Displaying publications 121 - 140 of 147 in total

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  1. Lim E, Lim R, Suhaimi A, Chan BT, Wahab AKA
    J Back Musculoskelet Rehabil, 2018;31(6):1041-1047.
    PMID: 30149436 DOI: 10.3233/BMR-171042
    BACKGROUND: Low frequency sound wave stimulation therapy has become increasingly popular in the rehabilitation fields, due to its ease, less fatiguing and time efficient application.

    OBJECTIVE: This 12-week pilot study examines the efficacy of applying low frequency sound wave stimulation (between 16-160 Hz) through both hands and feet on relieving pain and improving functional ability in patients with chronic back pain.

    METHODS: Twenty-three participants with chronic shoulder (eleven participants) or low back pain (twelve participants) underwent a 12-week vibration therapy program of three sessions per week. A low frequency sound wave device comprising four piezoelectric vibration-type tactile tranducers enclosed in separate 5-cm diameter circular plates, which generate sinusoidal vibratory stimuli at a frequency of 16-160 Hz, was used in this study. Primary outcome measure was pain sensation measured using the Visual Analogue Scale (P-VAS). The secondary outcome measures were pain-related disability measured using the pain disability index (PDI) and quality of life measured using the SF-12.

    RESULTS: At week 12, significant reductions in pain sensation and pain-related disability were observed, with mean reductions of 3.5 points in P-VAS and 13.5 points in the PDI scores. Sixty-five percent of the participants had a reduction of at least 3 points on the P-VAS score, while 52% participants showed a decrease of at least 10 points in the PDI score. Significant improvement was observed in the SF-12 physical composite score but not the mental composite score.

    CONCLUSIONS: The preliminary findings showed that passive application of low frequency sound wave stimulation therapy through both hands and feet was effective in alleviating pain and improving functional ability in patients with chronic back pain.

