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| 3. |
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| 4. |
- Glasbey, JC, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 5. |
- Feigin, Valery L., et al.
(författare)
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Global, regional, and national burden of stroke and its risk factors, 1990-2019 : a systematic analysis for the Global Burden of Disease Study 2019
- 2021
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Ingår i: Lancet Neurology. - : Elsevier. - 1474-4422 .- 1474-4465. ; 20:10, s. 795-820
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Tidskriftsartikel (refereegranskat)abstract
- Background Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels. Methods We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level. Findings In 2019, there were 12.2 million (95% UI 11.0-13.6) incident cases of stroke, 101 million (93.2-111) prevalent cases of stroke, 143 million (133-153) DALYs due to stroke, and 6.55 million (6.00-7.02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11.6% [10.8-12.2] of total deaths) and the third-leading cause of death and disability combined (5.7% [5.1-6.2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70.0% (67.0-73.0), prevalent strokes increased by 85.0% (83.0-88.0), deaths from stroke increased by 43.0% (31.0-55.0), and DALYs due to stroke increased by 32.0% (22.0-42.0). During the same period, age-standardised rates of stroke incidence decreased by 17.0% (15.0-18.0), mortality decreased by 36.0% (31.0-42.0), prevalence decreased by 6.0% (5.0-7.0), and DALYs decreased by 36.0% (31.0-42.0). However, among people younger than 70 years, prevalence rates increased by 22.0% (21.0-24.0) and incidence rates increased by 15.0% (12.0-18.0). In 2019, the age-standardised stroke-related mortality rate was 3.6 (3.5-3.8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3.7 (3.5-3.9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62.4% of all incident strokes in 2019 (7.63 million [6.57-8.96]), while intracerebral haemorrhage constituted 27.9% (3.41 million [2.97-3.91]) and subarachnoid haemorrhage constituted 9.7% (1.18 million [1.01-1.39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79.6 million [67.7-90.8] DALYs or 55.5% [48.2-62.0] of total stroke DALYs), high body-mass index (34.9 million [22.3-48.6] DALYs or 24.3% [15.7-33.2]), high fasting plasma glucose (28.9 million [19.8-41.5] DALYs or 20.2% [13.8-29.1]), ambient particulate matter pollution (28.7 million [23.4-33.4] DALYs or 20.1% [16.6-23.0]), and smoking (25.3 million [22.6-28.2] DALYs or 17.6% [16.4-19.0]). Interpretation The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries.
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| 6. |
- Abbasi, Mazhar Ali, et al.
(författare)
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Iron (III) Ion Sensor Based on the Seedless Grown ZnO Nanorods in 3 Dimensions Using Nickel Foam Substrate
- 2013
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Ingår i: Journal of Sensors. - : Hindawi Publishing Corporation. - 1687-725X .- 1687-7268. ; :382726
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, the seedless, highly aligned and vertical ZnO nanorods in 3 dimensions (3D) were grown on the nickel foam substrate. The seedless grown ZnO nanorods were characterised by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) techniques. The characterised seedless ZnO nanorods in 3D on nickel foam were highly dense, perpendicular to substrate, grown along the (002) crystal plane, and also composed of single crystal. In addition to this, these seedless ZnO nanorods were functionalized with trans-dinitro-dibenzo-18-6 crown ether, a selective iron (III) ion ionophore, along with other components of membrane composition such as polyvinyl chloride (PVC), 2-nitopentylphenyl ether as plasticizer (NPPE), and tetrabutyl ammonium tetraphenylborate (TBATPB) as conductivity increaser. The sensor electrode has shown high linearity with a wide range of detection of iron (III) ion concentrations from 0.005 mM to 100 mM. The low limit of detection of the proposed ion selective electrode was found to be 0.001 mM. The proposed sensor also described high storage stability, selectivity, reproducibility, and repeatability and a quick response time of less than 10 s.
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| 7. |
- Abbasi, Mazhar Ali, et al.
(författare)
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Potentiometric Zinc Ion Sensor Based on Honeycomb-Like NiO Nanostructures
- 2012
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 12:11, s. 15424-15437
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Tidskriftsartikel (refereegranskat)abstract
- In this study honeycomb-like NiO nanostructures were grown on nickel foam by a simple hydrothermal growth method. The NiO nanostructures were characterized by field emission electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) techniques. The characterized NiO nanostructures were uniform, dense and polycrystalline in the crystal phase. In addition to this, the NiO nanostructures were used in the development of a zinc ion sensor electrode by functionalization with the highly selective zinc ion ionophore 12-crown-4. The developed zinc ion sensor electrode has shown a good linear potentiometric response for a wide range of zinc ion concentrations, ranging from 0.001 mM to 100 mM, with sensitivity of 36 mV/decade. The detection limit of the present zinc ion sensor was found to be 0.0005 mM and it also displays a fast response time of less than 10 s. The proposed zinc ion sensor electrode has also shown good reproducibility, repeatability, storage stability and selectivity. The zinc ion sensor based on the functionalized NiO nanostructures was also used as indicator electrode in potentiometric titrations and it has demonstrated an acceptable stoichiometric relationship for the determination of zinc ion in unknown samples. The NiO nanostructures-based zinc ion sensor has potential for analysing zinc ion in various industrial, clinical and other real samples.
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| 8. |
- Khan, U. H., et al.
