EXTRACTION OF OIL FROM PRESSED PALM OIL (Elaes guineensis) FIBERS USING SUPERCRITICAL CO2

Residual fibers from palm oil production are a good source of carotene, since they contain more than 5% of the original oil, with about 5000 ppm of carotenoids. As carotenoids are thermosensitive molecules, supercritical CO2 can be used for oil recovery, because this technique employs low temperatures. In this work results of oil extraction experiments from pressed palm oil fibers are shown. Fibers were from AGROPALMA, an industry which is located in Tailândia (Pará, Brazil). Extractions were carried out at 200, 250 and 300 bar and at temperatures of 45 and 55oC. Oil was analyzed by UV/vis spectrophotometry for total carotene determination. Results showed a large increase in extraction rate from 200 to 250 bar and a small variation from 250 to 300 bar. The total amount of carotenes did not increase in the course of extraction at 300 bar, but it showed a large increase at 200 and at 250 bar. Free fatty acids are present in amounts larger than those found in commercial oils.

(E)-2-Nonenal determination in brazilian beers using headspace solid-phase microextraction and gas chromatographic coupled mass spectrometry (HS-SPME-GC-MS)

(E)-2-nonenal is considered an important off-flavor of beer, related to the flavor of beer staling. In this study, a new method for determination of (E)-2-nonenal in beer using headspace solid-phase microextraction and gas chromatographic coupled mass spectrometry (HS-SPME-GC-MS) was developed and applied in Brazilian beer samples. The extractions were carried out in CAR-PDMS (carboxen-polydimethylsiloxane) fiber and the best results were found with 15 minutes of equilibrium and 90 minutes of extraction at 50 °C. The method was linear in the range from 0.02 to 4.0 μg.L-1 with correlation coefficient of 0.9994. The limits of detection and quantification were 0.01 and 0.02 μg.L-1, respectively. 96.5% of recovery and 4% precision (RSD) were obtained in the fortification of beer samples with 2.0 μg.L-1 of (E)-2-nonenal. The developed method proved to be simple, efficient and highly sensitive to the determination of this analyte being easily applied in the quality control of the brewery. (E)-2-nonenal was found in all beer samples analyzed with levels between 0.17 and 0.42 μg.L-1.

Microbiological and physicochemical characterization of surimi obtained from waste of piramutaba fillet

The aim of this work was to perform the microbiological and physicochemical characterization of surimi made from waste of piramutaba filleting. The results of physicochemical characterization of the waste and surimi were: moisture (76.37 and 79.11%), total lipids (5.35 and 0.74%), proteins (14.92 and 10.79%), ash (3.03 and 2.35%), pH (6.9 and 7.4), caloric value (109.15 and 77.86 kcal.g-1), and water activity (both 0.98), respectively. The results of the levels of total volatile bases were 7.29 mgN/100-1 g (waste) and 7.01% carbohydrate (surimi). The values of total lipids and proteins were reduced during the preparation of surimi, probably due to successive washes during the processing. Waste and surimi were examined microbiologically and are in compliance with required parameters. The results show a loss of red (a* parameter) and yellow (b* parameter) color. On the other hand, the L* parameter (lightness) increased after the processing of surimi. It can be concluded that piramutaba waste can be used for surimi preparation and as a source of nutrients for human consumption, providing an alternative use of these wastes avoiding their disposal polluting the environment.

Physicochemical and antioxidative properties of black, brown and red rice varieties of northern Thailand

Rice, the seed of Oryza species, is the major cereal crop in most of the developing countries. Nearly 95% of global rice production is done in Asian countries, and about half of the world’s population consumes it. Some speciality rices are not commonly consumed. Colored rice is one of such variety. In these varieties, high amounts of anthocyanin pigment are deposited in the rice coat to form its black (also known as purple), brown and red colors. Minimum studies are there to explain the properties of these rice varieties of Thailand. Thus, the current study was aimed to assess the physicochemical and antioxidative properties of three rice varieties (Chiang Mai Black rice, Mali Red rice and Suphanburi-1 Brown rice) of different cultivars of northern Thailand. Rice bran extracts of these three cultivars were prepared with different solvents (polar and non-polar) for the evaluation of total phytochemical content and anti-oxidant free-radical-scavenging properties. Chiang Mai Black rice contained higher concentration of phenolic acid, flavonoids, and anthocyanins (Cyanidin 3-glucoside, peonidin 3-glucoside, cyanidin chloride). Chiang Mai Black rice is richer in free-radical-scavenging compounds and activities than the other tested varieties. Polar extractions of rice bran are high in anti-oxidative compounds and activities than non-polar extractions.

