Top PDF Performance of Different Acids on Sandstone Formations

Performance of Different Acids on Sandstone Formations

Performance of Different Acids on Sandstone Formations

Sandstone is primarily composed of Silica and Silicate minerals, including quartz, various forms of clays, feldspars and in rare cases zeolites. Sandstone Acidizing is used to stimulate the true permeability of sandstone formations. The fluids are pumped into the porosity of the rock at below the fracturing pressure and the acid reacts with a large portion of the formation. In sandstone acidization many reactions take place; the most important of them are the reactions of HCl and HF with carbonates, the reactions of HF with silicates, Quartz and feldspar. Hydrofluoric reactivity with the silica makes it unique in sandstone acidizing application. Other acids such as hydrochloric, nitric and sulphuric acids are unreactive with silica. [4]
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Effect of Different Dietary Concentrations of Amino Acids on the Performance of Two Different Broiler Strains

Effect of Different Dietary Concentrations of Amino Acids on the Performance of Two Different Broiler Strains

Results obtained from the present experiment agree with other studies that found that the performance of broilers worsens when low-protein diets are offered (Sklan & Noy, 2005; Lilly et al., 2011). Using data of six experiments, a reduction of more than 3% CP, even when corrected for the main limiting AA, resulted in worse performance (Dean, 2006). Reducing CP (20.8, 19.7 and 17.5%) of diets supplemented with synthetic AA had a negative effect on broiler WG and FCR between 21 and 28 days, indicating that, at this age, protein requirement may be higher than usual (20% CP) due to a higher rate of lean tissue accretion (Viola et al., 2008). It was clear that the increase in AA concentrations in the starter and growing periods improved performance. However, in the present study, the best performance was observed when the High NP was fed during the entire rearing period. Under practical field conditions, where challenges are always stronger than under experimental conditions, the advantages of High NP could last longer.
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Different criteria for feed formulation based on digestible amino acids for broilers

Different criteria for feed formulation based on digestible amino acids for broilers

An important function of animal production is to provide high-quality protein for human consumption. In order to fulfill this role, animals themselves require high-quality protein in correct proportions in their diets. There are many ways to assess the quality of proteins, but nevertheless they are all related to amino acid supply, which thus becomes a key feature in animal nutrition. For many years, poultry feed formulation was based on the concept of crude protein, which often resulted in higher amino acid levels than those required by the birds. Birds are not able to properly utilize this excess of amino acids, which is reduced to nitrogen and excreted as uric acid. Excessive protein levels in the feed do not only mean high formulation costs, but can also affect poultry performance. When synthetic amino acids became commercially available, nutritionists started to formulate lower cost feeds, with a proper level of amino acids, but still used high protein levels. Birds do not require high crude protein in the feed, but merely an amount that ensures sufficient nitrogen reserve for the synthesis of non-essential amino acids. As the number of economically available synthetic amino acids increase, the crude protein level will be increasingly reduced. According to Pack (1995), amino acid requirements must indubitably be expressed on digestible base, instead of total base.
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Jelena Bogdanović Pristov (2) and Vuk Maksimović (2)

Jelena Bogdanović Pristov (2) and Vuk Maksimović (2)

Abstract – The objective of this work was to evaluate the biochemical composition of six berry types belonging to Fragaria, Rubus, Vaccinium and Ribes genus. Fruit samples were collected in triplicate (50 fruit each) from 18 different species or cultivars of the mentioned genera, during three years (2008 to 2010). Content of individual sugars, organic acids, flavonols, and phenolic acids were determined by high performance liquid chromatography (HPLC) analysis, while total phenolics (TPC) and total antioxidant capacity (TAC), by using spectrophotometry. Principal component analysis (PCA) and hierarchical cluster analysis (CA) were performed to evaluate the differences in fruit biochemical profile. The highest contents of bioactive components were found in Ribes nigrum and in Fragaria vesca, Rubus plicatus, and Vaccinium myrtillus. PCA and CA were able to partially discriminate between berries on the basis of their biochemical composition. Individual and total sugars, myricetin, ellagic acid, TPC and TAC showed the highest impact on biochemical composition of the berry fruits. CA separated blackberry, raspberry, and blueberry as isolate groups, while classification of strawberry, black and red currant in a specific group has not occurred. There is a large variability both between and within the different types of berries. Metabolite fingerprinting of the evaluated berries showed unique biochemical profiles and specific combination of bioactive compound contents.
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Effect of unsaturated fatty acids on myocardial performance, metabolism and morphology

