Mapeamento de recifes no Rio Grande do Norte: Touros e Macau/RN

Studies on the Brazilian continental shelf were developed between Touros and Macau-RN (NE Brazil) with the aim to mapping carbonate buildups, and especially, reef ecosystems. Remote sensing, submarine movies, bathymetric survey and diving were the methods used. This paper will focus on three main aspects of the Rio Grande do Norte reefs: 1) characterization of the coral fauna; 2) the classification and, 3) the distribution of the main northriograndense carbonate buildups. Reefs environments are found predominantly on the inner shelf adjacent to Touros, at depths shallower than 10 m. These reefs generally show NW-SE orientation parallel to the coastline and constitute groupings of knolls and patch reefs. A prominent carbonate buildup, where the corals are almost absents and algae incrustation is thin, occurs in average depths of 25 m, along the northern part of Rio Grande do Norte State and is classified as sandstone bank. Others sandstone banks, with smaller lengths and heights were mapped around 10 m depth. They should be related to an ancient coastline; however the corresponding litostratigraphic unit was not defined. This work is a contribution to the mapping of coral reef, in particular, and carbonate buildups, in general, on the Rio Grande do Norte coast

Teor de fósforo e pH no bulbo molhado, com diferentes freqüências de fertirrigação, utilizando ácido fosfórico

A aplicação de fertilizantes fosfatados, tais como superfosfofato simples, superfosfofato triplo e monofosfato de amônio, via gotejamento, pode apresentar incrustações nas canalizações e obstruções de emissores. No presente trabalho, realizado na UNESP/Jaboticabal - SP, estudaram-se a distribuição do fósforo e a sua influência sobre o pH e a umidade em Latossolo Vermelho, fertirrigado durante um mês, com cinco aplicações semanais de ácido fosfórico. Utilizaram-se quatro repetições e oito tratamentos, constituídos da combinação de doses de P2O5 (0 e 50 kg ha-1) e freqüências de aplicação de 1; 3; 5 e 7 dias. Pelos resultados obtidos, observou-se que a freqüência de irrigação ou de fertirrigação não influenciou na distribuição final da umidade no bulbo molhado; aplicando-se o ácido fosfórico, o pH do solo até 30 cm do gotejador e até 40 cm em profundidade foi reduzido, atingindo valor de 3,6, e o teor de fósforo foi maior nessa mesma porção do bulbo, ultrapassando 1.500 mg dm-3. Isso permite indicar que o ácido fosfórico pode ser utilizado em irrigação localizada, com controle do pH do solo, pois sua redução influencia no desenvolvimento das culturas e, conseqüentemente, na produtividade.

Gênese e Classificação da Coquina de Camaquã, Formação Corumbataí (Neopermiano), na Região de Rio Claro, SP

Analysis of the taphonomic signatures of a well preserved, silicifled coquina (Pinzonella neotropica assemblage) from the Camaquã outcrop, upper part of the Corumbataí Formation (Late Permian), in the Rio Claro region, state of Sáo Paulo, allowed interpretation of processes involved in its origin as related to high energy events (storms). The coquina occurs as a lenticular body, 2-11 cm thick and extending laterally for about 120 m. Basal contact of the coquina is sharp and erosive. Its upper contact is sharp. The concentration is dominated by pelecypods including the shallow burrowers (Pinzonella neotropica, Jacquesia brasiliensis), intermediate burrower (Pyramus anceps) and semi-infaunal forms (Naiadopsis lamellosus). All these species are suspension feeders. Besides sand-sized or even smaller shell fragments, there occur disarticulated, complete shells which are commonly abraded but do not show any signs of bioerosion or incrustation. In vertical side view, the shells are mainly convex-up, nested or stacked, while in plan-view they show random orientation. Multiple discontinuous grading is visible. These taphonomic signatures suggest that the origin of the skeletal accumulation is related to high energy events (possibly storm flows) in a proximal environment. The amalgamated nature of the Camaquã coquina records several episodes of erosion and deposition.

