Despite the title, this blog is not about ballroom dances, but about something related to movement and how to guide your dance partner.
Have you ever felt how a footbridge sways when you walk over it or how a stadium stand vibrates under your feet when you are jumping and cheering up your favorite football team? If not, I highly recommend you to see these videos: Millenium Bridge London, Commerzbank-Arena Frankfurt or Volga Bridge Volgograd.
Why do these structures sway if they are building with strong and rigid materials like concrete or steel? In general, all structures vibrate in response to external excitation like people, vehicles or wind gust, but some structures sway more perceptible than others.
Structures perform more or less amplitude oscillations depending on their stiffness, mass and damping parameters. As a rule of thumb, the more slender, the more sensitive to develop noticeable rocking motions and even ones annoying and dangerous for people.
The best way to understand these concepts is by testing. If you are at home, I encourage you to go to the kitchen and take some spaghetti noodles and strawberries. Also you can use small balls made with a putty-like modelling material like plasticine® instead of the fruit. Now, hold tightly one end of a noddle and pierce a strawberry/plasticine® ball in the opposite end. Then, make small back and forth movement with your hand.
Changing the frequency of the movement you realize that the noddle performs big oscillationsand even is broken at a particular rate. This frequency is called resonance frequency and is defined by the noddle flexibility or “stiffness” and the strawberry/plasticine® weight or “mass”. If now you try with two noodles instead of one and later you use a heavier or lighter strawberry, you will perceive how the resonance frequency changes, being lower as long as you have lower stiffness and/or bigger mass.
With regard to damping, this property is related to the material used and basically it opposes to the movement. In other words, the more damping, the lower oscillations will be developed at the resonance frequency and the vibration will stop sooner once the excitation is ceased. This can be checked using a steel wire instead of the spaghetti. You notice the spaghetti damping is higher however it is more fragile than steel.
Coming back to structures, these ones are designed and built using different materials and geometries. Therefore they have different mass, stiffness and damping values and consequently different resonance frequencies. What would happen if one of the footbridge resonance frequencies was closed or the same to the people pacing rate crossing over it? As we saw in the experiment, the footbridge would sway perceptibly with lower or bigger oscillations depending on the damping. With a very low damping value, the oscillations performed would be so big that the structure must be closed to be modified. This was what happened three days after the London Millenium Bridge opening day.
Basically, there are two solutions to avoid noticeable vibrations in a structure. The first one would be modifying its resonance frequency changing its stiffness and/or mass. The second one would be based on adding damping to the structures. The first solution is in general expensive and would modify the final structure design becoming less slender what usually dislike the structure designer/architect. The second solution would be more affordable and unnoticeable. It would consist on adding damping devices along the structure in order to increase the structure global damping. Some examples of these devices are oil dampers and viscoelastic dampers. To work properly, these devices need to link two points of the structure with relative movement.
Other damping systems in what CARTIF has been working for years are the “Tuned Mass Dampers” or TMD. These systems consist on a mass attached to the structure by means of coil springs or metallic cables (pendulum TMD) and passive damping devices like oil dampers and neodymium magnets or active ones like magnetorheological dampers.
These systems only need to be attached to one point of the structure, being generally the one with the biggest oscillations. Its functioning principle is based on kinetic/inertial energy transference between the structure and the TMD. An example of these systems is the one recently installed in the second world tallest building, the Shanghai Tower, where a 1000 tons pendulum TMD drastically reduces the skyscraper oscillations in response to wind loads.
Summarizing, in spite of the fact that structures sway, it is always possible to “guide” them to gentle movements by means of damping system such as Tuned Mass Dampers.
‘Or from how to cultivate the energy consciousness of the tomorrow’s citizens through the education of today’s children’
Working in a technological centre where is made R & D & i is far from being the case of living in a futuristic bubble far away from the reality that is lived at grassroots level. On the contrary what we have in our handsday by day are challenges that any of us could meet. In my case, as a researcher working on issues of energy efficiency and sustainability, that is more than evident.
