APETT Engineering The Association of Professional...
Transcript of APETT Engineering The Association of Professional...
APETT Engineering
Magazine June 2018
June 2016 Edition
June 2018
Edition
The Association of
Professional Engineers of
Trinidad and Tobago
APETT’s Mission:
The Association of
Professional Engi-
neers of Trinidad and
Tobago is a learned
society of profession-
al engineers dedicat-
ed to the develop-
ment of engineers
and the engineering
profession. The asso-
ciation promotes the
highest standards of
professional practice
and stimulates
awareness of tech-
nology and the role
of the engineer in
society.
ISSUE 5
June 2018 Edition
Page 2 APETT Engineering Magazine June 2018
TABLE OF CONTENTS
Pipeline Hydraulic (Line Pack)
By: Vicard Gibbings
Article References
DISCLAIMER: Statements made and information presented by contributors to this Newsletter do not necessarily reflect
the views of APETT, and no responsibility can be assumed for them by APETT or its Executive Members and Editors.
Increasing Impact of Corrosion Control due to Change in Global Climate
By: Jerome Marshall
Page 6
Page 10
Application of Organic Communication Channels
By: Aaron Roopnarine and Dr. Sean Rocke Page 13
Hybridization of the Direct Stiffness and Macaulay Methods of Structural
Analysis
By: Jovon Jacob
Page 16
The Environmental Impacts of the Cement Manufacture Process
By: Jonathan V. Juman and Saara Sultan
Page 19
Page 26
Misunderstandings about Building Codes and T&T
By: Richard Clarke
Page 21
Page 23
Editor’s Message
Eng. Julio Bissessar Page 3
Eng. Julio Bissessar is cur-
rently a Management Trainee
and Technical Analyst for the
Senior Advisor at Massy Energy
& Industrial Gases Business
Unit. He is involved on a full-
time basis in the construction
and commissioning of the
CGCL Plant in La Brea. He has
over two years experience in
Process Engineering both at
Atlantic LNG and Petrotrin.
Julio holds a Masters of Engi-
neering in Process Engineering
from UTT and has won numer-
ous engineering competitions
solely and as a team including
BP’s UFT and the Prime Minis-
ter’s Awards for Scientific Inge-
nuity. Julio has avid interests and experience in Energy, Plant
Optimization and Design Engi-
neering as well as Mathematical
Modelling and Simulation De-
velopment.
Hello and welcome to another edition of APETT’s Engineering Magazine!
In this edition, we have a number of articles ranging from a beautiful fluids
problem in the upstream sector to the technical aspects of building foundations
and structures.
We continue to see the addition of value to the energy sector by our extremely
skilled and competent local engineers. Just by observation of the articles, it is
apparent of the level of technicality required which we engineers sometimes
take for granted. We must always take a step back and look at how our impact
affects the grander scheme of things.
As we head towards new local developments in the areas of renewables and
green energy, some of the articles featured touches on some of these factors
such as global warming impacts and the use of organic communication chan-
nels. It is extremely exciting to see what the future holds for us here in T&T.
I would like to thank all of my fellow editors who assisted greatly with the de-
velopment of this magazine. I would also like to give a special thanks to Eng.
Anna Warner and Eng. Vicard Gibbings for their continued support in ensur-
ing that this magazine is published to the highest standards and quality on
time.
Cheers!
Julio
Ms. S. Valerie Kelsick has an
extensive and diverse background covering over thirty (30) years com-bined experience in project manage-
ment, project finance, banking, finan-cial and management consulting, facility maintenance and consulting
engineering.
Ms. Kelsick holds an MBA in Finance & International Business, from Co-lumbia Business School (USA), a Bachelor of Science degree in Civil
Engineering from the University of Southampton (UK) and the PMI’s Project Management Professional
(PMP) (USA) credential. She is a Registered Engineer with the Board of Engineering as well as a Fellow of
the Association of Professional Engi-neers of Trinidad & Tobago. She also possesses various professional
credentials having completed cours-es including Chartered Director Programme from Caribbean Corpo-rate Governance Institute (TT),
public private sector partnerships, mediation and construction con-
tracts.
She is a project manager at Republic
Bank Limited managing construction and bank related projects. Ms Kel-sick is the current President of the
Association of Professional Engi-neers of Trinidad & Tobago (APETT) and also serves on the
Board of the Fondes Amandes Reaforestation Community Project
(FACRP).
Message from APETT’s President
Page 4
We are living in the best of times and the worst of times. Rapidly changing
technologies and new innovations lead to enhanced and deeper knowledge
whilst also causing some uncertainty and disruption. Engineers are faced
with the task of designing and implementing resilient systems and infra-
structure which will withstand adverse effects of climate change and increased
frequency and forces of natural disasters. Competing demands on limited
available financial, human and economic resources also demands of the Engi-
neer to continue to discover alternative viable options. We must commit to the
mandate for continuous professional development.
We applaud our contributors in their quest to produce worthy articles based on
sound research, analyses and practical applications. We also express our heart-
felt thanks to our Magazine Editor Eng. Julio Bissessar and the rest of his
hardworking team for their outstanding commitment to deliver this publication
which covers the full range of the core engineering disciplines. We are notably
impressed by the extent of the critiques. Future contributors, take note!
I would like to remind all members as well as inform the rest of the readership
that APETT will be hosting our annual Honors and Awards function as well as
our Technical Conference entitled “Engineering for Competitiveness: Re-
Booting Our Economy”, successively in September 2018. We too must observe
frugality.
Finally, we encourage us all to continue to support the APETT Magazine by
submitting articles for publication.
Valerie Kelsick
Page 5 APETT Engineering Magazine June 2018
Page 6 APETT Engineering Magazine June 2018
Pipeline Hydraulic (Line Pack)
By: Vicard Gibbings, B.Sc., AMAPETT, AMIChemE
Line Pack A pipeline, particularly in the oil and gas industry is used to transport natural gas from production well head to consumers
(few to several hundred miles in-between) and can also be used to store that gas before and during transportation to con-
sumers. Noteworthy, the compressibility of the gas allows the storing of gas in pipelines to be performed, temporarily. This
technique is called Line Packing, i.e., a method used for providing short-term gas storage in which natural gas is compressed
in transmission lines, providing additional amounts of gas to meet limited peak demand. Therefore, by using the line packing
technique, sustainability of gas supply to consumers can be ensured if there is an increase for gas demand or a problem
encountered by an upstream producer.
Generally, in a natural gas transfer pipeline, gas flows from point ‘A’ to point ‘B’. Main properties such as pressures and
temperatures vary along the pipeline length. In a single-phase line (Gas only or Liquid only), the volume of the respective
fluid contained in a given length of pipeline is simply the physical volume of the pipe segment. For example, consider a 1-
mile Nominal Pipe Size (NPS) 16-inch natural gas pipeline. The physical volume of the gas in this pipeline will be 7000 ft3.
This pipeline volume will represent the volume of gas in this 1-mile section at the actual gas temperature and pressure.
