Search results for: day night band

Authors: Irlana C. do Mar, Thayna A. Ferreira, Dayane S. Rezende, Bruno A. M. Figueira, José M. R. Mercury

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This work presents a low-cost Mn starting material to synthesis manganese oxide octahedral molecular sieve with Mg²⁺ in the tunnel (Mg-OMS-1), based on the Mn residues from Carajás Mineral Province (Amazon, Brazil). After hydrothermal and cation exchange procedures, the Mn residues transformed to a single phase, Mg-OMS-1. The raw material and the synthesis processes were analyzed by means of X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Infrared spectroscopy (FTIR). The tunnel structure was synthesized hydrothermally at 180 °C for three days without impurities. According to the XRD analysis, the formation of crystalline Mg-OMS-1 was identified through reflections at 9.8º, 12º and 18º (2θ), as well as a thermal stability around 300 ºC. The SEM analysis indicated that the final product presents good crystallinity with a homogeneous size. In addition, an intense and diagnostic FTIR band was identified at 515 cm⁻¹ related to the MnO₆ octahedral stretching vibrations.

Keywords: Mn residues , Octahedral Molecular Sieve, Synthesis, Characterization

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Authors: C. P. Autry, A. W. Roscoe, Mykhailo Magal

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We discuss the theoretical model underlying 2BPA (two-band peer authentication), a practical alternative to conventional authentication of entities and data in IoT. In essence, this involves assembling a virtual map of authentication assets in the network, typically leading to many paths of confirmation between any pair of entities. This map is continuously updated, confirmed, and evaluated. The value of authentication along multiple disjoint paths becomes very clear, and we require analogues of triangulation to extend authentication along extended paths and deliver it along all possible paths. We discover that if an attacker wants to make an honest node falsely believe she has authenticated another, then the length of the authentication paths is of little importance. This is because optimal attack strategies correspond to minimal cuts in the authentication graph and do not contain multiple edges on the same path. The authentication provided by disjoint paths normally is additive (in entropy).

Keywords: authentication, edge computing, industrial IoT, post-quantum resistance

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Authors: Guntur Bagus Pamungkas

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As part of a tropical country that is normally rich in forest land areas, Indonesia has always been in the world's spotlight due to its significantly increasing process of deforestation. In one hand, it is related to the mainstay for maintaining the sustainability of the earth's ecosystem functions. On the other hand, they also cover the various potential sources of the global economy. Therefore, it can always be the target of different scale of investors to excessively exploit them. No wonder the emergence of disasters in various characteristics always comes up. In fact, the deforestation phenomenon does not only occur in various forest land areas in the main islands of Indonesia but also includes Java Island, the most densely populated areas in the world. This island only remains the forest land of about 9.8% of the total forest land in Indonesia due to its long history of it, especially in Central Java Province, the most densely populated area in Java. Again, not surprisingly, this province belongs to the area with the highest frequency of disasters because of it, landslides in particular. One of the areas that often experience it is Banjarnegara District, especially in mountainous areas that lies in the range from 1000 to 3000 meters above sea level, where the remains of land forest area can easyly still be found. Even among them still leaves less untouchable tropical rain forest whose area also covers part of a neighboring district, Pekalongan, which is considered to be the rest of the world's little paradise on Earth. The district's landscape is indeed beautiful, especially in the Dieng area, a major tourist destination in Central Java Province after Borobudur Temple. However, annually hazardous always threatens this district due to this landslide disaster. Even, there was a tragic event that was buried with its inhabitants a few decades ago. This research aims to find part of the concept of effective forest management through monitoring the presence of remaining forest areas in this area. The research implemented monitoring of deforestation rates using the Stochastic Cellular Automata-Markov Chain (SCA-MC) method, which serves to provide a spatial simulation of land use and cover changes (LULCC). This geospatial process uses the Landsat-8 OLI image product with Thermal Infra-Red Sensors (TIRS) Band 10 in 2020 and Landsat 5 TM with TIRS Band 6 in 2010. Then it is also integrated with physical and social geography issues using the QGIS 2.18.11 application with the Mollusce Plugin, which serves to clarify and calculate the area of land use and cover, especially in forest areas—using the LULCC method, which calculates the rate of forest area reduction in 2010-2020 in Banjarnegara District. Since the dependence of this area on the use of forest land is quite high, concepts and preventive actions are needed, such as rehabilitation and reforestation of critical lands through providing proper monitoring and targeted forest management to restore its ecosystem in the future.

