diffusion, osmosis,membrane potential.pptx

biophysics

1. PRESSURE AT THE BOTTOM OF THE CYLINDER USING THERMODYNAMICS PRINCIPLES PRESENTED BY GROUP 2

2. OBJECTIVES Introduction of Pressure Formula and units of Pressure Pressure at the bottom of Cylinder Hydrostatic pressure in fluids Ideal gas law Factors affecting pressure Experiment using thermodynamics principles Pressure in biological processes Uses / advantages of pressure conclusion

3. PRESSURE continuous physical force exerted on or against an object by something in contact with it. Pressure is defined to be the amount of force exerted per area. P = F /A So to create a large amount of pressure, you can either exert a large force or exert a force over a small area (or do both).

4. FORMULA AND UNITS • Pressure Formula:The formula for pressure is: • P=F/A • P is pressure • F is force applied • A is the area covered • Pressure unit: • SI unit is Pascal • “Pascal” Where 1pascal = 1 Newton of force acting on an area of 1 m2 • 1 Pascal = 1Newton/1 meters square • Other units of pressure: • Bars • Pounds per square inch (psi) • Atmosphere (ATM)

5. Pressure at the bottom of a cylinder A diver is 45m below the free surface of the same. Find the pressure exerted on the diver. The biometric pressure is 101kpa and the specific gravity of water is 1.03 Patm =101kpa g=9.81m/s^2 H=45m P= park+pgh Calculation of density: SG=p/pH2O 1.03×1000=1030 kg/m^3 P=101000+(1030kg/m^3) (9.8m/s^2) (45m) Pressure=55693.5pa

6. PRESSURE AT THE BOTTOM OF A CYLINDER (1) Internal Combustion Engine (ICE) Combustion: In a four-stroke ICE, the piston reaches the bottom dead center during the compression stroke. The air-fuel mixture is trapped in the cylinder and compressed by the rising piston. This compression significantly increases the pressure and temperature of the mixture, creating ideal conditions for combustion when the spark plug ignites it.

7. (2) Hydraulic Cylinder Fluid Pressure: In a hydraulic cylinder, the pressure of the hydraulic fluid acts on the piston. At the bottom dead center, the entire area of the piston base experiences this pressure, generating a pushing force. The force can be calculated using the formula: Force = Pressure x Area, where the area is the base area of the piston

8. (3) Thermodynamics Analysis: State Variables: The pressure at the bottom dead center is a crucial state variable in thermodynamic analysis of these engines and cylinders. Understanding the pressure variation throughout the cycle allows engineers to calculate efficiency, work output, and heat transfer

9. HYDROSTATIC PRESSURE IN FLUIDS Hydrostatic pressure is the pressure exertef by a fluid at rest due to gravity Cause Gravity pulls down on every particle of the fluid.As depth increases, there are more fluid particles above exerting their weight, leading to a pressure increase with depth. Properties Acts in all directions equally. Imagine a submerged object; the pressure is pushing on it from all sides and the bottom. independent of the shape of the container as long as the fluid is at rest (hydrostatic equilibrium).

10. Formula: The pressure is calculated using the following formula :P = ρ gh P=Hydrostatic pressure (Pascals, Pa) ρ = Density of the fluid (kg/m³) g = Acceleration due to gravity (m/s²) h = Depth from the fluid surface (m)

11. IMPORTANCE OF HYDROSTATIC PRESSURE • Hydrostatic pressure is independent of the amount of fluid present, only depending on depth and density. • Hydrostatic pressure plays a crucial role in many areas of science and engineering, including hydraulics, oceanography, and fluid mechanics

12. IDEAL GAS LAW • The ideal gas law is a fundamental equation in thermodynamics that relates the pressure, volume, temperature, and amount of an ideal gas. It's a simplified model but provides a good approximation for the behavior of many real gases under certain conditions. Equation: PV=nRT • P=pressure • V=volume • N=numbers of moles • R=universal gas constant (R=8.314 joules /mol K • T=temperature (Kelvin)

13. LIMITATIONS OF IDEAL GAS LAW • The ideal gas law is a simplified model and assumes: • Gas particles are infinitely small and have no volume themselves. • There are no attractive or repulsive forces between the gas particles. • The gas particles are in constant, random motion, colliding perfectly elastically with each other and the container walls. • Real gases deviate from ideal behavior at high pressures and low temperatures, where these assumptions become less valid

14. APPLICATIONS Despite its limitations, the ideal gas law is a valuable tool in various applications, including: • Understanding the behavior of gases in engines, balloons, and other everyday objects. • Calculating gas properties like density or compressibility. • Studying thermodynamic processes involving gases.