    Matched MeSH terms: Vibration
  2. Azis RS, Che Muda NN, Hassan J, Shaari AH, Ibrahim IR, Mustaffa MS, et al.
    Materials (Basel), 2018 Nov 06;11(11).
    PMID: 30404131 DOI: 10.3390/ma11112190
    This paper investigates the effect of the ratio of ammonium nitrate (AN) on the structural, microstructural, magnetic, and alternating current (AC) conductivity properties of barium hexaferrite (BaFe12O19). The BaFe12O19 were prepared by using the salt melt method. The samples were synthesized using different powder-to-salt weight ratio variations (1:3, 1:4, 1:5, 1:6 and 1:7) of BaCO₃ + Fe₂O₃ and ammonium nitrate salt. The NH₄NO₃ was melted on a hot plate at 170 °C. A mixture of BaCO₃ and Fe₂O₃ were added into the NH₄NO₃ melt solution and stirred for several hours using a magnetic stirrer under a controlled temperature of 170 °C. The heating temperature was then increased up to 260 °C for 24 hr to produce an ash powder. The x-ray diffraction (XRD) results show the intense peak of BaFe12O19 for all the samples and the presence of a small amount of the impurity Fe₂O₃ in the samples, at a ratio of 1:5 and 1:6. From the Fourier transform infra-red (FTIR) spectra, the band appears at 542.71 cm - 1 and 432.48 cm - 1 , which corresponding to metal⁻oxygen bending and the vibration of the octahedral sites of BaFe12O19. The field emission scanning electron microscope (FESEM) images show that the grains of the samples appear to stick each other and agglomerate at different masses throughout the image with the grain size 5.26, 5.88, 6.14, 6.22, and 6.18 µm for the ratios 1:3, 1:4, 1:5, 1:6, and 1:7 respectively. From the vibrating sample magnetometer (VSM) analysis, the magnetic properties of the sample ratio at 1:3 show the highest value of coercivity Hc of 1317 Oe, a saturation magnetization Ms of 91 emu/g, and a remnant Mr of 44 emu/g, respectively. As the temperature rises, the AC conductivity is increases with an increase in frequency.
    Matched MeSH terms: Vibration
  3. Mahmodi H, Hashim MR, Soga T, Alrokayan S, Khan HA, Rusop M
    Materials (Basel), 2018 Nov 12;11(11).
    PMID: 30424494 DOI: 10.3390/ma11112248
    In this work, nanocrystalline Ge1-xSnx alloy formation from a rapid thermal annealed Ge/Sn/Ge multilayer has been presented. The multilayer was magnetron sputtered onto the Silicon substrate. This was followed by annealing the layers by rapid thermal annealing, at temperatures of 300 °C, 350 °C, 400 °C, and 450 °C, for 10 s. Then, the effect of thermal annealing on the morphological, structural, and optical characteristics of the synthesized Ge1-xSnx alloys were investigated. The nanocrystalline Ge1-xSnx formation was revealed by high-resolution X-ray diffraction (HR-XRD) measurements, which showed the orientation of (111). Raman results showed that phonon intensities of the Ge-Ge vibrations were improved with an increase in the annealing temperature. The results evidently showed that raising the annealing temperature led to improvements in the crystalline quality of the layers. It was demonstrated that Ge-Sn solid-phase mixing had occurred at a low temperature of 400 °C, which led to the creation of a Ge1-xSnx alloy. In addition, spectral photo-responsivity of a fabricated Ge1-xSnx metal-semiconductor-metal (MSM) photodetector exhibited its extending wavelength into the near-infrared region (820 nm).
    Matched MeSH terms: Vibration
  4. Amiri IS, Azzuhri SRB, Jalil MA, Hairi HM, Ali J, Bunruangses M, et al.
    Micromachines (Basel), 2018 Sep 11;9(9).
    PMID: 30424385 DOI: 10.3390/mi9090452
    Light has found applications in data transmission, such as optical fibers and waveguides and in optoelectronics. It consists of a series of electromagnetic waves, with particle behavior. Photonics involves the proper use of light as a tool for the benefit of humans. It is derived from the root word "photon", which connotes the tiniest entity of light analogous to an electron in electricity. Photonics have a broad range of scientific and technological applications that are practically limitless and include medical diagnostics, organic synthesis, communications, as well as fusion energy. This will enhance the quality of life in many areas such as communications and information technology, advanced manufacturing, defense, health, medicine, and energy. The signal transmission methods used in wireless photonic systems are digital baseband and RoF (Radio-over-Fiber) optical communication. Microwave photonics is considered to be one of the emerging research fields. The mid infrared (mid-IR) spectroscopy offers a principal means for biological structure analysis as well as nonintrusive measurements. There is a lower loss in the propagations involving waveguides. Waveguides have simple structures and are cost-efficient in comparison with optical fibers. These are important components due to their compactness, low profile, and many advantages over conventional metallic waveguides. Among the waveguides, optofluidic waveguides have been found to provide a very powerful foundation for building optofluidic sensors. These can be used to fabricate the biosensors based on fluorescence. In an optical fiber, the evanescent field excitation is employed to sense the environmental refractive index changes. Optical fibers as waveguides can be used as sensors to measure strain, temperature, pressure, displacements, vibrations, and other quantities by modifying a fiber. For some application areas, however, fiber-optic sensors are increasingly recognized as a technology with very interesting possibilities. In this review, we present the most common and recent applications of the optical fiber-based sensors. These kinds of sensors can be fabricated by a modification of the waveguide structures to enhance the evanescent field; therefore, direct interactions of the measurand with electromagnetic waves can be performed. In this research, the most recent applications of photonics components are studied and discussed.
    Matched MeSH terms: Vibration
  5. Ahmad Saffian H, Hyun-Joong K, Md Tahir P, Ibrahim NA, Lee SH, Lee CH
    Materials (Basel), 2019 Dec 05;12(24).
    PMID: 31817323 DOI: 10.3390/ma12244043
    In this study, the effects of lignin modification on the properties of kenaf core fiber reinforced poly(butylene succinate) biocomposites were examined. A weight percent gain (WPG) value of 30.21% was recorded after the lignin were modified with maleic anhydride. Lower mechanical properties were observed for lignin composites because of incompatible bonding between the hydrophobic matrix and the hydrophilic lignin. Modified lignin (ML) was found to have a better interfacial bonding, since maleic anhydrides remove most of the hydrophilic hydrogen bonding (this was proven by a Fourier-transform infrared (FTIR) spectrometer-a reduction of broadband near 3400 cm-1, corresponding to the -OH stretching vibration of hydroxyl groups for the ML samples). On the other hand, ML was found to have a slightly lower glass transition temperature, Tg, since reactions with maleic anhydride destroy most of the intra- and inter-molecular hydrogen bonds, resulting in a softer structure at elevated temperatures. The addition of kraft lignin was found to increase the thermal stability of the PBS polymer composites, while modified kraft lignin showed higher thermal stability than pure kraft lignin and possessed delayed onset thermal degradation temperature.
    Matched MeSH terms: Vibration
  6. Narayanan DA, Raman R, Chong AW
    Turk Arch Otorhinolaryngol, 2019 Sep;57(3):122-126.
    PMID: 31620693 DOI: 10.5152/tao.2019.3875
    Objective: The objectives are to determine and compare the degrees of hearing loss upon occlusion of the cartilaginous and the bony portion of the external ear canal (EAC).