(författare)
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A novel asterisk-shaped circularly polarized RFID tag for on-metal applications
- 2016
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Ingår i: Applied Computational Electromagnetics Society Journal. - : Applied Computational Electromagnetics Society (ACES). - 1054-4887. ; 31:9, s. 1035-1042
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Tidskriftsartikel (refereegranskat)abstract
- An asterisk-shaped, metal-mountable RFID tag with a minuscule footprint is presented. The proposed design makes use of multiple asymmetric slots patterned in a cross-shaped fashion to achieve circular polarization. The structure is excited capacitively using a terminally-grounded, T-shaped feed line positioned within the slots. This peculiar arrangement permits the attainment of circular polarized radiation characteristics over a wide band of operation. Impedance matching, antenna size reduction and read range enhancement are the additional advantages offered by the embedded feed line. The final design is realized on a commercially available FR-4 substrate over dimensions of 40 x 40 mm2 yielding an impedance bandwidth and an axial ratio bandwidth of 37 MHz and 20 MHz, respectively. Improvement in antenna gain (and consequently in the read range) is reported upon mounting the tag on metallic surfaces.
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| 9. |
- Abbasi, Mazhar Ali, et al.
(författare)
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Fabrication of UV photo-detector based on coral reef like p-NiO/n-ZnO nanocomposite structures
- 2013
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Ingår i: Materials letters (General ed.). - : Elsevier. - 0167-577X .- 1873-4979. ; 108, s. 149-152
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Tidskriftsartikel (refereegranskat)abstract
- In this research work, a UV photo-detector is fabricated on fluorine doped tin oxide (FTO) glass substrate by exploiting the advantageous features of p-n heterojunctions based on p-NiO and n-ZnO composite nanostructures forming a coral-reef like structures. Scanning electron microscopy (SEM) and X-ray diffraction results showed uniform morphology and good crystal quality of the synthesised nanostructures respectively. I-V measurements have shown nonlinear and rectifying response of the p-NiO/n-ZnO heterojunction. The proposed photodiode exhibited excellent UV response with acceptable photocurrent generation of about 3.4 mA and the responsivity of 2.27 A/W at -3 biasing voltage.
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| 11. |
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| 12. |
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| 13. |
- Aslam, Bilal, et al.
(författare)
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A compact implantable RFID tag antenna dedicated to wireless health care
- 2017
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Ingår i: International Journal of RF and Microwave Computer-Aided Engineering. - : John Wiley & Sons. - 1096-4290 .- 1099-047X. ; 27:5
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Tidskriftsartikel (refereegranskat)abstract
- Implantable tag antennas are an integral component of contemporary pervasive patient monitoring setups envisioned to reduce the medical errors and improve the quality of health care facilities. These tags, embedded into the human body, transmit critical patient information to the external equipment via a wireless communication link. This research article presents an implantable compact folded dipole antenna of size 10 mm 3 15 mm 3 2 mm, designed to operate in the industrial-scientificmedical band (2.4-2.48GHz). A three-layered phantom representing the human arm is used to evaluate the subcutaneous antenna performance. The tag antenna embedded in the middle of the fat layer offers a maximum gain of 216.3 dBi. The tag antenna performance as a function of implant position and phantom dimensions is analyzed. Link budget calculations show that with the achieved antenna gain the link power exceeds the required power by 38.37 dBm, and hence wireless communication is viable.
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| 14. |
- Aslam, B., et al.
(författare)
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Miniaturized decoupled slotted patch RFID tag antennas for wearable health care
- 2017
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Ingår i: International Journal of RF and Microwave Computer-Aided Engineering. - : John Wiley & Sons. - 1096-4290 .- 1099-047X. ; 27:1
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Tidskriftsartikel (refereegranskat)abstract
- In this article, a couple of two-layered RFID tag antenna designs exhibiting improved performance descriptors for on-body applications are presented. The antennas are designed to operate in the microwave band (2.4–2.48 GHz) ensuring high data transmission rates ideal for real-time subject monitoring applications. The radiating element of both the antennas is a slotted patch structure provisioned with a pair of T-shaped slots realized on a commercial FR4 substrate. The augmentation of a systematic sequence of narrow comb-like etchings into the design enhances the impedance bandwidth considerably. A high permittivity silicon layer embedded with the radiating patch provides resilience from the human body dielectric losses. A modified antenna design utilizing patch miniaturization technique, resulting in an overall footprint reduction by 32%, is also proposed. The designed tag antennas offer a gain of more than 1.8 dBi and an attractive read range greater than 6.8 m in the operating band.
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| 15. |
- Azam, Asad Muhammad, et al.
(författare)
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Analysis of degradation in UHMWPE a comparative study among the various commercial and laboratory grades UHMWPE
- 2016
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Ingår i: 14TH INTERNATIONAL SYMPOSIUM ON ADVANCED MATERIALS (ISAM 2015). - : IOP PUBLISHING LTD.
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Konferensbidrag (refereegranskat)abstract
- Oxidative degradation of the ultra-high molecular weight polyethylene ( UHMWPE) limits the life of implants. This degradation can be monitored to estimate the service life of UHMWPE following the standard protocols as defined by American Standards for Testing Materials ( ASTM). In this work, a comparative study has been carried on two commercially available UHMWPE grades i. e. GUR 1020 and GUR 1050 and one laboratory grade UHMWPE which was purchased from Sigma Aldrich. These powder samples were pressed while using hot press with controlled heating and cooling setup in open air under 200 bar of external pressure. These sheets were then subjected to accelerated aging in an oven at 80 degrees C for three weeks. The degradation of the UHMWPE was monitored by ATR-FTIR techniquefor three weeks. The oxidation index ( OI) measurement showed that the commercial grade UHMWPE i. e. GUR-1020 and GUR-1050 degrade more as compared to laboratory grade UHMWPE. The values of OI after three weeks of accelerating aging were found 0.18, 0.14, and 0.09 for GUR-1020, GUR-1050, and Sigma Aldrich, respectively. In addition to this, it was found that commercial grades of UHMWPE suffer more structural alterations as compared to laboratory grade one. We hope that these results will be of particular and fundamental importance for the researchers and orthopaedic industry.
