Search results for: breast solid lesion

Authors: Dibu Dave Mbako, Bin Cheng

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This paper study the stress variation of the welded joints in the rib-to-deck connection structure, the influence stress of the deck plate and u-rib thickness at different positions. A Finite-element model of orthotropic steel deck structure using solid element and shell element was established in ABAQUS. Under a single wheel load, the static response was analyzed to understand the structural behaviors and examine stress distribution. A parametric study showed that the geometric parameters have a significant effect on the hot spot stress at the weld toe, but has little impact on the stress concentration factor. The increase of the thickness of the deck plate will lead to the decrease of the hot spot stress at the weld toe and the maximum deflection of the deck plate. The surface stresses of the deck plate are significantly larger than those of the rib near the joint in the 80% weld penetration into the u-rib.

Keywords: orthotropic steel bridge deck, rib-to-deck connection, hot spot stress, finite element method, stress distribution

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Authors: Govind Sharma, Bahni Ray

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Ubiquitous nature of particle settling is governed by the presence of the surrounding fluid medium. Thermally stratified fluid alters the settling phenomenon of particles as well as their interactions. Direct numerical simulation (DNS) is carried out with an open-source library Immersed Boundary Adaptive Mesh Refinement (IBAMR) to quantify the fundamental mechanism based on Distributed Lagrangian Multiplier (DLM). The presence of background density gradient due to thermal stratification replaces the drafting-kissing-tumbling in a homogeneous fluid to drafting-kissing-separation behavior. Simulations are performed with a varying range of particle-fluid density ratios, and it is shown that the stratification effect on particle interactions varies with density ratio. It is observed that the combined role of buoyancy and inertia govern the physical mechanism of particle-particle interaction.

Keywords: direct numerical simulation, distributed lagrangian multiplier, rigidity constraint, sedimentation, stratification

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Authors: Taweechai Nuntawisuttiwong, Natasha Dejdumrong

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Geometric modeling plays an important role in the constructions and manufacturing of curve, surface and solid modeling. Their algorithms are critically important not only in the automobile, ship and aircraft manufacturing business, but are also absolutely necessary in a wide variety of modern applications, e.g., robotics, optimization, computer vision, data analytics and visualization. The calculation and display of geometric objects can be accomplished by these six techniques: Polynomial basis, Recursive, Iterative, Coefficient matrix, Polar form approach and Pyramidal algorithms. In this research, the coefficient matrix (simply called monomial form approach) will be used to model polynomial rectangular patches, i.e., Said-Ball, Wang-Ball, DP, Dejdumrong and NB1 surfaces. Some examples of the monomial forms for these surface modeling are illustrated in many aspects, e.g., construction, derivatives, model transformation, degree elevation and degress reduction.

Keywords: monomial forms, rectangular surfaces, CAGD curves, monomial matrix applications

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Authors: Yann Jean Tan, Hui Meng Er, Choy Sin Lee, Shew Fung Wong, Wen Huei Lim

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Griseofulvin is a long standing fungistatic agent against dermatophytosis. Nevertheless, it has several drawbacks such as poor and highly variable bio availability, long duration of treatment, systemic side effects and drug interactions. Targeted treatment for the superficial skin infection, dermatophytosis via topical route could be beneficial. Nevertheless, griseofulvin is only available in the form of oral preparation. Hence, it generates interest in developing a topical formulation for griseofulvin, by using lipid nano particle as the vehicle. Lipid nanoparticle is a submicron colloidal carrier with a core that is solid in nature (lipid). It has combined advantages of various traditional carriers and is a promising vehicle for topical delivery. The griseofulvin loaded lipid nano particles produced using high pressure homogenization method were characterized and investigated for its skin targeting effect in vitro. It has a mean particle size of 179.8±4.9 nm with polydispersity index of 0.306±0.011. Besides, it showed higher skin permeation and better skin targeting effect compared to the griseofulvin suspension.

Keywords: lipid nanoparticles, griseofulvin, topical, dermatophytosis

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Authors: Akram Boubakri, Fethi Choubani, Tan Hoa Vuong, Jacques David

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Nowadays, microwave hyperthermia is considered as an effective treatment for the malignant tumors. This microwave treatment which comes to substitute the chemotherapy and the surgical intervention enables an in-depth tumor heating without causing any diseases to the sane tissue. This technique requires a high precision system, in order to effectively concentrate the heating just in the tumor, without heating any surrounding healthy tissue. In the hyperthermia treatment, the temperature in cancerous area is typically raised up to over 42◦C and maintained for one hour in order to destroy the tumor sufficiently, whilst in the surrounding healthy tissues, the temperature is maintained below 42◦C to avoid any damage. Metamaterial lenses are widely used in medical applications like microwave hyperthermia treatment. They enabled a subdiffraction resolution thanks to the amplification of the evanescent waves and they can focus electromagnetic waves from a point source to a point image. Metasurfaces have been used to built metamaterial lenses. The main mechanical advantages of those structures over three dimensional material structures are ease of fabrication and a smaller required volume. Here in this work, we proposed a metasurface based lens operating at the frequency of 6 GHz and designed for microwave hyperthermia. This lens was applied and showed good results in focusing and heating the tumor inside a breast tissue with an increased and maintained temperature above 42°C. The tumor was placed in the focal distance of the lens so that only the tumor tissue will be heated. Finally, in this work, it has been shown that the hyperthermia area within the tissue can be carefully adjusted by moving the antennas or by changing the thickness of the metamaterial lenses based on the tumor position. Even though the simulations performed in this work have taken into account an ideal case, some real characteristics can be considered to improve the obtained results in a realistic model.

