Assessing terrestrial wildlife populations in the Toronto and Region Area of Concern

Beneficial use impairments (BUIs) under the Great Lakes Water Quality Agreement identify environmental issues requiring remedial action within the Great Lakes Areas of Concern (AOCs). We conducted this study to support the assessment of the wildlife component of BUI 3: degradation of fish and wildlife populations. We compared bird and amphibian (frogs and toads) data from the Toronto and Region Conservation Authority’s Terrestrial Long-term Monitoring Program in the Toronto and Region AOC to an adjacent, but otherwise similar, reference watershed, Duffins Creek. Twelve of 13 targets were met within the AOC for forest bird, wetland bird, meadow bird and amphibian populations based on averages of mean annual values at sites within the AOC that were within two standard deviations of averages at sites in the Duffins Creek reference watershed between 2008 and 2017. Even though wildlife populations within the AOC were within the normal range of variability expected from a reference watershed, they were often at lower levels than within the Duffins Creek reference watershed. In addition, forest bird and amphibian populations were negatively affected by urbanization within the AOC and meadow bird indices declined. We conclude that while wildlife populations within the AOC currently meet targets for BUI 3, they continue to be negatively impacted by numerous stressors that are primarily related to past and ongoing urbanization. Thus, continued restoration of wildlife habitat and protection of existing habitat within the AOC is highly recommended.     

Chitosan-based magnetic molecularly imprinted polymer: synthesis and application in selective recognition of tricyclazole from rice and water samples

A tricyclazole selective chitosan/Fe₃O₄ magnetic molecularly imprinted polymer (MMIP) was synthesized using non-covalent binding polymerization involving methacrylic acid (MAA) as functional monomer, divinylbenzene (DVB-80) as crosslinker, 2,2'-azobisisobutyronitrile as initiator, acetonitrile/toluene (75:25, v/v) as porogenic solvent and tricyclazole as template. Surface morphology and magnetic characterization of the prepared imprinted and non-imprinted polymers were done using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry and vibrating sample magnetometry, respectively. The adsorption kinetic data fitted best in pseudo-second-order model. The adsorption equilibrium was achieved in 30 min and the maximum binding capacity was 4579.9 µg/g. The Freundlich isotherm model was found suitable for explaining the binding isotherm data (R² > 0.99). Negative values of thermodynamic parameters ∆G (Gibb’s free energy), ∆H (enthalpy), and ∆S (entropy) revealed exothermic and spontaneous nature of adsorption processes. It also revealed decreased randomness at the solid–liquid interface during sorption. The scatchard plot analysis suggested heterogeneity of binding sites on MMIPs. The molecular recognition selectivity of MMIPs towards tricyclazole was much higher, as compared to its structural analogues, tebuconazole (α = 28.58) and hexaconazole (α = 37.16). The MMIPs were successfully applied to separate and enrich tricyclazole from fortified samples of rice and water, with a recovery percentage of 89.4% and 90.9%, respectively. These reusable imprinted polymers possessing high selectivity and specificity can be utilized as an adsorbent for solid-phase extraction in sample preparation for tricyclazole residue analysis in complex environmental matrices.

     

Minimization of organic chemical load in direct dyes effluent using low cost adsorbents

The work is carried out to minimize the organic chemical load (unexhausted dye contents) in direct dyes effluent using low cost adsorbents. The studies are made with different direct dyes, i.e. Direct Red 28, Direct Yellow 12, Direct Orange 26 and Direct Blue 1 with various adsorbents. Three different bio/natural materials have been selected as adsorbents. These includes, Sugarcane bagasse pith (SB), Saw dust (SD)—the plant origin products, and Brick powder (BP)—a silica based material obtained from earth's crust on thermal heating. These substances are almost discarded waste products with the possibility of use as adsorbents. Experimental work for the dye removal from the effluent by activated charcoal (AC) has also been carried out and the results are compared with other adsorbents. The amount of unexhausted organic dye present in the effluent is measured as chemical oxygen demand (COD) before and after the treatment. Adsorbent Sugarcane bagasse pith shows good performance as compared to Saw dust and Brick powder. For understanding the behaviour of adsorbents Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) has also been carried out.     

