scholarly journals Soil Chemical Property Changes in Response to Long‐Term Pineapple Cultivation in Costa Rica

age ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 1-9
Author(s):  
Leslie A. Sherman ◽  
Kristofor R. Brye
Keyword(s):  
Costa Rica ◽  
Chemical Property ◽  
Soil Chemical Property ◽  
Property Changes

scholarly journals Soil Chemical Property Changes in Eggplant/Garlic Relay Intercropping Systems under Continuous Cropping

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e111040 ◽  
Author(s):  
Mengyi Wang ◽  
Cuinan Wu ◽  
Zhihui Cheng ◽  
Huanwen Meng ◽  
Mengru Zhang ◽  
...  
Keyword(s):  
Chemical Property ◽  
Continuous Cropping ◽  
Soil Chemical Property ◽  
Relay Intercropping ◽  
Property Changes

Hydrogeological responses in tropical mountainous springs

2019 ◽  
Author(s):  
Ricardo Sánchez-Murillo
Keyword(s):  
Costa Rica ◽  
Isotope Composition ◽  
Central Valley ◽  
Distribution Functions ◽  
Geochemical Composition ◽  
Transit Times ◽  
Management Plans ◽  
Best Fit ◽  
Term Data

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.

scholarly journals Key indicator tools for shallow slope failure assessment using soil chemical property signatures and soil colour variables

2017 ◽  
Vol 24 (29) ◽  
pp. 22861-22872
Author(s):  
Rashidi Othman ◽  
Shah Irani Hasni ◽  
Zainul Mukrim Baharuddin ◽  
Khairusy Syakirin Has-Yun Hashim ◽  
Lukman Hakim Mahamod
Keyword(s):  
Chemical Property ◽  
Slope Failure ◽  
Key Indicator ◽  
Failure Assessment ◽  
Soil Chemical Property ◽  
Shallow Slope Failure

State-Owned Banks and Development

2016 ◽  
pp. 52-73 ◽  
Author(s):  
Thomas Marois
Keyword(s):  
South Africa ◽  
Costa Rica ◽  
Case Studies ◽  
Public Services ◽  
Viable Option ◽  
Public Banks ◽  
Neoliberal Restructuring ◽  
Crucial Part ◽  
Improve State

Thirty years of neoliberal restructuring have side-lined alternative financing practices, and propagated mainstream myths about state-owned banks. This chapter examines these neoliberal claims, arguing instead that state-owned banks can remain a crucial part of progressive, sustainable and democratic strategies for investments in long-term development and infrastructure. Drawing on past and present case studies, as well as the theoretical literature on finance, the chapter points to the potential to revive – and improve – state-owned banking as a viable option for financing public services and development. To this end the chapter dispels nine popular neoliberal claims about state-owned banks while discussing how state-owned banks have undergone neoliberal restructuring processes such as marketization and corporatization in ways that nonetheless challenge their status as ‘public' banks. To illustrate, the chapter looks at imperfect, but telling or inspiring, examples from Brazil, China, Costa Rica, India, South Africa, Turkey and Venezuela, among others.

scholarly journals Efficacy of the bivalent HPV vaccine against HPV 16/18-associated precancer: long-term follow-up results from the Costa Rica Vaccine Trial

2020 ◽  
Vol 21 (12) ◽  
pp. 1643-1652
Author(s):  
Carolina Porras ◽  
Sabrina H Tsang ◽  
Rolando Herrero ◽  
Diego Guillén ◽  
Teresa M Darragh ◽  
...  
Keyword(s):  
Costa Rica ◽  
Hpv Vaccine ◽  
Vaccine Trial ◽  
Hpv 16 ◽  
Long Term Follow Up

scholarly journals Nutrients Leaching in Response to Long-Term Fertigation and Broadcast Nitrogen in Blueberry Production

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1530
Author(s):  
Aimé J. Messiga ◽  
Kathryn Dyck ◽  
Kiera Ronda ◽  
Kolden van Baar ◽  
Dennis Haak ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Irrigation Water ◽  
Chemical Properties ◽  
Principal Component ◽  
Nutrient Leaching ◽  
N Leaching ◽  
Leaching Losses ◽  
Property Changes ◽  
Fertilizer Rates

Nutrient leaching losses from horticultural production threaten the quality of groundwater and freshwater systems worldwide. The objectives of this study were to (a) assess the effects of annual applications of ammonium sulfate fertilizer through fertigation (FERT) and broadcast (BROAD) on nutrient leaching losses and (b) determine the links among chemical property changes in leachates and soil with berry yields after 9 and 11 years of blueberry production. The long-term blueberry site was established in 2008 using seven combinations of treatments including an unfertilized control (CONT) and three N fertilizer rates (100%, 150%, 200% of recommended rates) using BROAD and FERT methods. Nutrients concentrations (NO3−-N, NH4+-N and SO42−-S) and chemical properties (pH and electrical conductivity (EC)) of leachate, sawdust and soil and berries were assessed. All FERT methods resulted in concentrations of NO3−-N in the leachates > 100 mg L−1 with a maximum of 200 mg L−1 for FERT-200 during the growing season due to the easy transport of dissolved nutrients with the irrigation water. All BROAD methods resulted into concentrations of NO3−-N in the leachates >10 mg L−1 with a maximum of 35 mg L−1 for BROAD-200 between April and July, as well as between November and April, indicating two periods of NO3−-N leaching losses. The pattern observed with BROAD indicates that irrigation water in the summer and heavy rainfall in the winter contribute to NO3−-N leaching losses. Concentrations of NH4+-N in the leachates >1 mg L−1 were measured under FERT with a peak at 64.78 mg L−1 for FERT-200, during the period April to August, due to NH4+’s ability to quickly move through the sawdust layer with irrigation water. Principal component analysis linked berry yield decrease with ammonium sulfate applications above recommended rates (FERT and BROAD) and with changes in soil pH and EC. Our results demonstrated that excess fertilizer applications above recommended rates using FERT and BROAD can threaten the sustainability of blueberry production by enhancing nutrient leaching losses and reducing berry yield.

Long-term artificially aging process and vibration analysis of pipes

2012 ◽  
Vol 3 (1) ◽  
pp. 15-19
Author(s):  
D. Kocsis ◽  
R. Horváth ◽  
S. Manó ◽  
Z. A. Godó
Keyword(s):  
Vibration Analysis ◽  
Aging Process ◽  
Experimental System ◽  
Measuring Instruments ◽  
Engineering Society ◽  
Aging Test ◽  
Vibration Tests ◽  
Property Changes ◽  
Pipe Materials

Abstract The identification of property changes and damage in various structures is one of the major points in the engineering society. This work contains the method and results of a long-term aging process implemented by an experimental system. We applied a chemical and heat artificial aging test on metal and plastic pipes to indicate the degradation levels and results with suitable measuring instruments. During our measurements of aged pipes vibration tests were performed to get information about the changing of the vibration spreading properties of different materials. We were searching for information about the property changing of widely used pipe materials to estimate the rate of degradation and the service life of these instruments more accurately.

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