998 resultados para Escarificação química


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The experiment was conducted with grama seda (Cynodon dactylon (L.) Pers.) hays stored with a low moisture content (12-15%) and without chemical treatment, and hays stored with a high moisture content (20-25%) and treated with anhydrous ammonia (NH3) al 0.5 and 1.0% of DM, and urea at 0.9 and 1.8% of DM. At 65 days after treatment (AT) under a plastic cover, the bales were opened and samples were taken at 3, 15 and 30 days to determine the chemical composition and in vitro digestibility (IVDMD) of the hays. For the identification of fungi, samples were taken at 0, 15 and 30 days AT. The data were analyzed according to a split-plot design with the effects of the chemical treatments studied in the main plot and the effects of the periods of post-treatment studied in the sub-plots, Fourteen genera of fungi were observed in the hays, not treated and treated with NH3 and urea, with a higher occurrence of Cladosporium, Curvularia, Aspergillus, and Penicillium. Treatment with anhydrous ammonia and 1.8% urea controlled the occurrence of Aspergillus; however, Penicillium decreased in hays treated with ammonia 30 days AT. Ammoniation did not influence the contents of ADF, cellulose and lignin in the hays, but NDF and hemicellulose decreased with the use of ammonia 30 days AT. The CP contents and the IVDMD increased with ammoniation. The CP contents decreased in hays treated with NH3 as days AT increase, while hays treated with urea did not change.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Seventy beef males of three breeding systems (BS), straightbreds Charolais (Ch) and Nellore (Ne), G1 crossbreds: 1/2 Ch + 1/2 Ne (1/2 Ch) and 1/2 Ne + 1/2 Ch (1/2 Ne) and G2 crossbreds: 3/4 Ch + 1/4 Ne (3/4 Ch) and 3/4 Ne + 1/4 Ch (3/4 Ne) were used. The number of animals by genetic group was, respectively, 15, 12,8, 12,14 and 9. Thirty-five males were castrated (C) at seven months and 35 were kept intact (1). The animals were feedlot finished from 20 to 24 months. The longissimus dorsi muscle was used for the meat evaluation. No significant interaction was observed between genetic composition and sexual condition, for the variables studied. The I males displayed meat with darker color (3.05 vs. 3.78 points) with less amount of marbling (4.26 vs. 5.75 points) and less amount of ether extract (1.73 vs. 2.88%). However they presented larger (66.03 vs. 60.50 cm(2)) longissimus dorsi area and meat with better palatability, juiciness and tenderness. Ch animals had larger longissimus dorsi than the Ne. In the G I group, the 1/2 Ch meat showed larger amount of marbling and ether extract and less cooking losses than the 1/2 Ne meat. Between G2 animals, the 3/4 Ne showed meat with larger thawing losses and larger amount of ether extract. In G1 animals meat, the heterosis level reached 18.54% for longissimus dorsiarea, 28.10% for ether extract and 64.01% for amount of marbling. In G2, the heterosis was -17.30% for lean texture and 10.40% for longissimus dorsi area.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this work was to revise the main concepts involved in the physical-chemistry of the sol-gel process. First, the preparation and its influence on the gel's structure are focalized; the sol-gel transition is revised under the thermodynamics of crytical phenomena point of view and by considering the kinetic models of aggregation. Second, the experimental methods usually used to characterize the sol-gel transition are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Elephant grass (Pennisetum purpureum Schum.), was cut after nine weeks of regrowth and mixed with 10, 20, 30 and 40% of sugar cane bagasse (SCB) with the objective of reducing the moisture content of the ensiled mass. Willing of the grass for eight and twelve hours was used as a comparative treatment. Initial dry matter of the grass (13%) increased in the forage mass to 17, 23, 24 and 27% by the addition of 10, 20, 30 and 40% of the SCB respectively. Wilting for eight and twelve hours increased initial dry matter to 18 and 24% respectively. Buffering capacity of elephant grass was reduced by the addition of 40% of SCB. Clostridium spores in the ensiled mass tended to be lower due to the effect of the two pre-treatments. Initial dry matter and number of spores of Clostridium were negatively correlated although without statistic significance. The addition of SCB reduced (P < 0.0.5) soluble carbohydrates and crude protein percentages in the ensiled mass. It was concluded that wilting is more effective than the addition of SCB in the practice of ensiling elephant grass.