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Atmospheric Lapse Rates and Air Stability An Environmental Engineering Guide Fundamental Concepts The Lapse Rate Decrease in temperature above Ground Level (G.L.) relative to rise in altitude. As height (H) increases, temperature (T) decreases. The Pressure-Temperature Relationship At higher attitudes, pressure decreases, causing air volumes to increase (expansion of plumes) and resulting ina loss of internal heat. Environmental Lapse Rate (ELR): Also known as the Prevailing or imbient Lapse Rate, representing the actual temperature change occurring in the surrounding environment at a specific site, Standards and Calculations U (Gaanse in Temperature ) Calculating the _ _! Lapse Rate H_ \divided by Change in Height), Troposphere 11 km: -57.1°C. (Upper limit of Troposphere example) Dry Weather Adiabatic Lapse Rate (ALR) Standard cooling rate of a rising air parcel is 9.8°C per = 1 kiiometer of attitude. Wi a 3 = Wet Weather Adiabatic = Lapse Rate (ALR) In wet weather conditions, cooling rate is slower, approximately 6.56°C per 1 kilometer of altitude. Sea Level (MSL): 18°C (Baseline) 1.5 km: 5.16°C (Based on aie km wet rate) TEMPERATURE (T) Temperature Inversion The Inversion Phenomenon Inversions create a cap that prevents air from rising, trapping pe near the surface and creating hazardous air quality conditions. i The “Bad Condition” for Air Quality aa lfttemperature increases from 30°C to 89°C over 1000m, the lapse rate is “5°C/lan, Atmospheric Stability Conditions Unstable Environment (Super-Adiabatic) Occurs when ELR > ALR (e.g., 15°C/km > 9.8°C/km); a , this leads to rapid air f mixing and is termed a super-adiabatic lapse rate. Neutral Condition ‘Occurs when the Environmental Lapse Rate is exactly equal to the Adiabatic Lapse Rate (ELR=ALR). Stable Environment (Sub-Adiabatic) Occurs when ELR< ALR (e.g. 5.5°C/km < 9.8°C/km), this condition limits air mixing and is termed a ‘sub-adiabatic lapse rate. Fundamentals of Gantry Girders and Steel Design: A Technical Overview GANTRY GIRDER (G.G) FUNDAMENTALS is @ Laterally Unsupported Steel Beam designed for dynamic industrial movements. Industrial Application Only: Used in workshops for transporting goods; NOT for residential buildings. Wind Load Immunity: | Composite Construction: : ! yyoeel iis oe ee to | Standard section witha | | Top(Ghannel | Minor Axis (VY) | increased Moment of inertia | wind loads in design H i i - : calculations. 2 H ei anioat ‘ane ioe (Top Channel | Major Axis (ZZ) | Increased Moment of inertia 25% Impact Load Factor Z| Gravity Loads Longitudinal Loads Lateral (Surge/Horizontal) ae Forces Load Bearing Stiffness: Specific design note for Plate Girders focusing on web contribution when load W is applied. Web Contribution Calculation: The effective web contribution towards stiffness is calculated as “20 ty" on either side of the stiffness. CHIMNEY HEIGHT CALCULATION CRITERIA MINIMUM HEIGHT STANDARDS a i i D General Factor The “Adopt Whichever is Greater” Rule = Plume {without Thennal Plan) Final chimney height (H) must be the highest value calculated between t S0,, SPM emissions, or the mandatory minimum heights for the facility type. Confeal!Flare 29. MINIMUM is $0, Emission Formula al = 1/3 —— Flue/Emergency Exit ops 220 H=14x [Qso2] Thermal Power METERS [= where Q is the quantity of SO, gas emission in kg/hr aif Generation — (P< 500MW) Ir SPM Emission Formula a H Chimney Structure = 0.27 H=74x [Qspm] 275 LL where Q is the quantity of Suspended Particulate Matter in tonnes/hr _| , METERS Thermal Power we MINIMUM Generation A De Design Neglections 7 . (P > SO0MW) While critical for environmental health, CO,, NO,, and Hydrocarbons Base Foundation (HC) are typically neglected in the specific mathematical design of chimney height. =I} R, CLASSIFICATION OF AIR POLLUTANTS SEPARATION OF PART! GAS SEPARATION METHODS PRIMARY SECONDARY Absorption Methods AIR POLLUTANTS AIR POLLUTANTS @ @ La) Cae ate such as @ @ water spraye, wet