Evaluation of the thermal performance and cost effectiveness of radiant barrier thermal insulation materials in residential construction

Reducing heating and cooling systems loads in buildings is a cost effective way to decrease energy consumption in residential houses. This reduction can be achieved in many ways including proper insulation of the building envelope. In recent years, considerable attention was given to the use of radiant reflective insulating barriers. Over the past years, reflective barrier insulation companies nationwide have experienced significant growth resulting in an industry average growth rate of 26.8%. This significant growth is expected to continue as a result of increased cooling demands and pressure from the energy sector and the economy. Growth is also predicted to be prevalent amongst the southern regions of the United States in efforts to reduce high cooling energy costs, which are expected to prevail. This significant growth has not been felt by the radiant barrier industry in Louisiana. This is mainly due to the lack of knowledge and amount of research available in quantifying radiant barriers thermal effectiveness for hot and humid climatic conditions widely encountered in the State. In order to improve the competitiveness of the reflective insulation industry, the primary goal of this research is to develop a simple estimating tool that may be used by homeowners, state agencies, and contractors to assess the effectiveness and economic benefits of radiant barrier insulation systems under the climatic conditions encountered in United States. Current research achieved this objective by adopting a multi‐dimensional research approach that developed this estimating tool over three main phases and then combined results of these phases to provide an overall assessment tool for this technology. In the first phase, the energy saving benefits of radiant barrier was quantified experimentally for the climatic conditions and construction practices prevalent in United States. A transient heat transfer finite element (FE) model was developed to predict the ceiling heat gain or loss through the attic space in residential buildings and to accurately estimate savings in cooling and heating loads produced by the radiant barrier application. Validity of the models was established by comparing their prediction with experimental data. In the second phase, economic effectiveness of radiant barrier technology was evaluated. In the third phase, development of the estimating tool and dissemination of the results was achieved. Results showed that radiant barrier can reduce heat flux transferred from roof to the condition space significantly

VALIDATING THE CANADIAN SEISMIC RISK MODEL

openCanada faces a scarcity of impactful earthquakes that can be used to validate seismic risk models, as the last significant damaging earthquakes occurred in the 1980s (Hobbs, Journeay, and Rotheram 2021). To overcome this limitation, this study aims to assess the reliability of the Canadian National Seismic Risk Model (CanadaSRM1) by analyzing the shaking intensities and physical impacts recorded from several recent events. These events include the 2010 Mw 5.5 Val-des-Bois and 2013 Mw 4.6 Ladysmith earthquakes in Eastern Canada, the 1985 M 6.9 Nahanni earthquake in Northern Canada, and the 2017 Mw 6.2 - 6.3 Mosquito Lake pair earthquakes in Western Canada. By evaluating the potential consequences of mentioned earthquakes in south-western Quebec, the Northwest Territories, and southern Yukon (near Whitehorse), the study aims to assess the potential impact on densely settled metropolitan areas across the country. In order to support disaster risk reduction efforts and advance the objectives of the Sendai Framework for Disaster Risk Reduction, Natural Resources Canada (NRCan) partnered with Global Earthquake Model Foundation, Italy (GEM) to develop a public Canadian Seismic Risk Model (Hobbs et al. 2023). This collaborative effort involved creating a national exposure inventory, Canadian-specific fragility and vulnerability curves, and adjusting the Canadian Seismic Hazard Model, which is the basis for the seismic provisions in the National Building Code of Canada. The risk modeling process, using GEM's OpenQuake-Engine (OQ), utilizes deterministic and probabilistic calculations to assess seismic risk at the neighborhood level for all Dissemination Areas (DAUID) in Canada. By considering baseline and simulated retrofit conditions, the model provides risk metrics such as expected immediate physical impacts, including building damage, casualties, and direct economic losses. This approach of Seismic Risk Assessment (SRA) relies on previous earthquake knowledge to estimate the potential consequences of future earthquakes, enabling the evaluation of proposed mitigation and adaptation measures for disaster risk reduction. This thesis presents a comprehensive analysis of the potential damage caused by benchmark scenario earthquakes, including shaking damage to buildings, financial losses, fatalities, and other impacts. The study utilizes the OQ Engine and the national exposure dataset, following the methodology of the CanadaSRM1. The primary findings, such as damage distributions, loss exceedance curves, and annual average losses, offer an accessible and quantifiable foundation of evidence for decision-making at various levels - local, regional, and national. These results demonstrate a high degree of consistency with observed or predicted impacts, taking into account economic and population growth adjustments. Consequently, this confirms the reliability of the first generation Canadian Seismic Risk Model, aligning it with industry standards and enabling the reproduction of recent destructive earthquakes. Given Canada's vast size, intricate seismic hazard model, and dispersed populations, this study holds unique significance. Nonetheless, the challenges faced, and solutions provided are likely to be valuable to other countries undertaking similar programs

