The link below is to an article reporting on the deaths of six rangers in the Virunga National Park in the Democratic Republic of Congo by poachers.
The link below is to an article that takes a look at the world’s first electrified road, an experimental road that charges the batteries of electric cars as they drive.
Watching plants and pollinators such as bees can teach us a lot about how complex networks work in nature.
There are thousands of species of bees around the world, and they all share a common visual system: their eyes are sensitive to ultraviolet, blue and green wavelengths of the light spectrum.
This ancient colour visual system predates the evolution of flowers, and so flowers from around the world have typically evolved colourful blooms that are easily seen by bees.
For example, flowers as perceived by ultraviolet-sensitive visual systems look completely different than what humans can see.
However, we know that flowers also produce a variety of complex, captivating scents. So in complex natural environments, what signal should best enable a bee to find flowers: colour or scent?
Our latest research uncovered a surprising outcome. It seems that rather that trying to out-compete each other in colour and scent for bee attention, flowers may work together to attract pollinators en masse. It’s the sort of approach that also works in the world of advertising.
Daunting amount of field work
Classic thinking would suggest that flowers of a particular species should have reasonably unique flower signatures. It makes sense that this should promote the capacity of a bee to constantly find the same rewarding species of flower, promoting efficient transfer of pollen.
So a competition view of flower evolution for different flower species with the same colour – for example purple – would suggest that each flowering plant species should benefit from having different scents to enable pollinator constancy and flower fidelity. By the same logic, flowers with the same scents should have different colours so they’re easily distinguished.
To know for sure what happens requires a daunting amount of field work. The challenges include measuring flower colours using a spectrophotometer (a very sensitive instrument that detects subtle colour differences) and also capturing live flower scent emissions with special pumps and chemical traps.
At the same time, in order to record the actual pollinator “clientele” of the flowers, detailed recordings of visits are required. These data are then built into models for bee perception. Statistical analyses allow us to understand the complex interactions that are present in a real world evolved system.
Not what we thought
And what we found was unexpected. In two new papers, published in Nature Ecology & Evolution and in Nature Communications, we found the opposite to competition happens: flowers have evolved signals that work together to facilitate visits by bees.
So flowers of different, completely unrelated species might “smell like purple”, whilst red coloured species share another scent. This is not what is expected at all by competition, so why in a highly evolved classical signal receiver has this happened?
The data suggests that flowers do better by attracting more pollinators to a set of reliable signals, rather than trying to use unique signals to maximise individual species.
By having reliable multimodal signals that act in concert to allow for easy finding of rewarding flowers, even of different species, more pollinators must be facilitated to transfer pollen between flowers of the same species.
Lessons for advertising
A lot of research on advertising and marketing is concerned with consumer behaviour: how we make choices. What drives our decision-making when foraging in a complex environment?
While a lot of modern marketing emphasises product differentiation and competition to promote sales, our new research suggests that nature can favour facilitation. It appears that by sharing desirable characteristics, a system can be more efficient.
This facilitation mechanism is sometimes favoured by industry bodies, for example Australian avocados and Australian honey. En masse promotion of the desirable characteristics of similar products can grow supporter base and build sales. Our research suggests evolution has favoured this solution, which may hold important lessons for other complex market based systems.
A successful colour–scent combination targeted at attracting bees can be adopted by several different plant species in the same community, implying that natural ecosystems can function as a “buyers markets”.
We also know from research that flowers can evolve and change colours to suit the local pollinators. Colours can thus be changed by flowers if instead of bees pollinating flowers, flies, with different colour perception and preferences, dominate the community.
These findings can also prove useful for identifying those colour-scent combinations that are the most influential for the community. This way, the restoration of damaged or disrupted plant-pollinator communities can become better managed to be more efficient in the future.
When next enjoying a walk in a blooming meadow, remember plants’ strategies. The colourful flowers and the mesmerising scents you experience may have evolved to cleverly allure the efficient pollinators of the region.
Energy giant AGL this week unveiled plans to produce hydrogen power at its Loy Yang A coal station. But how do we transform coal, which is often thought of as simply made of carbon, into hydrogen – a completely different element?
In fact, coal is not just made of carbon. It also contains other elements, one of which is hydrogen. But to get a lot of hydrogen, the coal needs to be “gasified” rather than burned, creating compounds that can then be reacted with water to make hydrogen. This is where the majority of hydrogen comes from in this case – not from the coal itself.
Why is hydrogen fuel making a comeback?
What is coal made of?
In simple terms, coal is a mixture of two components: carbon-based matter (the decayed remains of prehistoric vegetation) and mineral matter (which comes from the ground from which the coal is dug). The carbon-based matter is composed of five main elements: carbon, hydrogen, oxygen, nitrogen and sulfur.
You can think of coal’s formation process as a progression from biomass (newly dead plant matter) to charcoal (almost pure carbon). Over time, the oxygen and some hydrogen are gradually removed, leaving more and more carbon behind.
Brown coal thus contains slightly more hydrogen than black coal, although the biggest difference between the two is in their carbon and oxygen contents.
What is gasification?
We can understand gasification by first understanding combustion. Combustion, or burning, is the complete oxidation of a fuel such as coal, a process that produces heat and carbon dioxide. Carbon dioxide itself cannot be further oxidised, and thus is the non-combustible end product of the burning process.
In gasification, however, the coal is not completely oxidised. Instead, the coal is reacted with a compound called a gasification agent. Gasification is endothermic, which means it doesn’t produce heat. Quite the opposite, in fact – it needs heat input to progress. Because the resulting gas is not fully oxidised, that means it can itself be burned as a fuel.
So how do we make hydrogen?
