ByDr. Rathnasiri P.G

Dept of Chemical and Process EngineeringDate 10th May 2010 at DCPE

INTRODUCTION TO RESEARCHMETHODOLOGIES

Outline of presentation

What is research problem . Identifying your research problem Role of supervisor Expectations from a research studyConceptual diagram for explaining your research How to write a literature survey Define objectives of your work How do you achieve your objectives – Materials

and methods Conclusions drawn from your work What is your contributions to existing knowledge

What is the research problem

The research problem is one or two sentences that cannot be answered `yes' or `no'; it is the broad problem that the researcher will examine more precisely in the hypotheses and is the problem prompting and placing a boundary around the research without specifying what kind of research is to be done

Research problem

Research questions or hypothesis not answered in previous research

Literature review including parent disciplineResearch problem

area

Boundaries of research problem

Part of the research problem solved in previous work

Research methodology introduced in my studies

Waste (water) treatment

Anaerobic digestion process

Stability of the process

Membrane bioreactor technologies

Micro aerationMembrane micro aerated anaerobic biofilm

Role of facultative heterotrophesin an anaerobic sludge

Facultative zone

Ana

erob

ic z

one

(mic

roni

ches

)

Bulk liquid phase

AcedogensAcetogensHydrogenotrophesAcetoclastic methenogens

Facultative heterotrophesand methanotrophes

CH4

CO2

1.5

mm

0.1mm

Oxygen

How M.Sc research differs from P.hD researchThe research problem in a PhD thesis is often

more theoretical than the from Master’s theses , for a PhD research problem should not be merely a `problem-solving' one but should `test out' the limits of previously proposed generalizations (Phillips & Pugh 1987, p. 45). That is, `[PhD] research, even when narrowly and tightly defined, should be guided by some explicit theoretical or conceptual framework' and without this, the thesis becomes a `mindless ... theoretical wasteland' (Adams & White 1994, pp. 566, 574).

Expectations from a research

A distinct contribution to a body of knowledge through an original investigation or testing of ideas, worthy in part of publication

Competence in research processes, including an understanding of, and competence in, appropriate research techniques and an ability to report research

Mastery of a body of knowledge , including an ability to make critical use of published work and source materials

Background to research problemIn scientific journal how they address this issue

Establish overall field

Summarize previous research

Indicate the research gap

State what you want to do

Outline your work

What is Literature"the literature" means the works you consulted in order to

understand and investigate your research problem.

.

Books: books tend to be less up-to-date than for a journal article. Text books are unlikely to be useful for including in your literature review as they are intended for teaching, not for research

Journal articles: up-to-date information.for research, and because all reputable journals are refereed

Conference proceedings: these can be useful in providing the latest research, or research that has not been published. They are also helpful in providing information on which people are currently involved in which research areas, and so can be helpful in tracking down other work by the same researchers

Theses and dissertations: these can be useful sources of information. However there are disadvantages: 1) they can be difficult to obtain since they are not published, but are generally only available from the library shelf or through interlibrary loan; 2) the student who carried out the research may not be an experienced researcher and therefore you might have to treat their findings with more caution than published research.

Why write a literature review

The literature review is a critical look at the existing research that is significant to the work that you are carrying out. Although you need to summarize relevant research, it is also vital that you evaluate this work, show the relationships between different work, and show how it relates to your work. In other words, you cannot simply give a concise description of, for example, an article: you need to select what parts of the research to discuss (e.g. the methodology), show how it relates to the other work (e.g. What other methodologies have been used? How are they similar? How are they different?) and show how it relates to your work (what is its relationship to your methodology?).

Keep in mind that the literature review should provide the context for your research by looking at what work has already been done in your research area. It is not supposed to be just a summary of other people's work!

