University of New Brunswick
  • Fredericton, New Brunswick, Canada
Recent publications
A number of design codes and standards have begun to adopt a new expression for the effective moment of inertia used to compute immediate (short-term) deflection of reinforced (nonprestressed) concrete flexural members. This has led to renewed interest in serviceability requirements, including short- and long-term deflection of reinforced concrete, deflection of partially prestressed (cracked) concrete, and minimum thickness requirements for deflection control. Deflection of prestressed concrete is computed using properties of the gross (uncracked) section when the member is uncracked under service loads. Long-term deflection multipliers are available, but normally not prescribed for prestressed concrete as additional time dependent deflection needs to consider stresses in the concrete and steel under sustained load that include the effects of creep and shrinkage of concrete and relaxation of steel. Deflection of a cracked (partially) prestressed concrete member is more problematic and not well understood. A review of new and existing provisions for calculating deflection of reinforced and partially prestressed (cracked) concrete is provided, followed by development of a rational and comprehensive deformation model for computing short- and long-term deflection of reinforced and partially prestressed concrete that is cracked under service loads.
Background: Consuming discretionary snack foods high in calories, salt, sugar or fat in between regular meals can have a negative impact on weight management and health. Despite the intention to refrain from discretionary snacking, individuals often report feeling tempted by snack foods. A cognitive process to resolve food choice related tension may be dietary self-talk which is one's inner speech around dietary choice. This study aimed to understand the content and context of dietary self-talk before consuming discretionary snack foods. Methods: Qualitative semi-structured interviews based on Think-Aloud methods were conducted remotely. Participants answered open-ended questions and were presented with a list of 37 dietary self-talk items. Interview transcripts were analyzed thematically. Results: Interviews (n = 18, age: 19-54 years, 9 men, 9 women) confirmed the frequent use of dietary self-talk with all 37 content items endorsed. Reported use was highest for the self-talk items: 'It is a special occasion'; 'I did physical activity/exercise today'; and 'I am hungry'. Three new items were developed, eight items were refined. Identified key contextual themes were: 'reward', 'social', 'convenience', 'automaticity', and 'hunger'. Conclusions: This study lists 40 reasons people use to allow themselves to consume discretionary snack foods and identifies contextual factors of dietary-self talk. All participants reported using dietary self-talk, with variation in content, frequency and degree of automaticity. Recognising and changing dietary self-talk may be a promising intervention target for changing discretionary snacking behaviour.
The paper presents an extensive review on the fundamentals of drying, represented by drying kinetics, and models of some building materials and their importance as highlighted in several studies presented by researchers in this area. The objective of the review is to present gaps and existing approaches that will serve as reference pool for researchers working in this area. This helps to determine the end point of drying process of various building material to avoid negative effects, such as shrinkage, cracks, and deformations. Different developmental approaches for each model and methods of simulation in building materials drying were presented with attention given to the application of variable drying conditions. The review revealed that empirical, such as phenomenological model, mechanistic and numerical models, such as diffusion model and Whitaker model, have been applied to predict the drying behavior of building materials with coefficients and boundary conditions being product specific. The major factors considered in these models were type of material, thickness and its physical characteristics, as well as the operating conditions mainly represented by the temperature and humidity of the drying air. The literature review shows that the available simulation tools were TRHumidade, Wufi Pro software and CFD developed to simulate drying process of building materials. It important to mention that in this study the focus was on the mass transfer and then the presented tools or software were the ones able to show and predict the distribution of the moisture inside the drying product.
