Search results for: train formation

Authors: Georgi Y. Georgiev, Matthew Brouillet

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This research applies the power of agent-based modeling to a pivotal question at the intersection of biology, computer science, physics, and complex systems theory about the self-organization processes in open, complex, non-equilibrium thermodynamic systems. Central to this investigation is the principle of Maximum Entropy Production (MEP). This principle suggests that such systems evolve toward states that optimize entropy production, leading to the formation of structured environments. It is hypothesized that guided by the least action principle, open thermodynamic systems identify and follow the shortest paths to transmit energy and matter, resulting in maximal entropy production, internal structure formation, and a decrease in internal entropy. Concurrently, it is predicted that there will be an increase in system information as more information is required to describe the developing structure. To test this, an agent-based model is developed simulating an ant colony's formation of a path between a food source and its nest. Utilizing the Netlogo software for modeling and Python for data analysis and visualization, self-organization is quantified by calculating the decrease in system entropy based on the potential states and distribution of the ants within the simulated environment. External entropy production is also evaluated for information increase and efficiency improvements in the system's action. Simulations demonstrated that the system begins at maximal entropy, which decreases as the ants form paths over time. A range of system behaviors contingent upon the number of ants are observed. Notably, no path formation occurred with fewer than five ants, whereas clear paths were established by 200 ants, and saturation of path formation and entropy state was reached at populations exceeding 1000 ants. This analytical approach identified the inflection point marking the transition from disorder to order and computed the slope at this point. Combined with extrapolation to the final path entropy, these parameters yield important insights into the eventual entropy state of the system and the timeframe for its establishment, enabling the estimation of the self-organization rate. This study provides a novel perspective on the exploration of self-organization in thermodynamic systems, establishing a correlation between internal entropy decrease rate and external entropy production rate. Moreover, it presents a flexible framework for assessing the impact of external factors like changes in world size, path obstacles, and friction. Overall, this research offers a robust, replicable model for studying self-organization processes in any open thermodynamic system. As such, it provides a foundation for further in-depth exploration of the complex behaviors of these systems and contributes to the development of more efficient self-organizing systems across various scientific fields.

Keywords: complexity, self-organization, agent based modelling, efficiency

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Authors: Muhammad Shahzad Tufail, Iram Liaqat, Umer Sohail Meer, Muhammad Ishtaiq, Muhammad Sattar

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Nanotechnology is a vibrant field with numerous applications in many different branches of science and technology. Several methods are used to synthesize nanoparticles (NPs), which have multiple range of applications. Comparatively, the biogenic synthesis of NPs is a more economical and environmentally favourable method than the traditional chemical method. The current study aims to synthesize biogenically silver nanoparticles (AgNPs) using bacterial isolates. Four bacterial strains Escherichia coli (MT448673), Pseudomonas aeruginosa (MN900691), Bacillus subtilis (MN900684) and Bacillus licheniformis (MN900686) were used for the synthesis of AgNPs from silver nitrate (AgNO3) solution. The biofilm time kinetics of four bacterial isolates (P. aeruginosa, E. coli, B. licheniformis and B. subtilis) was analysed by incubating bacterial cultures at 37◦C in test tubes over a period of different time intervals i.e., 2, 3, 5 and 7 days following crystal violet staining method. All the four strains had ability to form strong biofilms between 48 to 72 hours of incubation. Two strains (B. subtilis and B. licheniformis) formed significant (p < 0.05) biofilm after 3 days of incubation period. The other two strains (E. coli and P. aeruginosa) showed strong biofilm formation after 2 days of incubation. Next, the antibiofilm activity of biogenically synthesized AgNPs (10 - 100 µgmL-1) was analysed against biofilm forming human pathogenic bacteria. Findings of the work revealed that 60-90% inhibition was observed at 60 µgmL-1 of AgNPs, while maximum inhibition (i.e.,100%) was found at highest concentration (90 µgmL-1). It was evident that highly significant (p < 0.05) decrease in biofilm formation was observed with increasing concentration of AgNPs.

Keywords: antibiofilm, biofilm formation, nanotechnology, pathogenic bacteria, silver nanoparticles

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Authors: Mohamed Hashelaf, Ahmed Al-Osdody

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In this paper, we focused our efforts on one of the vaguest subjects in astrophysics that is the formation and evolution of the universe until the arrival of humans. Through an in-depth exploration of the origins of the universe, understanding what has happened since the Big Bang until now and checking the history of creation, we can answer questions about the future of life, the possibility of its existence elsewhere in the universe and to be able to understand how we came, what our role in the circle of life is and what the future of our development will be. Here is where we used systematic steps that allowed us first and foremost to identify the reason behind the big bang itself that formed a large cloud of cosmic dust. Then after a period of time from the expansion of the universe and its coolness, the initial molecules of gases from the cosmic cloud began to condense, forming a very dense field of gravity that after millions of years led to the formation of stars, galaxies, even earth and the else planets. Finally, it became clear before us that after the earth has formed, the existence of liquid water made it possible for life to form, starting from the bacteria all the way until the appearance of the humans that we know today. But it does not stop here. If we look and contemplate in ourselves as humans, we will understand that the universe is inside us and that’s what makes us exceptional. All of this means that just as life on earth was created, it could have been on other planets as well. It also means that we are the universe’s key to understand itself.

