20 Posts in September Archive

Lab 4: Diodes

Objectives

1. To learn how to connect different diodes in an appropriate manner
2. To measure voltage drops across diodes and to ensure Kirchoff's voltage law still applies
3. To learn how a diode bridge works with the help of LEDs
4. To become familiar with an oscilloscope

Parts List

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Figures

Procedure

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Observations

1. Voltage drop across the LED is:
2. Maximum allowable current is:
3. Minimum resistance necessary to ensure diode safety for the applied voltage is:
4. Observations of the diode ...

Homework-4

Solve the following problems

Homework is due Monday 10/5/2009
Please find the cutoff frequencies for the following circuits and do the a.c. analysis just like you did for the lab
Figures 1 and 2 are series RC circuits and Figures 3 and 4 are parallel RC circuits .

Photos from China

Here are some photos from China from my camera:

China2009

Extraction of polyphosphate

Protocol for extraction of intact PolyP

1. The primary culture of agrobacterium is grown on LB over night at 37 degree C in shaking incubator. The shaker is set at 190 rpm

2. The secondary culture is then grown in LB with dilutions of 1:100 and 1:500.

3. Two samples are extracted every 2 hours and depending on the stage of growth of the culture one for the growth studies the other the extraction of poly P

4 ...

Greenhouse trip

Please provide a few thoughts on your trip to the plant biology greenhouse. Include a brief vision on what you'd like to see there, and how you may best contribute to it.

Lab 4: RC Filter Circuits

Errata

Vout for a low pass circuit is measured across the capacitor - not the resistor

Objectives

1. To learn how to use the function generator
2. To investigate the frequency response of high- and low- pass RC filter circuits
3. To compare experimentally observed responses with theoretically calculated ones

Parts List

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Figures

Procedure

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Calculations

Cutoff frequency for high pass filter:

Cutoff frequency for low pass filter:

Table 1: High Pass Filter: Theoretical calculation

Frequency	Xr=R	Xc=1/(2π.f.C)	Zt=(Xr ...

Meeting 09/18/09

List of chemicals made by Rekha 4 students enrolled for small scale algal cultivation ABE100 Sun presented the research paper : EFFECT OF NANOMATERIAL PHYSICOCHEMICAL PROPERTIES ON INVIVO TOXICITY. Rekha presented the paper ISOLATION OF INTACT CHAINS OF polyP FROM PROPIONIBACTERIUM shermanii Goutam taught the use of REFWORKS to build library of references.

Jilin, Changchun

It's been a while since I posted, and this post hopefully will allow me to catch up and note the highlights of our visits to Jilin University.

Professor Han hosted us. One of the first things we did was to go to an agricultural expo. It was immense in size, and included everything from model greenhouses growing a host of different food and landscape crops. A neat idea was the wooden trellises that were used to support variously shaped ...

Homework-3

Solve the following problems

Homework is due Monday 9/21/2009 1) Find the amount of energy stored in the following capacitor that have 120 V applied to them a) 100 μF b) 0.001F c) 10kF d) 1pF(pico Farad)
2) Find the capacitive reactance or capacitance in each of the following cases a) f=100 Hz C= 150 μF b) C=2.2 F f= 60Hz c) Xc = 15.92 Ω f= 50 Hz d) Xc = 60 Ω ...

Presentations at CAU

September 10 is celebrated as Teacher’s Day in China. We traveled to the west campus of CAU, where there were a large number of students carrying flowers - everything from single roses in clear plastic cones to elaborate arrangements with a number of exotic flowers. I had half a mind to ask the students or teachers if it impacted the grades. American humor seldom works the way we expect in another country, especially on this side of the world.

We ...

I see Husi

Husi foods is a supplier developed by OSI foods, who in turn is the major supplier for McDonalds. Husi basically produces salad components (iceberg lettuce, carrots, cucumbers), and also assembles the salads using an ingenious biomation (biological automation, a.k.a. good old cheap human labor) process.

The standards of cleanliness were state of the art, high pressure, 4C, full overalls, hair and face nets, hand wash stations and bleach baths for your rubber boots. I'd give a penny ...

Forbidden City

The Forbidden City is larger in footprint than one would imagine. I always thought it to be basically a large palace... maybe the size of Versailles - or that Casa Regia in southern Italy. But it's bigger. And apparently it's paved with 15 layers of thick basalt tiles. The stones line up close enough to not let any vegetation take hold and the general architecture of the place is what we generally see as the canonical Chinese architecture in ...

Fun with (policy) numbers

This morning our meeting was with Jikun Huang, Professor and Director of the Center for Chinese Agricultural Policy of the Chinese Academy of Sciences. He stated that the mission of his office was to 1) provide a scientific background for policy, 2) make policies for sustainability, 3) Education, 4) Outreach and multidisciplinarity (is that even a word?) and 5) Dissemination of research results.

Personally, I came away with a feeling that I learned a lot of new things and actually ...

The great wall

View Larger Map.

Yes - we visited the Great Wall. And it is great. And Twitter doesn't work in China. Unless they have an outage like they are prone to having. But that is neither here nor there.

So we went to the Badaling pass portion of the wall, which is generally well-maintained, and is the tourist trap of choice. Above is an image of the general area of our visit.

I had it in my mind to count the ...

Host with the MOST

Our host today was Dr. Renjie Dong, of the China Agricultural University. He holds a number of positions, including the Director for the Office of International Relations, and the Head of Energy Engineering. He brought us to the office of the Ministry of Science and Technology (MOST), where we were greeted by Director Yu Jian and the Vice Director for the Agricultural Technologies Division Sun Chuanfan.

Among the highlights of Sun Chunfan's presentation, was the so-called 8-6-3 program, which ...

Beijing

At the airport we were greeted by Zoe, who despite never having been to Europe or America, spoke as good English (and I mean like American English) as I've ever seen spoken by a Chinese. Including idioms. She is a fan of soap operas she says.

We had lunch at an interesting place, where they even had a show - including 4 Chinese girls doing their version of the macarena. The food was sumptuous and is probably the reason why ...

Incheon Airport in Korea

The first leg of the flight is done. 14 hours of bladder control. Incheon airport is nice. Lots of people wearing masks for fear of H1N1. There was also a quick temperature test at the arrival gate forest for fevers.
Interestingly, our departure out of Chicago was in the middle of the night and almost everything around the airport was closed. Not sure if that's the case all over or if it was a result of the recession.

Homework 2

Solve problems the following problems using using KVL and KCL

Homework is due Friday 9/11/2009
1) Use the algebraic method to find values of currents flowing through each resistor for the circuit in Fig.1
2) Solve for values of current flowing through each resistor for the circuit of Fig.2
3) Find I1 in Fig.3
4) Find I2 in Fig.4

Lab 3 - Eagle CAD

Objective

To learn to use Eagle CAD for building schematics.
Your lab report will consist of two parts:
1) The .sch file (the schematic file) that you create in Eagle) and
2) the exported graphic (in PNG, BMP or JPEG format) embedded in a Word Document.
Both files to be submitted electronically to me as well as Goutam.

Please replicate the following graphics. The logic symbol is an Exclusive OR .So search for XOR in the library

Open in a ...

Lab 2: Resistors

Instructions for lab writeup: All lab reports are to be typed. All sketches, tables and graphs are to be made using software (i.e. not by hand). Each report is due one week from doing the lab. The outline for the first lab report is as follows:

Objectives

1. To build a series-parallel circuit with resistors
2. To build a voltage divider with resistors
3. To validate Kirchoff's current and voltage laws
4. To learn about different types of resistors
5. To become familiar ...