A linear programming model for cash flow management in the Brazilian construction industry

A linear programming model has been developed for optimal cash flow management addressing specific cash flow issues related to the construction industry. These include typical financial transactions, possible delays on payments, use of available credit lines, effect of changing interest rates, and budget constraints that often occur in the construction industry. A small size project from the Brazilian construction industry is provided as a case study, aiming at evaluating the potential benefits from using the model. Different changes to the basic structure of the model allow and establish the consistency of the results. Alternative formulations are suggested to deal with uncertainties, longer planning horizons, and multiple subcontractors and suppliers. In addition to the tangible financial earnings derived from the optimization process, the simple structure of the model, as a network flow and corresponding equations, provides much visual insight concerning the relationships between the external inputs and the variables of the problem. Optimal results have yet to be achieved in a real life situation, but a better view of whole cash flow management is provided when using the model.     

Optimization of osmotic dehydration of yacon slices

Osmotic dehydration assisted by ultrasound (ODAU) at low temperatures reduces water activity (a_w) and maintains nutrients. The influence of solution concentration (SC; 20 to 60° Brix, xylitol and sorbitol) and ultrasound application time (t_us, 0 to 40 min) in ODAU of yacon was studied with the aid of a response surface method. The optimum condition with respect to mass transfer parameters, a_w, and fructan retention was SC of 60° Brix for both solutions and t_us of 2.67 min for xylitol samples and 0 min for sorbitol samples. The application of ultrasound improved dehydration but resulted in depolymerization of fructans.     

Preliminary Studies on Furfural Production from Lignocellulosics

This study focused on the production of furfural from agricultural and industrial biomass residues by a hydrodistillation process. Corncobs, sugarcane bagasse, and eucalypt wood were treated with sulfuric, hydrochloric, and phosphoric acids as catalysts, with different acid concentrations (1.5 to 5.2 mol.L ^?1). In addition, the eucalypt liquor from the auto-hydrolysis, kraft-dissolving pulp production process was also investigated as a source of furfural, using sulfuric and hydrochloric acids as a catalyst (0.9 and 3.9 mol.L ^?1) . Furfural yields of 30.2, 25.8, and 13.9% were achieved for corncob, sugarcane bagasse, and eucalypt wood, respectively, on the basis of biomass dry weight. The efficiency of conversion from pentose to furfural using eucalypt liquor from the auto-hydrolysis kraft process was 71.5% using HCl 3.9 mol.L ^?1 . Due to the presence of a high amount of pentose, corncob produced the highest amount of furfural, followed by sugarcane bagasse and then eucalypt wood.     

Physicochemical Properties,Lipid Oxidation,and Fatty Acid Composition of Sausage Prepared with Meat of Young Nellore Bulls Fed a Diet with Lauric Acid

This study evaluates the quality of sausage obtained from the meat of Nellore cattle fed diets containing different levels (0, 5, 10, and 15 g per kg total DM) of lauric acid (C12:0) from palm kernel cake. A linear reduction (p ≤ 0.05) in lipid oxidation, as reflected by linear decreases in the lightness (L*), yellowness (b*), and saturation (C*) color parameters, is observed on days 7, 14, and 21 of maturation of sausage, and these decreases are accompanied by linear increases in the redness (a*) color and the linoleic (C18:2n–6) and linolenic (C18:3n–3) fatty acid contents. The inclusion of lauric acid in the diet induces linear reductions in the shear force and cooking loss and does not significantly affect various indices, including the centesimal composition, water activity, water holding capacity, composition of most fatty acids (FA), hypocholesterolemic‐to‐hypercholesterolemic FA ratio, atherogenicity, thrombogenicity, and desirable fatty acids. The use of dietary lauric acid from palm kernel cake is recommended at doses up to 15 g per kg because its presence reduces lipid oxidation and improves color parameters, softness, and linoleic and linolenic FA without affecting the FA composition of sausage from Nellore bull's meat. Practical applications : Sausages are products manufactured from chopped or ground meats packaged into animal casings. This product appeared in Brazil through the adaptation of traditional recipes brought by German and Italian immigrant families to weather conditions and the national palate. However, due to its production characteristics, sausage can become a product with lipid characteristics that are undesirable for human consumption. The inclusion of lauric acid (C12:0) in the animal diet might change the biohydrogenation process in the rumen, improve the quality of the deposited FA and reduce lipid oxidation in sausage manufactured from meat. The FA composition and physicochemical properties of sausage predict its acceptance by the consumer market. An optimal advantage would be achieved if these products can be used as not only preservatives but also functional ingredients with antioxidant properties and products for the treatment of metabolic syndrome and cardiovascular diseases through atherogenic action.     