Keywords: focusing, hyperthermia, metamaterial lenses, metasurface, microwave treatment

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Authors: Theophilus Adjirackor, Frederic Sam, Irene Opoku-Ntim, David Okoh Kpeglo, Prince K. Gyekye, Frank K. Quashie, Kofi Ofori

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Indoor radon concentrations were collected monthly over a period of one year in 10 different levels in an underground goldmine, and the data was analyzed using a four-moving average time series to determine the relationship between the depths of the underground mine and the indoor radon concentration. The detectors were installed in batches within four quarters. The measurements were carried out using LR115 solid-state nuclear track detectors. Statistical models are applied in the prediction and analysis of the radon concentration at various depths. The time series model predicted a positive relationship between the depth of the underground mine and the indoor radon concentration. Thus, elevated radon concentrations are expected at deeper levels of the underground mine, but the relationship was insignificant at the 5% level of significance with a negative adjusted R2 (R2 = – 0.021) due to an appropriate engineering and adequate ventilation rate in the underground mine.

Keywords: LR115, radon concentration, rime series, underground goldmine

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Authors: Aikaterini-Melpomeni Papadopoulou, Kyriaki Apergi, Margarita-Vasiliki Panagopoulou, Olga Malisova

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Introduction: Adequate hydration is a vital factor that enhances concentration, memory, and decision-making abilities throughout the workday. Various factors may affect hydration status in workplace settings, and many variables, such as age, gender and activity level affect hydration needs. Employees frequently overlook their hydration needs amid busy schedules and demanding tasks, leading to dehydration that can negatively affect cognitive function, productivity, and overall well-being In addition, dietary habits, including fluid intake and food choices, can either support or hinder optimal hydration. However, factors that affect hydration balance among workers in Greece have not been adequately studied. Objective: This study aims to evaluate the hydration status of the working population in Greece and investigate the various factors that impact hydration status in workplace settings, considering demographic, dietary, and occupational influences in a Greek sample of employees from diverse working environments Materials & Methods: The study included 212 participants (46.2% women) from the working population in Greece. Water intake from both solid and liquid foods was recorded using a semi-quantified drinking frequency questionnaire the validated Water Balance Questionnaire was used to evaluate hydration status. The calculation of water from solid and liquid foods was based on data from the USDA National Nutrient Database. Water balance was calculated subtracting the total fluid loss from the total fluid intake in the body. Furthermore, the questionnaire including additional questions on drinking habits and work-related factors.volunteers answered questions of different categories such as a) demographic socio-economic b) work style characteristics c) health, d) physical activity, e) food and fluid intake, f) fluid excretion and g) trends on fluid and water intake. Individual and multivariate regression analyses were performed to assess the relationships between demographic, work-related factors, and hydration balance. Results: Analysis showed that demographic factors like gender, age, and BMI, as well as certain work-related factors, had a weak and statistically non-significant effect on hydration balance. However, the use of a bottle or water container during work hours (b = 944.93, p < 0.001) and engaging in intense physical activity outside of work (b = -226.28, p < 0.001) were found to have a significant impact. Additionally, the consumption of beverages other than water (b = -416.14, p = 0.059) could negatively impact hydration balance. On average, the total consumption of the sample is 3410 ml of water daily, with men consuming approximately 440 ml / day more water (3470 ml / day) compared to women (3030 ml / day) with this difference also being statistically significant. Finally, the water balance, defined as the difference between water intake and water excretion, was found to be negative on average for the entire sample. Conclusions: This study is among the first to explore hydration status within the Greek working population. Findings indicate that awareness of adequate hydration and individual actions, such as using a water bottle during work, may influence hydration balance.

Keywords: hydration, working population, water balance, workplace behavior

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Authors: Mefteh Bouhalleb

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With the recent progress in nanotechnology, nanofluids have excellent potentiality in many modern engineering processes, particularly for solar systems such as concentrated solar power plants (CSP). In this context, a numerical simulation is performed to investigate laminar natural convection nanofluids in an inclined rectangular enclosure. Mass conservation, momentum, and energy equations are numerically solved by the finite volume element method using the SIMPLER algorithm for pressure-velocity coupling. In this work, we tested the acting factors on the system response time, such as the particle volume fraction of nanoparticles, particle material, particle size, an inclination angle of enclosure and Rayleigh number. The results show that the diameter of solid particles and Rayleigh number plays an important role in the system response time. The orientation angle of the cavity affects the system response time. A phenomenon of hysteresis appears when the system does not return to its initial state.

