338 research outputs found

    Crash analysis of an aircraft fuselage under belly landing

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    Belly landing occurs when an aircraft lands without deploying its landing gear due to pilot error or mechanical failure. In the present work crash analysis of the fuselage under such belly landing is studied by numerical simulation using LS-DYNA software. In this study both the effect of sinking speed and the effect of different terrain properties on energy absorbing capacity is considered. Fuselage structure was modelled using LS-DYNA to simulate the crash analysis of the fuselage under vertical drop. The fuselage section similar to Boeing 737 aircraft was dropped at 7m/s and 10m/s on a rigid surface as well as on water and the deformations of fuselage were noted for each case and the energy absorbed by each of the components of the fuselage was evaluated. From the result obtained, it shows that frame and skin plays important roles in absorbing energy under crash

    Bambusa vulgaris: determination of mechanical strength as bio-composite material

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    This research examined the mechanical properties of the developed bio-composite material. The manufactured bio-composite was made from combinations of two materials, which are bamboo scientifically named as Bambusa Vulgaris and a polymer named HDPE. The main objective of this paper is to expose the performance of a bio-composite material in term of its tensile strength value. This parameter is considered as the critical advantage of the developed bio-composite material to be proposed in building structure applications. The possibility of replacing conventional materials used in structure application with the proposed material was also explored in this study. The bio-composite was manufactured using WPC technique before it becomes a solid bio-composite material. The tensile strength of this bio-composite material was measured using an experiment that follows ASTM D638 standard.Keywords: Bambusa Vulgaris; bio-composite; mechanical strength; tensile tes

    Effects of iso-nitrogenous fertilizers as nutrient sources on carp polyculture in Bangladesh

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    A 120-day long experiment was conducted to find out the effects of urea plus triple super phosphate (UT), cow manure (CM) and poultry manure (PM) having iso-nil:rogen content on pond productivity and fish yield. Three fertilizer treatments, with three replicates each, were randomly assigned into nine earthen ponds of 100 m2 each. The stocking fish were rohu (Labeo ruhita), catla ( Catla catla) and mrigal ( Cirrhinus mrigala) in each treatment pond at the rate of 10000/ha with the ratio of 1:1:1. All ponds were fertilized fortnightly at the rate of 125 kg/ha urea plus 100 kg TSP/ha, 7000 kg/ha cow manure and 3500 kg/ha poultry manure for the treatment of UT, CM and PM, respectively, having an iso-nitrogen content of 56 kg in each. Though the physicochemical water quality parameters were more or less similar in all treatment ponds, the chlorophyll-a content and abundance of total plankton were significantly higher (P < 0.05) in the ponds receiving the treatment PM. Final growth as well as per unit production of fish was significantly higher (p<O.OS) with the treatment of PM (2067 kg/ha/4 months) followed by UT (1639 kg/ha/4 months) and CM (1246 kg/ha/4 months). The overall results showed that the poultry manure proved to be superior to urea plus TSP and cow manure, even when nitrogen content is similar, in carp polyculture system under prevailing conditions

    On-Line Modelling And Forecasting Of Carbon Monoxide Concentrations Using Hybird Multilayered Perceptron Network.

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    This paper discusses on-line modelling and forecasting of carbon monoxide (CO) concentrations using Hybrid Multilayered Perceptron (HMLP) Network. Th¢ HMLP network is trained using Modified Recursive Prediction Error (MRPE) algorithm

    Measuring the underwater received power behavior for 433 mhz radio frequency based on different distance and depth for the development of an underwater wireless sensor network

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    Underwater wireless sensor network (UWSN) important to enhance the widely use of the application of the Internet of things (IoT) for underwater. Uses of the acoustics base of wave propagations are the best ways to establish the UWSN. But the unpracticality of the hardware due to the size and cost has limited the application of UWSN. Radio frequency (RF) wave propagation is the best way to overcome this situation. Low frequency of the RF wave is proven feasible and suitable for underwater communication. 433 MHz RF were chosen to measuring the underwater received power behavior between the transmitter node and receiver node based on different distance and depth. HC12 transceiver module was used as a transmitter and spectrum analyzer with the telescopic antenna was used as a receiver. The received power give a good reading when the transmitter note was at 0.5-meter depth with a maximum operating range within 12 meters from the receiver

    HMLP,MLP and Recurrent Networks for Carbon Monoxide Concentrations Forecasting: A Comparison Studies.

