Physical Volcanology of Pyroclastic Tephra Deposit at Batoke Mt. Cameroon, West Africa: An Over View.

In this contribution, we report an overview of the physical attributes of pyroclastic deposit at the foot of Mt. Cameroon, West Africa. In the deposit three facies types; which are the lava flow, the lapilli and ash are common. The ash is the dominant facies and occurs irregularly in alternation with the lapilli. The most common types of depositional features include cm-dm planar beds and impact sags. We infer from field observations of facies types, clasts types and depositional features that this deposit is a phreatomagmatic fall deposit which resulted from an interaction between lava flow and surface water. The occurrence in the deposit of accretionary lapilli, impact sags, fragments of country-rock and juvenile clasts is ambiguous evidence in support of phreatomagmatic activity. The presence of a lava flow flanked by the tephra pile, the lack of accidental clasts, and the scarcity of bombs are evidence in support of a surface water-lava flow interaction.KEY WORDS: Pyroclastic Deposit, Batoke, Mt. Cameroon

Spatial and seasonal variation of microphytoplankton community and the correlation with environmental parameters in a hypereutrophic tropical estuary - Maranhão - Brazil

O estuário do rio Bacanga apresenta um comportamento hidrodinâmico com fluxo de marés limitado por uma barragem. Ele é considerado como um ambiente hipereutrófico que recebe diariamente altas cargas de esgoto doméstico sem tratamento. Este trabalho teve como objetivo avaliar a variação espaço-sazonal da comunidade fitoplanctônica e suas relações com parâmetros ambientais. Amostragens bimestrais foram realizadas em seis pontos fixos entre 2012 e 2013, obtendo valores dos parâmetros físico-químicos e biológicos (clorofila a, composição e abundância do fitoplâncton) para realização das análises estatísticas. Os resultados indicam que a comunidade fitoplanctônica é representada por diatomáceas, sendo Skeletonema costatum a espécie dominante responsável por pulsos de florações em abril e junho de 2012. O predomínio dessa espécie está relacionado aos elevados teores de silicato, pH e turbidez da água. Outros eventos de florações como da Euglena gracilis e Chlamydomonas sp. foram registrados em fevereiro de 2013, quando os teores de fósforo total estiveram elevados e as taxas de oxigênio dissolvido foram superiores. Os dinoflagelados, cianobactérias e a diatomácea Thallassiosira sp. apresentaram ampla distribuição no período de estiagem e estão altamente correlacionados com a salinidade, transparência da água e nutrientes. Desta forma, a distribuição da comunidade fitoplanctônica é mais definida sazonalmente que espacialmenteThe Bacanga River Estuary has a hydrodynamic behavior and its tidal flow is limited by a dam. It is considered as a hypertrophic environment that receives daily high loads of domestic sewage without treatment. This study aimed to evaluate the spatial and temporal variation of phytoplankton community and its relationship with environmental parameters. Bi-monthly sampling campaigns were carried out at six fixed sites between 2012 and 2013. Physical-chemical and biological parameters were collected (chlorophyll a, phytoplankton composition and abundance) to perform the statistical correlations. The results indicate that phytoplankton community is mostly represented by diatoms, with Skeletonema costatum being the dominant species responsible for bloom in April and June of 2012. The dominance of this species is related to the high silicate concentrations, pH and turbidity. Other blooms events as well as the Euglena gracilis and Chlamydomonas sp. were recorded in February 2013, when the total phosphorus concentrations were high and the dissolved oxygen concentrations were higher. Dinoflagellates, cyanobacteria and diatom Thallassiosira sp. were widely distributed in the dry period and highly correlated with salinity, water transparency and nutrients. Hence, the distribution of phytoplankton community is more defined seasonally, rather than spatially

Lipomatous interatrial septal hypertrophy: an unusual cause of intracardiac mass.

Lipomatous hypertrophy of the interatrial septum is an uncommon entity that usually occurs in elderly patients. We report a patient who presented with atrial fibrillation, congestive cardiac failure and a large intracavitary mass in the right atrium on echocardiography. He underwent successful resection of the mass with septal reconstruction. Pathology was consistent with lipomatous hypertrophy of the interatrial septum

Biodiesel Production From High-free Fatty Acids Podocarpus falcatus Oil and Identification of Fatty Acid Methyl Esters by FT-IR, NMR (1H and 13C) and GC/MS Studies

Biodiesel occupies a prominent place as the alternative fuel to fossil diesel owing to socio-economic and environmental factors. In this present study, Podocarpus falcatus oil (PFO), having undergone a storage effect, was converted into biodiesel. PFO had a high fatty acid content (FFA = 8.19%). For this reason, a two-step transesterification procedure was developed to convert this high-free fatty acid (FFA) oils into their corresponding monoesters. In the initial step, an acid-catalyzed esterification was employed to lower the FFA content of the oil to below 2%. Subsequently, a second step involving an alkaline catalysis transesterification process was used to convert the product obtained in the first step into monoesters and glycerol. The methyl esters obtained were analyzed using nuclear magnetic resonance (H-1, C-13 NMR), Fourier transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), carbon, hydrogen, nitrogen, and sulfur (CHNS), and Gas chromatography-mass spectrometry (GC-MS) analysis. The identity FAME were Hexadecanoic acid, methyl ester (C16:0), 9,11-Octadecadienoic acid, methyl ester, (E, E)- (C18:0), 6-Octadecenoic acid, methyl ester, (Z)- (C18:2), Methyl stearate (C18:1), Methyl (Z)-5,11,14,17-eicosatetraenoate (C20:5), 11,14-Eicosadienoic acid, methyl ester (C20:3), 11-Eicosenoic acid, methyl ester (C20:2). The study examined the thermal stability of synthesized biodiesel, revealing it remained stable up to 189 degrees C. Furthermore, the physicochemical properties of biodiesel were validated using ASTM6751 standards