    Methods: There were 20 healthy participants with normal ears, and all gave an informed consent. After an otoscopy, a baseline pure tone audiogram (PTA) was conducted. If the PTA of the participant was normal, aqueous cream was applied with a syringe via an 18 G cannula, from the tympanic membrane up to the isthmus which corresponds to the bony ear canal. A second PTA was conducted, and subsequently the cream was removed via suction under microscope guidance. The procedure was then repeated with the cream applied from the isthmus to the aperture of the external ear canal using the same cannula followed by a PTA and removal of cream under microscope.

    Results: The mean threshold difference of occlusion at both portions of the ear canal were compared and analyzed. The mean threshold difference of hearing loss upon occlusion at the cartilaginous EAC was 37.5 to 48 dB. The mean threshold difference of hearing loss upon occlusion at the bony EAC was less, with a range of 21 to 24.95dB. There was a statistical difference (p<0.05) in the hearing loss between the blockage of the cartilaginous canal versus the blockage of the bony canal with a maximum difference at 2kHz.

    Conclusion: Cartilaginous block of the external ear canal causes more hearing loss than block of the bony ear canal. This correlates with the concept and properties of sound waves, resonance and impedance.

    Matched MeSH terms: Vibration
  7. Karlas T, Petroff D, Sasso M, Fan JG, Mi YQ, de Lédinghen V, et al.
    Aliment Pharmacol Ther, 2018 Apr;47(7):989-1000.
    PMID: 29446106 DOI: 10.1111/apt.14529
    BACKGROUND: Liver fibrosis is often accompanied by steatosis, particularly in patients with non-alcoholic fatty liver disease (NAFLD), and its non-invasive characterisation is of utmost importance. Vibration-controlled transient elastography is the non-invasive method of choice; however, recent research suggests that steatosis may influence its diagnostic performance. Controlled Attenuation Parameter (CAP) added to transient elastography enables simultaneous assessment of steatosis and fibrosis.

    AIM: To determine how to use CAP in interpreting liver stiffness measurements.

    METHODS: This is a secondary analysis of data from an individual patient data meta-analysis on CAP. The main exclusion criteria for the current analysis were unknown aetiology, unreliable elastography measurement and data already used for the same research question. Aetiology-specific liver stiffness measurement cut-offs were determined and used to estimate positive and negative predictive values (PPV/NPV) with logistic regression as functions of CAP.

    RESULTS: Two thousand and fifty eight patients fulfilled the inclusion criteria (37% women, 18% NAFLD/NASH, 42% HBV, 40% HCV, 51% significant fibrosis ≥ F2). Youden optimised cut-offs were only sufficient for ruling out cirrhosis (NPV of 98%). With sensitivity and specificity-optimised cut-offs, NPV for ruling out significant fibrosis was moderate (70%) and could be improved slightly through consideration of CAP. PPV for significant fibrosis and cirrhosis were 68% and 55% respectively, despite specificity-optimised cut-offs for cirrhosis.

    CONCLUSIONS: Liver stiffness measurement values below aetiology-specific cut-offs are very useful for ruling out cirrhosis, and to a lesser extent for ruling out significant fibrosis. In the case of the latter, Controlled Attenuation Parameter can improve interpretation slightly. Even if cut-offs are very high, liver stiffness measurements are not very reliable for ruling in fibrosis or cirrhosis.

    Matched MeSH terms: Vibration
  8. Lin H, Lee HW, Yip TC, Tsochatzis E, Petta S, Bugianesi E, et al.
    JAMA, 2024 Apr 16;331(15):1287-1297.
    PMID: 38512249 DOI: 10.1001/jama.2024.1447
    IMPORTANCE: Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently the most common chronic liver disease worldwide. It is important to develop noninvasive tests to assess the disease severity and prognosis.

