ari wibowo

Forestry Sector which in the context of climate change is included as LULUCF sector (Land use, land use change and forestry), is an important sector that should be covered in the activitiy of green house gas (GHG) inventory. Forestry plays important role in carbon cycle. It has the capability to release (emission) and to absorb CO2 (sink.) In global level,

Large area (20 cm2) epitaxial lifted-off (ELO) triple junction (TJ) solar cells based on inverted metamorphic (IMM) InGaP/GaAs/InGaAs were fabricated. These TJ IMM ELO solar cells exhibited efficiency >29% at one sun AM0 illumination, which is the highest reported efficiency for IMM ELO thin cells to date. The cells had fill factor >85%, open circuit voltage (Voc) = 2.93 V,

... [5] Rao Tatavarti, N. Pan, G. Hillier, C. Youtsey, G. Martin, A. Wibowo, R. Navaratnarajah, F. Tuminello, and M. Disabb, Proceedings of 34th IEEE PVSC conference, Philadelphia (2009). [6 ] CL Andre, DMWilt, AJ Pitera, ML Lee, EA Fitzgerald, and SA Ringel, J. Appl. Phys.,vol. ...

High-efficiency, low-cost InGaP/GaAs dual-junction epitaxial liftoff (ELO) solar cells have been fabricated on full 4" GaAs substrates. These dual-junction solar cells exhibited an efficiency of 28.69% at AM1.5D, one-sun illumination. This is the highest reported efficiency for dual-junction ELO solar cells to date. After application of antireflection coating, the dual-junction ELO cells also exhibited fill factor >85%, open circuit voltage

We demonstrated InGaP/GaAs heterojunction bipolar transistors (HBT's) with very low burn-in and high β/RsB ratios by optimization of emitter and base properties and in situ annealing. Some HBT's exhibited β/RsB ratios of 0.47 and less than 5% burn-in. The recombination analysis of the devices revealed that the emitter and emitter-base junction were unaffected from the burn-in reduction annealing. The devices

A novel MSI circuit and reliability test method has been developed to measure the probability of infant failure in InGaP/GaAs HBTs. This circuit enables simultaneous reliability testing of 200 HBTs per circuit, and has been used routinely to test 12,800 HBTs/wafer (and sometimes 100, 000HBTs/wafer) to measure the probability of infant failure Pqf on each wafer. We have applied this

Lightly reinforced concrete columns and soft storey configurations are prevalent in many old buildings in regions of lower seismicity. This type of structure is believed to have a very low lateral load and drift capacity from a conventional design perspective. Furthermore, the application of design standards in low and moderate seismic regions such as Australia, results in most of the lightly reinforced structures being deemed unsafe in an earthquake. Therefore, an earthquake damage reconnaissance, experimental field test, and laboratory study of non ductile columns has been undertaken to examine the drift capacity and failure mechanism of such columns. Firstly, a field reconnaissance was conducted in China after the Wenchuan Earthquake in 2008, particularly in regions with similar design intensity MMI VI to VIII experienced in Australia. A comparison between the Wenchuan Earthquake and the characteristics of design earthquakes in Australia was made to provide insight for the develo...

ABSTRACT Lightly reinforced concrete walls are commonly found in low-to-moderate seismic regions such as Australia. While many theoretical analyses on lateral load-displacement of structural walls have been proposed and widely used, not many have been developed for lightly reinforced concrete walls. The lateral load-displacement behaviour and failure mechanism of lightly reinforced structural walls differ to those of heavily reinforced concrete walls, particularly in terms of tension stiffening effects, possible failure mechanisms and drift capacities. An analytical study on lightly reinforced rectangular concrete walls is presented in this paper. A parametric study was conducted to provide initial insight into the effect of four design parameters (aspect ratio, axial load ratio, transverse reinforcement ratio and longitudinal reinforcement ratio) on the ultimate displacement capacity of reinforced concrete walls. Two analytical models were developed to predict the lateral load-displacement behaviour of lightly reinforced walls consisting of a detailed wall model and a simplified wall model that provides a quick and conservative estimate for initial design checking purposes using displacement-based principles. Both models are shown to provide good agreement with experimental results in the literature.

ABSTRACT This paper presents the findings of a research project investigating the lateral load drift behaviour of lightly reinforced concrete columns. Such columns are common in regions of low–moderate seismicity, and although their strength properties are well defined, the drift performance is less understood. The paper presents the results of an experimental study undertaken and the development of a theoretical model for predicting the lateral load–drift behaviour of lightly reinforced concrete columns. The model includes a study undertaken to estimate the drift capacity of lightly reinforced columns at lateral load failure and axial load failure based on a large database of previous experimental tests. The results of a case study example are presented and clearly indicate the dramatic impact that the axial load ratio has on the drift performance of lightly reinforced columns, particularly the significantly lower drift capacities that are available in compression dominated columns.

ABSTRACT A lightly reinforced column is commonly believed to be relatively brittle with a very low drift capacity. A research project has been undertaken to investigate collapse behaviour of such columns. The effect of variation of axial load ratio and longitudinal reinforcement ratio on flexural, yield penetration, and shear displacement as components of the drift capacity were observed. Interesting outcomes showed that lightly confined reinforced concrete was able to sustain gravity axial load considerably greater than the code recommendations. Moreover, the present shear predictions available are deficient for lightly reinforced columns, since they tend to overestimate the nominal shear strength of the column.

Page 1. Field Testing of a Soft-Storey Building in Melbourne Rupali S Bhamare 1 , Ari Wibowo 2 , Emad F Gad 1, 2 , Philip Collier 3 , John L Wilson 2 , Nelson TK Lam 1 , Kittipom Rodsin 4 1. Dept of Civil and Environmental Engineering, The University of Melbourne, VIC. ...