scholarly journals Avaliando o coeficiente de uniformidade de um sistema central de pivô / Evaluation of the coefficient of uniformity of a central pivot system

2021 ◽  
Vol 4 (2) ◽  
pp. 2385-2390
Author(s):  
Sergio Zamora Salgado ◽  
Félix Alfredo Beltrán Morales ◽  
José Guadalupe Loya Ramírez ◽  
Francisco Higinio Ruiz Espinoza
Keyword(s):  
Coefficient Of Uniformity

En las zonas áridas y semi-áridas del mundo, la producción agrícola depende de un riego eficiente, siendo el objetivo garantizar las mejores condiciones de utilización del agua y el óptimo aprovechamiento por parte de la planta. Cuando los sistemas de riego se utilizan para aplicar fertilizantes y pesticidas, la uniformidad de la aplicación se vuelve aún más crítica por lo que es importante que los propietarios y operadores de los sistemas de riego, en nuestro caso, pivote central, comprueben periódicamente la uniformidad de sus sistemas. La uniformidad de riego depende del grado de qué agua se aplica de manera uniforme en diferentes áreas del campo. Para su determinación se pueden utilizar varios métodos/fórmulas. Para un sistema de riego por pivote central, el método más habitual es el de Heerman y Hein que se basa en la norma UNE-EN ISO 1154. En la evaluación el valor obtenido fue de 82.43%, que está en el rango que permite considerarlo como razonable, pero que requiere ser monitoreado constantemente.

Design and development of manually operated gladiolus planter

2018 ◽  
Vol 5 (01) ◽  
Author(s):  
TAPAN K. KHURA ◽  
H. L. KUSHWAHA ◽  
SATISH D LANDE ◽  
PKSAHOO . ◽  
INDRA L . KUSHWAHA
Keyword(s):  
Coefficient Of Variation ◽  
Field Capacity ◽  
Power Source ◽  
Forward Speed ◽  
Cereal Crop ◽  
Maximum Coefficient ◽  
Coefficient Of Uniformity ◽  
The Mean ◽  
The Cost ◽  
Immense Potential

Floriculture is an age-old farming activity in India having immense potential for generating selfemployment and income to farmers. However, the cost of cultivation of flower is high as compared to cereal crop. Level of mechanization for different field operations is one but foremost reason for the higher cost of cultivation. As most of the Indian farmers are marginal and small, a need for manually operated gladiolus planter was felt. The geometric properties of gladiolus corm were determined for designing the seed metering system and seed hopper of the planter. The planter was evaluated in the field when pulled by two persons as a power source and guided by a person. The coefficient of variation and highest deviation from the mean spacing was observed as 12.93% and 2.65cm respectively. The maximum coefficient of uniformity of 90.59% was observed for a nominal corm spacing of 15cm at 0.56 kmh-1 forward speed. An average MISS percentage was observed as 2.65 and 2.25 for nominal corm spacing of 15 and 20 cm. The multiple index was zero for two levels corm spacing and forward speed of operation. The QFI was found in the range of 97.2 and 97.9 percent. The average field capacity of the planter was observed as 0.02 hah-1.The average draft requirement of the planter was found as 821 ± 50.3 N.

scholarly journals Spatial features of settlement network within physical­geographical regions of the Prut upper basin

2014 ◽  
pp. 254-260
Author(s):  
Volodymyr Krool’ ◽  
Olexandr Hadel’shyn
Keyword(s):  
Key Words ◽  
Geographical Area ◽  
Settlement Density ◽  
Spatial Features ◽  
Coefficient Of Uniformity

The territorial characteristics of settlement network per quantitative and settlement indicators within 35 physical and geographical areas of the upper basin of the Prut were analyzed: the number of settlements, settlement density and coefficient of uniformity of placing settlements. The regions of the insufficient development of the network of settlements and areas with their excessive were allocated. Key words: settlement network, physical, geographical area, settlement, settlement density.

scholarly journals PERFORMANCE EVALUATION OF HYDRAULIC PARAMETERS OF A DEVELOPED DRIP IRRIGATION SYSTEM

2019 ◽  
Vol 31 (2) ◽  
Author(s):  
Olorunwa Eric Omofunmi ◽  
Oluwaseun Ayodele Ilesanmi ◽  
Toluwalase Orisabinone
Keyword(s):  
Drip Irrigation ◽  
Irrigation System ◽  
Chemical Properties ◽  
Application Rate ◽  
Drip Irrigation System ◽  
Flow Variation ◽  
Agricultural Engineering ◽  
Normal Soil ◽  
Coefficient Of Uniformity ◽  
American Society

