Displaying publications 1 - 20 of 33 in total

Abstract:
Sort:
  1. Fulltext Role of Phase-Dependent Dielectric Properties of Alumina Nanoparticles in Electromagnetic-Assisted Enhanced Oil Recovery
    Adil M, Lee KC, Zaid HM, Manaka T
    Nanomaterials (Basel), 2020 Oct 06;10(10).
    PMID: 33036153 DOI: 10.3390/nano10101975
    The utilization of metal-oxide nanoparticles in enhanced oil recovery (EOR) has generated considerable research interest to increase the oil recovery. Among these nanoparticles, alumina nanoparticles (Al2O3-NPs) have proved promising in improving the oil recovery mechanism due to their prominent thermal properties. However, more significantly, these nanoparticles, coupled with electromagnetic (EM) waves, can be polarized to reduce water/oil mobility ratio and create disturbances at the oil/nanofluid interface, so that oil can be released from the reservoir rock surfaces and travelled easily to the production well. Moreover, alumina exists in various transition phases (γ, δ, θ, κ, β, η, χ), providing not only different sizes and morphologies but phase-dependent dielectric behavior at the applied EM frequencies. In this research, the oil recovery mechanism under EM fields of varying frequencies was investigated, which involved parameters such as mobility ratio, interfacial tension (IFT) and wettability. The displacement tests were conducted in water-wet sandpacks at 95 °C, by employing crude oil from Tapis. Alumina nanofluids (Al2O3-NFs) of four different phases (α, κ, θ and γ) and particle sizes (25-94.3 nm) were prepared by dispersing 0.01 wt. % NPs in brine (3 wt. % NaCl) together with SDBS as a dispersant. Three sequential injection scenarios were performed in each flooding scheme: (i) preflushes brine as a secondary flooding, (ii) conventional nano/EM-assisted nanofluid flooding, and (iii) postflushes brine to flush NPs. Compared to conventional nanofluid flooding (3.03-11.46% original oil in place/OOIP) as incremental oil recovery, EM-assisted nanofluid flooding provided an increase in oil recovery by approximately 4.12-12.90% of OOIP for different phases of alumina. It was established from these results that the recovery from EM-assisted nanofluid flooding is itself dependent on frequency, which is associated with good dielectric behavior of NPs to formulate the oil recovery mechanism including (i) mobility ratio improvement due to an electrorheological (ER) effect, (ii) interfacial disturbances by the oil droplet deformation, and (iii) wettability alteration by increased surface-free energy.
    Matched MeSH terms: Electromagnetic Fields
  2. Fulltext Low-Profile Slotted Metamaterial Antenna Based on Bi Slot Microstrip Patch for 5G Application
    Hoque A, Islam MT, Almutairi AF
    Sensors (Basel), 2020 Jun 11;20(11).
    PMID: 32545228 DOI: 10.3390/s20113323
    A low-profile high-directivity, and double-negative (DNG) metamaterial-loaded antenna with a slotted patch is proposed for the 5G application. The radiated slotted arm as a V shape has been extended to provide a low-profile feature with a two-isometric view square patch structure, which accelerates the electromagnetic (EM) resonance. Besides, the tapered patch with two vertically split parabolic horns and the unit cell metamaterial expedite achieve more directive radiation. Two adjacent splits with meta units enhance the surface current to modify the actual electric current, which is induced by a substrate-isolated EM field. As a result, the slotted antenna shows a 7.14 dBi realized gain with 80% radiation efficiency, which is quite significant. The operation bandwidth is 4.27-4.40 GHz, and characteristic impedance approximately remains the same (50 Ω) to give a VSWR (voltage Standing wave ratio) of less than 2, which is ideal for the expected application field. The overall size of the antenna is 60 × 40 × 1.52 mm. Hence, it has potential for future 5G applications, like Internet of Things (IoT), healthcare systems, smart homes, etc.
    Matched MeSH terms: Electromagnetic Fields
  3. Fulltext Quantum Physics Perspective on Electromagnetic and Quantum Fields Inside the Brain
    Idris Z
    Malays J Med Sci, 2020 Feb;27(1):1-5.
