Search results for: reaction diffusion equation

Authors: Nebbat El Amine

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The void is a dust free region inside the dust cloud in the plasma. It is found that the dust grain charge variation lead to the extension of the void. Moreover, for bigger dust grains, it is seen that the wave-like structure recedes when charge variation is dealt with. Furthermore, as the grain-grain distance is inversely proportional to density, the grain-grain interaction gets more important for a denser dust population and is to be included in momentum equation. For the result indicate above, the plasma is considered non viscous. But in fact, it’s not always true. Some authors measured experimentally the viscosity of this background and found that the viscosity of dusty plasma increase with background gas pressure. In this paper, we tack account the viscosity of the fluid, and we compare the result with that found in the recent work.

Keywords: voids, dusty plasmas, variable charge, viscosity

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Authors: Douglas Yeboah, Monishka Narayan, Jai Singh

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One of the key parameters in determining the power conversion efficiency (PCE) of organic solar cells (OSCs) is the open-circuit voltage, however, it is still not well understood. In order to examine the performance of OSCs, it is necessary to understand the losses associated with the open-circuit voltage and how best it can be improved. Here, an analytical expression for the open-circuit voltage of bulk heterojunction (BHJ) OSCs is derived from the charge carrier densities without considering the drift-diffusion current. The open-circuit voltage thus obtained is dependent on the donor-acceptor band gap, the energy difference between the highest occupied molecular orbital (HOMO) and the hole quasi-Fermi level of the donor material, temperature, the carrier density (electrons), the generation rate of free charge carriers and the bimolecular recombination coefficient. It is found that open-circuit voltage increases when the carrier density increases and when the temperature decreases. The calculated results are discussed in view of experimental results and agree with them reasonably well. Overall, this work proposes an alternative pathway for improving the open-circuit voltage in BHJ OSCs.

Keywords: charge carrier density, open-circuit voltage, organic solar cells, temperature

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Authors: S. Chikh, S. Boulifa

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The present study addresses the problem of ammonia evaporation during filling of a vertical cylindrical tank and the influence of various external factors on the stability of storage by determining the conditions for minimum evaporation. Numerical simulation is carried out by solving the governing equations namely, continuity, momentum, energy, and diffusion of species. The effect of temperature of surrounding air, the filling speed of the reservoir and the temperature of the filling liquid ammonia on the evaporation rate is investigated. Results show that the temperature of the filling liquid has little effect on the liquid ammonia for a short period, which, in fact, is function of the filling speed. The evaporation rate along the free surface of the liquid is non-uniform. The inlet temperature affects the vapor ammonia temperature because of pressure increase. The temperature of the surrounding air affects the temperature of the vapor phase rather than the liquid phase. The maximum of evaporation is reached at the final step of filling. In order to minimize loss of ammonia vapors automatically causing losses in quantity of the liquid stored, it is suggested to ensure the proper insulation for the walls and roof of the reservoir and to increase the filling speed.

Keywords: evaporation, liquid ammonia, storage tank, numerical simulation

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Authors: Sadia Arshad, Ayesha Sohail, Sana Javed, Khadija Maqbool, Salma Kanwal

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The dynamical study of the carriers play an essential role in the evolution and global transmission of infectious diseases and will be discussed in this study. To make this approach novel, we will consider the fractional order model which is generalization of integer order derivative to an arbitrary number. Since the integration involved is non local therefore this property of fractional operator is very useful to study epidemic model for infectious diseases. An extended numerical method (ODE solver) is implemented on the model equations and we will present the simulations of the model for different values of fractional order to study the effect of carriers on transmission dynamics. Global dynamics of fractional model are established by using the reproduction number.

Keywords: Fractional differential equation, Numerical simulations, epidemic model, transmission dynamics

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Authors: Lucia Silveira Alda

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This research aims to analyze critically a set of studies published in the Proceedings of the International Conference on Mobile Learning of IADIS, from 2008 until 2012, which addresses the issue of foreign language learning mediated by mobile phones. The theoretical review of this study is based on the Vygotskian assumptions about tools and mediated learning and the concepts of mobile learning, CALL and MALL. In addition, the diffusion rates of the mobile phone and especially its potential are considered. Through systematic review and meta-analysis, this research intended to identify similarities and differences between the identified characteristics in the studies on the subject of language learning and mobile phone. From the analysis of the results, this study verifies that the mobile phone stands out for its mobility and portability. Furthermore, this device presented positive aspects towards student motivation in language learning. The studies were favorable to mobile phone use for learning. It was also found that the challenges in using this tool are not technical, but didactic and methodological, including the need to reflect on practical proposals. The findings of this study may direct further research in the area of language learning mediated by mobile phones.

