Investigation of mirror-like surface finish in optical glass (BK7) lapping

Surface quality of optical glass is crucial for application in high precision products. This paper aim to investigate the surface roughness improvement and the limit surface roughness of the BK7 optical glass for mirror-like surface finish. Due to the brittleness of workpiece, lapping pressure need to be controlled diligently to prevent crack and brittle fracture from occurring. At first, the new lapping tool is installed on the collect chuck of the CNC milling machine and lapping is performed by the table movement in X and Y direction by NC control. Then, suitable lapping parameters are carefully selected for ductile mode machining in mirror-like finishing process. According to results, the mirror-like surface is achievd with proposed lapping method especially in low lapping pressure of 25MPa

Assessment of Global Geopotential Models for Modelling Malaysia Marine Geoid

The evaluation towards global geopotential models represents a significant part in modelling the localised Marine Geoid. The marine geoid provides the vertical reference information in Marine Spatial Data Infrastructures (MSDI) development response to United Nations Sustainable Development Goals 14 for the sustainable development in marine environment. The main purpose of this study is to select the best model from both combined missions and satellite-only missions for the Malaysian region. The gravity anomaly field from 30 global models were exclusively calculated over the selected study area within 11 years period-time. Afterwards, each dataset was extracted from the ICGEM server to evaluate with the airborne-derived gravity anomaly from the Department of Surveying and Mapping, Malaysia. The internal accuracy, root mean square error (RMSE) and differences between every model and airborne data were computed. The result indicates GGM-derived gravity anomaly for the best combined mission is GECO with RMSE of 8.44 mGal and the standard deviation value of 28.034 mGal. While, the model from Gravity field and steady state Ocean Circulation Explorer (GOCE) namely, the GO_CONS_GCF_2_DIR_R5 is the best for the satellite-only mission with RMSE of 17.43 mGal and the standard deviation value of 22.828 mGal. As a conclusion, GECO model is preferred as the best fit for determining the marine geoid as it has the lowest RMSE value between both mission and the maximum degree of 2109o coverage. The finding can assist in development of marine geoid for modelling precise surface elevation

Assessment of Global Geopotential Models for Modelling Malaysia Marine Geoid

The evaluation towards global geopotential models represents a significant part in modelling the localised Marine Geoid. The marine geoid provides the vertical reference information in Marine Spatial Data Infrastructures (MSDI) development response to United Nations Sustainable Development Goals 14 for the sustainable development in marine environment. The main purpose of this study is to select the best model from both combined missions and satellite-only missions for the Malaysian region. The gravity anomaly field from 30 global models were exclusively calculated over the selected study area within 11 years period-time. Afterwards, each dataset was extracted from the ICGEM server to evaluate with the airborne-derived gravity anomaly from the Department of Surveying and Mapping, Malaysia. The internal accuracy, root mean square error (RMSE) and differences between every model and airborne data were computed. The result indicates GGM-derived gravity anomaly for the best combined mission is GECO with RMSE of 8.44 mGal and the standard deviation value of 28.034 mGal. While, the model from Gravity field and steady state Ocean Circulation Explorer (GOCE) namely, the GO_CONS_GCF_2_DIR_R5 is the best for the satellite-only mission with RMSE of 17.43 mGal and the standard deviation value of 22.828 mGal. As a conclusion, GECO model is preferred as the best fit for determining the marine geoid as it has the lowest RMSE value between both mission and the maximum degree of 2109o coverage. The finding can assist in development of marine geoid for modelling precise surface elevation

Effect of Torrefaction Process on Crystallinity Index Properties of Empty Fruit Bunch’s Biochar

The effect of torrefaction process on crystallinity index (CrI) properties from biomass material which is empty fruit bunch’s biochar had been identified in this study. There are three major torrefaction parameters for biomass material which is particle size, holding temperature and residence time was determined. The investigation on the empty fruit bunch’s biochar had been done by X-ray diffraction (XRD). There was decreasing pattern for CrI occurred as the holding temperature increased from 200 to 300°C and residence time increased from 30 to 90 minutes, but there are no significant affected by the particle size parameter. This shows that the empty fruit bunch’s biochar cellulose crystallinity is reduced as the cellulose become completely amorphous

Effects of Torrefaction Process on Chemical Properties of Small Diameter Acacia mangium Wood

Torrefaction refers to a thermal process that involves the processing of biomass in a torrefied to produce a "charred" product that can be utilised as a fuel or as a soil amendment. People need energy sources to meet their basic needs and live the kind of life they want. Acacia mangium was selected in order to produce biochar and determine the lignocellulosic affected by the holding temperature and residence time. The chemical properties of torrefied Acacia mangium biochar were investigated at different holding temperatures and residence times. Torrefaction were carried out at several process temperatures, ranging from 200 to 300°C, with residence time ranging from 30 to 90 minutes. According to the findings, the effects of holding temperature and residence time on the chemical properties of torrefied Acacia mangium biochar was carried out. The results show that the chemical properties decreased with an increase in both the holding temperature and residence time except for the lignin percentage content. It shows that as the holding temperature and residence time increased, the lignin content increased. The results shows that the chemical properties are decreased, except for the lignin content, which is not affected by the factors. The chemical bond in lignin content is hard for breaking down. Hence, torrefaction is accountable for the decrease of chemical properties and the breaking of chemical bonds in chemical properties

Assessment of inspiration and expiration time using infrared thermal imaging modality

