Author: shelleys

Water electrolysis is an easy way to produce hydrogen gas. While hydrogen is considered a clean, renewable fuel, efficient electrolysis requires high electric potential, high pH and in most cases, catalysts based on ruthenium and other expensive metals. Due to the inherent promise of hydrogen, many research groups are striving to develop electrolysis technologies that will make it possible to produce hydrogen fuel at a low electric potential, at a pH between 7-9 and with catalysts based on available and inexpensive metals such as copper, manganese, and cobalt.

Now, Technion researchers have developed a unique system for producing hydrogen from water using little energy and inexpensive materials, as recently reported by The Journal of the American Chemical Society. It is the fastest system of its kind reported so far that operates with available metal (copper) catalysts. The research was led by Professor Galia Maayan, Head of the Biomimetic Chemistry Laboratory at the Schulich Faculty of Chemistry, along with doctoral student Guilin Ruan.

The researchers designed and developed a homogeneous electrolysis system, or in other words, a system in which the catalyst is soluble in water, so that all components of the system are in the same medium. The innovative and original system is based on (1) copper ions; (2) a peptide-like oligomer (small molecule) that binds the copper and maintains its stability; and (3) a compound called borate whose function is to maintain the pH in a limited range. The main discovery in this study is the unique mechanism that the researchers discovered and demonstrated: the borate compound helps stabilize the metallic center and participates in the process so that it helps catalyze it.

In previous studies, the research group demonstrated the efficacy of using peptide-like oligomers to stabilize metal ions exposed to oxygen – exposure that may oxidize them in the absence of the oligomer and break down the catalyst. Now, the researchers are reporting on the success in creating a very efficient and fast electrolysis system. The stable system oxidizes the water into hydrogen and oxygen under the same desired conditions: low electric potential, pH close to 9 and inexpensive catalysts.

According to Prof. Maayan, the system was inspired by enzymes (biological catalysts) that use the protein’s peptide chain to stabilize the metallic center and by natural energetic processes such as photosynthesis, which are driven by units that use solar energy to transport electrons and protons.

The research was supported by the Israel Science Foundation (ISF) and the Nancy and Stephen Grand Technion Energy Program.

 

SARS-CoV-2, the virus behind today’s global coronavirus pandemic, spreads primarily by inhalation of virus-laden aerosols at both short and long ranges, and a comprehensive new assessment of respiratory viruses finds that many others probably do as well. SARS-CoV, MERS-CoV, influenza, measles, and the rhinoviruses that cause the common cold can all spread via aerosols that can build up in indoor air and linger for hours, an international, interdisciplinary team of researchers has reported in a review published in Science.

Over the last century and at the beginning of this pandemic, it was widely believed that respiratory viruses, including SARS-CoV-2, mainly spread through droplets produced in coughs and sneezes of infected individuals or through touching contaminated surfaces. However, droplet and fomite transmission of SARS-CoV-2 fails to account for the numerous superspreading events observed during the COVID-19 pandemic, or the much higher transmission that occurs indoors versus outdoors.

Airborne transmission is the most likely route, not surface contacts or contact with large droplets

Motivated by a desire to understand the factors leading to the COVID-19 pandemic, researchers from Taiwan, the U.S., and Israel sought to identify as clearly as possible how the coronavirus and other respiratory viruses spread. For example, the team reviewed numerous studies of superspreading events observed during the COVID pandemic, and found the studies consistently showed that airborne transmission is the most likely transmission route, not surface contacts or contact with large droplets. One common factor at these superspreading events was the shared air people inhaled in the same room. Many were linked to crowded locations, exposure durations of one hour or more, poor ventilation, vocalization, and lack of properly worn masks.

The researchers also reviewed evidence collected from many other types of studies — air sampling, polymerase chain reaction (PCR)-based and/or cell culture studies, epidemiological analysis, laboratory and clinical studies, and modeling work — and concluded that airborne transmission is a major, or even dominant transmission pathway for most respiratory diseases, not just COVID-19. “Transmission through inhalation of virus-laden aerosols has been long underappreciated. It is time to revise the conventional paradigms by implementing aerosol precautions to protect the public against this transmission route”, said Chia C. Wang, director of the Aerosol Science Research Center and an aerosol physical chemist at National Sun Yat-sen University, Taiwan, who led the review.

Prevailing paradigms about respiratory disease transmission date back as much as a century, the team noted. Airborne transmission was paternalistically dismissed in the early 1900s by prominent public health figure Charles Chapin due to a concern that mentioning transmission by air would scare people into inaction and displace hygiene practices. An unsupported assumption that erroneously equated infections at close range with droplet transmission has shaped the current paradigm for controlling respiratory virus transmission. However, “this assumption neglects the fact that aerosol transmission also occurs at short distances, because the concentration of exhaled aerosols is higher when one is closer to the infected person emitting them”, said Kim Prather, director of the National Science Foundation Center for Aerosol Impacts on Chemistry of the Environment at UC San Diego’s Scripps Institution of Oceanography at UC San Diego and an aerosol chemist who co-led the review.

