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The characterization and properties of recycled natural latex gloves (rNL-G) filled acrylonitrile butadiene rubber (NBR) compounds
No full textMaster of Science in Polymer EngineeringThe utilization of waste rubber from recycled natural latex gloves (rNL-G) by means of
compounding together with synthetic rubber: acrylonitrile butadiene rubber (NBR)
could represents a new product with an acceptable properties. Results in first series
which NBR/ rNL-G compounds particularly fine size up to 20 phr loading of rNL-G,
showed overall improvement in cure characteristic, tensile, physical and thermal
properties compared to coarser size and other rNL-G loading. Meanwhile, in second
series, the incorporation of sawdust short fiber (SD) as natural filler at different loading
was studied with optimum rNL-G loading filled NBR from the first series. Results
indicated that, the addition of SD loading at 5 phr increased the adhesion between NBR
matrix, which led to improve the cure characteristics such as lower cure time and
increase the stiffness and rigidity such as modulus and hardness. At third series, the
addition of 6 phr of trans-polyoctylene rubber (TOR) as a compatibilizer has increased
the crosslinking density and enhanced the incorporation of NBR/ rNL-G compounds,
therefore improving the compatibility of NBR/ rNL-G compounds. Most of cure
characteristics, tensile, physical and thermal properties of compatibilised NBR/ rNL-G
compounds, particularly 6 phr TOR showed better overall properties than
uncompatibilised NBR/ rNL-G compounds. The combination of all material referring
from optimum loading of 1st series at 20 phr rNL-G/ fine size, 2nd series at 5 phr SD and
3rd series at 6 phr TOR. The NBR/ rNL-G /SD/TOR compound exhibited the most
improvement properties particularly the thermal stability, tensile and physical
properties. The tensile fracture surface of all series were supported by scanning electron
microscopy (SEM) observation proved the behavior of optimum strength of each
compound respectively
Understanding the effects of fake profiles in SNS on adolescents behavior: a grounded theory approach
No full textDoctor of Philosophy in Communication and Information TechnologyThis study aims at understanding the impact of fake profiles in SNS on teenagers’ behavior as a Grounded Theory Approach, and as the rapidly growing SNSs today are offering individuals endless possibilities for publicly expressing themselves, communicating with friends, and sharing information with people across the world since SNSs are the most common platforms on the Internet, on which millions of users register to share personal facts with their friends, there are still cases of fake profiling within the online communication system. Therefore, this study focused on investigating the overall aspects of fake profiling among adolescents by focusing on students with different age categories in schools in The Hashemite Kingdom of Jordan, by attempting to answer the study questions: What are the contexts and prevailing conditions that influence the
antecedents of the phenomenon? The second research question is what are the antecedents
that contribute toward the occurrence of central phenomenon? Consequently, the third
research question is what are the coping strategies resulting from fake profiling activities?
Finally, the fourth research question is what are the consequences resulting from the
coping strategies taken by the informants? A qualitative research method through
interview was conducted for this study using Strauss and Corbin’s GT framework on 78
adolescents and analyzed by using NVivo version 11. Interviews took place over a sevenmonth
period, between March 2015 and September 2015. The main findings of this study
indicate that informants, especially bullies, accomplished the concepts of “feelings of
pleasure” by exploiting online communication to taunt their victims. This has generated
negative behaviors that caused positive and negative impacts toward adolescents, which
could be regarded as the phenomenon in this study. Another finding shows that
informants engaged in fake profiling activities desired to get “a sense of satisfaction” in
their lives. This has also led to negative behaviors that caused positive and negative
impacts toward adolescents, and that could also be referred to as the phenomenon in this
study. The other findings are the significant contribution of social networking toward fake
profiling especially Facebook, the positive impacts fake profiling ‘offer’ to adolescents,
and two other factors that become antecedents of fake profiling – the supporters and the
instigators. In this regard, this study has contributed in clarifying the inter-relationships
between themes and subthemes of the fake profiling phenomenon between adolescents in
Jordan by highlighting the facts that fake profiling is an unaccepted social phenomenon,
and the faster and more effectively we can share ideas about it, the better we can make
our targeted aims, the better we can serve our targeted students, the better we can build
our targeted committed society. When implementing a successful understanding of fake
profiling, then the descriptions of the steps we should expect to take and avoid are
compulsory. Other policies and strategies that are influential to the overall growth of the
