Abstract: This study was carried out to develop a flotation
procedure for an oxide copper ore from a Region in Central Africa
for producing an 18% copper concentrate for downstream processing
at maximum recovery from a 4% copper feed grade. The copper
recoveries achieved from the test work were less than 50% despite
changes in reagent conditions (multistage sulphidisation, use of RCA
emulsion and mixture, use of AM 2, etc). The poor recoveries were
attributed to the mineralogy of the ore from which copper silicates
accounted for approximately 70% (mass) of the copper minerals in
the ore. These can be complex and difficult to float using
conventional flotation methods. Best results were obtained using
basic sulphidisation procedures, a high flotation temperature and
extended flotation residence time.
Abstract: A new, combinatorial model for analyzing and inter-
preting an electrocardiogram (ECG) is presented. An application of
the model is QRS peak detection. This is demonstrated with an
online algorithm, which is shown to be space as well as time efficient.
Experimental results on the MIT-BIH Arrhythmia database show that
this novel approach is promising. Further uses for this approach are
discussed, such as taking advantage of its small memory requirements
and interpreting large amounts of pre-recorded ECG data.
Abstract: Aspheric optical components are an alternative to the use of conventional lenses in the implementation of imaging systems for the visible range. Spherical lenses are capable of producing aberrations. Therefore, they are not able to focus all the light into a single point. Instead, aspherical lenses correct aberrations and provide better resolution even with compact lenses incorporating a small number of lenses.
Metrology of these components is very difficult especially when the resolution requirements increase and insufficient or complexity of conventional tools requires the development of specific approaches to characterization.
This work is part of the problem existed because the objectives are the study and comparison of different methods used to measure surface rays hybrid aspherical lenses.
Abstract: Pyrolysis of waste tire is one of alternative technique
to produce petrochemicals, such as light olefins, mixed C4, and monoaromatics.
Noble metals supported on acid zeolite catalysts were
reported as potential catalysts to produce the high valuable products
from waste tire pyrolysis. Especially, Pd supported on HBeta gave a
high yield of olefins, mixed C4, and mono-aromatics. Due to the high
prices of noble metals, the objective of this work was to investigate
whether or not a non-noble Ni metal can be used as a substitute of a
noble metal, Pd, supported on HBeta as a catalyst for waste tire pyrolysis.
Ni metal was selected in this work because Ni has high activity
in cracking, isomerization, hydrogenation and the ring opening of
hydrocarbons Moreover, Ni is an element in the same group as Pd
noble metal, which is VIIIB group, aiming to produce high valuable
products similarly obtained from Pd. The amount of Ni was varied as
5, 10, and 20% by weight, for comparison with a fixed 1 wt% Pd,
using incipient wetness impregnation. The results showed that as a
petrochemical-producing catalyst, 10%Ni/HBeta performed better
than 1%Pd/HBeta because it did not only produce the highest yield of
olefins and cooking gases, but the yields were also higher than
1%Pd/HBeta. 5%Ni/HBeta can be used as a substitute of
1%Pd/HBeta for similar crude production because its crude contains
the similar amounts of naphtha and saturated HCs, although it gave
no concentration of light mono-aromatics (C6-C11) in the oil. Additionally,
10%Ni/HBeta that gave high olefins and cooking gases was
found to give a fairly high concentration of the light mono-aromatics
in the oil.
Abstract: The present study examines the mediating effect of
online flow experience on the relationship between extraversionintroversion,
locus of control and loneliness, and depression and
satisfaction with life. The data was obtained using a structured
questionnaire prepared by adapting standardized scales available from
a sample of 102 engineering students from different technical
institutions at Bhubaneswar, India. The results indicate that there is a
positive significant relationship between introversion, external locus
of control, loneliness, depression and online flow experience, and
extraversion, internal locus of control and satisfaction with life. The
results also suggest that online flow experience mediates the
relationship between the aforementioned variables.
Abstract: In this paper, fabrication and study of electronic properties of Au/methyl-red/Ag surface type Schottky diode by current-voltage (I-V) method has been reported. The I-V characteristics of the Schottky diode showed the good rectifying behavior. The values of ideality factor n and barrier height b of Au/methyl-red/Ag Schottky diode were calculated from the semi-log I-V characteristics and by using the Cheung functions. From semi-log current-voltage characteristics the values of n and b were found 1.93 and 0.254 eV, respectively, while by using Cheung functions their values were calculated 1.89 and 0.26 eV, respectively. The effect of series resistance was also analyzed by Cheung functions. The series resistance RS values were determined from dV/d(lnI)–I and H(I)–I graphs and were found to be 1.1 k and 1.3 k, respectively.
