Search results for: atmospheric distillation unit

Authors: P. Chultheera, T. Rirksomboon, S. Kulprathipanja, C. Liu, W. Chinsirikul, N. Kerddonfag

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Gas separation by selective transport through polymeric membranes is one of the rapid growing branches of membrane technology. However, the tradeoff between the permeability and selectivity is one of the critical challenges encountered by pure polymer membranes, which in turn limits their large-scale application. To enhance gas separation performances, mixed matrix membranes (MMMs) have been developed. In this study, MMMs were prepared by a solution-coating method and tested for CO₂/CH₄ separation through permeability and selectivity using a membrane testing unit at room temperature and a pressure of 100 psig. The fabricated MMMs were composed of silicone rubber dispersed with the activated carbon individually absorbed with polyethylene glycol (PEG) as a liquid additive. PEG emulsified silicone rubber MMMs showed superior gas separation on cellulose acetate membrane with both high permeability and selectivity compared with silicone rubber membrane and alone support membrane. However, the MMMs performed limited stability resulting from the undesirable PEG leakage. To stabilize the MMMs, PEG was then incorporated into activated carbon by adsorption. It was found that the incorporation of solid and liquid was effective to improve the separation performance of MMMs.

Keywords: mixed matrix membrane, membrane, CO₂/CH₄ separation, activated carbon

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Authors: L. Oufni, M. Amrane, R. Rabi

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Radon (and thoron) is a naturally occurring radioactive noble gas, having variable distribution in the geological environment. The exposure of human beings to ionizing radiation from natural sources is a continuing and inescapable feature of life on earth. Radon, thoron and their short-lived decay products in the atmosphere are the most important contributors to human exposure from natural sources. The aim of this study is to determine alpha-and beta-activities per unit volume of air due to radon (222Rn), thoron (220Rn) and their progenies in the air of ancient mine of Aouli in which there is no working activity is situated at approximately 25 km north of the city of Midelt (Morocco), by using LR-115 type II and CR-39 solid state nuclear track detectors (SSNTDs). Equilibrium factors between radon and its daughters and between thoron and its progeny were evaluated in the studied atmospheres. The committed equivalent doses due to the 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the visitors of the considered ancient mine. The visitors in these mines spent a good amount of time. It was essential to let the staff know about these values and take the needed steps to prevent any health complications.

Keywords: radon, thoron, concentration, exposure dose, SSNTD, mine

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Authors: Sudhir Kumar Sharma, Ramesh Jagannathan

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The interaction of organic and inorganic matrices of biological origin resulting in self-assembled structures with unique properties is well established. The development of such self-assembled nanostructures by synthetic and bio-inspired techniques is an established field of active research. Among bio-materials, nacre, a laminar stack of calcium carbonate nanosheets, which are interleaved with organic material, has long been focused research due to its unique mechanical properties. In this paper, we present the development of nacre-like lamellar structures made up of calcium carbonate via a wet chemical route. We used the binding affinity of carboxylate anions and calcium cations using poly (acrylic) acid (PAA) to lead CaCO₃ crystallization. In these experiments, we selected calcium acetate as the precursor molecule along with PAA (Mw ~ 8000 Da). We found that Ca⁺²/COO⁻ ratio provided a tunable control for the morphology and growth of CaCO₃ nanostructures. Drop casting one such formulation on a silicon substrate followed by calcination resulted in co-planner, molecular sheets of CaCO₃, separated by a spacer layer of carbon. The scope of our process could be expanded to produce unit cell thick molecular sheets of other important inorganic materials.

Keywords: self-assembled structures, bio-inspired materials, calcium carbonate, wet chemical route

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Authors: Abdoulaye Maihatchi Ahamed, Zubin Arora, Benjamin Swobada, Jean-yves Lansot, Alexandre Chagnes

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Lithium-ion battery (LiB) is the technology of choice in the development of electric vehicles. But there are still many challenges, including the development of positive electrode materials exhibiting high cycle ability, high energy density, and low environmental impact. For this latter, LiBs must be manufactured in a circular approach by developing the appropriate strategies to reuse and recycle them. Presently, the recycling of LiBs is carried out by the pyrometallurgical route, but more and more processes implement or will implement the hydrometallurgical route or a combination of pyrometallurgical and hydrometallurgical operations. After producing the black mass by mineral processing, the hydrometallurgical process consists in leaching the black mass in order to uptake the metals contained in the cathodic material. Then, these metals are extracted selectively by liquid-liquid extraction, solid-liquid extraction, and/or precipitation stages. However, liquid-liquid extraction combined with precipitation/crystallization steps is the most implemented operation in the LiB recycling process to selectively extract copper, aluminum, cobalt, nickel, manganese, and lithium from the leaching solution and precipitate these metals as high-grade sulfate or carbonate salts. Liquid-liquid extraction consists in contacting an organic solvent and an aqueous feed solution containing several metals, including the targeted metal(s) to extract. The organic phase is non-miscible with the aqueous phase. It is composed of an extractant to extract the target metals and a diluent, which is usually aliphatic kerosene produced from the petroleum industry. Sometimes, a phase modifier is added in the formulation of the extraction solvent to avoid the third phase formation. The extraction properties of the diluent do not depend only on the chemical structure of the extractant, but it may also depend on the nature of the diluent. Indeed, the interactions between the diluent can influence more or less the interactions between extractant molecules besides the extractant-diluent interactions. Only a few studies in the literature addressed the influence of the diluent on the extraction properties, while many studies focused on the effect of the extractants. Recently, new low-carbon footprint aliphatic diluents were produced by catalytic dearomatisation and distillation of bio-based oil. This study aims at investigating the influence of the nature of the diluent on the extraction properties of three extractants towards cobalt, nickel, manganese, copper, aluminum, and lithium: Cyanex®272 for nickel-cobalt separation, DEHPA for manganese extraction, and Acorga M5640 for copper extraction. The diluents used in the formulation of the extraction solvents are (i) low-odor aliphatic kerosene produced from the petroleum industry (ELIXORE 180, ELIXORE 230, ELIXORE 205, and ISANE IP 175) and (ii) bio-sourced aliphatic diluents (DEV 2138, DEV 2139, DEV 1763, DEV 2160, DEV 2161 and DEV 2063). After discussing the effect of the diluents on the extraction properties, this conference will address the development of a low carbon footprint process based on the use of the best bio-sourced diluent for the production of high-grade cobalt sulfate, nickel sulfate, manganese sulfate, and lithium carbonate, as well as metal copper.