Keywords: Big Bang, cosmic dust, primary elements, universe

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Authors: A. Alharbi, R. Boukhanouf, T. Habeebullah, H. Ibrahim

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This paper presents a detailed description of evaporative cooling systems used for space cooling in Mina Valley, Saudi Arabia. The thermal performance and environmental impact of the evaporative coolers were evaluated. It was found that the evaporative cooling systems used for space cooling in pilgrims’ accommodations and in the train stations could reduce energy consumption by as much as 75% and cut carbon dioxide emission by 78% compared to traditional vapour compression systems.

Keywords: evaporative cooling, vapor compression, electricity consumption, CO2 emission

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Authors: Inga Balarjishvili, Ia Natsvlishvili

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Article aims to discuss the controversial character of the institutional preferences of elites and society in modern Georgia. Desktop research method is used to formulate the findings and analyze the outcomes. It is accepted that transformation process in Post-Soviet Georgia went with the prevalence of elites’ institutional preferences over the needs of the society that induced voluntarism in the process of formation of institutions. Hypothesis of 'quasi-inclusion trap' is put forward in the article as an effect of authoritarian modernization that is proved by instable paces of wealth and economic growth in the post-authoritarian period. On the one hand, monopolization of institutional choice by the elites, blocking formation of inclusive political and economic institutions for fear of losing status-quo worsen perspectives for achieving free availability regime. On the other hand, consciousness of the society is dominated by informal institutions, judicial nihilism and orientation on 'self-survival values.' This hinders its consolidation as a 'collective principal' against 'institutional utilitarianism,' result of which is hindered economic development.

Keywords: elites, hypothesis of 'quasi-inclusion trap', institutional preferences, post-Soviet Georgia

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Authors: Naouel Boussoualim, Hayat Trabsa, Imane Krache, Seddik Khennouf, Noureddine Charef, Lekhmici Arrar, Abderrahmane Baghiani

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Purpose: To evaluate the in-vitro inhibition of xanthine oxidase (purified from bovine milk) by extracts of Lycium arabicum, as well as it is in vivo hypouricemic and renal protective effects. Methods: Four extracts of Lycium arabicum, methanol (CrE), chloroform (ChE), ethyl acetate (EaE) and aqueous (AqE) extracts, were screened for their total phenolics and potential inhibitory effects on purified bovine milk xanthine oxidase (XO) activity by measuring the formation of uric acid or superoxide radical. The mode of inhibition was investigated and compared with the standard drugs, allopurinol, quercitin, and catechin. To evaluate their hypouricemic effect, the extracts were administered to potassium oxonate-induced hyperuricemic mice at a dose of 50 mg/kg body weight. Results: The results showed that EaE had the highest content of phenolic compounds and was the most potent inhibitor of uric acid formation (IC50 = 0.017 ± 0.001 mg/mL) and formation of superoxide (IC50 = 0.035 ± 0.001 mg/ml). Lineweaver-Burk analysis showed that CrE and EaE inhibited XO competitively, whereas the inhibitory activities exerted by ChE and AqE were of a mixed type. Intraperetoneal injection of L. arabicum extracts (50 mg/kg) elicited hypouricemic actions in hyperuricemic mice. Hyperuricemic mice presented a serum uric acid concentration of 4.71 ± 0.29 mg/L but this was reduced to 1.78 ± 0.11 mg/L by EaE, which was the most potent hyporuricemic extract. Conclusion: L. arabicum fractions have a strong inhibitory effect on xanthine oxidase and and also have a significantly lowering effect on serum and liver creatinine and urea levels in hyperuricemic mice.

Keywords: lycium arabicum, uric acid, creatinine, superoxide, phenolic compounds, flavonoids, hyperuricemia

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Authors: Hammad Majeed, Hanna Knuutila, Magne Hillestad, Hallvard F. Svendsen

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Formation of aerosols can cause serious complications in industrial exhaust gas cleaning processes. Small mist droplets and fog formed can normally not be removed in conventional demisting equipment because their submicron size allows the particles or droplets to follow the gas flow. As a consequence of this, aerosol based emissions in the order of grams per Nm³ have been identified from PCCC plants. The model predicts the droplet size, the droplet internal variable profiles, and the mass transfer fluxes as function of position in the absorber. The Matlab model is based on a subclass method of weighted residuals for boundary value problems named, orthogonal collocation method. This paper presents results describing the basic simulation tool for the characterization of aerosols formed in CO₂ absorption columns and describes how various entering droplets grow or shrink through an absorber and how their composition changes with respect to time. Below are given some preliminary simulation results for an aerosol droplet composition and temperature profiles.

Keywords: absorption columns, aerosol formation, amine emissions, internal droplet profiles, monoethanolamine (MEA), post combustion CO2 capture, simulation

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Authors: A. Ojha, Y. K. Gupta

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Organophosphate (OP) pesticides are among the most widely used synthetic chemicals for controlling a wide variety of pests throughout the world. Chlorpyrifos (CPF), methyl parathion (MPT), and malathion (MLT) are among the most extensively used OP pesticides in India. DNA strand breaks and DNA-protein crosslinks (DPC) are toxic lesions associated with the mechanisms of toxicity of genotoxic compounds. In the present study, we have examined the potential of CPF, MPT, and MLT individually and in combination, to cause DNA strand breakage and DPC formation. Peripheral blood lymphocytes of rat were exposed to 1/4 and 1/10 LC50 dose of CPF, MPT, and MLT for 2, 4, 8, and 12h. The DNA strand break was measured by the comet assay and expressed as DNA damage index while DPC estimation was done by fluorescence emission. There was significantly marked increase in DNA damage and DNA-protein crosslink formation in time and dose dependent manner. It was also observed that MPT caused the highest level of DNA damage as compared to other studied OP compounds. Thus, from present study, we can conclude that studied pesticides have genotoxic potential. The pesticides mixture does not potentiate the toxicity of each other. Nonetheless, additional in vivo data are required before a definitive conclusion can be drawn regarding hazard prediction to humans.

