Engineering Quarterly Winter 2022

Engineering Quarterly VOL.IV. . . No.2

WINTER 2022

W ELCOME !

Welcome to the winter issue of Engineering Quarterly, a newsletter published four times a year by the University of Mary School of Engineering. In it we try to include articles from each of the five engineering majors that we currently offer: Electrical Engineering, Mechanical Engineering, Civil Engineering, Computer Science, and Construction Management.

The intended audience of the Engineering Quarterly are engineers, engineering students, engineering alumni, future engineering students, and people working in fields closely related to engineering such as science, computing, and mathematics.

In this issue we include articles on design projects our students are working on, trips they have gone on, our annual engineering alumni event, the new construction we have underway for our Civil Engineering concrete wet lab, companies and organizations who have visited our campus, and interesting assignments and projects from our courses.

Enjoy!

Dr. Terry Pilling Dean of Engineering

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the insight to realize that, as a mechanical engineering student, he has the skills to solve these problems in a cost-effective way.

Even when the original supply chain issues have been resolved he is confident that he will have a product line and a success rate that will allow him to continue to supply these products as well as new ones throughout the manufacturing marketplace. It is likely that companies will continue to be supplied by his company even after the original overseas suppliers come back online.

“I’m still working on getting an LLC set up and to sit down with a patent attorney, but I have the packaging close to done. By the end of the week the product testing will be done so that’s exciting. As of today Moritz Sport and Marine has installed a total of 5 without any advertising or an official send off of the product!”

Karsen first noticed this with the Troll Master. There was a piece that the company was unable to get in order to install the device on their boats. Karsen took one home and studied it and then created a CAD design and used his 3D printer to print one.

Karsen then conducted strength and durability studies on the piece and tried several different 3D printing materials, contacting different companies to ask about material strength, the effect of the sun on materials over time, etc., until he finally decided A LUMNI E VENT that that carbon-fiber polycarbonate was the best material to use with a reasonable cost range. He printed the part numerous times from that material and conducted strength tests based on the needs of the final installed product. He noticed that it would shear from the side and so he invented a method of reinforcing the center of the piece with powder coated steel to prevent shear. It On November 5, 2021 we held our annual worked perfectly. alumni event on campus. This year, in addition to the usual beer, nachos, and socializing, we gave our former students a tour of the new Civil Engineering and Construction Management addition that is being constructed.

Mechanical Engineering student Karsen Meyer works part time at Moritz Sport and Marine while working on his degree and he noticed that over the past six months there has been a supply chain breakdown in the marine industry among many others due to the Covid19 outbreak. Oftentimes companies cannot complete a product because of one simple part that is missing and the product cannot be inSince then Karsen has made contact with stalled without it. other companies and is working on supply The supply chain issue is not, by any agreements with them as well. He has also exmeans, isolated to the marine industry. Sup- panded to solve simply chain breakdowns have affected compa- ilar supply chain isnies and products from diverse branches of sues in other areas of industry in the United States where crucial the marketplace. It components to their products or other essen- is clear that the suptial raw materials that come from other coun- ply chain problem is tries have become unavailable due to restric- a vast one and is not tions in shipping and other logistical issue re- going to end for some lated to the pandemic. time. Karsen has had

The space will house the concrete wet laboratory, an overhead crane and loading dock, as well as spaces for Civil engineering courses and construction projects.

The faculty of the UMary Engineering School are always thrilled to have our graduates return to campus and tell us about all of

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Engineering Quarterly WINTER 2022

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the cool things they have been up to and let us show them our new developments and the design projects of our current students.

M ECHANICAL E NGINEERING D ESIGN We plan to continue having an alumni event every year and hope to continue seeing the amazing progress our graduate are making in their careers as engineers.

C IVIL E NGINEERING D ESIGN Professional Engineer Michael Dora from Ulteig Engineers is teaching our Civil Engineering design course this year in the Fall semester. Mike has an masters degree in Environmental Engineering from New Mexico State University as well as a bachelors degree in Civil Engineering and a bachelors degree in Biology. He is licensed in eight states and we are very happy to have him sharing his vast experience with our design students.