Effect of unsaturated fatty acids on myocardial performance, metabolism and morphology

morphological changes of the myocardium, such as lipid deposit and mitochondrial mem- brane injuries, were only observed under electron microscopy while no alterations were seen under the light microscope. This contrasts with previous studies that observed necrosis (14) and abnormal myocardial stria- tion (15) using different kinds of UFA-rich diet. According to Lamers et al. (14), the mechanism by which an imbalance in di- etary fatty acids produces myocardial le- sions is completely unknown. However, oth- ers have suggested that these cardiac mor- phological injuries can be caused by oxida- tive stress induced by a diet rich in UFA (24,35,36). In the present study, we observed myocardial oxidative stress and light mor- phological injuries induced by the UFA- enriched chow. Increased dietary levels of UFA can cause these lipids to be incorpo- rated into membrane phospholipids, leading to oxidative stress (24,35,36).
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Humic substances isolated from residues of sugar cane industry as root growth promoter

Humic substances isolated from residues of sugar cane industry as root growth promoter

The first indirect evaluation of HA aromaticity via the E 4 /E 6 ratio was undertaken by Kononova (1961), who collected data from several HA isolated from many dif- ferent soils and showed an inverse relationship between the soil fertility and the E 4 /E 6 number. Consequently, the condensation reactions of organic matter could be easily evaluated through this parameter, since, in theory, as aro- maticity rises together with the humification, so the E 4 / E 6 ratio drops. Despite the controversies concerning the E 4 /E 6 ratio as an indicator of aromaticity degree, this tech- nique is still widely used. It was reported that the E 4 /E 6 ratio is mainly related to the size of the humic substances (Chen et al., 1977). The NMR CP/MAS 13 C techniques with polar dephashing (DD) measurements of condensed aromatic or substituted carbons demonstrated a negative significant correlation (R 2 =0.94) with the E
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The Influence of Small Amounts of Aluminium on the Spheroidization of Cast Iron with Cerium Mischmetal

The Influence of Small Amounts of Aluminium on the Spheroidization of Cast Iron with Cerium Mischmetal

Introduction of aluminium in the quantity of either about 0.6% (the alloy from melt No. 1) or about 1.1% (the alloy from melt No. 2) leads to the arising of the ferrite-pearlite matrix containing the precipitates of free cementite despite the significant silicon content in the cast iron (see data in Table 4 and Figs 2 and 4). The cast iron from these two melts did not contain the regular nodular graphite precipitates. In both cases the shape of graphite precipitates, according to the Standard [15], can be classified as II, its distribution as B, magnitude as 6 (see Figs 1 and 3).
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A QCAR model for predicting antioxidant activity of wild mushrooms

A QCAR model for predicting antioxidant activity of wild mushrooms

Wild mushrooms have been described as sources of natural antioxidants, particularly phenolic compounds. However, many other compounds present in wild mushrooms can also act as antioxidants (reducers), so whole extracts from a wide range of species need to be examined. To gain further knowledge in this area, the relationship between the antioxidant potential (scavenging effect and reducing power) and chemical composition of twenty three samples from seventeen Portuguese wild mushroom species was investigated. A wide range of analytical parameters reported by our research group (including ash, carbohydrates, proteins, fat, monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids, phenolics, flavonoids, ascorbic acid and -carotene) were studied and the data were analysed by partial least squares (PLS) regression analysis to allow correlation of all the parameters. Antioxidant activity correlated well with phenolic and flavonoid contents. A QCAR (Quantitative Composition-Activity Relationships) model was constructed, using the PLS method, and its robustness and predictability were verified by internal and external cross-validation methods. Finally, this model proved to be a useful tool in the prediction of mushrooms’ reducing power.
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Physical exercise-induced fatigue: the role of serotonergic and dopaminergic systems

Physical exercise-induced fatigue: the role of serotonergic and dopaminergic systems

Brain serotonin and dopamine are neurotransmitters related to fatigue, a feeling that leads to reduced intensity or interruption of physical exercises, thereby regulating performance. The present review aims to present advances on the understanding of fatigue, which has recently been proposed as a defense mechanism instead of a ‘‘physiological failure’’ in the context of prolonged (aerobic) exercises. We also present recent advances on the association between serotonin, dopamine and fatigue. Experiments with rodents, which allow direct manipulation of brain serotonin and dopamine during exercise, clearly indicate that increased serotoninergic activity reduces performance, while increased dopaminergic activity is associated with increased performance. Nevertheless, experiments with humans, particularly those involving nutritional supplementation or pharmaco- logical manipulations, have yielded conflicting results on the relationship between serotonin, dopamine and fatigue. The only clear and reproducible effect observed in humans is increased performance in hot environments after treatment with inhibitors of dopamine reuptake. Because the serotonergic and dopaminergic systems interact with each other, the serotonin-to-dopamine ratio seems to be more relevant for determining fatigue than analyzing or manipulating only one of the two transmitters. Finally, physical training protocols induce neuroplasticity, thus modulating the action of these neurotransmitters in order to improve physical performance.
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Distributions of grain parameters on the surface of aircraft engine turbine blades

