117 research outputs found

    Isolation and characterization of polyhydroxyalkanoates (PHAS) producing bacteria from brackish stream

    Get PDF
    Polyhydroxyalkanoates (PHAs) are biopolymers which have similar characteristics with petrochemical plastics but a step better due to its biodegradable property. A total of 23 strains were isolated from two different brackish sources. In order to detect the PHAs granules, the PHAs producing bacteria were first screened with Sudan Black B staining. Twenty strains were observed with lipid granules and were subjected to further confirmation with Nile blue staining. From the Nile blue staining, only 10 strains have the ability in producing PHAs and 2 were identified as strong PHAs producers. This study focuses on the 2 strains named S1 and L1. Further identification procedure was carried out and found that strain S1 and L1 belongs to Pseudomonas sp. L1 strain was found to be promising for PHAs production since it accumulated PHAs for about 88.3%. The PHAs produced by this strain was analyzed using Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) analysis and was identified as poly-3-hydroxybutyrate (P-3HB)

    A study of frequency and pulses for stepper motor controller system by using programmable logic controller

    Get PDF
    The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load

    Properties of resin impregnated oil palm wood (Elaeis Guineensis Jack)

    Get PDF
    Oil palm wood (OPW) was treated with medium-molecular weight PF resin (mmw-PF) through a modified impregnation-compression method. The method consists of four steps, namely, drying, impregnation, heating, and hot pressing densification. The objective of the study was to optimize the impregnation variables. The overall density of the OPW increased, whereas the density gradient between the two OPW structural elements (namely, parenchyma tissues and vascular bundles) decreased. The weight percent gain (WPG) significantly increased even with a very short impregnation period (i.e. 1 hour). Young`s Modulus of the compression parallel to the grain increased by 15 times (from 170 to 2600 MPa) and the shear strength increased by 7 times (from 1.9 to 13 MPa). The strength of the samples was increased exponentially against density increment. The treatment also made the two OPW structural elements to be strongly bonded that helped in enhancing the durability and machining characteristics of the material

    Development of cooling necklace system using vortex tube

    Get PDF
    A vortex tube is an intriguing, simple system capable of producing cold and hot streams at room temperature from a single compressed fluid supply. It is commonly used as a cooling system in many industrial applications because of its remarkable cooling capability and simplicity with no moving parts. This vortex tube does not need any refrigerants or chemical fluids to function as intended as a cooling device. The usage of the vortex tube as a cooling device that has been implemented in a cooling necklace has less to no substantial research data. Therefore, it is hard to determine the best possible outcome that could be achieved by integrating the vortex tube with a cooling necklace. Thus, the main objectives for this research are to determine the performance of vortex tube as a cooling device on a cooling jacket at different cold mass fraction and also to determine the performance of vortex tube as a cooling device on a cooling jacket at different inlet pressure. In this particular research, an experimental study was conducted in two different situational environments, one in a controlled environment which is indoors while the other is outdoors with direct sunlight to simulate real-life situations where the cooling necklace might be used. It can be concluded that cold mass fraction of 0.4 and the highest inlet pressure of 0.4 MPa are the optimum values to obtain the lowest temperature inside of the cooling jacket

    CO2 reforming of CH4 over Ni/SBA-15: Influence of Ni-loading methods

    Get PDF
    A series of Ni/SBA-15 catalysts were prepared with three different methods which are impregnation (IM), ion exchange (IE) and physical mixing (PM) for CO2 reforming of CH4. The XRD, BET, FTIR and TGA analyses showed that the quantity of Ni-support interaction (Ni-O-Si) by substitution of the OH with Ni species followed the order of Ni/SBA-15(IE) > Ni/SBA-15(IM) > Ni/SBA-15(PM), while the size of Ni particles and blockage of the pores increased with the order of Ni/SBA-15(IE) Ni/SBA-15(PM), while the stability of catalysts followed the order of Ni/SBA-15(IE) > Ni/SBA-15(IM) > Ni/SBA-15(PM). The excellent performance of Ni/SBA-15(IE) was related with the higher formation of Ni-support interaction, which altered the properties of catalyst towards an excellent catalytic performance. Meanwhile, the lowest activity of Ni/SBA-15(PM) was related with the higher agglomeration of Ni particles that were decorating on the surface part of SBA-15 arose from the weaker Ni-support interaction. This study provides new perspectives on the Ni-based catalyst, particularly on the influence of Ni-loading methods on the properties and catalytic performance of Ni/SBA-15 towards CO2 reforming of CH4

