the onset conditions for a multicellular pattern. This analysis is performed numerically by employing the shooting method. The neutral stability curves and the values of the critical Rayleigh number are evaluated for different retardation time and relaxation time characteristics of the fluid. The study highlights the extent to which the viscoelasticity has a destabilising effect on the buoyant flow. For the limiting case of a Newtonian fluid, the known results available in the literature are recovered, namely a critical value of the Darcy–Rayleigh number equal to 197.081 and a corresponding critical wavenumber of 1.05950
Chilled aeration to control pests and maintain grain quality during the summer storage of wheat in north central region of Kansas: Presentation
Chilled aeration allows to cool grain, independent of ambient conditions, to "safe" temperatures where insect, fungi, and spoilage is reduced to the minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses, compared to conventional aeration and storage strategies used during the summer storage of wheat in Central Kansas, U.S.A. The research trials were developed in two 1,350 metric ton (t) steel silos in a Farmer’s Cooperative during the summer and fall of 2015 and 2016. One of the silos was chilled and the other was used as a control managed by the Cooperative. Variables evaluated were: grain temperature, moisture content (MC), grain quality, insect development and reproduction rate. The chilling treatment reduced the grain temperature from 28°C- 39°C to a minimum of 17°C- 17.6°C in less than 250 hours. Grain temperatures below 25°C were not possible during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the MC by 0.5%. Reproduction rates of RFB and LGB were significantly reduced by chilled temperatures lower than 17°C. Lower temperatures also reduced insects discovered in probe traps and insect damaged kernels (IDK). The energy cost of the grain chiller was between 0.26 US /t higher than ambient aeration.Chilled aeration allows to cool grain, independent of ambient conditions, to "safe" temperatures where insect, fungi, and spoilage is reduced to the minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses, compared to conventional aeration and storage strategies used during the summer storage of wheat in Central Kansas, U.S.A. The research trials were developed in two 1,350 metric ton (t) steel silos in a Farmer’s Cooperative during the summer and fall of 2015 and 2016. One of the silos was chilled and the other was used as a control managed by the Cooperative. Variables evaluated were: grain temperature, moisture content (MC), grain quality, insect development and reproduction rate. The chilling treatment reduced the grain temperature from 28°C- 39°C to a minimum of 17°C- 17.6°C in less than 250 hours. Grain temperatures below 25°C were not possible during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the MC by 0.5%. Reproduction rates of RFB and LGB were significantly reduced by chilled temperatures lower than 17°C. Lower temperatures also reduced insects discovered in probe traps and insect damaged kernels (IDK). The energy cost of the grain chiller was between 0.26 US /t higher than ambient aeration
Le Archeidi di Giulio Turcato problematiche conservative e proposte di intervento
Le Archeidi, gruppo scultoreo composto da cinque elementi realizzati con laminati di ferro a struttura tubolare assemblati artigianalmente, sono alte circa quattro metri e il loro ingombro varia tra gli ottanta e i novanta centimetri. Vennero realizzate da Giulio Turcato nel 1989 per la citt\ue0 di Salerno, in occasione della prima edizione di \u201cSalerno Incontri d\u2019Arte\u201d, parallelamente alla mostra \u201cGiulio Turcato per/Corso\u201d, tenutasi in tre gallerie della citt\ue0 \u201cLa Bottegaccia\u201d, \u201cIl Catalogo\u201d e \u201cLa Seggiola\u201d. Il gruppo scultoreo era composto da quattro elementi che erano stati scherzosamente definiti dal maestro \u201caculei\u201d e da un quinto che ricordava le sembianze di un \u201cfiore\u201d. Purtroppo, appena le opere vennero collocate lungo il percorso cittadino, una sub\uec un atto vandalico mentre un\u2019altra venne trafugata. Le cinque sculture furono realizzate, seguendo il progetto dell\u2019artista, nella bottega di un fabbro salernitano e successivamente trattate cromaticamente. Le ragioni principali del degrado delle Archeidi sono legate alla collocazione in ambiente esterno e al fatto che l\u2019aspettativa di vita dei materiali utilizzati non garantisce la durabilit\ue0 del gruppo scultoreo. Quattro strutture, di propriet\ue0 del Comune di Salerno, si presentano oggi in un precario stato di conservazione, aggravato dall\u2019umidit\ue0 dello spazio dove sono conservate. Ad un\u2019osservazione preliminare si riscontra un viraggio completo dei colori e la presenza diffusa di ruggine. Le opere, dopo un accurato intervento di restauro, attendono di trovare una nuova collocazione che risponda alle necessit\ue0 di una buona conservazione e al tempo stesso alla natura di \u201copera ambientale\u201d cos\uec come ideata dall\u2019artista
Intra and interspecific variation assessment in Psocoptera using near spectoscopy
Several species of Psocoptera are associated with and damage grains and other stored products, books, historical documents, and insect collections. Their small size and lack of expressive morphological variation make it a difficult group for species identification. The spectra of adult males and females of 10 psocid species from the genus Liposcelis were obtained by near infrared spectroscopy (NIRS) and analyzed. Each specimen was placed on a diffuse reflectance accessory of a NIR spectrometer to obtain the respective spectrum, using ten replicates for each species or sex. All spectra were analyzed by combined methods of multivariate analysis using the technique of crossed validation for the multivariate models. The analysis discriminated the species without significant overlapping among the species spectral patterns. The NIRS also revealed variation in the metabolomic profile of males and females; however, it is still possible to distinguish the species using only males or females or even from mixed sex samples. NIRS technique proved to be a powerful tool to discriminate species both at intra and interspecific levels based on dispersion spectral patterns of individual specimens. Keywords: Biological systems, Liposcelididae, stored product pests, Vibrational spectroscopy
Molecular Perception for Visualization and Computation: The Proxima Library
Proxima is a molecular perception library designed with a double purpose: To be used with immersive molecular viewers (thus providing any required feature not supported by third party libraries) and to be integrated in workflow managers thus providing the functionalities needed for the first steps of molecular modeling studies. It thus stands at the boundary between visualization and computation. The purpose of the present article is to provide a general introduction to the first release of Proxima, describe its most significant features, and highlight its performance by means of some case studies. The current version of Proxima is available for evaluation purposes at https://bitbucket.org/sns-smartlab/proxima/src/master/
- …