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Incident Radiation
Published in Robert P. Bukata, John H. Jerome, Kirill Ya. Kondratyev, Dimitry V. Pozdnyakov, of Inland and Coastal Waters, 2018
Robert P. Bukata, John H. Jerome, Kirill Ya. Kondratyev, Dimitry V. Pozdnyakov
The sun is a relatively small, faint, cool star about which the Earth rotates yearly at an average distance (center of gravity to center of gravity) of 1.497 × 1011 m (1 astronomical unit). The mass of the sun is ∼333,400 times that of the Earth or 1.989 × 1030 kg. The rotation period of the sun about its own axis of rotation is a function of solar latitude, varying from about 26 days at the solar equator to about 34 days at the solar poles. An effective solar rotation period of 27 days is usually adequate for assessing and predicting recurring solar occurrences (such as sunspots and magnetic plage regions) that may affect the Earth’s atmosphere.
The Art and Science of Modeling with First-Order Equations
Published in Kenneth B. Howell, Ordinary Differential Equations, 2019
and the mass of the Sun ≈2× 1030kilograms.
Pollen clustering strategies using a newly developed single-particle fluorescence spectrometer
Published in Aerosol Science and Technology, 2020
Benjamin E. Swanson, J. Alex Huffman
A variety of multivariate analysis algorithms have been applied to the differentiation of spectral data from UV-LIF and other bioaerosol sensors (Huang et al. 2011; Pinnick et al. 2004). Algorithms can be divided into supervised or unsupervised classification techniques, where supervised techniques require prior input of data to train clusters, whereas this is not required for unsupervised techniques (Mohri, Rostamizadeh, and Talwalkar 2018). Unsupervised methods can thus be attractive to analyze particles from ambient observations, because no prior input is needed and so properties of test data do not bias results. For example, k-means clustering (unsupervised) was first applied to atmospheric aerosol data at least as early as 2004 (Erdmann et al. 2005), and has also been applied more recently, including with respect to particulate matter investigated using aerosol time-of-flight mass spectrometry and sun photometry (Elangasinghe et al. 2014; Rebotier and Prather 2007; Knobelspiesse et al. 2004). Unsupervised hierarchical agglomerative clustering (HAC) has also been frequently applied to study UV-LIF bioaerosol data, e.g., applied to WIBS data (Forde et al. 2019; Savage and Huffman 2018; Crawford et al. 2015; Robinson et al. 2013), and to fluorescence spectra from instrumentation that acquires LIF spectra at higher resolution than the WIBS (Könemann et al. 2019; Zhu, Liu, and Wu 2015; Pan et al. 2003).
How AD can help solve differential-algebraic equations
Published in Optimization Methods and Software, 2018
John D. Pryce, Nedialko S. Nedialkov, Guangning Tan, Xiao Li
To set up the Lagrangian formulation, comprising the 5 relative positions (each being a 3-vector) is converted to 6 positions of Sun and planets relative to their common centre of mass, which may be considered to be at rest in a Newtonian absolute frame. Namely let be the mass of the Sun and the masses of the planets and subtract from each component of to get . Then where G is the gravitational constant. The code, shown in the appendix, was made particularly compact using a C++ 3-vector class from [3].
A comparative study of energy and exergy performances of a PCM-augmented cement and fired-brick Trombe wall systems
Published in International Journal of Ambient Energy, 2022
Stephen A. Ajah, Benjamin O. Ezurike, Howard O. Njoku
Trombe walls are among the most notable passive structure that uses solar energy to heat, cool, ventilate and provide thermal comfort in buildings. In fact it is a real historical icon in bioclimatic design. It was first idealised and patented by Edward Morse in 1881, but was later popularised by Felix Trombe and Jacques Michel, hence the name ‘Trombe wall’ (Chel, Nayak, and Kaushik 2008). Passive solar heating/cooling systems have three basic functions which are solar energy collection, storage and distribution; and these are achieved by natural means without any electrical, electronic or mechanical controls (Jie et al. 2007). Figure 1 is an example of a Trombe wall and consists of a dark coloured wall of high thermal mass facing the sun. The wall is usually built with concrete, solid bricks or even Phase Change Materials (PCM), and is separated from the outer environment by a glazing (double or single), creating an air space in-between. Solar radiation passing through the glass is absorbed by the dark surface and is stored in the wall (Laurent et al. 2012). Trombe walls can also heat the internal space of the building by the release of the stored energy through natural convection heat flow. Upper and lower air vents in the wall are added to create convection currents, as cooler air from the room enters the air space through the lower part of the wall while the heated air from the air space gets into the room through the top. The vents must be operable to allow the occupants control the operation for optimum thermal comfort in the building. In high temperature regions, vent(s) may be introduced to the glazing to evacuate excess heat from the room side if this occurs.