    PMID: 32158340 DOI: 10.21315/mjms2020.27.1.1
    Brain energy is associated commonly with electrochemical type of energy. This energy is displayed in the form of electromagnetic waves or better known as brainwaves. This concept is a classical concept (Newtonian) in which the studied object, that is the brain is viewed as a large anatomical object with its functional brainwaves. Another concept which incorporates quantum principles in it can also be used to study the brain. This perspective viewing the brain as purely waves, including its anatomical substrate. Thus, there are two types of energy or field exist in our brain: electromagnetic and quantum fields. Electromagnetic field is thought as dominant energy in purely motor and sensory inputs to our brain, whilst quantum field or energy is perceived as more influential in brain cognitions. The reason for this notion lies in its features which is diffused, non-deterministic, varied, complex and oneness.
    Matched MeSH terms: Electromagnetic Fields
  4. Analysis of model-based and model-free CEST effect quantification methods for different medical applications
    Foo LS, Yap WS, Hum YC, Manan HA, Tee YK
    J Magn Reson, 2020 01;310:106648.
    PMID: 31760147 DOI: 10.1016/j.jmr.2019.106648
    Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) holds great potential to provide new metabolic information for clinical applications such as tumor, stroke and Parkinson's Disease diagnosis. Many active research and developments have been conducted to translate this emerging MRI technique for routine clinical applications. In general, there are two CEST quantification techniques: (i) model-free and (ii) model-based techniques. The reliability of these quantification techniques depends heavily on the experimental conditions and quality of the collected data. Errors such as noise may lead to misleading quantification results and thus inaccurate diagnosis when CEST imaging becomes a standard or routine imaging scan in the future. This paper investigates the accuracy and robustness of these quantification techniques under different signal-to-noise (SNR) levels and magnetic field strengths. The quantified CEST effect before and after adding random Gaussian White Noise using model-free and model-based quantification techniques were compared. It was found that the model-free technique consistently yielded larger average percentage error across all tested parameters compared to its model-based counterpart, and that the model-based technique could withstand SNR of about 3 times lower than the model-free technique. When applied on noisy brain tumor, ischemic stroke, and Parkinson's Disease clinical data, the model-free technique failed to produce significant differences between normal and abnormal tissue whereas the model-based technique consistently generated significant differences. Although the model-free technique was less accurate and robust, its simplicity and thus speed would still make it a good approximate when the SNR was high (>50) or when the CEST effect was large and well-defined. For more accurate CEST quantification, model-based techniques should be considered. When SNR was low (<50) and the CEST effect was small such as those acquired from clinical field strength scanners, which are generally 3T and below, model-based techniques should be considered over model-free counterpart to maintain an average percentage error of less than 44% even under very noisy condition as tested in this work.
    Matched MeSH terms: Electromagnetic Fields
  5. Fulltext Effect of nanoparticles concentration on electromagnetic-assisted oil recovery using ZnO nanofluids
    Adil M, Lee K, Mohd Zaid H, A Shukur MF, Manaka T
    PLoS One, 2020;15(12):e0244738.
    PMID: 33382855 DOI: 10.1371/journal.pone.0244738
    Utilization of metal-oxide nanoparticles (NPs) in enhanced oil recovery (EOR) has generated substantial recent research interest in this area. Among these NPs, zinc oxide nanoparticles (ZnO-NPs) have demonstrated promising results in improving oil recovery due to their prominent thermal properties. These nanoparticles can also be polarized by electromagnetic (EM) field, which offers a unique Nano-EOR approach called EM-assisted Nano-EOR. However, the impact of NPs concentrations on oil recovery mechanism under EM field has not been well established. For this purpose, ZnO nanofluids (ZnO-NFs) of two different particle sizes (55.7 and 117.1 nm) were formed by dispersing NPs between 0.01 wt.% to 0.1 wt.% in a basefluid of sodium dodecylbenzenesulfonate (SDBS) and NaCl to study their effect on oil recovery mechanism under the electromagnetic field. This mechanism involved parameters, including mobility ratio, interfacial tension (IFT) and wettability. The displacement tests were conducted in water-wet sandpacks at 95˚C, by employing crude oil from Tapis. Three tertiary recovery scenarios have been performed, including (i) SDBS surfactant flooding as a reference, (ii) ZnO-NFs flooding, and (iii) EM-assisted ZnO-NFs flooding. Compare with incremental oil recovery from surfactant flooding (2.1% original oil in place/OOIP), nanofluid flooding reaches up to 10.2% of OOIP at optimal 0.1 wt.% ZnO (55.7 nm). Meanwhile, EM-assisted nanofluid flooding at 0.1 wt.% ZnO provides a maximum oil recovery of 10.39% and 13.08% of OOIP under EM frequency of 18.8 and 167 MHz, respectively. By assessing the IFT/contact angle and mobility ratio, the optimal NPs concentration to achieve a favorable ER effect and interfacial disturbance is determined, correlated to smaller hydrodynamic-sized nanoparticles that cause strong electrostatic repulsion between particles.