Experiment was carried out in the department of Agricultural and Bioresources Engineering, during the period of August to October, 2017. The hydraulic performance of a developed drip irrigation system was assessed. The experimental work was conducted on field with irrigated field area of 7 m x 3 m and lateral spacing was 0.35 m. Sixty (60) hospital drip sets (given sets) were used for the experiment as improved emitters. Volumetric method was used to determine application rate (PR) and emitters discharge. The emission uniformity, emitter flow variation, co-efficient of uniformity and co-efficient of variation were determined accordance with the equations described by the American Society of Agricultural Engineering (ASAE). Soil chemical properties were determined accordance with the American Public Health Association (APHA). The findings revealed that the soil in the area is classified as sand clay loam and normal soil. Results indicated that the mean and standard deviation of the emitters were 9.639 L/hr and 0.07 L/hr respectively. There were no emitters clogging. The emitter flow variation was 2.5 % and less than 10 % which was desirable range, while coefficient of variation was 0.07 and less than 0.11 which was marginal. The application rate was 17 mm hr-1 which was within the recommended range of 15 – 25 mm hr-1. The emission uniformity and coefficient of uniformity were 99.4% and 99.2% respectively, which shows that the system was well-designed. This finding indicated that hospital drip sets proved to the high quality. Therefore, it can be used as standard emitter.

scholarly journals Enhancing the Flexural Strength of Concrete using Recycled Iron and Steel Slag Aggregate

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
A. A Raheem
Keyword(s):  
Tensile Strength ◽  
Flexural Strength ◽  
Concrete Beams ◽  
Steel Slag ◽  
Aggregate Size ◽  
Mineralogical Composition ◽  
Maximum Aggregate Size ◽  
Considerable Effort ◽  
Iron And Steel ◽  
Coefficient Of Uniformity

Concrete is strong in compression but weak in tension hence, considerable effort is required to improve concrete’s tensile strength by the use of pre-stressed concrete and addition of admixtures or additives. In this study, the use of recycled iron and steel slag (RISS) aggregate to improve the tensile strength of concrete was considered. The paper assessed the mineralogical composition of RISS and granite aggregates, and gradation. It also determines the effects of RISS aggregate on the flexural strength of concrete beams of 150 × 150 × 600 mm containing 0, 10, 20, 40 and 60% RISS aggregate replacement in mix ratios 1:1½:3, 1:2:4 and 1:3:6 with water cement ratios 0.65,0.60 and 0.55 respectively. Diffractograph of RISS and granite aggregate showed that RISS contains Magnetite, Ilmenite and Quartz, while granite contains Quartz, Annite, Microcline and Albite as the predominant minerals. The coefficient of uniformity and concavity of RISS and granite aggregate for maximum aggregate size of 37.5 mm are 4.35 and 1.33; and 4.64 and 1.76 respectively. Both aggregates contain quartz as the predominant mineral and are well graded. The result of the Flexural strength at 28 days curing is within 0.135 – 0.250 MPa specified byBS8500 – 2:2015. Flexural strength of concrete beams cast with RISS aggregate is relatively higher than concrete cast with granite aggregate. Flexural strength, a measure of tensile strength of concrete is improved as percentage RISS aggregate increased.

scholarly journals Analytic Representation of the Optimal Flow for Gravity Irrigation

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2710 ◽  
Author(s):  
Carlos Fuentes ◽  
Carlos Chávez
Keyword(s):  
Linear Relationship ◽  
Analytic Representation ◽  
Hydrodynamic Characteristics ◽  
One Dimensional ◽  
Coupled Equations ◽  
Irrigation Flow ◽  
Coefficient Of Uniformity ◽  
Relationship Of ◽  
Strip Length ◽  
Infiltration Parameters

The aim of this study is the deduction of an analytic representation of the optimal irrigation flow depending on the border length, hydrodynamic properties, and soil moisture constants, with high values of the coefficient of uniformity. In order not to be limited to the simplified models, the linear relationship of the numerical simulation with the hydrodynamic model, formed by the coupled equations of Barré de Saint-Venant and Richards, was established. Sample records for 10 soil types of contrasting texture were used and were applied to three water depths. On the other hand, the analytical representation of the linear relationship using the Parlange theory of infiltration proposed for integrating the differential equation of one-dimensional vertical infiltration was established. The obtained formula for calculating the optimal unitary discharge is a function of the border strip length, the net depth, the characteristic infiltration parameters (capillary forces, sorptivity, and gravitational forces), the saturated hydraulic conductivity, and a shape parameter of the hydrodynamic characteristics. The good accordance between the numerical and analytical results allows us to recommend the formula for the design of gravity irrigation.

