Mechanical Properties of Materials

In general, all the materials used by the engineers, may be classified, on the basis of their physical properties, into the following four types:

1) Elastic materials : When a material regains its original position, on the removal of the external force, it is called an elastic material.

2) Plastic materials : When a material doesn't not regain its original position, on the removal of the external force, it is called a plastic materials.

3) Ductile materials : When a material can undergo a considerable deformation without rupture (e.g. when a material can be drawn into wires), it is called a ductile material.

4) Brittle material : When a material cannot undergo any deformation  ( like glass) and it fails by rupture, it is called a brittle material. 

Mach number and its importance

The ratio of velocity of fluid, in an undisturbed stream (Vl), to the velocity of sound wave (Vs) is known as Mach Number. It gives us an important information about the type of flow. In general, the flow of a fluid is divided into the following four types depending upon the Mach number.

a) When the Mach number is less than unity, the flow is called a sub-sonic-flow. 
b) When the Mach number is equal to unity, the flow is called a sonic flow. 
c) When the Mach number is between 1 and 6, the flow is called a supersonic flow. 
d) When the Mach number is more than 6, the flow is called hyper-sonic flow. 

Types of forces present in a Moving Liquid

The important force present in a moving liquid are as follows:

a) Inertia force : It is the product of mass and acceleration of the moving liquid.

b) Viscous force : It is the product of shear stress due to viscosity and the cross sectional area of flow.

c) Gravity force : It is the product of mass and acceleration due to gravity of a flowing liquid.

d) Surface tension force : It is the product of surface tension per unit length and length of the surface of flowing liquid.

e) Pressure force : It is the product of intensity of pressure and the area of a flowing liquid.

f) Elastic force : It is the product of elastic stress and the area of flowing liquid. 

Dimensionless Numbers

a) Reynold's number: It is the ratio of the inertia force to the viscous force.

b) Froude's number: It is the ratio of the inertia force to the gravity force.

c) Weber's number: It is the ratio of the inertia force to the surface tension force.

d) Euler's number: It is the ratio of the inertia force to the pressure force.

e) Mach's number or Cauchy's number: It is the ratio of the inertia force to the elastic force.

Notches and Weirs

A notch may be defined as an opening provided in the side of a tank or vessel such that the liquid surface in the tank is below the top edge of the opening. It is generally made of a metallic plate. It is used for measuring the rate of flow of a liquid through a small channel or a tank.


A weir may be defined as any regular obstruction in an open channel over which the flow takes place. It is made of masonry or concrete. It is used for measuring the rate of flow of water in rivers or streams.

Hydraulic Coefficient

The following are the hydraulic coefficient:

1. Coefficient of contraction (Cc)
It is defined as the ratio of area of jet at vena contracta (Ac) to the area of the orifice (A) .

2) Coefficient of Velocity (Cv)
It is deifined as the ratio of the actual velocity of the jet at vena contracta (V0 to the theoritical velocity. (Vth)

3) Coefficient of discharge (Cd)
It is defined as the ratio of the actual discharge through the orifice (Q) to the theoretical discharge (Qth). The coefficient of discharge is wqual to the product of the Cc and Cv.

4) Coefficient of resistance (Cr)
It id defined as the ratio of loss of head in the orifice to the head of water available at the exit of the orifice. 

FRESH ENGINEERS JOBS

WHAT DO I DO ?

When I used to be in the final year of my engineering, I used to think what actually we have to do after joining the job. If you are a fresher or engineering student, you may also be thinking the same.
Here, I want to explain you some of the work that a new or fresh engineer should do after joining the job.

1) MY JOB

I work in TSC(Technical Support Center) - Banepa which is a joint project launched by Build Change in coordination with ARSOW Nepal. Its main aim is to provide the technical help to the victim of the earthquake to reconstruct their houses. We provide free municipal map , technical advice, construction strategies, process of getting government allowances etc. There are many offices for this particular project in earthquake affected district. In each office there are two staff and their work are as follows :

1) Architecture

1. Draw the municipal map as per the modal prescribed by NRA and Build change. 
2. Make weekly progress report 
3. Update the drawings in Build Change online portal

2) Civil  (ME)

1. Welcome the affected people in office 
2. Show them the models of house and explain their suitability, technical aspects  etc. 
3. Collect all the documents required for making municipal map 
4. Filing the documents
5. Prepare Location map and Site Plan 
6. Fill the required forms about the municipal drawing
7. Help architecture in drawings

2) SOME OTHER JOBS

Here are some other job that a fresher should do :

1) Surveyor 

• Going in the site for total station survey (It can be of road, irrigation or any specific site survey)
• GPS Survey where you will be given a GPS and you will record the co-ordinates. It is especially used in transmission line survey and site survey. 
• If you have idea of making topographic map then you will be given to prepare the detail topographic map with the data you have surveyed. 

2) Consultancy Intern

• Making BOQ (Bills of Quantity) 
• Helping in Autocad and 3D Drawings (Site Plan, Location Plan and Floor Plan)
• Estimation of the house in a pre-designed excel template
• Helping in the documentation 

3) Site Engineer

• Observing the site work and process of handling materials, equipment etc.
• You will have to record the materials entry and use of it for specific task 
• Recording the workers performance and guarantee their safety at work 
• Preparing weekly/monthly reports and submit to chief (after few months of work in site)

So, what are the things you should be good at for your fast placement ?