He has divided the students into two groups, the first group consisting of Logan Mahoney, Mitchell Oehme, and Davids Atelbauers are designing a new water tower and city water main for the city of Napoleon, ND., and the second group, consisting of Blake Rubio, Isaiah Bitz, and William Blewett are designing four options for new parking on campus ranging from resurfacing all the way to installing a parking garage.

Professor Dora has also arranged for the engineers from Moore Engineering A.J. Tuck, PE, and Jerod Klabunde, PE, to advise the students on the Napoleon water line upgrade and retired engineer, Robert Youness, PE, who actually designed the downtown Bismarck parking garage, to advise the second group.

It will be nice to see their final project presentations in April!

The mechanical engineering students presented their senior design projects on December 15, 2021. The first group consisting of James Jurek, Karsen Meyer, Mark Sammons, presented a project commissioned by Bobcat/Doosan in which the students were to design a innovative new auger attachment for the Bobcat skid-steer. Due to a non-disclosure agreement I cannot give further details. The project supervisor, Dennis Agnew, from Bobcat was very impressed with the students design and said that the company plans to use their design in future production.

The last group, consisting of Daniel Turner, Ethan Melder, and Lucas Mayer, designed a thermodynamics test station for use in educating students about refrigeration and HVAC systems.

They set it up with an entire refrigeration cycle as well as a series of pressure and temperature sensors and digital readouts so that the students can directly compare their thermodynamics calculations with the actual values in a working machine. We plan to incorporate their test station in to our thermodynamics courses in future semesters.

E LECTRICAL E NGINEERING D ESIGN Electrical engineering seniors Rami Douri, Michael Storrick, and Chandler Olson constructed a robotic chess board this semester using the Stockfish chess engine at its core with the player setting the difficulty rating of the computer by setting the number of moves the computer is allowed to look ahead.

The second group, consisting of Peter Smith, Daniel Minor, and Matthew Bitner designed a prosthetic arm for amputees which can be controlled in an interesting way using muscle movement. The project requires not only many 3-d printed linkages for the bones in the hand, but also many servos and electronics devices to control it. The group plans to continue with this design project this spring and hopes to have a working prototype by the end next semester.

They built a board and 3D printed the pieces so that they could have magnetic attachments underneath. They installed Hall effect sensors in order for the board to decide where all the pieces are as moves are made. The computer shows an image of the game on a computer screen as well as it is played. The students wrote the control code in Python and designed a Printed Circuit Board (PCB) with surface mounted electronics after the design phase had been completed. They are currently waiting for the completed PCB to come back

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Engineering Quarterly WINTER 2022

from the company that is manufacturing it. ucts and are committed to fostering a culture Next semester they plan to design and install a of innovation. robotic arm for the computer player so that, as Employee deyou make moves and the computer decides on velopment is a their move, a robotic arm will reach out over top priority, and the board and move the pieces for the comour company puter player. It will be fun to see the finished culture proproduct next semester! motes mentorship, training, and education through both internal development programs and professional development reimbursement D ICKINSON B US T RIP to ensure we are investing in the future of the company by investing in our team.”

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sion and leadership allowed Fisher Sand & Gravel Co. to quickly emerge as a leader in portable crushing operations.

Gene recognized a need for durable, customizable equipment. In 1967, he established the affiliate company, General Steel & Supply Company, to repair, remodel, design, and fabricate quality aggregate processing equipment. This partnership fueled the further success of Fisher Sand & Gravel Co., ultimately leading to the establishment of several more office locations in the upper Midwest.

NDSPE M EETING On Friday, November 12th, a number of our Mechanical and Electrical Engineering students left campus at 8:00am and traveled to Dickinson, ND. to visit some engineering companies and tour their manufacturing plants.

The final stop on the trip was Fisher Industries where the students were shown its Dickinson manufacturing plant and given an overview of the many exciting projects they have done around the country including sections of the southern border wall as well as an amazing The first stop was Killdeer Mountain Manubridge in Las Vegas. facturing. Killdeer Mountain Manufacturing, is a company committed to excelling in realms of their operations as well as commitment to community, country, and family. A cornerstone principle for the company is responsiveness to customers. This responsiveness has opened many doors for KMM on world-class platforms in support of our military and commercial aerospace. Our students were given a tour of their manufacturing plant which included their robotics tools and their military contract projects. It was a fun and exciting time for everyone.

