Abstract: In wastewater treatment processes, aeration introduces
air into a liquid. In these systems, air is introduced by different
devices submerged in the wastewater. Smaller bubbles result in more
bubble surface area per unit of volume and higher oxygen transfer
efficiency. Jet pumps are devices that use air bubbles and are widely
used in wastewater treatment processes. The principle of jet pumps is
their ability to transfer energy of one fluid, called primary or motive,
into a secondary fluid or gas. These pumps have no moving parts and
are able to work in remote areas under extreme conditions. The
objective of this work is to study experimentally the characteristics of
the jet pump and the size of air bubbles in the laboratory water tank.
The effect of flow rate ratio on pump performance is investigated in
order to have a better understanding about pump behavior under
various conditions, in order to determine the efficiency of receiving
air bubbles different sizes. The experiments show that we should take
care when increasing the flow rate ratio while seeking to decrease
bubble size in the outlet flow. This study will help improve and
extend the use of the jet pump in many practical applications.
Abstract: A field study was conducted to evaluate the efficacy of
safflower plant for phytoremediation of contaminated soils. The
experiment was performed on an agricultural fields contaminated by
the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. Field
experiments with randomized complete block design with five
treatments (control, compost amendments added at 20 and 40 t/daa,
and vermicompost amendments added at 20 and 40 t/daa) were
carried out. The quality of safflower seeds and oil (heavy metals and
fatty acid composition) were determined. Tested organic amendments
significantly influenced the chemical composition of safflower seeds
and oil. The compost and vermicompost treatments significantly
reduced heavy metals concentration in safflower seeds and oils, but
the effect differed among them. Addition of vermicompost and
compost leads to an increase in the content of palmitic acid and
linoleic acid, and a decrease in the stearic and oleic acids compared
with the control. A significant increase in the quantity of saturated
acids was observed in the variants with 20 t/daa of compost and 20
t/daa of vermicompost (9.1 and 8.9% relative to the control).
Safflower is a plant which is tolerant to heavy metals and can be
successfully used in the phytoremediation of heavy metal
contaminated soils. The processing of seeds to oil and using the
obtained oil for nutritional purposes will greatly reduce the cost of
phytoremediation.
Abstract: The atmospheres in many cities along the coastal lines
in the world have been rapidly changed to coastal-industrial
atmosphere. Hence, it is vital to investigate the corrosion behavior of
steel exposed to this kind of environment. In this present study,
Electrochemical Impedance Spectrography (EIS) and film thickness
measurement were applied to monitor the corrosion behavior of
weathering steel covered with a thin layer of the electrolyte in a
wet-dry cyclic condition, simulating a coastal-industrial environment
at 25oC and 60% RH. The results indicate that in all cycles, the
corrosion rate increases during the drying process due to an increase in
anion concentration and an acceleration of oxygen diffusion enhanced
by the effect of the thinning out of the electrolyte. During the wet-dry
cyclic corrosion test, the long-term corrosion behavior of this steel
depends on the periods of exposure. Corrosion process is first
accelerated and then decelerated. The decelerating corrosion process is
contributed to the formation of the protective rust, favored by the
wet-dry cycle and the acid regeneration process during the rusting
process.
Abstract: In Hungary, the society has changed a lot for the past
25 years, and these changes could be detected in educational
situations as well. The number and the intensity of conflicts have
been increased in most fields of life, as well as at schools. Teachers
have difficulties to be able to handle school conflicts. What is more,
the new net generation, generation Z has values and behavioural
patterns different from those of the previous one, which might
generate more serious conflicts at school, especially with teachers
who were mainly socialising in a traditional teacher – student
relationship.
In Hungary, the bill CCIV of 2011 declared the foundation of
Institutes of Teacher Training in higher education institutes. One of
the tasks of the Institutes is to survey the competences and needs of
teachers working in public education and to provide further trainings
and services for them according to their needs and requirements. This
job is supported by the Social Renewal Operative Programs 4.1.2.B.
The professors of a college carried out a questionnaire and surveyed
the needs and the requirements of teachers working in the region.
Based on the results, the professors of the Institute of Teacher
Training decided to meet the requirements of teachers and to launch
short teacher further training courses in spring 2015. One of the
courses is going to focus on school conflict management through
mediation.
The aim of the pilot course is to provide conflict management
techniques for teachers and to present different mediation techniques
to them. The theoretical part of the course (5 hours) will enable
participants to understand the main points and the advantages of
mediation, while the practical part (10 hours) will involve teachers in
role plays to learn how to cope with conflict situations applying
mediation. We hope if conflicts could be reduced, it would influence
school atmosphere in a positive way and the teaching – learning
process could be more successful and effective.