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| 16. |
- Hakeem, Abbas Saeed, et al.
(författare)
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Microstructure Evaluation and Impurities in La Containing Silicon Oxynitrides
- 2021
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Ingår i: Nanomaterials. - : MDPI. - 2079-4991. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Oxynitride glasses are not yet commercialised primarily due to the impurities present in the network of these glasses. In this work, we investigated the microstructure and instinctive defects in nitrogen rich La-Si-O-N glasses. Glasses were prepared by heating a powder mixture of pure La metal, Si3N4, and SiO2 in a nitrogen atmosphere at 1650-1800 degrees C. The microstructure and impurities in the glasses were examined by optical microscopy, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy in conjunction with electron energy-loss spectroscopy. Analyses showed that the glasses contain a small amount of spherical metal silicide particles, mostly amorphous or poorly crystalline, and having sizes typically ranging from 1 mu m and less. The amount of silicide was estimated to be less than 2 vol. %. There was no systematic relation between silicide formation and glass composition or preparation temperature. The microstructure examination revealed that the opacity of these nitrogen rich glasses is due to the elemental Si arise from the decomposition reaction of silicon nitride and silicon oxide, at a high temperature above similar to 1600 degrees C and from the metallic silicide particles formed by the reduction of silicon oxide and silicon nitride at an early stage of reaction to form a silicide intermetallic with the La metal.
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| 17. |
- Hatamie, Amir, et al.
(författare)
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Zinc Oxide Nanostructure-Modified Textile and Its Application to Biosensing, Photocatalysis, and as Antibacterial Material
- 2015
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Ingår i: Langmuir. - : AMER CHEMICAL SOC. - 0743-7463 .- 1520-5827. ; 31:39, s. 10913-10921
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Tidskriftsartikel (refereegranskat)abstract
- Recently, one-dimensional nanostructures with different morphologies (such as nanowires, nanorods (NRs), and nanotubes) have become the focus of intensive research, because of their unique properties with potential applications. Among them, zinc oxide (ZnO) nanomaterials has been found to be highly attractive, because of the remarkable potential for applications in many different areas such as solar cells, sensors, piezoelectric devices, photodiode devices, sun screens, antireflection coatings, and photocatalysis. Here, we present an innovative approach to create a new modified textile by direct in situ growth of vertically aligned one-dimensional (1D) ZnO NRs onto textile surfaces, which can serve with potential for biosensing, photocatalysis, and antibacterial applications. ZnO NRs were grown by using a simple aqueous chemical growth method. Results from analyses such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the ZnO NRs were dispersed over the entire surface of the textile. We have demonstrated the following applications of these multifunctional textiles: (1) as a flexible working electrode for the detection of aldicarb (ALD) pesticide, (2) as a photo catalyst for the degradation of organic molecules (i.e., Methylene Blue and Congo Red), and (3) as antibacterial agents against Escherichia coli. The ZnO-based textile exhibited excellent photocatalytic and antibacterial activities, and it showed a promising sensing response. The combination of sensing, photo catalysis, and antibacterial properties provided by the ZnO NRs brings us closer to the concept of smart textiles for wearable sensing without a deodorant and antibacterial control. Perhaps the best known of the products that is available in markets for such purposes are textiles with silver nanoparticles. Our modified textile is thus providing acceptable antibacterial properties, compared to available commercial modified textiles.
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| 18. |
- Hussain, Mushtaque, et al.
(författare)
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Comparative Study of Energy Harvesting from ZnO Nanorods Using Different Flexible Substrates
- 2014
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Ingår i: Energy Harvesting and Systems. - : Walter de Gruyter. - 2329-8774 .- 2329-8766. ; 1:1-2, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- The step toward the fabrication of nanodevices with low cost and improved performance is of high demand; therefore, in the present study, different flexible substrates like common paper, textile fabric, plastic and aluminum foil have been utilized to harvest electrical energy. ZnO nanorods (NRs) were grown by using lowtemperature aqueous chemical growth method. The obtained ZnO NRs were highly dense, well aligned, uniformly distributed over the substrates and exhibited good crystal quality. The structural study was carried out by using X-ray powder diffraction and scanning electron microscopy. The piezoelectric properties of ZnO NRs were investigated by the help of an atomic force microscope using contact mode. The measurements of generated piezoelectricity were around 16.2 mV, 23.2 mV, 38.5 mV and 43.3 mV for common paper, textile fabric, plastic and aluminum foil, respectively. This investigation is an important step in order to study the effect of different substrates influencing the magnitude of the output voltage under identical growth and measurement conditions. We expect that this study will help identify the most suitable flexible substrate for harvesting energy. It also offers a promising alternative powering source for the next generation nanodevices using non-conventional substrates like aluminum foil. Moreover, the use of aluminum foil as flexible and low cost substrate may pave the way to develop devices in different fields including energy harvesting.
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| 19. |
- Hussain, Mushtaque, et al.
