Analyzing the determinants of carbon emissions from transportation in European countries: the role of renewable energy and urbanization

Clean Technologies and Environmental Policy - The continuous growth of transport sector and the increase in carbon emissions from transportation attract the attention of policy makers in...     

The determination of the shelf-life of pasteurized and non-pasteurized sardine (Sardina pilchardus) marinades stored at 4 °C

In this study the shelf‐life of sardine marinades was investigated. After the marination process, sardine fillets were packed into glass jars with 2% citric acid, 4% sodium chloride and spices. The effect of pasteurization at 70 °C for 20 min on the shelf‐life of the sardine marinades was determined. At the end of 6 months storage the differences between thiobarbituric acid, free formaldehyde (FA(ex)), free and bound formaldehyde (FA(dest)) and peroxide value of pasteurized and non‐pasteurizated marinades were not significantly (P > 0.05) different, while the difference between total volatile basic nitrogen, trimethylamine, pH, total plate count and lactic acid bacteria count of pasteurized and non‐pasteurized marinades were. The shelf‐life of both pasteurized and non‐pasteurized sardine marinades was found to be 5 months at 4 °C.     

MODELING WATER LOSS DURING FRYING OF POTATO STRIPS: EFFECT OF SOLUTE IMPREGNATION

The effect of solute impregnation on water loss and oil uptake during potato strip frying was studied. Blanched potato strips were impregnated at 25°C by soaking in a solution of sucrose-NaCl-water, 20-5-75% by weight. After rinsing and air drying, strips were deep fried in sunflower oil at 160, 170 and 180°C. A control treatment, consisting of potato strips blanched but not soaked and later air dried was also conducted. Solute impregnation provided a decrease of the oil uptake. Two models, based on Fick's law were used to describe water loss during frying. The first one is the classic model with an effective moisture diffusion coefficient assumed a constant value. The second model considers that diffusion coefficient varies during the frying process. For a given frying temperature, constant diffusion coefficient for control potatoes resulted in lower values than the impregnated ones. The variable diffusivity model showed a two-stage behavior: during the first stage of frying, diffusion coefficient increased with frying temperatures, but from a given time on an inverse behavior began. This last fact was found to be related to an increase of the measured peak force needed to penetrate the potato crust.     

ANALYSIS OF OPEN SUN DRYING EXPERIMENTS

Open sun drying has lost its previous importance due to the fact that different factors affect its reliability and the quality of the products obtained.

One of the set-backs for the analysis of solar drying exoeriments is their deoendence on a non-controlled source of energy, i.e. solar radiation depends on climatic conditions and experiments are difficult to compare. It is thus necessary to investigate the advantages of a particular set up as well as the climatic influences. Open sun drying could constitute the natural reference, allowing the comparison of different drying strategies.

A new way of standardizing drying times, based on solar radiation inout, is proposed, to allow better evaluation of the experiments. An equivalent time is defined, allowing comparison of experiments carried out under different circumstances. Carrots and potatoes were used in these experiments.

The use of the average daily solar radiation 15.28 MJ m^-2.d^-1 in Palma de Mallorca (39.33°N, 2.37°E), is proposed for comparison purposes. An improvement of more than 12 % in the explained variance was observed, the unexplained variance being lower than 1 %.     

Influence of structure and counterions on physicochemical properties of linear alkylbenzene sulfonates

The effects of different inorganic and organic counterions on the physicochemical behavior of three commercial linear alkylbenzene sulfonates (LAS) have been studied. It has been found that the counterion hydration radius of the corresponding commercial linear alkylbenzene sulfonates has great influence on solubility, viscosity, surface tension and critical micelle concentration (CMC). The counterion has no influence on the detergency performance of the finished formulation. The alkyl chain length and the presence of tetralines have an important influence on solubility, viscosity and surface tension.     

SIMULATION OF COUNTER-DIFFUSIONAL MASS TRANSFER

The mathematical formulation of mass transfer in food processes is often based on the diffusion equation with the diffusion coeffcients considered as effective parameters. In some cases, more than one specie can be simultaneously diffusing in opposite directions. Therefore, the movement of one component could affect the movement of the remaining components. The aim of this work is to describe a mathematical procedure to obtain the diffusion coeffcients of different species that simultaneously diffuse in such a situation that each mass flux is affected by the existence of the others. The correspondent microscopic mass balances combined with Fick's law were simultaneously solved using a numerical finite difference method.     

HYDRODYNAMIC STUDIES IN A HALF SLOT-RECTANGULAR SPOUTED BED COLUMN

Experiments were carried out in a half slot-rectangular spouted bed to investigate the effects of slot width and lower section basal angle on column hydrodynamics. Flow regimes, minimum spouting velocity, spouting and maximum pressure drops, and maximum spoutable bed height were determined for 4 mm diameter polyethylene particles. The results are compared with those for conventional cylindrical and rectangular spouted beds. Correlations for each hydrodynamic parameter are developed and compared with equations available in the literature.     

A path planning model based on nested regular hexagons using weighted centroid localization

In many wireless sensor network (WSN) applications, the location of a sensor node is crucial for determining where the event or situation of interest occurred. Therefore, localization is one of the critical challenges in WSNs. Mobile anchor node assisted localization (MANAL) is one of the promising solutions for the localization of statically deployed sensors. The main problem in MANAL localization is that the path planning of the mobile anchor (MA) node should be done so that the localization error in the network will be minimal and that all unknown nodes in the network are covered. This paper proposes a new path planning approach called nested hexagons curves (NHexCurves) for MANAL. NHexCurves guarantees that it will receive messages from at least three non-collinear anchors to locate all unknown nodes in the network. The proposed model has compared six different path planning schemes in the literature using weighted centroid localization (WCL). In these comparisons, first of all, localization errors of the models are compared using some statistical concepts. Second, the variation of the localization error according to parameters such as resolution (R) and the standard deviation of noise (σ) is observed. Then, with similar approaches, the standard deviation of errors, localization ratio, scalability performances, and finally, path lengths of the models are examined. The simulation results show that the NHexCurves static path planning model proposed in this study stands out compared to other models with high localization error and localization ratio performance, especially at low resolutions, due to its path design. At the same time, the lowest error values according to σ are obtained with the proposed model among all models considered.     

A clonal selection algorithm for dynamic facility layout problems

The dynamic facility layout problem (DFLP) aims to minimize the sum of handling and re-layout costs by devising an individual layout for each distinctive production period. It is a complex combinatorial optimization problem. This paper proposes a clonal selection algorithm (CSA) for DFLP. The algorithm is capable of being extended to more general cases although equal area machines and standardized handling equipments with identical unit costs are assumed for the time being. The performance of the proposed algorithm is examined by using three test problems from the literature. CSA reached the best known solutions–even found better solutions for large sized problems–in 88% of the instances, while each of the former methods was successful only in a small fraction of those 50 problems. CSA also outperformed all the present methods as regards solution times.