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The concept behind active thermochemical tables (ATcT) is presented. As opposed to traditional sequential thermochemistry, ATcT provides reliable, accurate, and internally consistent thermochemistry by utilizing the thermochemical network (TN) approach. This involves, inter alia, a statistical analysis of thermochemically relevant determinations that define the TN, made possible by redundancies in the TN, such as competing measurements and alternate network pathways that interrelate the various chemical species. The statistical analysis produces a self-consistent TN, from which the optimal thermochemical values are obtained by simultaneous solution in error-weighted space, thus allowing optimal use of all of the knowledge present in the TN. ATcT offers a number of additional features that are not present nor possible in the traditional approach. With ATcT, new knowledge can be painlessly propagated through all affected thermochemical values. ATcT also allows hypothesis testing and evaluation, as well as discovery of weak links in the TN. The latter provides pointers to new experimental or theoretical determinations that will most efficiently improve the underlying thermochemical body of knowledge. The ATcT approach is illustrated by providing improved thermochemistry for several key thermochemical species. † Part of the special issue "Tomas Baer Festschrift".

This paper presents an estimation of the quantity of carbon fixed in trees in a one hectare (ha) plot at the Cerro Pelado-Gamboa Hydrology Tropical Observatory, which is located in the province of Colon, Panama. The estimation of carbon fixed in trees may provide significant information on carbon flux due to water circulation, which may ultimately enable evaluation of the carbon cycle. All trees larger than 10 cm diameter at breast height (DBH) in the plot were investigated. Carbon fixed within these trees was estimated using a parameterized formula. Tree biomass estimations for the plot were 97.21 Mg ha −1. We identified a rare arboreal pear species (Euphorbiaceous) with higher carbon density than other trees in the plot. The presence of this apparently unique species may be due to specific soil characteristics. The method was evaluated by comparing the results with a second study performed in 2011, which resulted in an estimate of net new carbon (biomass) increment (NNCI), which gives 3.88 Mg ha −1 year −1. In general, the estimation of the biomass and associated carbon content found in this investigation are useful comparative data for economic evaluation of tropical forests in terms of capacity to capture carbon.

Precipitation (P) Curve-Number (CN) relationships for different base flow ranges, obtained within the upper Chagres River watershed were applied to a 6.5 Ha microbasin located within the Panamá Canal watershed. These relationships estimate CN values from P data employing an equation established by Calvo et al (10). This equation uses k and CN ∞ as fitting parameters. Rainfall/Runoff data from the microbasin, collected over a six-month period, were analyzed. These analyses showed that CN values at the microbasin are closer to CN results predicted by the equation corresponding to the lower base-flow range (14-42 m 3 /s) at the upper Chagres watershed. These results were explained by considering not the absolute values of the base flow (Q base), but the value of this parameter relative to the basin area under study.

Precipitation (P) Curve-Number (CN) relationships for different base flow ranges, obtained within the upper Chagres River watershed were applied to a 6.5 Ha microbasin located within the Panamá Canal watershed. These relationships estimate CN values from P data employing an equation established by Calvo et al (10). This equation uses k and CN ∞ as fitting parameters. Rainfall/Runoff data from the microbasin, collected over a six-month period, were analyzed. These analyses showed that CN values at the microbasin are closer to CN results predicted by the equation corresponding to the lower base-flow range (14-42 m 3 /s) at the upper Chagres watershed. These results were explained by considering not the absolute values of the base flow (Q base), but the value of this parameter relative to the basin area under study.

This study elucidated the characteristics of climatological seasonal changes in the diurnal variations of precipitation at four ground stations in the upper Río Chagres basin in the Panama Canal watershed. The seasonal changes differed among the stations, although they are located within an area of only 414 km 2. Precipitation peaks in the early afternoon at 1500 local standard time (LST) were observed at all the stations. At Chamon, monthly-mean hourly precipitation at every hour exceeded 0.3 mm h-1 throughout November and December. The occurrence of morning precipitation in January and March distinguished the seasonal precipitation pattern at Esperanza from the pattern at the other stations. Analyses of the seasonal changes in the diurnal variation with pattern correlations and rotational empirical orthogonal functions grouped the stations into two pairs: no morning peak at Chico and Río Piedras in the downstream basin and morning peak at Chamon and Esperanza in the upstream basin.

