Abstract: The feasibility of applying a simple and cost effective sliding friction testing apparatus to study the friction behaviour of a clutch facing material, effected by the variation of temperature and contact pressure, was investigated. It was found that the method used in this work was able to give a convenient and cost effective measurement of friction coefficients and their transitions of a clutch facing material. The obtained results will be useful for the development process of new facing materials.
Abstract: Independent spanning trees (ISTs) provide a number of advantages in data broadcasting. One can cite the use in fault tolerance network protocols for distributed computing and bandwidth. However, the problem of constructing multiple ISTs is considered hard for arbitrary graphs. In this paper we present an efficient algorithm to construct ISTs on hypercubes that requires minimum resources to be performed.
Abstract: Chaiyaphum Starch Co. Ltd. is one of many starch
manufacturers that has introduced machinery to aid in manufacturing.
Even though machinery has replaced many elements and is now a
significant part in manufacturing processes, problems that must be
solved with respect to current process flow to increase efficiency still
exist. The paper-s aim is to increase productivity while maintaining
desired quality of starch, by redesigning the flipping machine-s
mechanical control system which has grossly low functional lifetime.
Such problems stem from the mechanical control system-s bearings,
as fluids and humidity can access into said bearing directly, in
tandem with vibrations from the machine-s function itself. The wheel
which is used to sense starch thickness occasionally falls from its
shaft, due to high speed rotation during operation, while the shaft
may bend from impact when processing dried bread. Redesigning its
mechanical control system has increased its efficiency, allowing
quality thickness measurement while increasing functional lifetime
an additional 62 days.
Abstract: The availability of water in adequate quantity and
quality is imperative for sustainable development. Worldwide,
significant imbalance exists with regards to sustainable development
particularly from a water and sanitation perspective. Water is a
critical component of public health, and failure to supply safe water
will place a heavy burden on the entire population. Although the 21st
century has witnessed wealth and advanced development, it has not
been realized everywhere. Billions of people are still striving to
access the most basic human needs which are food, shelter, safe
drinking water and adequate sanitation. The global picture conceals
various inequalities particularly with regards to sanitation coverage in
rural and urban areas. Currently, water scarcity and in particular
water governance is the main challenge which will cause a threat to
sustainable development goals. Within the context of water,
sanitation and health, sustainable development is a confusing concept
primarily when examined from the viewpoint of policy options for
developing countries. This perspective paper aims to summarize and
critically evaluate evidence of published studies in relation to water,
sanitation and health and to identify relevant solutions to reduce
public health impacts. Evidently, improving water and sanitation
services will result in significant and lasting gains in health and
economic development.
Abstract: We present design, fabrication, and characterization of
a small (12 mm × 12 mm × 8 mm) movable railway vehicle for sensor
carrying. The miniature railway vehicle (MRV) was mainly composed
of a vibrational structure and three legs. A railway was designed and
fabricated to power and guide the MRV. It also transmits the sensed
data from the MRV to the signal processing unit. The MRV with legs
on the railway was moving due to its high-frequency vibration. A
model was derived to describe the motion. Besides, FEM simulations
were performed to design the legs. Then, the MRV and the railway
were fabricated by precision machining. Finally, an infrared sensor
was carried and tested. The result shows that the MRV without loading
was moving along the railway and its maximum speed was 12.2 mm/s.
Moreover, the testing signal was sensed by the MRV.
Abstract: In this paper is reported an analysis about the outdoor air pollution of the urban centre of the city of Messina. The variations of the most critical pollutants concentrations (PM10, O3, CO, C6H6) and their trends respect of climatic parameters and vehicular traffic have been studied. Linear regressions have been effectuated for representing the relations among the pollutants; the differences between pollutants concentrations on weekend/weekday were also analyzed. In order to evaluate air pollution and its effects on human health, a method for calculating a pollution index was implemented and applied in the urban centre of the city. This index is based on the weighted mean of the most detrimental air pollutants concentrations respect of their limit values for protection of human health. The analyzed data of the polluting substances were collected by the Assessorship of the Environment of the Regional Province of Messina in the year 2004. A statistical analysis of the air quality index trends is also reported.
Abstract: Cu-mesoporous TiO2 is developed for removal acid
odor cooperated with ozone assistance and online- regeneration
system with/without UV irradiation (all weather) in study. The results
showed that Cu-mesoporous TiO2 present the desirable adsorption
efficiency of acid odor without UV irradiation, due to the larger
surface area, pore sizeand the additional absorption ability provided by
Cu. In the photocatalysis process, the material structure also benefits
Cu-mesoporous TiO2 to perform the more outstanding efficiency on
degrading acid odor. Cu also postponed the recombination of
electron-hole pairs excited from TiO2 to enhance photodegradation
ability. Cu-mesoporous TiO2 could gain the conspicuous increase on
photocatalysis ability from ozone assistance, but without any benefit
on adsorption. In addition, the online regeneration procedure could
process the used Cu-mesoporous TiO2 to reinstate the adsorption
ability and maintain the photodegradtion performance, depended on
scrubbing, desorping acid odor and reducing Cu to metal state.