Arsenic biosorption by psychrotrophic arctic bacteria

Arsenic is a well-known toxic pollutant for biological systems and known human carcinogen. Its presence in the environment increased because of mining, agricultural and manufacturing activities. Use of bacterial biomass for heavy-metal removal from environment gained high interest due to the limitations and disadvantages of various existing conventional methods. The aims of this study were to isolate novel arsenic-resistant psychrotrophic bacteria from Arctic samples and study their ability to adsorb As(III) at a broad range of temperature (10°C - 40°C ) characteristic of the tropic and polar regions. Parameters affecting biosorption of arsenite: pH, time, initial As(III) concentration, temperature and adsorbent dosage were also investigated. Findings showed that among the eight psychrotrophic bacteria with high metal resistance, 12D3 (Yersinia sp. strain SOM-12D3) and 15D1 (Pseudomonas sp. strain SOM-15D1) showed the highest As(III) adsorption at pH 7 and 30 °C. Batch experiments were carried out using untreated or acid-pretreated nonliving biomass prepared from 12D3 and 15D1 isolates. The results showed that acidpretreatment of bacterial biomasses increased the ability of As(III) adsorption. Based on the value of R2 (0.959 for 12D3-UB, 0.9617 for 12D3-AB, 0.935 for 15D1-UB and 0.953 for 15D1-AB), the Langmuir isotherm model fitted the equilibrium data better in comparison to Freundlich isotherm model. The maximum biosorption capacity of the sorbents, as obtained from the Langmuir isotherm, were 33.4 mg/g for 12D3-UB, 159 mg/g for 12D3-AB, 36.63 mg/g for 15D1-UB, and 129.87 mg/g for 15D1-AB. The sorption kinetic of As(III) followed well the pseudo-second-order rate equation for all types of non-living biomass. The acquired positive values of both ?S° and ?H° suggested an endothermic reaction and increased in randomness at the solid-liquid interface. Negative ?G° values indicated a spontaneous adsorption process. High recovery efficiency of As(III) (96% for 12D3-AB and 95% for 15D1-AB) were achieved at 1.5 g/l values of solid to liquid ratio (S/L) (metal-laden biosorbent to the volume of eluent) within four cycles indicated adsorption/desorption. The involvement of functional groups (hydroxyl, amide and amine) in As(III) biosorption process was shown via Fourier-Transform Infrared spectroscopy (FTIR) analysis. FESEM-EDAX analysis of the non-living biomass revealed that acid treatment removed particles from the surface of biomass, deformed cells, and created a pore structure on the biosorbent surface. Therefore, increased As(III) biosorption was because of increased metal binding sites after acid pretreatment. This study points to the potential of using acidpretreated non-living biomass of psychrotrophic bacteria, Yersinia sp. strain SOM- 12D3 and Pseudomonas sp. strain SOM-15D1, as a new biosorbent to remove As(III) from contaminated waters at tropical and polar regions

Scientometric Analysis of Scientific Products with Co-authorship Networks: The Case of Sharif University of Technology

Identifying the most important individuals, institutions, universities, and other academic activities related to scientific production can help in collaborating and also exchanging information in various fields of science. Scientific cooperation plays an important role in promoting qualitative and quantitative scientific publications. One of the forms of collaboration is co-authorship in which two or more authors collaborate to create scientific work. Co-authorship relationships form collaboration networks that can be analyzed and visualized. The structure of networks like co-authorship can reflect the degree of internal collaboration and show the changes of information through time and other variable

Anticancer Activity and Phenolic Compounds of Pistacia atlantica Extract

Recently a lot of studies have been conducted to identify natural compounds for prevention of the development and recurrence of cancers. The present study aimed to determine phytochemical content and anti proliferative activity of Pistacia atlantica extract. Ethanolic extract of Pistacia atlantica was prepared. The antioxidant activity, total phenol, flavonoid and flavonol content of the extract were evaluated. Cytotoxicity activity of extract on AGS and HeLa cell lines was evaluated by MTT assay 48 hours after treatment. The antioxidant activity of extract was 4.6 +/- 0.66 mu g/ml while it was 25.41 +/- 1.89 mu g/ml for butylated hydroxytoluene (BHT). The total phenol, flavonoid and flavonol contents were 269 mg GAE/g, 40.7 mg RUT/g and 88.12 mg RUT/g, respectively. The extract inhibited the proliferation of AGS, HeLa and HDFs cells with IC50 values of 382.3 mu g/m, 332.3 mu g/ml and 896.3, respectively. This study revealed that the extract of Pistacia atlantica can suppress the proliferation of gastric carcinoma and cervical cancer cells. The plant with high phytoconstituents could be a promising source of anticancer drugs

Sustainable Energy Systems Planning, Integration and Management (Volume II)

Affordable and clean energy is one of the sustainable development goals (SDGs) introduced by the United Nations that are required to be followed by all developed and developing countries [...