Keywords: diluent, hydrometallurgy, lithium-ion battery, recycling

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Authors: Anies Mutiari, Neha Bansal, Martin Artner, Veronika Mayer, Juergen Roth, Mathias Weil, Rachmat Adhi Wibowo

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Cu₂ZnSnS₄ (CZTS) compound (mineral name kesterite) has attracted considerable interests for photovoltaic application owing to its optoelectrical properties. Moreover, its elemental abundance in Earth’s crust offers a comparative advantage for envisaged large-scale photovoltaic deployment without any material shortage issues. In this contribution, we present an innovative route to prepare CZTS solar absorber layer for photovoltaic application from low-cost and up-scalable process. CZTS layers were spin coated on the Molybdenum-coated glass from two inks composed of different solvents; dimethylsulfoxide (DMSO) and ultrapure water. Into each solvent; 0.57M CuCl₂, 0.39M ZnCl₂, 0.53M SnCl₂, and 1.85M Thiourea or Na₂S₂O₃, as well as pre-synthesized CZTS nanopowder, were added as sources of Cu, Zn, Sn and S in the ink. The crystallisation of ink into CZTS dense layers was carried out by firstly annealing the as-deposited CZTS layer in open air at 300°C for 1 minute, followed by sulfurisation at 560–620°C under atmospheric pressure for 120 minutes. Complementary electron microscopy, grazing incidence X-ray diffraction and Raman spectroscopy investigations suggest that both solvents can be used for preparing high quality and device relevant CZTS solar absorber layers. The sulphurisation crystallizes the as-deposited CZTS into highly polycrystalline CZTS layer with tetragonal structure demonstrated by the presence of tetrahedrally-shaped grains with the size of 1 µm. An advancement of the CZTS layer preparation was made by gradual substitution of volatile organic compound solvent of DMSO with ultrapure water. It is revealed that by using similar air annealing and sulphurisation process, dense and compact CZTS layers can also be fabricated from an ink with reduced volatile organic compound content.

Keywords: kesterite, solar ink, spin coating, photovoltaics

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Authors: H. Daaou Nedjari, O. Guerri, M. Saighi

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A numerical study was conducted to optimize the positioning of wind turbines over complex terrains. Thus, a two-dimensional disk model was used to calculate the flow velocity deficit in wind farms for both flat and complex configurations. The wind turbine wake was assessed using the hybrid methods that combine CFD (Computational Fluid Dynamics) with the actuator disc model. The wind turbine rotor has been defined with a thrust force, coupled with the Navier-Stokes equations that were resolved by an open source computational code (Code_Saturne V3.0 developed by EDF) The simulations were conducted in atmospheric boundary layer condition considering a two-dimensional region located at the north of Algeria at 36.74°N longitude, 02.97°E latitude. The topography elevation values were collected according to a longitudinal direction of 1km downwind. The wind turbine sited over topography was simulated for different elevation variations. The main of this study is to determine the topography effect on the behavior of wind farm wake flow. For this, the wake model applied in complex terrain needs to selects the singularity effects of topography on the vertical wind flow without rotor disc first. This step allows to determine the existence of mixing scales and friction forces zone near the ground. So, according to the ground relief the wind flow waS disturbed by turbulence and a significant speed variation. Thus, the singularities of the velocity field were thoroughly collected and thrust coefficient Ct was calculated using the specific speed. In addition, to evaluate the land effect on the wake shape, the flow field was also simulated considering different rotor hub heights. Indeed, the distance between the ground and the hub height of turbine (Hhub) was tested in a flat terrain for different locations as Hhub=1.125D, Hhub = 1.5D and Hhub=2D (D is rotor diameter) considering a roughness value of z0=0.01m. This study has demonstrated that topographical farm induce a significant effect on wind turbines wakes, compared to that on flat terrain.