Keywords: language learning, mobile learning, mobile phones, technology

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Authors: Shahbaa F. Bdewi, Bakhtyar K. Aziz, Ayad A. R. Mutar

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Nano-materials show different surface properties due to their high surface area and active sites. This study investigates the feasibility of using nano-MgO (NMO) for removing Congo red (CR) dye from wastewater. NMO was prepared by molten salt method. Equilibrium experiments show the equilibrium was reached after 120 minutes and maximum adsorption efficiency was obtained in acidic media up to pH 6. Isotherm studies revealed the favorability of the adsorption process. The overall adsorption process was spontaneous and endothermic in nature with a maximum adsorption capacity of 1100 mg g-1 at 40°C as estimated from Langmuir isotherm. The adsorption kinetics was found to follow pseudo second-order rate equation. Relatively high activation energy (180.7 kJ mol-1) was obtained which is consistent with chemisorption mechanism for the adsorption process.

Keywords: adsorption, congo red, magnesium oxide, nanoparticles

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Authors: Robert Grzeszczak

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The article deals with one of the most significant issues concerning the functioning of the public sector in the European Union. The objectives of good governance were formulated by the EU itself and also the Scholars in reaction to the discussion that started a decade ago and concerned the role of the government in 21st century, the future of integration processes and globalization challenges in Europe. Currently, the concept of good governance is mainly associated with the improvement of management of public policies in the European Union, concerning both domestic and EU policies. However, it goes beyond the issues of state capacity and effectiveness of management. Good governance relates also to societal participation in the public administration and verification of decisions made in public authorities’ (including public administration). Indirectly, the concept and practice of good governance are connected to societal legitimisation of public bodies in the European Union.

Keywords: good governance, government, European law, European Union

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Authors: Shahid-ul-Islam, Faqeer Mohammad

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The present study was conducted to investigate the effect of annatto, teak and flame of the forest natural dyes on color, fastness, and antimicrobial property of protein based textile substrate. The color strength (K/S) of wool samples at various concentrations of dyes were analysed using a Reflective Spectrophotometer. The antimicrobial activity of natural dyes before and after application on wool was tested against common human pathogens Escherichia coli, Staphylococcus aureus, and Candida albicans, by using micro-broth dilution method, disc diffusion assay and growth curve studies. The structural morphology of natural protein fibre (wool) was investigated by Scanning Electron Microscopy (SEM). Annatto and teak natural dyes proved very effective in inhibiting the microbial growth in solution phase and after application on wool and resulted in a broad beautiful spectrum of colors with exceptional fastness properties. The results encourage the search and exploitation of new plant species as source of dyes to replace toxic synthetic antimicrobial agents currently used in textile industry.

Keywords: annatto, antimicrobial agents, natural dyes, green textiles

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Authors: Diana Codat

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Tweets' analysis is part of text mining. Each document is a written text. It's possible to apply the usual text search techniques, in particular by switching to the bag-of-words representation. But the tweets induce peculiarities. Some may enrich the analysis. Thus, their length is calibrated (at least as far as public messages are concerned), special characters make it possible to identify authors (@) and themes (#), the tweet and retweet mechanisms make it possible to follow the diffusion of the information. Conversely, other characteristics may disrupt the analyzes. Because space is limited, authors often use abbreviations, emoticons to express feelings, and they do not pay much attention to spelling. All this creates noise that can complicate the task. The tweets carry a lot of potentially interesting information. Their exploitation is one of the main axes of the analysis of the social networks. We show how to access Twitter-related messages. We will initiate a study of the properties of the tweets, and we will follow up on the exploitation of the content of the messages. We will work under R with the package 'twitteR'. The study of tweets is a strong focus of analysis of social networks because Twitter has become an important vector of communication. This example shows that it is easy to initiate an analysis from data extracted directly online. The data preparation phase is of great importance.

