Earth Sciences

The water sample from Ajuy River in Iloilo, Philippines, was found to exceed the maximum manganese contaminant level set by US-EPA due to the unregulated mining of nearby mineral extraction sites. Chemical water treatment is currently used to remove heavy metals, but it compromises water quality by leaving toxic residues. The discovery of organic polysaccharides like chitin in shell wastes of Philippine bivalves resulted to the natural removal of heavy metals through biosorption. The objective is to extract crude chitin from shell wastes of Bractechlamys vexillum, Perna viridis, and Placuna placenta to determine its adsorption capacity on manganese in actual and simulated mine water. Crude chitin extraction involved pulverization, deproteinization, demineralization, and decolorization of shells. Biosorption by flocculation followed 5 g: 50 mL chitin-to-water ratio. Filtrates were analyzed using MP-AES after 24 hours. In both actual and simulated mine water respectively, B. vexillum yielded the highest adsorption percentage of 91.43% and 99.58%, comparable to P. placenta of 91.43% and 99.37%, while significantly different to P. viridis of-57.14% and 31.53%, (p<0.05). FT-IR validated the presence of chitin in shells based on carbonyl-containing functional groups at peaks 1000-1300 cm-1 and 1550-1690 cm-1. SEM micrographs showed the amorphous and non-homogenous structure of chitin. Traces of calcite from characterization techniques denoted the crudity of chitin. Thus, this study reveals that crude chitin can be locally sourced from B. vexillum and P. placenta to become bio-sorbents for in situ water treatment of manganese-impacted effluents, promoting further conservation, cultivation, and management of Philippine bivalves.

This paper presents a modular Matlab tool, namely MORPHEO, devoted to the study of particle morphology by Fourier analysis. A benchmark made of four sample images with different features (digitized coins, a pebble chart, gears, digitized volcanic clasts) is then proposed to assess the abilities of the software. Attention is brought to the Weibull distribution introduced to enhance fine variations of particle morphology. Finally, as an example, samples pertaining to a lahar deposit located in La Lumbre ravine (Colima Volcano, Mexico) are analysed. MORPHEO and the benchmark are freely available for research purposes.

In this paper, we propose a new system for automatically measuring grain sizes in a range from pebbles to blocks. The system is based on use of the Microsoft Kinect device and a novel software developed by the authors which enables a tridimensional digital model of a selected area of an outcrop to be captured. With the tridimensional model, clasts are stacked using new segmentation algorithms based on level sets and Fourier analysis. The resulting binary image (clasts and matrix) is analyzed by means of the Rosiwal stereological method. The granulometric Cumulative Distribution Function (CDF), obtained automatically by this new methodology, was compared to the granulometric CDF, obtained manually by the Rosiwal technique, by means of a Kolmogorov-Smirnov test. The comparison showed good agreement between the methods and demonstrated that this inexpensive system (already used in several scientific fields) with great potential can also be used to obtain fast, automatic and accurate gr...

ABSTRACT The world is in the midst of a biodiversity crisis, threatening essential goods and services on which humanity depends. While there is an urgent need globally for biodiversity research, growing obstacles are severely limiting biodiversity research throughout the developing world, particularly in Southeast Asia. Facilities, funding, and expertise are often limited throughout this region, reducing the capacity for local biodiversity research. Although western scientists generally have more expertise and capacity, international research has sometimes been exploitative “parachute science,” creating a culture of suspicion and mistrust. These issues, combined with misplaced fears of biopiracy, have resulted in severe roadblocks to biodiversity research in the very countries that need it the most. Here, we present an overview of challenges to biodiversity research and case studies that provide productive models for advancing biodiversity research in developing countries. Key to success is integration of research and education, a model that fosters sustained collaboration by focusing on the process of conducting biodiversity research as well as research results. This model simultaneously expands biodiversity research capacity while building trust across national borders. It is critical that developing countries enact policies that protect their biodiversity capital without shutting down international and local biodiversity research that is essential to achieve the long-term sustainability of biodiversity, promoting food security and economic development.

Heavy metals were analyzed in different foods crops, milk, meat and blood samples collected from different age group subjects such as children (1-12 years), adolescent (12-18 years), adults (18-45 years) and old age (above 45 and 55 years for males and females, respectively) from polluted and relatively less polluted areas. The results revealed that the consumption of contaminated food crops, meat and milk have significantly increased the concentrations of selected metals in the human blood. Cu, Zn and Mn concentrations were significantly higher (p &lt; 0.05) in the blood samples collected from the polluted area as compared to control area. Old people had accumulated high concentrations of metals as compared to the younger ones within the same area. Males accumulated higher concentrations of metals as compared to females.

The terminal Neoproterozoic and its transition into the Cambrian witnessed major evolutionary and geochemical changes. Large fluctuations in the carbon isotope ratio for inorganic carbon (δ13Ccarb) across the Precambrian/Cambrian boundary (Pc/C boundary) indicate a significant change in the oceanic carbon cycle at that time. This work presents the first high-resolution δ13Corg chemostratigraphy of drill core samples across the Pc/C boundary

The Ediacaran period was one of the most important times for the evolution of life. However, the scarcity of well-preserved outcrops of Ediacaran rocks still leaves ambiguity in decoding ambient surface environmental changes and biological evolution.The Ediacaran strata in South China are almost continuously exposed, comprise mainly carbonate rocks with subordinate black shales and sandstones, and they contain many fossils,

Abstract: Apart from previously reported Small Shelly Fossils (SSFs), a macroscopic fossil assemblage, comprising abundant algae, cone-shaped tubular fossil forms, and probable impressions of a megascopic metazoan, comes from the Lower Cambrian Yanjiahe ...

Secondary organic aerosol (SOA) formed from C1-initiated oxidation of toluene was investigated in a home-made smog chamber. The size distribution and chemical composition of SOA particles were measured using aerodynamic particle sizer spectrometer and the aerosol laser time-of-flight mass spectrometer (ALTOFMS), respectively. According to a large number of single aerosol diameter and mass spectra, the size distribution and chemical composition of SOA were obtained statistically. Experimental results showed that SOA particles created by C1-initiated oxidation of toluene is predominantly in the form of fine particles, which have diameters less than 2.5 microm (i.e., PM2.5), and glyoxal, benzaldehyde, benzyl alcohol, benzoquinone, benzoic acid, benzyl hydroperoxide and benzyl methyl nitrate are the major products components in the SOA. The possible reaction mechanisms leading to these products are also proposed.

ABSTRACT A method is developed to generate digital elevation models by means of the dilation of contour lines stored in a raster grid. An iterative procedure produces an extension of contour lines by applying alternative four-connected and eight-connected erosions of the background until the produced surfaces become contiguous. The limits between these surfaces correspond to a new family of intermediate contour lines that are added to the raster grid. This procedure stops when no new contour lines can be generated. C subroutines are given. The algorithm is simple to apply and has a low computational cost.

The Ethiopian dome, comprising the Ethiopian and Yemeni Plateaus, formed as a result of the uplift of Red Sea, Gulf of Aden, and Ethiopian rift shoulders; the uplift was essentially due to a mantle-plume activity. A digital elevation model of this region before rifting, constructed by using the rotation of its constituent plates and pulling down the rift shoulders, reveals