Abstract: Chemical and physical functionalization of multiwalled
carbon nanotubes (MWCNT) has been commonly practiced to
achieve better dispersion of carbon nanotubes (CNTs) in polymer
matrix. This work describes various functionalization methods (acidtreatment,
non-ionic surfactant treatment with TritonX-100),
fabrication of MWCNT/PP nanocomposites via melt blending and
characterization of mechanical properties. Microscopy analysis
(FESEM, TEM, XPS) showed effective purification of MWCNTs
under acid treatment, and better dispersion under both chemical and
physical functionalization techniques combined, in their respective
order. Tensile tests showed increase in tensile strength for the
nanocomposites that contain MWCNTs up to 2 wt%. A decrease in
tensile strength was seen in samples that contain 4 wt% of MWCNTs
for both raw and Triton X-100 functionalized, signifying MWCNT
degradation/rebundling at composition with higher content of
MWCNTs. For the acid-treated MWCNTs, however, the tensile
results showed slight improvement even at 4wt%, indicating effective
dispersion of MWCNTs.
Abstract: Wind energy has been shown to be one of the most
viable sources of renewable energy. With current technology, the low
cost of wind energy is competitive with more conventional sources of
energy such as coal. Most blades available for commercial grade
wind turbines incorporate a straight span-wise profile and airfoil
shaped cross sections. These blades are found to be very efficient at
lower wind speeds in comparison to the potential energy that can be
extracted. However as the oncoming wind speed increases the
efficiency of the blades decreases as they approach a stall point. This
paper explores the possibility of increasing the efficiency of the
blades at higher wind speeds while maintaining efficiency at the
lower wind speeds. The design intends to maintain efficiency at
lower wind speeds by selecting the appropriate orientation and size
of the airfoil cross sections based on a low oncoming wind speed and
given constant rotation rate. The blades will be made more efficient
at higher wind speeds by implementing a swept blade profile.
Performance was investigated using the computational fluid
dynamics (CFD).
Abstract: Product Lead Time (PLT) is the period of time from
receiving a customer's order to delivering the final product. PLT is an
indicator of the manufacturing controllability, efficiency and
performance. Due to the explosion in the rate of technological
innovations and the rapid changes in the nature of manufacturing
processes, manufacturing firms can bring the new products to market
quicker only if they can reduce their PLT and speed up the rate at
which they can design, plan, control, and manufacture. Although
there is a substantial body of research on manufacturing relating to
cost and quality issues, there is no much specific research conducted
in relation to the formulation of PLT, despite its significance and
importance. This paper analyzes and formulates PLT which can be
used as a guideline for achieving the shorter PLT. Further more this
paper identifies the causes of delay and factors that contributes to the
increased product lead-time.
Abstract: This report aims to utilize existing and future Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing Wireless Local Area Network (MIMO-OFDM WLAN) systems characteristics–such as multiple subcarriers, multiple antennas, and channel estimation characteristics–for indoor location estimation systems based on the Direction of Arrival (DOA) and Radio Signal Strength Indication (RSSI) methods. Hybrid of DOA-RSSI methods also evaluated. In the experimental data result, we show that location estimation accuracy performances can be increased by minimizing the multipath fading effect. This is done using multiple subcarrier frequencies over wideband frequencies to estimate one location. The proposed methods are analyzed in both a wide indoor environment and a typical room-sized office. In the experiments, WLAN terminal locations are estimated by measuring multiple subcarriers from arrays of three dipole antennas of access points (AP). This research demonstrates highly accurate, robust and hardware-free add-on software for indoor location estimations based on a MIMO-OFDM WLAN system.
Abstract: This research aimed to find out the determining
factors for ISO 14001 EMS implementation among SMEs in
Malaysia from the Resource based view. A cross-sectional approach
using survey was conducted. A research model been proposed which
comprises of ISO 14001 EMS implementation as the criterion
variable while physical capital resources (i.e. environmental
performance tracking and organizational infrastructures), human
capital resources (i.e. top management commitment and support,
training and education, employee empowerment and teamwork) and
organizational capital resources (i.e. recognition and reward,
organizational culture and organizational communication) as the
explanatory variables. The research findings show that only
environmental performance tracking, top management commitment
and support and organizational culture are found to be positively and
significantly associated with ISO 14001 EMS implementation. It is
expected that this research will shed new knowledge and provide a
base for future studies about the role played by firm-s internal
resources.
