Abstract: This study aimed for improving wear resistance of AM60 magnesium alloy by Ti addition (0, 0.2, 0.5, 1wt%Ti). An electric resistance furnace was used to produce alloys. Pure Mg together with Al, Al-Ti and Al-Mn were melted at 750 0C in a stainless steel crucible under controlled Ar gas atmosphere and then poured into a metal mould preheated at 250 0C. Microstructure characterizations were performed by light optical (LOM) and scanning electron microscope (SEM) after the wear test. Wear rates and friction coefficients were measured with a pin-on-disk type UTS-10 Tribometer test device under a load of 20N. The results showed that Ti addition altered the morphology and the amount of b-Mg17Al12 phase in the microstructure of AM60 alloy. b-Mg17Al12 phases on the grain boundaries were refined with increasing amount of Ti. An improvement in wear resistance of AM60 alloy was observed due to the alteration in the microstructure by Ti addition.
Abstract: Applicability of a KTA crystal-based laser system with optical parametric oscillators (OPO) generation to lidar sounding of the atmosphere in the spectral range 3–4 µm is studied in this work. A technique based on differential absorption lidar (DIAL) method and differential optical absorption spectroscopy (DOAS) is developed for lidar sounding of trace atmospheric gases (TAG). The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases.
Abstract: The paper presents the results of DIAL measurements of the vertical ozone distribution. The ozone lidar operate as part of the measurement complex at Siberian Lidar Station (SLS) of V.E. Zuev Institute of Atmospheric Optics SB RAS, Tomsk (56.5ºN; 85.0ºE) and designed for study of the vertical ozone distribution in the upper troposphere–lower stratosphere. Most suitable wavelengths for measurements of ozone profiles are selected. We present an algorithm for retrieval of vertical distribution of ozone with temperature and aerosol correction during DIAL lidar sounding of the atmosphere. The temperature correction of ozone absorption coefficients is introduced in the software to reduce the retrieval errors. Results of lidar measurement at wavelengths of 299 and 341 nm agree with model estimates, which point to acceptable accuracy of ozone sounding in the 6–18 km altitude range.
Abstract: Performances analysis of remote sensing sensor is required to pursue a range of scientific research and application objectives. Laboratory analysis of any remote sensing instrument is essential, but not sufficient to establish a valid inflight one. In this study, with the aid of the in situ measurements and corresponding image of three-gray scale permanent artificial target, the in-flight radiometric performances analyses (in-flight radiometric calibration, dynamic range and response linearity, signal-noise-ratio (SNR), radiometric resolution) of self-developed short-wave infrared (SWIR) camera are performed. To acquire the inflight calibration coefficients of the SWIR camera, the at-sensor radiances (Li) for the artificial targets are firstly simulated with in situ measurements (atmosphere parameter and spectral reflectance of the target) and viewing geometries using MODTRAN model. With these radiances and the corresponding digital numbers (DN) in the image, a straight line with a formulation of L = G × DN + B is fitted by a minimization regression method, and the fitted coefficients, G and B, are inflight calibration coefficients. And then the high point (LH) and the low point (LL) of dynamic range can be described as LH= (G × DNH + B) and LL= B, respectively, where DNH is equal to 2n − 1 (n is the quantization number of the payload). Meanwhile, the sensor’s response linearity (δ) is described as the correlation coefficient of the regressed line. The results show that the calibration coefficients (G and B) are 0.0083 W·sr−1m−2µm−1 and −3.5 W·sr−1m−2µm−1; the low point of dynamic range is −3.5 W·sr−1m−2µm−1 and the high point is 30.5 W·sr−1m−2µm−1; the response linearity is approximately 99%. Furthermore, a SNR normalization method is used to assess the sensor’s SNR, and the normalized SNR is about 59.6 when the mean value of radiance is equal to 11.0 W·sr−1m−2µm−1; subsequently, the radiometric resolution is calculated about 0.1845 W•sr-1m-2μm-1. Moreover, in order to validate the result, a comparison of the measured radiance with a radiative-transfer-code-predicted over four portable artificial targets with reflectance of 20%, 30%, 40%, 50% respectively, is performed. It is noted that relative error for the calibration is within 6.6%.