Keywords: CFD, wind turbine wake, k-epsilon model, turbulence, complex topography

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Authors: M. S. Agha, A. M. Eshahiry, S. A. Aldabbar, Z. M. Alshahri

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The propagation of microwave is affected by rain and dust particles by way of signal attenuation and de-polarization. Computations of these effects require knowledge of the propagation characteristics of microwave and millimeter wave energy in the climate conditions of the studied region. This paper presents the effect of wind and humidity on wireless communication such as microwave links in the west north region of Libya (Al-Khoms), experimental procedure to study the effects mentioned above. The experimental procedure is done on three selected antennae towers (Nagaza stations, Al-Khoms center stations, Al-Khoms gateway stations) to determining of the attenuation loss per unit length and cross-polarization discrimination (XPD) change which coverage in the studied region, it is required to collect the dust particles carried out by the wind, measure the particles size distribution (PSD), calculate the concentration, and carry chemical analysis of the contents, then the dielectric constant can be calculated. The result showed that effect of the humidity and dust, the antenna height, the visibility, on the complex permittivity effects both attenuation and phase shift, there is some consideration that has to be taken into account in the communication power budget.

Keywords: attenuation, de-polarization, scattering, transmission loss

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Authors: Seema Chopra, Amandeep Kaur, Vanita Suri, Shalini Gainder, Minakshi Rohilla

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Background: Acute kidney injury (AKI) associated with pregnancy is a serious medical complication which can lead to significant maternal as well as perinatal morbidity and mortality. Material and methods: This prospective observational study was carried out in the Obstetrics and Gynaecology department and dialysis unit of Nephrology department of PGIMER, Chandigarh from July 2013 to June 2014. Forty antenatal/postnatal/postabortal patients who fulfilled the AKIN criteria were enrolled in the study. All patients were followed up till 3 months postpartum. Results: Majority of the patients 23/40 (57.5%) with AKI presented in postpartum period, 14/40 (35%) developed AKI in antenatal period, and 3/40 (7.5%) were postabortal. AKI was attributable mostly to sepsis in 11/40 (27.5%) and PPH in 5/40 (12.5%). Hypertension and its complications causing AKI included eclampsia in 5/40 (12.5%) followed by 3/40 (7.5%) as HELLP syndrome and abruption placentae in 2/40(5%) patients. Three patients each (7.5%) had AFLP, TMA, and HEV as the cause of AKI. Renal replacement therapy in the form of hemodialysis was the treatment in majority of them (28 (70%)). After the acute event, 25 (62.5%) had complete recovery of their renal functions at 3 months follow up. Maternal mortality was seen in 25% (n=10) of the study patients. Conclusion: Timely initiation of RRT in patients with AKI associated with pregnancy has a good maternal outcome in the form of complete recovery of renal functions in 62.5% (25/40) of patients.

Keywords: AKI, dialysis, hypertension, sepsis, renal parameters

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Authors: Niousha Bagheri Khulenjani, Mohammad Saniee Abadeh

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Learning from very big datasets is a significant problem for most present data mining and machine learning algorithms. MicroRNA (miRNA) is one of the important big genomic and non-coding datasets presenting the genome sequences. In this paper, a hybrid method for the classification of the miRNA data is proposed. Due to the variety of cancers and high number of genes, analyzing the miRNA dataset has been a challenging problem for researchers. The number of features corresponding to the number of samples is high and the data suffer from being imbalanced. The feature selection method has been used to select features having more ability to distinguish classes and eliminating obscures features. Afterward, a Convolutional Neural Network (CNN) classifier for classification of cancer types is utilized, which employs a Genetic Algorithm to highlight optimized hyper-parameters of CNN. In order to make the process of classification by CNN faster, Graphics Processing Unit (GPU) is recommended for calculating the mathematic equation in a parallel way. The proposed method is tested on a real-world dataset with 8,129 patients, 29 different types of tumors, and 1,046 miRNA biomarkers, taken from The Cancer Genome Atlas (TCGA) database.

Keywords: cancer classification, feature selection, deep learning, genetic algorithm

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Authors: Zamouche Meriem, Mehcene Ismahan, Temmine Manel, Bencheikh Lehocine Mosaab, Meniai Abdeslam Hassen

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In this study, the adsorption of Malachite Green (MG) by chemical treated sewage sludge has been studied. The sewage sludge, collected from drying beds of the municipal wastewater treatment station of IBN ZIED, Constantine, Algeria, was treated by different acids such us HNO₃, H₂SO₄, H₃PO₄ for modifying its aptitude to removal the MG from aqueous solutions. The results obtained shows that the sewage sludge activated by sulfuric acid give the highest elimination amounts of MG (9.52 mg/L) compared by the other acids used. The effects of operation parameters have been investigated, the results obtained show that the adsorption capacity per unit of adsorbent mass decreases from 18.69 to 1.20 mg/g when the mass of the adsorbent increases from 0.25 to 4 g respectively, the optimum mass for which a maximum of elimination of the dye is equal to 0.5g. The increasing in the temperature of the solution results in a slight decrease in the adsorption capacity of the chemically treated sludge. The highest amount of dye adsorbed by CSSS (9.56 mg/g) was observed for the optimum temperature of 25°C. The chemical activated sewage sludge proved its effectiveness for the removal of the Red Congo (RC), but by comparison the adsorption of the two dyes studies, we noted that the sludge has more affinity to adsorb the (MG).

