Displaying publications 101 - 120 of 353 in total

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  1. Fulltext Partial discharge characteristics of polymer nanocomposite materials in electrical insulation: a review of sample preparation techniques, analysis methods, potential applications, and future trends
    Izzati WA, Arief YZ, Adzis Z, Shafanizam M
    ScientificWorldJournal, 2014;2014:735070.
    PMID: 24558326 DOI: 10.1155/2014/735070
    Polymer nanocomposites have recently been attracting attention among researchers in electrical insulating applications from energy storage to power delivery. However, partial discharge has always been a predecessor to major faults and problems in this field. In addition, there is a lot more to explore, as neither the partial discharge characteristic in nanocomposites nor their electrical properties are clearly understood. By adding a small amount of weight percentage (wt%) of nanofillers, the physical, mechanical, and electrical properties of polymers can be greatly enhanced. For instance, nanofillers in nanocomposites such as silica (SiO2), alumina (Al2O3) and titania (TiO2) play a big role in providing a good approach to increasing the dielectric breakdown strength and partial discharge resistance of nanocomposites. Such polymer nanocomposites will be reviewed thoroughly in this paper, with the different experimental and analytical techniques used in previous studies. This paper also provides an academic review about partial discharge in polymer nanocomposites used as electrical insulating material from previous research, covering aspects of preparation, characteristics of the nanocomposite based on experimental works, application in power systems, methods and techniques of experiment and analysis, and future trends.
    Matched MeSH terms: Electricity*
  2. Fulltext A review on the fabrication of polymer-based thermoelectric materials and fabrication methods
    Kamarudin MA, Sahamir SR, Datta RS, Long BD, Mohd Sabri MF, Mohd Said S
    ScientificWorldJournal, 2013;2013:713640.
    PMID: 24324378 DOI: 10.1155/2013/713640
    Thermoelectricity, by converting heat energy directly into useable electricity, offers a promising technology to convert heat from solar energy and to recover waste heat from industrial sectors and automobile exhausts. In recent years, most of the efforts have been done on improving the thermoelectric efficiency using different approaches, that is, nanostructuring, doping, molecular rattling, and nanocomposite formation. The applications of thermoelectric polymers at low temperatures, especially conducting polymers, have shown various advantages such as easy and low cost of fabrication, light weight, and flexibility. In this review, we will focus on exploring new types of polymers and the effects of different structures, concentrations, and molecular weight on thermoelectric properties. Various strategies to improve the performance of thermoelectric materials will be discussed. In addition, a discussion on the fabrication of thermoelectric devices, especially suited to polymers, will also be given. Finally, we provide the challenge and the future of thermoelectric polymers, especially thermoelectric hybrid model.
    Matched MeSH terms: Electricity*
  3. Fulltext Prevalence of musculoskeletal disorders and related occupational causative factors among electricity linemen: A narrative review
    Padmanathan V, Joseph L, Omar B, Nawawi R
    Int J Occup Med Environ Health, 2016;29(5):725-34.
    PMID: 27518883 DOI: 10.13075/ijomeh.1896.00659
    Occupational tasks of linemen are highly associated with the development of work related musculoskeletal disorders (WRMDs). Although linemen are prone to develop WRMDs, there is paucity of information on the prevalence of WRMDs and related occupational causative factors. Therefore, the present review was conducted to report on the prevalence of WRMDs and to outline causative risk factors within occupational tasks in the lineman profession. Literature search was conducted in various databases such as Scopus, PubMed and ScienceDirect for articles published between 1996-2013. The articles were analyzed, selected and retrieved based on predetermined objectives, inclusion criteria and Medical Subject Headings (MeSH). In the review process only articles published in English were considered. The review identified moderate to high prevalence of WRMDs among the linemen population. Back and shoulder regions were highly affected compared to the other body regions. The review also reported occupational tasks such as bar installation, insulator fixation and manual handling of tools as high risk tasks that lead to the development of WRMDs. In addition, occupational tools such as ladders, manual cutters and manual presses were also identified as a potential ergonomic hazard. In conclusion, the current review identified that WRMDs are common in the back and shoulder regions among linemen. Also, a number of occupational risk factors were identified to be associated with WRMDs among the linemen. Hence, future research on prevention and intervention studies concerning lineman profession population in order to develop a good job practice are recommended. Int J Occup Med Environ Health 2016;29(5):725-734.
