A study of the backup reprovisioning problem for FIPP p-cycles on WDM networks

As networks grow in size and complexity, both the probability and the impact of failures increase. The pre-allocated backup bandwidth cannot provide 100% protection guarantee when multiple failures occur in a network. In this article, we focus on how to recover the protecting capabilities of FIPP (Failure-independent path-protecting) p-cycles against the subsequent links failure on WDM networks, after recovering the working paths affected by the failure of link. Two recovering policies are designed to recover the protecting capabilities of the FIPP p-cycles if possible, unless there is no sufficient network resource. They are Cycle Recovery Policy and Path Recovery Policy. In addition, a Cycle Adjust algorithm is proposed and used to recover the affected cycles. The simulation results of the proposed methods are also given.     

A Micromachined Reconfigurable Metamaterial via Reconfiguration of Asymmetric Split‐Ring Resonators

A micromachined reconfigurable metamaterial is presented, whose unit cell consists of a pair of asymmetric split‐ring resonators (ASRRs); one is fixed to the substrate while the other is patterned on a movable frame. The reconfigurable metamaterial and the supporting structures (e.g., microactuators, anchors, supporting frames, etc.) are fabricated on a silicon‐on‐insulator wafer using deep reactive‐ion etching (DRIE). By adjusting the distance between the two ASRRs, the strength of dipole–dipole coupling can be tuned continuously using the micromachined actuators and this enables tailoring of the electromagnetic response. The reconfiguration of unit cells endows the micromachined reconfigurable metamaterials with unique merits such as electromagnetic response under normal incidence and wide tuning of resonant frequency (measured as 31% and 22% for transverse electric polarization and transverse magnetic polarization, respectively). The reconfiguration could also allow switching between the polarization‐dependent and polarization‐independent states. With these features, the micromachined reconfigurable metamaterials may find potential applications in transformation optics devices, sensors, intelligent detectors, tunable frequency‐selective surfaces, and spectral filters.     

Determination of 210Po in various foodstuffs and its annual effective dose to inhabitants of Qena City, Egypt

The concentration of ²¹⁰Po was determined in different foodstuffs of plant origin purchased from markets in Qena City, Upper Egypt. Measurement of ²¹⁰Po has been carried out using alpha spectrometry technique in different food categories such as vegetables, fruits, cereals beverages and herbs. The general range of ²¹⁰Po activity levels ranged widely from < 0.010-18.6 ± 0.910 mBq g^− 1, with minimum being in cereal samples and maximum being in beverage samples. Tea samples recorded highest activity concentrations of ²¹⁰Po with lowest value of 10 ± 0.54 mBq g⁻¹ for Crown tea and highest value of 18.6 ± 0.910 mBq g⁻¹ for El maabad tea. The daily intake of ²¹⁰Po from food consumption reveals that vegetables are the biggest contributors, while beverages are the lowest. The effective ingestion dose has been estimated for Qena City residents and it was found in the range 0.008-38.3 μSv y⁻¹.     

Interaction between pile foundation and soil

Problems of interaction between a single long pile (more than 20 m) or a group of long piles as component parts of a pile foundation and soil are discussed on the basis of a new geomechanical model. The settlement of a pile or group of piles is caused primarily by shear deformations of a soil mass of limited area and depth, and also as a result of deformations of the mass beneath the lower ends of the piles. __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 2–7, March–April, 2007.     

Bio-film formation on stainless steels Part 2. The role of seasonal changes, seawater composition and surface roughness

Bio-film formation on type 254 SMO stainless steel in Arabian Gulfwater was followed by measuring the variation of the open circuit potentials of test coupons under a variety of conditions. The time-potential curves exhibited two plateaus corresponding to oxide thickening and later to bio film development. The rate of film formation was found to depend on the ambient seawater temperature, which varied with the season. The reduction of the biological activity of the water through additions of pre-boiled and cooled seawater resulted in the retardation of bio-film formation and in the shift of the final steady-state potential towards less positive values. Similar behaviour was obtained when concentrating seawater by the addition of solid salt. The simultaneous reduction of biological activity and of salt content resulted. The characteristics ofthe formed bio-film depend on the nature ofthe metal surfaces. Smooth surfaces allowed the development of thin clear films while thicker dark films formed on coarse rough surfaces. These were usually associated with the growth of worm-like structures, initiating crevice and pitting corrosion.     

The correlation between urodynamic and cystoscopic findings in elderly men with voiding complaints

PURPOSE: We evaluated the urethrocystoscopic findings and results of urodynamic studies in elderly men with voiding complaints. MATERIALS AND METHODS: A total of 492 consecutive patients with voiding complaints underwent a standardized screening program, including transrectal ultrasonography of the prostate, urodynamic investigations with pressure-flow study analysis and flexible urethrocystoscopy. RESULTS: A significant correlation was found between bladder trabeculation and grade of bladder outlet obstruction. Detrusor instability correlated significantly with grade of trabeculation. Grade of obstruction showed a clear correlation with prostatic occlusion of the urethra and the presence of a middle lobe at cystoscopy. CONCLUSIONS: The findings at urethrocystoscopy correlate well with those of urodynamic investigations.     

铟封稳频He－Ne激光器

稳频Ｈｅ－Ｎｅ激光器中布氏窗片的封接引起的各向异性损耗，是影响激光输出功率的主要因素。采用先进的铟封接技术，可以大大改善稳频管的窗口封接质量，从而减小了腔的损耗，明显地提高了稳频Ｈｅ－Ｎｅ激光器的输出功率。     

Peculiarities in the Behaviour of Thiourea as corrosion-inhibitor

The dissolution of Fe, cu, Zn and Al in nitric, hydrochlorid and sulfuric acids is retarded by low concentrations of thiourea, while higher thiourea concentrations may bring about a stimulation of corrosion. In nitric acid thiourea is probably oxidised (heat evolution); the dithioformamidine formed at first is then hydrolysed to give diaminocarbonyl disulfide which again is reduced to thiocarbamic acid at the cathodic sites of the surface. The depolarisation thus produced gives rise to accelerated dissolution. In non-oxidising acids a monomolecular layer of thiourea is adsorbed at the metal at first; its subsequent reduction to sulfide and hydrogen sulfide again gives rise to an enhancement of corrosion. The critical concentration of the transition from inhibition to stimulation depends ont he type of the acid and its concentration.     

RTD GPS技术在水下地形测量中的应用及探讨

阐述了RTDGPS技术的原理 ,结合生产实际论述了该方法在水下地形测量中的应用     

Inhibition of trypsin by t-Butyloxycarbonyl-α-aza-(4-aminophenyl)alanine phenyl ester

T-Butyloxycarbonyl-α-aza-(4-aminophenyl)alanine phenyl ester (Fig. 1, III: R = NH₂) has been synthesized. The rate of inhibition of trypsin (EC 3.4.21.4) by this compound (due to acylation followed by slower deacylation) shows a marked pH maximum at approximately 6. The shape of the pH—rate curve is discussed in terms of (i) the normal pH—activity curve of trypsin reacting with a charged substrate, i.e. the protonated form of the amino compound, (ii) the deprotonation of the 4-amino group with pK_a 4·3, and (iii) the lower rate of reaction of the enzyme with the uncharged, deprotonated form of the ester.