Electronic and vibrational excitations in layered highT c superconductors

In the series of the layered highT _c superconductors (A)_1,2 B₂Ca _n−1Cu _n O_2n+3,4 (A=Tl or Bi;B=Ba or Sr), withn=number of consecutive Cu-O layers, the electron energy states of some of the Tl-based systems have been investigated. The electron and phonon dispersion curves have been obtained. The electronic states near the Fermi level are dominated by the hybridized Cu(d) and the O(p) orbitals. The dispersion curves are highly two-dimensional with very small dispersion alongc-axis. The number of bands is enhanced with increase in the number of the consecutive Cu-O planes (n). The present results agree with those obtained earlier for other superconducting phases. The phonons are overall dominated by the vibrations of the light mass oxygen atom modes both lying in or outside the Cu-O planes. The low-frequency phonons involve the motions of the heavier Tl, Ba atoms etc.     

Identification of yeast strains isolated from marcha in Sikkim, a microbial starter for amylolytic fermentation

Marcha or murcha is a traditional amylolytic starter used to produce sweet-sour alcoholic drinks, commonly called jaanr in the Himalayan regions of India, Nepal, Bhutan, and Tibet (China). The aim of this study was to examine the microflora of marcha collected from Sikkim in India, focusing on yeast flora and their roles. Twenty yeast strains were isolated from six samples of marcha and identified by genetic and phenotypic methods. They were first classified into four groups (Group I, II, III, and IV) based on physiological features using an API test. Phylogenetic, morphological, and physiological characterization identified the isolates as Saccharomyces bayanus (Group I); Candida glabrata (Group II); Pichia anomala (Group III); and Saccharomycopsis fibuligera, Saccharomycopsis capsularis, and Pichia burtonii (Group IV). Among them, the Group I, II, and III strains produced ethanol. The isolates of Group IV had high amylolytic activity. Because all marcha samples tested contained both starch degraders and ethanol producers, it was hypothesized that all four groups of yeast (Group I, II, III, and IV) contribute to starch-based alcohol fermentation.     

Investigation on material mixing during FSW of AA7475 to AISI304

AA7xxx and AISI304 stainless steel (SS) are employed in promising applications. Al alloy-to-SS dissimilar joining is difficult and challenging. Major challenge in the joining of these alloys is the difficulty in mixing of these materials which possess exotic and widely distant properties. AA7475-T761 is a high strength aluminum alloy which is used in key aircraft components. Maiden AA7475-T761 and AISI304 dissimilar joints were fabricated using friction stir welding. Welding was performed with tool having pin diameter of 4 mm and offset of 1.25 mm on Aluminum side. Tool rotational speed, traverse speed and shoulder diameter were varied in the range of 450–560 rpm, 50–63 mm/min, and 12–14 mm, respectively. Mechanical tests showed that joint formed with 14 mm diameter, 560 rpm and 50 mm/min gave the best joint efficiency of 71% of Al-alloy at 7.31% elongation. The materials mixing issues during processing were analyzed with SEM mircrostructure and fractography. Metallography also revealed that offset is critical to the success of joint as it controlled effective mixing of SS and Al in 15 and 85 vol.%, respectively. SS fragments from thermo-mechanically affected zone of SS were found to be partially sheared forming layer of thickness equal to tool traverse/revolution ratio.     

Sustaining Reforms in Water Service Delivery: the Role of Service Quality,Salience, Trust and Financial Viability

Water Resources Management - The long-term success of water service reforms depends on sufficient revenues being collected from users to allow access to be extended and quality of service to be...     