Developing novel one-step processes for obtaining food-grade O/W emulsions from pressurized fluid extracts: processes description, state of the art and perspectives

Abstract In this work, a novel on-line process for production of food-grade emulsions containing oily extracts, i.e. oil-in-water (O/W) emulsions, in only one step is presented. This process has been called ESFE, Emulsions from Supercritical Fluid Extraction. With this process, emulsions containing supercritical fluid extracts can be obtained directly from plant materials. The aim in the conception of this process is to propose a new rapid way to obtain emulsions from supercritical fluid extracts. Nowadays the conventional emulsion formulation method is a two-step procedure, i.e. first supercritical fluid extraction for obtaining an extract; secondly emulsion formulation using another device. Other variation of the process was tested and successfully validated originating a new acronymed process: EPFE (Emulsions from Pressurized Fluid Extractions). Both processes exploit the supercritical CO2-essential oils miscibility, in addition, EPFE process exploits the emulsification properties of saponin-rich pressurized aqueous plant extracts. The feasibility of this latter process was demonstrated using Pfaffia glomerata roots as source of saponin-rich extract, water as extracting solvent and clove essential oil, directly extracted using supercritical CO2, as a model dispersed phase. In addition, examples of pressurized fluid-based coupled processes applied for adding value to food bioactive compounds developed in the past five years are reviewed.

Influence of temperate grass seed rotation systems on weed seed soil bank composition

Due to changing cropping practices in perennial grass seed crops in western Oregon, USA, alternative rotation systems are being considered to reduce weed infestations. Information is generally lacking regarding the effects of alternative agronomic operations and herbicide inputs on soil weed seed bank composition during this transition. Six crop rotation systems were imposed in 1992 on a field that had historically produced monoculture perennial ryegrass (Lolium perenne L.) seeds. Each system plot was 20 x 30 m, arranged in a randomized complete block design, replicated four times. Twenty to thirty soil cores were sampled in June 1997 from each plot. The weed species composition of the cores was determined by successive greenhouse grow-out assays. In addition to seed density, heterogeneity indices for species evenness, richness, and diversity were determined. The most abundant species were Juncus bufonius L. and Poa annua L. Changes in seed bank composition were due to the different herbicides used for the rotation crop components. Compared to the other rotation systems, no-tillage, spring-planted wheat (Triticum aestivum L.) and oat (Avena sativa L.) reduced overall weed seed density and richness, but did not affect weed species evenness or diversity. When meadowfoam (Limnanthes alba Hartweg ex Benth.) succeeded wheat in rotation, weed species richness was unaffected, but evenness and diversity were reduced, compared to the other rotation systems. For meadowfoam in sequence after white clover (Trifolium repens L.), crop establishment method (no-tillage and conventional tillage) had no effect on weed seed species density, evenness, or diversity.

Federalismo e endividamento subnacional: uma discussão sobre a sustentabilidade da dívida estadual

The subnational debt in Brazil was marked by successive bailouts by the federal government. The path of subnational debt induced some locals and state authorities to claim for further renegotiations. More specifically, some governors and mayors demanded a revision of the refinancing contracts. This article intends to present arguments sustained by simulations of the evolution of the path of the subnational debt, denying the necessity of changes in legal framework, which rules the state debt. The first section consists of a brief overview. The following section treats the institutional framework designed to safeguard the fiscal intertemporal balance. In the third section, the implications of new institutional framework on the subnational debt are approached; in the fourth, the possible causes that distorted the expected path of the debt are discussed. The fifth section analyses the future perspectives for the debt in general terms and focuses some specific cases, while the sixth section discusses the problem under a federal optics. Finally, the conclusion is presented.