This also applies for single-phase liquid pipelines, for example in condensate transfer pipelines. The quantity of gas con-
tained within the pipeline under pressure, measured at standard conditions (generally 14.7 psia and 60°F), is termed the
line pack volume whereas for single-phase liquid pipeline, the ‘pack volume’ is simply the physical volume of the pipeline
since liquid is incompressible. However, there are some instances where the fluid in the pipeline can experience two phase
phenomena – a particular example of multiphase flow. This will be explained in the Line Pack Calculation (Multiphase Meth-
od).
Line Pack Calculation (Single-Phase Method)
Consider pipe segment, of length L and inside diameter D, with upstream pressure (P1) and temperature (T1) and down-
stream pressure (P2) and temperature (T2), then the physical volume (Vp) of the pipe section is given by equation (1):
…Equation (1) (E. Shashi Menon, 2005)
This volume is the gas volume (assuming single-phase vapour) at pressures and temperatures ranging from P1, T1 (at the
upstream end) to P2, T2 (at the downstream end) of the pipe length L with internal diameter D. The gas volume calculated
is at actual conditions and thus needs to be converted to standard conditions of pressure (Pb) and temperature (Tb). We
apply the gas law in equation (2):
…Equation (2) (E. Shashi Menon, 2005)
Where Pavg = average gas pressure in pipe segment, Tavg = average gas temperature in pipe segment, Zavg = average gas com-
pressibility factor at Tavg and Pavg, Zb = compressibility factor at base conditions ~1.00 and Vb = line pack volume in pipe
segment at standard conditions. The average pressure (Pavg) is calculated from the upstream and downstream pressures, P1
and P2 respectively, using equation (3) below. This equation was utilized since at larger pressure drops, the percentage er-
ror increases.
Page 7
In addition, pressure drop vary non-linearly and the equation used can be the best representative of calculating Pavg. The
average temperature (Tf) can be taken as the arithmetic mean of the upstream and downstream temperatures T1 and T2
respectively. This approach for average temperature will be accurate only if we consider short segments of pipe. Finally, the
compressibility factor, Z can be calculated using equation (4). It is important to note that this compressibility factor is valid
when the average gas pressure is greater than 100 psig. For average pressures less than or equal to 100 psig, Z is approxi-
mately equal to 1.00. Alternatively, we can use an engineering software such as Aspen HYSYS to get the Z-value.
…Equation (3 ) (E. Shashi Menon, 2005)
…Equation (4) (E. Shashi Menon, 2005) Where G is the gas gravity (air =1)
From Equation (2), solving for line pack Vb at standard conditions, we get
…Equation (5) (E. Shashi Menon, 2005) Substituting Vp from equation (1) into equation (5) into yields
…Equation (6) (E. Shashi Menon, 2005) Where Vb = line pack in pipe segment in standard ft3, D = pipe inside diameter in ft, L = pipe segment length in ft. Since the pressure and temperature in a gas pipeline vary along the length, to improve the accuracy of calculations, the line
pack volume Vb is calculated for short segments of pipe and summed to obtain the line pack of the entire pipeline . It can be noted that the above calculation method is done for single-phase vapour. If liquid only is present in a pipeline, the
physical volume of the pipe will give you the volume of liquid in the pipeline as this fluid is incompressible. Refer to Equa-
tion (1).
Two-Phase Phenomena
In this discussion, before calculating the ‘Gas or Liquid Only’ Line Pack Volume in a multiphase pipeline, we need to under-
stand the phase behavior of two-phase fluid (multiphase) pipeline. Phase Behavior sometimes called Pressure-Volume-
Temperature (P-V-T) data is an important aspect for engineering designs especially in pipelines. Therefore, we need to have
accurate models to predict the accuracy of the P-V-T properties, especially in a gas as this is critical for pipeline design, gas
storage and gas measurement. It is necessary to distinguish between the transportation of ‘dry gases’ (no liquid, only va-
pour) and ‘wetter gases’ (multiphase conditions experience due to condensate dropout) as these can affect the cost and/or
supply expectations of the producer and consumer.
When gas flows through a pipeline, pressure and temperature changes (P-T trace) and this may cause formation of a liquid
phase owing to partial condensation of the gaseous medium. Retrograde phenomenon — typically found in multi-
component hydrocarbon systems — takes place by allowing condensation of the gas phase and liquid appearance even un-
der expansion of the flowing stream. The same phenomenon may also cause vapourization of the liquid phase such that it
re-enters the gas phase. Liquid and gas phase composition are continuously changing throughout the pipeline due to the
unceasing mass transfer between the phases. Generally, the amount of heavies in the stream determines the extent of the
retrograde behavior and liquid appearance.
Page 8
For a given compositional analysis, the prevailing pressure and temperature conditions will always determine if the fluid
state is all liquid (single-phase), all gas (single-phase) or gas-liquid (two-phase). If a richer gas comes into the system, it will
show a single-phase condition at the inlet, but after a certain distance the pressure and temperature conditions will be
within the two-phase region. If the system is transporting a wetter gas, it would encounter two-phase conditions both at
the inlet and at the outlet of the pipeline.
In summary, the liquid presence and/or formation in a pipeline is ultimately dictated by the properties of the gas that is
being transported and vice versa.
Line Pack Calculation (Multiphase Method)
As explained above, gas pipelines can experience liquid drop-out depending on the properties of gas or simply the gas
being ‘wet’ at the inlet of the pipeline. When we need to estimate the line pack volume, we need to consider the total
volume of liquid in the pipeline in order to arrive to a suitable solution. A simple and easy way for a suitable ‘ball-park’
estimation is using Aspen HYSYS where we can determine the stream properties and other properties such as liquid hold
-up (with slip) at each pipeline segment interval (5 is usually suitable). Figure (1) below illustrates the liquid hold-up frac-
tions at different pipeline lengths obtained from Aspen HYSYS by simulation of an oil and gas production stream. It is
necessary to find the total liquid inventory in the pipeline by using the equation (7) below:
…Equation (7)
Where VL is the liquid volume, HL is the liquid-holdup fraction and Vp is the pipe segment volume
Figure 1: Liquid Hold-Up Fraction along the pipeline.
After the total volume of liquid is obtained in the pipeline, the vapour space volume is calculated by subtracting the total
volume of liquid from the physical volume of the pipeline. This vapour volume is then used to determine the volume of
the gas in the pipeline at standard conditions by modifying equation (6) by substituting equation (8) into equation (6) to
yield equation (9):
…Equation (8)
… Equation (9)
Conclusion
As discussed, by using line packing technique, the assurance of
gas supply can be achieved if there is an increase in gas demand
or problems with producers. Consequently, if the line is single-
phase liquid, the physical volume of the pipeline will represent
the volume of liquid inventory in the pipeline and can be consid-
ered the ‘pack volume’ since liquid is incompressible. With respect to multiphase line, an easy method of finding the total
liquid hold-up inventory can be determined using Aspen HYSYS and hence vapour space volume can be calculated and the
line pack equation can be used to determine the pack volume of gas in the multiphase pipeline. It is recommended that de-
tailed modeling of multiphase pipelines in OLGA should be done to give a more accurate representation of the packed vol-
ume of gas and liquid hold-up inventory within the pipelines.
