Teams in Engineering Service

Teams in Engineering Service

Middle School Environmental Education Team

Spring 2009

Jose Alonso

Connie Cheung

Scott Hollwedel

Jeremy Jung

Blayne Lenoir

Hared Ochoa

Armita Pebdani

Zach Salin

Alan Toledo

Alan Turchik

Julianna Wang

Yon Xiao

Table of Contents

1. Introduction 3

2. Quarter Goals 3

3. Handheld PM Sensor 4

Background 4

ADC Program 4

Assembly 5

Testing 6

Vernier Sensor Attachment 7

4. Lesson Plan Development 7

5. Classroom Visits 8

Introduction 8

Coordinating Visits 9

Contacts 10

Lesson Plans 10

6. Assignment Antarctica Game 13

7. Preuss Science Olympiad 14

8. Lesson Plan Additions 15

Introduction 15

Food Batteries 15

UV Photography 16

9. Budget 18

10. Appendix 19

i. PM Sensor Parts 19

ii. Air Filter Lesson Plan 19

iii. ADC Source Code 20

1. Introduction

The main goal of this project is to increase interest in science and engineering in young students, with an emphasis on middle school girls. Studies have shown that this is the age group where the interest in science and engineering takes the most dramatic downturn. In order to accomplish this goal, this team focuses on several key components with a variety of functions. This team visits classrooms to assist teachers involved in the
I-TEST program, helps to test an educational computer game set in Antarctica, and develops environmentally oriented lesson plans. To enhance the lesson plans the team designs and builds a variety of equipment. One of the main areas is the use of particulate matter sensors due to the everyday impact that particulate matter has in an area that is prone to fires.

While still fulfilling the main overall goals of this team, this quarter the team concentrated on testing its handheld particulate matter sensor for optimum experimental conditions with the eventual goal of being introduced into classrooms along with complementing lesson plans. In addition, the team developed a lesson plan that focused on air filtration and proper protection against airborne matter. The team contacted the teacher in charge of Preuss School’s Science Olympiad and began mentoring teams on a weekly basis. Also, the team explored further into I-TEST lesson plans and sought to implement lesson plan concepts into contraptions appealing to middle school students. The team focused on the science behind food batteries and UV photography.

2. Quarter Goals

l  Two Classroom Visits Per Team Member

l  Assignment Antarctica Game Installations

l  Handheld PM Sensor

o  Reprogramming for Measurement Display

o  Assembly of Two More Sensors

o  Lesson Plan Development

o  Testing and Experimenting

l  Lesson Plan Additions

o  pH Scale and Food Batteries

o  UV Rays and UV Lenses

3. Handheld PM Sensor

Background

Air quality is becoming more of an environmental concern. Many daily and popular products emit pollutants that are deemed unhealthy, if not hazardous, to people’s health. Automobiles, for instance, emit carbon monoxide that is a colorless and tasteless yet highly toxic gas. Cigarette smoking as well as passive smoking provokes higher risks of asthma. Even common beauty supplies such as hairsprays contain many chemicals that result with various forms of irritation and nausea. Introducing students to air quality education at a younger age can teach awareness of these pollutants and, perhaps, inspire them to pursue and generate newer, environmental-friendly products and procedures.

This TIES team is developing a particulate matter (PM) sensor to accompany lesson plans on air quality. The main goal is to produce a light and portable system that allows students to manipulate and retrieve live data of the ambient air quality. This sensor is able to detect solid particles, such as dust and pollen, from 1 – 10 micrometers in size. This quarter the work on the sensor was mainly centered on tweaking the program running the sensor, assembling two more sensors, and testing.

ADC Program (Scott)

Some slight changes were made to the components on the newly built sensor. In particular, a much smaller Analog to Digital Converter (ADC) was used. Since we purchased a smaller ADC, we needed to alter stamp controller program to display the measurements, whether displaying each individual measurement or displaying an average of the measurements within a time frame. Figure 1. displays the pin outs from the stamp controller side.

