Investigación

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It is a recognition of the neuroscientists’ work at the University"

It is a recognition of the neuroscientists’ work at the University"

  • In this way, Dr. Rodolfo Madrid, from the Faculty of Chemistry and Biology, refers to the Conicyt  funds granted for implementing a research ring that will join top scientists. The challenge is to study the physiological role of the TRP ion channels involved in detecting thermal and pain stimuli, among many other physiological processes. Knowing how these channels work may allow the development of treatments for attacking diseases related to the their malfunction.

Three research groups and a common commitment -understanding the role of TRP channels in heat sensitivity, pain and synaptic plasticity-  define the project led by Dr. Rodolfo Madrid researcher at the Faculty of Chemistry and Biology. His initiative has recently received funds from the "2011 Fourth Contest of Research Rings in Science and Technology" organized by the National Commission for Scientific and Technological Research, CONICYT. (See related article).

"Study of the Physiological role of TRP Channels in Thermotransduction and Synaptic Plasticity" is an associative research project that joins three research groups: two correspond to the University’s laboratory of neurosciences at the Faculty of Chemistry and Biology -one led by Dr. Rodolfo Madrid and the other by Dr. Bernardo Morales-  the third is the Interdisciplinary Center for Neuroscience from Valparaiso, led by Dr. Patricio Orio. The joint challenge is to study the physiological role of various members of a group of membrane proteins: polymodal ion channels of the TRP (Transient Receptor Potential) superfamily in diverse physiological processes. For this purpose, they will have the annual funds of 150 million pesos, for three years.

"We want to study the role of various TRP channels in the electrical response of thermoreceptors of cold and nociceptors against various physiological and pathophysiological situations, in order to develop a mathematical model that could serve as a tool for predicting the electrical behavior of these neurons against modifications -that could be the result, for example, of an inflammatory process or an injury-  and  determining  the role of ion channels in regulating neuronal communication in particular regions of the central nervous system," Dr. Rodolfo Madrid explains.

"TRP channels are part of a large group of proteins involved in the detection of thermal stimuli and nociception, among many other physiological processes, and have recently been associated with learning and memory processes," the specialist says.
 

Advanced human capital

This associative research, will attract and train new high-level human capital. It will also  incorporate doctoral and postdoctoral students and, in this way, the group of neuroscientists at the University’s Faculty of Chemistry and Biology will become stronger.

"Besides, we will work with the collaboration of laboratories that belong to some of the world's best centers in the field, such as the Institute of Neuroscience in Alicante, Cambridge University and John Hopkins University, worldwide reference points in the study of neuroscience. This will not only help the growth and consolidation of  our group, but it will also allow our students go directly to stay in those centers,” the researcher says.

Besides, Dr. Madrid values ​​the grant of this ring project "as a recognition that should extend not only to the members of our group, but to all the neuroscientists at the University. From our point of view, this is the most important project of neuroscience that our institution has received and it means that our work has not been the result of improvisation, " he finally  points out.

Food protective film is developed using local byproducts

Food protective film is developed using local byproducts

  • Universidad de Santiago’s interdisciplinary research team, led by Dr. Silvia Matiacevich from the Technological Faculty, is focused on developing an edible film that could increase the shelf life of fresh foods by 30%.

Improving the way of preserving foods has been a permanent concern in food industry. This is the reason why packaging is essential for the quality and shelf life of the product. But this packaging should be in harmony with the environment.

In light of this situation, a sustainable alternative for food packaging has been developed: food covering edible films, which are being widely used and have become a world trend nowadays. At Universidad de Santiago, an interdisciplinary research team is trying to replicate this development, giving value added to different national byproducts.

This initiative will be viable thanks to the Associative Dicyt Project called “Bioactive Coatings for Foods”, which gathers together experts from different faculties of the University.

“We will use food industry byproducts which are considered as dispensable or waste material. We are going to give them a value added by adding antioxidant and antimicrobial components to them in order to increase the shelf life of fresh food products,” Dr. Daniel López says.

