3D model for indoor spaces using depth sensor

In recent years, 3D model for indoor spaces have become highly demanded in the development of technology. Many approaches to 3D visualisation and modelling especially for indoor environment was developed such as laser scanner, photogrammetry, computer vision, image and many more. However, most of the technique relies on the experience of the operator to get the best result. Besides that, the equipment is quite expensive and time-consuming in terms of processing. This paper focuses on the data acquisition and visualisation of a 3D model for an indoor space by using a depth sensor. In this study, EyesMap3D Pro by Ecapture is used to collect 3D data of the indoor spaces. The EyesMap3D Pro depth sensor is able to generate 3D point clouds in high speed and high mobility due to the portability and light weight of the device. However, more attention must be paid on data acquisition, data processing, visualizing, and evaluation of the depth sensor data. Hence, this paper will discuss the data processing from extracting features from 3D point clouds to 3D indoor models. Afterwards, the evaluation on the 3D models is made to ensure the suitability in indoor model and indoor mapping application. In this study, the 3D model was exported to 3D GIS-ready format for displaying and storing more information of the indoor spaces

Study of alcohol fuel of butanol and ethanol effect on the compression ignition (CI) engine performance, combustion and emission characteristic

Diesel engine which is one of the larger contributors to total consumption for petroleum is an attractive power unit used widely in many fields. However, diesel engines are among the main contributors to air pollutions for the large amount of emissions, such as CO, CO2 and NOx lead to an adverse effect on human health. Many researches have been done to find alternative fuels that are clean and efficient. Biodiesel is preferred as an alternative source for diesel engine which produces lower emission of pollutants. This study has focused on the evaluation of diesel and alcohol-diesel fuel properties and also the performance, combustion and exhaust emission from diesel engine fuelled with diesel and alcohol. Butanol and ethanol is blend with diesel fuel at 1:9 ratio. There are three test fuel that is tested which Diesel (100% diesel), D90BU10 (10% Butanol and 90% diesel) and D90E10 (10% Ethanol and 90% diesel). The comparison between diesel and alcohol-diesel blend has been made in terms of fuel properties characterization, engine performance such as brake power (BP) and brake specific fuel consumption (BSFC) also the in cylinder maximum pressure characteristic. Thus, exhaust gas emission of CO, CO2, NOx and O2 emission also has been observed at constant load of 50% but in different operating engine speed (1100 rpm, 1400 rpm, 1700 rpm, 2000 rpm and 2300 rpm). The results show the addition of 10% of each butanol and ethanol to diesel fuel had decreased the fuel density about 0.3% to 0.5% compared to mineral diesel. In addition, viscosity and energy content are also decrease. The addition of 10% butanol had improved the fuel cetane number however the ethanol blends react differently. In term of engine performance, as the engine speed increased, BP output also increase respectively. Hence, the alcohol blends fuel generates lower BP compared to diesel, plus BSFC for all test fuel shows decreasing trend at low and medium speed, however increased gradually at higher engine speed. Thus, D90BU10 had higher BSFC compared to mineral diesel and D90E10. In general, the addition of alcohol blend in diesel fuel had increase the BSFC. In term of in cylinder pressure, as the engine speed is increased, the crank angle noted to move away from TDC for all test fuel. The maximum cylinder pressure increased at low and medium speed, but decrease in higher engine speed. The addition of 10% of butanol and ethanol in the mineral diesel decreased the maximum cylinder pressure. Meanwhile, O2 emission of D90E10 is higher compared to D90BU10 due to higher oxygen content found in ethanol. The CO2 emission of D90BU10 recorded higher compared to mineral diesel due to the high oxygen contents in the alcohol. CO emission of alcohol blend on the other hand had lower emission at higher engine speed compared to mineral diesel. As engine speed is increased, NOx emission of mineral diesel and D90E10 had decreased gradually. However, D90BU10 had increased of NOx emission at lower to medium engine speed, than gradually decreased at higher engine speed

