Abstract: A problem of complex mineral resources development is urgent and priority, it is aimed at realization of the processes of their ecologically safe development, one of its components is revealing the influence of the forms of element compounds in raw materials and in the processing products. In view of depletion of the precious metal reserves at the traditional deposits in the XXI century the large-size open cast deposits, localized in black shale strata begin to play the leading role. Carbonaceous (black) shales carry a heightened metallogenic potential. Black shales with high content of carbon are widely distributed within the scope of Bureinsky massif. According to academician Hanchuk`s data black shales of Sutirskaya series contain generally PGEs native form. The presence of high absorptive towards carbonaceous matter gold and PGEs compounds in crude ore results in decrease of valuable components extraction because of their sorption into dissipated carbonaceous matter.
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: The knitted fabric suffers a deformation in its
dimensions due to stretching and tension factors, transverse and
longitudinal respectively, during the process in rectilinear knitting
machines so it performs a dry relaxation shrinkage procedure and
thermal action of prefixed to obtain stable conditions in the knitting.
This paper presents a dry relaxation shrinkage prediction of Bordeaux
fiber using a feed forward neural network and linear regression
models. Six operational alternatives of shrinkage were predicted. A
comparison of the results was performed finding neural network
models with higher levels of explanation of the variability and
prediction. The presence of different reposes is included. The models
were obtained through a neural toolbox of Matlab and Minitab
software with real data in a knitting company of Southern
Guanajuato. The results allow predicting dry relaxation shrinkage of
each alternative operation.
Abstract: The consumption of food contaminated with molds
(microscopic filamentous fungi) and their toxic metabolites results in
the development of food-borne mycotoxicosis. The spores of molds
are ubiquitously spread in the environment and can be detected
everywhere. Ochratoxin A is a toxic and potentially carcinogenic
fungal toxin found in a variety of food commodities. In this study, the
mycological quality of various ready-to-eat local and imported pork
meat and meat byproducts sold in Egyptian markets were assessed
and the presence of various molds was determined in pork used as a
raw material, edible organs as liver and kidney as well as in
fermented raw meat by-products. The study assessed the mycological
quality of pork raw meat and their by-products sold in commercial
shops in Cairo, Egypt. Mycological analysis was conducted on
(n=110) samples which included pig’s livers and kidneys from
Egyptian Bassatin slaughter house; local and imported processed
pork meat by-products from Egyptian pork markets. The isolates
were identified using traditional mycological and biochemical tests.
All kidney and liver samples were positive to molds growth while all
byproducts were negative. Ochratoxin A levels were quantitatively
analyzed using the high performance liquid chromatography (HPLC)
and the highest results were present in kidney 7.51 part per billion
(ppb) followed by minced meat 6.19 ppb generally the local samples
showed higher levels than the imported ones. To the best of our
knowledge, this is the first report on mycotoxins detection and
quantification from pork by-products in Egypt.
Abstract: This paper reports on the response of a fiber-optic
sensing probe to small concentrations of hydrogen peroxide (H2O2)
vapor at room temperature. H2O2 has extensive applications in industrial and medical
environments. Conversely, H2O2 can be a health hazard by itself. For
example, H2O2 induces cellular damage in human cells and its
presence can be used to diagnose illnesses such as asthma and human
breast cancer. Hence, development of reliable H2O2 sensor is of vital
importance to detect and measure this species. Ferric ferrocyanide, referred to as Prussian Blue (PB), was
deposited on the tip of a multimode optical fiber through the single
source precursor technique and served as an indicator of H2O2 in a
spectroscopic manner. Sensing tests were performed in H2O2-H2O
vapor mixtures with different concentrations of H2O2. The results of sensing tests show the sensor is able to detect H2O2
concentrations in the range of 50.6 ppm to 229.5 ppm. Furthermore,
the sensor response to H2O2 concentrations is linear in a log-log scale
with the adjacent R-square of 0.93. This sensing behavior allows us
to detect and quantify the concentration of H2O2 in the vapor phase.