Objective It has been postulated that social and economic inequalities may shape the distributions of comorbid diabetes and mental illness. This observational cohort study using linked population-based administrative and geospatial datasets aimed to describe associations between neighbourhood socioenvironments and disorder-specific mental health service use among adults with diabetes in the province of New Brunswick, Canada. Results A baseline cohort of 66,275 persons aged 19 and over living with diabetes was identified. One-quarter (26.3%) had used healthcare services for mood and anxiety disorders at least once during the six-year follow-up period 2012/2013–2017/2018. Based on Cox proportional hazards models, the risk of mental health service contacts was significantly higher among those residing in the most materially deprived neighbourhoods [HR: 1.07 (95% CI: 1.01–1.14)] compared to those in the least so, and those in areas characterized with the highest residential instability [HR: 1.13 (95% CI: 1.05–1.22)] compared to those in areas with the lowest instability. Among adults with incident diabetes (N = 4410), age and sex but not neighbourhood factors were related to differential help-seeking behaviours for mental health problems. These findings underscored the gap between theoretical postulations and population-based observations in delineating the syndemics of neighbourhood socioenvironments and mental health outcomes in populations with high diabetes prevalence.
Acupuncture is widely used around the whole world nowadays and exhibits significant efficacy against many chronic diseases, especially in pain-related diseases. With the rapid development of artificial intelligence (AI), its implementation into acupuncture has achieved a series of significant breakthroughs in many areas of acupuncture practice, such as acupoints selection and prescription, acupuncture manipulation identification, acupuncture efficacy prediction, and so on. The paper will discuss the significant theoretical and technical achievements in AI-directed acupuncture. AI-based data mining methods uncovered crucial acupoint combinations for treating various diseases, which provide a scientific basis for acupoints prescription in clinical practice. Furthermore, the rapid development of modern TCM instruments facilitates the integration of modern medical instruments, AI techniques, and acupuncture. This integration significantly improves the quantification, objectification, and standardization of acupuncture as well as the delivery of clinical personalized acupuncture therapy. Machine learning-based clinical efficacy prediction of acupuncture can help doctors screen patients who may benefit from acupuncture treatment. However, the existing challenges require additional work for developing AI-directed acupuncture. Some include a better understanding of ancient Chinese philosophy for AI researchers, TCM acupuncture theory-based explanation of the knowledge discoveries, construction of acupuncture databases, and clinical trials for novel knowledge validation. This review aims to summarize the major contribution of AI techniques to the discovery of novel acupuncture knowledge, the improvement for acupuncture safety and efficacy, the development and inheritance of acupuncture, and the major challenges for the further development of AI-directed acupuncture. The development of acupuncture can progress with the help of AI.
Global liquid packaging industry has been greatly spurred by the rapidly growing food & beverage industry all over the world. Liquid packaging board (LPB), as the main composition (75–80 %) of laminated liquid packaging cartons, must possess high-quality of hydrophobicity and physical properties for excellent leak-proof and protecting the packaged commodity. Herein, in this study, lignin is selected to prepare lignin cationic surfactant (LCS) by quaternary ammonium modification. Then cationic lignin modified rosin size (L-CDRS) with uniform microsphere structure and high colloidal stability is successfully synthesized via a phase inversion process to improve the sizing performance and mechanical properties of LPB. The cation modified LCS presents improved amphipathicity of rich cationic charges and hydrophobic benzene ring skeleton, thus enhancing the electrostatic interactions between LCS and pulp fibers and improving the sizing performance of L-CDRS. The sizing performance of LPB is evaluated by varying the LCS dosages within L-CDRS and concluded that the edge penetration value and Cobb value of LPB handsheets exhibit an improved size performance with 2 % LCS within L-CDRS, implying the formation of homogeneous hydrophobic surface layer induced by the well-distribution of L-CDRS. In addition, the tensile index of LPB increased from 19.74 N·m/g to 25.96 N·m/g assisted by 2 % LCS emulsified L-CDRS, indicating an improved mechanical property. This study puts forward a practical and facile strategy to improve the sizing performance and mechanical properties facilitated by lignin enhanced rosin size and will further broaden the application range of traditional rosin size and lignin in LPB products.