Instructions for Use of PM Sensor:

1.  The sensor must be vertical i.e. the screen should be pointed upwards.

2.  The screen should never read 0. If it does, the wire from the sensor to the ADC chip is loose and needs be reattached

3.  Air flows from the bottom to the top so whatever source is being measured should be on the bottom.

4.  The output of the sensor is usually variable due to the inherent variability in the ambient particulate matter concentrations (picture a cigarette smoke plume which is far from homogeneous). It has been validated against a high grade PM counter. It was found that the average of the handheld sensor output matched the high grade PM counter. For typical clean indoor air expect readings of 123 particles per liter.

5.  Use provided charger to recharge batteries.

Refer to A-ii for the ADC source code.

Assembly (Yon)

This quarter, we used a different Analog to Digital converter (ADC) than in previous quarters. The previous design called for a 20-bit ADC, which was more than necessary, so we went with an 8-bit ADC as a simpler model. The general pin outs of the ADC are displayed in Figure 3. We connected all the pins to the stamp controller by connecting VDD to pins 8 and 5 and grounding pins 1, 3, and 4. We connected the remaining pins to pins connected to the stamp controller as they are used for the data in and out of the clock.

For the LCD Backlight Screen, we soldered wires to the RX, 5V and GND parts of the backside of the screen. This allowed us to connect the wires to the stamp controller so that it could receive an input and output to display desired results.

We needed to find connectors for the particulate matter sensor because we were missing some sets. We purchased a set of 3pin and 4pin connectors as shown and are figuring out ways to incorporate longer strands of wires to connect it to the stamp controller.

We assembled two more enclosures to hold the particulate matter sensors. We used 3/16-inch acrylic to assemble front panels and covers. Each component was glued together using acrylic cement/glue. The hardware was screwed in using 4-40 machine bolts and the complementing nuts and washers. The cover and battery plate are screwed to the front panel using 4-40 machine bolts. Prior to assembly, each hole was tapped for these bolts; not tapping these holes can possibly result with cracked acrylic.

Refer to A-i for hardware parts list.

Testing (Alan Turchik)

Earlier this quarter we proposed assembling a box in order to test the handheld particulate matter sensor. A box was made out of clear acrylic, approximately 9 x 9 inches. A square hole was made on the front face of the box at the bottom of the face in which the sensor could be inserted. The idea was that a smoldering object could be placed inside the box. The smoke would fill the box and the sensor could read the density of particles inside the volume of the box. Other ideas involving atomizing flour inside the box were considered for testing the sensor’s capability.

Initial testing consisted of placing smoldering incense inside the box with the sensor. Two major problems arose with the box design. First, the box had the sensor opening located on the bottom of the front face, with the sensor setting on the table on which the box was mounted. The main sensor inlet was located on the underside of the handheld sensor, so the opening in the box effectively blocked the sensor inlet. The other immediately visible problem was that the concentration of smoke in the box became too high too quickly. The particle concentration in the highly concentrated smoke quickly exceeded the measurement range of the sensor.

The solution to these problems include mounting the sensor opening higher and mounting a fan on the backside of the box for air circulation inside the box to ensure that concentrations did not increase significantly. Below is a drawing of the proposed redesign of the box.

When we find the optimum conditions for testing the sensor, we can compare our sensor with an accurate sensor in Prof. Kimberly Prather’s lab.

Vernier Sensor Attachment (Scott)

An idea we investigated this quarter was possibly adapting the handheld particulate matter sensors to use the Vernier LabQuest handheld unit. While the idea was feasible, the LabQuest software would have to be customized whenever using the sensor. The analog voltage from the sensor could be displayed on the screen for the Vernier LabQuest unit, but special parameters would have to be set on the unit to convert the voltage into a particulate matter count. This would be an added level of complexity when using the LabQuest unit. In this regard the unit would be more difficult to use than the standalone sensor, but would provide the advantage of being able to read and analyze time series rather than instantaneous counts.

4. Lesson Plan Development (Alan Toledo)

This quarter we finalized and expanded on a previously developed particulate matter (PM) lesson plan to help increase student knowledge of particulate matter. The original lesson plan introduced students to operating the handheld PM sensor by measuring the concentration of air samples. This quarter we sought to alert students about the effects of air filtration.

