Search results for: alternative phase opposition disposition (APOD)

Authors: Neda Jamalimoghadam, Naval Heydari, Maliheh Abootalebi, Maryam Kasraeian, M. Emamghoreishi , Akbarzadeh Marzieh

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Background: The aim was to investigate the effect of aromatherapy using Citrus aurantium blossom essential oil on premenstrual syndrome in university students. Methods: In this double-blind clinical trial was controlled on 62 students from March 2016 to February 2017. The intervention with 0.5% of C. Aurantium blossom essential oil and control was inhalation of odorless sweet almond oil in the luteal phase of the menstrual cycle. The screening questionnaire (PSST) for PMSwas filled out before and also one and two months after the intervention. Results: Mean score of overall symptoms of PMS between the Bitter orange and control groups In the first (p < 0.003) and second months (p < 0.001) of the intervention was significant. Besides, decreased the mean score of psychological symptoms in the intervention group (p < 0.001), but on physical symptoms and social function were not significant (p > 0.05). Conclusion: The aromatherapy with Citrus aurantium blossom improved the symptoms of premenstrual syndrome.

Keywords: aromatherapy, Citrus Aurantium, premenstrual syndrome, oil, students

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Authors: José Leandro Melgar Néris, Claudinéia Brazil, Luciane Teresa Salvi, Isabel Cristina Damin

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The impact the climate change is not recent, the main variable in the hydrological cycle is the sequence and shortage of a drought, which has a significant impact on the socioeconomic, agricultural and environmental spheres. This study aims to characterize and quantify, based on precipitation climatic projections, the rainy and dry events in the region of the Uruguay River Basin, through the Standardized Precipitation Index (SPI). The database is the image that is part of the Intercomparison of Model Models, Phase 5 (CMIP5), which provides condition prediction models, organized according to the Representative Routes of Concentration (CPR). Compared to the normal set of climates in the Uruguay River Watershed through precipitation projections, seasonal precipitation increases for all proposed scenarios, with a low climate trend. From the data of this research, the idea is that this article can be used to support research and the responsible bodies can use it as a subsidy for mitigation measures in other hydrographic basins.

Keywords: climate change, climatic model, dry events, precipitation projections

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Authors: E.A. Kuchma

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Photodynamic therapy (PDT) is considered an alternative and minimally invasive cancer treatment modality compared to chemotherapy and radiation therapy. PDT includes three main components: a photosensitizer (PS), oxygen, and a light source. PS is injected into the patient's body and then selectively accumulates in the tumor. However, the light used in PDT (spectral range 400–700 nm) is limited to superficial lesions, and the light penetration depth does not exceed a few cm. The problem of PDT (poor visible light transmission) can be solved by using X-rays. The penetration depth of X-rays is ten times greater than that of visible light. Therefore, X-ray radiation easily penetrates through the tissues of the body. The aim of this work is to develop universal nanocomposites for X-ray photodynamic therapy of deep and superficial tumors using scintillation nanoparticles of gadolinium fluoride (GdF3), doped with Tb3+, coated with a biocompatible coating (PEG) and photosensitizer RB (Rose Bengal). PEG@GdF3:Tb3+(15%) – RB could be used as an effective X-ray, UV, and photoluminescent mediator to excite a photosensitizer for generating reactive oxygen species (ROS) to kill tumor cells via photodynamic therapy. GdF3 nanoparticles can also be used as contrast agents for computed tomography (CT) and magnetic resonance imaging (MRI).

Keywords: X-ray induced photodynamic therapy, scintillating nanoparticle, radiosensitizer, photosensitizer

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Authors: Raquel M. De sousa, Sofiane Labidi, Allan Kardec D. Barros, Alex O. Barradas Filho, Aldalea L. B. Marques

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Several parameters are established in order to measure biodiesel quality. One of them is the iodine value, which is an important parameter that measures the total unsaturation within a mixture of fatty acids. Limitation of unsaturated fatty acids is necessary since warming of a higher quantity of these ones ends in either formation of deposits inside the motor or damage of lubricant. Determination of iodine value by official procedure tends to be very laborious, with high costs and toxicity of the reagents, this study uses an artificial neural network (ANN) in order to predict the iodine value property as an alternative to these problems. The methodology of development of networks used 13 esters of fatty acids in the input with convergence algorithms of backpropagation type were optimized in order to get an architecture of prediction of iodine value. This study allowed us to demonstrate the neural networks’ ability to learn the correlation between biodiesel quality properties, in this case iodine value, and the molecular structures that make it up. The model developed in the study reached a correlation coefficient (R) of 0.99 for both network validation and network simulation, with Levenberg-Maquardt algorithm.