    OBJECTIVE: To study the prognostic implications of baseline levels and dynamic changes of the vibration-controlled transient elastography (VCTE)-based scores developed for the diagnosis of advanced fibrosis (Agile 3+) and cirrhosis (Agile 4) in patients with MASLD.

    DESIGN, SETTING, AND PARTICIPANTS: This cohort study included data from a natural history cohort of patients with MASLD who underwent VCTE examination at 16 tertiary referral centers in the US, Europe, and Asia from February 2004 to January 2023, of which the data were collected prospectively at 14 centers. Eligible patients were adults aged at least 18 years with hepatic steatosis diagnosed by histologic methods (steatosis in ≥5% of hepatocytes) or imaging studies (ultrasonography, computed tomography or magnetic resonance imaging, or controlled attenuation parameter ≥248 dB/m by VCTE).

    MAIN OUTCOMES AND MEASURES: The primary outcome was liver-related events (LREs), defined as hepatocellular carcinoma or hepatic decompensation (ascites, variceal hemorrhage, hepatic encephalopathy, or hepatorenal syndrome), liver transplant, and liver-related deaths. The Agile scores were compared with histologic and 8 other noninvasive tests.

    RESULTS: A total of 16 603 patients underwent VCTE examination at baseline (mean [SD] age, 52.5 [13.7] years; 9600 [57.8%] were male). At a median follow-up of 51.7 (IQR, 25.2-85.2) months, 316 patients (1.9%) developed LREs. Both Agile 3+ and Agile 4 scores classified fewer patients between the low and high cutoffs than most fibrosis scores and achieved the highest discriminatory power in predicting LREs (integrated area under the time-dependent receiver-operating characteristic curve, 0.89). A total of 10 920 patients (65.8%) had repeated VCTE examination at a median interval of 15 (IQR, 11.3-27.7) months and were included in the serial analysis. A total of 81.9% of patients (7208 of 8810) had stable Agile 3+ scores and 92.6% of patients (8163 of 8810) had stable Agile 4 scores (same risk categories at both assessments). The incidence of LREs was 0.6 per 1000 person-years in patients with persistently low Agile 3+ scores and 30.1 per 1000 person-years in patients with persistently high Agile 3+ scores. In patients with high Agile 3+ score at baseline, a decrease in the score by more than 20% was associated with substantial reduction in the risk of LREs. A similar trend was observed for the Agile 4 score, although it missed more LREs in the low-risk group.

    CONCLUSIONS AND RELEVANCE: Findings of this study suggest that single or serial Agile scores are highly accurate in predicting LREs in patients with MASLD, making them suitable alternatives to liver biopsy in routine clinical practice and in phase 2b and 3 clinical trials for steatohepatitis.