Abstract: In this paper the development of a software to
encrypt messages with asymmetric cryptography is presented. In
particular, is used the RSA (Rivest, Shamir and Adleman) algorithm
to encrypt alphanumeric information. The software allows to
generate different public keys from two prime numbers provided by
the user, the user must then select a public-key to generate the
corresponding private-key. To encrypt the information, the user must
provide the public-key of the recipient as well as the message to be
encrypted. The generated ciphertext can be sent through an insecure
channel, so that would be very difficult to be interpreted by an
intruder or attacker. At the end of the communication, the recipient
can decrypt the original message if provide his/her public-key and
his/her corresponding private-key.
Abstract: The Spalart and Allmaras turbulence model has been
implemented in a numerical code to study the compressible turbulent
flows, which the system of governing equations is solved with a
finite volume approach using a structured grid. The AUSM+ scheme
is used to calculate the inviscid fluxes. Different benchmark
problems have been computed to validate the implementation and
numerical results are shown. A special Attention is paid to wall jet
applications. In this study, the jet is submitted to various wall
boundary conditions (adiabatic or uniform heat flux) in forced
convection regime and both two-dimensional and axisymmetric wall
jets are considered. The comparison between the numerical results
and experimental data has given the validity of this turbulence model
to study the turbulent wall jets especially in engineering applications.
Abstract: The balancing numbers are natural numbers n satisfying
the Diophantine equation 1 + 2 + 3 + · · · + (n - 1) = (n + 1) +
(n + 2) + · · · + (n + r); r is the balancer corresponding to the
balancing number n.The nth balancing number is denoted by Bn
and the sequence {Bn}1
n=1 satisfies the recurrence relation Bn+1 =
6Bn-Bn-1. The balancing numbers posses some curious properties,
some like Fibonacci numbers and some others are more interesting.
This paper is a study of recurrent sequence {xn}1
n=1 satisfying the
recurrence relation xn+1 = Axn - Bxn-1 and possessing some
curious properties like the balancing numbers.
Abstract: Solar energy is not only sustainable but also a clean
alternative to be used as source of high temperature heat for many
processes and power generation. However, the major drawback of
solar energy is its transient nature. Especially in solar
thermochemical processing, it is crucial to maintain constant or semiconstant
temperatures inside the solar reactor. In our laboratory, we
have developed a mechanism allowing us to achieve semi-constant
temperature inside the solar reactor. In this paper, we introduce the
concept along with some updated designs and provide the optical
analysis of the concept under various incoming flux.
Abstract: Relevant agricultural information disseminator
(extension agent) ratio of 1:3500 farm families which become a
menace to agricultural production capacity in developing countries
necessitate this study. Out of 4 zones in the state, 24 extension agents
in each zone, 4 extension agents using cell phones and 120 farmers
using cell phone and 120 other farmers not using cell phone were
purposively selected to give 240 farmers that participated in the
research. Data were collected using interview guide and analysized
using frequency, percentage and t-test.. Frequency of contact with
agricultural information centers revealed that cell phone user farmers
had greater means score of X 41.43 contact as against the low mean
X19.32 contact recorded by farmers receiving agricultural
information from extension agents not using cell phone and their
production was statistically significant at P < 0.05. Usage of cell
phone increase extension agent contact and increase farmers-
production capacity.
Abstract: Optimal design of structure has a main role in reduction of material usage which leads to deduction in the final cost of construction projects. Evolutionary approaches are found to be more successful techniques for solving size and shape structural optimization problem since it uses a stochastic random search instead of a gradient search. By reviewing the recent literature works the problem found was the optimization of weight. A new meta-heuristic algorithm called as Cuckoo Search (CS) Algorithm has used for the optimization of the total weight of the truss structures. This paper has used set of 10 bars and 25 bars trusses for the testing purpose. The main objective of this work is to reduce the number of iterations, weight and the total time consumption. In order to demonstrate the effectiveness of the present method, minimum weight design of truss structures is performed and the results of the CS are compared with other algorithms.
Abstract: Using quantum hydrodynamical (QHD) model the linear dispersion relation for the electron plasma waves propagating in a cylindrical waveguide filled with a dense plasma containing streaming electron, hole and stationary charged dust particles has been derived. It is shown that the effect of finite boundary and stream velocity of electrons and holes make some of the possible modes of propagation linearly unstable. The growth rate of this instability is shown to depend significantly on different plasma parameters.