Abstract: In more complex systems, such as automotive
gearbox, a rigorous treatment of the data is necessary because there
are several moving parts (gears, bearings, shafts, etc.), and in this
way, there are several possible sources of errors and also noise. The
basic objective of this work is the detection of damage in automotive
gearbox. The detection methods used are the wavelet method, the
bispectrum; advanced filtering techniques (selective filtering) of
vibrational signals and mathematical morphology. Gearbox vibration
tests were performed (gearboxes in good condition and with defects)
of a production line of a large vehicle assembler. The vibration
signals are obtained using five accelerometers in different positions
of the sample. The results obtained using the kurtosis, bispectrum,
wavelet and mathematical morphology showed that it is possible to
identify the existence of defects in automotive gearboxes.
Abstract: In this work, two fermentations at different
temperatures (25 and 30ºC), with cell recycling, were accomplished
to produce ethanol, using a mix of commercial substrates, xylose
(70%) and glucose (30%), as organic source for Scheffersomyces
stipitis. Five consecutive fermentations of 80 g L-1 (1º, 2º and 3º
recycles), 96 g L-1 (4º recycle) and 120 g L-1 (5º recycle)reduced
sugars led to a final maximum ethanol concentration of 17.2 and 34.5
g L-1, at 25 and 30ºC, respectively. Glucose was the preferred
substrate; moreover xylose startup degradation was initiated after a
remaining glucose presence in the medium. Results showed that yeast
acid treatment, performed before each cycle, provided improvements
on cell viability, accompanied by ethanol productivity of 2.16 g L-1 h-
1 at 30ºC. A maximum 36% of xylose was retained in the
fermentation medium and after five-cycle fermentation an ethanol
yield of 0.43 g ethanol/g sugars was observed. S. stipitis fermentation
capacity and tolerance showed better results at 30ºC with 83.4% of
theoretical yield referenced on initial biomass.
Abstract: The use of engineered nanomaterials has increased as
a result of their positive impact on many sectors of the economy,
including agriculture. Silver nanoparticles (AgNPs) are now used to
enhance seed germination, plant growth, and photosynthetic quantum
efficiency and as antimicrobial agents to control plant diseases. In
this study, we examined the effect of AgNP dosage on the seed
germination of three plant species: corn (Zea mays L.), watermelon
(Citrullus lanatus [Thunb.] Matsum. & Nakai) and zucchini
(Cucurbita pepo L.). This experiment was designed to study the
effect of AgNPs on germination percentage, germination rate, mean
germination time, root length and fresh and dry weight of seedlings
for the three species. Seven concentrations (0.05, 0.1, 0.5, 1, 1.5, 2
and 2.5 mg/ml) of AgNPs were examined at the seed germination
stage. The three species had different dose responses to AgNPs in
terms of germination parameters and the measured growth
characteristics. The germination rates of the three plants were
enhanced in response to AgNPs. Significant enhancement of the
germination percentage values was observed after treatment of the
watermelon and zucchini plants with AgNPs in comparison with
untreated seeds. AgNPs showed a toxic effect on corn root
elongation, whereas watermelon and zucchini seedling growth were
positively affected by certain concentrations of AgNPs. This study
showed that exposure to AgNPs caused both positive and negative
effects on plant growth and germination.
Abstract: Hypersonic flows around spatial vehicles during their reentry phase in planetary atmospheres are characterized by intense aerothermodynamics phenomena. The aim of this work is to analyze high temperature flows around an axisymmetric blunt body taking into account chemical and vibrational non-equilibrium for air mixture species and the no slip condition at the wall. For this purpose, the Navier-Stokes equations system is resolved by the finite volume methodology to determine the flow parameters around the axisymmetric blunt body especially at the stagnation point and in the boundary layer along the wall of the blunt body. The code allows the capture of shock wave before a blunt body placed in hypersonic free stream. The numerical technique uses the Flux Vector Splitting method of Van Leer. CFL coefficient and mesh size level are selected to ensure the numerical convergence.
Abstract: The present study was carried out to investigate the
effect of alloying elements and thermo-mechanical treatment (TMT)
i.e. hot rolling and forging with different reduction ratios on the
hardness (HV) and impact toughness (J) of heat-treated low alloy
steels. An understanding of the combined effect of TMT and alloying
elements and by measuring hardness, impact toughness, resulting
from different heat treatment following TMT of the low alloy steels,
it is possible to determine which conditions yielded optimum
mechanical properties and high strength to weight ratio.
