Fernando Jove Wilches ¹, Jhon Jairo Feria Diaz ¹, Rodrigo Hernandez Avila ¹

Affiliations
1 Department of Civil Engineering, University of Sucre, Cra. 28 #5-267, Puerta Roja, Sincelejo, CO

Abstract

Objective: To determine damage factors of trucks that most frequently use national roads in the Colombian Caribbean Region. Methods/Analysis: Information provided by the National Institute of Colombian Roads was used according to a mobile weighing operation carried out in 2005. Damage factors for each truck type were obtained from the weights of each vehicular axle, by implementing three different methods: The AASHTO general method, AASHTO simplified method and SHELL method. Findings: 16,611 heavy trucks were totally analyzed in the operation. Subsequently, results obtained were compared with those observed in other similar studies carried out in the country. Application: Damage factors defined in this study for lighter vehicles have lower values than those observed in previous measurements. In contrast, for the case of heavier trucks, the opposite occurs.

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Alvaro J. Zabaleta ¹, Teobaldis Mercado ², Jose Luis Marrugo ³, Jhon Jairo Feria Diaz ⁴

Affiliations
1 School of Engineering, University of Cordoba, 6th Avenue No. 76–103. Monteria, Cordoba, CO
2 Agriculture Science School, University of Cordoba. 6th Avenue No. 76–103. Monteria, Cordoba, CO
3 Department of Chemistry, University of Cordoba. 6th Avenue No. 76–103. Monteria, Cordoba, CO
4 Department of Civil Engineering, University of Sucre, Cra. 28 #5-267, Sincelejo, CO

Abstract

Objective: This research study analyzed hydrological surface behavior of the lower basin of the Cauca, San Jorge and Loba tributaries of the Magdalena River in the so-called La Mojana Region in northern Colombia. Methods/Analysis: To determine hydrological behavior of the basins under study, an analysis of vegetation cover was used as the most dynamic condition; its soil use and granulometry as the natural condition, regarding the hydrological pressure degree of the territory, as well as climatic behavior in the last 40 years in the area. Findings: Results show that cover and land use do not contribute favorably to basin hydrological regulation, considering that 45.9% have pasture cover, being this least favored hydrological regulation. Application/Improvements: 92.3% of the total study area (21,650.2 km²) shows curve numbers greater than 80, so that there is a high hydrological pressure on the territory. At the meantime, temperature shows a 0.8°C increase, while Evapotranspiration (ET) and vapor density have increases of 50.6 mm and 0.7 g m^-1 respectively.

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Gaston Ballut Dajud ¹, Alcides Sampedro Marin ², Jhon Jairo Feria Diaz ¹

Affiliations
1 Department of Civil Engineering, University of Sucre, Carrera. 28 #5-267, Puerta Roja, Sincelejo, CO
2 Department of Biology and Chemistry, University of Sucre, Carrera 28 #5-267, Sincelejo, CO

Abstract

Objective: This research study aimed at verifying, through satellite monitoring, changes that land cover of Serrania de Coraza and Montes de Maria Protective Forestry Reserve has experienced from 1990 to 2017. Methods / Analysis: Unsupervised classification method, and Landsat and SPOT satellite images were used. Findings: There is a high proportion of bare soil during the first 20 years of the study, whereas in the last five years values considerably decrease. For the cover regarding the intervened areas, the opposite occurs, since during the first 20 years values are much lower than in the last five years, reaching a 43% proportion. Cover of primary forests has declined throughout the study period. Application / Improvements: Forced peasants’ displacement in Montes de Maria during the 1990s and 2000s, due to the armed conflict Colombia has experienced for years, could be related to the results. Urgent measures are required to preserve biological diversity in the region.

