Development of antioxidant food packaging materials with controlled release properties

In this study, cellulose acetate (CA) films with different morphological features were prepared in order to control the release rates of low molecular weight natural antioxidants, L-ascorbic acid and L-tyrosine. Increasing CA content in the casting solution decreased the average pore size and porosity of the films, thus, reduced the diffusion rates of both antioxidants through the films. Although both antioxidants have similar molecular weights, L-tyrosine released into water much more slowly than L-ascorbic acid. The highest antioxidant activity in release test solutions was observed with highly porous L-tyrosine containing films. However, when the porosity of the films reduced, the antioxidant activity of L-ascorbic acid released into solution was found to be higher due to trapping of significant amount of L-tyrosine in dense films. The use of different antioxidants caused different changes in morphological and mechanical properties of the CA films. Varying the structural features of the films with the preparation conditions or using different surfaces of the films allowed the controlled release of each antioxidant.     

Solar-energy availability in the north-eastern Arabian peninsula

The solar energy potential of north-east Saudi Arabia is investigated based on measurements of a complete year's data at a coastal location near Dhahran. High resolution, real time solar radiation data were collected and processed. Hourly, daily and monthly statistics of solar radiation were made from the 1 min averaged recorded values. Clearness index is discussed on the basis of hourly, daily and monthly averages. The variation of the diffuse fraction of total radiation is also determined and the results discussed.     

Research on ethanol production and use from sugar beet in Turkey

Emissions of greenhouse gases such as CO₂, CO, CH₄ and NO_X from fossil fuel use are implicated in climate change. The use of bioethanol is one means to reduce fossil fuel use and emissions of greenhouse gases. This study investigated research to produce ethanol from sugar beet and use as fuel in Turkey. The calculated demand for bioethanol amounted to some 220,000 m³ where a 5% ethanol mix in petrol was used. Turkey has the potential to produce 30 million ton of sugar beet, which is sufficient to meet the bioethanol demand.     

Mechanical and microstructural properties of low-carbon steel-plate-reinforced gray cast iron

In the present experimental study, strengthening of gray cast iron by reinforcing with steel plates was investigated in the as-cast and normalized conditions. Normalizing heat treatments were applied to the specimens at temperatures of 800 °C and 850 °C. Three-point bend specimens were manufactured from gray cast iron and also from gray cast iron with reinforced steel plates. Flexural strengths of the steel-plate-reinforced cast iron were calculated for four distinct volume fractions (V_r = 0.04, 0.08, 0.12, and 0.16). The current study shows that the steel-plate-reinforced gray cast iron has higher flexural strength and flexural modulus than the cast iron without reinforcement. The flexural strength considerably increases with slight increase in normalization temperature. Optical and scanning electron microscopy analyses were used to examine flake morphology and microstructures of gray cast iron and steel-plate-reinforced gray cast iron. It is noted that carbon diffuses from the gray cast iron to the steel plates. A transition region containing partially dissolved graphite and having high hardness was observed due to the carbon diffusion.     

Forecasting of entropy production due to buoyant convection using support vector machines (SVM) in a partially cooled square cross-sectional room

Forecasting of entropy generation of laminar natural convection in a partially cooled square cross-sectional room has been performed using support vector machines (SVM). The two-dimensional room was modeled as floor heating story with a window. Values of temperature and velocities were obtained by solving governing equations of natural convection with finite difference technique and using these values entropy generation was calculated with its definition. Forecasting of entropy generation due to fluid friction irreversibility (FFI) and heat transfer irreversibility (HTI) were made with known values for unknown parameters using SVM. Thus, calculation time was extremely reduced and values were obtained even for non-convergence cases. It was observed that the SVM was a strong method to predict the entropy generation without computational fluid dynamic analysis for all cases.     

