 |
Pavement
Management
|
Surface transportation infrastructure in the United States of America
(USA) is aging according to a report prepared by Department of Homeland
Security in 2014. The USA was ranked 16th in the overall quality of roads in a
report developed by World Economic Forum despite a 3rd place ranking in an
overall competitiveness of the economy among the rest of the world. The
American Society of Civil Engineers (ASCE) indicated in another study that it
would take up to $225 billion to upgrade the United States’ aging
transportation infrastructure to meet current demands and future growth. There
are two significant concerns regarding the aging transportation infrastructure:
the failing existing conditions, and how to prioritize and allocate funding for
their Maintenance and Rehabilitation (M&R). Hence, the need for the United
States Department of Transportation (USDOT) and local jurisdictions to develop
programs and efficient tools to improve and rehabilitate roadway systems. These
programs and tools can help local agencies to allocate fund to enhance and
preserve transportation networks appropriately. Read more>>>>>>
 |
| Fertigation |
Fertigation uniformity is
defined here as a composite parameter consisting of irrigation and fertilizer
application uniformity indicators. The field and computational procedures for
sprinkler irrigation uniformity evaluation has been the subject of various
studies. The objective of the study reported in this paper, however, is the
development of an analytical framework for the evaluation and analyses of
test-plot scale fertilizer application uniformity under solid-set sprinkler
irrigation systems. Irrigation uniformity indices are adapted for use in
fertilizer application uniformity evaluation. Fertilizer application rate,
given as a function of irrigation depth and fertilizer concentration, is
identified as the appropriate variable to express fertilizer application
uniformity indices. Pertinent mathematical properties of the uniformity indices
along with their practical fertigation management implications are outlined. Read more>>>>>>>
The
dependence of a vast majority of the global population on petroleum has led to
an acute concern regarding its negative environmental impact and long-term
sustainability of utilizing this finite resource. The control of its reservesby some, has left others vulnerable, and has made decision makers andintellectuals alike to mull over practical alternatives. Climate damage is tied
to radiative forcing that is affected strongly by carbon dioxide in the
atmosphere, a greenhouse gas that had cycled between about 170 to 280 ppm from
800,000 BCE till the start of industrial revolution in 1760, and since then has
been increasing continuously to today’s level of near 400 ppm, largely due to
anthropogenic activities such as transportation, power and electricity
generation.
Cost, renewability, environmental impact, and availability are some
of the most important considerations in finding substitutes for gasoline.
Cellulosic ethanol satisfies many of such criteria with cost being its main
hurdle to commercialization. Its pursuit over other fuels comes from the
learning that when produced through biological route from plant biomass, it is
currently the only known liquid fuel that can be produced at the high yields
and scale necessary to be able to compete with the well-established gasoline
fuel and its infrastructure. While it has begun its journey to penetrate the
fossil fuel supply chain, its cost needs to be lowered to a point at which
profit margins appear lucrative enough to attract investment and satisfy
requirements for sustainability. The current bottleneck for a high yielding biological
route for ethanol involves pre-treatment, enzymatic hydrolysis, and fermentation.
It is the higher in cost than economically desired due to in part to
pre-treatment costs and the quantity of enzyme employed to depolymerize
polysaccharides in biomass into fermentable sugars. High concentration of
sugars at low cost and low inhibitor levels not only leads to lower cost
cellulosic ethanol, but opens doors to industry to pursue fuel and chemical
production using pathways originating from sugars.
(Read more)
Reinforcements
are mostly used in the development of composite materials ranging from macro to
nano-scale. Nanofillers are commonly added as reinforcement to enhance the
performance of the adhesive properties of Epoxy resin. Due to their excellent
stiffness and strength and exceptional high aspect ratio combined with low
density, Carbon nanotubes are considered as an ideal candidate for the
reinforcement of conventional adhesives. The electrical, thermal and mechanical
property of CNT provides a new perspective for improving the conducting
performance of the mechanical adhesives.On this study the Epoxy resin was mixed
with multiwall carbon nanotubes (MWCNT) as a reinforcement to increase the
mechanical, thermal and electrical properties of Epoxy adhesives.(Read more)
The
main objective of this paper is to study the basic electrical machine types and
their applications. A DC machine can operate as a generator or motor.
Generators and motors are the rotating machines. Based on the mode of
operation, the mechanical power is converted in to electrical power and
electrical power is converted in to mechanical power. A DC machine works on thebasis of three modes of operation namely: Generating mode, Motoring mode andBraking mode. In first mode of operation, prime mover with mechanical power is
converted in to electrical power. In the second mode of operation, the
electrical power is converted in to mechanical power and this mechanical power
is used to drive the mechanical load.
In the third mode of operation, a machine
can operate as a generator and electrical power is pumped back to the system
for applying regenerative braking.An
electrical generator is a mechanism which converts mechanical energy into
electrical energy. The energy conversion is based on the principle of
electromagnetic induction. According to faraday’s law of electromagnetic
induction, whenever current carrying conductor is placed in a magnetic field,
it will cut the flux lines thereby leading to create a force and generator
tends to rotate.(Read more)
The
tasks performed by industrial robots are exciting. On the other hand, there are
lots of tasks remained to be done by human workers. These tasks include (1)
picking parts from cluster, (2) reorienting parts to certain poses, and (3)
force-based assembly. These tasks cannot be done using industrial robots and
teach pendants since: (1) The parts shapes and physical properties are varying.
It is difficult to manually specify the grasping strategies for infinite number
of parts. (2) The initial poses and goal poses of manipulated parts are
changing. It is difficult to teach the robots all motions to reorient different
parts. (3) The first two processes lead to variety in force control and
assembly, which also make pre-teaching difficult.(Read more)
Various
types of materials are used in the house construction industry depending on the
process to be used, the specifications of instruments, or the design employed.
Currently, the materials used in rapid manufacturing (RM) for considerable
parts of buildings are neither biodegradable nor eco-friendly. Although themain materials in use for rapid prototyping system include thermoplasticmaterials, epoxy resin, acrylonitrile butadiene styrene plastic, and polyester
materials, many scholars have made efforts to develop biofibres as fillers and
composite reinforcements for industrial building systems. Materials currently
in use in RM are limited to those that can be sintered or melted and solidified
quickly.
The problem with using polymeric materials lies mainly in their price
and non-ecofriendliness, both of which make the system inappropriate for adoption
in the construction field. Providing an eco-friendly material with
cost-effective components can allow the use of such systems within the
construction industry.Kenaf
fibres can be used in large quantities as excellent reinforcing fillers in
plastics and in thermoplastics, such as polypropylene (PP), for their many
unique properties and lower cost. Moreover, Kenaf, as a natural fibre
composite, has been shown to perform better in some mechanical activities, such
as flexural testing, compared with a number of other natural fibres.(Read More)
