An investigation on sliding wear behavior of PVD coatings

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de aditivos no valor nutritivo de silagens feitas com subproduto da extração do palmito de pupunha (Bactris gasipaes H.B.K.)

O objetivo deste experimento foi determinar a qualidade e o valor nutritivo de silagens do subproduto da pupunha, produzidas com aditivos, conforme os tratamentos: T1 - Testemunha (sem aditivo); T2 - Adição de 2,5% de açúcar; T3 - Adição de 10,0% de polpa cítrica e T4 - Adição de 10,0% de milho moído, base da matéria natural. Verificou-se que a adição 10% de polpa cítrica (PC) ou milho moído (MM) elevou o teor de matéria seca da massa a ser ensilada, bem como da silagem, em 6,5 e 8,0 unidades percentuais, respectivamente. Silagens com aditivos apresentaram menores valores de nitrogênio amoniacal (N-NH3 / NT) e pH. O consumo de matéria seca foi maior para as silagens feitas com PC ou MM, atingindo 85 g/kg PV0,75 ou 2,1% do PV, contra 44,7 g/kgPV0,75 ou 1,12%, para as silagens sem aditivo ou com 2,5% de açúcar. O coeficiente de digestibilidade aparente da matéria seca, também foi superior para as silagens contendo 10% de PC ou MM (65,0%) em relação à média das demais (52,0%). A digestibilidade da parede celular não mostrou tendência definida em função dos tratamentos. A silagem de subproduto da pupunha feita com a adição de 10% de polpa cítrica ou milho moído, apresentou valor nutritivo semelhante às silagens de forrageiras convencionais.

Influência da acrilamida e da poliacrilamida em sistema microemulsionado visando aplicação na recuperação avançada de petróleo

This work aims to study the influence of two additives, the monomer, acrylamide and its polymer, polyacrylamide, solubilized in microemulsion systems and applied on enhanced oil recovery. By the microemulsion system obtained, it was chosen points into the phase diagram, presenting these compositions: 25%, 30%, 35% C/T; 2% Fo (fixed for all points) e 73%, 68% e 63% Fa, respectively. However, the monomer and the polymer were solubilized in these microemulsion points with 0.1%; 0.5%; 1% e 2% of concentration, ordering to check the concentration influence at the physicochemical properties (surface tension and rheology) of the microemulsion. Through the salinity study, was possible to observe that the concentrations of 1% and 2% of polymer made the solution became blurred, accordingly, the study of surface tension and rheology only was made for the concentrations of 0.1% e 0.5% of monomer and polymer, respectively. By the surface tension study it was observed that how the concentration of active matter (C/T) was increasing the surface tension was amending for each system, with or without additives. In the rheology study, as it increases the concentration of active matter increases both the viscosity of the microemulsion system (SME) with no additive, as the SME with polymer (AD2). After the entire study, it was chosen the lower point of active matter (25% C/T; 2% Fo e 73% Fa), plus additives in concentrations of 0.1% and 0.5% to be used on enhanced oil recovery. Assays were made on sandstone from Botucatu Formation, where after the tests, it was concluded that among the studied points, the point who showed the best efficiency of advanced shift was the microemulsion system + 0.5% AD2, with a recovery of 28% of oil in place and a total of 96,49%, while the other solution with 0.5% of polymer presented the worst result, with 14.1% of oil in place and 67,39% of efficiency of total displacement

Novas formulações de fluidos de corte: otimização, propriedades e recuperação do óleo usado

Cutting fluids are lubricants used in metal-mechanical industries. Their complex composition varies according to the type of operation carried out, also depending on the metals under treatment or investigation. Due to the high amount of mineral oil produced in Northeastern Brazil, we have detected the need to better use this class of material. In this work, two novel formulations have been tested, both based on naphthenic mineral oil and additives, such as: an emulsifying agent (A), an anticorrosion agent (B), a biocide (C) and an antifoam agent (D). Each formulation was prepared by mixing the additives in the mineral oil at a 700-rpm stirring velocity for 10 min, at 25°C, employing a 24 factorial planning. The formulations were characterized by means of density, total acid number (TAN), viscosity, flash point and anticorrosion activity. In a subsequent study, oil-in-water emulsions were prepared from these novel formulations. The emulsions were analyzed in terms of stability, corrosion degree, percentage of foam formation, conductivity, accelerated stability and particle size. The samples were appropriately labeled, and, in special, two of them were selected for featuring emulsion properties which were closer to those of the standards chosen as references (commercial cutting oils). Investigations were undertaken on the ability of NaCl and CaCl2 to destabilize the emulsions, at concentrations of 2%, 5% and 10%, at an 800-rpm stirring velocity for 5 min and temperatures of 25º, 40º, 50º and 60ºC. The recovered oils were chemically altered by reincorporating the same additives used in the original formulations, followed by preparation of emulsions with the same concentrations as those of the initial ones. The purpose was to assess the possibility of reusing the recovered oil. The effluents generated during the emulsion destabilization step were characterized via turbidity index, contents of oil and grease, pH, and contents of anions and cations, observing compliance with the parameters established by the current environmental legislation (Brazil s CONAMA 357/05 resolution). It could be concluded that the formulations presented excellent physicochemical properties as compared to commercial cutting fluids, showing that the quality of the newly-prepared fluids is superior to that of the formulations available in the market, enabling technically and environmentally-safe applications