Two-dimensional drift-diffusion simulation of organic solar cells

The aim of this master's thesis is to develop a two-dimensional drift-di usion model, which describes charge transport in organic solar cells. The main bene t of a two-dimensional model compared to a one-dimensional one is the inclusion of the nanoscale morphology of the active layer of a bulk heterojunction solar cell. The developed model was used to study recombination dynamics at the donor-acceptor interface. In some cases, it was possible to determine e ective parameters, which reproduce the results of the two-dimensional model in the one-dimensional case. A summary of the theory of charge transport in semiconductors was presented and discussed in the context of organic materials. Additionally, the normalization and discretization procedures required to nd a numerical solution to the charge transport problem were outlined. The charge transport problem was solved by implementing an iterative scheme called successive over-relaxation. The obtained solution is given as position-dependent electric potential, free charge carrier concentrations and current densities in the active layer. An interfacial layer, separating the pure phases, was introduced in order to describe charge dynamics occurring at the interface between the donor and acceptor. For simplicity, an e ective generation of free charge carriers in the interfacial layer was implemented. The pure phases simply act as transport layers for the photogenerated charges. Langevin recombination was assumed in the two-dimensional model and an analysis of the apparent recombination rate in the one-dimensional case is presented. The recombination rate in a two-dimensional model is seen to e ectively look like reduced Langevin recombination at open circuit. Replicating the J-U curves obtained in the two-dimensional model is, however, not possible by introducing a constant reduction factor in the Langevin recombination rate. The impact of an acceptor domain in the pure donor phase was investigated. Two cases were considered, one where the acceptor domain is isolated and another where it is connected to the bulk of the acceptor. A comparison to the case where no isolated domains exist was done in order to quantify the observed reduction in the photocurrent. The results show that all charges generated at the isolated domain are lost to recombination, but the domain does not have a major impact on charge transport. Trap-assisted recombination at interfacial trap states was investigated, as well as the surface dipole caused by the trapped charges. A theoretical expression for the ideality factor n_id as a function of generation was derived and shown to agree with simulation data. When the theoretical expression was fitted to simulation data, no interface dipole was observed.

Viologen based electroactive polymers and composites for durable electrochromic systems

Electrochromism, the phenomenon of reversible color change induced by a small electric charge, forms the basis for operation of several devices including mirrors, displays and smart windows. Although, the history of electrochromism dates back to the 19th century, only the last quarter of the 20th century has its considerable scientific and technological impact. The commercial applications of electrochromics (ECs) are rather limited, besides top selling EC anti-glare mirrors by Gentex Corporation and airplane windows by Boeing, which made a huge commercial success and exposed the potential of EC materials for future glass industry. It is evident from their patents that viologens (salts of 4,4ʹ-bipyridilium) were the major active EC component for most of these marketed devices, signifying the motivation of this thesis focusing on EC viologens. Among the family of electrochromes, viologens have been utilized in electrochromic devices (ECDs) for a while, due to its intensely colored radical cation formation induced by applying a small cathodic potential. Viologens can be synthesized as oligomer or in the polymeric form or as functionality to conjugated polymers. In this thesis, polyviologens (PVs) were synthesized starting from cyanopyridinium (CNP) based monomer precursors. Reductive coupling of cross-connected cyano groups yields viologen and polyviologen under successive electropolymerization using for example the cyclic voltammetry (CV) technique. For further development, a polyviologen-graphene composite system was fabricated, focusing at the stability of the PV electrochrome without sacrificing its excellent EC properties. High electrical conductivity, high surface area offered by graphene sheets together with its non-covalent interactions and synergism with PV significantly improved the electrochrome durability in the composite matrix. The work thereby continued in developing a CNP functionalized thiophene derivative and its copolymer for possible utilization of viologen in the copolymer blend. Furthermore, the viologen functionalized thiophene derivative was synthesized and electropolymerized in order to explore enhancement in the EC contrast and overall EC performance. The findings suggest that such electroactive viologen/polyviologen systems and their nanostructured composite films as well as viologen functionalized conjugated polymers, can be potentially applied as an active EC material in future ECDs aiming at durable device performances.

