Effects of rosemary and sage tea extracts on the sensory,chemical and microbiological changes of vacuum‐packed and refrigerated sardine (Sardina pilchardus) fillets

The effect of the natural antioxidants and antimicrobials from ethanol extracts of rosemary and sage tea on sensory, chemical [Total volatile basic nitrogen (TVB‐N), thiobarbituric acid reactive substances (TBARs), peroxide value (PV), free fatty acid (FFA)] and microbiological (total viable count‐TVC and total coliform count) changes of vacuum‐packaged sardine (Sardina pilchardus) fillets stored at 3 ± 1 °C was investigated for 20 days. The fish fillets were divided into three groups: untreated group (control, C) and treated groups that were immersed in a 1 L of distilled water containing 10 g rosemary (R group) or sage tea (S group) extracts for 4 min. The shelf life of sardine fillets was found to be 13 days for control (C), 20 days for R and S groups according to sensory assessment results, whose corresponded microbiological assessment showed a shorter shelf life (5 days for C group, 9 for R and S groups). At the end of storage period, TBARs values were 0.98 mg malonaldehyde kg^?1 for C group, 0.66 malonaldehyde kg^?1 for R group and 1.44 mg malonaldehyde kg^?1 for S group. Microbiological results showed that natural compounds from rosemary and sage tea resulted in a lower bacterial growth in fish fillets during the storage period.     

General configuration for realizing current-mode first-order all-pass filter using DVCC

In this paper, a new general configuration for realizing current-mode all-pass filter circuits using differential voltage current conveyor (DVCC) is proposed. The proposed configuration is composed of a DVCC and five passive admittances. However, each of the circuits extracted from the proposed configuration uses only three passive elements. As an application, the proposed configuration is used to construct a quadrature oscillator. The theoretical results are verified by SPICE simulations.     

Effects of sintering temperature on the microstructure and dielectric properties of titanium dioxide ceramics

Nanostructured (~200 nm grain size) titanium dioxide (TiO₂) ceramics were densified at temperature as low as 800 °C by pressureless sintering in a pure oxygen atmosphere. Phase transition and microstructural development of sintered samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dielectric properties including d.c. conductivity, dielectric constant, loss tangent, and dielectric breakdown strength (BDS) were determined for samples sintered at various temperatures. The influence of sintering temperature on the microstructural development, defect chemistry, and dielectric properties of TiO₂ is discussed. Nanostructured TiO₂ ceramics with high sintering density (>98%) lead to improved dielectric properties; high BDS (~1800 kV/cm), low electrical conductivity (~5 × 10⁻¹⁵ S/cm), high dielectric constant (~130), and low loss tangent (~0.09% at 1 kHz), which is promising for application in high energy density capacitors.     

Effects of rosemary and sage tea extract on biogenic amines formation of sardine (Sardina pilchardus) fillets

Natural antimicrobials and antioxidants from rosemary (Rosmarinus officinalis) and sage tea (Salvia officinalis) were produced using solvent extraction method. The effect of two extracts on ammonia (AMN) and biogenic amines (BAs) formation in vacuum packed sardine (Sardina pilchardus) fillets stored at 3 ± 1 °C was investigated for 20 days. Although the effect of extracts was dependent on specific amine and storage time, phenolic compounds from rosemary and sage tea generally resulted in lower AMN and BAs accumulation in sardine muscle. Putrescine (PUT) and cadaverine (CAD) were the most abundant amines, while histamine (HIS) concentration ranged from 2.05 to 28.77 mg 100g^?1. Rosemary and sage tea extracts significantly reduced HIS, PUT, CAD and trimethylamine accumulation in the fish muscle (P < 0.05) while stimulating effect of extracts was observed on serotonin and agmatine formation. At the end of the storage period, PUT and CAD contents of control were 100‐fold higher than those of treated groups.     

