Efeitos no solo do gesso produzido em diferentes reações químicas da solução de ácido sulfúrico reciclada com carbonato de cálcio residual e óxido de cálcio.

2011

APONTAMENTOS ACERCA DA DISCUSSÃO SOBRE A INTRODUÇÃO DAS EMPRESAS DE CELULOSE NOS PAMPAS GAÚCHOS: PARA ONDE VAI A FRONTEIRA SANT´ANA DO LIVRAMENTO E RIVERA?

Os Municípios de Sant´Ana do Livramento – RS - Brasil e Rivera - Uruguai, instaladas no coração dos pampas gaúchos, apresentam uma paisagem que se caracteriza por uma vastidão de campos, coxilhas e gado, tem sua história associada a economia ganadeira e a cultura das gentes que habitam esse pampa, o gaúcho e sua vivência campeira símbolo de uma cultura que supera as barreiras da nacionalidade e das fronteiras impostas pelos colonizadores. Os pampas e seus habitantes passam por uma transformação profunda que está associada a decadência da economia ganadeira e a ascensão da economia madeireira. Cada vez mais observa-se a plantação de grandes extensões de terras com pinus e eucaliptus e a implantação, muitas vezes conflituosa, de empresas de celulose em locais onde antes reinavam os frigoríficos. O presente trabalho tem o objetivo de analisar o processo de substituição da economia ganadeira pela introdução da economia madeireira nessas cidades e avaliar as implicações sociais, econômicas, culturais e ambientais através de um extenso levantamento bibliográfico, de pesquisas junto a órgãos governamentais e de trabalhos de campo que permitam compreender as transformações atuais, as tendências de reprodução do grande capital associado ao latifúndio e as alternativas e formas de resistência a esse modelo hegemônico de “desenvolvimento” na fronteira. 

Produção e degradação da serrapilheira de espécies lenhosas da caatinga e sua contribuição na recuperação de áreas degradadas.