Abstract: Hydrogen is considered to be the most promising
candidate as a future energy carrier. One of the most used
technologies for the electrolytic hydrogen production is alkaline
water electrolysis. However, due to the high energy requirements, the
cost of hydrogen produced in such a way is high. In continuous
search to improve this process using advanced electrocatalytic
materials for the hydrogen evolution reaction (HER), Ni type Raney
and macro-porous Ni-Co electrodes were prepared on AISI 304
stainless steel substrates by electrodeposition. The developed
electrodes were characterized by SEM and confocal laser scanning
microscopy. HER on these electrodes was evaluated in 30 wt.% KOH
solution by means of hydrogen discharge curves and galvanostatic
tests. Results show that the developed electrodes present a most
efficient behaviour for HER when comparing with the smooth Ni
cathode. It has been reported a reduction in the energy consumption
of the electrolysis cell of about 25% by using the developed coatings
as cathodes.
Abstract: Given a parallel program to be executed on a heterogeneous
computing system, the overall execution time of the program
is determined by a schedule. In this paper, we analyze the worst-case
performance of the list scheduling algorithm for scheduling tasks
of a parallel program in a mixed-machine heterogeneous computing
system such that the total execution time of the program is minimized.
We prove tight lower and upper bounds for the worst-case
performance ratio of the list scheduling algorithm. We also examine
the average-case performance of the list scheduling algorithm. Our
experimental data reveal that the average-case performance of the list
scheduling algorithm is much better than the worst-case performance
and is very close to optimal, except for large systems with large
heterogeneity. Thus, the list scheduling algorithm is very useful in
real applications.
Abstract: Sophorolipids (SLs) production by the yeast Candida
bombicola was studied in batch shake flasks using synthetic dairy
wastewaters (SDWW) with or without any added external carbon and
nitrogen sources. A maximum SLs production of 38.76 g/l was
observed with the SDWW supplemented with low cost substrate of
sugarcane molasses at 50 g/l and soybean oil at 50 g/l. When the
SDWW was supplemented with more costly glucose, yeast extract,
urea and soybean oil, the production, however, got lowered to only
29.49 g/l, but with a maximum biomass production of 17.38 g/l
together with a complete utilization of the carbon sources.
Abstract: Shear walls are used in most of the tall buildings for
carrying the lateral load. When openings for doors or windows are
necessary to be existed in the shear walls, a special type of the shear
walls is used called "coupled shear walls" which in some cases is
stiffened by specific beams and so, called "stiffened coupled shear
walls".
In this paper, a mathematical method for geometrically nonlinear
analysis of the stiffened coupled shear walls has been presented.
Then, a suitable formulation for determining the critical load of the
stiffened coupled shear walls under gravity force has been proposed.
The governing differential equations for equilibrium and deformation
of the stiffened coupled shear walls have been obtained by setting up
the equilibrium equations and the moment-curvature relationships for
each wall. Because of the complexity of the differential equation, the
energy method has been adopted for approximate solution of the
equations.
Abstract: This paper presents an equivalent circuit model based on piecewise linear parallel branches (PLPB) to study solar cell modules which are partially shaded. The PLPB model can easily be used in circuit simulation software such as the ElectroMagnetic Transients Program (EMTP). This PLPB model allows the user to simulate several different configurations of solar cells, the influence of partial shadowing on a single or multiple cells, the influence of the number of solar cells protected by a bypass diode and the effect of the cell connection configuration on partial shadowing.
Abstract: Encrypted messages sending frequently draws the attention
of third parties, perhaps causing attempts to break and
reveal the original messages. Steganography is introduced to hide
the existence of the communication by concealing a secret message
in an appropriate carrier like text, image, audio or video. Quantum
steganography where the sender (Alice) embeds her steganographic
information into the cover and sends it to the receiver (Bob) over a
communication channel. Alice and Bob share an algorithm and hide
quantum information in the cover. An eavesdropper (Eve) without
access to the algorithm can-t find out the existence of the quantum
message. In this paper, a text quantum steganography technique based
on the use of indefinite articles (a) or (an) in conjunction with the nonspecific
or non-particular nouns in English language and quantum
gate truth table have been proposed. The authors also introduced a
new code representation technique (SSCE - Secret Steganography
Code for Embedding) at both ends in order to achieve high level of
security. Before the embedding operation each character of the secret
message has been converted to SSCE Value and then embeds to cover
text. Finally stego text is formed and transmits to the receiver side.
At the receiver side different reverse operation has been carried out
to get back the original information.
Abstract: Practicum placements are an critical factor for student teachers on Education Programs. How can student teachers become professionals? This study was to investigate problems, weakness and obstacles of practicum placements and develop guidelines for partnership in the practicum placements. In response to this issue, a partnership concept was implemented for developing student teachers into professionals. Data were collected through questionnaires on attitude toward problems, weaknesses, and obstacles of practicum placements of student teachers in Rajabhat universities and included focus group interviews. The research revealed that learning management, classroom management, curriculum, assessment and evaluation, classroom action research, and teacher demeanor are the important factors affecting the professional development of Education Program student teachers. Learning management plan and classroom management concerning instructional design, teaching technique, instructional media, and student behavior management are another important aspects influencing the professional development for student teachers.