Academics from three different faculties gathered for this purpose: Dr. Rubén Bustos, from the Faculty of Engineering (Department of Chemical Engineering); Dr. Diego Venegas and Dr. Marlén Gutiérrez, from the Faculty of Chemistry and Biology (Department of Materials Chemistry); and Dr. Daniel López and Dr. Silvia Matiacevich, from the Technological Faculty (Department of Food Science and Technology), being Dr. Matiacevich the leader of the project.

During the two years scheduled for the project, the researchers plan to study the synergistic effect of this combination of products and they expect to increase food shelf life by over 30%.

Interdisciplinarity

Most of the academics related to this project are part of a larger group created by the end of 2013 called Indi, Asociación de Investigadores por el Desarrollo e Interdisciplinariedad of Universidad de Santiago de Chile, a group of researchers that promotes development and interdisciplinarity at the university.

“All of us have participated in some of these initiatives at some point, seeking for this interdisciplinarity. This is how we have met other people and created contacts. What is good is that more than just admiring the work of others, we have the real possibility of conducting studies together. For this reason, we value this type of projects, as they promote the integration and interdisciplinarity that define a university,” Dr. Matiacevich says.

Translated by Marcela Contreras
 

Researchers develop software program that recognizes seismic signals from Llaima Volcano

Researchers develop software program that recognizes seismic signals from Llaima Volcano

  • The motion patterns typical of volcanoes can be predicted with a high rate of effectiveness as of data sent from the slopes of the Llaima Volcano in La Araucanía Region. This has been possible thanks to the work by Dr. Max Chacón, professor at the Department of Informatics Engineering of Universidad de Santiago, who developed a software program for this purpose. “In Chile, it is essential to increase the knowledge on volcanoes. In this way, we will be able to face emergency situations like eruptions, and even predict them and make timely decisions,” Dr. Chacón said.

 


Due to its location on the Pacific Ring of Fire, the Chilean territory has the second largest volcanic chain in the world, with more than 2,000 volcanoes, many of them located in the southern part of the country. Although they are considered among the most active volcanoes in Latin America, only 43 of them are being monitored. The main concern about these geological structures is their potential for eruptions and their seismic activity is a key factor in prevention. 

Researchers of Universidad de Santiago, Universidad de La Frontera, and the Southern Andean Volcano Observatory, Ovdas by its acronym in Spanish, conducted the study “Pattern recognition applied to seismic signals from the Llaima Volcano: an analysis of the events’ features”, which is available in the Journal of Volcanology and Geothermal Research.

According to Dr. Max Chacón, professor at the Department of Informatics Engineering of Universidad de Santiago and one of the developers of the program, “Based on the machine learning approach, we developed a piece of software that identifies the type of the seismic signal as of data sent by sensors located on the slopes of the volcano,” with an 80% accuracy in the Llaima Volcano.

“Volcano seismic signals are not related to the earthquakes typical of tectonic plate collisions, as one could deduce from a first interpretation of these phenomena. These movements are specific to volcanoes and they are caused by their distinctive features, like their activity, magma movement, gas movement, stiffness of components, etc.

Previously, the research team had studied the Villarrica Volcano, detecting the existence of three characteristic seismic event patterns: the LP (Long Period) event, which is related to the pressure of gas and other fluids in the conduit; the Tremor, which is related to changes in gas and magma densities; and lastly, the VT (Volcano Tectonic) event, which is associated to the fracture of the solid parts of the volcano or the conduits.

The researchers used the program again in a study on the Llaima Volcano, but they also tried to identify the features of data sent by the sensors in the volcano. Among these data, the amplitude, frequency and phase of the signals, and the way in which they appear together in each seismic signal, were particularly considered.

“With this, we tried to give more information to volcanologists, so that they could identify the signals more easily, also analyzing the way in which these features appeared in seismic events,” Dr. Chacón, an expert in system models, said.

According to Dr. Chacón, one of the most interesting conclusions was the similarity of the results in the two volcanoes, what contradicts the current idea that each volcano has unique seismic movements. The researcher says that for now, the hypothesis is that the similarity is due to the proximity between the two volcanoes; however, this has not been proved.

For the above, there are two potential steps to follow in the context of this research. First, a comparative study on these volcanoes to measure the exact differences between them; and second, the improvement of the program with the purpose of detecting the correlations between these seismic signals at the moment of the eruption.