Keywords: artificial neural networks, biodiesel, iodine value, prediction

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Authors: Sidique Gawusu, Xiaobing Zhang

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Turbulence models play a significant role in all computational fluid dynamics based modelling approaches. There is, however, no general turbulence model suitable for all flow scenarios. Therefore, a successful numerical modelling approach is only achievable if a more appropriate closure model is used. This paper evaluates different turbulence models in numerical modelling of oil-water flow within the Eulerian-Eulerian approach. A comparison among the obtained numerical results and published benchmark data showed reasonable agreement. The domain was meshed using structured mesh, and grid test was performed to ascertain grid independence. The evaluation of the models was made through analysis of velocity and pressure profiles across the domain. The models were tested for their suitability to accurately obtain a scalable and precise numerical experience. As a result, it is found that all the models except Standard-ω provide comparable results. The study also revealed new insights on flow in porous media, specifically oil reservoirs.

Keywords: turbulence modelling, simulation, multi-phase flows, water-flooding, heavy oil

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Authors: Mansilla, Juan Camilo

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According to many studies, public space in the cities of Global South is constantly morcellated and captured by a multiplicity of actors in a permanent struggle for power. This imposed public space restricts the access to services and political actions to many inhabitants. The author has conducted several focus group sessions using video in a reflective mode with low-income communities in Medellín, Colombia in order to study how people in this city are shift from a physical public space to a hybrid public space shaped by internet. Beyond the fragmented city and the violent urban context manifested by participants, these activities have highlighted how the access to the city is currently going through a dialectic movement between the physical and the digital space. The purpose of this article is to make explicit the link between this hybrid public space and the boundaries of exclusion in the city. Urban marginality is closely related with the idea of access and space. Low-income communities in Medellín assume the digital realm like a “not controlled space” of resistance, where alternative ways of expression like hip hop movement, graffiti, dance, video and virtual communities produce effective changes in the physical realm.

Keywords: access to the city, hybrid public space, low-income communities, Medellín, urban marginality

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Authors: Maria Alekxandra B. Sison, Reginald C. Mallare, Joseph Albert M. Mendoza

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Ammonia (NH₃) is the alternative carbon-free fuel of the future for its promising applications. Investigations on NH₃-fuel blends recommend using hydrogen (H₂) to increase the heating value of NH3, promote combustion performance, and improve NOx efflux mitigation. To further examine the effects of this concept, the study analyzed the combustion performance, in terms of turbulence, combustion efficiency (CE), and NOx emissions, of NH3/fuel with variations of combustor diameter ratio, H2 fuel mole fraction, and fuel mass flow rate (ṁ). The simulations were performed using Computational Fluid Dynamics (CFD) modeling to represent a non-premixed (NP) and partially premixed (PP) combustion under a two-dimensional ultra-low NOx Rich-Burn, Quick-Quench, Lean-Burn (RQL) combustor. Governed by the Detached Eddy Simulation model, it was found that the diameter ratio greatly affects the turbulence in PP and NP mode, whereas ṁ in PP should be prioritized when increasing CE. The NOx emission is minimal during PP combustion, but NP combustion suggested modifying ṁ to achieve higher CE and Reynolds number without sacrificing the NO generation from the reaction.

Keywords: combustion efficiency, turbulence, dual-stage combustor, NOx emission

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Authors: Kelvin Datonye Bob-Manuel

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The shipping industry has begun to seriously look at ways of reducing fossil fuel consumption so that current reserves can last longer and operate their ships in a more environmentally friendly way. The concept of Green Shipping or Sustainable Shipping with the use of alternative fuels is now becoming an important issue for ship owners, shipping lines and ship builders globally. This paper provides a critical review of the performance of biodiesel and natural gas-fuelled diesel engines for shipboard application. The emission reduction technique included the use of either neat or emulsified rapeseed methyl ester (RME) for pilot ignition and the emission of NOx, CO2 and SOx were measured at engine speed range of 500 - 1500 r/min. The NOx concentrations were compared with the regulated IMO MARPOL73/78, Annex VI, Tiers I, II, III and United States Environmental Protection Agency (US-EPA) standard. All NOx emissions met Tier I and II levels and the EPA standard for the minimum specification of category 1 engines at higher speed but none met the MARPOL Tier III limit which is for designated Emission Control Areas (ECAs). No trace of soot and SOx emission were observed.