cyclonic itect emissions including separation, or wet venturi systems Largest Particles (d> 50) Removed using Graxtrational Settling Chambers Large Particles id< 50p) Removed via Centrifngation or Bry Cyclonic Separation ee Medium Particles ‘Small Particles (d= 1p) (d= 1p to 2p) Processed through Captured using Wet Scrubbers, _E.S.P. (Electrostatic water sprays, or Wet Precipitation) Venturi separators ‘Smallest Particles (d< 1p) Filtered using Fabric Separators Adsorption Methods Passing gases through soiid media like activated carbon, activated alumins, or alum = ee 5 Essentials of Fluid Mechanics: Turbines and Pumps A comprehensive technical overview of specific speed (N,) for turbines, pump performance metrics, and discharge calculations. Defining Specific Speed INloyle TES cea The speed of a geometrically similar turbine that Ns Seta = ea i or HP) 1 kW (or 1 HP) under a water head of 1 meter. H/4 H= Head (meters) (M°L°T°), defining the machine's shape A Dimensionless Shape Number | through dimensional analysis. Pelton Wheel (Impulsive Turbine) ancis Turbine (Reaction Turb Specific Speed (N,): 8.5 - 30 (50) Specific Speed (N,): 50 - 350 (400) Specific Speed (N,): 300 - 850 (1000) Operating Head (H): > 250m Operating Head (H): 60m - 250m Operating Head (H): < 60m Flow Type: Tangential (Lowest discharge) Flow Type: Mixed (Moderate discharge) Flow Type: Axial (Highest discharge) Pump Performance and Configurations Reciprocating Pump Dynamics , Calculating Pum, A=Areaofpiston/cylinder Percentage Slip = Specific Speed for Pumps: in Series 9 Led { L = Stroke length Difference between theoretical and actual discharge. % Slip = (Se52=) x 100 Qn To find pumps for high lift: Divide total head by manometric of single pump (Hata / Hin). _N-VQ Ne H3/4 be 2 = Where: =» Power and Discharge Theoretical Discharge (Qty) “ Proportionality: elo Q = Discharge (Ips or m°/s) —s a A\Y With Qin of 17 Ips and Qac) of 16 Ips, H = Head (meters) PxQ:-H Q= a + th acl the pump experiences a slip of 5.88%. Slip Calculation Example | Mastering the Moment Distribution Method: iy om = A Step-by-Step Structural Analysis Guide ay 7 Y Step 1& 2: Initial Setup and Step 3: Determining Joint Stiffness Step 4, 5, 6, 7 & 8: The Hardy Cross Iteration Final Calculations Fixed-End Moments (FEM) and Distribution Factors (DF) Table & Summing Vertical Moments and Diagrams i i Final Support Moments : 2 — Hogging) Joint B Equal Span Distribution: DFea = 0.5 eat DFgc = 0.5 eat I M Stiffness (K) is defined by i material and geometry, : P. often K = 3EI/L Balance Joint B Maximum Sagging Moment Moments are assigned signs based on ) x= aL orientation: -wL?/12 for the left end x “ (anticlockwise) and +wL?/12 for the right (Structural Results Summary Summing Vertical Moments (B): end (clockwise) Distribution Factor (OF) atB: 0.5 Ms = 0 (Balanced Structure) Support Moment at B (Mp): w2/8 (Hegging) End Support Reactions (Ry, Re): 3/8 wL Center Support Reaction (Rg); 5/4 wh { Max Sagging Moment (Mz,,): 9/128 wh? =) Foundation Engineering: Methods for Calculating Pile Load Capacity Two geotechnical methods for determining load-carrying capacity in varying soil conditions (soft clay vs. expansive soil), The Static Formula Method (Standard Piles) Target Soil: Very Soft Clay Negative Skin Friction (Downward Drag) Occurs when soil settlement is greater than pile settlement, creating downward force. The Ultimate Load Formula (Q,,) Qu = Qpu + Qst — Qhst Base Resistance + Skin Friction - Negative Skin Friction Component Calculation @ ou=9x Fe? Q au=arcynat2 ©) Qer=a1C,ndl, Sum the first two and subtract the third into. Negative Skin Friction. Practical Calculation Example Ultimate Load (Qy) Clay cohesion _ Diameter Result: 189.4 kN ¢ = 40kPa d=0.3m Length Length L,=3m Lo = 12m Under-Reamed Piles for Expansive Soils Target Soil: Black Cotton Soil (Expansive) 35 1 _ The Under-Ream “Bulb” I Bored piles featuring enlarged bulbs for increased stability ) and capacity. ; I Single Bulb ‘ Two Bulbs: Moen Cnt =» Qu increases by 50% t (1.5 ¥ Qu) Design Specifications Stem Diameter (d): = 200mm (15-20cm) Pile Length (L): ~41 Bulb Diameter (D,): 2.5 x Stem Diameter Vertical Spacing (2 bulbs): 1.5 x Dy Horizontal Spacing: 2 x Dy Multi-Bulb Capacity Formula Total capacity combines Base Resistance + Bulb Resistance (9 C, (0,?