Effect of dried oregano (Origanum vulgare L.) plant material in feed on methane production,rumen fermentation,nutrient digestibility,and milk fatty acid composition in dairy cows

Essential oils (EO) from oregano may have antimicrobial properties, potentially representing a methane mitigation strategy suitable for organic production. This study aimed to (1) examine the potential of oregano in lowering enteric methane production of dairy cows fed differing levels of dried oregano (Origanum vulgare ssp. hirtum) plant material containing high levels of EO; (2) determine whether differing levels of dried oregano plant material of another subspecies (Origanum vulgare ssp. vulgare) with naturally low levels of EO in feed affected enteric methane production; and (3) evaluate the effect of various levels of the 2 oregano subspecies (containing high or low levels of EO) in feed on rumen fermentation, nutrient digestibility, and milk fatty acids. Each experiment had a 4 × 4 Latin square design using 4 lactating Danish Holstein dairy cows that had rumen, duodenal, and ileal cannulas and were fed 4 different levels of oregano. Experiment 1 used low EO oregano [0.12% EO of oregano dry matter (DM)] and evaluated a control (C) diet with no oregano and 3 oregano diets with 18 (low; L), 36 (medium; M), and 53 g of oregano DM/kg of dietary DM (high; H). Experiment 2 used high EO oregano (4.21% EO of oregano DM) with 0, 7, 14, and 21 g of oregano DM/kg of dietary DM for C, L, M, and H, respectively. Oregano was added to the diets by substituting grass/clover silage on a DM basis. Low or high EO oregano in feed did not affect dry matter intake (DMI) or methane production (grams per day, grams per kilogram of DMI, grams per kilogram of energy-corrected milk, and percentage of gross energy intake). Rumen fermentation was slightly affected by diet in experiment 1, but was not affected by diet in experiment 2. In both experiments, the apparent total-tract digestibility of DM, organic matter, and neutral detergent fiber decreased linearly and cubically (a cubic response was not observed for neutral detergent fiber) with increasing dietary oregano content, while milk fatty acids were slightly affected. In conclusion, dried oregano plant material with either high or low levels of EO did not lower the methane production of dairy cows over 4 consecutive days, and no substantial effects were observed on rumen fermentation or nutrient digestibility. This conclusion regarding methane production is in contrast with literature and requires further study.     

Oregano Essential Oil as an Antimicrobial and Antioxidant Additive in Food Products

Food consumers and industries urged the need of natural alternatives to assure food safety and quality. As a response, the use of natural compounds from herbs and spices is an alternative to synthetic additives associated with toxic problems. This review discusses the antimicrobial and antioxidant activity of oregano essential oil (OEO) and its potential as a food additive. Oregano is a plant that has been used as a food seasoning since ancient times. The common name of oregano is given to several species: Origanum (family: Lamiaceae) and Lippia (family: Verbenaceae), amongst others. The main compounds identified in the different OEOs are carvacrol and thymol, which are responsible for the characteristic odor, antimicrobial, and antioxidant activity; however, their content may vary according to the species, harvesting season, and geographical sources. These substances as antibacterial agents make the cell membrane permeable due to its impregnation in the hydrophobic domains, this effect is higher against gram positive bacteria. In addition, the OEO has antioxidant properties effective in retarding the process of lipid peroxidation in fatty foods, and scavenging free radicals. In this perspective, the present review analyzes and discusses the state of the art about the actual and potential uses of OEO as an antimicrobial and antioxidant food additives.     

An investigation of the harmonic characteristics of transformerexcitation current under nonsinusoidal supply voltage

This paper investigates the effect of supply voltage harmonics on the excitation current of a typical 25 kVA single-phase distribution transformer. A complete analytical model is developed to calculate the time domain waveform and the harmonic components of the excitation current. The key findings are: the phase angles of the supply voltage harmonics determine whether or not those voltage harmonics increase or decrease the distortion of the input current (with respect to the sinusoidal supply voltage case). A peaked input voltage wave distorted by 3rd, 7th, 11th, etc. harmonic components, or a flattened input voltage wave distorted by 5th, 9th, 13th, etc. harmonics, creates a flattened current (i.e., decreases the current harmonics and distortion). A flattened input voltage wave distorted by 3rd, 7th, 11th, etc. harmonic components, or a peaked input voltage wave distorted by 5th, 9th, 13th, etc. harmonics, creates a peaked current (i.e., increases the current harmonics and distortion): The 3rd harmonic component in the supply voltage has the highest effect on the current harmonics and distortion. The effect of higher voltage harmonics gradually diminishes with frequency. The magnitudes of the individual current harmonics follow the same decreasing/increasing pattern of changes as does current distortion variation. The corresponding variations in harmonic current phase angles is negligible     

