scholarly journals Tensile strength and root distribution of Acacia mangium and Macaranga tanarius at spatial variation(Case study: East-West highway, Malaysia)

2015 ◽  
Vol 6 (7) ◽  
pp. 18-28 ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 045-052 ◽  
Author(s):  
Lateh Habibah ◽  
◽  
Avani Nazi ◽  
Habibi Bibalani Ghassem ◽  
◽  
...  

2011 ◽  
Vol 3 (2) ◽  
pp. 1 ◽  
Author(s):  
Effendi Arsad

The utilization of acacia and kelampayan wood as  plywood materials  were done. There are two kinds of treatments with two cores samples.  Wood core with thickness 2 mm and 3 mm with the spreading rate of adhesive  150 gr/m2, 200 gr/m2 and 250 gr/m2.   Resuls showed  that the  water content  of plywood  are 9,01% - 14,29%  for acacia and 9,17% - 10,58%   for kelampayan wood material.  The density of the plywood are 0,62 gr/cm3 – 0,73 gr/cm3  for acacia and 0,44 gr/cm3 – 0,57 gr/cm3.  for kelampayan wood material.  The tensile  strength of plywood are tensile strength of  plywood  are 9,49 kg/cm2 – 14,73 kg/cm2  for acacia and 8,61 kg/cm2 – 12,58 kg/cm2   for kelampayan wood material.Keywords: acacia, kelampayan,  the spreading rate of adhesive,  physics       characteristic,  plywood


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Jiali Luo ◽  
Jiayao Song ◽  
Hongying Tian ◽  
Lei Liu ◽  
Xinlei Liang

We use ERA-Interim reanalysis, MLS observations, and a trajectory model to examine the chemical transport and tracers distribution in the Upper Troposphere and Lower Stratosphere (UTLS) associated with an east-west oscillation case of the anticyclone in 2016. The results show that the spatial distribution of water vapor (H2O) was more consistent with the location of the anticyclone than carbon monoxide (CO) at 100 hPa, and an independent relative high concentration center was only found in H2O field. At 215 hPa, although the anticyclone center also migrated from the Tibetan Mode (TM) to the Iranian Mode (IM), the relative high concentration centers of both tracers were always colocated with regions where upward motion was strong in the UTLS. When the anticyclone migrated from the TM, air within the anticyclone over Tibetan Plateau may transport both westward and eastward but was always within the UTLS. The relative high concentration of tropospheric tracers within the anticyclone in the IM was from the east and transported by the westward propagation of the anticyclone rather than being lifted from surface directly. Air within the relative high geopotential height centers over Western Pacific was partly from the main anticyclone and partly from lower levels.


Cities ◽  
2021 ◽  
Vol 110 ◽  
pp. 103063
Author(s):  
Chunliang Wu ◽  
Inhi Kim ◽  
Hyungchul Chung

2020 ◽  
Vol 10 (3) ◽  
pp. 808 ◽  
Author(s):  
Lv Zhou ◽  
Jiming Guo ◽  
Xuelin Wen ◽  
Jun Ma ◽  
Fei Yang ◽  
...  

Accurate dynamic characteristics of super high-rise buildings serve as a guide in their construction and operation. Ground-based real aperture radar (GB-RAR) techniques have been applied in monitoring and analyzing the dynamic characteristics of different buildings, but only few studies have utilized them to derive the dynamic characteristics of super high-rise buildings, especially those higher than 400 m and under construction. In this study, we proposed a set of technical methods for monitoring and analyzing the dynamic characteristics of super high-rise buildings based on GB-RAR and wavelet analysis. A case study was conducted on the monitoring and analysis of the dynamic characteristics of the Wuhan Greenland Center (WGC) under construction (5–7 July 2017) with a 636 m design height. Displacement time series was accurately derived through GB-RAR and wavelet analysis, and the accuracy reached the submillimeter level. The maximum horizontal displacement amplitudes at the top of the building in the north–south and east–west directions were 18.84 and 15.94 mm, respectively. The roof displacement trajectory of the WGC was clearly identified. A certain negative correlation between the temperature and displacement changes at the roof of the building was identified. Study results demonstrate that the proposed method is effective for the dynamic monitoring and analysis of super high-rise buildings with noninvasive and nondestructive characteristics.


The works in this study is to investigate and understand the nature of Acacia mangium axial fatigue strengths under repeated stress. Acacia mangium trees were cut to produce oven-dried Small Clear Specimens that were then tested until fracture in parallel to the grain direction. This was carried out in order to discover its Ultimate Tensile Strength, which was later identified as 143.87 MPa, in parallel to the grain direction (0° grain angle). In the next phase, specimens were tested for fatigue strengths in repeated-tensile sinusoidal waveform loading at 100 Hz frequency. The stress levels for this test were at the ratios of 80, 60, 40, 30, 20 and 10% of the Ultimate Tensile Strength (0° grain angle) for the construction of Life (N) - Stress (S) plots and empirical correlation. It was observed that the Acacia Mangium N-S (Wöhler) plots have an exponential correlation with the N – intercept of vertical axis at five (5) million cycles, while the intercept of horizontal, S – axis, was at 143.87 MPa. The study also observed that Acacia mangium achieves 106 life cycles at 10% stress level. For this reason, it is concluded that the material has a fatigue endurance limit at 10% of the Ultimate Tensile Strength for 0° grain angle.


Sign in / Sign up

Export Citation Format

Share Document