Experimental Correlations between hot work reduction ratio,
hardness and impact toughness for thermo-mechanically heat treated
low alloy steels are analyzed quantitatively, and both regression and
mathematical hardness and impact toughness models are developed.
Abstract: The effect of N2 pretreatment on the catalytic activity
of tungsten-based catalysts was investigated in the metathesis of
ethylene and trans-2-butene at 450oC and atmospheric pressure. The
presence of tungsten active species was confirmed by UV-Vis and
Raman spectroscopy. Compared to the WO3-based catalysts treated
in air, higher amount of WO4 2-tetrahedral species and lower amount
of WO3 crystalline species were observed on the N2-treated ones.
These contribute to the higher conversion of 2-butene and propylene
selectivity during 10 h time-on-stream. Moreover, N2 treatment led to
lower amount of coke formation as revealed by TPO of the spent
catalysts.
Abstract: The aims of this study were to determine the factor
structure and psychometric properties (i.e., reliability and convergent
validity) of the Malaysian Multi-Ethnic Discrimination Scale
(MMEDS). It consists of 71-items measure experience, strategies
used and consequences of ethnic discrimination. A sample of 649
university students from one of the higher education institution in
Malaysia was asked to complete MMEDS, as well as Perceived
Ethnic and Racial Discrimination. The exploratory factor analysis on
ethnic discrimination experience extracted two factors labeled ‘unfair
treatment’ (15 items) and ‘Denial of the ethnic right’ (12 items)
which accounted for 60.92% of the total variance. The two sub scales
demonstrated clear reliability with internal consistency above .70.
The convergent validity of the Scale was supported by an expected
pattern of correlations (positive and significant correlation) between
the score of unfair treatment and denial of the ethnic right and the
score of Perceived Ethnic and Racial Discrimination by Peers Scale.
The results suggest that the MMEDS is a reliable and valid measure.
However, further studies need to be carried out in other groups of
sample as to validate the Scale.
Abstract: Availability of different genetic tests after completion
of Human Genome Project increases the physicians’ responsibility to
keep themselves update on the potential implementation of these
genetic tests in their daily practice. However, due to numbers of
barriers, still many of physicians are not either aware of these tests or
are not willing to offer or refer their patients for genetic tests. This
study was conducted an anonymous, cross-sectional, mailed-based
survey to develop a primary data of Malaysian physicians’ level of
knowledge and perception of gene profiling. Questionnaire had 29
questions. Total scores on selected questions were used to assess the
level of knowledge. The highest possible score was 11. Descriptive
statistics, one way ANOVA and chi-squared test was used for
statistical analysis. Sixty three completed questionnaires were
returned by 27 general practitioners (GPs) and 36 medical specialists.
Responders’ age ranges from 24 to 55 years old (mean 30.2 ± 6.4).
About 40% of the participants rated themselves as having poor level
of knowledge in genetics in general whilst 60% believed that they
have fair level of knowledge; however, almost half (46%) of the
respondents felt that they were not knowledgeable about available
genetic tests. A majority (94%) of the responders were not aware of
any lab or company which is offering gene profiling services in
Malaysia. Only 4% of participants were aware of using gene profiling
for detection of dosage of some drugs. Respondents perceived greater
utility of gene profiling for breast cancer (38%) compared to the
colorectal familial cancer (3%). The score of knowledge ranged from
2 to 8 (mean 4.38 ± 1.67). Non- significant differences between score
of knowledge of GPs and specialists were observed, with score of
4.19 and 4.58 respectively. There was no significant association
between any demographic factors and level of knowledge. However,
those who graduated between years 2001 to 2005 had higher level of
knowledge. Overall, 83% of participants showed relatively high level
of perception on value of gene profiling to detect patient’s risk of
disease. However, low perception was observed for both statements
of using gene profiling for general population in order to alter their
lifestyle (25%) as well as having the full sequence of a patient
genome for the purpose of determining a patient’s best match for
treatment (18%). The lack of clinical guidelines, limited provider
knowledge and awareness, lack of time and resources to educate
patients, lack of evidence-based clinical information and cost of tests
were the most barriers of ordering gene profiling mentioned by
physicians. In conclusion Malaysian physicians who participate in
this study had mediocre level of knowledge and awareness in gene
profiling. The low exposure to the genetic questions and problems
might be a key predictor of lack of awareness and knowledge on
available genetic tests. Educational and training workshop might be useful in helping Malaysian physicians incorporate genetic profiling
into practice for eligible patients.