“In Chile, we live with many volcanoes, so it is essential to increase the knowledge about them. The more we know, the better we will be able to face emergency situations like eruptions, and even predict them and make timely decisions,” Dr. Chacón said.


Translated by Marcela Contreras

Outstanding position of Universidad de Santiago in the annual patent application ranking

Outstanding position of Universidad de Santiago in the annual patent application ranking

  • The National Institute of Industrial Property recognized Universidad de Santiago as the second Chilean university at filing the highest number of patent applications in 2014. “Chile has a scientific tradition that places the country at the forefront of the Latin American productivity, and numbers reflect this fact, like the second place reached by Universidad de Santiago (last year).” The award ceremony was held in the context of the World Intellectual Property Day.

 

Once again, Universidad de Santiago was among the three most outstanding universities in the patent category- a category related to the rights given by the Chilean State to an inventor for the development of a new technology- in the annual award ceremony organized by the National Institute of Industrial Property (Inapi). 

The ceremony was held at Patio Los Naranjos of Universidad de Santiago and it was headed by Katia Trusich, Under Secretary of Economy, Development and Tourism, and Inapi’s NationalDirector, Maximiliano Santa Cruz. The Under Secretary said that last year was a consolidation period for Inapi. And she added that the challenge now is to set out a long-term strategy to allow “the development of industrial property considering the specific requirements of the country with regards to productive development, innovation and business ventures.”

For his part, Inapi’s National Director emphasized that our institution has a very important commitment with regards to patent application processing. “In Chile, universities are doing a good job at patenting and, if they are considered all together, in 2014 they almost doubled the number of patent applications filed, in comparison to the previous year.”

Besides congratulating Universidad de Santiago for its great work and interest in patent matters, she said that our University “is making big efforts to obtain patents, something that should be continued and promoted. Generating new knowledge through scientific activity at universities is an essential tool for economic, social and cultural development.”

“Chile has a scientific tradition that places the country at the forefront of the Latin American productivity, and numbers reflect this fact, like the second place reached by Universidad de Santiago in the national patent application ranking of 2014”, Maximiliano Santa Cruz said.

Luis Magne, Head of the Department of Technology Management of Universidad de Santiago- the unit in charge of processing patent applications of the University, among other tasks- said: “Universidad de Santiago continues to keep its spirit of technological university, so it puts an emphasis on applied research and innovation in order to contribute to the society welfare and to have an impact on Chile and the world.”

According to the information given by the Department of Technology Management, in 2014, Universidad de Santiago filed 23 new patent applications with Inapi, doubling the number of patents filed in 2013. This placed the University in the third position of the ranking that year. In addition, it filed 44 invention and protection patent applications with international agencies.

These patents are related to the fields of Sciences, Engineering, Technology, and Chemistry and Biology, and most of them belong particularly to the areas of Biotechnology, Manufacturing and Aquaculture.

Universidad de Concepción was at the first place in the patent application ranking while Pontificia Universidad Católica was at the third place.

 

Translated by Marcela Contreras

 

Thermophiles 2015 Conference gathered world-class scientists at Universidad de Santiago

Thermophiles 2015 Conference gathered world-class scientists at Universidad de Santiago

  •  Dr Jenny Blamey, professor at the Faculty of Chemistry and Biology described the 13th International Thermophiles Meeting as a very important opportunity for the development of research at Universidad de Santiago and in the country. Worldwide prominent figures in microbiology, molecular biology, biochemistry, genetics, biocatalysis and biotechnology, participated in the conference. This is the first time that this global meeting is held in South America and Dr Blamey was in charge of the organization.

     

    In her closing speech, Dr Jenny Blamey, professor at the Faculty of Chemistry and Biology of Universidad de Santiago, evaluated this global meeting as a very important opportunity for the development of research at Universidad de Santiago and in the country.

    Dr Blamey highlighted the scientific importance of this conference that always leaves its imprint on the research centers and the countries where it is held. This also happened in our university and it should be reflected on the country.

    During the activity, worldwide leading scientists in this field presented their top-notch studies.

    These experts in microbiology, molecular biology, biochemistry, genetics, biocatalysis and biotechnology informed about the progress in their specialities, in order to have a better understanding of thermophiles.

