Adsorption of di-2-pyridyl ketone salicyloylhydrazone on Amberlite XAD-2 and XAD-7 resins: Characteristics and isotherms

The adsorption of DPKSH onto Amberlite XAD-2 (styrene resin) and XAD-7 (acrylic ester resin) has been investigated, at (25 +/- 1)degrees C and pH 4.7. The experimental equilibrium data were fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. These three models provide a very good fit for both resins and the respective constants K(L), K(F), and K(DR) were calculated. For the same DPKSH concentration interval, the minimum time of contact for adsorption maximum at XAD-7 was smaller than at XAD-2 and the maximum amount of DPKSH adsorbed per gram of XAD-2 is smaller than at XAD-7. The investigation indicates that the mean sorption energy (E) characterizes a physical adsorption and the surfaces of both resins are energetically heterogeneous. The constants obtained in these studied systems were correlated and compared with those obtained for the silica gel/DPKSH system. (C) 2008 Published by Elsevier Inc.

Automatic devices for monitoring environmentally induced auto-oxidative degradation of artistic materials in conservation sites

This paper describes an automatic device for in situ and continuous monitoring of the ageing process occurring in natural and synthetic resins widely used in art and in the conservation and restoration of cultural artefacts. The results of tests carried out under accelerated ageing conditions are also presented. This easy-to-assemble palm-top device, essentially consists of oscillators based on quartz crystal resonators coated with films of the organic materials whose response to environmental stress is to be addressed. The device contains a microcontroller which selects at pre-defined time intervals the oscillators and records and stores their oscillation frequency. The ageing of the coatings, caused by the environmental stress and resulting in a shift in the oscillation frequency of the modified crystals, can be straightforwardly monitored in this way. The kinetics of this process reflects the level of risk damage associated with a specific microenvironment. In this case, natural and artificial resins, broadly employed in art and restoration of artistic and archaeological artefacts (dammar and Paraloid B72), were applied onto the crystals. The environmental stress was represented by visible and UV radiation, since the chosen materials are known to be photochemically active, to different extents. In the case of dammar, the results obtained are consistent with previous data obtained using a bench-top equipment by impedance analysis through discrete measurements and confirm that the ageing of this material is reflected in the gravimetric response of the modified quartz crystals. As for Paraloid B72, the outcome of the assays indicates that the resin is resistant to visible light, but is very sensitive to UV irradiation. The use of a continuous monitoring system, apart from being obviously more practical, is essential to identify short-term (i.e. reversible) events, like water vapour adsorption/desorption processes, and to highlight ageing trends or sudden changes of such trends. (C) 2007 Elsevier B.V. All rights reserved.

Fluorescent probes with malononitrile side group in methyl methacrylate copolymers

Fluorescent probes derivated from auramine, 1-aminopyrene, and 9-aminoacridine containing a malononitrile group are copolymerized with methyl methacrylate. These new fluorescent polymeric materials are studied in solution of different solvents by steady-state and time-resolved emission techniques. Their spectroscopic properties and excited state dynamics are driven by charge transfer from the aromatic group to the electron withdrawing CN groups, and this factor is responsible for the non-exponential emission decay behavior. (c) 2008 Elsevier B.V. All rights reserved.

Utvärdering av mätmetoder för att fastställa lackmängden vid offsettryckning on-line

This project has been made in cooperation with Stora Enso Research Centre Falun (Research). Thebackground of the project is that Research has customers who demand a method to measure the quantityof varnish online in offset printing. The aim with the project is to investigate if any test method correlateswith the quantity of varnish and to improve the understanding of the variables in the varnishingunit. The goal with the project is to develop a functional method. Two printing trials have beenperformed. The aim with the first trial was to investigate how different factors in the printer influencedthe quantity of varnish using reduced factoranalysis. The aim of the second trial was to analyse onlya reduced numbers of factors in the varnishing unit. The methods that were used to measure the varnishingquantity are weighing, IR-analysis, gloss, whiteness and brightness. Results from the projectshow that the weighing method does not work in this study due to basis weight variations of the sheets.The results from weighing did not agree with the results from the other methods. On the other handthere is a strong correation between the IR- and the glossmethods.