Abstract: This paper deals principally with the socio-economic impact on the local Iban community in Mukah Division, Sarawak; with the commencement of the open-cut coal mining industry since 2003. To-date there are no actual studies being carried out by either the public or private sector to truly analyze how the Iban community is coping with the advent of a large influx of cash into their society. The Iban community has traditionally been practicing shifting cultivation and farming of domesticated animals; with a portion of the younger generation working as laborers and professional. This paper represents the views and observations of the author supported by some statistical facts extracted from published articles and non-published reports. The paper deals primarily in the following areas: • Background of the coal mining industry in Mukah Division, Sarawak; • Benefits of the coal mining industry towards the Iban community; • Issues / Problems arise in the Iban community because of the presence of the coal mining industry; and • Possible actions that need to be taken to overcome these issues/ problems.
Abstract: Ad hoc networks are characterized by multihop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols. We compare the performance of three routing protocols for mobile ad hoc networks: Dynamic Source Routing (DSR) , Ad Hoc On-Demand Distance Vector Routing (AODV), location-aided routing(LAR1).The performance differentials are analyzed using varying network load, mobility, and network size. We simulate protocols with GLOMOSIM simulator. Based on the observations, we make recommendations about when the performance of either protocol can be best.
Abstract: The increasing interest in plant sterol enriched foods
is due to the fact that they reduce blood cholesterol concentrations
without adverse side effects. In this context, enriched foods with
phytosterols may be helpful in protecting population against
atherosclerosis and cardiovascular diseases. The aim of the present
work was to evaluate in a population of Viseu, Portugal, the
consumption habits low-fat, plant sterol-enriched yoghurt. For this
study, 577 inquiries were made and the sample was randomly
selected for people shopping in various supermarkets. The
preliminary results showed that the biggest consumers of these
products were women aged 45 to 65 years old. Most of the people
who claimed to buy these products consumed them once a day. Also,
most of the consumers under antidyslipidemic therapeutics noticed
positive effects on hypercholesterolemia.
Abstract: The nanosized polymeric micelles release the drug
due to acoustic cavitation, which is enhanced in dual frequency
ultrasonic fields. In this study, adult female Balb/C mice were
transplanted with spontaneous breast adenocarcinoma tumors and
were injected with a dose of 1.3 mg/kg doxorubicin in one of three
forms: free doxorubicin, micellar doxorubicin without sonication and
micellar doxorubicin with sonication. To increase cavitation yield,
the tumor region was sonicated with low level dual frequency of 3
MHz and 28 kHz. The animals were sacrificed 24 h after injection,
and their tumor, heart, spleen, liver, kidneys and plasma were
separated and homogenized. The drug content in their tumor, heart,
spleen, liver, kidneys and plasma was determined using tissue
fluorimetry. The results show that in the group that received micellar
doxorubicin with sonication, the drug concentration in the tumor
tissue was nine and three times higher than in the free doxorubicin
group and the micellar doxorubicin without sonication group,
respectively. In the micellar doxorubicin with sonication group, the
drug concentration in other tissues was lower than other groups
(p
Abstract: The possibility of radionuclides-related contamination
of lands at agricultural holdings defines the necessity to apply special
protective measures in plant growing. The aim of researches is to
elucidate the influence of polymers applying on biological migration
of man-made anthropogenic radionuclides 90Sr and 137Cs in the
system water - soil – plant. The tests are being carried out under field
conditions with and without application of polymers in root-inhabited
media in more radioecological tension zone (with the radius of 7 km
from the Armenian Nuclear Power Plant). The polymers on the base
of K+, Caµ, KµCaµ ions were tested. Productivity of pepper
depending on the presence and type of polymer material, content of
artificial radionuclides in waters, soil and plant material has been
determined. The character of different polymers influence on the
artificial radionuclides migration and accumulation in the system
water-soil-plant and accumulation in the plants has been cleared up.
Abstract: For fire safety purposes, the fire resistance and the
structural behavior of reinforced concrete members are assessed to
satisfy specific fire performance criteria. The available prescribed
provisions are based on standard fire load. Under various fire
scenarios, engineers are in need of both heat transfer analysis and
structural analysis. For heat transfer analysis, the study proposed a
modified finite difference method to evaluate the temperature profile
within a cross section. The research conducted is limited to concrete
sections exposed to a fire on their one side. The method is based on
the energy conservation principle and a pre-determined power
function of the temperature profile. The power value of 2.7 is found
to be a suitable value for concrete sections. The temperature profiles
of the proposed method are only slightly deviate from those of the
experiment, the FEM and the FDM for various fire loads such as
ASTM E 119, ASTM 1529, BS EN 1991-1-2 and 550 oC. The
proposed method is useful to avoid incontinence of the large matrix
system of the typical finite difference method to solve the
temperature profile. Furthermore, design engineers can simply apply
the proposed method in regular spreadsheet software.
