Simple Mitigation Technique Research Articles

Effect of magnesium sulphate addition to broiler litter on the ammonia, nitrous oxide, carbon dioxide and methane emissions from housing

Poultry production is a significant source of gaseous emissions and will require economical and simple mitigation techniques that can be used by farmers. The aim of the present study was to assess the influence of magnesium sulphate (MgSO4.7H2O) addition to broiler litter on ammonia (NH3), nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) emission rates from housing under Mediterranean climate conditions. Two identical broiler houses located in a Portuguese commercial farm were used for this study: one house was a control and the other was treated with magnesium sulphate as litter additive. Data were collected during two fattening cycles of a whole year; first in the cold season (11.8 ± 1.9 °C) and second in the hot season (20.4 ± 1.0 °C). Results showed that the application of magnesium sulphate was a good mitigation technique to reduce NH3 and N2O emissions from broiler houses. The annual average emission rates of untreated house were reduced (p < 0.05) by 45% for NH3 and 25% for N2O by the application of magnesium sulphate whereas CO2 and CH4 emission rates were increased (p < 0.05) in about 20%. Furthermore, the global warming potential was increased (p < 0.05) till 20% by the litter additive.

Stiffness-Based Design for Mitigation of Residual Displacements of Buckling-Restrained Braced Frames

AbstractBuckling-restrained braced frames (BRBFs) are often used as primary seismic force resisting systems to achieve the desired seismic performance of building frames. However, significant residual displacements of these systems may cause concerns on their postearthquake performance, especially under long duration earthquakes and strong aftershocks. Although backup moment frames (MFs) along with the BRBFs, referred to as dual systems, can be used to mitigate their residual interstory drifts, there is no design criterion on how to determine the section sizes in the MF for this purpose. In the research reported in this paper, a simple mitigation technique was developed, which relies on a stiffness-based design in which the residual interstory drifts can be effectively controlled by increasing the elastic story stiffness using column sections with a higher moment of inertia. Nonlinear time-history analyses were carried out on low-to-high rise BRBFs for a set of 20 design basis earthquake (DBE) level groun...

Vulnerability of laptop computers to volcanic ash and gas

Laptop computers are vital components of critical infrastructure sectors and a common tool in broader society. As they become more widely used, their exposure to volcanic hazards will increase. Therefore, understanding how laptops will function in volcanic environments is necessary to provide suitable mitigation options. In this study, laptop computers were subjected to volcanic ash and gas in both laboratory and field settings. None of the laptops sustained permanent damage in laboratory experiments; however, ash contamination did reduce the functionality of keyboards, CD drives, and cooling fans. Several laptops shut down temporarily due to overheating following ash contamination. In field experiments, laptops were exposed to high concentrations of volcanic gases at White Island, New Zealand. These laptops did not sustain permanent damage as only a small amount of gas was able to enter the laptops. However, metal components on the outside of the laptop did sustain minor corrosion. Re-examination of the laptops after 6 months indicated they were in full working order. Printed circuit boards suffered significant corrosion damage and ceased working only when in direct and sustained contact with volcanic gases. Simple mitigation techniques such as isolating laptops inside heavy duty polyethylene bags were effective. Overall, our experiments demonstrate that laptops have a relatively low risk of damage from volcanic ash and gas exposure, but have a low-medium risk of loss of functionality in ash environments. We think this has implications for other electronic equipment used extensively in critical infrastructure services.

Shake table testing of museum display cases

Throughout history, objects of art have been damaged and sometimes destroyed in earthquakes. Research was undertaken to investigate the seismic vulnerability of art objects exhibited on display cases, and museum floor motions representative of Montreal seismic hazards were simulated for that purpose. Particular attention was paid to the effects on art object seismic vulnerability of support conditions, modified floor surfaces, sliding and rocking responses of unrestrained display cases, floor elevations, art object mass, and the dynamic properties of the display cases. Seismic vulnerability of art objects was evaluated based on the seismic response of the display cases at the level of art object display. Display cases were investigated experimentally using shake table testing. Floor contact conditions and elevation had a crucial effect on the unrestrained display cases, causing them to slide or rock vigorously. As a result of experimental analysis, recommendations and (or) simple mitigation techniques are provided to reduce the seismic vulnerability of art objects exhibited on these display cases.