Impact of the substitution of reference annual streamflow by monthly streamflow on the potential use of water resources

The consideration of the streamflow seasonality has a high potential to improve the water use. In order to give subsidies to the optimization of water use, it was evaluated the impact of the change of reference annual streamflow by the monthly streamflows in the potential water use throughout the hydrography of Paracatu sub-Basin. It was evaluated the impact on Q7,10 (lowest average streamflow during a 7-day period with an average recurrence of 10 years) and on Q95 (permanent flow present 95% of the time). The use of monthly streamflow to substitute the annual streamflow had a high potential of improvement of water resources use in the sub-Basin studied. The use of monthly Q 7,10 in substitution of annual Q 7,10 increases the potential water use that vary from about 10% in the months of lower water availability to values exceeding 200% in the months with higher availability of surface water resources. The use of monthly Q95 in substitution of the annual Q95 implies in changes oscillating from reduction of 37% in months of higher water restriction to values exceeding 100% in the months of higher availability, so the use of monthly Q95 instead of the annual Q95 enables the more rational and safe use of water resources.

Substitution-Newton-Raphson method applied to the modeling of a vapour compression refrigeration system using different representations of the thermodynamic properties of R-134a

This paper gives a detailed presentation of the Substitution-Newton-Raphson method, suitable for large sparse non-linear systems. It combines the Successive Substitution method and the Newton-Raphson method in such way as to take the best advantages of both, keeping the convergence features of the Newton-Raphson with the low requirements of memory and time of the Successive Substitution schemes. The large system is solved employing few effective variables, using the greatest possible part of the model equations in substitution fashion to fix the remaining variables, but maintaining the convergence characteristics of the Newton-Raphson. The methodology is exemplified through a simple algebraic system, and applied to a simple thermodynamic, mechanical and heat transfer modeling of a single-stage vapor compression refrigeration system. Three distinct approaches for reproducing the thermodynamic properties of the refrigerant R-134a are compared: the linear interpolation from tabulated data, the use of polynomial fitted curves and the use of functions derived from the Helmholtz free energy.

Comparison of Biomass Gasification Technologies for Natural Gas Substitution in Iron Ore Pelletizing Plants

The iron ore pelletizing process consumes high amounts of energy, including nonrenewable sources, such as natural gas. Due to fossil fuels scarcity and increasing concerns regarding sustainability and global warming, at least partial substitution by renewable energy seems inevitable. Gasification projects are being successfully developed in Northern Europe, and large-scale circulating fluidized bed biomass gasifiers have been commissioned in e.g. Finland. As Brazil has abundant biomass resources, biomass gasification is a promising technology in the near future. Biomasses can be converted into product gas through gasification. This work compares different technologies, e.g. air, oxygen and steam gasification, focusing on the use of the product gas in the indurating machine. The use of biosynthetic natural gas is also evaluated. Main parameters utilized to assess the suitability of product gas were adiabatic flame temperature and volumetric flow rate. It was found that low energy content product gas could be utilized in the traveling grate, but it would require burner’s to be changed. On the other hand, bio-SGN could be utilized without any adaptions. Economical assessment showed that all gasification plants are feasible for sizes greater than 60 MW. Bio-SNG production is still more expensive than natural gas in any case.

Thr(118)Met amino acid substitution in the peripheral myelin protein 22 does not influence the clinical phenotype of Charcot-Marie-Tooth disease type 1A due to the 17p11.2-p12 duplication

The Thr(118)Met substitution in the peripheral myelin protein 22 (PMP22) gene has been detected in a number of families with demyelinating Charcot-Marie-Tooth (CMT1) neuropathy or with the hereditary neuropathy with liability to pressure palsy, but in none of them has it consistently segregated with the peripheral neuropathy. We describe here a CMT1 family (a 63-year-old man, his brother and his niece) in which two mutations on different chromosomes were found in the PMP22 gene, the 17p duplication, detected by fluorescent semiquantitative polymerase chain reaction (PCR) of microsatellite markers localized within the duplicated region on chromosome 17p11.2-p12, and the Thr(118)Met substitution, detected by direct sequencing the four coding exons of the PMP22 gene. A genotype/phenotype correlation study showed that the neuropathy segregates with the duplication and that the amino acid substitution does not seem to modify the clinical characteristics or the severity of the peripheral neuropathy. We did not find any evidence to characterize this substitution as a polymorphism in the population studied and we propose that the high frequency reported for this point mutation in the literature suggests that the Thr(118)Met substitution may be a hotspot for mutations in the PMP22 gene.