Keywords: organophosphate, pesticides, DNA damage, DNA protein crosslink, genotoxic

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Authors: Gabriel Wosiak, Jeyse da Silva, Sthefany S. Sena, Renato N. de Andrade, Ernesto Pereira

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The bubble formation during hydrogen production by electrolysis and several electrochemical processes is an inherent phenomenon and can impact the energy consumption of the processes. In this work, it was reported both experimental and computational results describe the effect of bubble displacement, which, under the cases investigated, leads to the formation of a convective flow in the solution. The process is self-sustained, and a solution vortex is formed, which modifies the bubble growth and covering at the electrode surface. Using the experimental data, we have built a model to simulate it, which, with high accuracy, describes the phenomena. Then, it simulated many different experimental conditions and evaluated the effects of the boundary conditions on the bubble surface covering the surface. We have observed a position-dependent bubble covering the surface, which has an effect on the water-splitting efficiency. It was shown that the bubble covering is not uniform at the electrode surface, and using statistical analysis; it was possible to evaluate the influence of the gas type (H2 and O2), current density, and the bubble size (and cross-effects) on the covering fraction and the asymmetric behavior over the electrode surface.

Keywords: water splitting, bubble, electrolysis, hydrogen production

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Authors: Mohamad Saab, Sidi Souvi

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In a major nuclear accident, the released fission products (FPs) and the structural materials are likely to influence the transport of iodine in the reactor coolant system (RCS) of a pressurized water reactor (PWR). So far, the thermodynamic data on cesium and silver species used to estimate the magnitude of FP release show some discrepancies, data are scarce and not reliable. For this reason, it is crucial to review the thermodynamic values related to cesium and silver materials. To this end, we have used state-of-the-art quantum chemical methods to compute the formation enthalpies and entropies of AgHMoO₄, CsHMoO₄, and AgCsMoO₄ in the gas phase. Different quantum chemical methods have been investigated (DFT and CCSD(T)) in order to predict the geometrical parameters and the energetics including the correlation energy. The geometries were optimized with TPSSh-5%HF method, followed by a single point calculation of the total electronic energies using the CCSD(T) wave function method. We thus propose with a final uncertainty of about 2 kJmol⁻¹ standard enthalpies of formation of AgHMoO₄, CsHMoO₄, and AgCsMoO₄.

Keywords: nuclear accident, ASTEC code, thermochemical database, quantum chemical methods

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Authors: Amira Shakila Razali, Faridah Lisa Supian, Muhammad Mat Salleh, Suriani Abu Bakar

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Water contamination by toxic compound is one of the serious environmental problems today. These toxic compounds mostly originated from industrial effluents, agriculture, natural sources and human waste. These study are focused on modification of multiwalled carbon nanotube (MWCNTs) with nanoparticle of calixarene and explore the possibility of using this nanocomposites for the remediation of cadmium in water. The nanocomposites were prepared by dissolving calixarene in chloroform solution as solvent, followed by additional multiwalled carbon nanotube (MWCNTs) then sonication process for 3 hour and fabricated the nanocomposites on substrate by spin coating method. Finally, the nanocomposites were tested on cadmium ion (10 mg/ml). The morphology of nanocomposites was investigated by FESEM showing the formation of calixarene on the outer walls of carbon nanotube and cadmium ion also clearly seen from the micrograph. This formation was supported by using energy dispersive x-ray (EDX). The presence of cadmium ions in the films, leads to some changes in the surface potential and Fourier Transform Infrared spectroscopy (FTIR).This nanocomposites have potential for development of sensor for pollutant monitoring and nanoelectronics devices applications

Keywords: calixarene, multiwalled carbon nanotubes, cadmium, surface potential

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Authors: Mikhail V. Khachaturyan, Inga A. Koryagina, Maria Nikishova

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The study investigates the impact of the ongoing financial crisis, started in the 2^nd half of 2014, on marketing budgets spent by Fast-moving consumer goods companies. In these conditions, special importance is given to efficient possessory risk management systems. The main objective for establishing and developing possessory risk management systems for FMCG companies in a crisis is to analyze the data relating to the external environment and consumer behavior in a crisis. Another important objective for possessory risk management systems of FMCG companies is to develop measures and mechanisms to maintain and stimulate sales. In this regard, analysis of risks and threats which consumers define as the main reasons affecting their level of consumption become important. It is obvious that in crisis conditions the effective risk management systems responsible for development and implementation of strategies for consumer demand stimulation, as well as the identification, analysis, assessment and management of other types of risks of economic security will be the key to sustainability of a company. In terms of financial and economic crisis, the problem of forming and developing possessory risk management systems becomes critical not only in the context of management models of FMCG companies, but for all the companies operating in other sectors of the Russian economy. This study attempts to analyze the specifics of formation and development of company possessory risk management systems. In the modern economy, special importance among all the types of owner’s risks has the risk of reduction in consumer activity. This type of risk is common not only for the consumer goods trade. Study of consumer activity decline is especially important for Russia due to domestic market of consumer goods being still in the development stage, despite its significant growth. In this regard, it is especially important to form and develop possessory risk management systems for FMCG companies. The authors offer their own interpretation of the process of forming and developing possessory risk management systems within owner’s management models of FMCG companies as well as in Russian economy in general. Proposed methods and mechanisms of problem analysis of formation and development of possessory risk management systems in FMCG companies and the results received can be helpful for researchers interested in problems of consumer goods market development in Russia and overseas.