Abstract: The stilling basins are commonly used to dissipate the
energy and protect the downstream floor from erosion. The aim of
the present experimental work is to improve the roughened stilling
basin using T-shape roughness instead of the regular cubic one and
design this new shape. As a result of the present work the best
intensity and the best roughness length are identified. Also, it is
found that the T-shape roughness save materials and reduce the jump
length compared to the cubic one. Sensitivity analysis was performed
and it was noticed that the change in the length of jump is more
sensitive to the change in roughness length than the change in
intensity.
Abstract: Cryptography provides the secure manner of
information transmission over the insecure channel. It authenticates
messages based on the key but not on the user. It requires a lengthy
key to encrypt and decrypt the sending and receiving the messages,
respectively. But these keys can be guessed or cracked. Moreover,
Maintaining and sharing lengthy, random keys in enciphering and
deciphering process is the critical problem in the cryptography
system. A new approach is described for generating a crypto key,
which is acquired from a person-s iris pattern. In the biometric field,
template created by the biometric algorithm can only be
authenticated with the same person. Among the biometric templates,
iris features can efficiently be distinguished with individuals and
produces less false positives in the larger population. This type of iris
code distribution provides merely less intra-class variability that aids
the cryptosystem to confidently decrypt messages with an exact
matching of iris pattern. In this proposed approach, the iris features
are extracted using multi resolution wavelets. It produces 135-bit iris
codes from each subject and is used for encrypting/decrypting the
messages. The autocorrelators are used to recall original messages
from the partially corrupted data produced by the decryption process.
It intends to resolve the repudiation and key management problems.
Results were analyzed in both conventional iris cryptography system
(CIC) and non-repudiation iris cryptography system (NRIC). It
shows that this new approach provides considerably high
authentication in enciphering and deciphering processes.
Abstract: This paper presents a threshold voltage model of pocket implanted sub-100 nm n-MOSFETs incorporating the drain and substrate bias effects using two linear pocket profiles. Two linear equations are used to simulate the pocket profiles along the channel at the surface from the source and drain edges towards the center of the n-MOSFET. Then the effective doping concentration is derived and is used in the threshold voltage equation that is obtained by solving the Poisson-s equation in the depletion region at the surface. Simulated threshold voltages for various gate lengths fit well with the experimental data already published in the literature. The simulated result is compared with the two other pocket profiles used to derive the threshold voltage models of n-MOSFETs. The comparison shows that the linear model has a simple compact form that can be utilized to study and characterize the pocket implanted advanced ULSI devices.
Abstract: Rainfall data at fine resolution and knowledge of its
characteristics plays a major role in the efficient design and operation
of agricultural, telecommunication, runoff and erosion control as well
as water quality control systems. The paper is aimed to study the
statistical distribution of hourly rainfall depth for 12 representative
stations spread across Peninsular Malaysia. Hourly rainfall data of 10
to 22 years period were collected and its statistical characteristics
were estimated. Three probability distributions namely, Generalized
Pareto, Exponential and Gamma distributions were proposed to
model the hourly rainfall depth, and three goodness-of-fit tests,
namely, Kolmogorov-Sminov, Anderson-Darling and Chi-Squared
tests were used to evaluate their fitness. Result indicates that the east
cost of the Peninsular receives higher depth of rainfall as compared
to west coast. However, the rainfall frequency is found to be
irregular. Also result from the goodness-of-fit tests show that all the
three models fit the rainfall data at 1% level of significance.
However, Generalized Pareto fits better than Exponential and
Gamma distributions and is therefore recommended as the best fit.
Abstract: Based on 276 responses from academic staff in an
evaluation of an online learning environment (OLE), this paper
identifies those elements of the OLE that were most used and valued
by staff, those elements of the OLE that staff most wanted to see
improved, and those factors that most contributed to staff perceptions
that the use of the OLE enhanced their teaching. The most used and
valued elements were core functions, including accessing unit
information, accessing lecture/tutorial/lab notes, and reading online
discussions. The elements identified as most needing attention related
to online assessment: submitting assignments, managing assessment
items, and receiving feedback on assignments. Staff felt that using the
OLE enhanced their teaching when they were satisfied that their
students were able to access and use their learning materials, and
when they were satisfied with the professional development they
received and were confident with their ability to teach with the OLE.
Abstract: The large and small-scale shaking table tests, which
was conducted for investigating damage evolution of piles inside
liquefied soil, are numerically simulated and experimental verified by the3D nonlinear finite element analysis. Damage evolution of
elasto-plastic circular steel piles and reinforced concrete (RC) one with cracking and yield of reinforcement are focused on, and the failure patterns and residual damages are captured by the proposed constitutive models. The superstructure excitation behind quay wall is
reproduced as well.