EXPERIMENTAL STUDY ON USE OF FALL PREVENTION MEMBERS IN WALL AND COLUMN DEMOLITION

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Seiji Takanashi ◽  
Hiroki Takahashi ◽  
Tomohito Hori
Keyword(s):  
Experimental Study ◽  
Fall Prevention ◽  
Urban Areas ◽  
Steel Pipe ◽  
Small Scale ◽  
Bottom Part ◽  
Steel Pipes ◽  
Wire Ropes ◽  
Heavy Machinery ◽  
Measured Load

At demolition sites in Japan, columns and walls are pulled down and demolished by heavy machinery or wire ropes. In a small-scale building in urban areas, columns and walls are pulled down by wire ropes. Before pulling down, workers damage the bottom part of the columns and walls for weakening them. However, if the damage of the columns and walls are too much, they fall down before use of wire ropes. As a result, they may crush workers. In this study, a fall prevention material was proposed with its installation method and verified its effectiveness by experiments. In an experiment of this study, steel pipes for supporting 3m-column were examined. The steel pipes were installed diagonally to the column. The column was loaded horizontally. We measured load and deformation until the steel pipe failed. As a result of experiments, it was found that the steel pipe buckled or the bolt supporting the steel pipe damaged. We concluded that this method is effective because the steel pipes were found to be sufficiently strong against the load generated in the steel pipes when the columns fell.

Design and Operation of Small Wastewater Treatment Plants by the Microbial Film Process

1990 ◽  
Vol 22 (3-4) ◽  
pp. 139-144 ◽  
Author(s):  
S. Iwai ◽  
Y. Oshino ◽  
T. Tsukada
Keyword(s):  
Urban Areas ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
Small Scale ◽  
Small Communities ◽  
Fishing Villages ◽  
Sewer Systems ◽  
Water Treatment Plants ◽  
History Of ◽  
Microbial Film

Although the ratio of sewer systems to population in Japan has been improving in recent years, the construction of sewer systems in small communities such as farming or fishing villages, etc. had lagged behind that of urban areas. However, construction of small-scale sewer systems in farming and fishing villages has been actively carried out in recent years. This report explains the history of the promotion of small-scale sewer systems, why submerged filter beds are being employed in many cases, and introduces the design, operation and maintenance of representative waste-water treatment plants in farming and fishing villages which incorporate de-nitrogen and dephosphorization.

scholarly journals Canard optimization for enhancing the performance of small horizontal axis wind turbine at low wind speeds

2020 ◽  
Vol 37 ◽  
pp. 63-71
Author(s):  
Yui-Chuin Shiah ◽  
Chia Hsiang Chang ◽  
Yu-Jen Chen ◽  
Ankam Vinod Kumar Reddy
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Peak Performance ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Optimum Parameters ◽  
Low Wind Speeds

ABSTRACT Generally, the environmental wind speeds in urban areas are relatively low due to clustered buildings. At low wind speeds, an aerodynamic stall occurs near the blade roots of a horizontal axis wind turbine (HAWT), leading to decay of the power coefficient. The research targets to design canards with optimal parameters for a small-scale HAWT system operated at variable rotational speeds. The design was to enhance the performance by delaying the aerodynamic stall near blade roots of the HAWT to be operated at low wind speeds. For the optimal design of canards, flow fields of the sample blades with and without canards were both simulated and compared with the experimental data. With the verification of our simulations, Taguchi analyses were performed to seek the optimum parameters of canards. This study revealed that the peak performance of the optimized canard system operated at 540 rpm might be improved by ∼35%.

scholarly journals Understanding Spatial Variability of NO2 in Urban Areas Using Spatial Modelling and Data Fusion Approaches

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca
Keyword(s):  
Data Fusion ◽  
Spatial Variability ◽  
Urban Areas ◽  
Road Traffic ◽  
Dispersion Model ◽  
Low Cost ◽  
Spatial Modelling ◽  
City Centre ◽  
Small Scale ◽  
The City

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.

Small scale experimental study of the dynamic response of a tension leg platform wind turbine

2014 ◽  
Vol 6 (5) ◽  
pp. 053108 ◽  
Author(s):  
Anders Mandrup Hansen ◽  
Robert Laugesen ◽  
Henrik Bredmose ◽  
Robert Mikkelsen ◽  
Nikolaos Psichogios
Keyword(s):  
Experimental Study ◽  
Dynamic Response ◽  
Wind Turbine ◽  
Small Scale ◽  
Tension Leg Platform

Arrangement Characteristics and Wear Distribution of Wire Rope in Parallel Grooved Multi-Layer Winding

2013 ◽  
Vol 423-426 ◽  
pp. 842-845 ◽  
Author(s):  
Zhi Hui Hu ◽  
Yong Hu ◽  
Ji Quan Hu
Keyword(s):  
Experimental Study ◽  
Wire Rope ◽  
Wire Ropes ◽  
The Wire ◽  
Wear Damage

Based on the analysis of multi-layer winding arrangement characteristic of the wire rope in Lebus drum, the experimental study is carried on wear distribution of the wire rope in parallel grooved multi-layer winding. The result shows that, the wire rope is arranged regularly in each drum area in parallel grooved multi-layer winding; the wear of wire ropes in crossover zone is more serious than that of the parallel zone; in the same-layer wire rope winding in crossover zone, the wear damage during the wire rope winding in crossover zone at the end of each-layer drum is the most serious.

Sign in / Sign up

Export Citation Format

Share Document