The North Dakota Society of Professional Engineers held their Fall meeting here at the Engineering School this year. They brought pizza and sodas for the students and then stayed after their meeting for a tour of the engineering building. The NDSPE sponsors a scholarship every year for our engineering students and we are always happy to host them on campus. Hopefully plenty of our future students will join the NDSPE when they get their own PE licenses.

B ISMARCK M ETEORITE I MPACT

By TERRY PILLING

The next stop on our trip was Steffes where the students were given lunch and an introduction to the company by its executives including the founder Paul Steffes. Steffes is a steel fabrication and electrical services manufacturer serving diverse industries including oil and gas, electric thermal storage, and contract manufacturing.

“We use lean operating principles to reduce waste and increase customer value. Engineering teams at Steffes have extensive experience in the industries they serve and access to the latest technology including robots, parametric 3D modeling, mechanical systems, electrical systems, tool and die, hydraulics and pneumatics.”

“We take pride in the quality of our prod-

Fisher Industries is a family of businesses that encompass all aspects of the aggregate production and heavy civil construction industries. Their unique, vertically-integrated business model allows them to handle small projects, large scale operations, and every tough job in between. Their goal is to provide reliable products and sustainable solutions for innovative global infrastructure.

Their parent company, Fisher Sand & Gravel Co., was founded in rural North Dakota in 1952 by Gene Fisher. Gene’s vi-

On the morning of October 18, 2021, I received a call in my office from Troy Backstrom, a Bismarck resident, who said that he observed a meteorite impact the previous night on the lawn next to his apartment. “It had a three foot flame as it shot down from the sky and hit the lawn,” said Backstrom. I asked whether it left a crater and he confirmed that there was a small circular shaped crater in the yard but there was no meteorite in it. I told Troy that

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I would get some of the other faculty and we would come over and take a look.

After work, Rodrigo, Heather Wernke (Physics professor), and I went over to the site.

We found the crater and then took some samples of some tiny charred rocks that we found inside it using some biological test tubes given to us by Prof.

David Ronderos of the Biology department. We knew that even if the original meteorite disintegrated on impact there would still be tiny rock fragments that could be analyzed. We thanked Mr. Backstrom for calling us and, after taking some pictures and measurements of the impact crater, we left.

The next day Rodrigo and I grabbed some radiation measuring equipment as well as some magnets. Meteorites often contain Iron, which can be detected magnetically, and sometimes radioactive material such as Iridium.

We found that a number of the fragments were attracted to the magnet implying that they probably contained Iron.

F IBONACCI C ODE Two of our sophomore students, Megan Achbach and Maya Wald, presented their solution to a problem assigned in their ENR 304 course.

Engineering Quarterly WINTER 2022 related to the so-called ‘Golden Ratio’ and the ‘Golden Spiral’ and many biological systems seem to pattern themselves in this way. The way to generate Fibonacci numbers, Fn , is to start with F0 = 1 and F1 = 1 and then generate the next one by summing the two preceding ones. So, for example, F3 = F2 + F1 = 2.

The general formula for any n is thus Fn = Fn−1 + Fn−2 An interesting question is what solution do you get when you sum a power series whose coefficients are Fibonacci numbers? In other words, what is the sum of this series F =

∞ X Fn n=0

n!

Here is a clever way to do it. First solve the differential equation y 00 = y 0 + y using two methods. First use the method of power series you learned in your elementary differential equations course and then use elementary methods from that same course, i.e. substitute of exponential and setting the boundary conditions y(0) = 0, and y 0 (0) = 1. Since solutions are unique, the results from each method allow us to write down the following identity: √ ! ∞ X 2 x 5 Fn n x = √ e 2 sinh x n!

2 5 n=1 Of course, if you don’t feel like solving the differential equation yourself you can easily verify by substituting each side of the above into the differential equation and boundary conditions and then remind yourself via the existence and uniqueness theorem that the two solutions must be the same. Meaning they are also the same at the point x = 1. Setting x=1 gives √ ! √ ∞ X e 5 Fn =2 sinh n!