    Matched MeSH terms: Electricity*
  4. Role of dissolved oxygen on the degradation mechanism of Reactive Green 19 and electricity generation in photocatalytic fuel cell
    Lee SL, Ho LN, Ong SA, Wong YS, Voon CH, Khalik WF, et al.
    Chemosphere, 2018 Mar;194:675-681.
    PMID: 29247929 DOI: 10.1016/j.chemosphere.2017.11.166
    In this study, a membraneless photocatalytic fuel cell with zinc oxide loaded carbon photoanode and platinum loaded carbon cathode was constructed to investigate the impact of dissolved oxygen on the mechanism of dye degradation and electricity generation of photocatalytic fuel cell. The photocatalytic fuel cell with high and low aeration rate, no aeration and nitrogen purged were investigated, respectively. The degradation rate of diazo dye Reactive Green 19 and the electricity generation was enhanced in photocatalytic fuel cell with higher dissolved oxygen concentration. However, the photocatalytic fuel cell was still able to perform 37% of decolorization in a slow rate (k = 0.033 h-1) under extremely low dissolved oxygen concentration (approximately 0.2 mg L-1) when nitrogen gas was introduced into the fuel cell throughout the 8 h. However, the change of the UV-Vis spectrum indicates that the intermediates of the dye could not be mineralized under insufficient dissolved oxygen level. In the aspect of electricity generation, the maximum short circuit current (0.0041 mA cm-2) and power density (0.00028 mW cm-2) of the air purged photocatalytic fuel cell was obviously higher than that with nitrogen purging (0.0015 mA cm-2and 0.00008 mW cm-2).
    Matched MeSH terms: Electricity*
  5. On the physics of ferroelectrics
    Webb JF
    Sci Prog, 2003;86(Pt 3):203-34.
    PMID: 15079997
    The main physical properties of ferroelectric crystals are described, and the macroscopic and microscopic viewpoints are discussed along with some applications, such as in capacitors and nonlinear optics. The emphasis is on physical understanding, while the mathematical level is kept to a minimum or supplemented by graphical representations to make the article more accessible.
    Matched MeSH terms: Static Electricity*
  6. Distributed clock gating for power reduction of a programmable waveform generator for neural stimulation
    Noorsal E, Sooksood K, Bihr U, Becker J, Ortmanns M
    Annu Int Conf IEEE Eng Med Biol Soc, 2012;2012:3878-81.
    PMID: 23366775 DOI: 10.1109/EMBC.2012.6346814
    This paper describes how to employ distributed clock gating to achieve an overall low power design of a programmable waveform generator intended for a neural stimulator. The power efficiency is enabled using global timing control combined with local amplitude distribution over a bus to the local stimulator frontends. This allows the combination of local and global clock gating for complete sub-blocks of the design. A counter and a shifter employed at the local digital stimulator reduce the design complexity for the waveform generation and thus the overall power consumptions. The average power results indicate that 63% power can be saved for the global stimulator control unit and 89-96% power can be saved for the local digital stimulator by using the proposed approach. The circuit has been implemented and successfully tested in a 0.35 µm AMS HVCMOS technology.
    Matched MeSH terms: Electricity
  7. Application of TOPSIS and VIKOR improved versions in a multi criteria decision analysis to develop an optimized municipal solid waste management model
    Aghajani Mir M, Taherei Ghazvinei P, Sulaiman NM, Basri NE, Saheri S, Mahmood NZ, et al.
    J Environ Manage, 2016 Jan 15;166:109-15.