The goal of the Collaboratory for the Multi-scale Chemical Sciences (CMCS) [1] is to develop an informatics-based approach to synthesizing multi-scale chemistry information to create knowledge in the chemical sciences. CMCS is using a portal and metadata-aware content store as a base for building a system to support inter-domain knowledge exchange in chemical science. Key aspects of the system include configurable metadata extraction and translation, a core schema for scientific pedigree, and a suite of tools for managing data and metadata and visualizing pedigree relationships between data entries. CMCS metadata is represented using Dublin Core with metadata extensions that are useful to both the chemical science community and the science community in general. CMCS is working with several chemistry groups who are using the system to collaboratively assemble and analyze existing data to derive new chemical knowledge. In this paper we discuss the project’s metadata-related requiremen...

In this paper we report our work on the integration of existing scientific applications using Grid Services. We describe a general architecture that provides access to these applications via Web services-based application factories. Furthermore, we demonstrate how such services can interact with each other. Furthermore

The goal of the Collaboratory for the Multi-scale Chemical Sciences (CMCS) [1] is to develop an informatics-based approach to synthesizing multi-scale chemistry information to create knowledge in the chemical sciences. CMCS is using a portal and metadata-aware content store as a base for building a system to support inter-domain knowledge exchange in chemical science. Key aspects of the system include configurable metadata extraction and translation, a core schema for scientific pedigree, and a suite of tools for managing data and metadata and visualizing pedigree relationships between data entries. CMCS metadata is represented using Dublin Core with metadata extensions that are useful to both the chemical science community and the science community in general. CMCS is working with several chemistry groups who are using the system to collaboratively assemble and analyze existing data to derive new chemical knowledge. In this paper we discuss the project's metadata-related requirements, the relevant software infrastructure, core metadata schema, and tools that use the metadata to enhance science.

This work is focused on the detection of seepages caused by the affluent located in a small area of the Panama Canal Basin during the dry season, and to define the subsurface stratigraphy (Eocene sediments) that characterize this area through a geophysical survey. Two electrical resistivity tomography were developed to identify the extent of infiltration and the nature of the clay layers vertically and laterally, these results were corroborated by a drilling operation in the vicinity of electrical tests and based on this information, established a model for a two-dimensional geoelectric profile in order to compare (i) the pseudosections of synthetic and measured apparent electrical resistivity, and (ii) the electrical resistivity tomography as a result of the inversions of such pseudo-sections. The results of electrical resistivity tomography obtained in the two profiles revealed the existence of (i) a surface layer moderately resistant (18-85 ohm.m) with a thickness not exceeding 1,8 m, (ii) an area of high electrical conductivity (3,8 to 10,7 ohm.m) with a thickness not exceeding 9.5 m and (iii) a resistant substratum with electrical resistivity values calculated in excess of 30,1 ohm.m and a range depth ranging from 2 to 11,5 m. The drilling operation in the vicinity of the geophysical tests revealed the presence of clay with varying moisture content and density, and thicknesses that corroborate the results of the geophysical evidence. The two-dimensional geoelectrical model of Profile 1 was established according to the results of electrical resistivity tomography as well as the profile and information of the drilling operation. Based on the results of this study, we conclude that the infiltration generated by the affluent in this part of the Isthmus of Panama are very important, even in periods when precipitation levels are.

Climate change could have a critical impact on the Republic of Panama where a major segment of the economy is dependent on the operation of the Panama Canal. New capabilities to do targeted research around climate change impacts on Panama is therefore being established. This includes anew GPU-cluster infrastructure called Iberogun, based around 2 DGX1 servers (each running 16 NVIDIA Tesla P100 GPUs). This infrastructure will be used to evaluate potential climate models and models of extreme weather events. In this review we therefore present an evaluation of the GPGPU (General Purpose Graphic Processing Unit, here abbreviated GPU) implementation methods for the study of weather projections and dynamical downscaling in the Republic of Panama. Different methods are discussed, including: domain-specific languages (DSLs), directive-based porting methods, granularity optimization methods, and memory layout transforming methods. One of these approaches that has yielded interesting previou...