Resumo: O entendimento do fluxo de produção e do aporte de nutrientes via decomposição da serrapilheira e as interações do processo com parâmetros edáficos e ciclagem de nutrientes de espécies nativas da Caatinga têm sido pouco estudados. O conhecimento sobre ciclagem de nutrientes em florestas manejadas também permite inferências sobre as espécies com maior capacidade de reciclagem de nutrientes e seu potencial para recuperação de áreas degradadas. Objetivou-se com isso avaliar a produção e a degradação da serrapilheira de oito espécies lenhosas da Caatinga e mensurar os efeitos de sua aplicação sobre a fertilidade do solo e sobre a produção de sorgo em solo degradado. Para isso realizou-se três ensaios: para o ensaio I quantificou-se a produção de serrapilheira em um delineamento inteiramente casualizado com 6 repetições, por meio da instalação de coletores sob a projeção da copa das espécies (tratamentos): mofumbo, sabiá, jurema-preta, jucá, catingueira, pereiro, pau-branco e marmeleiro, sendo o material coletado mensalmente; foram quantificadas a produção das frações folhas, caule, material reprodutivo, miscelânea e total, bem como o aporte de nutrientes no período chuvoso e seco. Para o ensaio II avaliou-se a taxa de degradação da fração folhas de cada espécie citada por meio da utilização de litter bags, em delineamento inteiramente casualizado com 4 repetições, as coletas foram aos 0, 30, 60, 90, 120 e 150 dias, em seguida quantificou-se os macro e micronutrientes, celulose, lignina e carbono em cada tempo de amostragem. Para o ensaio III, realizou-se experimento em casa de vegetação para mensurar os efeitos da aplicação dos resíduos da serrapilheira das mesmas espécies mencionadas nos ensaios anteriores (I e II) sobre a fertilidade do solo e a produção de sorgo em solo degradado, neste experimento adotou-se o delineamento em blocos casualizados com 5 tratamentos e 5 repetições, sendo avaliadas doses equivalentes a: 0, 15, 30, 60 e 120 kg ha-1 de N dos resíduos de cada espécie e um tratamento adicional com adubação mineral, totalizando 30 unidades experimentais para cada espécie. As variáveis mensuradas foram biométricas, biomassa, teor relativo de clorofila e nitrogênio total, além de análises de fertilidade do solo. Com a análise dos dados verificou-se que a época de maior produção de serrapilheira ocorreu no final do período chuvoso para o início do período seco. A espécie jucá apresentou maior produção de serrapilheira, comparado às outras espécies. O nutriente cálcio apresentou maior acúmulo na serrapilheira para as espécies mofumbo, sabiá, catingueira, pereiro e marmeleiro e o nitrogênio foi superior para as espécies jurema-preta, jucá e pau-branco. Para todas as espécies avaliadas no ensaio de degradação houve redução significativa na sua biomassa em relação ao tempo zero, apresentando a seguinte ordem de velocidade de decomposição: jurema-preta > catingueira > pau-branco > jucá > marmeleiro > mofumbo > pereiro > sabiá. No ensaio de fertilização com os resíduos verificou-se que o marmeleiro promoveu efeitos negativos no solo, como acidificação. Porém, a aplicação dos resíduos da espécie pau-branco foi a que promoveu aumento nos valores de K, SB e CEC do solo e na produção do sorgo os resíduos de jurema-preta e pau-branco foram as que promoveram aumento na massa seca das plantas. Enquanto a adubação mineral proporcionou aumento na produção de massa seca do sorgo, demonstrando que a associação entre adubo mineral e o uso da serrapilheira de espécies da Caatinga pode ser uma opção viável para acelerar a recuperação de solos degradados. Abstract: The understanding of the production flow and nutrient supply via decomposition of litter and process interactions with edaphic parameters and nutrient cycling of native species of the Caatinga has been little studied. The knowledge of nutrient cycling in managed forests also allow inferences about species with capacity greater nutrient recycling capacity and its potential for recovery of degraded areas. This study aimed to evaluate the production and litter degradation 8 woody species of Caatinga and measure the effects of its application on soil fertility and production of sorghum in degraded soil. To this was carried out three tests: for the test I quantified the production of litter in a completely randomized design with 6 replications, by installing collectors under the canopy projection in the species (treatments): mofumbo, sabiá, jurema-preta, jucá, catingueira, pereiro, pau-branco and marmeleiro for each species, and the material collected monthly, were quantified the production of fractions leaves, stem, reproductive material, miscellany and total nutrient intake in the rainy and dry season. For II test evaluated the degradation rate of the fraction leaves through the use of litter bags, in a completely randomized design with 4 replications, the collected was 0, 30, 60, 90, 120 and 150 days and quantitated nutrients, cellulose, lignin and carbon at each evaluation time. For the III test, there was the experiment in a greenhouse to measure the effects of the application of litter waste of the same species of previous tests (I and II) on soil fertility and production of sorghum in degraded soil, was adopted the randomized block design with 5 treatments and 5 replications and evaluated doses equivalent to: 0, 15, 30, 60 and 120 kg ha-1 N of waste each species and an additional treatment with mineral fertilizer, totaling 30 experimental units for each species. Biometric analysis and biomass, relative chlorophyll content and total nitrogen were proceeded. In addition to soil fertility analysis. With the data analysis it was found that the time of greatest litterfall occurred at the end of the rainy season to the beginning of the dry season. The jucá species showed higher production compared to other species. The nutrient calcium had higher accumulation for the species mofumbo, sabiá, catingueira, pereiro and marmeleiro and nitrogen was higher for species jurema-preta, jucá and pau-branco. All species evaluated in degradation test had a significant reduction in biomass over time zero. They presented the following order of decomposition rate: jurema-preta > catingueira > pau-branco > jucá > marmeleiro > mofumbo > pereiro > sabiá. For fertility test it was found that marmeleiro promoted negative effects on soil, such as acidification. However, pau-branco was the specie that promoted further improvements in the K values, SB and CEC to the soil and for the production of sorghum, the waste jurema-preta and pau-branco promoted increase in dry matter plants. While the mineral fertilization provided an increase in dry matter production of sorghum, demonstrating that the combination of mineral fertilizer and the use of litter of Caatinga species may be a viable option to speed up the recovery of degraded soils.

