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| Registros recuperados: 1.561 | |
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| Amirouche, mawhoub. |
| The search for decision-making tools is essential in order to control agricultural practices and plan for sustainable agriculture that respects the environment. To this end, FAO has developed an evaluation model called AquaCrop, which covers most technical routes, including fertilization. In this perspective, this study focuses on the AquaCrop model (v6.1) to calibrate it for the simulation of lettuce crop yields (Lactuca sativa L), under different fertilization levels for the trial periods (2015/2016) and (2016/2017). Four levels of fertilization were examined under rain conditions, namely T1 (0 kg N/ha), T2 (60 kg N/ha), T3 (120 kg N/ha) and T4 (180 kg N/ha). The model performance was evaluated using the coefficient of determination (R2), the square root... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: AquaCrop; Lettuce; Calibration; Validation; Fertility stress; Water productivity. |
| Ano: 2021 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/6195 |
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| Kreutz Rosa, Stefanie Lais; Moretti de Souza, Jorge Luiz; de Oliveira , Cibelle Tamiris; Yoiti Tsukahara, Rodrigo. |
| The Campos Gerais region, located in the Subtropical Zone in Southern Brazil, stands out for presenting agricultural yields above the national average, especially for soybean. This study aimed to calibrate and validate the AquaCrop model for soybean crop in the edaphoclimatic conditions of Campos Gerais region. The data used were from the experimental stations of ABC Foundation in Arapoti, Castro and Ponta Grossa, Parana State, and Itaberá, São Paulo State. The input data (climate, crop, soil and soil management) from the 2006/07 to 2015/16 harvests were collected at the respective experimental stations and entered in the AquaCrop model for yield simulations. The data for model calibration were different from those used in the validation. The observed and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2023 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/8245 |
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| Mehari Zewde Tekeste; Deere&Co; Desale H Habtzghi; Department of Statistics, The University of Akron, Akron, OH; Jos Koolen; Wagenigen University. |
| Modeling of soil elastic and permanent plastic volumetric strains (compaction) caused by loading from machinery vehicles using the modified Cam-clay soil constitutive model requires understanding the behaviors of compression and rebound parameters under unsaturated soil conditions. Oedometer tests were conducted on a sandy loam, a loam, and a clay loam soil, all tropical soils, at three initial soil moisture contents and five maximum stress levels (50, 100, 200, 300 and 400 kPa). The objectives were to investigate the effects of soil moisture content and maximum applied stress on the modified compression index (l*) and modified rebound index (k*) parameters of a modified Cam-clay soil model on the three soils and predict the compressibility indices using... |
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Palavras-chave: Modified compression index (l*); Modified rebound index (k*); Axial stress; Uniaxial compression cyclic test; Soil moisture; Soil types. |
| Ano: 2013 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2214 |
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| S. Pedersen; V. Blanes-Vidal; H. Joergensen; A. Chwalibog; A. Haeussermann; M. J. W. Heetkamp; A.J.A. Aarnink. |
| This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers.Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20 oC) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient... |
| Ano: 1969 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/1205 |
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| Samer, Mohamed. |
| To perform the calculations required for sizing anaerobic digesters and computing energy production and biogas and methane yields, various procedures should be conducted; this requires time and efforts, with the risk of making mistakes. The objective of this study was to create a tool to aid users and specialists in managing these computations by offering an application which can be installed on cell phones. A mathematical model was developed to perform the calculations. Then, a flowchart was created, and the mathematical model was incorporated into the flowchart. Then, MIT App Inventor was used to configure an application software by combining the flowchart and the mathematical model and making the user interface. Data were acquired from governmental... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2023 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/8263 |
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| Obayopo, Surajudeen Olanrewaju; Oluwasanmi, Alonge. |
| Fish preservation is the most important post-harvest process in commercial fishery. The traditional methods of fish preservation are inefficient and susceptible to contamination. Few existing solar fish dryers are not designed for optimal drying performance. In this study, a direct solar dryer for fish was numerically modelled, fabricated and evaluated for performance enhancement. The modeling was performed using computational fluid dynamics (CFD) code to simulate different dimensions of the designed dryer at varying fan speeds. By applying desirability function method, (70 × 60 × 40) cm3 drying chamber with a plane of 25 cm away from the base for tray location gives optimal temperature and the best uniform air flow distribution. The performance of the... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2019 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/5051 |
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| Kic, Pavel. |
| This paper is focused on the Computational fluid dynamics (CFD) modeling of regenerative heat exchanger suitable for animal houses. Buildings used for housing of animals in farms with intensive breeding, like poultry or pig houses, are characterized by high generation of heat inside, partly produced by animals, and in the case of small young animals, supplemented also by heating. On the other side these buildings need intensive ventilation which causes big losses of energy by exhausted air. A good way how to reduce heat losses can be the use of technical systems of heat recovery. There are two principal constructions of heat exchangers for heat recovery. There are either recuperative or regenerative heat exchangers. Industrially produced heat exchangers,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Animal houses; Ventilation; Energy; Parameters; Czech Republic. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3137 |