Value-based power system reliability planning

In a competitive energy market, in which power supply reliability can influence customer purchasing decisions, electric utilities throughout the world are rapidly recognizing that they cannot ignore customer preferences. Today's energy market is characterized by intense price competition, and electric utilities are faced with new challenges of large debts, budget constraints, safety, environment and economic issues, lower load growth than in the past, need for more involvement of public at large in the planning and design process, and more competitive nonconventional suppliers of electricity. In addition, in a deregulated competitive energy market, electric utilities are under conflicting pressures of providing even higher standards of service reliability and holding the line on rates. Value-based system facility planning offers a rational response to these conflicting customer demands. This paper presents two case studies to illustrate the basic concepts and applications of value-based power system planning. The paper also presents a methodology for determining the unique composite customer cost of interruptions (i.e. damage functions) for changing area system network configurations. These techniques are presently being used in the decision-making processes at Alberta Power Limited, Edmonton, Alta., Canada     

DPSK 32×10 Gb/s transmission modeling on 5×90 kmterrestrial system

Reduction of DWDM nonlinear fiber penalties by the use of DPSK modulation and an optically preamplified self-homodyning receiver is discussed. Maintaining a constant instantaneous channel power by phase shift keying, we can anticipate reduction of cross-phase modulation penalties. Our modeling results show 0.9-dB benefit in Q performance for 50-GHz spaced, 32×10 Gb/s transmissions with nonzero dispersion shifted fiber     

HYDROMAGNETIC UNSTEADY RIVLIN-ERICKSEN THIRD-GRADE FLOW FOR STOKES' SECOND PROBLEM

In this article, the flow of an unsteady third-grade Rivlin-Ericksen fluid on an oscillating plate is discussed. The magnetic lines of force act perpendicular to the flow field. Several interesting features of the flow are obtained. The physical interpretation of the second-grade parameters, third-grade parameters, oscillating frequency, and magnetohydrodynamic parameters are examined graphically and then are deduced to already known results in the literature.     

Experimental Study on Air Cooling Via a Multiport Mesochannel Cross-Flow Heat Exchanger

The air-side heat transfer and flow characteristics of cross-flow multiport slab mesochannel heat exchanger are investigated experimentally in this article. The multiport slab mesochannel heat exchanger consists of 15 finned aluminum slabs; each slab contains 68 flow channels of 1 mm circular diameter. The cold deionized water at a constant mass flow rate was forced to flow through the mesochannels, whereas the hot air at different velocities was allowed to pass through the finned passages of the heat exchanger core in cross-flow orientation. The heat transfer and fluid flow key parameters were examined in the region of the air-side Reynolds number in the range of 972–2758, with a constant water-side Reynolds number of 135. The effect of air-side Reynolds number on air-side Nusselt number was examined and a general correlation of Nusselt number with Reynolds number was obtained. The Nusselt number value was found to be higher in comparison with other research works for the corresponding Reynolds number range. The multiport mesochannel flat slab geometry has offered uniform temperature distribution into the core. This uniform temperature distribution leads to higher heat transfer over stand-alone inline flow tube bank.     

Temperature dependent time-to-breakdown (TBD) of TiN/HfO2 n-channel MOS devices in inversion

Effect of temperature on time-to-breakdown (T_BD) of n⁺-ringed n-channel MOS capacitors with atomic layer deposited TiN/HfO₂ based gate stacks is studied. While interfacial layer (IL) growth condition and thickness varied the high-κ layer thickness and processing was unchanged. These devices were investigated by applying a constant voltage stress (CVS) in inversion (substrate injection) at room and elevated temperatures. For high electric fields (10-15 MV/cm) across IL, it is observed that T_BD is thermally activated irrespective of IL condition. Activation energies (2-3 eV after correction), found from Arrhenius plots of T_BD for different IL conditions, show good matches with those associated with field-driven thermochemical model of breakdown developed for SiO₂.     

Compound noise separation in digital circuits using blind source separation

Analysis of individual noise sources in pre-nanometer circuits cannot take into account the evolving reality of multiple noise sources interacting with each other. Noise measurement made at an evaluation node will reflect the cumulative effect of all the active noise sources, while individual and relative severity of various noise sources will determine what types of remedial steps can be taken, pressing the need for development of algorithms that can analyze the contributions of different noise sources when a noise measurement is available. This paper addresses the cocktail-party problem inside integrated circuits with multiple noise sources. It presents a method to extract the time characteristics of individual noise source from the measured compound voltage in order to study the contribution and properties of each source. This extraction is facilitated by application of blind source separation technique, which is based on the assumption of statistical independence of various noise sources over time. The estimated noise sources can aid in performing timing and spectral analysis, and yield better circuit design techniques.