Jordanian adolescents sector are also suggested through the findings on the investigated
selected constructs
Computational design and synthesis of molecular imprinted membranes for selective extraction of Quercetin
No full textMaster of Science in Materials EngineeringThis thesis presents the fabrication of quercetin imprinted membranes (QIM) for selective extraction of quercetin through surface polymerization method. In the development of QIM, selection of functional monomer and the optimum molar ratio of template-monomer were facilitated by the application of molecular modelling through the use of HyperChem software. Three functional monomers were investigated including acrylamide, methacrylic acid and 4-vinylpyridine and the optimization of pre-polymerization complex was conducted at molar ratio of 1:1 to 1:5 for each of the monomers. The results indicated that molar ratio of 1:4, which involving the interaction between quercetin and acylamide could provide potentially favourable pre-polymerization complex prior to the synthesis of QIM. After this step had been established, QIM were developed based on the computational results. In order to deposit the imprinted layer on the surface of membrane, polyvinylidene fluoride (PVDF) membrane was used as the polymer support and then, they were subjected to thermal polymerization process and subsequent removal of template from the polymer matrix. QIM and non-imprinted membranes (NIM) were synthesized to evaluate and characterize the differences with respect to their morphology, chemical functionality as well as their binding behaviour towards quercetin and other components. The confirmation on the presence of imprinted layer on PVDF membrane was done through FTIR, FESEM and AFM analysis. From the results obtained, it can be summarized that imprinted layer composed of recognition sites were successfully formed
and distributed evenly on the surface of QIM. For the binding performance evaluation, batch binding, kinetic binding and selectivity tests were conducted. The maximum binding capacity of QIM in batch binding was 25.63 mg/g, which is higher than binding capacity of NIM with the capacity value of 7.47 mg/g. Apart from that, QIM also exhibits higher adsorption rate at the initial stage of adsorption process and the saturation time was achieved after 3-4 hours contact time. Modelling of isotherm and kinetic adsorption showed that QIM has a homogenous surface and followed Elovich kinetic model, respectively. Finally, the selectivity test of QIM was investigated by using sinensetin and rosmarinic acid as competitive components. It demonstrated that QIM showed higher recognition capability towards quercetin compared to sinensetin and rosmarinic acid
Design of 0.5 hp induction motor rotor bars with 0.35 mm and 0.50 mm thickness of steel sheets for rotor fabrication
No full textDoctor of Philosophy in Electrical Systems EngineeringIn this project, the 0.5 Hp three phase induction motor have been thoroughly investigated and analyzed in terms of the induction motor parameter, torque, efficiency, power factor, losses reduction, transfer mechanism and economic aspects. Throughout
this project, the performance and the development of the three phase induction motor when it design and modelling by using 0.35 mm and 0.50 mm thickness of steel sheets was fabricated and compared it. First, the mathematical analysis of alternating current
(AC) induction motor is done to calculate all the loss and equivalent circuit parameters for 0.5 Hp 3 phase induction motor. This is to show the efficiency and the amount of energy that is consumed in an induction motor. Second, the research involves designing
and simulating the 0.5 Hp 3 phase induction motor using MotorSolve IM software, AutoCAD software, Opera 2D software and MATLAB software. From the simulation, analysis such as power loss, magnetic flux density, eddy current density, torque vs.
speed, power loss vs. speed, efficiency vs. speed, and power factor vs. speed is done. A comparative study is done between the uses of 0.35 mm and 0.50 mm thickness of material in the rotor of induction motor. Third, the rotor part of an induction motor for
different thicknesses are fabricated and investigated in terms of its efficiency increment, power factor improvement, flux distribution and loss reduction capabilities
Characterization and properties of Recycled Acrylonitrile Butadiene Rubber (rNBR) filled Epoxidized Natural Rubber (ENR 25) compound
No full textMaster of Science in Materials EngineeringThe uses of recycled rubber in rubber compounding become an alternative method to reduce the landfill of rubber waste and gives opportunity to produce new product. In this research, the study on the properties of recycled acrylonitrile butadiene rubber (rNBR) gloves filled epoxidized natural rubber (ENR 25) has been done. The compounding process was conducted by using two roll mills at room temperature and semi-efficient vulcanization (SEV) system was selected in this study. The scorch time (t2), cure time (t90), maximum torque (MH) and minimum torque (ML) were determined by using a Monsanto rheometer. The determination of rubber vulcanizate’s properties includes tensile test, hardness test, resilience test, swelling test, crosslink density, and SEM.
