995 research outputs found
Cyclostationary Noise Mitigation for SIMO Powerline Communications
No full textThe cyclostationary noise in low-voltage narrowband powerline communications (NB-PLC) severely degrades the communication reliability. In this paper, we adopt single-input multi-output (SIMO) transmission to enhance the reliability of NB-PLC. Considering the SIMO receiver structure, we exploit the NB-PLC noise cyclostationarity and the high spatial correlations across multiple receive phases to design practical and efficient noise mitigation techniques. In particular, we propose two time-domain frequency shift (FRESH) filtering-based cyclostationary signal recovery techniques with different performance and complexity levels. The proposed time-domain-based FRESH filtering techniques minimize the mean squared error in estimating the orthogonal frequency division multiplexing (OFDM) information signal in the time-domain The FRESH filtering exploits the cyclic auto-correlation of both the NB-PLC noise and the OFDM information signal in addition to their cyclic cross-correlation across the receive phases. Moreover, we propose a frequency-domain-based cyclostationary noise mitigation technique that minimizes the mean squared error in estimating the OFDM information signal in the frequency-domain The proposed frequency domain-based technique exploits the cyclostationarity of the noise to estimate its power spectral density as well as the cross-correlation, per frequency subchannel, over multiple stationary noise temporal regions. Our proposed SIMO NB-PLC noise mitigation techniques are shown via simulation results conducted using noise field measurements to achieve considerable performance gains over single-input single-output techniques. In addition, we show that our proposed techniques achieve considerable performance gains over the conventional SIMO maximal-ratio-combiner designed assuming stationary noise.Erik Jonsson School of Engineering and Computer Scienc
Impact of Poultry Manure-Derived Biochar and Bio-Fertilizer Application to Boost Production of Black Cumin Plants (Nigella sativa L.) Grown on Sandy Loam Soil
No full textBiochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growthpromoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha−1, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha−1) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR
significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield productio
Shape Control Method For Nanoparticles For Making Better And New Catalysts
No full textA method for shape controlled synthesis of colloidal metal nanoparticles includes providing a solution of 8x10-5 M K₂ PtCl₄ and water in a reaction vessel and maintaining the vessel at a constant temperature of approximately 25°C. 0.1 M sodium polyacrylate is then added to the solution. Thereafter, argon gas is bubbled through the solution for approximately 20 minutes, and then hydrogen gas is bubbled through the solution for approximately 5 minutes to saturate the solution and so that platinum ions in the solution are reduced. The reaction vessel is sealed and the solution is allowed to stand for approximately 12 hours, whereby platinum colloidal nanoparticles possessing a particular shape distribution and size distribution are formed. The shape and size distributions of produced nanoparticles can be manipulated by changing the ratio of the concentration of sodium polyacrylate to platinum ions in a subsequently formed solution while maintaining all other variables constant.Georgia Tech Reseach Corporatio
Cataglyphis laylae Cedric A. Collingwood & Donat Agosti & Mostafa R. Sharaf & Antonius van Harten 2011, nov. spec.
