Server Room Monitoring System Capable of Remote Status Querying and Remote Administrating

In Conferences - Full Text
Kumara, D. M. D. D. P., Thiruparan, B., Jayaweera, H. H. E. & Ariyaratne, T. R.
 27th technical sessions.Institute of Physics
Publication year: 2019

ABSTRACT:
Development of a standalone device together with three application software in different platform for server room environment monitoring is reported. The developed hardware is connected to different sensor networks to detect/measure door opening, relative humidity, temperature, flood, power line status. User can define critical situation as a function of sensor inputs. In case, a critical situation is detected, the system produces warning messages to the stored phone numbers through short messaging service (SMS) and on-site audio visual warnings also produces. The hardware can be operated using the keypad and liquid crystal display (LCD) available on the hardware itself or using web application or using SMS. An application runs on a computer allows the hardware to connect to the internet. The data registered in the sensors are uploaded to a web database as a web based data log. A mobile application has been developed to make possible the remote administration through the mobile phone more user-friendly.User in the system can be given different credentials, such as operating device, adding new users and changing critical situation detection function. The system is capable of the authorizing user through password or using iButton (in case of on-site authorization). The main requirements to operate the hardware are power supply (which is battery backed up) and global system for mobile communication (GSM) coverage. The internet connectivity is optional, if connected additional functionalities are enabled.

Solar thermal energy harnessing using a parabolic trough concentrator

In Conferences - Full Text
Kumara P.D.C, Viraj M.P.S, Suraweera S.K.K, Jayaweera H.H.E., Muzathik A.M and Ariyaratne T. R
3rd International conference on Advances in Computing and technology (ICACT 2018)
Publication year: 2018

ABSTRACT:
This paper reports the results of a study carried out in the development of a solar thermal energy harnessing plant using a parabolic trough concentrator. In the field of energy production one of the most concerned factors today is the air pollution, and it is linked with carbon and sulphur emissions from burning of fossil fuels. It is estimated that the global fossil fuel consumption will increase by 48% by 2040. In this context the Solar energy is still considered as the most prominent clean source of energy. Parabolic trough concentrator (PTC) is the most mature and commercially proven technology among the other solar thermal energy harnessing methods. The objective of this study is to design and develop a high efficiency PTC using locally available technologies and materials. The first Sri Lankan PTC thermal energy plant having dimensions of 4.5 m × 4.8 m and an aperture area of 22.3 m2 has been successfully constructed under this project and are in operation at the University of Colombo. Solar mirror films (3M 1100) pasted on stainless steel sheets are used as parabolic reflectors and they are mounted on Unplasticized Polyvinyl Chloride profiles clamped on a Galvanized Iron structure. A heat transfer fluid (Mobil Therm-605) is used to transfer the harnessed energy from PTC to the secondary energy conversion modules such as steam generator. When designing the mechanical structure, effect of the wind load was taken in to account in order to achieve the maximum stability and precision-focusing. The maximum daytime wind speed of the location of interest is around 8.3 m s-1 and the calculated maximum wind load and torque were found to be 3.19 kN and 3.64 kNm respectively for a gust factor of 1.53. The structural design was optimized using a computer simulation to bring the maximum stress below the yield point, and when stress is 23.72 MPa the total deformation was found to be 1.12 mm which does not affect the focusing significantly. The concentration ratio of the plant is 1:66 and it lies well within the range of the corresponding parameter (1:30 and 1:80) available for commercial plants. The focusing efficiency of the system is 79% which is also on par with the values available for commercial plants. However, the overall efficiency of solar thermal utilization is found to be 28.7%, hence the thermal capacity of the power plant is 5 kW. Improvements are underway to reduce the heat loss from the receiver tube. It is estimated that the overall efficiency of the system can be increased up to 65% to 70% by using evacuated glass receiver tubes.

Mechanical design and flow simulation of a steam generator for parabolic trough solar thermal energy harnessing plant

In Conferences - Full Text
Kumara P.D.C, Viraj M.P.S, Suraweera S.K.K, Jayaweera H.H.E., Muzathik A.M and Ariyaratne T.R
17th International Conference on Advances in ICT for Emerging Regions (ICTer 2017)
Publication year: 2017

ABSTRACT:

