Research

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  • An innovative dual-column system for heavy metallic ion sorption by natural zeolite
    An innovative dual-column system for heavy metallic ion sorption by natural zeolite
    This study investigates the design and performance of a novel sorption system containing natural zeolite. The apparatus consists of packed, fixed-bed, dual-columns with custom automated controls and sampling chambers, connected in series and stock fed by a metering pump at a controlled adjustable distribution. The purpose of the system is to remove heavy metallic ions predominately found in acid mine drainage, including lead (Pb2+), copper (Cu2+), iron (Fe3+), nickel (Ni2+) and zinc (Zn2+), combined in equal equivalence to form an acidified total 10 meq/L aqueous solution. Reported trends on the zeolite’s preference to these heavy metallic ions is established in the system breakthrough curve, as Pb2+ >> Fe3+ > Cu2+ > Zn2+ >> Ni2+. Within a 3-h contact period, Pb2+ is completely removed from both columns. Insufficient Ni2+ removal is achieved by either column with the promptest breakthrough attained, as zeolite demonstrates the least affinity towards it; however, a 48.97% removal is observed in the cumulative collection at the completion of the analysis period. The empty bed contact times for the first and second columns are 20 and 30 min, respectively; indicating a higher bed capacity at breakthrough and a lower usage rate of the zeolite mineral in the second column. This sorption system experimentally demonstrates the potential for industrial wastewater treatment technology development. Keywords: zeolite; sorption; packed fixed-bed columns; heavy metallic ions; automated sampling design, Ciosek, A. L., Luk, G. K. (2017). An Innovative Dual-Column System for Heavy Metallic Ion Sorption by Natural Zeolite. Applied Sciences, 7(8), 795., (This article belongs to the Special Issue Wastewater Treatment and Reuse Technologies)
    An interval-size illusion: The influence of timbre on the perceived size of melodic intervals
    An interval-size illusion: The influence of timbre on the perceived size of melodic intervals
    In four experiments, we investigated the influence of timbre on perceived interval size. In Experiment 1, musically untrained participants heard two successive tones and rated the pitch distance between them. Tones were separated by six or seven semitones and varied in timbre. Pitch changes were accompanied by a congruent timbre change (e.g., ascending interval involving a shift from a dull to a bright timbre), an incongruent timbre change (e.g., ascending interval involving a shift from a bright to a dull timbre), or no timbre change. Ratings of interval size were strongly influenced by timbre. The six-semitone interval with a congruent timbre change was perceived to be larger than the seven-semitone interval with an incongruent timbre change (interval illusion). Experiment 2 revealed similar effects for musically trained participants. In Experiment 3, participants compared the size of two intervals presented one after the other. Effects of timbre were again observed, including evidence of an interval illusion. Experiment 4 confirmed that timbre manipulations did not distort the perceived pitch of tones. Changes in timbre can expand or contract the perceived size of intervals without distorting individual pitches. We discuss processes underlying interval size perception and their relation to pitch perception mechanisms.
    Analysis of Stability-To-Chaos in the Dynamic Evolution of Network Traffic Flows under a Dual Updating Mechanism
    Analysis of Stability-To-Chaos in the Dynamic Evolution of Network Traffic Flows under a Dual Updating Mechanism
    This paper proposes a traffic-flow evolutionary model under a dual updating mechanism that describes the day-to-day (DTD) dynamics of traffic flow and travel cost. To illustrate the concept, a simple two-route network is considered. Based on the nonlinear dynamic theory, the equilibrium stability condition of the system is derived and the condition for the division between the bifurcation and chaotic states of the system is determined. The characteristics of the DTD dynamic evolution of network traffic flow are investigated using numerical experiments. The results show that the system is absolutely stable when the sensitivity of travelers toward the route cost parameter (θ) is equal to or less than 0.923. The bifurcation appears in the system when θ is larger than 0.923. For values of θ equal to or larger than 4.402, the chaos appears in the evolution of the system. The results also show that with the appearance of chaos, the boundary and interior crises begin to appear in the system when θ is larger than 6.773 and 10.403, respectively. The evolution of network traffic flow is always stable when the proportion of travelers who do not change the route is 84% or greater., Liu, S., Yan, H., Easa, S.M., Guo, L., Tang, Y. (2018). Analysis of Stability-To-Chaos in the Dynamic Evolution of Network Traffic Flows under a Dual Updating Mechanism. Sustainability, 10, 4182.