Ohjelmoinnin opetus peruskoulussa: toiminnallisuutta ja graafista ohjelmointikieltä hyödyntävien opetusmenetelmien vertailu

Ohjelmoinnin opettaminen yleissivistävänä oppiaineena on viime aikoina herättänyt kiinnostusta Suomessa ja muualla maailmassa. Esimerkiksi Suomen opetushallituksen määrittämien, vuonna 2016 käyttöön otettavien peruskoulun opintosuunnitelman perusteiden mukaan, ohjelmointitaitoja aletaan opettaa suomalaisissa peruskouluissa ensimmäiseltä luokalta alkaen. Ohjelmointia ei olla lisäämässä omaksi oppiaineekseen, vaan sen opetuksen on tarkoitus tapahtua muiden oppiaineiden, kuten matematiikan yhteydessä. Tämä tutkimus käsittelee yleissivistävää ohjelmoinnin opetusta yleisesti, käy läpi yleisimpiä haasteita ohjelmoinnin oppimisessa ja tarkastelee erilaisten opetusmenetelmien soveltuvuutta erityisesti nuorten oppilaiden opettamiseen. Tutkimusta varten toteutettiin verkkoympäristössä toimiva, noin 9–12-vuotiaille oppilaille suunnattu graafista ohjelmointikieltä ja visuaalisuutta tehokkaasti hyödyntävä oppimissovellus. Oppimissovelluksen avulla toteutettiin alakoulun neljänsien luokkien kanssa vertailututkimus, jossa graafisella ohjelmointikielellä tapahtuvan opetuksen toimivuutta vertailtiin toiseen opetusmenetelmään, jossa oppilaat tutustuivat ohjelmoinnin perusteisiin toiminnallisten leikkien avulla. Vertailututkimuksessa kahden neljännen luokan oppilaat suorittivat samankaltaisia, ohjelmoinnin peruskäsitteisiin liittyviä ohjelmointitehtäviä molemmilla opetus-menetelmillä. Tutkimuksen tavoitteena oli selvittää alakouluoppilaiden nykyistä ohjelmointiosaamista, sitä minkälaisen vastaanoton ohjelmoinnin opetus alakouluoppilailta saa, onko erilaisilla opetusmenetelmillä merkitystä opetuksen toteutuksen kannalta ja näkyykö eri opetusmenetelmillä opetettujen luokkien oppimistuloksissa eroja. Oppilaat suhtautuivat kumpaankin opetusmenetelmään myönteisesti, ja osoittivat kiinnostusta ohjelmoinnin opiskeluun. Sisällöllisesti oppitunneille oli varattu turhan paljon materiaalia, mutta esimerkiksi yhden keskeisimmän aiheen, eli toiston käsitteen oppimisessa aktiivisilla leikeillä harjoitellut luokka osoitti huomattavasti graafisella ohjelmointikielellä harjoitellutta luokkaa parempaa osaamista oppitunnin jälkeen. Ohjelmakoodin peräkkäisyyteen liittyvä osaaminen oli neljäsluokkalaisilla hyvin hallussa jo ennen ohjelmointiharjoituksia. Aiheeseen liittyvän taustatutkimuksen ja luokkien opettajien haastatteluiden perusteella havaittiin koulujen valmiuksien opetussuunnitelmauudistuksen mukaiseen ohjelmoinnin opettamiseen olevan vielä heikolla tasolla.

Traités scientifiques d'Isaac MARTIN, secrétaire du roi.

Contient : I Traités Originaux portant le nom de l'auteur ; « Traicté de la Perspective », avec de nombreuses figures ; à la suite (pages 89 et suiv.), devait se trouver une série de dessins à la plume, dont il ne reste plus que deux (page 89, et page 91, anciennement cotée 103) ; « Arithmétique » ; « Practique de géométrie » ; II Traités Originaux sans nom d'auteur, mais d'Isaac Martin ; « Des règles de la Proportion » ; « De la Progression » arithmétique ; « De la Progression géométrique » ; « Des extractions de Racine » ; « Questions militaires sur la Racine quarrée » ; Figures de géométrie

Investigative links between cognitive function and moderate-to-vigorous physical activity in elementary physical education

Research has noted both physical and psychosocial benefits when children participate in regular physical activity. Recent studies are indicating that there may also be academic benefits and that students may be more efficient learners with participation in physical activity. This study investigated the influence of acute moderate-to-vigorous physical activity on four cognitive functions: planning, attention, simultaneous processing, and successive processing. Three classes (59 students) were each tested twice using a balanced design (intervention, balance, and control groups). It was found that the intervention group had a large increase in planning abiHty (ES = 1.67) when compared to the balance (ES = .80) and control (ES = -.89) groups. On the three remaining cognitive functions, the intervention group showed effect sizes similar to that of the balance and control groups. These results indicate that improved planning after physical activity may playa role in improving student performance.