Abstract: CO2 capture and storage technologies play a significant role in contributing to the control of climate change through the reduction of carbon dioxide emissions into the atmosphere. The present study evaluates and optimizes CO2 capture through a process, where carbon dioxide is passed into pH adjusted high salinity water and reacted with sodium chloride to form a precipitate of sodium bicarbonate. This process is based on a modified Solvay process with higher CO2 capture efficiency, higher sodium removal, and higher pH level without the use of ammonia. The process was tested in a bubble column semi-batch reactor and was optimized using response surface methodology (RSM). CO2 capture efficiency and sodium removal were optimized in terms of major operating parameters based on four levels and variables in Central Composite Design (CCD). The operating parameters were gas flow rate (0.5–1.5 L/min), reactor temperature (10 to 50 oC), buffer concentration (0.2-2.6%) and water salinity (25-197 g NaCl/L). The experimental data were fitted to a second-order polynomial using multiple regression and analyzed using analysis of variance (ANOVA). The optimum values of the selected variables were obtained using response optimizer. The optimum conditions were tested experimentally using desalination reject brine with salinity ranging from 65,000 to 75,000 mg/L. The CO2 capture efficiency in 180 min was 99% and the maximum sodium removal was 35%. The experimental and predicted values were within 95% confidence interval, which demonstrates that the developed model can successfully predict the capture efficiency and sodium removal using the modified Solvay method.
Abstract: The most important elements of a novel are the characters, events and background. The background represents the time, place and situation that character appears, and conveys event and atmosphere more realistically. If readers have the proper knowledge about background of novels, it may be helpful for understanding the atmosphere of a novel and choosing a novel that readers want to read. In this paper, we are targeting Korean historical novels because spatio-temporal background especially performs an important role in historical novels among the genre of Korean novels. To the best of our knowledge, we could not find previous study that was aimed at Korean novels. In this paper, we build a Korean historical national dictionary. Our dictionary has historical places and temple names of kings over many generations as well as currently existing spatial words or temporal words in Korean history. We also present a method for recognizing spatio-temporal background based on patterns of phrasal words in Korean sentences. Our rules utilize postposition for spatial background recognition and temple names for temporal background recognition. The knowledge of the recognized background can help readers to understand the flow of events and atmosphere, and can use to visualize the elements of novels.
Abstract: Design criteria for achieving an acceptable indoor radon concentration are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization in most countries. The three design criteria are; first, establishing a radon barrier facing the ground; second, lowering the air pressure in the lower zone of the slab on ground facing downwards; third, diluting the indoor air with outdoor air. The first two criteria can prevent radon from infiltrating from the ground, and the third criteria can dilute the indoor air. By combining these three criteria, the indoor radon concentration can be lowered achieving an acceptable level. In addition, a cheap and reliable method for measuring the radon concentration in the indoor air is described. The provision on radon in the Danish Building Regulations complies with the latest recommendations from the World Health Organization. Radon can cause lung cancer and it is not known whether there is a lower limit for when it is not harmful to human beings. Therefore, it is important to reduce the radon concentration as much as possible in buildings. Airtightness is an important factor when dealing with buildings. It is important to avoid air leakages in the building envelope both facing the atmosphere, e.g. in compliance with energy requirements, but also facing the ground, to meet the requirements to ensure and control the indoor environment. Infiltration of air from the ground underneath a building is the main providing source of radon to the indoor air.
Abstract: This work studies the effect of thickness on structural
and electrical properties of CuAlS2 thin films grown by two stage
vacuum thermal evaporation technique. CuAlS2 thin films of
thicknesses 50nm, 100nm and 200nm were deposited on suitably
cleaned corning 7059 glass substrate at room temperature (RT). In
the first stage Cu-Al precursors were grown at room temperature by
thermal evaporation and in the second stage Cu-Al precursors were
converted to CuAlS2 thin films by sulfurisation under sulfur
atmosphere at the temperature of 673K. The structural properties of
the films were examined by X-ray diffraction (XRD) technique while
electrical properties of the specimens were studied using four point
probe method. The XRD studies revealed that the films are of
crystalline in nature having tetragonal structure. The variations of the
micro-structural parameters, such as crystallite size (D), dislocation
density ( ), and micro-strain ( ), with film thickness were
investigated. The results showed that the crystallite sizes increase as
the thickness of the film increases. The dislocation density and
micro-strain decreases as the thickness increases. The resistivity ( )
of CuAlS2 film is found to decrease with increase in film thickness,
which is related to the increase of carrier concentration with film
thickness. Thus thicker films exhibit the lowest resistivity and high
carrier concentration, implying these are the most conductive films.