1) Good in communication, presentation and writings.

2) You should be good in Total Station Surveying. GPS is plus point. 

3) Autocad is the most important. ( Municipal Drawing. Topographic Map )

4) Should be good in excel for preparing BOQ and Estimation.

5) Finally, the most important is the Network you have established during student period through seminars, workshops and your performance in activities other than academics. 

Buoyancy

When a body is immersed wholly or partially in a liquid , it is lifted up by a force equal to the weight of liquid displaced by the body. This statement is known as Archimedes's Principle.
The tendency of a liquid to upliftment an immersed body, because of the upward thrust of the liquid is known as buoyancy. the force tending to lift up the body is called the force of buoyancy or buoyant forces and it is equal to the weight of the liquid displaced. the point through which the buoyant force is supposed to act, is known as center of buoyancy. It may be noted that

a) If the force of buoyancy is more than the weight of the liquid displaced, then the body will float.

b) If the force of buoyancy is less than the weight of the liquid displaced, then the body will sink down.

Equilibrium of floating Bodies

The equilibrium of floating bodies is of the following three types:

1) Stable Equilibrium: If the body floating in a liquid returns back to its original position, when given a small angular displacement, then the body is said to be in stable equilibrium.


2) Unstable equilibrium: If a body floating in a liquid does not return back to its original position and heels farther away when given a small angular displacement, then the body is said to be in unstable equilibrium.


3) If a body is floating in a liquid occupies a new position and remains at rest in this new position, when given a small angular displacement, then the body is said to be in neutral equilibrium.

This can be more understood through this picture:

Types of Energy or Head

The following are the three types of energies or head of the flowing liquids:

1) Potential energy or potential head
It is due to the position above some suitable datum line. It is denoted by z.

2) Kinetic energy or kinetic head
It is due to the velocity of flowing liquid. Its value if givin by v2/2g, where c is the velocity of flow and g is the acceleration due to gravity.

3) Pressure energy or pressure head
It is due to the pressure of liquid. Its value is given by p/w, where p is the pressure in N/m2 and w is the weight density of the liquid in N/m3 .

BEARINGS: WCB & Quadrantal System

The following two system are commonly used to express the bearings:

1) Whole Circle System 

In the whole circle system, the bearing of a line is always measured clockwise from the north point of the reference meridian towards the line right round the circle. The angle thus measured is called Whole Circle Bearing (W.C.B). It may have any value between 0 degree and 360 degree. The bearing observed with a prismatic compass or a theodolite are the whole bearings. 

2) Quadrantal System 

The bearing of a line is measured clockwise or anticlockwise from the north point or the south point whichever is nearer the line, towards the east or west. In this system, the bearing is reckoned from 0 degree to 90 degree in each quadrant. The bearings observed with a surveyor's compass are the quadrantal bearings. 

REACTION TURBINES

The following important points may be noted for reaction turbines:

a) In a reaction turbine, the water enters the wheel under pressure and flows over the varies.
b) The hydraulic efficiency of a reaction turbine is the ration of the work done on the wheel to the energy (or head of water) actually supplied to the turbine.
c) The overall efficiency of a reaction turbine is the ratio of the power produced by the turbine to the energy supplied by the turbine.
d) A Kaplan turbine is an axial flow reaction turbine. The number of blades are generally 4 to 8 in a Kaplan turbine runner.
e) A Francis turbine is an outward flow reaction turbine. The number of blades are generally 16 to 24 in a Francis turbine runner.

IMPULSE TURBINES

The following points may be noted for the impulse turbines:

a) The hydraulic efficiency of an impulse turbine is the ratio of the work done on the wheel to the energy of the jet.
b) The hydraulic efficiency of an impulse turbine is maximum when the velocity of wheel is one-half the velocity of jet of water at inlet.
c) The maximum hydraulic efficiency of an impulse turbine is given by
Nmax = (1+COS phi )/2 , phi = angle of blade at outlet
d) The mechanical efficiency of an impulse turbine is the ratio of the actual work available at the turbine to the energy imparted to the wheel.
e) The overall efficiency of an impulse turbine is the ratio of the actual power produced to the energy actually by the turbine.
f) The width of the bucket for a Pelton wheel is generally five times the diameter of jet.
g) The depth of the bucket for a  Pelton wheel is generally 1.2 times the diameter of jet.
h) The number of buckets on the periphery of a Pelton wheel is given by (D/2d + 15) , where D is the pitch of the wheel and d is the diameter of jet.
i) The ratio of D/d is called the jet ratio.
j) The maximum number of jets , generally , employed on Pelton wheel are six.

HYDRAULIC TURBINE

A hydraulic turbine is a machine which converts the hydraulic energy into mechanical energy. The hydraulic turbines area also known as water turbines. Following two types of hydraulic turbines are important.

1) Impuse Turbine (Click Here)

In impulse turbine, the total energy ar the inlet of a turbine is only kinetic energy. The pressure of water both at entering and leaving the vanes is atmospheric. It is used for high head of water. A Pelton wheel is a tangential flow impulse turbine.

