Validation of an analytical methodology for the quantitative analysis of petroleum hydrocarbons in marine sediment samples

This work describes a validation of an analytical procedure for the analysis of petroleum hydrocarbons in marine sediment samples. The proposed protocol is able to measure n-alkanes and polycyclic aromatic hydrocarbons (PAH) in samples at concentrations as low as 30 ng/g, with a precision better than 15% for most of analytes. The extraction efficiency of fortified sediments varied from 65.1 to 105.6% and 59.7 to 97.8%, for n-alkanes and PAH in the ranges: C16 - C32 and fluoranthene - benzo(a)pyrene, respectively. The analytical protocol was applied to determine petroleum hydrocarbons in sediments collected from a marine coastal zone.

New strategies for treatment and reuse of spent sulfidic caustic stream from petroleum industry

This work examines traditional and new routes for removal of H2S and other sulfur compounds from spent sufidic caustic (SSC). SH- (hydrogenosulfide) and S2- (sulfide) ions were quantitatively oxidized at 25 ºC using H2O2, NaOCl or a spent sulfochromic mixture. SH-/S2- ions were also removed via reaction with freshly prepared iron or manganese hydroxides, or after passing the SSC through strong basic anion exchange resins (OH- form). The treated caustic solution, as well as iron/manganese hydroxides, removed H2S from diesel samples at 25 ºC. SSC treatment via strong basic anion-exchange resins produced the treated caustic solution with the highest free alkalinity.

Straightforward synthesis of 2,2,4,4,5,7,7-d7-cholestane: a new deuterated standard in petroleum analysis

A short and efficient synthesis of heptadeuterated 2,2,4,4,5,7,7-d7-cholestane (1) from cholesterol (3) is described. The deuterated material will be useful for the analysis of different sources of petroleum in analytical geochemistry laboratories as internal standard for quantification of steranes via gas chromatography-mass spectrometry (GC-MS).

USE OF A LOW-COST TEMPLATE-FREE ZSM-5 FOR ATMOSPHERIC PETROLEUM RESIDUE PYROLYSIS

To understand the physicochemical properties and catalytic activity during the pyrolysis of atmospheric petroleum residue, a template-free ZSM-5 zeolite was synthesized using a direct method without additional seeds or an organic structure director and compared with conventionally synthesized ZSM-5. The crystallinities of the two zeolites were evaluated by XRD and FTIR and were quite similar; however, structural analyses using SEM and argon physisorption revealed that the zeolites diverged in particle diameter and in the external surface area of the micropores. The synthesis procedure without a template incorporated additional aluminum into the crystalline network, according to ICP-AES and TPD NH3 experiments. The catalytic pyrolysis performed over the template-free ZSM-5 generated results comparable to those for pyrolysis performed over the conventional ZSM-5 according to its hydrocarbon distribution. The selectivity to aromatics compounds was exactly the same for both ZSM-5 zeolites, and these values stand out compared to thermal pyrolysis. The template-free ZSM-5 produced 20% of light hydrocarbons (C4-C6), where such compounds are olefins and paraffins of great interest to the petrochemical industry. Therefore, template-free ZSM-5 is promising for industrial use due to its lowered synthesis time, low-cost and significant distribution to light hydrocarbons.

Avaliação do desempenho analítico do método de determinação de TPH (Total Petroleum Hydrocarbon) por detecção no infravermelho

No presente trabalho os parâmetros de desempenho (validação intralaboratorial) da metodologia de determinação de TPH (Total Petroleum Hydrocarbons) foram determinados por detecção na região do infravermelho com o equipamento da Infracal TOG/TPH, visando aplicação em amostras de areia contaminadas com petróleo. Os ensaios foram realizados utilizando Óleo Marine Fuel 380, com densidade igual 0,987 g cm-3 e viscosidade de 5313 cP a 20°C. Este óleo foi fornecido pelo Centro de Pesquisa da Petrobrás (CENPES/PETROBRÁS/RJ), sendo o mesmo óleo derramado no acidente ocorrido em janeiro de 2000, na Baia de Guanabara, RJ, quando 1.300 m3 vazaram do duto que interliga a REDUC (Refinaria Duque de Caxias, RJ) ao terminal da Ilha d’Água/RJ, atingindo praias. Os resultados da validação indicaram que o desempenho da metodologia foi favorável à aplicação que se destina. Entre os parâmetros metrológicos obtidos neste trabalho, o limite de detecção do método foi de 4,06 mg L-1, consideravelmente inferior à faixa de concentração normalmente obtida para amostras em tais situações.