In this study, we reported for the first time that the natural protein/polysaccharide hybrid nanoparticles (PPH NPs) with a diameter of ∼ 129 nm, originating from Lactobacillus plantarum fermented cheese whey, could act as green-based NPs for stabilizing Pickering emulsions. Characterizations of PPH NPs showed that the negative-charged PPH NPs were composed of ∼ 37.7% total protein and ∼ 7.3% polysaccharide bearing several functional groups, such as –OH, –NH, –COOH, etc.; and displayed excellent emulsifying capacity in preparing oil-in-water Pickering emulsions. The obtained emulsions exhibited gel-like behavior with excellent stability against the variation of pH, ionic strength, and temperature. Confocal observations showed that PPH NPs effectively adsorbed and anchored at the oil–water interface, thus creating the steric hindrance to inhibit droplet coalescence. This research is of importance in developing novel and biocompatible Pickering stabilizers with outstanding performance, as well as enable a versatile design of stable Pickering emulsions suitable for food industries.
Black liquor and Fenton sludge are common industrial wastes that come from the conventional kraft pulping process and the Fenton wastewater treatment process, respectively. In this study, the biochar-supported iron-based catalysts were synthesized through a simple one-step pyrolysis method using acid-precipitated black liquor (APBL) as carbon source and Fenton sludge as iron source, and were then applied for Fenton-like removal of rhodamine B (RhB) dyes. The optimized catalyst ([email protected]FAK), pyrolyzed at 900 ºC with KOH as the activator, was mesoporous biochar-supported nanoscale zero-valent iron (nZVI). Under the optimal conditions (50 mg L⁻¹ RhB, initial pH 3, 2 mM H2O2 concentration, catalyst dosage of 0.2 g L⁻¹), the [email protected]FAK/H2O2 system achieved almost 100% RhB dye removal within 10 min. Moreover, the [email protected]FAK/H2O2 system also exhibited excellent removal efficiencies for malachite green, crystal violet, and methylene blue. The [email protected]FAK had a good magnetic separation ability (146.4 emu g⁻¹) and maintained a high removal efficiency of RhB (83.8%) in the presence of H2O2 after five times of recycling/reuse. The degradation of RhB dye was mainly attributed to •OH, including surface-bound •OH and free •OH. Besides the excellent catalytic ability and Fe(III) reduction ability of nZVI itself, the biochar supports with high specific surface area and mesoporous structure also played important roles in the removal of RhB dye, such as adsorbing RhB dyes, alleviating nZVI aggregation, and accelerating the reduction of Fe(III) to Fe(II).
Supercapacitors (SC), as one of the most competitive energy storage devices, are receiving great attention in R&D community. Carbonaceous materials for supercapacitor electrodes with high performance possess many attractive advantages, such as large specific surface area (SSA), hierarchical porous superstructures and excellent conductivity. Herein, biomass based materials are often utilized as versatile precursors for activated carbon production due to their inherent merits, including low cost, abundance, renewability, high carbon content, environmental friendliness, genetically unique nature structure. As known, the capacitance performance of biomass based carbon-assembled supercapacitors is mainly directly proportional to the exceptional skeleton robustness, high SSA and electroactive site content within carbonaceous framework. In this review, special attentions will be paid to the latest research progress of carbonaceous materials derived from biomass with tailored hierarchical superstructures to highlight their impact on the electrochemical performance of assembled supercapacitor. The objective of this paper is to present a critical review on the most recent publication related to biomass oriented carbonaceous electrodes for outstanding supercapacitor electrodes. Furthermore, the perspective for the progress and development of biomass based carbonaceous electrodes for high performance supercapacitors will also be provided, to underscore the current critical issues and future opportunities.