Abstract: This article deals with special structuralism
approaches to explain a certain kind of social problem. Widespread
presence of poverty is a reminder of deep-rooted unresolved
problems of social relations. The expected role from an individual for
the social system recognizes poverty derived from an interrelated
social structure. By the time, enabled to act on his role in the course
of social interaction, reintegration of the poor in society may take
place. Poverty and housing type are reflections of the underlying
social structure, primarily structure’s elements, systemic
interrelations, and the overall strength or weakness of that structure.
Poverty varies based on social structure in that the stronger structures
are less likely to produce poverty.
Abstract: The world crude oil demand is projected to rise to 108.5 million bbl/d by the year 2035. With reserves estimated at 869 billion tonnes worldwide, coal remains an abundant resource. The aim of this work was to produce a high value hydrocarbon liquid product using a Direct Coal Liquefaction (DCL) process at, relatively mild operating conditions. Via hydrogenation, the temperature-staged approach was investigated in a dual reactor lab-scale pilot plant facility. The objectives included maximising thermal dissolution of the coal in the presence of tetralin as the hydrogen donor solvent in the first stage with 2:1 and 3:1 solvent: coal ratios. Subsequently, in the second stage, hydrogen saturation, in particular, hydrodesulphurization (HDS) performance was assessed. Two commercial hydrotreating catalysts were investigated viz. NickelMolybdenum (Ni-Mo) and Cobalt-Molybdenum (Co-Mo). GC-MS results identified 77 compounds and various functional groups present in the first and second stage liquid product. In the first stage 3:1 ratios and liquid product yields catalysed by magnetite were favoured. The second stage product distribution showed an increase in the BTX (Benzene, Toluene, Xylene) quality of the liquid product, branched chain alkanes and a reduction in the sulphur concentration. As an HDS performer and selectivity to the production of long and branched chain alkanes, Ni-Mo had an improved performance over Co-Mo. Co-Mo is selective to a higher concentration of cyclohexane. For 16 days on stream each, Ni-Mo had a higher activity than Co-Mo. The potential to cover the demand for low–sulphur, crude diesel and solvents from the production of high value hydrocarbon liquid in the said process, is thus demonstrated.
Abstract: Chitosan polyacrylic acid composite membranes were
prepared by a bulk polymerization method in presence of N, N'-
methylene bisacrylamide (crosslinker) and ammonium persulphate as
initiator. Membranes prepared from this copolymer in presence and
absence of Ag nanoparticles were characterized by measuring
mechanical and physical properties, water up-take and antibacterial
properties. The results obtained indicated that the prepared
membranes have antibacterial properties which increase with adding
Ag nanoparticles.
Abstract: This paper presents an analytical approach for
evaluating distribution system reliability indices in the presence of
distributed generation. Modeling distributed generation and
evaluation of distribution system reliability indices using the
frequency duration technique. Using model implements and case
studies are discussed. Results showed that location of DG and its
effect in distribution reliability indices. In this respect, impact of DG
on distribution system is investigated using the IEEE Roy Billinton
test system (RBTS2) included feeder 1. Therefore, it will help to the
distribution system planners in the DG resource placement.
Abstract: MHD chemically reacting viscous fluid flow towards
a vertical surface with slip and convective boundary conditions has
been conducted. The temperature and the chemical species
concentration of the surface and the velocity of the external flow are
assumed to vary linearly with the distance from the vertical surface.
The governing differential equations are modeled and transformed
into systems of ordinary differential equations, which are then solved
numerically by a shooting method. The effects of various parameters
on the heat and mass transfer characteristics are discussed. Graphical
results are presented for the velocity, temperature, and concentration
profiles whilst the skin-friction coefficient and the rate of heat and
mass transfers near the surface are presented in tables and discussed.