Results in first series indicated that the fine size, S1 of rNBR filled ENR 25 compound contributed to the better properties such as cure characteristics, tensile properties, physical properties and morphology compare to coarser size, S2 of rNBR, mainly at 15
phr of rNBR content. However, the coarse size of rNBR particles size exhibited deterioration in all properties due to agglomeration of rNBR during vulcanization process. The optimum properties (having 15 phr of rNBR filled ENR 25) were selected
for further study in second series with incorporation of Imperata Cylindrica as natural
filler. Result shows a decrement in tensile properties with the increment of Imperata
Cylindrica loading. However, cure characteristics, physical properties and
morphological properties show better result at 5 phr loading of Imperata Cylindrica
powder especially for fine size, C1 powder. At third series, the incorporation of transpolyoctylene
rubber(TOR) as compatibilizer into optimum properties in series 2 shows highest tensile properties at 6 phr of TOR and the rubber become softer as the compatibilizer content increased. Other properties such as cure characteristics, physical properties and morphological properties show an improvement with the presence of
TOR into rubber compound
Fabrication of SAC107 and Sn-0.7Cu lead free composite solder reinforced with Si3N4 via powder metallurgy route
No full textMaster of Science in Materials EngineeringThe composite technology is the new approach to improve the service temperature capabilities and thermal stability of the solder joints. Low-silver Sn98.3-Ag1.0-Cu0.7 (SAC107) and Sn99.3-Cu0.7 (Sn-0.7Cu) solders were used as matrix while silicon nitride
(Si3N4) with different weight fractions (0, 0.25, 0.5, 0.75 and 1.0 wt. %) were added as reinforcement particles. The solder composites were prepared by using powder metallurgy method consists of mixing, compaction and sintering via microwave assisted rapid sintering. This microwave sintering approach results in more uniform heating with cost-effective and energy efficiency. The research project was divided into two phases. The first phase involves the fabrication and characterization of electrical, thermal, microstructural and mechanical properties of the bulk composite solder. The second phase was the studies on the properties of microstructural, solderability and mechanical properties as-reflowed solder joint/interconnection. It was noted that finer and well distributed reinforcement precipitates has led to higher microhardness and slightly decreased in melting point and electrical resistivity of bulk composite solder. The wettability performance of composite solder was improved. Correspondingly, the intermetallic compound (IMC) thickness was suppressed during the soldering. The dispersion strengthening effect enhances the shear strength and the fracture surface exhibit the ductile fracture mode with rough dimple surface instead of brittle fracture mode at the interface (substrate/solder) of composite solder joints. Overall, the addition of reinforcements into lead-free solder alloy matrix has improved all the listed properties of the solder materials
Intelligent classifier for incipient phase fire in building
No full textDoctor of Philosophy in Mechatronic EngineeringEarly fire detection is one of the most promising sub-fields in indoor air quality research. Ability to give early fire indication can help the building occupants to take responsive actions in order to prevent the fire. Delay in having such indication not
only leading to property and money losses, but also life losses. This research is a preliminary research intended to detect the early fire and the material (common fire sources and building construction materials) involved in the fire using intelligent
classifier. Indoor Air Quality (IAQ) database is formed as the testing database, while Portable Electronic Nose 3 (PEN3) database is formed to verify the IAQ database. The databases consist of gas sensor inputs from the test materials, heated up at different
temperatures in the testbed. Seven temperatures, range from 50°C up to 250°C have been tested. For incipient phase fire, data for temperature range 75°C up to 125°C shows a very significant result. The data is pre-processed and normalised into five
types of normalised features. Out of the five normalised features, only three were statistically selected for proposed multi- stage feature selection and feature fusion process. As an output to the proposed process, a new robust feature, IAQ-Hybrid
feature is formed. IAQ-Hybrid feature is consisting of dimensionally reduced principal components fused by the feature fusion technique. ANOVA F- Test and Principal Component Analysis are used for selecting the useful and non- redundant
data for the proposed feature formulation. The proposed feature and the other normalised features (three types of normalised features which were statistically selected earlier) are tested with various common unsupervised, semi- supervised and
supervised classifiers