Keywords: deforestation, populous area, LULCC method, proper control and effective forest management

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Authors: Moqbil S. Alenazi, Magdy. M. Elkhateeb

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A comprehensive photometric study and evolutionary state for the newly discovered Beta Lyr systems V0487 Lac, V0566 Hya, and V0666 Lac were carried out by means of their first photometric observations. New times of minima were estimated from the observed light curves, and first (O-C) curves were established for all systems. A windows interface version of the Wilson and Devinney code (W-D) based on model atmospheres and a pass band prescription have been used for the radiative treatment. The accepted models reveal some absolute parameters for the studied systems, which are used in adopting the spectral type of the system's components and their evolutionary status. Distances to each system were calculated, and physical properties were estimated. Locations of the systems on the theoreticalmass–luminosity and mass–radius relations revealed a good fit for all systems components except for the secondary component of the system V0487 Lac.

Keywords: eclipsing binaries, light curve modelling, evolutionary state

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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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Using the first-principles method, we investigate the structural, electronic, and magnetic properties of the diluted magnetic semiconductors CdCoTe and CdMnTe in the zinc blende phase with 12.5% of Cr. The calculations are performed by a developed full potential augmented plane wave (FP-L/APW) method within the spin density functional theory (DFT). As exchange–correlation potential, we used the new generalized gradient approximation GGA. Structural properties are determined from the total energy calculations and we found that these compounds are stable in the ferromagnetic phase. We discuss the electronic structures, total and partial densities of states and local moments. Finally, CdCoTe and CdMnTe in the zinc-blend phase show the half-metallic ferromagnetic nature and are expected to be potential materials for spintronic devices.

Keywords: DFT, GGA, band structures, half-metallic, spintronics

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Authors: Manjunath Attibele, Alsawafi Manal, Al Dughaishi Tamima

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Introduction: The purpose of this study was to describe the clinical characteristics and types of mechanisms of injuries caused by Motor vehicle accidents (MVA) during pregnancy. To analyze the patterns of accidents during pregnancy and its adverse consequences on both maternal and fetal outcome. Methods: This was a retrospective cohort study on pregnant patients who met with MVAs The study period was from January 1, 2010, to December 31, 2019. All relevant data were retrieved from electronic patients’ records from the hospital information system and from the antenatal ward admission register Results: Out of 168 women who had motor vehicle accidents during the study period, of which, 39 (23.2%) women during pregnancy. Twenty-one (53.8%) women were over 30 years old. Thirty-five (89.7%) women were Omanis, and 27 (69.2%) were in their third trimester. Twenty-three (59%) of accidents happened at night, and 31 (79.5%) of them happened on a weekday. Twenty-two (56.4%) of women were driving themselves, and 24 (61.5%) of them were not using any seatbelt. Accident related abdominal & back pain was seen in 23(59%) women. Regarding the outcome of pregnancy, 23 (74.2%) had a normal vaginal delivery. The mean accident to delivery interval was 7 weeks. Thirty (96.7%) of involved newborns were relatively healthy. One woman (3.2%) had a ruptured uterusleading to fetal death (3.2%). Conclusion: This study showed that the incidence of motor vehicle accidents during pregnancy is around 23.2% . Majority had trauma-associated pain. One serious injury to a woman causing a ruptured uterus which lead to fetal death. Majority of involved newborns were relatively healthy. No reported maternal death.