Keywords: nanofluid, nanoparticles, heat transfer, time response

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Authors: Liliana Crăc, Nicolae Giorgi, Gheorghe Fometescu

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In Romania, billions of tonnes of wastes are generated yearly, an important amount being stored within industrial dumps that covers high soil areas and affects the environment quality, especially of ground and surface waters. Landfill represents in Romania the most important way for wastes removal, over 75% being generated every year, the costs with the dumps construction being considerable. In most of the cases, the wastes generated mainly by the energy industry, oil exploitation and metallurgy, are still considered wastes with NO-use, and their removal and neutralization represent for transport, handling and storing, high non-productive expenses which raise the cost of the useful products obtained. The paper presents a recycling idea of three types of wastes in order to use them for building materials manufacturing, by promoting ECOWASTES LIFE+ project, whose aim is to demonstrate that the recycling of waste from energy industry (coal combustion waste), petroleum extraction (drilling mud) and metallurgy (steelmaking slag) is technically feasible.

Keywords: fly ash, drilled solid wastes, metallurgical slag, recycling, building materials

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Authors: Guoheng Liu, Zhilong Huang

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For more than the past ten years, oil and gas production from marine shale such as the Barnett shale. In addition, in recent years, major breakthroughs have also been made in lacustrine shale gas exploration, such as the Yanchang Formation of the Ordos Basin in China. Lucaogou Formation shale, which is also lacustrine shale, has also yielded a high production in recent years, for wells such as M1, M6, and ML2, yielding a daily oil production of 5.6 tons, 37.4 tons and 13.56 tons, respectively. Lithologic identification and classification of reservoirs are the base and keys to oil and gas exploration. Lithology and lithofacies obviously control the distribution of oil and gas in lithological reservoirs, so it is of great significance to describe characteristics of lithology and lithofacies of reservoirs finely. Lithofacies is an intrinsic property of rock formed under certain conditions of sedimentation. Fine-grained sedimentary rocks such as shale formed under different sedimentary conditions display great particularity and distinctiveness. Hence, to our best knowledge, no constant and unified criteria and methods exist for fine-grained sedimentary rocks regarding lithofacies definition and classification. Consequently, multi-parameters and multi-disciplines are necessary. A series of qualitative descriptions and quantitative analysis were used to figure out the lithofacies characteristics and its effect on oil accumulation of Lucaogou formation fine-grained sedimentary rocks in Santanghu basin. The qualitative description includes core description, petrographic thin section observation, fluorescent thin-section observation, cathode luminescence observation and scanning electron microscope observation. The quantitative analyses include X-ray diffraction, total organic content analysis, ROCK-EVAL.II Methodology, soxhlet extraction, porosity and permeability analysis and oil saturation analysis. Three types of lithofacies were mainly well-developed in this study area, which is organic-rich massive shale lithofacies, organic-rich laminated and cloddy hybrid sedimentary lithofacies and organic-lean massive carbonate lithofacies. Organic-rich massive shale lithofacies mainly include massive shale and tuffaceous shale, of which quartz and clay minerals are the major components. Organic-rich laminated and cloddy hybrid sedimentary lithofacies contain lamina and cloddy structure. Rocks from this lithofacies chiefly consist of dolomite and quartz. Organic-lean massive carbonate lithofacies mainly contains massive bedding fine-grained carbonate rocks, of which fine-grained dolomite accounts for the main part. Organic-rich massive shale lithofacies contain the highest content of free hydrocarbon and solid organic matter. Moreover, more pores were developed in organic-rich massive shale lithofacies. Organic-lean massive carbonate lithofacies contain the lowest content solid organic matter and develop the least amount of pores. Organic-rich laminated and cloddy hybrid sedimentary lithofacies develop the largest number of cracks and fractures. To sum up, organic-rich massive shale lithofacies is the most favorable type of lithofacies. Organic-lean massive carbonate lithofacies is impossible for large scale oil accumulation.

