Design and Evaluation of Open Graded Hot Mix Asphalt Using Cement as A Grouting Material |
Author : Gulzar Hussain Jatoi, Naeem Aziz Memon, Pervez shaikh, Abdul Qudoos Malano, Abdul Hafeez Memon |
Abstract | Full Text |
Abstract :Road networks ought to be efficiently designed to be safe, speedy and loading sustaining as it has a significant
importance in country’s development. For that, pavement should be designed efficiently to exhibit better
strength, durability and economical at the same time. Generally, a pavement is classified as Flexible or Rigid.
Flexible pavement is opened early to traffic, has good riding quality and ease of maintenance but owing to heavy
loading conditions these pavements are more susceptible to wear and tear. On the contrary rigid pavement is
load sustaining, durable but having higher construction cost and poor riding quality. World is heading to semirigid pavement which exhibits characteristics of both these pavements. It is the combination of cement concrete
and porous asphalt concrete which is achieved by leaving 25% to 30% air voids infused by cement grouts and is
known as Semi-rigid pavement.In this research, semi-rigid pavement was designed using ratio of grout of
optimum mix was 1:0.55 at water cement ratio by 2% of cement dosage with SP. Study concludes that, Semirigid pavement’s Marshall stability of 7 days was almost 85% of rigid pavement and 28 days compressive
strength of semi-rigid pavement was almost 30.5% that of rigid pavement. Besides, it has been ensured that 7
days strength is comparable to 28 days strength of Semi-rigid pavement. |
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Design of Cold Recycled Emulsified Asphalt Mixtures Using Portland Cement as A Partial Replacement of Aggregate Mineral Filler |
Author : Engr. Abdul Qudoos Malano, Prof. Dr. Naeem Aziz Memon, Engr. Gulzar Hussain Jatoi, Engr. Abdul Hafeez Memon |
Abstract | Full Text |
Abstract :Cold Recycling is getting popularity in research sector and construction industries because it overcomes all the
issues of Hot Mix Asphalt of more consumption of natural resources, high production energy, central plant
recycling, effect of greenhouse gases and non-feasibility in colder regions. In this research study, a cold recycled
mixture is designed and compared in terms of mechanical and volumetric properties with control hot mix asphalt
mixture, using 60% RAP (reclaimed asphalt pavement) aggregates and 40 % virgin aggregates to fulfill gradation
requirements. Asphalt emulsion for cold recycled mixtures is used as a binder with varying five contents (4.3%,
4.8%, 5.3%, 5.8% and 6.3%). Also, a modified cold recycled mixture is prepared at optimum emulsion content of
control cold recycled mixture by partially replacing conventional aggregate mineral filler with three different
contents of Portland cement (2%, 3% and 4%) of total dry mass of aggregates. Marshall mix design procedure
was adopted to calculate the optimum (bitumen, emulsion and filler content) for control hot mix asphalt, control
cold recycled mixture and modified cold recycled mixtures respectively. Mechanical properties of each of these
mixtures were compared with each other and it was found that modified cold recycled mixtures were better than
controlled cold recycled mixture and comparable in properties to hot mix asphalt mixtures and Optimum filler
content of Portland cement for modified cold recycled mixture was found to be at 4%.
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Thermodynamic Analysis of Cooling Tower with Air to Air Heat Exchanger for Reducing Evaporative Losses |
Author : Ans Ahmed Memon, Muhammad waqas Chandio, Saadat Ali khokhar |
Abstract | Full Text |
Abstract :In this paper a thermodynamic analysis of cooling tower with air-to-air heat exchanger is presented. During
manual operation of conventional cooling tower, a good quantity of water is evaporated which requires equivalent
amount of makeup water for their condensers. So, in this regard, the thermodynamic model of a cooling with an
air to air heat exchanger is developed using engineering equation solver (EES) software and then simulated in
different climatic conditions of two major cities of Pakistan namely Karachi and Jamshoro through the period of
June & December 2017. The results show a significant variation in water vapor recovery with respect to
atmospheric conditions mainly humidity and ambient air temperature. Results reveal that the when a cooling
tower coupled with air to air heat exchanger maximum amount of water vapors are recovered at Karachi and
ranges up to 67% and 62% in Jamshoro during the month of December. |
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Modeling and Development of Pneumatic Accumulating System |
Author : Engr. Riaz Hussain, Prof. Dr. Dur Muhammad, Dr. Saifullah, Engr. Muhammad Atif |
Abstract | Full Text |
Abstract :In the recent few years the quest for renewable energy has been increased. In developing countries like
Pakistan, energy crises are considered as critical problem for country’s economy. In this scenario there are two
possibilities either to improve the efficiency of energy conversion method or to discover new energy resources
i.e. renewable sources. Therefore, the main concern of this study is to develop an accumulating system which
can harness some amount of wasted energy of moving road vehicles. It has been found that road moving
vehicles are wasting huge amount of their potential energy. This wasted energy can be harvested by installing a
pneumatic accumulating system underneath the transient rout of moving vehicle, which can simulate wasted
energy for useful work. For the proposed system, mathematical model with governing equations is developed,
that shows efficient conversation of potential energy to the pressure energy. Developed model is programmed in
MATLAB for the real time comparison of output. It is observed that the proposed system is applicable to extract
wasted energy of road vehicle for useful purpose |
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A Machine Learning based Network Sharing System Design with MPTCP |
Author : Yu-Ching Lin |
Abstract | Full Text |
Abstract :The information and communication technologies (ICT) integrate different types of wireless communication to
provide IT-enabled services and applications. The great majority end devices are equipped with multiple network
interfaces such as Wi-Fi and 4G. Our goal is to integrate the available network interfaces and technologies to
enhance seamless communication efficiency and increase resources utilization. We proposed a heterogeneous
network management algorithm based on machine learning methods which includes roaming and sharing
functions. The roaming function provides the multiple network resources in physical and media access control
layers. The sharing function supports multiple network resources allocation and the service handover process
based on the Multi-Path TCP protocol. The simulation result also shows that the proposed scheme can increase
the network bandwidth utilization effectively. The sharing system could be used in home, mobile and vehicular
environments to realize ubiquitous social sharing networks.