Vicard Gibbings is currently a Junior
Process Engineer at Massy Wood Group
(MWG). Vicard has approximately one (1)
year’s experience in brownfield engineering
in the oil and gas industry, all at MWG. He
holds a B.Sc. in Chemical and Process
Engineering (Hons.) at the University of
West Indies, St. Augustine (U.W.I) in which
he graduated in 2017. He was the Class
Representative for his tenure at U.W.I and
he has also won awards such as the EOG
Resources Trinidad Ltd. award for producing the best Chemical and Process
Engineering Research Project together with his accomplishment of being
placed in the Dean’s Honour Role.
Moreover, in his spare time, Vicard is a Personal Tutor where he tutors
children (ages 11 until). He started his private tutoring services late 2017. In
addition, Vicard loves to play sports, mainly football and currently plays for a
team called Central A Renegades.
Page 9 APETT Engineering Magazine June 2018
Page 10 APETT Engineering Magazine June 2018
Increasing Impact of Corrosion Control
due to Change in Global Climate
By: Jerome Marshall, M.Sc Project Management,
B.Sc Mechanical Engineering, PMP
Existing Situation of Climate Change One of the key topics on everyone’s lips in the scientific and
global community has been the growing concern around the
incremental increase in global temperatures. As human in-
dustrialization has increased, there has been a significant
rate of increase (shown below) in the global ambient tem-
perature (currently approximated at 0.90oC/year), with
many new historic highs being reached. As a tropical coun-
try, these changes hold the potential for significant cata-
strophic outcomes in the longer term, but can have subtle
and unexpected effects in the short term.
Figure 1. Source: NASA Vital Signs: Shaftel, H. (2018). Global Tem-
perature
Trends in Global Corrosion Cost
One of those subtle and unexpected areas of impact is in
the area of corrosion control. Corrosion control is a signifi-
cant on a global basis, with economic losses being reported
on global basis by most estimates. According to the Nation-
al Association of Corrosion Engineers’ (NACE) Internation-
al Measures of Prevention, Application and Economics of
Corrosion Technology (IMPACT) study, completed in 2013,
corrosion is believed to have a global cost of 2.5 trillion
United States dollars, or 3.4% of the global GDP. This cost
is an estimation of the direct impact of repair and replace-
ment costs, but corrosion can have significant unaccounted
cost. The risk of equipment failure and lost opportunity cost
as a result of corrosion is not quantified for example, nei-
ther is the cost to human life and welfare (e.g. corrosion of
water piping leading to decrease water quality and health)
or the cost of increased unsafe working condition controls
that can be introduced as a result.
Types of Corrosion The impacts of corrosion can literally be seen in any space
where metal exists. There are eight main corrosion types
listed by NACE, which can all lead to the failure of equip-
ment or any other metallic object. The types of corrosion
are shown below, with brief explanation of each.
Figure 2. Source: NACE – Corrosion 101: Fontana & Greene
(1967). Eight Forms of Corrosion
Estimate of Impact in Trinidad and Tobago The NACE IMPACT Study categorized the economic im-
pact of corrosion in the groupings of ‘Services’, ‘Industry’
and ‘Agriculture & Allied Activities’. Services are thought to
include elements such as accommodation, food service,
transportation, storage, recreation and more. Industry in-
cludes items such as mining/quarrying, manufacturing, con-
struction, utilities, and more. Agriculture & Allied Activities
are thought to include agriculture, forestry and fishing. As-
suming that the cost of corrosion in Trinidad and Tobago
follows global norms of 3.4% GDP, based on Trinidad and
Tobago’s 2016 GDP of US$20.99 billion (Source: tradingec-
onomics.com, https://tradingeconomics.com/trinidad-and-
tobago/gdp), corrosion can be assumed to be a problem
worth US$713.66 million across all sectors.
Page 11
Change in Climate of Trinidad and Tobago
Trinidad and Tobago whilst perhaps not severely impacted
as yet has not been immune to the phenomenon of climate
change. The graph below was constructed from World Bank
Data, which shows a steady increase in the local tempera-
ture. (Source: Climate Change Knowledge Portal, 2018). It is
also notable that a prominent feature of climate change is
increased rainfall in affected areas, which can possibly be
manifest in the future.
Figure 3. Climate Change Knowledge Portal, 2018
Likely Impact on the Cost of Corrosion A question to be answered however, is the impact that cli-
mate change will have on corrosion control. There are sev-
eral issues which can impact the economic future of corro-
sion as a result of global warming. One element which has
changed as a result of greenhouse gas emissions is the in-
creased incidence of acid rain and dissolved carbon dioxide.
Carbon Dioxide (CO2) is known to form carbonic acid
(H2CO3) when dissolved in water, leading to the leaching of
iron from steel and degradation of it. Another known ele-
ment is the acceleration of corrosion due to metallic creep
(potentially likely in areas with existing significant tempera-
ture fluctuations, such as industrial plants or areas with
heavy machinery), as a result of greater extremes of temper-
ature as a result of global warming and the potential for in-
creased rainfall. These all have the potential to lead to addi-
tional costs in replacement of equipment, equipment/
infrastructure failures and additional lost opportunity costs
in the future.
Future Solutions: Design for Corrosion Control
Within the realm of mechanical engineering, the potential
exists to mitigate the impact that this phenomenon will have
on Trinidad and Tobago. With a knowledge of the potential
impact that global warming will have on a global scale to a
significant cost, mechanical and structural engineers have a
responsibility to include a Design for Maintenance philoso-
phy (DfM) and Design against Corrosion Damage philosophy
into the project design process. Careful process must be
implemented, including the selection of materials (to avoid
galvanic corrosion as far as reasonably possible), the minimi-
zation of irregular connections and spaces which collect
corrosive fluids (to minimize crevice corrosion), and imple-
ments which allow for regular inspection of metallic surfac-
es. The design of machines, plant fabric and structures which
lend themselves to predictive maintenance should be consid-
ered, as well as initial protective measures such as the use of
sacrificial metals, cathodic protection, the application of pro-
tective coatings and much more. Efforts should also be made
to remain abreast of the newest materials and protection
systems that may arise. Given the increasing relevance of
global and local climate change to us as a collective and as
individuals, we should continue to remain educated and dili-
gent to avoid this silently growing threat to profitability and
safety in each industry.
Eng. Jerome Marshall graduated from the University of the West Indies in 2010
with a B.Sc in Mechanical Engineering. He further went on to complete a M.Sc in
Project Management and is a certified PMP. He started his professional career
working in Anti-Corrosion Technical Services Limited and is now a Project
Engineer for Business Development for the Massy Energy and Industrial Gases
Business Unit, responsible for the development and evaluation of new business
models and technologies. He is also a contributor in Massy Energy’s drive to ensure
realize its vision of being a ‘Force for Good’ by evaluating socially responsible
energy projects in various parts of the Caribbean.