Abstract: The manufacture of large-scale precision aerospace
components using CNC requires a highly effective maintenance
strategy to ensure that the required accuracy can be achieved over
many hours of production. This paper reviews a strategy for a
maintenance management system based on Failure Mode Avoidance,
which uses advanced techniques and technologies to underpin a
predictive maintenance strategy. It is shown how condition
monitoring (CM) is important to predict potential failures in high
precision machining facilities and achieve intelligent and integrated
maintenance management. There are two distinct ways in which CM
can be applied. One is to monitor key process parameters and
observe trends which may indicate a gradual deterioration of
accuracy in the product. The other is the use of CM techniques to
monitor high status machine parameters enables trends to be
observed which can be corrected before machine failure and
downtime occurs.
It is concluded that the key to developing a flexible and intelligent
maintenance framework in any precision manufacturing operation is
the ability to evaluate reliably and routinely machine tool condition
using condition monitoring techniques within a framework of Failure
Mode Avoidance.
Abstract: The present work analyses different parameters of pressure die casting to minimize the casting defects. Pressure diecasting is usually applied for casting of aluminium alloys. Good surface finish with required tolerances and dimensional accuracy can be achieved by optimization of controllable process parameters such as solidification time, molten temperature, filling time, injection pressure and plunger velocity. Moreover, by selection of optimum process parameters the pressure die casting defects such as porosity, insufficient spread of molten material, flash etc. are also minimized. Therefore, a pressure die casting component, carburetor housing of aluminium alloy (Al2Si2O5) has been considered. The effects of selected process parameters on casting defects and subsequent setting of parameters with the levels have been accomplished by Taguchi-s parameter design approach. The experiments have been performed as per the combination of levels of different process parameters suggested by L18 orthogonal array. Analyses of variance have been performed for mean and signal-to-noise ratio to estimate the percent contribution of different process parameters. Confidence interval has also been estimated for 95% consistency level and three conformational experiments have been performed to validate the optimum level of different parameters. Overall 2.352% reduction in defects has been observed with the help of suggested optimum process parameters.
Abstract: Not all types of mobile phone are successful in entering the market because some types of the mobile phone have a negative perception of user. Therefore, it is important to understand the influence of mobile phone's characteristics in the local user perception. This research investigates the influence of QWERTY mobile phone's forms in the perception of Indonesian user. First, some alternatives of mobile phone-s form are developed based on a certain number of mobile phone's models. At the second stage, some word pairs as design attributes of the mobile phone are chosen to represent the user perception of mobile phone. At the final stage, a survey is conducted to investigate the influence of the developed form alternatives to the user perception. Based on the research, users perceive mobile phone's form with curved top and straight bottom shapes and mobile phone's form with slider and antenna as the most negative form. Meanwhile, mobile phone's form with curved top and bottom shapes and mobile phone-s form without slider and antenna are perceived by the user as the most positive form.
Abstract: Some quality control tools use non metric subjective information coming from experts, who qualify the intensity of relations existing inside processes, but without quantifying them. In this paper we have developed a quality control analytic tool, measuring the impact or strength of the relationship between process operations and product characteristics. The tool includes two models: a qualitative model, allowing relationships description and analysis; and a formal quantitative model, by means of which relationship quantification is achieved. In the first one, concepts from the Graphs Theory were applied to identify those process elements which can be sources of variation, that is, those quality characteristics or operations that have some sort of prelacy over the others and that should become control items. Also the most dependent elements can be identified, that is those elements receiving the effects of elements identified as variation sources. If controls are focused in those dependent elements, efficiency of control is compromised by the fact that we are controlling effects, not causes. The second model applied adapts the multivariate statistical technique of Covariance Structural Analysis. This approach allowed us to quantify the relationships. The computer package LISREL was used to obtain statistics and to validate the model.