    Matched MeSH terms: Vibration
  9. Halim I, Omar AR
    Int J Occup Saf Ergon, 2012;18(1):85-96.
    PMID: 22429532
    Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.
    Matched MeSH terms: Vibration/adverse effects
  10. Rozali A, Rampal KG, Shamsul Bahri MT, Mohd Sidik S, Shamsul Azhar S, Khairuddin H, et al.
    Med J Malaysia, 2009 Sep;64(3):197-204.
    PMID: 20527267 MyJurnal
    A cross sectional study was conducted among military armoured vehicle drivers in the two largest mechanized battalions with the objective to determine the prevalence of low back pain (LBP), and its association with whole body vibration (WBV) and other associated factors. A self-administered questionnaire and Human Vibration Meter were used in this study. A total of 159 respondents participated in this study and 102 (64.2%) of them were subjected to WBV measurement. One-hundred-and-seventeen respondents complained of LBP for the past 12 months giving a prevalence of 73.6%. The prevalence of LBP among tracked armoured vehicle drivers was higher (81.7%) as compared to wheeled armoured vehicle drivers (67.0%). The mean acceleration at Z-axis in tracked armoured vehicles (1.09 +/- 0.26 ms(-2)) and wheeled armoured vehicles (0.33 +/- 0.07 ms) were the dominant vibration directions. The mean estimated vibration dose value (eVDV) for eight-hour daily exposure at Z-axis (19.86 +/- 4.72 ms(-1.75)) in tracked armoured vehicles showed the highest estimation. Based on the European Vibration Directive (2002), the mean eVDV at Z-axis in tracked armoured vehicles exceeded exposure action value (EAV) (> 9.1 ms(-1.75), but did not exceed exposure limit value (ELV) (<21.0 ms(-1.75)). Logistic regression analysis revealed that only driving in forward bending sitting posture (OR = 3.63, 95% CI 1.06-12.42) and WBV exposure at X-axis (OR = 1.94, 95% CI 1.02-3.69) were significant risk factors to LBP. Preventive measures should be implemented to minimize risk of WBV and to improve ergonomic postures among drivers.
    Matched MeSH terms: Vibration/adverse effects*
  11. Daud R, Maeda S, Kameel NN, Ripin MY, Bakrun N, Md Zein R, et al.
    Ind Health, 2004 Apr;42(2):189-95.
    PMID: 15128168
    The purpose of this paper is to clarify the reference vibrotactile perception thresholds (VPT) for healthy people in Malaysia. The measurement equipment standard, ISO 13091-1, of the vibrotactile perception thresholds for the assessment of nerve dysfunction and the analysis and interpretation of measurements at the fingertips standard, ISO 13091-2, were published in ISO/TC108/SC4/WG8 on 2001 and 2003 individually. In the ISO 13091-2 standard, the reference VPT data were obtained from few research papers. Malaysian people's VPT data don't include to this standard. In Malaysia, when the VPT is using to diagnose of the hand-arm vibration syndrome, the reference VPT data need to compare with the worker's ones. But, Malaysia does not have the reference VPT data yet. So, in this paper, the VPT was measured by using ISO 13091-1 standard equipment to obtain the reference data for Malaysian people. And these data were compared with the ISO reference data on the ISO 13091-2 standard. From the comparison of these data, it was clear that the Malaysian healthy people's VPT data were consistent with the reference data of the ISO 13091-2 standard.
    Matched MeSH terms: Vibration*
  12. Tamrin SB, Yokoyama K, Jalaludin J, Aziz NA, Jemoin N, Nordin R, et al.
    Ind Health, 2007 Apr;45(2):268-78.
    PMID: 17485871
    To determine the risk factors associated with complain of low back pain. A cross sectional study was done from June 2004 until August 2005. Seven hundred and sixty commercial vehicle drivers from 11 bus companies in central, northern and eastern regions in Malaysia participated in this study. Modified Nordic questionnaire was used to determine the prevalence of low back pain; Maestro human vibration meter was used to measure the personal R.M.S values of lateral, anterior-posterior and vertical axes. Modified Owas was used to assess the awkward posture of the driver torso namely, bending forward movement, leaning, sitting straight and twisting. Profile of Mood States (POMS) was used to evaluate the mood states of bus drivers with complain of low back pain. A high prevalence of low back pain (60.4%) among Malaysian commercial vehicle drivers was found. Logistic regression analysis controlling for age, income, education level and non occupational activities revealed that the following factors were related to low back pain: Tension-anxiety [1.080, 95% CI 1.041-1.121], depression dejection [1.047, 95% CI 1.023-1.072], anger-hostility [1.053, 95% CI 1.027-1.081], fatigue [1.132, 95% CI 1.089-1.177] and confusion [1.114, 95% CI 1.061-1.169] of POMS, length of employment [1.001, 95% CI 1.0-1.003], steering wheel adjustment [1.521, 95% CI 1.101-2.101], perception of exposing to vibration [1.943, 95% CI 1.389-2.719]. In conclusion, combinations of risks lead to high increase of low back pain complain among Malaysian bus drivers.