    The Thermophiles International Conference is a global meeting held every second year. For the first time the meeting was carried out in South America, under the general supervision of Dr Blamey, and with the support of an efficient team who coordinated different tasks for the organizing bodies: Bioscience Foundation and the Faculty of Chemistry and Biology of Universidad de Santiago.

    The program included sessions on topics like genomics and biochemical processes, keynote lectures and poster presentations.

    International experts like Dr Karl Stetter, Dr Michel Adams and Dr Juergen Wiegel met with students, researchers and Chilean and foreign scientists.

    They shared their questions and their knowledge about the last developments and potential biotechnological applications of thermophiles, which are considered key to science development in our country and the world.

    A space for discussion and proposals

    “For Universidad de Santiago de Chile, hosting and promoting this type of activity is essential, since our purpose as a public, state and complete university is to create, preserve, disseminate and apply knowledge for the welfare of society,” Dr Juan Manuel Zolezzi, President of Universidad de Santiago, said.

    The Thermophiles 2015 International Conference contributed “To our institutional essential work, as it became a space for discussion and proposals, in a multidisciplinary and pluralistic dialogue; on this occasion, in the field of extremophiles, a new important field worldwide, not only for biological sciences but also for industrial biotechnology,” he added.

    For his part, Dr Gustavo Zúñiga, Dean of the Faculty of Chemistry and Biology, highlighted the importance of having been selected to organize the activity and receive these distinguished scientists, and give the students the opportunity to ask questions and talk to them.

    Translated by Marcela Contreras

Scientist works on mathematical model to prevent wooden structures from collapsing

Scientist works on mathematical model to prevent wooden structures from collapsing

  • Dr Erick Saavedra Flores, researcher at the Department of Civil Works Engineering of Universidad de Santiago de Chile, is studying new mathematical techniques to computer simulate the performance of wood at extreme ranges of deformation, cracking and ductile processes and its possible progressive collapse.

 

Wooden structures in a seismic country like Chile require constant inspection to check on its resistance in case of critical events such as earthquakes.

Dr Erick Saavedra Flores, researcher at the Department of Civil Works Engineering of Universidad de Santiago de Chile, is studying new mathematical techniques to computer simulate the performance of wood at extreme ranges of deformation, cracking and ductile processes and, eventually, in a progressive collapse.

Dr Saavedra explains that failures in wooden structures are divided into two groups: brittle and ductile failures. Both will determine the time before wood collapses. “Usually, structures fail abruptly, without previous notice. This type of failure is classified as ‘brittle’. However, at a local level, close to metal joints or fittings, wood fails in a “ductile” manner, i.e., it fails gradually in time. This latter type of failure is very common in very high buildings made of wood,” he says.

With the resources provided by a Fondecyt Regular project, Dr Saavedra will present a new model based on a mathematical technique called “homogenization”, which seeks to detect cracking and irreversible deformation processes at different spatial scales.

Worldwide efforts

“Achieving this goal will be a big challenge, because we require to extend the existing theory to incorporate the damage factor, i.e., degradation, loss of material stiffness and cracks into the multi-scale mechanical response of the material. In the past few years, big efforts have been made worldwide; however, predicting the mechanical performance of materials in this context remains to be a problem without a solution that is fully accepted by the scientific community,” he says.

He explains that he intends to incorporate this new material model to the advanced analysis of large-scale structures, because the big challenge posed by this goal is to computer simulate the progressive collapse of structures during seismic events.

In this regard, modeling this problem is extremely difficult as it involves extreme deformation processes, the interaction of elements that fall during the collapse process and their consequent fragmentation.

The project also considers experimental testing to validate the numerical predictions obtained during the study. Running these tests will be possible with the acquisition of a vibrating table for the Department of Civil Works Engineering.

As a final result of this study, the researcher expects to have material advanced models able to capture extreme deformation processes that allow to calculate ductility measures.

“I believe that the major impact my project may have is in the area of design and construction of buildings and large-scale structures. In the case of wood, particularly, it is possible to promote the use of radiata pine to construct tall buildings if we have a more precise knowledge of its performance during failures or eventual structural collapse,” Dr Saavedra explains. 