Respiratory aerosols are formed by expiratory activities, such as breathing, talking, singing, shouting, coughing, and sneezing. Before COVID-19, the traditional size cut-off between aerosols which float like smoke and droplets which drop had been set at 5 µm, however, 100 µm is a more appropriate size distinction. This updated size better represents the largest particles that can remain suspended in still air for more than five seconds (from a height of 1.5 meters), travel beyond one meter from the infected person, and be inhaled. The physical size predominantly determines how long they can stay suspended in the air, how far they can reach, whether they are inhalable, and how deep they can enter into the respiratory tract if inhaled. “The majority of aerosols produced by respiratory activities are smaller than 5 µm, which allows them to travel deep into the bronchiolar and alveolar regions and deposit there. Studies find that viruses are more enriched in aerosols smaller than 5 µm”, said Prof. Josué Sznitman, an associate professor and head of the Biofluids Laboratory at the Technion’s Faculty of Biomedical Engineering.

Another distinct behavior of aerosols that should be taken into serious consideration is their capacity to be influenced by airflow and ventilation. Ensuring sufficient ventilation rates, filtration, and avoiding recirculation help reduce airborne transmission of infectious virus-laden aerosols. “Monitoring CO2 with portable meters helps verify that ventilation is sufficient, and implementing portable HEPA (high efficiency particulate air) purifiers and upper room UV disinfection systems also help reduce the concentrations of virus-laden aerosols”, added Jose-Luis Jimenez, an atmospheric aerosol chemist of the University of Colorado Boulder. On the other hand, the plexiglass barriers commonly used to block droplet spray from coughs and sneezes in indoor spaces may “impede proper ventilation and create higher exposures for some people,” said Linsey Marr of Virginia Tech, who has studied airborne transmission of pathogens for years. “They are not recommended except for brief, face-to-face transactions, but even then, masks are better because they help remove aerosols, while barriers just divert them.”

With the surge in infections caused by the Delta variant and the increasing occurrence of “COVID-19 breakthrough cases” (infections among people who have been fully vaccinated), many governments and national disease control agencies have resumed universal masking in public. Universal masking is an effective and economic way to block virus-laden aerosols, reported in the review. However, “we need to consider multiple barriers to transmission such as vaccination, masking, and ventilation. One single strategy is unlikely to be strong enough to eliminate transmission of emerging SARS-CoV-2 variants”, added Seema S. Lakdawala, a virologist of the University of Pittsburgh.

Health benefits extend well beyond the COVID-19 pandemic

As the evidence for airborne transmission of SARS-CoV-2 has increased over time and become particularly strong, agencies have taken notice. In April and May 2021, the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) acknowledged inhalation of virus-laden aerosols as a main route in spreading COVID-19 at both short and long ranges. This means that to mitigate transmission and end this pandemic, decision makers should consider implementing aerosol precautionary measures, including universal masking with attention to mask fit, improving ventilation rates in indoor spaces, avoiding recirculation of contaminated indoor air, installation of air filtration such as HEPA purifiers that can effectively remove airborne particles, and using UV disinfection lamps. “What are traditionally called droplet precautions are not replaced wholesale, but instead are modified, expanded and deployed in a more effective manner in accordance with actual transmission mechanisms,” noted Zeynep Tufekci, a sociologist at the University of Columbia who studies societal challenges in COVID-19 pandemic. Having the correct mental model of transmission of this disease and other respiratory diseases will also allow ordinary people to make better decisions in everyday situations and administrators and officials to create better guidelines and working and socializing environments even after the pandemic, she added.

This pandemic vividly illuminates the importance of the long underestimated airborne transmission route and the necessity of preserving people’s right to breathe clean and pathogen-free air. “What we have learned from this pandemic also lights up the ways for us to make appropriate changes to enter the post-epidemic era,” said Wang. As addressed at the end of this review, these aerosol precautionary measures will not only protect against airborne transmission of respiratory diseases, but also improve indoor air quality and result in health benefits extending well beyond the COVID-19 pandemic.

Read the Science article here.

Technion – Israel Institute of Technology wishes you a happy and healthy new year, a year to create, develop, research, study, and inspire one another.

To watch our Rosh Hashana video and read about charging electric cars faster, a solution to the oldest conundrums in physics, and other exciting news, check out our September 2021 newsletter, by clicking here.

To read previous issues of Technion LIVE, click here. To subscribe, click here. 

Projects focused on DNA simulation, image denoising and augmented reality won the best project competition held recently at the Technion’s Henry and Marilyn Taub Faculty of Computer Science. The best projects received certificates and an award sponsored by Israeli software giant Amdocs.

Overall, 21 projects were presented at the June 16 event, their scope ranging from smart traffic lights to reducing hospital paperwork, a project which is already in use at the Galilee Medical Center in Nahariya, Israel.

The Mona Lisa converted into virtual DNA

“There is interest in storing information in the form of DNA,” students Gadi Chaykin and Nili Furman said about their award-winning project, advised by Prof. Eitan Yaakobi and Omer Sabary from the Information Storage and Memories Laboratory. “It requires very little space and energy.” However, “the idea is still in development,” they emphasized, “and development is hindered by the high costs of DNA synthesis and sequencing, that is, reading and writing on the ‘memory.’”