The present study provides a quantitative summary of findings on the correlation between emotional intelligence and romantic relationship satisfaction as well as an examination of possible moderating variables for this correlation. The final sample of 90 effect sizes from 78 samples included a comprehensive set of studies measuring emotional intelligence and relationship satisfaction, relationship quality, or marital adjustment among individuals in a romantic relationship. Results of the analysis showed a mean estimated zr of 0.392 (95% confidence interval = 0.338, 0.447), reflecting a mean estimated correlation of 0.373. Location of testing, internal consistency of the emotional intelligence scale, relationship satisfaction measure type (adjustment, quality, or satisfaction), and relationship status (married, unmarried, mix) were significant moderators of the effect sizes. The discussion notes the implications of present findings in the context of emotional intelligence training in couple therapy. We also emphasize avenues for future work, such as the use of measures of emotional intelligence with high internal consistency and examining more closely the potential role of gender equality in a cross-cultural perspective.
Kerogen assessment is essential to evaluation of shale reservoir quality. Routine analysis techniques are sample destructive and time-consuming. ¹H magnetic resonance (MR) methods offer a fast, robust, and non-destructive alternative. However, kerogen MR signal detection and quantification is challenging due to its short signal lifetime and requires new MR methods. In this work, the T1-T2* relaxation correlation method was investigated for assessment of kerogen in shales. Step pyrolysis experiments were conducted coupled with MR T1-T2* relaxation correlation measurements and thermogravimetric analysis (TGA). The results show that the short relaxation lifetime signal observed in the shale samples was dominated by the kerogen species. The shale signal was resolved in the T1-T2* relaxation correlation measurement that was calibrated to report kerogen, oil, and water ¹H content of the shale samples. Kerogen ¹H content was then used to evaluate the hydrocarbon generation potential of kerogen. An elemental balance analysis was conducted to estimate the kerogen chemical evolution in the Van Krevelen diagram. The results proved that a simple FID measurement was adequate to resolve and quantify the kerogen signal component in shales.
Climate change is expected to have significant impacts on forests by affecting the successional dynamics of tree species and the performance of plantations, among others. Research is needed to better understand how these factors will affect forests and economies in different regions, and how we can best adapt. To shed some light on these issues, we couple an economic (Computable General Equilibrium) model with a forest management (Woodstock) model to analyze the potential climate change impacts and adaptation options on timber supply and the economy over the 2015–95 period in a case-study province of New Brunswick, Canada. We estimate that climate change may have relatively large negative impacts on softwood timber supply (at 26% by 2095), softwood forestry & logging sector output quantity (at 12% by 2095), and softwood-dependent forestry manufacturing sector output (ranging from 6% to 27% by 2095). Negative impacts on GDP may be relatively smaller (at up to a 0.33% reduction by 2095). Adapting to these climate-related changes by planting drought-resistant softwood seedlings or hardwood seedlings in place of failed softwood plantations can minimize these negative impacts, and in the latter case, positively impact hardwood timber supply and output. While the former adaptation option is supported using cost-benefit analysis, the latter is not – due to the large incremental costs of growing, planting, and tending hardwood seedlings. Methods developed in this study can be applied in other regions to help guide decision-making around forest management in the face of a changing climate.
Alloy 625 is an important alloy in many industries, including aerospace, providing good mechanical properties in high temperature and corrosive environments. It also retains good properties when additively manufactured using Laser Powder Bed Fusion (LPBF). The LPBF process introduces complex heating and cooling cycles in the material used, thereby affecting the mechanical properties. As a result, existing constitutive models for alloy 625, are not applicable for the LPBF-fabricated material. Therefore, this study sought to establish appropriate constitutive models to simulate the mechanical response of LPBF-fabricated alloy 625 in the desired range of conditions for aerospace applications: high strain rates and temperatures. This was completed by compressing the samples at two strain rates, 700 s⁻¹ and 1700 s⁻¹, and temperatures ranging from 298 K to 773 K using a Split Hopkinson Pressure Bar (SHPB). The information gained from the models was reinforced with micrographs and electron backscatter diffraction (EBSD) images to examine the microstructure of alloy 625 after LPBF. The results from the SHPB testing were then used to calculate the coefficients for five constitutive models, the Johnson-Cook model, a modified Johnson-Cook model, the Hensel-Spittel model, a modified Hensel-Spittel model, and a modified Zerilli-Armstrong model. The Average Absolute Relative Error (AARE) of these models was calculated, and it was determined that the modified Zerilli-Armstrong model had the lowest AARE of the models used, 2.88 % for as-printed alloy 625 and 2.71 % for heat-treated alloy 625.
