Optimized PPP-insulated pipe type cable system for the commercialvoltage range

An EPRI project with the objective of developing an optimized 345 kV paper-polypropylene-paper pipe cable system is discussed. Highlights of the design and manufacture of the new reduced-wall cable are detailed. Pertinent aspects of a major corollary development, establishing a US domestic supplier of PPP, are described. Laboratory qualification tests suggest that reasonable cable optimization is achieved. An optimized PPP joint design is described. The economic advantages and versatility of this new cable system are summarized     

Irrigated agricultural expansion planning in developing countries: Performance vs. resilience vs. reliability

The conflict between performance measured in terms of economic and income redistribution objectives, resilience and reliability of irrigated agricultural expansions in developing countries is investigated via a planning framework consisting of three sequential optimization models. The first model determines the most economic planning alternatives. The second model examines, in terms of an income redistribution criterion, the social attractiveness of each plan. The third model determines resilience and operating rules of the various alternatives. The planning framework is appled for a hypothetical agricultural expansion on the order of 30 000 hectares based on data from the Nile Delta in Egypt. The trade-off between system performance, reliability and resilience is derived.     

Insecticidal properties of citrus oils against Culex pipiens and Musca domestica

Peel oils of lemon, grapefruit and navel orange were tested for insecticidal activities against larvae and adults of Culex pipiens and Musca domestica. Lemon peel oil was the most effective against larvae and adults of C. pipiens. Grapefruit peel oil was more toxic to adults of M. domestica while lemon oil, was more toxic Musca larvae. On the other hand, the orange peel oil was the least effective against larvae and adults of both species. The toxicity of oils applied to larval stages was extended to pupal and adult stages. C. pipiens adults appeared with paralyzed legs, while M domestica adults appeared normal. The weights of pupae treated as larvae were generally less than that of the control. All oils produced deleterious effects on fecundity of survivors of sublethal doses. The effect was obviously recorded in treated adults. Treatment of Culex & Musca with oils caused serious latent effect.     

Isomorphism between pulsed-wave Doppler ultrasound anddirection-of-arrival estimation. II. Experimental results

For pt. I see ibid., vol. 43, no. 5, p. 911-22 (1996). Pt. I presented the basic principles for applying high-resolution wide-band direction-of-arrival estimation techniques to pulsed-wave Doppler ultrasound. Such techniques provide high-resolution velocity profiles and enable the identification of multiple velocity components inside a sample volume. Another important application is the identification and rejection of wall clutter signals. A first and essential step in applying these techniques is to convert the wide-band echoes to narrow band. The 2D DFT projection method is used for this conversion. Two different narrow-band high-resolution methods are then applied to estimate the velocity distributions; the minimum variance (MV) and the multiple signal classification (MUSIC). Experimental results are presented to illustrate the potentials and limitations of applying wide-band DOA methods to different applications in pulsed-wave Doppler ultrasound     

A dip process for thermal barrier coating on superalloys

A new cerium oxide thermal barrier coating for superalloys has been investigated. The coating is applied by hot dipping superalloy substrates into a molten bath of low melting point Ce-Ni alloy. Annealing and selective oxidation of cerium at low oxygen activities produce a duplex coating of a continuous outer layer of cerium oxide (CeO₂) and an inner composite CeO₂-substrate layer.The effects of coating composition and processing variables on the microstructure and integrity of the coating on nickel- and cobalt-base alloys were studied in detail. Isothermal and cyclic oxidation tests showed that coating spallation could occur and was associated with the oxidation of nickel and cobalt incorporated in the coating. A model for the formation of the CeO₂ barrier and the subscale region is proposed that explains the presence of unwanted nickel and cobalt.     

Structural and optical properties of Cd x Zn(1 − x)Te thin films

Seven Cd _x Zn_{(1 ? x} Te solid solutions with x = 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 were synthesized by fusing stoichiometric amounts of CdTe and ZnTe constituents in silica tubes. Each composition was used in the preparation of a group of thin films of different thicknesses. Structural investigation of the obtained films indicates they have a polycrystalline structure with predominant diffraction lines corresponding to (111) (220) and (311) reflecting planes, which can be attributed to the characteristics of growth with the (111) plane. The optical constants (the refractive index n, the absorption index k, and the absorption coefficient α) of Cd _x Zn_{(1 \s -x)} Te thin films were determined in the spectral range 500–2000 nm. At certain wavelengths it was found that the refractive index, n, increases with increasing molar fraction, x. It was also found that plots of α² (hv) and α^1/2 (hv) yield straight lines, corresponding to direct and indirect allowed transitions respectively obeying the following two equations: $$\begin{gathered} E_g^d = 1.583 + 0.277x + 0.197x^2 \hfill \\ E_g^{ind} = 1.281 + 0.111x + 0.302x^2 \hfill \\ \end{gathered}$$      

A low-profile internet of things-controlled frequency reconfigurable triple band antenna for microwave sensing applications