    PMID: 26496840 DOI: 10.1016/j.jenvman.2015.09.028
    Selecting a suitable Multi Criteria Decision Making (MCDM) method is a crucial stage to establish a Solid Waste Management (SWM) system. Main objective of the current study is to demonstrate and evaluate a proposed method using Multiple Criteria Decision Making methods (MCDM). An improved version of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) applied to obtain the best municipal solid waste management method by comparing and ranking the scenarios. Applying this method in order to rank treatment methods is introduced as one contribution of the study. Besides, Viekriterijumsko Kompromisno Rangiranje (VIKOR) compromise solution method applied for sensitivity analyses. The proposed method can assist urban decision makers in prioritizing and selecting an optimized Municipal Solid Waste (MSW) treatment system. Besides, a logical and systematic scientific method was proposed to guide an appropriate decision-making. A modified TOPSIS methodology as a superior to existing methods for first time was applied for MSW problems. Applying this method in order to rank treatment methods is introduced as one contribution of the study. Next, 11 scenarios of MSW treatment methods are defined and compared environmentally and economically based on the waste management conditions. Results show that integrating a sanitary landfill (18.1%), RDF (3.1%), composting (2%), anaerobic digestion (40.4%), and recycling (36.4%) was an optimized model of integrated waste management. An applied decision-making structure provides the opportunity for optimum decision-making. Therefore, the mix of recycling and anaerobic digestion and a sanitary landfill with Electricity Production (EP) are the preferred options for MSW management.
    Matched MeSH terms: Electricity
  8. Nanostructured SnO2-Ge Multi-layer thin Films with Quantum Confinement Effects for Solar Cell
    Khan AF, Sajjad W, Rahim NA
    Recent Pat Nanotechnol, 2016;10(1):77-82.
    PMID: 27018275
    BACKGROUND: It is well-known that multi-layer films with nanostructure can give novel properties by interfacial phenomenon and quantum confinement effects. Nanostructured multi-layer thin films are presently being analyzed for their vast applications in the area of optoelectronics technology particularly photovoltaics. Hereof, two dimensional thin films with nanostructure are of prime importance due to their structure dependent optical, electrical, and opto-electronic properties. It has been revealed that these films exhibit quantum confinement effects with band gap engineering. The main focus of the research is to evaluate the effect on structural and optical properties with number of layers.

    METHODS: Nanostructured SnO2-Ge multi-layer thin films were fabricated using electron beam evaporation and resistive heating techniques. Alternate layers of SnO2 and Ge were deposited on glass substrate at a substrate temperature of 300 °C in order to obtain uniform and homogeneous deposition. The substrate temperature of 300 °C has been determined to be effective for the deposition of these multi-layer films from our previous studies. The films were characterized by investigating their structural and optical properties. The structural properties of the as-deposited films were characterized by Rutherford Backscattering Spectroscopy (RBS) and Raman spectroscopy and optical properties by Ultra-Violet-Near infrared (UV-VIS-NIR) spectroscopy.

    RESULTS: RBS studies confirmed that the layer structure has been effectively formed. Raman spectroscopy results show that the peaks of both Ge and SnO2 shifts towards lower wavenumbers (in comparison with bulk Ge and SnO2, suggesting that the films consist of nanostructures and demonstrate quantum confinement effects. UV-VIS-NIR spectroscopy showed an increase in the band gap energy of Ge and SnO2 and shifting of transmittance curves toward higher wavelength by increasing the number of layers. The band gap lies in the range of 0.9 to 1.2 eV for Ge, while for SnO2, it lies between 1.7 to 2.1 eV.

    CONCLUSION: Analysis of results suggests that the nanostructured SnO2-Ge multi-layer thin film can work as heterojunction materials with quantum confinement effects. Accordingly, the present SnO2-Ge multi-layer films may be employed for photovoltaic applications. Few relevant patents to the topic have been reviewed and cited.

    Matched MeSH terms: Electricity
  9. Fulltext Coherently Tunable Triangular Trefoil Phaseonium Metamaterial
    Nguyen DM, Soci C, Ooi CH
    Sci Rep, 2016;6:21083.
    PMID: 26879520 DOI: 10.1038/srep21083
    Phaseonium is a three-level Λ quantum system, in which a coherent microwave and an optical control (pump) beams can be used to actively modulate the dielectric response. Here we propose a new metamaterial structure comprising of a periodic array of triangular phaseonium metamolecules arranged as a trefoil. We present a computational study of the spatial distribution of magnetic and electric fields of the probe light and the corresponding transmission and reflection, for various parameters of the optical and microwave beams. For specific values of the probing frequencies and control fields, the phaseonium can display either metallic or dielectric optical response. We find that, in the metallic regime, the phaseonium metamaterial structure supports extremely large transmission, with optical amplification at large enough intensity of the microwave thanks to strong surface plasmon coupling; while, in the dielectric regime without microwave excitation, the transmission bandwidth can be tuned by varying the control beam intensity. Implementation of such phaseonium metamaterial structure in solid-state systems, such as patterned crystals doped with rare-earth elements or dielectric matrices embedded with quantum dots, could enable a new class of actively tunable quantum metamaterials.