2) Reaction Turbine (Click Here)

In reaction turbine, the total energy at the inlet of a turbine is kinetic energy as well as pressure energy. It is used for low head of water. The Francis and Kaplan turbines are inward flow and axial flow reaction turbines respectively.

RECONSTRUCTION HOUSE MODELS

Hello everyone,

I am a civil engineer graduated from Khwopa College of Engineering (TU).
Here are the list of documents which an engineer/engineering student (final year) must go through if he/she wants to work in reconstruction project either in government job or through NGO/INGOs.

SMM 1.1

House Models and related documents can be downloaded from here:

1) House Models Volume I
2) House Models Volume II
3) Engineers Trainig I
4) Engineers Training II
5) Mason training

Thank you !!

Ganesh Pandey
ganeshgpks@gmail.com 

Requirements of Good Brick Earth

A good brick earth should fulfill the following requirements:

1. It must have proper proportions of sand, silt and clay.
2) It must be homogeneous
3) It should have sufficient plasticity (so that the bricks can be properly and conveniently moulded with sharp and well defined edges)
4) It must be free from lumps of lime or nodules of kankar.
5) It must be free from earth containing alkaline salts, kankar or reh etc.
6) It must be free from pebbles, grits and lumps of earth.
7) It must not contain vegetable and organic matter.
8) It should not be mixed with salty water.
9) It should be well brunt.

Preparation of Boring Logs

The detailed information gathered from each borehole is presented in a graphical form called the boring log. As a borehole is advanced downward, the driller generally should record the following information in a standard log:

1) Name and address of the drilling company
2) Driller's name
3) Job description and number
4) Number, type and location of boring
5) Date of boring
6) Subsurface stratification, which can be obtained by visual observation of the soil brought out by auger, split-spoon sampler, and thin-walled Shelby tube sampler.
7) Elevation of water table and date observed, use of casing and mud losses and so on.
8) Standard penetration resistance and the depth of SPT
9) Number, type and depth of soil sample collected
10) In case of rock coring, type of core barrel used and for each run. the actual length of coring, length of core recovery and RQD.

FACTORS FOR DECIDING CONTOUR INTERVAL

Contour interval on a map is decided on the following considerations:

1) Scale of the map
The contour interval is kept inversely proportional to the scale of the map. Smaller the scale of the map, larger the contour interval. On the other hand, if the scale of the map is large, the contour interval should be small. If, on a small scale map, a small contour interval is adopted the horizontal distance between two consecutive contours i.e. horizontal equivalent, is also small and when plotted on the scale of the map, the two contours might unite together. It necessitates to increase the contour interval on small scale maps.

2) Purpose of the map
The contour interval on a map also depends upon the purpose for which the map is to be utilized. If the map is prepared for setting out a high-way on hills slopes, a large contour interval might suffice. But, if the map is required for the construction of an university campus, a small contour interval will be required for accurate work.

3) Nature of the ground
The contour interval depends upon the general topography of the terrain. In flat ground, contours at small intervals are surveyed to depict the general slope of the ground whereas high hills can only be depicted with contours at larger contour interval. In other words, we may say that the contour interval is inversely proportional to the flatness of the ground i.e. steeper the terrain, larger the contour interval.

4) Availability of time and funds
If the time available is less, greater contour interval is adopted to complete the project in the specified time. On the other hand, if sufficient time is at the disposal, a smaller contour interval might be decided, keeping in view all the other factors already described.

PRINCIPLE OF E.D.M

EDM instruments for surveying may be divided into two classes:

i) Those in which a beam of light is the carrier and which is reflected back from a mirror located at the other end. Such instruments are less expansive because one active instrument and a battery are only needed at one end and instrument at the other end is simply a reflecting mirror centered over the ground station mark. Such instruments are used for shorter distances only. When the distance between the stations is comparative large, a telescope is used for aiming the beam at the mirror and laser is used as carrier, because this has a very small angle of spread.

ii) Those which transmit short radio waves (micro-waves) as carrier. In these type of instruments, an active instrument and operator are acceded at each end of the line. The signal is re-transmitted on another carrier wave back to the originating instrument. The wavelengths of the carrier of such instrument varies from 8 to 10 mm. These instruments do not require precise directional setting because the spread angle of carrier waves is between 5 degree to 10 degree. Instruments using microwaves are generally used for the long distances required in primary triangulation and precise traversing. 

KATHMANDU OUTER RING ROAD

Outer Ring Road is one of the most awaited project in Kathmandu Valley. 
(The following figure is prepared by me on the basis of the proposed plan by Ministry of Urban Development )

You can read here all the aspects and importance of this project. This document is prepared by the GOVERNMENT OF NEPAL, MINISTRY OF URBAN DEVELOPMENT and presented by Ar. Rama Maiya Manandhar , Senior Divisional Engineer ,Ministry of Urban Development.

It includes:

• CONCEPT OF OUTER RING ROAD
• Strategies for urban transport development
• Why Outer Ring Road?
• Proposed Alignment of Outer Ring road
• Typical CrossTypical Cross--Section of Outer Ring Road
• Problems for Implementation of ORR
• REASONS  FOR ALTERNATE PLANNING APPROACH  
• Key Issues and recommendation

CLICK HERE TO DOWNLOAD 

ENDANGERED BIRDS IN NEPAL

Here are the endangered birds of Nepal. It also includes the national bird of Nepal i.e. Danphe. 