To facilitate the research and development of the platform, the two created a DNA simulator, enabling scientists to test algorithmic approaches at little cost. “In the process of copying a DNA molecule, errors of insertion, deletion, and substitution naturally occur,” they said. “We simulated these errors, creating a tool that would allow researchers to examine new coding techniques and new algorithms for DNA storage systems.”

To demonstrate, the two students showed an image of the Mona Lisa converted into virtual DNA, then reconstructed with errors resulting from the simulated DNA-replication process, and finally corrected using an algorithm they wrote.

Denoising photographs

Students Guy Ohayon and Theo Adrai, advised by Gregory Vaksman and Prof. Michael Elad from the Geometric Image Processing (GIP) lab, showcased a novel way of denoising photographs.

Every camera and every sensor currently in use produce an image with some amount of “noise” resulting from bad lighting, imperfect electronics and more. Removal of that noise is thus crucial, but remains one of the most complex challenges in the field of computer vision. Current denoising methods, the students explained, produce a “plastic,” artificial-looking image, reminiscent of a computer avatar rather than a person. Something of the vitality of the image gets lost with the noise.

Using deep learning, the group created a novel algorithm that “reimagined” the lost details, resulting in a series of many possible “recovered images” that look much more pleasant to the eye and appear close to the original. An academic article was published based on this project.

Augmenting augmented reality? 

Finally, students Almog Brand, Dani Ginsberg, and Lior Wandel showcased their project, focused on improving augmented reality. Augmented reality is meant to be an experience where computer-generated elements are added to the real world we see. Popular mobile game Pokémon-Go is a well known example.

While the virtual objects in augmented reality might appear realistic, the shadows they cast do not, creating a visual dissonance. “Current algorithms might take into account one’s location, season and time of day,” the students explained, “but you might be in a building or outside, with your back to the light source or facing it. We want the shadows to reflect that.”

To achieve this, the group created a novel device that continuously samples the lighting situation and inputs it into the augmented reality scene in real-time. The project was advised by Yaron Honen, Boaz Sternfeld and Boris Van-Sosin from the Geometric Image Processing (GIP) lab, the Virtual & Augmented Reality Lab (AVRL) and the Center for Graphics and Geometric Computing (CGGC).

The annual competition, open to undergraduate computer sciences students, aims to recognize the value of independent work as part of a graduate’s training process. It highlights projects that stand out for their innovation and execution. Projects were completed as part of various courses during the students’ studies; they were recommended for the competition by the faculty member in charge of the project. Amdocs has been sponsoring the competition since 2009.

Technion scientists have created a wearable motion sensor capable of identifying movements such as bending and twisting. This smart ‘e-skin’ was produced using a highly stretchable electronic material, which essentially forms an electronic skin capable of recognizing the range of movement human joints normally make, with up to half a degree precision.

This breakthrough is the result of collaborative work between researchers from different fields in the Laboratory for Nanomaterial-Based Devices, headed by Professor Hossam Haick from the Technion Wolfson Faculty of Chemical Engineering. It was recently published in Advanced Materials and was featured on the journal’s cover.

“This sensor has many possible applications,” Prof. Haick stated. “It can be used in early disease diagnosis, alerting of breathing alterations, and motor system disorders such as Parkinson’s disease. It can be used to assist patients’ motor recovery and be integrated into prosthetic limbs. In robotics, the feedback it provides is crucial for precise motion. In industrial uses, such sensors are necessary in monitoring systems, putting them at the core of the fourth industrial revolution.”

Prof. Haick’s lab is focused on wearable devices for various uses. Currently existing wearable motion sensors can recognize bending movement, but not twisting. Existing twisting sensors, on the other hand, are large and cumbersome. This problem was overcome by Ph.D. candidate Yehu David Horev and postdoctoral fellow Dr. Arnab Maity. Horev found a way to form a composite material that was both conductive (and thus, usable as a sensor) and flexible, stretchable, breathable, and biocompatible, and that did not change its electrical properties when stretched. Dr. Maity then solved the mathematics of analyzing the received signal, creating an algorithm capable of mapping bending and twisting motion – the nature of the movement, its speed, and its angle. The novel sensor is breathable, durable, and lightweight, allowing it to be worn on the human body for prolonged periods.

“Electrically conductive polymers are usually quite brittle,” said Yehu about the challenge the group had overcome. “To solve this, we created a composite material that is a little like fabric: the individual polymer ‘threads’ cannot withstand the strain on the material, but their movement relative to each other lets it stretch without breaking. It is not too different from what lends stretch to t-shirts. This allows the conductive polymer withstand extreme mechanical conditions without losing its electrical properties.”

“We want the technological advances we achieve to benefit everyone, regardless of their geographic location and socioeconomic status”

What makes this achievement more important is that the materials the group used are very cheap, resulting in an inexpensive sensor. “If we make a device that is very expensive, only a small number of institutions in the Western World can afford to use it. We want the technological advances we achieve to benefit everyone, regardless of their geographic location and socioeconomic status,” said Prof. Haick. True to his word, among the laboratory’s other projects is a tuberculosis-diagnosing sticker patch, sorely needed in developing countries.