Keywords: motor vehicle accidents, pregnancy, maternal outcome, fetal outcome

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Authors: Tokuei Sako, Paul-Antoine Hervieux

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The energy-level structure of a pair of electron and positron confined in a quasi-one-dimensional nano-scale potential well has been investigated focusing on its trend in the small limit of confinement strength ω, namely, the Wigner molecular regime. An anisotropic Gaussian-type basis functions supplemented by high angular momentum functions as large as l = 19 has been used to obtain reliable full configuration interaction (FCI) wave functions. The resultant energy spectrum shows a band structure characterized by ω for the large ω regime whereas for the small ω regime it shows an energy-level pattern dominated by excitation into the in-phase motion of the two particles. The observed trend has been rationalized on the basis of the nodal patterns of the FCI wave functions.

Keywords: confined systems, positron, wave function, Wigner molecule, quantum dots

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Authors: Djeddi Mabrouk

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The slow coming together between the Afro-Eurasia plates seems to be the main cause of the active deformation in the whole of North Africa which in consequence come true in Algeria with a large zone of deformation in an enough large limited band, southern through Saharan atlas and northern through tell atlas. Maghrebin and Atlassian Chain along North Africa are the consequence of this convergence. In junction zone, we have noticed a compressive regime NW-SE with a creases-faults structure and structured overthrust. From a geological point of view the north part of Algeria is younger then Saharan platform, it’s changing so unstable and constantly in movement, it’s characterized by creases openly reversed, overthrusts and reversed faults, and undergo perpetually complex movement vertically and horizontally. On structural level the north of Algeria it's a part of erogenous alpine peri-Mediterranean and essentially the tertiary age It’s spread from east to the west of Algeria over 1200 km.This oogenesis is extended from east to west on broadband of 100 km.The alpine chain is shaped by 3 domains: tell atlas in north, high plateaus in mid and Saharan atlas in the south In extreme south we find the Saharan platform which is made of Precambrian bedrock recovered by Paleozoic practically not deformed. The Algerian north and the Saharan platform are separated by an important accident along of 2000km from Agadir (Morocco) to Gabes (Tunisian). The seismic activity is localized essentially in a coastal band in the north of Algeria shaped by tell atlas, high plateaus, Saharan atlas. Earthquakes are limited in the first 20km of the earth's crust; they are caused by movements along faults of inverted orientation NE-SW or sliding tectonic plates. The center region characterizes Strong Earthquake Activity who locates mainly in the basin of Mitidja (age Neogene).The southern periphery (Atlas Blidéen) constitutes the June, more Important seism genic sources in the city of Algiers and east (Boumerdes region). The North East Region is also part of the tellian area, but it is characterized by a different strain in other parts of northern Algeria. The deformation is slow and low to moderate seismic activity. Seismic activity is related to the tectonic-slip earthquake. The most pronounced is that of 27 October 1985 (Constantine) of seismic moment magnitude Mw = 5.9. North-West region is quite active and also artificial seismic hypocenters which do not exceed 20km. The deep seismicity is concentrated mainly a narrow strip along the edge of Quaternary and Neogene basins Intra Mountains along the coast. The most violent earthquakes in this region are the earthquake of Oran in 1790 and earthquakes Orléansville (El Asnam in 1954 and 1980).

Keywords: alpine chain, seismicity north Algeria, earthquakes in Algeria, geophysics, Earth

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Authors: A. O. Boyo, A. T. Akinwunmi

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The effect of extracting solvent and adjustment of pHs on the stability of Terminalia catappa L. dye-sensitized solar cell was investigated. We introduced ZnO as an alternative to TiO2 in the dye sensitized solar cells (DSSCs) due to its band gap similar to TiO2, higher electron mobility, and flexible procedures of preparations. Dye-sensitized solar cells (DSSCs) based on Terminalia catappa L. was extracted in water (A), ethanol (B) and the mixture of ethanol and water in the ratio 1:1by volume (C). The best performance Solar cells sensitized was from extracts A and achieved up to Jsc 1.51 mAcm−2, Voc 0.75V, FF 0.88 and η 0.63%. We notice that as pHs decreases there is the increase in DSSC efficiency. There is Long period stability in efficiency of the cells prepared using A than in C and a fair stability in efficiency of B cell. The results obtained with extracts B and C confirmed that Ethanol with water could not be considered as a suitable solvent for the extraction of natural dye.