    Analysis of Ultrasound Backscatter from Ensembles of Cells and Isolated Nuclei
    Analysis of Ultrasound Backscatter from Ensembles of Cells and Isolated Nuclei
    Online version of a conference paper originally published as: Analysis of Ultrasound Backscatter from Ensembles of Cells and Isolated Nuclei, M.C. Kolios, G.J. Czarnota, M. Hussain, F. S. Foster, J.W. Hunt and M.D. Sherar (2001), In Proceedings of the 2001 IEEE International Ultrasonics Symposium Publisher URL: http://ieeexplore.ieee.org/xpls/abs_all.jsp?isnumber=21384&arnumber=991948&count=205&index=92
    Analysis of the Summon Service at Ryerson University
    Analysis of the Summon Service at Ryerson University
    Poster Presented at CLA 2012 National Conference and Trade Show Ottawa, ON : Ottawa Convention Centre: May 30 - June 2, 2012
    Analytical and experimental solution for heat source located under skin:  chest tumor detection via IR camera
    Analytical and experimental solution for heat source located under skin: chest tumor detection via IR camera
    Infrared (IR) imaging could be used as both noninvasive and nonionizing technology. Utilizing IR camera, it is possible to measure skin temperature with the aim of finding any superficial tumors. Since tumors are highly vascular and usually have a higher temperature than the rest of the body, using thermograms, it is possible to assess various tumor parameters, such as depth, intensity, and radius. In this study, we have developed an analytical method to detect tumor parameters in both spherical and cubical tissues to represent female breast and male chest tissue. This includes development of analytical solution for solving inverse bio-heat problem as well as laboratory set up for further validation of the analytical achievements. The models were developed by solving Penne’s Bioheat equation for each tissue under certain conditions and two main assumptions: 1. The tumor was assumed as separate heat source; 2. The developed model does not change with time (steady state condition). Finally, the analytical findings were validated by utilizing a laboratory test set-up containing an IR camera, 1% Agar solution (tissue phantom), and a heater of variable powers. The models were set to test by adjusting the heater (0.9W) in various depth and imaging the tissue phantom. Comparing the analytically obtained results with the experimental results, it can be concluded that the method is able to detect superficial tumors of small size only by measuring the body surface temperature and ambient temperature.
    Analyzing the Usability of an Argumentation Map as a Participatory Spatial Decision Support Tool
    Analyzing the Usability of an Argumentation Map as a Participatory Spatial Decision Support Tool
    Argumentation Maps support participants in geographically referenced debates as they occur, for example, as part of urban planning processes. In a quasi-naturalistic case study, 11 student participants discussed planning issues on the University of Toronto downtown campus. The analysis of this case study focuses on general usability aspects of an Argumentation Map prototype, such as cost of entry, efficiency, interactivity, and connectivity. By applying usability analysis methods from the field of human-computer interaction, we evaluate the learnability, memorability, and user satisfaction with this tool’s functionality. Our findings indicate that the participants were generally satisfied, but we include specific suggestions for improving the functionality of Argumentation Maps, e.g., with respect to map navigation, display of discussion contributions, and online status of participants. On a more general level, this case study contributes to the methods spectrum of research into participatory spatial decision support systems as an example of user testing in a realistic decision-making context., Originally published as: Sidlar, C. L., & Rinner, C. (2007). Analyzing the usability of an argumentation map as a participatory spatial decision support tool. URISA Journal, 19(1), 47-55. Publisher URL: https://www.urisa.org/resources/urisa-journal-archive/
    Antiproliferative and Antioxidant Activities and Mycosporine-Like Amino Acid Profiles of Wild-Harvested and Cultivated Edible Canadian Marine Red Macroalgae
    Antiproliferative and Antioxidant Activities and Mycosporine-Like Amino Acid Profiles of Wild-Harvested and Cultivated Edible Canadian Marine Red Macroalgae
    Antiproliferative and antioxidant activities and mycosporine-like amino acid (MAA) profiles of methanol extracts from edible wild-harvested (Chondrus crispus, Mastocarpus stellatus, Palmaria palmata) and cultivated (C. crispus) marine red macroalgae were studied herein. Palythine, asterina-330, shinorine, palythinol, porphyra-334 and usujirene MAAs were identified in the macroalgal extracts by LC/MS/MS. Extract reducing activity rankings were (p < 0.001): wild P. palmata > cultivated C. crispus = wild M. stellatus > wild low-UV C. crispus > wild high-UV C. crispus; whereas oxygen radical absorbance capacities were (p < 0.001): wild M. stellatus > wild P. palmata > cultivated C. crispus > wild low-UV C. crispus > wild high-UV C. crispus. Extracts were antiproliferative against HeLa and U-937 cells (p < 0.001) from 0.125–4 mg/mL, 24 h. Wild P. palmata and cultivated C. crispus extracts increased (p < 0.001) HeLa caspase-3/7 activities and the proportion of cells arrested at Sub G1 (apoptotic) compared to wild-harvested C. crispus and M. stellatus extracts. HeLa cells incubated with wild P. palmata and cultivated C. crispus extracts also exhibited morphological changes characteristic of apoptosis (shrinkage, rounding). Thus, extracts rich in low-polarity usujirene and polar palythine and asterina-330 MAAs were antiproliferative as inducers of apoptosis in HeLa cells., Athukorala, Y., Trang, S., Kwok, C., & Yuan, Y. V. (2016). Antiproliferative and antioxidant activities and mycosporine-like amino acid profiles of wild-harvested and cultivated edible canadian marine red macroalgae. Molecules (Basel, Switzerland), 21(1), E119. doi:10.3390/molecules21010119, (This article belongs to the Special Issue Antioxidants—A Risk-Benefit Analysis for Health)