Effect of residual vanadyl ions on the spectroscopic analysis of humic acids: a multivariate approach.

In a study of the vanadyl (VO2þ)-humic acids system, the residual vanadyl ion suppressed fluorescence and specific electron paramagnetic resonance (EPR) and NMR signals. In the case of NMR, the proton rotating frame relaxation times (T1qH) indicate that this suppression is due to an inefficient H-C cross polarization, which is a consequence of a shortening of T1qH. Principal components analysis (PCA) facilitated the isolation of the effect of the VO2þ ion and indicated that the organic free radical signal was due to at least two paramagnetic centres and that the VO2þ ion preferentially suppressed the species whose electronic density is delocalized over O atoms (greater g-factor). additionally, the newly obtained variables (principal components ? PC) indicated that, as the result of the more intense tillage a relative increase occurred in the accumulation of: (i) recalcitrant structures; (ii) lignin and long-chain alkyl structures; and (iii) organic free radicals with smaller g-factors.

Obtenção de lignina em escala nanométrica.

2016

Relationships between residual intake and gain, performance, feeding behavior and body measures in Brahman young bulls

2016

Celulose de fibra longa a partir de sorgo biomassa, um significativo potencial para o setor de papel e celulose na região Centro-Oeste.

2016

Residual effects of pesticides in peach orchards on the maize weevil Sitophilus zeamais (Coleoptera: Curculionidae)¹.

2016

Association analyses pointed the TIPARP as a potential candidate gene influencing residual feed intake variation in Nelore cattle.

2016

Ossidazione elettrocatalitica della lignina su schiume di Ni attivate

La depolimerizzazione ossidativa della lignina è un processo promettente per la produzione di molecole aromatiche, attualmente ottenute prevalentemente per via petrolchimica. Dalla degradazione della lignina Kraft è possibile ottenere Vanillina, un prodotto ad elevato valore aggiunto impiegato nell’industria alimentare e farmaceutica.Recentemente è in fase di studio la depolimerizzazione ossidativa della lignina a Vanillina per via elettrochimica, un processo innovativo che permette l’impiego di condizioni di reazione blande, evitando l’utilizzo di O2. In questo lavoro di tesi è stato investigato come i parametri di reazione (tempo, temperatura e potenziale) influenzino l’attività catalitica di schiume di Ni a cella aperta calcinate a 500°C per 1 h, nella degradazione elettrochimica di una soluzione 10g/L di lignina Kraft, in NaOH 1M a 0,6V vs SCE. Si è osservato che la resa in Vanillina aumenta al decrescere del tempo di reazione, da 5h a 0,5h, con il massimo registrato dopo elettroosidazione per 1h. Queste condizioni limitano le reazioni parassite, che portano alla formazione di sottoprodotti tramite reazioni di ripolimerizzazione e ricondensazione dei prodotti. La temperatura non ha effetti significativi sulla produzione di Vanillina, quindi può essere conveniente lavorare a 25°C piuttosto che a 60°C. La calcinazione delle schiume di Ni attiva l’elettrodo per il processo studiato, infatti, a parità di condizioni, la resa in Vanillina ottenuta per la schiuma calcinata è maggiore rispetto alla Ni bare. Questa attività catalitica si manifesta anche a potenziali più bassi (0,5 V vs SCE, 1h 25°C), condizione in cui la schiuma di Ni non manifestava formazione di Vanillina.