Tafonomia de Pelecípodes da Formação Teresina (Permiano), Tiaraju, RS, Brasil

Taphonomic analysis of pelecypod concentration in the part of the Teresina Formation (Passa Dois Group), Tiaraju region, State of Rio Grande do Sul, indicates its origins as due to high energy events (storms). The fauna include shallow-burrowing suspensivorous species, associated with this byssate semi-infauna species. Several taphonomic characteristics indicate that the fossiliferous assemblage was subject to little selective processes during transportation. These are: predominance of disarticulated valves (although articulated valves are frequent) and perpendicular, oblique, concordant and nested arrangement of bioclasts in the sedimentary matrix. Absence of fragmentation, bioerosion and incrustation of the bioclasts, suggest fast burial of shells due to high sedimentation rate events. Diagenetic features, indicate that the fossils were later submitted to refossilization and mixing with other non-coeval bioclasts, resulting in some degree of time-averaging.

Análise da velocidade crítica de escoamento e estudo reológico de polpas de caulim da bacia do rio capim em dutos circulares

A indústria mineral representa um grande estimulador da economia do estado, e como destaque nessa indústria podemos mencionar o setor do beneficiamento de Caulim. As soluções dos problemas relacionados a essa atividade mostram-se como uma oportunidade rara de interação universidade-indústria, além de ser um campo fértil para o desenvolvimento científico. Um ponto importante a ser estudado trata do escoamento da suspensão de caulim em dutos e equipamentos relacionados; problemas como incrustação e calculo da perda de carga não foram ainda resolvidos de forma definitiva pela indústria. Nesse contexto o presente trabalho se dispõe a desenvolver uma metodologia para o cálculo dos parâmetros de escoamento principalmente da velocidade mínima necessária para que as partículas em suspensão não depositem no interior dos dutos. Assim o objetivo macro desta dissertação reside em analisar através da implementação de metodologia, o cálculo da velocidade de deposição durante o escoamento de polpas de caulim com diferentes frações mássicas (% em peso de sólidos) no interior de dutos circulares; a partir do estudo reológico de amostras obtidas no seu processo de beneficiamento; propiciando assim, subsídio teórico aos técnicos e Engenheiros que desejam dimensionar um sistema de bombeamento aplicado a polpas de caulim; minimizando seus problemas de sub e superdimensionamento, que acarreta a deposição do material, causando danos à produção e meio ambiente, visto que se fará necessário à abertura da tubulação para remoção dos depósitos oriundos da baixa velocidade.

Revestimento, qualidade física e fisiológica de sementes de cenoura (Daucus carota L.) cv. Brasília

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribuição de bivalve invasor Limnoperna fortunei (Dunker, 1857) na Bacia do Rio Prata após vinte anos (1991-2014) de sua introdução na America do Sul

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

"Brienzi" - The blue Vivianite man of Switzerland: Time since death estimation of an adipocere body

In 1996, a cadaver in adipocere condition was discovered in a bay of the Brienzer See in Switzerland. The torso was named "Brienzi" following the "Iceman" Ötzi. Several outer parts of the body were incrusted; the incrustation was in blue color. Further investigations showed that the bluish covering of parts of the adipocere torso were a mineral known as Vivianite. Vivianite (Fe(3)(PO(4))(2-)(H(2)O)(8)) is an iron phosphate mineral with needle lengths between 100 and 150μm. It is normally associated in a context with organic archaeological and geological materials (some hundreds to millions of years old). Hitherto, it is only described in three cases of human remains. We were able to reconstruct the following facts about 'Brienzi': The man drowned in Lake Brienz or in one of its tributaries during the 1700s. The body was subsequently covered with sedimentation and thus buried under water. An earthquake produced an underwater landslide which eventually exposed the corpse.

Endocoronas de resina compuesta : presentación de un caso clínico

Las restauraciones de inserción rígidas, tanto incrustaciones como coronas, cuentan con el aval de una amplia experiencia clínica. En nuestra práctica diaria se nos presentan a menudo casos en los que no podemos resolver el problema de una gran destrucción coronaria con ninguno de estos tratamientos. En este trabajo se presenta un caso clínico solucionado mediante la confección de una endocorona de resina compuesta debido a la contraindicación clínica de las restauraciones tradicionales, ya que el elemento a ser tratado presentaba una perforación en el piso de la cámara pulpar con un pronóstico de sobrevida reservado.