Breathing is one of the important vital signs assessed by healthcare practitioner for patient monitoring and disease management. There are several methods used to evaluate breathing activities such as respiratory inductive plethysmography, impedance pneumography, bioacoustics method, spirometry and manual assessment. Most of these devices require external attachment on patient such as belt, electrodes and sensor which could be inconvenient if used over a long period of time. Infrared Thermal Imaging (ITI) is a contactless device that detects temperature changes which can be used to assess breathing since hot air particles are being released to surrounding through nose which create temperature variance during breathing. Majority of studies conducted on breathing function were focused on respiratory rate. Therefore, this study assessed the timing of inspiration (TI) and expiration (TE) in three different breathing patterns which are normal, prolonged expiration and rapid breathing by using Infrared Thermal Imaging (ITI). A total of thirty-three subjects were required to simulate various breathing patterns by using a video-guided method. The assessment of TI and TE was recorded using ITI and Respiratory Inductive Plethysmograph (RIP) simultaneously. Results obtained from the ITI images show consistent deflections on the plotted graph which reflect the transition point of inspiration and expiration. This transition point allowed us to measure the TI and TE between ITI and RIP. Our analysis shows that there are no significant differences of the reading obtained between ITI and RIP in TI and TE. Correlation analysis also shows that there was positive correlation between measurement obtained by ITI and RIP. These findings suggest that ITI technique could be used as an alternative method to assess breathing dynamics

Development of automated parallel parking system in small mobile vehicle

Collisions can happen during reversing or parking the car especially in the limited space. Since many drivers acknowledge that parallel parking is a very tedious task. This research aims to develop the parallel parking system by developing small mobile vehicle as a model. Design of prototype vehicle is considered for the real-life parallel parking. Hence, it can detect a parking space, execute the parking maneuver, avoid hitting the front, rear obstacles and reduce the time for parking. The parking maneuver is simplified by choosing the optimum turning angle for both the first and second parts of the parking maneuvers. At the first stage, ultrasonic sensors sense the parking environment and if the space is sufficient, a safe parking maneuver is generated. In second stage, positioning phase, the mobile vehicle will execute reverse motion into the parking space without any collisions. The last stage, it moves to the correct parking position in the parking space while adjusting itself to a safe distance from front and rear obstacles respectively. It is discovered from the result that developed system required just 1.33 times longer parking space than vehicle overall length. Small mobile vehicles successfully able to manage the parallel park itself without hitting or touching front and rear obstacles

Source camera identification: a distributed computing approach using Hadoop

Abstract The widespread use of digital images has led to a new challenge in digital image forensics. These images can be used in court as evidence of criminal cases. However, digital images are easily manipulated which brings up the need of a method to verify the authenticity of the image. One of the methods is by identifying the source camera. In spite of that, it takes a large amount of time to be completed by using traditional desktop computers. To tackle the problem, we aim to increase the performance of the process by implementing it in a distributed computing environment. We evaluate the camera identification process using conditional probability features and Apache Hadoop. The evaluation process used 6000 images from six different mobile phones of the different models and classified them using Apache Mahout, a scalable machine learning tool which runs on Hadoop. We ran the source camera identification process in a cluster of up to 19 computing nodes. The experimental results demonstrate exponential decrease in processing times and slight decrease in accuracies as the processes are distributed across the cluster. Our prediction accuracies are recorded between 85 to 95% across varying number of mappers

Effect of short-term ketogenic diet on end-tidal carbon dioxide

Background & aims: Previous studies have shown that end-tidal carbon dioxide (EtCO2) is lower with the presence of supraphysiological ketones as in the case of chronic ketogenic diet (KD) and diabetic ketoacidosis (DKA). This study aimed to determine changes in EtCO2 upon short term KD. Methods: Healthy subjects were screened not to have conditions that exerts abnormal EtCO2 nor contraindicated for KD. Subjects underwent seven days of KD while the EtCO2 and blood ketone (beta-hydroxybutyrate; ß-OHB) parameters were sampled at day zero (t0) and seven (t7) of ketosis respectively. Statistically, the t-test and Pearson's coefficient were conducted to determine the changes and correlation of both parameters. Results: 12 subjects completed the study. The mean score ± standard deviation (SD) for EtCO2 were 35.08 ± 3.53 and 35.67 ± 3.31 mm Hg for t0 and t7 respectively. The mean score ±SD for ß-OHB were 0.07 ± 0.08 and 0.87 ± 0.84 mmol/L for t0 and t7 respectively. There was no significant difference of EtCO2 between the period of study (p > 0.05) but the ß-OHB increased during t7 (p < 0.05). There was also no correlation between the parameters. Conclusions: These findings suggest that EtCO2 may not be utilized to determine short term nutritional ketosis

Study of drug resistance-associated genetic mutations, and phylo-genetic analysis of HCV in the Province of Sindh, Pakistan

Abstract Current management of HCV infection is based on Direct-Acting Antiviral Drugs (DAAs). However, resistance-associated mutations, especially in the NS3 and NS5B regions are gradually decreasing the efficacy of DAAs. The aim of the current study was to identify such mutations in the NS3, and NS5B genes in DAAs treatment-naïve Pakistani chronic HCV 3a patients. Peripheral blood samples were collected from 233 chronic HCV 3a patients at different tertiary care hospitals in Karachi, Pakistan, between August 2020 to September 2021. PCR-amplified target regions of the NS3/NS5B gene were subjected to Sanger sequencing to identify resistance-associated mutations. Phylogenetic analysis of the identified amino acid sequences was performed using HCV3a sequences of the global population in the virus pathogen resource (VIPR) database. Sequence analysis identified five amino acid mutations, Leu36Pro, Gln41His, Gln80Lys/Arg, Ala156Tyr, and Gln168Arg in the NS3 region, and two mutations Leu159Phe and Cys316Arg in the NS5B region. Phylogenetic analysis revealed a high genetic diversity in the studied isolates. Overall, the prevalence of resistance-associated substitutions was almost similar to other geographic regions worldwide. This data could be helpful in selecting the most effective treatment regimen for HCV chronically infected people in Pakistan