Keywords: lithofacies classification, tuffaceous shale, oil enrichment, Lucaogou formation

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Authors: Joshna Rani S., Ahmadi Banu

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Artificial Intelligence (AI) has a significant task to carry out in the medical care contributions of things to come. As AI, it is the essential capacity behind the advancement of accuracy medication, generally consented to be a painfully required development in care. Albeit early endeavors at giving analysis and treatment proposals have demonstrated testing, we anticipate that AI will at last dominate that area too. Given the quick propels in AI for imaging examination, it appears to be likely that most radiology, what's more, pathology pictures will be inspected eventually by a machine. Discourse and text acknowledgment are now utilized for assignments like patient correspondence and catch of clinical notes, and their utilization will increment. The best test to AI in these medical services areas isn't regardless of whether the innovations will be sufficiently skilled to be valuable, but instead guaranteeing their appropriation in day by day clinical practice. For far reaching selection to happen, AI frameworks should be affirmed by controllers, coordinated with EHR frameworks, normalized to an adequate degree that comparative items work likewise, instructed to clinicians, paid for by open or private payer associations, and refreshed over the long haul in the field. These difficulties will, at last, be survived, yet they will take any longer to do as such than it will take for the actual innovations to develop. Therefore, we hope to see restricted utilization of AI in clinical practice inside 5 years and more broad use inside 10 years. It likewise appears to be progressively evident that AI frameworks won't supplant human clinicians for a huge scope, yet rather will increase their endeavors to really focus on patients. Over the long haul, human clinicians may advance toward errands and work plans that draw on remarkably human abilities like sympathy, influence, and higher perspective mix. Maybe the lone medical services suppliers who will chance their professions over the long run might be the individuals who will not work close by AI

Keywords: artificial intellogence, health care, breast cancer, AI applications

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Authors: Ivana Hrebickova, Maria Sevcikova, Romana Slamberova

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The present study was aimed at evaluation of cognitive changes following scheduled neonatal methamphetamine exposure in combination with long-term exposure in adulthood of female Wistar rats. Pregnant mothers were divided into two groups: group with indirect exposure (methamphetamine in dose 5 mg/ml/kg, saline in dose 1 ml/kg) during early lactation period (postnatal day 1–11) - progeny of these mothers were exposed to the effects of methamphetamine or saline indirectly via the breast milk; and the second group with direct exposure – all mothers were left intact for the entire lactation period, while progeny was treated with methamphetamine (5 mg/ml/kg) by injection or the control group, which was received needle pick (shame, not saline) at the same time each day of period of application (postnatal day 1–11). Learning ability and memory consolidation were tested in the Morris Water Maze, which consisted of three types of tests: ‘Place Navigation Test ‘; ‘Probe Test ‘; and ‘Memory Recall Test ‘. Adult female progeny were injected daily, after completion last trial with saline or methamphetamine (1 mg/ml/kg). We compared the effects of indirect/direct neonatal methamphetamine exposure and adult methamphetamine treatment on cognitive function of female rats. Statistical analyses showed that neonatal methamphetamine exposure worsened spatial learning and ability to remember the position of the platform. The present study demonstrated that direct methamphetamine exposure has more significant impact on process of learning and memory than indirect exposure. Analyses of search strategies (thigmotaxis, scanning) used by females during the Place Navigation Test and Memory Recall Test confirm all these results.

Keywords: methamphetamine, Morris water maze, neonatal exposure, strategies, Wistar rats

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Authors: Mina Kargozari, Isabel Revilla Martin, Ángel A. Carbonell-Barrachina, Antoni Szumny

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The profiles of volatile compounds of differently formulated sausages including CH (camel meat-hump), CB (camel meat-beef fat), BH (beef-hump) and BB (beef-beef fat) were analyzed by gas chromatography/mass spectrometry (GC-MS) using a solid phase micro-extraction (SPME) in order to investigate the role of meat and fat type in aroma compounds release. A total of 47 compounds identified, were consisted of 3 acids, 1 ester, 3 alcohols, 7 aldehydes, 5 sulphur compounds, and 27 terpenes. The significant differences were observed in the aroma compounds among four batches. The CH sucuk samples containing the highest (p<0.05) fat amount among the others showed higher amounts of volatiles in consequence. The sausages prepared with hump showed higher amounts of aldehydes and lower amounts of terpenes compared to the sausages made with beef fat (p<0.05). It seemed that meat type had an inconsiderable effect on the volatile profile of the sausages.

Keywords: aromatic compounds, camel meat, hump, SPME

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Authors: R. Benakcha, M. Omari

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Powders of La1-xMgxAlO3 (0 ≤ x ≤ 5) oxides, with large surface areas were synthesized by sol-gel process, utilizing citric acid. Heating of a mixed solution of CA, EtOH, and nitrates of lanthanum, aluminium and magnesium at 70°C gave transparent gel without any precipitation. The formation of pure perovskite La1-xMgxAlO3, occurred when the precursor was heat-treated at 800°C for 6 h. No X-ray diffraction evidence for the presence of crystalline impurities was obtained. The La1-xMgxAlO3 powders prepared by the sol-gel method have a considerably large surface area in the range of 12.9–20 m^2.g^-1 when compared with 0.3 m^2.g^-1 for the conventional solid-state reaction of LaAlO3. The structural characteristics were examined by means of conventional techniques namely X-ray diffraction, infrared spectroscopy, thermogravimetry and differential thermal (TG-DTA) and specific surface SBET. Pore diameters and crystallite sizes are in the 8.8-11.28 nm and 25.4-30.5 nm ranges, respectively. The sol-gel method is a simple technique that has several advantages. In addition to that of not requiring high temperatures, it has the potential to synthesize many kinds of mixed oxides and obtain other materials homogeneous and large purities. It also allows formatting a variety of materials: very fine powders, fibers and films.

