Investigations on mode-division multiplexed free-space optical transmission for inter-satellite communication link

Wireless Networks - Inter-satellite data transmission links are very crucial for providing global inter-connectivity. We report designing and investigations on high date rate inter-satellite...     

Osmotic Dehydration Kinetics of Pomegranate Seeds Using Date Juice as an Immersion Solution Base

Pomegranate seeds were osmodehydrated using date juice added with sucrose (final °Brix, 55) as immersion solution. The kinetics of osmotic dehydration showed that the most significant changes of mass transfer took place during the first 20 min of the process, regardless of date juice varieties. During this time, seed water loss and solid gain were estimated to be ∼39% and ∼6%, respectively. After 20 min of the process, the percentage of water loss and solid gain varied slightly and ranged on average close to ∼40% and ∼9%, respectively. During osmotic dehydration, there was a leaching of natural solutes from seeds into the solution, which is quantitatively not negligible, and might have an important impact on the sensorial and nutritional value of seeds and date juices. Both scanning electron microscopy and texture (compression) analysis revealed that osmotic dehydration process induced modifications of seed texture and cell structure. Sucrose was found to be the essential element which influences the texture of seed and the viscosity of date juice. Additionally, natural sugar present in date juice permits substituting 35% of the total quantity of sucrose added to the osmotic solution.     

Efficiently solving quantified bit-vector formulas

In recent years, bit-precise reasoning has gained importance in hardware and software verification. Of renewed interest is the use of symbolic reasoning for synthesising loop invariants, ranking functions, or whole program fragments and hardware circuits. Solvers for the quantifier-free fragment of bit-vector logic exist and often rely on SAT solvers for efficiency. However, many techniques require quantifiers in bit-vector formulas to avoid an exponential blow-up during construction. Solvers for quantified formulas usually flatten the input to obtain a quantified Boolean formula, losing much of the word-level information in the formula. We present a new approach based on a set of effective word-level simplifications that are traditionally employed in automated theorem proving, heuristic quantifier instantiation methods used in SMT solvers, and model finding techniques based on skeletons/templates. Experimental results on two different types of benchmarks indicate that our method outperforms the traditional flattening approach by multiple orders of magnitude of runtime.     

Nonlinear state feedback design for continuous polynomial systems

The objective of this paper is to simplify the complexity of practical implementation of the input-state feedback linearization technique for the control of input-affine systems. A polynomial approach which makes use of the Taylor series expansion and the Kronecker product is developed. Our work aims to address the problem of synthesizing a polynomial control via a nonlinear analytical coordinates transformation. To check the effectiveness of the investigated approach, we consider the control problem of a series DC motor. A comparative study with the input-state feedback linearization control is developed.     

Physicochemical properties of fermented Arabian mares' milk

Due to its numerous benefits, including health-promoting characteristics, there is increasing interest in finding product applications for mares' milk. In the present study, the physicochemical properties, turbidity and conductivity of Arabian mares' milk were studied during acidification by fermentation at 30 °C and compared with those of bovine milk. The data for the acidification rate were modelled using a logistic equation. Mares' milk showed a longer latency phase (284 min) and lower acidification rate (μ_max = 0.0052 dpH min^?1) compared with bovine milk (194 min and 0.0098 dpH min^?1 respectively). The general shape of the curves of the turbidity versus time and pH were similar in nature for the acidification of both milks. However, the characteristic points were different, due to the differences in casein micelle composition. Measurement of electrical conductivity during acidification showed that maximum demineralization of casein micelles started around pH 6.09 and 5.31, for mares' and bovine milk, respectively. In conclusion, the technological characteristics of mares' milk were very different from those of bovine milk, due to intrinsic physicochemical properties of both milks.     

Fluorescence spectroscopy coupled with factorial discriminant analysis technique to identify sheep milk from different feeding systems

Rapid measurements of milk properties and discrimination of milk origin are necessary techniques for quality control of milk products. The present study was undertaken to evaluate the potential of using front face fluorescence spectroscopy (FFFS) and synchronous fluorescence spectroscopy (SFS) for monitoring the quality of forty-five ewe’s milk samples originating from different feeding systems. Physico-chemical analyses and fluorescence spectra were conducted on samples during lactation periods (the first 11 weeks). The principal component analysis (PCA) separately applied to the physico-chemical and fluorescence spectral data showed only small discrimination between milk samples based on lactation periods and diet compositions. Similar results were obtained by separately applying factorial discriminant analysis (FDA) on each technique. In a second step, concatenation technique were applied to FFF spectra acquired after excitation set at 250, 290, 380 nm and emission set at 410 nm. Results obtained showed a good discrimination among milk samples with regard to feeding systems given to the ewes throughout the lactation periods. In addition, a better discrimination was observed with FFFS than with SFS.     

Physico-Chemical,antioxidant activities,textural, and sensory properties of yoghurt fortified with different states and rates of pomegranate seeds (Punica granatum L.)

This study examines the effects of incorporating fresh, frozen, osmodehydrated, and dried pomegranate seeds, at different concentrations (5, 10, and 20%) on the physicochemical, antioxidant, textural, and sensory properties of yoghurt. Antioxidant activity, pH, acidity, syneresis, and color of yoghurt were also evaluated during the storage (28 days) at 4°C. The principal component analysis (PCA) was performed to assess the correlations between different yoghurt formulation and their sensory attributes. Data showed that the addition of pomegranate seeds reduced pH and modified the chromatics coordinate (L*, a*, b*, C*, h°) and firmness of the yoghurt samples. In addition, acidity, °Brix, and syneresis increased compared to the control. Thanks to their high anthocyanin content, pomegranate seeds considerably improved the antioxidant activity essentially for yoghurt enriched with frozen seeds. In addition, the supplementation of 20% of frozen seeds into yoghurt was the most appreciated by panelists and improved the sensory properties in comparison to other formulation. According to PCA, taste and appearance were the main criteria for the overall acceptability of yoghurt. After 28 days of storage, the reddish color was reinforced; however, the antioxidant activity of yoghurts was reduced. Overall, it can be concluded that pomegranate seeds can be used as a natural ingredient to develop a novel yoghurt with high nutritional properties.     

Changes in wheat and potato starches induced by gamma irradiation: A comparative macro and microscopic study

Wheat and potato starches were treated by gamma irradiation (0, 3, 5, 10, 20, 35, and 50 kGy). Apparent amylose content, gelatinization maximum consistency, swelling power, viscosity, and textural parameters decreased in potato and wheat starch pastes as irradiation dose increased. Nevertheless, the decrease of apparent amylose content and swelling power was greater in potato starch than in wheat one. High gamma irradiation doses made potato starch granules more sensitive to shear. On the other hand, no modification in the granule shape was observed by scanning electron microscopy. However, through heat-treatment, starch granules destroyed as irradiation dose increased. Consequently, the effect of irradiation on granular structure appeared to be greater in potato starch than in wheat starch.