(författare)
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Effect of Post Growth Annealing on the Structural and Electrical Properties of ZnO/CuO Composite Nanostructures
- 2014
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Ingår i: Acta Physica Polonica. A. - : Polish Academy of Sciences, Institute of Physics. - 0587-4246 .- 1898-794X. ; 126:3, s. 849-854
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, ZnO/CuO composite nanostructures have been grown on fluorine doped tin oxide coated glass substrate by aqueous chemical growth method. To observe the effect of post growth annealing (500 degrees C, 1 min) on the structural properties of ZnO nanorods scanning electron microscope and X-ray diffraction techniques have been utilized. SEM images of post growth annealed (post growth annealed) sample reveal that the average diameter of ZnO NRs has considerably increased in comparison with as grown sample. Moreover after post growth annealing the ZnO NRs showed more clearly hexagonal wurtzite structure. Beside this the NRs are also uniform and well aligned with a high aspect ratio of similar to 10. In XRD pattern the strongly intense (002) peak of the post growth annealing sample suggest that the crystal quality of the NRs have also been improved significantly. Since the structural improvement have a significant impact on charge transport properties as well, therefore the effect of post growth annealed has also been investigated by the electrical characterization of ZnO/CuO based heterojunction. The current-voltage measurements of the post growth annealed sample showed improvement in the current in comparison with as grown sample. The impedance study has also confirmed that the post growth annealed has influence on the electrical properties. The presented post growth annealed heterojunction of ZnO/CuO may have space in applications like sensors and oxide based diodes in the devices fabrication.
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| 20. |
- Hussain, Mushtaque, et al.
(författare)
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Synthesis of CuO/ZnO Composite Nanostructures, Their Optical Characterization and Valence Band Offset Determination by X-Ray Photoelectron Spectroscopy
- 2014
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Ingår i: Journal of Nanoelectronics and Optoelectronics. - : American Scientific Publishers. - 1555-130X .- 1555-1318. ; 9:3, s. 348-356
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Tidskriftsartikel (refereegranskat)abstract
- The study of the optical properties of zinc oxide (ZnO) nanorods and its composite nanostructures is an appealing issue in order to have highly efficient optoelectronic devices in the future. Zinc oxide, copper oxide (CuO) and their composite nanostructures were grown by the hydrothermal growth technique. The structural properties of the grown ZnO, CuO and their composite NSs were investigated by scanning electron microscopy and X-ray diffraction techniques. UV-visible spectroscopy, Cathodoluminescence and photoluminescence techniques were used for the study of optical properties of the as synthesized nanomaterials. X-ray photoelectron spectroscopy was used to measure the valence band offset of the CuO/ZnO composite nanostructures. Cathodoluminescence study of pure ZnO nanorods showed more insight for lateral luminescence compared to the top surface of the nanorods which opened a novel investigation in the area of optical properties of ZnO nanomaterial. While the room temperature cathodoluminescence spectra of CuO/ZnO composite nanostructures have demonstrated excellent luminescence in the UV region compared to the cathodoluminescence spectra observed at 4 K. The measured values for valence band offset and conduction band offset are found to be 2.83 eV and 0.73 eV, respectively for the prepared CuO/ZnO composite nanostructures. It was observed that CuO/ZnO composite nanostructures have type-II band alignment. The conclusion from both the cathodoluminescence and the photoluminescence studies showed that the luminescence in the visible region is only originated from the ZnO nanomaterial and that the CuO absorbs this visible emission as it covers the ZnO. This provides evidence suggesting that the use of CuO/ZnO in the fabrication of LEDs in the visible range is not appropriate.
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| 21. |
- Hussain, Mushtaque, et al.
(författare)
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The effect of oxygen-plasma treatment on the mechanical andpiezoelectrical properties of ZnO nanorods
- 2014
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Ingår i: Chemical Physics Letters. - : Elsevier. - 0009-2614 .- 1873-4448. ; 608, s. 235-238
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the effect of oxygen plasma treatment on piezoelectric response and on the mechanical stability of ZnO nanorods synthesized on FTO by using ACG method. XRD and SEM techniques have shown highly dense and uniformly distributed nanorods. The piezoelectric properties and mechanical stability of as-grown and oxygen plasma treated samples were investigated by using nanoindentation technique. The comparison of load–displacement curves showed that the oxygen plasma treated samples are much stiffer and show higher generated piezo-voltage. This study demonstrates that the oxygenplasma treatment is a good option to fabricate reliable and efficient nanodevices for enhanced generation of piezoelectricity.
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| 22. |
- Hussain, Mushtaque, et al.
(författare)
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Use of ZnO nanorods grown AFM tip in the architecture of piezoelectric nanogenerator
- 2014
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Ingår i: Micro & Nano Letters. - : Institution of Engineering and Technology (IET). - 1750-0443. ; 9:8, s. 539-543
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Tidskriftsartikel (refereegranskat)abstract
- The piezoelectric potential output has been studied using a ZnO nanorods (NRs) grown atomic force microscope (AFM) tip in lieu of the normally used AFM tip. The ZnO NRs were synthesised on the AFM tip and on the fluorine-doped tin oxide (FTO) glass substrate using the aqueous chemical growth method. The as-grown ZnO NRs were highly dense, well aligned and uniform both on the tip and on the substrate. The structural study was performed using X-ray diffraction and scanning electron microscopy techniques. The piezoelectric properties of as-grown ZnO NRs were investigated using an AFM in contact mode. In comparison to the AFM tip without ZnO NRs, extra positive voltage peaks were observed when the AFM tip with ZnO NRs was used. The pair of ZnO NRs on the AFM tip and on the FTO glass substrate together worked as two oppositely gliding walls (composed of ZnO NRs) and showed an enhancement in the amount of the harvested energy as much as eight times. This approach demonstrates that the use of the AFM tip with ZnO NRs is not only a good alternative to improve the design of nanogenerators to obtain an enhanced amount of harvested energy but is also simple, reliable and cost-effective.