BIRDS

Great Horabill

Danphe

Bengal Florican

Black Stork

White Stork

Crimson-horned Pheasant

Cheer Pheasant

Lesser Florican

Saurus Crane

ENDANGERED SPECIES IN NEPAL

These are some endangered species of Nepal. You may be shocked to hear that we have only 50 Dolphins, 198 Tigers, 198 Gharial, 645 One horned Rhino and 1000 Red Panda. Even our national bird " DANPHE " is listed in endangered list. We are lucky to see them in real, our generation might end up seeing them in pictures and books. 

I request students of Forestry, Agriculture or anyone who is interested in these things, make your presence, jump into it and contribute for at least 1 species. Convert that 50 to 500 and 1,000 to 10,000. 

Hats-off to those who are already working in this fields.

Thanks !! 

Here are the list of Species with figures: !! MAMMALS, BIRDS AND REPTILES !! 

MAMMALS 

BENGAL TIGER

Red Panda

SNOW LEOPARD

ONE HORNED RINHO

Himalayan Musk Deer

DOLPHIN

VENTURIMETER

It is an instrument used to measure the discharge of liquid flowing in a pipe. It consists of three parts i.e. the converging cone, the throat and the diverging cone. The length of the divergent cone is made about three to four times longer than that of the divergent cone in order to avoid tendency of breaking away the stream of liquid and to minimize frictional losses. It may be noted that

a) The velocity if liquid at the throat is higher than that of inlet.
b) The pressure of liquid at the throat is lower than that of inlet.
c) The velocity and pressure of liquid flowing through the divergent portion decreases.

The discharge through a Venturimeter is given by:

TOP 5 APPS FOR CIVIL ENGINEER

Here are the top 5 mobile application for Civil Engineer:

1) AutoCAD Dwg viewer and Editor

Functions:
a) Open Dwg File and edit it
b) Create the plan in mobile
c) Draw shapes on the mobile

2) Unit Converter

Function
1) Convert all the units of measurement like area, volume, force, temp, currency and much more.

3) Civil Engineering Dictionary 

Function:
1) To see the definition of civil engineering terms
2) To search the definition as well


4) Quantity Estimator 

Function
1) To estimate the quantity of the wall, beam, column, cost etc.
2) It has more options in the paid version which are very useful,

5) Concrete Mix Design 

Function:
1) To find the quantity needed for the design of the required grade of concrete.

To find other important apps, please watch this video till the end :

DEMO OF ALL APPS

TRAFFIC SIGNALS

The most common device for regulating, warning and guide drivers is called traffic signs.

It has following types:

1) Regulatory and Mandatory Signs

These signs impose the legal restrictions applicable at particular locations being usually unenforceable in the absence of such signs. The violation of these signs is a legal offence. The signs include Stop and Give-way signs; Prohibitory signs; No parking and No Stopping Signs; Speed Limit and Vehicle Control Signs, Restriction Ends Sign, Compulsory direction control and other signs. 

2) Warning or Cautionary Signs

These signs are used to warn the road users of certain hazardous conditions that exit on or adjacent to the roadway. The warning signs include bends, dips, road, junctions, schools, level crossings, narrow bridges, U-Turns and cross roads etc. The signs such as "Road Under Repair" and "Speed Breaker Ahead" are also warning signs. These signs are painted on rectangular plates 40 cm, 45 cm. An equilateral plate of 45 cm sides is provided 15 cm above each of these signs. The bottom of the triangle is kept 2.75 m above the ground level. 

3) Inflammatory or Guide Signs

these signs are used to guide the roads user along routes inform them of destination and distance and provide with information such as "End of Speed Limit", "Parking Zone" etc. 

TRAFFIC CAPACITY

The traffic capacity or highway capacity may be defined as the total number of vehicles that can pass a given point on the highway in a unit period of time.

The highway or traffic density is defined as the total number of vehicles that can be accommodated on a unit length of the road.

In a mixed traffic flow, the traffic capacity is generally expressed as Passenger Car Unit (PCU) per hour and the traffic density as PCU per kilometre length of lane.

The highway capacity, depending upon a number of prevailing roadway and traffic conditions, are as follows:

a) Basic Capacity: The basic capacity is the maximum number of passenger cars that can pass a given point on a lane or a roadway during one hour under the most ideal roadway and traffic conditions that can possibly be attained.

b) Possible Capacity: The possible capacity is the maximum number of vehicles that can pass a given point on a lane or a roadway during one hour under the prevailing roadway and traffic conditions. The possible capacity of a road is generally much lower than the prevailing conditions referred to under the possible capacity are ideal if
i) There are at least two lanes for the exclusive use to traffic moving in one direction.
ii) All the vehicles move at the same uniform speed.
iii) The width of lanes, shoulders and clearness to vertical obstruction beyond the edge of the traffic lane are adequate.
iv) There are no restrictive sight distance, grades, improperly super-elevated curves, intersections or interference by pedestrians.

c) Practical Capacity: The practical capacity is the maximum number of vehicles that can pass a given point on a lane or a roadway during one hour with creating unreasonable delay under the prevailing roadway and traffic conditions. The values of the practical capacity is less than the possible capacity.

d) Design Capacity: It is the practical capacity or a smaller value determined for use in designing the highway to accommodate the design hourly volume (D.H.V). It is a term, normally, applied to existing highways.

e) Theoretical Capacity : The theoretical capacity is the number of vehicles passing any point in one hour per lane. It depends upon the average length of the vehicle and the average spacing of the moving vehicles. Mathematically, theoretical capacity,

C= 1000V/S

V = Design Speed of the vehicle in kmph
S = Center to center spacing of moving vehicle
   = Reaction distance + Average Length of Vehicle 

Features of Contours

The features of the contours are as follows:

1) Two contours of different elevations do not cross each other except in the case of overhanging cliff.

