Temperature dependence of electrical parameters of SMD ferrite components for EMI suppression

This paper presents how electrical characteristics of ferrite EMI suppressors depend on the operating frequency and temperature. These multi-layer surface-mounted components consist of conductive platinum layer embedded in the middle of nickel-zinc ferrite monolithic structure. In order to analyze variation of performances with temperature changes, a simulation tool has been developed to predict behavior of the SMD ferrite components for EMI suppression. Results for the impedance and inductance as a function of frequency in the temperature range from +25 °C to +120 °C are presented. Proposed EMI suppressors were experimentally tested in the frequency range 1 MHz-1 GHz using an Agilent 4191A RF Impedance analyzer. The calculated results were in very good agreement with the measured ones.     

Complement of Source Equation of Elastic Line

A new notion of joint, defined in terms of the state of motor (active or locked) and type of the elastic or rigid element, gear and/or link that follows after the motor, is introduced. Special attention is paid to the motion of the flexible links in the robotic configuration. The paper deals with the relationship between the equation of elastic line equilibrium, the “Euler–Bernoulli approach” (EBA), and equation of motion at the point of elastic line tip, the “Lumped-mass approach” (LMA). The Euler–Bernoulli equations (which have for a long time been used in the literature) should be expanded according to the requirements of the motion complexity of elastic robotic systems. The Euler–Bernoulli equation (based on the known laws of dynamics) should be supplemented with all the forces that are participating in the formation of the elasticity moment of the considered mode. This yields the difference in the structure of Euler–Bernoulli equations for each mode. The stiffness matrix is a full matrix. Mathematical model of the actuators also comprises coupling between elasticity forces. Particular integral of Daniel Bernoulli should be supplemented with the stationary character of elastic deformation of any point of the considered mode, caused by the present forces. General form of the elastic line is a direct outcome of the system motion dynamics, and cannot be described by one scalar equation but by three equations for position and three equations for orientation of every point on that elastic line. The choice of reference trajectory is analyzed. Simulation results are shown for a selected robotic example involving the simultaneous presence of elasticity of the gear and of the link (two modes), as well as the environment force dynamics.     

Training and capacity building in central and eastern Europe through the EuroFIR and CEE networks

Capacity building in food and nutrition aims to enhance knowledge and support infrastructural development in this field. International Network of Food Data Systems (INFOODS) was established on the basis of the recommendations of an international group convened under the auspices of the United Nations University (UNU). The European Food Information Resource Network (EuroFIR, Network of Excellence) aims to develop and integrate food composition data through Europe including CEE countries. EuroFIR, joined forces with the United Nations University/UN System Standing Committee on Nutrition, in capacity building. Inventories have been initiated by EuroFIR on food composition data base status and on capacity development needs. The inventories showed that many activities are already ongoing, providing a good potential for developments needed. Substantial differences exist between the countries, including lack of understanding about the concepts and what quality implies. Assessing the quality, frequency of the capacity development activities and the number of staff trained is needed. Several countries lacked adequate information; 6 of 8 had established Food Composition Databases, but none had electronic versions of the Food Composition Databases. Most had national databases, but needs for additional equipment seems considerable. Education, training, workshops, networking and sharing of experiences were cross-cutting themes for most countries. It is concluded that capacity development is a long-term, continuing process, with policies, plans, and activities and should have national priority. Special attention should be given to the capacity development dimensions generated by global and European strategies. Capacity development networks would be important tools in addressing present and future needs in various countries. The EuroFIR training and exchange program is a valuable tool in achieving this.     

Exploitation of geothermal energy as a priority of sustainable energetic development in Serbia

The actual global economic crisis, including all other well-known problems of sustainable development, reflects the direction of development of all countries in the world. Serbia, as a European country in its early stage of development, is trying to synchronize its progress with experience of other countries from the field of sustainable development and in accordance with rules in the field of energetic and energetic efficiency, and, as well as to promote and develop the sector of use of renewable sources of energy. On the other hand, Serbia is a country which largely depends on import of all forms of energy, which to a great extent affects its economic stability. Therefore, in Serbia the strategy for development of energetic was imposed and it considers all the aspects of development of energetic until 2015 and it also defines the priorities which can be mostly seen in the choice of forms of alternative sources of energy. These sources, based on some criteria, can be considered the most convenient for a gradual substitution of energy which is gotten from the conventional sources. Taking into account strategically defined goals and domestic potentials which are at disposal, as well as economic parameters, an alternative source of energy of basic importance for the future exploitation on the territory of Serbia geothermal energy, was chosen. The research points to the fact that Serbia will be capable to respond adequately to Kyoto protocol demands and to the European rules regarding the substitution of a certain amounts of fossil fuels by the fuel origin from the raw biological materials. The research defines the existent and non-existent capacities and the assessment of positive effects of usage of geothermal energy. At the moment, 160 long holes are being exploited whose water temperature is around 60 °C (140 °F) and their heat power reach 160 MJ/s. It was stated that adequate exploitation of existing and new geothermal sources a yearly would save about 500,000 tons of fossil fuels what is proportional to the 10% of the today's heating system. The total amount of heat accumulated at geothermal deposit sites in Serbia, up to 3 km of depth, is two times greater than the total amount of heat that may be generated by burring all available coal reserves in Serbia. Price of electrical energy produced from geothermal springs is estimated to be between 9.2 US cents/kWh and 11.5 US cents/kWh. In order to support exploitation of geothermal energy (as well as all other renewable sources of energy) the decision that all the producers of energy from renewable sources get a status of privileged producers were made.     