Keywords: aluminate, lanthan, perovskite, sol-gel

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Authors: T. Zitoun, M. Bouhadef

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When a partially or completely immersed solid moves in a liquid such as water, it undergoes a force called hydrodynamic drag. Reducing this force has always been the objective of hydrodynamic engineers to make water slide better on submerged bodies. This paper deals with the examination of the different terms composing the analytical solution of the flow over an obstacle embedded at the bottom of a hydraulic channel. We have chosen to use a linear method to study a two-dimensional flow over an obstacle, in order to understand the evolution of the drag. We set the following assumptions: incompressible inviscid fluid, irrotational flow, low obstacle height compared to the water height. Those assumptions allow overcoming the difficulties associated with modelling these waves. We will mathematically formulate the equations that allow the determination of the stream function, and then the free surface equation. A similar method is used to determine the exact analytical solution for an obstacle in the shape of a sinusoidal arch.

Keywords: analytical solution, free-surface wave, hydraulic channel, inviscid fluid

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Authors: Mohammad Kousara, Françoise Dumas, Rama Ibrahim, Joëlle Dubois, Joël Raingeaud

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Suberosanes are a small group of marine natural sesquiterpenes discovered since 1996 by Boyd, Sheu and Qi from three gorgonians. Their skeleton was previously found in quadranes produced by the terrestrial fungus Aspergillus terreus. Up to date, eleven suberosanes are described from which (-)-suberosanone and (-)-suberosenol A are reaching the picomolar cytotoxicity level on human solid tumors cell lines. Due to their impressive cytotoxic properties and their limited availability, we undertook an asymmetric synthesis of the most active members of this family in order to get insight into their absolute configurations and their biological properties. The challenge of their synthesis is the regio- and stereoselective elaboration of the compact bridged tricyclic skeleton with up to five all adjacent asymmetric centers, including a central quaternary carbon one. Our strategy is based on an aza-ene-synthesis key step which is regio-and stereo-controlled by the choice of a chiral amine enantiomer. it approach is concise and flexible, the enantiopur ABC tricyclic intermediate that have been synthesized being the common precursor of suberosanes.

Keywords: suberosanes, asymmetric synthesis, sesquiterpenes, quadranes

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Authors: M. E. Semenov, U. Zh. Mirzakimov, A. S. Stoporev, R. S. Pavelev, M. A. Varfolomeev

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Gas hydrates are host-guest compounds. Guest molecules can be low molecular weight components of associated petroleum gas (C1-C4 hydrocarbons), carbon dioxide, hydrogen sulfide, nitrogen. Gas hydrates have a number of unique properties that make them interesting from a technological point of view, for example, for storing hydrocarbon gases in solid form under moderate thermobaric conditions. Currently, the possibility of storing and transporting hydrocarbon gases in the form of solid hydrate is being actively explored throughout the world. The hydrate form of gas has a number of advantages, including a significant gas content in the hydrate, relative safety and environmental friendliness of the process. Recently, new developments have been proposed that seek to reduce the number of steps to obtain the finished hydrate, for example, using a pressing device/screw inside the reactor. However, the energy consumption required for the hydrate formation process remains a challenge. Thus, the goal of the current work is to study the patterns and mechanisms of the hydrate formation process using small additions of hydrate formation promoters under static conditions. The study of these aspects will help solve the problem of accelerated production of gas hydrates with minimal energy consumption. New compounds have been developed at Kazan Federal University that can accelerate the formation of methane hydrate with a small amount of promoter in water, not exceeding 0.1% by weight. These promoters were synthesized based on available natural compounds and showed high efficiency in accelerating the growth of methane hydrate. To test the influence of promoters on the process of hydrate formation, standard experiments are carried out under dynamic conditions with stirring. During such experiments, the time at which hydrate formation begins (induction period), the temperature at which formation begins (supercooling), the rate of hydrate formation, and the degree of conversion of water to hydrate are assessed. This approach helps to determine the most effective compound in comparative experiments with different promoters and select their optimal concentration. These experimental studies made it possible to study the features of the formation of associated petroleum gas hydrate from promoter solutions under static conditions. Phase transformations were studied using high-pressure micro-differential scanning calorimetry under various experimental conditions. Visual studies of the growth mode of methane hydrate depending on the type of promoter were also carried out. The work is an extension of the methodology for studying the effect of promoters on the process of associated petroleum gas hydrate formation in order to identify new ways to accelerate the formation of gas hydrates without the use of mixing. This work presents the results of a study of the process of associated petroleum gas hydrate formation using high-pressure differential scanning micro-calorimetry, visual investigation, gas chromatography, autoclave study, and stability data. It was found that the synthesized compounds multiply the conversion of water into hydrate under static conditions up to 96% due to a change in the growth mechanism of associated petroleum gas hydrate. This work was carried out in the framework of the program Priority-2030.