Keywords: FMCG companies, marketing budget, risk management, owner, Russian economy, organization, formation, development, system

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Authors: Seyedeh Narjes Hosseini, Mohammad Hossein Enayati, Fathallah Karimzadeh, Nigel Mark Sammes

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The synthesis of CuFe2O4 spinel powders by an optimized combustion-like process followed by calcinations is described herein. The samples were characterized by X-ray diffraction (XRD), differential thermal analysis (TG/DTA), scanning electron microscopy (SEM), dilatometry and 4-probe DC methods. Different glycine to nitrate (G/N) ratios of 1 (fuel-deficient), 1.48 (stoichiometric) and 2 (fuel-rich) were employed. Calcining the as-prepared powders at 800 and 1000°C for 5 hours showed that the 2 ratio results in the formation of desired copper spinel single phase at both calcinations temperatures. For G/N=1, formation of CuFe2O4 takes place in three steps. First, iron and copper nitrates decomposes to iron oxide and pure copper. Then, copper transforms to copper oxide and finally, copper and iron oxides react to each other to form copper ferrite spinel phase. The electrical conductivity and the coefficient of thermal expansion of the sintered pelletized samples were obtained 2 S.cm-1 (800°C) and 11×10-6 °C-1 (25-800°C), respectively.

Keywords: SOFC interconnect coatings, Copper ferrite, Spinels, electrical conductivity, Glycine–nitrate process

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Authors: Vishwa Joshi

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The study of mood recognition in the field of music has gained a lot of momentum in the recent years with machine learning and data mining techniques and many audio features contributing considerably to analyze and identify the relation of mood plus music. In this paper we consider the same idea forward and come up with making an effort to build a system for automatic recognition of mood underlying the audio song’s clips by mining their audio features and have evaluated several data classification algorithms in order to learn, train and test the model describing the moods of these audio songs and developed an open source framework. Before classification, Preprocessing and Feature Extraction phase is necessary for removing noise and gathering features respectively.

Keywords: music, mood, features, classification

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Authors: Pawel Magryta, Tytus Tulwin, Paweł Karpiński

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The ASz62IR engine is a radial aircraft engine with 9 cylinders. This object is produced by the Polish company WSK "PZL-KALISZ" S.A. This is engine is currently being developed by the above company and Lublin University of Technology. In order to provide an effective work of the technological development of this unit it was decided to made the simulation model. The model of ASz-62IR was developed with AVL BOOST software which is a tool dedicated to the one-dimensional modeling of internal combustion engines. This model can be used to calculate parameters of an air and fuel flow in an intake system including charging devices as well as combustion and exhaust flow to the environment. The main purpose of this model is the analysis of the charge exchange and mixture formation in this engine. For this purpose, the model consists of elements such: as air inlet, throttle system, compressor connector, charging compressor, inlet pipes and injectors, outlet pipes, fuel injection and model of fuel mixing and evaporation. The model of charge exchange and mixture formation was based on the model of mass flow rate in intake and exhaust pipes, and also on the calculation of gas properties values like gas constant or thermal capacity. This model was based on the equations to describe isentropic flow. The energy equation to describe flow under steady conditions was transformed into the mass flow equation. In the model the flow coefficient μσ was used, that varies with the stroke/valve opening and was determined in a steady flow state. The geometry of the inlet channels and other key components was mapped with reference to the technical documentation of the engine and empirical measurements of the structure elements. The volume of elements on the charge flow path between the air inlet and the exhaust outlet was measured by the CAD mapping of the structure. Taken from the technical documentation, the original characteristics of the compressor engine was entered into the model. Additionally, the model uses a general model for the transport of chemical compounds of the mixture. There are 7 compounds used, i.e. fuel, O2, N2, CO2, H2O, CO, H2. A gasoline fuel of a calorific value of 43.5 MJ/kg and an air mass fraction for stoichiometric mixture of 14.5 were used. Indirect injection into the intake manifold is used in this model. The model assumes the following simplifications: the mixture is homogenous at the beginning of combustion, accordingly, mixture stoichiometric coefficient A/F remains constant during combustion, combusted and non-combusted charges show identical pressures and temperatures although their compositions change. As a result of the simulation studies based on the model described above, the basic parameters of combustion process, charge exchange, mixture formation in cylinders were obtained. The AVL Boost software is very useful for the piston engine performance simulations. This work has been financed by the Polish National Centre for Research and Development, INNOLOT, under Grant Agreement No. INNOLOT/I/1/NCBR/2013.

