Lecture 1.pdf

PLANT AND LIVESTOCK SYSTEMS AND ENVIRONMENTAL CONTROL ENGINEERING ENGR. AZEREEL C. SUOR 1ST SEMESTER 2024-2025 PLANT AND LIVESTOCK SYSTEMS AND ENVIRONMENTAL CONTROL ENGINEERING Environmental parameters and their interrelationships in a plan...

PLANT AND LIVESTOCK SYSTEMS AND ENVIRONMENTAL CONTROL ENGINEERING ENGR. AZEREEL C. SUOR 1ST SEMESTER 2024-2025 PLANT AND LIVESTOCK SYSTEMS AND ENVIRONMENTAL CONTROL ENGINEERING Environmental parameters and their interrelationships in a plant and livestock production system; microclimate modification for COURSE DESCRIPTION plants and livestock; principles of environmental control engineering; analysis and design of environmentally controlled AB structures. ENVIRONMENT: Surroundings AERIAL PLANT ENVIRONMENT ROOTS ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 ENVIRONMENT: Surroundings PHYSICAL ANIMAL THERMAL ENVIRONMENT SOCIAL MICROBIAL ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 WHY? ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 WHY? ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 PHYSICAL FACTORS AFFECTING THE BIOLOGICAL ENVIRONMENT Solar Radiation Temperature Humidity Atmospheric Pressure Atmospheric Contaminants ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Black Body ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Black Body ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Black Body Ideal object that is a perfect emitter and a perfect absorber of radiation It absorbs all incoming radiation without reflecting any It re-emits radiation perfectly according to its temperature (Plank’s Law) Radiates energy in a characteristic spectrum that depends on its temperature, and it does so with maximum efficiency ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Emissivity (𝜺) Measure of how effectively a material emits thermal radiation compared to a perfect black body. It’s dimensionless number ranging from 0 to 1, where: 1 represents a perfect black body, which emits the maximum amount of radiation possible at a given temperature 0 represents a perfect reflector, which emits no thermal radiation at all Used to quantify how much radiation an object emits relative to what a black body would emit under the same conditions. ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Emissivity (𝜺) Depends on several factors, Materials surface properties Texture Wavelength of the emitted radiation Examples: Metals typically have low emissivity because they reflect most of the incident radiation Polished aluminum have an emissivity of about 0.1 Non-metals or rougher surfaces generally have higher emissivity Rough blackened surface can have an emissivity close to 0.9 or higher ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Absorptivity (𝜶) material property that describes how well a material absorbs radiation, particularly electromagnetic radiation like light or thermal radiation the fraction of the incident radiation that is absorbed by the material 0 indicates that the material does not absorb any radiation (it reflects or transmit all of it) 1 means that the material absorbs all the incident radiation Kirchhoff’s Law: for a body in thermal equilibrium, the absorptivity and emissivity at a given wavelength are equal A good absorber of radiation at a certain wavelength is also a good emitter at that wavelength ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Reflectivity (𝝆 or 𝑹) Is a material property that describes how much of the incident radiation on a surface is reflected back. It Is the ratio of the reflected radiation to the total incident radiation and is a dimensionless quantity that ranges from 0 to 1. 0 means that the material absorbs all incident radiation (no reflection) 1 means that the material reflects all incident radiation (no absorption) Can also depend at which the radiation strikes the surface Reflectivity increase as the angle of incidence increase, especially when the angle approaches 90 degrees (grazing incidence) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Reflectivity (𝝆 or 𝑹) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Transmissivity (𝝉 or 𝑻) Is a material property that describes how much of the incident radiation passes through a material. It is the ratio of the transmitted radiation to the total incident radiation. 