5 2 n=1

4 Fibonacci.c # i n c l u d e < s t d i o . h> # i n c l u d e < s t d l i b . h> # i n c l u d e <gmp . h> i n t u s a g e ( char * name ) ; i n t main ( i n t a r g c , char ** a r g v ) { i f ( a r g c != 2) return usage ( argv [ 0 ] ) ; int N = a t o i ( argv [ 1 ] ) ; / / I n i t i a l i z e gmp v a r i a b l e s s e t t i n g them e q u a l t o 0 mpq_t Fib , I , F , F1 , F2 , y , i f a c t o r i a l ; mpq_init ( Fib ) ; mpq_init ( I ) ; mpq_init (F) ; mpq_init ( i f a c t o r i a l ) ; m p q _ i n i t ( F1 ) ; m p q _ i n i t ( F2 ) ; mpq_init ( y ) ; / / s e t 0 ! t o be 1 mpq_set_ui ( i f a c t o r i a l , 1 , 1 ) ; m p q _ s e t _ u i ( F2 , 1 , 1 ) ; / / v a r i a b l e f o r t h e a n s w e r ????? mpf_t ( answer ) ; m p f _ i n i t 2 ( answer , 5 0 0 0 ) ; / / Okay now do some l o o p y s t u f f f o r ( i n t i = 1 ; i <=N; i ++) { mpq_set_ui ( I , i , 1 ) ; mpq_mul ( i f a c t o r i a l , i f a c t o r i a l , I ) ; mpq_div ( Fib , F2 , i f a c t o r i a l ) ; mpq_canonicalize ( Fib ) ; mpq_add ( y , y , F i b ) ; m p q _ s e t ( F , F1 ) ; m p q _ s e t ( F1 , F2 ) ; mpq_add ( F2 , F1 , F ) ; } m p f _ s e t _ q ( answer , y ) ; g m p _ p r i n t f ( " %.1234 F f " , a n s w e r ) ; / / C l e a r gmp v a r i a b l e s mpq_clear ( I ) ; mpq_clear ( Fib ) ; mpq_clear ( F ) ; m p q _ c l e a r ( F1 ) ; m p q _ c l e a r ( F2 ) ; mpq_clear ( y ) ; mpq_clear ( i f a c t o r i a l ) ; mpf_clear ( answer ) ; return 0; } i n t u s a g e ( char * name ) { p r i n t f ( " Usage : %s < p o s i t i v e number > \ n " , name ) ; return 1; }

P ROBLEMS TO TRY Here are some problems from our courses this semester that you might like to try. The solutions can be found at the end of this issue.

H UMAN DNA

By TERRY PILLING

The Project Gutenberg website has files from the Human Genome Project which contain the DNA base pair sequences for human chromosomes. Download the eφ+ − eφ− data from the human X chromosome ( √ = 5 https://www.gutenberg.org/ebooks/3523 ) √ and find the character statistics.

Comwhere φ± = 1±2 5 are the Golden Ratio and pare your result with the following (note it’s conjugate. that the first line comes from the ‘end of line’ (EOL) character). Now do the same with the human male Y chromosome ( https://www.gutenberg.org/ebooks/3524 ).

Statistics ---------total = 281540876 characters read

character --------A C The numerical value of the Fibonacci G series, to 25 decimal places, is: N 2.0143227334583157365813462 The students T

were asked to write a C program to generate the first 1234 digits in the Fibonacci series F . Note that this is not as easy as you might assume due to the limits of the computer and the variable types in programming languages.

To solve this problem, Megan and Maya used The problem was to write a computer program the Gnu Multiprecision Library, which allows to calculate the first 1234 digits of a series one to work with astronomically large numcalled the Fibonacci Series. Fibonacci num- bers. Here is their solution code: bers occur many places in nature. They are

occurs -----61491611 44064858 44001920 65030485 61431592

percent ------21.84% 15.65% 15.63% 23.10% 21.82%

The N’s are not DNA bases, but are regions where information is missing. Modify the program to exclude the N’s and the EOL characters and take another look at the statistics.

Do each of the 4 bases appear with the same percentage frequency? Is there any pattern in the frequency with which each of them appear? Could you use this statistical method to distinguish between two people? or two animals from different species?

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CSC 457 P ROBLEM

By TERRY PILLING

In CSC 457 Students learn how to design their own computer programming language and write the compiler. The tools that are used to create the compiler are the Lex/Flex lexical analyzer and the Yacc/Bison grammar parser.