Keywords: aviation propulsion, AVL Boost, engine model, charge exchange, mixture formation

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Authors: Andriy Fedorenko

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Background Early closure of the open abdomen is a priority after damage control laparotomy to prevent retraction of fascial layers and prevent hernia formation that requires definitive repair at a later stage. This substantially reduces the complications associated with ventral hernia formation for up to a year after initial surgery. TopClosure® is an innovative method that employs stress-relaxation and mechanical creep for skin stretching. Its use enables the primary closure of large abdominal wall defects and mitigates large ventral hernia formation. Materials and Methods A 7-year-old girl presented with severe blast injury. She underwent initial laparotomy in a facility within the conflict zone and was transferred in a state of septic shock to our facility for further care. Her abdominal injuries included liver lacerations, multiple perforations of the transverse colon and ileum, and a 8x16cm oblique abdominal wall defect. Further damage control laparotomy was performed with primary suture of the colon and ileum and temporary closure of the abdomen using a Bagota bag. Twelve hours later, negative pressure wound therapy (NPWT) was applied to the abdominal wound after relook laparotomy. Five days later, TopClosure® was applied to the lower part of the wound incorporating NPWT to the upper wound. Results The patient suffered leak from the colonic suture line and required relaparotomy. TopClosure® abdominal closure was achieved after every laparotomy. Conclusion TopClosure® utilizes the viscoelastic properties of the skin achieving full closure of the abdominal wall (including the fascia and skin),eliminating the need for prolonged NPWT, skin graft, and delayed ventral hernia repair surgery.

Keywords: topclosure, abdominal wall defect, hernia, damage control

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Authors: Benjaporn Buranrat, Nootchanat Mairuae

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Cratoxylum formosum (Jack) Dyer (CF) has been used for the traditional medicines in South East Asian and Thailand. Normally, northeast Thai vegetables have proven cytotoxic to many cancer cells. Therefore, the present study aims to explore the molecular mechanisms underlying CF-induced cancer cell death and apoptosis on breast and liver cancer cells. The cytotoxicity and antiproliferative effects of CF on the human breast MCF-7 and liver HepG2 cancer cell lines were evaluated using sulforhodamine B assay and colony formation assay. Cell migration assay was measured using wound healing assay. The apoptosis induction mechanisms were investigated through reactive oxygen species formation, caspase 3 activity, and JC-1 activity. Gene expression by real-time PCR and apoptosis related protein levels by Western blot analysis. CF induced MCF-7 and HepG2 cell death by time- and dose-dependent manner. Furthermore, CF had the greater cytotoxic potency on MCF-7 more than HepG2 cells with IC50 values of 85.70+4.52 μM and 219.03±9.96 μM respectively, at 24 h. Treatment with CF also caused a dose-dependent decrease in colony forming ability and cell migration, especially on MCF-7 cells. CF induced ROS formation, increased caspase 3 activities, and decreased the mitochondrial membrane potential, and causing apoptotic body production and DNA fragmentation. CF significantly decreased expression of the cell cycle regulatory protein RAC1 and downstream proteins, cdk6. Additionally, CF enhanced p21 and reduced cyclin D1 protein levels. CF leaf extract induced cell death, apoptosis, antimigration in both of MCF-7 and HepG2 cells. CF could be useful for developing to anticancer drug candidate for breast and liver cancer therapy.

Keywords: cratoxylum formosum (jack) dyer, breast cancer, liver cancer, cell death

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Authors: Pajaree Donkhampa, Fuangfa Unob

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Ceftazidime is an antibiotic drug commonly used to treat several human and veterinary infections. However, the presence of ceftazidime residues in the environment may induce microbial resistance and cause side effects to humans. Therefore, monitoring the level of ceftazidime in environmental resources is important. In this work, a melamine foam platform was proposed for simultaneous extraction and colorimetric detection of ceftazidime based on the azo dye formation on the surface. The melamine foam was chemically modified with polyethyleneimine (PEI) and characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Ceftazidime is a sample that was extracted on the PEI-modified melamine foam and further reacted with nitrite in an acidic medium to form an intermediate diazonium ion. The diazotized molecule underwent an azo coupling reaction with chromotropic acid to generate a red-colored compound. The material color changed from pale yellow to pink depending on the ceftazidime concentration. The photo of the obtained material was taken by a smartphone camera and the color intensity was determined by Image J software. The material fabrication and ceftazidime extraction and detection procedures were optimized. The detection of a sub-ppm level of ceftazidime was achieved without using a complex analytical instrument.

Keywords: colorimetric detection, ceftazidime, melamine foam, extraction, azo dye

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Authors: Fatima Ammari, Meriem Chenouf

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Synthesis of gold nano particles has attracted much attention since the pioneering discovery of the high catalytic activity of supported gold nano particles in the reaction of CO oxidation at low temperature. In this research field, we used Na-montmorillonite for gold nanoparticles stabilization; different loading percentage 1, 2 and 5%. The gold nano particles were obtained using chemical reduction method using NaBH4 as reductant agent. The obtained gold nano particles Au-mont stabilized in Na-montmorillonite were used as catalysts for reduction of 4-nitrophenol to aminophenol with sodium borohydride at room temperature. The UV-Vis results confirm directly the gold nano particles formation. The XRD and N2 adsorption results showed the formation of gold nano particles in the pores of montmorillonite with an average size of 5 nm obtained on samples with 2%Au-mont. The gold particles size increased with the increase of gold loading percentage. The reduction reaction of 4-nitrophenol into 4-aminophenol with NaBH4 catalyzed by Au-Na-montmorillonite catalyst exhibits remarkably a high activity; the reaction was completed within 9 min for 1Au-mont and within 3 min for 2Au-mont.

