Ceramic Crucible Corrosion by Heavy Metal Oxide Glasses, Part II: Diffusion Study

Due to their low cost and high resistance to corrosion, ceramic crucibles can be used for the melting of PBG glasses (PbO-BiO 1.5GaO 1.5). These glasses present good window transmission from ultra-violet to infrared, making their use as optical fibres promising. However, their disadvantage is the high reactivity, leading to the corrosion of different crucibles, including gold and platinum ones. In this work, the corrosion of Al 2O 3, SnO 2 and ZrO 2 crucibles after melting at temperatures varying from 850 to 1000°C, was evaluated by Scanning Electronic Microscopy (SEM) in conjunction with microanalysis by EDS. The lead diffusion profile in the crucible material was obtained. Diffusion coefficients were calculated according to the Fick and Fisher theories. Results indicated that the different crucibles presented similar behaviour: in the region near the interface, diffusion occurs in the volumetric way and in regions away from the interface, diffusion occurs through grain boundary.

Modal Analysis of a Beam with a Tip Rotor by Using a Fundamental Response

The shape modes of a damped-free beam model with a tip rotor are determined by using a dynamical basis that is generated by a fundamental spatial free response. This is a non-classical distributed model for the displacements in the transverse directions of the beam which turns out to be coupled through boundary conditions due to rotation. Numerical calculations are performed by using the Ritz-Rayleigh method with several approximating basis.

Influence of age on combined effects of cyclosporin and nifedipine on rat alveolar bone

Background: There is some evidence showing that cyclosporin A (CsA) and nifedipine (NIF) affect bone metabolism. The purpose of this work was to study the effects of CsA and NIF, given alone or concurrently, on alveolar bone of rats of different ages. Methods: Rats 15, 30, 60, and 90 days old were treated daily with 10 mg/kg body weight of CsA subcutaneously injected and/or 50 mg/kg body weight of NIF/day given orally for 60 days. Alveolar bone of the first lower molars was morphologically and stereologically evaluated in serial 5 μm bucco-lingual paraffin sections, stained with hematoxylin and eosin. Serum calcium and alkaline phosphatase levels were measured in all animals at the end of the experimental period. Results: Rats treated with CsA or NIF alone or CsA and NIF concurrently showed decreased alveolar bone density. CsA was more effective than NIF. A significant decrease in serum calcium was found only in animals treated with CsA or CsA/NIF. The results were similar regardless of age. Conclusions: These results indicate that the decrease in the alveolar bone volume in rats caused by CsA and NIF alone or concurrently is not age dependent. Furthermore, NIF (50 mg/kg) did not further increase the loss of alveolar bone volume induced by CsA (10 mg/kg).

Análise retrospectiva da toxicidade de gotas otológicas, medicamentos tópicos nasais e orofaríngeos registrada na Grande São Paulo.

BACKGROUND: Retrospective analysis of human toxicity files involving topical medicines for treatment of upper airways diseases (eardrops, topical nasal medicines, lozenges, drops and sprays for oropharyngeal affections). METHODS: Thirty-four brands of eardrops, 48 of topical nasal medicines and 22 of tablets, lozenges and sprays for oropharyngeal affections were selected, from a total of 104 products available in Brazil. We analyzed the registries in the electronic database from the Poison Control Centre of São Paulo (CCI-Jabaquara), Brazil, for the period from January 1996 through December 2000. The cases related to selected pharmaceuticals were collected. RESULTS: 10,823 cases of human toxicity caused by medicines were voluntarily reported to CCI-Jabaquara. Topical medicines for treatment of upper airways diseases accounted for 291 cases (2.68%), from which 240 (82.5%) represented poisoning; 12 (4.1%) involved ear drops, 268 (92%), topical nasal medicines and 11 (3.9%), topical medicines for oropharyngeal affections. Among topical nasal medicines, vasoconstrictors predominated (233 cases), and among medicines for oropharyngeal affections, it was tetracaine (four cases). Considering age distribution, toxicity predominated significantly in children aged from 1 to 4 years (p=0.0003). The main causes of toxicity were: accidental intake of medicines (43%) and error in drug administration (14.8%). Hypereflexia and vomiting were the most frequent symptoms related to toxicity. CONCLUSIONS: There was significant incidence of systemic toxicity due to eardrops, topical nasal and oropharyngeal medicines in children 1 to 4 years-old, whose main cause was accidental intake of these medicines.

Emprego do reagente de fenton como agente coagulante na remoção de substâncias húmicas de água por meio da flotação por ar dissolvido e filtração

Fenton 's reagent was used as coagulant agent to treat water with high true color (100 ± 5 HU) caused by the introduction of humic substances extracted from peat, using dissolved air flotation. The pair value of coagulant dosage x coagulation pH was optimized to posterior construction of coagulation diagrams, reaching apparent color removal efficiency slightly superior to 60%. It was tried to simulate a treatment with complete cycle, carrying out an experiment with sand filtration after flotation, obtaining an effluent with excellent quality, presenting remnant apparent color, turbidity and absorbance of 253.7 nm less or equal to 2 HU, 0.40 TU and 0.009 cm -1, respectively, and residual total iron < 0.005 mg/L and DOC < 0.001 mg/L.