Low electrical resistivity and high carrier concentration are widely
used as the essential components in various optoelectronic devices
such as light-emitting diode and photovoltaic cells.
Abstract: The combination of the properties of graphene oxide
(OG) and PVDF homopolymer makes their combined composite
materials as multifunctional systems with great potential. Knowledge
of the molecular structure is essential for better use. In this work, the
degradation of PVDF polymer exposed to gamma irradiation in
oxygen atmosphere in high dose rate has been studied and compared
to degradation of PVDF/OG composites. The samples were irradiated
with a Co-60 source at constant dose rate, with doses ranging from
100 kGy to 1,000 kGy. In FTIR data shown that the formation of
oxidation products was at the both samples with formation of
carbonyl and hydroxyl groups amongst the most prevalent products
in the pure PVDF samples. In the other hand, the composites samples
exhibit less presence of degradation products with predominant
formation of carbonyl groups, these results also seen in the UV-Vis
analysis. The results show that the samples of composites may have
greater resistance to the irradiation process, since they have less
degradation products than pure PVDF samples seen by spectroscopic
techniques.
Abstract: The irradiation of polymeric materials has received
much attention because it can produce diverse changes in chemical
structure and physical properties. Thus, studying the chemical and
structural changes of polymers is important in practice to achieve
optimal conditions for the modification of polymers. The effect of
gamma irradiation on the crystalline structure of poly(vinylidene
fluoride) (PVDF) has been investigated using differential scanning
calorimetry (DSC) and X-ray diffraction techniques (XRD). Gamma
irradiation was carried out in atmosphere air with doses between 100
kGy at 3,000 kGy with a Co-60 source. In the melting thermogram of
the samples irradiated can be seen a bimodal melting endotherm is
detected with two melting temperature. The lower melting
temperature is attributed to melting of crystals originally present and
the higher melting peak due to melting of crystals reorganized upon
heat treatment. These results are consistent with those obtained by
XRD technique showing increasing crystallinity with increasing
irradiation dose, although the melting latent heat is decreasing.
Abstract: Lead being a toxic heavy metal that mankind is
exposed to the highest levels of this metal. There are different sources
of environmental pollution with lead as lead alkyl additives in petrol
and manufacturing processes. The contaminated atmosphere in urban
and industrial areas by lead in Egypt may lead to the contamination
of foods beside the other different sources. The present investigation
studied the risk assessment of lead in some Egyptian edible
vegetables and fruits collected from different environments in Greater
Cairo Governorate, i.e. industrial, heavy traffic and rural areas. A
total of 325 leafy and fruity vegetables and fruits samples belonging
to 11, 6 and 4 different species, respectively were randomly collected
from markets of the three main models. Data indicated the variation
of lead levels in different three areas. The highest levels of lead were
detected in the samples collected from industrial and traffic areas.
However, the lowest levels were found in the rural areas. It could be
concluded that determination of lead levels in foods from different
localities and environments at regularly is very important.
Abstract: This paper focuses on the questions raised through the
work of Unit 5: ‘In/Out Crisis, emergent and adaptive’; an
architectural research-based studio at [ARC] University of Nicosia. Students were asked to delve into state of Art Technologies in
order to propose sustainable Emergent and Adaptive Architectures
and Urbanities, the resulting unprecedented spatial conditions and
atmospheres of the emergent new ways of living are deemed to be the
ultimate aim of the investigation. Students explored a variety of sites
and crisis conditions seen through their primary ingredient identified
as soil, water and air and their paired combination. Within this
methodology, crisis is seen as a mechanism for allowing an
emergence of new and fascinating ultimate sustainable future cultures
and cities by taking advantage of the primary materiality of the sites.
Abstract: In this study, we have collected cases with adipocere
formation, which were from the South Delhi region (average room
temperature 27-390C) and autopsied at our centre. Details of the
circumstances of the death, cause and time of death, surrounding
environment and demographic profile of the deceased were taken into
account. Total 16 cases were included in this study. Adipocere
formation was predominantly present over cheeks, shoulder, breast,
flanks, buttocks, and thighs. Out of 16, 11 cases were found in a dry
atmosphere, 5 cases were brought from the water. There were 5 cases
in which adipocere formation was seen in less than 2 days, and
among them, in 1 case, as early as one day. This study showed that
adipocere formation can be seen as early as 1 day in a hot and humid
environment.