Page 12 APETT Engineering Magazine June 2018
Page 13 APETT Engineering Magazine June 2018
Application of Organic Communication
Channels
By: Aaron Roopnarine, B. Sc. Electrical and Computer Engineering,
UWI and Dr. Sean Rocke , Electrical Engineering
Abstract
Organic Communication Channels (OCCs) show great poten-
tial when considering what has been accomplished with Hu-
man Body Communication (HBC). For example, improvement
in the efficiency of rescue operations, harvesting operations
and surveillance. However, not much work has been done in
extending HBC to other OCCs. Consequently, this paper
investigates the current work done on OCCs, proposes com-
munication techniques to apply to all OCCs and suggests pos-
sible use cases for this area. Consequently, based on these
preliminary findings, the feasibility of the use of OCCs is plau-
sible.
Introduction
Organic Communication Channels (OCCs) consist of any pe-
troleum-based media e.g. animals, vegetation and soil. The
interest in this area stems from the tremendous accomplish-
ments made thus far for Human Body Communication in Body
Area Networks (BANs). Body Area Networks (BANs) allow
for the systematic monitoring of heath and so reduces the
reliance on medical personnel.
BANs consist of three communication modes: Narrowband,
Ultra-wideband (UWB), and Human body communication
(HBC) PHY. The IEEE 802.15.6 regulate communication in
these modes. NB and UWB use RF based propagation tech-
niques whilst HBC uses a non-RF based technique that uses
the human body as the transmission medium [1]. HBC recent-
ly emerged as an alternative to short range RF communication
as it achieves higher data rates, greater spectral efficiency,
better security- as the communication is localized to the hu-
man body- and better power efficiency.
HBC is well researched covering areas such as channel charac-
terization, transceiver design, standardization of different lay-
ers of communication and proposals for improvement upon
the format of these communication layers [2-4]. However, not
much research has been done on the other OCCs. Soil based
communication has been investigated in the literature. Howev-
er, no standardization exists for soil based communication
from literature surveyed. To the best of the authors’
knowledge, no work has been done on vegetation based and
oil based OCCs.
Consequently, this article will focus on the possible use cas-
es for OCCs and the communication techniques proposed
for this area. This will provide insight into the feasibility us-
ing OCCs.
Communication techniques for OCCs
To the extent of the literature surveyed, soil based communica-
tion and HBC are the only OCCs that have been researched.
Since HBC is standardized, higher data rates are achieved when
compared to soil based communication [3, 5, 6]. Hence, HBC
communication techniques should be used with other OCCs.
HBC communication techniques are divided into 2 categories:
electric HBC (eHBC) and magnetic HBC (mHBC).
eHBC involves the use of electric fields [3]. It is the usual tech-
nique employed in HBC systems.The signal generated- modulat-
ed with the data to be sent- by the transmitter is electrically
coupled to the receiver through electrodes. The transmitted
signal is captured by the receiver using similar electrodes at
another part of the body. eHBC could be further classified into
two types: capacitive coupling and galvanic coupling[2]. In gal-
vanic coupling, the induced signal is controlled by current flow.
An alternating current (AC) is coupled into the body which is
considered as the transmission line. A differential electrical sig-
nal is applied between the two electrodes at the transmitter
and induces galvanic currents [7]. Figure 1 (a) shows this for
another OCC.
However, galvanic coupling only works with small distances-
approximately 15cm- between electrodes. In capacitive cou-
pling, the induced signal is controlled by an electric potential
caused by leaving 1 electrode from the transmitter and 1 from
the receiver floating. Hence, a return path is created. Figure 1
Figure 1: Galvanic (a) and Capacitive (b) Coupling
Page 14
mHBC involves the use of magnetoquasistatic fields through
magnetic induction. This technique is typically used in soil
based communication[5]. In this system the transmitter and
receiver both have conducting loops. The principle of
mHBC is similar to a transformer: where the current in the
transmit coil induces a changing magnetic field which is cou-
pled to the receive coil, inducing a current there. Figure 2
shows this applied to another OCC. This current is modu-
lated with the data to be sent. Therefore, there is magnetic
coupling between the transmitter and receiver coils form
the communication channel. Since the magnetic permeability
of most surrounding materials are the same, an mHBC will
be more channel resilient when compared to eHBC tech-
niques [8].
Thus, eHBC and mHBC techniques can be applied to OCCs
for feasible communication. Magnetic induction shows most
promise as it may contribute to channel resilience. The
standardization of HBC communication through the IEEE
802.15.6 document facilitates interoperability amongst de-
vices and higher data rates compared to a non-standardized
method. Hence, this standard should be modified for other
OCCs to achieve a universal standard for OCC communica-
tion.
Use Cases The possible applications of OCCs are endless. OCC com-
munication techniques can be leveraged to develop cyber-
physical systems that can be applied to the Internet of
Things (IoT). Through HBC, BANs present the possibility of
averting medical crises such us heart attacks and strokes [9].
BANs could be applied to the field of sport through real-
time physiological monitoring of athletes to maximize player
performance by preventing injuries and burnouts [10]. Thus,
BANs reduce the strain imposed on healthcare personnel
and hence serve to as mechanism to deal with the increase
in demand for healthcare services. Now consider expanding
to other OCCs. Figure 1 shows how these OCCs can be
utilized for cyber-physical systems.
Furthermore, OCCs can be used in IoT technology to de-
velop a natural resources management system which moni-
tors climate, soil health, land use and plant health which will
mitigate food insecurity for countries [11]. Clearly, the po-
tential for OCCs is seen.
Conclusion
OCCs show great potential as seen in its use cases. Based
on the literature surveyed, HBC techniques can be applied
to other OCCs to achieve feasible communication. A modi-
fied version of the IEEE 802.15.6 standard is proposed for
specification of the different communication layers for all
OCCs to achieve reasonable data rates and interoperability.
Figure 2: Magnetic Coupling Figure 3: Use cases for OCCs
Aaron Roopnarine received his BSc.
degree in Electrical and Computer Engineer-
ing in 2017 at the University of the West
Indies with First Class Honours. He is cur-
rently pursuing his Master of Philosophy
degree in Electrical & Computer Engineering
at the University of the West Indies. He co-
authored two other publications in the
International Journal of Signal Processing, Image
Processing and Pattern Recognition. His current
research interests include areas include
areas where the principles of Electrical and
Computer Engineering can be expanded to
other domains, as with OCCs.
Sean Rocke received his BSc in Electrical & Comput-
er Engineering from The University of the West Indies
in 2002, his Masters in Communications Management
and Operational Communications from Coventry
University in 2004, and his Ph.D. in Electrical & Com-
puter Engineering from Worcester Polytechnic Insti-
tute in 2013. His areas of interest include signal pro-
cessing and optimization techniques relating to wire-
less communications and energy systems, statistical
signal processing, biosensor development and biologi-
cal data mining.
Page 15 APETT Engineering Magazine June 2018
Page 16 APETT Engineering Magazine June 2018
Hybridization of the Direct Stiffness and
Macaulay Methods of Structural Analysis
It is in the designer's best interest to validate the output of programs they have used for structural analyses. Occasionally,
they may not do so due to their confidence in the reliability of certain programs out of many years of use and/or due to
doubts in their capability to successfully perform such checks. Furthermore, from longevity in practice one often develops
a keen eye to detect errors intuitively. Supervisors are cognizant that less experienced engineers usually do not possess
these skills and depending on the complexity of the design, may encourage their junior colleagues to perform calculations
themselves i.e. without the use of structural analysis software. The latter is also used as a means to assess whether trainees
have understood a particular topic at the degree level.