0 means that no radiation passes through the material (it is completely opaque) 1 means that all incident radiation passes through (the material is completely transparent) The thickness of material can significantly affectits transmissivity As the thickness increases, the transmissivity generally decreases, because more of the incident radiation is absorbed or reflected before it can pass through the material ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation Transmissivity (𝝉 or 𝑻) Can depend on the angle at which radiation enters the material. At steeper angles, the path length though the material is longer, which can reduce transmissivity, especially if the material is not perfectly transparent ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation 𝝆+𝜶+𝝉=𝟏 ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation STEFAN-BOLTZMANN LAW Describes the power radiated from a blackbody in terms of its temperature. The total energy radiated per unit surface area of a blackbody per unit time (also known as the blackbody’s emissive power) is directly proportional to the fourth power of the blackbody’s absolute temperature (in Kelvin) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation STEFAN-BOLTZMANN LAW 𝑬 = 𝝈𝑻𝟒 Where 𝐸 is the emissive power or radiated energy per unit area (watts per square meter, 𝑊/𝑚2 ) 𝑇 is the absolute temperature of the blackbody (in Kelvin, 𝐾) 𝜎 is the Stefan-Boltzmann constant ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation STEFAN-BOLTZMANN CONSTANT (𝝈): The Stefan-Boltzmann constant 𝜎 is a physical constant with a value of approximately: 𝝈 ≈ 𝟓. 𝟔𝟕𝟎𝒙𝟏𝟎−𝟖 𝑾/𝒎𝟐 𝑲𝟒 ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation WEIN’S DISPLACEMENT LAW Describes the relationships between the temperature of a blackbody and the wavelength at which it emits radiation most strongly. The wavelengths at which the emission of a blackbody spectrum peaks is inversely proportional to the absolute temperature of the blackbody ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation WEIN’S DISPLACEMENT LAW 𝒃 𝝀𝒎𝒂𝒙 = 𝑻 Where 𝜆𝑚𝑎𝑥 is the peak wavelength (the wavelength at which the emission is strongest) in meters 𝑇 is the absolute temperature of the blackbody in Kelvin (𝐾) 𝑏 is Wein’s displacement constant ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation WEIN’S DISPLACEMENT CONSTANT (𝒃) The constant 𝑏 has a value of approximately: 𝒃 ≈ 𝟐. 𝟖𝟗𝟖 𝒙 𝟏𝟎−𝟑 𝒎. 𝑲 ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation PLANCK’S LAW Describes the spectral distribution of electromagnetic radiation emitted by a blackbody in thermal equilibrium at a given temperature It provides the formula of radiation emitted at each wavelength (or frequency) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation PLANCK’S LAW (In terms of Wavelength) 𝟐𝒉𝒄𝟐 𝟏 𝑰 𝝀, 𝑻 = 𝟓 𝒙 𝒉𝒄 𝝀 𝒆𝝀𝒌𝑩𝑻 −𝟏 Where 𝑰 𝝀, 𝑻 is the spectral radiance, or the amount of energy emitted per unit area per unit time per unit wavelength, at a given wavelength 𝝀 and temperature 𝑻 𝒉 is Planck’s constant (6.626 𝑥 10−34 𝐽𝑠) 𝑚 𝒄 is the speed of light in a vacuum 3 𝑥 108 𝑠 𝐽 𝒌𝑩 is the Boltzmann constant 1.381 𝑥 10−23 𝐾 𝑻 is the absolute temperature of the blackbody in 𝐾 𝝀 is the wavelength of the radiation 1ST ENGR. AZEREEL SUOR SEMSTER AY 2024-2025 Solar Radiation PLANCK’S LAW (In terms of Frequency) 𝟐𝒉𝒗𝟑 𝟏 𝑰 𝒗, 𝑻 = 𝟐 𝒙 𝒉𝒗 𝒄 𝒆𝒌𝑩𝑻 −𝟏 Where 𝑰 𝒗, 𝑻 is the spectral radiance at a given frequency 𝑣 and temperature 𝑇 𝒗 is the frequency of the radiation ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation PLANCK’S LAW ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation PLANCK’S LAW For a body in thermal equilibrium, the emissivity (𝜖) of the body is equal to its absorptivity (𝛼) at every wavelength 𝝐 𝝀, 𝑻 = 𝜶(𝝀, 𝑻) Where 𝝐 𝝀, 𝑻 is the emissivity of the material at a specific wavelength 𝜆 and temperature 𝑇 𝜶(𝝀, 𝑻) is the absorptivity of the material at the same wavelength 𝜆 and temperature 𝑇 ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation FACTORS AFFECTING SOLAR ENERGY RECEIPTS Latitude Local Weather Patterns Seasonal Variations Day Length Time of Day Solar Activity Solar Constant Altitude Angle of Incidence Atmospheric Conditions Topography Surface Albedo Distance from the Sun ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation SOLAR CONSTANT - is a measure of the amount of solar radiation received per unit area at the outer edge of Earth's atmosphere, on a surface normal to the Sun's rays. - It represents the intensity of sunlight arriving at earth ≈ 𝟏, 𝟑𝟔𝟏 𝑾/𝒎𝟐 ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation ANGLE OF INCIDENCE - The angle formed between a ray of incoming light (or other type of radiation) and the normal (a perpendicular line) to a surface at the point of incidence. - It affects the amount of solar radiation that a surface receives - 0 degrees ( e.i., light is coming directly perpendicular to the surface), the maximum amount of solar energy is absorbed - As the angle increases, the effective area exposed