Agricultural engineering at UNICAMP: undergraduate student dropout analysis

Nowadays, dropping out in B.Sc. courses practically occurs in all Universities of the contemporary world. Undergraduate student withdraw could means several losses as, to the student, not to graduate, to the teacher, for not accomplishing his goal as educator, to the university, for not attending its mission, to the society, economic and social losses and also to the family for unfulfilling the dreams. The objective of this research is to present a quantitative study on the dropping out rate in the Agricultural Engineering B.Sc. program (BSAGENG) at State University of Campinas (UNICAMP), seeking to contribute to the understanding of this issue. It has been determined the dropping out rate from 1995 to 2006 based on the university official data, by employing four different methods of calculation. Three of the methods revealed that dropping out rate is very close to the graduation index, i.e., close to 50%. Regardless of the adopted method for the dropping rate estimation and the statistics demonstrating that the agricultural engineering undergraduate course at UNICAMP figures falls within similar courses normality in Brazil, it should be recognized that a public institution of education should be concerned in presenting such figures. A detailed and deep analysis must be outlined in further studies seeking for specific actions aiming to reduce dropping out process.

Insights on bovine genetic engineering and cloning

Transgenic technology has become an essential tool for the development of animal biotechnologies, and animal cloning through somatic cell nuclear transfer (SCNT) enabled the generation of genetically modified animals utilizing previously modified and selected cell lineages as nuclei donors, assuring therefore the generation of homogeneous herds expressing the desired modification. The present study aimed to discuss the use of SCNT as an important methodology for the production of transgenic herds, and also some recent insights on genetic modification of nuclei donors and possible effects of gene induction of pluripotency on SCNT.

Genetic engineering of baker's and wine yeasts using formaldehyde hyperresistance-mediating plasmids

Yeast multi-copy vectors carrying the formaldehyde-resistance marker gene SFA have proved to be a valuable tool for research on industrially used strains of Saccharomyces cerevisiae. The genetics of these strains is often poorly understood, and for various reasons it is not possible to simply subject these strains to protocols of genetic engineering that have been established for laboratory strains of S. cerevisiae. We tested our vectors and protocols using 10 randomly picked baker's and wine yeasts all of which could be transformed by a simple protocol with vectors conferring hyperresistance to formaldehyde. The application of formaldehyde as a selecting agent also offers the advantage of its biodegradation to CO2 during fermentation, i.e., the selecting agent will be consumed and therefore its removal during down-stream processing is not necessary. Thus, this vector provides an expression system which is simple to apply and inexpensive to use

Microencapsulation and tissue engineering as an alternative treatment of diabetes

In the 70's, pancreatic islet transplantation arose as an attractive alternative to restore normoglycemia; however, the scarcity of donors and difficulties with allotransplants, even under immunosuppressive treatment, greatly hampered the use of this alternative. Several materials and devices have been developed to circumvent the problem of islet rejection by the recipient, but, so far, none has proved to be totally effective. A major barrier to transpose is the highly organized islet architecture and its physical and chemical setting in the pancreatic parenchyma. In order to tackle this problem, we assembled a multidisciplinary team that has been working towards setting up the Human Pancreatic Islets Unit at the Chemistry Institute of the University of São Paulo, to collect and process pancreas from human donors, upon consent, in order to produce purified, viable and functional islets to be used in transplants. Collaboration with the private enterprise has allowed access to the latest developed biomaterials for islet encapsulation and immunoisolation. Reasoning that the natural islet microenvironment should be mimicked for optimum viability and function, we set out to isolate extracellular matrix components from human pancreas, not only for analytical purposes, but also to be used as supplementary components of encapsulating materials. A protocol was designed to routinely culture different pancreatic tissues (islets, parenchyma and ducts) in the presence of several pancreatic extracellular matrix components and peptide growth factors to enrich the beta cell population in vitro before transplantation into patients. In addition to representing a therapeutic promise, this initiative is an example of productive partnership between the medical and scientific sectors of the university and private enterprises.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based scaffolds for tissue engineering

Development and selection of an ideal scaffold is of importance for tissue engineering. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biocompatible bioresorbable copolymer that belongs to the polyhydroxyalkanoate family. Because of its good biocompatibility, PHBHHx has been widely used as a cell scaffold for tissue engineering. This review focuses on the utilization of PHBHHx-based scaffolds in tissue engineering. Advances in the preparation, modification, and application of PHBHHx scaffolds are discussed.