|—||“Harvard students’ invention puts cake in a can,” Boston Globe (July 18, 2014).|
|—||Sujata Bhatia, Assistant Director of Undergraduate Studies in Biomedical Engineering, asking, "What does it mean to be an engineer?"|
Scientists have long known that bacteria can double their population in as little as 20 minutes, but a series of pioneering studies in the late 1960s revealed that it takes about an hour from the time DNA replication starts until cell division occurs.
The remaining mystery has been in how those two processes are coordinated.
“The answer is quite remarkable,” Amir said. “… What bacteria do is actually start the DNA replication process for subsequent generations. A single bacterial cell may actually be replicating DNA for its grandchildren, or even its great-grandchildren.”
Read the entire article in the Harvard Gazette
"I think it’s incredibly important that they learn to work with their hands, and take what’s in their head and actually make it."
—Stan Cotreau, manager of the Instructional SEAS/Physics Machine Shop, which is open to all students
Photo by Jon Chase / Harvard Staff Photographer
During a recent visit to James W. Hennigan Elementary School in Jamaica Plain for a science fair, Carlos Brambila recalled the lasting impact a similar fair had on him. When he was in grade school in California, a scientist from a local university came to his school to show the students how smoking affects the body.
“It was an eye-opener,” Brambila said. “After that experience, I was always asking why things happen and how they work. I realized how science could really be applied in the real world.”
Now a senior bioengineering major at San Diego State University (SDSU), Brambila is conducting research in the lab of David Weitz, Mallinckrodt Professor of Physics and Applied Physics at Harvard University, over the summer. He jumped at the chance to participate in science demonstrations at the Hennigan.
“I remember how strongly that can impact someone’s life, because it did for me. That’s when I started to question why things are they way they are, and why things happen. If it weren’t for those early experiences, I don’t know if I would think the way I do now.”
Prof. Roger Brockett, a 45-year member of the Harvard SEAS faculty, has been honored “for inspirational mentorship of generations of graduate students who have participated in defining the field of control engineering.”
He received the AACC’s 2014 John R. Ragazzini Education Award.
Chemists are targeting military pyrotechnics, such as the deployed decoy flares shown here, for more eco-friendly formulations.
Typical pyrotechnics function by burning, so their basic chemical components consist of an oxidant and a fuel. Black powder, the original pyrotechnic, blends potassium nitrate oxidizer with charcoal and sulfur fuel. Set this witch’s brew alight, and in a flash the nitrate oxidizes the charcoal and sulfur, producing glowing solids and a vast volume of hot gases. Other components, such as colorants, binders, and propellants, can be added to the mix, depending on the task the pyrotechnic has to perform.
Over the years, perchlorate has become the oxidizer of choice for most pyrotechnic applications, supplanting less stable chlorate oxidants that were the cause of numerous deadly explosions. “Potassium perchlorate is the ideal oxygen donor to use in pyrotechnics in terms of safety, cost, and reproducibility,” says John A. Conkling, a pyrotechnics expert and adjunct professor of chemistry at Washington College, in Chestertown, Md.
Unfortunately, perchlorate has also been identified as a potential human health hazard. Studies suggest that it inhibits the thyroid’s ability to take up iodine from the bloodstream and can reduce the production of thyroid hormone. And because the anion is highly water soluble, it readily slips into groundwater. “The major effort in most areas of environmentally friendly pyrotechnics research is to find perchlorate replacement materials,” Conkling says.
Pyrotechnics for the Planet: Chemists seek environmentally friendlier compounds and formulations for fireworks and flares
|—||Hosang Yoon, a grad student who measured the mass of ‘massless’ electrons in graphene|
These illustrations come from the first book about a calculating machine written in English, and are thus some of the earliest images in the history of computers.
Morland, Samuel, Sir, 1625-1695. The description and use of two arithmetick instruments : together with a short treatise, explaining and demonstrating the ordinary operations of arithmetick, 1673.
Houghton Library, Harvard University
Materials scientists at Harvard University have created lightweight cellular composites via 3D printing. These fiber-reinforced epoxy composites mimic the structure and performance of balsa wood. Because the fiber fillers align along the printing direction, their local orientation can be exquisitely controlled. These 3D composites may be useful for wind turbine, automotive and aerospace applications, where high stiffness- and strength-to-weight ratios are needed. Read more about the technology.