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Moisture Adsorption Isotherms Characteristics of a New Moisture Adsorbers |
Author : Yué Bi Yao Clément, Bouatene Djakalia, Tano Kablan |
Abstract | Full Text |
Abstract :The purpose of the study was to analyze the effect of the replacement rate of the most hygroscopic moisture
adsorber on the adsorption properties of a new moisture adsorbers formulated. Moisture adsorption isotherms
of this new moisture adsorbers formulated were determined at 4 ± 1 °C, using the standard static gravimetric
method. All moisture adsorption isotherms of new moisture adsorbers were type II following Brunauer’s
classification. The moisture isotherms were sigmoid shaped and showed a clear dependence on the substitution
rates of the most hygroscopic moisture adsorber (ads 3). Of the eighteen new moisture adsorbers formulated,
only AB (40:60) and AL (60:40) adsorbers had the characteristic appearance of better moisture adsorbeers in
modified atmosphere packaging of fruits and vegetables (tomato and mushroom). Thus, their incorporation into
the packaging could avoid the condensation of water vapor by maintaining an optimal relative humidity. Based
on statistical parameters, additive isotherm approach of Labuza (1968) could not correctly describe the
adsorption characteristics of all this new moisture adsorbers formulated. However, this model gave better
prediction with the new AB moisture adsorbers than with the new AL moisture adsorbers with sums of relative
mean errors of 165.89% and 293.71%, respectively. |
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Disputes Impact in Pakistan Construction Industry: A Comprehensive Study of Road Development Projects |
Author : Saeed Ahmed, Dr. Nafees Ahmed Memon, Engr. Ali Raza Khoso, Syed Abdullah Shah Hashmi, Dr. Aftab Hameed Memon |
Abstract | Full Text |
Abstract :The road construction works have tendency to build strong variances among the stakeholder which involved in
projects, they can turn quickly into disputes and become difficult to resolve them. All developing countries are
increasing their economic growths, Pakistan is one of them which rapidly growing its resources spending on
construction projects effectively. Road construction disputes are one the major issues which will affect the
successful completion of the projects. This research aim to analyze the causes and impacts of disputes in roads
construction projects of Pakistan construction industry. This study is undertaken to identify the causes, impacts
and remedial measures/appropriate suggestion to overcome from disputes. The construction claims are
considered as one of the most unpleasant and disruptive event of a construction project, which will effects intern
of costs overrun, time overrun and dynamic nature of projects. This study is limited to determination of causes
and Impacts of disputes as observed by Clients, contractors and consultants working in road construction projects.
Get a path way to manage disputes from informed, selection of remedial measures. The data were collected from
respondents which are concerned in road construction, after analysis of the data, concluded that incomplete
documentation, inappropriate contract system, unrealistic price of tenders, errors in design and overstated claims
are the major Causes of disputes in construction projects. Mediation and negotiation were identified the common
desired method to manage disputes. |
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The Geotechnical Properties of Jamshoro Soil (Shale) With Cement |
Author : Gul Zaman, Dr. Zaheer Ahmed Almani, Dr. Aneel Kumar Hindu |
Abstract | Full Text |
Abstract :The geology of Jamshoro soil is nearly consist of multilayers in alternative form. The alternative layer of
Jamshoro soil occur in the form of lime stone and shale or vice versa. The basic aim of this research is to improve
the geotechnical properties of Jamshoro soil (shale) by using the cement as the stabilized material. This paper
reports the effect of cement on the geotechnical characteristic of the cohesive soil and swelling potential of the
Jamshoro soil. The soil sample used for testing purpose are thoroughly mixed to obtain the homogeneity. After
that thoroughly mixed was dried in the oven. Oven dried sample was mixed with cement at different proportion
that was 5% ,10%, 15% and 20% by the soil weight. Water content used in the mixture to form the specimens at
optimum moisture contents of the soil. The compacted this prepared soil specimen was done by followed the
procedure of standard proctor test. Compacted specimens were cured for the period of 1, 7, 14 and 28 days. After
the completion of curing duration of specimen direct shear test was done. On the base of experimental result, it
was concluded that the cement showed an appreciable improvement of the cohesion with the curing period.
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Design and Simulation Analysis of Sliding Mode Controller for DC-DC Cuk Converter |
Author : Amir Muhammad, Dr. Anwar Ali Sahito, Prof. Dr. Abdul Sattar Larik, Faisal Nawab |
Abstract | Full Text |
Abstract :Due to compact size and fast dynamic response DC-DC converters are used to a great extent. DC-DC Cuk
converter has switching transients which leads to switching losses and harmonics generation. With a linear
controller like Proportional integral derivative (PID), the transients and oscillations under supply and load
variations cannot be controlled. So, it becomes necessary to use a nonlinear controller to make transient
performance of the converter stable increase its efficiency. A great advantage of this controller includes, it’s
based on large signal model of DC to DC converters hence its stability is not bounded by the size of the
interpretations around the working point. In this research work, simulation model of cuk converter with sliding
mode controller is developed and tested using MATLAB SIMULINK. Effectiveness of proposed sliding mode
controller for cuk converter is proved from simulation results. |
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