    Matched MeSH terms: Electromagnetic Fields
  6. 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: Electromagnetic Fields
  7. Fulltext Measurement and Mapping of Wi-Fi Radiation Level at Students Hostel in Universiti Sains Malaysia Health Campus
    Abu Amat, N. H., Mohd Taib, N. H., Supardi, N. F., Yusoff, M. N. S.
    Physics and Technology in Medicine, 2020;1(1):38-44.
    MyJurnal
    The increasing use of wireless communication devices, particularly Wi-Fi has raised public concerns on the exposure to electromagnetic field (EMF) and its possible effect on human health. As the exposure level of the EMF radiation varies between different locations, measurement of the EMF strength at various locations is vital. In this study, we aimed to measure the EMF exposure which is described by four specific parameters, specifically 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 performed at the second floor in Nurani hostel block in Desasiswa Murni Nurani, 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 in a student room, television room, prayer room, and ironing room. The average radiation level was compared with the standard limit set by International Commission on Non-Ionizing Radiation Protection (ICNIRP). It was observed that the strength of Wi-Fi signal was highest in students’ room followed by television room. Both of these rooms exhibited high signal strength. While moderate but lower signal level was observed in prayer room followed by ironing room. The electromagnetic field and power density were found highest in students’ room, followed by television room, prayer room, and ironing room. Comparison with standard ICNIRP limit showed that the radiation level is still far below the acceptable limit, which is only 2% of the exposure level. To conclude, students’ room exhibited the strongest Wi-Fi signal and the highest radiation level. However, the radiation level especially power density is still far below the ICNIRP limit.
    Matched MeSH terms: Electromagnetic Fields
  8. Radiofrequency electromagnetic radiation-induced behavioral changes and their possible basis
    Narayanan SN, Jetti R, Kesari KK, Kumar RS, Nayak SB, Bhat PG
    Environ Sci Pollut Res Int, 2019 Oct;26(30):30693-30710.
    PMID: 31463749 DOI: 10.1007/s11356-019-06278-5
    The primary objective of mobile phone technology is to achieve communication with any person at any place and time. In the modern era, it is impossible to ignore the usefulness of mobile phone technology in cases of emergency as many lives have been saved. However, the biological effects they may have on humans and other animals have been largely ignored and not been evaluated comprehensively. One of the reasons for this is the speedy uncontrollable growth of this technology which has surpassed our researching ability. Initiated with the first generation, the mobile telephony currently reaches to its fifth generation without being screened extensively for any biological effects that they may have on humans or on other animals. Mounting evidences suggest possible non-thermal biological effects of radiofrequency electromagnetic radiation (RF-EMR) on brain and behavior. Behavioral studies have particularly concentrated on the effects of RF-EMR on learning, memory, anxiety, and locomotion. The literature analysis on behavioral effects of RF-EMR demonstrates complex picture with conflicting observations. Nonetheless, numerous reports suggest a possible behavioral effect of RF-EMR. The scientific findings about this issue are presented in the current review. The possible neural and molecular mechanisms for the behavioral effects have been proposed in the light of available evidences from the literature.
