Search results for: reference values

Authors: C. Okonkwo Ugochukwu, E. Sinebe Jude, N. Odoh Blessing, E. Okafor Christian

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In this paper, a modification on repair workshop queuing system using multi priority scheme was carried out. Chi square goodness of fit test was used to determine the random distribution of the inter arrival time and service time of crankshafts that come for maintenance in the workshop. The chi square values obtained for all the prioritized classes show that the distribution conforms to Poisson distribution. The mean waiting time in queue results of non-preemptive priority for 1st, 2nd and 3rd classes show 0.066, 0.09, and 0.224 day respectively, while preemptive priority show 0.007, 0.036 and 0.258 day. However, when non priority is used, which obviously has no class distinction it amounts to 0.17 days. From the results, one can observe that the preemptive priority system provides a very dramatic improvement over the non preemptive priority as it concerns arrivals that are of higher priority. However, the improvement has a detrimental effect on the low priority class. The trend of the results is similar to the mean waiting time in the system as a result of addition of the actual service time. Even though the mean waiting time for the queue and that of the system for no priority takes the least time when compared with the least priority, urgent and semi-urgent jobs will terribly suffer which will most likely result in reneging or balking of many urgent jobs. Hence, the adoption of priority scheme in this type of scenario will result in huge profit to the Company and more customer satisfaction.

Keywords: queue, priority class, preemptive, non-preemptive, mean waiting time

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Authors: Sadia Arshad, Yifa Tang, Dumitru Baleanu

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A fractional order mathematical model is proposed that incorporate CD8+ cells, natural killer cells, cytokines and tumor cells. The tumor cells growth in the absence of an immune response is modeled by logistic law as it was the simplest form for which predictions also agreed with the experimental data. Natural Killer Cells are our first line of defense. NK cells directly kill tumor cells through several mechanisms, including the release of cytoplasmic granules containing perforin and granzyme, expression of tumor necrosis factor (TNF) family members. The effect of the NK cells on the tumor cell population is expressed with the product term. Rational form is used to describe interaction between CD8+ cells and tumor cells. A number of cytokines are produced by NKs, including tumor necrosis factor TNF, IFN, and interleukin (IL-10). Source term for cytokines is modeled by Michaelis-Menten form to indicate the saturated effects of the immune response. Stability of the equilibrium points is discussed for biologically significant values of bifurcation parameters. We studied the treatment of fractional order system by investigating analytical conditions of tumor eradication. Numerical simulations are presented to illustrate the analytical results.

Keywords: cancer model, fractional calculus, numerical simulations, stability analysis

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Authors: Siddeeq Y. Ameen, Mohammed K. Yousif

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Cooperative communication systems are considered to be a promising technology to improve the system capacity, reliability and performances over fading wireless channels. Cooperative relaying system with a single antenna will be able to reach the advantages of multiple antenna communication systems. It is ideally suitable for the distributed communication systems; the relays can cooperate and form virtual MIMO systems. Thus the paper will aim to investigate the possible enhancement of cooperated system using decode and forward protocol. On decode and forward an attempt to cancel or at least reduce the interference instead of increasing the SNR values is achieved. The latter can be achieved via the use group of relays depending on the channel status from source to relay and relay to destination respectively. In the proposed system, the transmission time has been divided into two phases to be used by decode and forward protocol. The first phase has been allocated for the source to transmit its data whereas the relays and destination nodes are in receiving mode. On the other hand, the second phase is allocated for the first and second groups of relay nodes to relay the data to the destination node. Simulations results have shown an improvement in performance is achieved compared to the conventional decode and forward in terms of BER and transmission rate.

Keywords: cooperative systems, decode and forward, interference cancellation, virtual MIMO

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Authors: Babak Safaei, A. M. Fattahi

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In the present study we have investigated axial buckling characteristics of nanocomposite beams reinforced by single-walled carbon nanotubes (SWCNTs). Various types of beam theories including Euler-Bernoulli beam theory, Timoshenko beam theory and Reddy beam theory were used to analyze the buckling behavior of carbon nanotube-reinforced composite beams. Generalized differential quadrature (GDQ) method was utilized to discretize the governing differential equations along with four commonly used boundary conditions. The material properties of the nanocomposite beams were obtained using molecular dynamic (MD) simulation corresponding to both short-(10,10) SWCNT and long-(10,10) SWCNT composites which were embedded by amorphous polyethylene matrix. Then the results obtained directly from MD simulations were matched with those calculated by the mixture rule to extract appropriate values of carbon nanotube efficiency parameters accounting for the scale-dependent material properties. The selected numerical results were presented to indicate the influences of nanotube volume fractions and end supports on the critical axial buckling loads of nanocomposite beams relevant to long- and short-nanotube composites.