Keywords: data mining, language R, social networks, Twitter

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Authors: Fathilahbinti Ali, Jamarosliza Jamaluddin, Arun Kumar Upadhyay

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Poly(lactic acid) (PLA) is a biodegradable polymer which has good mechanical properties, however, its brittleness limits its usage especially in packaging materials. Therefore, in this work, PLA based polyurethane films were prepared by synthesizing with different types of isocyanates; methylene diisocyanate (MDI) and hexamethylene diisocyanates (HDI). For this purpose, PLA based polyurethane must have good strength and flexibility. Therefore, polycaprolactone which has better flexibility were prepared with PLA. An effective way to endow polylactic acid with toughness is through chain-extension reaction of the polylactic acid pre-polymer with polycaprolactone used as chain extender. Polyurethane prepared from MDI showed brittle behaviour, while, polyurethane prepared from HDI showed flexibility at same concentrations.

Keywords: biodegradable polymer, flexible, poly(lactic acid), polyurethane

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Authors: N. Behidj, K. Benyounes, T. Dahmane, A. Allem

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The aim of this study was to investigate the antimicrobial activity of flavonoids isolated from the aerial part of a medicinal plant which is Thymus inodorusby the middle agar diffusion method on following microorganisms. We have Staphylococcus aureus, Escherichia coli, Pseudomonas fluorescens, AspergillusNiger, Aspergillus fumigatus and Candida albicans. During this study, flavonoids extracted by stripping with steam are performed. The yields of flavonoids is 7.242% for the aqueous extract and 28.86% for butanol extract, 29.875% for the extract of ethyl acetate and 22.9% for the extract of di - ethyl. The evaluation of the antibacterial effect shows that the diameter of the zone of inhibition varies from one microorganism to another. The operation values obtained show that the bacterial strain P fluoresces, and 3 yeasts and molds; A. Niger, A. fumigatus and C. albicansare the most resistant. But it is noted that, S. aureus is shown more sensitive to crude extracts, the stock solution and the various dilutions. Finally for the minimum inhibitory concentration is estimated only with the crude extract of Thymus inodorus flavonoid.Indeed, these extracts inhibit the growth of Gram + bacteria at a concentration varying between 0.5% and 1%. While for bacteria to Gram -, it is limited to a concentration of 0.5%.

Keywords: antimicrobial activity, organic extracts, aqueous extracts, Thymus numidicus

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Authors: Yogita Mishra, Arijit Roy, Dhruval Bhavsar

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The study estimates the nitrogen concentration in selected vegetation community’s i.e. chir pine (pinusroxburghii) by using hyperspectral satellite data and also identified the appropriate spectral bands and nitrogen indices. The Short Wave InfraRed reflectance spectrum at 1790 nm and 1680 nm shows the maximum possible absorption by nitrogen in selected species. Among the nitrogen indices, log normalized nitrogen index performed positively and negatively too. The strong positive correlation is taken out from 1510 nm and 760 nm for the pinusroxburghii for leaf nitrogen concentration and leaf nitrogen mass while using NDNI. The regression value of R² developed by using linear equation achieved maximum at 0.7525 for the analysis of satellite image data and R² is maximum at 0.547 for ground truth data for pinusroxburghii respectively.

Keywords: hyperspectral, NDNI, nitrogen concentration, regression value

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Authors: Krittapast Dara-Opast, Sureeporn Ruengsangtongkul, Jumreang Tummatorn, Kittipong Chainok, Onrapak Reamtong, Somsak Ruchirawat, Charnsak Thongsornkleeb

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Selective synthesis of gem-dihalo spiroisobenzofuran and spiroisocoumarin can be performed via halogenative double cyclization of methyl 2-(hydroxyalk-1-yn-1-yl) benzoates in the presence of either N-chlorosuccinimide (NCS) or N-bromosuccinimide (NBS) and chlorotrimethylsilane (TMSCl). The combination of NCS and TMSCl led to the generation of electrophilic chlorine in situ, which activated the alkyne functional group of the substrate leading to the cyclization via either 5-exo-dig or 6-endo-dig mode of cyclization to produce the target compounds in moderate yields. The protocol could be carried on a broad scope of substrates under mild conditions (0 °C to rt). The parent compounds showed good antiparasitic activity compared to standard drug albendazole. Further investigation of the scope of the reaction and their antiparasitic activities is underway.