15. FACTORS AFFECTING PRESSURE • Fluid pressure is the pressure exerted by a fluid (liquid or gas) at rest on an immersed object. It is dependent on three main factors: • Depth: The pressure in a fluid increases with depth. This is because as you go deeper in a fluid, there is more and more fluid above you pushing down. The pressure can be calculated using the following equation: P = pgh

16. Density: The pressure in a fluid is also dependent on the density of the fluid. Denser fluids exert greater pressure than less dense fluids at the same depth. Gravity: The pressure in a fluid is also affected by gravity. Stronger gravity will result in greater pressure at a given depth

17. GAS PRESSURE Gas Pressure Gas pressure is the pressure exerted by a gas on the walls of its container. It is dependent on two main factors: 1. Temperature: The pressure of a gas increases with increasing temperature. This is because as the temperature increases, the gas molecules move faster and collide with the walls of the container more frequently and with more force. 2. Volume: The pressure of a gas is inversely proportional to its volume. This means that if you decrease the volume of a gas container, the pressure of the gas will increase, and vice versa. This is explained by Boyle's Law

18. Pressure exerted by gas molecules

19. PRESSURE IN BIOLOGICAL PROCESSES Medical professionals use pressure in a variety of ways for diagnosis, treatment, and monitoring patients. Here are some key applications: Blood Pressure Monitoring: This is perhaps the most common use. Measuring blood pressure is crucial for assessing cardiovascular health and diagnosing conditions like hypertension (high blood pressure).Doctors use inflatable cuffs and pressure sensors to measure the force of blood pushing against artery walls Pressure Sensors: These tiny devices are integrated into various medical equipment. For example, they monitor pressure within ventilators for proper airflow delivery to patients or measure pressure changes in infusion pumps to ensure accurate medication delivery

20. Hyperbaric Therapy: This treatment involves placing a patient in a pressurized chamber. The increased pressure helps deliver more oxygen to tissues and can be beneficial for treating conditions like decompression sickness (the bends), gangrene, and even some infections. Wounds Management: Specialized dressings can apply controlled pressure to wounds, which can promote healing and reduce swelling. This is particularly helpful for wounds that struggle to close on their own. Pneumatic Compression Devices: These inflatable garments worn on limbs use rhythmic pressure to improve circulation and reduce swelling, often used for post-surgical recovery or treatment of chronic venous insufficiency. dialysis: This treatment for kidney failure uses controlled pressure to remove waste products and excess fluid from the blood.

21. USES/ADVANTAGES OF PRESSURE Daily Life: • Inflating objects: We use pressure to inflate tires on bikes, cars, and other vehicles. The compressed air pushes outwards, giving the tire its round shape and supporting the weight of the vehicle. • Using a straw: When you drink with a straw, you decrease the pressure inside the straw by creating suction with your mouth. This pressure difference allows the liquid to flow up the straw. • Hydraulics: Hydraulic systems use pressurized fluids to transfer power. These systems are found in construction equipment, brakes in cars, and many other machines

22. Industry: • Food processing: High-pressure processing (HPP) uses pressure to inactivate bacteria, mold, and yeast in food products, extending shelf life and improving food safety. • Metal forming: In manufacturing, pressure is used to shape metals into desired forms through processes like forging and stamping. • Machining: Cutting tools and machines use pressure to remove material from work pieces during processes like drilling and milling

23. Energy: • Airplanes: The wings of airplanes are designed to create lift using pressure differentials between the top and bottom surfaces. As air flows over the wing, the pressure on the top is lower than the pressure on the bottom, creating lift that keeps the airplane airborne. • Steam turbines: In power plants, high- pressure steam spins turbines to generate electricity

24. Medicine: • Blood pressure: As mentioned earlier, blood pressure is a crucial vital sign used to diagnose and monitor various health conditions. • Hyperbaric chambers: These chambers use pressure to increase the amount of oxygen delivered to the body, used to treat conditions like decompression sickness and certain wounds.

25. Scientific Research: • Diamond formation: The extreme pressure and heat conditions deep within the Earth are necessary for the formation of diamonds. • Studying biological processes: Scientists use pressure to study how various biological systems function at different pressure levels

26. CONCLUSION Pressure is a ubiquitous force that plays a critical role in many aspects of our world, from the microscopic world of cells to the vastness of space. We encounter it in our daily lives, from inflating tires to using a straw, and it underpins numerous industrial processes and technological advancement. • P