Abstract: Technology, multimedia in Open Educational
Resources, can contribute positively to student performance in an
online instructional environment. Student performance data of past
four years were obtained from an online course entitled Applied
Calculus (MA139). This paper examined the data to determine
whether multimedia (independent variable) had any impact on
student performance (dependent variable) in online math learning,
and how students felt about the value of the technology. Two groups
of student data were analyzed, group 1 (control) from the online
applied calculus course that did not use multimedia instructional
materials, and group 2 (treatment) of the same online applied calculus
course that used multimedia instructional materials. For the MA139
class, results indicate a statistically significant difference (p = .001)
between the two groups, where group 1 had a final score mean of
56.36 (out of 100), group 2 of 70.68. Additionally, student
testimonials were discussed in which students shared their experience
in learning applied calculus online with multimedia instructional
materials.
Abstract: Chrome tannery wastewater causes serious environmental hazard due to its high pollution potential. As a result, rigorous treatment is necessary for abatement of pollution from this type of wastewater. There are many research studies on chrome tannery wastewater treatment in the field of physical, chemical, and biological methods. In general, biological treatment process is found ineffective for direct application because of adverse effects by toxic chromium, sulphide, chloride etc. However, biological methods were employed mainly for a few sub processes generating significant amount of organic matter and without chromium, chlorides etc. In this context the present paper reviews the characteristics feature and pollution potential of wastewater generated from chrome tannery units and treatment of the same. The different biological processes used earlier and their chronological development for treatment of the chrome tannery wastewater are thoroughly reviewed in this paper. In this regard, the scope of hybrid bioreactor - an advanced technology option has also been explored, as this kind of treatment is well suited for the wastewater having inhibitory substances.
Abstract: Introduction: Researchers globally have strived to explore diverse factors that augment the continuation and uptake of family planning methods. Clients’ satisfaction is one of the core determinants facilitating continuation of family planning methods. There is a major debate yet scanty evidence to contrast public and private sectors with respect to client satisfaction. The objective of this study is to compare quality-of-care provided by public and private sectors of Pakistan through a client satisfaction lens. Methods: We used Pakistan Demographic Heath Survey 2012-13 dataset on 3133 women. Ten different multivariate models were made. to explore the relationship between client satisfaction and dependent outcome after adjusting for all known confounding factors and results are presented as OR and AOR (95% CI). Results: Multivariate analyses showed that clients were less satisfied in contraceptive provision from private sector as compared to public sector (AOR 0.92, 95% CI 0.63-1.68) even though the result was not statistically significant. Clients were more satisfied from private sector as compared to the public sector with respect to other determinants of quality-of-care follow-up care (AOR 3.29, 95% CI 1.95-5.55), infection prevention (AOR 2.41, 95% CI 1.60-3.62), counseling services (AOR 2.01, 95% CI 1.27-3.18, timely treatment (AOR 3.37, 95% CI 2.20-5.15), attitude of staff (AOR 2.23, 95% CI 1.50-3.33), punctuality of staff (AOR 2.28, 95% CI 1.92-4.13), timely referring (AOR 2.34, 95% CI 1.63-3.35), staff cooperation (AOR 1.75, 95% CI 1.22-2.51) and complications handling (AOR 2.27, 95% CI 1.56-3.29). Discussion: Public sector has successfully attained substantial satisfaction levels with respect to provision of contraceptives, but it contrasts previous literature from a multi country studies. Our study though in is concordance with a study from Tanzania where public sector was more likely to offer family planning services to clients as compared to private facilities. Conclusion: In majority of the developing countries, public sector is more involved in FP service provision; however, in Pakistan clients’ satisfaction in private sector is more, which opens doors for public-private partnerships and collaboration in the near future.
Abstract: A chromium-loaded ash originating from incineration of tannery sludge under anoxic conditions was mixed with low grade soda-lime glass powder coming from commercial glass bottles. The relative weight proportions of ash over glass powder tested were 30/70, 40/60 and 50/50. The solid mixtures, formed in green state compacts, were sintered at the temperature range of 800o C up to 1200o C. The resulting products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDXS) and micro-indentation. The above methods were employed to characterize the various phases, microstructure and hardness of the produced materials. Thermal treatment at 800o C and 1000o C produced opaque ceramic products composed of a variety of chromium-containing and chromium-free crystalline phases. Thermal treatment at 1200o C gave rise to composite products, where only chromium-containing crystalline phases were detected. Hardness results suggest that specific products are serious candidates for structural applications.