Cure Induced Residual Stresses on Thick Composite Components Manufactured by Additive Process

This study investigates the effect of an additive process in manufacturing of thick composites. Airstone 780 E epoxy resin and 785H Hardener system is used in the analysis since it is widely used wind turbine blade, namely thick components. As a fiber, fabric by SAERTEX (812 g/m2) with a 0-90 degrees layup direction is used. Temperature overshoot is a major issue during the manufacturing of thick composites. A high temperature overshoot leads to an increase in residual stresses. These residual stresses are causing warping, delamination, dimensional instability, and undesired distortion of composite structures. A coupled thermo-mechanical model capable of predicting cure induced residual stresses have been built using the commercial FE software Abaqus®. The possibility of building thick composite components by means of adding a finite number of sub-laminates has been investigated. The results have been compared against components manufactured following a standard route. The influence of pre-curing of the sub-laminates has also been addressed and results compared with standard practice. As a result of the study, it is found that introducing additive process can prevent temperature overshoot to occur and benefits the residual stresses generation during the curing process. However, the process time required increases by 50%, therefore increasing the manufacturing costs. An optimized cure cycle is required to minimize process time and cure induced defects simultaneously.

Endoscopic Endonasal Transsphenoidal Resection Of Pituitary Adenomas: Preliminary Evaluation Of Consecutive Cases.

Endoscopic endonasal transsphenoidal surgery has gained increasing acceptance by otolaryngologists and neurosurgeons. In many centers throughout the world, this technique is now routinely used for the same indications as conventional microsurgical technique for pituitary tumors. To present a surgical experience of consecutive endoscopic endonasal trans-sphenoidal resections of pituitary adenomas. In this study, consecutive patients with pituitary adenomas submitted to endoscopic endonasal pituitary surgery were evaluated regarding the rate of residual tumor, functional remission, symptoms relief, complications, and tumor size. Forty-seven consecutive patients were evaluated; 17 had functioning adenomas, seven had GH producing tumors, five had Cushing's disease, and five had prolactinomas. Of the functioning adenomas, 12 were macroadenomas and five were microadenomas; 30 cases were non-functioning macroadenomas. Of the patients with functioning adenomas, 87% improved. 85% of the patients with visual deficits related to optic nerve compression progressed over time. Most of the patients with complaints of headaches improved (76%). Surgical complications occurred in 10% of patients, which included with two carotid lesions, two cerebrospinal fluid leaks, and one death of a patient with a previous history of complications. Endoscopic endonasal pituitary surgery is a feasible technique, yielding good surgical and functional outcomes, and low morbidity.

Effect Of Daily Use Of An Enzymatic Denture Cleanser On Candida Albicans Biofilms Formed On Polyamide And Poly(methyl Methacrylate) Resins: An In Vitro Study.

Candida biofilms on denture surfaces are substantially reduced after a single immersion in denture cleanser. However, whether this effect is maintained when dentures are immersed in cleanser daily is unclear. The purpose of this study was to evaluate the effect of the daily use of enzymatic cleanser on Candida albicans biofilms on denture base materials. The surfaces of polyamide and poly(methyl methacrylate) resin specimens (n=54) were standardized and divided into 12 groups (n=9 per group), according to study factors (material type, treatment type, and periods of treatment). Candida albicans biofilms were allowed to form over 72 hours, after which the specimens were treated with enzymatic cleanser once daily for 1, 4, or 7 days. Thereafter, residual biofilm was ultrasonically removed and analyzed for viable cells (colony forming units/mm(2)) and enzymatic activity (phospholipase, aspartyl-protease, and hemolysin). Factors that interfered with the response variables were analyzed by 3-way ANOVA with the Holm-Sidak multiple comparison method (α=.05). Polyamide resin presented more viable cells of Candida albicans (P<.001) for both the evaluated treatment types and periods. Although enzymatic cleansing significantly (P<.001) reduced viable cells, daily use did not maintain this reduction (P<.001). Phospholipase activity significantly increased with time (P<.001) for both materials and treatments. However, poly(methyl methacrylate) based resin (P<.001) and enzymatic cleansing treatment (P<.001) contributed to lower phospholipase activity. Aspartyl-protease and hemolysin activities were not influenced by study factors (P>.05). Although daily use of an enzymatic cleanser reduced the number of viable cells and phospholipase activity, this treatment was not effective against residual biofilm over time.

