Impacts of Ground Slope on Main Performance Figures of Solar Chimney Power Plants: A Comprehensive CFD Research with Experimental Validation

Geometric parameters in solar chimney power plants are numerically optimised for the purpose of better power output figures. Several parameters have been investigated in the pilot plant such as chimney height and diameter, collector diameter and slope, and slenderness. However, ground slope has not been studied to date despite its perspicuous impact on turbulent flow. In this study, the impacts of the different slope angles of the ground, where the solar radiation is absorbed through the collector, on the main performance parameters of the system are numerically analysed through a reliable CFD software ANSYS FLUENT. By considering the actual geometric figures of the pilot plant, a 3D model is constructed through DO (discrete ordinates) solar ray tracing algorithm and RNG k-ε turbulence model. For the solar intensity of 1000 W/m2, the maximum velocity inside the system is found to be 14.2 m/s, which is in good accordance with the experimental data of 15.0 m/s. Starting from 5 m inside the collector, the chimney inlet heights are reconfigured 0.209, 0.419, 0.625, 0.838, and 1.04 m, respectively, and when the ground slope is 0.1, 0.2, 0.3, 0.4, and 0.5°, the changes in the performance output of the system are investigated. For the reference case which refers to the horizontal ground, the maximum air velocity is determined to be 14.2 m/s and the power output is 54.3 kW. However, when the ground slope is made 0.5°, it is observed that the maximum velocity increases by 37% to 19.51 m/s, and the power output is enhanced to 63.95 kW with a rise of 17.7%. Sloping ground is found a key solution to improve the turbulent effects inside the plant, thus to enhance the electrical power output.

Effect of the Ground Slope and Soil Infiltration on the Water Nitrate Ion Concentrations

Soil characterization plays an essential role in the water flow and availability of nutrients. In accordance with the above, this research sought to find a relationship between the soil slope, soil particle grain size distribution, infiltration rate, and the nitrate ion movement through the soil profile and in the water table of the Quebrada La Nitrera, located in a Colombian tropical nature forest reserve. It was observed that the slope and the rate of infiltration explain the nitrate concentrations from one site to another. Additionally, in April 2018, where on average there is more precipitation for the study area, the highest groundwater nitrate ions concentration (18 mg / L) was reported according to the standard value for natural waters (10 mg / L). This suggests that hydrological events also influence the transport of these minerals.

On numerical investigation of stability of roadbeds reinforced by gabion structures

The stability of roadbed in seismic prone areas is vital for the sustainable economic development of regions. The gabion structures are one of the methods of road strengthening. Gabion structures are used to avoid damage to the roadbed under loads of natural ground slope due to earthquake or other reasons. This approach is one of the most economical and efficient solutions for the stabilization of natural ground slopes, and it is efficient as a drainage system. Field tests give precise results about the efficiency of gabion types for different sites. However, in some cases, it is expensive and numerical calculation can be used for the estimation of the applicability of gabions. The stability of roadbed by using finite element approaches was investigated here. Stability was considered as results of calculations by two cases with gabions and without ones were compared. The dynamic and seismic impact was taken into account according to local normative documents.

Perencanaan Jaringan Pipa Sistem Penyaluran Air Buangan Terpusat (Off-Site System) di Kecamatan Pasar Jambi, Kota Jambi

Improving the quality of service and processing of infrastructure and facilities for wastewater has been programmed in the national development program 2000-2004 as stated in Law No. 25 of 2000. For this reason, the need for waste management and treatment to minimize environmental pollution, one of which is liquid waste generated from the community in the form of wastewater, centralized wastewater pipeline planning in Pasar Kecamatan, Jambi City, as an illustration or engineering in environmental management especially wastewater, because this area is dense with buildings and settlements, making it feasible to build a wastewater distribution pipeline system. Based on the analysis in this plan, the total number of service blocks for Jambi Market District consists of 11 service blocks with coverage in 4 Kelurahan, namely Beringin kelurahan with 3 service blocks, Orang Kayo Hitam Subdistrict 3 service blocks, Sungai Asam with 3 service blocks, and Pasar Jambi 2 service blocks, for the total pipe needs, the total number of lateral pipes is 61 pipes with a total length of 6579.2 m, for the total branch pipes are 17 pipes with a total length of 5801 m, and for the main pipe consists of 10 main pipes to drain water discharge to WWTP, totaling 10 main pipes with a total length of 2075, the diameter on the market from the smallest is 90 mm and the largest is 800 mm. Complementary buildings consist of clean out as many as 134 clean out terminals, 80 manholes, 2 pumps, and 1 siphon or crossing building, minimum digging depth for lateral pipes is 0.88 m and the deepest follows the ground slope or assuming with requirement if the ground pipe slope is less than 0, the final drainage of each pipe meets the drainage standard that is 0.6 m / sec <Vp <3 m / sec.