The study will be conducted in the context of the Fondecyt Regular project 2016 (1160691), “Advanced Modelling of Ductility and Damage in Mass Timber Structures by Computational Homogenization.”

 

Translated by Marcela Contreras

Educational attainment reduces maternal mortality

Educational attainment reduces maternal mortality

  • Damian Clarke, Associate Professor at the Faculty of Administration and Economics of Universidad de Santiago de Chile, together with Sonia Bhalotra, Professor of Economics at the University of Essex, conducted a study that relates maternal mortality to education.

 

 

In 2015, the World Health Organization estimated that 830 women died every day at childbirth. These numbers could have been prevented with timely access to contraceptive methods and obstetric care, as a result of the policies established by the Millennium Development Goal (MDGs) and the Sustainable Development Goals (SDGs).

The goal was to reduce maternal mortality by at least 75% over a 30-year-period. In spite of the progress in this field, the MDG was not achieved; therefore, implementing new policies is urgently required.

In view of this situation, Damian Clark, PhD in Economics from the University of Oxford and Associate Professor at the Faculty of Administration and Economics of Universidad de Santiago, together with Sonia Bhalotra, Professor of Economics at the University of Essex, decided to study the reduction of maternal mortality caused by education. They conducted the study “Maternal mortality and Education,” in which they established an empirical relation between both factors.

The World Institute Development Economics Research (UNU-WIDER), in Helsinki, prepared a video that summarizes this important study in order to disseminate it worldwide through different media. 

UNU-WIDER is a unique blend of think tank, research institute, and UN agency that provides a range of services from policy advice to governments as well as freely available original research coordinated by a core group of resident and non-resident researchers and undertaken by a global network of collaborators.

The study

In the study, the researchers suggest that together with the typical policies of birth attendance, prenatal care and the status of health services, an increase in the level of education of women reduces the probability of dying at childbirth.

“Policy papers on maternal mortality rarely suggest the lack of education as a cause for maternal mortality. Academic and public policy literature has little to say about this issue. But in Economics, there is living literature that documents a positive correlation between education and other health indicators,” Clarke says.

They analyzed cases in countries like Kenya, Nepal and Cameroon and considering the question why education reduces maternal mortality? they found that women who have received education are more likely to avoid pregnancy complications like pre-eclampsia, bleeding and infections by adopting simple and low-cost practices to maintain hygiene, reacting to symptoms like bleeding or high blood pressure and having qualified birth attendance.

Besides, women with more education are more likely to use public health services, they have delivered their children at an older age (not during adolescence) and have had less children.

These results suggest that the levels of education attained by women in any country have significant effects on maternal mortality rates.

Translated by Marcela Contreras

Solutions for optimizing wine making industry processes

Solutions for optimizing wine making industry processes

  • One of the most difficult procedures in the wine making industry around the world is cleaning and removing the remaining marc from the traditional fermentation vats. Through a project funded by Corfo’s Innova Chile, Dr. Lucio Cañete, together with professors Andrés Pérez de Arce and Héctor Barrera, of the Technological Faculty, are working on the design of devices to make this task easier, providing a solution both safe for workers and economical for the industry.


 
Andrés Pérez de Arce and Héctor Barrera, together with Dr. Lucio Cañete, the three of them professors at the Technological Faculty, are analyzing the technological viability of a device to solve one of the most complex problems for the wine industry: the cleaning of the traditional vats where the must is fermented.

Up to now, the fermentation process occurs in huge steel tanks that are filled up with crushed grape juice that stays there for a week or two, until the must is removed.

As the marc - the solid residue of seeds, skins, stalks and other impurities- remains in the tank, getting it clean before using it again is a problem for the industry, because it means that a worker has to go inside the vat through a lateral hatch, what puts his health at risk because of the toxic gas build-up in this dark and damp environment.

This is one of the most required works by the wine industry but with the least supply of workers due to the hostile work conditions; that is why companies usually offer additional bonuses to attract workers, but this is still not enough.