No full textCataglyphis laylae Collingwood nov. spec. Plates 96–103 Cataglyphis desertorum Forel, 1894, teste Collingwood, 1985; unavailable name according to Agosti (1990). Specimens examined: Holotype: 1 ☿, United Arab Emirates, al-Ain [24°13'N 55°46'E], iii.1995, leg. C.A. Collingwood (MHNG). Paratypes: 3 ☿, al-Ain zoo, 13.iii.2005, CAC. 1 ☿, Remah, 9.iii.1995, CCA. 3 ☿, Remah, resthouse, 250 m, irrigated sand dune [24°10'37"N 55°18'6"E], 18.iii.1995, leg. D. Agosti. 6 ☿, Remah, resthouse, 250 m, irrigated sand dune, nest with one entrance, [24°10'37"N, 55°18'6"E], 18.iii.1995, leg. D. Agosti. 1 ☿, Sharjah Desert Park, 5–6.x.2004, AvH; 1 ☿, 3.iii.2005, CAC. 1 ☿, al- Za'aba, 100 m, sandy soil with Rhaisa stricta [23°43'20"N, 55°33'49"E], 22.iii.1995, leg. D. Agosti. Description: A large worker from al-Ain was selected as holotype. The measurements are as follows: total length 8.40; head width 3.60; head length 4.20; scape length 3.84; funicular segment I 0.40; funicular segment II 0.23; petiole length 1.10; petiole width 0.72. Colour dark reddish brown. There are no exterior hairs on the scapes or hind tibia. The gaster, petiole and propodeum have dorsal hairs. Remarks: This species thought to correspond with C. desertorum has to be described as a new species. In fact it is one of the commonest Cataglyphis in southern Arabia. The main distinguishing feature compared with other dark Cataglyphis is the slender petiole, which has the anterior face more sloped than in other similar species such as C. niger (André, 1882) and C. savignyi (Dufour, 1862). Biology: Cataglyphus laylae nov. spec. does not appear to occur in open sandy desert and is most abundant in disturbed habitats such as man-developed plantations and open cultivated fields. Distribution: This species was recorded by Collingwood (1985) as C. desertorum from Saudi Arabia and Oman and as Cataglyphis spec. by Collingwood & Agosti (1996). Etymology: The new species is named after a village settlement called “Layla”, just north of Riyadh (Saudi Arabia) in the area where the author (CAC) first encountered it in numbers in an Acacia plantation.Published as part of Cedric A. Collingwood, Donat Agosti, Mostafa R. Sharaf & Antonius van Harten, 2011, Order Hymenoptera, family Formicidae, pp. 1-70 in Arthropod fauna of the UAE 4 on page 54, DOI: 10.5281/zenodo.116858
AN IN-VITRO COMPARISON OF THE RETENTION OF PREFABRICATED PARALLEL-SIDED VENTED TITANIUM POSTS CEMENTED WITH THREE DIFFERENT DUAL-POLYMERIZABLE RESIN CEMENTS
No full textAbstractAN IN-VITRO COMPARISON OF THE RETENTION OF PREFABRICATED PARALLEL-SIDED VENTED TITANIUM POSTS CEMENTED WITH THREE DIFFERENT DUAL-POLYMERIZABLE RESIN CEMENTSBy Maha M. El-Sayed, B.D.S., D.M.D.A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University.Virginia Commonwealth University, 2003Thesis Director: David R. Burns, D.M.D. Associate Professor and Program DirectorGraduate ProsthodonticsDepartment of ProsthodonticsPurpose: The purpose of this in-vitro study was to compare the retentive strength of an autopolymerizing resin cement to three dual-polymerizable resin cements when used to cement paraposts without light activation and to relate diametral tensile stress and hardness as a measure of the degree of polymerization to the retentive strength of the different dual-polymerizable resin cements. Material and methods: 60 human extracted premolar teeth were endodontically-treated and randomly divided into 4 test groups (n=15). Parapost XP posts (size 5) were cemented using Panavia 21(control), Panavia F, RelyX Unicem and Linkmax resin cements. The latter three cements were dual-polymerizable and were not light-activated, and the control cement was autopolymerizable. Also, 140 resin cement samples were fabricated for diametral tensile stress and Knoop hardness testing. Each test had 70 samples, 10 of each of the following groups: Panavia 21, Panavia F light-activated, Panavia F autopolymerized, RelyX Unicem light-activated, RelyX Unicem autopolymerized, Linkmax light-activated, Linkmax autopolymerized. Post retention, diametral tensile stress and surface hardness tests were performed 1 week after sample fabrication or post cementation.Results: ANOVA and Tukey-Kramer statistical analysis revealed significant differences among the test groups for the three tests. Conclusions: Within the limitations of this in vitro study, tested dual-polymerization resin cements had similar or superior parapost retention to the control autopolymerizing resin cement without photoactivation. Dual-polymerizable resin cements had improved diametral tensile stress and surface hardness when light-activated than when autopolymerized. No correlation was observed between surface hardness and diametral tensile stress or between the tested physical properties of the resin cements and their retentive qualitie