Keywords: gas hydrate, gas storage, promotor, associated petroleum gas

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Authors: L. Nouri Taiba, Y. Bouhamidi, F. Kaouah, Z. Bendjama, M. Trari

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In the present study, an ecofriendly biocomposite namely calcium alginate immobilized Ammi Visnaga (Khella) extraction waste (SWAV/CA) was prepared by electrostatic extrusion method and used on the cadmium biosorption from aqueous phase with and without the assistance of ultrasound in batch conditions. The influence of low frequency ultrasound (37 and 80 KHz) on the cadmium biosorption kinetics was studied. The obtained results show that the ultrasonic irradiation significantly enhances and improves the efficiency of the cadmium removal. The Pseudo first order, Pseudo-second-order, Intraparticle diffusion, and Elovich models were evaluated using the non-linear curve fitting analysis method. Modeling of kinetic results shows that biosorption process is best described by the pseudo-second order and Elovich, in both the absence and presence of ultrasound.

Keywords: biocomposite, biosorption, cadmium, non-linear analysis, ultrasound

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Authors: Rosana Goncalves Das Dores, Maira Fonseca, Fernando Finger, Vicente Casali

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Equisetum hyemale L. (horsetail, Equisetaceae) is a medicinal plant used and commercialized in simple paper bags or non-ecological packaging in Brazil. The aim of this work was to evaluate the relation between the bioactive compounds of horsetail stems stored in ecological packages (multi-ply paper sacks) at room temperature. Stems in primary and secondary stage were harvested from an organic estate, on December 2016, selected, measured (length from the soil to the apex (cm), stem diameter at ground level (DGL mm) and breast height (DBH mm) and cut into 10 cm. For the post-harvest evaluations, stems were stored in multi-ply paper sacks and evaluated daily to the respiratory rate, fresh weight loss, pH, presence of fungi / mold, phenolic compounds and antioxidant activity. The analyses were done with four replicates, over time (regression) and compared at 1% significance (Tukey test). The measured heights were 103.7 cm and 143.5 cm, DGL was 2.5mm and 8.4 mm and DBH of 2.59 and 6.15 mm, respectively for primary and secondary stems stage. At both stages of development, in storage in multi-ply paper sacks, the greatest mass loss occurred at 48 h, decaying up to 120 hours, stabilizing at 192 hours. The peak respiratory rate increase occurred in 24 hours, coinciding with a change in pH (temperature and mean humidity was 23.5°C and 55%). No fungi or mold were detected, however, there was loss of color of the stems. The average yields of ethanolic extracts were equivalent (approximately 30%). Phenolic compounds and antioxidant activity were higher in secondary stems stage in up to 120 hours (AATt0 = 20%, AATt30 = 45%), decreasing at the end of the experiment (240 hours). The packaging used allows the commercialization of fresh stems of Equisetum for up to five days.

Keywords: paper sacks, phenolic content, antioxidant activity, medicinal plants, post-harvest, ecological packages, Equisetum

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Authors: Nastaran Soltani

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Heavy metals such as Mercury are toxic elements that enter the environment through different ways and endanger the environment, plants, animals, and humans’ health. Microbial activities reduce the amount of heavy metals. Therefore, an effective mechanism to eliminate heavy metals in the nature and factory slops, is using bacteria living in polluted areas. Karun River in Khuzestan Province in Iran has been always polluted by heavy metals as it is located among different industries in the region. This study was performed based on the data from sampling water and sediments of four stations across the river during the four seasons of a year. The isolation of resistant bacteria was performed through enrichment and direct cultivation in a solid medium containing mercury. Various bacteria such as Pseudomonas sp., Serratia Marcescens, and E.coli were identified as mercury-resistant bacteria. The power of these bacteria to remove mercury varied from 28% to 86%, with strongest power belonging to Pseudomonas sp. isolated in spring making a good candidate to be used for mercury biological removal from factory slops.

Keywords: bacteria, Karun River, mercury, biological removal, mercury-resistant

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Authors: Orathai Pornsunthorntawee, Wareerom Polrut, Nopphawan Phonthammachai

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In the present work, the effects of additives, including contents of the added antioxidants and type of the selected metallic stearates (either calcium stearate (CaSt) or zinc stearate (ZnSt)), on the thermal stabilities of carbon black (CB)/high density polyethylene (HDPE) compounds were studied. The results showed that the AO contents played a key role in the thermal stabilities of the CB/HDPE compounds—the higher the AO content, the higher the thermal stabilities. Although the CaSt-containing compounds were slightly superior to those with ZnSt in terms of the thermal stabilities, the remaining solid residue of CaSt after heated to the temperature of 600 °C (mainly calcium carbonate (CaCO3) as characterized by the X-ray diffraction (XRD) technique) seemed to catalyze the decomposition of CB in the HDPE-based compounds. Hence, the quantification of CB in the CaSt-containing compounds with a muffle furnace gave an inaccurate CB content—much lower than actual value. However, this phenomenon was negligible in the ZnSt-containing system.