    Matched MeSH terms: Electromagnetic Fields/adverse effects*
  9. Molecular orbitals of delocalized electron clouds in neuronal domains
    Poznanski RR, Cacha LA, Latif AZA, Salleh SH, Ali J, Yupapin P, et al.
    Biosystems, 2019 Sep;183:103982.
    PMID: 31195028 DOI: 10.1016/j.biosystems.2019.103982
    We have further developed the two-brains hypothesis as a form of complementarity (or complementary relationship) of endogenously induced weak magnetic fields in the electromagnetic brain. The locally induced magnetic field between electron magnetic dipole moments of delocalized electron clouds in neuronal domains is complementary to the exogenous electromagnetic waves created by the oscillating molecular dipoles in the electro-ionic brain. In this paper, we mathematically model the operation of the electromagnetic grid, especially in regard to the functional role of atomic orbitals of dipole-bound delocalized electrons. A quantum molecular dynamic approach under quantum equilibrium conditions is taken to illustrate phase differences between quasi-free electrons tethered to an oscillating molecular core. We use a simplified version of the many-body problem to analytically solve the macro-quantum wave equation (equivalent to the Kohn-Sham equation). The resultant solution for the mechanical angular momentum can be used to approximate the molecular orbital of the dipole-bound delocalized electrons. In addition to non-adiabatic motion of the molecular core, 'guidance waves' may contribute to the delocalized macro-quantum wave functions in generating nonlocal phase correlations. The intrinsic magnetic properties of the origins of the endogenous electromagnetic field are considered to be a nested hierarchy of electromagnetic fields that may also include electromagnetic patterns in three-dimensional space. The coupling between the two-brains may involve an 'anticipatory affect' based on the conceptualization of anticipation as potentiality, arising either from the macro-quantum potential energy or from the electrostatic effects of residual charges in the quantum and classical subsystems of the two-brains that occurs through partitioning of the potential energy of the combined quantum molecular dynamic system.
    Matched MeSH terms: Electromagnetic Fields
  10. Risk Communication Strategies for Possible Health Risks From Radio-Frequency Electromagnetic Fields (RF-EMF) Emission by Telecommunication Structures
    Fernandez PR, Ng KH, Kaur S
    Health Phys, 2019 06;116(6):835-839.
    PMID: 30844902 DOI: 10.1097/HP.0000000000001037
    There is widespread anxiety and speculation about RF-EMF emissions by telecommunication base stations and structures, as it is perceived by some to be unsafe and a threat to public health. Scientists, medical experts, politicians, journalists, and mobile telecommunication company specialists are involved in an active debate on whether people are immune to RF or if we are gambling with our future. Interviews with 31 individuals from 7 stakeholder groups in Malaysia reveal that the residents' main concerns are that the telecommunication companies do not follow guidelines and as a result the telecommunication structures are constructed close to their homes, which they perceive as a threat to public health. Some residents also do not want these structures because of cultural reasons, while some are jealous over rental income received by the landlords. Meanwhile, the authorities entrusted with safe-guarding public health are involved in a blame game as there is no agency that is clearly in charge. The interviews also highlight that the current risk communication initiatives are more reactive rather than proactive, and that the authorities do not speak in one voice. Based on the outcome of the interviews, eleven recommendations are formulated to improve risk communication initiatives in Malaysia. The recommendations stress on repairing, building, and strengthening trust, because trust in agencies, along with credibility, determines risk communication initiatives' effectiveness. These strategies can also be effectively replicated across regions to deal with contestations over RF-EMF emissions and the impact on health.
    Matched MeSH terms: Electromagnetic Fields/adverse effects*
  11. Graphene oxide and gold nanoparticle based dual platform with short DNA probe for the PCR free DNA biosensing using surface-enhanced Raman scattering
    Khalil I, Yehye WA, Julkapli NM, Rahmati S, Sina AA, Basirun WJ, et al.
    Biosens Bioelectron, 2019 Apr 15;131:214-223.