    Matched MeSH terms: Electricity
  10. Pushing microbial desalination cells towards field application: Prevailing challenges, potential mitigation strategies, and future prospects
    Salehmin MNI, Lim SS, Satar I, Daud WRW
    Sci Total Environ, 2021 Mar 10;759:143485.
    PMID: 33279184 DOI: 10.1016/j.scitotenv.2020.143485
    Microbial desalination cells (MDCs) have been experimentally proven as a versatile bioelectrochemical system (BES). They have the potential to alleviate environmental pollution, reduce water scarcity and save energy and operational costs. However, MDCs alone are inadequate to realise a complete wastewater and desalination treatment at a high-efficiency performance. The assembly of identical MDC units that hydraulically and electrically connected can improve the performance better than standalone MDCs. In the same manner, the coupling of MDCs with other BES or conventional water reclamation technology has also exhibits a promising performance. However, the scaling-up effort has been slowly progressing, leading to a lack of knowledge for guiding MDC technology into practicality. Many challenges remain unsolved and should be mitigated before MDCs can be fully implemented in real applications. Here, we aim to provide a comprehensive chronological-based review that covers technological limitations and mitigation strategies, which have been developed for standalone MDCs. We extend our discussion on how assembled, coupled and scaled-up MDCs have improved in comparison with standalone and lab-scale MDC systems. This review also outlines the prevailing challenges and potential mitigation strategies for scaling-up based on large-scale specifications and evaluates the prospects of selected MDC systems to be integrated with conventional anaerobic digestion (AD) and reverse osmosis (RO). This review offers several recommendations to promote up-scaling studies guided by the pilot scale BES and existing water reclamation technologies.
    Matched MeSH terms: Electricity
  11. Fulltext Solar tree
    Madya Mastika binti Ahmad, Amirah binti Mohd Arif
    Journal of Engineering and Science Research, 2018;2(4):34-38.
    MyJurnal
    In this day and age, with the ever-growing population and energy demand, we should take the renewable option route in our energy source. We should also keep in mind that said energy should not cause any lasting environmental damage, one of the perfect example being solar energy. A country that is hot and sunny all year long is the perfect contributor to solar energy, case in point, Malaysia. With that in mind Solar Tree is designed and developed to facilitate consumers who need electric power at any place, anytime, anywhere. The objective of this study is to assess a mini project in the likes of Solar Tree that can generate electricity without harming the environment, despite the weather. Intended specifically to be a mini project, it is understandable that electricity generated is limited, with only up to 500W in total. As a trial, two electronic devices were tested, specifically a mobile phone and a laptop, as both devices are used almost every day. The data collected is then tabulated and analysed. It was concluded the solar tree developed proved efficient in charging both devices and will continue to do so given enough sunlight.
    Matched MeSH terms: Electricity
  12. Fulltext The development of a power recycling prototype for renewable energy using dc motor
    Wan Nor Shela Ezwane Wan Jusoh, Md Razak Daud
    Journal of Engineering and Science Research, 2018;2(6):50-54.
    MyJurnal
    Energy consumption is an important part of life today because without the power a work cannot be done. The energy used today will be lost or waste without renewable energy or power recycle back. In reality, energy use has always had a noticeable impact on the environment. Overconsumption of energy is the main trigger for the global warming that is now threatening to cause devastation in many areas of the world. Each year, electricity consumption in Malaysia is always an increase. This can contribute to the occurrence of global warming. This project will be designed for renewable energy or recycle power to avoid waste of energy from lost. Also, this project consider regarding the Green Technology without polluting the environment. The objective is to develop a prototype or hardware that aims to renewable energy using the 12V DC Motor as a generator which is use rear shaft of table fan as a medium to drive the 12V DC Motor and also to analyze the power consumption of table fan before and after install with hardware. The methods used to design the connector and DC motor holder is using a solidwork software, then construct the circuit simulation using a proteus software and also use a microcontroller PIC16F877A as a controller. The result obtained from the testing and experiments by integrating the hardware part, electrical part and software part. Finally, with the development of a power recycling prototype for renewable energy using DC Motor application, the wasted energy can be reused from conversion to other energy and energy can be used as renewable energy.