Effects of logging activities on ecological water quality indicators in the Berasau River, Johor, Malaysia

Influence of deforestation on biodiversity of aquatic organisms was investigated in a stream in the Ulu Sedili Forest Reserve. The stream was monitored five (5) times from December 2011 until December 2012 with 2-month intervals. Sampling of benthic communities was carried out using rectangular dip net while water quality study using a YSI ProPlus meter and the rest were done in the laboratory. Physicochemical parameters and water quality index (WQI) calculation showed no significant difference among the investigated events. WQI classified the Berasau River between Class II (good) to III (moderate) of river water quality. In total, 603 individuals representing 25 taxa that were recorded with Decapods from genus Macrobrabchium were widely distributed. Several intolerant taxa, especially Ephemeroptera and Odonata, were also observed in this river. According to Pearson's correlation analysis, the richness and diversity indices were generally influenced by water quality parameters represented by WQI (P < 0.01). In conclusion, logging activities have strong attributes for variation in benthic macroinvertebrate assemblage

Nitrate pollution in groundwater: a cross-sectional study in three villages in Bachok District, Kelantan, Malaysia during the paddy pre-planting season

Nitrate fertilizer is extensively used to produce healthy crops on a wide scale, and paddy planting is no exception. Nitrate that is not used by plants is able to penetrate the soil and end up in groundwater. This, if not checked, can give rise to health problems including infant methemoglobinaemia, a disease where hemoglobin in erythrocytes are changed into methemoglobin by nitrite which, in turn, makes it unable to transport oxygen to body cells. Nitrite is formed from ingested nitrate that is altered by bacteria present in the infant’s stomach. This cross-sectional study was conducted in February 2019 for 2 weeks’ observation during the paddy pre-planting season, and a total of 149 wells across three villages were sampled for nitrate. Readings were compared to the Drinking Water Quality Standard stated by the Ministry of Health, Malaysia. The maximum acceptable value for nitrate in drinking water is 45 mg/L nitrate (NO3-). The three villages, namely Keting, Kuchelong and Telaga Ara, were chosen as they are located near paddy fields and water from wells were used for drinking and cooking without filtration. It was found that only one (0.67%) of the wells had nitrate above the maximum acceptable value (56.85 mg/L NO3-). This highest value was found in Telaga Ara village and the location of the well was 50m from the nearest paddy fields. In Kuchelong village, the mean nitrate level was 5.10 +0.85 mg/L with a range of 0.73 to 27.10 mg/L. While in Telaga Ara village, the mean nitrate levels was 10.52 +1. 24 mg/L with a range of 1.67 to 56.85 mg/L. Mean nitrate level in Keting village was 5.34 + 4.94 mg/L with a range of 0.40 -23.65 mg/L. In general, nitrate levels were found to be below the maximum acceptable value in the villages concerned and therefore did not pose any health risks to users. Periodic assessment of nitrate in groundwater is still important as to ensure the levels remain below the acceptable value, and in turn, safeguard the health of its users

Tunable passively Q-switched ultranarrow linewidth erbium-doped fiber laser

A tunable passively Q-switched erbium-doped fiber laser with ultranarrow linewidth is proposed and demonstrated. With the single wall carbon nanotubes (SWCNTs) as the passive Q-switch, the ultranarrow linewidth laser operation is realized based on spectral filtering effect. using an ultranarrow tunable bandpass filter (UNTBF). The Q-switched laser spectrum is tunable from 1525 to 1561 nm, covering a wavelength range of 36 nm. At 1545 nm, the highest repetition rate of ~38 kHz and the lowest pulse width of 1.15 μs are obtained, with the corresponding pulse energy of approximately 0.18 nJ. The linewidth measurement using self-heterodyne technique yields a linewidth value of 17.5 kHz, which may be the narrowest linewidth for a Q-switched fiber laser to the best of our knowledge