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| 23. |
- Khan, Azam, et al.
(författare)
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Analysis of direct and converse piezoelectric responses from zinc oxide nanowires grown on a conductive fabric
- 2015
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Ingår i: Physica Status Solidi (a) applications and materials science. - : John Wiley & Sons. - 1862-6300 .- 1862-6319. ; 212:3, s. 579-584
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Tidskriftsartikel (refereegranskat)abstract
- Single crystalline hexagonal wurtzite zinc oxide nanowires were grown on conductive commercial textile fabric as piezoelectric material. Aqueous chemical growth (ACG) method was used for the synthesis of ZnO nanowires. Field emission surface scanning electron microscopy and X-ray diffraction techniques were used for surface and structural analysis of grown nanowires. The mechanical and piezoelectric properties of the nanowires were investigated by nanoindantation. Piezoelectric potentials up to 0.013 V were measured in response to direct applied loads in the range 0 - 11 mN. Also, a DC voltage was applied for measurement of converse piezoelectric response under a low constant applied force (~5 μN) and the piezoelectric coefficient was found to be 33.2 pm/V. This study performed on commercial conductive textile demonstrates the feasibility to fabricate wearable nanogenerator clothing.
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| 24. |
- Khan, Azam, et al.
(författare)
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Analysis of junction properties of gold-zinc oxide nanorods-based Schottky diode by means of frequency dependent electrical characterization on textile
- 2014
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Ingår i: Journal of Materials Science. - : Springer Verlag (Germany). - 0022-2461 .- 1573-4803. ; 49:9, s. 3434-3441
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Tidskriftsartikel (refereegranskat)abstract
- Present work is an effort to reveal the junction properties of gold/zinc oxide (ZnO) nanorods-based Schottky diode by using the frequency dependent electrical properties. The most important electrical parameters such as conductance, resistance, capacitance, and impedance were studied as function of frequency across the series of AC voltages. Moreover, current density-voltage (J-V) was measured to know the performance of present Schottky diode. The effect of native defects was also studied by using cathodoluminescence spectroscopy measured at different accelerating voltage. The textile substrate was used for the growth of ZnO nanorods by using the aqueous chemical growth method and Schottky diode fabrication. Diode fabrication on textile fabric is a step forward toward the fabrication of electronic devices on nonconventional, economical, soft, light weight, flexible, wearable, washable, recyclable, reproducible, and nontoxic substrate.
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| 25. |
- Khan, Azam
(författare)
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Analysis of the piezoelectric and current transport properties of zinc oxide nanostructures grown on fiber
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- It seems that nowadays the world is becoming as a small village due to the advancement in communication devices technology. These devices are playing an important role in the wellbeing of our life as almost each and every person is utilizing at least one of these devices. These devices consume energy and with our increased use of technology, we are faced with energy crises. Therefore, the research community is keen in trying to explore alternative resources. One possibility is to search for the alternative resources from our environment. The attempt in this thesis was to utilize the piezoelectric properties by harvesting electrical energy from nanostructures. By utilizing the piezoelectric property of some materials, mechanical energy can be harvested as electrical output. It is worth mention that the ambient mechanical energy is the most available source of energy around us. Hence it is of interest to utilize it to develop future smart devices having the self-powered property. In this connection various experimental and mathematical techniques have been utilized for achieving this target.In this thesis zinc oxide (ZnO) nanostructures grown on textile substrates were the material. The use of textile as substrate is quite unique property of the presented work. Since textile is an essential and fundamental component of our everyday lives, therefore the use of textile as substrate can pave the way for the fabrication of novel self-powered devices. As in comparison with conventional and expensive substrates textile is very economical, lightweight, highly flexible, recyclable, reproducible, disposable, wearable and washable.I started my research work by integrating ZnO nanorods based nanogenerator on conductive textile fiber for the analysis of piezoelectric properties of ZnO nanorods. The acceptance of my work among the research community encouraged me to continue with it in order to improve the performance of the fabricated device. It is well known that piezoelectricity is a linear electromechanical coupling of the material in which mechanical energy is converted into electrical energy. Therefore, the piezoelectric properties of ZnO nanorods were investigated with regard to different physical parameters. In the electromechanical phenomena the analysis of the direct and the converse piezoelectric effect is also critical if conductive textile is used as a substrate. Therefore analysis of the direct and the converse piezoelectric effect was performed for ZnO nanowires grown on conductive textile fiber by using the nanoindentation method.Since the morphology of ZnO nanostructures can have an influence on the piezoelectric properties, the energy harvesting properties of ZnO nanoflowers were investigated and the achieved results confirmed that morphology has a strong influence on the piezoelectric properties. In addition, since there is an interest to generate a direct current (DC) piezoelectricity, a Schottky junction fabricated to one side of the nanogenerator material is needed. Therefore, ZnO nanorods based Schottky diode (Cu/ZnO) on textile fabric was fabricated and investigated. Moreover, frequency dependence electrical characterization was performed for analysis of current-transport properties of another Schottky diode (Au/ZnO) for understanding the carrier flow at the interface of the metal-semiconductor. Nevertheless, the consistency and stability of the constructed devices (ZnO nanogenerators and Schottky diodes) need some additional work to overcome these problems to achieve commercial realization of these devices in the future.
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| 26. |
- Khan, Azam, et al.
