ISSN e: 2007-4026 / ISSN print:2007-3925

       

 
 
 
 
 
 
 
 

    Volume Vol. 9, issue 2, Issue 2 July - December 2017   Creative Commons License

      
 

     Vol. 9, issue 2 July - December 2017  

   Creative Commons License

 
  
 
 
  • Calculation of the volumetric capacity in Humaya main channel dikes using an acoustic Doppler current profiler

  • Cálculo de la capacidad volumétrica en diques del canal principal Humaya usando un perfilador de efecto Doppler

Alberto González-Sánchez; Ernesto Olvera-Aranzolo

bathymetry, sediment, real-time kinematic satellite navigation, conservation.

10.5154/r.inagbi.2017.05.010

Received: 2017-05-16
Accepted: 2017-10-10
Available online: 2017-12-22
Pages:51-62

Introduction: The capacities of the Humaya main channel (HMC) dikes were determined in 1966 and currently, because they are receptors of rough waters, they present varying degrees of sediment accumulation. This situation has caused a decrease in their initial capacity, so there is a need to update the bathymetry of the dikes.
Objectives: Determine the bathymetry of the HMC dikes using an acoustic Doppler current profiler to estimate the volumetric capacity, the flooded area and the maximum depth of each dike.
Materials and methods: A total of 11 dikes were studied, in which the experimental phase consisted of two stages. First, the coordinates of the water mirror of each dike were collected. Subsequently, the information was introduced into a modeling software by interpolation for the construction of three-dimensional models, which allow estimating the volume and contour lines of the dikes.
Results and discussion: Dikes 1 and 2 increased their capacity due to recent maintenance and enlargement work. On the other hand, Batamote, Agua fría, Hilda, Mariquita and Cacachila showed a loss of volumetric capacity (of 16.87 % on average), most likely due to the sediment problem. Conclusions: The acoustic Doppler current profiler is an extremely useful tool to obtain information about dike depth. However, its use was limited by the presence of aquatic weeds and excessive sediment accumulation. Therefore, only seven dikes could be sounded correctly. It is essential to carry out an effective sediment control program in the most affected dikes.

Introduction: The capacities of the Humaya main channel (HMC) dikes were determined in 1966 and currently, because they are receptors of rough waters, they present varying degrees of sediment accumulation. This situation has caused a decrease in their initial capacity, so there is a need to update the bathymetry of the dikes.
Objectives: Determine the bathymetry of the HMC dikes using an acoustic Doppler current profiler to estimate the volumetric capacity, the flooded area and the maximum depth of each dike.
Materials and methods: A total of 11 dikes were studied, in which the experimental phase consisted of two stages. First, the coordinates of the water mirror of each dike were collected. Subsequently, the information was introduced into a modeling software by interpolation for the construction of three-dimensional models, which allow estimating the volume and contour lines of the dikes.
Results and discussion: Dikes 1 and 2 increased their capacity due to recent maintenance and enlargement work. On the other hand, Batamote, Agua fría, Hilda, Mariquita and Cacachila showed a loss of volumetric capacity (of 16.87 % on average), most likely due to the sediment problem. Conclusions: The acoustic Doppler current profiler is an extremely useful tool to obtain information about dike depth. However, its use was limited by the presence of aquatic weeds and excessive sediment accumulation. Therefore, only seven dikes could be sounded correctly. It is essential to carry out an effective sediment control program in the most affected dikes.

 
 
  • Influence of locust bean and xanthan gums on the stability and acceptability of dairy cream

  • Influencia de gomas de algarrobo y xantana en la estabilidad y aceptabilidad de crema láctea

optimization, consistency, viscosity, mixture design, JAR scale.

10.5154/r.inagbi.2017.04.008

Received: 2017-03-26
Accepted: 2017-11-21
Available online: 2017-12-22
Pages:63-84

Introduction: In making a cream, various additives can be added, among which gums, which have been the subject of interest due to their advantages in industrial production, stand out.
Objective: To evaluate the effect of xanthan and locust bean gums on the physical and sensory properties of acidified dairy creams.Materials and methods: The factors studied were: concentration (xanthan gum from 0.025 to 0.5 % and locust bean gum from 0.05 to 0.5 %) and acidity percentage (from 0.5 to 0.65 % in both gums). A mixture design was applied with the concentrations of the two gums studied. The variables viscosity, drainage stability, consistency and adhesiveness were measured instrumentally, while sensorially the consistency, viscosity and acidity were evaluated with a JAR (Just About Right) test using five-point scales, and on the acceptability for attributes and overall acceptability a nine-point hedonic scale was used.
Results and discussion: The creams with the greatest acceptability corresponded to concentrations of 0.2 to 0.38 % xanthan gum and 0.46 to 0.5 % locust bean gum. The JAR test showed that the best mixture was the one containing 0.325 and 0.175 % xanthan and locust bean gums, respectively; this last treatment was compared with three commercial creams and one of them presented viscosity and consistency values (10 kg∙m-1∙s-1 and 4,000 gf, respectively) similar to those of the mixture obtained.
Conclusions: It is possible to assume the existence of a masking effect of the sensory perception of acidity due to the high viscosities provided by xanthan gum. On the other hand, the viscosity acceptability and overall acceptability curves showed a maximum.

