Buildings subjected to torsional effect may result to the floors of the building not only translate laterally but also rotate vertically. Torsional effects may significantly modify the seismic response of buildings, a...
Buildings subjected to torsional effect may result to the floors of the building not only translate laterally but also rotate vertically. Torsional effects may significantly modify the seismic response of buildings, and even cause severe damage or collapse of structures. The current practices in earthquake design is to apply single earthquake on structure during modelling and analysis. However, in real earthquake occurrence, the earthquakes normally occurred repeatedly after the first event. This phenomenon can affect the stiffness and strength of the structural system especially for repeated strong motions. With greater damage expected and lack of time, any rehabilitation action is impractical. Slab rotation, a major response parameter to represent the severity of the torsional response of eccentric systems, is considered. The centre of strength (CR) and centre of stiffness (CS), as two interdependent and important factors to the torsional response of buildings, are investigated via eighty positions of strength eccentricities (er) and stiffness eccentricities (es). Hence, this paper presents the torsional behaviour of a single storey, three-dimensional asymmetric building under the excitation of single and repeated strong ground motions. These motions are applied in the z-direction and analysed for elastic and inelastic conditions. The results are interpreted based on two position models. Position Model A concludes that the effectiveness of CS reduces gradually until CS ratio (es/bz) ≤0.2; thereafter effectiveness of CR increases to cause elastic slab rotation. With repeated ground motion, the magnitude of inelastic rotation is increased; however es/bz ≤0.2 is maintained showing effectiveness of stiffness eccentricity irrespective of nature of ground motion. Position Model B shows that slab rotation is affected by repeated ground motion. Elastic/inelastic analysis under repeated ground motion must be conducted in oppose to current practice, so that the designed str
The purpose of this research is to know how influence of mixture of pertamax with Tuak Nias (Tuonifaro) to fuel consumption at 125 cc engine To prove that Tuak Nias or Tuonifaro can be used as fuel mixture on motorcyc...
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Quantum tunneling phenomenon allows a high-barrier reaction to occur even though thermal energy is not sufficient to surmount the barrier. The phenomenon has been suggested to exist in the isomerization of methylhydro...
Quantum tunneling phenomenon allows a high-barrier reaction to occur even though thermal energy is not sufficient to surmount the barrier. The phenomenon has been suggested to exist in the isomerization of methylhydroxycarbene which occured at 11 K. Here we study the quantum tunneling that occured in the isomerization of methylhydroxycarbene to acetaldehyde and to vinyl alcohol based on density functional calculations. The isomerization pathways are determined under the effect of various solvents which are modeled by polarizable continuum model (PCM). We use Wentzel-Kramers-Brillouin (WKB) approximation to calculate the tunneling probability (T) and extend the usefulness of T into isomerization rate. The results show that the solvents give a significant effect on the isomerization rate of methylhydroxycarbene to acetaldehyde but an insignificant one on the isomerization rate to vinyl alcohol.
The objective of this study was to evaluate the physical and mechanical properties of a bamboo-oriented strand board (BOSB) under various compression ratios. The raw material of BOSB was betung (Dendrocalamus asper) s...
The objective of this study was to evaluate the physical and mechanical properties of a bamboo-oriented strand board (BOSB) under various compression ratios. The raw material of BOSB was betung (Dendrocalamus asper) strand that steamed and followed by rinsing with a 1% NaOH solution. BOSB with the dimensions of 30 × 30 × 0.9 cm3 were manufactured with a compression ratio of five levels i.e. 1.15; 1.25; 1.35; 1.44; and 1.54. Three layers of BOSB were made with a shelling ratio of 50:50. Phenol formaldehyde (PF) adhesive (SC=43%) was added with 8% concentration, while paraffin was used as much as 1% of the dry weight of the oven strand. Strand geometry evaluation was carried out on 100 strands randomly. The physical and mechanical properties were evaluated according to JIS A 5908-2003. The results showed that relatively homogeny strand geometry in this research was suitable to manufacture of BOSB. Increasing in BOSB compression ratio up to 1.54 increased mechanical properties. However, the increase of the BOSB compression ratio was decreased the dimensional stability. The optimum BOSB compression ratio was 1.35.
Penaeid shrimps are widely distributed from Indian to western Pacific Oceans and some which are economically important. In this study, we reported full mitochondrial genome of an endemic shrimp species,Penaeus acehens...
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Penaeid shrimps are widely distributed from Indian to western Pacific Oceans and some which are economically important. In this study, we reported full mitochondrial genome of an endemic shrimp species,Penaeus acehensis, which inhabits exclusively in the coastal water of Aceh, Indonesia. Full length of circular mitogenome ofP. acehensiswas 15,991 bp in length, which contained 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region. Start codons of all protein-coding genes were ATN except for COX1 in which ACG was used. Incomplete stop codon (T- -) was found in five genes including COX2, COX3, NAD5, NAD4, and NAD4L. Among its relatives,P. acehensiswas most closely related toPenaeus monodonshowing 89% sequence identity in its mitogenome, which was corresponding to morphological analysis. Phylogenetic tree result showed thatP. acehensiswas clustered together with those were distributed in Indo-West Pacific region (clade II), which is distinct from Eastern Pacific region (clade I).