A steam generator is designed for a parabolic trough solar thermal plant of aperture area 22.3 m 2 , which uses Mobil Therm-605 as the heat transfer fluid (HTF). The potential energy input rate from the plant to the steam generator is 4.56 kW, and the flow rate and temperature of the HTF of the plant are 11 min -1 and 268 °C respectively. The steam generator was designed as a shell and tube heat exchanger and the tubes are arranged in reflection symmetric configuration (n=6). Flow simulations was done by using SolidWorks CAD software, based on Finite Element Method were carried out for the steam generator design in order to find the optimum conditions by varying the parameters such as tube diameter, HTF flow velocity distribution and thickness of HTF thermal barrier, while minimizing the fluid pressure and maintaining even flow distribution through the tubes. The simulation scheme narrowed down to …

Machine counting of Malaria infected blood cells

In Conferences - Full Text
Wijesighe, P. & Jayaweera, H. H. E.
31st technical sessions.Institute of Physics
Publication year: 2015

ABSTRACT:

The most widely used laboratory confirmation technique for malaria is visual inspection of Giemsa stained blood smears on microscope. A detection and counting method for malaria infected blood cells in a colour (RGB) microscopic image was developed with th e help of machine vision and artificial neural networks (ANN). The developed system is capable of detecting individual blood cells in the image and recognized them as malaria infected or non – infected. The system is capable of producing the number of blood cells in each category, which can be use d as an indicator of severity of infection. The system was trained for 40 blood cells (from seven images) manually marking them as infected or non – infected , and 120 blood cells (from 15 images) were used to test the system. The sensitivity and the specificity of the system for that data set was found to be 90.0 % and 95.7 % respectively for the images of blood cells of malaria infected and uninfected by Plasmodium falciparum parasites.

LED based chlorophyll sensor

In Conferences - Full Text
Silva, T. D. & Jayaweera, H. H. E.
31st technical sessions.Institute of Physics
Publication year: 2015

Silva, T. D. & Jayaweera, H. H. E., (2015) LED based chlorophyll sensor. 31st technical sessions.Institute of Physics – Sri Lanka

Evaluation of temperature dependence of oscillation frequency of an internal RC oscillator of a microcontroller as a temperature sensor

In Conferences - Full Text
Kumara, D. M. D. D. P., Thiruparan, B., Jayaweera, H. H. E. & Ariyaratne, T. R.
Research Symposium - University of Colombo
Publication year: 2011

ABSTRACT:

A novel, low cost and reliable method of using a microcontroller has been tested and evaluated for measuring temperature. Most of the microcontrollers come with a Watch Dog Timer (WDT) which is clocked by an internal Resistor Capacitor (RC) oscillator. Theoscillating frequency of the RC oscillator depends on the temperature. The time-out periods (in counts) of WDT of Microchip PIC16F877A microcontroller were measured at different temperatures by means of a LM35 sensor from National Semiconductor Inc. It isfound to give a good linear relationship (correlation coefficient R2=0.997) between time-out period and the temperature with a scale factor of 6 counts per 1C and an accuracy of 0.8 C for the range ,5C to 60 C when the microcontroller runs by a 4 MHz crystal oscillator. The response time is found to be 48 s with the water sealing material. There was no hysteresis effect found on these measurements and for the same series microcontroller the measurements lie within the given accuracy. The microcontroller isprogrammed to produce the reading in RS232 protocol and it can easily be software altered to any other standard protocol.

Electronic implementation of sun algorithm

In Conferences - Full Text
Suraweera, S. K. K., Jayaweera, H. H. E., Thiruparan, B. & Ariyaratne, T. R.
Research Symposium – University of Colombo
Publication year: 2011

ABSTRACT:

Abstract Implementation of Solar Position Algorithm (SPA) on an electronic platform is presented. The system consists of a microcontroller and a real time clock. Solar angles according to the SPA were calculated on a computer for 5 years (for each minute). The calculated solar angles indexed according to the time and downloaded to secure digital (SD) through the microcontroller based SD card read/write system. Solar angles for any given time can be retrieved by providing the time index to the look up table recorded in the SD card. 5 MB of space is required to store such a data set for one year. The performance of this system was evaluated by interfacing to a manual sun tracking system of a parabolic trough solar concentrator. It was found to be that the maximum variation of the focal line is 1.5 cm and it is within the full acceptance angle of 3.8 º.

