What are students’ opinions of ‘Flipped learning’ in secondary science?

Flipped learning has emerged in recent years as an alternative method of teaching. The premise of Flipped learning is that students learn new material at home, and then use lesson time to tackle problems and interact with the subject matter. The rationale behind this is that students get more time with a teacher when they are solving problems or applying knowledge in the classroom, so teachers can help build higher levels of understanding. It also allows the lesson to be more interactive, as less time is spent teaching new material. Whilst many recent studies have concentrated on how Flipped learning is used at university level teaching, I was eager to undertake my enquiry on Flipped learning at secondary school. Having spoken at length to teachers about their opinions on Flipped learning, I was keen to discover what students’ opinions were. This enquiry made use of a questionnaire, and interview with sixth form biology students at an all-girls grammar school who are taught via Flipped learning. Student opinions were largely positive, with students expressing being able to learn at their own pace, more interactive lessons and being better prepared for lesson time among the benefits of Flipped learning

Crew factors in flight operations. Part 3: The operational significance of exposure to short-haul air transport operations

Excessive flightcrew fatigue has potentially serious safety consequences. Laboratory studies have implicated fatigue as a causal factor associated with varying levels of performance deterioration depending on the amount of fatigue and the type of measure utilized in assessing performance. These studies have been of limited utility because of the difficulty of relating laboratory task performance to the demands associated with the operation of a complex aircraft. The performance of 20 volunteer twin-jet transport crews is examined in a full-mission simulator scenario that included most aspects of an actual line operation. The scenario included both routine flight operations and an unexpected mechanical abnormality which resulted in a high level of crew workload. Half of the crews flew the simulation within two to three hours after completing a three-day, high-density, short-haul duty cycle (Post-Duty condition). The other half flew the scenario after a minimum of three days off duty (Pre-Duty) condition). The results revealed that, not surprisingly, Post-Duty crews were significantly more fatigued than Pre-Duty crews. However, a somewhat counter-intuitive pattern of results emerged on the crew performancemeasures. In general, the performance of Post-Duty crews was significantly better than that of Pre-Duty crews, as rated by an expert observer on a number of dimensions relevant to flight safety. Analyses of the flightcrew communication patterns revealed that Post-Duty crews communicated significantly more overall, suggesting, as has previous research, that communication is a good predictor of overall crew performance

Control of steam input to the pyrolysis-gasification of waste plastics for improved production of hydrogen or carbon nanotubes

Carbon nanotubes (CNTs) have been proven to be possible as high-value by-products of hydrogen production from gasification of waste plastics. In this work, steam content in the gasification process was investigated to increase the quality of CNTs in terms of purity. Three different plastics-low density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS) were studied in a two stage pyrolysis-gasification reactor. Plastics samples were pyrolysed in nitrogen at 600°C, before the evolved gases were passed to a second stage where steam was injected and the gases were reformed at 800°C in the presence of a nickel-alumina catalyst. To investigate the effect that steam plays on CNT production, steam injection rates of 0, 0.25, 1.90 and 4.74gh-1 were employed. The CNTs produced from all three plastics were multiwalled CNTs with diameters between 10 and 20nm and several microns in length. For all the plastic samples, raising the steam injection rate led to increased hydrogen production as steam reforming and gasification of deposited carbon increased. High quality CNTs, as observed from TEM, TPO and Raman spectroscopy, were produced by controlling the steam injection rate. The largest yield for LDPE was obtained at 0gh-1 steam injection rate, whilst PP and PS gave their largest yields at 0.25gh-1. Overall the largest CNT yield was obtained for PS at 0.25gh-1, with a conversion rate of plastic to CNTs of 32wt%

Hydrogen and Carbon Nanotubes from Pyrolysis-Catalysis of Waste Plastics: A Review