Keywords: antiparasitic activities, halogenative annulation, spirocycles, spirocyclization

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Authors: R. Abdulrahman, A. Eardley, A. Soliman

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The proliferation in the development of mobile learning (m-learning) has played a vital role in the rapidly growing electronic learning market. This relatively new technology can help to encourage the development of in learning and to aid knowledge transfer a number of areas, by familiarizing students with innovative information and communications technologies (ICT). M-learning plays a substantial role in the deployment of learning methods for nursing students by using the Internet and portable devices to access learning resources ‘anytime and anywhere’. However, acceptance of m-learning by students is critical to the successful use of m-learning systems. Thus, there is a need to study the factors that influence student’s intention to use m-learning. This paper addresses this issue. It outlines the outcomes of a study that evaluates the unified theory of acceptance and use of technology (UTAUT) model as applied to the subject of user acceptance in relation to m-learning activity in nurse education. The model integrates the significant components across eight prominent user acceptance models. Therefore, a standard measure is introduced with core determinants of user behavioural intention. The research model extends the UTAUT in the context of m-learning acceptance by modifying and adding individual innovativeness (II) and quality of service (QoS) to the original structure of UTAUT. The paper goes on to add the factors of previous experience (of using mobile devices in similar applications) and the nursing students’ readiness (to use the technology) to influence their behavioural intentions to use m-learning. This study uses a technique called ‘convenience sampling’ which involves student volunteers as participants in order to collect numerical data. A quantitative method of data collection was selected and involves an online survey using a questionnaire form. This form contains 33 questions to measure the six constructs, using a 5-point Likert scale. A total of 42 respondents participated, all from the Nursing Institute at the Armed Forces Hospital in Saudi Arabia. The gathered data were then tested using a research model that employs the structural equation modelling (SEM), including confirmatory factor analysis (CFA). The results of the CFA show that the UTAUT model has the ability to predict student behavioural intention and to adapt m-learning activity to the specific learning activities. It also demonstrates satisfactory, dependable and valid scales of the model constructs. This suggests further analysis to confirm the model as a valuable instrument in order to evaluate the user acceptance of m-learning activity.

Keywords: mobile learning, nursing institute students’ acceptance of m-learning activity in Saudi Arabia, unified theory of acceptance and use of technology model (UTAUT), structural equation modelling (SEM)

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Authors: Vladimír Frišták, Martin Pipíška, Juraj Lesný

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Alginate has been evaluated as an efficient pollution control material. In this paper, alginate from maar Pinciná (SR) for removal of Cd2+ ions from aqueous solution was studied. The potential sorbent was characterized by X-Ray Fluorescence Analysis (RFA) analysis, Fourier Transform Infrared Spectral Analysis (FT-IR) and Specific Surface Area (SSA) was also determined. The sorption process was optimized from the point of initial cadmium concentration effect and effect of pH value. The Freundlich and Langmuir models were used to interpret the sorption behaviour of Cd2+ ions, and the results showed that experimental data were well fitted by the Langmuir equation. Alginate maximal sorption capacity (QMAX) for Cd2+ ions calculated from Langmuir isotherm was 34 mg/g. Sorption process was significantly affected by initial pH value in the range from 4.0-7.0. Alginate is a comparable sorbent with other materials for toxic metals removal.

Keywords: alginates, Cd2+, sorption, QMAX

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Authors: Mohamed Khedr, Ahmed Farghali, Waleed El Rouby, Abdelrhman Hamdeldeen

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Pure CeO2, Sm and Gd doped CeO2 were successfully prepared via hydrothermal method. The effect of hydrothermal temperature, reaction time and precursors were investigated. The prepared nanoparticles were characterized using X-ray diffraction (XRD), FT-Raman Spectroscopy, transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM). The prepared pure and doped CeO2 nanoparticles were used as photo-catalyst for the degradation of Methylene blue (MB) dye under UV light irradiation. The results showed that Gd doped CeO2 nano-particles have the best catalytic degradation effect for MB under UV irradiation. The degradation pathways of MB were followed using liquid chromatography (LC/MS) and it was found that Gd doped CeO2 was able to oxidize MB dye with a complete mineralization of carbon, nitrogen and sulfur heteroatoms into CO2, NH4+, NO3- and SO42-.