Administration of a β-glucan-enriched extract activates beneficial hepatic antioxidant and anti-inflammatory mechanisms in streptozotocin-induced diabetic rats

The beneficial effect of a commercially available β-glucan-enriched extract (BGEE) from cereal grain, against a diabetes-induced hepatic redox imbalance and inflammatory response in streptozotocin-induced diabetic rats was evaluated. Diabetic rats that were treated with BGEE exhibited lower hyperglycaemia and improved biochemical parameters of liver damage. BGEE attenuated hepatic oxidative stress, revealed by a decreased concentration of thiobarbituric acid reactive substances and a restored GSH/GSSG ratio. BGEE also exerted an anti-inflammatory effect on the liver, evidenced by the normalization of the serum concentrations of the “positive” and “negative” acute-phase proteins, α₂-macroglobulin and albumin, respectively, as well as by upregulation of anti-inflammatory cytokine IL-10 and IL-4 mRNA expression, and inhibition of RAGE/NF-κB signaling. These findings suggest that BGEE application exerts a beneficial effect in the liver of streptozotocin-induced diabetic rats via its antioxidant and anti-inflammatory activities, and that it therefore possesses an important potential in diabetes management.     

Phytochemical profiles and antioxidant activities of Serbian table and wine grapes

Three table grapes and 4 wine grapes collected from a southern Serbian vineyard were evaluated and compared for their antioxidant properties and phenolic profile. Among the varieties tested, ‘Cabernet Sauvignon’ contained the highest total phenolic content with 173.6 mg/100 g of fresh weight. Also, the total flavonoid and antocyanin content of ‘Cabernet Sauvignon’ was significantly higher from the other. ‘Cabernet Sauvignon’ and ‘Merlot’ had the strongest DPPH· radicals scavenging activity (1,318.6 and 1,282.0 μmol Trolox equivalent/100 g, respectively). ‘Cabernet Sauvignon’, ‘Merlot’, ‘Prokupac’, ‘Vranac’, ‘Muscat Hamburg’, and ‘Ribier’ grape varieties were found to be rich in malvidin-3-O-glucoside, while ‘Cardinal’ grape variety was found to be rich in peonidin-3-O-glucoside. The following compounds were also identified and quantified using HPLC-DAD: 2 flavan-3-ols and 4 hydroxycinnamic acids in all grape samples. The results suggested that phytochemicals in the selected table and wine grapes have potent antioxidant activities in correlation with phenolic content.     

Optimization of Hull‐Less Pumpkin Seed Roasting Conditions Using Response Surface Methodology

Abstract: Response surface methodology (RSM) was applied to optimize hull‐less pumpkin seed roasting conditions before seed pressing to maximize the biochemical composition and antioxidant capacity of the virgin pumpkin oils obtained using a hydraulic press. Hull‐less pumpkin seeds were roasted for various lengths of time (30 to 70 min) at various roasting temperatures (90 to 130 °C), resulting in 9 different oil samples, while the responses were phospholipids content, total phenols content, α‐ and γ‐tocopherols, and antioxidative activity [by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free‐radical assay]. Mathematical models have shown that roasting conditions influenced all dependent variables at P < 0.05. The higher roasting temperatures had a significant effect (P < 0.05) on phospholipids, phenols, and α‐tocopherols contents, while longer roasting time had a significant effect (P < 0.05) on γ‐tocopherol content and antioxidant capacity, among the samples prepared under different roasting conditions. The optimum conditions for roasting the hull‐less pumpkin seeds were 120 °C for duration of 49 min, which resulted in these oil concentrations: phospholipids 0.29%, total phenols 23.06 mg/kg, α‐tocopherol 5.74 mg/100 g, γ‐tocopherol 24.41 mg/100 g, and an antioxidative activity (EC₅₀) of 27.18 mg oil/mg DPPH. Practical Application: A well‐defined roasting process is very important for the food industry to be able to produce pumpkin seed oil with desirable nutritive and chemical characteristics of this unique salad oil, which changes during the roasting. This study contributes to the knowledge of a product design process for the roasting conditions of naked pumpkin seeds based on results that have demonstrated that an increase in roasting temperature significantly increased the biochemical values and antioxidant properties of the obtained virgin oils.