As you may have already seen in previous posts of my colleagues if you’re a regular reader of this blog, in the energy area we work on numerous projects that address energy efficiency in different fields and at different scales. We approach the problem from building level to city level, going through community and district or neighbourhood scales. These projects have a multitude of more or less complex technical implications that we analyse from different perspectives and profiles (architecture, engineering, computer science or telecommunications among others) seeking the optimal solutionsforeach case, but as would Ende, that is another story and shall be told another time.
Today I want to focus my attention on a necessary pillar to achieve efficiency and sustainability that is not a technical one: the user, the neighbour, the citizen. In short, people. You and me that after all are the ones who make things work as they do. As we have seen through the results of the DIRECTION project, in which they were built two buildings of very low energy consumption in Valladolid and Munich, the behaviour of users of buildings and their awareness have a great influence on the consumption and comfort final values.
Although there is an increasingly widespread awareness on energy and sustainability, in many cases it remains somewhat generic and fails to lead to changes in our habits. As my colleague Ana Quijano commented in his post, a key element is to ensure that the actions at a certain scale are profitable. This is certainly true in general terms, but in day to day life something more is needed. Social acceptance is an aspect that affects more than we might think. It is necessary that each of us become aware of our effect of our ability to act when it comes to getting energy savings and of our responsibility. For this to be so, it is necessary knowledge, mainly about the possibilities each one can have, and of course education. At this point it is when it starts to make sense the title of this post.
If the awareness of each of us as today’s individuals is essential, educating those who will be tomorrow’s citizens it is crucial. Only in this way it will be possible to find a way out of the energy and environmental crossroad where we have placed our planet. For those like me who have already reached a certain age, to act accordingly to energy consciousness might require changes in our traditional habits, and that’s not always easy to assimilate. It would have been simpler if we had them assimilated from childhood as normal, and this is where we can influence to improve the future from the present, through the education of children. The importance of teaching children in energy efficiency and energy and natural resources saving, lies not only in the transmission of adequate personal and social values, but in that they can assimilate as their own some behaviours that most adults have had to acquire belatedly, if we have done it.
There are increasingly more initiatives in this line in which the smallest of the house are the focus of attention. In schools, camps and other activities are routinely included resources relating to recycling and the reduction of the use of natural resources and their efficient use. How the energy is produced, transformed and used, as well as the consequences of each step are already part of the curricular itinerary. Recently, our colleague Laura López was speaking us in her post about an event organized by CARTIF in collaboration with the Municipality of Valladolid with the aim of raising awareness to children about recycling, specifically about the plastic named expanded polystyrene (EPS). Such initiatives are very important in strengthening on the education of children their awareness and responsibility. However, as a mother, I cannot fail to recognize that in this matter (as in many others) education at home is essential even more through the example. Our children reflect on their habits what they see in us, what they live every day, so we must strive to also (and especially) at home act with environmental and energy consciousness.
To achieve energy savings we can basically act in two ways, through solutions to reduce demand or consumption, or through energy efficiency solutions. Or to put it another way, spending less and spending better. It is no longer difficult to reduce the amount of energy we use by choosing devices and services of low or lower consumption and avoiding the waste of energy (holding lighted only the necessary lights, completely turning off electronic devices in the home, adjusting thermostats to suitable temperatures …).
Although it can seem difficult to see, children can also help us in these tasks. What might be more complex for us is to convince ourselves that such actions should not be a sort of imposition of our times but rather that saving energy is beneficial to us, both as individuals and as a society. Beyond the potential economic savings, reducing the general pollution with its consequent health benefits and reducing emissions of greenhouse gases that helps reducing the effects of climate change are positive consequences for all derived from individual appropriate attitudes and behaviour.
