Abstract: The levels of maximum power density of GSM
signals in the cities of Lagos, Ibadan and Abuja were studied.
Measurements were made with a calibrated hand held spectrum
analyzer 200m away from 271 base stations, at 1.2m to the ground
level. The maximum GSM 900 signal power density was
139.63μW/m2 in Lagos, 162.49μW/m2 in Ibadan and 5411.26μW/m2
in Abuja. Also, the maximum GSM 1800 signal power density was
296.82μW/m2 in Lagos, 116.82μW/m2 in Ibadan and 1263.00μW/m2
in Abuja. The level of power density of GSM 900 and GSM 1800
signals in the cities of Lagos, Ibadan and Abuja are far less than the
recommended value of 4.5W/m2 for GSM 900 and 9.0 W/m2 for
GSM 1800 by the ICNRP guideline. It can be concluded that
exposure to GSM signals in these cities cannot contribute to the
health detriments caused by thermal effects of radiofrequency
radiation.
Abstract: The importance of using mother tongue and
translation in foreign language classrooms cannot be ignored and
translation can be utilized as a method in English Language Teaching
courses. There exist researches advocating or objecting to the use of
translation in foreign language learning but they all have a point in
common: Translation should be used as an aid to teaching, not an end
in itself. In this research, prospective English language teachers’
opinions about translation use and use of mother tongue in foreign
language teaching are investigated and according to the findings,
some explanations and recommendations are made.
Abstract: The objective of this study was to determine effect of
dietary essential oil (EO) compounds, which contained
cinnamaldehyde, eugenol, peppermint, coriander, cumin, lemongrass,
and an organic carrier on feed intake, milk composition, and rumen
fermentation of dairy cows during heat exposure. Thirty-two Holstein
cows (days in milk= 60 ± 5) were assigned to one of two treatment
groups: a Control and EO fed. The experiment lasted 28 days. Dry
matter intake (DMI) was measured daily while and milk production
was measured weekly. Our result showed that DMI and milk yield
was decreased (P < 0.01) in control cows relative to EO cows.
Furthermore, supplementation with EO was associated with a
decrease in the molar proportion of propionate (P < 0.05) and
increase (P < 0.05) in acetate to propionate ratio. In conclusion, EO
supplementations in diets can be useful nutritional modification to
alleviate for the decrease DMI and milk production during heat
exposure in lactating dairy cows.
Abstract: The exposure to outdoor air pollution causes lung
cancer and increases the risk of bladder cancer. Because air pollution
in urban areas is mainly caused by transportation, it is necessary to
evaluate pollutant exhaust emissions from vehicles during their realworld
use. Nevertheless their evaluation and reduction is a key
problem, especially in the cities, that account for more than 50% of
world population.
A particular attention was given to the slope variability along the
streets during each journey performed by the instrumented vehicle.
In this paper we dealt with the problem of describing a
quantitatively approach for the reconstruction of GPS coordinates and
altitude, in the context of correlation study between driving cycles /
emission / geographical location, during an experimental campaign
realized with some instrumented cars.
Finally the slope analysis can be correlated to the emission and
consumption values in a specific road position, and it could be
evaluated its influence on their behaviour.
Abstract: Pesticides and drugs used in agriculture and veterinary
medicine may end up in aquatic environments and bioaccumulate in
the food chain, thus causing serious problems for fauna and human
health. For determination of the toxic effects of atrazine herbicide on
Caspian kutum, Rutilus frisii kutum larvae, the 96-h LC50 of atrazine
was measured for newly hatched larvae as 18.53 ppm. Toxicity of
atrazine herbicide on Caspian kutum larvae was investigated using
concentrations: 9.25ppm, 4.62 ppm and 2.31 ppm for 7 days.
Comparison of the length, weight and condition factor showed that
no significant differences between atrazine exposed and control
groups. The concentration of Na+, K+, Ca2+, Mg2+ and Cl- in whole
body of larvae in control and atrazine exposure groups were
measured and the results showed that concentrations of all these ions
is higher in atrazine exposure group than control group. It is obvious
from this study that atrazine negatively affects osmoregulation
process and changes ion compositions of the body even at sublethal
concentration and acute exposure but have no effects on growth
parameters of the body.
