Achieving the aims of school practical work with microchemistry

“Chemistry is fundamentally an experimental subject…education in chemistry must have an ineluctable experimental component”. This quote from an IUPAC report reflects a core belief of all chemistry  educators. However we must define our aims for practical activities, and design and prepare for them in  the context of national curricula. All this is necessary whatever the scale (macro or micro) of equipment that might be employed. At the present time traditional macroscale equipment dominates the school scene and penetration of microscale use is slow. This dominance is not because there are no problems with the status quo; quite the opposite. Most schools have no equipment at all or, if they have some, never use it. This despite national curricula explicitly encouraging practical science activities. Based primarily upon the experiences of our group in South Africa, this paper addresses the following questions:1. what are the aims of school practical work?2. can microscale chemistry deliver as well as, or better than, macroscale?3. why is practical work (macro or micro) problematic in schools?4. can microchemistry ameliorate these problems?5. could recognition of the concept of Zone of Feasible Innovation help us?Microchemistry has so much to offer school chemistry, that answering these questions and acting accordingly should be a priority. [African Journal of Chemical Education—AJCE 6(1), January 2016

The chemist’s triangle and a general systemic approach to teaching, learning and research in chemistry education

The three levels of science thought (macro, micro, symbolic), identified by Johnstone and represented by a triangle, may be viewed as a core closed-cluster concept map of the type advocated in the systemic approach to teaching and learning of chemistry. Some of the implications of this view for teaching, learning and research are explored. [AJCE 4(2), Special Issue, May 2014

Microchemistry in Africa A Reassessment

Microscale chemistry has been talked about and experimented with for many decades. Even the microscale chemistry deliberately designed for school-based practical activities has been around for more than 30 years. It is timely to reassess its scope and limitations, because many of the concerns that stirred interest originally are not diminishing but strengthening

The systemic approach to teaching and learning chemistry and the big ideas of science education

The systemic approach to teaching and learning chemistry has been implemented and researched for a number of years. There is substantial evidence of learning benefits from its application in the context of specific chemistry topics. In the wider context of science curricula however, the ambition of Fahmy and Lagowski to change curricula from linearity to systemic seems yet to be realized. We suggest that such a change could be initiated by introducing the Big Ideas of Science Education into existing curricula in a systemic manner. We exemplify our proposal with the case of the Grade 7-9 Natural Sciences curriculum in South Africa

High-intensity efforts in elite soccer matches and associated movement patterns, technical skills and tactical actions. Information for position-specific training drills.

This study aimed to translate movement patterns, technical skills and tactical actions associated with high-intensity efforts into metrics that could potentially be used to construct position-specific conditioning drills. A total of 20 individual English Premier League players' high-intensity running profiles were observed multiple times (n = 100) using a computerised tracking system. Data were analysed using a novel high-intensity movement programme across five positions (centre back [CB], full-back [FB], central midfielder [CM], wide midfielder [WM] and centre forward [CF]). High-intensity efforts in contact with the ball and the average speed of efforts were greater in WMs than CBs, CMs and CFs (effect sizes [ES]: 0.9-2.1, P < 0.05). WMs produced more repeated efforts than CBs and CMs (ES: 0.6-1.3, P < 0.05). In possession, WMs executed more tricks post effort than CBs and CMs (ES: 1.2-1.3, P < 0.01). FBs and WMs performed more crosses post effort than other positions (ES: 1.1-2.0, P < 0.01). Out of possession, CFs completed more efforts closing down the opposition (ES: 1.4-5.0, P < 0.01) but less tracking opposition runners than other positions (ES: 1.5-1.8, P < 0.01). CFs performed more arc runs before efforts compared to CBs, FBs and WMs (ES: 0.9-1.4, P < 0.05), however, CBs completed more 0-90° turns compared to FBs, CMs and WMs (ES: 0.9-1.1, P < 0.01). The data demonstrate unique high-intensity trends in and out of possession that could assist practitioners when devising position-specific drills