Abstract: The Ad Hoc on demand distance vector (AODV) routing protocol is designed for mobile ad hoc networks (MANETs). AODV offers quick adaptation to dynamic link conditions; it is characterized by low memory overhead and low network utilization. The security issues related to the protocol remain challenging for the wireless network designers. Numerous schemes have been proposed for establishing secure communication between end users, these schemes identify that the secure operation of AODV is a bi tier task (routing and secure exchange of information at separate levels). Our endeavor in this paper would focus on achieving the routing and secure data exchange in a single step. This will facilitate the user nodes to perform routing, mutual authentications, generation and secure exchange of session key in one step thus ensuring confidentiality, integrity and authentication of data exchange in a more suitable way.
Abstract: In recent years demolished concrete waste handling and management is the new primary challenging issue faced by the countries all over the world. It is very challenging and hectic problem that has to be tackled in an indigenous manner, it is desirable to completely recycle demolished concrete waste in order to protect natural resources and reduce environmental pollution. In this research paper an experimental study is carried out to investigate the feasibility and recycling of demolished waste concrete for new construction. The present investigation to be focused on recycling demolished waste materials in order to reduce construction cost and resolving housing problems faced by the low income communities of the world. The crushed demolished concrete wastes is segregated by sieving to obtain required sizes of aggregate, several tests were conducted to determine the aggregate properties before recycling it into new concrete. This research shows that the recycled aggregate that are obtained from site make good quality concrete. The compressive strength test results of partial replacement and full recycled aggregate concrete and are found to be higher than the compressive strength of normal concrete with new aggregate.
Abstract: Nagaland, the 16th state of India in order of
statehood, is situated between 25° 6' and 27° 4' latitude north and
between 93º 20' E and 95º 15' E longitude of equator in the North
Eastern part of the India. Endowed with varied topography, soil and
agro climatic conditions it is known for its potentiality to grow all
most all kinds of horticultural crops. Pineapple being grown since
long organically by default is one of the most promising crops of the
state with emphasis being laid for commercialization by the
government of Nagaland. In light of commercialization, globalization
and scope of setting small-scale industries, a research study was
undertaken to examine the socio-economic and personal
characteristics, entrepreneurial characteristics and attitude of the
pineapple growers towards improved package of practices of
pineapple cultivation. The study was conducted in Medziphema
block of Dimapur district of the Nagaland state of India following ex
post facto research design. Ninety pineapple growers were selected
from four different villages of Medziphema block based on
proportionate random selection procedure. Findings of the study
revealed that majority of the respondents had medium level of
entrepreneurial characteristics in terms of knowledge level, risk
orientation, self confidence, management orientation, farm decision
making ability and leadership ability and most of them had
favourable attitude towards improved package of practices of
pineapple cultivation. The variables age, education, farm size, risk
orientation, management orientation and sources of information
utilized were found important to influence the attitude of the
respondents. The study revealed that favourable attitude and
entrepreneurial characteristics of the pineapple cultivators might be
harnessed for increased production of pineapple in the state thereby
bringing socio economic upliftment of the marginal and small-scale
farmers.
Abstract: Horseradish (Armoracia rusticana) is a perennial herb belonging to the Brassicaceae family and contains biologically active substances. The aim of the current research was to determine best method for extraction of phenolic compounds from horseradish roots showing high antiradical activity. Three genotypes (No. 105; No. 106 and variety ‘Turku’) of horseradish roots were extracted with eight different solvents: n-hexane, ethyl acetate, diethyl ether, 2-propanol, acetone, ethanol (95%), ethanol / water / acetic acid (80/20/1 v/v/v) and ethanol / water (80/20 by volume) using two extraction methods (conventional and Soxhlet). As the best solvents ethanol and ethanol / water solutions can be chosen. Although in Soxhlet extracts TPC was higher, scavenging activity of DPPH˙ radicals did not increase. It can be concluded that using Soxhlet extraction method more compounds that are not effective antioxidants.
Abstract: Interior brick-infill partitions are usually considered as
non-structural components and only their weight is accounted for in
practical structural design. In this study, their effect on the progressive
collapse resistance of an RC building subjected to sudden column loss
is investigated. Three notional column loss conditions with four
different brick-infill locations are considered. Column-loss response
analyses of the RC building with and without brick infills are carried
out. Analysis results indicate that the collapse resistance is only
slightly influenced by the brick infills due to their brittle failure
characteristic. Even so, they may help to reduce the inelastic
displacement response under column loss. For practical engineering, it
is reasonably conservative to only consider the weight of brick-infill
partitions in the structural analysis.