Keywords: antioxidant, stearate, carbon black, polyethylene

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Authors: Abdur Rosyid, Mohamed El-Madany, Mohanad Alata

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Due to simplicity and low cost, rotordynamic system is often modeled by using lumped parameters. Recently, finite elements have been used to model rotordynamic system as it offers higher accuracy. However, it involves high degrees of freedom. In some applications such as control design, this requires higher cost. For this reason, various model reduction methods have been proposed. This work demonstrates the quality of model reduction of rotor-bearing-support system through substructuring. The quality of the model reduction is evaluated by comparing some first natural frequencies, modal damping ratio, critical speeds and response of both the full system and the reduced system. The simulation shows that the substructuring is proven adequate to reduce finite element rotor model in the frequency range of interest as long as the numbers and the locations of master nodes are determined appropriately. However, the reduction is less accurate in an unstable or nearly-unstable system.

Keywords: rotordynamic, finite element model, timoshenko beam, 3D solid elements, Guyan reduction method

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Authors: Esra Öztürk, Erkul Karacaoglu

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Pyrochlores, having compounds of the general formula, A2B2O7 (A and B are metals/rare earths) are important class of materials thanks to having technological applications like in luminescence, ionic conductivity, nuclear waste immobilization etc. The rare earths included pyrochlore compounds have also potential photoluminescence characteristics. In this context, Er3+-activated Lu2Ti2O7 pyrochlore was chosen and synthesized through a high-temperature solid-state reaction route that was sintered under the open atmosphere in this study. The optimal reaction conditions to obtain expected single phase system, the thermal analysis (DTA/TG) were carried out. The X-ray powder diffraction (XRD) was used to determine phase properties of the sample. The photoluminescence (PL) results were done to obtain excitation, emission and decay time properties by a PL spectrometer under room temperature. According to the PL, there are excitation bands at 352 nm, 388 nm, 423 nm and 453 nm that are due to 4I15/2 → 2G7/2, 4I15/2 → 4G11/2 and 4I15/2 → 4F5/2 transitions of Er3+ ions, respectively. The emission bands are placed at 582 nm, 677 nm and 762 nm that are associated with 2H11/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2, 4I9/2 → 4I15/2 transitions of Er3+ ions, respectively.

Keywords: Er3+, Lu2Ti2O7, photoluminescence, pyrochlore, rare-earths

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Authors: Francielo Vendruscolo

Abstract:

This review summarizes the potential of starch agroindustrial residues as substrate for biohydrogen production. Types of potential starch agroindustrial residues, recent developments and bio-processing conditions for biohydrogen production will be discussed. Biohydrogen is a clean energy source with great potential to be an alternative fuel, because it releases energy explosively in heat engines or generates electricity in fuel cells producing water as only by-product. Anaerobic hydrogen fermentation or dark fermentation seems to be more favorable, since hydrogen is yielded at high rates and various organic waste enriched with carbohydrates as substrate result in low cost for hydrogen production. Abundant biomass from various industries could be source for biohydrogen production where combination of waste treatment and energy production would be an advantage. Carbohydrate-rich nitrogen-deficient solid wastes such as starch residues can be used for hydrogen production by using suitable bioprocess technologies. Alternatively, converting biomass into gaseous fuels, such as biohydrogen is possibly the most efficient way to use these agroindustrial residues.

Keywords: biofuel, dark fermentation, starch residues, food waste

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Authors: Roopam Gaur, K. Chandramani Singh, Radhapiyari Laishram

Abstract:

In order to produce lead free piezoceramics with optimum piezoelectric and dielectric properties, KNN modified with Li+ (as an A site dopant) and Sb5+ (as a B site dopant) (K0.49Na0.49Li0.02) (Nb0.96Sb0.04) O3 (referred as KNLNS in this paper) have been synthesized using solid state reaction method and conventional sintering technique. The ceramics were sintered in the narrow range of 10500C-10900C for 2-3 hours to get precise information about sintering parameters. Detailed study of dependence of microstructural, dielectric and piezoelectric properties on sintering conditions was then carried out. The study suggests that the volatility of the highly hygroscopic KNN ceramics is not only sensitive to sintering temperatures but also to sintering durations. By merely reducing the sintering duration for a given sintering temperature we saw an increase in the density of the samples which was supported by the increase in dielectric constants of the ceramics. And since density directly or indirectly affects almost all the associated properties, other dielectric and piezoelectric properties were also enhanced as we approached towards the most suitable sintering temperature and duration combination.