Keywords: nanocomposites, molecular dynamics simulation, axial buckling, generalized differential quadrature (GDQ)

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Authors: S. Deswal, M. Pal

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The paper aims to compare the performance of vertical and inclined multiple plunging jets and to model and predict their mass transfer capacity by multi-linear regression based approach. The multiple vertical plunging jets have jet impact angle of θ = 90O; whereas, multiple inclined plunging jets have jet impact angle of θ = 600. The results of the study suggests that mass transfer is higher for multiple jets, and inclined multiple plunging jets have up to 1.6 times higher mass transfer than vertical multiple plunging jets under similar conditions. The derived relationship, based on multi-linear regression approach, has successfully predicted the volumetric mass transfer coefficient (KLa) from operational parameters of multiple plunging jets with a correlation coefficient of 0.973, root mean square error of 0.002 and coefficient of determination of 0.946. The results suggests that predicted overall mass transfer coefficient is in good agreement with actual experimental values; thereby suggesting the utility of derived relationship based on multi-linear regression based approach and can be successfully employed in modelling mass transfer by multiple plunging jets.

Keywords: mass transfer, multiple plunging jets, multi-linear regression, earth sciences

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Authors: Marijn Tangelder, Ingeborg Mulder, Jeroen Wijsman, John Janssen, Tom Ysebaert

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The delta works in the Southwest Netherlands drastically changed the estuarine nature of this area. The Grevelingen estuary was dammed off and became a lake in 1971. Since 1978 a connection with the North Sea exists to keep the lake saline but management of the sluices varied over time. Our research of several decades of monitoring data shows that water management practices lead to drastic changes in water quality and consequent ecological shifts in benthic fauna, fish, and bird species. Benthic biomass, dominated by molluscs, showed major changes with an important role for invasive species. Fish migration and, therefore, fish stock in the lake changed with recently smaller fish species and lower biomass values, with consequences for fish eating birds. Implications are made towards future management to re-introduce micro-tide in connection with the North Sea to improve water quality and the ecological status of the lake, as well as consequences for the bordering Natura 2000 terrestrial habitats, including rare dune vegetations, are discussed.

Keywords: ecosystem study, Grevelingen, Natura 2000, water management, water quality

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Authors: Ana Gavardashvili

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The field-and-scientific studies to evaluate the modern ecological state in the water area of the estuaries of the major water-abundant rivers in the coastal line of the Black Sea (Chorokhi, Kintrishi, Natanebi, Supsa, Khobistskali, Rioni and Enguri) and sea ports (Batumi, Poti) and sea terminals of the oil pipeline (Baku-Tbilisi-Supsa, Kulevi) were accomplished in the months of June and July of 2015. GPS coordinates and GIS programs were used to fix the areas of the estuaries of the above-listed rivers on a digital map, with their values varying within the limits of 0,861 and 20,390 km2. Water samples from the Black Sea were taken from the river estuaries and sea ports during the field works, with their statistical series of 125 points. The temperatures of air (t2) and water in the Black Sea (t1) were measured locally, and their relative value is (t1 /t2 ) = 0,69 – 0,92. 125 water samples taken from the study object in the Black Sea coastal line were subject to laboratory analysis, and it was established that the Black Sea acidity (pH) changes within the limits of 7,71 – 8,22 in the river estuaries and within 8,42 - 8,65 in the port water areas and at oil terminals. As for the Sea water salinity index (TDS), it changes within the limits of 6,15 – 12,67 in the river estuaries, and (TDS) = 11,80 – 13,67 in the port water areas and at oil terminals. By taking the gained data and climatic changes into account, by using the theories of reliability and risk at the following stage, the nature of the changes of the function of the Black Sea ecological parameters will be established.

Keywords: acidity, estuary, salinity, sea

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Authors: Yang Chen, Lili Fu

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Promoting urban regeneration in existing areas has been elevated to a national strategy in China. In this context, because of the multidimensional sustainable effect through the intensive use of land, mixed-use development has become an important objective for high-quality urban regeneration in the inner city. However, in the long period of time since China's reform and opening up, the "unbalanced phenomenon" of mixed-use development in China's inner cities has been very serious. On the one hand, the excessive focus on certain individual spaces has led to an increase in the level of mixed-use development in some areas, substantially ahead of others, resulting in a growing gap between different parts of the inner city; On the other hand, the excessive focus on a one-dimensional element of the spatial organization of mixed-use development, such as the enhancement of functional mix or spatial capacity, has led to a lagging phenomenon or neglect in the construction of other dimensional elements, such as pedestrian permeability, green environmental quality, social inclusion, etc. This phenomenon is particularly evident in the central area of the inner city, and it clearly runs counter to the need for sustainable development in China's new era. Therefore, a rational qualitative and quantitative analysis of the "unbalanced phenomenon" will help to identify the problem and provide a basis for the formulation of relevant optimization plans in the future. This paper builds a dynamic evaluation method of mixed-use development based on a meta-dimensional model and then uses spatial evolution analysis and spatial consistency analysis with ArcGIS software to reveal the "unbalanced phenomenon " in over the past 40 years of the central city area in Nanjing, a China’s typical city facing regeneration. This study result finds that, compared to the increase in functional mix and capacity, the dimensions of residential space mix, public service facility mix, pedestrian permeability, and greenness in Nanjing's city central area showed different degrees of lagging improvement, and the unbalanced development problems in each part of the city center are different, so the governance and planning plan for future mixed-use development needs to fully address these problems. The research methodology of this paper provides a tool for comprehensive dynamic identification of mixed-use development level’s change, and the results deepen the knowledge of the evolution of mixed-use development patterns in China’s inner cities and provide a reference basis for future regeneration practices.