Though conducive to hand calculations, classical methods of structural analysis such as Clapeyron's Theorem of Three Mo-
ments (Hearn 2000), the Slope-Deflection Method (Hibbeler 2012), and the Moment Distribution Method (Williams 2009)
can be daunting especially if used for preliminary designs or to double-check intermediate work, in which cases these calcu-
lations may be irrelevant at the final design stage. The aforesaid methods can also be restrictive according to the type of
structure, its support conditions and indeterminacy, even if implemented in spreadsheets which are ubiquitous nowadays.
For instance, the applicability of the Theorem of Three Moments is limited to beams which have at least two spans, or sys-
tems which can be modelled as such. Due to the simultaneous equations involved in the Slope-Deflection Method, it be-
comes cumbersome when the number of unknown displacements are large. Likewise, the Moment Distribution Method
inherently assumes members are axially rigid, it is a numerical method—thus its accuracy is reliant on the number of itera-
tions performed—and the method can become laborious for frames where sway is uninhibited as well as for non-prismatic
members.
Matrix methods are perhaps the most versatile techniques for structural analysis and are readily adaptable to features
which are complicated to model when using classical procedures. Examples of these are: hinges for Gerber beams and
springs, used in the analysis of beams on elastic foundations (Bowles 1996). Matrix methods gained prominence in the
1950s with the advent of digital computers (Hearn 2000) and are used within the vast majority of structural analysis pro-
grams (Hibbeler 2012). One form of these matrix methods is the Direct Stiffness Method (DSM), which can be used to
calculate nodal forces as well as displacements (Megson 2005).
The first use of singularity functions in structural analyses is most often credited to William Herrick Macaulay, hence, such
techniques are referred to as Macaulay’s Method (Megson 2005, Hearn 2000). This Method is convenient and simplifies the
determination of deflections along a beam (Beer, et al. 2012, Williams 2009). A typical singularity function is shown in Ta-
ble 1 below, and for values of the exponent (n) greater than or equal to unity, these functions can be simplified algorithmi-
cally using the maximum function.
Comprehensive explanations of the DSM and Macaulay Methods are outside the scope of this article. However, the two
can be hybridised to produce an innovative technique which can be used for structural analysis as follows: reactions and
displacements at extreme nodes are calculated using DSM; Beams, more so those with up to three spans are fundamental
structural design elements since they can be used to model systems with larger numbers of spans. This is because load ap-
plied to adjacent spans has a reducing effect the further it is from the span being analysed (McCormac and Brown 2014).
By: Jovon Jacob, B.Sc Civil Engineering
Table 1. Singularity Functions
Page 17
Additionally, some structural elements may be modelled as a continuous member with three geometrically distinct sec-
tions, these include: gently tapered cantilevers, beams with stepped haunches or a span of a slab with drop panels (Portland
Cement Association 2013). The hybridised Direct Stiffness and Macaulay Methods have been set up for the analysis of the
aforesaid structures in a spreadsheet, “3Span_v1.xlsm” which is available for download at https://goo.gl/ffxtTd.
A screenshot of the file is shown in Figure 1 hereafter. It is anticipated that such applications of a spreadsheet would re-
sult in cost saving from not having to purchase licenses for more expensive programs, especially if the structural analyses
to be performed are relatively simple. Additionally, time should be saved, as this is intrinsic of automated calculation but
also because spreadsheets typically require minimal computer resources to run optimally.
The determination of fixed-end reactions are prerequisite to the use of DSM. Generic equations for linearly-distributed
loads were derived using Macaulay’s Method and are stated in Table 2 since these have not been seen in any other litera-
ture. Such equations for point loads and couples are published in most structural analysis text books as well as design ta-
bles, however are included here for completeness. To avoid confusion with the bending moment equation presented here-
after, couples with the symbol “c” were chosen over the traditional nomenclature of “M” for applied moments.
Figure 1. Screenshot of 3Span_v1.xlsm
Page 18 APETT Engineering Magazine June 2018
Equations in Table 2 are based on the sign convention
of upward forces and anticlockwise moments being
positive, which is typical for matrix methods. Once the
vertical reaction (Ryn), moment (Rzn), slope (θn) and
deflection (un) at the near node (left end) of the mem-
ber have determined from DSM, the deflection (u) at all
points along the member (0 ≤ x ≤ L) can be obtained
using Equation 1 below.
The above uw, up and uc are functions also derived
from Macaulay’s Method which model the effect of line-
arly-distributed, point and couple loads respectively
(see Equations 2-4). For elastic systems, individual
load effects can be superposed (Williams 2009) hence,
the summation. It should be noted that the near-node vertical reaction, Ryn is a sum consisting of components (Rynw, Rynp
and/or Rync) for the load types applied; Rzn, θn and un are similarly aggregated.
Equation 1 is differentiable, and the Euler-Bernoulli theory is
used to obtain bending moments and shears. Due to the load-
ing sign convention already applied, in order for bending mo-
ments (M) and shears (V) to be consistent with their tradition-
al sign conventions (Hibbeler 2012) shown in Figure 2 below, the relations hereunder are utilised.
Advantages of using the hybrid approach opposed to DSM exclusively for structural analyses are best illustrated with an ex-
ample. If DSM only is used for the analysis of the discretized simply supported beam in Figure 3, the size of assembled stiff-
ness matrix would be 20x20 before it is condensed to 18x18 to solve for unknown degrees of freedom (DOFs). Once all 18
DOFS are solved, they can be used to determine the moments and shears at all 10 nodes, however, the slopes obtained for
the 8 intermediate nodes may not be useful beyond that.
From analysing the simple span above with the hybrid method, the typical
4x4 beam stiffness matrix will be used—this is much smaller thus faster to
process. The stiffness matrix will then be condensed to 2x2 for determi-
nation of the slopes at nodes 1 and 10. After the reactions have been
solved, they can be plugged into the Macaulay equations for deflection,
moment and shear. All of these equations are functions of “x,” so one can
accurately locate points of contra-flexure, maximum moment etc. easily,
by expanding the range of x; or running the relevant equation through a
solver; without having to redo the matrix analysis, as would be the case
with the DSM only approach if the member is insufficiently discretised.
Additionally, with the hybrid approach, fewer fixed end loads would have
to be calculated for the force vector while slopes for the intermediate
nodes can be solved only if necessary, as these are not generally used for
design. The hybridised Direct Stiffness and Macaulay Methods can also be
used for the analysis of frames as will be shown in a document to be re-
leased in future, as part of the Civil Division Council’s Peer-Reviewed
Spreadsheet (PReSs) initiative.
Eng. Jovon Jacob is a graduate civil
engineer who assists professional design engineers in the preparation
of reports, spreadsheets and CAD drawings. Jovon believes that with
clever programming, spreadsheets can become invaluable design aids
for practitioners and, revolutionary teaching tools for students. His
article, ‘Microsoft Excel as a Ge-otechnical Engineering Teaching
Tool’ is being considered for publica-tion in the European Journal of
Engineering Education. Jovon holds a B.Sc. in Civil Engineering, from UWI
St. Augustine, has over 9 years of experience in AutoCAD drafting. He
was also awarded a GoRTT National Scholarship in 2011 and member of
the winning team for in IStructE’s Young Structural Engineers Design
and Build Competition that year.
