The Cambridge Engineer: Lent Edition 2020

Cambridge Engineering Society Lent · Jan 2020

My first three month in BP

Photo by Zichuan Han from Pexels

Temperature controlled “Incubator” style enclosure

Kilifi Recycle Team

Words from the Diversity Officer

THE CAMBRIDGE ENGINEER CUES MAGAZINE W W W. C U E S . O R G . U K

1

Table of Content Words from CUES Diversity Officer

Sponsor s

My first three month in BP Grants article - Kilifi Recycle Team Grants article - Peter Scott Puzzle Page

2

CUES MAGAZINE W W W. C U E S . O R G . U K

4 10 14 22 28

CUES MAGAZINE W W W. C U E S . O R G . U K

3

this, my role is to help promote engineering diversity within the department e.g. through Outreach activities and by working closely with the CUES Access Officer Areeg. The other part of my role is to help students from under-represented backgrounds with the department to feel more comfortable and confident in the department through workshops, events and schemes.

CUES, with the support of Athena SWAN, started this year off with a bang for the Black History Month display that showcases the stories of black engineers past and present all around the world.

It was hard to manage with the IDP and juggling all that is second year engineering, but the display was put up in the canteen on 1st November and the plan is to roll it out in other sites linked to the engineering department.

H

Words from the

Diversity Officier - Tse

and stereotypes that exist around it. Within

i, my name is Tse (pronounced: Shay). I am a 2nd Year students at St Catharine’s College and am also the Outreach and Diversity for CUES for this year!

I decided to apply for the role for the CUES Diversity Office because I am passionate about changing the stereotype of what an engineer looks like or is like and debunking the myths 4

CUES MAGAZINE W W W. C U E S . O R G . U K

CUES MAGAZINE W W W. C U E S . O R G . U K

5

For Black History Month, CUES (Cam-

over 320 students, I was the only black girl, I often

bridge University Engineering Society)

found myself overthinking things, feeling a strange

put together a display to celebrate the

sense of being out of place and putting unneces-

black engineers and innovators across

sary pressure on myself to show that black girls

the world and over the centuries. The

are qualified and worthy engineers. The feeling

aim of display was to bring to light

could be best described by a quote by Kayisha

some of the amazing and influential

Paine the founder of Black British in STEM (BBM)

that black and minority eth-

contribution black people made in the

a not-for profit organisation that aims to inspire

nic graduates are twice as

field of engineering.

black students to pursue STEM field which states

likely to be underemployed

The display takes viewers through a

that:

two years after finishing

brief and pit-stop history of black engi-

‘[At] industry events, workshops and conferences,

their studies than their white

neers across the world to change the

and I am constantly reminded by the stark lack

counterparts and being in

of representation of black scientists. I have yet

an ethnic minority was a

to attend a conference where there was a black

bigger obstacle to employ-

speaker, or facilitator and I often find that I’m the

ment than any other factor

only black person in the room. When attending

they considered – including

As one of the few black students on

events, should I even be thinking about race? It’s

degree classification, at-

my course, I could understand the

almost impossible. Race inevitably defines the ex-

tending a less prestigious

importance of having black role mod-

periences of who I am, how society identifies me

university, or gender. [2]

els in the engineering field to inspire

and how society interacts with me.’ [1]

This often comes as a result

and motivate you and to reaffirm the

This quote emphasises the importance of increas-

of unconscious bias in the

fact that you are an able, qualified

ing the representation of black people in STEM

recruitment process where

and are following some amazing

fields as well as raising the profile of current and

people are more likely to

foot-steps; you don’t need to look a

past black engineers who made huge contribu-

have a bias to people who

certain way or come from a certain

tions to the field. This personal experience by

background to be an engineer. When

Paine was echoed in a report produced by the

Photo by Ingo Joseph from Pexels

face of what an engineer looks like.

it dawned on me that in my course of

6

CUES MAGAZINE W W W. C U E S . O R G . U K

Photo from Pexels

Article

Royal Academy of Engineering which revealed

CUES MAGAZINE W W W. C U E S . O R G . U K

7

look and may have had a similar experience to them – essentially, a ‘younger them’. This bias in recruitment over the last few years would not have much changed without the active campaigning by various groups to promote women and other under-represent groups in STEM. This unconscious bias works in reverse as well: black children and students would be less likely

It is also hoped that a similar exhibition can be run for

to see themselves in the STEM figures currently in the media which can

other engineers of minority ethnic backgrounds.

make it more difficult for them to see STEM fields as a viable career option for them. Mary Jackson, NASA’s first black female engineer summarised it