Your literature review should answer following questions

What do we already know in the immediate area concerned? What are the characteristics of the key concepts or the main

factors or variables? What are the relationships between these key concepts, factors

or variables? What are the existing theories? Where are the inconsistencies or other shortcomings in our

knowledge and understanding? What views need to be (further) tested? What evidence is lacking, inconclusive, contradictory or too

limited? Why study (further) the research problem? What contribution can the present study be expected to make? What research designs or methods seem unsatisfactory

See literature survey done by a research student, What is wrong

JACHOWSKI (1964) developed a model investigation conducted on the interlocking precast concrete block seawall. After a result of a survey of damages caused by the severe storm at the coast of USA, a new and especially shaped concrete block was developed for use in shore protection. This block was designed to be used in a revetment type seawall that would be both durable and economical as well as reduce wave run-up and overtopping, and scour at its base or toe. It was proved that effective shore protection could be designed utilizing these units.

HOM-MA and HORIKAWA (1964) studied waves forces acting on the seawall which was located inside the surf zone. On the basis of the experimental results conducted to measure waves forces against a vertical wall, the authors proposed an empirical formula of wave pressure distribution on a seawall. The computed results obtained by using the above formula were compared well with the field data of wa

How to write a good literature review

Features of a good review

Remember the purpose: You'll see that you should use the literature to explain your research - after all, you are not writing a literature review just to tell your reader what other researchers have done. You aim should be to show why your research needs to be carried out, how you came to choose certain methodologies or theories to work with, how your work adds to the research already carried out, etc.

Read with a purpose: you need to summarize the work you read but you must also decide which ideas or information are important to your research (so you can emphasize them), and which are less important and can be covered briefly or left out of your review. You should also look for the major concepts, conclusions, theories, arguments etc. that underlie the work, and look for similarities and differences with closely related work. This is difficult when you first start reading, but should become easier the more you read in your area.

Write with a purpose: your aim should be to evaluate and show relationships between the work already done (Is Researcher Y's theory more convincing than Researcher X's? Did Researcher X build on the work of Researcher Y?) and between this work and your own. In order to do this effectively you should carefully plan how you are going to organize your work.

How to be more specific in literature

When you read for your literature review, you are actually doing two things at the same time

you are trying to define your research problem: finding a gap, asking a question, continuing previous research, counter-claiming

you are trying to read every source relevant to your research problem.

Naturally, until you have defined your problem, you will find that there are hundreds of sources that seem relevant. However, you cannot define your problem until you read around your research area. This seems a vicious circle, but what should happen is that as you read you define your problem, and as you define your problem you will more easily be able to decide what to read and what to ignore

New contribution with respect to existing MBR technologies

Membrane attachedbiofilm reactors

Membrane Aerated BiofilmReactors (MABR)

Extractive MembraneBioreactor (EMB)

Organic carbon degradation,Nitrification and Denitrification

Organic Carbon degradation

Volatile Organic Carbon Degradation

Membrane Biofilter

Membrane Microaerated Anaerobic Digester (MMAD)

Micro aeration in Anaerobic conversion process

Structured approach to research

Candidates research

Body of knowledge

INTRODUCTION

Model and hypothesis

Analysis of collected

dataMethods for

Data collection

Contribution to

Body of knowledge

Bioenergetics of micro aerationNew bioenergetic model for micro aeration

Aerobic growthO2 for 1C-moleGlucose

Limited O2

supply rangeAerobicityParameter (Ω)

O2 in TCA andFermentation paths

ATP andBiomass yield

Balanced growthreactions

Enthalpy and free energy in solution

Elementary, Heat & Free energybalance

Solution technique using MATLAB

Stoichiometry, heat &free energy dissipation forMicro aerated anaerobic process

New strategy developed for Membrane Micro-aerating Anaerobic Process

SubstrateMembrane BiofilmO2

O2

CO2 and CH4

O2

O2 and small amountof CO2 and CH4

CO2 ,CH4 and biomass

CO2CH4

Oxygensaturatedwater

O2 in H2O

Feed

Membraneloop

CH4 CO2

AD

O2 in H2O

Introduction to MMAD principle

Fig. 1-6, page 9

• Micro-aeration and bioenergetics• micro-aerating techniques• Oxygen mass transfer• MMAD• In-situ OTR measurements• Characterization of biofilms• Membrane for monitoring• Mathematical modelling