    PMID: 30844598 DOI: 10.1016/j.bios.2019.02.028
    Surface-enhanced Raman scattering (SERS) based DNA biosensors have considered as excellent, fast and ultrasensitive sensing technique which relies on the fingerprinting ability to produce molecule specific distinct spectra. Unlike conventional fluorescence based strategies SERS provides narrow spectral bandwidths, fluorescence quenching and multiplexing ability, and fitting attribute with short length probe DNA sequences. Herein, we report a novel and PCR free SERS based DNA detection strategy involving dual platforms and short DNA probes for the detection of endangered species, Malayan box turtle (MBT) (Cuora amboinensis). In this biosensing feature, the detection is based on the covalent linking of the two platforms involving graphene oxide-gold nanoparticles (GO-AuNPs) functionalized with capture probe 1 and gold nanoparticles (AuNPs) modified with capture probe 2 and Raman dye (Cy3) via hybridization with the corresponding target sequences. Coupling of the two platforms generates locally enhanced electromagnetic field 'hot spot', formed at the junctions and interstitial crevices of the nanostructures and consequently provide significant amplification of the SERS signal. Therefore, employing the two SERS active substrates and short-length probe DNA sequences, we have managed to improve the sensitivity of the biosensors to achieve a lowest limit of detection (LOD) as low as 10 fM. Furthermore, the fabricated biosensor exhibited sensitivity even for single nucleotide base-mismatch in the target DNA as well as showed excellent performance to discriminate closely related six non-target DNA sequences. Although the developed SERS biosensor would be an attractive platform for the authentication of MBT from diverse samples including forensic and/or archaeological specimens, it could have universal application for detecting gene specific biomarkers for many diseases including cancer.
    Matched MeSH terms: Electromagnetic Fields
  12. Fulltext Dielectric properties for selected wall material in the development of microwave-encapsulation-drying
    Mohamad SNH, Muhamad II, Mohd Jusoh YM, Khairuddin N
    J Food Sci Technol, 2018 Dec;55(12):5161-5165.
    PMID: 30483013 DOI: 10.1007/s13197-018-3327-3
    Dielectric properties study is important in understanding the interaction between materials within electromagnetic field. By knowing and understanding the dielectric properties of materials, an efficient and effective microwave heating process and products can be designed. In this study, the dielectric properties of several encapsulation wall materials were measured using open-ended coaxial probe method. This method was selected due to its simplicity and high accuracy. All materials exhibited similar behavior. The result inferred that β-cyclodextrin (BC), starch (S), Arabic (GA) and maltodextrin (M) with various dextrose equivalent exhibited effective encapsulation wall materials in microwave encapsulation-drying technique owing to loss tangent values which were higher than 0.1 at general application frequency of 2.45 GHz. Thus, these were found to be suitable as wall material to encapsulate the selected core material in this microwave encapsulation-drying method. On contrary, sodium caseinate showed an ineffective wall material to be used in microwave encapsulation-drying. The differences in the values of dielectric constant, loss factor and loss tangent were found to be contributed by frequency, composition and bulk density.
    Matched MeSH terms: Electromagnetic Fields
  13. Fulltext Stochastic electromagnetic field propagation- measurement and modelling
    Gradoni G, Russer J, Baharuddin MH, Haider M, Russer P, Smartt C, et al.
    Philos Trans A Math Phys Eng Sci, 2018 Oct 29;376(2134).
    PMID: 30373944 DOI: 10.1098/rsta.2017.0455
    This paper reviews recent progress in the measurement and modelling of stochastic electromagnetic fields, focusing on propagation approaches based on Wigner functions and the method of moments technique. The respective propagation methods are exemplified by application to measurements of electromagnetic emissions from a stirred, cavity-backed aperture. We discuss early elements of statistical electromagnetics in Heaviside's papers, driven mainly by an analogy of electromagnetic wave propagation with heat transfer. These ideas include concepts of momentum and directionality in the realm of propagation through confined media with irregular boundaries. We then review and extend concepts using Wigner functions to propagate the statistical properties of electromagnetic fields. We discuss in particular how to include polarization in this formalism leading to a Wigner tensor formulation and a relation to an averaged Poynting vector.This article is part of the theme issue 'Celebrating 125 years of Oliver Heaviside's 'Electromagnetic Theory''.