Abstract: The sub-task pattern in terms of deviations and defects
should be identified and understood in order to improve the quality of
practices in construction projects. Therefore, sub-task susceptibility
to exposure to deviations and defects has been evaluated and
classified via six classifications proposed in this study. Thirty-four
case studies of specific sub-tasks (from compression members in
constructed concrete structures) were collected from seven
construction projects in order to examine the study’s proposed
classifications. The study revealed that the sub-task has a high
sensitivity to deviation, where 91% of the cases were recorded as
deviations; however, only 19% of cases were recorded as defects.
Other findings were that the actual work during the execution process
is a high source of deviation for this sub-task (74%), while only 26%
of the source of deviation was due to both design documentation and
the actual work. These findings significantly imply that the study’s
proposed classifications could be used to determine the pattern of
each sub-task and develop proactive actions to overcome issues of
sub-task deviations and defects.
Abstract: This paper considers the characterization of a complex
electromagnetic environment due to multiple sources of
electromagnetic radiation as a five-dimensional surface which can be
described by a set of several surface sections including: instant EM
field intensity distribution maps at a given frequency and altitude,
instantaneous spectrum at a given location in space and the time
evolution of the electromagnetic field spectrum at a given point in
space. This characterization if done over time can enable the
exposure levels of Radio Frequency Radiation at every point in the
analysis area to be determined and results interpreted based on
comparison of the determined RFR exposure level with the safe
guidelines for general public exposure given by recognized body
such as the International commission on non-ionizing radiation
protection (ICNIRP), Institute of Electrical and Electronic Engineers
(IEEE), the National Radiation Protection Authority (NRPA).
Abstract: Immunomodulators are substances that alter immune
system via dynamic regulation of messenger molecules. It can be
divided into immunostimulant and immunosuppressant. It can help to
increase immunity of people with a low immune system, and also can
help to normalize an overactive immune system. Aim of this study is
to investigate the effects of in vitro exposure to low and high doses of
several immunomodulators which include caffeine, kaloba and
quercetin on antigen-stimulated whole blood culture cytokine
production. Whole blood samples were taken from 5 healthy males
(age: 32 ± 12 years; weight: 75.7 ± 6.1 kg; BMI: 24.3 ± 1.5 kg/m2)
following an overnight fast with no vigorous activity during the
preceding 24 h. The whole blood was then stimulated with 50 μl of
100 x diluted Pediacel vaccine and low or high dose of
immunomodulators in the culture plate. After 20 h incubation (5%
CO2, 37°C), it was analysed using the Evidence Investigator to
determine the production of cytokines including IL-2, IL-4, IL-10,
IFN-γ, and IL-1α. Caffeine and quercetin showed a tendency towards
decrease cytokine production as the doses were increased. On the
other hand, an upward trend was evident with kaloba, where a high
dose of kaloba seemed to increase the cytokine production. In
conclusion, we found that caffeine and quercetin have potential as
immunosuppressant and kaloba as immunostimulant.
Abstract: This paper attempts to evaluate the effect of fire
damage on concrete by using nonlinear resonance vibration method,
one of the nonlinear nondestructive method. Concrete exhibits not
only nonlinear stress-strain relation but also hysteresis and discrete
memory effect which are contained in consolidated materials.
Hysteretic materials typically show the linear resonance frequency
shift. Also, the shift of resonance frequency is changed according to
the degree of micro damage. The degree of the shift can be obtained
through nonlinear resonance vibration method. Five exposure
scenarios were considered in order to make different internal micro
damage. Also, the effect of post-fire-curing on fire-damaged concrete
was taken into account to conform the change in internal damage.
Hysteretic nonlinearity parameter was obtained by amplitudedependent
resonance frequency shift after specific curing periods. In
addition, splitting tensile strength was measured on each sample to
characterize the variation of residual strength. Then, a correlation
between the hysteretic nonlinearity parameter and residual strength
was proposed from each test result.
Abstract: Chloride resistance in Ultra High Performance
Concrete (UHPC) is determined in this paper. This work deals with
the one dimension chloride transport, which can be potentially
dangerous particularly for the durability of concrete structures. Risk
of reinforcement corrosion due to exposure to the concrete surface to
direct the action of chloride ions (mainly in the form de-icing salts or
groundwater) is dangerously increases. The measured data are
investigated depending on the depth of penetration of chloride ions
into the concrete structure. Comparative measurements with normal
strength concrete are done as well. The experimental results showed
that UHCP have improved resistance of chlorides penetration than
NSC and also chloride diffusion depth is significantly lower in
UHCP.