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this study was to establish equations to estimate the empty body chemical composition of Nellore steers using the following indirect techniques: 1) physical composition of the 9-10-11(th) rib cut;) physical composition of the 10(th) rib cut; and 3) chemical composition of the 10(th) rib cut. Thirty-one Nellore steers with weights ranging from 245 to 489 kg and ages from 20 to 29.7 months at slaughter were utilized. The empty body chemical composition was established through samples collected after grinding all animal tissues. The equations using the percentage of dissectable fat in the 9-10-11(th) rib cut shored a high precision for estimating the percentage of water (r(2) = 0.91; Syx = 1.168) and ether extract (r(2) = 0.94; Syx = 1.298) of the empty body; the same was observed when the percentage of dissectable fat in the 10(th) rib cut was used (r(2) = 0.82 and 0.85; Syx = 1.658 and 1.942, respectively, for water and ether extract). The equations using the percentage of ether extract in the 10(th) rib cut showed a high precision for estimating the percentage of water (r(2) = 0.89; Syx = 1.311) and the ether extract (r(2) = 0.89; Syx = 1.730) of the empty body, but there was no advantage over the physical composition of the 9-10-11(th) and 10(th) rib cut. Multiple regressions using carcass weight and the percentage of bones and kilograms of lean, fat, and bones dissectable in the 10(th) rib cut improved the coefficients of determination for water and ether extract to 0.87 and 0.91. The equations to estimate the percentages of protein and ach showed a low precision, indicating that those techniques are not recommended to estimate these components in the empty body of Nellore steers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of the present study was to carry out the physical, chemical and nutritional analyses of the alternative substrates formulated from wood and agroindustrial residues of the Amazon for Pleurotus ostreatus (Jacq.:Fr.) Kummer cultivation. The determination of C, N, pH, humidity, soluble solids, protein, fat, total fiber ash, carbohydrates (total and available) and energy were carried out. The substrates were formulated from sawdust of Simarouba amara Aubl. (marupa), Ochroma piramidale Cav. ex. Lam. (pau de balsa) and from the stein of Bactris gasipaes Kunth (pupunheira palm tree), and from Saccharum officinarum L. (sugar cane bagasse). The results demonstrated that the nutritional composition of the substrate is variable and the improvement of the quality of the spent substrate (energy and protein increment) promoted by the metabolism of the fungus during the cultivation, contributed for a more nutritive substrate than the initial one, which could be used as a compost for Agaricus sp. cultivation, as organic fertilizer and for bioremediation for contaminated soils.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aiming to know the influence of the pluviometric precipitation over the physical chemical and bacteriological characteristics of the water coming from three sources of public supply, and to verify the probable origin of faecal contamination, tests of total coliforms, faecal coliforms, faecal streptococci and mesophilic microorganisms, as well as the determination of pH, temperature and turbidity of 156 water samples were done. The samples were taken from a stream, a drain and an artesian well, located in the city of Jaboticabal, SP, Brazil. The results obtained showed that the occurrence of pluviometric precipitation determined a significant increase of the number of total coliforms in the water samples from the stream. The use of the ratio CF/EF, indicate the probable origin of the faecal contamination only in the samples of the water coming from the stream, which were defined as being of human origin. In relation to the physical-chemical composition it was noticed that the influence of the pluviometric precipitation over the turbidity appeared to be higher and significant in the samples of water of the stream.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chemically modified electrodes based on hexacyanometalate films are presented as a tool in analytical chemistry. Use of amperometric sensors and/or biosensors based on the metal-hexacyanoferrate films is a tendency. This article reviews some applications of these films for analytical determination of both inorganic (e.g. As3+, S2O3 2-) and organic (e.g. cysteine, hydrazine, ascorbic acid, gluthatione, glucose, etc.) compounds.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The hybrid Mentha pulegium x spicata, also well-known as poejo de praia, it is a perennial, low plant, with fields, violet stem and opposite leaves, with lance format and sawed board, presenting characteristic smell. The objective of the present work was accomplish a study of the leaf anatomy, including a biometric study of tissue and quantitative analysis of secretory trichomes/mm2 and of stomata/mm2 in both faces of the epidermis, besides a chemical analysis of the essential oil. Histological permanent laminas were made for anatomical analysis of the leaf surface and also sheets of the impression to foliate for the count of the trichomes number and stomatas. The chemical studies were made through the extraction of the essential oil by hydrodistillation and analyzed in GC-MS. The capitate and peltates trichomes are present on both sides of the leaf, even so they prevail in the abaxial surface. The variance analysis show that there are significant differences for the number of capitate trichomes and tectores between the adaxial and abaxial surfaces, but they are not significant for the peltate trichoma. The analyzed of essential oil shows the presence of a majority component, trans piperitone epoxide, being it responsible for more than 80% of the relative composition in the essential oil.