    Matched MeSH terms: Vibration/adverse effects
  13. Arunagiri C, Subashini A, Saranya M, Thomas Muthiah P, Thanigaimani K, Abdul Razak I
    PMID: 25084236 DOI: 10.1016/j.saa.2014.07.016
    The molecular structure of a new Schiff base, 2-[4-hydroxy benzylidene]-amino naphthalene (HBAN) has been examined by HF and B3LYP/6-311++G(d,p) calculations. The X-ray structure was determined in order to establish the conformation of the molecule. The compound, C17H13NO, crystallizes in the orthorhombic, P212121 space group with the cell dimension, a=6.2867(2), b=10.2108(3), c=19.2950(6) Å, α=β=γ=90° and z=4. The asymmetric unit contains a molecule of a Schiff base. A strong intermolecular O-H⋯N and a weak C-H⋯O hydrogen bonds stabilized the crystal structure. The vibrational spectra of HBAN have been calculated using density functional theoretical computation and compared with the experimental. The study is extended to the HOMO-LUMO analysis to calculate the energy gap (Δ), Ionization potential (I), Electron Affinity (A), Global Hardness (η), Chemical Potential (μ) and Global Electrophilicity (w). The calculated HOMO and LUMO energy reveals that the charge transfer occurs within the molecule.
    Matched MeSH terms: Vibration
  14. Azimi M, Bin Adnan A, Sam AR, Tahir MM, Faridmehr I, Hodjati R
    ScientificWorldJournal, 2014;2014:802605.
    PMID: 25309957 DOI: 10.1155/2014/802605
    The seismic performance of RC columns could be significantly improved by continuous spiral reinforcement as a result of its adequate ductility and energy dissipation capacity. Due to post-earthquake brittle failure observations in beam-column connections, the seismic behaviour of such connections could greatly be improved by simultaneous application of this method in both beams and columns. In this study, a new proposed detail for beam to column connection introduced as "twisted opposing rectangular spiral" was experimentally and numerically investigated and its seismic performance was compared against normal rectangular spiral and conventional shear reinforcement systems. In this study, three full scale beam to column connections were first designed in conformance with Eurocode (EC2-04) for low ductility class connections and then tested by quasistatic cyclic loading recommended by ACI Building Code (ACI 318-02). Next, the experimental results were validated by numerical methods. Finally, the results revealed that the new proposed connection could improve the ultimate lateral resistance, ductility, and energy dissipation capacity.
    Matched MeSH terms: Vibration
  15. Woi PM, Bakar MA, Rosli AN, Lee VS, Ahmad MR, Zain S, et al.
    J Mol Model, 2014 May;20(5):2219.
    PMID: 24770548 DOI: 10.1007/s00894-014-2219-3
    DFT and G4 results reveal that cations display the following trends in imparting its positive charge to acrylonitrile; H⁺ > Li⁺ > Na⁺ > K⁺ for group I and Be²⁺ > Mg²⁺ > Ca²⁺ for group II. Solvation by water molecules and interaction with cation make the cyano bond more polarized and exhibits ketene-imine character. Bond order in nitrile-cation complexes has been predicted based on the s character of the covalent bond orbitals. Mulliken, CHELPG, and NPA charges are in good agreement in predicting positive charge buildup and GIAO nuclear deshileding on C1. G4 enthalpies show that Mg²⁺ is more strongly bound to acrylonitrile than to acetonitrile by 3 kcal mol⁻¹, and the proton affinity of the former is higher by 0.8 kcal mol⁻¹. G4 enthalpies of reductions support prior experimental observation that metalated conjugated nitriles show enhanced reactivity toward weak nucleophiles to afford Michael addition products.
    Matched MeSH terms: Vibration
  16. Chidan Kumar CS, Fun HK, Parlak C, Rhyman L, Ramasami P, Tursun M, et al.
    PMID: 24858359 DOI: 10.1016/j.saa.2014.04.155
    A novel (2E)-1-(5-chlorothiophen-2-yl)-3-(naphthalen-2-yl)prop-2-en-1-one [C17H11ClOS] compound has been synthesized and its structure has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The isomers, optimized geometrical parameters, normal mode frequencies and corresponding vibrational assignments of the compound have been examined by means of the density functional theory method, employing, the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. Reliable vibrational assignments and molecular orbitals have been investigated by the potential energy distribution and natural bonding orbital analyses, respectively. The compound crystallizes in the monoclinic space group P2₁/c with the unit cell parameters a=5.7827(8)Å, b=14.590(2)Å, c=16.138(2)Å and β=89.987 (°). The CC bond of the central enone group adopts an E configuration. There is a good agreement between the theoretically predicted structural parameters and vibrational frequencies and those obtained experimentally.
