Dyeing the lake pink! It’s for science…丨Environmental Trumpet

Hello everyone, this is the 18th issue of the Environmental Trumpet column. In this issue, we have collected the following environmental research and news worth reading:

1) Drought in Greece, underwater village resurfaces

2) Dyeing the lake pink! It’s for science…

3) Mid-Autumn Festival mooncakes, made of air?

4) The Titanic is about to disappear

5) Will cars also need wireless charging? Charging stations: I am free!

Drought in Greece causes underwater village to resurface

The ancient city of Pompeii was overturned by a volcano, but the ruins of the current village have reappeared due to drought. The continuous drought has caused the water level of the Mornos reservoir, one of the main water sources of Athens, to drop by 30%, and the ruins of the village of Kallio, which was originally submerged, have reappeared .

In the late 1970s, Greece built the Mornos Dam to ensure water supply to Athens, and the village of Kallio was submerged in the dam reservoir. Local villagers were forced to evacuate their homes, and nearly 80 houses, churches, schools and other buildings sank to the bottom of the water.

The remains of Kallio village resurfaced due to drought | phys.org

The revelation of the village ruins is closely related to the abnormally high temperatures experienced in Greece this year . In June and July this year, Greece welcomed the hottest months in history. The average temperature in Greece in summer 2024 was 1°C higher than the hottest summer in the past.

The abnormally high temperatures not only triggered large-scale wildfires, but also exacerbated the water shortage problem in Greece. Drought has occurred in many parts of Greece, and the drought is particularly severe in the area around Athens due to low rainfall. Government authorities have begun to call on people to save water.

In fact, this is not the first time that Kallio Village has resurfaced. In the early 1990s, drought caused the remains of the village to see the sun again. This time, under the dual pressure of local tourism development and reduced rainfall , the water resource problem may be more serious. The Greek government has also taken some countermeasures, including investing in new backup reservoirs and desalination plants, reducing leakage in water pipelines, improving agricultural irrigation water systems, and using more recycled water.

Dyeing the lake pink! It’s for science…

The lake has changed color! In Stockton, California, people poured dye into McLeod Lake, turning the lake pink .

This was done to explore the cause of the algal bloom in the lake. In 2020 and 2022, algal blooms suddenly broke out in Lake McLeod. The reproduction rate of plankton such as cyanobacteria accelerated abnormally, and the lake surface was gradually invaded by algae. Algal blooms not only turn the lake surface green, but also easily produce toxic and harmful substances, causing harm to aquatic animals and even humans. But strangely, the outbreak time of the algal bloom in the lake is irregular, so people began to wonder if there are other reasons behind it.

Researchers injected dye into lake water at different depths, and the lake quickly began to change color | Hearst

To find out, researchers poured rhodamine dye into the lake. Rhodamine is a general term for a class of dyes, including rhodamine B, rhodamine 123, etc. In addition to being used for paper dyeing, they can also be used to determine the direction and speed of water flow . The dye stays in the lake for a short time and does not cause harm to the human body. It's just that when the lake turns pink, people's eyes may be slightly shocked.

The spread of algal blooms is inseparable from water flow. Researchers can use the spread of dye in the lake to understand the direction of water flow in Lake McLeod, the impact of upstream and downstream on the lake water, explore the factors that affect algal blooms from the beginning to the outbreak , and predict the time and location of future algal blooms. Just one injection is not enough. Researchers plan to inject dye into the lake again in early 2025 to explore the flow of lake water under different humidity conditions.

Mid-Autumn Festival mooncakes, made of air?

Solar Foods, a Finnish company, and Ajinomoto, a Japanese company, have jointly launched a new mooncake. At first glance, the skin of this mooncake is no different from traditional mooncakes, except that the color is more gorgeous. But you would never guess that the raw material of this mooncake is air!

Eating air is like eating nothing (not really) | Solar Foods

The mooncakes use Solein protein developed by Solar Foods. This protein is produced by microbial fermentation, using carbon dioxide, hydrogen and oxygen , and is ultimately converted into mooncake ingredients. Solein protein replaces the protein used in traditional processes, reducing mooncakes' reliance on dairy products and lowering their carbon emissions.