Distributions of grain parameters on the surface of aircraft engine turbine blades

The results of calculations of the areas of non-planar grain surfaces and the grain areas on the projection plane for correct and incorrect macrostructures are presented as distributions with a logarithmic width of classes in Figs. 6 and 7, respectively. 7. Parameters of the grain size distributions in 3D and 2D spaces are presented in Table 1. A supplementary evaluation of the grain size consists of a calculation of the shape and elongation coefficients. The results of the calculations are presented as distributions these values in Figures 8, 9, 10 and 11, respectively, while statistical parameters are shown in Tables 2 and 3.
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Multi-Response Ergonomic Evaluation of Higher Age Group  CNC Machine Operators

Multi-Response Ergonomic Evaluation of Higher Age Group CNC Machine Operators

The population of the developed countries is becoming older while computer use is affecting increasingly wide aspect of life (Hawthorn, 2000). It is increasingly important that interface designs make software accessible to older adults. The study noticed that there is almost no research on what makes an interface usable for older adults. Hawthorn (2000) reviews the findings on the effects of age on relevant abilities and uses this information to provide suggestions to consider when designing interfaces for older users. The study concludes with indications of the needed research in the area of interface design for older users. Kang and Yoon (2008) observed the behavior of younger adults (20-29 years old) and middle-aged adults (46-59 years old) interacting with complicated electronic devices. The study examined various aspects of interaction behaviors in terms of performance, strategies, error consequences, physical operation methods and workload. The analysis of age-related differences included differences in background knowledge. The results revealed that differences in age meaningfully affected the observed error frequency, the number of interaction steps, the rigidity of exploration, the success of physical operation methods and subjective perception of temporal demand and performance. In contrast, trial- and-error behavior and frustration levels were influenced by background knowledge rather than age. Designing human-machine interfaces that respect the ergonomic norms and following rigorous approaches constitute a major concern for automated systems designers. The increased need on easily accessible and usable interfaces leads researchers in this domain to create methods and models that make it possible to evaluate these interfaces in terms of utility and usability. Two different approaches are currently used to evaluate human-machine interfaces (Chikhaoui and Pigot, 2010), empirical approaches that require user involvement in the interface development process and analytical approaches that do not associate the user during the interface development process. This work presents studies of user performance on three principal tasks (cognitive, motor action and applied force) of the machine panel interface, developed in the context of CNC machine system. Chikhaoui and Pigot (2010) investigated that cognitive models show better accuracy of the user
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Identification of AG10 alloy’s mechanical properties on base of ATND method

Identification of AG10 alloy’s mechanical properties on base of ATND method

Knowledge about run of crystallization process of alloys constitutes a source of information on development of a new technology to prepare liquid metal and to control of preparation process of alloys within industry. Complicated shapes and big differences in wall thickness of castings made from Al.-Mg alloy and their behavior under changing loads require elaboration and implementation of a methods enabling determination of mechanical properties of the alloys on preparation stage before casting process. The paper presents application of simultaneous ATND method (thermal-voltage derivative analysis) in determination of mechanical properties of AG10 alloy. Investigated alloy was melted in electric resistance furnace, and next, one has performed registration of crystallization with use of ATND method and regression analysis aimed at elaboration of equations to determine mechanical properties of the investigated alloy. Obtained mathematical dependencies enable prompt check of the mechanical properties of the alloy as early as in stage of its preparation. The research performed in laboratory conditions needs verification in industry conditions with targeted production of automated control stand
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Influence of tungsten and titanium on the structure of chromium cast iron

Influence of tungsten and titanium on the structure of chromium cast iron

Studies have proved that structure of the chromium cast iron greatly depends on the additionally introduced elements such as titanium and tungsten. Titanium is a carbide-forming element, but in contrast to other elements of this type it does not form complex carbides in the chromium cast iron, but only a TiC carbide, which is formed at high temperature in the liquid metal. Tungsten is also a carbide-forming (and pearlite-forming) element but, like titanium, is rarely used in the manufacture of chromium cast iron. High melting points of tungsten and titanium may cause difficulties in the metallurgical process of chromium cast iron manufacture. Tungsten effect on the mechanical properties is similar to that of molybdenum, although it is weaker. Tungsten increases the hardenability of cast iron. Currently, the use of tungsten can be justified because of its price slightly lower than that of molybdenum.
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The modification process of AlSi21CuNi silumin and its effect on change of mechanical properties of the alloy

The modification process of AlSi21CuNi silumin and its effect on change of mechanical properties of the alloy

Considering mechanism of modification of these precipitations one should take into account that effect of modification of hypereutectic silumins depends on earlier transition to liquid phase of sparingly soluble crystals of primary silicon [1-3]. Tests performed by authors of the studies [4-10] enable utilization of modification treatments together with making use of a various micro additives in order to improve properties of hypereutectoid alloys.