Table 2. Equations for Fixed End Reactions.
Page 19 APETT Engineering Magazine June 2018
The Environmental Impacts of the
Cement Manufacture Process
By: Jonathan V. Juman, Yr 2 B.A.Sc. Civil Engineering, UTT
Saara Sultan, Yr 2 B.A.Sc. Civil Engineering, UTT
The vast and rapidly expanding industry of construction and
infrastructural development over time has required a stable
and cheap yet strong alternative to the construction of old
that once used timber and raw materials for their infrastruc-
ture. It sought for many years to find a suitable material that
can be moulded, formed, capable of a wide variety of uses
and most importantly cheap. The introduction of concrete as
a mainstream and easily accessible building material has revo-
lutionized the construction market and with new and ever
improving machinery and processes, the ease of access and
availability for this man made wonder has never been greater.
Early and mid-1900’s saw the exponential growth of the use
of concrete; from buildings, roads, sidewalks, bridges, pipes,
electrical poles, man-made waterways and dams, and even
missile silos are made of concrete either in part or as a
whole. Concrete has overtaken the market in terms of mate-
rials with a high demand and an even higher use spectrum;
anywhere that there is development, there is concrete.
Amidst all this expansion, the 21st century brought along cli-
mate change and deforestation that sparked the call for envi-
ronmental awareness above all else. Many factories and man-
ufacturers have reinvented their manufacturing processes in
an effort to reduce their carbon footprint and facilitate the re
-growth of the environment. Concrete however, has two
processes to production that has not changed from its incep-
tion. The wet and dry processes both require blasted raw
material, a crushing and burning process to create the fin-
ished product. In an effort to help the environment, this re-
port is done on the environmental impacts of concrete; from
production to end of life.
Cement Manufacture Process
Cement, also known as Portland cement, is one of the three
core components that formulate concrete along with aggre-
gate and water. Its main purpose serves as the binder in the
concrete and gives the concrete its strength when dry as it
holds and hardens the mixture together. There are several
processes that take place before cement reaches its final
state.
Stage one of the manufacture process is the quarrying for
all raw materials needed.
This may be done either by machine quarrying an open pit
mine or by Blasting which requires the use of explosive
charges and creates severe dust clouds that cause severe air
pollution and pollute nearby waterways when it settles. Dust
in the air can contaminate nearby vegetation depending on
meteorological conditions and has the potential to cause
damage. Chemical changes to soil composition may occur
due to the chemical composition of the dust. Limestone pro-
duces dust that is highly alkaline and although it has been
used before to influence crop sensitivity, the dust would not
be near the quality needed and may cause more damage than
good. Flyrock, formed due to the energy produced from
blasting may endanger employees and nearby personnel.
Blasting also produces high amounts of waste energy that is
converted to seismic vibration, noise, heat and light. This may
not only disturb neighbouring structures due to its loudness
but may also cause damage to their infrastructure and com-
promise their structural integrity to an extent. The effects of
this excess energy may also disturb coastal and marine envi-
ronments, historic landmarks and nature reserves.
Machinery in the quarrying industry increases productivity
with increasing the rate the job is performed due to large
scale movement by the equipment. Crawler tractors are used
to strip surfaces and mine softer raw material such as sand or
clay.
Figure 1. Basic Process Flow of Cement Manufacturing Process.
Page 20
Wheel loaders take the mined raw material to load them
onto the trucks for transportation to the crushing and
washing equipment. They have large buckets that can hold
up to 35 tonnes of material. Smaller scale loaders are used
to load the finished material onto smaller, road legal trucks.
Off-highway trucks carry the extracted material from the
open pit to the crushing and washing equipment. These
trucks have a maximum capacity of 3600 tonnes and ex-
tremely powerful diesel engines making the time for
transport of material relatively short in comparison to reg-
ular dump trucks. These equipment are all diesel powered
and emit carbon monoxide that affect concentrations of
other greenhouse gases such as methane, tropospheric
ozone and carbon dioxide. The carbon monoxide readily
reacts with the hydroxyl radical to form carbon dioxide,
increasing the concentration of methane as methane is re-
moved by the hydroxyl radical in the atmosphere.
Stage two is a fairly simple and short step where the ma-
terials are mixed together. This is where both dry and wet
processes become distinct. The dry process has the materi-
als mixed without any addition whereas the wet process
adds water. This water is used to create a paste-like tex-
ture in the mixture. This liquid mix does not differ much in
process and result from the dry mixture but it does have a
positive impact environmentally. This comes in the form of
a reduction of carbon footprint. Due to the liquid state, the
mixture can be transported from the quarry to the cement
manufacturing plant without the use of trucks or fuel pow-
ered vehicles. Instead, it is transported by means of large
pipes that are on a constant gradient so it flows from the
quarry to the plant. This reduces the use of fuel, the
amount of carbon monoxide, carbon dioxide and methane,
and overall increases the plant’s productivity because there
is not only a constant flow of material but also a faster in-
flow of it when compared to dump truck transport.
Stage three is the heating process. The mixture falls
through a pre-heat tower and becomes heated partially
heated before entering the kiln. Once in the kiln it is fully
heated to 1500°C. This heating process however is not
completely environmentally friendly. Oxides of sulphur are
formed from the combustion of fuels containing sulphur
and the burning of raw material containing sulphur. All the
materials that is used to produce the clinker contains sul-
phur. Once the sulphur oxides are exposed to water va-
pour in the atmosphere with the presence of sunlight, it
becomes sulphuric acid that would mix together with the
water droplets in the air as condensation and eventually
precipitate as what is known as acid rain. This affects soil
pH causing imbalance in the soil’s composition which can
result in deformed and underperforming crop harvests and
can also impact on humans as respiratory illnesses are
closely linked to higher sulphur oxide levels.
The heating and burning process of the rotary kiln also pro-
duces high Carbon oxides from its fuel and the decarboni-
sation of the raw materials, with particular attention drawn
to limestone. Burning of fossil fuels and the process of ther-
mal oxidisation occurs at between 1200oC-1600oC. This
involuntary process creates oxides of nitrogen that are also
released into the atmosphere and can cause serious health
and environmental issues due to the various compounds of
nitrogen including nitrogen dioxide, nitric acid and nitrates.
These compounds react with water to form various acidic
compounds and can cause imbalance to several water bod-
ies such as lakes, making their pH more acidic. Plant and
animal life may also be dependent on the pH balance and
the change may create difficulty for them to survive. Ni-
trous oxide is also a greenhouse gas that collects in the
earth’s atmosphere and gradually causes atmospheric tem-
perature rise.
Stage four is the final stage of the manufacturing process.
The material that comes out of the kiln, known as clinker,
is the agglomerated form of cement powder. This is taken
from the kiln and cooled before being ground into fine
powder. This step is executed with the use of a ball mill.
The milling process generates heat and as a result needs to
be cooled by spraying water onto the outside of the mill.