Introduction: Coronavirus disease-2019 (COVID-19) is a new viral disease that has spread rapidly worldwide since December 2019 and there is no effective treatment for it. The current study aimed to investigate the psychological consequences and related factors among COVID-19 survivors. Methods: This descriptive analytical study was conducted on 152 patients with COVID-19 referred to referral hospitals in southeastern Iran in 2020. Data collection tools were three questionnaires of demographic and background information, Depression Anxiety stress Scale (DASS-21) and Impact of Events Scale-Revised (IESR). Descriptive and inferential statistics and SPSS25 were used to analyze the data. Results: The mean age of patients was 39.52 ± 13.16 years. The patients were mostly female (63.8%). Seventy-three percent of the patients had severe posttraumatic stress disorder, 26.3% had moderate depression and 26.3% had severe anxiety. The mean scores of posttraumatic stress, depression, and anxiety among patients with COVID-19 were 41.59 ± 17.28, 12.13 ± 9.16, and 12.45 ± 10.71, respectively. Intensive care unit (ICU) admission, divorce, illiteracy, and retirement were all associated with higher psychological load among patients. Discussion and conclusion: The results showed that patients with COVID-19 had different levels of anxiety, depression, and posttraumatic stress. These results may direct the attention of the medical staff to the mental health of COVID-19 patients, necessitating timely psychological care and intervention during an epidemic.
Balsam fir (Abies balsamea) is one of the most abundant softwood species in eastern Canada but is projected to be adversely affected by climate change. Balsam fir decline could occur due to a combination of reduced germination and regeneration, lower growth and competitive ability, and higher rates of mortality. However, tree regeneration represents one of the most vulnerable stages to climate-induced stress. In this paper, we synthesize potential and observed effects of climate change on balsam fir regeneration. Recent studies have shown no detrimental effects of increased temperatures on either germination or seedling growth of balsam fir, but clear deleterious effects of decreased water availability. Balsam fir seeds require 28–60 days of cold stratification to become germinable, and such conditions should still be met under climate change across most of the species’ range. Sampling along a north-south climatic gradient throughout the Acadian Forest Region of eastern Canada indicated effects are complex and do not suggest a clear decline under warmer, drier conditions for the species. Thus, effects of global warming on balsam fir may be more gradual than projected in modeling studies and occur primarily via reduced competitive ability and/or higher mortality in overstory trees, rather than regeneration failure.
As the climate changes, warmer spring temperatures are causing earlier leaf-out1–3 and commencement of CO2 uptake1,3 in temperate deciduous forests, resulting in a tendency towards increased growing season length3 and annual CO2 uptake1,3–7. However, less is known about how spring temperatures affect tree stem growth8,9, which sequesters carbon in wood that has a long residence time in the ecosystem10,11. Here we show that warmer spring temperatures shifted stem diameter growth of deciduous trees earlier but had no consistent effect on peak growing season length, maximum growth rates, or annual growth, using dendrometer band measurements from 440 trees across two forests. The latter finding was confirmed on the centennial scale by 207 tree-ring chronologies from 108 forests across eastern North America, where annual ring width was far more sensitive to temperatures during the peak growing season than in the spring. These findings imply that any extra CO2 uptake in years with warmer spring temperatures4,5 does not significantly contribute to increased sequestration in long-lived woody stem biomass. Rather, contradicting projections from global carbon cycle models1,12, our empirical results imply that warming spring temperatures are unlikely to increase woody productivity enough to strengthen the long-term CO2 sink of temperate deciduous forests. Warmer spring temperatures affect the timing of stem diameter growth of temperate deciduous trees but have little effect on annual growth.