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Proximate Amino Acid Anti-Nutritional Factor And Mineral Composition Of Different Varieties Of Raw Lablab Purpureus Seeds

Proximate Amino Acid Anti-Nutritional Factor And Mineral Composition Of Different Varieties Of Raw Lablab Purpureus Seeds

The proximate chemical composition of the three varieties of lablab seed studied is shown in Table 1. The dry matter ranged between 90.27-94.11g/100g while the crude fibre and ash respectively ranged from 7.22-9.73 and 4.77- 8.82g/100g The Highworth variety contained lower dry matter, crude fibre and ash, but was higher in crude protein and ether extract than the Rongai varieties. The crude protein and ether extract ranged between 24.88- 34.33g/100g and 2.99-5.87g/100g respectively. This study has shown that the mean crude protein (CP) content of the three varieties of lablab seed was 29.20% with the Highworth variety having the highest content of 34.30%. The crude protein of each of the Rongai varieties is within 23-28% range reported by Murphy and Colucci, (1999) and Ogundipe et al. (2003). The crude protein value of the Highworth variety is closer to that of full fat soyabean (FFSB) compared to the Rongai varieties. The mean crude protein content of the three varieties of lablab seed assayed in the present study is similar (P>0.05) to the 29% crude protein content of mucuna seed; a wild leguminous plant (6), but higher than 21% crude protein content of pigeon pea seed (Iorgyer, 2010) and 24% CP of cowpea (8). Each of the three varieties of lablab seed analyzed in the present study contained less (7.22-9.23%) crude fibre (CF) than the 11.19% CF reported by Murphy and Colucci (1999) for lablab seed. The CF values obtained from this study are higher than the amount of CF in FFSB (5.55%), pigeon pea (5.00%) and Mucuna (5.53%) as reported by Tuleun and Patrick (2007); Ogundipe et al. (2003); Murphy and Colucci (1999) respectively. The ether extract (EE) content (2.99- 5.87%) of lablab seed in the present study is low compare to the 9.13% EE (5), but higher than the 1.9% EE (Osman
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Affinity chromatography in plasmid DNA purification for therapeutic applications

Affinity chromatography in plasmid DNA purification for therapeutic applications

In Fig. 3(a) it is possible to observe an expected increase on retention when the molecular mass of the adenine oli- gonucleotides was increased. Thus, at a constant temper- ature and for a fixed salt gradient, in the absence of addi- tional effects (such as the presence of secondary struc- tures), the retention time of the oligonucleotides was proportional to its number of hydrophobic bases, in accordance to what has been described by a previous work [22]. But in the case of guanine oligonucleotides (monoG, oligoG3, oligoG6, polyG15 and polyG30) in Fig. 3(b), the retention pattern was different from the expected one. Heterogeneity on the G6 oligonucleotide is evident as a minor peak at about 5.5 mL and a major peak at about 9 mL (Fig. 3(c)) is found. Moreover, the retention time of polyG15 is higher than that for polyG30. This behaviour suggests that different secon- dary structures of the oligonucleotide can coexist under these conditions. These secondary structures were already described as frequent and are usually designated by guanine quadruplexes that may occur due to the pos- sible interactions between molecules of guanine leading to inter- or intramolecular associations, depending on the size of oligonucleotide [23, 24]. The quadruplexes can form arrays of four hydrogen bonds in which each base acts as both donor and acceptor of two hydrogen bonds with other guanines, and pairing between bases is of Hoogsteen type [25]. This unique structure has recently been proposed to exist in living cells and has drawn attention as a target for gene expression control, cell divi- sion [26], and selective anticancer agents (telomerase inhibitors and/or transcriptional repressors of c-MYC oncogene) [27]. Studies regarding G-quadruplex binding selectivity are essential to the development of G-quadru- plex ligands for therapeutic use [27]. The potential of gua- nine oligonucleotides to be organised in different secon- dary structures induces a heterogeneity when they are in solution which is reflected in a two peaks profile (Fig.
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Performance evaluation of waste stabilization pond in Birjand, Iran for the treatment of municipal sewage