Abstract: At the time where electronic books, or e-Books, offer
students a fun way of learning , teachers who are used to the paper
text books may find it as a new challenge to use it as a part of
learning process. Precisely, there are various types of e-Books
available to suit students- knowledge, characteristics, abilities, and
interests. The paper discusses teachers- perceptions on the use of ebooks
as a paper text book in the classroom. A survey was conducted
on 72 teachers who use e-books as textbooks. It was discovered that a
majority of these teachers had good perceptions on the use of ebooks.
However, they had little problems using the devices. It can be
overcome with some strategies and a suggested framework.
Abstract: A key aspect of the design of any software system is
its architecture. An architecture description provides a formal model
of the architecture in terms of components and connectors and how
they are composed together. COSA (Component-Object based
Software Structures), is based on object-oriented modeling and
component-based modeling. The model improves the reusability by
increasing extensibility, evolvability, and compositionality of the
software systems. This paper presents the COSA modelling tool
which help architects the possibility to verify the structural coherence
of a given system and to validate its semantics with COSA approach.
Abstract: Human Resource (HR) applications can be used to
provide fair and consistent decisions, and to improve the
effectiveness of decision making processes. Besides that, among
the challenge for HR professionals is to manage organization
talents, especially to ensure the right person for the right job at the
right time. For that reason, in this article, we attempt to describe
the potential to implement one of the talent management tasks i.e.
identifying existing talent by predicting their performance as one of
HR application for talent management. This study suggests the
potential HR system architecture for talent forecasting by using
past experience knowledge known as Knowledge Discovery in
Database (KDD) or Data Mining. This article consists of three
main parts; the first part deals with the overview of HR
applications, the prediction techniques and application, the general
view of Data mining and the basic concept of talent management
in HRM. The second part is to understand the use of Data Mining
technique in order to solve one of the talent management tasks, and
the third part is to propose the potential HR system architecture for
talent forecasting.
Abstract: The main objective of this paper is to estimate the cost of road traffic accidents in Egypt. The Human Capital (HC) approach, specifically the Gross-Loss-of-Output methodology, is adopted for estimation. Moreover, cost values obtained by previous national literature are updated using the inflation rates. The results indicate an estimated cost of road traffic accidents in Egypt of approximately 10 billion Egyptian Pounds (about $US 1.8 billion) for the year 2008. In addition, it is expected that this cost will rise in 2009 to 11.8 billion Egyptian Pounds (about $US 2.1 billion).
Abstract: The IFRS for Small and Medium-sized Entities
(SMEs) was issued in July 2009 and currently regulators are
considering various implementation strategies of this standard.
Romania is a member of the European Union since 2007, thus
accounting regulations were issued in order to ensure compliance
with the European Accounting Directives. As the European
Commission rejected recently the mandatory use of IFRS for SMEs,
regulatory bodies from the Member States have to decide if the
standard will affect or not the accounting practices of SMEs from
their countries. Recently IASB invited stakeholders to discuss the
revision of IFRS for SMEs. Empirical studies on the differences and
similarities between national standards and IFRS for SMEs could
inform decision makers on the actual level of convergence in
different countries. The purpose of this paper is to provide empirical
evidences on the convergence of the Romanian regulations with IFRS
for SMEs analyzing the results in the context of the last revisions
proposed to the EU Accounting Directives.
Abstract: The experiment was performed to study the
relationship between excreta viscosity and Nitrogen-corrected true
metabolisable energy quantities of soybean meals using conventional
addition method (CAM) in adult cockerels for 7 d: a 3-d preexperiment
and a 4-d experiment period. Results indicated that
differences between the excreta viscosity values were (P
Abstract: As the fossil fuels kept on depleting, intense research in developing hydrogen (H2) as the alternative fuel has been done to cater our tremendous demand for fuel. The potential of H2 as the ultimate clean fuel differs with the fossil fuel that releases significant amounts of carbon dioxide (CO2) into the surrounding and leads to the global warming. The experimental work was carried out to study the production of H2 from palm kernel shell steam gasification at different variables such as heating rate, steam to biomass ratio and adsorbent to biomass ratio. Maximum H2 composition which is 61% (volume basis) was obtained at heating rate of 100oCmin-1, steam/biomass of 2:1 ratio, and adsorbent/biomass of 1:1 ratio. The commercial adsorbent had been modified by utilizing the alcoholwater mixture. Characteristics of both adsorbents were investigated and it is concluded that flowability and floodability of modified CaO is significantly improved.