This paper presents the design and analysis of IoT (Internet of Things) controlled frequency reconfigurable triple-band antenna for WiMAX, ISM (Industrial, Scientific, and Medical) band, and X band microwave sensing applications. The designed antenna is constructed on polyimide substrate with a limited ground plane with compact dimensions of 27.5?×?8?×?0.6 mm³. The fabricated antenna is sensing the microwave signals that fall under WiMAX, ISM, & WLAN, and X band with a tunable frequency range of 3.2–3.9, 5.1–6.5, and 8.2–12 GHz, respectively. The operating frequency bands can be tuned by PIN diodes and which will be controlled by using the IoT-based NodeMCU module. The designed antenna resonates at 3.5, 5.9, and 8.45 GHz when the PIN diodes are in ON state and resonating at 3.79, 5.8, and 10.48 GHz when PIN diodes are in OFF state. The proposed antenna has bidirectional radiation at upper-frequency bands and unidirectional at lower frequency bands with gain ranging from 2.2 to 3.25 dB. The proposed frequency reconfigurable triple-band antenna has a more than 90% radiation efficiency at all the operating frequencies in the ON state. A good similarity between the measured (Antenna measurement setup with Vector Network Analyzer) and simulated results (CST Microwave Studio) is observed. In the real-time environment, the proposed reconfigurable antenna is tested by the CDAC (Centre for Development of Advanced Computing, India) Cmote unit found its suitability to microwave sensing applications.

     

Application of Fourier transform infrared spectroscopy to study the interactions of poly(acrylic acid) and mixtures of poly(acrylic acid) and polyacrylamide with bone powders and hydroxyapatites

Fourier transform infrared (FTIR) spectroscopy was used to study the interactions of aqueous solutions of poly(acrylic acid) (PAA) and mixtures of aqueous solutions of PAA and polyacrylamide (PAAm) with chemically and thermally treated bone powders (BPs) and two commercial hydroxyapatites (HAs). An analysis of the spectra of the precipitates that resulted from the mixtures of PAA and the chemically treated samples of BP revealed that the spectra exhibited three new bands at 1544, 1552, and 1661 cm^?1. The first band was attributed to the formation of calcium–polycarboxylate resulting from the interaction between the carboxylic acid groups of PAA and the calcium ions of BP. The appearance of the other two bands, in addition to the disappearance of the band corresponding to the absorption of the acid groups of PAA, provided strong evidence for the existence of other interactions between the carboxylic acid groups and the amide groups of the organic matrix of BP. On the other hand, the FTIR spectra of the samples that resulted from the mixture of PAA and thermally treated BP and the two commercial HAs showed only a new absorption band at 1544 cm^?1. The interactions of mixtures of the aqueous solutions of PAA and PAAm, adjusted at low or high pH values, with the different BPs and HAs were examined. The mixtures of the aqueous solutions of PAA and PAAm interacted with the different BPs and two HAs, resulting in the formation of ternary PAA–BP–PAAm and PAA–HA–PAAm complexes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

REMOTE SPECTRAL SENSING OF TEMPERATURE PROFILES IN FLAMES

Knowledge of the temperature profile of the gases produced by the combustion of fossil fuels with air is a desirable step in the thermal protection systems. These gases are generally associated with high temperatures and steep temperature gradients. The measurement of temperature profiles of combustion products are often hard to make using thermocouples and other immersed pyrometers because such probes may have to be immersed in inaccessible and possibly destructive media. Determination of gas temperature profiles from multi-frequency radiative measurements seems an attractive alternative. This could be accomplished by radiative heat transfer probing and the application of the principle of inversion, where inversion is the process of inferring the internal parameters of a system of outside measurements, without the interruption of the combustion system itself.

This paper discusses the development of models to retrieve the temperature distribution in a flame system by remote spectral sensing. Mixed Gray-Gas models were developed to calculate water vapor and carbon dioxide standard emissivities. The evaluation of combustion system spectral radiant flux was simulated and a model was developed and successfully tested for the application of temperature inversion.     

Influence of small Pt additions on Al2O3 scale adherence

The effects of small Pt additions (1 or 3 wt.%) on the oxidation behavior of Co-10Cr-11Al and a similar alloy containing Hf have been studied. An intermetallic phase was present in the alloy containing Hf and Pt but not in that containing Pt alone. The size and distribution of the intermetallic was comparable to that of similar alloys containing oxide dispersions produced by a controlled internal oxidation treatment. As a consequence it promoted the formation of inwardly growing Al₂O₃ pegs that helped key the surface scale to the substrate and improve the scale-metal adhesion in both isothermal and cyclic oxidation tests. The improvement in overall oxidation resistance relative to an addition-free alloy was considerable, and similar to that of the best oxide dispersion-containing alloys.Formerly Department of Metallurgy and Materials Science, University of Liverpool, Liverpool, England.