Keywords: adsorption, chemical activation, malachite green, sewage sludge

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Authors: W. A. Gonçalves, E. P. Souza, C. R. Alcântara

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The ISCCP-Tracking database offers an opportunity to study physical and morphological characteristics of Convective Systems based on geostationary meteorological satellites. This database contains 26 years of tracking of Convective Systems for the entire globe. Then, Tropical Squall Lines which occur in Brazil are certainly within the database. In this study, we propose a methodology for identification of these systems based on the ISCCP-Tracking database. A physical and morphological characterization of these systems is also shown. The proposed methodology is firstly based on the year of 2007. The Squall Lines were subjectively identified by visually analyzing infrared images from GOES-12. Based on this identification, the same systems were identified within the ISCCP-Tracking database. It is known, and it was also observed that the Squall Lines which occur on the north coast of Brazil develop parallel to the coast, influenced by the sea breeze. In addition, it was also observed that the eccentricity of the identified systems was greater than 0.7. Then, a methodology based on the inclination (based on the coast) and eccentricity (greater than 0.7) of the Convective Systems was applied in order to identify and characterize Tropical Squall Lines in Brazil. These thresholds were applied back in the ISCCP-Tracking database for the year of 2007. It was observed that other systems, which were not Squall Lines, were also identified. Then, we decided to call all systems identified by the inclination and eccentricity thresholds as Linear Convective Systems, instead of Squall Lines. After this step, the Linear Convective Systems were identified and characterized for the entire database, from 1983 to 2008. The physical and morphological characteristics of these systems were compared to those systems which did not have the required inclination and eccentricity to be called Linear Convective Systems. The results showed that the convection associated with the Linear Convective Systems seems to be more intense and organized than in the other systems. This affirmation is based on all ISCCP-Tracking variables analyzed. This type of methodology, which explores 26 years of satellite data by an objective analysis, was not previously explored in the literature. The physical and morphological characterization of the Linear Convective Systems based on 26 years of data is of a great importance and should be used in many branches of atmospheric sciences.

Keywords: squall lines, convective systems, linear convective systems, ISCCP-Tracking

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Authors: Michelangelo Liban, Debbie Liquete

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A case of a 93-year-old Filipina who experienced a sudden onset of left-sided hemichorea hemiballismus after falling from a standing height due to dizziness and then sought consult at the Emergency Room. She was not known to have diabetes mellitus nor experienced any symptoms of diabetes aside from its rare neurological manifestation of hemichorea-hemiballismus prior to this consult. On further workup, her baseline laboratory tests at the Emergency Room Department showed a CBG of 340mg/dL, an HbA1c of 15%, no ketones were detected in her urine but a hyperdensity with a Hounsfeld unit of 38 on CT, and hyperintensity on T1 weighted MRI on her right striatum with an incidental finding of a subdural hematoma measured as a 0.7cm hyperdensity on her right temporoparietal area with no midline shift. She was then treated with Clonazepam 2mg ¼ tab twice a day before bedtime and insulin 70/30 16 units in the morning and eight units in the evening, which provided good glycemic control maintained at 140-180 mg/dL, complete cessation of the left-sided hemichorea hemiballismus was also observed. The subdural hematoma was deemed non-surgical, and she refused admission into our institution; hence observation on an outpatient basis was done. This is a case of a rare neurological manifestation of diabetes mellitus but with good treatment response to anti-chorea medications combined with diabetes medications.

Keywords: hemichorea, hemiballismus, striatopathy, diabetes

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Authors: Sambit Supriya Dash, Rahul Ravi R, Vikram Ramanan, Vinayak Malhotra

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Combustion in itself is a complex phenomenon that involves the interaction and interplay of multiple phenomena, the combined effect of which gives rise to the common flame that we see and use in our daily life applications from cooking to propelling our vehicles to space. The most important thing that goes unnoticed about these flames is the effect of the various phenomena from its surrounding environment that affects its behavior and properties. These phenomena cause a variety of energy interactions that lead to various types of energy transformations which in turn affect the flame behavior. This paper focuses on experimentally investigating the effect of one such phenomenon, which is the acoustics or sound energy on diffusion flames. The subject in itself is extensively studied upon as thermo-acoustics globally, whereas the current work focuses on studying its effect on soot formation on diffusion flames. The said effect is studied in this research work by the use of a butane as fuel, fitted with a nozzle that houses 3 arrays consisting of 4 holes each that are placed equidistant to each other and the resulting flame impinged with sound from two independent and similar sound sources that are placed equidistant from the centre of the flame. The entire process is systematically video graphed using a 60 fps regular CCD and analysed for variation in flame heights and flickering frequencies where the fuel mass flow rate is maintained constant and the configuration of entrainment holes and frequency of sound are varied, whilst maintaining constant ambient atmospheric conditions. The current work establishes significant outcomes on the effect of acoustics on soot formation; it is noteworthy that soot formation is the main cause of pollution and a major cause of inefficiency of current propulsion systems. This work is one of its kinds, and its outcomes are widely applicable to commercial and domestic appliances that utilize combustion for energy generation or propulsion and help us understand them better, so that we can increase their efficiency and decrease pollution.

