Performance of Reinforced Concrete Beam with Polystyrene Blocks at Various Regions

Lightweight materials, such as polystyrene, can be embedded in reinforced concrete (RC) beams to reduce its weight. However, this may, to some extent, affect the performance of the structure. This research investigates the behaviour of the lightweight beams under load and determines the best position of polystyrene blocks in beams. Nine specimens with a size of 175 mm x 300 mm x 1600 mm were tested under four-point load test. The number and position of polystyrene blocks in the beams were varied. The specimens were evaluated for effectiveness in terms of effective strength to weight ratio (s-w ratio). The lightweight beam was effective when the polystyrene blocks were placed at the neutral and tensile region, offering an s-w ratio of greater than 1. The beam lost 3.8% strength with 8.4% reduction of weight.

The Utilization Of Cocopeat As Environmentally Friendly Composite

The purpose of this study was to find environmentally friendly-based composite materials by utilizing natural materials that have been underutilized. The environmentally friendly composite is biodegradable which means that if it is not used it can decompose and will not affect or damage the environment. Not all natural ingredients are environmentally friendly; this depends on the application of the material. Composites made from cocopeat utilization can be applied to broad technical requirements. The maximum composite tensile strength test results were 13,473 MPa obtained in composites with 60% matrix with 40% coconut powder, shape and size using ASTM D638-3 and average impact strength 0,00994 J/mm2 obtained from composite 60% matrix with coconut powder 40 % the shape and size using ASTM D790-3, the process of using hand lay up. Adding a polyester matrix to the composite can increase the mechanical strength of the composite. On the other hand, excessive coconut powder in the mass fraction composite will reduce its mechanical strength. The observation of SEM photos in coconut powder shows the pores that can be used further to tie more matrices and able to increase the mechanical strength of the coconut powder composite.

Hospital Waste Management through Green QFD Implementation

Based on case studies conducted in various health institutions, the high production of medical waste is one proof that medical waste management is still problematic. This study examines various problems in the field of medical waste management. This study explores staff perceptions of medical waste management. This study aims to determine the level of knowledge and attitudes as well as the role of health workers on medical waste management. Here we study the quality index and environmental index of two health care centers, one is a private hospital and one is a government hospital and compared these two indices with each other via a questionnaire survey. To produce more environmentally friendly services, customers, and environmental criteria must be considered during the decision-making process, and the Implementation of Green QFD (G-QFD) provides a very useful methodology to meet this goal.

Heat Flux Condensation on Coconut Shell Activated Charcoal Porous Media

One way to keep the air humidity is by increasing the heat transfer with the porous media model. Increasing heat transfer depends on the value of the heat flux on the porous media. The heat flux value can be determined by inserting the porous media into the test section and then flow the vapor. The amount of heat absorbed is influenced by the large diameter of the porous on the media used. Therefore, this study aimed to optimize coconut shell charcoal by activating the charcoal. The purpose of activating coconut shell charcoal is to enlarge the pores so that it absorbs heat better than charcoal that has not been activated. The research method used is an experimental method and compares the results of research with previous studies. The porous media was vaporized for 60 minutes with a vapor temperature of 30 °C, while the vapor speed was varied, namely 1 m/s, 2m/s and 3 m/s. From the research results, that by using coconut shell activated charcoal, the heat flux value was higher than using coconut shell charcoal media. This is because the pore size in activated charcoal is larger and more numerous than charcoal that has not been activated so that it absorbs more heat. In addition, the greater the vapor speed, the higher the heat flux, because in the test section more vapor enters than vapor that comes out so that the porous media has a long time to absorb heat in the vapor. The heat transfer that occurs in porous media includes forced convection heat transfer because it has a value of Gr/Re2 < 1.

Comparative Analysis Of Mechanical Properties Of Rubber-Kenaf-Wire-Cotton Lamination On Epoxy-Carbon-Ramie Composite

The use of fiber has been widely researched but the use of several fibers as reinforcement does not necessarily result in optimal mechanical properties. This study aimed to determine the tensile strength and impact strength of composite materials using an epoxy matrix with the addition of rubber variations to increase the ductility of the matrix. Meanwhile, the fibers used for reinforcement are carbon fiber and ramie. In this study, the reinforcement added a variety of kenaf fiber, wire and cotton. This was to compare the role of kenaf fiber, wire and cotton in improving the mechanical properties of composite materials. The percentage of rubber volume fraction added to the epoxy is 30%, 40% and 50%.The highest tensile test results were shown in the 30% epoxy rubber-carbon fiber-ramie fiber-kenaf specimen which was 10.67 Kgf / mm2, and the lowest result was the epoxy 50% rubber-carbon fiber-ramie-wire specimen, which was 5.752 kgf / mm2. The fracture analysis of the tensile test showed that the fracture area is formed by debonding phenomena between fibers and matrices.The highest impact strength was found in the 50% epoxy rubber-carbon fiber-ramie-wire specimen, which was 0.039 kgf / mm2. Meanwhile, the lowest impact strength was found in the 40% epoxy rubber-carbon fiber-ramie fiber-cotton specimen, which was 0.030 kgf/ mm2. In general, the trend of impact test data shows that as the percentage volume fraction of rubber increases, the impact strength of the composite material increases.Based on the test analysis, it was concluded that increasing the percentage of rubber will increase the impact strength of the woven wire reinforcement. However, the impact strength is inversely proportional to kenaf fiber reinforcement, where the addition of the percentage of rubber will reduce the impact strength. This showed that the mechanical properties were not always influenced by the percentage of rubber but were very dependent on the type of fiber. This was also shown in the results of the tensile strength test. In general, it was known that the adhesion between fiber and matrix laminates affected the mechanical properties in addition to the strength of the reinforcement.