By means of a recently customary nonparametric method future climate analogues were predictable for West South American capital cities. The nonparametric scheme showed in this research for identifying climate analogues can be applied for impact assessments under a changing climate. MRI-AGCM3.2H with a horizontal resolution of 60 km, three convection schemes, four sea surface temperature distributions, and two initial conditions and under scenario A1B of the Special Report on Emissions Scenarios were used. The total ensemble scope was 24, with a simulation period of 25 years. Utmost of the future analogues are at lower latitudes than their target cities. Estimated seasonal variations in surface air temperature and rainfall in Santiago de Chile City look similar to the present-day climate of Cape Town, located in South Africa and for La Paz City a climate analogue is found at Oruro in Bolivia.

Developing countries are aimed to protect and expand their forests as a mitigation action to Climate Change. Tropical soils contain a 32% of the total amount of carbon stored in soils. With the incrementation of anthropogenic CO 2 in the atmosphere, there is a necessity to understand soil CO 2 complex interaction with abiotic and biotic factors and their interplay with soil CO 2 production and transport, so a clear comprehension, could lead researchers of this subject to forecast with precise models,CO 2 flux in tropical forests soils for the next decades. This paper describes the field work that has been done for 21 months, and the preliminary results of continuously measurements of soil CO 2 flux, soil temperature and soil humidity on a 1 ha plot in the artificial island of Barro Colorado; using a closed long term chamber method with an infrared gas analyzer. The mean for soil CO 2 flux in the study period was 2.92 μmol/m²s. There is a positive correlation with soil humidity and soil temperature, soil CO 2 flux can be explained in this particular plot by this abiotic factors. Finally, we conclude that our measurements need to be done continuously and for a long period of time in order to evaluate the spatial and seasonal variability of soil CO 2 flux. Keywords-soil CO 2 flux, soil respiration, closed chamber, Barro Colorado Island.

In this article, we evaluate the impact of temperature and precipitation at the end of the 21st century (2075–2099) on the yield of maize in the Azuero Region in Panama. Using projected data from an atmospheric climate model, MRI-ACGM 3.2S, the study variables are related to maize yield (t ha−1) under four different sea surface Temperature (SST) Ensembles (C0, C1, C2, and C3) and in three different planting dates (21 August, 23 September, and 23 October). In terms climate, results confirm the increase in temperatures and precipitation intensity that has been projected for the region at the end of the century. Moreover, differences are found in the average precipitation patterns of each SST-ensemble, which leads to difference in maize yield. SST-Ensembles C0, C1, and C3 predict a doubling of the yield observed from baseline period (1990–2003), while in C1, the yield is reduced around 5%. Yield doubling is attributed to the increase in rainfall, while yield decrease is related to the ...

Plasticity in metallic glasses depends on their stoichiometry. We explore this dependence by molecular dynamics simulations for the case of CuZr alloys using the compositions Cu$$_{64.5}$$ 64.5 Zr$$_{35.5}$$ 35.5 , Cu$$_{50}$$ 50 Zr$$_{50}$$ 50 , and Cu$$_{35.5}$$ 35.5 Zr$$_{64.5}$$ 64.5 . Plasticity is induced by nanoindentation and orthogonal cutting. Only the Cu$$_{64.5}$$ 64.5 Zr$$_{35.5}$$ 35.5 sample shows the formation of localized strain in the form of shear bands, while plasticity is more homogeneous for the other samples. This feature concurs with the high fraction of full icosahedral short-range order found for Cu$$_{64.5}$$ 64.5 Zr$$_{35.5}$$ 35.5 . In all samples, the atomic density is reduced in the plastic zone; this reduction is accompanied by a decrease of the average atom coordination, with the possible exception of Cu$$_{35.5}$$ 35.5 Zr$$_{64.5}$$ 64.5 , where coordination fluctuations are high. The strongest density reduction occurs in Cu$$_{64.5}$$ 64.5 Zr$$_{35...

Soil CO2 fluxes from tropical forests into the atmosphere are expected to increase due to global warming. Studies of environmental conditions that contribute to carbon flux are now an important focus for climate change research. However, carbon flux in tropical areas such as Panama has received less attention. In Panama, water sources, rainforests, and soil conditions are vital natural resources, particularly within the Panama Canal watershed. Mature and secondary forests represent around 60% of Panama land cover. Secondary forests are considered potential carbon sinks and they are of economic interest as a means of mitigating increasing anthropogenic CO2 emissions; however, the dynamics of carbon fluxes in the soil of secondary forests remain poorly understood. This research investigated which environmental factors influence soil CO2 efflux. We used a closed chamber method to measure soil CO2 in the tropical forest of Barro Colorado Island, Panama. During 2016 to 2017, humidity had...