Emergy-based life cycle assessment (Em-LCA) of multi-unit and single-family residential buildings in Canada

AbstractThe construction and building process depends on substantial consumption of natural resources with far-reaching impacts beyond their development area. In general, a significant portion of annual resource consumption by the building and construction industry is a result of applying traditional building strategies and practices such as designing and selecting types of development (e.g. multi-unit condo and single-family house, etc.), building materials and structure, heating/cooling systems, and planning renovation and maintenance practices. On the other hand, apart from structural suitability, building developers mostly consider the basic requirements of public owners or private occupants of the buildings, where the main criteria for selecting building strategies are costs, and long-term environmental and socio-economic impacts are generally ignored. The main purpose of this paper is to develop an improved building sustainability assessment framework to measure and integrate different sustainability factors, i.e. long-term environmental upstream and downstream impacts and associated socio-economic costs, in a unified and quantitative basis. The application of the proposed framework has been explained through a case study of single-family houses and multi-unit residential buildings in Canada. A comprehensive framework based on the integration of emergy synthesis and life cycle assessment (LCA) has been developed and applied. The results of this research prove that the proposed emergy-based life cycle assessment (Em-LCA) framework offers a practical sustainability assessment tool by providing quantitative and transparent results for informed decision-making

Assessment of water quality in distribution networks through the lens of disinfection by-product rules

Disinfection with chlorine is a common practice to ensure secured drinking water, but results in  potentially harmful disinfection by-products (DBPs), when excess chlorination is done. The US Environmental Protection Agency (US EPA) has established Stage 1 and Stage 2 disinfection by-product Rules (DBP rules) to control DBP exposure. A modified version of the Canadian Council of Ministries of the Environment water quality index (CCME WQI) is used to assess water quality. CCME WQI is a  globally accepted index to assess water quality, but is too generic to be used for DBP rules. The study developed a scheme to make the index suitable for DBP rules. A scoring method based on an analytic  hierarchy process (AHP) is applied to assign weights based on DBP rules. A previously modified CCME WQI (Islam et al., 2014) is adapted along with the weights to perform the assessment at the distribution network (DN). A case study was performed on 7 sampling stations in a Québec City DN. The spatial water quality variations are presented using kriging – a geostatistical method, which identifies the regions with relatively poor water quality and highlights the potential locations for re-chlorination points. The proposed assessment formulation is flexible to handle situations with limited data, which makes it especially suited to smaller municipalities.Keywords: CCME water quality index, Stage 1 DBP Rule, Stage 2 DBP Rule, chlorinatio

Antibiotic Sensitivity Patterns of Uropathogens in Children: The Current Trend

Background: The emergence of antibiotic-resistant infections has led to increased health care costs and mortality among children. The purpose of this study was to determine the causative organisms responsible for urinary tract infection and their antibiotic sensitivity pattern among pediatric patients of Rawalpindi/Islamabad. Material and Methods: This cross-sectional study was carried out from June 2014 to June 2015, in the Department of Microbiology, Army Medical College, Rawalpindi, affiliated with the Military Hospital, Rawalpindi. About 270 urine samples of children with UTI were analyzed through Analytical Profile Index (API) 20E and biochemical test strips system. Their antibiotic susceptibility was determined by using standard techniques. Data were assessed and analyzed by SPSS version 17. Results: Most common uropathogen was Escherichia coli (61.48%), followed by Proteus (15.5), Klebsiella (12.3%), Pseudomonas (4.5%), Enterococcus (3.7%) and Enterobacter (2.5%). Gram-negative rods, were most sensitive to imipenem (100%), Gentamycin (86%) and Amikacin (78.3%). They were least sensitive to Ampicillin (4.2%) and Norfloxacin (5.5%). Gram-positive cocci showed highest sensitivity for Vancomycin (100%) while displayed relatively less sensitivity for Nitrofurantoin (61.2%) and Gentamycin (48.7%). Cephalosporins also showed increased resistance with only 14% of gram-negative rods showing sensitivity to Cefotaxime. These organisms were highly resistant to Penicillin, showing a sensitivity of only 12.4%. Conclusion: Decreased sensitivity against penicillin and cephalosporins is seen in uropathogens causing UTI in children. High sensitivity towards Nitrofurantoin makes this drug an empirical treatment in UTI.  Regular surveillance of the developing resistance in uropathogens due to inappropriate use of antibiotic is necessary to reduce complication in children with urinary tract infection

Framework for optimizing chlorine dose in small- to medium-sized water distribution systems: A case of a residential neighbourhood in Lahore, Pakistan

To maintain desirable residual chlorine for a groundwater source, optimizing the chlorine dose in small- to medium-sized water distribution systems (SM-WDS) is a daunting task in developing countries. Mostly,  operators add a random chlorine dose without recognizing the smaller size of their distribution network.  In this research, a modelling framework for optimizing chlorine dose in SM-WDS is developed. In order to  evaluate its practicality, the proposed framework has been applied in a case study of a residential  neighbourhood in Lahore (Pakistan) with a small network spanning over 0.35 km2. Three datasets for residual chlorine were monitored at 6 locations spread over the study area. EPANET 2.0 software was  used for hydraulic and residual chorine modelling. The bulk decay coefficient (Kb) was determined in the  laboratory, whereas the wall decay coefficient (Kw) was estimated by calibrating the simulation results  with the residual chlorine determined in the field. Based on the calibrated EPANET simulations, a fuzzy  rule-based model was developed for pragmatic application of the proposed framework. Scenario analyses for different situations have also been carried out for achieving residual chlorine required at the consumer end. This exercise revealed that much lower chlorine doses than the existing practice can generate detectable chlorine residuals. Moreover, the model can be used to deal with emergency situations, which may arise in developing countries due to viral outbreaks and cross-contamination events in SM-WDS.Keywords: small- to- medium-sized water distribution systems, residual chlorine modelling, water  quality, chlorine decay coefficients, fuzzy rule-based modelling, EPANE

Active caseinate/guar gum films incorporated with gallic acid: physicochemical properties and release kinetics

Composite active films based on sodium caseinate/guar gum were prepared by the incorporation of gallic acid at different concentrations to investigate its effect on the structure, physicochemical properties, and the release kinetics from the film. The incorporation of gallic acid imparted changes in the FT-IR spectra. Water vapor permeability (WVP) of films decreased up to 21% after the incorporation of gallic acid in the film. The gallic acid released from the films GAI*60 μg.ml−1, GAII*250 μg.ml−1 and GAIII*650 μg.ml−1 was 67%, 32% and 30% respectively. Similarly, the diffusion coefficient was also affected by an increase in the concentration and was: 8.10 × 10−12 m2s−1, 6.23 × 10−12 m2s−1, and 4.5 × 10−12 m2s−1 for GAI, GAII and GAIII films respectively. Molecular docking suggested the potential inactivation of oxidative enzymes due to binding of gallic acid near their active sites. Therefore, gallic acid releasing films maybe considered as an active food packaging for fruits and vegetables (F&V)