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Abstract

This paper is about comparing the effectiveness of the sorbent materials of granulated activated carbon in removing of bromates from drinking water. The limit value (10 µgl−1) of bromates in the drinking water was stated by World Health Organization. In order to insure the reduced concentration of bromates in the drinking water, an experiment was performed using the batch test. In this experiment different types of sorbent materials with different properties were testing. Based on batch test were measured the parameters like the immediate adsorption capacity, the adsorption efficiency, and the concentration of bromates after the adsorption were measured at the evaluated time.

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The aim of this publication is to show the process of computer aided designing of the spur gear pairs having normal and modified straight teeth. For designing, the determination of the geometrical parameters is needed. Computer programs have been developed with which gear pairs having normal and modified teeth, with any arbitrary parameters can be analysed, designed and modelled. With these programs gear pairs having concrete geometry have been designed and CAD models have also been drawn to have further meshing, geometrical and TCA (Tooth Contact Analysis).

Open access
COMSeg technique for MRI knee cartilage segmentation

Segmentation is one of important methods in medical images processing, particularly as it allows images to be analysed. The method used for segmentation depends on the image problem to be resolved. In this research, knee cartilage needs to be segmented to determine the level of the Osteoarthritis (OA) and for further treatment. Knee cartilage is a soft hyline sponge that is located at the end of the femur, tibia and patella bone to release friction during movement. OA is a knee cartilage problem wherein there is a thinning of the cartilage that results in a shift especially happening between femur and tibia bone causing discomfort and pain. Thinning of the knee cartilage is due to many factors such as age, body weight, genetic, accident, sport injury and extreme use such as physical work. OA can occur to a male or female, child or adult. The effects experienced by patients with OA are such as difficulty to walk, limited movement, and pain in the thin cartilage areas. Monitoring of patients' condition needs to be done to help reduce the problem and thereby enable specialists to perform the appropriate treatment. Imaging is a method used today to monitor the condition of patients with OA. Previous studies showed that MRI is a suitable method for monitoring the condition of patients with OA because of its advantages in visualising knee cartilage more clearly than other imaging methods. Thus, for segmenting the knee cartilage which as mentioned before is an important process in medical images processing, the MR images were selected based on many factors. Segmentation in this study was aimed to obtain the cartilage region to diagnose patient OA level. Various segmentation techniques have been developed by researchers in segmenting the knee cartilage region but they have been unable to segment precisely due to the thin structure of the knee cartilage, especially for patients with intermediate and severe OA. COMSeg technique was developed to segment knee cartilage, especially for those experiencing a normal and intermediate OA and try to implement it to severe OA. The development of this new technique takes into account the imaging method used, the images feature obtained so it can be suitable to process knee image and then selection of an appropriate technique to be applied to the selected images as input.

Open access

Cooling rates of meteoritic iron–nickel alloys were estimated using a processing of morphological features of their structure. All data have been acquired with optical and scanning electron microscopy. Two types of cooling rates were obtained. Slow cooling during the formation of the meteoroid parent body determined the first type. The second type is a result of melt crystallization after a shock event.

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Abstract

Human beings live in a complex and magical system of nature. The constitution of everything is like the structure science of architecture, which presents various forms and combinations. The development of structure science makes modern architecture show the high unity of internal structure and external contour. Through the study of branch networks formed by rivers, the mystery of branch growth can be found, for instance fractal self-similarity, preferential growth at the tops, avoidance of homogeneity, etc. Based on the understanding of branch ecosystem, everyone can try to build a sustainable surface structure by mimicking the laws of river network.

Open access

A new method for preparing multi-layered graphene oxide powder was developed. In this method, the raw material was commercially available micro-sized graphite powder. The graphite powder was milled using a high speed attritor mill to reduce the particle size of the graphite to nanometer and to exfoliate the graphite into multi-layered graphene particles. The graphene particles were then oxidized into graphene oxide (GO) using the combination of strong oxidizing agents, thermal oxidizing, and sonication. Thorough morphological characterizations have been carried out to reveal the structure and the size of GO particles. The results confirmed that the oxidation process was successful.