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| Pavel Kic. |
| This paper is focused on the Computational fluid dynamics (CFD) modeling of regenerative heat exchanger suitable for animal houses. Buildings used for housing of animals in farms with intensive breeding, like poultry or pig houses, are characterized by high generation of heat inside, partly produced by animals, and in the case of small young animals, supplemented also by heating. On the other side these buildings need intensive ventilation which causes big losses of energy by exhausted air. A good way how to reduce heat losses can be the use of technical systems of heat recovery. There are two principal constructions of heat exchangers for heat recovery. There are either recuperative or regenerative heat exchangers. Industrially produced heat exchangers,... |
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Palavras-chave: Animal houses; Ventilation; Energy; Parameters; Czech Republic. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3137 |
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| Kyu-Hyun Park; Ngwa Martin Ngwabie; University of Guelph; Claudia Wagner-Riddle. |
| Composting has the potential to mitigate methane (CH4) and nitrous oxide (N2O) emissions from manure. The heterogeneous nature of emitting surfaces makes it difficult to quantify these emissions. CH4 and N2O fluxes measured using eight small chambers (0.72 m2) and a mega chamber (90 m2) were compared, and the effect of aeration on the fluxes during composting was studied. Two batches of compost were placed in three channels and 2-3 small flux chambers were deployed on each channel. The channels were enclosed by a building serving as a mega chamber. Chamber location significantly affected gas fluxes, pointing to strong spatial heterogeneity. Mean CH4 fluxes from the small chambers were similar or... |
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Palavras-chave: Chamber; Compost; Greenhouse gases; Aeration; Flux. |
| Ano: 2014 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2467 |
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| Park, Kyu-Hyun; Ngwabie, Ngwa Martin; Wagner-Riddle, Claudia. |
| Composting has the potential to mitigate methane (CH4) and nitrous oxide (N2O) emissions from manure. The heterogeneous nature of emitting surfaces makes it difficult to quantify these emissions. CH4 and N2O fluxes measured using eight small chambers (0.72 m2) and a mega chamber (90 m2) were compared, and the effect of aeration on the fluxes during composting was studied. Two batches of compost were placed in three channels and 2-3 small flux chambers were deployed on each channel. The channels were enclosed by a building serving as a mega chamber. Chamber location significantly affected gas fluxes, pointing to strong spatial heterogeneity. Mean CH4 fluxes from the small chambers were similar or 1.4 times higher compared to the mega chamber. Mean... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chamber; Compost; Greenhouse gases; Aeration; Flux. |
| Ano: 2014 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2467 |
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| Swarnakar, Dr. Ajay Kumar; Gurdeep Kumar; Das, Susanta Kumar. |
| Puffed rice is a popular product in Southeast Asia due to its Ready-to-Eat nature and sensorial qualities. Preconditioned polished rice is heated in hot sand to produce puffed rice. Bran layer of rice resists the expansion during the puffing. This study is carried out to improve quality and analyze the acceptability of puffed brown rice in hot sand. In this study, puffed rice was produced from parboiled brown rice (unpolished rice) with sand heating method at different preconditioning levels by varying salt levels (0-6% (w/w)). Quality parameters hardness and expansion are determined by texture analyser and method mentioned in previous literature, respectively. The fuzzy logic technique is used for analysis of sensory parameters such as taste, texture, and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2023 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/8761 |
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| S. Pedersen; P. Ravn. |
| In respect to improving animal welfare and to minimize the ammonia emission from animal facili-ties, it is important to have appropriate information on the impact of the flooring system in pig pens. Twelve different floors, six commercially available and six experimental floors for pig pens, were investigated in respect to four different characteristics: friction coefficients, shock absorption, am-monia emission and heat conduction. The friction coefficients were measured as dynamic friction for dry floors and floors wetted with water and rapeseed oil and as static friction for dry floors. The floor elasticity was measured as shock absorption when letting a weight fall on the test floors. The ammonia emission was measured in a wind tunnel with ammonia... |
| Ano: 1969 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/1202 |
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| Nkem, Owoidoho; Olayemi Ayobami , Oladejo; Folarin Alonge, Akindele. |
| Convective hot air drying of cocoyam slices was investigated at different drying temperature (40 to 90) and slice thickness (2, 4, 6 mm) at an air velocity of. The effect of drying temperature and slice thickness on the drying characteristics and drying time were determined to study the effects of heat on processed cocoyam. Mathematical modeling of the thin layer drying process was performed using eight thin layer drying models. The models were tested for validity using coefficient of determination (), chi square () and root mean square error (RMSE). The effect of the drying temperature on the colour of dried cocoyam was also investigated. The colour was measured using CIE L* a* b* method. The results showed that, increasing the drying air temperature and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2023 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/8709 |
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| Registros recuperados: 1.561 | |
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