Keywords: chemical reduction, gold, montmorillonite, nano particles, 4-nitrophenol

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Authors: Deepti Mishra, K. K Pant, Xiu Song Zhao, Muxina Konarova

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Catalytic transformation of simplest hydrocarbon methane into benzene and valuable chemicals over Mo/HZSM-5 has a great economic potential, however, it suffers serious hurdles due to the blockage in the micropores because of extensive coking at high temperature during methane dehydroaromatization (MDA). Under such conditions, it necessitates the design of micro/mesoporous ZSM-5, which has the advantages viz. uniform dispersibility of MoOx species, consequently the formation of active Mo sites in the micro/mesoporous channel and lower carbon deposition because of improved mass transfer rate within the hierarchical pores. In this study, we report a unique strategy to control the porous structures of ZSM-5 through a dual templating approach, utilizing C6 and C12 -surfactants as porogen. DFT studies were carried out to correlate the ZSM-5 framework development using the C6 and C12 surfactants with structure directing agent. The structural and morphological parameters of the synthesized ZSM-5 were explored in detail to determine the crystallinity, porosity, Si/Al ratio, particle shape, size, and acidic strength, which were further correlated with the physicochemical and catalytic properties of Mo modified HZSM-5 catalysts. After Mo incorporation, all the catalysts were tested for MDA reaction. From the activity test, it was observed that C6 surfactant-modified hierarchically porous Mo/HZSM-5(H) showed the highest benzene formation rate (1.5 μmol/gcat. s) and longer catalytic stability up to 270 min of reaction as compared to the conventional microporous Mo/HZSM-5(C). In contrary, C12 surfactant modified Mo/HZSM-5(D) is inferior towards MDA reaction (benzene formation rate: 0.5 μmol/gcat. s). We ascribed that the difference in MDA activity could be due to the hierarchically interconnected meso/microporous feature of Mo/HZSM-5(H) that precludes secondary reaction of coking from benzene and hence contributing substantial stability towards MDA reaction.

Keywords: hierarchical pores, Mo/HZSM-5, methane dehydroaromatization, coke deposition

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Authors: Titis Indah Adi Rahayu

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Angiogenesis is the process of generating new capillary from pre-existing blood vessels. VEGFA is a major regulator in angiogenesis that binds and activates two tyrosine kinase receptors, VEGFR1 (Flt-1) and VEGFR2 (Flk-1/KDR) which regulate pathological and physiological angiogenesis. Disruption of VEGFA and VEGFR2 regulation lead to many diseases. The study of α-Mangostin (derivate of xanthone) as anti-oxidant and anti inflammation has been explored recently and both of them have relation to vasculature however the effect of α-Mangostin in blood vessel formation in healthy tissue in vivo has not been studied. Zebrafish is a powerful model in studying angiogenesis and shared many advantages that is a viable whole animal model for screening small molecules that affect blood vessel formation. Therefore the aim of this study is to evaluate angiogenic activity of α-Mangostin in healthy tissue in vivo in zebrafish embryo in relation of patterning blood vessel. Blood vessel patterning is highly characteristic in the developing of zebrafish embryo and the subintestinal vessel (SIV) can be stained and visualized microscopically as a primary screen for α-Mangostin that effect angiogenesis. The zebrafish embryos are divided into 2 groups. Group one consists of the zebrafish embryos at 1 dpf for 4 days which are tested to α-Mangostin in several concentration 2 µM, 4 µM, 6 µM, 8 µM and 10 µM whereas in group two the zebrafish larva at 4 dpf are exposed to α-Mangostin 1,75 µM, 2,3 µM, 2,9 µM, 3,8 µM dan 5 µM for 2 days. DMSO is served as a control for each group. The level expression of vegfa and vegfr2 are observed quantitatively using real time q-PCR and patterning of SIV are then analized via alkaline phospatase staining. Result shows that the level expression of vegfa and vegfr2 is repressed quantitatively as shown in real time q-PCR in the group of 1-4 days of α-Mangostin exposure where it is increased in the group of 4-6 days of α-Mangostin exposure. The result is then compared to alkaline phospatase staining of SIV using stereo microscope. It indicates that α-Mangostin does not disturb the patterning of SIV formation in zebrafish.

Keywords: angiogenesis, Danio rerio, α-Mangostin, SIV, vegfa, vegfr2

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Authors: Tahani Hallek, Dhaou Akrout, Riadh Ahmadi, Mabrouk Montacer

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The present work is an organic geochemical study of the Fahdene Formation outcrops at the Mahjouba region belonging to the Eastern part of the Kalaat Senan structure in northwestern Tunisia (the Kef-Tedjerouine area). The analytical study of the organic content of the samples collected, allowed us to point out that the Formation in question is characterized by an average to good oil potential. This fossilized organic matter has a mixed origin (type II and III), as indicated by the relatively high values of hydrogen index. This origin is confirmed by the C29 Steranes abundance and also by tricyclic terpanes C19/(C19+C23) and tetracyclic terpanes C24/(C24+C23) ratios, that suggest a marine environment of deposit with high plants contribution. We have demonstrated that the heterogeneity of organic matter between the marine aspect, confirmed by the presence of foraminifera, and the continental contribution, is the result of an episodic anomaly in relation to the sequential stratigraphy. Given that the study area is defined as an outer platform forming a transition zone between a stable continental domain to the south and a deep basin to the north, we have explained the continental contribution by successive forced regressions, having blocked the albian transgression, allowing the installation of the lowstand system tracts. This aspect is represented by the incised valleys filling, in direct contact with the pelagic and deep sea facies. Consequently, the Fahdene Formation, in the Kef-Tedjerouine area, consists of transgressive system tracts (TST) brutally truncated by extras of continental progradation; resulting in a mixed influence deposition having retained a heterogeneous organic material.

