Historic Climate in Heritage Building and Standard 15757: Proposal for a Common Nomenclature

Research on the relationship between microclimate and heritage buildings or historic buildings has increased dramatically in the last few decades. Research has focused on indoor climate or indoor microclimate or the environment or micro-environment, and the field of these studies regards several variables, physical—air temperature, air speed, relative humidity—or chemical, dust, CO2, pollution, etc., all of which can have an effect or damage buildings or artifacts inside buildings. Moreover, all these variables should be monitored in a monitoring campaign following the standard EN 15757; in spite of this, scientific literature contains mistakes with regard to the words and objects of study. In this short contribution, the author proposes a common nomenclature in the research field of climate and microclimate in heritage buildings and heritage artifacts. A new nomenclature should be useful for the community of heritage scientists working on preventive measures to distinguish between climate and environment, or the object of study, e.g., the room (wall, wood structure, fresco, etc.) where the artifacts are or the air around them (painting, canvas, statue, piece of furniture, documents, books, etc.).

The effect of air velocity on the performance of the direct evaporative cooling system

This experimental study aimed to determine the effect of airflow velocity on the performance of a direct evaporative cooling system. Rectangular-shaped honeycomb cooling pads with a length of 34 cm, a width of 25 cm, and a thickness of 3.5 cm are used as cooling media. The main parameters of the study are low air velocity (2.3 ms−1), medium (3.2 ms−1), and high velocity (3.7 ms−1). The data collected include dry bulb temperature, wet bulb temperature, output air temperature, input and output air velocity, input and output humidity, and solar radiation. These data are used to determine saturation efficiency, cooling capacity, temperature decreases, and feasibility index. The experimental results are presented in the form of tables and graphs and analysed based on existing theories. The results showed that the evaporative cooling system could produce output temperatures up to 27.5°C with input 31.4°C at low airspeed, 27.97°C with input 31.47oC at medium speed, and 27.7°C with input 31.30°C at high air speed. It was concluded that a low airflow rate would add to the cooling efficiency, and the higher the airflow rate, the lower the cooling efficiency. The results showed that evaporative cooling is achievable with a feasibility index of 19.89 ≤ F*≤ 20.67. The results also affirmed that cooling capability is higher where the feasibility indexes are comparatively low.

Thermal Comfort Performances of Temporary Shelters Using Experimental and Computational Assessments

This paper examines the thermal comfort of temporary shelters under Taiwan’s subtropical summer conditions. The temperature within the tent was higher compared to the standard configuration of the temporary shelter, but its relative humidity was lower. During the time period 09:30 to 14:30, temperatures at the center of the tent at positions 0.10 m, 1.10 m and 1.70 m above ground were 3.1 °C, 5.5 °C and 6.0 °C higher, respectively, than the average ambient temperature of 36.3 °C. However, temperatures for the standard configuration at similar central positions of 0.10 m, 1.10 m and 1.70 m above ground were 1.2 °C, 0.5 °C and 0.7 °C lower, respectively, than the same average ambient. In the afternoon, the standard configuration (PMV of 3.14 and PPD of 100) performed better than the tent (PMV of 5.03 and PPD of 100), although neither achieved thermal comfort. Various experimental configurations showed that double layers of roof lowered temperatures, but the thermal comfort (PMV of 3.32 and PPD of 100) remained unchanged. Various computational configurations showed that closing the door and one window and installing a mechanical fan of average speed 2.75 m/s lowered the temperature and increased the air speed to achieve thermal comfort with PMV and PPD values of 1.49 and 50, respectively.

Separation of switchgrass seeds by aerodynamic properties as a way of quality improvement

The article presents the research results on the effect of seed separation (by aerodynamic properties) regime on germination energy and germination in order to reduce the biological dormancy of seeds and significantly improve the quality. Methods. Laboratory, measuring and weighing, mathematical and statistical. Results. With speed increasing in the aspiration column channel from 2.5 to 5.2 m/sec there was a slight change in the 1000-seed weight. There was not dependency in increase in the 1000-seed weight along with increasing air velocity. Thus, if in the control the 1000-seed weight was 1.65 g, then at the maximum 5.2 m/sec air velocity in the aspiration channel it was 1.68 g (SSD0.05 = 0.10 g). Germination energy and seed germination significantly increased in all separation modes except for the mode with 2.50 m/sec air velocity in the aspiration channel. The 1000-seed weight that fell into the waste naturally increased with increasing air velocity in the aspiration channel from 0.15 g to 0.40 g, and germination energy and seed similarity were at the level of 0−1%. Increasing the air speed to 7.87 m/sec provided a significant increase in seed germination energy and germination compared to the control and sorting of seeds at an air speed of 5.6 m/sec and 7.49 m/sec, and waste losses in waste increased by 28.0%. Conclusions. Separation of switchgrass seeds of different years of vegetation, collected from panicles of different tiers and maturation dates provided a significant increase in its germination energy and germination and can be introduced into production but it does not completely solve the problem of reducing the biological dormancy of seeds.