Pre-service teachers’ misconceptions about current and potential difference in electric circuits – using microscience kits in a POE activity

Third year BEd students in a Physical Sciences content course answered a questionnaire about basic concepts of electric circuits, prior to attending lectures and practicals on the subject. Several well-known misconceptions were found to be prevalent. This led us to design a PredictObserve-Explain (POE) practical activity, using microscience kits. The results from this activity confirmed the prevalence of misconceptions, but also the reluctance of the student-teachers to change them. Our discussion of one important misconception, namely the confusion between current and potential difference, suggests that treating the cell as simply a store of energy and a source of energy without explanation may be the cause of the confusion. A chemist’s approach to this part of physics could avoid the misconception

Temperature-index modelling of runoff from adeclining Alpine glacier

The Gornera River, in the Pennine Alps, Switzerland, drains meltwater fromGornergletscher and its tributary glaciers, which contribute a large proportion of therunoff from this highly-glacierised basin. As the mass of ice has declined, recessionof many smaller tributary glaciers has resulted in their separation from the trunkGornergletscher. Declining glacier surface area might be expected to have reduced theice melt contribution to runoff, and since the Little Ice Age Maximum extent,Gornergletscher has revealed a strong link between climatic change and ice-cover.Glaciers in the Swiss Alps have revealed a total ice volume loss since the 1870s ofabout 13 km3. Approximately 8.7 km3 of ice loss occurred since the 1920s, and afurther 3.5 km3 of ice mass were lost between 1980 and the present day.This study aims to address three aspects of how changing temperatures and reducingice areas influence meltwater runoff.1. Modelling runoff response from scenarios of modified air temperatures and iceareas (e.g. a +1°C scenario with 20% reduced ice area), with the aim of finding theextent to which the modified conditions influence ice melt. In order to model runoffresponse, a temperature index model called RRM (Runoff Response Model) was setup. RRM uses formulae to calculate runoff by inputting the following forcingvariables to the model: positive air temperature values, and ice area measurements byelevation band, together with a degree day factor (DDF), and an air temperature lapserate.2. By using the same method, the effects of climate variations on ice area wereinvestigated by generating modelled runoff quantities from each elevation band. Thepurpose of doing this was to indicate how various areas of the glacier contributediffering quantities of melt to runoff during the ablation season, and the potentialimpact of loss of areas of ice. Using the model to show the highest contributing areaswas applied to Gornergletscher using the hypsometry of the basin – the second largestglacier in the Alps. Gornergletscher differs from other Alpine glaciers as a result ofits wide and relatively flat trunk.3. The study aims to calculate whether there is a linear or non-linear trend in ice areachange with elevation following model tuning. It is generally thought withGornergletscher that greatest ice areas are distributed at mid-elevations around thetrunk, where the tributaries join or joined the main ice body. Ice area in theory shouldbe most liable to melt at low and mid-elevations where both positive degree days andexposed ice areas exceed those of higher elevations. The influence of basinhypsometry on ice area change was studies by modifying the model to respond todiffering scenarios of energy availability and ice area available for melt.The investigation aimed to calculate whether there is a linear/non-linear relationshipbetween ice area change and elevation in a modified climate scenario. It is consideredfor Gornergletscher, that surface ice area distribution is greatest at mid-elevations,where tributaries connect to the main glacier body. Ice melt in theory should beproduced most at mid-elevations where both - more ice area is exposed than that oflower elevations and positive degree days exceed those of higher elevations.Basin hypsometry is of interest for ice area changes because of the irregular ice areadistribution with elevation in the basin. The relationship between the wide and flathypsometry of the Gornera Basin and ice melt at elevation was considered bymodifying the model input values to reflect different scenarios of energy availabilityand ice area available for melt

‘Context is King’ when Interpreting Match Physical Performances

‘I was blind, now I can see’. Thus, is it time to retire the ‘blind’ distance covered model that’s been used in football for decades and replace it with an integrated model that contextualises physical efforts during matches