The scientists who contributed to this study are Yehu David Horev, Dr. Arnab Maity, Dr. Youbin Zheng, Yana Milyutin, Dr. Muhammad Khatib, Dr. Ning Tang, and Prof. Hossam Haick from the Department of Chemical Engineering and Russell Berrie Nanotechnology Institute at the Technion-Israel Institute of Technology; Miaomiao Yuan from the Eighth Affiliated Hospital, Sun Yat-sen University, China; Dr. Ran Yosef Suckeveriene from the Department of Water Industry Engineering at the Kinneret Academic College; and Prof. Weiwei Wu from the School of Advanced Materials and Nanotechnology at Xidian University, China.

While the damages of private transportation are no secret, a new article published in Scientific Reports presents a more disturbing picture, yet suggests sustainable solutions. The articles was authored by Professor Emeritus Avishai (Avi) Ceder of the Faculty of Civil and Environmental Engineering at the Technion, an international transportation expert, who served as the Chief Scientist of the Israeli Ministry of Transportation.

His paper, which demonstrates the magnitude of traffic and transportation damages, provides a comparison of private and public vehicle travel times, as well as a model for autonomous transportation. Ceder has developed measures for representing transportation problems globally, with data from 19 countries across five continents, including developing countries.

According to Ceder, the damages of private transportation include:

• Direct fatalities – traffic accidents account for 35.6% of all deaths from accidents of any kind.
• Indirect fatalities – transportation contributes the most to global warming and mortality from pollution.
• Wasting time – 22.5% of the time we spend traveling, during peak times, is spent in traffic jams.
• Wasting space – the average vehicle is only in motion 5.3% of the time every day; 94.7% of the time, it stands idle, taking up precious space, without serving its intended purpose.

Prof. Ceder has also found that, contrary to common belief, in 94% of the cases, public transport brings passengers to their destinations in less time than a privately owned car. A comparison of traveling from the suburbs to city centers reveals that using autonomous buses over autonomous privately owned vehicles, will reduce the number of vehicles on the roads by 66%. 

Finally, the transition from a private car to any kind of public vehicle must be based on the individual’s decision to prefer public transport vehicles. Prof. Ceder stresses that the changes will only emerge if proactive government actions are taken in two major directions: developing autonomous vehicles exclusively for public transport and setting standards for automatic connections of different vehicles. He believes that many patterns in our lifestyles that changed due to Covid-19 are likely to provide leverage for change in the world of transportation.

“Driving habits have to change,” he says. “The addiction to driving is similar to the addiction to smoking, and here too, real withdrawal is required.” Prof. Ceder believes that “the jolting experience of the pandemic offers new ways of thinking. We can’t afford to lose the momentum.”

Click here for the full paper in Scientific Reports (Springer Nature Publishing Group)

Energy & Environmental Science has reported a scientific breakthrough in the study of hematite, an important and promising material in the conversion of solar energy into hydrogen through photoelectrochemical water splitting. The research project was headed by Professor Avner Rothschild of the Faculty of Materials Science and Engineering at the Technion – Israel Institute of Technology and Yifat Piekner, a doctoral student in the Nancy and Stephen Grand Technion Energy Program (GTEP).

The importance of solar energy to our lives is obvious. The sun transmits energy to Earth continuously, and if we are able to harness it for our needs, use of fossil fuels and pollutants such as petroleum and gas will no longer be necessary. The main challenge in switching to solar energy lies in the varying availability of sunlight as the day progresses and seasons change. Every place on earth experiences sunlight for a limited period during the day, but naturally, there is no sunlight at night. Since the electrical grid needs a stable power at all hours of the day and night, use of solar energy depends on our ability to store it so that we are able to use it at night and on overcast days. The problem is that the known form of electrical energy storage – batteries – is inapplicable when it comes to the supply of electricity for a city, a neighborhood, manufacturing site, etc. Moreover, the energy stored in batteries is adequate for a few hours, but batteries cannot provide a solution for long-term storage between seasons.

A possible solution to the storage problem is to convert solar energy into hydrogen using photoelectrochemical solar cells. These cells are similar to photovoltaic cells, which convert solar energy into electricity, but instead of producing electricity, they produce hydrogen using the electric power (current × voltage) generated in them. The power is used for photoelectrochemical water splitting – the use of sunlight energy to directly dissociate water molecules into hydrogen and oxygen.

The advantage of hydrogen over electricity lies in the fact that it easy to store and can be used when needed to generate electricity or for other requirements, such as to power FCEVs (fuel cell electric vehicles). In such cases, the fuel cell replaces the heavy, expensive batteries in Tesla cars and similar vehicles, and could also be used for residential and industrial heating, and the production of ammonia and other raw materials. The advantage of hydrogen as fuel is that its production and consumption do not involve greenhouse gas emissions, or any other emissions, other than oxygen and water.

One of the main challenges in photoelectrochemical cells is the development of efficient and stable photoelectrodes in a base or acid electrolyte, which is the chemical environment in which water can be efficiently split into hydrogen and oxygen. The photoelectrodes absorb the photons emitted by the sun, and use their energy to generate electronic charge carriers (electrons and holes, or missing electrons) that produce hydrogen and oxygen, respectively. Silicon, which is the semiconductor material used in photovoltaic cells, cannot serve as a photoelectrode of this kind, since it is unstable in an electrolyte.

