Papers by Leonardo Marcílio
Chemical Engineering Journal, 2010
In this study we investigated the production of soluble iron and chromium sulfate complexes from ... more In this study we investigated the production of soluble iron and chromium sulfate complexes from high carbon ferrochromium alloy (Fe-Cr-HC) for utilization as a tanning agent. The temperature, sulfuric acid concentration, and the reaction time between Fe-Cr-HC and sulfuric acid were selected as independent variables for iron and chromium conversion. A quadratic response surface model was adjusted using the Box-Behnken statistical experimental design technique. The results obtained by solving multi-objective optimization problem have shown about 98.6-100% Cr and 86.9-89.1% Fe conversions. Perchloric acid and ammonium sulfate additions were investigated in order to determine the system limitations. The results have showed that an increase of perchloric acid concentration decreased the quantity of soluble chromium and iron compounds, while an ammonium sulfate addition improved the conversion of chromium up to 100%.
The species Plantago ovata has great importance for the pharmaceutical industry due to the high m... more The species Plantago ovata has great importance for the pharmaceutical industry due to the high mucilage level in its seeds. Thus, the present study aimed to verify proline level and amylase and ascorbate peroxidase activity in the germination of seeds subjected to stress, which was induced by using PEG, NaCl and CaCl 2 solutions. Fifty seeds were placed into filter paper moistened with 15 mL of such solutions at the potentials 0,-0.2, -0.4, -0.6 and -0.8 MPa in the presence of light at 25ºC. Proline levels decreased during Plantago ovata germination under water and salt stress, whereas the activity of ascorbate peroxidase and amylase was higher under PEG-induced stress, relative to those induced by NaCl and CaCl 2 .
Journal of Hazardous Materials, 2009
The leather waste generated by the footwear industry is considered dangerous due to the presence ... more The leather waste generated by the footwear industry is considered dangerous due to the presence of trivalent chromium, derived from the salt utilized to tan hides. In Brazil, the majority of this waste is disposed on landfills and only about 3% are recycled. The thermal treatment is an alternative method for purification of such residues. By using this technique it is possible to generate energy and recover the chromium present in the ash for the production of basic chromium sulfate (tanning industry), high carbon ferrochromium or carbon-free ferrochromium (steel industry). In the last 10 years, the gasification and combustion of footwear leather waste have been intensively studied at the Federal University of Rio Grande do Sul. The research experiment for characterization of the emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were carried out in a semi-pilot unit (350 kW th ). From new investments the thermal capacity of the unit will increase to 600 kW th . The unit will produce power from the heat generated in the combustion. The experimental results indicated that during the thermal treatment of footwear leather wastes, the formation mechanism of PCDD/F is the de novo synthesis. Most of PCDD/F were found in the particulate phase (>95%). A kinetic model was used for discussion of the achieved experimental results. The model is based in the carbon gasification, PCDD/F formation, desorption and degradation. From the conclusions obtained in this work will be possible minimize the PCDD/F formation in process of combustion of footwear leather wastes.
Sao Paulo Medical Journal, 2004
CONTEXT: Hemangiopericytoma is a relatively rare tumor, first described in 1942, with approximate... more CONTEXT: Hemangiopericytoma is a relatively rare tumor, first described in 1942, with approximately 300 cases described in the literature to date. In most cases, it affects the trunk and lower extremities. The head and neck incidence is less than 20%, mostly in adults. We describe a case of malignant head and neck hemangiopericytoma in a child. TYPE OF STUDY: Case report. CASE REPORT: A twelve-year-old male patient noted the presence of a firm painless right-side retroauricular lymph node of 1 cm in diameter, which at first remained unchanged for six months, but subsequently enlarged progressively. He denied having had previous trauma at that site. In November 2000, he presented nasal obstruction and voluminous epistaxis that required hospitalization and blood transfusion. During dental treatment one month later, a cranial x-ray revealed bone alterations. A subsequent computed tomography scan showed an extensive lesion of soft tissue density that had invaded the maxillary fossa, eroding the skull base and middle and nasal fossa. The child was then referred to our service, where biopsy was performed, giving a diagnosis of hemangiopericytoma. Shortly afterwards, magnetic resonance imaging revealed that this lesion had undergone significant growth, while maintaining the same invasion pattern. The patient was submitted to conservative surgery in April 2001, with only partial resection of the tumor because of its extent. Histopathological examination of the specimen confirmed the presence of malignant hemangiopericytoma. Following the surgery, the patient presented fast regrowth of the lesion, with partial response to chemotherapy and radiotherapy.
Arquivos De Neuro-psiquiatria, 2005
Spinal schwannomas are frequently observed among patients treated in a reference neurosurgery cen... more Spinal schwannomas are frequently observed among patients treated in a reference neurosurgery center. Cystic spinal schwannomas, however, are very scantly found. Due to its indolent behavior and benign course, the diagnosis of schwannomas may pose a challenge to the care giver, and the imaging findings can be misleading. In this article, we illustrate an example of a pauci-symptomatic 55 year-old male patient whose complaint was solely a non specific lumbar pain. Investigation revealed a large cystic lesion comprising the lower lumbar intradural space. He was then treated with microneurosurgical technique involving complete removal of the tumor and reconstruction of the duramater. Histological and immunohystochemical diagnosis were consistent with cystic schwannoma. The patient presented with complete recovery of his symptom. In this article we aim to emphasize the clinical presentation and treatment of lumbar spine schwannomas, and to illustrate the imaging findings within this uncommon case.
Fuel and Energy Abstracts, 2011
The footwear leather waste (FLW) has shown some distinct features of a conventional biomass, amon... more The footwear leather waste (FLW) has shown some distinct features of a conventional biomass, among which high concentrations of sulfur and chromium. The paper presents the obtained experimental results from gasification and combustion of FLW performed in a semi-pilot plant (350 kW th ). The corrosion tests were carried out with one low carbon steel and three stainless steels at temperature around 500°C. The obtained corrosion rates for all the tested alloys were significantly lower than those observed on other types of biomass. The presence of chromium oxide and sulfur dioxide in the flue gas was associated with reduction in the corrosion rate.
Aspect-oriented programming has introduced new possibilities for developing frameworks, but it al... more Aspect-oriented programming has introduced new possibilities for developing frameworks, but it also brought complexity to aspectoriented framework reuse. Therefore, if an aspect-oriented framework does not have well documented extension points and reuse steps, it becomes very difficult for the application developer to reuse it. This work presents AFR (Aspect-oriented Framework Reuse), an approach to facilitate the aspect-oriented framework reuse. The AFR assists application developer when placing application specific needs into frameworks extension points.
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Papers by Leonardo Marcílio