Composition of bioclastic sands, carbonates and pyroclastic rocks of the Great Meteor and Josephine Seamounts, eastern North Atlantic

1. Great Meteor Seamount (GMS) is a very large (24,000 km**3) guyot with a flat summit plateau at 330-275 m; it has a volcanic core, capped by 150-600 m of post-Middle-Miocene carbonate and pyroclastic rocks, and is covered by bioclastic sands. The much smaller Josephine Seamount (JS, summit 170- 500 m w. d.) consists mainly of basalt which is only locally covered by limestones and bioclastic sands. 2. The bioclastic sands are almost free of terrigenous components, and are well sorted, unimodal medium sands. (1) "Recent pelagic sands" are typical of water depths > 600 m (JS) or > 1000 m (GMS). (2) "Sands of mixed relict-recent origin" (10-40% relict) and (3) "relict sands" (> 40% relict) are highly reworked, coarse lag deposits from the upper flanks and summit tops in which recent constituents are mixed with Pleistocene or older relict material. 3. From the carbonate rocks of both seamounts, 12 "microfacies" (MF-)types were distinguished. The 4 major types are: (1) Bio(pel)sparites (MF 1) occur on the summit plateaus and consist of magnesian calcite cementing small pellets and either redeposited planktonic bioclasts or mixed benthonic-planktonic skeletal debris ; (2) Porous biomicrites (MF 2) are typical of the marginal parts of the summit plateaus and contain mostly planktonic foraminifera (and pteropods), sometimes with redeposited bioclasts and/or coated grains; (3) Dense, ferruginous coralline-algal biomicrudites with Amphistegina sp. (MF 3.1), or with tuffaceous components (MF 3.2); (4) Dense, pelagic foraminiferal nannomicrite (MF 4) with scattered siderite rhombs. Corresponding to the proportion and mineralogical composition of the bioclasts and of the (Mgcalcitic) peloids, micrite, and cement, magnesian calcite (13-17 mol-% MgCO3) is much more abundant than low-Mg calcite and aragonite in rock types (1) and (2). Type (3) contains an "intermediate" Mg-calcite (7-9 mol-X), possibly due to an original Mg deficiency or to partial exsolution of Mg during diagenesis. The nannomicrite (4) consists of low-Mg calcite only. 4. Three textural types of volcanic and associated gyroclastic rocks were distinguished: (1) holohyaline, rapidly chilled and granulated lava flows and tuffs (palagonite tuff breccia and hyaloclastic top breccia); (2) tachylitic basalts (less rapidly chilled; with opaque glass); and (3) "slowly" crystallized, holocrystalline alkali olivine basalts. The carbonate in most mixed pyroclastic-carbonate sediments at the basalt contact is of "post-eruptive" origin (micritic crusts etc.); "pre-eruptive" limestone is recrystallized or altered at the basalt contact. A deuteric (?hydrothermal) "mineralX", filling vesicles in basalt and cementing pyroclastic breccias is described for the first time. 5. Origin and development of GMS andJS: From its origin, some 85 m. y. ago, the volcano of GMS remained active until about 10 m. y. B. P. with an average lava discharge of 320 km**3/m. y. The volcanic origin of JS is much younger (?Middle Tertiary), but the volcanic activity ended also about 9 m. y. ago. During L a t e Miocene to Pliocene times both volcanoes were eroded (wave-rounded cobbles). The oldest pyroclastics and carbonates (MF 3.1, 3.2) were originally deposited in shallow-water (?algal reef hardground). The Plio (-Pleisto) cene foraminiferal nannomicrites (MF 4) suggest a meso- to bathypelagic environment along the flanks of GMS. During the Quaternary (?Pleistocene) bioclastic sands were deposited in water depths beyond wave base on the summit tops, repeatedly reworked, and lithified into loosely consolidated biopelsparites and biomicrites (MF 1 and 2; Fig. 15). Intermediate steps were a first intragranular filling by micrite, reworking, oncoidal coating, weak consolidation with Mg-calcite cemented "peloids" in intergranular voids and local compaction of the peloids into cryptocrystalline micrite with interlocking Mg-calcite crystals up to 4p. The submarine lithification process was frequently interrupted by long intervals of nondeposition, dissolution, boring, and later infilling. The limestones were probably never subaerially exposed. Presently, the carbonate rocks undergo biogenic incrustation and partial dissolution into bioclastic sands. The irregular distribution pattern of the sands reflects (a) the patchy distribution of living benthonic organisms, (b) the steady rain of planktonic organism onto the seamount top, (c) the composition of disintegrating subrecent limestones, and (d) the intensity of winnowing and reworking bottom current