This is the backdrop against which photoelectrochemical cells based on hematite photoelectrodes were developed. Hematite is an iron oxide that has a similar chemical composition to rust. Hematite is inexpensive, stable and nontoxic, and has properties that are suitable for water splitting. However, hematite also has its disadvantages, one of which is the gap between its theoretical energy yield and the yield achieved in practice in actual devices. For reasons that have not been clarified to date despite decades of research, the photon-to-hydrogen conversion efficiency in hematite-based devices is not even half of the theoretical limit for this material. By comparison, the conversion efficiency of photons in silicon solar cells is very close to the theoretical limit. In the present research, which extends and augments the findings recently published in Nature Materials, the research team headed by Prof. Rothschild puts forth an explanation for the mystery. It transpires that the photons absorbed by hematite produce localized electronic transitions that are “chained” to a specific atomic location in the hematite crystal, thus rendering them incapable of generating the electric current used for water splitting, i.e. the separation of water into its elements, hydrogen, and oxygen. (You can read more about the phenomenon on our site, here.)

And now for the good news: Using a new analysis method developed by Yifat Piekner with the help of her research colleagues, Dr. David Ellis of the Technion and Dr. Daniel Grave, senior lecturer at Ben-Gurion University of the Negev, the following data were measured for the first time:

• Quantum efficiency in the generation of mobile (productive) and localized (nonproductive) electronic transitions in a material as a result of photon absorption at different wavelengths
• Electron-hole separation efficiency

This is the first time that these two properties (the first, optical in nature and the second, electrical) have been measured separately, whereas previous studies measured the combined effect of both properties together. Their separation allows for deeper understanding of the factors that influence the energy efficiency of materials for the conversion of solar energy into hydrogen or electricity.

Besides the achievement in terms of practical application, this is a scientific breakthrough that paves a new way for research into light-matter interaction in correlated electron materials.

The research study was sponsored by the Israel Science Foundation’s research center for photocatalysts and photoelectrodes for hydrogen production in the Petroleum Alternatives for Transportation Program, the Grand Technion Energy Program (GTEP) and the Russell Berrie Nanotechnology Institute (RBNI) at the Technion.

Click here for the paper in Energy & Environmental Science

The Technion is 94th on a list of the world’s top 100 universities, according to a report published yesterday by Shanghai Ranking, the world’s leading index for higher education. The Technion – Israel Institute of Technology is also on the top 50 list in two fields: aerospace engineering (16th place) and automation & control (46th place). In chemistry, the Technion ranks among the top 50-75 universities in the world. The Technion has consistently made the top 100 list of the Shanghai Ranking since 2012 (with one exception in 2020).

“The Technion is one of the world’s leading universities, and we will continue to invest efforts and resources to maintain this position for years to come,” said Technion President Prof. Uri Sivan. “The Technion’s strength lies in its excellent human capital, which leads to numerous achievements and breakthroughs in research and teaching. This is the result of hard work and dedication by Technion faculty, deans, administrative staff, and management.”

Prof. Sivan added that the Technion’s listing on the Shanghai Ranking and other indices “is not a purpose on its own. Global academic competition is rapidly intensifying, and while many governments around the world are steadily increasing their investments in academia and research, Israeli universities rely almost entirely on donations, which are becoming increasingly difficult to get.”

According to Prof. Sivan, “in order for Israel to preserve its standing at the forefront of global research, and to ensure the nation’s security, as well as its academic and economic future, the government should significantly increase investment in research and teaching, as well as adopt a welcoming stance toward the absorption of foreign faculty and students.”

While Prof. Sivan is “pleased that the Technion is among the three Israeli academic institutions on the top 100 list, we must remember that without government support and globalization of our research institutions, it will be harder for us to maintain this position.”

The Shanghai Ranking, first published in 2003, categorizes academic institutions according to objective criteria, such as the number of Nobel Prize laureates and other prestigious awards; the number of scientific articles published in the leading journals Nature and Science; the number of times scientific articles published by university researchers have been quoted; and researchers who’ve been frequently quoted in academic journals, relative to their peers in the field.

The index looks at 1,800 universities, from which the top 1,000 are selected. Leading the list are Harvard University, Stanford University, University of Cambridge, MIT and UC Berkeley. For the full ranking, click here.

 

 

The three-body problem is one of the oldest problems in physics: it concerns the motions of systems of three bodies – like the Sun, Earth, and the Moon – and how their orbits change and evolve due to their mutual gravity. The three-body problem has been a focus of scientific inquiry ever since Newton.

When one massive object comes close to another, their relative motion follows a trajectory dictated by their mutual gravitational attraction, but as they move along, and change their positions along their trajectories, the forces between them, which depend on their mutual positions, also change, which, in turn, affects their trajectory et cetera. For two bodies (e.g. like Earth moving around the Sun without the influence of other bodies), the orbit of the Earth would continue to follow a very specific curve, which can be accurately described mathematically (an ellipse). However, once one adds another object, the complex interactions lead to the three-body problem, namely, the system becomes chaotic and unpredictable, and one cannot simply specify the system evolution over long time-scales. Indeed, while this phenomenon has been known for over 400 years, ever since Newton and Kepler, a neat mathematical description for the three-body problem is still lacking.

