Natural gas engine driven heat pump system – a case study of an office building

ABSTRACT

An eQUEST model was developed to conduct a simulation study of a natural gas engine-driven heat pump (GEHP) for an office building in Woodstock, Ontario, Canada. Prior to the installation of the GEHP, the heating and cooling demands of the office building were provided by rooftop units (RTUs), comprising of natural gas heater and electric air conditioner. Energy consumption for both GEHP and RTUs were monitored for operation in alternating months. These recorded energy consumptions along with weather data were used in the regression analysis. The developed eQUEST models were validated and calibrated with the regression analysis results with respect to the ASHRAE Guideline 14–2014. The eventual models were then applied to investigate the potential annual energy consumption, greenhouse gas (GHG) emission and energy cost savings achieved by using the GEHP in Woodstock, and other cities in Canada, particularly in Ontario.     

Mechanistic aspects of poly(ethylene terephthalate) recycling–toward enabling high quality sustainability decisions in waste management

Environmental Science and Pollution Research - Since plastic waste pollution is a severe environmental concern in modern life, the demand for recycling poly(ethylene terephthalate) (PET) has...     

Effects of cimetidine and N-acetylcysteine on paraquat-induced acute lung injury in rats: a preliminary study

Abstract

Lung injury in rats challenged with paraquat at 20?mg kg^?1 body weight was histopathologically evident by inflammation, hemorrhage, and vascular congestion. Increased levels of reactive oxygen species and lipid peroxidation, decreased glutathione content, and lower tissue antioxidant capacity was found. The effects of N-acetylcysteine and cimetidine, a well-known potent inhibitor for organic cation transport, were examined. Lung injury was attenuated by N-acetylcysteine but not by cimetidine. The findings are consistent with the assumption that beneficial effects of N-acetylcysteine administration in paraquat-challenged animals might be linked to its ability for preserving the cellular redox environment and preventing oxidative stress, while cimetidine might even hasten paraquat-induced lung injury. On the other hand, the effects of cimetidine on paraquat-induced lung injury underline the importance of future studies on the role of transporters in this complication.     

A multivariable approach for estimation of vapor cloud explosion frequencies for independent congested spaces to be used in occupied building risk assessment

API Recommended Practice 752 is one of the most referenced practices for evaluating vapor cloud explosion (VCE) impacts to site occupied buildings. This reference introduces generic VCE frequencies for different types of process units that are based on VCE incidents database. Although these reported VCE frequencies are not capable of illustrating all parameters that affect explosion likelihood, they are widely used in risk analysis studies and software packages. This paper delineates the structure of a more realistic method for estimation of local VCE frequencies for independent congested spaces or units as a function of process, site, and meteorological variables. Compared to traditional methods for VCE frequency estimation, the new proposed approach is supported by an obviously more populated and precisely categorized database of leakage frequencies and features a multi-variable functionality of process/plant conditions. Contrary to previous procedures that aimed at finding the frequency of occurrence for a single VCE incident, this proposed methodology characterizes each congested space with a local VCE frequency. This frequency is an integration of the frequencies pertaining to VCE's that are likely to be initiated by each congested space. This new VCE frequency can also be used to determine the level of explosion hazard in each unit and in risk matrix analysis.     

Exposure to ionizing radiations and changes in blood cells and interleukin-6 in radiation workers

Environmental Science and Pollution Research - Long-term exposure to ionizing radiation (IR) can cause dire health consequences even less than the dose limits. Previous biomonitoring studies have...     

Combating desertification in Iran over the last 50 years: An overview of changing approaches

Desertification in Iran was recognized between the 1930s and 1960s. This paper traces Iran’s attempts to reclaim desertified areas, evaluates the anti-desertification approaches adopted, and identifies continuing challenges. Iran has areas vulnerable to desertification due to extensive areas of drylands and increasing population pressure on land and water resources. Over-grazing of rangelands is a particular problem. Initially desertification was combated mainly at the local level and involved dune stabilization measures, especially the use of oil mulch, re-vegetation and windbreaks. Insufficient technical planning in the early years has led to changed approaches to plant densities and species diversity in plantations, and increased on-going management of existing plantations. Since the late 1980s forage and crop production has increased in areas where runoff control techniques are practiced. The social and economic aspects of anti-desertification programs have assisted in poverty reduction by providing off-season employment in rural areas. In 2004 a national plan to combat desertification was ratified and this placed an emphasis on community participation. Continuing challenges include managing existing desertified areas as well as taking into account potential future problems associated with rapidly depleting groundwater supplies and a predicted reduction in the plant growth period accompanying climate change.     

Subnational exposure to secondhand smoke in Iran from 1990 to 2013: a systematic review

Environmental Science and Pollution Research - Every year, almost eight million people die from tobacco-related diseases, among which around 1.2 million die from secondhand smoke (SHS) exposure....     

Groundwater Vulnerability Assessment Using Fuzzy Logic: A Case Study in the Zayandehrood Aquifers, Iran

Groundwater is an important source of water, especially in arid and semi-arid regions where surface water is scarce. Groundwater pollution in these regions is consequently a major concern, especially as pollution control and removal in these resources are not only expensive but at times impossible. It is, therefore, essential to prevent their contamination in the first place by properly identifying vulnerable zones. One method most commonly used for evaluating groundwater pollution is the DRASTIC method, in which the Boolean logic is used to rank and classify the parameters involved. Problems arise, however, in the application of the Boolean logic. In this paper, the fuzzy logic has been used to avoid the problems. For this purpose, three critical cases of minimum, maximum, and mean values have been considered for the net recharge parameter. The process has been performed on the Zayandehrood river basin aquifers. The fuzzy-DRASTIC vulnerability map thus obtained indicates that the western areas of the basin generally have the maximum pollution potential followed by the areas located in the east. The central parts of the study area are found to have a low pollution potential. Finally, two sensitivity analyses are performed to show the significance of each value of the net recharge parameter in the calculation of vulnerability index.     

Cross‐sectoral and participatory approaches to combating desertification: The Iranian experience

Anti‐desertification planning in Iran operates at the national level through the Five Year Development Plans, the National Plan to Combat Desertification — a long‐running scheme for which the Forest, Rangeland and Watershed Management Organisation (FRWO) is responsible — and the recently developed National Action Programme to Combat Desertification (the NAP). The Iranian NAP was formulated following the country's ratification of the United Nations Convention to Combat Desertification and drew heavily on the experience, expertise and collaboration of personnel in FRWO. Development and implementation of the NAP has had major policy impacts in Iran in the two main areas of generating cross‐sectoral cooperation between government instruments at the national planning level and by community participation in local projects to combat desertification. Documenting the evolution of cross‐sectoral and participatory approaches to desertification in Iran shows that the NAP provided impetus towards a transformation of previous procedures, a policy impact that is continuing to generate change.