Keywords: mixed-use development, unbalanced phenomenon, the meta-dimensional model, over the past 40 years of Nanjing, China

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Authors: Rui G. Serôdio, Carina Martins, Alexandra Serra, José A. Lima, Luísa Catita, Paula Lopes

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Building on social identity approach, we tested the impact of social categorization and comparison in the psychosocial process by which social entrepreneurs define their group identity. Specifically, we address how both differentiation and assimilation processes are set of in the context of constructing a novel, distinctive and socially salient – social entrepreneurs. As part of a larger research line, a quasi-experimental study with Social and Business Entrepreneurs, as well as “Lay People” provided evidence consistent with our predictions: (1) Social Entrepreneurs, in contrast with Lay People and Business Entrepreneurs, value more strongly social identity than personal identity, and the later is the only group that values Personal Differentiation; (2) unlike Entrepreneurs, Social Entrepreneurs display an ingroup bias across group evaluations; (3) Lay People, display a self-serving bias, although, overall, they allocate a more positive image to the target groups; (4) combining own vs. others evaluations across all groups, Social Entrepreneurs receive the more positive value. From the standpoint of social identity and self-categorization theories and their approach to group process, we discuss the processes of intergroup comparison and differentiation as core processes in the construction of a positive social identity. We illustrate it within the context of social entrepreneurship, a political and social “wave” that flows across Europe at this time.

Keywords: group processes, social entrepreneurship, social identity, business entrepreneurs

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Authors: Anusha Vaddiraj Pallapu

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Measuring urban sustainable development is at the forefront in contributing to overall sustainability, and it refers to attaining social equity, environmental protection and minimizing the impacts of urbanization. Assessing performance of urban issues ranging from larger consumption of natural resources by humans in terms of lifestyle to creating a polluted nearby environment, social and even economic dimensions of sustainability major issues observed such as water quality, transportation, management of solid waste and traffic pollution. However, relying on the framework of the project to do the goals of sustainable development or minimization of urban impacts through management practices is not enough to deal with the present urban issues. The aim of the sustainability is to know how severely the resources are depleted because of human consumption and how issues are characterized. The paper aims to assign benchmarks for the selected sustainability indicators for research, and analysis is done through multivariate analysis in Indian context a case of Nagpur city to identify the play role of each urban issues in the overall sustainability. The main objectives of this paper are to examine the indicators over by time basis on various scenarios and how benchmarking is used, what and which categories of values should be considered as the performance of indicators function.

Keywords: environmental sustainability indicators, principal component analysis, urban sustainability, urban clusters, benchmarking

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Authors: Sabah El-Sawalhi, Elie Fayad, Roula M. Abdel-Massih

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Ilex paraguariensis (Yerba Mate) is a medium to large tree commonly consumed by South Americans. Its leaves and stems are associated with different biological activities. The purpose of this study was to evaluate the antibacterial activity of Yerba Mate against Gram-positive and Gram-negative bacterial strains and its action against some resistant bacteria with different resistance profiles. Yerba Mate aqueous extracts were prepared at 70°C for 2 hrs, and the microdilution method was used to determine the minimum inhibitory concentration (MIC). Gram-positive bacteria exhibited a stronger antibacterial activity (MIC ranged between 0.468 mg/mL and 15 mg/mL) than Gram-negative bacteria. Yerba Mate was also extracted with acetone: water (1:1) and then further sub-fractionated with hexane, chloroform, and ethyl acetate. MIC values against Staphylococcus aureus ranged from 0.78 to 2.5 mg/ml for the chloroform fraction, from 1.56 to 3.75 mg/ml for the ethyl acetate fraction, and 0.78 to 1.87 mg/ml for the water fraction. The water fraction also exhibited antibacterial activity against Salmonella species (MIC ranged from 1.56 mg/ml to 3.12 mg/ml). The water fraction exhibited the highest antibacterial activity among all the fractions obtained. More studies are needed to determine the molecule or molecules responsible for this activity.

Keywords: antibacterial activity, bacterial resistance, minimum inhibitory concentration, yerba mate

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Authors: Handan Ucun Özel, Halil Barış Özel

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The toxic effects of copper and cadmium on seed germination, seedling, root, shoot length, and seedling dry biomass of oriental beech (Fagus orientalis Lipsky) was evaluated under laboratory conditions compared to control values. Copper and cadmium treatments at 50, 100, 150, and 200 mg/l affect seed germination and seedling growth of oriental beech as compared to control. Copper treatments at 50, 100, 150, and 200 mg/l concentrations produced significant (p < 0.01) effects on seed germination and seedling length of oriental beech while copper treatment at 150 mg/l significantly affected root growth and seedling dry biomass as compared to control. Similarly, cadmium treatments from 50 to 200 mg/l affected the seed germination, root, shoot length, and seedling dry biomass of oriental beech as compared to control. Cadmium treatments showed an adverse effect on seedlings of oriental beech as compared to copper, copper and cadmium treatments at 200mg/l exhibited the lowest percentage of tolerance in seedlings of oriental beech as compared to control.