Challenges in my research study

Materials and Methods

[2]. Batch reactor experiments for acclimation of inoculums

[6]. Transient responses usingbatch experiments

[3]. Intermittent micro aeration and in-situ OUR measurements

[4]. Continous micro aeration using external membrane loop

[5]. External reactor chamber experiments for biofilmcharacterization

[1]. Mass transfer analysis of a membrane loop reactor

Development of Membrane Microaerated AnaerobicDigester (MMAD)

Schematic diagram of newly developed MMAD

Dis

solv

ed o

xyge

nin

wat

er

Rub

ber

cap

Sili

cone

tub

ular

mem

bran

esM

etal

tub

es

Dis

solv

ed o

xyge

nin

wat

er

Rub

ber

cap

Sili

cone

tub

ular

mem

bran

esM

etal

tub

es

Auxiliary batch experiment supporting MMAD experiments

Schematic diagram of the batch experiments

(1) anaerobic digester (1 liter glass bottle) (2) water bath, (3) thermo meter, (4) liquid inlet / outlet (feeding and removal of mixed liquid) (5) gas sampling outlet (6) Teflon tube for gas flow outlet (7) cover (to prevent evaporation of water) (8) insulation layer (9) magnetic stirrer and heater (10) gas collection bottle with barrier solution (11) gas release valve (12) liquid transmission tube (13) liquid collection bottle (14) supporter (15) electronic scale.

Mass transfer analysis

1 2

3

7

9

10

11

4

5

6

8

12

1. Transmitter for O2, pH and redox (Mycom CPM 152), 2. Potentiometer (LAZER Research lab), 3. Temperature controlled chamber, 4. Glass reactor, 5. Tubular silicone membranes (Versilic-saint gobain,France), 6. Microelectrode (Model DO-166FT), 7. Magnetic stirrer, 8. Peristaltic pump (Ismatec mini-660), 9. Nitrogen supply, 10.Magnetic stirrer, 11. Water beaker, 12. Air/pure oxygen supply.

Schematic view of membrane loop reactor

Results from batch experiments

Transient VFA accumulation from ‘shock load’

Slight

Medium

StrongUse modeling whenever experimentingIs difficult

Continuous micro-aeration

6

6.1

6.2

6.3

6.4

6.5

6.6

6.7

6.8

6.9

8:44

:06

9:34

:07

10:24

:07

11:14

:07

12:04

:08

12:54

:08

13:44

:08

14:34

:09

15:24

:09

16:14

:09

17:04

:10

17:54

:10

18:44

:10

Time

Ox

yg

en

co

nc

en

tra

tio

n

in m

em

bra

ne

tu

be

(m

g/l)

Measured data

20 per. Mov. Avg.(Measured data)

Not feeding MMAD at 10.00 am

No feeding Intermittent feeding

Oxygen concentration varying inside close membrane loop

Bulk phase VFA during continuous micro aeration

0

20

40

60

80

100

120

140

160

180

200

0 5 10 15 20 25

Time (hr)

VF

A (

mg

/l)

Acetic acid

Propionic acid

Total VFA

C. Measured and simulated specific biogas production rates

Results from batch experiments

Scenario 1. Slight inhibition (OLR-2 and 1day NFP) Scenario 2. Medium inhibition (OLR-4 and 2 day NFP) Scenario 3 Maximum inhibition (OLR-3 and 8 day NFP)

Scenario 1 Scenario 2

Scenario 3

Modeling for parameterestimation

Bioenergetics of micro-aeration

Effect on biogas composition

Effect on biomass yield

CONCLUSIONS

•Shock load; reduced methane production

•Shock extent depends on load/biomass ratio

•ADM1 simulate transient responses for moderate shock loads

•Bioenergetic model; oxygen supply range for micro aeration

•Micro aerobic heat dissipation resemble anaerobic growth

•New micro aeration strategy; controlled oxygen supply to anaerobic process

•No oxygen transfer to head space after biofilm development

•Highest OTR in membrane lumen just after feeding MMAD

•OTR is function of OUR in membrane biofilm

•VFA in bulk phase is in phase with lumen oxygen profile

CONCLUSIONS

Biogas composition and production do not vary with/without micro aeration

OUR is mass transfer limited not reaction limited

Biofilm activity is independent of aeration history

Facultative heterotrophes are abundant in MMAD