Keywords: zinc oxide, dye-sensitized solar cell, terminalia catappa L., TiO2

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Authors: Misbahuddin Mahammad, P. Chandra Sekhar, Metuku Shyamsunder

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The oversampled output of a sigma-delta modulator is decimated to Nyquist sampling rate by decimation filters. The decimation filters work twofold; they decimate the sampling rate by a factor of OSR (oversampling rate) and they remove the out band quantization noise resulting in an increase in resolution. The speed, area and power consumption of oversampled converter are governed largely by decimation filters in sigma-delta A/D converters. The scope of the work is to design a decimation filter for sigma-delta ADC and simulation using MATLAB. The decimation filter structure is based on cascaded-integrated comb (CIC) filter. A second decimation filter is using CIC for large rate change and cascaded FIR filters, for small rate changes, to improve the frequency response. The proposed structure is even more hardware efficient.

Keywords: sigma delta modulator, CIC filter, decimation filter, compensation filter, noise shaping

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Authors: Vincent Alexander, Rizkita Esyanti

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Leaves of Stevia rebaudiana contain steviol glycoside which mainly comprise of stevioside, a natural sweetener compound that is 100-300 times sweeter than sucrose. Current cultivation method of Stevia rebaudiana in Indonesia has yet to reach its optimum efficiency and productivity to produce stevioside as a safe sugar substitute sweetener for people with diabetes. An alternative method that is not limited by environmental factor is in vitro temporary immersion system (TIS) culture method using recipient for automated immersion (RITA^®) bioreactor. The aim of this research was to evaluate the effect of red LED light induction towards shoot growth and stevioside accumulation in TIS RITA^® bioreactor system, as an endeavour to increase the secondary metabolite synthesis. The result showed that the stevioside accumulation in TIS RITA^® bioreactor system induced with red LED light for one hour during night was higher than that in TIS RITA^® bioreactor system without red LED light induction, i.e. 71.04 ± 5.36 μg/g and 42.92 ± 5.40 μg/g respectively. Biomass growth rate reached as high as 0.072 ± 0.015/day for red LED light induced TIS RITA^® bioreactor system, whereas TIS RITA^® bioreactor system without induction was only 0.046 ± 0.003/day. Productivity of Stevia rebaudiana shoots induced with red LED light was 0.065 g/L medium/day, whilst shoots without any induction was 0.041 g/L medium/day. Sucrose, salt, and inorganic consumption in both bioreactor media increased as biomass increased. It can be concluded that Stevia rebaudiana shoot in TIS RITA^® bioreactor induced with red LED light produces biomass and accumulates higher stevioside concentration, in comparison to bioreactor without any light induction.

Keywords: LED, Stevia rebaudiana, Stevioside, TIS RITA

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Authors: Temesgen Geremew

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This study investigates the evolution of polythiophene nanoparticles (PThNPs) as surface-enhanced Raman spectroscopy (SERS) sensors for Pb²⁺ detection in river water. We analyze the PThNPs' optical, structural, and morphological properties at different stages of their development to understand their SERS performance. Techniques like UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) are employed for characterization. The SERS sensitivity towards Pb²⁺ is evaluated by monitoring the peak intensity of a specific Raman band upon increasing metal ion concentration. The study aims to elucidate the relationship between the PThNPs' characteristics and their SERS efficiency for Pb²⁺ detection, paving the way for optimizing their design and fabrication for improved sensing performance in real-world environmental monitoring applications.

