Academic literature on the topic 'Chemical and botanical characteristic'

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2000.<br>Includes bibliographical references (leaves 230-238) and index.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Technologies for dynamic simulation of chemical process flowsheets, as implemented in equation-based dynamic simulators,allow solution of fairly sophisticated process models, that include detailed descriptions of physical phenomena along with operating policies and discrete events. Simulation of flowsheet models with this level of detail forms the basis for a wide variety of activities, such as process optimization, startup and shutdown studies, process design, batch policy synthesis, safety interlock validation, and operator training. Technologies that make these activities possible for plant-scale models include sparse linear algebra routines, robust backward difference formula time integration methods, guaranteed state event location algorithms, generation of analytical Jacobian information via automatic differentiation, efficient algorithms for consistent initialization that may also be used to analyze the index of the model equations, automatic index reduction algorithms, and path-constrained dynamic optimization methods. An equation-based dynamic process simulator takes as input the model equations that describe process behavior, along with a description of the operating policy. The input language allows for model decomposition, inheritance, and reuse, which facilitates construction of plant-scale dynamic models. Technologies like the ones mentioned above allow the simulator to then analyze the model for inconsistencies and perform calculations based on dynamic simulation, with a minimum of intervention from the engineer. This reduces both the time and numerical expertise required to perform simulation-based activities. Results, in some cases made possible or economically feasible only by the modeling support provided by a simulator,<br>(cont.) have been impressive. However, these capabilities apply to flowsheet models that consist only of differential-algebraic, or lumped, unit models. Sometimes behavior in a particular unit cannot be adequately described by a lumped formulation, when variation with other independent variables like distance along a PFTR, film coordinate, or polymer chain length are important. In this case, behavior is most naturally modeled with partial differential, or distributed, unit models. Partial differential equations in network flow simulations bring an additional set of mathematical and numerical issues. For a distributed model to bema thematically well-posed, proper initial and boundary conditions must be specified. Boundary condition requirements for nonlinear unit models may change during the course of a dynamic simulation, even in the absence of discrete events. Some distributed models, due to improper formulation or simple transcription errors, may be ill-posed because they do not have a mathematical property called continuous dependence on data. Finally, the model equations must be discretized in the proper manner. This thesis contributes two new analyses of distributed unit models. The first relies on the definition of a differentiation index for partial differential equations developed in this thesis. It is by design a very natural generalization of the differentiation index of differential-algebraic equations.<br>by Wade Steven Martinson.<br>Ph.D.

This study was done in the subtropical high Andes of Ulla Ulla. Its objectives were to determine the botanical composition, nutritional value, and preferred forages in the wetlands (hydromorphic and mesico) diet, by season (dry and wet), and by botanical family (12 families). Three-hundred sixty samples were collected from 6 alpacas with esophageal fistulations, and from them nutritional value and botanical composition were determined; the latter was compared with the botanical composition of the wetlands to determine preference. The results are highly significant (p<0.01) for botanical families, interaction between season and family, interaction of wetland type and family, and interaction of the season with wetland type and family. Species from the family Juncaceae were the most consumed with 27.78%, followed by moderate consumption of Cyperaceae (21.03%), Gramineae (15.02%), and Rosaceae (12.39%). Lower consumption occurred with Umbeliferaceae and Asteraceae with 6.61% and 5.64%, respectively, and the lowest consumption was of Plantaginaceae, Scrophulariaceae, minor plants, Gentianiaceae, unidentified plants, and Ranunculaceae with 2.86%, 2.50%, 2.17%, 2.08%, 1.03%, and 0.89%, respectively. The botanical families with the greatest preference value (PV) were Gramineae (PV=6.48), Scrophulariaceae (PV=8.75), Gentianiaceae (PV=7.55), and Ranunculaceae (PV=8.16). Proportional preference was observed in Juncaceae (PV=1.49), Cyperaceae (PV= -1.72), Rosaceae (PV=1.82), and Umbeliferaceae (PV= -0.82). The Asteraceae family was classified as a forced preference (PV= -6.29). The average nutritional value of the diet shows high values: 14.69% of raw protein, 14.58% ash, 85.42% organic matter, 21.43% raw fiber, and 31.00% neutral detergent fiber. It was concluded that alpacas efficiently select their diet for nutritional value, however, consumption is not appropriate, which results in negative live weight gain, especially in the dry season. On the other hand, the plants' preference values correspond to the lowest and one of the highest is a forced preference, according to the botanical composition of the wetland, which suggests that the preferred plants are repeatedly consumed in current continual pastures, and that alpacas are forced to consume unpalatable plants. This reflects on bad CANAPAS wetlands management in Ulla Ulla. Consequently, reversing this situation implies changes in pasture management and a reduction of the animal load.