Valuation of Reliability Index in Distribution Network 13.8 kV

This study is proposed to calculate and analyze the level of reliability of the 13.8 kV distribution system. To calculate the reliability index based on the reliability index of the value of the failure that occurred. The method used throughout this study is the Reliability Index Assessment (RIA) when this method takes into account momentary interruption. The distribution network is considered as the object of this study has six feeders. Based on blackout data obtained, the reliability index becomes smaller and can be distinguished between permanent and temporary disruptions. The calculation results show the reliability index of SAIDI, SAIDI, and MAIFI based on the type of disturbance; the results of this calculation will be compared with SPLN and IEEE. A comparison of the results of the calculation of SAIFI values from the six feeders analyzed all meet the SPLN and IEEE rules. However, in one of the feeders, the SAIDI index exceeds the established standard, which is 24 hours/year/customer, with the SPLN regulation being 21 hours/year/customer, and the IEEE standard is 2.3 hours/customer/year. And finally, the results of an analysis of the MAIFI index for all feeders meet the IEEE standard of 5 times/year/customers.

Behaviour of Reinforced Concrete Beams With Circular Transverse Openings Under Static Loads

Transverse opening in a reinforced concrete beam allows the crossing of mechanical and electrical services through the beam. However, it affects the strength of a beam. Understanding its structural behaviour is crucial to ensure a safe design of the beam. For that, an experimental study was carried out on reinforced concrete beams with circular transverse openings. The four-point load test was conducted to study the effects of the size and the position of the opening on the beam performance under the shear and flexural loads. In addition, three reinforcing methods for the opening were tested. The beams were evaluated in terms of the load-displacement responses, mechanical properties, deflections, and failure modes. The opening with the diameter not exceeding 0.25 times beam height affected about 20% of beam strength (without reinforcements at the opening). The diagonal bar reinforcing method effectively restored the beam strength for the opening size not exceeding 1/3 of beam height. The equation model proposed conservatively predicted the ultimate capacity of the beam with a transverse opening.

Mountain Bicycle Cycling Comfort on Different Road Surfaces

Mountain bicycle is one of the types of bicycles, and it is made for off-road cycling. The main objective of the research is to focus on the surface of the road and weight to obtain and measure the vibration produce on the mountain bicycle. In order to investigate the vibrations, an accelerometer is placed under the saddle of the bicycle in order to get an accurate reading for different types of surfaces and the vibration of the weight. The cyclist had to cycle for 400 m in the average of 5.1 to 6.1 revolutions per minute on four different surfaces, and four different weight were investigated. The results show that the highest acceleration produced is which refers to mean value is the acceleration of loose gravel which is 0.46190. There is an insignificant value in the weight of the driver weighing 60 kg if replaced with 70 kg, 80 kg if the bike is running on four different kinds of roads.

Do We Need Taxi Counter at Major Transportation Hubs

Taxi service at major international airport is usually an exclusive service where only those registered with the airport authority can serve passengers. Intending passengers need to register and pay a fixed fare at the taxi counter before using the service. Many customers complain that the fixed fare is significantly higher than if it was based on meter. This paper discusses the benefits or disbenefits of having taxi counter at major transportation hubs, trying to find the best solution for the benefit of all concerned parties: taxi drivers, customers and the authority. Data for analysis was obtained from observations at a number of airports and rail stations in Indonesia and Malysia. Result of the analysis suggests that it is ideal to have taxi counter, but use of the service should be made possible without having the customers to visit the counter.

Skyhook-PID Control Strategy to Improve Performance of a Pneumatic Active Suspension System

The research applies a skyhook-PID control method for an active suspension system. The control strategy has three feedback control loops. They are the innermost loop for the force tracking of the pneumatic actuator, the intermediate loops applying skyhook strategy for the elimination of the disturbances, and the outermost loop using PID controller for the determination of the desired force. Some experiments were carried out on a physical test rig with a hardware-in-the-loops feature. The performance of the proposed control method was evaluated and benchmarked to examine the effectiveness of the system in suppressing the disturbance effect of the suspension system. It was found that the experimental results demonstrate the superiority of the active suspension system with Skyhook-PID scheme compared to the PID and passive suspension systems.