Sign Off

nicely in the quote: “We have to do

The plan is to expand this display series out

something […] to

throughout the year to showcase other

get them interested

ethnic minorities groups’ contri-

in science. Some-

tion to the field of engineer-

times they are not

also hoping to run a

aware of the num-

other events and schemes

ber of black scien-

outreach and diversity love so watch this space!

tists, and don't even

Please do let me know if you have any other ideas as to

know of the career

how I can make the engineering department as inclu-

opportunities until it

sive and welcoming as possible!

buing. I am whole host of to share some

is too late.” [3] This display may Photo by Mike from Pexels

not inspire the next

generation of black engineers as it is in a space where most people there have already chosen to study the field of engineering, but perhaps it could bring these issues to light to some of the leading academics and visiting industry figures in the world of engineering.

The hope going into the future would be to bring to light more of the stories

[1] https://www.physoc.org/magazine-articles/the-only-one-in-the-room-why-i-set-up-bbstem/ [2] https://www.raeng.org.uk/publications/reports/employment-outcomes-of-engineering-graduates-key-f [3] https://www.nasa.gov/image-feature/mary-jackson-a-life-of-service-and-a-love-of-science/

of black engineers from a diverse range of periods and backgrounds such as pre-18th Century, Afro-Latino and Caribbean engineers and inventors.

8

CUES MAGAZINE W W W. C U E S . O R G . U K

CUES MAGAZINE W W W. C U E S . O R G . U K

9

"The work is fast paced with multiple prospects being analysed at a time. "

My first three month in BP

L

ooking back over the past three months, I can’t work out where the time has gone! It doesn’t seem that long ago that I was sat in a room with 50 new graduates being inducted into the company. I graduated from Cambridge last year with a Master’s in Chemical Engineering and have joined the Chemical and Process Engineering graduate scheme. I am currently working as a development engineer in GCD’s (Global Concept Development’s) PreGPO (Pre-Global Projects Organisation) team. A development engineer’s job is to undertake the very early stage engineering assessment for development prospects all around the world. We work with the exploration team and other teams within BP to try to estimate the cost of development and decide if the prospect is suitable to progress into more detailed design. The work is fast paced with multiple prospects being analysed at a time. It is really exciting to know that I am working on BP’s future projects and helping to shape their future portfolio.

10

CUES MAGAZINE W W W. C U E S . O R G . U K

CUES MAGAZINE W W W. C U E S . O R G . U K

11

I

t’s not all desk work though, I have had the chance to take part in a wide range of training site visits since starting in September. In my second week, I was lucky enough to visit the carbon capture plant at Imperial College, London. It was really useful to get hands-on experience by going onto the plant and into the control room to see how the equipment operated. Towards the end of October I spent a week in Aberdeen on a training course with some other graduates. I really enjoyed visiting another BP office and spending the week with graduates. The course aimed to teach us the theory of designing and operating production facilities around the world.

12

CUES MAGAZINE W W W. C U E S . O R G . U K

"I feel very lucky to have had such a varied, interesting and enjoyable first few months."

It was very detailed and a lot to take in in a week, but it was incredibly useful to get an understanding of the industry and see how my university content is applied. he following week I had the chance to visit a BP site near Baku in Azerbaijan. This was a fantastic opportunity and I found the week really rewarding. The purpose of the visit was to perform a constructability review for a project on the site. It was invaluable to see how the equipment looked, operated and compared to the design on paper.

Baku itself is a fascinating city from the UNESCO world heritage site in the old town to the huge skyscrapers shooting up in the

T

Photo by Igor Starkov from Pexels

new town. You can really see the influences of both Asia and Europe!

Most recently I took part in the Upstream graduate induction week where we spent time getting to know each other and learnt about all the different aspects of the upstream business including playing an energy company simulation game. feel very lucky to have had such a varied, interesting and enjoyable first few months. I feel that I have been given real responsibilities and projects and the people I have met have been interesting and very generous with their time. I look forward to the rest of the year!

I

CUES MAGAZINE W W W. C U E S . O R G . U K

13

Grant Article

The Shredder

T

Photo by Artem Beliaikin from Pexels

Kilifi Recycle Team

Introduction

F

ollowing the work initiated by a group of MET students from 2018 where they developed a machine to turn plastic waste and sand into floor tiles, over the last year, the Takaungu community built another machine and started using them to make bricks. Our team of six first-year engineers worked on

14

CUES MAGAZINE W W W. C U E S . O R G . U K

this task since January with the aim of making the process of making bricks more efficient. We are grateful for the funding we received from CUES which allowed us to properly research the different problems and existing solutions, develop designs for a second-generation kiln and shredder, prototype and iterate the final design in the Dyson Centre and ultimately go to Kenya to build them.

he aim of the shredder was to shred whole plastic bottles into smaller pieces with the aim of reducing the time taken to melt the plastic bottle, thus reducing both labour time and the amount of firewood required. These two reductions would also lead to a reduction in the production costs of each brick making it a more viable building material for the community.