    Matched MeSH terms: Vibration
  17. Ramesh S, Yuen TF, Shen CJ
    PMID: 17600757
    Polymer electrolytes based on poly(ethylene oxide)-lithium triflate (PEO-LiCF3SO3) and poly(ethylene oxide)-lithium sulphate (PEO-Li2S4) were prepared by using solution casting method. Measurements of conductivity and dielectric were carried out on these films as a function of frequency at various temperatures. It was observed that PEO-LiCF3SO3 polymer electrolytes have higher conductivity. The interaction between PEO and Li salts were studied by Fourier transform infrared (FTIR).
    Matched MeSH terms: Vibration
  18. Ramesh S, Leen KH, Kumutha K, Arof AK
    Spectrochim Acta A Mol Biomol Spectrosc, 2007 Apr;66(4-5):1237-42.
    PMID: 16919998
    The polymer electrolytes composing of the blend of polyvinyl chloride-polymethyl methacrylate (PVC/PMMA) with lithium triflate (LiCF3SO3) as salt, ethylene carbonate (EC) and dibutyl phthalate (DBP) as plasticizers and silica (SiO2) as the composite filler were prepared. FTIR studies confirm the complexation between PVC/PMMA blends. The CCl stretching mode at 834 cm-1 for pure PVC is shifted to 847 cm-1 in PVC-PMMA-LiCF3SO3 system. This suggests that there is interaction between Cl in PVC with Li+ ion from LiCF3SO3. The band due to OCH3 at 1150 cm-1 for PVC-PMMA blend is shifted to 1168 cm-1 in PVC-PMMA-LiCF3SO3 system. This shift is expected to be due to the interaction between Li+ ion and the oxygen atom in PMMA. The symmetric vibration band and the asymmetric vibration band of LiCF3SO3 at 1033 and 1256 cm-1 shifted to 1075 and 1286 cm-1 in the DBP-EC plasticized PVC-PMMA-LiCF3SO3 complexes. The interaction between Li+ ions and SiO2 will lead to an increase in the number of free plasticizers (which does not interact with Li+ ions). When the silica content increases from 2% to 5%, the intensity of the peak at 896 cm-1 (due to the ring breathing vibration of free EC) increases in PVC-PMMA-LiCF3SO3-DBP-EC system.
    Matched MeSH terms: Vibration
  19. Treshi-marie Perera A, Newport R, McKenzie KJ
    Exp Brain Res, 2015 Nov;233(11):3153-61.
    PMID: 26195170 DOI: 10.1007/s00221-015-4384-8
    Research has suggested that altering the perceived shape and size of the body image significantly affects perception of somatic events. The current study investigated how multisensory illusions applied to the body altered tactile perception using the somatic signal detection task. Thirty-one healthy volunteers were asked to report the presence or absence of near-threshold tactile stimuli delivered to the index finger under three multisensory illusion conditions: stretched finger, shrunken finger and detached finger, as well as a veridical baseline condition. Both stretching and shrinking the stimulated finger enhanced correct touch detections; however, the mechanisms underlying this increase were found to be different. In contrast, the detached appearance reduced false touch reports-possibly due to reduced tactile noise, as a result of attention being directed to the tip of the finger only. These findings suggest that distorted representations of the body could have different modulatory effects on attention to touch and provide a link between perceived body representation and somatosensory decision-making.
    Matched MeSH terms: Vibration
  20. Islam MS, Al-Majid AM, Barakat A, Soliman SM, Ghabbour HA, Quah CK, et al.
    Molecules, 2015 May 07;20(5):8223-41.
    PMID: 25961163 DOI: 10.3390/molecules20058223
    This paper describes an efficient and regioselective method for the synthesis of novel fluorinated spiro-heterocycles in excellent yield by cascade [5+1] double Michael addition reactions. The compounds 7,11-bis(4-fluorophenyl)-2,4-dimethyl- 2,4-diazaspiro[5.5] undecane-1,3,5,9-tetraone (3a) and 2,4-dimethyl-7,11-bis (4-(trifluoromethyl)phenyl)-2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraone (3b) were characterized by single-crystal X-ray diffraction, FT-IR and NMR techniques. The optimized geometrical parameters, infrared vibrational frequencies and NMR chemical shifts of the studied compounds have also been calculated using the density functional theory (DFT) method, using Becke-3-Lee-Yang-Parr functional and the 6-311G(d,p) basis set. There is good agreement between the experimentally determined structural parameters, vibrational frequencies and NMR chemical shifts of the studied compounds and those predicted theoretically. The calculated natural atomic charges using NBO method showed higher polarity of 3a compared to 3b.The calculated electronic spectra are also discussed based on the TD-DFT calculations.
    Matched MeSH terms: Vibration
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