The results revealed that increasing the strength of the magnetic field
increases the skin-friction coefficient and the rate of heat and mass
transfers toward the surface. The velocity profiles are increased
towards the surface due to the presence of the Lorenz force, which
attracts the fluid particles near the surface. The rate of chemical
reaction is seen to decrease the concentration boundary layer near the
surface due to the destructive chemical reaction occurring near the
surface.
Abstract: In this paper we studied sono catalytic oxidative desulfurization of oil and diesel fraction from “Zhanazhol” oil deposits. We have established that the combined effect of the ultrasonic field and oxidant (ozone-air mixture) in the presence of the catalyst on the oil is potentially very effective method of desulfurization of oil and oil products. This method allows increasing the degree of desulfurization of oil by 62%.
Abstract: Anammox is a novel and promising technology that has changed the traditional concept of biological nitrogen removal. The process facilitates direct oxidation of ammonical nitrogen under anaerobic conditions with nitrite as an electron acceptor without addition of external carbon sources. The present study investigated the feasibility of Anammox Hybrid Reactor (AHR) combining the dual advantages of suspended and attached growth media for biodegradation of ammonical nitrogen in wastewater. Experimental unit consisted of 4 nos. of 5L capacity AHR inoculated with mixed seed culture containing anoxic and activated sludge (1:1). The process was established by feeding the reactors with synthetic wastewater containing NH4-H and NO2-N in the ratio 1:1 at HRT (hydraulic retention time) of 1 day. The reactors were gradually acclimated to higher ammonium concentration till it attained pseudo steady state removal at a total nitrogen concentration of 1200 mg/l. During this period, the performance of the AHR was monitored at twelve different HRTs varying from 0.25-3.0 d with increasing NLR from 0.4 to 4.8 kg N/m3d. AHR demonstrated significantly higher nitrogen removal (95.1%) at optimal HRT of 1 day. Filter media in AHR contributed an additional 27.2% ammonium removal in addition to 72% reduction in the sludge washout rate. This may be attributed to the functional mechanism of filter media which acts as a mechanical sieve and reduces the sludge washout rate many folds. This enhances the biomass retention capacity of the reactor by 25%, which is the key parameter for successful operation of high rate bioreactors. The effluent nitrate concentration, which is one of the bottlenecks of anammox process was also minimised significantly (42.3-52.3 mg/L). Process kinetics was evaluated using first order and Grau-second order models. The first-order substrate removal rate constant was found as 13.0 d-1. Model validation revealed that Grau second order model was more precise and predicted effluent nitrogen concentration with least error (1.84±10%). A new mathematical model based on mass balance was developed to predict N2 gas in AHR. The mass balance model derived from total nitrogen dictated significantly higher correlation (R2=0.986) and predicted N2 gas with least error of precision (0.12±8.49%). SEM study of biomass indicated the presence of heterogeneous population of cocci and rod shaped bacteria of average diameter varying from 1.2-1.5 mm. Owing to enhanced NRE coupled with meagre production of effluent nitrate and its ability to retain high biomass, AHR proved to be the most competitive reactor configuration for dealing with nitrogen laden wastewater.
Abstract: This study intends to show the influence of the
hydrolytic degradation on the properties of the e-PTFE/NOMEX®
membranes used in fire-protective clothing. The modification of
water vapour permeability, morphology and chemical structure was
examined by MOCON Permatran, electron microscopy scanning
(SEM), and ATR-FTIR, respectively. A decrease in permeability to
water vapour of the aged samples was observed following closure of
transpiration pores. Analysis of fiber morphology indicates the
appearance of defects at the fibers surface with the presence of micro
cavities. ATR-FTIR analysis reveals the presence of a new absorption
band attributed to carboxylic acid terminal groups generated during
the amide bond hydrolysis.