Entropy generation in the flow system generated in between two parallel plates due to bivertical motion of the top plate

Thermodynamic irreversibility in the flow system provides information on the energy and power losses in the system. Minimization of entropy generation in the flow system enables for the parametric optimization of the system operation. In the present study, parallel plates, in between, filled with the fluid are considered. The fluid motion resulted from the bi-vertical compression of the top plate of the parallel plates is examined. The entropy generation rate in the flow system is formulated after considering the constant movement of the top plate, constant applied load, and the combination of the constant velocity and applied load to the top plate. The optimum operating conditions related to the fluid motion in between the parallel plates is determined through the entropy analysis. It is found that the combination of the constant velocity and the constant applied load resulted in the low entropy generation rate.     

Multirelational k-Anonymity

k-Anonymity protects privacy by ensuring that data cannot be linked to a single individual. In a k-anonymous data set, any identifying information occurs in at least k tuples. Much research has been done to modify a single-table data set to satisfy anonymity constraints. This paper extends the definitions of k-anonymity to multiple relations and shows that previously proposed methodologies either fail to protect privacy or overly reduce the utility of the data in a multiple relation setting. We also propose two new clustering algorithms to achieve multirelational anonymity. Experiments show the effectiveness of the approach in terms of utility and efficiency.     

Effects of environmental factors on the adhesion and durability characteristics of epoxy-bonded concrete prisms

This work is concerned with the effects of environmental factors on the adhesion and durability characteristics of epoxy-bonded concrete prisms. The results indicate that the presence of liquid water at the interfacial zone during the epoxy injection process disrupts the initial bond configurations. The freezing and thawing up to about 40 cycles do not have a significant effect on the bond stability. An adequate degree of chemical stability is maintained in the bond line by the epoxy adhesives after 120 days of exposure to corrosive environments such as MgSO₄ and MgCl₂. However, there is a pronounced effect of these chemical substances on the concrete strength. The load-bearing capacity of epoxy-bonded concrete prisms decreases with increasing temperature. Despite this fact, the EP3-bonded concrete prisms give relatively high joint strengths at temperatures up to 100 °C.     

Neural extension of experimental data to investigate using phosphogypsume in light brick production

In this study, usability of wastes produced in phosphoric acid plants in structural brick manufacture has been investigated. There are several parameters involved in using these wastes in brick production namely the rate of added waste, firing speed and firing temperature. The performance of these parameters can be measured by several criteria such as natural drying shortening, water absorption and weight loss. Therefore, so many experiments are needed to investigate the effects of these parameters on the bricks produced with these wastes. The result of a series of experiments were utilized to achieve this end. The results have shown that the industrial wastes considered improve the performance of the bricks in terms of the criteria mentioned above. However, the results have also shown that further investigations are needed to explore the effects of interim values on the performance of the bricks. To achieve that end, a neural experimental study is adopted. For this purpose, the results of the experiments conducted were used to construct an artificial neural network. The trained and tested network was then used to check the effects of 280 different combinations for each type of material mixtures mentioned. The outcome of these artificial tests have provided the optimal values for the waste addition rate, firing speed and firing temperature based on the four criteria mentioned previously.     

RFID behavior study in enclosed marine container for real time temperature tracking

The performance of radio waves in open environments has been studied for years. In contrast, the behavior of Radio Frequency Identification (RFID) inside metal enclosed areas is not yet understood. This research project focuses on the 3-D mapping of RFID signal strength inside a 12 m refrigerated marine container instrumented with three different types of radio frequency (RF) emitters: 915 MHz reader; 2.45 GHz reader and 433 MHz RF transmitter. The main goal is to find a frequency/configuration that would allow real time reading of the temperature in a shipment of perishable products using RFID. Only one frequency and one antenna were used at a time. The RF transmitter antenna was mounted at two different places inside the container; at the top of the front wall (facing back) and on the ceiling in the middle of the container (facing down). The signal strength was acquired by a spectrum analyzer and its antenna was mounted on a small electric cart inside the container. The cart was programmed to move along the length of the container and stop repeatedly, allowing three automated measures per position. All data were analyzed in terms of power level and attenuation. The maps showed that the RFID antenna positioned at the front of the container delivered slightly better results than the one in the middle of the ceiling. The results showed a significantly higher performance at the 433 MHz level. This article was presented at Food Processing Automation Conference, American Society of Agricultural and Biological Engineering (ASABE), Providence, RI, June 28–29 2008.