AFM is a scanning probe technique which is used for the Nano scale measurement. The atomic force microscope (AFM was invented in 1986 by Binnig, Quate, and Gerber. Atomic force microscopy (AFM) provides a 3D profile of the surface at Nano scale, by measuring forces between a sharp tip(which is made up of antimony doped silicon) and surface which is at very short distance(0.2-10 nm tip-sample separation). The tipis mounted at the end of a flexible cantilever which is made up of silicon, which bends in respond to the force exerted on the tip by the sample The AFM tip “gently” touches the surface and records the small force between the probe and the surface. Atomic force microscopy consist of two main modules and every module has its own work.
It is a technique that excludes the use of solvent. SPME comprise of a fiber that are coated with either a liquid, solid or solid along with liquid. This coated fiber is use to concentrate the various kind of analytes from distinct media. After the extraction process, the targeted analytes can be separated and quantified by introducing the fibers into the analytical instrument. The instruments used can be Mass Spectrometry or Gas chromatography.
AIM: To model diffusion in a practical form and investigate the effect of surface area to volume ratio. HYPOTHESIS: It is hypothesised the smaller the cube the quicker and bigger the rate of diffusion will be and with a larger cube there will be a smaller percentage of diffusion due to its bigger volume. VARIABLES: There are independent variables, dependent variables, and controls. the one that is being tested and the one that is the inconsistent variable in the Independent variable like the volume and surface area of the agar cubes. The variable that is kept consistent is the dependent variable such as the percentage of diffusion of pigment in the agar cubes.
1. INTRODUCTION TO MICROSCOPY A microscope is an instrument used to see objects that are very small for the naked eye. The science of examining small objects using such a tool is called microscopy. Microscopic means invisible to the eye except aided by a microscope. 2.
The purpose of this lab was to implement the use of a Scanning Electron Microscope (SEM) to examine and analyze metal samples that were subject to different failure tests. These failure tests included tensile tests, impact tests, and fatigue tests. SEM’s are useful because they provide a 3D view of the surface of the material, which improves the ability to examine the failure type at a microscopic level. In addition to this, the resolving power of a SEM is much stronger than that of a standard microscope, which enables the user to obtain much more detailed images of the samples. The experiment was performed by analyzing failure tested samples that were prepared before the experiment.
Young’s double slit experiment shows how an electron behaves as a particle and as a wave. The experiment shows that if one slit is open you get a pattern as you would with any particles. When repeated with the second slit open you get the same pattern corresponding to that slit, with an interference pattern in the centre. When both slits are open you get a completely different interference pattern, one that has similar properties to waves such as light. This then shows how electrons can behave as particles and also as waves.
2.2 – Calibration of the cantilever – 2.2 (a) - Determination of the spring constant of the AFM cantilever – For the triangular cantilever, the force/spring constant was evaluated by the thermal noise method  while for the rectangular cantilever (AIOAl), the Sader method , was used by the IGOR software to calculate the same parameter. The methods are detailed below. 2.2 (a) – (i) – Thermal Noise Method - The spring constant and sensitivity of the above cantilever is calibrated using the thermal method. This essentially stems from the equipartition theorem which states that the thermal energy present in all terms in the Hamiltonian of a system that are quadratically dependent on a generalized co-ordinate is equal to kBT/2, where kB is the Boltzmann’s constant and T the absolute temperature in Kelvin. If one treats the cantilever as an ideal spring of constant k, a measurement of the thermal noise <x2> in its position allows the spring constant to be determined as k = kBT/<x2> (1) Relation (1) is an idealization and a more physically accurate formula , is given
Ultrasonic waves are of an acoustic frequency beyond the range of human audibility. All current ultrasonic lithotriptors use piezoceramic crystals through which an electric current is applied to create the ultrasonic wave. The ultrasonic wave energy is transmitted along a probe and converted to vibration at the tip. Stone fragmentation occurs because of the mechanical energy of the probe and is not related to the shockwaves or heat produced. Therefore, direct contact is necessary for efficient stone fragmentation and evacuation.
The diverse mode of vibrations were identified and consigned to conclude the functional groups in the sample. Morphology study of the nanoparticles The morphological characteristics (size and shape) of the nanoparticles were examined using a Scanning Electron Microscope (SEM) machine (Phillips C M 12). The sample was placed on a sample holder followed by coating with a conductive metal such as copper, using a sputter coater. The sample is then scanned with a focused fine beam of electrons (Jores et al., 2004). Membrane filtration technique The membrane filtration techniques provide a direct count of total coliforms and faecal coliforms in the water sample.
On the other hand, these membranes were resulted low swelling in thickness along with appreciable change in planner direction. It is clearly observed that, the enhancement on water uptake is due to the increasing amounts of additives of ionic SPEEK polymer and hydrophilic MMT nano clay filler. The existence of water molecules can facilitates ionic transfer and also improves the ionic conductivity of electrolyte membranes. Further, the proton conductivity of the membranes could depend on the presence of available acid groups and also due their dissociation capability in water, which can desire by means of ionic sites generation. Moreover, the membrane PSM2 identified as best canditate than the others.