Now we know the key concepts, let’s start again at the start. To produce hydrogen from coal, the process begins with partial oxidation, which means some air is added to the coal, which generates carbon dioxide gas through traditional combustion. Not enough is added, though, to completely burn the coal – only enough to make some heat for the gasification reaction. The partial oxidation also makes its own gasification agent, carbon dioxide.
Carbon dioxide reacts with the rest of the carbon in the coal to form carbon monoxide (this is the endothermic gasification reaction, which needs heat input). No hydrogen yet.
Carbon monoxide in the gas stream is now further reacted with steam, generating hydrogen and carbon dioxide. Now we are making some hydrogen. The hydrogen can then be run through an on-site fuel cell to generate high-efficiency electricity, although the plan at Loy Yang A is to pressurise the hydrogen and ship it off to Japan for their Olympic showcase.
Brown coals are generally preferred for gasification over black coals for several reasons, which makes the brown coal of Victoria’s Latrobe Valley a good prospect for this process.
The main reason is that, because of the high oxygen content of this type of coal, it is less chemically stable and therefore easier to break apart during the gasification reaction. Plus there is a small boost from the hydrogen that is already present in the coal.
Hydrogen produced in this way is not a zero-emission fuel. Carbon dioxide is emitted through the combustion and thermal decomposition reactions, and is also a product of the reaction between carbon monoxide and water to make hydrogen and carbon dioxide.
So why bother making hydrogen?
When hydrogen is used as a fuel, it releases only water as a byproduct. This makes it a zero-emission clean fuel, at least at the point of use.
Producing hydrogen from coal in a large, central facility means pollution control can be put in place. Particulates, and potentially carbon dioxide, can be removed from the gas stream very efficiently.
This is not possible on a small scale, such as hanging off the back of your car. Road transport currently emits dangerous levels of pollutants in our cities every day.
Gasification processes that use hydrogen fuel cells on site can substantially increase their efficiency compared with traditional coal-fired power. However, depending on the end-use of the hydrogen, and subsequent transport processes, you might be better off in terms of energy output, or efficiency (and therefore carbon emissions), just straight-up burning the coal to make electricity.
But by using gasification of coal to make hydrogen, we can start building much-needed infrastructure and developing consumer markets (that is, hydrogen fuel cell vehicles) for a truly clean future fuel.
I predict that hydrogen power will be zero-emission one day. It can be made in a variety of ways through pure water splitting (including electrolysis, or through solar thermochemical and photoelectrochemical technologies, to name a few). It’s not there yet in terms of price or practicality, but it is certainly on its way. Boosting development of the hydrogen economy through production from coal in the meantime is, in my book, not a terrible idea overall.
The manufacturer of White King “flushable” wipes has been fined A$700,000 because these are not, in fact, flushable. The wipes, advertised as “just like toilet paper”, cannot disintegrate in the sewerage system, and cause major blockages.
The Federal Court found Pental Products and Pental Limited, which manufacture the wipes, guilty of making false and misleading representations. In particular, Pental claimed that the wipes would break down in the sewerage system, like toilet paper does.
So-called flushable wipes, now sold for everything from make-up removal to luxury toilet paper, are a growing hazard to public health. Sydney Water says 75% of all sewer blockages in the city’s waste-water system involve wipes.
Don’t trust the label
While wipes might look a bit like toilet paper, there are major differences. Wipes are made from a very tough material called “air-laid paper”, and are often impregnated with cleansing chemicals, disinfectants and cosmetic scents.
Air-laid paper behaves very differently in sewers to toilet paper and does not readily disintegrate in water.
When in sewer pipes the resilient wipes have a tendency to entangle with other wipes and create blockages. This is a bit like the knot of tangled clothing sometimes found in the washing machine. Sewerage system managers around the globe seem powerless to prevent the problem.
Sewer blockages caused by wipes look grotesque. Unpleasant work in confined places is required to remove the blockages (some of which is done by hand!). In 2016 Newcastle’s Hunter Water removed an ugly seven-metre snake of wipes and assorted sewage debris, weighing roughly a tonne, from its sewers.
Wither do you wipe?
Wipes become very popular in the 1990s to help in cleaning babies’ bottoms while changing nappies. Since then, many similar products (“wet wipes”, “baby wipes” and “face wipes”) have proliferated well beyond the baby aisle.
Wipes may be advertised for personal hygiene, removing makeup and cleaning hands. Others are marketed for cleaning bathroom surfaces, toilets and other household areas. The marketing of wipes often boasts how easy they are to dispose by simply flushing them down the toilet.
More recently, a booming adult market is expanding their use as a luxury alternative to toilet paper, buoyed by endorsements from celebrities like Will Smith and Will.i.am. Research by Sydney Water found that males in the 15-44 bracket particularly preferred to use wipes rather than toilet paper. The same market survey estimated that a quarter of Sydney Water’s 4.6 million customers flush wipes down the toilet rather than putting them in a bin.
The three Ps
The fine imposed on Pental Products and Pental Limited for their “flushable” wipes is an important signal to others in this growing market.
However, wipes are not the only waste item that people should not flush down the toilet. This issue gained international notoriety in 2017 when Thames Water in London removed a 130-tonne monster sewer blockage, in a difficult and laborious three-week operation. The blockage was an accumulation of solids called a fatberg – a nightmarish combination of wipes, congealed fat, nappies, female sanitary products, and condoms.
Have we forgotten what toilets are for? The Australia Water Association reminds us that they are for the three Ps: pee, poo and paper (toilet paper only).
Perhaps people should visit an Irish website called think before you flush. It lists other common waste objects that should not be flushed, such as cigarette butts, cotton buds, dental floss, hair and unwanted medication. It also advises that a bin be placed in each bathroom.
Hopefully, packets of wipes will now carry warning labels to advise users not to flush them down the toilet. Just because you can flush something down the toilet does not mean it is good for the environment or society to do so.