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The Nueva Vizcaya State University is a public university in the Philippines. It is mandated to provide advanced instruction and professional training in agriculture, arts, science, technology, education and other related fields. It is also mandated to undertake research and extension services, and provide progressive leadership in its area of specialization. Its main campus is located in Bayombong, Nueva Vizcaya, Philippines. The University was established through the merger of Nueva Vizcaya State Institute of Technology in Bayombong and Nueva Vizcaya State Polytechnic College in Bambang. Wikipedia.

Bitog J.P.,Nueva Vizcaya State University | Lee I.-B.,Seoul National University
Acta Horticulturae | Year: 2013

Windbreak systems play an active role in improving the quality of the natural environment, accelerating the development of agriculture, forestry and animal husbandry, and increasing ecological, social and economical benefits. In a vast reclaimed land, where dusts are of enormous concern, windbreak's main purpose can be exclusively to control soil erosion, dust generation and dispersion. Artificial and natural windbreaks are very effective in reducing the wind velocity in the dust source areas, where wind is the main catalyst of soil erosion, dust generation and diffusion. In this study, numerical simulation was utilized to evaluate the performance of both artificial and natural windbreaks in minimizing wind velocity. Windbreak fences of various height and porosity arranged in an array with different gap distances were studied. For natural windbreaks, the effectiveness of trees in reducing the wind velocity was measured and quantified. Field experiments and wind tunnel studies were conducted to establish the validity of the simulation models. Simulation results were evaluated and suitable windbreak design for artificial and natural windbreaks were recommended. The numerical technique used in the study has proven its validity in investigating dusts generation and diffusion which saves significant amount of time, labor and cost.

Combalicer E.A.,Korea forest Research Institute | Combalicer E.A.,Nueva Vizcaya State University | Cruz R.V.O.,University of the Philippines at Los Banos | Lee S.H.,Korea forest Research Institute | Im S.,Korea forest Research Institute
Journal of Tropical Forest Science | Year: 2010

tropical forest watershed in the Philippines. Hydrologic modelling has become an indispensable tool and cost-effective process in understanding the movement of water loss in the Molawin rainforest watershed, Philippines. The study aimed to optimise the use of a lumped BROOK90 model and simulate the hydrologic processes distribution in a given watershed. The rating curve model was developed as a basis for hydrologic modelling. The model was calibrated at catchment scale to avoid subjectivity of various variable parameters by considering the topography, morphology, climate, soil and canopy characteristics. Five years of streamflow discharge measurements were considered for the model sensitivity analysis, calibration and validation. Results showed a good agreement between observed and simulated streamflows during calibration (r = 0.87 and E = 0.87) and validation (r = 0.84 and E = 0.81) periods. As a consequence, the major hydrologic processes distribution accounted for 41% of the precipitation that turned into evaporation, while 49% became streamflow and 10% remained in deep seepage loss. Overall, the distribution of hydrologic components is primarily reflected during pronounced seasonal variations and fluctuating patterns in precipitation.

Combalicer E.A.,Nueva Vizcaya State University | Combalicer E.A.,Seoul National University | Cruz R.V.O.,University of the Philippines at Los Banos | Lee S.,Seoul National University | Im S.,Seoul National University
Journal of Earth System Science | Year: 2010

A statistical downscaling known for producing station-scale climate information from GCM output was preferred to evaluate the impacts of climate change within the Mount Makiling forest watershed, Philippines. The lumped hydrologic BROOK90 model was utilized for the water balance assessment of climate change impacts based on two scenarios (A1B and A2) from CGCM3 experiment. The annual precipitation change was estimated to be 0.1-9.3% increase for A1B scenario, and -3.3 to 3.3% decrease/increase for the A2 scenario. Difference in the mean temperature between the present and the 2080s were predicted to be 0.6-2.2°C and 0.6-3.0°C under A1B and A2 scenarios, respectively. The water balance showed that 42% of precipitation is converted into evaporation, 48% into streamflow, and 10% into deep seepage loss. The impacts of climate change on water balance reflected dramatic fluctuations in hydrologic events leading to high evaporation losses, and decrease in streamflow, while groundwater flow appeared unaffected. A study on the changes in monthly water balance provided insights into the hydrologic changes within the forest watershed system which can be used in mitigating the effects of climate change. © Indian Academy of Sciences.

Lee I.-B.,Seoul National University | Bitog J.P.P.,Seoul National University | Bitog J.P.P.,Nueva Vizcaya State University | Hong S.-W.,Seoul National University | And 4 more authors.
Computers and Electronics in Agriculture | Year: 2013

Computational fluid dynamics (CFD) is a proven simulation tool which caters to almost any field of study. The CFD technique is utilized to simulate, analyze, and optimize various engineering designs. In this review, the discussion is focused on the application of CFD in the external atmospheric processes as well as modeling in land and water management. With respect to its application in environmental investigations, numerous CFD studies have been done in the atmospheric processes where generally only the fluid flow characteristics are investigated. The application of CFD to soil and water management is still limited. However, with the present demand for conservation and sustainable management of our soil and water resources, CFD application in this field is fast emerging especially in structure designs of dams and reservoirs where CFD offers fast reliable results with less labor and cost. Every CFD model should be validated in order to be considered accurate and reliable. However, a benchmark or standard procedures in validating CFD models is not yet available. This probably answers why the success of the CFD models is still mostly attributed to the user's skills and experience. At present, the degree of application of CFD to the agro-environmental field is limited by the computing power and software used, however, the fast ever computing power of PCs continually expands the potential of CFD and can be generally more flexible at accounting for the unique aspects of every CFD project. This allows easy access to conduct simulation studies from simple to complex models. In this paper, after a state of art analysis of the past and present application of CFD in the agro-environmental applications, its future directions were discussed, in order to potentially serve as a guide for researchers and engineers on what project or investigations can be conducted. © 2012 Elsevier B.V.

Yago J.I.,University of Florida | Yago J.I.,Nueva Vizcaya State University | Lin C.-H.,University of Florida | Lin C.-H.,Brown University | Chung K.-R.,University of Florida
Molecular Plant Pathology | Year: 2011

Fungi respond and adapt to different environmental stimuli via signal transduction systems. We determined the function of a yeast SLT2 mitogen-activated protein (MAP) kinase homologue (AaSLT2) in Alternaria alternata, the fungal pathogen of citrus. Analysis of the loss-of-function mutant indicated that AaSLT2 is required for the production of a host-selective toxin, and is crucial for fungal pathogenicity. Moreover, the A.alternata slt2 mutants displayed hypersensitivity to cell wall-degrading enzymes and chemicals such as Calcofluor white and Congo red. This implicates an important role of AaSLT2 in the maintenance of cell wall integrity in A.alternata. The A.alternata slt2 mutants were also hypersensitive to a heteroaromatic compound, 2-chloro-5-hydroxypyridine, and a plant growth regulator, 2,3,5-triiodobenzoic acid. Developmentally, the AaSLT2 gene product was shown to be critical for conidial formation and hyphal elongation. Compared with the wild-type, the mutants produced fewer but slightly larger conidia with less transverse septae. The mutants also accumulated lower levels of melanin and chitin. Unlike the wild-type progenitor, the A.alternata slt2 mutants produced globose, swollen hyphae that did not elongate in a straight radial direction. All defective phenotypes in the mutant were restored by transformation and expression of a wild-type copy of AaSLT2 under the control of its endogenous promoter. This study highlights an important role of the AaSLT2 MAP kinase-mediated signalling pathway, regulating diverse physiological, developmental and pathological functions, in the tangerine pathotype of A.alternata. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

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