Construction and Evaluation of a Drying Chamber Powered by Parabolic Trough Solar Concentrator

In Conferences - Full Text
Ruvinda, K. K. D. L., Suraweera, S. K. K., Jayaweera, H. H. E., Ranasinghe, O. K. & Ariyaratne, T. R.
27th technical sessions.Institute of Physics
Publication year: 2011

ABSTRACT:

This work reports a design and construction of a drying chamber powered by parabolic trough solar concentrator. The construc ted drying chamber is made of thin aluminum sheet material with two compartments; one is fo r installation of standby electrica l heaters and the other is for material pallet. The chamber is powered by a para bolic trough solar concen trator with aperture area of 5 m 2 . An electrical heater backup was employed to maintain the temperature inside the chamber at a given constant temperature when solar energy is not sufficient. The maximum variation of the temperature insi de the chamber along the length of the material pallet was found to be 8 °C when the chamber is powered by sola r concentrator. This va riation was 16 °C when the chamber is powered by electric heaters. Temper ature variation across the vertical direction is almost constant when the chamber is empty and a 10 % drop in temperature was observed over the material pallet relative to the other areas. The drying characteristics of samples of cabbage, boiled rice, scraped coconut, dry le aves and grass for different te mperatures obtained using the drying chamber are found to be fitted well with the page mode l and the corresponding drying constants at 80 °C are found to be 0.0197, 0.0139, 0.0319, 0.0296, 0.0564 respectively.

Vibration effects in vehicular road transportation

In Conferences - Full Text
Ranatunga, C. L., Jayaweera, H. H. E., Suraweera, S. K. K., Ruvinda, K. K. D. L., Wattage, S. C. & Ariyaratne, T. R.
26th technical sessions. Institute of Physics
Publication year: 2010

ABSTRACT:

This study focuses to certain elements of th e Road-Vehicle-Load system which are responsible for the inflicted damage to consignment during road transportation. Bruising injury depends on the energy absorbed by the cargo. Distribution of the power spectral density (PSD) was used as a measure of the vibration energy generated during transportation. “Poor” quality (IRI range 10 to 5) roads induce nearly four times severe damage than that induced by “fair” or “good” quality roads (IRI range 3.5 to 2 or, 2 to 0.9). PSD of the generated vibration is relatively higher in the critical frequency range below 10 Hz. In this frequency range, the rear side of the truck bed indicates nearly a 10 times higher PSD compared to that of the front side of the truck. A higher PSD distribution was also observed at tomatoes occupying higher layer levels in multi-layered tomato columns. Higher PSD levels were observed at very poor quality roads even at lower vehicle speeds. Fair quality roads also produced higher PSD levels, but when travelling at higher speeds. In case of stacked cargo boxes, an increase in PSD level was observed with stack height from the truck bed. Studies performed using the instrumented sphere reveals that, among the positions of multilayered items within the cargo box, the position of the topmost item registered highest PSD level. In addition, the top most item in multilayered cargo packages, has freedom to move and resulting damage can be even higher. The PSD generated by the truck has a good relationship to the quality of the road (judged by a panel in terms of PSR or IRI) and the speed of the truck.

Development of an online chess game emulator

In Conferences - Full Text
Kumara, D. M. D. D. P., Thiruparan, B., Jayaweera, H. H. E. & Lelwala, R.
26th technical sessions.Institute of Physics
Publication year: 2010

Kumara, D. M. D. D. P., Thiruparan, B., Jayaweera, H. H. E. & Lelwala, R., (2010) Development of an online chess game emulator. 26th technical sessions.Institute of Physics – Sri Lanka.

Thin-Layer Drying of Some Sri Lankan Paddy Varieties Under Low Humid Environment

In Conferences - Full Text
Shyamali, A. K., Jayaweera, H. H. E. & Ariyaratne, T. R.
25th technical sessions.Institute of Physics
Publication year: 2009

ABSTRACT:

Thin-layer drying characteristics of paddy were examined within the relative humidity range from 30% to 60%. A test chamber has been constructed with Perspex and continuously flushed with low humid air to control the inside relative humidly at required levels and several homogeneous thin layer paddy samples were dried inside the chamber. BG 300, BG 352 and BG 357 paddy varieties developed by Rice Research and Development Institute, Bathalegoda, Sri Lanka have been used in this study. Normalized drying data was transformed into dimensionless parameter called Moisture Ratio, and fitted with four semi-theore tical models. Correlation coefficients, standard errors and residual plots were used as criteria for evaluating the goodnes s-of-fit. Of the models used the two-term exponential model was found to fit well with the experimental data and is recommended as the thin-layer drying model for paddy.