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    Carbon Monoxide (CO) is a primary pollutant in urban area, due to the major emission from motor vehicles. Forecasting of CO or other gas pollutants concentration are very important since preventive action can be taken if the forecasted CO level exceeds certain value

    Correction to: Towards achieving nanofinish on silicon (Si) wafer by μ-wire electro-discharge machining

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    [No abstract available]This work was supported by the Fundamental Research Grant (FRGS/1/2014/TK01/UIAM/02/2) sponsored by the Ministry of Higher Education Malaysia. Authors also acknowledge the research support provided by the International Islamic University Malaysia

    An Early Drowning Detection System for Internet of Things (IoT) Applications

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    Drowning is the leading cause of injury or death for children and teenagers. Designing a drowning detection device by implementing an Internet of Thing (IoT) is needed. An Early Drowning Detection System (EDDS) is a system that gives an early alarm to the guardians (parents and lifeguard) if the detector triggered an abnormal heartbeat and the victims are submerged under the water for a long time. A microcontroller was used to control the signal received from a pulse sensor and time for the signal lost under the water before it is transmitted to the access point. The access point acts as a data forwarding to the database via an internet connection. Universal Asynchronous Receiver/Transmitter (UART) 433MHz radio frequency transceiver has been used to create the wireless communication between drowning detection device and monitoring hub. A triggered warning signal will be transmitted to the guardians via Android apps and web page

    Organoleptic and microbiological quality changes of catla (Catla catla) in immediate and delayed ice storage and at ambient temperature

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    An investigation was carried out on the quality changes of Catla (Catla calla) stored immediately (0 h) in ice, after 6 hours in ice and at ambient temperature. The samples were examined for organoleptic and microbiological parameters in summer. Organoleptically, the acceptability of fish varied between 16-20 days in both the iced storage conditions and 12-13.5 hours at ambient temperature (28°C). When fish were organoleptically just acceptable on the 16th day of storage, bacterial load were 6.23 and 6.17 log10 cfu/g, respectively for 0 hour and after 6 hours iced fish. But on the 20th day of storage, when fish were just unacceptable SPC were 6.51 and 6.62 log10 cfu/g. In case of ambient temperature storage condition standard plate count was 8.36 log10 cfu/g on 13.5 hours, when fish were organoleptically just unacceptable. At the time of rejection for fish stored in ice (0 hour and after 6 hours) on 20th day, gram negative and gram positive values were 55.45%, 44.55% and 44.52%, 55.48% respectively. While fish were rejected after 13.5 hours at ambient temperature gram negative and gram positive bacteria were found as 43.02% and 56.98%. The differences in SPC, gram positive and gram negative bacteria between the storage times were statistically significant (p<0.05)

    Multi-objectives process optimization in end milling process of aluminium alloy 6061-T6 using genetic algorithm

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    Manufacturing industries are business driven and profits are generated by increasing annual revenue and reducing total manufacturing costs. The cost involves multiple resources such as raw materials, manpower, equipment and even manufacturing time. Thus, every manufacturing process from the frontline to the backline must run up to the maximum capacity and effectiveness without compromising products’ yield and quality. End milling is one of the crucial processes to produce geometry shape products mainly in the automotive and aerospace industries. Therefore, this paper aims to obtain optimum conditions of ethe nd milling process for three cutting inserts with multi-objective parameters using a combination of mathematical modelling and genetic algorithm. The responses studied are surface roughness, cutting temperature, cutting force and flank wear. The target is to obtain the lowest value of all the responses studied by considering both input and response parameters simultaneously at one time. The process involved multi parameters and responses, thus in this study, multi-objective optimization genetic algorithms (MOGA-II) were applied. The optimization process parameters of end milling were obtained using response surface methodology, mathematical models and the MOGA-II approach. The optimum parameters were determined according to the design flow, constraints value and mathematical algorithm. Based on MOGA-II analysis, every workflow generated 1600 feasible solutions for optimization that meet the design space requirement. However, only a final solution was selected according to the multi-objective optimization of each insert used in the experiments. Subsequently, multi-criteria decision-making is required to choose the final optimization of the machining performance. Based on the parallel coordinates plot in MOGA-II and the multi-criteria decision-making approach, the final iteration number representing a single combination of optimum parameters was obtained for each cutting insert. The results of end milling process parameters with optimised machining conditions are presented and discussed. In the confirmation analysis, all the results are less than 10% of marginal error, thus, indicating that the model that was developed for the response studied is reasonably accurate. All the actual values are within a 95% prediction interval. Therefore, it can be concluded that the process was optimized which regards the lowest value obtained for the responses studied. In addition, the process was enhanced significantly with a combination of the MQL technique and the application of tri-hybrid nanofluids in end milling even for the low-cost cutting insert like uncoated tungsten carbide. For future study, other methods or algorithms can be applied in other machining processes to obtain optimum machining parameters
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