Abstract: The current paper presents the results of a conducted
case study. During the past few years the number of children
diagnosed with Learning Difficulties has drastically augmented and
especially the cases of ADHD (Attention Deficit Hyperactivity
Disorder). One of the core characteristics of ADHD is a deficit in
working memory functions. The review of the literature indicates a
plethora of educational software that aim at training and enhancing
the working memory. Nevertheless, in the current paper, the
possibility of using for the same purpose free, online games will be
explored. Another issue of interest is the potential effect of the
working memory training to the core symptoms of ADHD. In order
to explore the abovementioned research questions, three digital tests
are employed, all of which are developed on the E-slate platform by
the author, in order to check the levels of ADHD’s symptoms and to
be used as diagnostic tools, both in the beginning and in the end of
the case study. The tools used during the main intervention of the
research are free online games for the training of working memory.
The research and the data analysis focus on the following axes: a) the
presence and the possible change in two of the core symptoms of
ADHD, attention and impulsivity and b) a possible change in the
general cognitive abilities of the individual. The case study was
conducted with the participation of a thirteen year-old, female
student, diagnosed with ADHD, during after-school hours. The
results of the study indicate positive changes both in the levels of
attention and impulsivity. Therefore, we conclude that the training of
working memory through the use of free, online games has a positive
impact on the characteristics of ADHD. Finally, concerning the
second research question, the change in general cognitive abilities, no
significant changes were noted.
Abstract: Investigating the dynamic responses of high rise
structures under the effect of siesmic ground motion is extremely
important for the proper analysis and design of multitoried structures.
Since the presence of infilled walls strongly influences the behaviour
of frame systems in multistoried buildings, there is an increased need
for developing guidelines for the analysis and design of infilled
frames under the effect of dynamic loads for safe and proper design
of buildings. In this manuscript, we evaluate the natural frequencies
and natural periods of single bay single storey frames considering the
effect of infill walls by using the Eigen value analysis and validating
with SAP 2000 (free vibration analysis). Various parameters obtained
from the diagonal strut model followed for the free vibration analysis
is then compared with the Finite Element model, where infill is
modeled as shell elements (four noded). We also evaluated the effect
of various parameters on the natural periods of vibration obtained by
free vibration analysis in SAP 2000 comparing them with those
obtained by the empirical expressions presented in I.S. 1893(Part I)-
2002.
Abstract: This paper presents the influences on the entrainment
of serpentines by grinding and reagents during copper–nickel sulfide
flotation. The previous bench flotation tests were performed to extract
the metallic values from the ore in Yunnan Mine, China and the
relatively satisfied results with recoveries of 86.92% Cu, 54.92% Ni,
and 74.73% Pt+Pd in the concentrate were harvested at their grades of
4.02%, 3.24% and 76.61 g/t, respectively. However, the content of
MgO in the concentrate was still more than 19%. Micro-flotation tests
were conducted with the objective of figuring out the influences on the
entrainment of serpentines into the concentrate by particle size,
flocculants or depressants and collectors, as well as visual
observations in suspension by OLYMPUS camera. All the tests results
pointed to the presences of both “entrapped-in” serpentines and its
coating on the hydrophobic flocs resulted from strong collectors
(combination of butyl xanthate, butyl ammonium dithophosphate,
even after adding carboxymethyl cellulose as effective depressant.
And fine grinding may escalate the entrainment of serpentines in the
concentrate.
Abstract: The present work is aimed at examining carbon steel
oil pipelines corrosion using three natural extracts (Eruca Sativa,
Rosell and Mango peels) that are used as inhibitors of different
concentrations ranging from 0.05-0.1wt. %. Two sulphur compounds
are used as corrosion mediums. Weight loss method was used for
measuring the corrosion rate of the carbon steel specimens immersed
in technical white oil at 100ºC at various time intervals in absence
and presence of the two sulphur compounds. The corroded specimens
are examined using the chemical wear test, scratch test and hardness
test. The scratch test is carried out using scratch loads from 0.5 Kg to
2.0 Kg. The scratch width is obtained at various scratch load and test
conditions. The Brinell hardness test is carried out and investigated
for both corroded and inhibited specimens. The results showed that
three natural extracts can be used as environmentally friendly
corrosion inhibitors.
