06 - 서울에서의 나의 회의

How hard is it to hide 10 millions of people? In Seoul it seems possible! During 1 week I never had the sensation to be in a megalopolis. Most the time on the metro or on the bus I could have a sit and I have never seen traffic jam. My first answer for this unexpected scenario is that all Seoul residents are crammed in the skyscrapers and they go out from 2 to 7 a.m.

The second hypothesis, perhaps more credible, is that Seoul is very well organized in terms of transportation, with real-time information to move buses, cars and trains with maximum efficiency. This also explain why Seoul is the best place to host ICSC2019 (International Conference on Smart Cities). The main theme of ICSC 2019 was the sustainable and disaster resilient maintenance and rehabilitation of smart city facilities, with special sessions dedicated to the smart pavements and infrastructures.

Figure 1 - Logo of ICSC2019

I took advantage of the theme (and not just of the place as surely you are thinking!!!) to present my paper titled “A novel hybrid road system for the energy harvesting”.

During the conference I also attended a poster session and I had the possibility to share my project with experts from academia and industry. My poster took the attention of the Korean company Han Soo, which works on road pavement. I had some interesting feedback and we planned to start a collaboration. They proposed two solutions: a polyurethane binder having a very short curing time and a semi-transparent non-slip tape that could be directly implemented on the top of my prototype.

Figure 2 - An interesting discussion

 

Depsite the conference filled the whole day, I carved out time to visit the Seoul. Firstly I visited the Dongdaemun Design Plaza, designed by Zaha Hadid. It is a landscaped park that serves as a green oasis and a public plaza. The building coexists perfectly in the urban environment and it hosts event and art exhibitions. A mandatory stop is also the Gyeongbokgung, the royal palace of the Korean dynasty. From an engineering point of view, I could appreciate the typical home heating system called “Ondol”. It is the early version of the underfloor heating and it consists on heating some stones placed under the floor. When the fire is lit in the fireplace, the fire and the hot smoke pass through the gorae under the rooms, raising the temperature of the floor and then passing through the chimney at the end. 

Figure 3 - Scheme of the typical korean heating system

 

 Not far from the royal palace, I had a walk to the Bukchon Hanok Village, a picturesque residential area with the typical Korean houses. Along the street there were a lots of cartels with the ban on speaking loud to not disturb the residents. It was a surreal situation, where hundreds of tourists walked in silence around the village and the only noise was the click of some camera. This reminded me a touristic neighborhood of Naples called “quartieri spagnoli”. There the noise is a kind of background music that goes on for all the day!

 Anyway I have to remind myself that this blog is not my travel diary! If you want know more about the most important monuments, attractions and traditions of Seoul I suggest you to read the guide “Seoul” edited by Lonely Planet!

In the next post I will talk about a software for the realization of animated presentation called videoscribe. Stay tuned!!!

By for now

Domenico

“The research presented in this report/paper/deliverable was carried out as part of the H2020-MSCA-ETN-2016. This project has received funding from the European Union’s H2020 Programme for research, technological development and demonstration under grant agreement number 721493”

05 - EATA2019: you never forget your first conference!

Hi guys,

1 month ago I had the pleasure to take part to a great conference: EATA2019. Well, if you are not into the domain of pavement engineering, the acronym could remind you the wifi password of your neighbor, but believe me, it is one of the most important conference regarding the bitumen.

 

It took place in Granada, a vibrant city in the south of Spain, known throughout the world for the Alhambra, the flamenco and the tapas for free!

Walking for the old town, the first feeling is the strong influence of the islamic culture in the architecture. The best example is the Alhambra, a palace and fortress complex built between 1238 and 1358 at the end of Moors rule. After the christian reconquista, the site became the royal palace of Ferdinand and Isabella, undergoing the renaissance style.

Unfortunately I couldn’t visit the Alhambra because of the limited number of tickets (my suggestion is to book the ticket in advance, even before your flight!!!). At least I admired the building from an advantage point called Mirador San Nicolas. You should go there during the night, so you can enjoy the beautiful lighting of the Alhambra, while someone is playing the guitar.

Now I’d like to tell you more about EATA (European Asphalt Technology Association). It is an organization of European engineers and scientists involved in asphalt technology research. They hold a technical meeting every two or three years and publish a volume of papers, which are presented and discussed. During the conference we attended 9 sessions regarding the sustainability and the circular economy, the future trends in asphalt pavements, advanced tests and methods, the mechanics of asphalt material, the durability and the long term performances.