2) Contour drawn closer depict a steep slope and, if drawn far apart represents a gentle slope. 

3) Contours of different elevations do not unite to form one contour except in the case of vertical cliff.

4) Contours equally spaced depict a uniform slope, when contours are parallel equidistant and straight, these represents an inclined plane surface.

5) Contour at any point is perpendicular to the line of the steepest slope at the point.

6) A contour line must close itself but need not be necessarily within the limits of the map itself.

7) A set of ring contours with higher values inside, depict a hill whereas a set of ring contours with lower values inside depict a pond or a depression without an outlet. 

8) When contours cross a ridge or V-shaped valley, they form sharp V-shapes across them. Contours represent a ridge line, if the concavity of higher value contour lies towards the next lower value contour and on the other hand these represent a valley if the concavity of the lower value contour, lies towards the higher value contour.

9) The same contour must appear on both the sides of a ridge or a valley.

10) Contours do not have sharp turnings. 

Difference between Height of Collimation method to Rise and Fall method

The difference between Height of Collimation Method (HCM)  and Rise and Fall Method (RFM) are as follows:

HCM :It is more rapid and saves a considerable time and labour.
RFM : It is laborious as the staff reading of each station is compared to get a rise or fall.


HCM : It is well adopted for reduction of levels for construction work such as longitudinal or cross-section levelling operations.
RFM : It is well adopted for determining the difference in levels of two points where precision is required.

HCM :  There is no check on reduction of R.L. of intermediate stations.
RFM : There is a complete check on the reduction of RL of the intermediate stations.

HCM : There are only two arithmetical checks i.e. the difference between the sum of the fore sights must be equal to be the difference in R.L. of the last station and first station.
RFM : There are three arithmetical checks i.e the difference between the sum of the back sights and the sum of fore sights must be equal to the difference between the sum of the rises and the sum of the falls as well as it must also be equal to the difference in RL of the last station and first station.

HCM : Errors if any in intermediate sights are not detected.
RFM : Errors in intermediate sights are noticed as these are used for finding out rises and falls. 

Types of Slump

There are three types of Slump that may occur in slumps test, namely
True Slump, Shear Slump and Collapse Slump.

True Slump refers to general drop of the concrete mass evenly all around without disintegration.

Shear Slump implies that the concrete mix is deficient in cohesion.
Consequently, it may undergo segregation and bleeding and thus is undesirable for durability of concrete.

Collapse Slump indicates that concrete mix is too wet and the mix is deemed to be harsh and lean.

What is the causes of Faulting ?

Fault Plane

The interior of the earth becoming cooler day by day, which is sure to cause some shrinkage in the earth crust. The stink age is responsible for the stress to be developed withing the earth crust. These stresses, when greater in magnitude exert so much pressure that the layers of the earths crust are fold due to compressive stresses and afterwards when the stresses are released, fractures are formed. If the stresses still continue, the blocks move up and down along the fault plane depending upon the direction of stresses and their intensity. Such a fracture, along which a movement has taken place, is called a fault. 

Fault

What is Warping ?

Warping is the bending of the concrete slab due to uneven expansion or contraction of top and bottom slab surfaces. It is caused by any differences in temperature above and below the slab or caused by the moisture differences.

Warping of Slab 

What is PCU ?

PCU is Passenger Car Unit.

For traffic analysis, all the vehicles are converted to car by multiplying with their PCU value.

List of vehicles with their PCU value are :

Motercycle : 0.5
Bus ,Truck ,Tractor : 3.5
Car : 1
Bicycle: 0.2
Horse Drawn Vehicle : 4

What is the difference between absorption and adsorption ?

Absorption generally refers to two phenomena, which are largely unrelated. In one case, it refers to when atoms, molecules, or ions enter some bulk phase - gas, liquid or solid material. For instance, a sponge absorbs water when it is dry.
 Absorption also refers to the process by which the energy of a photon is taken up by another entity, for example, by an atom whose valence electronic energy levels. The absorbed energy may be re-emitted as radiant energy or transformed into heat energy. The absorption of light during wave propagation is often called attenuation/ The tools of spectroscopy in chemistry are based on the absorption of photons by atoms and molecules.

Adsorption is similar, but refers to a surface rather than a volume; adsorption is a process that occurs when a gas or liquid solute accumulates on the surface of a solid or, more rarely, a liquid (adsorbent), forming a molecular or atomic film(the adsorb-ate). It is different from absorption, in which a substance diffuses into a liquid or solid to form a solution. 