Synthesis and Characterization of Porogen Based Porous Low-k Thin Films

The present work is focused towards the lowering of the k value of deposited SiO₂ thin films by varying solvent concentration i.e. ethanol in the range 4-10 ml. Porous low-k thin films were synthesized by using the sol-gel spinon technique. A non-ionic surfactant polysorbate 80 (Tween 80) was used as a porogen to generate the porosity in the film matrix. The lower values of refractive index and film density were measured to be 1.19 and 0.94 gm/cm³ respectively for 10 ml solvent concentration. Further, the lowest k value of 2.2 and highest porosity percentage of 58.5 % were obtained for the same film due to the dilution of coating solution at higher solvent concentration. The water contact angle of the film was observed to be increased to 106.3° which indicates the transformation of the deposited film surface from hydrophilic to hydrophobic. The change in chemical structure as an effect of solvent concentration is studied by using FTIR. From FTIR spectra the disappearance of Si-OH groups at higher solvent concentration reveals the increase in condensation rate. Overall in this study, the result shows the significant change in structural, chemical and optical properties of the deposited films at 10 ml solvent concentration. Such deposited porous thin films with lower k value and enhanced hydrophobicity can be used as an interlayer dielectric (ILD) for back end of line (BEOL) in CMOS technology.     

Photocatalytic and Photochemical Oxidation of Ethylene: Potential for Storage of Fresh Produce—a Review

The phytohormone ethylene exerts numerous beneficial and detrimental effects on postharvest quality and storage life of fruit and vegetables. In view of the current global challenge of reducing postharvest losses and waste of fruit and vegetables, the importance of ethylene management in the supply chain is paramount. For this purpose, various methods have been applied along the supply chain over the years; however, effective management of ethylene under real-time storage and transport conditions still remains a challenging task. This review explores the potential of photocatalytic and photochemical oxidation of ethylene for effective removal of this gas along the value chain of fruit and vegetables. These techniques involve the use of ultraviolet (UV) radiation with or without a catalyst. In photocatalytic oxidation, a semiconductor such as titanium dioxide is essential which acts as a photocatalyst on irradiation with UV light and thus facilitates the oxidation of ethylene at its surface, whereas in photochemical oxidation, extreme short wave (i.e. below 200 nm) vacuum ultraviolet radiation (VUV) consisting of high-energy photons eliminates ethylene in the gaseous state. This review gives a brief overview of current commercial techniques used in ethylene removal and then focuses on the photocatalytic and the photochemical oxidation of ethylene and the combination of both methods. The various factors affecting these processes are also discussed including the advantages and the drawbacks associated with them, and current applications of these methods in fruit and vegetable storage systems are highlighted. In addition, a future outlook on the application of these methods in postharvest storage of fresh produce is given.     

Principal components null space analysis for image and video classification.

We present a new classification algorithm, principal component null space analysis (PCNSA), which is designed for classification problems like object recognition where different classes have unequal and nonwhite noise covariance matrices. PCNSA first obtains a principal components subspace (PCA space) for the entire data. In this PCA space, it finds for each class "i," an Mi-dimensional subspace along which the class' intraclass variance is the smallest. We call this subspace an approximate null space (ANS) since the lowest variance is usually "much smaller" than the highest. A query is classified into class "i" if its distance from the class' mean in the class' ANS is a minimum. We derive upper bounds on classification error probability of PCNSA and use these expressions to compare classification performance of PCNSA with that of subspace linear discriminant analysis (SLDA). We propose a practical modification of PCNSA called progressive-PCNSA that also detects "new" (untrained classes). Finally, we provide an experimental comparison of PCNSA and progressive PCNSA with SLDA and PCA and also with other classification algorithms-linear SVMs, kernel PCA, kernel discriminant analysis, and kernel SLDA, for object recognition and face recognition under large pose/expression variation. We also show applications of PCNSA to two classification problems in video--an action retrieval problem and abnormal activity detection.