Secagem de misturas de polpa de frutas tropicais em leito de jorro

Drying of fruit pulps in spouted beds of inert particles has been indicated as a viable technique to produce fruit powders. Most of the processes employed to produce dried fruit pulps and juices, such as Foam Mat, encapsulation by co-crystallization and spray drying utilize adjuvant and additives (such as thickeners, coating materials, emulsifiers, acidulants, flavors and dyes), which is not always desirable. The fruit pulp composition exerts an important effect on the fruit powder production using a spouted bed. In the study by Medeiros (2001) it was concluded that lipids, starch and pectin contents play an important role on the process performance, enhancing the powder production; however, the drying of fruit pulps containing high content of reducing sugars (glucose and fructose) is practically unviable. This work has the objective of expanding the studies on drying of fruit pulps in spouted bed with aid of adjuvant (lipids, starch and pectin) aiming to enhance the dryer performance without jeopardizing the sensorial quality of the product. The optimum composition obtained by Medeiros (2001) was the basis for preparing the mixtures of pulps. The mixture formulations included pulps of mango (Mangifera indica), umbu (Spondias tuberosa) and red mombin (Spondia purpurea) with addition of cornstarch, pectin and lipids. Different products were used as lipids source: olive and Brazil nut oils, coconut milk, heavy milk, powder of palm fat and palm olein. First of all, experiments were conducted to define the best formulation of the fruit pulps mixture. This definition was based on the drying performance obtained for each mixture and on the sensorial characteristics of the dry powder. The mixture formulations were submitted to drying at fixed operating conditions of drying and atomizing air flow rate, load of inert particles, temperature and flow rate of the mixture. The best results were obtained with the compositions having powder of palm fat and palm olein in terms of the drying performance and sensorial analysis. Physical and physicochemical characteristics were determined for the dry powders obtained from the mixtures formulations. Solubility and reconstitution time as well as the properties of the product after reconstitution were also evaluated. According to these analyses, the powder from the mixtures formulations presented similar characteristics and compatible quality to those produced in other types of dryers. Considering that the palm olein is produced in Brazil and that it has been used in the food industry substituting the palm fat powder, further studies on drying performance were conducted with the composition that included the palm olein. A complete factorial design of experiments 23, with three repetitions at the central point was conducted to evaluate the effects of the air temperature, feeding flow rate and intermittence time on the responses related to the process performance (powder collection efficiency, material retained in the bed and angle of repose of the inert particles after the process) and to the product quality (mean moisture content, loss of vitamin C and solubility). Powder production was uniform for the majority of the experiments and the higher efficiency with lower retention in the bed (59.2% and 1.8g, respectively) were obtained for the air temperature of 80°C, mixture feed rate of 5ml/min in intervals of 10 min. The statistical analysis of the results showed that the process variables had individual or combined significant influences on the powder collection efficiency, material retention in the bed, powder moisture content and loss of vitamin C. At the experimental ranges of this work, the angle of repose and solubility were not influenced by the operating variables. From the results of the experimental design, statistical models were obtained for the powder moisture content and loss of vitamin C

Avaliação das propriedades físico-químicas de sistemas a base de carboximetilcelulose e poli (N-isopropilacrilamida) em soluções aquosas para aplicação na indústria do petróleo