Keywords: CeO2, doped CeO2, photocatalysis, methylene blue

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Authors: Sandeep Kumar, Naveen Gupta

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The propagation of the Non-Gaussian laser beam results in strong self-focusing as compare to the Gaussian laser beam, which helps to achieve a prerequisite of the plasma-based electron, Terahertz generation, and higher harmonic generations. The theoretical investigation on the evolution of non-Gaussian laser beam through the collisional plasma with ramped density has been presented. The non-uniform irradiance over the cross-section of the laser beam results in redistribution of the carriers that modifies the optical response of the plasma in such a way that the plasma behaves like a converging lens to the laser beam. The formulation is based on finding a semi-analytical solution of the nonlinear Schrodinger wave equation (NLSE) with the help of variational theory. It has been observed that the decentred parameter ‘q’ of laser and wavenumber of ripples of medium contribute to providing the required conditions for the improvement of self-focusing.

Keywords: non-Gaussian beam, collisional plasma, variational theory, self-focusing

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Authors: Afaf Bouchoucha, Karima Si Larbi, Mohamed Amine Bourouaia, Salah.Boulanouar, Safia.Djabbar

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The synthesis, characterization and comparative biological study of manganese (II) and copper (II) complexes with an heterocyclic ligand used in pharmaceutical field (Scheme 1), were reported. Two kinds of complexes were obtained with derivative sulfonamide, [M (L)₂ (H₂O)₂].H₂O and [M (L)₂ (Cl)₂]3H₂O. These complexes have been prepared and characterized by elemental analysis, FAB mass, ESR magnetic measurements, FTIR, UV-Visible spectra and conductivity. Their stability constants have been determined by potentiometric methods in a water-ethanol (90:10 v/v) mixture at a 0.2 mol l-1 ionic strength (NaCl) and at 25.0 ± 0.1 ºC using Sirko program. DFT calculations were done using B3LYP/6-31G(d) and B3LYP/LanL2DZ. The antimicrobial activity of ligand and complexes against the species Escherichia coli, P. aeruginosa, Klebsiella pneumoniae, S. aureus, Bacillus subtilisan, Candida albicans, Candida tropicalis, Saccharomyces, Aspergillus fumigatus and Aspergillus terreus has been carried out and compared using agar-diffusion method. Also, the toxicity study was evaluated on synchesis complexes using Mice of NMRI strain.

Keywords: hetterocyclic ligand, complex, stability constant, antimicrobial activity, DFT, acute and genotoxicity study

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Authors: Blaž Likozar, Andraž Pavlišič, Matic Pavlin, Taja Žibert, Aleksandra Zamljen, Sašo Gyergyek, Matej Huš

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Ammonia is gaining recognition as a carbon-free fuel for energy-intensive applications, particularly transportation, industry, and power generation. Due to its physical properties, high energy density of 3 kWh kg-1, and high gravimetric hydrogen capacity of 17.6 wt%, ammonia is an efficient energy vector for green hydrogen, capable of mitigating hydrogen’s storage, distribution, and infrastructure deployment limitations. Chemicalstorage in the form of ammonia provides an efficient and affordable solution for energy storage, which is currently a critical step in overcoming the intermittency of abundant renewable energy sources with minimal or no environmental impact. Experiments were carried out to validate the modelling in a packed bed reactor, which proved to be agreeing.

Keywords: hydrogen, ammonia, catalysis, modelling, kinetics

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Authors: Fahmida Khalique Nitu

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Little is known on the biosafety level of Vibrio parahaemolyticus in estuarine fish in Bangladesh. The purpose of this study was to investigate the prevalence and concentration of V. parahaemolyticus in estuarine fishes using the Polymerase Chain Reaction( PCR) method . The study was conducted on 37 fishes of different species from different types of estuarine fish commonly sold at city markets. Sampling was done on the intestinal tract and gills of each fish. The prevalence of V. parahaemolyticus was found to be 29.72% with higher percentages detected in samples from the gills (89.28%) followed by the intestinal tract (10.71%). The density of Vibrio spp. in the gill of estuarine fishes with an average was 4.4 x103CFU/g and in the intestine samples was 1.5x103 CFU/g. The outcome of the biosafety assessment V. parahaemolyticus in estuarine fish indicates another potential source of food safety issues to consumers.