Keywords: molecular geochemistry, biomarkers, forced regression, deposit environment, mixed origin, Northern Tunisia

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Authors: Luan Trong Nguyen, M. Azizur Rahman, Yusuke Tamenori, Toshihiro Yoshimura, Nozomu Iwasaki, Hiroshi Hasegawa

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This study investigated the distribution of magnesium (Mg), phosphorus (P), sulfur (S) and strontium (Sr) using micro X-ray fluorescence (µ-XRF) along the annual growth rings in the skeleton of Japanese red coral Paracorallium japonicum. The Mg, P and S distribution in µ-XRF mapping images correspond to the dark and light bands along the annual growth rings observed in microscopic images of the coral skeleton. The µ-XRF mapping data showed a positive correlation (r = 0.6) between P and S distribution in the coral skeleton. A contrasting distribution pattern of S and Mg along the axial skeleton of P. japonicum indicates a weak negative correlation (r = -0.2) between these two trace elements. The distribution pattern of S, P and Mg reveals linkage between their distributions and the formation of dark/light bands along the annual growth rings in the axial skeleton of P. japonicum. Sulfur and P were distributed in the organic matrix rich dark bands, while Mg was distributed in the light bands of the annual growth rings.

Keywords: µ-XRF, trace element, precious coral, Paracorallium japonicum

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Authors: J. K. Alhassan, C. S. Actsu

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This study is on the prediction of feature performance of undergraduate students with Artificial Neural Networks (ANN). With the growing decline in the quality academic performance of undergraduate students, it has become essential to predict the students’ feature academic performance early in their courses of first and second years and to take the necessary precautions using such prediction-based information. The feed forward multilayer neural network model was used to train and develop a network and the test carried out with some of the input variables. A result of 80% accuracy was obtained from the test which was carried out, with an average error of 0.009781.

Keywords: academic performance, artificial neural network, prediction, students

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Authors: Tsutomu Iwayama, Takayuki Hama

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Si ion implantation was widely used to synthesize specimens of SiO2 containing supersaturated Si and subsequent high temperature annealing induces the formation of embedded luminescent Si nanocrystals. In this work, the potentialities of excimer UV-light (172 nm, 7.2 eV) irradiation and rapid thermal annealing (RTA) to enhance the photoluminescence and to achieve low temperature formation of Si nanocrystals have been investigated. The Si ions were introduced at acceleration energy of 180 keV to fluence of 7.5 x 1016 ions/cm2. The implanted samples were subsequently irradiated with an excimer-UV lamp. After the process, the samples were rapidly thermal annealed before furnace annealing (FA). Photoluminescence spectra were measured at various stages at the process. We found that the luminescence intensity is strongly enhanced with excimer-UV irradiation and RTA. Moreover, effective visible photoluminescence is found to be observed even after FA at 900 oC, only for specimens treated with excimer-UV lamp and RTA. We also prepared specimens of Si nanocrystals embedded in a SiO2 by reactive pulsed laser deposition (PLD) in an oxygen atmosphere. We will make clear the similarities and differences with the way of preparation.

Keywords: Ion implantation, photoluminescence, pulsed laser deposition, rapid thermal anneal, Si nanocrystals

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Authors: Satyananda Behera, Ritwik Sarkar

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In iron and steel industries, MgO–C refractories are widely used in basic oxygen furnaces, electric arc furnaces and steel ladles due to their excellent corrosion resistance, thermal shock resistance, and other excellent hot properties. Conventionally magnesia carbon refractories contain about 8-20 wt% of carbon but the use of carbon is also associate with disadvantages like oxidation, low fracture strength, high heat loss and higher carbon pick up in steel. So, MgO-C refractory having low carbon content without compromising the beneficial properties is the challenge. Nano carbon, having finer particles, can mix and distribute within the entire matrix uniformly and can result in improved mechanical, thermo-mechanical, corrosion and other refractory properties. Previous experiences with the use of nano carbon in low carbon MgO-C refractory have indicated an optimum range of use of nano carbon around 1 wt%. This optimum nano carbon content was used in MgO-C compositions with flaky graphite followed by aluminum and silicon metal powder as an anti-oxidant. These low carbon MgO-C refractory compositions were prepared by conventional manufacturing techniques. At the same time 16 wt. % flaky graphite containing conventional MgO-C refractory was also prepared parallel under similar conditions. The developed products were characterized for various refractory related properties. Nano carbon containing compositions showed better mechanical, thermo-mechanical properties, and oxidation resistance compared to that of conventional composition. Improvement in the properties is associated with the formation of in-situ ceramic phase-like aluminum carbide, silicon carbide, and magnesium aluminum spinel. Higher surface area and higher reactivity of N220 nano carbon black resulted in greater formation in-situ ceramic phases, even at a much lower amount. Nano carbon containing compositions were found to have improved properties in MgO-C refractories compared to that of the conventional ones at much lower total carbon content.