Although it is called a mooncake, it looks more like a sandwich biscuit. The outer skin of the mooncake is made into a flower shape, and the inside is filled with candy made of fruit paste. Currently, there are 4 flavors of mooncakes, namely grapefruit, matcha, raspberry and blackcurrant. Yes, there is no red bean paste, egg yolk, five kernels...

The mooncake is now available in Singapore, with plans to sell it in more countries in the future.

The Titanic is unbreakable.

Almost gone

As time passes, the Titanic is disappearing. A recent survey of the wreck by an undersea exploration company found that the ship is riddled with holes and its iconic bow railings have decayed away .

Titanic, is that you? | RMC Titanic Inc

Like many shipwrecks, the Titanic has become a new home for marine life . The president of OceanGate Expeditions said that they found hundreds of species in the shipwreck area, including crabs, corals, etc. In addition, the hull is also full of metal-eating bacteria, digesting hundreds of pounds of iron every day. Under the invasion of deep ocean currents and bacteria, the ship may disappear completely in a few decades .

Diana statue from Versailles found near shipwreck | RMS Titanic Inc

Therefore, people are trying to salvage the precious artifacts from the ship before it disappears. Recently, a bronze statue called Diana of Versailles was found from the shipwreck. This artifact was placed in the first-class cabin of the Titanic and displayed to passengers. In 1986, Robert Ballard found it in the wreckage and captured the beauty of the statue with a camera. Unfortunately, until the statue was unearthed recently, people found that the statue had been damaged to a certain extent by the erosion of sea water during the sinking of the cruise ship.

The Diana statue in Versailles was discovered in 1986 (left). Currently, a replica of the statue (right) is located in the Louvre in Paris | Wikipedia & RMS Titanic, Inc

At present, thousands of items have been salvaged from the shipwreck, some of which have been sent to various parts of the world for exhibition, telling people the history of the shipwreck.

Wireless charging for cars?

Charging station: I am free!

Imagine driving an electric car on the road in the future without having to worry about where to charge it. Electric cars can be charged while driving on the road ! In South Korea, a group of researchers are working to make it a reality, and the experimental concept has been published in the journal Applied Energy.

To realize this idea, they used a high school physics knowledge point: electromagnetic induction . When a conductor cuts magnetic flux lines in a magnetic field, an electromotive force can be generated. If the conductors are connected to form a closed loop, then a current can be formed in the loop.

Wireless power transmission system design: Charging pile, you are free! | Applied Energy (2024)

In order to preliminarily verify their ideas, the research team used logistics robots to symbolize cars and tested their ideas in the experiment. The researchers designed a dynamic wireless power transmission system that uses a series of wires to generate a broad magnetic field , allowing the test robot to travel on the track laid by the wires. Through the algorithm model, the researchers further optimized the design of the optimal distance between the wires and the structure of the inductive receiver to ensure efficient transmission of electricity. The experiment found that the power transmission efficiency generated by electromagnetic induction can reach 90% , and even when the robot is turning and changing lanes, the transmission efficiency can still be higher than 80%. In reality, there is rarely only one car on a road, so this situation is also taken into account in the design to ensure that multiple robots can still charge efficiently when driving.

The design of track electromagnetic induction allows people to no longer rely on expensive ferromagnetic materials to generate current. However, too strong a magnetic field may also cause harm to the human body . To this end, researchers simulated the scene of human body exposure to magnetic field to ensure that the magnetic field strength can meet the relevant industry standards. If it is really realized, wouldn’t the world of the future be a huge magnetic field?

References

[1]https://phys.org/news/2024-09-sunken-village-emerges-greek-drought.html

[2]http://www.xinhuanet.com/20240830/3cc08a7044cd491ba94052f2ece0060f/c.html

[3]https://phys.org/news/2024-08-california-lake-pink-week-science.html

[4]https://www.yahoo.com/news/california-dyeing-lake-pink-why-184306582.html

[5]https://www.greenqueen.com.hk/solar-foods-ajinomoto-solein-protein-from-air-singapore-mooncakes/

[6]https://www.cbsnews.com/news/titanic-decaying-expedition/

[7]https://techxplore.com/news/2024-09-wireless-track-ev-transit.html

[8]https://www.sciencedirect.com/science/article/pii/S0306261924013266?via%3Dihub#s0065

[9]https://www.bbc.com/news/articles/crkm82enkgko

Author: Xiao Xiaoze

Edited by: Yellowtail Pollock