    Antitumor Effects of Combining Docetaxel (Taxotere) with the Antivascular Action of Ultrasound Stimulated Microbubbles
    Antitumor Effects of Combining Docetaxel (Taxotere) with the Antivascular Action of Ultrasound Stimulated Microbubbles
    Ultrasound stimulated microbubbles (USMB) are being investigated for their potential to promote the uptake of anticancer agents into tumor tissue by exploiting their ability to enhance microvascular permeability. At sufficiently high ultrasound transmit amplitudes it has also recently been shown that USMB treatments can, on their own, induce vascular damage, shutdown blood flow, and inhibit tumor growth. The objective of this study is to examine the antitumor effects of ‘antivascular’ USMB treatments in conjunction with chemotherapy, which differs from previous work which has sought to enhance drug uptake with USMBs by increasing vascular permeability. Conceptually this is a strategy similar to combining vascular disrupting agents with a chemotherapy, and we have selected the taxane docetaxel (Taxotere) for evaluating this approach as it has previously been shown to have potent antitumor effects when combined with small molecule vascular disrupting agents. Experiments were conducted on PC3 tumors implanted in athymic mice. USMB treatments were performed at a frequency of 1 MHz employing sequences of 50 ms bursts (0.00024 duty cycle) at 1.65 MPa. USMB treatments were administered on a weekly basis for 4 weeks with docetaxel (DTX) being given intravenously at a dose level of 5 mg/kg. The USMB treatments, either alone or in combination with DTX, induced an acute reduction in tumor perfusion which was accompanied at the 24 hour point by significantly enhanced necrosis and apoptosis. Longitudinal experiments showed a modest prolongation in survival but no significant growth inhibition occurred in DTX–only and USMB-only treatment groups relative to control tumors. The combined USMB-DTX treatment group produced tumor shrinkage in weeks 4–6, and significant growth inhibition and survival prolongation relative to the control (p<0.001), USMB-only (p<0.01) and DTX-only treatment groups (p<0.01). These results suggest the potential of enhancing the antitumor activity of docetaxel by combining it with antivascular USMB effects., Goertz DE, Todorova M, Mortazavi O, Agache V, Chen B, Karshafian R, et al. (2012) Antitumor Effects of Combining Docetaxel (Taxotere) with the Antivascular Action of Ultrasound Stimulated Microbubbles. PLoS ONE 7(12): e52307.
    Anxiety, depression, and self-management: a systematic review
    Anxiety, depression, and self-management: a systematic review
    The purpose of this article was to address the clinically relevant question: In the presence of anxiety and/or depression, do patients who have had heart surgery engage in self-management behaviours following hospital discharge? A systematic review of 16 studies that examined the psychological condition of patients who had coronary artery bypass graft (CABG) and/or valvular replacement surgery was conducted. Moderate to severe levels of anxiety and depression exist during the first month of home recovery and appear to have an effect on performance of self-management behaviors. As the influence of patients' psychological condition is continued to be examined, it is imperative for health care providers to manage increased rates of anxiety and/or depression following heart surgery. Music and relaxation therapy are presented as evidenced based recommendations for managing anxiety and depression in patients following heart surgery., Fredericks, S., Lapum, J., Lo, J. (2012). Anxiety, depression, and self-management: A systematic review. Clinical Nursing Research: An International Journal, 21(4), 411-429.
    Apoyo a la participación de padres en las escuelas primarias: Un estudio etnográfico sobre un grupo latinoamericano en Canadá
    Apoyo a la participación de padres en las escuelas primarias: Un estudio etnográfico sobre un grupo latinoamericano en Canadá
    Online version of an article originally published as: Bernhard, J.K., Freire, M., Pacini-Ketchabaw, V. (2000). Apoyo a la participación de padres en las escuelas primarias: Un estudio etnográfico de un grupo latino americano en Canadá. Educational Policy Analysis Archives, 8(52).
    Application Of Mathieu functions And The Point Matching Method To Elliptic Conductors
    Application Of Mathieu functions And The Point Matching Method To Elliptic Conductors
    Magnetics Conference, 1997. 1-4 Apr 1997. EP-04 - EP-04., Analysis of elliptic conductors, carrying a known total current, using the point matching method (PMM) in circular-cylinder coordinates [l] failed for the values of axes ratio b / a < 05, where a and b are the major and minor axes of the ellipse, respectively. This work shows that the use of elliptic-cylinder coordinates in conjunction with the point matching method overcomes this problem. This paper is a part of the work investigating the difficulties encountered in the point matching method, and is motivated by the fact that, despite its limitations, the method is still attractive as suggested by its use in recent papers [2]-141.