While inspiration was taken from the open source Precious Plastics, we adapted it to make the shredder compatible with a bicycle to allow sustained use of the machine. To this end we plasma cut the pieces required for the shredder unit (i.e. the blades and the frame) in the UK and added a bicycle as a power source.

C

oming to Kenya, the plan was to assemble the pieces and weld structures in place. However, we understood the importance of co-creation throughout the project and we were open to the ideas and suggestions of the fundi technicians and other community members. Examples of this was when we replaced the uni-struts and slotted angles we had initially used to build the bicycle and shredder stand with rebar which the technicians felt more comfortable working with.

O

ne of the biggest challenges faced with the build and implementation of the shredder was trying to make such an intricate piece of machinery function in the environment it would ultimately be in in the recycling centre. This was often outdoor, rocky, corrion-prone environments. To this end, we faced multiple problems with our axle getting stuck due to rust; being able to properly brace the machine to keep it stable while in use; and the alignment of the blades. It tooks us numerous attempts over the majority of days to address each one of the re-

curring problems one after the other. Towards the end of the trip, we tried an alternative approach and decided to investigate methods to power the shredder by hand as opposed to the cyclepower.

A hand powered shredder may have made the shredder more difficult to power for

CUES MAGAZINE W W W. C U E S . O R G . U K

15

long periods of time compared to a bicycle but meant the issues such as excess torque were addressed.

This design change worked relatively well and could shred partially cut bottles. In addition, the circular wheel handle also acted as a flywheel for the system. This meant that although it might be harder to get the shredder to start with these changes, the system didn't jam so easily.

W

e are glad to say we left the community with a working shredder with identified areas of improvement to help boost cutting efficiency. The next steps for the team in Cambridge would be to look at designing a shredder that could be fully made and assembled with the tools and resources available to the community in Takaungu.

Inspection of the existing two first-generation kiln

The Kiln Overview ver the summer of 2019, the kiln team worked on developing their design concept, prototyping in cardboard and sheet metal, and finally modelling the effects of the proposed design changes. The main features of the second-generation kiln focused on the combustion chamber which would now

O

Inspection of the existing two first-generation kiln

16

CUES MAGAZINE W W W. C U E S . O R G . U K

have a sheet metal, rather than oil drum, enclosure, would have an insulation layer and would have air intake from the bottom rather than sides. The design was modelled in Autodesk CFD, which showed a significant improvement in the performance of the kiln, particularly in heat retention of the combustion chamber. The designs and manufacture plan were prepared with as much detail and flexibility as possible, which guided the team step by step when we arrived in Kenya.

Manufacture in Kenya ur initial steps were to first gather information about the state of the first-generation kilns: how they worked, how they were used and how they were maintained over the year. We found that most of the machine was either badly rusted or worn away by intensive use. Therefore, we took the decision to both remake the plastic chamber and chimney, initially planned to be taken from the existing machines, out of galvanised steel to protect against rust, to ensure its long-term durability. uring the manufacture, we learned a great deal from talking and working with the fundi technicians who were creative and industrious: they continually provid-

O

D

CUES MAGAZINE W W W. C U E S . O R G . U K

17

Photo by Quang Nguyen Vinh from Pexels

ed insight into how our proposed design could be modified and improved given the constraints of the immediate environment of Takaungu.

F

Testing n the last two days of the trip, we tested our machine. A total of five full tests were carried out with the primary purpose of producing bricks that could be examined back in the UK. This involved changing the ratios of sand to plastic as well as the type of plastic.

O

I

mprovements to the kiln were carried out immediately after the first test, addressing issues of blade contact and wear against the base of the plastic mixing chamber, widening the chimney hole and air intake slits and refining the procedure itself, specifically the management of the fire. n the last day, we carried out a full demonstration and presentation to the Takaungu community. During the hour-long demonstration, we presented our design and in return, the villagers asked questions and gave feedback on different aspects of it. It was the culminating point of the trip where

O

18

CUES MAGAZINE W W W. C U E S . O R G . U K

the project was shown as a collaborative enterprise that the whole village could partake to take charge of their environmental and economic development.