    Matched MeSH terms: Electricity
  13. Fulltext Electrical Conductivity Performance of Predicted Modified Fibre Contact Model for Multi-Filler Polymer Composite
    Mohd Radzuan NA, Sulong AB, Hui D, Verma A
    Polymers (Basel), 2019 Aug 30;11(9).
    PMID: 31480276 DOI: 10.3390/polym11091425
    Polymer composites have been extensively fabricated given that they are well-fitted for a variety of applications, especially concerning their mechanical properties. However, inadequate outcomes, mainly regarding their electrical performance, have limited their significant potential. Hence, this study proposed the use of multiple fillers, with different geometries, in order to improve the electrical conductivity of a polymer composite. The fabricated composite was mixed, using the ball milling method, before being compressed by a hot press machine at 3 MPa for 10 min. The composite plate was then measured for both its in-plane and through-plane conductivities, which were 3.3 S/cm, and 0.79 S/cm, respectively. Furthermore, the experimental data were then verified using a predicted electrical conductivity model, known as a modified fibre contact model, which considered the manufacturing process, including the shear rate and flow rate. The study indicated that the predicted model had a significant trend and value, compared to the experimental model (0.65 S/cm for sample S1). The resultant fabricated composite materials were found to possess an excellent network formation, and good electrical conductivity for bipolar plate application, when applying compression pressure of 3 MPa for 10 min.
    Matched MeSH terms: Electricity
  14. A synergistic heterostructured ZnO/BaTiO3 loaded carbon photoanode in photocatalytic fuel cell for degradation of Reactive Red 120 and electricity generation
    Ong YP, Ho LN, Ong SA, Banjuraizah J, Ibrahim AH, Lee SL, et al.
    Chemosphere, 2019 Mar;219:277-285.
    PMID: 30543963 DOI: 10.1016/j.chemosphere.2018.12.004
    Photocatalytic fuel cell (PFC) is considered as a sustainable green technology which could degrade organic pollutant and generate electricity simultaneously. A synergistic double-sided ZnO/BaTiO3 loaded carbon plate heterojunction photoanode was fabricated in different ratios by using simple ultrasonication and mixed-annealed method. The double-sided design of photoanode allowed the lights irradiated at both sides of the photoanode. The ferroelectricity fabricated photoanode was applied in a membraneless PFC with platinum-loaded carbon as the cathode. Results revealed that the photoanode with 1:1 ratio of BaTiO3 and ZnO exhibited a superior photocatalytic activity among all the photoanodes prepared in this study. The heterojunction of this photoanode was able to achieve up to a removal efficiency of 93.67% with a maximum power density of 0.5284 μW cm-2 in 10 mg L-1 of Reactive Red 120 (RR120) without any supporting electrolyte. This photoanode was able to maintain at high performance after recycling 3 times. Overloading of ZnO above 50% on BaTiO3 could lead to deterioration of the performance of PFC due to the charge defects and light trapping ability. The interactions, interesting polarizations of the photocatalysts and proposed mechanism of the n-n type heterojunction in the photoanode of ZnO/BaTiO3 was also discussed.
    Matched MeSH terms: Electricity
  15. Fulltext Big Data acquired by Internet of Things-enabled industrial multichannel wireless sensors networks for active monitoring and control in the smart grid Industry 4.0
    Faheem M, Fizza G, Ashraf MW, Butt RA, Ngadi MA, Gungor VC
    Data Brief, 2021 Apr;35:106854.
    PMID: 33659599 DOI: 10.1016/j.dib.2021.106854
    Smart Grid Industry 4.0 (SGI4.0) defines a new paradigm to provide high-quality electricity at a low cost by reacting quickly and effectively to changing energy demands in the highly volatile global markets. However, in SGI4.0, the reliable and efficient gathering and transmission of the observed information from the Internet of Things (IoT)-enabled Cyber-physical systems, such as sensors located in remote places to the control center is the biggest challenge for the Industrial Multichannel Wireless Sensors Networks (IMWSNs). This is due to the harsh nature of the smart grid environment that causes high noise, signal fading, multipath effects, heat, and electromagnetic interference, which reduces the transmission quality and trigger errors in the IMWSNs. Thus, an efficient monitoring and real-time control of unexpected changes in the power generation and distribution processes is essential to guarantee the quality of service (QoS) requirements in the smart grid. In this context, this paper describes the dataset contains measurements acquired by the IMWSNs during events monitoring and control in the smart grid. This work provides an updated detail comparison of our proposed work, including channel detection, channel assignment, and packets forwarding algorithms, collectively called CARP [1] with existing G-RPL [2] and EQSHC [3] schemes in the smart grid. The experimental outcomes show that the dataset and is useful for the design, development, testing, and validation of algorithms for real-time events monitoring and control applications in the smart grid.