    Matched MeSH terms: Electromagnetic Fields
  14. Fulltext Dry Thermotropic Glycolipid Self-Assembly:A Review
    Hashim R, Zahid NI, Velayutham TS, Aripin NFK, Ogawa S, Sugimura A
    J Oleo Sci, 2018 Jun 01;67(6):651-668.
    PMID: 29760332 DOI: 10.5650/jos.ess17261
    Also recognized as carbohydrate liquid crystals, glycolipids are amphiphiles whose basic unit comprises of a sugar group attached to an alkyl chain. Glycolipids are amphitropic, which means these materials form liquid crystal self-assemblies when dry (thermotropic) as well as when dissolved in solvents (lyotropic/surfactants) such as water. Many glycolipids are also naturally derived since these can be found in cell membranes. Their membrane and surfactant functions are largely understood through their lyotropic properties. While glycolipids are expected to play major roles as eco-friendly surfactants in the global surfactant market, their usefulness as thermotropic liquid crystal material is, to date, unknown, due to relatively lack of research performed and data reported in the literature. Understandably since glycolipids are hygroscopic with many hydroxy groups, removing the last trace water is very challenging. In recent time, with careful lyophilization and more consistent characterization technique, some researchers have attempted serious studies into "dry" or anhydrous glycolipids. Motivated by possible developments of novel thermotropic applications, some results from these studies also provide surprising new understanding to support conventional wisdom of the lyotropic systems. Here we review the dry state of glycosides, a family of glycolipids whose sugar headgroup is linked to the lipid chain via a glycosidic oxygen linker. The structure property relationship of both linear and anhydrous Guerbet glycosides will be examined. In particular, how the variation of sugar stereochemistry (e.g. anomer vs. epimer), the chain length and chain branching affect the formation of thermotropic liquid crystals phases, which not only located under equilibrium but also far from equilibrium conditions (glassy phase) are scrutinized. The dry glycolipid assembly has been subjected to electric and magnetic fields and the results show interesting behaviors including a possible transient current generation.
    Matched MeSH terms: Electromagnetic Fields
  15. Fulltext Combination effect of argan oil and low frequency electromagnetic field on open wound in mice
    Siti F. Masre, Muzamir, M.K, Sabarina, I., Jehan, N., Yanti Rosli
    Jurnal Sains Kesihatan Malaysia, 2018;16(101):41-45.
    MyJurnal
    This study was conducted to evaluate the effect of argan oil with the exposure of low frequency electromagnetic field (EMF) on open wound healing in mice. Eighteen male mice (20-40 g) were divided into three groups: phosphate buffer saline (PBS) as negative control, solcoseryl gel as positive control, and argan oil with the exposure of low frequency EMF, 1.2 mT (treatment group). Full thickness wounds (4 mm diameter) were induced on the shaved dorsal of the mouse. All mice were sacrificed on day 12 after the final treatment. Macroscopic observation, wound contraction rate, histopathology analysis and total protein content were examined in this study. Results showed that wounds treated with argan oil and exposed to low frequency EMF has a significant increase in wound contraction rate (p < 0.05) and total protein content (p < 0.05). Moreover, histopathological analysis on the wound tissues displayed complete re-epithelization with thick and dense collagen fibers in the argan oil with low frequency EMF exposure treated group. In conclusion, topical treatment of argan oil with low frequency EMF exposure yield a better healing progress and showed the ability to accelerate wound healing
    Matched MeSH terms: Electromagnetic Fields
  16. Fulltext Enhancement of mesenchymal stem cell chondrogenesis with short-term low intensity pulsed electromagnetic fields
    Parate D, Franco-Obregón A, Fröhlich J, Beyer C, Abbas AA, Kamarul T, et al.
    Sci Rep, 2017 08 25;7(1):9421.