Keywords: copper, cadmium, toxicity, oriental beech

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Authors: Domenica Bona

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Colin Chant and David Goodman argue that historians of Chinese pre-industrial cities tend to underestimate revolutions and overestimate cyclic patterns: periods of peace and prosperity in the earl part of each d nast , followed b peasants’ rebellions and upheavals. Boyd described these cyclic patterns as part of the background of Chinese town planning and architecture. Thus old ideals of city planning-square plan, southward orientation and a palace along the central axis - are revived again and again in the ascendant phases of several d nastic c cles (e.g. Chang’an, Kaifen, and Beijing). Along this line of thought, m paper questions the relationship between the “magic square rule” and modern Chinese urban- planning. As a matter of fact, the classical theme of “cosmic Taoist urbanism” is still a reference for planning cities and new urban developments, whenever there is the intention to express nationalist ideals and “cultural straightforwardness.” Besides, some case studies can be related to “modern d nasties”: the first Republic under the Kuo Min Tang, the red People’s Republic and the post-Maoist open country of Deng Xiao Ping. Considering the project for the new capital of Nanjing in the Thirties, Beijing’s Tianan Men area in the ifties, and Shenzhen’s utian CBD in late 20th century, I argue that cyclic patterns are still in place, though with deformations related to westernization, private interests and lack of spirituality. How far new Chinese cities are - or simply seem to be - westernized? Symbolism, invisible frameworks, repeating features and behavioural patterns make urban China just “superficiall” western. This can be well noticed in cities previousl occupied b foreigners, like Hong Kong, or in newly founded ones, like Shenzhen, where both Asians and non-Asian people can feel the gender-shift from New-York-like landscapes to something else. Current planning in main metropolitan areas shows a blurred relationship between public policies and private investments: two levels of decisions and actions, one addressing the larger scale and infrastructures, the other concerning the micro scale and development of single plots. While zoning is instrumental in this process, master plans are often laid out over a very poor cartography, so much that any relation between the formal characters of new cities and the centuries-old structure of the related territory gets lost.

Keywords: China, contemporary cities, cultural heritage, shenzhen, urban planning

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Authors: Godiva Kwan, Winton Au, Fanny Cheung

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Authenticity, being true to oneself and acting in congruence with one’s values and beliefs, is a basic human strength, and is instrumental to understanding well-being. While dispositional authenticity was found to be associated with positive affect and subjective well-being, others have demonstrated that individuals assumed different levels of authenticity when they took up different social roles, suggesting that state authenticity can be an alternative mechanism. This study examined the relation between workplace authenticity and job satisfaction. We hypothesize that state authenticity at work will be predicted by psychological safety climate (organizational climate where employees feel safe to speak up without being embarrassed or rejected). Employees are expected to experience higher subjective well-being and job satisfaction as a result of being authentic at work. Survey results provided support to the hypotheses. Psychological safety climate enhanced employees’ authenticity state at work, which in turn improved well-being and job satisfaction. In conclusion, we found that employees become more authentic at work in an organizational climate where they feel safe to express themselves, leading to a higher job satisfaction and well-being. The current study contributes to the understanding of underlying mechanisms behind experiencing authenticity at work among employees in Hong Kong. Our findings are expected to provide insights and to raise organizations’ awareness of creating an open and trustful culture in order to enhance job satisfaction of employees through encouraging them to “be themselves”.

Keywords: authenticity, job satisfaction, psychological safety climate, organizational climate

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Authors: Anto Antony Samy, Atefeh Golbang, Edward Archer, Alistair McIlhagger

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Fused deposition modelling (FDM) is one of the additive manufacturing techniques that has become highly attractive in the industrial and academic sectors. However, parts fabricated through FDM are highly susceptible to geometrical defects such as warpage, shrinkage, and delamination that can severely affect their function. Among the thermoplastic polymer feedstock for FDM, semi-crystalline polymers are highly prone to part distortion due to polymer crystallization. In this study, the influence of FDM processing conditions such as chamber temperature and print bed temperature on the induced thermal residual stress and resulting warpage are investigated using the 3D transient thermal model for a semi-crystalline polymer. The thermo-mechanical properties and the viscoelasticity of the polymer, as well as the crystallization physics, which considers the crystallinity of the polymer, are coupled with the evolving temperature gradient of the print model. From the results, it was observed that increasing the chamber temperature from 25°C to 75°C lead to a decrease of 1.5% residual stress, while decreasing bed temperature from 100°C to 60°C, resulted in a 33% increase in residual stress and a significant rise of 138% in warpage. The simulated warpage data is validated by comparing it with the measured warpage values of the samples using 3D scanning.