    Matched MeSH terms: Electricity
  16. Fulltext Energy production using solar-powered electrolyzer and hydrogen fuel cell
    Teoh Wei Hern, Samihah Abdullah, Shabinar Abdul Hamid, Solahuddin Yusuf Fadhlullah
    ESTEEM Academic Journal, 2019;15(1):10-17.
    MyJurnal
    This study presented the implementation of a small-scale (50 W) solar energy harvesting system coupled with an electrolyzer and proton exchange membrane (PEM) fuel cell. The energy from the solar panel would be utilized by the electrolyzer to produce hydrogen gas. The hydrogen gas would be used, in turn, by the PEM fuel cell to generate electricity which supports both DC and AC load. Excess energy from the solar panel is also used to charge the lead-acid backup battery. Analysis of the system showed that 400 mL of hydrogen gas could be produced within every 17 minutes in optimal conditions; between 11 am until 4 pm with bright sunlight. For every 400 mL of hydrogen gas, the PEM fuel cell could sustain continuous operation of a 5V 500 mA DC load for 95 seconds. Theoretically, more than 7000 mL of hydrogen gas could be produced within 5 hours in strong sunlight, which could power up a 50 mA and 500 mA load for 4.7 hours and 28 minutes respectively, during evening or night operations. The proposed system could complement the traditional battery-based storage system while remaining as a clean source of energy production.
    Matched MeSH terms: Electricity
  17. Fulltext Electrical Performance of Polymer-Insulated Rail Brackets of DC Transit Subjected to Lightning Induced Overvoltage
    Abd Rahman FA, Ab Kadir MZA, Ungku Amirulddin UA, Osman M
    Materials (Basel), 2021 Mar 29;14(7).
    PMID: 33805583 DOI: 10.3390/ma14071684
    The fourth rail transit is an interesting topic to be shared and accessed by the community within that area of expertise. Several ongoing works are currently being conducted especially in the aspects of system technical performances including the rail bracket component and the sensitivity analyses on the various rail designs. Furthermore, the lightning surge study on railway electrification is significant due to the fact that only a handful of publications are available in this regard, especially on the fourth rail transit. For this reason, this paper presents a study on the electrical performance of a fourth rail Direct Current (DC) urban transit affected by an indirect lightning strike. The indirect lightning strike was modelled by means of the Rusck model and the sum of two Heidler functions. The simulations were carried out using the EMTP-RV software which included the performance comparison of polymer-insulated rail brackets, namely the Cast Epoxy (CE), the Cycloaliphatic Epoxy A (CEA), and the Glass Reinforced Plastic (GRP) together with the station arresters when subjected by 30 kA (5/80 µs) and 90 kA (9/200 µs) lightning currents. The results obtained demonstrated that the GRP material has been able to slightly lower its induced overvoltage as compared to other materials, especially for the case of 90 kA (9/200 µs), and thus serves better coordination with the station arresters. This improvement has also reflected on the recorded residual voltage and energy absorption capacity of the arrester, respectively.
    Matched MeSH terms: Electricity
  18. Fulltext Production and Status of Bacterial Cellulose in Biomedical Engineering
    Moniri M, Boroumand Moghaddam A, Azizi S, Abdul Rahim R, Bin Ariff A, Zuhainis Saad W, et al.
    Nanomaterials (Basel), 2017 Sep 04;7(9).