Keywords: piezoelectric, dielectric, Li, Sb, KNN, conventional sintering

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Authors: Yusuf Ziya Halefoğlu

Abstract:

Phosphorescence, classically, excitation effects (radiation, electron beam, electric field, temperature, etc.) is the name given after the elimination of materials that glow in the visible region. This event continues to glow after the elimination of the effect of excitation is called phosphorescence. In this study were synthesized by the method of the combustion lanthanide doped alkaline earth aluminates. High temperature and long reaction time required and the sol-gel method of combustion according to the methods of solid state synthesis temperature lower than the short reaction time, a small particle size, convenience, and is superior in terms of being secured. Their microstructures and its effect on the photoluminescence properties were studied. Phosphorescence is derived in the dark when produced materials are held in sunlight or under ultraviolet light typically at 365-520 nm wavelength range. In this study, the optimal ratio of rare earth elements, in terms of brightness and glow duration was examined by SEM, XRD and photoluminescence analysis.

Keywords: persistence luminescence, phosphorescence, trap depth, combustion method

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Authors: Anil P. Dewani, Alok S. Tripathi, Anil V. Chandewar

Abstract:

Present manuscript reports the development and validation of a quantitative high performance liquid chromatography method for the pharmacokinetic evaluation of Glimepiride (GLM) and Ilaprazole (ILA) in rat plasma. The plasma samples were involved with Solid phase extraction process (SPE). The analytes were resolved on a Phenomenex C18 column (4.6 mm× 250 mm; 5 µm particle size) using a isocratic elution mode comprising methanol:water (80:20 % v/v) with pH of water modified to 3 using Formic acid, the total run time was 10 min at 225 nm as common wavelength, the flow rate throughout was 1ml/min. The method was validated over the concentration range from 10 to 600 ng/mL for GLM and ILA, in rat plasma. Metformin (MET) was used as Internal Standard. Validation data demonstrated the method to be selective, sensitive, accurate and precise. The limit of detection was 1.54 and 4.08 and limit of quantification was 5.15 and 13.62 for GLM and ILA respectively, the method demonstrated excellent linearity with correlation coefficients (r2) 0.999. The intra and inter-day precision (RSD%) values were < 2.0% for both ILA and GLM. The method was successfully applied in pharmacokinetic studies followed by oral administration in rats.

Keywords: pharmacokinetics, glimepiride, ilaprazole, HPLC, SPE

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Authors: Bello Yusuf Idi

Abstract:

The Gongola arm of the Upper Banue Trough, Northeastern Nigeria is predominantly covered by the outcrops of Limestone-bearing rocks in form of Sandstone with intercalation of carbonate clay, shale, basaltic, felsphatic and migmatide rocks at subpixel dimension. In this work, subpixel classification algorithm was used to classify the data acquired from landsat 7 Enhance Thematic Mapper (ETM+) satellite system with the aim of producing fractional distribution image for three most economically important solid minerals of the area: Limestone, Basalt and Migmatide. Linear Spectral Unmixing (LSU) algorithm was used to produce fractional distribution image of abundance of the three mineral resources within a 100Km2 portion of the area. The results show that the minerals occur at different proportion all over the area. The fractional map could therefore serve as a guide to the ongoing reconnaissance for the economic potentiality of the formation.

Keywords: linear spectral un-mixing, upper benue trough, gongola arm, geological engineering

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Authors: Jaswinder Kumar, Kulbir Singh Sandhu

Abstract:

Friction stir processing (FSP) is a solid-state surface processing technique. A single-pass FSP was performed on Aluminum alloy at combinations of different tool rotational speeds with cylindrical threaded pin profiled tool. The effect of these parameters on tribological properties was studied. The wear resistance is found to be increased from base metal to a single pass FSP sample. The results revealed that with an increase in tool rotational speed, the wear rate increases. The high heat generation causes matrix softening, which results in an increased wear rate; on the other hand, high heat generation leads to coarse grains, which also affected tribological properties. Furthermore, Microstructure results showed that FSPed alloy has a more refined grain structure as compare to the base material, which may be resulted in enhancement of hardness and resistance to wear in FSP.

Keywords: friction stir processing, aluminium alloy, microhardness, microstructure

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Authors: Ali A. Hashim Habib, Ahmed A. Abdel-Rehim

Abstract:

Assuredly, massive amounts of wastes that are not utilized and dumped in uncontrolled dumpsites will be one of the major sources of diseases, fires, and emissions. With easy steps and minimum effort, energy can be produced from these gases. The present work introduces an experimental and theoretical analysis to estimate the amount of landfill gas and the corresponding energy which can be produced based on actual Egyptian municipal wastes composition. Two models were utilized and compared, EPA (Environmental Protection Agency) model and CDM (Clean Development Mechanisms) model to estimate methane generation rates and total CH4 emissions based on a particular landfill. The results showed that for every ton of municipal waste, 140 m3 of landfill gas can be produced. About 800 kW of electricity for a minimum of 24 years can be generated form one million ton of municipal waste. A total amount of 549,025 ton of carbon emission can be avoided during these 24 years.

Keywords: energy from landfill gases, landfill biogas, methane emission, municipal solid waste, renewable energy sources

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