Beating cancer in multiple ways using nanogold
No full textGold nanoparticles possess a unique combination of properties which allow them to act as highly multifunctional anti-cancer agents (X. H. Huang, P. K. Jain, I. H. El-Sayed and M. A. El-Sayed, Nanomedicine, 2007, 2, 681–693; P. Ghosh, G. Han, M. De, C. K. Kim and V. M. Rotello, Adv. Drug Delivery Rev., 2008, 60, 1307–1315; S. Lal, S. E. Clare and N. J. Halas, Acc. Chem. Res., 2008, 41, 1842–1851; D. A. Giljohann, D. S. Seferos, W. L. Daniel, M. D. Massich, P. C. Patel and C. A. Mirkin, Angew. Chem., Int. Ed., 2010, 49, 3280–3294). Not only can they be used as targeted contrast agents for photothermal cancer therapy, they can serve as scaffolds for increasingly potent cancer drug delivery, as transfection agents for selective gene therapy, and as intrinsic antineoplastic agents. This tutorial review will highlight some of the many forms and recent applications of these gold nanoparticle conjugates by our lab and others, as well as their rational design and physiologic interactions. © 2011 The Royal Society of Chemistry
Correction: Surgical specialists face higher a risk for malpractice compared to their non-surgical colleagues
No full textCorrection to: Scientific Reportshttps://doi.org/10.1038/s41598-024-81058-x, published online 05 December 2024 The original version of this Article contained an error in the spelling of the author M. M. Mokhles which was incorrectly given as Mostafa Mokhles. The original Article has been corrected
Widefield fluorescence correlation spectroscopy
No full textFluorescence correlation spectroscopy has become a standard technique for modern biophysics and single molecule spectroscopy research. Here is presented a novel widefield extension of the established single-point technique. Flow in microfluidic devices was used as a model system for microscopic motion and through widefield fluorescence correlation spectroscopy flow profiles were mapped in three dimensions. The technique presented is shown to be more tolerant to low signal strength, allowing image data with signal-to-noise values as low as 1.4 to produce accurate flow maps as well as utilizing dye-labeled single antibodies as flow tracers. With proper instrumentation flows along the axial direction can also be measured. Widefield fluorescence correlation spectroscopy has also been utilized to produce super-resolution confocal microscopic images relying on the single-molecule microsecond blinking dynamics of fluorescent silver clusters. A method for fluorescence modulation signal extraction as well as synthesis of several novel noble metal fluorophores is also presented.Ph.D
Computational design of optimal discrete-time output feedback controllers
No full textAbstract This paper considers the problem of designing a stabilizing static output feedback controller of linear discrete-time systems that minimizes certain quadratic performance index. A trust-region method is developed to solve an equivalent optimization problem of this optimal control problem. In addition, a first-order method is introduced to compute suboptimal stabilizing output feedback controllers that are used to initiate the trust-region method. Finally some numerical results that illustrate the performance of the proposed methods are given
Sub-Stoichiometric Titania as a Viable Support for Pt Electrodes
No full textThe growing demand for fossil fuels has resulted in inevitable environmental consequences along with the gradual depletion of fuel sources. As a result, extensive efforts are focused on developing environmentally benign and sustainable alternatives such as fuel cells. While fuel cells alone would not rid greenhouse gas emissions, they can contribute to their reduction. Barriers hindering the commercialization of fuel cells include performance, durability, cost, and storage. A major contributor to the high cost of fuel cells is the use of Pt at the electrode. Therefore, research has been devoted to overcoming these issues by reducing the loading of Pt, alloying Pt with a less noble metal, implementing Pt free catalyst. Furthermore, carbon has been the most traditionally used catalyst support in fuel cell applications; however, carbon is susceptible to corrosion resulting in the loss of the support and Pt nanoparticle agglomeration/detachment. In this thesis, I showcase the synthesis, characterization, and use of Ti2O3 and Ti3O5 supports as a stable support for Pt-based electrocatalyst use in several prominent fuel cell reactions.Ph.D
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