Keywords: dual-fuel, biodiesel, natural gas, NOx, SOx, MARPOL 73/78 Annex VI. USEPA Tier 3, EURO V &VI

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Authors: Jonida Canaj

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A simple method of extraction and determination of fifteen priority polycyclic aromatic hydrocarbons (PAHs) from drinking water using high performance liquid chromatography (HPLC) has been validated with limits of detection (LOD) and limits of quantification (LOQ), method recovery and reproducibility, and other factors. HPLC parameters, such as mobile phase composition and flow standardized for determination of PAHs using fluorescent detector (FLD). PAH was carried out by liquid-liquid extraction using dichloromethane. Linearity of calibration curves was good for all PAH (R², 0.9954-1.0000) in the concentration range 0.1-100 ppb. Analysis of standard spiked water samples resulted in good recoveries between 78.5-150%(0.1ppb) and 93.04-137.47% (10ppb). The estimated LOD and LOQ ranged between 0.0018-0.98 ppb. The method described has been used for determination of the fifteen PAHs contents in drinking water samples.

Keywords: high performance liquid chromatography, HPLC, method validation, polycyclic aromatic hydrocarbons, PAHs, water

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Authors: Hua Tan, David Salamon

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In this study, γ-Al2O3 powders doped with various amounts of iron were sintered via SPS process. Two heating modes – auto and manual mode were applied to observe the role of electrical induction on heating. Temperature, electric current, and pulse pattern were experimented with grade iron γ-Al2O3 powders. Phase transformation of γ to α -Al2O3 serves as a direct indicator of internal temperature, independently on measured outside temperature. That pulsing in SPS is also able to induce internal heating due to its strong electromagnetic field when dopants are conductive metals (e.g., iron) is proofed during SPS. Density and microstructure were investigated to explain the mechanism of induction heating. In addition, the role of electric pulsing and strong electromagnetic field on internal heating (induction heating) were compared and discussed. Internal heating by iron doping within electrically nonconductive samples is able to decrease sintering temperature and save energy, furthermore it is one explanation for unique features of this material fabrication technology.

Keywords: spark plasma sintering, induction heating, alumina, microstructure

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Authors: Mohamed Ayoub

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We perform computational investigation using density functional theory, B3LYP with aug-cc-pVTZ basis set followed by natural bond orbital analysis (NBO), which provides best single “natural Lewis structure” (NLS) representation of chosen wavefunction (Ψ) with natural resonance theory (NRT) to provide an analysis of molecular electron density in terms of resonance structures (RS) and weights (w). We selected for the study a wide range of gas phase dimers (B…HA), with hydrogen bond dissociation energies (ΔEB…H) that span more than two orders of magnitude. We demonstrate that charge transfer from a donor Lewis-type NBO (nB:) to an acceptor non-Lewis-type NBO (σHA*) is the primary cause for H-bonding not classical electrostatic (dipole-dipole or ionic). We provide a variety of structure, and spectroscopic descriptors to support the conclusion, such as IR frequency shift (ΔνHA), H-bond penetration distance (ΔRB..H), bond order (bB..H), charge-transfer (CTB→HA) and the corresponding donor-acceptor stabilization energy (ΔE(2)).

Keywords: natural bond orbital, hydrogen bonding, electron donor, electron acceptor

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Authors: Sheetla Prasad

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The objective of this study is ‘discovering the real psyche of human beings for prediction of mode, direction and strength of the potential of actions of the individual. The human face was taken as a source of central point to search for the route of real psyche. Analysis of the face architecture (shape and salient features of face) was done by three directional photographs ( 600 left and right and camera facing) of human beings. The shapes and features of the human face were scaled in 177 units on the basis of face–features locations (FFL). The mathematical analysis was done of FFLs by self developed and standardized formula. At this phase, 800 samples were taken from the population of students, teachers, advocates, administrative officers, and common persons. The finding shows that real psyche has two external rings (ER). These ER are itself generator of two independent psyches (manifested and manipulated). Prima-facie, it was proved that micro differences in FFLs have potential to predict the state of art of the human psyche. The potential of psyches was determined by the saving and distribution of mental energy. It was also mathematically proved.