Introduction: In making a cream, various additives can be added, among which gums, which have been the subject of interest due to their advantages in industrial production, stand out.
Objective: To evaluate the effect of xanthan and locust bean gums on the physical and sensory properties of acidified dairy creams.Materials and methods: The factors studied were: concentration (xanthan gum from 0.025 to 0.5 % and locust bean gum from 0.05 to 0.5 %) and acidity percentage (from 0.5 to 0.65 % in both gums). A mixture design was applied with the concentrations of the two gums studied. The variables viscosity, drainage stability, consistency and adhesiveness were measured instrumentally, while sensorially the consistency, viscosity and acidity were evaluated with a JAR (Just About Right) test using five-point scales, and on the acceptability for attributes and overall acceptability a nine-point hedonic scale was used.
Results and discussion: The creams with the greatest acceptability corresponded to concentrations of 0.2 to 0.38 % xanthan gum and 0.46 to 0.5 % locust bean gum. The JAR test showed that the best mixture was the one containing 0.325 and 0.175 % xanthan and locust bean gums, respectively; this last treatment was compared with three commercial creams and one of them presented viscosity and consistency values (10 kg∙m-1∙s-1 and 4,000 gf, respectively) similar to those of the mixture obtained.
Conclusions: It is possible to assume the existence of a masking effect of the sensory perception of acidity due to the high viscosities provided by xanthan gum. On the other hand, the viscosity acceptability and overall acceptability curves showed a maximum.

 
 
  • Quantification of the error of digital terrain models derived from images acquired with UAV

  • Cuantificación del error de modelos digitales de terreno derivados de imágenes adquiridas con UAV

Sergio Iván Jiménez-Jiménez; Waldo Ojeda-Bustamante; Ronald Ernesto Ontiveros-Capurata; Jorge Flores-Velázquez; Mariana de Jesús Marcial-Pablo; Braulio David Robles-Rubio

photogrammetry, high resolution topography, Ground Control Points, point clouds, flight plan, drone.

10.5154/r.inagbi.2017.03.007

Received: 2017-03-02
Accepted: 2017-11-25
Available online: 2017-12-22
Pages:85-100

Introduction: Topographic surveys based on traditional methods (total stations and GPS) enable representing in detail the characteristics of the terrestrial surface, but they mean a high cost in terms of resources and time. With the use of unmanned aerial vehicles (UAVs) it is possible to obtain digital terrain models (DTMs) with high spatial resolution, but they require field validation to obtain high-accuracy topographic products.
Objective: To estimate the precision of DTMs generated from high-resolution images acquired with a UAV by means of the geolocation of 23 terrestrial points (11 control and 12 verification ones) obtained in the field with a GPS-RTK (Global Positioning System - Real Time Kinematic).
Materials and methods: For the generation of each DTM, a photogrammetric restitution process with a different number of Ground Control Points (GCPs) was used: 4, 5, 6, 8, 9, 10 and 11. To evaluate the precision of the DTMs, four statistical parameters were used.Results and discussion: The DTM processed with four points had a root-mean-square error (RMSE) > 3 m, and those of 9, 10 and 11 had an RMSE < 7 cm. The georeferenced DTM with 11 GCPs represented the topography of the site with better accuracy. The largest RMSE was 5.9 cm, which is less than three times the spatial resolution of the orthomosaic (2 cm∙pixel-1).
Conclusions: At least five terrestrial GCPs are well distributed throughout the study area for every 15 ha of surveyed area; in addition, it is necessary to add one point for each additional 3 ha to obtain a minimum accuracy of 6 cm on the Z axis and 7 cm on the plane (X, Y, Z).

Introduction: Topographic surveys based on traditional methods (total stations and GPS) enable representing in detail the characteristics of the terrestrial surface, but they mean a high cost in terms of resources and time. With the use of unmanned aerial vehicles (UAVs) it is possible to obtain digital terrain models (DTMs) with high spatial resolution, but they require field validation to obtain high-accuracy topographic products.
Objective: To estimate the precision of DTMs generated from high-resolution images acquired with a UAV by means of the geolocation of 23 terrestrial points (11 control and 12 verification ones) obtained in the field with a GPS-RTK (Global Positioning System - Real Time Kinematic).
Materials and methods: For the generation of each DTM, a photogrammetric restitution process with a different number of Ground Control Points (GCPs) was used: 4, 5, 6, 8, 9, 10 and 11. To evaluate the precision of the DTMs, four statistical parameters were used.Results and discussion: The DTM processed with four points had a root-mean-square error (RMSE) > 3 m, and those of 9, 10 and 11 had an RMSE < 7 cm. The georeferenced DTM with 11 GCPs represented the topography of the site with better accuracy. The largest RMSE was 5.9 cm, which is less than three times the spatial resolution of the orthomosaic (2 cm∙pixel-1).
Conclusions: At least five terrestrial GCPs are well distributed throughout the study area for every 15 ha of surveyed area; in addition, it is necessary to add one point for each additional 3 ha to obtain a minimum accuracy of 6 cm on the Z axis and 7 cm on the plane (X, Y, Z).