Keywords: thermoacoustics, entrainment, propulsion system, efficiency, pollution

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Authors: Eun Young Choi, So Hui Choe, Jin Yi Hyeon, Ji Young Jin, Bo Ram Keum, Jong Min Lim, Hyung Rae Cho, Kwang Keun Cho, In Soon Choi

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This research analyzed the effect of β-glucan that is expected to alleviate the production of inflammatory mediator in macrophagocyte, which was processed by the lipopolysaccharide (LPS) of Escherichia, a pathogen related to allergy. The incubated layer was used for nitric oxide (NO) analysis. The DNA-binding activation of the small unit of NF-κB was measured using ELISA-based kit. In RAW264.7 cells that were vitalized by E.coli LPS, β-glucan inhibited both the combatant and rendering phases of inducible NO synthase (iNOS)-derived NO. β-glucan increased the expression of heme oxygenase-1 (HO-1) in the cell that was stimulated by E.coli LPS, and HO-1 activation was inhibited by SnPP. This shows that NO production induced by LPS is related to the inhibition effect of β-glucan. The phosphorylation of JNK and p38 induced by LPS were not influenced by β-glucan, and IκB-α decomposition was not influenced either. Instead, β-glucan remarkably inhibited the phosphorylation of STAT1 that was induced by E.coli LPS. Overall, β-glucan inhibited the production of NO in macrophagocyte that was vitalized by E.coli LPS through HO-1 induction and STAT1 pathways inhibition in this research. As the host inflammation reaction control by β-glucan weakens the progress of allergy, β-glucan can be used as an effective treatment method.

Keywords: β-glucan, lipopolysaccharide (LPS), nitric oxide (NO), RAW264.7 cells, STAT1

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Authors: S. Aouabdi, M. Taibi

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The supervision of chemical processes is the subject of increased development because of the increasing demands on reliability and safety. An important aspect of the safe operation of chemical process is the earlier detection of (process faults or other special events) and the location and removal of the factors causing such events, than is possible by conventional limit and trend checks. With the aid of process models, estimation and decision methods it is possible to also monitor hundreds of variables in a single operating unit, and these variables may be recorded hundreds or thousands of times per day. In the absence of appropriate processing method, only limited information can be extracted from these data. Hence, a tool is required that can project the high-dimensional process space into a low-dimensional space amenable to direct visualization, and that can also identify key variables and important features of the data. Our contribution based on powerful techniques for development of a new monitoring method based on multi-scale entropy MSE in order to characterize the behaviour of the concentrations of different gases present in synthesis and soft sensor based on PCA is applied to estimate these variables.

Keywords: ammonia synthesis, concentrations of different gases, soft sensor, multi-scale entropy, multivarite statistics

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Authors: Vikram Chowdhary, Marek Vins

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The profitability of the pharmaceutical drug business has attracted considerable interest, but it also faces significant challenges. Counterfeiters take advantage of the industry's vulnerabilities, which are further exacerbated by the globalization of the market, online trading, and complex supply chains. Governments and organizations worldwide are dedicated to creating a secure environment that ensures a consistent and genuine supply of pharmaceutical products. In 2019, the European authorities implemented regulation EU 2016/161 to strengthen traceability and transparency throughout the entire drug supply chain. This regulation requires the addition of enhanced security features, such as serializing items to the saleable unit level or individual packs. Despite these efforts, the incidents of pharmaceutical counterfeiting continue to rise globally, with regulated territories being particularly affected. This paper examines the effectiveness of the drug serialization system implemented by European authorities. By conducting a systematic literature review, we assess the implementation of drug serialization and explore the potential benefits of integrating emerging digital technologies, such as RFID and Blockchain, to improve traceability and management. The objective is to fortify pharmaceutical supply chains against counterfeiters and manipulators and ensure their security.

Keywords: blockchain, counterfeit drugs, EU drug serialization, pharmaceutical industry, RFID

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Authors: Adeyemi Kamil Hamzah

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The contiguity of nations in international system suggests that world is a composite of socio-economic unit with people exploring and exploiting the potentials in the world via migrations. Thus, cross border migration has made positive contributions to social and economic development of individuals and nations by increasing the household incomes of the host countries. However, the cross border migrations in West Africa are becoming part of a dynamic and unstable world migration system. This is due to the nature and consequences of trans-border crimes in West Africa, with both short and long term effects on the socio-economic viability of developing countries like West African States. The paper identified that migration influenced cross-border crimes as well as the high spate of insurgencies in the sub-region. Furthermore, the consequential effect of a global village has imbalanced population flows, making some countries host and parasites to others. Also, stern and deft cross-border rules and regulations, as well as territorial security and protections, ameliorate cross border crimes and migration in West African sub-regions. Therefore, the study concluded that cross border migration is the linchpin of all kinds of criminal activities which affect the security of states in the sub-region.

Keywords: cross-border migration, border crimes, security, West Africa, development, globalisation

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Authors: Virginie Hergault, Siham Chebbah, Bertrand Frere

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Following in-house objectives, Central laboratory of Paris police Prefecture conducted a general review on models and Computational Fluid Dynamics (CFD) codes used to simulate pollutant dispersion in the atmosphere. Starting from that review and considering main features of Large Eddy Simulation, Central Laboratory Of Paris Police Prefecture (LCPP) postulates that the Fire Dynamics Simulator (FDS) model, from National Institute of Standards and Technology (NIST), should be well suited for air pollutant dispersion modeling. This paper focuses on the implementation and the evaluation of FDS in the frame of the European COST ES1006 Action. This action aimed at quantifying the performance of modeling approaches. In this paper, the CUTE dataset carried out in the city of Hamburg, and its mock-up has been used. We have performed a comparison of FDS results with wind tunnel measurements from CUTE trials on the one hand, and, on the other, with the models results involved in the COST Action. The most time-consuming part of creating input data for simulations is the transfer of obstacle geometry information to the format required by SDS. Thus, we have developed Python codes to convert automatically building and topographic data to the FDS input file. In order to evaluate the predictions of FDS with observations, statistical performance measures have been used. These metrics include the fractional bias (FB), the normalized mean square error (NMSE) and the fraction of predictions within a factor of two of observations (FAC2). As well as the CFD models tested in the COST Action, FDS results demonstrate a good agreement with measured concentrations. Furthermore, the metrics assessment indicate that FB and NMSE meet the tolerance acceptable.