- d)) + Shaft Friction Master Geotechnical Engineering: Pile Foundation Solved Problems Step-by-step solutions for pile foundation capacities (tensile, skin friction, pullout, group resistance) from standard engineering exam problems, focused on four key scenarios from Indian institutes. IIT Madras - Ultimate Tensile Capacity Tensile Capacity of Under-Reamed Piles Total capacity = self-weight + skin friction + bearing pressure on bulb projection. 301 KN tubo:7500m Total Capacity ,ghesion The Mathematical Formula Total Capacity = 20KN + (u-C-n-d-L) +(9-¢-2: (0,2-<°)) d= shaft diameter D, = bulb diameter (a): 0.3 Cohesion { 50 kPa | IIT Roorkee — Pullout Force in Submerged Soil Accounting for Water Table Effects Effective unit weight (V,y,) = Bulk unit weight (18 kN/m?) - Unit weight of water (10 kN/m?) 104.9 kN Pullout Force Pile L: 5m in sand Interface friction 6) 24" IISc Bangalore - Skin Friction Analysis Pure Skin Friction in Cohesive Soil For straight pile in clay (®=0), resistance depends entirely on soil cohesion and shaft surface area. 565 KN Pica.on Resistance conesion i The Alpha Method (Q,,): Qy=a-C-n-d-L IIT Delhi - Group Pile Resistance Efficiency of Pile Groups Group efficiency (n) = ste (1.0), group acts as a cohesive blo: 10,053.09 kN Side Resistance 16>pile group (4x4) Soil Cohesion (C): 100 kPa Single Pile | Group (n=16) Earth pressure coeff (K): 1.5 Diameter (a): 0.5m | 4x4 configuration Average Effective Stress Calculation: Single vs. Group Resistance Length (L): 10m | 10m Pullout force = (Average vertical effective stress at mid-depth) - K - tan(5) Single Pile Base Resistance: 176.71KN Cohesion (C): 100 kPa | 100 kPa Group Resistance: determined by the perimeter of the entire block (4: Width-L) Base Resistance: 176.71 KN | Block Action Focused ology Essentials: Measuring and Mode Eeeervait = C, x (Fo U.S. Class “A’ Pan Is} Pan Comparative Pan Performance: U.S. Class “A” pan has ~14% higher evaporation rate than the ISI Pan, influencing CG, Standard Pan Types and Coefficients The Pan-to-Reservoir Relationship: Exaporation from a pan is always higher; Pan Coefficient (C,) adjusts for reservoir loss estimate. Ear hay Meter Sie ban Coefficient) = US. Class °A" Pan Galy. lron; Dia: 1.21m; Depth: 25.5em 07 Chemical Bvaporaiion Retardants: S IS..Pan (Modified) Copper; Dia: 1.22m; Depth: 25.5cm 0.8 (Range: 0.65 - 1.1) Cetyl Alcohol Hecederane) and Stearyl Alcohol _ ‘S@ Colorado Sunken Pan 920mm x 920mm x 460mm. 0.78 ese applied at 3.5 N/hect/day to minimize SS US. Floating Pan 800mm x 900mm x 460mm 08 FACTORS AND FORMULAS ctors Affecting Evaporation Dalton’s Law of Evaporation: . Mechanism/Remark E = (i [e, -@ ] Evaporation is proportional to the difference i Temperature Increases Higher temp reduces cohesion between water moleceles. a between saturated (e,) and actual (e,) STE Saar t t vapour pressure.” =) Wind Speed Increases _Valid only up to a certain limit of wind speed. Saturated Actual si Se ath Ja Altitude Increases _Rarometric pressure decreases at higher altitudes. vapour vapour EA (ate Salget Enevay budger ance 25 Specific Gravity, Increases Salty water evaporates 2.9% slower than fresh water. eke Like Aleahe Mass Transter Equations. \ a Water Depth Decreases Shallow water bodies evaporate faster than deep ones. =z INFILTRATION AND HORTON'S MODEL = é > Horton's Decay Equation: MY @00 eS fy Infiltration Eapacity (f) decays Hl} My ‘ ad Au exponentially over time (t) to a 2 f,=f,+ (fy - f.je"ht constant rate. e 2 Variables in Horton's Equation: = Fo fy: Initial rate ji i i 21, |e #,: Constant final rate Infiltration: Infiltration Capacity (f,): wee = wee ahh ec So fe: MOvETERIGC Walerial M axa a ity Ua) ift>f,thenf=f, if f