In order to learn Flex we begin by using it as a controller which will read in a series of instructions and convert them into a series of tokens that will perform and action – in this case turning LEDs on or off. The problem is to write a Flex script that recognizes the words “ON”, “OFF”, “SWITCH”, and “END”. The first two will return messages stating that an LED is begin turned on or off, the SWITCH instruction will switch between the two LEDs, and the END instruction will end the control program. After the student have written and compiled their code they should test it by feeding in a string of instructions and ensuring that the correct output is generated. This code can then be modified so that the actions access the GPIO of a raspberry by or the USB port of their computer and connected to physical LEDs to make the LEDs behave accordingly.

ENR 200 P ROBLEMS

By DAMIAN OWEIS

Problem 1: Find the final values of Rose, Lily, Tulip, iris and jasmine in the following MATLAB/Octave code.

Engineering Quarterly WINTER 2022 Here was the final project from our ComputerAided Analysis course for the Fall semester this year.

A lake is a very complicated ecosystem and is difficult to effectively model mathematically. To have a truly effective model one would need to include its dimensions, depth, temperature, chemical concentrations, biological concentrations, interactions among a plethora of organisms both plant and animal that live in or near the lake, human activity from cities and agriculture that are near the lake, climate changes over time, etc. However, one might hope that if we are only interested in particular problems with the lake we might be able to develop much simpler models to help us study those problems while ignoring all of the other details that, we hope, don’t have a huge effect on the problem we are studying. This may not be possible since many problems in nature derive from a vast number of small effects rather than a small number of large effects. A lake may be like this too, in which case the task of developing a model would take a huge amount of mathematical modeling and data collection. In this project we will assume that modeling a few of the effects on the lake will be enough to study the problem at hand. How our results compare with the data will indicate whether our assumption is valid or not.

Eutrophication

A lake may be Oligotrophic which is a state with low nutrient input, low levels of plant material, and relatively clear water. A lake may also be Eutrophic which is a state characterized by high nutrient levels, high amounts of plant production, and toxic, murky, water.

The problem that we would like to study in this project is lake eutrophication, how it persists, and what methods we might use to reverse it so that we can restore a eutrophied lake to a clear and clean state.

Ultimately, eutrophication is caused by Problem 2: Find the values of out if the user inputs each of the following values of num excessive inputs of nutrients as a byproduct of agriculture, forestry, or urban development. if num < -8 | num > 10 The primary nutrient that causes eutrophicaout = (num)^2 elseif num > 0 && num <= 5 tion is phosphorus from agricultural and urban out = (num)^3 runoff. The phosphorus accumulates in sedielseif num < 0 && num >= -5 ment at the bottom of the lake and then recyout = abs(num) cles back from the sediment to water again. else This recycling of the phosphorus may be a out = 100 endif larger contribution to the phosphorus levels in the water than the flow into the lake from the where outside.

Since phosphorus seems to be the largest num = -20, out = contributor to eutrophication in a lake our first num = 4, out = attempt at modeling the problem is to model num = 10, out = the phosphorus levels. num = -2, out = num = -7, out = num = 6, out = Mathematical Model num = 0, out = The model we will use as our jump-off point is the one that was developed in 1999 by Carpenter, Ludwig, and Brock 1 . They use p(t) P ROJECT: L AKE M ENDOTA as the amount of phosphorus in the water, L as the rate of input of phosphorus from E UTROPHICATION the outside watershed, the rate of loss of phosphorus from sedimentation is assumed to Rose = 0; Lily = 0; Tulip = 0; for iris = 2:3:25 for jasmine = 30:-4:1 Rose = Rose+1; if mod(iris,2) == 0 Lily = Lily+2; endif end for Tulip = Tulip+3; end for

1

5

be proportional to the amount of phosphorus present with proportionality constant s, and they model the recycling of phosphorus from the sediment by r

pq mq + pq

where r is the maximum recycling rate of phosphorus, m is the concentration of phosphorus at which its recycling is half of its maximum rate, and the power q where q ≥ 2 may range from 20 for a shallow, warm, lake down to 2 for a deep, cold, lake. Putting these contributions together they arrive at the following equation for the change in phosphorus over time pq dp = L − sp + r q dt m + pq

