Aspectos químicos e potencial terapêutico de imidas cíclicas: uma revisão da literatura

Cyclic imides consists of an important family of organic compounds with therapeutic potential. In this review, emphasis will be given to the chemical and biological aspects of several sub-classes of this family, incluing maleimides, succinimides, glutarimides, naphtalimides, etc. Additionally, will be focused the contribution of our research group in this field.

Bioenergiaa ja ravinteita kasvi- ja eläinperäisistä sivuainevirroista Parikkalassa

Euroopan unionissa pyritään lisäämään uusiutuvien energialähteiden käyttöä. Tämän työn tavoitteena oli selvittää Parikkalan kunnan alueella muodostuvat biomassat sekä tutkia niiden hyötykäyttömahdollisuuksia sähkön, lämmön sekä lannoitteiden tuotannossa. Käsiteltäviä biomassoja ovat eläintilojen lietteet ja lannat, biojätteet ja yhdyskuntalietteet, vesistöjen kunnostuksessa syntyvät biomassat sekä peltobiomassat ja metsäbiomassa. Mädätyksen kannalta olennaisinta on materiaalien kosteus ja haihtuvan orgaanisen aineksen pitoisuus sekä siitä saatava biokaasumäärä. Poltossa polttoaineen kuiva-aineen lämpöarvo ja kosteus määrittelevät saadun hyödyn. Kompostoinnissa on tärkeää huolehtia riittävästä ilman saannista ja riittävästä viipymäajasta. Hyödynnettäessä biokaasua sähkön ja lämmön yhteistuotannossa on tärkeää löytää hyötykäyttö myös muodostuvalle lämmölle. Poltosta saatavan tuhkan hyötykäyttö onnistuu metsälannoitteena, kun poltetaan turvetta tai puuta. Kompostia voidaan hyödyntää maanparannusaineena. Parikkalan alueella tarkasteltiin biomassojen nykyistä ja mahdollista tulevaa hyötykäyttöä. Tarkastelu tehtiin skenaarioiden avulla. Skenaarioihin kuuluvat mädätyksen ja polton maksimipotentiaalit sekä keskitetyn ja hajautetun käsittelyn skenaariot. Alueelta on saatavissa paljon biomassoja, joista massaltaan suurin on eläintilojen lannat. Alueella on hankaluutena löytää sopiva kulutuskohde biokaasusta tuotetulle lämmölle, mutta sopivana kohteena voisi toimia alueella oleva suuri sikala tai lämpökeskukset.

Recuperação de sílica-gel utilizando processos oxidativos avançados: uma alternativa simples e de baixo custo

Silica gel is widely used as adsorbent for isolating and purifying natural compounds. Intensive use and high cost make this process expensive and generate solid residues contaminated with many different organic compounds. In the present work a simple method for recycling silica was investigated, by using Advanced Oxidative Processes. Silica gel was treated with H2O2/solar light and compared with a sample treated by conventional methods (high temperature and oxidation with KMnO4). High temperature treatment changes the structure of the silica and, consequently, the separation efficiency. Oxidation by using KMnO4 requires multiple steps and produces residues, including manganese and oxalic acid. The method using H2O2/solar light to recuperate silica gel does not modify its separation efficiency and is less expensive than the traditional methods. Additionally, HPLC and GC-MS analysis indicate that H2O2/solar light eliminates all residues of the silica gel.

Hajupäästöjen tutkiminen Saint-Gobain Rakennustuotteet Oy:n Hyvinkään lasivillatehtaalla

