M. Verwaal
info
Please Note
<p>This page displays the records of the person named above and is not linked to a unique person identifier. This record may need to be merged to a profile.</p>
4 records found
1
Journal article
(2022)
-
Tjark Roozendaal, Martin Verwaal, Alice Buso, Rob B.N. Scharff, Yu Song, Peter Vink
Sitting comfort is an important factor for passengers in selecting cars, airlines, etc. This paper proposes a soft robotic module that can be integrated into the seat cushion to provide better comfort experiences to passengers. Building on rapid manufacturing technologies and a data-driven approach, the module can be controlled to sense the applied force and the displacement of the top surface and actuate according to four designed modes. A total of 2 modules were prototyped and integrated into a seat cushion, and 16 subjects were invited to test the module’s effectiveness. Experiments proved the principle by showing significant differences regarding (dis)comfort. It was concluded that the proposed soft robotics module could provide passengers with better comfort experiences by adjusting the pressure distribution of the seat as well as introducing a variation of postures relevant for prolonged sitting.
...
Sitting comfort is an important factor for passengers in selecting cars, airlines, etc. This paper proposes a soft robotic module that can be integrated into the seat cushion to provide better comfort experiences to passengers. Building on rapid manufacturing technologies and a data-driven approach, the module can be controlled to sense the applied force and the displacement of the top surface and actuate according to four designed modes. A total of 2 modules were prototyped and integrated into a seat cushion, and 16 subjects were invited to test the module’s effectiveness. Experiments proved the principle by showing significant differences regarding (dis)comfort. It was concluded that the proposed soft robotics module could provide passengers with better comfort experiences by adjusting the pressure distribution of the seat as well as introducing a variation of postures relevant for prolonged sitting.
Preparation of Injera, the cultural staple bread food
item in Ethiopia, is known for its intensive energy consuming
cooking. Baking this food item in the traditional three stone stoves,
with an efficiency of 5-15%, consumes huge amounts of firewood
and causes consequent problems like deforestation, global warming
and household air pollution. Electrical injera stoves (mitads) are a
sound alternative in Ethiopia because of the relatively wide
availability of electricity (hydropower). However, these electrical
Mitad have designs dating back to the 1960’s and are highly
inefficient as well and are overloading the electricity grid.
Consequently, a research and design project called ‘Magic Mitad’
was initiated to develop an energy-efficient electric injera mitad.
Starting with the introduction of a new type of fuel-efficient baking
plate a range of research and design experiments were initiated to
further optimize the energy-efficiency as well as the baking quality
of the Magic Mitad. In the first experiment the ‘start-up energy’ of
different baking plates was tested in order to identify and select the
most energy efficient one. During the next experiment, the chosen
type of baking plate was used for baking injeras to study the heat
distribution. A uniform heat distribution is key to produce high
quality injeras. From the result obtained it was concluded that a
different type of heating element was needed. Ten types of
alternative heating elements were selected of which four were
tested in a lab-setting. Ribbon wire heating element was selected,
and optimized in its lay-out. Finally, the prototypes were tested in
Addis Ababa on quality performance and energy-efficiency
compared to electrical clay mitads. The outcomes were successful
in the sense of quality and increased efficiency by 30%. ...
item in Ethiopia, is known for its intensive energy consuming
cooking. Baking this food item in the traditional three stone stoves,
with an efficiency of 5-15%, consumes huge amounts of firewood
and causes consequent problems like deforestation, global warming
and household air pollution. Electrical injera stoves (mitads) are a
sound alternative in Ethiopia because of the relatively wide
availability of electricity (hydropower). However, these electrical
Mitad have designs dating back to the 1960’s and are highly
inefficient as well and are overloading the electricity grid.
Consequently, a research and design project called ‘Magic Mitad’
was initiated to develop an energy-efficient electric injera mitad.
Starting with the introduction of a new type of fuel-efficient baking
plate a range of research and design experiments were initiated to
further optimize the energy-efficiency as well as the baking quality
of the Magic Mitad. In the first experiment the ‘start-up energy’ of
different baking plates was tested in order to identify and select the
most energy efficient one. During the next experiment, the chosen
type of baking plate was used for baking injeras to study the heat
distribution. A uniform heat distribution is key to produce high
quality injeras. From the result obtained it was concluded that a
different type of heating element was needed. Ten types of
alternative heating elements were selected of which four were
tested in a lab-setting. Ribbon wire heating element was selected,
and optimized in its lay-out. Finally, the prototypes were tested in
Addis Ababa on quality performance and energy-efficiency
compared to electrical clay mitads. The outcomes were successful
in the sense of quality and increased efficiency by 30%. ...
Preparation of Injera, the cultural staple bread food
item in Ethiopia, is known for its intensive energy consuming
cooking. Baking this food item in the traditional three stone stoves,
with an efficiency of 5-15%, consumes huge amounts of firewood
and causes consequent problems like deforestation, global warming
and household air pollution. Electrical injera stoves (mitads) are a
sound alternative in Ethiopia because of the relatively wide
availability of electricity (hydropower). However, these electrical
Mitad have designs dating back to the 1960’s and are highly
inefficient as well and are overloading the electricity grid.
