34 research outputs found
A comparative evaluation of dried activated sludge and mixed dried activated sludge with rice husk silica to remove hydrogen sulfide.
The aim of this study was to investigate the effectiveness of dried activated sludge (DAS) and mixed dried activated sludge with rice husk silica (DAS & RHS) for removal of hydrogen sulfide (H2S). Two laboratory-scale filter columns (packed one litter) were operated. Both systems were operated under different conditions of two parameters, namely different inlet gas concentrations and different inlet flow rates. The DAS & RHS packed filter showed more than 99.96% removal efficiency (RE) with empty bed residence time (EBRT) of 45 to 90 s and 300 mg/L inlet concentration of H2S. However, the RE decreased to 96.87% with the EBRT of 30 s. In the same condition, the DAS packed filter showed 99.37% RE. Nonetheless, the RE was shown to have dropped to 82.09% with the EBRT of 30 s. The maximum elimination capacity (EC) was obtained in the DAS & RHS packed filter up to 52.32 g/m3h, with the RE of 96.87% and H2S mass loading rate of 54 g/m3h. The maximum EC in the DAS packed filter was obtained up to 44.33 g/m3h with the RE of 82.09% and the H2S mass loading rate of 54 g/m3h. After 53 days of operating time and 54 g/m3h of loading rates, the maximum pressure drop reached to 3.0 and 8.0 (mm H2O) for the DAS & RHS packed and DAS packed filters, respectively. Based on the findings of this study, the DAS & RHS could be considered as a more suitable packing material to remove H2S
Combining Nitrous Oxide with Carbon Dioxide Decreases the Time to Loss of Consciousness during Euthanasia in Mice — Refinement of Animal Welfare?
Carbon dioxide (CO2) is the most commonly used euthanasia agent for rodents despite potentially causing pain and distress. Nitrous oxide is used in man to speed induction of anaesthesia with volatile anaesthetics, via a mechanism referred to as the “second gas” effect. We therefore evaluated the addition of Nitrous Oxide (N2O) to a rising CO2 concentration could be used as a welfare refinement of the euthanasia process in mice, by shortening the duration of conscious exposure to CO2. Firstly, to assess the effect of N2O on the induction of anaesthesia in mice, 12 female C57Bl/6 mice were anaesthetized in a crossover protocol with the following combinations: Isoflurane (5%)+O2 (95%); Isoflurane (5%)+N2O (75%)+O2 (25%) and N2O (75%)+O2 (25%) with a total flow rate of 3l/min (into a 7l induction chamber). The addition of N2O to isoflurane reduced the time to loss of the righting reflex by 17.6%. Secondly, 18 C57Bl/6 and 18 CD1 mice were individually euthanized by gradually filling the induction chamber with either: CO2 (20% of the chamber volume.min−1); CO2+N2O (20 and 60% of the chamber volume.min−1 respectively); or CO2+Nitrogen (N2) (20 and 60% of the chamber volume.min−1). Arterial partial pressure (Pa) of O2 and CO2 were measured as well as blood pH and lactate. When compared to the gradually rising CO2 euthanasia, addition of a high concentration of N2O to CO2 lowered the time to loss of righting reflex by 10.3% (P<0.001), lead to a lower PaO2 (12.55±3.67 mmHg, P<0.001), a higher lactataemia (4.64±1.04 mmol.l−1, P = 0.026), without any behaviour indicative of distress. Nitrous oxide reduces the time of conscious exposure to gradually rising CO2 during euthanasia and hence may reduce the duration of any stress or distress to which mice are exposed during euthanasia
Urban planning policy must do more to integrate climate change adaptation and mitigation actions
Well-designed urban planning policy can mitigate greenhouse gas emissions and adapt to anticipated climate change impacts. However, there has been limited analysis of the extent to which urban planning policy documents addresses climate change adaptation and or mitigation. There is a need to rapidly reduce greenhouse gas emissions to limit warming to 1.5°C above pre-industrial levels by 2100, and to be well adapted to this change (in line with the Paris Agreement). Achieving this goal will assist in limiting damage and loss to humans and the natural environment. This paper presents a detailed qualitative and quantitative evaluation of urban planning documents (policy, regulation and law) in the state of Victoria, Australia, and the degree to which climate change mitigation and adaptation (with a focus on sea level rise) are addressed and integrated. Two scales of government (state and local) were analysed across three policy disciplines (urban planning, climate change and flood management). The evaluation framework contributes to the few tools for analyzing legislation, regulation and strategic policies for climate change adequacy. The findings reveal limited climate change adaptation and mitigation actions in urban planning documents. Additionally, there is limited integration of adaptation and mitigation actions. Important opportunities for better alignment of policies across disciplines and government levels in line Paris Agreement goals are identified, to ensure implementation in decisions made about land use and development. The analysis finds that urban planning policy must do more to include and integrate climate change adaptation and mitigation actions
Survey of post polio syndrome in Tehran
"nBackground: The long-term effects of poliomyelitis are known in many of countries. In despite of one accrue title for these signs and symptoms; there are similarity aspects in patients' problems. In the signs of explained, absence of strength and endurance, musculoskeletal difficulties, respiratory dysfunction, sleep disorders are more generalized. Prevalence of post polio syndrome (PPS) is aim of this study. "nMethods: 150 subjects with history of poliomyelitis (80 male and 70 female) in Tehran city contributes in this study and complete question forms. "nResults: Muscle pain was reported in 88% of subjects. Thigh muscle weakness was at 42/28%, also muscle spasm indicated at 66%. Recurrent falling of subjects appeared in 74/7%. Early fatigue reported 86%. Above five signs selected for PPS. In this study 85 subjects had four signs of above criteria or 56.66% of subjects had PPS. "nConclusion: &nbsp;Depended of evaluation and observation there is post polio syndrome in Tehran. Recommended for physical therapy of post polio syndrome attend to stages of progression of this syndrome. In aim to this procedure, physical treatment of these patients must limit to muscle fatigue and also severe physical and exercise activities must be reduce, also some mild aerobic activities without fatigue can be useful