Kinematics of wings from Caudipteryx to modern birds

This study seeks to better quantify the parameters that drove the evolution of flight from non-volant winged dinosaurs to modern birds. In order to explore this issue, we used fossil data to model the feathered forelimbs of Caudipteryx, the most basal non-volant maniraptoran dinosaur with elongated pennaceous feathers that could be described as forming proto-wings. In order to quantify the limiting flight factors, we created three hypothetical wing profiles for Caudipteryx with incrementally larger wingspans. We compared them with what revealed through fossils in wing morphology. These four models were analyzed under varying air speed, wing beat amplitude, and wing beat frequency to determine lift, thrust potential, and metabolic requirements. We tested these models using theoretical equations in order to mathematically describe the evolutionary changes observed during the evolution of modern birds from a winged terrestrial theropod like Caudipteryx. Caudipteryx could not fly, but this research indicates that with a large enough wing span, Caudipteryx-like animal could have flown. The results of these analyses mathematically confirm that during the evolution of energetically efficient powered flight in derived maniraptorans, body weight had to decrease and wing area/wing profile needed to increase together with the flapping angle and surface area for the attachment of the flight muscles. This study quantifies the morphological changes that we observe in the pennaraptoran fossil record in the overall decrease in body size in paravians, the increased wing surface area in Archaeopteryx relative to Caudipteryx, and changes observed in the morphology of the thoracic girdle, namely, the orientation of the glenoid and the enlargement of the sternum.

Study of urban microclimate conditions in a commercial area of an urban centre and the environmental regeneration potential

Urban heat island (UHI) is a phenomenon that affects the urban microclimate. Land use, urban geometry, cover materials, vegetation, the water element and human activities are the most important factors that affect the UHI. This research focused on the study and analysis of the urban microclimate of three sections of a commercial street area that differ in their morphology. The first area includes a stream near the road, the second area includes the purely commercial part of the street and the third area includes the fringes of a hill in (Thessaloniki, “Toumpa”, Gr Lampraki Street). Using the Envimet V4 program, three simulations were performed for the selected study areas for the hottest day of the previous year, August 1, 2020. The values with the largest variations in all three areas were those of relative and specific humidity and finally air speed. The air temperature was higher in relation to the suburban area (UHI) and did not show significant differences in the three study areas. This leads us to the conclusion that the urban morphology, orientation and geographical location of the three study areas played the most important role in shaping the urban microclimate. Finally, is suggested one alternative scenario for optimizing the microclimate in the most burdened area of the three.

Heat transfer analysis in fluidized bed dryer with heat exchanger pipe for corn material

This research aims to know the heat transfer process on the fluidized bed dryer for corn material. In this study conducted observations on the temperature and heat produced during the drying process, with three different pipe heat exchanger: spiral, parallel, and combination; The air of the air was 2 m/s, 4 m/s, and 6 m/s and the mass of corn material was1.5 kg with an initial moisture content of 24%. Test results showed that the highest-produced temperature in the combination heat exchanger pipe with a drying room temperature averaged 54°C. The value of the highest convection coefficient of heat transfer in the combination heat exchanger pipe flow treatment with the air velocity of 6 m/s by 29.4 W/m2K. The heat energy that enters at the treatment of combination heat exchanger pipe with the air speed of 6 m/s by 1774 Watts. Heat energy is lost through the highest wall drying chamber at the combination heat exchanger pipe flow treatment with the air velocity of 6 m/s by 409 Watts. The heat energy used is 335 Watts to dry the highest material in the combination heat exchanger pipe flow treatment with the air speed of 6 m/s.

Classification of helicopter’s typical flight state based on threshold

Dividing the 37 flying state of a certain line number helicopter. Firstly, dividing the helicopter rotation and single-engine flight. Secondly, performing preliminary state division for the remaining samlpes, the specific division of yaw angle, helicopter flight altitude and indicated air speed are different states, the least squares polynomial method is used for smoothing respectively. Calculating the extreme value of each parameter data, with the difference value of the extreme value of the parameter data being less than 10 as the limiting condition, dividing the original data segment into non-turning, level flight and steady speed state. The remaining sampling points are in the state of unsteady turning and non-level flight. Taking the difference value 0 as the limiting condition, further divide the non-steady speed and non-level flight state. Dividing the state of turning and non-turning, level flight, ascent and descent, steady speed, increase speed and deceleration state, which is the preliminary division state. Finally, dividing the near-ground and non-near-ground, classifying the helicopter status according to the height threshold, and analyze the accuracy of the classification results. The results show that this method is versatile, can quickly divide helicopters with different flight complexity, and has high accuracy.

Stay cool without fossil fuel. A passive eco-cooler for low-income population in informal settlements

With climate change severe events, more and more vulnerable populations suffer from extreme heat waves. This paper presents a hands-on experimental idea for testing vernacular passive cooling strategies using traditional Shisha clay funnels for the Egyptian hot dry climate. Several clay funnels were investigated in terms of shape, size and form. The clay funnels were measured and simulated for their efficiency in accelerating air flow inside residential units and ability to enhance the air velocity if used combined with cross ventilation strategies. Computational Fluid Dynamics (CFD) simulations were conducted in ANSYS Fluent to understand the airflow behaviour inside the simulated test shoe boxes resembling living rooms - using the standard k-∈ turbulence model - for single and multi-units’ configurations. Followed by experimental test cells application for the cooling system and monitoring for testing thermal performance. The simulation results showed significant enhancement in air flow and air speed inside the test room compared to conventional windows, while the test cells monitoring showed an average reduction in indoor temperature and humidity with 2 degrees and 15 % respectively. Further monitoring is needed for other alternations of the eco-cooler funnel design for better performance.