Keywords: biosafety, estuarine, prevalence, Vibrios

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Authors: Vida Jodaeian, Behzad Sani

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Copper nanoparticles were successfully synthesized and characterized on green-extracted Carrageenan from seaweed by precipitation method without using any supporter and template with precipitation method. The crystallinity, optical properties, morphology, and composition of products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transforms infrared (FT-IR) spectroscopy. The effects of processing parameters on the size and shape of Cu- nanostructures such as effect of pH were investigated. It is found that the reaction at lower pH values (acidic) could not be completed and pH = 8.00 was the best pH value to prepare very fine nanoparticles. They as synthesized Cu-nanoparticles were used as catalysts for the reduction of aromatic nitro compounds in presence of NaBH4. The results showed that Cu-nanoparticles are very active for reduction of these nitro aromatic compounds.

Keywords: nanoparticles, carrageenan, seaweed, nitro aromatic compound

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Authors: Khlif Hamadi

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Customer Relationship Management has become the main interest of researchers and practitioners especially in the domains of Management and Information Systems (IS). This paper is an overview of success factors that could facilitate successful adoption of CRM. There are 2 factors: the organizational climate and the capacity for innovation. The survey was developed with 200 CRM users. Empirical research is in the positivist paradigm based on the hypothetico-deductive method. Indeed, the approach adopted is the quantitative approach based on a questionnaire complied by Tunisian companies operating in different sectors of activity. For the data analyses, the structural equations method was used to conduct our exploratory and confirmatory analysis. The results revealed that the creative organizational climate and high innovation capacity positively influence the success of CRM practice.

Keywords: CRM practices, innovation capacity, organizational climate, the structural equation

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Authors: Hari Govindmishra, Sarabjot Singh

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The study offers an approach to understand different determinants of shopping behaviour, and the effect of ethnicity on shopping behaviour. The results reveal that the Indian culture is composite in nature and because of which there is no difference between different ethnic groups in their preference for three shopping behaviour determinants, viz., status consciousness, need for touch and companion opinion. The research model investigates the relevant relationship between these constructs by using a structural equation modelling approach, which reveals that status consciousness, need for touch and companion opinion are significant determinants of shopping behaviour. Consequently, the shopping behaviour managers have to understand the collective nature of Indian ethnic consumers in their shopping behaviour.

Keywords: ethnic groups, status consciousness, companion opinion, need for touch, shopping behaviour

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Authors: Mohamed A. Abou-Shouk, Mahamoud M. Hewedi

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This study extends technology acceptance model (TAM) to investigate the antecedents and consequences of social media adoption by tourists and travel agents. It compares their perceptions on social media adoption and its consequences. Online survey was addressed to tourists and travel agents for data collection purposes. Structural equation modelling was employed for analysis purposes. The findings revealed that the majority of tourists and travel agents involved in the study believe in the usefulness of social media adoption for travel planning and marketing purposes. They agree that adopting social media could change the attitude of tourists towards specific destination or attraction and influence their purchasing decisions. This study contributes to knowledge by extending TAM and provides some managerial implication to marketers.

Keywords: TAM, social media, travel and tourism, travel agents

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Authors: Anna Romanova, Morteza A. Alani

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Corrosion of concrete sewer pipes induced by sulfuric acid is an acknowledged problem and a ticking time-bomb to sewer operators. Whilst the chemical reaction of the corrosion process is well-understood, the indirect roles of other parameters in the corrosion process which are found in sewer environment are not highly reflected on. This paper reports on a field studies undertaken in Austria and United Kingdom, where the parameters of temperature, pH, H2S and CO2 were monitored over a period of time. The study establishes that (i) effluent temperature and pH have similar daily pattern and peak times, When examined in minutes scale, (ii) H2S and CO2 have an identical hourly pattern, (iii) H2S instant or shifted relation to effluent temperature is governed by the root mean square value of CO2.

Keywords: concrete corrosion, carbon dioxide, hydrogen sulphide, sewer pipe, sulfuric acid

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Authors: Geta Bekalu Belayneh, Solmoi Park

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This study examines the role of slag in the process of hydration and carbonation of carbonation-cured slag cement. Carbonation-cured slag-blended cement paste samples were prepared with varying slag percentages of 0%, 10%, 30%, and 50%. The curing process lasted for a maximum of 28 days. The findings demonstrated that the carbonation depth increased as the curing period was extended, and a larger slag percentage promoted a more extensive penetration of carbonation. The degree of belite reaction was greatly enhanced in the slag-blended cement, resulting in an increased ability to bind CO₂ in the blended cement. These findings enhance comprehension of the behaviour of blended cement produced through carbonation-curing, facilitating the advancement of more environmentally friendly and long-lasting concrete constructions.