Development of probiotic fruit juice powders by spray-drying: A review

The use of spray-drying for the production of powdered fruit juices has been a common practice in recent years since it is a simple, economic, and advantageous technique. The current knowledge on the different spray-drying parameters, allowing the best conditions to obtain high-quality powders, is presented in this review. The incorporation of probiotic cultures into fruit juices can enhance the functional characteristics of fruit juices. The selection of these probiotics and their benefits to consumers’ health are briefly discussed. As maintaining the viability of probiotics is extremely important in the development of a probiotic functional product, the factors that influence and improve survival, in all pre- and post-spray-drying steps, are also detailed. Finally, a few studies on probiotic fruit juices obtained by spray-drying are cited. Industries should bet on their development and commercialization, since despite being challenging to develop, these are very innovative and attractive products meeting modern consumer demands.     

A comparative study of the purification of betanin

Betanin is a natural pigment with antioxidant properties used as a food colourant. This work describes the spectrophotometric and chromatographic quantification of betanin (2S/15S) and its epimer isobetanin (2S/15R) in fresh beetroot juice, food-grade beetroot powder and betanin standard diluted in dextrin. Absorption spectra of all three samples were deconvoluted using a mixed three-function model. Food-grade beetroot powder has the largest amount of violet-red impurities, probably formed during processing. The purification of betanin from these complex matrices was carried out by seven different methods. Ion exchange chromatography was the most efficient method for the purification of betanin from all samples; however, fractions contain high amounts of salt. Reversed-phase HPLC as well as reversed-phase column chromatography also produced good results at a much faster rate. The longer retention time of isobetanin when compared to betanin in reversed-phase conditions has been investigated by means of quantum-mechanical methods.     

Scheduling links for heavy traffic on interfering routes in wireless mesh networks

We consider wireless mesh networks and the problem of scheduling the links of a given set of routes under the assumption of a heavy-traffic pattern. We assume some TDMA protocol provides a background of synchronized time slots and seek to schedule the routes’ links to maximize the number of packets that get delivered to their destinations per time slot. Our approach is to construct an undirected graph G and to heuristically obtain node multicolorings for G that can be turned into efficient link schedules. In G each node represents a link to be scheduled and the edges are set up to represent every possible interference for any given set of interference assumptions. We present two multicoloring-based heuristics and study their performance through extensive simulations. One of the two heuristics is based on relaxing the notion of a node multicoloring by dynamically exploiting the availability of communication opportunities that would otherwise be wasted. We have found that, as a consequence, its performance is significantly superior to the other’s.     

Analysis of Brazilian SHP policy and its regulation scenario

This article presents the main regulatory changes that occurred in the Brazilian power sector in 2009, along with the impacts these changes caused on the market, especially related to small hydropower (<30 MW). This study addresses regulatory issues based on inventory studies and records of basic projects, changes related to the compensation of the assured energy of SHPs in the Brazilian energy reallocation market, the socio-economic impact resulting from the construction of SHPs, SHPs in alternative resource auctions and finally the general outlook for the growth scenario for SHPs in Brazil according to the ten-year plan (2010–2019). The overall conclusions of this investigation were that the 2008/2009 biennium was a period of great changes in the regulation of small hydropower plants in Brazil, and the SHP market has shown maturity. Additionally, despite SHP being a type of technology that is completely dominated by domestic industry, in recent years, they have experienced policy disincentives caused by changes to rules that inhibit their growth.     

Can Brazil replace 5% of the 2025 gasoline world demand with ethanol?

Increasing use of petroleum, coupled with concern for global warming, demands the development and institution of CO₂ reducing, non-fossil fuel-based alternative energy-generating strategies. Ethanol is a potential alternative, particularly when produced in a sustainable way as is envisioned for sugarcane in Brazil. We consider the expansion of sugarcane-derived ethanol to displace 5% of projected gasoline use worldwide in 2025. With existing technology, 21 million hectares of land will be required to produce the necessary ethanol. This is less than 7% of current Brazilian agricultural land and equivalent to current soybean land use. New production lands come from pasture made available through improving pasture management in the cattle industry. With the continued introduction of new cane varieties (annual yield increases of about 1.6%) and new ethanol production technologies, namely the hydrolysis of bagasse to sugars for ethanol production and sugarcane trash collection providing renewable process energy production, this could reduce these modest land requirements by 29–38%.