土木与环境工程学报

Noise Barriers are widely installed to control the propagation of vehicle noise from highway. However, the installation may result in a secondary noise caused by reflection, especially, if there exists a residential area on the opposite side. Hence, to effectively use noise barrier, it is mandatory to first predict the noise sources taking place on the roadsides and to apply the findings afterwards. In this study, by evaluating the reduction effects of reflection noise according to different panel shapes including wing, zigzag and curved type, the optimal soundproof panel shape and design factor that can minimize the reflection noise are suggested. The sound reduction was modeled by general linear model for the case of zigzag and curved shape with nominal variances. To simulate the effects of each shape, Nord 2000 with sound traveling model was used. As a result, all panel types have shown reduction effects on reflected sound, with maximum of 2.2 dB for zigzag and 1.2 dB for curved shapes. The designing factors had impact on the density of zigzag type and on the degree of bending in the curved shape. Specifically, for first noise level (up to 5 story building), reduction effect is improved for smaller size of wing type, wider angle between zigzag type panels and gentle slope of curved type. Overall, curved noise barrier labeled as C-9 is found to be the best in diminishing reflection noise. This type of barrier can be effectively used to control damages caused by reflection noise at downtown region, where extent of traffic is increasing from day to day.

Strap-down air borne gravimeter is the core sensor of strap-down gravimetry system. In this paper, A new strap-down airborne gravimeter called SGA-WZ has been developed by the Laboratory of Inertial Technology of the National University of Defense Technology. Precise gravity anomaly data reconstruction is the key technology in airborne gravimetry based on the SGA-WZ. This paper explores a method for large scale precise gravity anomaly data reconstruction using the theory of Compressed Sensing (CS). Based on the CS theory, the gravity anomaly data reconstruction can be transformed into the one-norm convex quadratic program to be solved by several methods such as interior point methods (IPM). This paper presents an improved IPM for performing the large scale gravity anomaly data reconstruction precisely that uses the Preconditioned Conjugate Gradients Algorithm (PCG) to compute the search direction. And then, a flight test has been carried out in China with SGA-WZ. The test results have shown that the PCG-IPM algorithm can reconstruct the large scale gravity anomaly data with higher accuracy than the existing nearest interpolation method in airborne gravimetry.

The lube oil wastewater is produced from Lube Oil Bending Facilities (LOBF) located in Egypt. Currently the lube oil wastewater is treated by oil separator followed by Dissolved Air Flotation (DAF) system. Unfortunately, DAFTreated Lube Oil Wastewater (DTLOWW) contains high concentration of the soluble COD. The first part of this work examined the treatability of DAF-Treated Lube Oil Wastewater (DTLOWW) using bench-scale Fenton process. Effects of H2O2, Fe2+ doses at different reaction time and wastewater strength have been studied. Optimum H2O2 dose was 0.8 g/l for normal DTLOWW strength (sCOD<2000 mg/l) and 1.2 g/l for high DTLOWW strength (sCOD>2000 mg/l). Optimum H2O2/FeSO4 ratio of 3 was achieved for the normal and high strength DTLOWW at pH 3.5. The Second part of this work studied the performance of Pilot-scale Fenton process. Pilot scale Fenton reactor was installed in the field and conducted under the optimum H2O2/FeSO4 ratio that achieved from the bench scale work. The reactor was operating in batch basis at 8 hour cycle period divided in six phases. The results showed that residual sCOD was 788 ± 56 mg/l with sCOD removal of 53.6% which amply met with the local discharge Standards for discharging the industrial wastewater to the municipal sewage network. The Fenton process could be used for treatment of the DTLOWW with daily chemicals cost of 1.25-1.50 $/m3.

This paper explores the potential of the Soil Conservation Service Curve Number (SCS-CN) approach in water quality modeling of kinetic wastewater treatment process using the experimentally derived pan evaporation data. Parameter CN is found to be dependent on evaporation and abstraction as well in addition to the influent concentration. For very low or very high values of influent concentration, CN exhibited an asymptotic variation approaching hundred and zero, respectively. Using the data on source water quality and removal, it is possible to compute CN and subsequently, the removal quality at an abstraction well.