Incrustação em poço produtor de petróleo e gás natural: um estudo de caso

Water and gas is a common by - product of the oil production process. Production may be compromised by the precipitation of inorganic salts in both the reservoir and producing well, through scale formation. This precipitation is likely the cause of the formation damage. High temperatures and h igh pressures (HTHP) may favor the precipitation of insoluble salts. The most common types of scale in oil fields are calcium carbonate and calcium sulphate, strontium and barium sulphate. New types of scale formation have attracted special attention such as zinc sulphide and lead. This precipitation may occur in the pores of reservoir rocks, in the production string and in equipment, causing obstructions and consequent production losses. In this study, the influence of well depth on incrustation compositio n was investigated to design removal treatments and assess the behavior of these deposits along the string, through the analysis of pressure and temperature. Scale residues were recovered from the inside of the production string of an oil and gas well duri ng the string removal operation. A total of 10 samples from different depths (15.4 m to 4061.5 m) were obtained. Initially a dissolution test was conducted in weak acid, similar to that used in removal operations with this type of scale formation. Majority composition was defined and confirmed by dissolution tests using X - Ray Fluorescence Spectroscopy (XRF), X - Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) techniques. Residues with distinct characteristics were observed in different proportion s, showing a tendency toward increased and/or decreased mass with depth. In the samples closest to the surface, typical sandstone residues were found, with calcium (45% Ca) as the metal of highest concentration. The obtained results indicate correlations o f the scale types studied with the depth and, consequently, with the thermodynamic conditions of pressure and temperature.

Application of low temperature plasmas for restoration/conservation of archaeological objects

The low-temperature low-pressure hydrogen based plasmas were used to study the influence of processes and discharge conditions on corrosion removal. The capacitive coupled RF discharge in the continuous or pulsed regime was used at operating pressure of 100-200 Pa. Plasma treatment was monitored by optical emission spectroscopy. To be able to study influence of various process parameters, the model corroded samples with and without sandy incrustation were prepared. The SEM-EDX analyzes were carried out to verify corrosion removal efficiency. Experimental conditions were optimized for the selected most frequent materials of original metallic archaeological objects (iron, bronze, copper, and brass). Chlorides removal is based on hydrogen ion reactions while oxides are removed mainly by neutral species interactions. A special focus was kept for the samples temperature because it was necessary to avoid any metallographic changes in the material structure. The application of higher power pulsed regime with low duty cycle seems be the best treatment regime. The low pressure hydrogen plasma is not applicable for objects with a very broken structure or for nonmetallic objects due to the non-uniform heat stress. Due to this fact, the new developed plasmas generated in liquids were applied on selected original archaeological glass materials.

Remolding a company through a compliance program : the case of Siemens

Abstract : Since at least the 1980's, a growing number of companies have set up an ethics or a compliance program within their organization. However, in the field of study of business management, there is a paucity of research studies concerning these management systems. This observation warranted the present investigation of one company's compliance program. Compliance programs are set up so that individuals working within an organization observe the laws and regulations which pertain to their work. This study used a constructivist grounded theory methodology to examine the process by which a specific compliance program, that of Siemens Canada Limited, was implemented throughout its organization. In conformity with this methodology, instead of proceeding with the investigation in accordance to a particular theoretical framework, the study established a number of theoretical constructs used strictly as reference points. The study's research question was stated as: what are the characteristics of the process by which Siemens' compliance program integrated itself into the existing organizational structure and gained employee acceptance? Data consisted of documents produced by the company and of interviews done with twenty-four managers working for Siemens Canada Limited. The researcher used QSR-Nvivo computer assisted software to code transcripts and to help with analyzing interviews and documents. Triangulation was done by using a number of analysis techniques and by constantly comparing findings with extant theory. A descriptive model of the implementation process grounded in the experience of participants and in the contents of the documents emerged from the data. The process was called "Remolding"; remolding being the core category having emerged. This main process consisted of two sub-processes identified as "embedding" and "appraising." The investigation was able to provide a detailed account of the appraising process. It identified that employees appraised the compliance program according to three facets: the impact of the program on the employee's daily activities, the relationship employees have with the local compliance organization, and the relationship employees have with the corporate ethics identity. The study suggests that a company who is entertaining the idea of implementing a compliance program should consider all three facets. In particular, it suggests that any company interested in designing and implementing a compliance program should pay particular attention to its corporate ethics identity. This is because employee's acceptance of the program is influenced by their comparison of the company's ethics identity to their local ethics identity. Implications of the study suggest that personnel responsible for the development and organizational support of a compliance program should understand the appraisal process by which employees build their relationship with the program. The originality of this study is that it points emphatically that companies must pay special attention in developing a corporate ethics identify which is coherent, well documented and well explained.