Omslagstrender - en studie av vad som höjer uppmärksamhetsvärdet hos tidskrifter

Through interviews, a questionnaire survey and an in­depth analysis of the Swedish magazines Veckorevyn and Magazine Café has a number of parameters been made visible. It was difficult to obtain an unambiguous result when the journal's target audience is crucial for the cover design. Nevertheless, we can generally say that the transparent varnish of covers, PMS colors and enclosing the journal in plastic do not increase the attention value, as this occurs in many magazines. Due to today's tough competition among journals, we believe that they will need to niche themselves much harder to survive. We also believe that the new, big trend is that more covers will become more plain and stylistically pure, with one big communicating image and fewer coverlines, as many covers were designed during the 1940s.

Unga vuxnas åsikter kring bokomslags formgivning : En enkät- och fokusgruppsundersökning

Bokomslaget är ofta läsarens första möte med en bok och det är därför viktigt att bokomslaget tilltalar och sänder ut rätt signaler till konsumenten. Målgruppen unga vuxna, individer mellan 16 och 27 år, är enligt bokbranschen en grupp som är svår att nå. Svårigheten kan ligga i att det finns en viss okunskap i vad unga vuxna tilltalas av på bokomslag. Det är även en bred målgrupp med många olika sorters individer. Målet med denna studie är att ge en bild av vad målgruppen unga vuxna tilltalas av i ett bokomslag. Vi ville ta reda på hur viktigt bokomslaget är för val av bok, samt hur målgruppen ser på omslagets specifika designfaktorer färg, typografi, illustration, fotografi och efterbehandling. För att ge oss en bild av dagens kunskapsläge har litteraturstudier och intervjuer med formgivare av bokomslag genomförts. Genom en omfattande enkätundersökning och utförda fokusgrupper fick vi fram målgruppens syn och tankar kring bokomslag. Fokusgrupper utfördes för att ge oss en djupare förståelse rörande hur målgruppen ser på bokomslag samt ge oss ett djupare resonemang kring de olika bokomslagen. Resultatet visar att unga vuxna lägger stor vikt vid identitet och ett bokomslag bör således sända tydliga signaler som kan bekräfta läsarens identitet. Typografin ska vara lättläst. Målgruppen ser helst fotografiska bilder på bokomslaget och omslaget ska förmedla en känsla av bokens innehåll. Färger i en dovare färgskala tilltalar unga vuxna, rött och svart tycks vara de populäraste färgerna överlag. Efterbehandlingen (t.ex. lackering och foliering) på ett bokomslag bör vara sparsam och användning av färgen rosa lika så.

Desevolvimento de nanocompósitos de poli(metacrilato de metila)/argila processados por mistura no estado fundido

Poly(methyl methacrylate)/clay nanocomposites were prepared by melt mixing using a montmorillonite-rich clay (MMT). The clay in natura was treated with acrylic acid to facilitate the dispersion in the polymer matrix. A masterbatch of PMMA/clay was prepared and combined with the pure PMMA and then subjected to extrusion process using singlescrew and twin-screw extruders followed by injection. Nanocomposites were processed with clay contents of 1, 3, 5 and 8 wt.%. The effect of shear processing on the morphology of the nanocomposites was evaluated by XRD, SEM and TEM. Thermal and mechanical properties of the nanocomposites were investigated through TGA, DSC, HDT, VICAT, tensile and impact tests, to evaluate the effect of the addition of clay to the PMMA matrix. Flammability tests were also conducted to investigate the effect of the addition of clay on the flame retardation properties. SEM images of the nanocomposites indicated the presence of clay agglomerates, which resulted in the reduction of properties such as thermal stability, mechanical strength and impact resistance, and increased the rate of burning for materials processed by both extrusion routes

Estudo de revestimentos inorgânicos com inibidor de corrosão aplicado na superfície do concreto