In vitro study of antimicrobial effects of Rosmarinus officinalis and Glycyrrhiza glabra extracts against some pathogens

Background and aims: Disease causing bacteria have always been considered a major cause of morbidity and mortality in humans. The appearance of resistant microorganisms paved the way to the occurrence of infections that are only treated by a limited number of antimicrobial agents. The present study was, the antimicrobial effects of Rosmarinus officinalis and Glycyrrhiza glabra extract against some pathogens. Methods: In this study, the antibacterial activity using 9 Gram-positive and Gram-negative bacterial strains includes: Streptococcus pyogenes ATCC® 19615, Streptococcus pneumoniae ATCC 49619, S. saprophyticus ATCC®15305, Hafnia alvei ATCC 51873, Acinetobacter baumannii ATCC 19606, Enterococcus faecalis ATCC 29212, Proteus mirabilis ATCC 35659, Serratia marcescens ATCC 274 and Staphylococcus aureus ATCC® 25923 with micro dilution methods was studied. The MIC, MBC were studied also, resistance of these bacteria to standard antibiotics such as erythromycin, cefixime, ceftazidime, tetracycline, ampicillin and amikacin were compared. Results: In this study, the minimum inhibitory concentration (MIC) was used. The levels of MIC of R. officinalis were in ranges from 6.25 to 25 mg/ml. The highest MIC value was observed at 25 ppm against S. pyogenes, S. pneumoniae and P. mirabilis and the levels of MIC of G. glabra were in ranges from 6.25 to 12.5 ppm. The highest MIC value was observed at 12.5 ppm against S. pyogenes, S. pneumoniae, P. mirabilis and S. marcescens. Conclusion: In important human pathogens, drug resistance is increasing according to the results of this study, and may be proposed that this plant can be used as a drug. It can be a good way to replace herbs with chemical drugs

Necessity of the Adaptive Comfort Standard for the Middle East in the Times of Rising Energy Use

Middle East (ME) supplies more than 47% oil exported in the world (IEA 2013) and has highest energy self-sufficiency in the world. It includes 12 countries and has a population of 205 million in 2010, which increased by about 61.4% from 1990 (IEA 2010). Its energy demand has increased astronomically at the rate of 7% per year, since 1971-2013, faster than in any other region in the world. Buildings majorly contribute to this. Building energy (residential, commercial and public use buildings) use in the ME has increased by about 46% in the period 2003-13 (IEA 2010). Ironically ME houses only about 3% of the world's population, but it contributes to 13% of global CO2 emissions. Understandable, its per capita CO2 emission is one of the highest in the world at 7.53 tons of CO2/capita, 68% higher than the world average. Therefore improving the energy efficiency remains a key challenge for the region. International Energy Agency (IEA) identifies the development and enforcement of building energy codes coupled with energy consumption data generation as the top energy efficiency policy recommendations for this region (IEA 2014). Qatar's per capita energy consumption is one of the highest, consuming 30.184 TWh as of 2012 (IEA 2012) Buildings contribute majorly (80%) to this, with air-conditioning taking a lion's share. With the absence of custom-made energy/thermal comfort standards, the buildings tend to follow western standards meant for colder climates verbatim. Cheap energy availability and tariffs exacerbate this practice (Fattouha and El-Katiri 2013). Often times, energy analysis and conservation come as postmortem ideas than at the design stage. And the energy subsidies often prove to be unrealistic and unsustainable in the long run. Qatar has little research on occupant thermal comfort and preferences in buildings. Energy efficient building design necessitates this. As part of large energy conservation web tool design for Qatar, we conduct year long occupant surveys in office buildings to understand the nature of the building stock and occupant thermal comfort and preferences along side their thermal adaptations. Saudi Arabia stands sixth in world's oil consumption and already uses a quarter of its own production. Building energy consumption in Saudi Arabia went up astronomically by 60.8% in five years from 2007 to 2012. Energy analysts argue that Saudi Arabia could turn into a net oil importer by 2030 if current demand, growth patterns continue. Air conditioning majorly contributes to this. Recent research posits that the building envelope codes have a limited role to play in reducing energy consumption (Radhi 2009). Saudi building code specifies two design temperatures of 20 C and 25.5 C for winter and summer, for all climate and building types, much similar to the building codes of other countries like UAE (SBCNC 2007). Relying on Fanger's heat balance model (Fanger 1972), the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard -55 (1992) formed the basis for this. This Standard is long since superseded (ASHRAE 1992). Environments designed based on this model produce thermal monotony (uniform indoor temperatures yearlong), with the indoor environments delinked from the outdoors. It ignores the local climate, clothing, culture or comfort practices of Saudis. Researchers all across the globe criticized such rigid and unsustainable indoor temperatures. The Adaptive model of Thermal Comfort on the other hand hinges on the field studies in real life buildings. People in their everyday environments are studied in order to develop the temperature standards that truly represent local climate, people, their comfort practices and adaptation mechanisms. Saudi Arabia is yet to develop its Adaptive Thermal Comfort Standards (ACS) (Nicol and Humphreys 2009) (CIBSE, (The Chartered Institution of Building Services Engineers) 2006, Indraganti, et al. 2014) (ASHRAE 2010) (ASHRAE 2010). The potential of occupant's adaptation and the ACS is in producing sustainable indoor environments is long since been recognized. Therefore, this presentation highlights the necessity of the Adaptive Comfort Standards for the ME in the context of its growing energy concerns. It relies on the results of the first field studies we have conducted in Japan and India, KSA and Qatar and also draws heavily from the current research around the world.Qscienc