Keywords: numerical simulations, atmospheric dispersion, cost ES1006 action, CFD model, cute experiments, wind tunnel data, numerical results

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Authors: Stephen Olusanmi Akintayo

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Access to safe drinking water remains a major challenge in Nigeria, and where available, the quality of the water is often in doubt. An alternative to the inadequate clean drinking water is being found in treated drinking water packaged in electrically heated sealed nylon and commonly referred to as “sachet water”. “Sachet water” is a common thing in Nigeria as the selling price is within the reach of members of the low socio- economic class and the setting up of a production unit does not require huge capital input. The bacteriological quality of selected “sachet water” stored at room temperature over a period of 56 days was determined to evaluate the safety of the sachet drinking water. Test for the detection of coliform bacteria was performed, and the result showed no coliform bacteria that indicates the absence of fecal contamination throughout 56 days. Heterotrophic plate count (HPC) was done at an interval 14 days, and the samples showed HPC between 0 cfu/mL and 64 cfu/mL. The highest count was observed on day 1. The count decreased between day 1 and 28, while no growths were observed between day 42 and 56. The decrease in HPC suggested the presence of residual disinfectant in the water. The organisms isolated were identified as Staphylococcus epidermis and S. aureus. The presence of these microorganisms in sachet water is indicative for contamination during processing and handling.

Keywords: coliform, heterotrophic plate count, sachet water, Staphyloccocus aureus, Staphyloccocus epidermidis

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Authors: Aikaterini Kentroti, Theodore H. Kaskalis

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Today, web servers are expected to serve thousands of client requests concurrently within stringent response time limits. In this paper, we evaluate experimentally and compare the performance as well as the resource utilization of popular web servers, which differ in their approach to handle concurrency. More specifically, Central Processing Unit (CPU)- and I/O intensive tests were conducted against the thread-based Apache and Go as well as the event-based Nginx and Node.js under increasing concurrent load. The tests involved concurrent users requesting a term of the Fibonacci sequence (the 10th, 20th, 30th) and the content of a table from the database. The results show that Go achieved the best performance in all benchmark tests. For example, Go reached two times higher throughput than Node.js and five times higher than Apache and Nginx in the 20th Fibonacci term test. In addition, Go had the smallest memory footprint and demonstrated the most efficient resource utilization, in terms of CPU usage. Instead, Node.js had by far the largest memory footprint, consuming up to 90% more memory than Nginx and Apache. Regarding the performance of Apache and Nginx, our findings indicate that Hypertext Preprocessor (PHP) becomes a bottleneck when the servers are requested to respond by performing CPU-intensive tasks under increasing concurrent load.

Keywords: apache, Go, Nginx, node.js, web server benchmarking

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Authors: Waqas Ashraf, Yasir Nawab, Haritham Khan, Habib Awais, Shahbaz Ahmad

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Seersucker is a popular lightweight fabric widely used in men’s and women’s suiting, casual wear, children’s clothing, house robes, bed spreads and for spring and summer wear. The puckered effect generates air spaces between body and the fabric, keeping the wearer cool in hot conditions. The aim of this work was to develop knitted seersucker fabric on single cylinder weft knitting machine using plain jersey structure. Core spun cotton yarn and cotton spun yarn of same linear density were used. Core spun cotton yarn, contains cotton fiber in the sheath and elastase filament in the core. The both yarn were fed at regular interval to feeders on the machine. The loop length and yarn tension were kept constant at each feeder. The samples were then scoured and bleached. After wet processing, the fabric samples were washed and tumble dried. Parameters like loop length, stitch density and areal density were measured after conditioning these samples for 24 hours in Standard atmospheric condition. Produced sample has a regular puckering stripe along the width of the fabric with same height. The stitch density of both the flat and puckered area of relaxed fabric was found to be different .Air permeability and moisture management tests were performed. The results indicated that the knitted seersucker fabric has better wicking and moisture management properties as the flat area contact, whereas puckered area held away from the skin. Seersucker effect in knitted fabric was achieved by the difference of contraction of both sets of courses produced from different types of yarns. The seer sucker fabric produce by knitting technique is less expensive as compared to woven seer sucker fabric as there is no need of yarn preparation. The knitted seersucker fabric is more practicable for summer dresses, skirts, blouses, shirts, trousers and shorts.