Among all and for the common good, we must help our children to take responsibility and behave in a critical way and have energy and environmental consciousness, to make it real that they are the kind of citizen of the future “our” planet needs. Particularly as a researcher in energy efficiency and sustainability, as a citizen who aspires to be part of a conscious and committed to energy efficiency and environmental protection society, and as a mother of a little citizen, I hope so.
VideoGames, social networks and wearables have been installed in our lives since a few years. They occupy much of our free time, allowing new methods of interacting with families and friends. They are part of the so called Information and Communication Technologies (ICTs), a pillar of the new concept of health eHealth that gives meaning to the use of social networks, videogames and wearables in order to improve the quality of life of the people.
The World Health Organization (WHO) defines eHealth as “the use of information and communication technologies for better health monitoring; for example, for the treatment of certain patients, promote research, create tools for education students, do screaning in various diseases”. The main participants of the eHealth, patients (ePatient) and doctors (eDoctor) are aware of that technology can improve the performance of health systems and make use of it for their benefit.
The objective of eHealth is to focus the health system on the specific needs of citizens by providing and exchanging information. Hence patients, professionals and health managersprovide knowledge to the care chain with the aim of promoting the prevention, diagnosis early and specialized treatment.
The main services that provide e-health are telemedicine, telecare, online consultations, telematic management, monitoring and treatment delivery and management big data the health management entails. Professionals, patients and managers are closer, easing efforts, avoiding displacements and reducing resources while improving service.
The new technologies, social networks, specialized blogs, wikis, podcasts, videos and messaging services, video games, wearables, of whom know their lucid and social part allow the exchange of information and knowledge, basic aspect in e-health, through:
Patients’ Communities in whom share experiences, talk about their disease, treatments and resources available. Patients have company.
Professionals’ Communities to share experiences, knowledge, approaches, concerns, views, etc.
Health networks that connect patients with professionals, and provide useful information to users. They often include valuation services, testimonials, advice, recommendations, etc.
Health information Sources available to patients and professionals who report on the latest developments and report on the health aspect.
Direct communication through the latest technologies (videoconferencing, chat, blogs, forums, etc.) that enable remote assistance, and allow the patient and the professional maintain a close relationship.
Patient monitoring and treatment, application usage and wearables devices that allow continuous monitoring of the health conditions of patients, especially chronic, and evaluate, motivate and guide their treatment.
Treatments and health monitoring of chronic patients require monitoring professionals who perform the testing and evaluation of patients. So far, it requires the need to go to the health center and make an appointment with the appropriate professionals. Mobile applications, wearables and video games allow the patient can perform their own testsat home providing professional data necessary to carry out the necessary assessments without resorting to consultation, reducing costs, increasing the rate of monitoring and increased adherence to treatment.
There are a lot of applications related to eHealth and especially chronic patients such as diabetes. Videogames, or Serious Games, as they are called, are a kind of applications that go beyond entertainment and allow motivate, evaluate and inform patients, allow greater adherence to treatment in patients. These applications and devices can increase patient knowledge about their disease and enhance training and skills development and extraction of valuable information for professionals, while fun and involves the patient.
It is clear that eHealth offers many advantages but, are they accessible to everyone? The basis of eHealth is ICT and therefore requires knowledge and assimilation of them. Not everybody dominate these technologies. The elderly have greater difficulty in accessing Internet so that, there is a handicap to overcome in order to they can be part of eHealth. They also tend to have misgivings about changes and prefer not to change.
As you can read, eHealth facilitates the exchange of knowledge, treatment adherence reducing costs and increasing the knowledge of patients and professionals. But its implementation is slow because it depends not only on technology but the attitude of people to them.
‘And because I do not like dry steaks, mom, take a little sauce and flavor’. As this Spanish rumba says, in our country we use ‘salt-cellar’, in the full sense of the word. In fact, we consume 9,8 g of salt daily, which is almost twice the recommended amount. But we are not the only ones. Americans follow us closely eating an average of 8,5 g every day. World Health Organization (WHO) admits that we have a serious global problem, establishing salt reduction as a priority measure in preventing cardiovascular disease.