Keywords: face architecture, psyche, potential, face functional ratio, external rings

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Authors: Adam Beaunoyer, Cory Beaunoyer, Mohammed Elmorsy, Hanan Saleh

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This research aims to create a reinforcement learning agent capable of racing in challenging simulated environments with a low collision count. We present a reinforcement learning agent that can navigate challenging tracks using both a Deep Q-Network (DQN) and a Soft Actor-Critic (SAC) method. A challenging track includes curves, jumps, and varying road widths throughout. Using open-source code on Github, the environment used in this research is based on the 1995 racing game WipeOut. The proposed reinforcement learning agent can navigate challenging tracks rapidly while maintaining low racing completion time and collision count. The results show that the SAC model outperforms the DQN model by a large margin. We also propose an alternative multiple-car model that can navigate the track without colliding with other vehicles on the track. The SAC model is the basis for the multiple-car model, where it can complete the laps quicker than the single-car model but has a higher collision rate with the track wall.

Keywords: reinforcement learning, soft actor-critic, deep q-network, self-driving cars, artificial intelligence, gaming

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Authors: Obsi Terfasa, Bhanupriya Das, Shiao-Shing Chen

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Converting coal fly ash (CFA) waste into ceramic membranes presents a promising alternative to traditional disposal methods, offering potential economic and environmental advantages that warrant further investigation. This research focuses on the creation of ceramic membranes exclusively from CFA using a uniaxial compaction technique. The membranes' properties were examined through various analytical methods: Scanning Electron Microscopy (SEM) revealed a porous and flawless membrane surface, X-Ray Diffraction (XRD) identified mullite and quartz crystalline structures, and Fourier-Transform Infrared Spectroscopy (FTIR) characterized the membrane's functional groups. Thermogravimetric analysis (TGA) determined the ideal sintering temperature to be 800°C. To evaluate its separation capabilities, the synthesized membrane was tested on wastewater from denim jeans production at 0.2 bar pressure. The results were impressive, with 97.42% removal of Chemical Oxygen Demand (COD), 95% color elimination, and a pure water flux of 4.5 Lm⁻²h⁻¹bar⁻¹. These findings suggest that CFA, a byproduct of thermal power plants, can be effectively repurposed to produce ultrafiltration membranes suitable for various industrial purification and separations.

Keywords: wastewater treatment, separator, coal fly ash, ceramic membrane, ultrafiltration

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Authors: Shouyong Zhou, Meisheng Li, Yijiang Zhao

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The environmentally acceptable disposal of oily wastewater is a current challenge to many industries. The membrane separation technologies, which is no phase change, without pharmaceutical dosing, reprocessing costs low, less energy consumption, etc., have been widely applied in oily wastewater treatment. In our lab, a kind of low cost ceramic microfiltration membranes with a separation layer of attapulgite nanofibers (attapulgite nanofiber-like microfiltration membranes) has been prepared and applied in the purification of cellulase fermentation broth and TiO2 nanoparticles system successfully. In this paper, this new attapulgite nanofiber-like microfiltration membrane was selected to try to separate water from oily wastewater. The oil-in water emulsion was obtained from mixing 1 g/L engine oil, 0.5 g/L Tween-80, 0.5 g/L Span-80 and distilled water at mild speed in blender for 2 min. The particle size distribution of the oil-in-water emulsion was controlled. The maximum steady flux and COD rejection for a 0.2 um attapulgite nanofiber-like microfiltration membrane can reach about 450 L. m-2. h-1 and 98% at 0.2 MPa. The results obtained in this work indicated that the attapulgite microfiltration membrane may represent a feasible pretreatment for oily wastewater.

Keywords: attapulgite, microfiltration membrane, oily wastewater, cross-flow filtration

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Authors: Elmongi Elbellili, Ben Lauwens, Daan Huybrechs

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The increasing complexity of modern engineering systems presents a challenge to the digital simulation of these systems which usually can be represented by differential equations. The Linearly Implicit Quantized State System (LIQSS) offers an alternative approach to traditional numerical integration techniques for solving Ordinary Differential Equations (ODEs). This method proved effective for handling discontinuous and large stiff systems. However, the inherent discrete nature of LIQSS may introduce oscillations that result in unnecessary computational steps. The current oscillation detection mechanism relies on a condition that checks the significance of the derivatives, but it could be further improved. This paper describes a different cycle detection mechanism and presents the outcomes using LIQSS order one in simulating the Advection Diffusion problem. The efficiency of this new cycle detection mechanism is verified by comparing the performance of the current solver against the new version as well as a reference solution using a Runge-Kutta method of order14.

