Now showing 1 - 5 of 5
  • Publication
    Reduced Graphene Oxide UWB Array Sensor: High Performance for Brain Tumor Imaging and Detection
    A low cost, with high performance, reduced graphene oxide (RGO) Ultra-wide Band (UWB) array sensor is presented to be applied with a technique of confocal radar-based microwave imaging to recognize a tumor in a human brain. RGO is used to form its patches on a Taconic substrate. The sensor functioned in a range of 1.2 to 10.8 GHz under UWB frequency. The sensor demonstrates high gain of 5.2 to 14.5 dB, with the small size of 90 mm × 45 mm2, which can be easily integrated into microwave imaging systems and allow the best functionality. Moreover, the novel UWB RGO array sensor is established as a detector with a phantom of the human head. The layers’ structure represents liquid-imitating tissues that consist of skin, fat, skull, and brain. The sensor will scan nine different points to cover the whole one-sided head phantom to obtain equally distributed reflected signals under two different situations, namely the existence and absence of the tumor. In order to accurately detect the tumor by producing sharper and clearer microwave image, the Matrix Laboratory software is used to improve the microwave imaging algorithm (delay and sum) including summing the imaging algorithm and recording the scattering parameters. The existence of a tumor will produce images with an error that is lower than 2 cm.
  • Publication
    Effect of Nozzle Diameter on Temperature Behavior in Spray Dryer Via Computational Fluid Dynamics
    ( 2022-01-01)
    Mohammad Azrul Rizal Alias
    ;
    ; ; ;
    Yang L.W.
    ;
    Samat A.A.
    ;
    Raja Ibrahim R.M.Z.
    ;
    Shabri M.S.M.
    Spray dryer comes at the end of the processing line since it is a critical step in monitoring the quality of the final product. It has certain advantages such as rapid drying rates, a wide range of operating temperatures and short residence times. This research focuses on the effect of inlet air temperature in the spray dryer chamber. The result from previous studies has shown that the increment of the inlet air temperature has caused the dying rate to increase. From the simulation, we have identified the performance in the spray dryer with different inlet air temperature as the parameter. The higher the inlet air temperature, the less the number of incomplete particles inside the spray dryer chamber, the more the success of the drying particles. The most optimized condition of inlet air temperature inside the spray dryer chamber from different parameters was identified as 225 K after the analysis on the results of simulation data. The main impact of this study is to increase the efficiency of drying particles inside the spray dryer chamber via computational fluid dynamics. In conclusion, researchers should concentrate more on the feed inlet air temperature of spray drying for future analysis because it plays an important role that can influence the impact on droplet conversion.
  • Publication
    Influence of Nozzle Diameter Towards Velocity Distribution in Spray Dryer Via Computational Fluid Dynamics
    ( 2022-01-01)
    Mohammad Azrul Rizal Alias
    ;
    ; ; ;
    Yang L.W.
    ;
    Abdullah Abdul Samat
    ;
    Raja Ibrahim R.M.Z.
    ;
    Shabri M.S.M.
    Spray drying is commonly used in the chemical and food industries and is the preferred drying process for many materials, such as dairy products, foods, pharmaceuticals, polymers, etc. This research focuses on the effect of the nozzle diameter in the spray drying region against velocity distribution. The results from previous studies have shown that CFD can be a useful tool for predicting the pattern of gas flow and particle histories such as temperature, velocity, time of residence and place of effect. The predictions from these model were validated against reported experimental results, and other simulations. From the simulation analysis, the present studies have identified the performance in the spray dryer through with different size of spray nozzle diameter as the parameter. For the nozzle diameter part, the smaller the spray nozzle diameter, the higher the velocity of the droplets with beneficial to the thermal efficiency of drying particles. The statements finding from the simulation of nine different case study with different nozzle diameter found that the higher velocity has been identified in simulation results due to incomplete vaporize droplets. The main impact of this study is to identify the most optimized condition of the spray dryer chamber after the analysis of the results of simulation data. In conclusion, the design on the chamber has many potential ways to be developed and improved. These findings will benefit the designing of spray dryers.
      1  16
  • Publication
    Spray Drying Optimization for Rice Bran Protein (RBP) Powder Using Response Surface Methodology (RSM)
    Rice bran is a by-product of the rice milling process which contain a high concentration of protein. It’s are often used as a feed cattle, fertilizer, and fuel. Its application as a source of human nutrition is rare due to high lipid concentration. This lipid concentration can be reduced through the extraction process. After the extraction process, the rice bran extract needs to be converted into powder form through a drying process for the quality preservation. In this study, spray drying is utilized as drying technique. The aims of this study were to optimize the spray drying parameter; inlet temperature, feed flowrate and air flowrate for rice bran protein (RBP) powders production. Box Behnken Design (BBD) model in response surface methodology (RSM) are utilized in this study to maximize the RBP powder yield and protein concentration. Raw rice bran (RRB) was extracted using thermal water-based extraction method before the drying process. The optimum condition suggested by the model are at the inlet temperature of 120oC, feed flowrate of 18.38% and air flowrate of 670 L/hr which produced RBP powder yield of 19.42 g RBP/100g RRB and protein concentration of 17.32 mg/ml. The model obtains in this study show a low error between the predicted value and experimental data at 1.68 % and 1.14 % for RBP powder yield and protein concentration respectively. The model can be used to evaluate the process characteristic and understanding.
      2  9
  • Publication
    Pulsed UV Integrated Infrared Dryer System for Orthosiphon Stamineus Herb.
    The drying system is an important part for food and herbs preservation. Therefore, an effective drying system are needed to ensure the increase the shelf life of the food and herb without degrade its good nutrient and bioactive compound. In this study, Orthosiphon stamineus herb was used to dry using an Infrared dryer and combination of Pulsed UV light treatment + Infrared drying. Infrared drying involves transferring heat by radiation from a hot source to a lower-temperature substance that has to be heated or dried, meanwhile the pulsed UV light is a non-thermal treatment. The temperature of the heated element determines the peak wavelength of the radiation. The objective of this study is to design an infrared dryer system and analyze the quality of the dried herb. The Orthosiphon Stamineus have been dried using a 200W Infrared dryer system at 60°C. Total phenolic compounds and antioxidant capacity were determined using the Folin- Ciocalteu method and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay measured using a UV/VIS Spectrophotometer. A moisture analyzer was used to look at the changes in moisture content, and a colorimeter was used to look at the colour changes. The result showed that drying Orthosiphon stamineus by using an Infrared dryer and combination of Pulsed UV light treatment + Infrared drying under 60°C has significantly affected the herbal leaves quality in terms of moisture content, colour properties, Antioxidant capacity, and Total phenolic content.
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