SW ROAD TUTORIALS

This is a tutorial of the road design software called SW-ROAD. This software is made in Nepal and it is one of the most used and most easy software for designing the road. In this tutorial series, you will learn following things:
1) SW Road Introduction
2) Importing Topo Map and fixing horizontal alignment
3) Profile Alignment
4) Data Input and Calculation
5) Cross Section Design
6) Drawing output
7) Quantity Output for estimation

FUNCTIONS OF INGREDIENTS OF CEMENT

1) Lime: It makes the cement sound and strong. The lime in excess quantity makes the cement unsound and cause the cement to expand and disintegrate.

2) Silica: It provides strength to the cement due to the formation of dicalcium and tricalcium silicates. The silica in excess quanity causes the cement to set slowly.

3) Alumina: It provides quick setting property to the cement and lowers the clinkering temperature.

4) Iron Oxide: It provides colour, hardness and strength to the cement. It also helps the fusion of raw materials during the manufacture of cement.

5) Magnesium Oxide: It provides hardness and colour to the cement, when present in small quantity. The magnesium oxide in excess quantity makes the cement unsound.

6) Sulphur trioxide: It makes the cement sound, when present in very small quantity. The sulphur trioxide in excess quantity makes the cement unsound.

7) Alkalies: These should be present in small quantities. The alkalies in excess quantity will cause efflorescence.

COFFER DAM

What is Coffer Dam? 

A temporary Structure concstructed in a river, lack etc. for ecvluding water from a gicen site to enable the building operation to be performed on the dry surface, is called a coffer dam. It may be made of earth materials, timber or steel sheet piling or a combination thereof.

Some of the common types of coffer dams are as follows:

1) Cantilever sheet pile Coffer Dams

2) Braces Coffer Dam

3) Embankment Protected Coffer Dams

4) Double Wall Coffer Dams

5) Cellular Coffer Dam

The cantilever sheet pile coffer dams are suitable for small heights. The braces coffer dams are economical for small to moderate heights. There us no height limitation for embanking type coffer dams. The double wall coffer dams are suitable for moderate heights while the cellular coffer dams are suitable for moderate and large heights. 

Figures:

Classification of Piles

The piles are classified as follows:

1) Classification based on the function

The piles based upon the function or use may be classified as follows:

a) Bearing Piles: The piles which do not support the load by themselves, but act as a medium to transmit the load from the foundation to the resisting sub-stratum are known as bearing piles.

b) Friction Piles: The piles which are driven in the type of soil whose strength does not increase with depth or where rate of increase in strength with depth is very slow, are known as friction piles.

c) Compaction Piles: The piles which are driven in granular soil with the aim of increasing the bearing capacity of the soil, are known as compaction piles.

d) Batter Piles: The piles which are driven at an inclination to resist large horizontal or inclined force, are known as batter piles.

e) Fender Pile: The piles used to protect concrete deck or other water front structures from the abrasion or impact are called fender piles.

f) Sheet piles: These piles are commonly used as bulk heads or as impervious cut off to reduce seepage and uplift under hydraulic structures. These piles are not meant for carrying any vertical load. The sheet piles are made of wood, steel or concrete.

2) Classification based on materials and composition

The piles based on the materials and composition are as follows:

a) Concrete Piles: They are made up of concrete and can be precast or cast-in-situ.

b) Steel Piles: A steel pipe can be rolled section, a fabricated shape or a piece of sheet pole.

c) Timber Piles: The timber piles are generally square or circular in cross section, having cast iron show at the bottom.

d) Composite Piles: The composite pile is made of two portions of two different materials driven on above the other. The two materials can be steel, timber or concrete.

e) Screw Piles: This is made of a hollow cast iron or steel shaft. The external diameter of the shaft may vary from 150 to 300 mm , which mat terminate into a helix or screw base at its base.

f) Disc Pile: A disc pile consists of hollow cast iron pipe with a disc or casing of enlarged size at the bottom, to enlarge area to very great extent. The diameter of dics pile may vary from 0.6 to 1.2m.

Types of levelling

levelling may be classified as under :

1. Differential levelling
2. Cross-sectioning levelling
3. Check levelling 
4. Reciprocal levelling 
5. Profile levelling 
6. Precision levelling

1. Differential levelling.

The operation of spirit levelling which is employed to determine the elevations of a number of points some distance apart to establish Bench Marks in the area is called differential levelling. It is done regardless of the horizontal positions of the points with respect to each other. It is also sometimes known as taking fly levels or simply fly levelling.

2. Check levelling.

The operation of running level line to check the accuracy of the bench marks previously fixed is called check levelling. The stability of the existing bench marks can only be ascertained if the difference in line of the sections between three bench marks agree with the observed differences obtained by check levelling.

3. Profile levelling.

The operation of levelling carried out to determine the elevations of the points at known distances apart and also other known features at a given straight line is called profile levelling. If we plot the elevations of different points as ordinates and the horizontal distances between the points as abscissa, then the line joining the ends of the ordinates, gives the profile of the surface of the earth. Profile levelling is also called Longitudinal !culling.

4. Cross-sectioning levelling

The operation of levelling which is carried out to provide levels on either side of the main line at right angles, in order to determine the vertical section of the earth surface on the ground, is called cross sectioning.