Health benefits related to consumption of whole grains have been attributed in part to phytochemical and micronutrient composition. Understanding the composition, structure and distribution of these components in different cereal grains is of potential importance in aiding the selection of whole grains and their processed fractions for inclusion in the diet, and as ingredients in development of new food products. The aim of this research was to characterise the chemical components in the botanical fractions of yellow corn, barley, wheat. Manual separation, a tedious and laborious technique that yields pure fractions, suitable for compositional analysis, was used to separate whole grains into pericarp, aleurone layer, germ and endosperm fractions. Component identification and quantification of tissue components was accomplished by several techniques. The study also explored the possibility of using spectral characteristics fluorescence intensity values to provide rapid estimates of the concentrations and distribution of ferulic acid (FA), a major phenolic compound in cereal grains. While composition of phenolic acids and carotenoids was similar, the distribution was significantly different (P < 0.05) among cereal types and grain fractions. Phenolic acids were concentrated in pericarp and aleurone fractions, followed by the germ and the endosperm had the lowest levels. Yellow corn exhibited the highest values. Carotenoids, lutein and zeaxanthin were concentrated in the germ and aleurone layer of wheat and barley while in yellow corn it was in the endosperm and aleurone layer. This is the first study to report on carotenoid composition of aleurone fractions. Mineral elements, thiamine and niacin were higher in wheat aleurone than in purple barley and yellow corn aleurone layers. These findings suggest that yellow corn aleurone layers have potential as a functional food ingredient despite the low micronutrient content. A positive, significant correlation (r= 0.421, p < 0.0001) was found between fluorescence intensity values and ferulic acid concentration. Thus, fluorescence intensity profiles are a promising approach for rapid assessment of FA concentration in grain in-situ. This work has provided information that would act as a database for selection of cereal fractions and guide the miller to obtain grain fractions with enriched levels of phytochemicals and micronutrients.<br>February 2016

Llamas (Lama glama) take advantage of poor natural forage (grasses and others) due to their efficient digestive physiology that is adapted for this type of forage. The problem now faced is the gradual exhaustion of the native grassland (low phytomass production). The vegetation does not cover the dry matter consumption requirements, and less so the nutrient requirements, of these animals. Because of this there is the necessity of determining the botanical composition, pasture selection by plant parts, and chemical composition of what llamas ingest in order to improve these animals' nutrition in the pasture. This study occurred at the Larqa Uma ranch, located on Cachaca hill, north of the community of Pujrata, Santiago de Callapa municipality, Pacajes province, department of La Paz. It is located between 4390 and 4530 meters above sea level, at 17° 14' South latitude by 68° 18' West longitude. The botanical composition, plant parts, and chemical composition (organic matter content, raw protein, and neutral detergent fiber) of pastured llama ingestions were determined on the reserved pasture and the pasture with native grasses during February, March, and April in the rainy season. Three male q'ara-variety llamas of three ages were used. They were fistulated at the esophagus to collect ingestion samples. Determination of botanical composition of the ingestions was done by the point stereoscopic technique (Heady and Torrel 1959), and the chemical composition by Proximal Weende analysis (organic matter and raw protein) and the Van Soest method (neutral detergent fiber). The variance analysis showed highly significant differences for the botanical composition of llama ingestions by pasture groups (p<0.05) and significant differences for the monthly evaluation interaction with pasture groups (p<0.05). Meanwhile, the month of evaluation, pasturing site, monthly evaluation interactions with pasturing site, pasturing site with pasture groups, and month of evaluation with pasturing sight with pasture groups did not have significant differences (p>0.05). The llamas selected 80.13% grasses, higher than the other pasture groups: 8.64% for grassoids and 8.63% herbs, which were selected in similar proportions (p>0.05). Statistically, there are no differences between these pasture groups found in llama ingestions. Shrubs contributed a very low proportion of ingestion (2.86%). Selection for grasses (84.95%) during February was higher than the month of April and similar to March. In contrast, the March average of 80.62% is similar to the first month and higher than in April (74.83%). Shrub consumption of 4.36% during April was higher than in February and similar to in March. March's average of 3.92% is similar to the last month and higher than in February (0.20%). During February, March, and April, grass consumption by llamas (84.95%, 80.62%, and 74.83%, respectively) was higher than the average consumption of the other pasture groups. Grassoids, herbs, and shrubs were selected in similar proportions (p>0.05). The variance analysis showed highly significant differences for selection for parts of the plants, interaction between the evaluation month with parts of the plant, and interaction of pasturing site with plant parts (p<0.05).