(författare)
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Fabrication of zinc oxide nanoneedles on conductive textile for harvesting piezoelectric potential
- 2014
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Ingår i: Chemical Physics Letters. - : Elsevier. - 0009-2614 .- 1873-4448. ; 612, s. 62-67
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Tidskriftsartikel (refereegranskat)abstract
- Keeping the fact in mind that different morphologies have strong influence on piezoelectric properties, ZnO NNs were synthesized on textile for harvesting piezoelectricity. Piezoelectric potential was captured from ZnO NNs grown on textile by using AFM in contact mode. Structural study was carried out by using FESEM, HRTEM and XRD techniques. The recorded output potential and current was more than 45 mV and 150 nA. The combination of ZnO NNs and textile can be used effectively for energy harvesting applications and the use of textile fabric can pave the way for cheap, flexible, wearable, washable and environment friendly nanodevices.
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| 27. |
- Khan, Azam, et al.
(författare)
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Harvesting piezoelectric potential from zinc oxide nanoflowers grown on textile fabric substrate
- 2013
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Ingår i: Physica Status Solidi. Rapid Research Letters. - : Wiley-VCH Verlag. - 1862-6254 .- 1862-6270. ; 7:11, s. 980-984
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Tidskriftsartikel (refereegranskat)abstract
- ZnO nanoflowers were synthesized on conductive flexible textile fabric substrate by using the simple low-temperature aqueous chemical growth method and were used for piezoelectric energy harvesting source. Structural characterization of ZnO nanoflowers was carried out by using surface scanning electron microscopy and X-ray diffraction. The ZnO nanoflowers are uniformly grown over the entire sample. They are composed of needle-like nanorods, which have hexagonal wurtzite structure with good crystalline quality. The current-voltage characteristics showed good rectifying Schottky behaviour. Contact-mode atomic force microscopy was used for measuring the piezoelectric output potential. The maximum output potential was found to be more than 600 mV and the corresponding current also recorded was near approximate to 650 nA.
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| 28. |
- Khan, Azam, et al.
(författare)
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Mechanical and piezoelectric properties of zinc oxide nanorods grown on conductive textile fabric as an alternative substrate
- 2014
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Ingår i: Journal of Physics D. - : Institute of Physics Publishing (IOPP). - 0022-3727 .- 1361-6463. ; 47:34, s. 345102-
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Tidskriftsartikel (refereegranskat)abstract
- The present research is devoted to understanding the mechanism and causes of variation in the piezoelectric potential generated from vertically aligned zinc oxide (ZnO) nanorods (NRs), which were grown on a conductive textile fabric as an alternative substrate by using the aqueous chemical growth method. The piezoelectric voltage was harvested from vertically aligned ZnO NRs having different physical parameters by using atomic force microscopy in contact mode and the variation in the generated piezoelectricity was investigated. The generated output potential indicates that different physical parameters such aspect ratio, crystal size and lattice internal crystal strain have a strong influence on the piezoelectric properties of vertically aligned ZnO NRs, which were grown on a textile fabric. Presented results indicate that textiles can be used as an alternative substrate just like the other conventional substrates, because our results are similar/better than many reported works on conventional substrates.
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| 29. |
- Khan, Azam, et al.
(författare)
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Piezoelectric nanogenerator based on zinc oxide nanorods grown on textile cotton fabric
- 2012
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Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 101:19
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Tidskriftsartikel (refereegranskat)abstract
- This investigation explores piezoelectricity generation from ZnO nanorods, which were grown on silver coated textile cotton fabrics using the low temperature aqueous chemical growth method. The morphology and crystal structure studies were carried out by x-ray diffraction, scanning electron microscopic and high resolution transmission electron microscopic techniques, respectively. ZnO nanorods were highly dense, well aligned, uniform in spatial distribution and exhibited good crystal quality. The generation of piezoelectricity from fabricated ZnO nanorods grown on textile cotton fabrics was measured using contact mode atomic force microscopy. The average output voltage generated from ZnO nanorods was measured to be around 9.5 mV. This investigation is an important achievement regarding the piezoelectricity generation on textile cotton fabric substrate. The fabrication of this device provides an alternative approach for a flexible substrate to develop devices for energy harvesting and optoelectronic technology on textiles.
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| 30. |
- Khan, Azam, et al.
(författare)
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RETRACTED: A novel investigation on carbon nanotube/ZnO, Ag/ZnO and Ag/carbon nanotube/ZnO nanowires junctions for harvesting piezoelectric potential on textile
- 2014
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Ingår i: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 116:3, s. 034505-
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, three junctions were fabricated on textile fabric as an alternative substrate for harvesting piezoelectric potential. First junction was formed on ordinary textile as (textile/multi-walled carbon nanotube film/zinc oxide nanowires (S1: T/CNTs/ZnO NWs)) and the other two were formed on conductive textile with the following layer sequence: conductive textile/zinc oxide nanowires (S2: CT/ZnO NWs) and conductive textile/multi-walled carbon nanotubes film/zinc oxide nanowires (S3: CT/CNTs/ZnO NWs). Piezoelectric potential was harvested by using atomic force microscopy in contact mode for the comparative analysis of the generated piezoelectric potential. ZnO NWs were synthesized by using the aqueous chemical growth method. Surface analysis of the grown nanostructures was performed by using scanning electron microscopy and transmission electron microscopy. The growth orientation and crystalline size were studied by using X-ray diffraction technique. This study reveals that textile as an alternative substrate have many features like cost effective, highly flexible, nontoxic, light weight, soft, recyclable, reproducible, portable, wearable, and washable for nanogenerators fabrication with acceptable performance and with a wide choice of modification for obtaining large amount of piezoelectric potential.
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| 31. |
- Khan, Azam, et al.