Partial substitution of nitrite by chitosan and the effect on the quality properties of pork sausages

The aim of the study was to evaluate the influence of partial nitrite replacement by chitosan on the quality of Ham Visking (a type of pork sausages). Five Ham Visking formulations were elaborated modifying the sodium nitrite (0.011; 0.016 or 0.0212%) and chitosan concentrations (0.25 or 0.5%) in the products. Sausages were stored at 4 ºC and physicochemical, microbiological, and sensorial evaluations were performed in order to estimate their shelf life. Chitosan can be used in pork sausages without affecting ensory attributes such as color although the panelists detected textural differences among the samples with chitosan, which suggests that there is some influence of deacetylation degree of chitosan on the textural behavior of sausages which still needed to be explained for a successful application of chitosan in meat products. The reduction of residual sodium nitrite did not affect the color and flavor of such products, but the use of chitosan increasedsignificantly the shelf life of sausages.

Industrialization in Sub-Saharan Africa and import substitution policy

This article aims to contribute to the understanding of the process of import substitution in Sub-Saharan Africa. The process of industrialization in Sub-Saharan Africa occurred in two phases: a first step, even very early during the colonial regime began around the 1920s and ended in the late forties; a second phase of industrialization began in the late fifties and gained momentum in the sixties, when import substitution was implemented more widely. Although these countries were the last to embark on the strategy of import substitution, they followed the same steps of Latin American countries, and as the structural domestic and external constraints were too strong, the failure of the policy of import substitution arrived early and the negative impact on these economies had a greater magnitude.

Philippe-Égalité et M. Chiappini, histoire d'une substitution... / Maurice Vitrac,...

Collection : Les énigmes de l'histoire

Construction of bovine adenovirus type 3 E1 and E3, substitution plasmids and the sequencing analysis of DNA pol and pTP /

The relative ease to concentrate and purify adenoviruses, their well characterized mid-sized genome, and the ability to delete non-essential regions from their genome to accommodate foreign gene, made adenoviruses a suitable candidate for the construction of vectors. The use of adenoviral vectors in gene therapy, vaccination, and as a general vector system for expressing foreign genes have been documented for some time. In this study, the objective was to rescue a BAV3 E1 or E3 recombinant vector carrying the kanamycin resistant gene, a dominant selectable marker with useful applications in studying vectored gene expression in mammalian cells. To accomplish the objective of this study, more information about BAV3 DNA sequences was required in order to make the manipulation of the virus genome accessible. Therefore, sequencing of the BAV3 genome from 1 1 .7% to 30.8% was carried out. Analysis of the determined sequences revealed the primary structure of important viral gene products coded by E2 including BAV3 DNA pol and precursor to terminal protein. Comparative analysis of these proteins with their counterparts from human and non human adenoviruses revealed important insights as to the evolutionary lineage of BAV3. In order to insert the kanamycin resistance gene in either E1 or E3, it was necessary to delete BAV3 sequences to accommodate the foreign gene so as not to exceed the limit of the packaging capacity of the virus. To construct a recombinant BAV3 in which a foreign gene was inserted in the deleted E1 region, an E1 shuttle vector was constructed. This involved the deletion from the viral sequences a region between 1.3% to 9% and inserting the kanamycin resistance gene to replace the deletion. The E1 shuttle vector contained the left (0%- 53.9%) segment of the genome and was expected to generate BAV3 recombinants that can be grown and propagated in cells that can complement the missing E1 functions. To construct a similar shuttle vector for E3 deletion, DNA sequences extending from 78.9% to 82.5% (1281 bp) were deleted from within the E3 region that had been cloned into a plasmid vector. The deleted region corresponds to those that have been shown to be non-essential for viral replication in cell culture. The resulting plasmid was used to construct another recombinant plasmid with BAV3 DNA sequences extending from 37.1% to 100% and with a deletion of E3 sequences that were replaced by kanamycin resistance gene. This shuttle plasmid was used in cotransfections with digested viral DNA in an attempt to rescue a recombinant BAV3 carrying the kanamycin resistance gene to replace the deleted E3. In spite of repeated attempts of transfection, El or E3 recombinant BAV3 were not isolated. It seems that other approaches should be applied to make a final conclusion on BAV3 infectivity.