Keywords: numerical integration, quantized state systems, ordinary differential equations, stiffness, cycle detection, simulation

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Authors: Youji Miyake

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In aircraft assembly, a large number of preparatory holes are required for screw and rivet joints. Currently, many holes are drilled manually because it is difficult to machine the holes using conventional computerized numerical control(CNC) machines. The application of industrial robots to drill the hole has been considered as an alternative to the CNC machines. However, the rigidity of robot arms is so low that vibration is likely to occur during drilling. In this study, it is proposed constant-load feed machining as a method to perform high-precision drilling while minimizing the thrust force, which is considered to be the cause of vibration. In this method, the drill feed is realized by a constant load applied onto the tool so that the thrust force is theoretically kept below the applied load. The performance of the proposed method was experimentally examined through the deep hole drilling of plastic and simultaneous drilling of metal/plastic stack plates. It was confirmed that the deep hole drilling and simultaneous drilling could be performed without generating vibration by controlling the tool feed rate in the appropriate range.

Keywords: constant load feed machining, robotic drilling, deep hole, simultaneous drilling

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Authors: Vaclav Heral

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Ideas about the mechanism of heterogeneous catalytic hydrogenation are diverse. The Horiuti-Polanyi mechanism is most often referred to, based on the idea of a semi-hydrogenated state. In our opinion, it does not represent a satisfactory explanation of the hydrogenation mechanism, because, for example: (1) It neglects the fact that the bond of atomic hydrogen to the metal surface is strongly polarized, (2) It does not explain why a surface deprived of atomic hydrogen (by thermal desorption or by alkyne) loses isomerization capabilities, but hydrogenation capabilities remain preserved, (3) It was observed that during the hydrogenation of 1-alkenes, the reaction can be of the 0th order to hydrogen and to the alkene at the same time, which is excluded during the competitive adsorption of both reactants on the catalyst surface. We offer an alternative mechanism that satisfactorily explains many of the ambiguities: It is the idea of an independent course of olefin isomerization, catalyzed by acidic atomic hydrogen bonded on the surface of the catalyst, in addition to the hydrogenation itself, in which a two-layer complex appears on the surface of the catalyst: olefin bound to the surface and molecular hydrogen bound to it in the second layer. The rate-determining step of hydrogenation is the conversion of this complex into the final product. We believe that the Horiuti-Polanyi mechanism is flawed and we naturally think that our two-layer theory better describes the experimental findings.

Keywords: acidity of hydrogenation catalyst, Horiuti-Polanyi, hydrogenation, two-layer hydrogenation

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Authors: Anurita Selvarajoo, Svenja Hanson

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Growing energy needs and increasing environmental issues are creating awareness for alternative energy which substitutes the non-renewable and polluting fossil fuels. Agricultural wastes are a good feedstock for biochar production through the pyrolysis process. There is potential to generate solid fuel from agricultural wastes, as there are large quantities of agricultural wastes available in Malaysia. This paper outlines the experimental study on the pyrolysis of banana peel. The effects of pyrolysis temperatures on the yield of biochar from the banana peel were investigated. Banana peel was pyrolysed in a horizontal tubular reactor under inert atmosphere by varying the temperatures between 300 and 700 0C. With increasing temperature, the total biochar yield decreased with increased heating value. It was found that the pyrolysis temperature had major effect on the yield of biochar product. It also exerted major influence on the heating value and C,H and O composition. The obtained biochar ranged between 31.9 to 56.7 %wt, at different pyrolysis temperatures. The optimum biochar yield was obtained at 325 0C. Biochar yield obtained at optimum temperature was 47 % wt with a heating value of 25.9 MJ kg-1. The study has been performed in order to demonstrate that agricultural wastes like banana peel are also important source of solid fuel.