The corrosive phenomenon on reinforced concrete structures is one of the most founded pathologies on the coastal area. With the objective to prevent the process development, or even, retard its beginning, it was studied the application of inorganic covering over concrete surfaces, after its cure, as well as, evaluate the efficiency of the covering applied on the concrete in reducing its porosity of concrete preventing the entrance of aggressive agents to preserve the integrity of the existing armor inside it, comparing the result obtained with the body-of-proof reference, that didn´t receive covering protection. On the concrete production it was used Portland Cement CP II 32, coarse aggregate, fine aggregate and water from the local distributive. Two types of covering were used, one resin based of silicon and solvent and other white cement based, selected sands and acrylic resin. The concrete mixture adopted was 1:1,5:2,5 (cement, fine aggregate, coarse aggregate) and 0.50 water/cement ratio. With the concrete on fresh state was made the experiment test to determinate the workability. On the hardened state was made the concrete resistance experiment, absorption of water and electrochemical experiments, through polarization curves. Also was held optical microscopy and Scanning Electron Microscopy experiments to analyze the layer of the covering applied to the concrete surface and the interface between the concrete and the layer. The obtained results shows that the covering applied to the concrete surface didn´t affect the resistance towards compression. On the absorption of water occurred a diminution of the percentage absorbed, improving the concrete development by making it more impermeable towards the entrance of aggressive agents. The electrochemical experiment results confirmed the water absorption results; the body-of-proof covered presented larger protection towards the development of corrosives process and retarded the evolution of the corrosive phenomenon

Identificação e fatores de virulência de Candida spp isoladas da cavidade bucal de transplantados renais do hospital universitário Onofre Lopes em Natal-RN

Despite Candida species are often human commensals isolated from various oral sites such as: tongue, cheek and palatal mucosa plus subgingival region, there are some properties linked to the organism commonly known as virulence factors which confer them the ability to produce disease. Oral candidiasis is one of the main oral manifestations reported in literature related to kidney transplant patients. The objectives of the present study were to identify and investigate virulence factors of yeasts isolated from the oral cavity of kidney transplant recipients admitted at the Hospital Universitário Onofre Lopes, in Natal RN. Seventy Candida species isolated from 111 kidney transplant recipients were investigated in this study. Identification of the isolates was performed by using the evidence of germ tube formation, hypertonic broth, tolerance to grow at 42°C, micromorphology and biochemical profiles. We observed a high rate of isolation of yeasts from the oral cavity of kidney transplant recipients (63.1%) being C. albicans was the most prevalent species. Oral candidiasis was diagnosed in 14.4% of transplant recipients. We evaluated virulence properties of the isolates regarding to: biofilm formation on polystyrene microplates as well as XTT reduction, adherence to acrylic resin and human buccal epithelial cells and proteinase activity. Most isolates were able to form biofilm by the method of adhesion to polystyrene. All isolates of Candida spp. remained viable during biofilm formation when analyzed by the method of XTT reduction. The number of CFU attached to the acrylic resin suggested high adherence for C. parapsilosis. C. albicans isolates showed higher median adherence to human buccal epithelial cells than non-C. albicans Candida isolates. Nevertheless, this difference was not statistically significant. C. dubliniensis showed low ability to adhere to plastic and epithelial cells and biofilm formation. Proteolytic activity was observed for all the isolates investigated, including the unique isolate of C. dubliniensis. There was a statistically significant association between proteinase production and the presence of oral candidiasis. Studies related to oral candidiasis in renal transplant recipients are limited to clinical and epidemiological data, but investigations concerning Candida spp. virulence factor for this group of individuals are still scarce. We emphasize the importance of studies related to virulence factors of yeasts isolated from this population to contribute to the knowledge of microbiological aspects of oral candidiasis

Revestimento de sementes de milho superdoce (sh2)