Effect of wheat sprout powder incorporation on lipid oxidation and physicochemical properties of beef patties

The aim of this study was to determine the effects of incorporation of wheat sprout flours (WSF) on lipid oxidation and some quality characteristics of beef patties. Two wheat sprout flour samples (WSF1 and WSF2) were obtained by germination, drying and milling of two different wheat varieties. The beef patties were stored at +4 °C for 6 days or at ?18 °C for 180 days and analysed for their proximate composition, pH, sensory properties, colour parameters and lipid oxidation. TBA formation in WSF‐added patties was reduced approximately by as much as 20% when compared to that of the control at the 180th day of the storage, while favourable results were detectable in the storage period at +4 °C. Again, up to 4% WSF1 or WSF2 incorporation gave acceptable sensorial scores to the beef patties. As a conclusion, it was confirmed that WSF could be incorporated into beef patties to improve their quality parameters and retard lipid peroxidation.     

A theoretical analysis of zero-field splitting parameters of Mn doped dicadmium diammonium sulfate Cd2(NH4)2(SO4)3 single crystal

The superposition model (SPM) and crystallographic data are utilized to determine the zero-field splitting (ZFS) parameters (ZFSPs) for Mn²⁺ ions in Cd₂(NH₄)₂(SO₄)₃ single crystal, assuming that the Mn²⁺ ions locate at either Cd²⁺ or NH⁴⁺ site. The SPM results has been verified by the fourth-order perturbation formulae analysis. Experimental suggestions about Mn²⁺ ions substituting at Cd²⁺ sites have been confirmed theoretically for the first time.     

Hydrogen production from 2-propanol over Pt/Al2O3 and Ru/Al2O3 catalysts in supercritical water

One of the alternative energy sources to fossil fuels is the use of hydrogen as an energy carrier, which provides zero emission of pollutants and high-energy efficiency when used in fuel cells, hydrogen internal combustion engines (HICE) or hydrogen-blend gaseous fueled internal combustion engines (HBICE). The gasification of organics in supercritical water is a promising method for the direct production of hydrogen at high pressures, with very short reaction times. In this study, hydrogen production from 2-propanol over Pt/Al₂O₃ and Ru/Al₂O₃ catalysts was investigated in supercritical water. To investigate the influences on hydrogen production, the experiments were carried out in the temperature range of 400–550 °C and in the reaction time range of 10–30 s, under a pressure of 25 MPa. In addition, different 2-propanol concentrations and reaction pressures were tested in order to comprehend the effects on the gasification yield and hydrogen production. It was found that Pt/Al₂O₃ catalyst was much more selective and effective for hydrogen production when compared to Ru/Al₂O₃. During the catalytic gasification of a 0.5 M solution of 2-propanol, a hydrogen content up to 96 mol% for a gasification yield of 5 L/L feed was obtained.     

Nonlinear system identification of automotive dampers: A time and frequency-domain analysis

This paper provides an overview of a number of nonlinear system identification methods as applied to the analysis of nonlinear automotive dampers. The motivation for illustrating a number of approaches is that each method provides different insights into the behavior of the systems and therefore the methods are complementary. The background for each of the methods is given and each is demonstrated through an experimental case study.     

Retrieving 2D shapes using caterpillar decomposition

Graphs provide effective data structures modeling complex relations and schemaless data such as images, XML documents, circuits, compounds, and proteins. Given a query graph, finding sufficiently similar database graphs without performing a sequential search is an important problem arising in different domains. In this paper, we propose a new method for indexing tree structures based on a graph-theoretic concept called caterpillar decomposition. Our algorithm starts by representing each tree along with its subtrees in the geometric space using its caterpillar decomposition. After representing the query in the same fashion, similar database trees are retrieved efficiently by means of nearest neighbor searches. We have successfully evaluated the proposed algorithm on two shape databases and include a set of perturbation experiments that establish the algorithm’s robustness to noise. We have also shown that the approach compares favorably to previous approaches for shape retrieval on these datasets.