Each gram of common salt (sodium chloride or NaCl) provides us approximately 0,6 g of chlorine (Cl) and 0,4 g of sodium. Sodium, although is needed in small quantities, is clearly ‘the bad guy’. Sodium excess causes fluid retention (weight increase), heart problems and hypertension. WHO suggests that the quantity of salt that an adult should consume daily is 5 g, equivalent to approximately 2 g of sodium. Attention! 5 g is only a little teaspoon or a thimble.
We just have to look at the following table elaborated from the data about the salt content of a group of foodsof the ‘Plan Cuidate+’, created by the Agencia Española de Seguridad Alimentaria y Nutrición (AESAN). So if we get four ham slices, we have made the day as far as salt is concerned. And if we eat it in a refrigerated sandwich, I do not think more… I just hope that WHO has calculated well because, according with them, it seems very easy to overcome the recommend intake daily. In addition, anyone dares to say to WHO something about the salt of a ham sandwich, because I imagine they would say: and who tells you to eat ham? Do not you know our recommendations about the processed meat consumption?
We are going to suppose that we try to reduce our salt consumption. In this case, it is not too easy, because the 72% of our salt consumption comes from processed food (prepared meals, fast food, snacks, cheese, cereals, etc.). This is what is known as ‘hidden salt’, and here is where manufacturers have to make an effort. In this sense, the FDA (Food and Drug Administration) in The United States of America is developing a guide in order to promote, voluntarily, the reformulation and development of new products reduced in sodium. To do this, from 2 June to 31 August, we can send them comments about sodium reduction
Little by little, our palate should get used to a less salty taste. Surely, everyone has seen that salty foods are able to modify our behavior: they are a generator of appetite and they stimulate our intake. We just have to eat pipes with salt and without salt. You can’t stop to eat the bag with salt until you finish it. (It is not an experiment with scientific rigor, but it serves to get an idea).
In July 2015 we were surprised by the news that a robot kills factory worker after picking him up and crushing him against a metal plate at Volkswagen plant in Baunatal (Germany). They insisted the death was a result of human error and not any malfunction on the part of the robot. A Volkswagen spokesman stressed that “the robot was not one of the new generation of lightweight collaborative robots that work side-by-side with workers on the production line and forgo safety cages”.
The application of robots in industrial processes is widespread in industry (mainly automotive), where they perform a multitude of tasks, mostly sequential, repetitive and at high speed. Accidents caused by robots are highly unusual. Many robot accidents do not occur under normal operating conditions but, instead during programming, maintenance, repair, testing, setup, or adjustment. During many of these operations the operator, programmer, or corrective maintenance worker may temporarily be within the robot’s working envelope where unintended operations could result in injuries. During normal operation, robots are confined in safety cages precisely to prevent incidents in contact with humans.
Without adequate safety measures traditional industrial robots can cause serious accidents to people by crushing and trapping (occur when a worker’s limb or other body part can be trapped between a robot’s arm and other peripheral equipment, or the worker may be physically driven into and crushed by other peripheral equipment; it can be deadly, as in the case of Baunatal), collision or impact (occur when a robot’s movements become unpredictable and a worker is struck by the robot) or by projection of materials (occur when parts of the robot , tool or product handled, breaks and fly off and hits a worker).
By rules applicable throughout the EU, it has been mandatory to provide a sufficiently large security perimeter to the entire workspace of the industrial robot that prevents access to the robot when in operation. When it will be necessary to enter to this area, the worker must perform some action to stop the robot, facilitating the access. Harmonised standards ISO 10218-1 and ISO 10218-2, “Safety requirements for industrial robots”, contain the minimum requirements for safe operation of these industrial robots.