Performance evaluation of waste stabilization pond in Birjand, Iran for the treatment of municipal sewage

The study wastewater stabilization pond is located in East of Iran, Birjand, and the capital city of Southern Khorasan province. It is situated at latitude of 32˚86' N and longitude of 59˚21'E and about 1490 m above sea level. Birjand city has a cold and dry climate. The average annual temperature is 16.35°C with the warmest time in June (average 27.5°C) and the coldest in February (average 3.2°C).The annual mean evaporation and wind speed 321.74 mm/month and 12.92 m/s respectively. Birjand wastewater Treatment Plant has been constructed with a capacity of 10 500 m³ per day for a population of 64 000 people and in two modules in parallel. The classical pond configurations are divided to anaerobic and facultative and maturation ponds (Fig. 1). The operation of the module1 has started with a capacity of 60 l/s in 2005 but the structure of module 2 has performed. The wastewater treatment plant of Birjand has pretreatment units that include grit chamber and screens that followed by the WSP systems. Table 1 shows the physical characteristics of the BWSP systems.
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Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil

Spatial distribution of epibenthic molluscs on a sandstone reef in the Northeast of Brazil

Fleshy algae in large covers could also influence the low molluscan richness in Maracajaú, once this algae category is considered unpalatable to many herbivorous animals (Littler and Littler, 1983; Hay et al., 1987; Hay and Fenical, 1988; Steneck and Dethier, 1994). In general, fleshy algae are not palatable to large herbivores such as fish and sea urchins in tropical habitats, meanwhile small herbivores (mesograzers) such as amphipods, isopods and polychaetas often feed on these macroalgae (see review of Duffy and Hay, 1990). The mainly fleshy algae registered in this study were the green algae C. racemosa and brown algae of the Order Dictyotales. The former is an algae avoided by many herbivores due to its chemical and morphological defense, even so ascoglossan gastropods (very small sea slugs) feed on them, which sequester their chemical defenses (see review of Duffy and Hay, 1990). On the other hand, studies on chemical defense of Brazilian tropical algae demonstrated that algae species of the Order Dictyotales (Pereira et al., 2000; Pereira et al., 2002), the other most recorded algae in this study, have Table 4. BIO-ENV analysis showing associations between 10 environmental variables* and molluscan community structure for the different habitats. R is the correlation coefficient.
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ELECTROFACIES CHARACTERIZATION USING SELF-ORGANIZING MAPS

ELECTROFACIES CHARACTERIZATION USING SELF-ORGANIZING MAPS

The geological models of hydrocarbon reservoirs are based on the estimates of reservoir properties, such as: lithology, porosity, permeability and fluid type (e.g. Alhoniemi et al., 1999; Bhatt & Helle, 2002; Matos et al., 2004; Stundner & Oberwinkler, 2004). The use of robust mathematical methods aims at reducing uncer- tainties when generating such models, the more reliable the re- sults the more they help to minimize exploration risks and costs. Among these, artificial intelligence technologies are the most used methods in geosciences, with emphasis on Artificial Neural Networks (ANN) (Haykin, 1999). These ANNs have the ability to model non-linear relationships among the variables involved, are highly adaptable to input dataset and do not require prior knowl- edge of data statistical distribution. These fundamental features rank ANN among the most important clustering and classification methods of the last decade (Haykin, 1999; Stunder & Oberwin- kler, 2004), and it is therefore, largely used in reservoir geology, which involves geological heterogeneities on various scales and treatment of data sets from several sources (Kohonen, 2001; Bhatt & Helle, 2002; Stundner & Oberwinkler, 2004; Esposito et al., 2008). As example of such application, Stundner & Oberwinkler (2004) mention three basic ANN uses to treat data from well logs: prediction of permeability and/or porosity; generation of synthetic wells and determination of electrofacies.
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Effect of heat treatment parameters on the properties of low-alloy cast steel with microadditions of vanadium

Effect of heat treatment parameters on the properties of low-alloy cast steel with microadditions of vanadium

This article examines the effect of prolonged time of holding at the temperature of 620 0 C on the processes of secondary phase precipitation and mechanical properties of low-alloy cast steel with an addition of vanadium subjected to two variants of heat treatment, i.e. U:1150 0 C+H:950 0 C+O:620 0 C and H:950 0 C+O:620 0 C. To determine an impact of the applied heat treatment operations, testing of mechanical properties and microstructural examinations of the cast steel with 0,21 and 0,27%C were carried out.
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