Keywords: air permeability, knitted structure, moisture management, seersucker

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Authors: Ami Nomura, Ken Imanishi, Yukinori Taniguchi, Etsuko Ueda, Tadahiro Wada, Shinichi Enoki

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Recently, there have been a lot of earthquakes in Japan. It is necessary to promote seismic isolation devices for buildings. The devices have been hardly diffused in attached houses, because the devices are very expensive. We should develop a low-cost seismic isolation device for detached houses. We suggested a new seismic isolation device which uses a two-layer circular tube as a unit. If hysteresis is produced in the two-layer circular tube under lateral compression load, we think that the two-layer circular tube can have energy absorbing capacity. It is necessary to contact the outer layer and the inner layer to produce hysteresis. We have previously reported how the inner layer comes in contact with the outer layer from a perspective of analysis used mechanics of materials. We have clarified that the inner layer comes in contact with the outer layer under a lateral compression load. In this paper, we explored contact area between the outer layer and the inner layer under a lateral compression load by using FEA. We think that changing the inner layer’s thickness is effective in increase the contact area. In order to change the inner layer’s thickness, we changed the shape of the inner layer. As a result, the contact area changes depending on the inner layer’s thickness. Additionally, we experimented to check whether hysteresis occurs in fact. As a consequence, we can reveal hysteresis in the two-layer circular tube under the condition.

Keywords: contact area, energy absorbing capacity, hysteresis, seismic isolation device

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Authors: Sharad Singh, Ajay Kumar Sinha

Abstract:

Coupled dampers like viscoelastic-frictional dampers for supplemental damping are a newer technique. In this paper, innovative Visco-frictional damping models have been presented and investigated. This paper attempts to couple frictional and fluid viscous dampers into a single unit of supplemental dampers. Visco-frictional damping model is developed by series and parallel coupling of frictional and fluid viscous dampers using Maxwell and Kelvin-Voigat models. The time analysis has been performed using numerical simulation on an SDOF system with varying fundamental periods, subject to a set of 12 ground motions. The simulation was performed using the direct time integration method. MATLAB programming tool was used to carry out the numerical simulation. The response behavior has been analyzed for the varying time period and added damping. This paper compares the response reduction behavior of the two modes of coupling. This paper highlights the performance efficiency of the suggested damping models. It also presents a mathematical modeling approach to visco-frictional dampers and simultaneously suggests the suitable mode of coupling between the two sub-units.

Keywords: hysteretic damping, Kelvin model, Maxwell model, parallel coupling, series coupling, viscous damping

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Authors: Divya Pathak, James Sloane

Abstract:

Surgical treatment of midface fractures should ideally occur within two weeks of injury, after which bony healing and consolidation make the repair more difficult for the operating surgeon. The oral and maxillofacial unit at the Royal Surrey Hospital is the tertiary referral center for maxillofacial trauma from five regional hospitals. This is a complete audit cycle of midface trauma referrals managed over a one year period. The standard set was that clinical assessment of the midface fracture would take place in a consultant led outpatient clinic within 7 days, and when indicated, surgical fixation would occur within 10 days of referral. Retrospective data was collected over one year (01/11/2018 - 31/12/2019). Three key changes were implemented: an IT referral mailbox, standardization of an on-call trauma table, and creation of a trauma theatre list. Re-audit was carried out over six months completing the cycle. 283 midface fracture referrals were received, of which 22 patients needed surgical fixation. The average time from referral to outpatient follow-up improved from 14.5 days to 8.3 days, and time from referral to surgery improved from 21.5 days to 11.6 days. Changes implemented in this audit significantly improved patient prioritization to appropriate outpatient clinics and shortened time to surgical intervention.

Keywords: maxillofacial trauma, midface trauma, oral and maxillofacial surgery, surgery fixation

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Authors: Chajira Garrote, Laura Arango, Lourdes Merino

Abstract:

This research explains how to obtain nutritious powder from a variety of ripe mango peels Hilacha (Mangifera indica L.) to use it as a food additive. Also, this study intends to use efficiently the by-products resulting from the operations of mango pulp manufacturing process by processing companies with the aim of giving them an added value. The physical and chemical characteristics of the mango peels and the benefits that may help humans, were studied. Unit operations are explained for the processing of mango peels and the production of nutritive powder as a food additive. Emphasis is placed on the preliminary operations applied to the raw material and on the drying method, which is very important in this project to obtain the suitable characteristics of the nutritive powder. Once the powder was obtained, it was subjected to laboratory tests to determine its functional properties: water retention capacity (WRC) and oil retention capacity (ORC), also a sensory analysis for the powder was performed to determine the product profile. The nutritive powder from the ripe mango peels reported excellent WRC and ORC values: 7.236 g of water / g B.S. and 1.796 g water / g B.S. respectively and the sensory analysis defined a complete profile of color, odor and texture of the nutritive powder, which is suitable to use it in the food industry.

Keywords: mango, peel, powder, nutritive, functional properties, sensory analysis

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Authors: Magy Magdy Danial Riad

Abstract:

Introduction: Glycosides: Enzymatic and hydrolysis reactions of glycosides, mechanism of action, SAR, therapeutic uses and toxicity of glycosides. Cardiac glycosides of digitalis, bufa and squill. Structure of salicin, hesperidin and rutin. Glycosides are certain molecules in which a sugar part is bound to some other part. Glycosides play numerous important roles in living organisms. Formally, a glycoside is any molecule in which a sugar group is bonded through its anomeric carbon to another group and form glycosidic bonds via an O-glycosidic bond or an S-glycosidic bond; glycosides involving the latter are also called thioglycosides. The purpose: the addition of sugar be bonded to a non-sugar for the molecule to qualify as a glycoside, The sugar group is then known as the glycone and the non-sugar group as the aglycone or genin part of the glycoside. The glycone can consist of a single sugar group (monosaccharide) or several sugar groups (oligosaccharide). The glycone and aglycone portions can be chemically separated by hydrolysis in the presence of acid. Methods: There are also numerous enzymes that can form and break glycosidic bonds. Results: The most important cleavage enzymes are the glycoside hydrolases, and the most important synthetic enzymes in nature are glycosyltransferases. Mutant enzymes termed glycosynthases have been developed that can form glycosidic bonds. Conclusions: There are a great many ways to chemically synthesize glycosidic bonds.