Abstract: In this paper, we present a new segmentation approach
for focal liver lesions in contrast enhanced ultrasound imaging. This
approach, based on a two-cluster Fuzzy C-Means methodology,
considers type-II fuzzy sets to handle uncertainty due to the image
modality (presence of speckle noise, low contrast, etc.), and to
calculate the optimum inter-cluster threshold. Fine boundaries are
detected by a local recursive merging of ambiguous pixels. The
method has been tested on a representative database. Compared to
both Otsu and type-I Fuzzy C-Means techniques, the proposed
method significantly reduces the segmentation errors.
Abstract: In this article, we deal with a variant of the classical
course timetabling problem that has a practical application in many
areas of education. In particular, in this paper we are interested in
high schools remedial courses. The purpose of such courses is to
provide under-prepared students with the skills necessary to succeed
in their studies. In particular, a student might be under prepared in
an entire course, or only in a part of it. The limited availability
of funds, as well as the limited amount of time and teachers at
disposal, often requires schools to choose which courses and/or which
teaching units to activate. Thus, schools need to model the training
offer and the related timetabling, with the goal of ensuring the
highest possible teaching quality, by meeting the above-mentioned
financial, time and resources constraints. Moreover, there are some
prerequisites between the teaching units that must be satisfied. We
first present a Mixed-Integer Programming (MIP) model to solve
this problem to optimality. However, the presence of many peculiar
constraints contributes inevitably in increasing the complexity of
the mathematical model. Thus, solving it through a general-purpose
solver may be performed for small instances only, while solving
real-life-sized instances of such model requires specific techniques
or heuristic approaches. For this purpose, we also propose a heuristic
approach, in which we make use of a fast constructive procedure
to obtain a feasible solution. To assess our exact and heuristic
approaches we perform extensive computational results on both
real-life instances (obtained from a high school in Lecce, Italy) and
randomly generated instances. Our tests show that the MIP model is
never solved to optimality, with an average optimality gap of 57%.
On the other hand, the heuristic algorithm is much faster (in about the
50% of the considered instances it converges in approximately half of
the time limit) and in many cases allows achieving an improvement
on the objective function value obtained by the MIP model. Such an
improvement ranges between 18% and 66%.
Abstract: Effects of nicotine on pre-partum body weight and
preimplantation embryonic development has been reported
previously. Present study was conducted to determine the effects of
annatto (Bixa orellana)-derived delta-tocotrienol (TCT) (with
presence of 10% gamma-TCT isomer) on the nicotine-induced
reduction in body weight and 8-cell embryonic growth in mice.
Twenty-four 6-8 weeks old (23-25g) female balb/c mice were
randomly divided into four groups (G1-G4; n=6). Those groups were
subjected to the following treatments for 7 consecutive days: G1
(control) were gavaged with 0.1 ml tocopherol stripped corn oil. G2
was subcutaneously (s.c.) injected with 3 mg/kg/day of nicotine. G3
received concurrent treatment of nicotine (3 mg/kg/day) and 60
mg/kg/day of δ-TCT mixture (contains 90% delta & 10% gamma
isomers) and G4 was given 60 mg/kg/day of δ-TCT mixture alone.
Body weights were recorded daily during the treatment. On Day 8,
females were superovulated with 5 IU Pregnant Mare’s Serum
Gonadotropin (PMSG) for 48 hours followed with 5 IU human
Chorionic Gonadotropin (hCG) before mated with males at the ratio
of 1:1. Females were sacrificed by cervical dislocation for embryo
collection 48 hours post-coitum. Collected embryos were cultured in
vitro. Results showed that throughout Day 1 to Day 7, the body
weight of nicotine treated group (G2) was significantly lower
(p