Abstract: Lead (Pb) poisoning is one of the most common and
preventable environmental health problems. There are different
sources of environmental pollution with lead as lead alkyl additives
in petrol and manufacturing processes. Pb in the atmosphere can be
deposited in urban soils, and may then be re-suspended to re-enter the
atmosphere. This could increase human exposure to Pb and cause
long-term health effects. Thus, monitoring Pb pollution is considered
one of the major tasks in controlling pollution. Scalp hair can be
utilized for the determination of lead (Pb) concentration. It provides a
lasting record of metal intakes of weeks or even months, and for most
metals, their accumulation in hair reflects their accumulation in the
whole body. This work was conducted to investigate the
concentration of lead in male scalp hair of Cairo (residential-traffic
and residential-industrial) and rural residents after twenty years of
phasing out of leaded gasoline. Results indicated that the mean
concentration of lead in hair of residential-traffic (9.7552 μg/g ±0.71)
and residential-industrial (12.3288 μg/g ±1.13) was significantly
higher than that in rural residents (4.7327 μg/g ±0.67). The mean
concentration of lead in hair of resident’s industrial areas was the
highest among Cairo residents and not the traffic areas as it was
before phasing out of leaded gasoline. Twenty years of phasing out of
leaded gasoline in Cairo has greatly improved the lead pollution
among residents of traffic areas, but industrial areas residents were
still suffering from lead pollution, which needs more efforts to
control the sources of lead pollution.
Abstract: High resolution seismic reflection has recently been carried out on Zaria batholith, with the aim of characterizing the granitic Zaria batholiths in terms of its lithology. The geology of the area has revealed that the older granite outcrops in the vicinity of Zaria are exposures of a syntectonics to late-tectonic granite batholiths which intruded a crystalline gneissic basement during the Pan-African Orogeny. During the data acquisition the geophone were placed at interval of 1 m, variable offset of 1 and 10 m was used. The common midpoint (CMP) method with 12 fold coverage was employed for the survey. Analysis of the generated 3D surface of the p wave velocities from different profiles for densities and bulk modulus revealed that the rock material is more consolidated in South East part of the batholith and less consolidated in the North Western part. This was in conformity with earlier identified geology of the area, with the South Eastern part majorly of granitic outcrop, while the North Western part is characterized with the exposure of gneisses and thick overburden cover. The difference in lithology was also confirmed by the difference in seismic sections and Arial satellite photograph. Hence two major lithologies were identified, the granitic and gneisses complex which are characterized by gradational boundaries.
Abstract: Wireless communications have been expanded very fast in recent decades. This technology relies on an extensive network of base stations and antennas, using radio frequency signals to transmit information. Devices that use wireless communication, while offering various services, basically act as sources of non-ionizing electromagnetic fields (EMF). Such devices are permanently present in human vicinity and almost constantly radiate, causing EMF pollution of the environment. This fact has initiated development of modern systems for observation of the EMF pollution, as well as for risk assessment. This paper presents the Serbian electromagnetic field monitoring network – SEMONT, designed for automated, remote and continuous broadband monitoring of EMF in the environment. Measurement results of the SEMONT monitoring at one of the test locations, within the main campus of the University of Novi Sad, are presented and discussed, along with corresponding exposure assessment of the general population, regarding the Serbian legislation.
Abstract: Cross-laminated timber is increasingly being used in
the construction of high-rise buildings due to its simple
manufacturing system. In term of fire resistance, cross-laminated
timber panels are promoted as having excellent fire resistance,
comparable to that of non-combustible materials and to heavy
timber construction, due to the ability of thick wood assemblies to
char slowly at a predictable rate while maintaining most of their
strength during the fire exposure. This paper presents an overview of
fire performance of cross-laminated timber and evaluation of its
resistance to elevated temperature in comparison to homogeneous
timber panels. Charring rates for cross-laminated timber panels of
those obtained experimentally were compared with those provided by
Eurocode simplified calculation methods.
Abstract: Plant preparations from thyme and garlic have been shown to be effective acaricides against the poultry red mite, Dermanyssus gallinae. In a layer house with a history of D. gallinae problem, mites were detected in the monitoring traps for the first time and number of them was counted. Then, some rows of layer house was sprayed twice using a concentration of 0.21 mg/cm2 thyme essential oil and 0.07 mg/cm2 garlic juice and a similar row was used as an untreated control group. Red mite traps made of cardboard were used to assess the mite density during days 1 and 7 after treatment and always removed after 24 h. the collected mites were counted and the efficacy against all mite stages (larvae, nymphs and adults) was calculated. Results showed that on day 1 and 7 after the administration of garlic extract efficacy rate was 92.05% and 74.62%, respectively. Moreover, efficacy rate on day 1 and 7 was 89.4% and 95.37% when treatment was done with thyme essential oil. It is concluded that using garlic juice to control of D. gallinae is more effective on short time. But thyme essential oil has a long time effect in compare to garlic preparation.