Keywords: glycosides, bufa, squill, thioglycosides

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Authors: Win Nee Phong, Tau Chuan Ling, Pau Loke Show

Abstract:

From an industrial perspective, the exploitation of microalgae for protein source is of great economical and commercial interest due to numerous attractive characteristics. Nonetheless, the release of protein from microalgae is limited by the multiple layers of the rigid thick cell wall that generally contain a large proportion of cellulose. Thus an efficient cell disruption process is required to rupture the cell wall. The conventional downstream processing methods which typically involve several unit operational steps such as disruption, isolation, extraction, concentration and purification are energy-intensive and costly. To reduce the overall cost and establish a feasible technology for the success of the large-scale production, microalgal industry today demands a more cost-effective and eco-friendly technique in downstream processing. One of the main challenges to extract the proteins from microalgae is the presence of rigid cell wall. This study aims to provide some guidance on the selection of the efficient solvent to facilitate the proteins released during the cell disruption process. The effects of solvent types such as methanol, ethanol, 1-propanol and water in rupturing the microalgae cell wall were studied. It is interesting to know that water is the most effective solvent to recover proteins from microalgae and the cost is cheapest among all other solvents.

Keywords: green, microalgae, protein, solvents

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Authors: Javaid Ahmad Dar, Mohammad Asif

Abstract:

The present study investigates the long-run impact of financial development, energy consumption and economic growth on greenhouse gas emissions for India, in presence of endogenous structural breaks, over a period of 1971-2013. Autoregressive distributed lag bounds testing procedure and Hatemi-J threshold cointegration technique have been used to test the variables for cointegration. ARDL bounds test did not confirm any cointegrating relationship between the variables. The threshold cointegration test establishes the presence of long-run impact of financial development, energy use and economic growth on greenhouse gas emissions in India. The results reveal that the long-run relationship between the variables has witnessed two regime shifts, in 1978 and 2002. The empirical evidence shows that financial sector development and energy consumption in India degrade environment. Unlike previous studies, this paper finds no statistical evidence of long-run relationship between economic growth and environmental deterioration. The study also challenges the existence of environmental Kuznets curve in India.

Keywords: cointegration, financial development, global warming, greenhouse gas emissions, regime shift, unit root

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Authors: L. L. Ivy-Yap, H. A. Bekhet

Abstract:

As the Malaysian residential electricity consumption continued to increase rapidly, effective energy policies, which address factors affecting residential electricity consumption, is urgently needed. This study attempts to investigate the relationship between residential electricity consumption (EC), real disposable income (Y), price of electricity (Pe) and population (Po) in Malaysia for 1978-2011 periods. Unlike previous studies on Malaysia, the current study focuses on the residential sector, a sector that is important for the contemplation of energy policy. The Phillips-Perron (P-P) unit root test is employed to infer the stationary of each variable while the bound test is executed to determine the existence of co-integration relationship among the variables, modeled in an Autoregressive Distributed Lag (ARDL) framework. The CUSUM and CUSUM of squares tests are applied to ensure the stability of the model. The results suggest the existence of long-run equilibrium relationship and bidirectional Granger causality between EC and the macroeconomic variables. The empirical findings will help policy makers of Malaysia in developing new monitoring standards of energy consumption. As it is the major contributing factor in economic growth and CO2 emission, there is a need for more proper planning in Malaysia to attain future targets in order to cut emissions.

Keywords: co-integration, elasticity, granger causality, Malaysia, residential electricity consumption

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Authors: Joseph Carl Macalintal, Erlinda Armovit

Abstract:

Magnesium sulfate has been a mainstay in the management of preeclampsia and is associated with a decreased incidence of morbidity and mortality. The syndrome has an unpredictable course, sometimes rapidly evolving to full-blown disease. In patients with deteriorating status, it is indicated to terminate the pregnancy via cesarean section. The anesthesiologists would prefer to have the procedure done under regional anesthesia; however, there may be cases when neuraxial anesthesia is contraindicated, or a general anesthesia would permit prompt delivery of the fetus. A patient with severe preeclampsia was given magnesium sulfate intrapartum, wherein a primary cesarean section was indicated for arrest in cervical dilatation, and was performed under general anesthesia. The patient developed acute respiratory failure and the causes of this occurrence were investigated in this report. It was later found out that neither the hypermagnesemia nor the muscle relaxant alone caused the patient’s condition but the interaction between the two. The patient was managed expectantly at the intensive care unit (ICU) and was eventually extubated during the 1st post-operative day. Knowledge of this drug interaction would allow obstetricians to advise their patients and their family about the possibility of prolonged intubation and ICU admission. This would also bring to the anesthesiologists’ attention the need to decrease the dose of muscle relaxant and to prepare drugs for immediate decurarisation.

Keywords: eclampsia, magnesium sulfate, preeclampsia, rocuronium bromide

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