Stolen kisses are often portrayed as resulting from uncontrollable passion and a need to connect intimately with another. This study examined stolen kisses, defined as kissing someone for the first time when the kisser perceived the kiss recipient was not expecting it, and had not provided consent for the kiss. These kisses were examined from the perspective of the individual initiating the kiss. Participants (N = 130; Mage = 32.27; 67% identified as male) completed an anonymous online survey assessing kissing experiences of having stolen a kiss and their open-ended responses were analyzed here. Men were more likely than women to report having stolen a kiss in line with traditional heterosexual scripts. Three scenarios emerged through content analysis: mutual attraction leading to a new relationship; no known mutual attraction but a positive outcome; and no known mutual attraction and a negative outcome. Stealing a kiss from someone for whom there was mutual attraction often led to the onset of an intimate relationship; thus, the kiss constituted a relationship catalyst. When there was no known shared attraction, some interactions ended positively, but others resulted in an end to cordial relations and often strong negative reactions. Findings are discussed in terms of the limited literature on kissing generally and the nonconsensual nature of these events.
For flexible strain sensors, the optimization between sensitivity and working range is a significant challenge due to the fact that high sensitivity and high working range are usually difficult to obtain at the same time. Herein, a breathable flexible strain sensor with a double-layered conductive network structure was designed and developed, which consists of a thermoplastic polyurethane (TPU)/carbon nanotube (CNT) layer (as a substrate layer) and a Ag nanowire (AgNW) layer. The TPU/CNT layer is made of electrospinning TPU with CNTs deposited onto the surface of TPU fibers, and the flexible TPU/CNT mat guarantees the integrity of the conductive path under a large strain. The AgNW layer was prepared by depositing different amounts of AgNWs on the surface of the TPU/CNT layer, and the high-conductivity AgNWs offer a low initial resistance. Benefitting from the synergistic two-layer structure, the as-obtained flexible strain sensor exhibits a very high sensitivity (up to 1477.7) and a very wide working range (up to 150%). Besides, the fabricated sensor exhibits fast response (88 ms), excellent dynamical stability (7000 cycles), and excellent breathability. The working mechanism of the strain sensor was further investigated using various techniques (microscopy, equivalent circuit, and thermal effects of current). Furthermore, the as-fabricated flexible strain sensors accurately detect the omnidirectional human motions, including subtle and large human motions. This work provides an efficient approach to achieve the optimization between high sensitivity and large working range of strain sensors, which may have great potential applications in health monitoring, body motion detection, and human-machine interactions.
The way in which the effect of temperature on the development rate of crustacean larvae is simulated in larval dispersal models potentially impacts the inferences made about population recruitment and connectivity. In this study, we contrasted dispersal and connectivity predictions made by a large‐scale dispersal model of American lobster (Homarus americanus H. Milne Edwards, 1837) larvae using three temperature‐dependent larval development functions proposed in the literature: (1) “warm‐source lab”, (2) “warm‐source field”, and (3) “cold‐source lab”. Differences in predictions using each function were contrasted in the northern (colder) and southern (warmer) portions of the species' range. Using these different development functions resulted in significant and marked differences (61.3–162.4 km in the north and 30.9–81.9 km in the south) in the distances dispersed by larvae from hatch to settlement. In general, predicted self‐seeding, retention, and local connectivity were increased, and predicted connectivity among distant locations was decreased, when a function predicting faster development was used. The field‐derived function predicted much less connectivity and decreased dispersal overall than both lab‐derived functions. The cold‐source lab function predicted more retention in northern regions, but less in southern regions, than the warm‐source lab function. Our findings indicate the need for more studies to quantify the rate at which lobster larvae develop in nature, including how this may vary over space and time.
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4,685 members
David Wagner
  • Faculty of Education
Hilary du Cros
  • Department of Humanities & Languages
Ted Mcdonald
  • Department of Economics
Tommi Linnansaari
  • Canadian Rivers Institute, Department of Biology and Faculty of Forestry and Environmental Management
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