Keywords: polythiophene, Pb2+, SERS, nanoparticles

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Authors: P. Kaewchanthuek, R. Rawonghad, B. Marungsri

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This paper presents the experimental results of high-density polyethylene cable spacers for 22 kV distribution systems under salt water dip wheel test based on IEC 62217. The strength of anti-tracking and anti-erosion of cable spacer surface was studied in this study. During the test, dry band arc and corona discharge were observed on cable spacer surface. After 30,000 cycles of salt water dip wheel test, obviously surface erosion and tracking were observed especially on the ground end. Chemical analysis results by fourier transforms infrared spectroscopy showed chemical changed from oxidation and carbonization reaction on tested cable spacer. Increasing of C=O and C=C bonds confirmed occurrence of these reactions.

Keywords: cable spacer, HDPE, ageing of cable spacer, salt water dip wheel test

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Authors: Joseph Salim

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This paper proposes the development of a supervised machine learning system to predict the consequences of untreated bruxism (teeth grinding) on gingival (gum) recession and jaw pain (most often bilateral jaw pain with possible headaches and limited ability to open the mouth). As a general dentist in a multi-specialty practice, the author has encountered many patients suffering from these issues due to uncontrolled bruxism (teeth grinding) at night. The most effective treatment for managing this problem involves wearing a nightguard during sleep and receiving therapeutic Botox injections to relax the muscles (the masseter muscle) responsible for grinding. However, some patients choose to postpone these treatments, leading to potentially irreversible and costlier consequences in the future. The proposed machine learning model aims to track patients who forgo the recommended treatments and assess the percentage of individuals who will experience worsening jaw pain, gingival (gum) recession, or both within a 3-to-5-year timeframe. By accurately predicting these outcomes, the model seeks to motivate patients to address the root cause proactively, ultimately saving time and pain while improving quality of life and avoiding much costlier treatments such as full-mouth rehabilitation to help recover the loss of vertical dimension of occlusion due to shortened clinical crowns because of bruxism, gingival grafts, etc.

Keywords: artificial intelligence, machine learning, predictive insights, bruxism, teeth grinding, therapeutic botox, nightguard, gingival recession, gum recession, jaw pain

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Authors: M. E. Velásquez Torres, F. Tzompantzi, J. C. Castillo-Rodríguez, A. G. Romero Villegas, S. Mendéz-Salazar, C. E. Santolalla-Vargas, J. Cardoso-Martínez

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Photocatalytic degradation, as an advanced oxidation technology, is a promising method in organic pollutant degradation. In this sense, chlorophenols should be removed from the water because they are highly toxic. The TiO₂ - X% ZnS photocatalysts, where X represents the molar percentage of ZnS (3%, 5%, 10%, and 15%), were synthesized using the one-step sol-gel method to use them as photocatalysts to degrade 4-chlorophenol. The photocatalysts were synthesized by a one-step sol-gel method. They were refluxed for 36 hours, dried at 80°C, and calcined at 400°C. They were labeled TiO₂ - X%ZnS, where X represents the molar percentage of ZnS (3%, 5%, 10%, and 15%). The band gap was calculated using a Cary 100 UV-Visible Spectrometer with an integrating sphere accessory. Ban gap value of each photocatalyst was: 2.7 eV of TiO₂, 2.8 eV of TiO₂ - 3%ZnS and TiO₂ - 5%ZnS, 2.9 eV of TiO₂ - 10%ZnS and 2.6 eV of TiO2 - 15%ZnS. In a batch type reactor, under the irradiation of a mercury lamp (λ = 254 nm, Pen-Ray), degradations of 55 ppm 4-chlorophenol were obtained at 360 minutes with the synthesized photocatalysts: 60% (3% ZnS), 66% (5% ZnS), 74% (10% ZnS) and 58% (15% ZnS). In this sense, the best material as a photocatalyst was TiO₂ -10%ZnS with a degradation percentage of 74%.