Air filtration is a concept that people practice daily—whether for work or for personal health—in order to prevent the passage of foreign particulate matter into or out of the respiratory system. Doctors use surgical masks in order to prevent loose hair or spit from entering the patient as well as block any microbes or bacteria from entering their air passageways. Construction workers are constantly surrounded by air born debris and wear face masks in order to prevent inhaling particulate matter. A recent out break of the swine flu in San Diego caused some people to wear face masks to decrease their chances of contamination. In general, particulate matter is a known cause of respiratory illnesses such as bronchitis and aggravated asthma. By filtering air via handkerchiefs or masks, people try to limit their intake of particulate matter.

For this lesson plan, students measure an air sample and use that result as the control experiment. For each following measurement, students measure the same air sample with various materials separating the PM sensor from the air sample. Using multiple materials to filter the air sample, students will understand that particulate matter can penetrate some materials easier than other materials.

Refer to A-i for soft copy of lesson plan.

5. Classroom Visits (Julianna, Hared)

Introduction

Throughout the quarter, TIES students participate in the project “Information Technology-Engineering and Environmental Education Tools” (ITEST1). ITEST is lead by UCSD Jacob’s School of Engineering, in partnership with the San Diego Super Computer Center (SDSC). ITEST works with San Diego middle school teachers to develop hands-on environmental science experiments, utilizing the Vernier LabQuest handheld sensors.2 TIES students attend middle school classes during these experiments, and provide technical and scientific support to the teachers while using the LabQuest sensors. The lesson plans and LabQuest sensors are designed to spark student interest in science and technology as well as increase student awareness about current environmental issues.

1 http://ties.ucsd.edu/ITEST/aboutite3tools.html

2 http://www.vernier.com/labquest/

Coordinating Visits

A TIES team member is assigned as the teacher visit coordinator at the beginning of each quarter. The coordinator is responsible for arranging the visit schedule which best accommodates both teachers and TIES students. The following is a guideline on how the organization can be done efficiently:

1)  Access ITEST coordination website to obtain equipment rotation schedule. The rotation schedule provides information on which teacher(s) will have the equipment during which week(s). Passwords can be obtained from the TIES team advisors.

2)  Contact teacher(s). Contact the teacher(s) a week in advance to inquire their class schedule (day and time). This is done primarily on email, and preferably on Monday to give the teachers time to respond.

3)  Create online poll. After obtaining teachers’ schedule, create an online poll (www.doodle.com). The rest of the team will provide their availability using the poll, and the coordinator can decide on the visit time that best accommodate both the teacher(s) and the TIES students. The poll is generally created on Wednesday.

4)  Inform the teacher(s) of the visit times. After obtaining the result from the poll, the coordinator will contact the teacher(s) with the visiting times for the following week. This is also done via email, preferably early Thursday so the teacher(s) will have time to respond before the weekend. Ask the teacher(s) to respond in email as a confirmation on the schedule.

5)  Confirm with teammates. Upon receiving the confirmation from the teacher(s), inform teammates with date, time, and location of the visit.

6)  Online Survey. After each visit, participated TIES students are required to fill out an online survey form for the ITEST research team to gather data about the lessons.3 Additionally, participants need to answer the following questions to complete the survey process (email to ):

Teacher Name:

Observation Date:

How prepared was the teacher to lead the lesson you observed? (Choose one)

a) Extremely prepared – he/she had seemed to have reviewed the lesson plan ahead of time, the lesson seemed to be implemented according to a clear plan, and the teacherexperienced few (if any) hiccups

b) Generally prepared – he/she seemed to have reviewed for the lesson and seemed to have a general plan, but the lesson would have benefited from more specific planning

c) Unprepared – he/she had not reviewed the lesson beforehand and/or did not seem to have a clear plan for the lesson

Why did you choose that rating? (No more than a few sentences)

3 http://www.grgsurvey.net/cgi-bin/rws3.pl?FORM=LessonReportCard

Contacts

Questions regarding overall ITEST operation