SELECTIVE LASER SINTERING Selective laser sintering is a power based rapid prototyping process where it involves method of sintering and building up powder particles heated with a carbon dioxide, (〖CO〗_2) laser beam. The sintering process is when a roller spread the fine powder uniformly on the machine bed and it scanned selectively by a laser of power 25-100W such that the surface tension of the grains is overcome and they are sintered together. First powder is pre-heated to temperature slightly below the sintering temperature of the material by infra-red heaters to minimize thermal distortion and to facilitate fusion to the previous layer. The laser beam then scans the cross-sectional area identified for the current slice, thus sintering of the powder takes place. A fresh layer of powder is deposited again across the part bed, and the process is repeated until the final part has been completed. During this process the previous layers of un-sintered powder act as a support for any overhanging features. Once the build is complete, the part, encased in un-sintered powder, is left to cool to …show more content…
Any material can be process in Selective Laser Sintering which are polymers, reinforced and filled polymers, metals and ceramics. However, it is an unavoidable shrinkage happen during sintering process where thermal imbalance occurs in the build chamber. A study has found that there are a few parameters influence the shrinkage happen where laser power and scan length are to be most significant process variables influencing shrinkage in X- direction. Along Y-direction, laser power and beam speed are the significant parameters and along Z-direction beam speed, hatch spacing and part bed temperature are found to be most influenced factors affecting shrinkage. Shrinkage (%) for the specimen in each direction is calculated by using the following
Discussion 1. Zn0 (s)+ Cu2+S6+O42-(aq) →Cu0(s) + Zn2+S6+O42-(aq) Zn0(s) → Zn2+(aq) + 2e- Cu2+(aq) + 2e- → Cu0(s) Zn0(s) + Cu2+(aq) → Zn2+(aq) + Cu0(s) Oxidant (oxidizing agent) is the element which reduces in experiment.
Experiment 7 In this experiment we configured several DC circuits consisting of an emf and a network of resistors. The circuits were composed of a power supply, two DMMs, a circuit board, an SPST switch, and an assortment of known resistors along with one unknown resistor. We measured the current and voltage of the entire circuit as well as the potential drops across each resistor to determine the parameters of the circuit including the resistance, voltage, and current for each component.
%% Init % clear all; close all; Fs = 4e3; Time = 40; NumSamp = Time * Fs; load Hd; x1 = 3.5*ecg(2700). ' ; % gen synth ECG signal y1 = sgolayfilt(kron(ones(1,ceil(NumSamp/2700)+1),x1),0,21); % repeat for NumSamp length and smooth n = 1:Time*Fs '; del = round(2700*rand(1)); % pick a random offset mhb = y1(n + del) '; %construct the ecg signal from some offset t = 1/
Jessica Vandeventer 23 March 2016 Quantitative Spectroscope and Visible Light Purpose/Question- The purpose of the lab is to build a diffraction grating spectroscope, and to view different lights. We also are going to draw the light spectra of the various light sources.
\section{Facility Static and Dynamic Control}\label{Calibr} The facility calibration is the transfer function between the oscillating gauge pressure $P_C(t)$ in the chamber (described in ~\autoref{Sub31}) and the liquid flow rate $q(t)$ in the distributing channel, i.e. the test section. Due to practical difficulties in measuring $q(t)$ within the thin channel, and being the flow laminar, this transfer function was derived analytically and validated numerically as reported in ~\autoref{Sub32} and ~\autoref{Sub33}. \subsection{Pressure Chamber Response}\label{Sub31} Fig.\ref{fig:2a} shows three example of pressure signals $P_C(t)$, measured in the pneumatic chamber.
The four test specimens are all made from cold drawn steel. When steel is cold drawn, the crystal structure changes and creates stress. The stress in the grains can be reduced by the process of annealing. Quenching creates small stresses because carbon does not have time to escape. The annealing process is when
Copper Cycle Lab Report Ameerah Alajmi Abstract: A specific amount of Copper will undergo several chemical reactions and then recovered as a solid copper. A and percent recovery will be calculated and sources of loss or gain will be determined. The percent recovery for this experiment was 20.46%.
Shrinkage crack is caused by contraction of the total body due to loss of water content or moisture. Plastic shrinkage cracks are also formed by loss of water content in the concrete structure by evaporation. When the pace at which the water is evaporating exceeds the rate at which moisture is being supplied to it (via bleeding from the concrete), plastic shrinkage cracks are formed. It generally occurs in the plastic state (partially hardened state). Plastic shrinkage crack may not affect the strength of structure but will ruin the appearance of the structure and the crack to full depth may allow water to penetrate it.
The percent recovery of the copper was calculated using the equation, percent recovery = (the mass of the copper recovered after all the chemical reactions/the initial mass of the copper) x 100. The amount of copper that was recovered was 0.32 grams and the initial mass of the copper was 0.46 grams. Using the equation, (0.32 grams/0.46 grams) x 100 equaled 69.56%. The amount of copper recovered was slightly over two-thirds of the initial amount.
The Bessemer process was the first inexpensive industrial process for mass production of steel from molten pig iron “Bessemer Process”. The effect of the Bessemer process on the American Industry was unreal. It was something people have never seen or experienced before. There were many effects of the Bessemer process, one of them being manufacturing. Manufacturing this process was easy to make and inexpensive.
Jaspreet Singh Professor Paratore Biology 1 November 1, 2014 Spectrophotometry Identifying Solutes and Determining Their Concentration Statement of the Exercise or of the Problem The purpose of the lab experiment was to attain the following objectives: • Learning to Operate the Spectrophotometer • Construct absorption spectra for cobalt chloride and chlorophyll. Hypothesis If greater and higher concentrations of cobalt chloride are added to each solution then greater amounts of light would be absorbed by each solution. Thus a liner relationship will result in which the absorbance of a substance would be proportional to its concentration, which will be depicted, in a linear graph.
Light Refraction Lab Final Write-Up When light passes through any obstacle, it is affected in different ways, especially when the obstacle is transparent. In this lab, the objective was to show students what happens when light passes through water. “When light refracts into a substance in which it must slow down, the light ray will bend toward a line perpendicular to the surface it strikes” (Wile). Water forces a light ray to slow down, and so the light ray will bend.
A small amount of sand was added after the layer of cotton. After that, a layer of silica filled almost 1/3 of the column. Finally, another small amount of sand was added just above the silica. The column was given a little tap with an aspirator to make the silica more compact. Figure 2.
BMW The 7-Series Project (A) AGENDA 1) Abstract/Executive Summary 2) Problem Statement 3) Case Analysis 4) Alternative Solutions 5) Recommendations 6) Limitations 7) Appendix Abstract/Executive Summary • To explore the BMW decision about how to manufacture the Prototype vehicles. • Previously, BMW prototypes were handcrafted at the company by skilled artists. • There is a proposal to change the process and make prototypes inorder to better understand the issues that may arise during final production phase.
Purpose This experiment is to determine the concentration of the solute copper sulfate pentahydrate, and the unknown solution, by passing different wavelengths of light through each solution. Procedure Weigh out approximately 5g of copper sulfate pentahydrate. Record the mass and place the solute into a 50 mL volumetric flask. Fill half of the flask with distilled water, add the stopper for the flask, and lightly shake the flask, until the copper sulfate pentahydrate fully dissolved.