Keywords: agricultural Wastes, banana peel, biochar, pyrolysis

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Authors: Pavlo Selyshchev, Samuel Akintunde

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A theoretical approach to consider formation of chemical compound layer at the interface between initial substances A and B due to the interfacial interaction and diffusion is developed. It is considered situation when speed of interfacial interaction is large enough and diffusion of A-atoms through AB-layer is much more then diffusion of B-atoms. Atoms from A-layer diffuse toward B-atoms and form AB-atoms on the surface of B-layer. B-atoms are assumed to be immobile. The growth kinetics of the AB-layer is described by two differential equations with non-linear coupling, producing a good fit to the experimental data. It is shown that growth of the thickness of the AB-layer determines by dependence of chemical reaction rate on reactants concentration. In special case the thickness of the AB-layer can grow linearly or parabolically depending on that which of processes (interaction or the diffusion) controls the growth. The thickness of AB-layer as function of time is obtained. The moment of time (transition point) at which the linear growth are changed by parabolic is found.

Keywords: phase formation, binary systems, interfacial reaction, diffusion, compound layers, growth kinetics

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Authors: Deokyeong Choe, Sung Hun Youn, Younggon Kim, Chul Soo Shin

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L-Cysteine, a sulfur-containing amino acid, has been often used in the pharmaceutical, cosmetic, food, and feed additive industries. This amino acid has been usually produced by acid-hydrolysis of human hair and poultry feathers. There are many problems, such as avoidance for use of animal hair, low yields, and formation of harmful waste material. As an alternative, the enzymatic conversion of D, L-2-amino-Δ2-thiazoline-4-carboxylic acid (ATC) to L-cysteine has been developed as an environmental-friendly method. However, the substrate solubility was too low to be used in industry. In this study, high concentrations of eutectic substrate solutions were prepared to solve the problem. Eutectic melting occurred at 39°C after mixing ATC and malonic acid at a molar ratio of 1:1. The characteristics of eutectic mixtures were analyzed by FE-SEM, EDS mapping, and XPS. However, since sorbitol, MnSO4, and NaOH should be added as supplements to the substrate mixture for the activation and stabilization of the enzyme, strategies for sequential addition of total five compounds, ATC, malonic acid, sorbitol, MnSO4, and NaOH were established. As a result, eutectic substrate mixtures of 670 mM ATC were successfully formulated. After 6 h of enzymatic reaction, 550 mM L-cysteine was made.

Keywords: D, L-2-amino-Δ2-thiazoline-4-carboxylicacid, enzymatic conversion, eutectic solution, l-cysteine

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Authors: A.Zitouni, S.Bentata, B.Bouadjemi, T.Lantri, W. Benstaali, Z.Aziz, S.Cherid, A. Sefir

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Structural, electronic, and magnetic properties of Co and Mn-doped CdTe have been studied by employing the full potential linear augmented plane waves (FP-LAPW) method within the spin-polarized density functional theory (DFT). The electronic exchange-correlation energy is described by generalized gradient approximation (GGA) as exchange–correlation (XC) potential. We have calculated the lattice parameters, bulk modulii and the first pressure derivatives of the bulk modulii, spin-polarized band structures, and total and local densities of states. The value of calculated magnetic moment per Co and Mn impurity atoms is found to be 2.21 µB for CdCoTe and 3.20 µB for CdMnTe. The calculated densities of states presented in this study identify the half-metallic of Co and Mn-doped CdTe.

Keywords: electronic structure, density functional theory, band structures, half-metallic, magnetic moment

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Authors: Kianoosh Shojae

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In recent years, the environmental challenges due to the excessive use of fossil fuels have led to heightened greenhouse gas production. In response, biodiesel has emerged as a cleaner alternative, offering reduced pollutant emissions compared to traditional fuels. The large-scale production of biodiesel, involving ester exchange of animal fats or vegetable oils, results in a surplus of crude glycerin. With environmental regulations on the rise and an increasing demand for biodiesel, glycerin production has seen a significant upswing. This paper focuses on the economic significance of glycerin through its pyrolysis as a raw material, particularly in the synthesis of metals. As industries pivoted towards cleaner fuels, glycerin, as a byproduct of biodiesel production, is poised to remain a cost-effective and surplus product. In this work, for evaluating the possible performance of using the gaseous products from the pyrolysis reaction of glycerol, we concerned the glycerin pyrolysis reactions, emphasizing the catalytic role of activated carbon, various reaction pathways and the impact of carrier gas flow rate on hydrogen production, providing valuable insights into the evolving landscape of sustainable fuel alternatives.