The nucleophillic substitution of various chloroanthraquinones of their possible rearrangement via aryne intermediates

The work in this thesis deals mainly with nucleophilic substitution of chloroanthraquinones as a route to various starting materials which might rearrange, via aryne intermediates to afford fused-ring heterocy1ic carboxylic acids. 1-Amino-5-chloroanthraquinone was successfully prepared by reacting 1,5-dichloroanthraquinone with sodium aZide in ref1uxing dimethylsulfoxide (DMSO). It could also be prepared from the same starting material by reaction with ammonia (gas) in DMSO in the presence of potassium fluoride. Treatment of l-amino-5-chloroanthraquinone with potassium amide in liquid ammonia or with potassium t-butoxide in t-butylbenzene returned mainly starting material, although in the latter case some 1-amino-5-hydroxyanthraquinone was also isolated. 1-Hydroxy-5-chloroanthraquinone was ultimately prepared by diazotization of the amino-analog. It was recovered almost quantitatively after treatmenu'with potassium amide in liquid ammonia. The reaction with potassium t-butoxide in t-buty1benzene was anomalous and gave 1-hydroxyanthraquinone as the only iso1able product. Acridines were successfully prepared by the action of 70% sulfuric acid on 1,5-bis(p-toluidino)-anthraquinone and 1-p-toluidino-5- ch10roanthraquinone, and in the latter case, cleavage to give an acridinecarboxylate was attempted. Substituted anthraquinones reacted with sodium azide in sulfuric acid to give azepindiones by -NH insertion. Methods for separating and identifying isomeric mixtures of these compounds were examined. Attempted decarbonylation of selected azepindiones to give acridones gave mainly what were thought to be amino-benzophenone derivatives. Chloroanthraquinones were found to react with hexamethylphosphoramide (HMPA) to give mixtures of the dimethylamino- and methylaminoderivatives. Under the same conditions halogeno-nitrobenzenes and nitrophenols were substituted to give the appropriate dimethyl aminobenzenes, except in two cases. 3-Chloronitrobenzene reacted anomalously to give a small amount of 3,3'-dichloroazobenzene and a trace of 4-dimethylamino-nitrobenzene. Pentachlorophenol reacted to give a pentachlorophenylphosphorodiamidate in good yield.

Diastereoselective Lithiation-Substitution of N-Silyl-Protected-(S)-Tetrahydro-1H-pyrrolo[1,2-c]imidazole-3(2H)-ones and Applications of Their Derivatives

This thesis describes a method involving the preparation of an L-proline-derived imidazolone protected with an N-triethylsilyl group that undergoes diastereoselective lithiation followed by electrophile quench to give C5-substituted products with syn stereochemistry. The N-silylated derivatives may be more easily N-deprotected as compared to previous N-t-Bu analogues to give secondary ureas. These may serve as precursors to N-phenyl chiral bicyclic guanidines or as NHC precursors for synthesis of corresponding complexes.

Diastereoselective Lithiation-Substitution of N-Silyl-Protected-(S)-Tetrahydro-1H-pyrrolo[1,2-c]imidazole-3(2H)-ones and Applications of Their Derivatives

This thesis describes a method involving the preparation of an L-proline-derived imidazolone protected with an N-triethylsilyl group that undergoes diastereoselective lithiation followed by electrophile quench to give C5-substituted products with syn stereochemistry. The N-silylated derivatives may be more easily N-deprotected as compared to previous N-t-Bu analogues to give secondary ureas. These may serve as precursors to N-phenyl chiral bicyclic guanidines or as NHC precursors for synthesis of corresponding complexes.

Risk Aversion, Intertemporal Substitution, and Option Pricing

This paper develops a general stochastic framework and an equilibrium asset pricing model that make clear how attitudes towards intertemporal substitution and risk matter for option pricing. In particular, we show under which statistical conditions option pricing formulas are not preference-free, in other words, when preferences are not hidden in the stock and bond prices as they are in the standard Black and Scholes (BS) or Hull and White (HW) pricing formulas. The dependence of option prices on preference parameters comes from several instantaneous causality effects such as the so-called leverage effect. We also emphasize that the most standard asset pricing models (CAPM for the stock and BS or HW preference-free option pricing) are valid under the same stochastic setting (typically the absence of leverage effect), regardless of preference parameter values. Even though we propose a general non-preference-free option pricing formula, we always keep in mind that the BS formula is dominant both as a theoretical reference model and as a tool for practitioners. Another contribution of the paper is to characterize why the BS formula is such a benchmark. We show that, as soon as we are ready to accept a basic property of option prices, namely their homogeneity of degree one with respect to the pair formed by the underlying stock price and the strike price, the necessary statistical hypotheses for homogeneity provide BS-shaped option prices in equilibrium. This BS-shaped option-pricing formula allows us to derive interesting characterizations of the volatility smile, that is, the pattern of BS implicit volatilities as a function of the option moneyness. First, the asymmetry of the smile is shown to be equivalent to a particular form of asymmetry of the equivalent martingale measure. Second, this asymmetry appears precisely when there is either a premium on an instantaneous interest rate risk or on a generalized leverage effect or both, in other words, whenever the option pricing formula is not preference-free. Therefore, the main conclusion of our analysis for practitioners should be that an asymmetric smile is indicative of the relevance of preference parameters to price options.