World problem

For this reason, Professors Lucio Cañete and Héctor Herrera, of the Department of Industrial Technologies, together with Professor Andrés Pérez de Arce, of the Department of Agrarian Management of the Technological Faculty, were awarded funds through Corfo’s InnovaChile for the project Extractor de Residuos Cohesivos Desde Medianas y Grandes Cubas Viníferas, code 13IDL1-25426 (Cohesive Residues Extractor for Medium and Large-sized Wine Making Tanks), in order to develop a device to solve this problem.

“The problem affects wine making not only at a domestic level, but worldwide,” Professor Cañete explained. Although some wine producers have vats than can be turned upside down to facilitate the removal of the marc, they are very expensive, so most companies use the traditional steel or concrete tanks.

After studying different possibilities, Professors Cañete, Barrera and Pérez de Arce decided to design a device to vacuum the marc without destroying it (as it is sometimes pressed again) and without needing a worker to enter the vat.

In a few days, the researchers should deliver the first progress report. They received the funding last April and it considers the creation of a test prototype; however, the researchers have already tested their proposal in wine producing companies.

A few weeks ago, they presented the idea in the conference of the Asociación Nacional de Ingenieros Agrónomos Enólogos de Chile (National Association of Oenologist- Agronomical Engineers of Chile), held in Molina. “We had a good response, because it is a real problem for the wine industry. Our solution seeks to reduce the workers’ health risk and to optimize the available time of the vats to make the most of the harvest time,” Professor Pérez de Arce said.

Today, the project is at an initial stage of development, testing the hypothesis to model the equipment and further creation of the prototype. The most advanced methods in this process are leading to ripper-vacuum cleaner-like and Archimedes’ screw-like solutions. In both cases, the device will be introduced in the tank through the hatch, but the worker would have the possibility of controlling it from the outside.


Translated by Marcela Contreras
 

Researchers at Universidad de Santiago find similarity between algae physiological functioning and human nervous system

Researchers at Universidad de Santiago find similarity between algae physiological functioning and human nervous system

  • Researchers at the Faculty of Chemistry and Biology of Universidad de Santiago discovered the existence of functional TRP ion channels in the marine alga Ulva Compressa that are similar to the ones present at the nervous system in mammals and humans. “At first, it was difficult to imagine that these channels could exist in a marine alga, especially when they exist in mammals but not in terrestrial plants,” Dr Alejandra Moenne, researcher at the Department of Biology, says.

 


TRP channels are cellular sensors that detect and respond to different environmental stimuli, like temperature changes, pain and taste, what makes them key to many physiological processes.

“At first, it was difficult to imagine that these channels could exist in a marine alga, especially when they exist in mammals but not in terrestrial plants,” Dr Alejandra Moenne, researcher at the Department of Biology, says.

“Before having these results, we found that copper stress activates voltage dependent calcium channels (VDCC) similar to the ones present at the central nervous system of mammals. So, how the activation of voltage dependent channels was possible? We thought that the activation of VDCC depended on the previous activation of TRP channels, something difficult to imagine in a marine alga,” the researcher explains.

These results mean a change in the way how the physiological functioning of marine algae - organisms that have been present on Earth for about a thousand million years- is understood. They were published by the journal Frontiers in Plant Science in the paper "Copper-induced activation of TRP channels promotes extra cellular calcium entry, activation of CaMs and CDPKs, copper entry and membrane depolarization in Ulva compressa.” 

The researcher explains that they not only found that “there are functional TRP channels that respond to copper but also that copper stress induces the release of amino acids and amino acid derived neurotransmitters similar to the ones released by human neurons. Even more, we have preliminary evidence that suggests that there is communication among different marine algae species through these molecules.”


Future research 

In terms of research and to give answers to the new questions, Dr Moenne says that she intends to apply for a Proyecto Anillo together with researchers Juan Pablo García-Huidobro (Universidad de Santiago), Claudio Sáez (Universidad de Playa Ancha) and Erasmo Macaya (Universidad de Concepción), in order to deepen the knowledge on the communication among green, red and brown marine algae.

“As algae release amino acids and neurotransmitters- and have TRP channels and voltage dependent channels- algae functioning would be more and more similar to neurons, but with a slower response in minutes or hours, instead of the milliseconds of the neurons response,” she explains.