A semente de milho doce é leve e rugosa. A rugosidade torna difícil a classificação das sementes quanto à forma e ao tamanho e isso dificulta a semeadura. Uma solução para esse problema seria a utilização da técnica de revestimento. Assim, este trabalho teve por objetivo avaliar diferentes materiais de enchimento, cimentantes e corantes na peletização de sementes de milho superdoce e verificar quais combinações de materiais seriam eficientes na manutenção da qualidade fisiológica das sementes após o armazenamento e que permitissem vazão e distribuição uniformes durante a semeadura. Foram então testados doze materiais de enchimento (calcários 1 e 2, caulim, carvão vegetal ativado, areia, vermiculita, fubá de milho, farinha de trigo, polvilho de mandioca, amido de milho, celite e terra de diatomáceas), dois cimentantes (goma arábica e cascorez extra) e seis corantes (tintas guache, acrílica, plástica e para tecido, corante para alimento e gelatina). As avaliações da qualidade física e fisiológica das sementes revestidas e nuas foram efetuadas por meio dos testes: teor de água, fragmentação, peso de mil sementes, volume aparente e plantabilidade, germinação, primeira contagem da germinação e emergência de plântulas em campo. O revestimento de sementes de milho superdoce proporciona homogeneidade de forma e tamanho às sementes, melhora a vazão e a distribuição dos péletes na semeadura e não compromete a emergência de plântulas em campo depois de quatro meses de armazenamento.

Desenvolvimento de uma planta piloto para estudos de poços de petróleo produzindo por plunger lift

This document proposes to describe a pilot plant for oil wells equipped with plunger lift. In addition to a small size (21,5 meters) and be on the surface, the plant s well has part of its structure in transparent acrylic, allowing easy visualization of phenomena inherent to the method. The rock formation where the well draws its pilot plant fluids (water and air) is simulated by a machine room where they are located the compressor and water pump for the production of air and water. To keep the flow of air and water with known and controlled values the lines that connect the machine room to the wellhole are equipped with flow sensors and valves. It s developed a supervisory system that allows the user a real-time monitoring of pressures and flow rates involved. From the supervisor is still allowed the user can choose how they will be controlled cycles of the process, whether by time, pressure or manually, and set the values of air flow to the water used in cycles. These values can be defined from a set point or from the percentage of valve opening. Results from tests performed on the plant using the most common forms of control by time and pressure in the coating are showed. Finally, they are confronted with results generated by a simulator configured with the the pilot plant s feature

Desenvolvimento de protótipo de coletor automático destinado à coleta de amostras de água em corpos aquáticos para análise em laboratório

The aim of this approach is to describe the design and construction of a low-cost automated water sampler prototype. In recent years, there is an increasing need on the use of automated equipments for hydro climatic variables to be use in urban and rural environments. Such devices are always used to provide measured information which is of crucial importance on the development of water resources strategies at watershed scale. Actually, many research and water public institutions have been using these kinds of equipments. In most of the cases, automated equipments are expensive and need to be imported, generating a situation of technologic dependency. The prototype is based on an electronic system which controls a peristaltic pump functioning, five solenoid valves and an ultrasonic sensor connected to a datalloger. An interface with the user allows communication with a PC, when the equipment functioning parameters can be provided. The equipment has a hydraulic module composed by a 12V peristaltic pump connected to a distribution circuit composed by five solenoid valves, one of them being used to clean the circuit before each sampling procedure. Samples are collected by four 1.95 polyethylene bottles. The sampler body was made of acrylic material, with a cylindrical shape, and dimensions 0.72 m and 0.38 m height and diameter, respectively. The weight of the equipment without samples is approximately 15 kg, which infers to its portability. The prototype development total cost budget was approximately US$ 1,560.00. Laboratory tests aimed to evaluate the equipment performance and functioning demonstrated satisfactory results

A new method to quantify macroalgae and a practical sampler for experimentation in lotic habitats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Rheological, mechanical and mucoadhesive properties of thermoresponsive, bioadhesive binary mixtures composed of poloxamer 407 and carbopol 974P designed as platforms for implantable drug delivery systems for use in the oral cavity