Keywords: finite element analysis, fused deposition modelling, residual stress, warpage

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Authors: Hanwei Gao, Louis Jezequel, Eric Cabrol, Bernard Vitry

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The chassis system is composed of complex elements that take up all the loads from the tire-ground contact area and thus it plays an important role in numerous specifications such as durability, comfort, crash, etc. During the development of new vehicle projects in Renault, durability validation is always the main focus while deployment of comfort comes later in the project. Therefore, sometimes design choices have to be reconsidered because of the natural incompatibility between these two specifications. Besides, robustness is also an important point of concern as it is related to manufacturing costs as well as the performance after the ageing of components like shock absorbers. In this paper an approach is proposed aiming to realize a multi-objective optimization between chassis endurance and comfort while taking the random factors into consideration. The adaptive-sparse polynomial chaos expansion method (PCE) with Chebyshev polynomial series has been applied to predict responses’ uncertainty intervals of a system according to its uncertain-but-bounded parameters. The approach can be divided into three steps. First an initial design of experiments is realized to build the response surfaces which represent statistically a black-box system. Secondly within several iterations an optimum set is proposed and validated which will form a Pareto front. At the same time the robustness of each response, served as additional objectives, is calculated from the pre-defined parameter intervals and the response surfaces obtained in the first step. Finally an inverse strategy is carried out to determine the parameters’ tolerance combination with a maximally acceptable degradation of the responses in terms of manufacturing costs. A quarter car model has been tested as an example by applying the road excitations from the actual road measurements for both endurance and comfort calculations. One indicator based on the Basquin’s law is defined to compare the global chassis durability of different parameter settings. Another indicator related to comfort is obtained from the vertical acceleration of the sprung mass. An optimum set with best robustness has been finally obtained and the reference tests prove a good robustness prediction of Chebyshev PCE method. This example demonstrates the effectiveness and reliability of the approach, in particular its ability to save computational costs for a complex system.

Keywords: chassis durability, Chebyshev polynomials, multi-objective optimization, polynomial chaos expansion, ride comfort, robust design

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Authors: Sahriye Sonmez, Sedat Citak

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The objective of this study was to evaluate the effects of different organic manures on antioxidant activity, vitamin C and nitrate concentrations of broccoli (Brassica oleracea L. var italica) plants. For this purpose, broccoli plants were grown on open field conditions in 2 successive years (2011-2013) including 4 different seasons [(Spring 1 (March-June, 2011), Autumn 1 (September 2011-January 2012), Spring 2 (March-June, 2012), Autumn 2 (September 2012-January 2013)]. Organic manures (Farm manure (FM), vermicompost (VC) and leonardite (L) and its mixture (50 % FM+50% L, 50 % VC+50% FM, 50% L+50% VC and 33% FM+33% VC+33% L), one chemical fertilizer and one control, collectively 9 applications was investigated. The results indicated that the vitamin C concentrations of broccoli plants ranged from 31.4-55.8 mg/100 g, 43-631 mg/kg in nitrate concentrations and 11.0-56.7 mg/ml as IC50 inhibition values in antioxidant activities of broccoli plants. Also, it was determined that the effective applications were at the 50 % VC+50% FM for vitamin C concentrations, at the chemical fertilizer for nitrate concentrations and at the 100 % FM for antioxidant activities.

Keywords: broccoli, chemical fertilizer, farm manure, leonardite, vermicompost

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Authors: M. Merabet-Khelassi, Z. Houiene, L. Aribi-Zouioueche, O. Riant

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Lipases (EC.3.1.1.3) are efficient biotools widely used for their remarkable chemo-, regio- and enantio-selectivity, especially, in kinetic resolution of racemates. They offer access to a large panel of enantiopure building blocks, such as secondary benzylic alcohols, commonly used as synthetic intermediates in pharmaceutical and agrochemical industries. Due to the stability of lipases in both water and organic solvents poor in water, they are able to catalyze both transesterifications of arylalkylcarbinols and hydrolysis of their corresponding acetates. The use of enzymatic hydrolysis in aqueous media still limited. In this presentation, we expose a practical methodology for the preparation of optically enriched acetates using a Candida antarctica lipase B-catalyzed hydrolysis in non-aqueous media in the presence of alkaline carbonate salts. The influence of several parameters which can intervene on the enzymatic efficiency such as the impact of the introduction of the carbonates salts, its amount and the nature of the alkaline earth metal are discussed. The obtained results show that the use of sodium carbonate with CAL-B enhances drastically both reactivity and selectivity of this immobilized lipase. In all cases, the resulting alcohols and remaining acetates are obtained in high ee values (up to > 99 %), and the selectivities reach (E > 500).

Keywords: alkaline-hydrolysis, enzymatic kinetic resolution, lipases, arylalkylcarbinol, non-aqueous media

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Authors: Safoin Aktaou, Aya Al Masri, Kamel Guerchouche, Malorie Martin, Fouad Maaloul

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Introduction: In the ‘Magnetic Resonance Imaging (MRI)’ department, all workers involved in preparing the patient, setting it up, tunnel cleaning, etc. are likely to be exposed to ‘ElectroMagnetic fields (EMF)’ emitted by the MRI device. Exposure to EMF can cause adverse radio-biological effects to workers. The purpose of this study is to propose an organizational process to manage and control EMF risks. Materials and methods: The study was conducted at seven MRI departments using machines with 1.5 and 3 Tesla magnetic fields. We assessed the exposure of each one by measuring the two electromagnetic fields (static and dynamic) at different distances from the MRI machine both inside and around the examination room. Measurement values were compared with British and American references (those of the UK's ‘Medicines and Healthcare Regulatory Agency (MHRA)’ and the ‘American Radiology Society (ACR)’). Results: Following the results of EMF measurements and their comparison with the recommendations of learned societies, a zoning system that adapts to needs of different MRI services across the country has been proposed. In effect, three risk areas have been identified within the MRI services. This has led to the development of a good practice guide related to the magnetic protection of MRI workers. Conclusion: The guide established by our study is a standard that allows MRI workers to protect themselves against the risk of electromagnetic fields.