Morfologia de plântulas e estádios juvenis de espécies invasoras

The morphology of 20 species of weeds that occur in the most common crops in Maringá, Paraná State, Brazil and adjacent regions were described at early developmental stages, in order to identify the species in the field and provide information for taxonomic and ecological works. Sixteen species featured epigeal-foliaceous seedlings. The seedling in Cardiospenuum halicacabum is epigeal-fleshy; in Cenchrus echinatus and Digitaria horizontalis it is hypogeal and in Commelina virginica is epigeal-cryptocotyledonar. The differentiation of the first eophyll occurred within ten (Digitaria horizontalis) to 35 days (Bidens pilosa) and the first metaphyll appeared within 22 (Commelina virginica) to 49 days (Acanthospenuum australe). The number of eophylls varied from one to four, and the phyllotaxis varied from alternate to opposite.

Citologia do lavado broncoalveolar de eqüinos da polícia militar do distrito federal

The objective of this study was evaluate the airways' cells types from horses of the military police of Federal District. It was used 24 horses, divided into 2 groups of 12: group I - animals in policy activity and group II - animals out of policy activity. At the inspection, physical exam and blood exam, the results agreed with no present clinical pathologies. It was infused 240mL of saline solution in the bronchoalveolar wash. In the bronchoalveolar wash, the group I registered 25.25±7.3 squamous cells, 20.2±5.5 epithelial cells, 22.2±6.23 macrophages and 2.02±5.77 erythrocytes, and in the group II, it was observed 31.0±9.47 squamous cells, 19.0±5.20 epithelial cells, 43.0±13.88 macrophages, 4.0±1.52 eosinophile and 3.0±1.0 erythrocytes. Verifying the occurrence of side effects after the experiment, there was no problem from the used technique.

A medical information system to manage a cancer database

Cancer is the second main cause of death in Brazil, and according to statistics disclosed by INCA - National Cancer Institute 466,730 new cases of the disease are forecast for 2008. The storage and analysis of tumour tissues of various types and patients' clinical data, genetic profiles, characteristics of diseases and epidemiological data may provide more precise diagnoses, providing more effective treatments with higher chances for the cure of cancer. In this paper we present a Web system with a client-server architecture, which manages a relational database containing all information relating to the tumour tissue and their location in freezers, patients, medical forms, physicians, users, and others. Furthermore, it is also discussed the software engineering used to developing the system.

La salud bucal en la percepción del adolescente

Objective An individual does not always experience the best health and vitality indexes during her/his adolescence. This study evaluated young people's awareness of their oral health and the factors involved in dental maintenance and promotion Material and Method Adolescents (n=493) from the Mirim Foundation in the town of Araçatuba in the state of São Paulo, Brazil, were asked to fill in a semi-structured questionnaire. Results 68.4 % of the youngsters interviewed regarded oral health as referring to hygiene and 16.2 % to physical appearance; 53.6 % of the group perceived their oral health to be good and 24 % optimum. 90.1 % indicated oral hygiene when asked how oral health could be ensured; however, only 4.8 % mentioned brushing their tongues. Physical appearance (62.9 %) was one of the main reasons stated as being important for teeth. A statistically significant relationship was observed between perception of regular dental and mouth health and having visited the dentist at least six months beforehand (x2=30.75; p<0.05). Conclusion Even though the youngsters had a general idea regarding their oral health, its maintenance and promotion, better information should be made available regarding such topics and be approached through health education so that these adolescents can have good oral health for the rest of their lives, as well as becoming knowledge multiplying agents for those who do not have access to the same information.

Modulation of insulin secretion by physical training during recovery from protein malnutrition in rats

Objective: The purpose of the present study was to examine insulin secretion in rats submitted to protein restriction and nutritional recovery associated or not to physical training. Methods: The experiment was designed in two sets of five weeks each. In the first set the rats were fed a nonnal-protein diet(17%-control group) or a low-protein diet (6%-malnourished group) for five weeks. After this, all animals were fed the 17% protein diet and separated into four groups: sedentary control(SC); trained eontrol(TC); sedentary recovered(SR) and trained recovered(TR). TC and TR rats performed swimming exercise. Results: The results indicated efficiency of the 6% protein diet in producing signs of malnutrition, as reduction in body weight gain and serum albumin levels, as well as liver fat. Serum insulin in the fed state and insulin secretion by isolated pancreatic islets in response to glucose were Keduced,but peripheral sensitivity to insulin was increased and glucose tolerance was not changed in the protein deficient rats, indicating adaptation to malnutrition. Diet protocol for nutritional recovery was efficient in repairing body weight gain, serum albumin and liver fat levels of the previously malnourished rats. Glucose induced insulin release by pancreatic islets remained low after nutritional recovery. Insulin secretion by the islets isolated from rats submitted to exercise training during nutritional recovery was improved when compared with the sedentary animals. Conclusion: This indicates that exercise training may be useful in the treatment of protein calorie malnutrition, concerning to glucose induced insulip secretion.