Hajupäästöillä tarkoitetaan tavallisesti teollisen toiminnan aiheuttamia hajuaineiden päästöjä ympäristöön. Suomessa ympäristölainsäädäntö ei varsinaisesti kiellä hajuaineiden päästöjä mutta edellyttää kuitenkin, ettei niistä aiheudu merkittävää viihtyvyyshaittaa. Tässä työssä tutkittiin hajupäästöjä Saint-Gobain Rakennustuotteet Oy:n Hyvinkään lasivillatehtaalla. Tavoitteena työssä oli selvittää, mikä on tehtaan aiheuttamien päästöjen hajuvaikutus, ja mitä hajuyhdisteitä valmistusprosessissa muodostuu. Lisäksi työssä selvitettiin miten hajupäästöjä pystyttäisiin vähentämään. Työn kokeellisten tutkimusten aikana kerättiin tietoa hajun esiintymisestä valitulta tarkasteluajanjaksolta sekä mitattiin mm. tehtaan savukaasujen hajupitoisuutta ja koostumusta. Mittauksissa kaasunäytteiden hajupitoisuudeksi saatiin 170 HY/m3, joka kuvaa suhteellisen mietoa hajua. Näytteistä analysoidut haihtuvat orgaaniset yhdisteet olivat suurelta osin peräisin lasivillan valmistuksessa käytetystä sideaineesta, jota lisätään tuotteen joukkoon kuidutusvaiheessa. Ympäristöstä otetuista näytteistä ei kuitenkaan havaittu piipun yhdisteitä, mikä viittaisi siihen, että mittausjaksonaikana tehtaan päästöjen leviäminen ympäristöön on tapahtunut melko pieninä pitoisuuksina. Lisäksi on mahdollista, että ulkoilmassa yhdisteissä tapahtuu kemiallista muutuntaa ja hajontaa, jonka seurauksena yhdisteet muuttuvat. Tehtaan hajuhaitat vaikuttaisivat tutkimustulosten mukaan johtuvan savupainumaksi kutsutusta ilmiöstä. Savupainumaan vaikuttavat kaasun lämpömäärä sekä ympäristön olosuhteet ja topografia. Hajuhaittojen poistamiseksi olisi muodostuvia hajuyhdisteitä pystyttävä vähentämään 95-100 %.

Hidrogenação de compostos orgânicos utilizando método eletroquímico para geração de hidrogênio in situ: hidrogenação eletrocatalítica

Electrocatalytic hydrogenation (HEC) may be compared to catalytic hydrogenation (HC). The difference between these methods is the hydrogen source: HC needs a hydrogen gas supply; HEC needs a source of protons (solvent) to be reduced at a cathode surface. HEC has presented interesting advances in the last decades due to investigation of the influence of the supporting electrolyte, co-solvent, surfactant, presence of inert gas and the composition of the electrode on the reaction. Several classes of organic compounds have been hydrogenated through HEC: olefins, ketones, aldehydes, aromatics, polyaromatics and nitro-compounds. This paper shows some details about the HEC which may be regarded as a promising technique for the hydrogenation of organic compounds both in industrial processes and in laboratories.

Contaminação de águas por BTXs e processos utilizados na remediação de sítios contaminados

After decades of polluting actions the environment manifests serious and global consequences. The contamination of soils and groundwater by organic compounds is a widespread problem mainly on account of contamination by leakage from underground storage tanks, which often results in the release of gasoline or other chemicals. The main problem about groundwater contamination is due to the toxicity of water-soluble components such as benzene, toluene and xylene (BTX). In the present work a study about classical and modern methods for remediation of BTX is reported.

Esquema para interpretação de espectros de substâncias orgânicas na região do infravermelho

This article decribes a simple and systematic method to interpret an infrared spectrum using a flow chart to elucidate the structure of a simple organic compound. It is aimed at undergraduate courses of organic chemistry to make beginners proficient. The proposed flow chart for infrared spectrum interpretation and characterization of organic compounds is suitable for theoretical and experimental courses.

Análise sistemática de reagentes e resíduos sem identificação

This work presents a detailed routine applied to the identification of unknown chemicals and wastes. 786 specimens were analyzed during 20 months. Unknown materials fell into three basic classes: (i) commercial chemicals without labels or illegible ones; (ii) laboratory synthesis products; (iii) used solvents (including mixtures). Uranium and thorium were recovered form their wastes. Unknown chemicals were mainly inorganic compounds, many of which had never been opened. Alkaline salts were dominant, but also precious metal compounds were identified. Laboratory synthesis products were organic compounds. The final destination depended on the nature of the chemical. Most organic compounds were sent to incineration; inorganic salts were distributed among several public organizations, including secondary and technical schools. The work described in this paper greatly reduced the amount of wastes that had to be sent to disposal.

Extração no ponto nuvem de compostos orgânicos homólogos e isômeros

In this work, the feasibility of employing micelle-mediated extraction for selective separation of homologous or isomeric organic compounds is demonstrated. Firstly, the main parameters controlling extraction performances, such as surfactant concentration and temperature were varied. A Scheffé-type experimental design was demonstrated as a novel and useful method to characterize the various experimental factors. At each point selected in the two-phase domain and for a given solute, extraction percentage (E%), concentration ratio, phase volume ratio, and equilibrium partition coefficient (K C) were determined. The values of E% and K C decrease in the following order: phenol > 1-phenylethanol ~ 2-phenylethanol > benzyl alcohol.