S. Reciprocal levelling.

The operation of levelling in which difference in elevations between the points is accurately determined by two sets of reciprocal observations. it called reciprocal levelling. Reciprocal levelling is employed when it is not possible to set up the level between two points due to an intervening structures such as large water bodies.

6. Precision levelling.

The operation of levelling in which further refinement of field technique, is made by using precise staves and levels, and special precautions are taken Turing observation, to eliminate all errors, is known as precision (evening. G.T.S. bench marks are established by carrying out precision levelling -

Principle of Levelling

The principle of levelling lies in furnishing a horizontal line of sight and finding the vertical distances of points above or below the line of sight.
The line of sight is provided with a level and a graduated levelling staff is used for measuring the height of the line of sight above the staff positions.

How to detect local attraction ?

The magnetic needle is seriously deflected from its normal position when it is under the influence of external attractive forces. Such a disturbing influence is known as local attraction. The term is also used to amount of deviation of the needle form its normal position.

Detection of local attraction
The presence of local attraction at any station may be detected by observing the fore and back bearing of the line. If the difference between fore and back bearing is 180 degree, both end stations are free from the local attraction. If not, the discrepancy may be due to :

a) An error in observation of either fore or back bearing or both.
b) Presence of local attraction at either station.
c) Presence of local attraction at both the stations.

Correcting method

1) Method of elimination of local attraction by included angles

- Compute the included angle at each station from the observed bearings .
- Starting from the unaffected line, rub down the correct bearing of the successive sides.

2) Method of elimination of local attraction by applying correction in bearing

- Calculate the magnitude and direction of the error due to local attraction at each affected station.
- Run down the bearings, starting from the bearing unaffected by local attraction.

Adjustment of Surveyor's Compass

The adjustment of surveying compass are:

a) Temporary Adjustment 

The adjustments which are required to be made at every set up of the instrument are known or stationary adjustment. It includes:

1) Centering
The process of centering the instruments i.e. making the pivot exactly vertically over the ground station mark is called centering. The compass is fixed on the top of a tripod. By adjusting the legs of the tripod, centering is achieved. A plumb bob may be hung from the center of the circular box, to check the cantering  of the compass. If the compass is centered perfectly, the pebble will fall exactly over the ground station mark.
If the bob is not provides, centering can be done by dropping the stone freely from the center of the bottom of the cylinder box.

2) Levelling 
The process of holding the compass in such a way that its graduated rings swings freely, is called levelling. The levelling is done by eye judgement. Generally the compass is provided with a ball and socket arrangement attached to the tripod for achieving quick levelling of the instrument.

3) Focusing the prism
The process of moving up and down the prism for obtaining the figures and graduations sharp and clear, is called focusing the prism. 

b) Permanent Adjustment
The adjustments which are made only if the fundamental relations between the various parts of a compass, are disturbed due to careless handling or otherwise are called permanent adjustments.

The following fundamental relationship between different parts of a compass, are established by making permanent adjustments:

1) when plate bubbles. if provided are at the centers of their run, the vertical axis of  the compass should be truly vertical.
2) When the instrument is perfectly levelled, sight vanes should be vertical.
3) The ends of the needle and the center of the picot should lie in the same vertical plane.
4) The center of the pivot should coincide with the geometrical center of the graduated ring.

Its main adjustments includes:
1) Adjustment of the plate levels
To make the vertical axis truly vertical when plate bubbles are at he center for their run.

2) Adjustment of sight vanes
To make sight vane and object vane vertical when the compass is level.

3) Adjustment of magnetic needdle
To straighten the magnetic needle

4) Adjustment of the pivot
To set the pivot point at the geometric center of the graduated ring 

Surveying Compass

Surveying Compass are of following two types:

1) Prismatic Compass
2) Surveyor's Compass

1) Prismatic Compass
It is most suitable type of surveying compass which consists of a circular box about 100mm in diameter. Prismatic compass can be used as a hand instrument or on a tripod. Prismatic compass can be accurately centered over the ground station mark.

2) Surveyor's Compass
Surveyor's compass is similar to the construction to the prismatic compass with a few modifications stated below:
a) The graduated ring is directly attached to the circular box and not wiht the megnetic needle.
b) The edge bar magnetic needle floats freely over the pivot.
c) The eye vane consists of a simple metal vane with a fine sight hole.
d) Readings are taken against the north end of the needle.
e) The ring is graduated in quadrilateral system having o degree at North and south ends, 90 degree at East and West Ends.

Traverse and it types

A series of connected lines each joining two points on the ground is called a traverse. Each points are known as traverse stations and straight lines between two consecutive stations are called traverse legs.

There are two types of traverse:

1) Closed traverse: The traverse which either originated from a stations and returns to the same stations completing a circuits or run between two known stations (Linked Traverse) is called closed traverse. The closed circuits of the traverse legs is known as traverse circuit.

2) Open Traverse
The traverse which neither returns to the starting stations not closes on any other known station, is called the open traverse. In this case as series of connecting lines extends in teh same general direction.