This “separation” between workers and robots in an industrial environment is weakened through collaborative robots already available on the market (Universal Robots family of robots, ABB’s YuMi, KUKA’s LBR iiwa…) and the new technical specification ISO/TS 15066:2016, “Collaborative Robots”, that specifies the safety requirements for collaborative industrial robot systems and the work environment. The standard describes different concepts of collaboration and requirements needed to achieve them. The ISO standard also points out that the collaborative operation is a developing field and the new technical specification is likely to evolve in future editions.
Collaborative robots are designed to operate in a shared workspacewith workers without the need for conventional protections, safety cages or safety barriers. The main premise in the design of these robots is the safety of workers (Asimov’s first law of robotics: “a robot will not harm a human being”). These robots are designed to work side by side with workers.
The proximity of workers and robots requires a great safety design based on a combination of mechanical design and control measures, both the manipulator and the workspace. So rather than talking about collaborative robots, in CARTIF we prefer to speak of safe collaboration spaces (collaborative spaces). Besides the robot is safe, so it is the applications and working environments.
To ensure safety can be used different technologies and security measures. Lightweight manipulatorswithout shearing or cutting points, with rounded geometries, smooth surfaces and deformable or elastic components. Speed, acceleration and power can be limited. Current, force, torque sensors can be integrated to detect collisions. Real-time movement of the robot can be adjusted with proximity and tactile sensors. In order to be “aware of the collaborative space” it can be added visual systems based on 2D/3D computer vision technologies.
Usually, collaborative robots are similar to traditional industrial robots but smaller, lighter, less fast and powerful, cheaper and easier to install and configure. These robots do not need to be fast or powerful as they are specially designed to interact with workers. As experts say, in a collaborative space, the worker can bring skills, flexibility and, above all, ability to identify, understand and solve problems, and the robot provides repeatability, accuracy and endurance. Nevertheless, the ISO/TS 15066:2016 standard does not limit the capabilities of the robot in collaborative applications.
Without doubt, the search for solutions that reduce emissions of passenger transport is one of the points where more efforts are being made. The electrification of urban bus is one of the points where most are working, there are several strategies that we will be reduced to two:
• Vehicles with a large capacity battery: ensure autonomy and recharge while standing. The main problem is the batteries: high cost, weight and volume to the Service.
• Vehicles with fast / ultrafast load at stops start / finish line: they need recharging infrastructure with high power at some stops. In this option, the bus will take the bus a motor that will ensure the service.
The REMOURBAN project, led by CARTIF, will work to integrate in Valladolid line 7 a demonstrator based on the second option.
The main objective of the project is to demonstrate a pilot fleet of innovative public transport vehicles (buses) that combine outstanding performance with low-energy consumption. This will be achieved by introducing hybrid buses with a newly developed plug-in technology, which makes it possible to electrify a major part of the city bus lines.
The project will demonstrate that this technology can contribute to reducing harmful emissions from European city public transport systems.
The project will demonstrate:
• A new plug-in technology for hybrid buses: the complete vehicle will be optimised to ensure high standards of drivability, performance, durability and safety;
• A fast charging service for the buses: a reliable and efficient solution for charging is of crucial importance for the future use of plug-in technology. An effective service must take account of the location of the charging system, as well as safety, time efficiency, environmental and spatial considerations.
• The new hybrid plug-in technology and charging service will be demonstrated on an existing public bus route: The ultimate goal of the project is to test both of these important factors in city traffic.
Expected results:
• Reduced CO2 emissions: reduced fuel consumption, combined with electricity generated from renewable sources, will reduce CO2-emissions, compared to standard diesel vehicles;
• Improved energy efficiency: less energy consumption than standard diesel buses;
• Reducing emissions of hazardous substances: a substantial reduction in diesel consumption, combined with more favorable driving conditions, will result in a reduction in emissions of NOx, PM, HC and CO;
• Less noise: in electrical operation will radically reduce the noise of the buses, especially in sensitive areas;
• Zero-emission areas: in selected areas, the buses will run on electricity only, making these “zero emission” areas.