(författare)
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Study of transport properties of copper/zinc-oxide-nanorods-based Schottky diode fabricated on textile fabric
- 2013
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Ingår i: Semiconductor Science and Technology. - : Institute of Physics: Hybrid Open Access. - 0268-1242 .- 1361-6641. ; 28:12, s. 125006-
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a copper/zinc-oxide (ZnO)-nanorods-based Schottky diode was fabricated on the textile fabric substrate. ZnO nanorods were grown on a silver-coated textile fabric substrate by using the hydrothermal route. Scanning electron microscopy and x-ray diffraction techniques were used for the structural study. The electrical characterization of copper/ZnO-nanorods-based Schottky diodes was investigated by using a semiconductor parameter analyzer and an impedance spectrometer. The current density-voltage (J-V) and capacitance-voltage (C-V) measurements were used to estimate the electrical parameters. The threshold voltage (V-th), ideality factor (eta), barrier height (phi(b)), reverse saturation current density (J(s)), carrier concentration (N-D) and built-in potential (V-bi) were determined by using experimental data and (simulated) curve fitting. This study describes the possible fabrication of electronic and optoelectronic devices on textile fabric substrate with an acceptable performance.
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| 32. |
- Khan, Umar Hasan, et al.
(författare)
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Compact RFID Enabled Moisture Sensor
- 2016
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Ingår i: Radioengineering. - : Spolecnost Pro Radioelektronicke Inzenyrstvi. - 1210-2512 .- 1805-9600. ; 25:3, s. 449-456
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Tidskriftsartikel (refereegranskat)abstract
- This research proposes a novel, low-cost RFID tag sensor antenna implemented using commercially available Kodak photo-paper. The aim of this paper is to investigate the possibility of stable, RFID centric communication under varying moisture levels. Variation in the frequency response of the RFID tag in presence of moisture is used to detect different moisture levels. Combination of unique jaw shaped contours and T-matching network is used for impedance matching which results in compact size and minimal ink consumption. Proposed tag is 1.4x9.4 cm(2) in size and shows optimum results for various moisture levels upto 45 % in FCC band with a bore sight read range of 12.1 m.
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| 33. |
- Khan, Umar Hasan, et al.
(författare)
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Novel chipless displacement sensor circuit using spurline resonantor
- 2016
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Ingår i: IEICE Electronics Express. - : Institute of Electronics Information Communication Engineers. - 1349-2543. ; 13:23
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Tidskriftsartikel (refereegranskat)abstract
- A novel uni-dimensional chipless displacement sensor circuit based on spurline resonators is presented. Sensor circuit design consists of two components: series of spurline resonators and a selector element. In response to displacement, the selector element slides over the spurline resonator slots that translating this movement into a corresponding change in the circuit's frequency response. The designed circuit offers a capacity of 16 bits in the 2-4.2 GHz frequency band. Half of the bits are designated as the sensory bits, while the other half are attributed as the ID bits. The formulated sensor has a dynamic range from 0-3.75 mm and a minimum resolution of 0.25 mm. The proposed sensor is a prime candidate for deployment in smart cities for ubiquitous infrastructural health monitoring.
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| 34. |
- Naqvi, S. I., et al.
(författare)
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A planar flexible quad-band antenna for WLAN/WiMAX/LTE applications
- 2019
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Ingår i: 2019 2nd International Conference on Computing, Mathematics and Engineering Technologies, iCoMET 2019. - : Institute of Electrical and Electronics Engineers Inc.. - 9781538695098
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Konferensbidrag (refereegranskat)abstract
- In this work a quad-band, planar, low-profile and compact antenna envisioned for incorporation into portable wireless devices is presented. The antenna is modeled on flexible Rogers RT/Duroid 5880 substrate of 0.127mm thickness. The proposed antenna structure consists of symmetrically placed F-shaped slits and a curved rectangular shaped ground plane with a CPW feed line. The four bands obtained for the radiator operates at the resonant frequencies 2.8, 3.9, 5.45 and 6.2 GHz with impedance bandwidths of 14%, 14.5%, 5.7%, and 5% respectively. Thus the proposed antenna supports WLAN, LTE, WiMAX, and C-band applications. The peak gain achieved for the antenna is 3.4 dB.
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| 35. |
- Naqvi, Syeda, I, et al.
(författare)
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An Integrated Antenna System for 4G and Millimeter-Wave 5G Future Handheld Devices
- 2019
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Ingår i: IEEE Access. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2169-3536. ; 7, s. 116555-116566
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Tidskriftsartikel (refereegranskat)abstract
- In this work, an integrated antenna system with Defected Ground Structure (DGS) is presented for Fourth Generation (4G) and millimeter (mm)-wave Fifth Generation (5G) wireless applications and handheld devices. The proposed design with overall dimensions of 110 mm x 75 mm is modeled on 0.508 mm thick Rogers RT/Duroid 5880 substrate. Radiating structure consists of antenna arrays excited by the T-shape 1 x 2 power divider/combiner. Dual bands for 4G centered at 3.8 GHz and 5.5 GHz are attained, whereas the 10-dB impedance bandwidth of 24.4 - 29.3 GHz is achieved for the 5G antenna array. In addition, a peak gain of 5.41 dBi is demonstrated across the operating bandwidth of the 4G antenna array. Similarly, for the 5G mm-wave configuration the attained peak gain is 10.29 dBi. Moreover, significant isolation is obtained between the two antenna modules ensuring efficient dual-frequency band operation using a single integrated solution. To endorse the concept, antenna prototype is fabricated and far-field measurements are procured. Simulated and measured results exhibit coherence. Also the proposed design is investigated for the beam steering capability of the mm-wave 5G antenna array using CST(R)MWS(R). The demonstrated structure offers various advantages including compactness, wide bandwidth, high gain, and planar configuration. Hence, the attained radiation characteristics prove the suitability of the proposed design for the current and future wireless handheld devices.