Environmental impacts of the milling process is minimal
other than the dust that is produced by the mill grinding
the clinker into powder form. The ball mill would also pro-
duce exhaust fume emissions similar to all other machinery
that would pollute the atmosphere and as a result, cause
some production of greenhouse gases. A positive take-away
from this process can see the exhausted heat be rerouted
to the pre-heater to raise its temperature therefore using
less fuel and lowering total emissions.
The use of concrete as the most easily accessible building
material for construction has been in use for years and will
continue to be the most highly preferred material for the
provision of a reliable standing foundation. The manufacture
of cement is a complex topic when it comes to identifying
its environmental impacts, some effects are harmful where-
as some are beneficial. Cement being the major component
of concrete has its environmental impacts which are thor-
oughly discussed in its manufacturing process above. Work-
ing with cement has numerous concerns therefore different
measures are to be considered and variation in methods
are to be implemented to reduce the likelihood of addition-
al environmental issues and to prevent ongoing issues from
worsening.
Jonathan V. Juman is a 2nd year student at the University of Trinidad &
Tobago, currently pursuing his Bachelors of Applied Science Degree in the
field of Civil Engineering. In 2016 he completed his National Technician’s
Diploma in Civil Engineering also from UTT and hopes one day to further
his studies in the field of Structural Engineering with specific focus on
mitigation systems for buildings against seismic activity. He also hopes to
bring awareness to the engineering community about the vast effects that
construction practices can have on the environment to one day help these
processes become more eco-friendly and preserve the eco-system while
expanding the human infrastructure.
Saara Sultan is a 2nd year student at the University of Trinidad &
Tobago, currently pursuing her Bachelors of Applied Science
Degree in the field of Civil Engineering Systems. Prior to her
pursuit of the engineering degree, her occupation saw her become
a maintenance technician at the Ministry of Works and Transport
and this peaked her interest which gave her a passion to pursue
Civil Engineering. She hopes to one day become a project manager
as well as a lead site/construction engineer and run a management
firm that operates throughout the Caribbean.
Page 21
Misunderstandings about Building Codes
and T&T
By: Dr. Richard Clarke, Technical Committee Member of the ASCE 41-17
Technical Committee Member of the TTBS Small Building Guide
Senior Lecturer, Department of Civil Engineering, UWI
Former Chair of the BOE/APETT/TTBS Structures Codes Committee
Right now, unless you are in an open field, your safety is dependent on a structural engineer (or civil engineer depending on
the employer) since gravity is trying to collapse the building you are in, or if an earthquake or hurricane were to occur right
now, the associated forces will also conspire to cause the building to collapse. The engineer is protecting you by ensuring
the structure is built based on her or his implementation of an appropriate building code.
Upon attending the JCC meeting at the Hyatt Regency yesterday, it is clear that we continue to harbour significant misun-
derstandings about the building codes in terms of their intent and roles and our capacity to properly implement them. The
need to clarify the matter has become more pressing given the apparent increase in the frequency of the natural hazards of
hurricanes and earthquakes within the past months throughout the Caribbean, and the anticipated increase in the near fu-
ture. Furthermore, there is the need for decision-makers to invest in risk reduction in the correct distribution hence based
on a correct order of priority of the national risk factors. This topic is therefore so important that the author will mention
the names of the critical documents so that they may enter the discourse of the nonprofessional T&T citizenry as least so
that they can begin to empower their own safety. The principal misunderstandings are: (1) not having a T&T building code
increases the risk to the public, (2) to derive a T&T building code by adopting a building code used elsewhere is a simple
task, and (3) lack of enforcement of a building code is a major source of risk to the public.
The demands on a building due to an earthquake are higher both in terms of determining what an earthquake will do to a
building, and how the material is to be arranged, compared to the demands due to a hurricane. However in selecting a
building code or set of codes as a model or basis for T&T, that selection must cater for both earthquakes and hurricanes.
As regards the first misunderstanding, this is simply false. All that is needed is for the engineer to base their calculations on
a seismic building code, and knowledge of the extent of ground shaking to be expected during the service life of the build-
ing. Such a code has been available and used in T&T since 1970, when the Seismic Committee of the Association of Profes-
sional Engineers of T&T (APETT) recommended the seismic code then in use in California, U.S.A – the Structural Engineers
Association of California (SEAOC) seismic code, for use in T&T. Use of this code was supplemented by studies by a num-
ber of seismologists within the period 1970 to 1978 to provide the required information on the levels of ground shaking for
the Caribbean territories. At the present point in time, the Designs Engineering Branch (DEB) of the Ministry of Works
and Transport (MOW) will approve a building design if based on the American Society of Civil Engineers/Structural Engi-
neering Institute (ASCE/SEI) document called the ASCE 7-05 (2005), and the seismic maps published by the Seismic Re-
search Centre of the University of the West Indies, St. Augustine. In keeping with the original 1970 decision, the U.S.A
codes are the preferred choice. As regards hurricanes, again the ASCE 7-05 caters for this, but information on the extent
of the wind speed to be expected during the service life of the building is required. This information is also provided by the
DEB based on studies of the Caribbean by world-renowned expert Dr. Peter Vickery. One may have heard of the Interna-
tional Building Code (IBC), but this code is largely dependent on the ASCE 7.
However, referring to the ASCE 7 is not sufficient. Note that when mentioning the ASCE 7 code above, it is the 7-05
(2005) that is cited. Since that time, the ASCE 7 has evolved to the ASCE 7-10, then to the ASCE 7-16. However, our
engineers cannot use any of these codes without taking the personal risk of specifying what the level of earthquake should
be. This is because these codes require a type of seismic map that does not as yet exist for the Caribbean territories. This
is a big problem and is causing engineers to be unable to make consistent and proper use of the latest knowledge available
in these codes.
Page 22
The need for this type of map (called a risk-targeted map) became necessary in the U.S.A in order to remove certain in-
consistencies. But in doing so, this has now required engineers, for the first time ever, to be knowledgeable of more ad-
vanced technology. A similar quantum leap in the knowledge required by the engineer to properly implement the code
took place in the period from 2010 to 2016. This is due to the adoption of a new design paradigm and associated tech-
nology called “performance-based design” which has been embodied in the ASCE 7-16. Also for the first time, the ASCE
7 refers substantially to the document which is the source of new paradigm - the ASCE 41. The ASCE 41-17 is the most
advanced code document derived by any organization worldwide to date and as codes evolve, it will become the main
building code. Unless a local engineer invests in receiving the training in these developments (i.e. the risk basis and per-
formance-based design) these codes cannot be properly applied and the engineer is not motivated to do this since T&T
does not as yet have an effective Continuing Professional Development (CPD) programme which will make such training
mandatory.
As regards the second misunderstanding, though a local building code can be derived by adopting a U.S.A code, such
codes nowadays are strict as regards the intellectual property requirements. If one selects say the Los Angeles building
code for earthquake-resistant design and the Florida building code for hurricane-resistant design, those codes adopt the
IBC. The International Code Council, who publishes the IBC, requires special contractual arrangements and so-called
“application documents” for territories external to the U.S.A.. Another misconception is that payment must be made to
participants in the code development process. The international practice is that the input of technical professionals is
done on a pro bono basis hence no such individual should be paid and providing service to one’s country on a technical
committee should be regarded as an honour and privilege and not a job, especially in this period of austerity.