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Carmen Sampayo Benavides ¹, Jhon Jairo Feria Diaz ¹, Teobaldis Mercado Fernandez ²

Affiliations
1 Department of Civil Engineering, University of Sucre, Cra. 28 #5-267, Puerta Roja, Sincelejo, CO
2 Agriculture Science School, University of Córdoba, 6th Avenue No 76 – 103 Monteria, CO

Abstract

Objective: This work aimed at assessing acute toxicity in Artemia salina of waters treated with natural coagulants (Moringa Oleifera) and with synthetic coagulants (Aluminum Sulfate Type B). Methods/Analysis: Acute toxicity tests were carried out on Artemia salina larvae to solutions with the highest coagulant activity by means of standard eco toxicology techniques and procedures. In addition, adjustments of sigmoid curve models were made to estimate mean lethal concentration (LC50) in this organism. Findings: Results obtained showed that the natural coagulant has low toxicity, making it a friendly alternative to replace aluminum sulphate, in water treatment. Application/Improvements: Moringa oleifera can have advantages over aluminum sulphate due to biodegradability. This is an efficient and non-toxic coagulant that can be used in water treatment for domestic use in urban and rural areas.

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Jhon Jairo Feria Diaz ¹, Fernando Jove Wilches ¹, Rodrigo Hernandez Avila ¹

Affiliations
1 Department of Civil Engineering, University of Sucre, Carrera 28 No. 5-267, Puerta Roja, Sincelejo, CO

Abstract

Objective: To determine turbidity removal efficiency of raw water samples, by using Multi-Stage Filtration technology and complemented with natural coagulants. Methods/Analysis: Water samples were taken from the Sinu River. A pilot plant was set up in laboratory, and treatability tests were carried out on samples with different scenarios. Findings: The best treatment for raw water was obtained when 240 m³m^-2d^-1 rates were applied for 200 NTU initial turbidity. There were no alterations in pH and water alkalinity after treatability tests. Application: This raw water treatment technology is very useful and appropriate to be applied in rural areas with difficult access and scarce economic resources, since its simplicity does not require costly inputs or maintenance.

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Rodrigo Gregorio Hernandez Avila ¹, Jhon Jairo Feria Diaz ¹, Fernando Jove Wilches ¹

Affiliations
1 Department of Civil Engineering, University of Sucre, Carrera. 28, No. 5-267, Puerta Roja, Sincelejo, CO

Abstract

Objective: To analyze flexural behavior of insulated footings supported on granular material and subject to low loads. Methods/Analysis: Experimental program included tests on 30 square reinforced concrete footings, 450 mm in length and reinforced with 6.3 mm bars. Experimental results were compared with theoretical results, according to the ACI 318- 14 Code. Findings: Results showed an average relationship between moment of experimental and theoretical cracking, in a range from 1.03 to 1.55. It was discovered that the value of rupture modulus recommended by the code was conservative. Application: It is required to continue with a more detailed study to establish influence of steel amount on the magnitude of the cracking moment of isolated footings.

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Maria Jose Tavera Quiroz ¹, Jhon Jairo Feria Diaz ², Nora Cristina Bertola ³

Affiliations
1 Department of Agroindustrial Engineering, University of Sucre, Sincelejo, CO
2 Department of Civil Engineering, University of Sucre, Sincelejo, CO
3 Department of Engineering, National University of La Plata, La Plata, Buenos Aires, AR

Abstract

Objective: In this research work, properties of the methylcellulose films were studied to be applied as coatings on Costeno cheese. Methods /Analysis: Methylcellulose (A4M) solutions were prepared at 1.5% w/v in 0.25, 0.25 and 0.75% sorbitol concentrations; and 1, 5 and 10% (w/w MC) citric acid. Nine formulations obtained from a 3² factorial experimental design were prepared to determine effect of sorbitol and citric acid addition on physicochemical and mechanical properties of films; the effect of addition of sorbitol as a plasticizer, and citric acid as a crosslinker of the polymer matrix. Findings: Transparent and flexible films were obtained for all cases. The 1.5 g MC, 0.25% sorbitol and 10% citric acid formulation was selected as the coating forming solution to be applied in Costeno cheese. A decline in weight loss and conservation of color of stored cheese was observed for 15 days under refrigeration once this formative solution was applied to Costeno cheese. Application /Improvements: Thus, the development of this research contributes to conservation of intermediate moisture products, such as Costeno cheese by using materials from renewable sources as an alternative to plasticmaterials.

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