    PMID: 28842627 DOI: 10.1038/s41598-017-09892-w
    Pulse electromagnetic fields (PEMFs) have been shown to recruit calcium-signaling cascades common to chondrogenesis. Here we document the effects of specified PEMF parameters over mesenchymal stem cells (MSC) chondrogenic differentiation. MSCs undergoing chondrogenesis are preferentially responsive to an electromagnetic efficacy window defined by field amplitude, duration and frequency of exposure. Contrary to conventional practice of administering prolonged and repetitive exposures to PEMFs, optimal chondrogenic outcome is achieved in response to brief (10 minutes), low intensity (2 mT) exposure to 6 ms bursts of magnetic pulses, at 15 Hz, administered only once at the onset of chondrogenic induction. By contrast, repeated exposures diminished chondrogenic outcome and could be attributed to calcium entry after the initial induction. Transient receptor potential (TRP) channels appear to mediate these aspects of PEMF stimulation, serving as a conduit for extracellular calcium. Preventing calcium entry during the repeated PEMF exposure with the co-administration of EGTA or TRP channel antagonists precluded the inhibition of differentiation. This study highlights the intricacies of calcium homeostasis during early chondrogenesis and the constraints that are placed on PEMF-based therapeutic strategies aimed at promoting MSC chondrogenesis. The demonstrated efficacy of our optimized PEMF regimens has clear clinical implications for future regenerative strategies for cartilage.
    Matched MeSH terms: Electromagnetic Fields*
  17. Fulltext Measurement of extremely low frequency (ELF) magnetic flux in the vicinity of the overhead high voltage transmission line in Universiti Kebangsaan Malaysia
    Faizal Mohamed, Irman Abdul Rahman, Ngu, Thieng Kui, Syazwani Mohd Fadzil, Firdaus Pozi, Amran Ab. Majid, et al.
    Journal of Nuclear and Related Technologies, 2017;14(2):1-10.
    MyJurnal
    Electricity has become one of the necessities for human daily activities. The presence of electric
    current produces electromagnetic fields (EMF) at extremely low frequency (ELF). The problem arises
    when scientists suggests a possible connection between ELF exposure to human health and safety.
    Concerned about the safety and health of students and staff, Universiti Kebangsaan Malaysia (UKM)
    took the initiative to identify possible ELF sources and measure their exposure in various locations
    around the UKM main campus in Bangi. This paper reports the results obtained from the monitoring
    of the magnetic flux density at three identified locations in the vicinity of the overhead high-voltage
    transmission line which transverses the university compound and compare the maximum value results
    with the exposure limit suggested by the International Committee on Non Ionising Radiation
    Protection (ICNIRP) for ELF. Measurements were done with an (Extech) Three Axis
    Electromagnetic Field (EMF) Meter (Model 430826) to determine the magnetic flux density. The
    lateral profile method was applied as the standard measurement methodology. Results showed that the
    maximum value of the magnetic flux density was 12.5 mG, which is below the suggested ICNIRP
    public exposure limit of 1000 mG, or in percentage ratio, 1.25% of ICNIRP public exposure limit.
    Results from the statistical Kruskal-Wallis test showed that there is a significant difference in the
    distributions of the magnetic flux densities at the different locations (P < 0.05). In conclusion, the
    measured locations are still safe for people in short-term exposure. However, long-term exposure
    measurements still need to be done to provide concrete data on the ELF-emission levels in UKM.
    Matched MeSH terms: Electromagnetic Fields
  18. Fulltext Microwave bio-sensor based on symmetrical split ring resonator with spurline filters for therapeutic goods detection
    Alahnomi RA, Zakaria Z, Ruslan E, Ab Rashid SR, Mohd Bahar AA, Shaaban A
    PLoS One, 2017;12(9):e0185122.