Equilibrium Condition In the case where the lake is eutrophic and has constant high levels of phosphorus. The equilibrium will occur when the amount of phosphorus flowing in to the lake is equal to the amount of phosphorus flowing out (by sedimentation). From the equation for the model we see that dp/dt = 0 (equilibrium) will occur when pq sp = L + r q m + pq which says the outflow is equal to the inflow. If we define this equilibrium value of outflow/inflow as Q and plot each side on a graph of Q versus p we see that the outflow side of the equation is Q = sp which is a straight line through the origin with slope equal to s. The inflow side of the equation is Q = L + rpq /(mq + pq ) which is a curve.

Equilibrium values occur when the line intersects the curve so that they both have the same value (i.e. when outflow is equal to inflow).

The result is the above graph which plots the outflow and inflow functions for arbitrarily chosen values of the constants to see where they intersect. The graph shows that the two functions do cross each other at three different phosphorus concentrations. If we were to change the values of the various parameters of the model it would change the phosphorus levels where equilibria occur.

The graph shows three equilibrium levels, a low phosphorus one corresponding to a oligotrophic lake, a medium phosphorus one, and a high phosphorus one corresponding to a eutrophic lake. The medium level equilibrium is an unstable one and the high and low level

Management of eutrophication for lakes subject to potentially reversible change, S.R. Carpenter, D. Ludwig, and W.A. Brock, Ecological Applications, 9, 751-771 (1999).

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ones are stable equilibria. The challenge of water quality management is to control a lake that is at a eutrophic equilibrium and move it to an oligotrophic equilibrium. Recall that you can decide whether equilibria are stable or unstable by examining the second derivative or by plotting the direction field.

If we were to increase the value of L, meaning we increase the rate of phosphorus inflow from the watershed a we get the following graph instead

Engineering Quarterly WINTER 2022

for Lake Mendota are correct but the values of m and r are m = 100, 000kg and r = 800, 000 kg/year. What is the state of the lake and can it be saved?

4. Suppose the values for Lake Mendota are correct and then a developer makes a one-time dump of 40,000kg of phosphorus into the lake. What is the effect on the lake?

6 graphs, pictures, explanations, results, and suggestions for possible solutions.

• Create a LATEX poster using the poster template provided and have it printed on our large format printer in the Engineering office to be used in a poster session presenting your solution.

ENR 351 P ROJECTS

By ERIC GARCIA

5. Suppose the values for Lake Mendota are correct and then a new development raises the phosphorus input level to 8000 kg per year. What is the effect on the lake?

Project Guidelines Your goal is to study the four Yahara lakes in Wisconsin using the simulation methods we explored in class as well as the outline given Junior level civil engineering students which shows that the low level and medium above. The following points are some of the completed several projects in ECI 351 Struclevel equilibria have disappeared and all there ones that you should address in your study. tural Mechanics, a truss bridge and a wind is left is the high level eutrophic one. In this • Explore the issue by searching the tunnel project which was a collaboration with case the inflow of phosphorus from the waterliterature and the internet.

For extheir ENR 306 Fluid Mechanics class. shed is so high that there is nothing that can ample see the article by Dan Corcobe done except try to reduce that inflow. ran which can be found on whywiIn the case where there are both oligidea.journalism.wisc.edu otrophic and eutrophic equilibria the goal • Collect all of the relevant data on would be to reduce the phosphorus concentrathe Yahara lakes: Mendota, Menona, tion to below the unstable equilibrium. Then Kegonsa and Waubesa. These can be it would continue to flow naturally over time found on Wikipedia and other sites. to the oligotrophic state.

Lake Mendota One of the most studied lakes in the world is Lake Mendota which is next to the campus of the University of Wisconsin in Madison. Detailed measurements have been taken over the course of 20 years of the phosphorus levels and phosphorus input to the lake. The following are the estimates of the parameters of the model based on the data:

s = 0.817 /year r = 731000 kg/year m = 116000 kg q = 7.88 Unfortunately there is a huge amount of uncertainty in these estimates and whether the lake can be saved or not depend on these parameters.

Exercises 1. Given the parameters in equation for lake Mendota above, what is the state of the lake?