Keywords: comparison with international references, measurement of electromagnetic fields, magnetic protection of workers, magnetic resonance imaging

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Authors: Lamla Thungathaa, Conrad Mahlasea, Lisa Ngcebesha

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1,4-Diamino-3,6-dinitropyrazolo[4,3-c]pyrazole (LLM-119) and its structural isomer 3,6-dinitropyrazolo[3,4-c]pyrazole-1,4(6H)-diamine were designed by structural reorientation of the fused pyrazole rings and their respective substituents (-NO2 and -NH2). Structural reorientation involves structural rearrangement which result in different structural isomers, employing this approach, six structural isomers of LLM-119 were achieved. The effect of structural reorientation (isomerisation and derivatives) on the enthalpy of formation, detonation properties, impact sensitivity, and density of these molecules is studied Computationally. The computational method used are detailed in the document and they yielded results that are close to the literature values with a relative error of 2% for enthalpy of formation, 2% for density, 0.05% for detonation velocity, and 4% for detonation pressure. The correlation of the structural reorientation to the calculated thermochemical and detonation properties of the molecules indicated that molecules with a -NO2 group attached to a Carbon atom and -NH2 connected to a Nitrogen atom maximize the enthalpy of formation and detonation velocity. The joining of pyrazole molecules has less effect on these parameters. It was seen that density and detonation pressure improved when both –NO2 or -NH2 functional groups were on the same side of the molecular structure. The structural reorientation gave rise to 3,4-dinitropyrazolo[3,4-c]pyrazole-1,6-diamine which exhibited optimal density and detonation performance compared to other molecules.

Keywords: LLM-119, fused rings, azole, structural isomers, detonation properties

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Authors: Masoud Ghermezi

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Studying the sheet metals is one of the most important research areas in the field of metal forming due to their extensive applications in the aerospace industries. A useful method for determining the forming limit of these materials and consequently preventing the rupture of sheet metals during the forming process is the use of the forming limit curve (FLC). In addition to specifying the forming limit, this curve also delineates a boundary for the allowed values of strain in sheet metal forming; these characteristics of the FLC along with its accuracy of computation and wide range of applications have made this curve the basis of research in the present paper. This study presents a new model that not only agrees with the results obtained from the above mentioned theory, but also eliminates its shortcomings. In this theory, like in the M-K theory, a thin sheet with an inhomogeneity as a gradient thickness reduction with a sinusoidal function has been chosen and subjected to two-dimensional stress. Through analytical evaluation, ultimately, a governing differential equation has been obtained. The numerical solution of this equation for the range of positive strains (stretched region) yields the results that agree with the results obtained from M-K theory. Also the solution of this equation for the range of negative strains (tension region) completes the FLC curve. The findings obtained by applying this equation on two alloys with the hardening exponents of 0.4 and 0.24 indicate the validity of the presented equation.

Keywords: sheet metal, metal forming, forming limit curve (FLC), M-K theory

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Authors: Dita Mayasari, Zahrina Mardina, Riki Siswanto, Agresta Ifada, Ova Oktavina, Prihartini Widiyanti

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Heart failure is a serious major health problem with high number of mortality per year. Bypass is one of the solutions that has often been taken. Natural vascular graft (xenograft) as the substitute in bypass is inconvenient due to ethic problems and the risk of infection transmission caused by the usage of another species transgenic vascular. Nowadays, synthetic materials have been fabricated from polymers. The aim of this research is to make a synthetic vascular graft with great physical strength, high biocompatibility, and good affordability. The method of this research was mixing PLGA and collagen by magnetic stirrer. This composite were shaped by spinneret with water as coagulant. Then it was coated by chitosan with 3 variations of weight (1 gram, 2 grams, and 3 grams) to increase hemo and cytocompatibility, proliferation, and cell attachment in order for the vascular graft candidates to be more biocompatible. Mechanical strength for each variation was 5,306 MPa (chitosan 1 gram), 3,433 MPa (chitosan 2 grams) and 3,745 MPa (chitosan 3 grams). All the tensile values were higher than human vascular tensile strength. Toxicity test showed that the living cells in all variations were more than 60% in number, thus the vascular graft is not toxic.

Keywords: chitosan, collagen, PLGA, spinneret

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Authors: Andy Obinna Ibeje

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In this study, the erodibility indices and some soil properties of some cassava farms in selected areas of Abia and Imo States were investigated. This study involves taking measurements of some soil parameters such as permeability, soil texture and particle size analysis from which the erodibility indices were compared. Results showed that soils of the areas are very sandy. The results showed that Isiukwuato with index of 72 has the highest erodibility index. The results also showed that Arondizuogu with index of 34 has the least erodibility index. The results revealed that soil erodibility (k) values varied from 34 to 72. Nkporo has the highest sand content; Inyishie has the least silt content. The result indicates that there were respectively strong inverse relationship between clay and silt contents and erodibility index. On the other hand, sand, organic matter and moisture contents as well as soil permeability has significantly high positive correlation with soil erodibility and it can be concluded that particle size distribution is a major finger print on the erodibility index of soil in the study area. It is recommended that safe cultural practices like crop rotation, matching and adoption of organic farming techniques be incorporated into farming communities of Abia and Imo States in order to stem the advances of erosion in the study area.