Abstract: Ceramic obtained on the base of aluminum oxide has
wide application range, because it has unique properties, for example,
wear-resistance, dielectric characteristics, and exploitation ability at
high temperatures and in corrosive atmosphere. Low temperature
synthesis of α-Al2O3 is energo-economical process and it is topical
for developing technologies of corundum ceramics fabrication. In the present work possibilities of low temperature transformation
of oxyhydroxides in α-Al2O3, during the presence of small amount of
rare–earth elements compounds (also Th, Re), have been discussed.
Aluminum unstable oxyhydroxides have been obtained by hydrolysis
of aluminium isopropoxide, nitrates, sulphate, and chloride in
alkaline environment at 80-90ºC temperatures. β-Al(OH)3 has been
received from aluminum powder by ultrasonic development. Drying
of oxyhydroxide sol has been conducted with presence of various
types seeds, which amount reaches 0,1-0,2% (mas). Neodymium,
holmium, thorium, lanthanum, cerium, gadolinium, disprosium
nitrates and rhenium carbonyls have been used as seeds and they
have been added to the sol specimens in amount of 0.1-0.2% (mas)
calculated on metals. Annealing of obtained gels is carried out at 70–
1100ºC for 2 hrs. The same specimen transforms in α-Al2O3 at
1100ºC. At this temperature in case of presence of lanthanum and
gadolinium transformation takes place by 70-85%. In case of
presence of thorium stabilization of γ-and θ-phases takes place. It is
established, that thorium causes inhibition of α-phase generation at
1100ºC, and at the time when in all other doped specimens α-phase is
generated at lower temperatures (1000-1050ºC). Synthesis of various
type compounds and simultaneous consolidation has developed in the
furnace of OXY-GON. Composite materials containing oxide and
non-oxide components close to theoretical data have been obtained in
this furnace respectively. During the work the following devices have
been used: X-ray diffractometer DRON-3M (Cu-Kα, Ni filter,
2º/min), High temperature vacuum furnace OXY-GON, electronic
scanning microscopes Nikon ECLIPSE LV 150, NMM-800TRF,
planetary mill Pulverisette 7 premium line, SHIMADZU Dynamic
Ultra Micro Hardness Tester, DUH-211S, Analysette 12 Dyna sizer.
Abstract: One of the major problems being faced by human society is that the global temperature is believed to be rising due to human activity that releases carbon IV Oxide (CO2) to the atmosphere. Carbon IV Oxide is the most important greenhouse gas influencing global warming and possible climate change. With climate change becoming alarming, reducing CO2 in our atmosphere has become a primary goal of international efforts. Forest lands are major sink and could absorb large quantities of carbon if the trees are judiciously managed. The study aims at estimating the carbon sequestration capacity of Pinus caribaea (pine) and Tectona grandis (Teak) under the prevailing environmental conditions and exploring tree growth variables that influences the carbon sequestration capacity in Omo Forest Reserve, Ogun State, Nigeria. Improving forest management by manipulating growth characteristics that influences carbon sequestration could be an adaptive strategy of forestry to climate change. Random sampling was used to select Temporary Sample Plots (TSPs) in the study area from where complete enumeration of growth variables was carried out within the plots. The data collected were subjected to descriptive and correlational analyses. The results showed that average carbon stored by Pine and Teak are 994.4±188.3 Kg and 1350.7±180.6 Kg respectively. The difference in carbon stored in the species is significant enough to consider choice of species relevant in climate change adaptation strategy. Tree growth variables influence the capacity of the tree to sequester carbon. Height, diameter, volume, wood density and age are positively correlated to carbon sequestration. These tree growth variables could be manipulated by the forest manager as an adaptive strategy for climate change while plantations of high wood density species could be relevant for management strategy to increase carbon storage.
Abstract: This paper focuses on how judiciaries in post-conflict societies can gain legitimacy through reformation. Legitimacy plays a pivotal role in shaping people’s behavior to submit to the law and verifies the rightfulness of an organ for taking binding decisions. Among various dynamics, judicial independence, access to justice and behavioral changes of the judicial officials broadly contribute to legitimation of judiciary in general, and the courts in particular. Increasing independence of judiciary through reform limits, inter alia, government interference in judicial issues and protects basic rights of the citizens. Judicial independence does not only matter in institutional terms, individual independence also influences the impartiality and integrity of judges, which can be increased through education and better administration of justice. Finally, access to justice as an intertwined concept both at the legal and moral spectrum of judicial reform avails justice to the citizens and increases the level of public trust and confidence. Efficient legal decisions on fostering such elements through holistic reform create a rule of law atmosphere. Citizens neither accept an illegitimate judiciary nor do they trust its decisions. Lack of such tolerance and confidence deters the rule of law and thus, undermines the democratic development of a society.