Emprego do carvão ativado para remoção de cobre em cachaça

Copper content is of great concern among sugarcane-spirit producers. It is released from copper-made distillers, during the distillation process. Activated carbon has been used to remove copper. However, depending on the amount of carbon and the duration of reaction, it can also remove higher alcohols and esters, which are important in the final product. A sugarcane spirit with 9 mg L-1 of copper was shaken with 2 to 26 g L-1 of activated carbon, during 10 to 1440 minutes. Then, copper and organic compounds were measured. At least 12 g L-1 of carbon and 60 min shaking time were necessary to decrease copper bellow 5 mg L-1. However, other components of the product were also affected.

Espectrometria de massas com ionização por "electrospray": processos químicos envolvidos na formação de íons de substâncias orgânicas de baixo peso molecular

An overview of the current literature on the chemical processes involved in the ion formation from low molecular weight organic compounds by electrospray ionization mass spectrometry is given.

Distribution Patterns of Soil Properties in a Rural Mediterranean Area in Northeastern Spain

Soil properties on the Cap de Creus Peninsula, NE Spain depend primarily on scarce agricultural practices and early abandonment. In the study area, 90% of which is mainly covered by Cistus shrubs, 8 environments representing variations in land use/land cover and soil properties at different depths were identified. In each environment variously vegetated areas were selected and sampled. The soils, collected at different depths, were classified as Lithic Xerorthents according to the United States Department of Agriculture system of soil classification (USDA-NRCS 1975). Differences in soil properties were largely found according to the evolution of the plant canopy and the land use history. To identify underlying patterns in soil properties related to environmental evolution, factor analysis was performed and factor scores were used to determine how the factor patterns varied between soil variables, soil depths and selected environments. The three-factor model always accounted for 80% of the total variation in the data at the different soil depths. Organic matter was the more relevant soil property at 0–2 cm depth, whereas active minerals (silt and clay) were found to be the most relevant soil parameters controlling soil dynamics at the other depths investigated. Results showed that vineyards and olive tree soils are poorly developed and present worse conditions for mineral and organic compounds. Analysis of factor scores allowed independent assessment of soils, depth and plant cover and demonstrated that soils present the best physico-chemical characteristics under Erica arborea and meadows. In contrast, soils under Cistus monspeliensis were less nutrient rich and less well structured

O pKa de indicadores ácido-base e os efeitos coloidais

An experiment is proposed that can be included in undergraduate courses of chemistry. The subject is the acidity of organic compounds, which are employed as pH indicators, particularly in acid-base titrations. The indicators used are methyl orange, bromophenol blue and bromocresol green in aqueous medium. The influence of colloidal systems on the equilibrium is evaluated by the pKa. The colloids employed are surfactants like sodium dodecyl sulfate, cetyl-trimethylammonium bromide and a polymeric non-ionic F127 (pluronics). The effect of stabilization promoted by the system on the acidic or basic structureof the indicator establishes the action mechanism of the colloid on the pKa values.

Métodos emergentes para aumentar a eficiência do ozônio no tratamento de águas contaminadas

Many industrial processes produce effluents with a wide variety of xenobiotic organic pollutants, which cannot be efficiently degraded by conventional biological treatments. Thus, the development of new technologies to eliminate these refractory compounds in water has become very imperative in order to assure the quality of this important resource. Ozonation is a very promising process for the treatment of wastewaters containing non-easily removable organic compounds. The present work aims at highlighting new methods of enhancing the efficiency of ozone towards the removal organic pollutants in aqueous solution. Special attention is given to catalytic ozonation processes contemplating homo- and heterogeneous catalysis, their activity and mechanisms. Recent results and future prospects about the application of these processes to real effluents are also evaluated.

Esquema geral para elucidação de substâncias orgânicas usando métodos espectroscópico e espectrométrico

This work describes a systematic method to be applied in undergraduate courses of organic chemistry, correlating infrared spectra, hydrogen and carbon-13 nuclear magnetic resonance, and mass spectra. To this end, a scheme and a table were developed to conduct the elucidation of the structure of organic compounds initially using infrared spectra. Interpretation of hydrogen and carbon-13 nuclear magnetic resonance spectra and of mass spectra is used to confirm the proposed structure.