Keywords: biodiesel, glycerin pyrolysis, activated carbon catalysis, syngas

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Authors: Flutura Tahiraj, Emine Abdyli

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As a new alternative, mediation is integrated in the legislation of both developed and developing countries in Europe. Various researches in member states of the Council of Europe revealed obstacles, particularly related to the implementation of mediation in criminal matters. They are addressed through several recommendations and non-binding guidelines. However, there is limited empirical research on how the mediation in criminal matters is being implemented in the contexts of developing countries in South-Eastern Europe. Hence, the purpose of this qualitative study is to assess mediation in criminal matters in Kosovo by exploring how the main stakeholders describe the legal basis and implementation process and what it indicates for future practices. The data were gathered through 11 semi-structured interviews with judges, prosecutors, mediation clerks and mediators. Results show that laws and other guidelines that have been introduced since 2008 constitute a solid legal ground that facilitates mediation in criminal matters. The stakeholders are well aware of benefits mediation brings and express their willingness to advance its application to criminal matters. Results also indicate uncertainty among judges and prosecutors regarding the assessment and referral of certain criminal offences to mediation. To address it, specialized trainings, exchange programs and continuous monitoring and evaluation of the process could be supportive.

Keywords: mediation in criminal matters, legislation, implementation of mediation

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Authors: Marcin Zieliński, Marcin Dębowski, Mirosław Krzemieniewski

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The anaerobic degradation of substrates is limited especially by the rate and effectiveness of the first (hydrolytic) stage of fermentation. This stage may be intensified through pre-treatment of substrate aimed at disintegration of the solid phase and destruction of substrate tissues and cells. The most frequently applied criterion of disintegration outcomes evaluation is the increase in biogas recovery owing to the possibility of its use for energetic purposes and, simultaneously, recovery of input energy consumed for the pre-treatment of substrate before fermentation. Hydrodynamic cavitation is one of the methods for organic substrate disintegration that has a high implementation potential. Cavitation is explained as the phenomenon of the formation of discontinuity cavities filled with vapor or gas in a liquid induced by pressure drop to the critical value. It is induced by a varying field of pressures. A void needs to occur in the flow in which the pressure first drops to the value close to the pressure of saturated vapor and then increases. The process of cavitation conducted under controlled conditions was found to significantly improve the effectiveness of anaerobic conversion of organic substrates having various characteristics. This phenomenon allows effective damage and disintegration of cellular and tissue structures. Disintegration of structures and release of organic compounds to the dissolved phase has a direct effect on the intensification of biogas production in the process of anaerobic fermentation, on reduced dry matter content in the post-fermentation sludge as well as a high degree of its hygienization and its increased susceptibility to dehydration. A device the efficiency of which was confirmed both in laboratory conditions and in systems operating in the technical scale is a hydrodynamic generator of cavitation. Cavitators, agitators and emulsifiers constructed and tested worldwide so far have been characterized by low efficiency and high energy demand. Many of them proved effective under laboratory conditions but failed under industrial ones. The only task successfully realized by these appliances and utilized on a wider scale is the heating of liquids. For this reason, their usability was limited to the function of heating installations. Design of the presented cavitation generator allows achieving satisfactory energy efficiency and enables its use under industrial conditions in depolymerization processes of biomass with various characteristics. Investigations conducted on the laboratory and industrial scale confirmed the effectiveness of applying cavitation in the process of biomass destruction. The use of the cavitation generator in laboratory studies for disintegration of sewage sludge allowed increasing biogas production by ca. 30% and shortening the treatment process by ca. 20 - 25%. The shortening of the technological process and increase of wastewater treatment plant effectiveness may delay investments aimed at increasing system output. The use of a mechanical cavitator and application of repeated cavitation process (4-6 times) enables significant acceleration of the biogassing process. In addition, mechanical cavitation accelerates increases in COD and VFA levels.

Keywords: hydrodynamic cavitation, pretreatment, biomass, methane fermentation, Virginia fanpetals

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Authors: Nataša Kalajdžija, Strahinja Kovačević, Davor Lončar, Sanja Podunavac Kuzmanović, Lidija Jevrić

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In order to investigate the relationship between retention and structure, a quantitative Structure Retention Relationships (QSRRs) study was applied for the prediction of retention times of a set of 23 secoestrane derivatives in a reversed-phase thin-layer chromatography. After the calculation of molecular descriptors, a suitable set of molecular descriptors was selected by using step-wise multiple linear regressions. Artificial Neural Network (ANN) method was employed to model the nonlinear structure-activity relationships. The ANN technique resulted in 5-6-1 ANN model with the correlation coefficient of 0.98. We found that the following descriptors: Critical pressure, total energy, protease inhibition, distribution coefficient (LogD) and parameter of lipophilicity (miLogP) have a significant effect on the retention times. The prediction results are in very good agreement with the experimental ones. This approach provided a new and effective method for predicting the chromatographic retention index for the secoestrane derivatives investigated.