Traverse can also be classified on the basis of the instruments used:

a) Chain Traversing
b) Compass Traversing
c) Plane Table Traversing
d) Theodolite Traversing
e) Thermometric Traversing 

Error in Surveying

Generally there are two types of error:

1) Cumulative Errors
2) Compensating Errors

1) Commutative Errors

The errors which occur in the same direction and tend to accumulate, or to add up, are called cumulative Errors/ Such an error makes the apparent measurements always either too long or too short.

a) Positive Commutative Error: Measures length more than the actual length .
Eg: Knots in connecting links, incorrect alignment, working in windy weather etc.

b) Negative Cumulative Error: Measures length less than the actual length.
Eg: Flattening of connecting ribs, opening of ring joints etc.

2) Compensating Error 

The error which are liable to occur in either direction and tend to compensate are called compensating errors. These are caused in the following situations:
a) Incorrect holding of the chain
b) The chain is not uniformly calibrated throughout its length.
c) Refinement is not made in plumping during stepping method.

DO I KNOW MYSELF???

Suraj Shah

Civil Engineer

Many people end their life with a one question ‘Actually who was I? , if I lived my life with being myself or just I survived life by being copy or being rubber to mould shape to impress other.’ I just want to request my readers to focus on word “survived”.

I have thought that I am younger for this article but later I thought that I have passed one quarter of life so I may be able to answer who are seeking answer of myself in early quarter of precious life. Many Sad guru and Sadhu are there who have found answer of myself and so they are called spiritual man who are free of love, affection and relation.

By the age of 24, I realised there is always you who is with your physical body in the jungle of 7 billion people which you born and end with your physical body. Nobody knows you better than you even your mother doesn’t know you better. Recently I have watched one inspiring story, in which one man travelling in a train has lost money and accuse another man travelling beside him a thief for a money but so called culprit man say very beautiful line “ he knows me for a hour but I know myself for 23 years how can I stole his money”. And next very popular example of myself is of life of prince Gautam who is popularly known as Gautam Buddha , he had no any lack in life he had family wealth and health and strong kingdom of which he was likely to become king very soon. But he give-up his family wealth and kingdom for the search of question of who is he in actual and he finally found answer and become Buddha and ultimately the light of Asia and creator of Buddhism.

When I generally used to read spiritual book which ultimately focus on know yourself but before 1 yrs. I haven’t explore that there is myself in my heart I just used to think that I have been controlled by mind and I’m slave of that master. I’m young guy and my friends used to told me that I’m boring guy which don’t drink and smoke and they used to force me also and keep taunting but I refuse because I don’t like to have these all stuffs and I can’t live without being me and can’t change my will for them because that will not be me that will be just mask of another person who is unknown to me and my heart. One thing I'd like to add here people who have survived for a years without exploring inner part have been living in dilemma by asking does she/he is actually doing that/this for happiness or for compulsion and ultimately their life ruins but when they know themselves they abandon every cover or networks or spider like net which were disconnecting freedom of life. I have seen many people who were used to throw dust in people’s eye by being wearing fake mask of not being themselves and ultimately are in worst condition. But I don’t see wrong in that too because society don’t accept you easily when you have known yourself because society have not changed as society is busy in fulfilling the physical needs so there is no time for accepting people’s reality at all. And you wear fake mask to impress society but u can’t afford that for a long time because that is not you and individual can’t hide his/her identity for a period.

My conclusion up to couple of decades that if u have abandon or fulfilled physical needs, then only we can think about spiritual needs and can think about this question neither there will be only showoff or fake . If you know yourself you will stop to survive for others and live your own life ruled by you and you will establish your kingdom in which you will be king and for 1000% you will be enlighten and feel so light you can fly and feel every aspects of nature , you can imagine it ……………..

So all my friends that the ultimate conclusion of knowing myself is that you will live your life with protection of your wish and wills which will spread love and happiness and I want to focus here word “ live”.

There is difference between surviving and living in life……………………………

Concrete Tests

Here are all the tests of concrete:

*** HARDENED CONCRETE ***

Important Tests

1) Compressive Strength Test

2) Permeability Test on concrete

3) Tensile Strength Test

4) Water Absorption Test

5) Schmidt Hammer Test 

6) Ultrasonic Test

Other 

7) Density Test

8) Shrinkage Test

9) Creep

10) ModuluS of Rupture

11) Resistance to Abrasion

12) Bond to reinforcement


*** FRESH CONCRETE ***

Important tests

1) Workability Test : Slump Test

2) Setting Time 

3) Bleeding 

4) Compaction Factor

Other

5) Air Content

6) Segregation Resistance

7) Unit Weight

8) Wet Analysis

9) Temperature

10) Heat Generation

11 ) Uee- Bee Test

CEMENT TESTS

Here are the list of all the cement tests :

(Important tests are written in the format of : 
TITLE, INSTRUMENTS REQUIRED,PROCEDURE, OBSERVATION & CALCULATION, RESULT & CONCLUSION. Please Click on the respective test for reading in this format )

Important Tests

1) Fineness Test

2) Soundness Test

3) Consistency Test

4) Initial and Final Setting Time of cement 

5) Tensile Strength Test 


Other Test 

6) Heat and Hydration Test

7) Chemical Composition Test

8) Color Test

9) Presence of Lumps

10) Adulteration Test

11) Temperature Test

12) Float Test

13) Date of Packing