Open access

Every year the library of IIUM subscribes to quite a number of online databases with huge expenses but the utilization of these databases is countable. 10 out of 53 subscriptions have been terminated by 2015 to save the cost go in vain. The purpose of this paper is to develop a model based on the ISB elements to identify the reason behind this low usage and to increase the usage of online databases in the future. It has undertaken a quantitative approach to identify the elements of ISB among undergraduate (UG) students. The primary data has been collected through questionnaires based on the variables identified in the objective. There are 118 samples participating in this research and the proposed model has been adapted from Savolainen and Wilson. Psychological perception, searching strategies and the information resources have been considered as the independent variable and measured the usage of the online database among UG students as the dependent variable. The results have shown that there are seven elements which have an influence on the usage of the online database among IIUM UG students. Despite the limited number of samples and a specific group of students, the proposed model can enhance the usage of online database system subscribed to by IIUM library and a search engine can be developed to get the usage increased. In that sense, it is recommended to involve more participants from the different levels of students and users to get diverse elements of ISB. However, the paper contributes to bridging the gap between the online database usage and the users, believed to have an effective outcome for online database subscription. It is hoped that the proposed model would significantly fill this gap and help the library to increase the number of users for their expensive databases.

Open access

This study was conducted to evaluate the effect of bioactive compounds (BACs): linalool (LIN) and piperine (PIP) on chicken meat characteristics. The meat was treated with 500, 1000 ppm of BACs, vacuum packaged and stored at 4 °C for 8 days. Physicochemical characteristics, lipid oxidation (thiobarbituric acid reactive substances, TBARS), microbiological status, and sensorial (electronic-nose based) properties were investigated. Both BACs significantly increased the redness (a*) and chroma (C*) values in meat compared to increased lightness (L*) and higher TBARS in control. Although both BACs showed overlapping aroma profile, the E-nose was able to distinguish between the different meat groups. LIN with various dilution ratios, particularly 1:10 (v:v), showed in vitro growth inhibition against Escherichia coli, Staphylococcus aureus, Salmonella Typhimurium, and Bacillus cereus, concomitantly Listeria monocytogenes required 1:80 (v:v) to be inhibited, and no inhibition was detected for Pseudomonas lundensis. In contrast, PIP at different dilutions did not exhibit inhibitory activity. Regarding aerobic mesophilic counts (AMC), less than 7 log CFU g−1 were recorded except for control showing higher log. Both BACs have potential to improve quality characteristics and increase the shelf life of meat and meat products.

Open access

The technique of electrospinning has been researched for several decades. Almost all parameters have been investigated in the past years, e.g., solution parameters, process parameters, and environmental conditions. Among the solution parameters, the viscosity of the polymer solution is an extremely important factor for fiber formation and morphology. In general, however, viscosity of the polymer solution is mostly controlled by the solution concentration or by the molecular weight of the polymer in electrospinning field. Herein, we described the reason of a well-known but not completely explained conclusion that the needle diameter can have an influence on the fiber morphology. In this study, polyethylene-oxide (PEO) with a molecular weight of 400,000 g/mol was dissolved in a mixture of ethanol and water with a proportion of 1:3. The relationship between the viscosity of the polymer solution and shear rate was characterized by a plate–plate rheometer. A shear flow model was discussed, while polymer material was flowing through a needle, which presented that different deformation rates were imposed on materials due to variable needle diameters. Combining the rheological experiments and analysis of the shear flow model, the viscosity of polymer solution flowing out the needle was predicted by needle diameter. Through observing the obtained fibers' morphology by scanning electron microscopy and measuring their diameters by image processing software, it was found that the fiber diameter increased with the increase of needle diameter, as expected, which agreed with the relationship of fiber diameter and polymer viscosity.

Open access

The aim of this research is the analysis of the effect of the modification of the base profile angles of x-zero gear drives for the TCA parameters. We analyze the normal stress, the normal deformation and the normal elastic strain on the connecting zone of the gear pairs. Based on the received results we create diagrams which show the fluctuation of the analyzed TCA parameters in the function of the changing of the selected parameter of the x-zero gear drives. After the analysis we determine the consequences and select the appropriate variant.

Open access