Keywords: N220nano carbon black, refractory properties, conventionally manufacturing techniques, conventional magnesia carbon refractories

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Authors: Yong Chen

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To understand the detailed molecular mechanisms of memory formation in engram cells is one of the most fundamental questions in neuroscience. Recent single-cell RNA-seq (scRNA-seq) and single-nucleus RNA-seq (snRNA-seq) techniques have allowed us to explore the sparsely activated engram ensembles, enabling access to the molecular mechanisms that underlie experience-dependent memory formation and consolidation. However, the absence of specific and powerful computational methods to detect memory-related genes (modules) and their regulatory relationships in the sc/snRNA-seq datasets has strictly limited the analysis of underlying mechanisms and memory coding principles in mammalian brains. Here, we present a deep-learning method named SCENTBOX, to detect memory-related gene modules and causal regulatory relationships among themfromsc/snRNA-seq datasets. SCENTBOX first constructs codifferential expression gene network (CEGN) from case versus control sc/snRNA-seq datasets. It then detects the highly correlated modules of differential expression genes (DEGs) in CEGN. The deep network embedding and attention-based convolutional neural network strategies are employed to precisely detect regulatory relationships among DEG genes in a module. We applied them on scRNA-seq datasets of TRAP; Ai14 mouse neurons with fear memory and detected not only known memory-related genes, but also the modules and potential causal regulations. Our results provided novel regulations within an interesting module, including Arc, Bdnf, Creb, Dusp1, Rgs4, and Btg2. Overall, our methods provide a general computational tool for processing sc/snRNA-seq data from case versus control studie and a systematic investigation of fear-memory-related gene modules.

Keywords: sc/snRNA-seq, memory formation, deep learning, gene module, causal inference

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Authors: Sonia Barbouchi, Meriem Samcha

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Scale deposition during water injection into aquifer of oil reservoirs is a serious problem experienced in the oil production industry. One of the primary causes of scale formation and injection well plugging is mixing two waters which are incompatible. Considered individually, the waters may be quite stable at system conditions and present no scale problems. However, once they are mixed, reactions between ions dissolved in the individual waters may form insoluble products. The purpose of this study is to identify the causes of well plugging in a southern Tunisian oilfield, where fresh water has been injected into the producing wells to counteract the salinity of the formation waters and inhibit the deposition of halite. X-ray diffraction (XRD) mineralogical analysis has been carried out on scale samples collected from the blocked well. Two samples collected from both formation water and injected water were analysed using inductively coupled plasma atomic emission spectroscopy, ion chromatography and other standard laboratory techniques. The results of complete waters analysis were the typical input parameters, to determine scaling tendency. Saturation indices values related to CaCO3, CaSO4, BaSO4 and SrSO4 scales were calculated for the water mixtures at different share, under various conditions of temperature, using a computerized scale prediction model. The compatibility study results showed that mixing the two waters tends to increase the probability of barite deposition. XRD analysis confirmed the compatibility study results, since it proved that the analysed deposits consisted predominantly of barite with minor galena. At the studied temperatures conditions, the tendency for barite scale is significantly increasing with the increase of fresh water share in the mixture. The future scale inhibition and removal strategies to be implemented in the concerned oilfield are being derived in a large part from the results of the present study.

Keywords: compatibility study, produced water, scaling, water injection

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Authors: Yousef Bakhbakhi

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Crystallization with supercritical fluids (SCFs), as a developed technology to produce particles of micron and sub-micron size with narrow size distribution, has found appreciable importance as an environmentally friendly technology. Particle synthesis using SCFs can be achieved employing a number of special processes involving solvent and antisolvent mechanisms. In this study, the compressed antisolvent (PCA) process is utilized as a model to analyze the theoretical complexity of crystallization with supercritical fluids. The population balance approach has proven to be an effectual technique to simulate and predict the particle size and size distribution. The nucleation and growth mechanisms of the particles formation in the PCA process is investigated using the population balance equation, which describes the evolution of the particle through coalescence and breakup levels with time. The employed mathematical population balance model contains a set of the partial differential equation with algebraic constraints, which demands a rigorous numerical approach. The combined Collocation and Galerkin finite element method are proposed as a high-resolution technique to solve the dynamics of the PCA process.

Keywords: particle formation, particle size and size distribution, PCA, supercritical carbon dioxide

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Authors: Yuksel Akinay, Fatih Hayat

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The influence of Ni elements on mechanical properties and microstructure of twinning induced plasticity (TWIP) steels were investigated in this study. TWIP 1 (0,6C, 24Mn) and TWIP 2 (0,6C, 24Mn, 1Ni) high Mn TWIP (Twinning Induced Plasticity) steels were fabricated, and were annealed at 700°C, 800°C and 900°C for 150 minute and then air-cooled. The microstructures and mechanical properties of specimens were analysed to investigate influence of Ni element on TWIP steel. The carbide precipitations have seen in microstructure of TWIP 1 and TWIP 2 specimen annealed at 700 °C. However, the microstructures of TWIP 1 annealed at 800°C and 900°C are fully austenite and some grains are including annealing twins. However twining did not occur at TWIP 2 specimens annealed at 700 °C, 800 °C and 900 °C. TWIP 2 steel contains also Ni element differently from TWIP 1 steel. It can conclude that, Nickel (Ni) was restrained formation of twinning. The reversion of the tensile strength occurred between 700°C and 800°C because of the carbide precipitation hardening. Beside that, hardness value has decreased between 800 °C and 900 °C, which show a good agreement with the equilibrium dissolution temperature of M3C carbides. However, the results show that, carbide precipitations also are as strong barriers for the formation of twining. For this reason, twinning was not obtained at 700 °C.

Keywords: high manganese, heat treatment, SEM, TWIP steel, cold rolling, nickel

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