In the past, physicists – including Newton himself – have tried to solve this so-called three-body problem; in 1889, King Oscar II of Sweden even offered a prize, in commemoration of his 60th birthday, to anybody who could provide a general solution. In the end, it was the French mathematician Henri Poincaré who won the competition. He ruined any hope for a full solution by proving that such interactions are chaotic, in the sense that the final outcome is essentially random; in fact, his finding opened a new scientific field of research, termed chaos theory.

The absence of a solution to the three-body problem means that scientists cannot predict what happens during a close interaction between a binary system (formed of two stars that orbit each other like Earth and the Sun) and a third star, except by simulating it on a computer, and following the evolution step-by-step. Such simulations show that when such an interaction occurs, it proceeds in two phases: first, a chaotic phase when all three bodies pull on each other violently, until one star is ejected far from the other two, which settle down to an ellipse. If the third star is on a bound orbit, it eventually comes back down towards the binary, whereupon the first phase ensues, once again. This triple dance ends when, in the second phase, one of the star escapes on an un-bound orbit, never to return.

In a paper accepted for publication in Physical Review X this month, Ph.D. student Yonadav Barry Ginat and Professor Hagai Perets of the Technion-Israel Institute of Technology used this randomness to provide a statistical solution to the entire two-phase process. Instead of predicting the actual outcome, they calculated the probability of any given outcome of each phase-1 interaction. While chaos implies that a complete solution is impossible, its random nature allows one to calculate the probability that a triple interaction ends in one particular way, rather than another. Then, the entire series of close approaches could be modeled by using a particular type of mathematics, known as the theory of random walks, sometimes called “drunkard’s walk.” The term got its name from mathematicians thinking about a drunk would walk, essentially of taking it to be a random process – with each step the drunk doesn’t realize where they are and takes the next step in some random direction. The triple system behaves, essentially, in the same way. After each close encounter, one of the stars is ejected randomly (but with the three stars collectively still conserving the overall energy and momentum of the system). One can think of the series of close encounters as a drunkard’s walk. Like a drunk’s step, a star is ejected randomly, comes back, and another (or the same star) is ejected to a likely different random direction (similar to another step taken by the drunk) and comes back, and so forth, until a star is completely ejected to never come back (and the drunk falls into a ditch).

Another way of thinking about this is to notice the similarities with how one would describe the weather. It also exhibits the same phenomenon of chaos the Poincaré discovered, and that is why the weather is so hard to predict. Meteorologists therefore have to recourse to probabilistic predictions (think about that time when a 70% chance of rain on your favorite weather application ended up as a glorious sunshine in reality). Moreover, to predict the weather in a week from now, meteorologists have to account for the probabilities of all possible types of weather in the intervening days, and only by composing them together can they get a proper long-term forecast.

What Ginat and Perets showed in their research was how this could be done for the three-body problem: they computed the probability of each phase-2 binary-single configuration (the probability of finding different energies, for example), and then composed all of the individual phases, using the theory of random walks, to find the final probability of any possible outcome, much like one would do to find long-term weather forecasts.

“We came up with the random walk model in 2017, when I was an undergraduate student,” said Mr. Ginat, “I took a course that Prof. Perets taught, and there I had to write an essay on the three-body problem. We didn’t publish it at the time, but when I started a Ph.D., we decided to expand the essay and publish it.”

The three-body problem was studied independently by various research groups in recent years, including Nicholas Stone of the Hebrew University in Jerusalem, collaborating with Nathan Leigh, then at the American Museum of Natural History, and Barak Kol, also of the Hebrew University. Now, with the current study by Ginat and Perets, the entire, multi-stage, three-body interaction is fully solved, statistically.

“This has important implications for our understanding of gravitational systems, and in particular in cases where many encounters between three stars occur, like in dense clusters of stars,” said Prof. Perets. “In such regions many exotic systems form through three-body encounters, leading to collisions between stars and compact objects like black holes, neutron stars and white dwarves, which also produce gravitational waves that have been first directly detected only in the last few years. The statistical solution could serve as an important step in modelling and predicting the formation of such systems.”

The random walk model can also do more: so far, studies of the three-body problem treat the individual stars as idealized point particles. In reality, of course, they are not, and their internal structure might affect their motion, for example, in tides. Tides on Earth are caused by the Moon and change the former’s shape slightly. Friction between the water and the rest of our planet dissipates some of the tidal energy as heat. Energy is conserved, however, so this heat must come from the Moon’s energy, in its motion about the Earth. Similarly for the three-body problem, tides can draw orbital energy out of the three-bodies’ motion.

“The random walk model accounts for such phenomena naturally,” said Mr. Ginat, “all you have to do is to remove the tidal heat from the total energy in each step, and then compose all the steps. We found that we were able to compute the outcome probabilities in this case, too.” As it turns out a drunkard’s walk can sometime shed light on some of the most fundamental questions in physics.

