A recent evaluation of the accuracy of the National Physical Laboratory (NPL) primary frequency standard NPL-CsF1 by K Szymaniec et al (2005 Metrologia 42 49–57) reported an overall frequency uncertainty of δν/ν0 = 1 × 10−15. This stated uncertainty includes a correction of a frequency bias of δν/ν0 = 8 × 10−16 ± 3 × 10−16 attributed by the authors to microwave leakage. We believe that the stat...

OBJECTIVE In order to utilize fat from broiler byproducts efficiently, it is necessary to develop an appropriate rendering procedure and establish quality information for the rendered fat. A study was therefore undertaken to evaluate the influence of rendering methods on the amounts and general properties of the fat recovered from broiler skin. METHODS The yield and quality of the broiler ski...

Optically injected semiconductor laser under periodone oscillation is investigated as a source for photonic microwave transmission over fiber. The period-one nonlinear dynamics of an optically injected laser is studied for the purpose of minimizing the microwave power penalty induced by chromatic dispersion. Over a large range of injection strengths and frequency detunings, we first obtain the ...

A 0.9 to 1.5 kW, 2.45 GHz atmospheric pressure air microwave plasma torch has been operated efficiently with less than 1 % reflected power. The plasma is sustained in a 28 mm internal diameter fused quartz tube which penetrates perpendicularly through the wide walls of a tapered and shorted WR-284 (72 x 17 mm cross-section) waveguide. A study has been made of the effects of power and airflow on...

Results of theoretical and experimental studies of a GW-class, large diameter microwave oscillator are presented. The device consists of a large cross-section (overmoded), slow-wave structure with a unique profile of wall radius specifically designed to support surface waves and to provide a strong beam-wave coupling at moderate voltage (500 kV), an internal adjustable microwave reflector, a co...

The effect of microwave-assisted convective air-drying on the drying kinetics and quality of mango was evaluated. Both microwave power and pretreatment time were significant factors but the effect of power was more profound. Increase in microwave power and pretreatment time had a positive effect on drying time. The nonenzymatic browning index of the fresh samples increased from 0.29 to 0.60 whi...

In the present study, Aminoazines were prepared from the reaction of amidrazone hydroiodide with various aromatic aldehydes in the presence of a solid base under microwave irradiation with power level of 850 W for 2-7 min in high yields. The amidrazone hydroiodide can also be prepared by the reaction of S-methyl isothiobenzamide hydroiodide and hydrazine in methanol under nitrogen gas. All synt...

background: cutaneous leishmaniasis caused by l. major is an important public health problem in endemic areas. the aim of this study was to explore the therapeutic effect of microwave and or infrared radiation in the treatment of lesion induced in balb/c mice by l. major inoculation. methods: the footpad lesion was induced in balb/c mice by inoculation of l. major promastigotes subcutaneously. ...

Applying basic physical principles to recent observational results, we derive upper and lower limits on microwave anisotropy from point sources over the range of frequencies 10-1000 GHz. We examine the level of noise in the observations as a possible indication of source confusion at subarcminute scales. We also derive an upper limit on microwave anisotropy caused by the sources responsible for...

Ultra-low-noise microwave oscillators are often required to serve as reference signals in precision phase modulation (PM) noise measurement systems and in a host of other applications. We have significantly improved the spectral purity of NIST’s traditional cavity-stabilized microwave oscillator design, which uses a conventional air-dielectric cavity resonator as a frequency discriminator. We d...