    PMID: 32962322 DOI: 10.3390/nano7090257
    Bacterial cellulose (BC) is a highly pure and crystalline material generated by aerobic bacteria, which has received significant interest due to its unique physiochemical characteristics in comparison with plant cellulose. BC, alone or in combination with different components (e.g., biopolymers and nanoparticles), can be used for a wide range of applications, such as medical products, electrical instruments, and food ingredients. In recent years, biomedical devices have gained important attention due to the increase in medical engineering products for wound care, regeneration of organs, diagnosis of diseases, and drug transportation. Bacterial cellulose has potential applications across several medical sectors and permits the development of innovative materials. This paper reviews the progress of related research, including overall information about bacterial cellulose, production by microorganisms, mechanisms as well as BC cultivation and its nanocomposites. The latest use of BC in the biomedical field is thoroughly discussed with its applications in both a pure and composite form. This paper concludes the further investigations of BC in the future that are required to make it marketable in vital biomaterials.
    Matched MeSH terms: Electricity
  19. Fulltext Methods and variables in Electrical discharge machining of titanium alloy - A review
    Pramanik A, Basak AK, Littlefair G, Debnath S, Prakash C, Singh MA, et al.
    Heliyon, 2020 Dec;6(12):e05554.
    PMID: 33344787 DOI: 10.1016/j.heliyon.2020.e05554
    Titanium alloys are difficult to machine using conventional methods, therefore, nonconventional processes are often chosen in many applications. Electrical discharge machining (EDM) is one of those nonconventional processes that is used frequently for shaping titanium alloys with their respective pros and cons. However, a good understanding of this process is very difficult to achieve as research results are not properly connected and presented. Therefore, this study investigates different types of EDM processes such as, wire EDM, die-sink EDM, EDM drill and hybrid EDM used to machine titanium alloys. Machining mechanism, tool electrode, dielectric, materials removal rate (MRR), and surface integrity of all these processes are critically analysed and correlated based on the evidence accessible in literature. Machining process suffer from lower material removal rate and high tool wear while applied on titanium alloys. Formation of recast layer, heat affected zone and tool wear is common in all types of EDM processes. Additional challenge in wire EDM of titanium alloys is wire breakage under severe machining conditions. The formation of TiC and TiO2 are noticed in recast layer depending on the type of dielectrics. Removal of debris from small holes during EDM drilling is a challenge. All these restricts the applications EDMed titanium alloys in high-tech applications such as, aerospace and biomedical areas. Most of these challenges come up due to extraordinary properties such as, low thermal conductivity, high melting point and high hardness, of titanium alloys. Though hybrid EDM has been introduced and there is some work on simulation of EDM process, further developments in EDM of this alloy is required for widening the application of this methods.
    Matched MeSH terms: Electricity
  20. Fulltext Measurement and Mapping of Wi-Fi Radiation Level at Hamdan Tahir Library, Universiti Sains Malaysia Health Campus
    Supardi, N. F., Mohd Taib, N. H., Abu Amat, N. H., Yusoff, M. N. S.
    Physics and Technology in Medicine, 2020;1(1):52-57.
    MyJurnal
    Wi-Fi is a wireless communication technology that uses specific electromagnetic frequencies. The increasing use of Wi-Fi has raised public concerns about the impact of electromagnetic radiation on the environment and human health. Since the exposure level of the electromagnetic field (EMF) radiation differs between different locations, it is important to measure the strength of the EMF at various locations under observation. This study aimed to obtain specific values related to the radiofrequency and microwave EMF which is described by four specific parameters, that are 1) the frequency of the wave, 2) the electric field strength E, 3) the magnetic field strength H, and 4) the power density S. This study was carried out at the first floor area of Hamdan Tahir Library, Universiti Sains Malaysia Health Campus. Mapping of Wi-Fi signal and measurement of Wi-Fi radiation level was performed at four specific locations, that are Laptop zone 1, Laptop zone 2, Computer lab, and Cozy corner. The average radiation level was compared with the ICNIRP standard limit for public user. It was observed that the Wi-Fi signal was highest in Laptop zone 2 followed by Laptop zone 1 which displayed a moderate signal strength. Whereas moderate but lower signal level was detected in Computer lab zone and Cozy corner. The electric and magnetic fields as well as power density were found highest in Laptop zone 1, followed by Laptop zone 2, Cozy corner, and Computer lab. Comparison with standard ICNIRP limit showed that the radiation level is still far below the ICNIRP limit, which is only 2% of exposure level. To conclude, Laptop zone 2 exhibited the strongest Wi-Fi signal whereas Laptop zone 1 displayed the highest radiation level. However, the strength of the electric and magnetic fields as well as power density is still far below the ICNIRP limit.
    Matched MeSH terms: Electricity
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