Academic and Personal Development

T

he experience as a whole fostered a spirit of collective learning and practice, widened our understanding of what it means to engage in sustainable development and allowed us to explore the dynamics of working as a team.

irstly, we learned about what it means to design for people. We understood that formulating grand plans or in-depth calculations were often ineffective and actually inhibited the progress of the manufacture, and rather testing ideas as we developed them was more effective. This meant that making mistakes led to insight that could allow us to address that problem in the next iteration. Realising that each and every person who talked with us or even observed the project from afar could be co-creators in that design process allowed us to reach out to greater numbers and draw them closer to the heart of the project. Many of these understandings will prove essential in our academic lives as we participate in countless projects that design products for people.

S

econdly, we developed our understanding of how sustainable development takes place and the conditions that are conducive to this process. As the project progressed, we began to realise the wider social implications such an initiative could have on a community’s way of life. Shifting our concep-

CUES MAGAZINE W W W. C U E S . O R G . U K

19

tion of the priorities that were prevalent in European thought to that of the Kenyan’s formed a key part of our discussions around the future of the project. At all times, we were aware of the significant interest being generated throughout Takaungu and we tried to learn how we could channel that interest into further engagement and ultimately drawing them closer to the project as a co-participant in bringing this recycling centre to fruition. Essentially, we developed our personal capacities to guide and accompany others in a process of sustainable development as well as strengthened our desire to continue using our engineering knowledge and skills towards the end of bettering communities.

F

inally, we had to learn to learn, discuss and act as a team. The importance of being aware of one’s contribution of ideas and attitude towards the group whilst being conscious of the spirit and collective 20

CUES MAGAZINE W W W. C U E S . O R G . U K

understanding of the group as a whole was underlined as the days passed. Each member of the group became more aware of their characteristics as an individual in group discussions, reflected on how they could work more effectively to achieve unity of thought within the group and as a result, the team advanced more coherently and with greater purpose. We found ourselves returning again and again back to clarifying the purpose and vision of each task in order to focus attention on tasks and ensure everyone is moving together. The twelve days we spent eating, working, and living with each other became a joyous time to learn together, as colleagues and as friends, as we drew closer through the spirit of fellowship that increasingly marked our interactions as the hours progressed. These personal as well as collective learnings about working effectively as one team will permeate our activities, both in the academic and social sphere, as we return to Cambridge and beyond.

CUES MAGAZINE W W W. C U E S . O R G . U K

21

Grant Report

by Peter Scott Grant Application

T

emperature controlled “Incubator” style enclosure, for low volume production of fermentation products such as Kefir.

W

orking on the request of a family member for a small size temperature-controlled enclosure for a more reliable fermentation time on their homemade Kefir, I have already prototyped a simple polystyrene box with Peltier heat pump controlled by a thermostat circuit. I would like to produce a more permanent version of this with some improvements: - Custom size and shape 3D printed enclosure to fit a glass jar while reducing footprint - Ability to cool as well as heat using Peltier module (optimum temperature for 24h fermentation is ~18°C, which could be above or below room temperature) Digital Circuitry to provide datalogging and graph display, possibly time varying temperature profile High resolution temper-

ature control, preferably below 0.1°C Improved user input (current temperature control is a very sensitive potentiometer)

A

s part of this project I would like to explore the possibilities of using low infill density 3D printed parts as an insulator instead of polystyrene.

A

CUES grant would go towards 3D printing costs (My aim is to work in the Dyson Centre over the Summer vacation) as well as materials and electronic components including a microcontroller, temperature sensors, display and possibly a custom PCB. Summary of Activities Undertaken

T

he first step of development was to verify that the ‘Stack’ (consisting of the Peltier heat pump, external heatsink and internal aluminium plate) would be able to perform to requirements. The plate and heatsink were sized to be slightly larger than the largest diameter glass jar to be used in the fermentation process. The choice of a TEC112706 heat pump was purely for its ubiquity and low price. As the fermentation time for Kefir is about 24 hours, I set a goal of the fermentation product reaching within 1°C of desired temperature within 2 hours.