Keywords: erodibility, indices, soil, sand

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Authors: Akhtar Naveed, Kanwal Shahla, Khan HMS, Rasool Fatima, Ijaz Shakeel

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The focus of the study was to design, develop and characterize in vivo, a stable Emulgel formulation containing Anacardium occidentale L.(cashew extract) as an active ingredient. The formulation was prepared and kept at 8ºC, 25 ºC, 40ºC and 40ºC±RH for a period of 28 days. During this time period, stability, pH values, conductivity, organoleptic features (color, liquefaction, phase separation) were conducted at the intervals of day 1st, 2nd, 3rd , 7th, 14th and 28th days. In In vivo studies, the test formulation (5% Anacardium occidentale L, extract) and a base formulation (without cashew extract) were prepared and both were applied on cheek areas of healthy human female volunteers, after the skin sensitivity test of each volunteer, for a study period of 8 weeks after getting consent from them. Various parameters of skin like Melanin level, Erythema level, and skin elasticity were measured at regular time intervals. Results of the study were analyzed by statistical techniques i.e. Two Way ANOVA and paired sample t-test. The result showed significant results as the p ≤ 0.05. Findings of paired sample t-test explained that test formulation have profound effects on skin parameters when compared with control formulation.

Keywords: Anacardium occientale L., anti-oxidant, cashew nut, emulgel

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Authors: Ali Reza Tahavvor‚ Saeed Hosseini, Behnam Amiri

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Concentric and eccentric annulus is used frequently in technical and industrial applications such as nuclear reactors, thermal storage system and etc. In this paper, computational fluid dynamics (CFD) is used to investigate two dimensional free convection of laminar flow in annulus with isotherm cylinders surface and cooler inner surface. Problem studied in thirty different cases. Due to natural convection continuity and momentum equations are coupled and must be solved simultaneously. Finite volume method is used for solving governing equations. The purpose was to obtain the eccentricity effect on Nusselt number in different Rayleight numbers, so streamlines and temperature fields must be determined. Results shown that the highest Nusselt number values occurs in degree of eccentricity equal to 0.5 upward for inner cylinder and degree of eccentricity equal to 0.3 upward for outer cylinder. Side eccentricity reduces the outer cylinder Nusselt number but increases inner cylinder Nusselt number. The trend in variation of Nusselt number with respect to eccentricity remain similar in different Rayleight numbers. Correlations are included to calculate the Nusselt number of the cylinders.

Keywords: natural convection, concentric, eccentric, Nusselt number, annulus

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Authors: Sridhar A. Malkaram, Tamer E. Fandy

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Purpose: 5-Azacytidine (5AC) and decitabine (DC) are DNA hypomethylating agents. We recently demonstrated that both drugs increase the enzymatic activity of the histone deacetylase enzyme SIRT6. Accordingly, we are comparing the changes H3K9 acetylation changes in the whole genome induced by both drugs using leukemia cells. Description of Methods & Materials: Mononuclear cells from the bone marrow of six de-identified naive acute myeloid leukemia (AML) patients were cultured with either 500 nM of DC or 5AC for 72 h followed by ChIP-Seq analysis using a ChIP-validated acetylated-H3K9 (H3K9ac) antibody. Chip-Seq libraries were prepared from treated and untreated cells using SMARTer ThruPLEX DNA- seq kit (Takara Bio, USA) according to the manufacturer’s instructions. Libraries were purified and size-selected with AMPure XP beads at 1:1 (v/v) ratio. All libraries were pooled prior to sequencing on an Illumina HiSeq 1500. The dual-indexed single-read Rapid Run was performed with 1x120 cycles at 5 pM final concentration of the library pool. Sequence reads with average Phred quality < 20, with length < 35bp, PCR duplicates, and those aligning to blacklisted regions of the genome were filtered out using Trim Galore v0.4.4 and cutadapt v1.18. Reads were aligned to the reference human genome (hg38) using Bowtie v2.3.4.1 in end-to-end alignment mode. H3K9ac enriched (peak) regions were identified using diffReps v1.55.4 software using input samples for background correction. The statistical significance of differential peak counts was assessed using a negative binomial test using all individuals as replicates. Data & Results: The data from the six patients showed significant (Padj<0.05) acetylation changes at 925 loci after 5AC treatment versus 182 loci after DC treatment. Both drugs induced H3K9 acetylation changes at different chromosomal regions, including promoters, coding exons, introns, and distal intergenic regions. Ten common genes showed H3K9 acetylation changes by both drugs. Approximately 84% of the genes showed an H3K9 acetylation decrease by 5AC versus 54% only by DC. Figures 1 and 2 show the heatmaps for the top 100 genes and the 99 genes showing H3K9 acetylation decrease after 5AC treatment and DC treatment, respectively. Conclusion: Despite the similarity in hypomethylating activity and chemical structure, the effect of both drugs on H3K9 acetylation change was significantly different. More changes in H3K9 acetylation were observed after 5 AC treatments compared to DC. The impact of these changes on gene expression and the clinical efficacy of these drugs requires further investigation.