Keywords: carbonation curing, blast furnace slag, characterization, Portland cement

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Authors: Gaye Ibrahima, Mendy Gervais, Seck Diaraf, Ouya Samuel

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In this paper, we consider the influence maximization in social networks. Here we give importance to initial diffuser called the seeds. The goal is to find efficiently a subset of k elements in the social network that will begin and maximize the information diffusion process. A new approach which treats the social network before to determine the seeds, is proposed. This treatment eliminates the information feedback toward a considered element as seed by extracting an acyclic spanning social network. At first, we propose two algorithm versions called SCG − algoritm (v1 and v2) (Spanning Connected Graphalgorithm). This algorithm takes as input data a connected social network directed or no. And finally, a generalization of the SCG − algoritm is proposed. It is called SG − algoritm (Spanning Graph-algorithm) and takes as input data any graph. These two algorithms are effective and have each one a polynomial complexity. To show the pertinence of our approach, two seeds set are determined and those given by our approach give a better results. The performances of this approach are very perceptible through the simulation carried out by the R software and the igraph package.

Keywords: acyclic spanning graph, centrality measures, information feedback, influence maximization, social network

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Authors: K. Khadidja

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Solitons are stable solution of nonlinear Schrodinger equation. Their stability is due to the exact combination between nonlinearity and dispersion which causes pulse broadening. Higher order solitons are born when nonlinear length is N multiple of dispersive length. Soliton order is determined by the number N itself. In this paper, evolution of higher order solitons is illustrated by simulation using Matlab. Results show that higher order solitons change their shape periodically, the reason why they are bad for transmission comparing to fundamental solitons which are constant. Partial analysis of a soliton of higher order explains that the periodic shape is due to the interplay between nonlinearity and dispersion which are not equal during a period. This class of solitons has many applications such as generation of supercontinuum and the impulse compression on the Femtosecond scale. As a conclusion, the periodicity which is harmful to transmission can be beneficial in other applications.

Keywords: dispersion, nonlinearity, optical fiber, soliton

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Authors: Girum Tedla Assefa

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Background: Granulomatous mycosis fungoides is an extremely rare type of cutaneous T-cell lymphoma (<55 cases reported worldwide). Case report: A 36-year-old female presented with soft tissue atrophy of right lower limb (dermis + hypodermis) of 22 years and plaques over trunk of 3 years duration. Histological examination of a biopsy taken from the atrophied tissue showed a granulomatous reaction with epidermotropic atypical lymphocytes. However, in other areas there were only findings of conventional MF without granuloma. Conclusion: The diagnosis of a granulomatous mycosis fungoides depends exclusively on the histological demonstration of granulomas. Distinct clinical characteristics are not present. This case highlights the importance of thorough investigation of lipoatrophic skin changes in the adult to exclude underlying causes, including MF.

Keywords: cutaneous lymphoma, granulomatous skin lymphoma, mycoses fungoides, skin atrophy

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Authors: H. Yousefnia, S. Zolghadri, AR. Jalilian, A. Mirzaei, A. Bahrami-Samani, M. Erfani

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The objective of this study is the preparation of 111In-DOTMP as a new bone imaging agent. 111In was produced at the Agricultural, Medical and Industrial Research School (AMIRS) by means of 30 MeV cyclotron via natCd(p,x)111In reaction. Complexion of In‐111 with DOTMP was carried out by adding 0.1 ml of the stock solution (50 mg/ml in 2 N NaoH) to the vial containing 1 mCi of 111In. pH of the mixture was adjusted to 7-8 by means of phosphate buffer. The radiochemical purity of the complex at the optimized condition was higher than 98% (by using whatman No.1 paper in NH4OH:MeOH: H2O (0.2:2:4)). Both the biodistribution studies and SPECT imaging indicated high bone uptake. The ratio of bone to other soft tissue accumulation was significantly high which permit to observe high quality images. The results show that 111In-DOTMP can be used as a suitable tracer for diagnosis of bone metastases by SPECT imaging.

Keywords: biodistribution, DOTMP, 111In, SPECT

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