    Bioinformatics in Malaysia: Hope, Initiative, Effort, Reality, and Challenges

    Get PDF
    The published articles in PLoS Computational Biology on the development of computational biology research in Mexico, Brazil, Cuba, Costa Rica, and Thailand have inspired us to report on the development of bioinformatics activities in Malaysia. Rapid progress in molecular biology research and biotechnology in Malaysia has created sufficient demand for bioinformatics in Malaysia. Although bioinformatics in Malaysia started in the early 1990s, the initial focus on the development of the biotechnology industry has curtailed the early gains and overshadowed the systematic development of bioinformatics in Malaysia, which currently lacks in human capital development, research, and commercialization. However, government initiatives have been devised to develop the necessary national bioinformatics network and human resource development programs and to provide the necessary infrastructure, connectivity, and resources for bioinformatics. Stakeholders are experiencing reorientation and consolidating existing strengths to align with the global trends in bioinformatics. This exercise is expected to reinvigorate the bioinformatics industry in Malaysia. Tapping into niche expertise and resources such as biodiversity and coupling it with the existing biotechnology infrastructure will help to create sustainable development momentum for the future. An initiative arose from several senior scientists across local universities in Malaysia to promote this new scientific discipline in the country

    Pilot Proof of Concept Clinical Trials of Stochastic Targeted (STAR) Glycemic Control

    Get PDF
    (open access)Introduction: Tight glycemic control (TGC) has shown benefits but has been difficult to achieve consistently. STAR (Stochastic TARgeted) is a flexible, model-based TGC approach directly accounting for intra- and inter- patient variability with a stochastically derived maximum 5% risk of blood glucose (BG) < 4.0 mmol/L. This research assesses the safety, efficacy, and clinical burden of a STAR TGC controller modulating both insulin and nutrition inputs in pilot trials. Methods: Seven patients covering 660 hours. Insulin and nutrition interventions are given 1-3 hourly as chosen by the nurse to allow them to manage workload. Interventions are calculated by using clinically validated computer models of human metabolism and its variability in critical illness to maximize the overlap of the model-predicted (5-95th percentile) range of BG outcomes with the 4.0-6.5 mmol/L band while ensuring a maximum 5% risk of BG < 4.0 mmol/L. Carbohydrate intake (all sources) was selected to maximize intake up to 100% of SCCM/ACCP goal (25 kg/kcal/h). Maximum insulin doses and dose changes were limited for safety. Measurements were made with glucometers. Results are compared to those for the SPRINT study, which reduced mortality 25-40% for length of stay ≥3 days. Written informed consent was obtained for all patients, and approval was granted by the NZ Upper South A Regional Ethics Committee. Results: A total of 402 measurements were taken over 660 hours (~14/day), because nurses showed a preference for 2-hourly measurements. Median [interquartile range, (IQR)] cohort BG was 5.9 mmol/L [5.2-6.8]. Overall, 63.2%, 75.9%, and 89.8% of measurements were in the 4.0-6.5, 4.0-7.0, and 4.0-8.0 mmol/L bands. There were no hypoglycemic events (BG < 2.2 mmol/L), and the minimum BG was 3.5 mmol/L with 4.5% < 4.4 mmol/L. Per patient, the median [IQR] hours of TGC was 92 h [29-113] using 53 [19-62] measurements (median, ~13/day). Median [IQR] results: BG, 5.9 mmol/L [5.8-6.3]; carbohydrate nutrition, 6.8 g/h [5.5-8.7] (~70% goal feed median); insulin, 2.5 U/h [0.1-5.1]. All patients achieved BG < 6.1 mmol/L. These results match or exceed SPRINT and clinical workload is reduced more than 20%. Conclusions: STAR TGC modulating insulin and nutrition inputs provided very tight control with minimal variability by managing intra- and inter- patient variability. Performance and safety exceed that of SPRINT, which reduced mortality and cost in the Christchurch ICU. The use of glucometers did not appear to impact the quality of TGC. Finally, clinical workload was self-managed and reduced 20% compared with SPRINT

