Water safety

Collaborators from Argonne National Laboratory and the Pritzker School of Molecular Engineering—including Haihui Pu, Junhong Chen, and Xiaoyu Sui, PhD’22—and from the University of Wisconsin–Milwaukee have developed a reliable, mass-producible water sensor. Each sensor can detect one common contaminant (E. coli, lead, mercury), and multiple sensors can be used simultaneously to detect contaminants in real time. The sensor, described in a July 13 paper in Nature Communications, houses a silicon substrate coated in a nanometer of graphene. Gold electrodes are imprinted onto the graphene surface, which is then insulated with a nanometer of aluminum oxide. Results were analyzed with machine learning algorithms that measured toxin levels in parts per billion. The sensor could help ensure water safety and optimize water reuse.

Theory, tested

A team led by physicist Cheng Chin has successfully observed “quantum superchemistry” in the lab for the first time, confirming previous theories of what are known as “quantum-enhanced” chemical reactions, and realizing a goal that scientists have pursued for 20 years. To achieve these reactions, the researchers cooled cesium gas to near absolute zero, where they could bring each cesium atom into the same quantum state (a term that describes characteristics such as spin and energy levels). Next they manipulated the magnetic field to instigate reactions. Under normal conditions, these chemical reactions would take place individually as particles collide, but when the atoms entered the same quantum state, molecules formed collectively. The reactions occurred more quickly, and the final molecules shared identical chemical and physical properties. Researchers also observed that the reactions involved three atoms, with two forming a molecule and the third remaining single. The experiment’s findings, published July 24 in Nature Physics, help scientists understand quantum many-body chemistry and how to control quantum-enhanced chemical reactions, paving the way for experiments with more complex molecules.

Compassion’s limits

Compassion can bridge divides among humans. But a team from psychologist Fan Yang’s Human Nature and Potentials Lab and the University of California, Santa Barbara, found that compassion has limits. In a paper published in Cognition in August, the team concludes that we are less likely to extend compassion or help to those we believe have immoral intention, character, or group membership. And if something bad happens to these people, we are also more likely to feel that they deserve to suffer—and to feel morally justified in doing so. In one of the four studies comprising the experiment, groups of US adult subjects who self-identified as Democrats or Republicans responded to three scenarios, one in which a member of the opposing party experienced suffering as a result of a political action, one in which a member of the opposing party suffered due to an apolitical act, and a third in which someone with no stated political affiliation suffered after an apolitical action. Researchers found that subjects felt less compassion and less willingness to help those with an opposing political identity, even if their suffering was not connected to a political act. These findings indicate that moral judgment is a barrier to alleviating suffering.