Optical properties of organic superconductor K-(BETS)2FeBr4 /

/c-(BETS)2FeBr4 is the first antiferromagnetic organic superconductor with successive antiferromagnetic and superconducting transitions at Ta^=2.5K and Tc=l.lK respectively at ambient pressure. Polarized reflectance measurements were performed on three single crystalsamples of this material using a Briiker IFS66V/S Interferometer, and a Bolometer detector or an MCT detector, at seven temperatures between 4K and 300K, in both the far-infrared and mid-infrared frequency range. After the reflectance results were obtained, the Kramers-Kronig dispersion relation was apphed to determine the optical conductivity of /c-(BETS)2FeBr4 at these seven temperatures. Additionally, the optical conductivity spectra were fitted with a Drude/Lorentz Oscillator model in order to study the evolution of the optical conductivity with temperature along the a-axis and c-axis. The resistivities calculated from the Drude model parameters along the a-axis and c-axis agreed reasonably with previous transport measurements.

A comparative study of protoheme and heme d catalases : role of the heme and the heme pocket in catalysis and ligand binding

Catalase dismutes H20 2 to O2 and H20. In successive twoelectron reactions H20 2 induces both oxidation and reduction at the heme group. In the first step the protoheme prosthetic group of beef liver catalase forms compound I, in which the heme has been oxidized from Fe3+ to Fe4+=0 and a porphyrin radical has been created. Compound II is formed by the oneelectron reduction of comp I. It retains Fe4+=0 but lacks the porphyrin radical and is catalytically inert. Molecular structures are available for Escherichia coli Hydroperoxidase II, Micrococcus Iysodeiktus, Penicillium vitale and beef liver enzymes, which contain different hemes and heme pockets. In the present work, the pockets and substrate access channels of protoheme (beef liver & Micrococcus) and heme d (HPII of E. coli and Penicillium) catalases have been analysed using Quanta™ and CharmMTM molecular modeling packages on the Silicon Graphics Iris Indigo 2 computer. Experimental studies have been carried out with two catalases, HPII (and its mutants) and beef liver. Fluoride and formate' are inhibitors of both enzymes, and their binding is modulated by the heme and by distal residues N201 & H128. Both HPII and beef liver enzymes form compound I with H202 or peracetate. The reduction of beef liver enzyme compound I to II and the decay of compound II are accelerated by fluoride. The decay of compound II is also accelerated by formate, and this reagent acts as a 2-electron donor towards compound I of both enzymes. It is concluded that heme d enzymes (Penicillium and HPII of E. coli) are formed by autocatalytic transformation of protoheme in a modified pocket which contains a characteristic serine residue as well as a partially occluded heme channel. They are less active than protoheme enzymes but also do not form the inactive compound II species. Binding of peroxide as well as fluoride and formate is prevented by mutation of H128 and modulated by mutation of N201.

Specific heat of UPdâ Siâ

The specific heat of single-crystal U Pd2 Si2 has been studied using both the step heating and continious heating methods for the temperature range 2 to 250 K. Successive phase transitions at Tl = 136I< and T2 = 108I< are reported, which are consistent with current publications. The transition at 40K, which was previously reported, has not been detected. Recent published elastic neutron scattering data, magnetic susceptibility and resistivity results suggest that U Pd2 Si2 may be a heavy fermion compound, however, the electronic specific heat coefficient I (= 18.97 ;~), obtained from the specific heat Cv measurements, is smaller than that of the conventional heavy fermion system. The Debye temperature of U Pd2Si2 is found to be 116.55K. The possibility is discussed that the maximum in CIT in the low-temperature range 2 to 4K corresponds to Schottky anomaly induced by localized magnetic impurities .