Abstract: Wavelength Division Multiplexing (WDM) is the dominant transport technology used in numerous high capacity backbone networks, based on optical infrastructures. Given the importance of costs (CapEx and OpEx) associated to these networks, resource management is becoming increasingly important, especially how the optical circuits, called “lightpaths”, are routed throughout the network. This requires the use of efficient algorithms which provide routing strategies with the lowest cost. We focus on the lightpath routing and wavelength assignment problem, known as the RWA problem, while optimizing wavelength fragmentation over the network. Wavelength fragmentation poses a serious challenge for network operators since it leads to the misuse of the wavelength spectrum, and then to the refusal of new lightpath requests. In this paper, we first establish a new Integer Linear Program (ILP) for the problem based on a node-link formulation. This formulation is based on a multilayer approach where the original network is decomposed into several network layers, each corresponding to a wavelength. Furthermore, we propose an efficient heuristic for the problem based on a greedy algorithm followed by a post-treatment procedure. The obtained results show that the optimal solution is often reached. We also compare our results with those of other RWA heuristic methods
Abstract: Hydrothermal liquefaction (HTL) is a technique for obtaining clean biofuel from biomass in the presence of heat and pressure in an aqueous medium which leads to a decomposition of this biomass to the formation of various products. A role of operating conditions is essential for the bio-oil and other products’ yield and also quality of the products. The effects of these parameters were investigated in regards to the composition and yield of the products. Chlorellaceae microalgae were tested under different HTL conditions to clarify suitable conditions for extracting bio-oil together with value-added co-products. Firstly, different microalgae loading rates (5-30%) were tested and found that this parameter has not much significant to product yield. Therefore, 10% microalgae loading rate was selected as a proper economical solution for conditioned schedule at 250oC and 30 min-reaction time. Next, a range of temperature (210-290oC) was applied to verify the effects of each parameter by keeping the reaction time constant at 30 min. The results showed no linkage with the increase of the reaction temperature and some reactions occurred that lead to different product yields. Moreover, some nutrients found in the aqueous product are possible to be utilized for nutrient recovery.
Abstract: Lignocellolusic material is a substance that is resistant to be degraded by microorganisms or hydrolysis enzymes. To be used as materials for biofuel production, it needs pretreatment process to improve efficiency of hydrolysis. In this work, chemical pretreatments on rice straw using three diluted organic acids, including acetic acid, citric acid, oxalic acid, were optimized. Using Response Surface Methodology (RSM), the effect of three pretreatment parameters, acid concentration, treatment time, and reaction temperature, on pretreatment efficiency were statistically evaluated. The results indicated that dilute oxalic acid pretreatment led to the highest enhancement of enzymatic saccharification by commercial cellulase and yielded sugar up to 10.67 mg/ml when using 5.04% oxalic acid at 137.11 oC for 30.01 min. Compared to other acid pretreatment by acetic acid, citric acid, and hydrochloric acid, the maximum sugar yields are 7.07, 6.30, and 8.53 mg/ml, respectively. Here, it was demonstrated that organic acids can be used for pretreatment of lignocellulosic materials to enhance of hydrolysis process, which could be integrated to other applications for various biorefinery processes.
Abstract: Rice straw is lignocellulosic biomass which can be utilized as substrate for the biogas production. However, due to the property and composition of rice straw, it is difficult to be degraded by hydrolysis enzymes. One of the pretreatment methods that modify such properties of lignocellulosic biomass is the application of lignocellulose-degrading microbial consortia. The aim of this study is to investigate the effect of microbial consortia to enhance biogas production. To select the high efficient consortium, cellulase enzymes were extracted and their activities were analyzed. The results suggested that microbial consortium culture obtained from cattle manure is the best candidate compared to decomposed wood and horse manure. A microbial consortium isolated from cattle manure was then mixed with anaerobic sludge and used as inoculum for biogas production. The optimal conditions for biogas production were investigated using response surface methodology (RSM). The tested parameters were the ratio of amount of microbial consortium isolated and amount of anaerobic sludge (MI:AS), substrate to inoculum ratio (S:I) and temperature. Here, the value of the regression coefficient R2 = 0.7661 could be explained by the model which is high to advocate the significance of the model. The highest cumulative biogas yield was 104.6 ml/g-rice straw at optimum ratio of MI:AS, ratio of S:I, and temperature of 2.5:1, 15:1 and 44°C respectively.