scholarly journals Evaluation of the coefficient of uniformity and non-uniformity of irrigation for wide-range irrigators in various field conditions

2018 ◽  
Vol 64 (No. 2) ◽  
pp. 55-62
Author(s):  
Jobbágy Ján ◽  
Krištof Koloman
Keyword(s):  
Linear Model ◽  
Evaluation Methods ◽  
Field Conditions ◽  
Work Quality ◽  
Specific Field ◽  
Irrigation Uniformity ◽  
Wide Range ◽  
Coefficient Of Uniformity ◽  
Input Variables

The aim of this paper is to address an issue of work quality of irrigation machines with eight parameters that were selected and defined as input variables. The objective of the study was to determine possibilities of different evaluation methods for a wide range of irrigation machines and their versatility. All input conditions that could affect the results were recorded and analysed. The results were statistically analysed by a linear model (ANOVA). The results confirm that there are no statistically significant differences in used evaluation methods (p > 0.05) when the effect of locality was not considered. When the effect of locality was considered, statistically significant differences were observed (p < 0.05). When considering the coefficient of non-uniformity, statistically significant differences were not observed, however in case of considering different irrigation machines, statistically significant differences were observed. The obtained results indicate that the evaluation of irrigation uniformity is possible to carry out with other methods; however, the specific field conditions are not interchangeable as a parameter.  

Effect of Combination Factors of Operating Pressure, Nozzle Diameter and Riser Height on Sprinkler Irrigation Uniformity

2014 ◽  
Vol 695 ◽  
pp. 380-383 ◽  
Author(s):  
Manal Osman ◽  
Suhaimi B. Hassan ◽  
Khamaruzaman B. Wan Yusof
Keyword(s):  
Irrigation System ◽  
Sprinkler Irrigation ◽  
Nozzle Diameter ◽  
Operating Pressure ◽  
Irrigation Uniformity ◽  
Distribution Uniformity ◽  
Coefficient Of Uniformity ◽  
Riser Height ◽  
Design Factors ◽  
Pressure Nozzle

The irrigation uniformity of sprinkler irrigation system depends on many design factors such as nozzle type, nozzle diameter, operating pressure and riser height. An experimental study was performed to investigate the effect of combination factors of operating pressure, nozzle diameter and riser height on sprinkler irrigation uniformity. Different operating pressures, nozzle diameters and riser heights have been used. The irrigation uniformity coefficients such as coefficient of uniformity (CU) and distribution uniformity of low quarter (DUlq) have been studied. This study concluded that, the irrigation uniformity of sprinkler irrigation system was more affected by the combination of operating pressure, nozzle diameter and riser height.

Dissipation Pattern of Excess Pore Pressure After Liquefaction in Saturated Sand Deposits

2003 ◽  
Vol 1821 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Ik Soo Ha ◽  
Young Ho Park ◽  
Myoung Mo Kim
Keyword(s):  
Grain Size ◽  
Pore Pressure ◽  
Dynamic Loading ◽  
Time History ◽  
Excess Pore Pressure ◽  
Pore Pressures ◽  
Dissipation Pattern ◽  
Effective Grain Size ◽  
Coefficient Of Uniformity ◽  
Excess Pore

In liquefied areas, the amount of damage to a structure is mainly affected by the postliquefaction behavior of the liquefied ground. Understanding postliquefaction behavior requires understanding the dissipation pattern of excess pore pressure after liquefaction. It is difficult to measure pore pressures generated and dissipated during an earthquake because of the more-or-less randomness of earthquake events. Researchers have artificially generated liquefaction with sand samples in the laboratory and have simulated curves for the time history dissipation of excess pore pressure. To estimate variation in permeability during dynamic loading, which should be known for settlement predictions of the ground undergoing liquefaction, 1-g shaking table tests were carried out on five kinds of sands, all with high liquefaction potentials. During tests, excess pore pressures at various depths and surface settlements were measured. The measured curve of the excess pore pressure dissipation was simulated using the solidification theory. From analysis of the velocity of dissipation, the dissipation pattern of excess pore pressure after liquefaction was examined. Permeability during dissipation was calculated using the measured settlement and dissipation velocity, also used for estimating permeability during dynamic loading. The dissipation velocity of excess pore pressure after liquefaction had a linear correlation with the effective grain size divided by the coefficient of uniformity. The increase in the ground’s initial relative density played a role in shifting this correlation curve toward increased dissipation velocity. Permeability during liquefaction increased 1.4 to 5 times compared with the permeability of the original ground, the increase becoming greater as the effective grain size of the test sand increased and the coefficient of uniformity decreased.

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