作者:
Bunyamin1Civil Engineering Program
Faculty of Engineering Iskandarmuda Univerisity Jl. Kampus Unida-Surien Kota Banda Aceh Telp. (0651) 42225 - 42098 – 42219 Indonesia
In 2004, an earthquake and tsunami occured and destroyed thousands of houses in Aceh, so that there were housing built with hollow block concrete in some areas of Aceh. The hollow block concrete needs to be reviewed f...
In 2004, an earthquake and tsunami occured and destroyed thousands of houses in Aceh, so that there were housing built with hollow block concrete in some areas of Aceh. The hollow block concrete needs to be reviewed for the strength of its structure such as beams and columns. This study was specified to the bending strength of hollow block and then compared with normal reinforced concrete beams. The research was conducted by testing the reinforced concrete block material of hollow block and normal reinforced concrete that were loaded with capacity of 50 Ton. The samples of this study consisted of: Ringbalk Reinforcement Concrete (RRC), Ringbalk Hollow Block (RHB), Sloof Reinforcement Concrete (SRC), and Sloof Hollow Block (SHB) with beam size are: 150 mm x 200 mm x 2100 mm. In addition, TDS-302 data loggers and tranducers were used to read burden and deflection arising. From this research it was found that: the maximum deflection due to the RRC beam was 2,183 cm; RHB beam was 2,341 cm; SRC beam was 1.981 cm; and the SHB beam was 2,022 cm. RHB and SHB samples had a high deflection compared to RRC and SRC samples.
The aim of this study is to investigate the soil organic matter (SOM) status in various land uses and management in Kayangan Sub-District, North Lombok, and its accuracy measurement using near infrared spectroscopy (N...
The aim of this study is to investigate the soil organic matter (SOM) status in various land uses and management in Kayangan Sub-District, North Lombok, and its accuracy measurement using near infrared spectroscopy (NIRS). A total of 100 soil samples (0-10 cm depth) were collected from several land uses and management (rain-fed areas, irrigated areas, areas planted 1-3 times with seasonal crops, areas planted with 1-3 perennial plants) in the study area, which were dried, ground and sieved, then analyzed using Walkley and Black method and scanned using near infrared spectroscopy (NIRS). Partial least square regression (PLSR) was used to create SOM prediction models. The results showed that the SOM content varied from very low to moderate with most of them were low. The content of SOM was significantly higher in the irrigated areas compared to that of in the rain-fed areas, and also higher in the areas planted with seasonal crops 3 times a year compared to the areas planted 1-2 times a year. SOM content was higher in areas planted with 2-3 types of perennial plants, compared to with 1 type of perennial plant. NIRS technology was moderately accurate in measuring SOM, which can be used to monitor spatially changes in SOM.
A successful geothermal field size assessment requires integrative data analysis of all aspects to determine the optimum capacity to be installed. Nowadays, numerical simulation becomes a powerful tool in a geothermal...
A successful geothermal field size assessment requires integrative data analysis of all aspects to determine the optimum capacity to be installed. Nowadays, numerical simulation becomes a powerful tool in a geothermal resource assessment process. However, this method involves significant uncertainty of subsurface information as an input. Then a study of resource assessment methods, such as heat stored and experimental design, needs inputs coming from the result/output of reservoir numerical. The calculation of both methods based on a range of reservoir parameter values can be carried out using stochastic methods (Monte Carlo Simulation). It applies a probabilistic method of resource assessment to capture uncertainties. A sophisticated numerical reservoir model of Ciwidey-Patuha Geothermal Field, West Java-Indonesia in the natural state condition was used as a case study to determine the generating potential of the reservoir.
In this applied research, a solar energy powered process control monitoring system of inorganic fertilizer plant with capacity of 300 liters has been developed. The process control system consists of PLC with solar en...
In this applied research, a solar energy powered process control monitoring system of inorganic fertilizer plant with capacity of 300 liters has been developed. The process control system consists of PLC with solar energy panel as its power source and a monitoring process system. The monitoring process system includes a Raspberry Pi minicomputer, an LCD touchscreen, level shifter converters, Arduino Nano, RS485 modules, four analog sensors, and one digital sensor. This system works by collecting temperature, humidity, and gas concentrations data and controlling the heater, exhaust fan, and aerator to maintain desired processing ***-22 digital sensor measures temperature and humidity, pH probe analog sensor measures pH values, MQ-4, MQ-7 and MiCS-2714 measures methane, carbon monoxide, and nitrogen dioxide gases respectively. Analog output sensor is read by PLC's analog to digital converter while digital output sensor is read by 1-wire bus by Arduino. The collected data is send over RS485 to Raspberry Pi. The plant temperature is set constant at 40°C. The heater is turned on at temperature of ≤ 38°C, when temperature reach ≤ 42°C the aerator, exhaust fan, and mixer will be on and will be switched off all together at 40°C. The temperature, humidity and PH are set as the reference of the control process.
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