Keywords: lipophilicity, QSRR, RP TLC retention, secoestranes

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Authors: M. Zamurad Shah, M. Kemal Ozgoren, Raza Samar

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This paper presents a 3D guidance scheme for Unmanned Aerial Vehicles (UAVs). The proposed guidance scheme is based on the sliding mode approach using nonlinear sliding manifolds. Generalized 3D kinematic equations are considered here during the design process to cater for the coupling between longitudinal and lateral motions. Sliding mode based guidance scheme is then derived for the multiple-input multiple-output (MIMO) system using the proposed nonlinear manifolds. Instead of traditional sliding surfaces, nonlinear sliding surfaces are proposed here for performance and stability in all flight conditions. In the reaching phase control inputs, the bang-bang terms with signum functions are accompanied with proportional terms in order to reduce the chattering amplitudes. The Proposed 3D guidance scheme is implemented on a 6-degrees-of-freedom (6-dof) simulation of a UAV and simulation results are presented here for different 3D trajectories with and without disturbances.

Keywords: unmanned aerial vehicles, sliding mode control, 3D guidance, nonlinear sliding manifolds

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Authors: Kshitish Ch. Mistri, Abhishek Kumar Singh

Abstract:

The effect of undulatory boundary surface of a medium as well as the degree of bonding between two consecutive mediums, on the propagation of surface waves is an unavoidable matter of fact. Therefore, this paper investigates the propagation of Rayleigh-type wave in a corrugated fibre-reinforced layer overlying an initially stressed orthotropic half-space under gravity. Also, the two mediums are assumed to be loosely (or imperfectly) bonded. Numerical computation of the obtained frequency equation has been carried out which aids to analyze the influence of corrugation, loose bonding, initial stress and gravity on the phase velocity of Rayleigh-type wave. Moreover, the presence and absence of corrugation, loose bonding and initial stress are also discussed in a comparative manner.

Keywords: corrugated boundary surface, fibre-reinforced layer, initial stress, loose bonding, orthotropic half-space, Rayleigh-type wave

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Authors: John Pomerat, Aviv Segev

Abstract:

Recently, deep learning has had many theoretical breakthroughs. For deep learning to be successful in the industry, however, there need to be practical algorithms capable of handling many real-world hiccups preventing the immediate application of a learning algorithm. Although AI promises to revolutionize the healthcare industry, getting access to patient data in order to train learning algorithms has not been easy. One proposed solution to this is data- sharing. In this paper, we propose an alternative protocol, based on multi-party computation, to train deep learning models while maintaining both the privacy and security of training data. We examine three methods of training neural networks in this way: Transfer learning, average ensemble learning, and series network learning. We compare these methods to the equivalent model obtained through data-sharing across two different experiments. Additionally, we address the security concerns of this protocol. While the motivating example is healthcare, our findings regarding multi-party computation of neural network training are purely theoretical and have use-cases outside the domain of healthcare.

Keywords: neural network aggregation, multi-party computation, transfer learning, average ensemble learning

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Authors: Liliana M. Marinelli, Cristina T. Varanese

Abstract:

In the last few years, students from higher education have difficulties in grasping mathematical concepts which support physical matters, especially those in the first years of this education. Classical Physics teaching turns to be complex when students are not able to make use of mathematical tools which lead to the conceptual structure of Physics. When derivation and integration rules are not used or developed in parallel with other disciplines, the physical meaning that we attempt to convey turns to be complicated. Due to this fact, it could be of great use to see the Classical Mechanics from an axiomatic approach, where the correspondence rules give physical meaning, if we expect students to understand concepts clearly and accurately. Using the Minkowski point of view adapted to a two-dimensional space and time where vectors, matrices, and straight lines (worked from an affine space) give mathematical and physical rigorosity even when it is more abstract. An interesting option would be to develop the disciplinary contents from an axiomatic version which embraces the Classical Mechanics as a particular case of Relativistic Mechanics. The observation about the increase in the difficulties stated by students in the first years of education allows this idea to grow as a possible option to improve performance and understanding of the concepts of this subject.

Keywords: axioms, classical physics, physical concepts, relativity

Procedia PDF Downloads 308