Click here for the paper in Physical Review X

From detecting cardiovascular disease, to fighting coronavirus, Faculty of Biomedical Engineering students recently presented an array of innovative projects that integrated everything they had learned.

During project development, the students had to go through all the stages needed to bring an idea to fruition. Starting with a medical problem which they had to tackle, they had to combine and implement medical know-how with engineering skills and scientific knowledge in order to provide a real-world solution. This hands-on experience exposes and prepares Technion graduates to the high-tech and biomed industries, and to biomedical research in a way that encourages multidisciplinary work. Therefore, such projects are vital for their future career and entrepreneurial skills.

Here’s a glimpse into some of the most intriguing (and often lifesaving) student projects in biomedical engineering.

Early detection of cardiovascular disease 

Sivan Barash and Shachar Zigron took first place in the student project competition, presenting a novel way of labelling macrophage cells, making them detectable by MRI. Macrophages are cells involved in the detection and destruction of bacteria. Cardiovascular disease is strongly associated in the public mind with fat storage in the body, but recent studies have shown significant involvement of inflammation in the process. Since macrophage cells have a major role in inflammation, being able to observe their movement within the body would facilitate scientists’ exploration of the connection between inflammation and cardiovascular disease. The duo’s project has lain the groundwork for in-vivo studies soon to be conducted in the laboratory of Prof. Katrien Vandoorne.

AI-based decision support machine for fetal monitoring 

Second place went to Amit Parizat and Rotem Shapira, who created an artificial intelligence (AI) system to analyze the output of the fetal monitor during labor and serve as a decision support machine. Complications during labor develop rapidly and can harm mother and child. The fetal monitor alerts healthcare providers of complications during labor. However, analyzing the monitor’s long signals manually is challenging and leads to obstetrics teams recommending a Caesarean “just in case” at the slightest indication, to the point that currently a third of all births in the U.S. involve a C-section, and only 20% of C-sections are later found to have been necessary. C-sections carry risks to the mother and involve a long recovery and long-term side effects. Amit and Rotem proved the feasibility of training an AI machine to predict complications during childbirth, preventing unnecessary invasive intervention, while ensuring that intervention is performed when needed. To achieve this, the two worked with the Obstetrics and Newborn Medicine Division at the Carmel Medical Center.

Treating cancer 

Orel Shahadi and Or Levy, coming in third, developed a 3D model that simulates drug penetration into solid tumors, facilitating development of new drugs and drug combinations to treat cancer. Their innovative model features an inner cluster of cells engineered to display fluorescence, surrounded by an outer layer of cells. Change in the cells’ fluorescence served as an indicator, providing a way to measure drug penetration into the tumor with a high level of precision.

Detecting heart rhythm problems through the color of your skin  

Yonathan Belicha and Daniel Cherniavsky, who took fourth place, explored a novel approach to diagnosing cardiac arrhythmias (heart rhythm problems), using nothing more than a few 1-minute videos of the patient – the kind of videos one might make using one’s smartphone. The natural contraction and relaxation of the heart cause minute changes in the human skin color. Yonathan and Daniel extracted those very small changes from the video, and from them – the subject’s pulse. Using this, they trained an AI system to recognize cardiac arrhythmia.

Fighting coronavirus with… ultrasound! 

Finally, Mor Ventura, Dekel Brav and Omri Magen, coming in fifth, tackled one of the challenges posed by the COVID-19 epidemic. Classification of the COVID-19 severity degree is usually done in hospitals using CT. However, CT machines’ availability is strained, they are expensive, and the process is further complicated by the need to transfer a patient with a highly contagious disease to and from the machine. Mor and Omri explored the possibility of using lung ultrasound instead, obtaining the necessary diagnostic information faster and more easily at the patient’s bedside, also significantly reducing the workload in healthcare facilities. To this end, they first developed an image-processing algorithm to “read” and label lung ultrasounds, identifying areas of interest and ignoring artefacts. Using the results of this algorithm, the trio then trained a neural network to classify the ultrasound videos and identify the severity of the patient’s illness. The project was conducted in collaboration with the Tel Aviv Sourasky Medical Center.

Award-winning FemTech startup

Asaf Licht and Zeinat Awwad presented the entrepreneurship project. Just finishing their bachelor’s degree, the two have already turned their project into a startup called Harmony. Their project is a FemTech initiative, developing a wearable, continuous, and non-invasive tracker to monitor women’s hormonal levels, aiming to ease the process of IVF, but also relevant for avoiding pregnancy, or alternatively for increasing the chances of getting pregnant. Currently, IVF procedures requires a blood test multiple times a week; Harmony seeks to replace that with an at-home device that provides continuous measurements while reducing discomfort. This project won first place in the EuroTech Innovation Day startup competition.

To read about additional student projects recently presented at the Technion, click here, here, and here.

Story by Tanya Haykin

The elderly population appears to be more vulnerable to COVID-19, and vaccines are less effective in protecting them. Why? In her doctoral thesis under the guidance of Professor Doron Melamed, Reem Dowery discovers the answer, explores the aging process of the immunes system, and presents means of rejuvenating it. The findings were recently published in the journal Blood.