The third aforesaid misunderstanding is so because it misses the point by putting the cart before the horse. A code must
be made mandatory before it can be enforced. In T&T by far the highest risk to the public is housing because in the vast
majority of cases the roof is supported on 100 mm (i.e. 4 inch) block walls. This applies to single-storey houses and the
top-storey of most 2-storey houses. Extensive state-of-the-art studies have shown the inadequacy of this form of con-
struction hence exposure to the national economy. Collectively, this means that approximately seventy percent of all
buildings in T&T do not comply with code requirements. This situation exists because the Small Building Guide, published
by the T&T Bureau of Standards, and which has the correct methods, is not mandatory. This must be done before it can
be enforced and implies the need for a very large retrofitting effort in order to reduce the risk to acceptable levels.
In the author’s view, the most significant factors negatively impacting the risk to the public due to earthquakes and hurri-
canes in T&T are (in descending order) – that the Small Building Guide is not mandatory; lack of risk-consistent seismic
maps, and lack of training and an effective CPD program for structural and civil engineers in T&T to ensure they are up-to
-date with the most recent codes.
Dr. Richard P. Clarke is a structural and quality engineer with extensive indus-
trial experience and has authored papers in leading international journals and sym-
posia in the areas of seismic retrofitting, hysteresis modeling, seismic nonlinear
structural dynamics, and vulnerability analysis. His research interests are in the
areas of earthquake resistant seismic design and assessment, structural cementi-
tious composite materials, sustainable affordable and multi-hazard resistant hous-
ing, and computer-based education.
Page 23 APETT Engineering Magazine June 2018
ARTICLE REFERENCES
Pipeline Hydraulic (Line Pack) Campbell, M.J. (Feb, 2004). Gas conditioning and Processing, Vol. 1: The Basic Principles.
Menon, E.S. (2005). Gas Pipeline Hydraulics.
Increasing Impact of Corrosion Control due to Change in Global Climate Climate Change Knowledge Portal (2018). Obtained from http://sdwebx.worldbank.org/climateportal/index.cfm?
page=downscaled_data_download&menu=futureGCM Fontana & Greene (1967). Eight Forms of Corrosion. NACE International. Obtained from https://www.nace.org/Corrosion-Central/
Corrosion-101/Eight-Forms-of-Corrosion/
Shaftel, H. (2018). Global Temperature. NASA. Obtained from https://climate.nasa.gov/vital-signs/global-temperature/
Application of Organic Communication Channels [10] A. Dhamdhere, H. Chen, A. Kurusingal, V. Sivaraman, and A. Burdett, (2010)."Experiments with wireless sensor networks for
real-time athlete monitoring," in Local Computer Networks (LCN), 2010 IEEE 35th Conference on, 2010, pp. 938-945. [6] A. R. Silva and M. Moghaddam, (2016). "Design and implementation of low-power and mid-range magnetic-induction-based
wireless underground sensor networks," IEEE Transactions on Instrumentation and Measurement, vol. 65, pp. 821-835, 2016. [11] FAO and ITU, E-AGRICULTURE STRATEGY GUIDE Piloted in Asia-Pacific countries, (2016). Bangkok: The Food and Agriculture
Organization of the United Nations and International Telecommunication Union, 2016. [1] H. Wang, "Intra-Body Communication Channel Modeling and High Performance IBC Transceiver System Design Based on Ad-
vanced Techniques, (2015)." The Chinese University of Hong Kong (Hong Kong), 2015. [3] IEEE Standards Association, "IEEE Standard for Local and Metropolitan Area Networks—Part 15.6: Wireless Body Area Net-
works, (2015)." IEEE Standard for Information Technology, IEEE, vol. 802, pp. 1-271, 2012.
[9] J. M. Smith, (2011). "The doctor will see you ALWAYS," iEEE SpEctrum, vol. 48, 2011.
[7] M. H. Seyedi, (2014). "A Novel Intrabody Communication Transceiver for Biomedical Applications," Victoria University, 2014.
[2] M. D. Pereira, G. A. Alvarez-Botero, and F. R. de Sousa, (2015). "Characterization and modeling of the capacitive HBC channel,"
IEEE Transactions on Instrumentation and Measurement, vol. 64, pp. 2626-2635, 2015. [8] T. Ogasawara, A.-i. Sasaki, K. Fujii, and H. Morimura, (2014). "Human body communication based on magnetic coupling," IEEE
Transactions on Antennas and Propagation, vol. 62, pp. 804-813, 2014. [5] X. Tan, Z. Sun, and I. F. Akyildiz,(2015) "Wireless Underground Sensor Networks: MI-based communication systems for under-
ground applications," IEEE Antennas and Propagation Magazine, vol. 57, pp. 74-87, 2015. [4] Y. Zhang, B. Kou, D. Fan, Y. Liu, Z. He, and X. Chen,(2016)."A dynamic pilot interval adjustment scheme for HBC channel esti-
mation," in Communications in China (ICCC Workshops), 2016 IEEE/CIC International Conference on, 2016, pp. 1-5.
Hybridization of the Direct Stiffness and Macaulay Methods of Structural Analysis
Beer, Ferdinand P., E. Russel Johnston, Jr., John T. DeWolf, and David F. Mazaurek. (2012). Mechanics of Materials. McGraw Hill.
Bowles, Joseph E. 1996. Foundation Analysis and Design. McGraw Hill.
Hearn, E.J. (2000). Mechanics of Materials 1: An Introduction to the Mechanics of Elastic and Plastic Deformation of Solids and Structural
Materials. Butterworth-Heinemann.
Hibbeler, R.C. (2012). Structural Analysis. Prentice Hall.
McCormac, Jack C., and Russell H. Brown. (2014). Design of Reinforced Concrete. John Wiley and Sons.
Megson, THG. (2005). Structural and Stress Analysis. Butterworth-Heinemann.
Portland Cement Association. (2013). Notes on ACI 318-11 Building Code Requirements for Structural Concrete with Design Applications.
Williams, Alan. (2009). Structural Analysis in Theory and Practice. Butterworth-Heinemann.
The Environmental Impacts of the Cement Manufacture Process Braen, D. and Braen, D. (2017). Recycled Concrete: The Advantages It Offers Your Project. [online] Braen Stone. Obtained from http://
www.braenstone.com/2015/04/recycled-concrete-advantages/ [Accessed 29 Apr. 2018]. Cabonne. (2017). Impacts of Waste on the Environment. [online]. Obtained from http://www.cabonne.nsw.gov.au/sites/cabonne/files/
public/images/documents/cabonne/environment/4.%20Impacts%20of%20Waste%20on%20the%20Environment.pdf [Accessed 29
Apr. 2018]. Collins, M. (2017). Environmental Impact of Aggregates. [online] Concrete.org.uk. Obtained from http://www.concrete.org.uk/
fingertips-nuggets.asp?cmd=display&id=148 [Accessed 29 Apr. 2018].
Green Building Design & Products for Sustainable Construction (2017). Obtained from: http://www.greenspec.co.uk