    PMID: 28934301 DOI: 10.1371/journal.pone.0185122
    A novel symmetrical split ring resonator (SSRR) based microwave sensor with spurline filters for detecting and characterizing the properties of solid materials has been developed. Due to the weak perturbation in the interaction of material under test (MUT) and planar microwave sensor, spurline filters were embedded to the SSRR microwave sensor which effectively enhanced Q-factor with suppressing the undesired harmonic frequency. The spurline filter structures force the presented sensor to resonate at a fundamental frequency of 2.2 GHz with the capabilities of suppressing rejected harmonic frequency and miniaturization in circuit size. A wide bandwidth rejection is achieved by using double spurlines filters with high Q-factor achievement (up to 652.94) compared to single spurline filter. The new SSRR sensor with spurline filters displayed desired properties such as high sensitivity, accuracy, and performance with a 1.3% typical percentage error in the measurement results. Furthermore, the sensor has been successfully applied for detecting and characterizing solid materials (such as Roger 5880, Roger 4350, and FR4) and evidently demonstrated that it can suppress the harmonic frequency effectively. This novel design with harmonic suppression is useful for various applications such as food industry (meat, fruit, vegetables), biological medicine (derived from proteins and other substances produced by the body), and Therapeutic goods (antiseptics, vitamins, anti-psychotics, and other medicines).
    Matched MeSH terms: Electromagnetic Fields
  19. Transient electro-magneto-hydrodynamic two-phase blood flow and thermal transport through a capillary vessel
    Mirza IA, Abdulhameed M, Vieru D, Shafie S
    Comput Methods Programs Biomed, 2016 Dec;137:149-166.
    PMID: 28110721 DOI: 10.1016/j.cmpb.2016.09.014
    Therapies with magnetic/electromagnetic field are employed to relieve pains or, to accelerate flow of blood-particles, particularly during the surgery. In this paper, a theoretical study of the blood flow along with particles suspension through capillary was made by the electro-magneto-hydrodynamic approach. Analytical solutions to the non-dimensional blood velocity and non-dimensional particles velocity are obtained by means of the Laplace transform with respect to the time variable and the finite Hankel transform with respect to the radial coordinate. The study of thermally transfer characteristics is based on the energy equation for two-phase thermal transport of blood and particles suspension with viscous dissipation, the volumetric heat generation due to Joule heating effect and electromagnetic couple effect. The solution of the nonlinear heat transfer problem is derived by using the velocity field and the integral transform method. The influence of dimensionless system parameters like the electrokinetic width, the Hartman number, Prandtl number, the coefficient of heat generation due to Joule heating and Eckert number on the velocity and temperature fields was studied using the Mathcad software. Results are presented by graphical illustrations.
    Matched MeSH terms: Electromagnetic Fields*
  20. Evaluation of Interference of Cellular Phones on Electronic Apex Locators: An In Vitro Study
    Sidhu P, Shankargouda S, Dicksit DD, Mahdey HM, Muzaffar D, Arora S
    J Endod, 2016 Apr;42(4):622-5.
    PMID: 26850688 DOI: 10.1016/j.joen.2015.12.027
    INTRODUCTION: Use of mobile phone has been prohibited in many hospitals to prevent interference with medical devices. Electromagnetic radiation emitted from cellular phones might interfere with electronic working length determination. The purpose of this in vitro study was to evaluate the effect of a smart phone (Samsung Galaxy Note Edge) on working length determination of electronic apex locators (EALs) Propex II and Rootor.

    METHODS: Fifteen intact, non-carious single-rooted teeth were decoronated at the cementoenamel junction. Visually, working length was determined by using a #15 K-file under stereomicroscope (×20). The effect of cellular phones on electronic working length (EWL) was determined under 2 experimental settings: (1) in a closed room with poor signal strength and (2) in a polyclinic set up with good signal strength and 5 conditions: (1) electronically, without cellular phone in room; (2) electronically, with cellular phone in physical contact with EAL; (3) electronically, with mobile phone in physical contact with EAL and in calling mode for a period of 25 seconds; (4) electronically, mobile phone placed at a distance of 40 cm from the EAL; and (5) electronically, mobile phone placed at a distance of 40 cm and in calling mode for a period of 25 seconds. The EWL was measured 3 times per tooth under each condition. Stability of the readings was scored from 1 to 3: (1) good stability, (2) stable reading after 1 attempt, and (3) stable reading after 2 attempts. The data were compared by using analysis of variance.

    RESULTS: The EWL measurements were not influenced by the presence of cellular phone and could be determined under all experimental conditions.

    CONCLUSIONS: Within the limitations of this study, it can be concluded that mobile phones do not interfere with the EWL determination.

    Matched MeSH terms: Electromagnetic Fields
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links