The paper "Copper-induced activation of TRP channels promotes extra cellular calcium entry, activation of CaMs and CDPKs, copper entry and membrane depolarization in Ulva compressa" (that received the recognition of the Editor of the journal Frontiers in Planet Science) was written by the research team of this project: Melissa Gómez, Alberto González, Claudio Sáez, Bernardo Morales and Alejandra Moenne. It is available online at http://journal.frontiersin.org/article/10.3389/fpls.2015.00182/abstract 


Translated by Marcela Contreras

Researchers develop solar energy accumulator to dry agroproducts

Researchers develop solar energy accumulator to dry agroproducts

  • In order to reduce the effects of the day-night fluctuations of solar radiation, researchers at the Department of Chemical Engineering of Universidad de Santiago developed a low-cost accumulator that allows storing solar thermal energy and avoid interruptions of the drying processes of different agricultural products. The research team is led by Dr Alejandro Reyes and the study is called “Design and evaluation of a heat exchanger that uses paraffin wax and recycled materials as solar energy accumulator”.

 

Chile has high levels of solar radiation, particularly in the northern and central zones of the country. This makes our territory an ideal area for studying and developing new methods to use solar energy. 

In this context, Dr Alejandro Reyes published part of the results of his study in the Elsevier’s journal Energy Conversion and Management. The article is called “Design and evaluation of a heat exchanger that uses paraffin wax and recycled materials as solar energy accumulator.”

Through this study, Professor Reyes seeks to solve one of the biggest problems posed by solar thermal energy: its fluctuation between day and night. He has the goal of extending the use of solar energy to hours when it is not directly received.

Solar energy can be thermally or electrically stored in batteries, by means of photovoltaic panels. In thermal storage, solids or liquids can be heated and sensible heat is stored. However, Dr Reyes’ study is focused on the phase change, i.e., the use of a solid that melts when it is heated.

Paraffin wax

Paraffin wax, similar to the one used in candle making, was the best option for this study, as it remains solid below 56OC and, above this temperature, it changes to liquid.

The change in state of paraffin wax depends on energy input or output. “For a phase transition from solid to liquid, much energy is required, so we get it from the sun. And from liquid to solid, we need to take the energy inside out,” Professor Reyes explained.

In order to melt wax and transform it to liquid and accumulate energy, Dr Reyes designed a heat accumulator that works with low-cost materials, like soft drink cans. “We designed a device in which we put paraffin in a group of soft drink cans that we painted black. We put the cans inside a box, and we closed the upper face with a glass cover, facing the sun. The solar energy melts the wax and then a cold air flow is passed trough the cans and goes out as hot air,” he said.

However, this process has some drawbacks related to the low thermal conductivity of paraffin wax that makes more difficult sucking out the heat from the cans: when liquid paraffin wax starts getting solid inside the cans, the extraction of the energy remaining in the centre of the cans is very slow.

This problem was solved by embedding aluminium wool in the paraffin wax, doubling its thermal conductivity. Aluminium strips were also placed outside the cans to improve the energy transfer to the air.

Mathematical equations

Professor Reyes says that the empirical results are correlated with the models that they have been able to develop through mathematical equations.

“Evidently, if we build a device with more cans, the energy accumulation would be proportionally higher. We have another piece of equipment with 300 cans placed on the roof of the Department of Chemical Engineering that allows extending the drying process of agroproducts to up to five hours. We have the help of thesis students and experts in modelling and a piece of software that allows predicting the results of the equipment, based on its size and the environmental conditions,” he said.

Dr Reyes expects to replicate the energy accumulator and use it for different purposes. “On the roof, we have an accumulator made of cans, plus a standard solar panel, both connected to a dryer with a drying capacity of 25 kg of agricultural products. Up to date, we have dehydrated mushrooms, onion flakes, and sweet peppers, among others.”

As the process of drying agricultural products is slow, during the day the dryer uses the solar energy obtained through the solar panel, and then at night, when the solar radiation is null, the air for drying is heated in the energy accumulator and the drying time is extended to up to 5 additional hours.

“We seek to extend the drying process all night long, by using solar energy, in spite of the radiation fluctuations between day and night,” the researcher said.

Translated by Marcela Contreras

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