My presentation titled “viscoelastic characterization of transparent binders for application on solar roads” was included in the future trends in asphalt pavements and I had the opportunity to share my results with an expert audience. Considering that it was my first presentation in an international conference, I was a little nervous. I was worried about the questions, because all the people were expert in pavement engineering and there were no parallel sessions. It means that I had the attention of all the participants for 25 minutes!!! Finally I had interesting discussions, remarks and new points of view, which will be helpful to advance my research.

I also attended a seminar regarding the new challenges in asphalt pavement and I briefly presented my research work, paying attention to the methodology, in order to receive some feedback.

But the conference was not just a formal event, I had the pleasure to meet other PhD students involved in the European project saferup and I enjoyed the gala dinner, tasting some glass of vino tinto (the number of glasses in not relevant for this blog).

The next city to host EATA2021 will be Vienna, it means that I have two years to publish some good paper and attend again this conference!

Bye for now

Domenico

04 - Serious post title, attempt number 1: Measurement of the transparency loss of the semi-transparent layer

Hi guys,

I want to reassure everyone that all my samples are yet on my roof (proof in Figure 1).

Figure 1 - Proof

  
For sure you are wondering: why did you put your samples there? Well, the reason is that I’m studying the effect of the weather changes on my semi-transparent layer and in particular I want to investigate the reduction of transparency because of the aging of the polyurethane glue.

For this purpose, with the help of the technicians of IFSTTAR, I realized a low cost device for the measurement of the power reduction of the solar cell because of the presence of the top layer. The idea is to simulate the sunlight in a controlled environment and, as a good engineer, I made some simplifications.

The sun is replaced by an halogen lamp which is able to generate an irradiance power of about 300-400 W/m²_. The lamp is placed in a dark box (basically is an old bedside table with sliding doors) and the distance between the sample for the test and the lamp is about 60 cm (Figure 2).

Figure 2 - Very low cost device for the measurement of the power reduction of the solar cell

The electrical instrumentation is composed by:

• a solar cell having a peak power of 15W, an open circuit voltage Voc of 19.5V and a short circuit current Isc of 0.97A (these values are measured in the standard conditions of 1000W/m² of irradiance and 25°C and they are useful for discriminating the different characteristics of the solar cells in the market);
•  a solarimeter to measure the radiation of the lamp and to verify that it is always constant during all the test;
•  a set of resistances between 2 and 5000 Ω;
• two mutlimeters in order to measure at the same time the intensity and  the  voltage of the solar cell for each value of resistance;
•  a thermometer to check the temperature and verify that the box is not becoming a pizza oven;
•  a plate for the connection of all the devices.

Once all the equipment is installed, the test can be performed. The idea is to measure simultaneously the current intensity and the voltage of the solar cell for different values of resistances.

The data can be plotted in a graph having for abscissa the voltage and for ordinate the current intensity. With a miserable effort of fantasy we will call this plot intensity-voltage curve.

The goal is to find the highest power output of the solar panel (P max), which is given by the product of the intensity and the voltage (Figure 3).

Now the question is: what happens to the Maximum Power Point when the solar cell is covered by the semi-transparent layer? As you can expect, the maximum power point decreases and the reduction depends on the phenomena of absorption, reflection and diffraction between the solar radiation and the sample.

In order to well-quantify the power reduction, we are going to introduce a novel term called ‘’performance loss’’ (please, appreciate again the originality of the name).

 

  where:

-          P_max,unc is the maximum power point of the solar cell;

-          P_max,c  is the maximum power point of the solar cell covered by the semi-transparent layer.

Figure 3 - Example of Intensity-Voltage curve

The performance loss ranges theoretically between 0% (sample perfectly transparent) and 100% (sample totally black). My first samples had a value around 70%, but after the optimization of the mixture, I reached a value of 46%.

In terms of aging effect due the exposition to the weather changes, I observed an average increase of the performance loss of about 10%.

Recently I also studied the effect of each variable (thickness, glue content, grading curve) on the transparency and I quantified their impact through the factorial design, an experimental method commonly used in chemistry able to measure the effect of a variable on the outcome. Regarding this, I will probably dedicate a new post because it’s a very interesting topic and also because my blog will be more attractive with some matrices and formulas!

Bye for now and see you soon!

Domenico

 

“The research presented in this report/paper/deliverable was carried out as part of the H2020-MSCA-ETN-2016. This project has received funding from the European Union’s H2020 Programme for research, technological development and demonstration under grant agreement number 721493”