Memory B lymphocytes are cells within the human body that are responsible for long-term production of effective antibodies. They are formed when the body is exposed to a new pathogen (i.e. virus, microbe, etc.). Upon consequent exposures to the same pathogen, they recognize it and elicit an enhanced antibody response to trigger an accelerated and augmented immunity. These cells are long-lived, capable of surviving and maintaining immune memory for many years. They are what vaccines attempt to generate, providing the body with the first exposure to what it interprets as the pathogen.

It has been known for some time that the formation of memory B lymphocytes is not as effective in elderly population, putting them at greater risk when facing new pathogens such as COVID-19. Now, for the first time the research group of Prof. Doron Melamed of the Technion’s Ruth and Bruce Rappaport Faculty of Medicine were able to explain why this is so. The group found that as with many other systems in the body, the immune system maintains a steady-state, homeostasis. It turns out that existing memory B lymphocytes (responsible for immune memory), by means of hormonal signals, impede the production of new ones. As a result, with age, the human immune system becomes more adept in responding to pathogens it had encountered before, but less capable of adapting to new threats. The same process makes vaccines less effective in protecting the elderly population.

Providing the right preventive measures

With the explanation found, and the signaling pathway through which the phenomenon occurs explained, the researchers wondered, could it be possible to alter, or to rejuvenate the immune system? To answer that question, Prof. Melamed’s lab collaborated with the departments of hematology and rheumatology at the Sourasky Medical Center and the Rambam Health Care Campus, respectively. As part of the treatment for some medical conditions (among them lupus, lymphoma, and multiple sclerosis), patients undergo B-cell depletion. In other words, a significant amount of memory B lymphocytes are removed from their body. Examining aged patients who underwent this procedure, the research team found their immune system had been rejuvenated, and their body able to produce new, highly potent B lymphocytes once again.

An effect similar to B-cell depletion can be produced by inhibiting one of the hormones in the signaling pathway that suppresses the production of new memory B lymphocytes. This groundbreaking proof-of-concept study of Reem Dowery and Prof. Melamed has opened the way for exploring the rejuvenation of the immune system. Its more immediate implications are on understanding the immune response in elderly populations, and providing the right preventive measures in light of this new information, in particular with regard to the current COVID-19 pandemic.

Click here for the paper in Blood

Air drums, dancing “spiders,” and robodogs were among many cool student projects presented recently at the Henry and Marilyn Taub Faculty of Computer Science.

In a project fair held at the end of the spring semester, students graduating from the Technion’s Faculty of Computer Science presented their work. The faculty values independent work as part of the graduates’ training process, and such projects give students an opportunity to integrate what they have learned.

The students presented various projects in the field of computer science, focused on the challenges they chose to tackle. Some created mobile apps for different uses; some developed programs to solve diverse problems; some delved into virtual reality; and others built devices, in the evolving field of Internet of Things (IoT). Multiple projects focusing on the Internet of Things were led by Itai Dabran and supervised by Tom Sofer, Michael Mendelson Mints, Vladimir Parakhin, Alon Binder, and others.

Here are some of the most intriguing projects presented.

 

Play drums without disturbing the neighbors

Almog Algranti, Nadav Abayov, and Yarden Wolf, created air drums: using computer vision algorithms, their app detects the drumsticks in the user’s hands, and plays music as if the user were seated at a drum set, recognizing both which drum is being struck, in what manner and with what force. “I play the piano, and recently got interested also in drums,” Algranti (filmed, below) explained. “This was an opportunity for me to create an ‘instrument’ that would let me practice without the financial investment in a drum set, and without disturbing the neighbors.”

Vintage computer game ‘Icy Tower’ now requires taking actual steps!

Suad Mansour, Sereen Diab and Aseel Khateeb, turned nostalgic computer game Icy Tower into a sports app by attaching an exercise stepper. Now, the game character would only move so long as the player kept moving. If the player stopped, the character would fall, resulting in a game-over. Like any sports app, the project displays feedback about steps walked and calories burned, as well as the game’s leaderboard. “As children, we played this game, and it as a lot of fun,” the three explained, “but it’s not very healthy to spend a long time by the computer, moving nothing but the arrow keys.”

Smart clotheslines

Eliezer Alter, Barel Cohen Adiv and Eliad Ben Haiem, who all three live in the campus dorms, decided to “smartify” their clothesline. Equipped with a water sensor, a light sensor, and a tarp, their clothesline now unrolls the tarp over the clothes if it rains, folds the tarp back when the sun comes out, and even sends reminders to do the laundry when the weather promises to be fine.

No (real) dog, no mess: meet the robodog!

Nadav Ashkenazi, Asaf Bialystok and Nathan Voldman constructed a dog that recognizes its owners, follows them around, and barks at strangers. Ethan Baron, Ron Klaz and Snir Green’s “spider” recognizes music and dances to the rhythm. Daniel Shkolnik, Omer Hemo and Mordechai Ben Harush created a queuing app for individual exercise machines at the gym.

All in all, students created useful and fun projects, all demonstrating implementation of diverse skills. A considerable number of projects stood out for being purposely built to help the community. You can read about those here.