Dynamic Behavior of Pile-Supported Structures with Batter Piles according to the Ground Slope through Centrifuge Model Tests

Pile-supported structures incorporating batter piles are commonly used, and can be installed both on the horizontal and inclined ground. Recent studies have considered the positive role of batter piles during earthquakes, highlighting their satisfactory contribution to structural seismic performance. However, in these structures, even though the dynamic system responses can vary greatly depending on the ground slope, few previous studies have evaluated the seismic performance of batter piles relative to the ground slope. Therefore, this study evaluates the seismic performance of pile-supported structures with batter piles, relative to the ground slope using dynamic centrifuge model tests. The acceleration, displacement, moment, and axial force of the system were experimentally derived and reviewed, and the pile moment and axial force (M–N) interaction diagrams of the pile cross-sections were analyzed. The installation of the batter piles resulted in a greater reduction in the system response in the inclined-ground model (acceleration: −48%, displacement: −50%, and moment: −84%) compared to that in the horizontal-ground model (acceleration: −27%, displacement: +650%, and moment: −77%). Overall, batter piles showed better seismic performance in the inclined-ground model than in the horizontal-ground model.

Accurate Heuristic Terrain Prediction in Powered Lower-Limb Prostheses Using Onboard Sensors

This study describes the development and offline validation of a heuristic algorithm for accurate prediction of ground terrain in a lower limb prosthesis. This method is based on inference of the ground terrain geometry using estimation of prosthetic limb kinematics during gait with a single integrated inertial measurement unit. We asked five subjects with below-knee amputations to traverse level ground, stairs, and ramps using a high-range-of-motion powered prosthesis while internal sensor data were remotely logged. We used these data to develop two terrain prediction algorithms. The first employed a state-of-the-art machine learning approach, while the second was a directly tuned heuristic using thresholds on estimated prosthetic ankle joint translations and ground slope. We compared the performance of these algorithms using resubstitution error for the machine learning algorithm and overall error for the heuristic algorithm. Our optimal machine learning algorithm attained a resubstitution error of $3.4\%$ using 45 features, while our heuristic method attained an overall prediction error of $2.8\%$ using only 5 features derived from estimation of ground slope and horizontal and vertical ankle joint displacement. Compared with pattern recognition, the heuristic performed better on each individual subject, and across both level and non-level strides. These results demonstrate a method for heuristic prediction of ground terrain in a powered prosthesis. The method is more accurate, more interpretable, and less computationally expensive than state-of-the-art machine learning methods, and relies only on integrated prosthesis sensors. Finally, the method provides intuitively tunable thresholds to improve performance for specific walking conditions.

Morphometric Analysis of Baltira Watershed Using QGIS Platform

In India due to rising in the population, resources like land and water goes on decreasing. So, it is absolutely necessary to conserve these natural resources and exertion of the resources in an effective way. From the administrative point of view, the watersheds act as the basic units for conservation of resources. For detail characterization of landforms and properties, the morphometric analysis of basins is of great help in understanding by interpreting the information available from dimensionless analysis which helps to find out the linear and aerial aspects. Morphometric analysis is the most acceptable method to be considered for reservoir basin. For developing the topographic and geomorphologic conditions, it is necessary to understand various parameters of diverse basins. In this study, a detailed morphometric assessment is done by QGIS for Baltira watershed which covers an area of 273 km2 . Baltira is one of the tributaries of Man River. The result of morphometric analysis reveals that watershed of Baltira in which geology is reasonably homogeneous, having high relief and steep ground slope. For this study, ASTER-DEM is utilized for watershed delineation and drainage parameter calculation by the hydrological module of QGIS software

Productivity of a Portable Winch System Used in Salvage Logging of Storm-Damaged Timber

Storm damages result in serious losses in many regions, primarily by stem breakage or blowdown. Extraction of storm-damaged trees often requires more difficult than normal skidding activities due to obstacles created during the storm. In this study, the productivity of a portable winch was evaluated as a possible alternative to recover storm-damaged timber. Field measurements were conducted in the Alabarda Forest Enterprise Chief located near the city of Kütahya in western Turkey, where storm damage often occurs during the winter season. The time study was implemented in two slope classes (35% and 55%) and two skidding distances (40 m and 60 m). All timber was skidded uphill. A regression mode was developed that related productivity to log volume, ground slope and skidding distance. The highest percentage of total cycle time was observed for skidding logs to the landing. The highest productivity (3.96 m3/hour) was found at the shorter skidding distance (40 m) and the lower ground slope (35%). Statistical analyses indicated that productivity was most highly affected by log volume, followed by skidding distance and ground slope. Larger log loads increased productivity, while both longer skidding distances and steeper slopes reduced productivity.