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| 36. |
- Nour, Eiman, et al.
(författare)
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A Flexible Sandwich Nanogenerator for Harvesting Piezoelectric Potential from Single Crystalline Zinc Oxide Nanowires
- 2014
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Ingår i: Nanomaterials and Nanotechnology. - : InTech. - 1847-9804. ; 4:24
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Tidskriftsartikel (refereegranskat)abstract
- High-quality single crystalline zinc oxide nanowires were grown on silver and gold coated plastic substrates for the fabrication of a sandwich-like nanogenerator using the aqueous chemical growth method. The applicability of this configuration as a nanogenerator is demonstrated by studying the harvested electrical output under mechanical deformation. Three different configurations were fabricated and utilized for harvesting piezoelectric potential by applying an external force. The maximum resulting output open circuit voltage and short circuit current were 2.4 V and 152.2 mu A, respectively. The comparison between the different configurations indicates that more piezoelectric potential can be harvested by using two arrays of ZnO NWs placed face-to-face than by using a single nanowire configuration. In addition, the use of a piezoelectric polymer will enhance the amount of generated piezoelectric potential. The obtained results from different configurations of zinc oxide nanowire nanogenerators offer a cost-effective, flexible, long term stable nanogenerator for promising application. The principle of the sandwich nanogenerator demonstrated a new idea for novel self-powering nanotechnology that harvests electricity from the environment for applications such as portable electronics.
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| 37. |
- Shah, Said Nasir, et al.
(författare)
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Bioactive, antioxidant and antimicrobial properties of chemically fingerprinted essential oils extracted from Eucalyptus globulus: in-vitro and in-silico investigations
- 2023
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Ingår i: Frontiers in Chemistry. - : FRONTIERS MEDIA SA. - 2296-2646. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Innovative approaches are urgently required to treat divestating bacterial diseases in the face of rising bacterial resistance rates. The current investigative work focused on hydro-distilling Tasmanian blue gum (Eucalyptus globulus) to isolate the essential oil, which was then tested for bioactivity, antioxidant capacity, and antibacterial activity using in-vitro and in silico assays. The antioxidant activity was avualated against DPPH and FRAP. With results of 69.63 RSA (%) (mu L/L AAE) at a concentration of 5 mL/L and 51.56 (mu L/L AAE) at concentration of 90 ppm in the 2,20-diphenyl-1-picryl hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays, respectively, the extracted oil indicated considerable antioxidant activity. The extracted oil demonstrated powerful antibacterial activity in in-vitro tests against both Gram-positive and Gram-negative bacterial strains, including Bordetella bronchiseptica (21 mm), Staphylococcus epidermidis (19 mm), and Staphylococcus aureus (19 mm), with significant minimal inhibitory (MIC) and minimum bactericidal (MIB) concentrations. Additionally, GC-MS analysis of the oil from E. globulus identified several low-molecular-weight compounds, including Eucalyptol, gamma-Terpinene, Shisool acetate, 1,3-trans,5-cis-Octatriene, 2,6-Dimethyl-1,3,5,7-octatetraene, E,E, Cyclohexene, 1-methyl-4-(1-methylethylidene), Benzene, 1-methyl-4-(1-methylethenyl), Butanoic acid, 3-methyl-, 3-methylbutyl ester, and 1,3,8-p-Menthatriene. Several other compounds were also identified, including Fenchol, 2-Methyl-trans-3a,4,7,7a-tetrahydroindane, (E,E,E)-2,4,6-Octatriene, 1,2,3,6-Tetrahydrobenzylalcohol, acetate, Alloaromadendrene, Phenol, 2-ethyl-4,5-dimethyl, Phenol, 2-methyl-5-(1-methylethyl)-, p-Cymen-7-ol, 1,5,5-Trimethyl-6-methylene-cyclohexene, 1,3-Cyclohexadiene, 1-methyl-4-(1-methylethyl)-, 2,6-Octadien-1-ol, 3,7-dimethyl-, acetate, (Z), and more. The bioactive potential of Eucalyptus globulus essential oil against 1AJ6 and 1R4U was highlighted by molecular docking analyses, suggesting its utility as a natural source of antioxidant and antibacterial compounds with the potential to replace chemical disinfectants in a variety of applications.
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| 38. |
- Zahid, Nida, et al.
(författare)
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Psychosocial factors influencing quality of life in patients with primary brain tumors in Pakistan : an analytical cross-sectional study
- 2023
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Ingår i: BMC Research Notes. - : Springer Nature. - 1756-0500. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveDespite quality of life (QoL) being recognized as an important outcome in neuro-oncology, there is a lack of research from Pakistan where sociocultural differences may influence QoL. This study aimed to measure the QoL in patients with primary brain tumors (PBTs) and assess its association with mental health outcomes and social support.ResultsOur study included a total of 250 patients, with a median age of 42 years (range 33-54 years). The commonest brain tumors were glioma (46.8%) and meningioma (21.2). The mean global QoL of the sample was 75.73 +/- 14.9. The majority of patients had high social support (97.6%) and were not depressed (90%) or anxious (91.6%).On multivariable linear regression, global QoL was inversely associated with no or low income (beta coefficients: -8.75 to -11.84), having hypertension (-5.53), currently using a urine catheter (-13.55), having low social support (-28.16) suffering from mild (-15.31) or symptomatic (-23.84) depression, or mild anxiety (-13.22).
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