Comparative Study Of Planned And Unplanned Excisions For The Treatment Of Soft Tissue Sarcoma Of The Extremities.

Unplanned excision of soft tissue sarcomas is common because benign soft tissue lesions are very frequent. This study evaluated the impact of unplanned resections on overall survival, local recurrence and distant metastasis in patients with soft tissue sarcomas of the extremities. In total, 52 patients who were diagnosed with soft tissue sarcomas between May 2001 and March 2011 were analyzed in a retrospective study. Of these patients, 29 (55.8%) had not undergone previous treatment and the remaining 23 (44.2%) patients had undergone prior resection of the tumor without oncological planning. All subsequent surgical procedures were performed at the same cancer referral center. The follow-up ranged from 6 to 122 months, with a mean of 39.89 months. Age, lesion size and depth, histological grade, surgical margins, overall survival, local and distant recurrence and adjuvant therapies were compared. Residual disease was observed in 91.3% of the re-resected specimens in the unplanned excision group, which exhibited greater numbers of superficial lesions, low histological grades and contaminated surgical margins compared with the re-resected specimens in the planned excision group. No differences were observed in local recurrence and 5-year overall survival between the groups, but distant metastases were significantly associated with planned excision after adjustment for the variables. There was no difference between patients undergoing unplanned excision and planned excision regarding local recurrence and overall survival. The planned excision group had a higher risk of distant metastasis, whereas there was a high rate of residual cancer in the unplanned excision group.

Diagnosis, Treatment, And Follow-up Of Medullary Thyroid Carcinoma: Recommendations By The Thyroid Department Of The Brazilian Society Of Endocrinology And Metabolism.

Medullary thyroid carcinoma (MTC) originates in the thyroid parafollicular cells and represents 3-4% of the malignant neoplasms that affect this gland. Approximately 25% of these cases are hereditary due to activating mutations in the REarranged during Transfection (RET) proto-oncogene. The course of MTC is indolent, and survival rates depend on the tumor stage at diagnosis. The present article describes clinical evidence-based guidelines for the diagnosis, treatment, and follow-up of MTC. The aim of the consensus described herein, which was elaborated by Brazilian experts and sponsored by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism, was to discuss the diagnosis, treatment, and follow-up of individuals with MTC in accordance with the latest evidence reported in the literature. After clinical questions were elaborated, the available literature was initially surveyed for evidence in the MedLine-PubMed database, followed by the Embase and Scientific Electronic Library Online/Latin American and Caribbean Health Science Literature (SciELO/Lilacs) databases. The strength of evidence was assessed according to the Oxford classification of evidence levels, which is based on study design, and the best evidence available for each question was selected. Eleven questions corresponded to MTC diagnosis, 8 corresponded to its surgical treatment, and 13 corresponded to follow-up, for a total of 32 recommendations. The present article discusses the clinical and molecular diagnosis, initial surgical treatment, and postoperative management of MTC, as well as the therapeutic options for metastatic disease. MTC should be suspected in individuals who present with thyroid nodules and family histories of MTC, associations with pheochromocytoma and hyperparathyroidism, and/or typical phenotypic characteristics such as ganglioneuromatosis and Marfanoid habitus. Fine-needle nodule aspiration, serum calcitonin measurements, and anatomical-pathological examinations are useful for diagnostic confirmation. Surgery represents the only curative therapeutic strategy. The therapeutic options for metastatic disease remain limited and are restricted to disease control. Judicious postoperative assessments that focus on the identification of residual or recurrent disease are of paramount importance when defining the follow-up and later therapeutic management strategies.