Abstract: Although properly made concrete is inherently a durable material, there are many physical and chemical forces in the environment which can contribute to its deterioration. This paper deals with two aspects of concrete durability in chemical aggressive environment: degradation effect of particular aggressive exposure and role of particular mineral additives. Results of the study of leaching and acid corrosion processes in samples prepared with specific dosage of microsilica and zeolite are given in the paper.
Corrosion progress after 60-day exposition is manifested by increasing rate of both Ca and Si release, what is identified by XRF method. Kind and dosage of additions used in experiment was found to be helpful for stabilization of concrete microstructure.The lowest concentration of mean elements in leachates was observed for mixture V1 (microsilica only) unlike the V2 (microsilica + zeolite). It is surprising in the terms of recommendations of zeolite application for acid exposure. Using microsilica only seems to be more effective.
Abstract: Bisphenol-A (BPA) is one of the highest volume chemicals produced worldwide in the plastic industry. This compound is mostly used in producing polycarbonate plastics that are often used for food and beverage storage, and BPA is also a component of epoxy resins that are used to line food and beverage containers. Studies performed in this area indicated that BPA could be extracted from such products while they are in contact with food. Therefore, BPA exposure is presumed. In this paper, the chemical structure of BPA, factors affecting BPA migration to food and beverages, effects on health, and recent regulations will be reviewed.
Abstract: The effect of the modification of ZnO powders by ZrO2, Al2O3, TiO2, SiO2, CeO2 and Y2O3 nanoparticles with a concentration of 1-30 wt % is investigated by diffuse reflectance spectra within the wavelength range 200 to 2500 nm before and after 100 keV proton and electron irradiation. It has been established that the introduction of nanoparticles ZrO2, Al2O3 enhances the optical stability of the pigments under proton irradiation, but reduces it under electron irradiation. Modifying with TiO2, SiO2, CeO2, Y2O3 nanopowders leads to decrease radiation stability in both types of irradiation. Samples modified by 5 wt. % of ZrO2 nanoparticles have the highest stability of optical properties after proton exposure. The degradation of optical properties under electron irradiation is not high for this concentration of nanoparticles. A decrease in the absorption of pigments modified with nanoparticles proton exposure is determined by a decrease in the intensity of bands located in the UV and visible regions. After electron exposure the absorption bands have in the whole spectrum range.
Abstract: The study comprises evaluation of suitability of passive layer created on the surface of AISI 316L stainless steel for products that are intended to have contact with blood. For that purpose, prior to and after chemical passivation, samples were subject to 7 day exposure in artificial plasma at the temperature of T=37°C. Next, tests of metallic ions infiltration from the surface to the solution were performed. The tests were performed with application of spectrometer JY 2000, by Yobin – Yvon, employing Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). In order to characterize physical and chemical features of electrochemical processes taking place during exposure of samples to artificial plasma, tests with application of electrochemical impedance spectroscopy were suggested. The tests were performed with application of measuring unit equipped with potentiostat PGSTAT 302n with an attachment for impedance tests FRA2. Measurements were made in the environment simulating human blood at the temperature of T=37°C. Performed tests proved that application of chemical passivation process for AISI 316L stainless steel used for production of goods intended to have contact with blood is well-grounded and useful in order to improve safety of their usage.
Abstract: Occupational Self Efficacy (OSE) reflects the
conviction of a person’s ability to fulfill his job related behavior at a
perfectly acceptable level to the employer. Transformational
leadership improves followers’ commitment by influencing their
needs, values, and self-esteem. Employees also develop a dyadic
relationship with their immediate superiors. Study was conducted
amongst one hundred and twenty two (122) bank managers in Sri
Lanka. They were selected based on multi-stage (seniority in the
hierarchy, gender, department-wise etc.) stratified random sampling.
Major objectives of this study were to analyze the impact of
Transformational leadership style, and OSE along with Sociodemographic
factors, and Career, Job and Organizational experience,
to the Career satisfaction of managers. SPSS software was used for
parametric and non-parametric statistical analyses. Career satisfaction
had positive impacts with their Transformational leadership style, and
their relationships with the immediate superior. Impact of sociodemographic
factors, and career exposure to career satisfaction was
assessed.