Desenvolvimento vegetativo de quatro espécies de grama irrigadas com efluente doméstico

This research aimed to compare the development of four grasses species irrigated by dripping with an effluent from a domestic wastewater station treatment in a small rural community, and supply water from Sabesp. For this purpose, an experiment was conducted in a greenhouse at the FCA/UNESP (Botucatu - SP) for 12 months in a completely randomized 4 × 3 factorial design, with four replications, totalizing 48 parcels. Grass species used in this experiment were: Santo Agostinho (Stenotaphrum secandatum (Walt.) Kuntze); Bermudas (Cynodum dactylon); Esmeralda (Zoysia japônica) and São Carlos (Axnopus sp). The treatments were: T1- Irrigation with re-use; T2- Irrigation with re-use + chemical fertilization and T3- Irrigation with supply water from Sabesp + chemical fertilization (control). Data were submitted to comparison of means by Tukey's test at 5 %. The results showed that nitrogen in the wastewater was enough for the good development of the grass species. However, its use caused higher potassium loss.

SIG - SPRING aplicado na determinação da capacidade de uso das terras da microbacia do Ribeirão Pouso Alegre - Jaú (SP)

A população mundial vem sofrendo, cada vez mais, as conseqüências das agressões efetuadas pelo homem ao meio ambiente, principalmente quanto à ocupação e uso inadequado das terras, o que ocasiona empobrecimento e depauperamento do solo, influenciando na qualidade e disponibilidade de água, levando à destruição das reservas florestais. Assim, é necessária a implantação de políticas públicas, que contemplem o desenvolvimento econômico, urbano, rural e social de uma região, preservando os recursos naturais para futuras gerações. A bacia em estudo está localizada entre as coordenadas UTM 764942; 7546214 e 741816; 7534759, com uma área de 14699,7ha. Este trabalho visou definir as classes de capacidade de uso de terra da microbacia do Ribeirão Pouso Alegre - Jaú (SP) através do Sistema de Informações Geográficas - SPRING. A carta de capacidade de uso da terra foi elaborada a partir do cruzamento das cartas clinográfica e de solo, que foram elaboradas pelo SIG Spring, e o cruzamento de dados foi feito através do LEGAL - Linguagem Espacial para Geoprocessamento Algébrico. Os resultados mostraram que a microbacia é constituída essencialmente pelas classes II e III e o SIG-SPRING permitiu através dos seus módulos discriminarem e quantificar as áreas das classes de terras, declive e capacidade de uso da terra rapidamente.

On stability of differential equations with piecewise constant argument using dichotomic maps

This paper deals with the study of the basic theory of existence, uniqueness and continuation of solutions of di®erential equations with piecewise constant argument. Results about asymptotic stability of the equation x(t) =-bx(t) + f(x([t])) with argu- ment [t], where [t] designates the greatest integer function, are established by means of dichotomic maps. Other example is given to illustrate the application of the method. Copyright © 2011 Watam Press.

Prevalence and microscopic features of enamel pearls from permanent human molars

Enamel pearls are ectopic structures observed mainly on the roots of permanent teeth and could be related to periodontal diseases. Aim: To evaluate the prevalence of enamel pearls in extracted human molars and characterize their structures using light and scanning electron microscopy. Methods: The study comprised 2,201 extracted human permanent molars. The teeth were analyzed and classified according to morphological features. The presence, location and shape of enamel pearls were investigated. Fifteen human molars with enamel pearls were embedded in acrylic resin and observed by light microscopy. Results: Seventy-one enamel pearls were identified on third molar root. Microscopically, most pearls were composed of prismatic irregular enamel and normal dentin. The dentinoenamel junction presented an irregular course. The number of dentinal tubules was normal and they presented curvature to continue within the root dentin of the carrier tooth. Dentinal tubules below the enamel pearls were closer to each other. Conclusions: Scanning electron microscopic analysis revealed that the enamel pearls were similar to coronal enamel.

On-line collaborative learning for in-service teacher education

This article brings some of the results of a study that analyzes a hybrid course for in-service teachers in the Project Teletandem Brazil: foreign languages for all. In this project, Brazilian teachers of Spanish as a foreign language took part in a blended tandem learning course, communicating via videoconferencing with Uruguayan teachers of Portuguese as a foreign language. The aim of the study was to verify Brazilian teachers' concepts and beliefs concerning language and culture and how the teletandem interactions affected them. After the interactions, teachers' views of culture seemed to also incorporate aspects of culture as an interpersonal process, instead of the factual and static view which was previously predominant. Therefore teacher education programs must consider the possibility of conjugating theory and reflective practice through the use of videoconference tools in order to allow teachers to experience culture rather learn facts about it. © 2011 ACADEMY PUBLISHER.