to the sunlight decreases, resulting in less energy being absorbed ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation ANGLE OF INCIDENCE ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation ATMOSPHERIC TURBIDITY - Refers to the degree to which particles and pollutants in the atmosphere affect the clarity of the air and the transmission of sunlight. - Measure of how much light is scattered or absorbed by aerosols (tiny particles or droplets) in the air, including dust, smoke, water vapor, and other contaminants ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Solar Radiation ATMOSPHERIC TURBIDITY ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Temperature - Is a measure of how hot or cold an object or environment is. - Celsius (OC), Fahrenheit (OF), or Kelvin (OK) - Is a measure of a body’s ability to transfer heat energy. ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Temperature TEMPERATURE VS ALTITUDE ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Temperature TEMPERATURE VS SOIL DEPTH ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Temperature GROUND TEMPERATURE ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025  is a measure of a body’s ability Temperature to transfer heat energy. SENSIBLE HEAT - Is the amount of heat energy that causes a change in temperature of a substance without changing its phase - it is transferred through conduction, convection, or radiation 𝑸 = 𝒎𝒄𝒑 𝜟𝑻 Where 𝑄 sensible heat (J) 𝑚 mass of the substance (kg) 𝑐𝑝 specific heat capacity of the substance (J/kg-OC) 𝛥𝑇 change in temperature (OC or OK) 1ST ENGR. AZEREEL SUOR SEMSTER AY 2024-2025  is a measure of a body’s ability Temperature to transfer heat energy. LATENT HEAT - Amount of heat energy absorbed or release by a substance during a phase change (transition from one state of matter to another) without a change in temperature. - Latent heat of fusion - Latent heat of vaporization - Latent heat of sublimation 𝑸 = 𝒎𝒉𝒇𝒈 Where 𝑄 latent heat (J) 𝑚 mass of the substance (kg) ℎ𝑓𝑔 latent heat of the phase change (J/kg) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025  is a measure of a body’s ability Temperature to transfer heat energy. LATENT HEAT Latent heat of fusion – energy required to change a substance from solid to liquid (melting point), released (freezing point) Latent heat of vaporization – hear energy required to change a substance from liquid to gas (boiling point), released – gas to liquid (condensation point) Latent heat of sublimation – solid to gas without passing through the liquid phase, released (gas to solid) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025  Is a measure of the amount of water Humidity vapor present in the air Absolute Humidity - Actual amount of water vapor in the air (g/m3) - Can vary depending on temperature and pressure - Higher temperature, the air can hold more water vapor - Higher pressure, the air is denser and can also have more water vapor Specific Humidity - Is the mass of water vapor per unit mass of air (including the water vapor), (g/kg) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025  Is a measure of the amount of water Humidity vapor present in the air Relative Humidity - Ratio of the partial pressure of water vapour in the mixture to the equilibrium water vapour pressure over a flat surface of pure water at a given temperature - Expressed as percentage Mixing Ratio - Amount of water vapor present in the air relative to the mass of dry air. - Mass of water vapor per unit mass of dry air (g/kg) ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 Atmospheric Pressure Also known as air pressure, is the force exerted by the weight of air molecules above a given point. Force exerted at any given point on the Earth’s surface by the weight of the air above that point - It decreases with increasing altitude (less air above the surface) - Commonly measured by barometer Standard atmospheric pressure = 𝟏𝟎𝟏, 𝟑𝟐𝟓 𝑷𝒂 1ST ENGR. AZEREEL SUOR SEMSTER AY 2024-2025 Atmospheric Contaminants Substances present in the atmosphere that can have harmful effects on health, the environment, or both. Can be natural or man-made Types of Atmospheric Contaminants Sources of Atmospheric Contaminants - Particulate Matter (PM) - Natural Sources - Dust, soot smoke, liquid droplets - Volcanic eruption, wildfires, dust - Gaseous Contaminants storms - CO, NO2, SO2, O3, VOCs - Anthropogenic (Man-Made) Sources - Heavy metals - Transportation, industries, - Lead, mercury, cadium agricultural activities - Greenhouse Gases (GHGs) - CO2, CH4, N2O ENGR. AZEREEL SUOR 1ST SEMSTER AY 2024-2025 The End. ENGR. AZEREEL SUOR 1STSEMSTER AY 2024-2025