Abstract: The first laboratory synthesis of hard materials such as
diamond proceeded to attack of developing materials with high
hardness to compete diamond. Boron rich solids are good candidates
owing to their short interatomic bond lengths and strong covalent
character. Boron containing hard material was synthesized by modifiedmicrowave
method under nitrogen atmosphere by using a fuel
(glycine or urea), amorphous boron and/or boric acid in appropriate
molar ratio. Characterizations were done by x-ray diffraction (XRD),
Fourier transform infrared (FTIR) spectroscopy, scanning electron
microscopy/energy dispersive analyze (SEM/EDS), thermo
gravimetric/differential thermal analysis (TG/DTA).
Abstract: In recent years, the use of the aluminum based alloys
in the industry and technology are increasing. Alloying elements in
aluminum have further been improving the strength and stiffness
properties that provide superior compared to other metals. In this
study, investigation of physical properties (microstructure,
microhardness, tensile strength, electrical conductivity and thermal
properties) in the Al-12.6wt.%Si-%2wt.Ni ternary alloy were
investigated. Al-Si-Ni alloy was prepared in vacuum atmosphere. The
samples were directionally solidified upwards with different growth
rate V (8.3−165.45 μm/s) at constant temperature gradient G (7.73
K/mm). The flake spacings (λ), microhardness (HV), ultimate tensile
strength (σ), electrical resistivity (ρ) and thermal properties (H, Cp,
Tm) of the samples were measured. Influence of the growth rate and
spacings on microhardness, ultimate tensile strength and electrical
resistivity were investigated and relationships between them were
obtained. According to results, λ values decrease with increasing V,
but HV, σ and ρ values increase with increasing V. Variations of
electrical resistivity (ρ) of solidified samples were also measured.
The enthalpy of fusion (H) and specific heat (Cp) for the alloy was
also determined by differential scanning calorimeter (DSC) from
heating trace during the transformation from liquid to solid. The
results in this work were compared with the previous similar
experimental results.
Abstract: The development of transport systems has negative
impacts on the environment although it has beneficial effects on
society. The car policy caused many problems such as: - the
spectacular growth of fuel consumption hence the very vast increase
in urban pollution, traffic congestion in certain places and at certain
times, the increase in the number of accidents. The exhaust emissions
from cars and weather conditions are the main factors that determine
the level of pollution in urban atmosphere. These conditions lead to
the phenomenon of heat transfer and radiation occurring between the
air and the soil surface of any town. These exchanges give rise, in
urban areas, to the effects of heat islands that correspond to the
appearance of excess air temperature between the city and its
surrounding space. In this object, we perform a numerical simulation
of the plume generated by the cars exhaust gases and show that these
gases form a screening effect above the urban city which cause the
heat island in the presence of wind flow. This study allows us: 1. To
understand the different mechanisms of interactions between these
phenomena.2. To consider appropriate technical solutions to mitigate
the effects of the heat island.
Abstract: This paper presents the results obtained by numerical
simulation using the software ANSYS CFX-CFD for the air
pollutants dispersion in the atmosphere coming from the evacuation
of combustion gases resulting from the fuel combustion in an electric
thermal power plant. The model uses the Navier-Stokes equation to
simulate the dispersion of pollutants in the atmosphere. It is
considered as important factors in elaboration of simulation the
atmospheric conditions (pressure, temperature, wind speed, wind
direction), the exhaust velocity of the combustion gases, chimney
height and the obstacles (buildings). Using the air quality monitoring
stations it is measured the concentrations of main pollutants (SO2,
NOx and PM). The pollutants were monitored over a period of 3
months, after that the average concentration are calculated, which is
used by the software. The concentrations are: 8.915 μg/m3 (NOx),
9.587 μg/m3 (SO2) and 42 μg/m3 (PM). A comparison of test data
with simulation results demonstrated that CFX was able to describe
the dispersion of the pollutant as well the concentration of this
pollutants in the atmosphere.