Sustainable development is a major challenge in the oil industry and has aroused growing interest in research to obtain materials from renewable sources. Carboxymethylcellulose (CMC) is a polysaccharide derived from cellulose and becomes attractive because it is water-soluble, renewable, biodegradable and inexpensive, as well as may be chemically modified to gain new properties. Among the derivatives of carboxymethylcellulose, systems have been developed to induce stimuli-responsive properties and extend the applicability of multiple-responsive materials. Although these new materials have been the subject of study, understanding of their physicochemical properties, such as viscosity, solubility and particle size as a function of pH and temperature, is still very limited. This study describes systems of physical blends and copolymers based on carboxymethylcellulose and poly (N-isopropylacrylamide) (PNIPAM), with different feed percentage compositions of the reaction (25CMC, 50CMC e 75CMC), in aqueous solution. The chemical structure of the polymers was investigated by infrared and CHN elementary analysis. The physical blends were analyzed by rheology and the copolymers by UV-visible spectroscopy, small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and zeta potential. CMC and copolymer were assessed as scale inhibitors of calcium carbonate (CaCO3) using dynamic tube blocking tests and chemical compatibility tests, as well as scanning electron microscopy (SEM). Thermothickening behavior was observed for the 50 % CMC_50 % PNIPAM and 25 % CMC_75 % PNIPAM physical blends in aqueous solution at concentrations of 6 and 2 g/L, respectively, depending on polymer concentration and composition. For the copolymers, the increase in temperature and amount of PNIPAM favored polymer-polymer interactions through hydrophobic groups, resulting in increased turbidity of polymer solutions. Particle size decreased with the rise in copolymer PNIPAM content as a function of pH (3-12), at 25 °C. Larger amounts of CMC result in a stronger effect of pH on particle size, indicating pH-responsive behavior. Thus, 25CMC was not affected by the change in pH, exhibiting similar behavior to PNIPAM. In addition, the presence of acidic or basic additives influenced particle size, which was smaller in the presence of the additives than in distilled water. The results of zeta potential also showed greater variation for polymers in distilled water than in the presence of acids and bases. The lower critical solution temperature (LCST) of PNIPAM determined by DLS corroborated the value obtained by UV-visible spectroscopy. SAXS data for PNIPAM and 50CMC indicated phase transition when the temperature increased from 32 to 34 °C. A reduction in or absence of electrostatic properties was observed as a function of increased PNIPAM in copolymer composition. Assessment of samples as scale inhibitors showed that CMC performed better than the copolymers. This was attributed to the higher charge density present in CMC. The SEM micrographs confirmed morphological changes in the CaCO3 crystals, demonstrating the scale inhibiting potential of these polymers

Transplante de glândulas salivares menores no tratamento da ceratoconjuntivite seca em cães

Relatou-se o efeito do transplante de glândulas salivares menores (TGSM) em cães portadores de ceratoconjuntivite seca (CCS) e estudaram-se os efeitos da secreção dessas glândulas usadas como alternativa de lubrificação ocular. A aplicação da técnica foi satisfatória, uma vez que resultou em melhora no quadro clínico oftalmológico sem que houvesse mínimas intercorrências pós-operatórias.

Influence of diet on oxidative DNA damage, uracil misincorporation and DNA repair capability

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enzima e simbiótico para frangos criados nos sistemas convencional e alternativo

O objetivo deste trabalho foi estudar os efeitos da inclusão de enzima e simbiótico nas rações de frangos de corte criados nos sistemas convencional e alternativo sobre o desempenho, rendimento de carcaça, cortes e gordura abdominal e também avaliar economicamente o uso destes aditivos em ambos os sistemas de criação. Foram utilizados 720 pintos machos Cobb, com um dia de idade, distribuídos em um delineamento em blocos casualizados no esquema fatorial 2x3, com dois sistemas de criação: convencional (com promotor de crescimento) e alternativo (sem promotor de crescimento) e três aditivos: sem outro aditivo (SA), com simbiótico (SI) e com enzima + simbiótico (SIE), com 4 repetições de 30 aves cada. Aos 42 dias de idade, o fator de produção (FP) foi menor (P<0,05) para aves SA (324), quando comparadas às tratadas com SI (334) e SIE (337). Aves criadas no sistema convencional apresentaram maior (P<0,05) FP (338), quando comparadas às do sistema de criação alternativo (325). No sistema alternativo, a conversão alimentar foi melhor (P<0,05) para aves SI (1,77), quando comparadas às SIE (1,82) e SA (1,85). O uso de SI e SIE favorece o desempenho dos frangos aos 42 dias de idade e não influencia o rendimento de carcaça, cortes e gordura abdominal, tanto no sistema convencional como no alternativo, sendo que estes aditivos aumentam os custos de produção em ambos os sistemas. O sistema alternativo de criação proporciona maior retorno econômico, apesar do menor fator de produção.

Probiosis: concepts and prospects

The use of probiotics in animal and human feeding has been a subject of increasing interest both for the academia and the industry, mostly due to their potential positive effects on health and profitability. However, the knowledge on the composition of bacterial gastrointestinal communities in humans and animals, as well as its respective nutritional requirements, is far from being elucidated. Due to the ban of the use of antibiotic growth promoters in animal feeds, there has been an increasing interest on the utilization of probiotics to improve animal intestinal health under commercial settings. However, the possibility of horizontal transference of antibiotic-resistant genes between probiotic bacteria and pathogenic species has become a concern of poultry farmers and consumers around the world. Innovative ideas have emerged, such as the addition of essential oils, spices, and other plant extracts to feeds of monogastric animals to promote intestinal health. These natural compounds are considered ecologically adequate and safe for feeding purposes. This new reality will probably change the direction of research and of the use of additives in poultry production.

Effects of adding polyclonal antibody preparations on ruminal fermentation patterns and digestibility of cows fed different energy sources

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Regulation and action of fibroblast growth factor 17 in bovine follicles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of ion supplementation of a commercial soft drink on tooth enamel erosion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

DNA and heparin chaperone the refolding of purified recombinant replication protein A subunit 1 from Leishmania amazonensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)