    Development of Ground Penetrating Radar Hybrid System Using Vivaldi Antenna for Buried Object Detection

    Get PDF
    Ground penetrating radar (GPR) is categorized based on the number of antenna and modulation technique used for buried object detection. GPR systems that were often studied are the GPR of amplitude modulation and GPR of frequency modulation. Based on these two types of GPR system, the GPR of frequency modulation which is known as Stepped Frequency Continuous Wave (SFCW) is easy to be developed using only antenna and vector network analyzer (VNA). This study combined the Pulse modulation and SFCW GPR to form the GPR Hybrid. The combination was made in order to develop Pulse modulation GPR system of amplitude modulation GPR type using VNA. Discussion on this developed Hybrid GPR using the CST studio Suite 2014 software, included the design of a GPR antenna called the Vivaldi antenna of patch types, the design on simulation system of GPR Hybrid system, and the implementation of GPR Hybrid system using vector network analyzer. After the validation process, the developed GPR Hybrid system equipment was able to successfully detect a metal object that was buried in a wooden chamber containing dry sand

    Malaysian politicians’ connection pattern on twitter using sna: a case of Najib Razak

    Get PDF
    Najib Razak is one of the most prominent politicians in Malaysia whose popularity has risen worldwide over the years due to his political sharp-witted strategy and various political scandals. He is also identified as one of the most followed Malaysian politicians on social media, especially Twitter. Hence, this study aims to apply Social Network Analysis (SNA) to further examine the interactions between Twitter users and the relationship formed with Najib Razak. A complete network of Najib Razak's Twitter account is used to study the connection pattern, influence, and groups developed between account users in the network. Netlytic is used to extract the data on Twitter, and based on the extracted dataset, it is discovered that 1004 nodes that represent Twitter users, follows and mentions the @najibrazak Twitter account. The dataset was further analyzed using R to explore the interaction and the connection patterns were visualized using Gephi. Based on the findings, the connectivity, centrality and clustering of the top 10 most influential Twitter users that contribute to the discussion and mention of Najib Razak on Twitter were determined. The previous work using Najib Razak's twitter account focused on finding the relations between public and politicians by analyzing the issues discussed through language processing at topical and lexical level. Unlike the previous achievement, the results from this proposed SNA technique can be further analyzed to gather greater insights on the hidden relationship built between politicians to strengthen their position and distinguish their possible future followers for further investigations

    Physical and morphological properties of nanoclay in low molecular weight phenol formaldehyde resin by ultrasonication

    Get PDF
    The aim of the present study was to examine the characteristics and physical properties of a low molecular weight phenol formaldehyde resin (LmwPF, mw approximately 600) and modified nanoclay admixture. LmwPF resins (45% w/v) were combined separately with 0.5%, 1.0% and 1.5% w/w montmorillonite nanoclay nanomer (based on solid PF). Each of the solutions was ultrasonicated in a sonifier. The dispersion of nanoclay in LmwPF was examined using X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM). It was found that ultrasonication in a sonifier at 50 kHz for 60 min was able to disperse modified nanoclay up to 1.5% into the resin. XRD and TEM analyses showed that the nanoclay dispersion in the resin were either intercalated or exfoliated. The results also showed that the presence of nanoclay in the admixture significantly increased non-volatile content and reduced gelation time and pH values
    corecore