2. Suppose the values of s, r and m for Lake Mendota are correct but a huge error has been made in the estimate of q so that actually q = 2. What is the state of the lake and can it be brought to oligotrophic equilibrium?

3. Suppose the values of s and q

• Write a computer simulation in C which takes the lake parameters as input (this can be from the command line or read from a file.) and outputs the phosphorus levels in the lake over time.

• Can these lakes be saved? In other words can the input level L or the output levels in the lake be altered in some The truss bridge project is an annual project way so that the lake will switch to an where students are tasked to construct a truss bridge that would span a 10 foot gap only usoligotrophic equilibrium state? ing 1 × 2’s and 1/2in plywood. They had • Run the code for the model given above to design the bridge to not deflect more than and compare with the data.

L/400 (0.3in.) and L/800 (0.15in.) when • Can you can find a modified model that loaded with three team members and just the does a better job of fitting the data than professor, respectively. the model of Carpenter, et.al.

• Come up with some possible solutions to the Eutrophication problem and think of a way to include your solutions in the model. For example you could have nutrients extracted at a certain rate by filtering machines, you could introduce other species into the lake that feed on the algae, or many other possibilities.

The important part is to figure out how to include those effects in your simulation model.

• Explain your reasoning and the math- Students performed analysis of material ematics behind your changes to the strengths, influence lines, deflections using energy methods, and modeling using RISA to model. do the design work.

• Simulate the lake eutrophication over The wind tunnel project was in collabotime with your solutions included in the ration with their ENR 306 Fluid Mechanics model and see how it works. class. Students designed, built and conducted • Write up your project report in LATEX experiments to compare the theoretical forces using the project template provided in- they calculate using the methods they learned cluding the discussion, the source code, in the class to the experimental values.

Engineering Quarterly WINTER 2022

VOL.IV. . . No.2

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could work to distinguish between different led 0 is now 1 species. Of course, finding out all of the base led 0 is now 0 pairs like this in their proper order would al- switching to led 1 led 1 is now 1 ready allow a complete genetic profile and a detected END statement, exiting... statistical analysis like we do here would not be needed. It is interesting though at a more and can be hooked up to physical LEDs for fundamental level. direct control via commands or a script.

CSC 457: Flex Code Here is the flex code: Students designed structures with three varying degrees of roof slope, as well as the test chamber and the sensor mechanisms setup to detect the forces.

led.l %{ i n t led = 0; i n t on = 0 ; %}

ENR 200: Problem 1 Rose = 64 Lily = 64 Tulip = 24 iris = 23 jasmine =2

%% { on = 1 ; p r i n t f ( " l e d %d i s now %d \ n " , l e d , on ) ; } "OFF" { on = 0 ; p r i n t f ( " l e d %d i s now %d \ n " , l e d , on ) ; } "SWITCH" { l e d = ( l e d + 1)%2 ; p r i n t f ( " s w i t c h i n g t o l e d %d \ n " , l e d ) ; } "END" { p r i n t f ( " d e t e c t e d END s t a t e m e n t , e x i t i n g . . . \ n" ) ; exit (1) ; } . { /* skip */ } "ON"

S OLUTIONS TO P ROBLEMS

%% ENR 304: Human DNA The solution to this i n t main ( i n t a r g c , c h a r ** a r g v ) { was given in the problem statement. It is interyylex ( ) ; p r i n t f ( " l e d = %d , \ t o n = %d \ n " , l e d , on ) ; esting that the students who solved this found } some very interesting things. For example, Brian Biver discovered that the the CG base pair occurs with a frequency that is 2/3 that of It is compiled to an executable as follows the AT base pair and that this pattern seems to flex led.l occur with other chromosomes as well. Also gcc -o led lex.yy.c -lfl the frequencies of these base pairs seem to be the same regardless of the chromosome we and tested with are looking at. It seems that if you use the echo "ON OFF SWITCH ON END"|./led lengths of the chromosomes (how many base pairs there are) along with the percentages, it which returns the following control output

ENR 200: Problem 2 num = -20, out = 400 num = 4, out = 64 num = 10, out = 100 num = -2, out = 2 num = -7, out = 100 num = 6, out = 100 num = 0, out = 100

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VOL.IV. . . No.2

Engineering Quarterly WINTER 2022

8