A

nnoyingly, testing was during the hottest summer

Display Examples (top: readout, bottom: graph)

Initial Model for testing Upgraded test setup 22

CUES MAGAZINE W W W. C U E S . O R G . U K

CUES MAGAZINE W W W. C U E S . O R G . U K

23

Photo by Kaboompics .com from Pexels

Final PCB Design

on record and carried out in my attic room in college, meaning environmental conditions were very different to the ones experienced by the prototype (a cold kitchen during winter). Focussing on the cooling capabilities of the heat pump, I quickly found that a fan would be needed to remove heat by convection from the hot external heatsink to enure a large enough temperature difference could be achieved between the environment and the cold internal plate.

tact between the concave bottom of the jar and the aluminium plate. Throughout the summer I experimented with thermal interfaces between the plate and jar to improve performance, but I am yet to find something with good thermal conductivity that is food safe, as well as soft enough to provide good contact to both surfaces. Glass containers are much preferred over stainless steel for home fermentation as they are easy to source, clean, sterilise and observe the fermentation process. Also concerns were raised that the acidic fermentation product could have a chemical effect on stainless steel and that an electrochemical cell could be formed between dissimilar metals if condensation formed.

T

he upgraded setup included a fan blowing air upwards at the heatsink, and a 3D printed housing with lid to provide insulation. Measurements were taken of outside air temperature, surface temperature of the aluminium plate and the temperature of water in a glass jar, standing in for the Kefir.

T

he limiting factor in heat transfer to and from the water was found to be the glass jar used for fermentation. This is because of the low thermal conductivity of glass, and also poor con-

24

CUES MAGAZINE W W W. C U E S . O R G . U K

T

he electronics design is based on an ATSAMD21E18 ARM Cortex M0 microcontroller. A bootloader provided by Adafruit allows this single chip to run arduino code and provide serial debugging over USB. I individually tested the functional parts (Temperature sensing, Peltier control, OLED display, Rotary encoder) on a bread-

CUES MAGAZINE W W W. C U E S . O R G . U K

25

Second Enclosure Design

board to ensure they would work.

I then designed a circuit schematic and PCB in EAGLE which I had produced by JLCPCB. Using the IC oven in the Dyson Centre I was able to solder all the components and program the bootloader with open source software on a Raspberry Pi. The PCB was designed such that a single board could be populated and soldered, then broken up into smaller parts for mounting in the final enclosure. designed a second revision of an enclosure which would be suitable for use by the user.

The aims of this second design was to reduce the number of parts to print separately and assemble, provide dedicated locations to mount electronics and the user display and rotary encoder, as well as add a door to access the inside.

I

T

his version of the enclosure is currently with the user and although has only been opera-

26

CUES MAGAZINE W W W. C U E S . O R G . U K

tional for about a week has been successful in speeding up the fermentation process compared to before its introduction, when temperatures had dropped significantly enough to cause fermentation to take over 24 hours.

Using USB serial data it was possible to plot a graph to show that 300ml of water at 8°C could be heated to 18°C in about 3 hours using a 5V 800mA supply. The user likes the easier user interface compared to the prototype, which allows setting the desired temperature in 0. 1°C increments with a clicky rotary encoder. The feedback from the OLED screen of current temperature and heating/cooling status also reassures the user that the system is working properly.

W

ith the possibility of making more enclosures for friends and family I will need to work on simplifying the design. The current print time for all the 3D printed components is over 5 days and the cost of plastic is a significant portion of the overall cost of the product. One possible improvement is replacing the upper housing with a readily available polystyrene one. Although 3D printing this gives flexibility to the design, it takes the most time and plastic to make without being a functional improvement over polystyrene while also being prone to damage.

I

also wish to do further investigation into making my own thermal interface material from silicone mixed with graphite or another conductive powder.

Enclosure in use ->

CUES MAGAZINE W W W. C U E S . O R G . U K

27

Crossword Source: RF Cafe

Crossword

ACROSS 4Powerful celestial radio source 7Adjust the specification for temperature 9Peak Inverse Voltage 11Adds an impurity to a semiconductor 12First magnitude star in Auriga 13Equal about an axis 15German physicist after whom theuncertainty principle is named 17Type of current 20Chemical symbol for arsenic 21Put a new program on a computer 22The most common conductor metal 24Type of power supply25Web page language 26Ham's code for "What is the name of yourstation?"

27Meet all test requirements DOWN 1BASIC looping keyword

28

CUES MAGAZINE W W W. C U E S . O R G . U K

2Stock symbol for Boeing 3The "K" in ASK 5Unit of capacitance (abbr.)

6Brightest star in the Aquila constellation 8X-ray film image (pl.)

9Time duration of an energy signal (2 wds.)

10Numbers that can be expressed as a/b,where a, b are integers 11Atmospheric condensation cool surfaces 14Determined the similarity of twowaveforms as a function of a time 15Vacuum tube element that generates freeelectrons for current flow 16Assemble 18Run through compliance testing 19Pulse used to initiate a circuit action 22The shortest-duration modulation state ina spread spectrum system 23Unintentionally change the oscillatorfrequency 24Subject a circuit to extreme operation