Waxy crude oils (1/3 of oil produced worldwide), pumping through pipelines considered risky operation due to the crude wax content (15-40 wt.%) and to the temperature at which wax supersaturates and precipitates, leading to the danger of pipe blockage, eventually resulting, in multimillion dollars loss in production and maintenance. This research undertaken to develop operational strategy of waxy crude pipelines, considering the crude and crude gel properties and flow conditions. The research problem was approached by characterizing the crude gel with and without additives using chromatography (GC), differential scanning calorimetry (DSC), cross polarised microscopy (CPM), controlled stress and oscillatory shear rheology (CSR and OSR), the principal parameters being the crude temperature and the rate at which the crude was cooled. GC and DSC were useful in establishing wax composition, content and wax appearance temperature (WAT). Control stress rheometer proved to be the most appropriate as it measured the reduction in apparent viscosity at full production (10-50 s-1 shear rate), near shutdown (1 s-1 ) and yielding when the oil was statically cooled. On this basis, it was established that the wax inhibitor was the most effective. CPM revealed that only the wax inhibitor changed the structure of the gel, disrupting its otherwise knitted crystal network. Dilution with the light crude oil merely reduced the wax content and the pour point depressant reduced the gelling temperature. OSR provided a check on CSR and confirmed the gelation temperature measured. CSR provided the yield stress measured, it also provided comprehensive data that can be used for theoretical modelling of this complex flow.<br>Libyan Petroleum Institute, Libya

A tecnologia tradicional de envelhecimento de aguardentes vínicas,em vasilha de madeira, envolve um custo elevado, devido ao longo período de contacto entre a madeirae a aguardente e à existência de uma perda significativa desta última por evaporação. A necessidade de reduzir o custo de investimento, justifica pois a procura de sistemas alternativos de envelhecimento.Como tal, o objetivo do presente trabalho consiste noestudo das características físico-químicas das madeiras de duas espécies botânicas (carvalho francês Limousin e o castanheiro), com queima média mais, utilizadas em simultâneo no envelhecimento deuma aguardente vínica Lourinhã nos sistemas tradicional (vasilhas de 650 L) e alternativo (aduelas colocadas em depósitos de aço inoxidável de 3000 L).Os resultados obtidos permitem concluir que, embora a madeira destinada aos dois sistemas de envelhecimento tivesse teoricamente sido sujeita ao mesmo nível de queima, na prática o tratamento térmico foi mais intenso na madeira utilizada no sistema alternativo, originando maior acumulação de compostos extraíveis e, por consequência, uma cor mais evoluída, que se pode repercutir nas características da correspondente aguardente envelhecida. O tratamento térmico origina, em qualquer das espécies botânicas, um aumento substancial do índice de polifenóis totais, do extrato seco e da maioria dos compostos de massa molecular baixa, com particular incidência nos aldeídos furânicos; Phenolic composition andchromatic characteristicsof Limousin oak wood and chestnut wood used as wooden barrels and staves in the ageing of wine brandy ABSTRACT: The traditional technology of wine brandies’ageing, using wooden barrels, involves a high cost due to the long period of contact between the wood and the brandy and to the significant loss of brandy by evaporation. It is necessary to reduce the cost of investment, which justifies the search for alternative ageing systems. As such, the aim of this work is the study of physical and chemical characteristics of the wood of two botanical species (Limousin oak and chestnut) with medium toasting used simultaneously in the ageing of a Lourinhã wine brandy in traditional system (650 L wooden barrels) and alternative system (stainless steel tanks with wood staves). The results obtained allow concluding that, although the wood used in the two systems theoretically had been subjected to the same toasting level, in the practice the heat treatment was more intense in the wood used in the alternative technology, resulting in a greater accumulation of extractable compounds and therefore more evolved colour that can influence the characteristics of the corresponding aged brandy.The heat treatment causes a strong increase of the total phenolic content, dry extract and of the majority of low molecular weight compounds, mainly of furanic derivatives, in both botanical species.