Keywords: DNA methylation, leukemia, decitabine, 5-Azacytidine, epigenetics

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Authors: Alireza Jafarzadeh, Bahram Amu-Oqhli Tabrizi, Hadi Khayat Nouri, Arash Khaki

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30 head of adult Vistar rats were chosen to evaluate the chronic narcotic effects of crack on some biochemical parameters. The rats weighted approximately 200 to 250 g. They were divided into 5 groups of 6 and were housed in identical condition in terms of food and ambience. Rats were maintained at 12 hours light and 12 hours darkness. Rats were injected 7.8 mg/kg BW crack intraperitoneally. The groups one to four received daily medication for one to four weeks respectively. The control groups were injected identical dose of saline. The blood was taken from control and test groups then serum was separated from. Serum biochemical parameters of amylase, lipase, triglycerides, cholesterol, HDL, LDL, VLDL, protein and albumin were measured by diagnostic kits. Serum protein and albumin levels did not show statistically significant changes. Serum lipase and amylase showed significant changes both of which were increased. The serum levels of cholesterol, LDL and HDL demonstrated no significant changes. Triglycerides values showed a significant increase in serum. Serum VLDL in groups 3 and 4 exhibited significant changes compare to other groups.

Keywords: albumin, amylase, cholesterol, crack, HDL, LDL, lipase, protein, rat, triglycerides, VLDL

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Authors: Mohammad Bakhshi, Firas Al Janabi

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High resolution rain data are very important to fulfill the input of hydrological models. Among models of high-resolution rainfall data generation, the temporal disaggregation was chosen for this study. The paper attempts to generate three different rainfall resolutions (4-hourly, hourly and 10-minutes) from daily for around 20-year record period. The process was done by DiMoN tool which is based on random cascade model and method of fragment. Differences between observed and simulated rain dataset are evaluated with variety of statistical and empirical methods: Kolmogorov-Smirnov test (K-S), usual statistics, and Exceedance probability. The tool worked well at preserving the daily rainfall values in wet days, however, the generated data are cumulated in a shorter time period and made stronger storms. It is demonstrated that the difference between generated and observed cumulative distribution function curve of 4-hourly datasets is passed the K-S test criteria while in hourly and 10-minutes datasets the P-value should be employed to prove that their differences were reasonable. The results are encouraging considering the overestimation of generated high-resolution rainfall data.

Keywords: DiMoN Tool, disaggregation, exceedance probability, Kolmogorov-Smirnov test, rainfall

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Authors: Morteza Khorrami

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The idea of final triumph of peace and justice on evil force, conflict and global spread of the religious faith, the full deployment of human values, constitute a utopia and the ideal society is discussed by many of religions. Thus, mankind has always been waiting for a savior and has received good tidings for coming of Great Savior at the end of Time. Of course, various persons were introduced as the Promised Saviors by different religions, but all of the religions share in this fact that the future of humanity is very bright and promising and the future will belong to the righteous and justice. In this article which is written with a descriptive and analytic method, the author tries to show the vision of global justice at the end of time. The opinion of various religions such as Judaism, Christianity, Zoroastrianism, Islam and even idolatry about the great savior as well as the justice status in his era in the world will be discussed. Also the viewpoint of Muslims and specially Shiites, which is explained clearly in their scripts, will be depicted. Current human responsibility towards this golden era will be discussed, too. Based on paper findings, religious doctrine promises that a heaven person and sacred character will come as a reformer of the world. In his era, humanity will be saved from tyranny, oppression and inequality, and the earth will be filled with peace, security, justice, and equity. Moreover promoting justice, truth and spreading religion in the world, economic, scientific, political and moral development will be happened.

Keywords: future of humanity, global justice, islam, religions

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Authors: Imene Skhakhfa, Lahbaci Ouerdachi

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To ensure the overall coherence of simulated results, it is necessary to develop a robust validation process. In many applications, it is no longer content to calibrate and validate the model only in relation to the hydro graph measured at the outlet, but we try to better simulate the functioning of the watershed in space. Therefore the timing also performs compared to other variables such as water level measurements in intermediate stations or groundwater levels. As part of this work, we limit ourselves to modeling flood of short duration for which the process of evapotranspiration is negligible. The main parameters to identify the models are related to the method of unit hydro graph (HU). Three different models were tested: SNYDER, CLARK and SCS. These models differ in their mathematical structure and parameters to be calibrated while hydrological data are the same, the initial water content and precipitation. The models are compared on the basis of their performance in terms six objective criteria, three global criteria and three criteria representing volume, peak flow, and the mean square error. The first type of criteria gives more weight to strong events whereas the second considers all events to be of equal weight. The results show that the calibrated parameter values are dependent and also highlight the problems associated with the simulation of low flow events and intermittent precipitation.

Keywords: model calibration, intensity, runoff, hydrograph

Procedia PDF Downloads 486