The effects of human resource management practices and knowledge management strategies on organizational performance among Jordanian banks total quality management as a moderator
No full textDoctor of Philosophy in ManagementWith the ever increasing attrition rate of organizational performance in national banks, the Jordanian banks continue to face a number of economic difficulties and imbalances in the economic structure, banking results witnessed a decline in many case. Therefore, this study aims to investigate the effects of total quality management (TQM) on the relationship between human resource management (HRM) practices and knowledge management (KM) strategies towards organizational performance of Jordanian banks. A total of 135 heads of department from Jordanian national banks participated in the survey. The result of partial least squares (PLS) path analysis supports all variables in the hypothesized direct relationship with organizational performance. Specifically, the relationship between HRM practices (training and development, performance appraisal
and compensation) and KM strategies (knowledge acquisition, knowledge conversion, knowledge protection, knowledge application and knowledge sharing) towards organizational performance are found to be significant. The results of the analysis also suggest that TQM moderates the relationship between HRM practices (training and development and performance appraisal), KM strategies (knowledge conversion, knowledge protection, knowledge application, and knowledge sharing) and
organizational performance; while the moderation effects of TQM on compensation, knowledge acquisition and organizational performance are not been supported. Taken together, the findings of this study lend empirical support to the view that joint creation of value between variables will confer competitive advantage. Jordanian national banks particularly should focus on the implementation of TQM, HRM practices and KM strategies to enhance managers performance and increase productivity and effectiveness for sustainable internationalization benefits
Performance analysis of IEEE802.15.4 wireless sensor network to mitigate IEEE802.11 wireless local area network interference
No full textMaster of Science in Computer EngineeringWireless Sensor Networks (WSN) technology is rapidly deployed in applications such as robotic, healthcare, military, environmental monitoring, and other low-power large scale monitoring that requires high data accuracy with possibly minimal latency and data losses. The Quality of Service (QoS) of WSN is often compromised by the interference from other wireless technologies that are high in transmission power and bandwidth such as Wireless Local Area Network (WLAN), Bluetooth, microwave oven, cordless phone and wirelessUSB. The ubiquitous increase in the number of wireless devices leads to the frequency spectrum occupancy issues as various wireless technologies are forced to share the free and unlicensed 2.4GHz frequency band.
Compared to other wireless technologies, the interference from the WLAN devices
caused a significant packet loss experienced by WSN. This study focuses on
investigating the effect of WLAN interference on WSN performance through
experimental study. This research provides an empirical study on the effect of WLAN
on WSN performance in terms of Energy Detection (ED) and packet loss. A WLAN
access point (AP) or router, laptops as end-client and IxChariot software are used to
emulate WLAN traffic while Waspmote is used as WSN nodes. Tests had been
conducted in two different environments, which is in controlled and uncontrolled
environment. Preliminary test found that scan duration need to be set to 3 in order to
achieve the best ED value after considering the tradeoff between accuracy and false
detection. Result from this study demonstrates that ED is around -84dBm with no
packet loss for test conducted without WLAN interferer. Similarly, test conducted with
one WLAN interferer (without traffic) shows that there is no packet loss but there is
high increase in ED reading that is approximately -44dBm. Besides that, this research
found that the density of traffic yield from WLAN network does not significantly affect
the ED (around -41dBm) by WSN in comparison to when the WLAN AP is simply
turned on without traffic (ED value is around -44dBm). However, the WLAN traffic
does affect the WSN packet loss where packet loss increases from 14% to 36% when
traffic increased from 10% to 30% in controlled environment. Despite that, further tests
revealed that the frequency offset between WLAN and WSN centre frequency did affect
the ED by the WSN. The ED value when the frequency offset between WLAN and
WSN is less than or equal to 3MHz is approximately -42dBm and the ED value for
frequency offset is 8MHz and 13MHz is approximately -54dBm and -68dBm
respectively. In addition, this research also studies the performance of WSN for fixed
channel allocation. Besides that, this research also proposed a technique to improve
WSN performance by performing dynamic channel selection. The technique reduces the
WSN packet loss from 7% to approximately 0% packet loss