This study described the formulation and characterisation of the viscoelastic, mechanical and mucoadhesive properties of thermoresponsive, binary polymeric systems composed of poloxamer (P407) and poly(acrylic acid, C974P) that were designed for use as a drug delivery platform within the oral cavity. Monopolymeric and binary polymeric formulations were prepared containing 10, 15 and 20% (w/w) poloxamer (407) and 0.10-0.25% (w/w) poly(acrylic acid, 934P). The flow theological and viscoelastic properties of the formulations were determined using controlled stress and oscillatory rheometry, respectively, the latter as a function of temperature. The mechanical and mucoadhesive properties (namely the force required to break the bond between the formulation and a pre-hydrated mucin disc) were determined using compression and tensile analysis, respectively. Binary systems composed of 10% (w/w) P407 and C934P were elastoviscous, were easily deformed under stress and did not exhibit mucoadhesion. Formulations containing 15 or 20% (w/w) Pluronic P407 and C934P exhibited a sol-gel temperature T(sol/gel), were viscoelastic and offered high elasticity and resistance to deformation at 37 degrees C. Conversely these formulations were elastoviscous and easily deformed at temperatures below the sol-gel transition temperature. The sol-gel transition temperatures of systems containing 15% (w/w) P407 were unaffected by the presence of C934P; however, increasing the concentration of C934P decreased the T(sol/gel) in formulations containing 20%(w/w) P407. Rheological synergy between P407 and C934P at 37 degrees C was observed and was accredited to secondary interactions between these polymers, in addition to hydrophobic interactions between P407 micelles. Importantly, formulations composed of 20% (w/w) P407 and C934P exhibited pronounced mucoadhesive properties. The ease of administration (below the T(sol/gel)) in conjunction with the viscoelastic (notably high elasticity) and mucoadhesive properties (at body temperature) render the formulations composed of 20% (w/w) P407 and C934P as potentially useful platforms for mucoadhesive, controlled topical drug delivery within the oral cavity. (c) 2009 Published by Elsevier B.V.

Resposta comportamental e hormonal de machos não reprodutores de sagüi, callithrix jacchus, a estímulos sensoriais de filhotes não aparentados

Parental care in mammals is influenced by somatosensory stimuli from infants, such as vocalization and sight and by changes in the hormone levels of caretakers. The aim of this study was to evaluate the behavioral and hormonal responses of twelve non reproductive adult male common marmosets (Callithrix jacchus) to infant cues, vocalization recordings, sight and physical contact with newborn. Six out of twelve males had previous experience in caretaking. In article 1, adult males were exposed to newborn vocalizations for 10 minutes. On control condition no sound was presented. In article 2, males were tested on two conditions: a) Control: an empty acrylic transparent box (test box) was placed in male s cage for 15 minutes, and b) Experimental: males were exposed to newborns into a closed text box for 15 minutes. The cage was kept closed to prevented from tactile, smell and acoustic stimulation by the infant on common marmoset males. In article 3, males were exposed to an open or closed text box, which allowed or not their access to and social interaction with the infants. After each observation sessions, blood samples were collected to evaluate the cortisol levels of males. In all studies, behavioral response of adult males was significantly modified by newborns sight, vocalization and physical contact. Males approached and spent more time near the sound source and showed an increase in locomotion during sound exposure. Furthermore, males approached, smelled and spent more time near the test box when the newborn was inside it. There was no difference in behavioral pattern between experienced and non-experienced males in articles 1 and 2. In article 3, behavioral pattern of males was influence by previous caretaking experience. Experienced males recovered quicker and carried the infants more than the inexperienced ones. However, inexperienced males showed a decrease in recovery latency and an increase in carrying time after successive exposure to infants. Cortisol levels changed after exposure to infant s vocalization, especially for experienced adult males. Male hormonal profile was not affected by the sight of infants neither by their previous experienced in caretaking. The occurrence of social interaction between the caretaker and infant did not modify the hormonal profile of common marmoset males; however, as much as experienced males carried the infants their cortisol levels decreased. Thus, members of a social group or potential caretakers common marmosets exposed to sensory cues from dependent infant such as vocalization, sight, smell and physical contact, changed their behavioral and hormonal responses that are physiological modulators of parental behavior in common marmoset