Effect of measurement of non-destructive firmness on tomato quality and a comparison between non-destructive and destructive methods

In Conferences - Full Text
Ranatunga, C. L., Jayaweera, H. H. E., Suraweera, S. K. K. & Ariyaratne, T. R.
25th technical sessions. Institute of Physics
Publication year: 2009

ABSTRACT:

Almost all instrumental non-destructive (ND) type firmness test methods which involve a physical contact with the tomato when used for testing, deliver at least a minute damage to the fruit. The damage induced on a fruit was estimated when a so-called non-destructive firmness test was performed repeatedly on tomato fruit. The common method of firmness testing uses Magness-Taylor (MT) type firmness tester and in this destructive type test method, after having peeled, the tomato pulp is pierced with a probe. Qualitest (HPE-ll-FFF model) tester and the Bishop (FT 327 model) tester were used as ND and MT type firmness testers, respectively. Tomato variety “Rajitha” grown in Rathkinda area in Matale, during Maha season (Sept 2008) was subjected to this investigation. In a series of repeated ND type firmness test , a loss of firmness of 9.5 % was observed between the fi rst and the second measurement, regardless the ripeness level of tomato. At lower ripeness leve ls, tomato exhibited an exponential decay in percentage loss of firmness when subjected to repeated ND test, while red-ripe tomatoes demonstrated a slightly deviated behaviour. A study on the behaviour of MT vs. ND type firmness suggests a good linear relationship with a non-zero intercept. The relationship proposes a ND type firmness of 0.405 kg for a tomato which registers zero MT type firmness. Hence the contribution of the peel to th e ND type firmness would be 0.405 kg.

Development and evaluation of a calibration procedure for a 2D accelerometer as a tilt and vibration sensor

In Conferences - Full Text
Hewawasam, K., Jayaweera, H. H. E., Ranatunga, C. L. & Ariyaratne, T. R.,
25th technical sessions.Institute of Physics
Publication year: 2009

ABSTRACT:

Measuring tilt and vibration are two of the major applications of accelerometers. An experimental method to calibrate a commercially available 2D accelerometer (ADXL202JQC) as a tilt and a vibration measuring device is discus sed in this publication. Calibration of tilt measurements (measuring acceleration due to th e gravity – the static case) was done by rotating the accelerometer in a vertical plane. Also the effect of minor inclinations of the plane rotation of this experiment was investigated and observed to be minute. Based on the calibration for the static case, the accelerometer was tested in a dynamic case. A known type of motion; the motion of a tip of a cantilever, was us ed to test the calibration of the accelerometer for the dynamic case. Motion of the tip of a cant ilever was considered as a damping oscillation thus the variation of acceleration of the tip of the cantilever was considered a decaying sinusoidal. The measurements obtained through accelerometer agreed to this proposed model with R 2 values in the range of 0.93 to 0.98. The frequency of osc illation of the cantilever was varied by changing the length of the cantilever. The periods of oscillation obtained by the accelerometer agreed with the same values obtained from a stroboscope to maximum percentage deviation of approximately 3%.

Comparison of firmness of tomato varieties grown in Sri Lanka

In Conferences - Full Text
Ranatunga, C. L., Jayaweera, H. H. E. & Ariyaratne, T. R.
24th technical sessions.Institute of Physics
Publication year: 2008

ABSTRACT:

Firmnesses of farm fresh samples of three tomato (Lycopersicon esculentum) varieties grown in Sri Lanka, named, Maheshi, HF-2 and T-146 were studied. The firmness of the tomatoes was measured using Effegi type Bishop FT 327 firmness tester. Measurements were carried out for three consecutive days after plucking them from plants. Ever since tomatoes were harvested, the firmness was found to decrease daily. Throughout the three-day period of shelf life, all three varieties registered a higher firmness value for sun-shaded side than the corresponding firmness value for the sun-exposed side. Among the three tomato varieties, Maheshi at all times registered the highest firmness value while T-146 variety registered the lowest. Also the Maheshi variety indicated the lowest rate of loss-of-firmness with time. As a result, the first officially released hybrid tomato variety Maheshi stands out with its superior and promising quality over the other two varieties, throughout the handling process, storage and shelf life in marketing chain.(The firmness measurements were made on peeled-off tomatoes, with a plunger of diameter 11.3 mm).

Construction of telephone operable messaging system. 23rd technical sessions

In Conferences - Full Text
Jayaweera, H. H. E. & Lelwala, R.
23rd technical sessions.Institute of Physics
Publication year: 2007

ABSTRACT:

A password protected, dynam i c LCD (Liquid Crystal Display) m e ssaging board is developed to use with ordinary telephone is discussed in this publication. The device should be connected in parallel to a fixed- line telephone (called host telephone) and can be operated via host telephone itself or any other fixed-line or m obile telephone. After authentication, user can feed a m e ssage by using the built in standard m e ssage list or by typing each character via telephone keypa d. There are 9 standard m e ssages and a standard m e ssage can be extended up to 250 ch aracters and any of the ASCII characters can be used but only capital English letters, 0 to 9 and space are allowed when user feeding his own m e ssage through a telephone keypad.