Consequently, a research and design project called ‘Magic Mitad’
was initiated to develop an energy-efficient electric injera mitad.
Starting with the introduction of a new type of fuel-efficient baking
plate a range of research and design experiments were initiated to
further optimize the energy-efficiency as well as the baking quality
of the Magic Mitad. In the first experiment the ‘start-up energy’ of
different baking plates was tested in order to identify and select the
most energy efficient one. During the next experiment, the chosen
type of baking plate was used for baking injeras to study the heat
distribution. A uniform heat distribution is key to produce high
quality injeras. From the result obtained it was concluded that a
different type of heating element was needed. Ten types of
alternative heating elements were selected of which four were
tested in a lab-setting. Ribbon wire heating element was selected,
and optimized in its lay-out. Finally, the prototypes were tested in
Addis Ababa on quality performance and energy-efficiency
compared to electrical clay mitads. The outcomes were successful
in the sense of quality and increased efficiency by 30%.
item in Ethiopia, is known for its intensive energy consuming
cooking. Baking this food item in the traditional three stone stoves,
with an efficiency of 5-15%, consumes huge amounts of firewood
and causes consequent problems like deforestation, global warming
and household air pollution. Electrical injera stoves (mitads) are a
sound alternative in Ethiopia because of the relatively wide
availability of electricity (hydropower). However, these electrical
Mitad have designs dating back to the 1960’s and are highly
inefficient as well and are overloading the electricity grid.
Consequently, a research and design project called ‘Magic Mitad’
was initiated to develop an energy-efficient electric injera mitad.
Starting with the introduction of a new type of fuel-efficient baking
plate a range of research and design experiments were initiated to
further optimize the energy-efficiency as well as the baking quality
of the Magic Mitad. In the first experiment the ‘start-up energy’ of
different baking plates was tested in order to identify and select the
most energy efficient one. During the next experiment, the chosen
type of baking plate was used for baking injeras to study the heat
distribution. A uniform heat distribution is key to produce high
quality injeras. From the result obtained it was concluded that a
different type of heating element was needed. Ten types of
alternative heating elements were selected of which four were
tested in a lab-setting. Ribbon wire heating element was selected,
and optimized in its lay-out. Finally, the prototypes were tested in
Addis Ababa on quality performance and energy-efficiency
compared to electrical clay mitads. The outcomes were successful
in the sense of quality and increased efficiency by 30%.
This article presents a simple comparative model which has been developed for the estimation of the performance of photovoltaic (PV) products' cells in indoor environments. The model predicts the performance of PV solar cells, as a function of the distance from a spectrum of artificial (fluorescent light, halogen light, and light-emitting diodes) and natural light. It intends to support designers, while creating PV-integrated products for indoor use. For the model's validation, PV cells of 12 commercially available PV-powered products with power ranging from 0.8 to 4 mWp were tested indoors under artificial illumination and natural light. The model is based on the physical measurements of natural and artificial irradiance indoors, along with literature data of PV technologies under low irradiance conditions. The input data of the model are the surface of the solar cell (in m2), the wavelength-dependent spectral response (SR) of the PV cell, the spectral irradiance indoors, and solar cell's distance from light sources. The model calculates solar cells' efficiency and power produced under the specific indoor conditions. If using the measured SR of a PV cell and the irradiance as measured indoors, the model can predict the performance of a PV product under mixed indoor light with a typical inaccuracy of around 25%, which is sufficient for a design process. Measurements revealed that under mixed indoor lighting of around 20 W/m2, the efficiency of solar cells in 12 commercially available PV products ranges between 5% and 6% for amorphous silicon (a-Si) cells, 4–6% for multicrystalline silicon (mc-Si) cells, and 5–7% for the monocrystalline silicon (c-Si) cells.
...
This article presents a simple comparative model which has been developed for the estimation of the performance of photovoltaic (PV) products' cells in indoor environments. The model predicts the performance of PV solar cells, as a function of the distance from a spectrum of artificial (fluorescent light, halogen light, and light-emitting diodes) and natural light. It intends to support designers, while creating PV-integrated products for indoor use. For the model's validation, PV cells of 12 commercially available PV-powered products with power ranging from 0.8 to 4 mWp were tested indoors under artificial illumination and natural light. The model is based on the physical measurements of natural and artificial irradiance indoors, along with literature data of PV technologies under low irradiance conditions. The input data of the model are the surface of the solar cell (in m2), the wavelength-dependent spectral response (SR) of the PV cell, the spectral irradiance indoors, and solar cell's distance from light sources. The model calculates solar cells' efficiency and power produced under the specific indoor conditions. If using the measured SR of a PV cell and the irradiance as measured indoors, the model can predict the performance of a PV product under mixed indoor light with a typical inaccuracy of around 25%, which is sufficient for a design process. Measurements revealed that under mixed indoor lighting of around 20 W/m2, the efficiency of solar cells in 12 commercially available PV products ranges between 5% and 6% for amorphous silicon (a-Si) cells, 4–6% for multicrystalline silicon (mc-Si) cells, and 5–7% for the monocrystalline silicon (c-Si) cells.