More than 27 million tonnes of waste plastics are generated in Europe each year representing a considerable potential resource. There has been extensive research into the production of liquid fuels and aromatic chemicals from pyrolysis-catalysis of waste plastics. However, there is less work on the production of hydrogen from waste plastics via pyrolysis coupled with catalytic steam reforming. In this paper, the different reactor designs used for hydrogen production from waste plastics are considered and the influence of different catalysts and process parameters on the yield of hydrogen from different types of waste plastics are reviewed. Waste plastics have also been investigated as a source of hydrocarbons for the generation of carbon nanotubes via the chemical vapour deposition route. The influences on the yield and quality of carbon nanotubes derived from waste plastics are reviewed in relation to the reactor designs used for production, catalyst type used for carbon nanotube growth and the influence of operational parameters

Processing real-world waste plastics by pyrolysis-reforming for hydrogen and high-value carbon nanotubes

Producing both hydrogen and high-value carbon nanotubes (CNTs) derived from waste plastics is reported here using a pyrolysis-reforming technology comprising a two-stage reaction system, in the presence of steam and a Ni-Mn-Al catalyst. The waste plastics consisted of plastics from a motor oil container (MOC), commercial waste high density polyethylene (HDPE) and regranulated HDPE waste containing polyvinyl chloride (PVC). The results show that hydrogen can be produced from the pyrolysis-reforming process, but also carbon nanotubes are formed on the catalyst. However, the content of 0.3 wt.% polyvinyl chloride in the waste HDPE (HDPE/PVC) has been shown to poison the catalyst and significantly reduce the quantity and purity of CNTs. The presence of sulfur has shown less influence on the production of CNTs in terms of quantity and CNT morphologies. Around 94.4 mmol H g plastic was obtained for the pyrolysis-reforming of HDPE waste in the presence of the Ni-Mn-Al catalyst and steam at a reforming temperature of 800 C. The addition of steam in the process results in an increase of hydrogen production and reduction of carbon yield; in addition, the defects of CNTs, for example, edge dislocations were found to be increased with the introduction of steam (from Raman analysis)

Capital Cost Comparisons between Low Impact Development (LID) and Conventional Stormwater Management Systems in Florida

Low impact development (LID), an ecologically sensitive development strategy and stormwater management (SWM) method, is beginning to be implemented in more suburban and metropolitan projects. However, construction firms that work in Florida have been relatively slow to adopt LID. One significant reason being that many professionals in the development community believe LID practices raise the cost of construction compared to conventional, “pipe and pond” methods. Our objective for this study was to determine how specific capital costs differed between LID and conventional SWM methods. We surveyed a group of LID-experienced design professionals to collect cost data from projects that were designed using both a LID and conventional scheme. Data on four such projects was received and reported on. We focused on site grading and stormwater piping costs because combined they typically represent a large percentage of conventional SWM costs. Our analysis of the data showed that using LID methods consistently reduced excavation and stormwater piping needs compared to conventional practices. LID cost savings, when site grading and stormwater piping costs were totaled, ranged from $237,850 to$2,925,000. Results suggest that development practitioners should give adequate consideration to LID because it could possibly reduce overall SWM costs compared to conventional practices

Oral anticoagulants Patient care and control

SIGLE2. edGBUnited Kingdo

Thermal processing of plastics from waste electrical and electronic equipment for hydrogen production

Plastic waste from waste electrical and electronic equipment (WEEE) produced from a real-world commercial WEEE recycling centre has been processed using pyrolysis–gasification using a two-stage reaction system to produce hydrogen. In the first stage, the plastic fraction was pyrolysed at 600 °C and the evolved pyrolysis gases were passed directly to a second reactor at 800 °C and reacted with steam in the presence of a Ni/Al2O3 catalyst. In addition, high impact polystyrene (HIPS) and acrylonitrile–butadiene–styrene (ABS) which were the main components of the WEEE plastic were reacted to compare with the WEEE plastic. The results showed that the introduction of steam and the catalyst increased the yield of hydrogen. Increasing the nickel content in the catalyst also resulted in higher hydrogen yield. The comparison of the results of WEEE with those of HIPS and ABS showed that WEEE plastic was mainly composed of ABS. The catalyst, after reaction, showed significant deposition of coke composed of filamentous and layered type carbon. Overall the novel processing of waste plastic from electrical and electronic equipment using a two stage pyrolysis–gasification reactor shows great promise for the production of hydrogen