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The work aimed to study the formation of Tabebuia chrysotricha Standi, seedlings in function of four substrates, varying the covering fertilization solutions. To compose the substrate it was used fibrous and granulated coconut fiber obtaining the following treatments: 100% fibrous (100% F), 60% fibrous + 40% granulated (60% F+40% G), 40% fibrous + 60% granulated (40% F+60% G) and 100% granulated (100% G). The basis fertilization was the same for all treatments and the solutions of covering fertilization varied in order to obtain complete solutions with electric conductivities of 1.06 dS m-1, 2.12 dS m-1, 3.2 dS m-1 and 4.25 dS m-1. The propagative material was sowed directly in plastic containers (120mL) with the respective substrates. The fertilization was received through sub-irrigation once a week, respecting the treatments of fertilizations. Seedlings produced in 100%G had been taller and higher than the others. The chemical analyses of aerial part were obtained when the seedlings were ready for expedition (height of 20 cm). The seedlings production in substrate 100% F and 60% F+40% G allowed them to have higher N, S, B, Mn and Zn concentrations in the aerial part. The production of T. chrysotricha seedlings is recommended in granulated coconut fiber substrate and fertilizer solutions with EC of 1.06 dS m-1.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this trial was to evaluate the effect of the chemical (urea, sodium benzoate, and sodium hydroxide) and microbiological (Propionibacterium acidipropionici + Lactobacillus plantarum, and Lactobacillus buchneri) additives on the sugarcane nutritive value, ensiled crude or after burned, using a factorial scheme 2 (burned or crude sugar cane) x 6 (five additives urea, sodium benzoate, sodium hydroxide, Propionibacterium acidipropionici + Lactobacillus plantarum, and Lactobacillus buchneri plus control). It was evaluated the sugar cane chemical composition, before and after ensilage. The sugar cane NDF contents increased (51.3%, before ensilage) to 67.8% after fermentation period. The highest true digestible dry matter recovery values, 83.6 and 79.8% were observed on the burned sugar cane silage treated with NaOH or L. buchneri, respectively. The NaOH, and L. buchneri showed more efficiency in reducing nutritive looses during the fermentation phase of the crude or burned sugar cane silage.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aiming to evaluate the association of hydroponic lettuce cultivation with residues from a fish intensive breeding system, a project was carried out in the Aquaculture Center in the FCAV-UNESP at Jaboticabal, SP, Brazil. A closed system was designed in order to allow the water to circulate through the fish tanks, a clarifier tank for removal of residues, a reservoir for biological conversion of ammonia into nitrate, and the hydroponic system. After this process, water returned back to the fish tanks. Three varieties of lettuce, constituting the treatments with four repetitions were evaluated. The results of the chemical analysis of the residual water from the fish tanks indicated the presence of the majority of the mineral nutrients necessary for vegetable development. Their concentration was close to that found in nutrient solutions, used for lettuce hydroponic cultivation, except for potassium and magnesium. The low concentration of magnesium in the water did not prevent lettuce development, although the plants presented visual symptoms of deficiency of this nutrient. Differences were not found between the varieties produced, regarding productivity and the mean weight of fresh plants.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The curimbata constitutes species of fish of wide distribution in the Neotropical area and high economic value. This work focused to evaluate processing yield and the chemical composition of the fillet in the male and female migratories and residents stocks of Prochilodus lineatus. The using the plotting was completely randomized by 4x2 factorial scheme, having as factors four stocks (one resident and three migratories) and two genders (male and female) with thirty replicates, considering each fish as an experimental unit. Each individual was submitted to the manual filleted and determination of the corporal composition (texts of moisture, crude protein, lipids, ashes and energy). They following parameters of yield had been evaluated (%): visceral entire fish (RPIE %); yield of boneless fillet (RFILE %) and processing yield of fillet with bone (RFILEC %). There was a significant difference (p<0.05) between the stocks and the studied samples. The biggest yield of boneless fillet were observed for the fish of the migrator stock I (45.77%). Males and females of the migrator stock I presented biggest fillet yield (46.79% and 43.93%, respectively), while the migrator III presented smaller yield (37.29% for males and 38.44% for females). The migratories stocks I, II and III presented values significantly smaller (p<0.05) of lipids level (0.98%; 2.01% and 1.97%, respectively) and an increase in the content of corporal protein in relation to the resident stock. It concluded that the male weighing 591g on average, belonging of the stock migrator I (captured in December), presented better thread yield and the stocks migratories are fish that has low fat tenor and high protein tenor.