Keywords: 4-chlorophenol, photocatalysis, water pollutant, sol-gel

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Authors: O. P. Yadav

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Nano-size Ag-N co-doped ZnO/CuO composite photo-catalyst has been synthesized by chemical method and characterized using XRD, TEM, FTIR, AAS and UV-Vis spectroscopic techniques. Photo-catalytic activity of as-synthesized nanomaterial has been studied using degradation of methyl orange as a probe under UV as well as visible radiations. Ag-N co-doped ZnO/CuO composite showed higher photo-catalytic activity than Ag- or N-doped ZnO and undoped ZnO-CuO composite photo-catalysts. The observed highest activity of Ag-N co-doped ZnO-CuO among the studied photo-catalysts is attributed to the cumulative effects of lowering of band-gap energy and decrease of recombination rate of photo-generated electrons and holes owing to doped N and Ag, respectively. Effects of photo-catalyst load, pH and substrate initial concentration on degradation of methyl orange have also been studied. Photo-catalytic degradation of methyl orange follows pseudo first order kinetics.

Keywords: degradation, nanocomposite, photocatalyst, spectroscopy, XRD

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Authors: Dahmane Mohamed, Tab Asma, Trari Mohamed

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BaMnO₃ nanoparticles were synthesized by a nitrate route. Its structure and physical properties were characterized by means of X-ray powder diffraction, radio crystallographic analysis, ultraviolet-visible absorption spectroscopy in diffuse reflectance mode, infrared spectroscopy, and electrochemical measurements. The optical study showed that barium manganese oxide presents a direct transition with band energy 2.13 eV. The electrochemical study allowed us to identify the redox peaks and the corrosion parameters. Capacitance measurement clearly showed n-type conductivity. The photodegradation of paracetamol by BaMnO₃ was followed by UV-visible spectrophotometry; the results were then confirmed by HPLC. BaMnO₃ has shown its photocatalytic efficiency in the photodegradation of 10 mg/L paracetamol under solar irradiation, with a yield of ≈ 88%. The kinetic study has shown that paracetamol degrades with first-order kinetics.

Keywords: BaMnO₃, photodegradation, paracetamol, electrochemical measurements, solar light

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Authors: R. A. Akande, M. L. Mnisi

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Introduction: Aloe vera (Aloe barbadensis miller) flowers are carried in a large candelabra-like flower-head. Aloe barbadensis miller has been known as a traditional herbal medicine for the treatment of many diseases and sicknesses mainly for skin conditions such as sunburns, cold sores and frostbite. It is also used as a fresh food preservative. The main objective of this study is to determine the antioxidant activity of Aloe barbadensis miller. Methodology: The plant material (3g) was separately extracted with 30 mL of solvent with varying polarities (methanol and ethyl acetate)(technical grade, Merck) in 50ml polyester centrifuge tubes. The tubes was be shaken for 30 minutes on a linear shaker and left over night. The supernatant was filtered using a Whitman No. 1 filter paper before being transferred into pre-weighed glass containers. The solvent was allowed to evaporate under a fan in a room to quantify extraction efficacy. The, tin layer chromatography(TLC) plates were prepared and Pasteur pipette was used for spotting each extractant (methanol and ethyl acetate) on the TLC plates and the plate was developed in saturated TLC tank .and dipped in vanillin sulphuric acid mixture and heated at 110 to detect separate compound .and dipped in DDPH in methanol to detect antioxidant. Expected contribution to knowledge: It was observed that different compounds which interact differently with different solvent such as methanol, ethyl acetate having difference polarities were observed. The yellow spots also observed from the plate dipped in DDPH indicate that Aloe barbadensis miller has antioxidant.

Keywords: antioxidant activity, Aloe barbadensis miller, tin layer chromatography, DDPH

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Authors: T. Bielewicz, S. Dogan, C. Klinke

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Two-dimensional, solution-processable semiconductor materials are interesting for low-cost electronic applications [1]. We demonstrate the synthesis of lead sulfide nanosheets and how their size, shape and height can be tuned by varying concentrations of pre-cursors, ligands and by varying the reaction temperature. Especially, the charge carrier confinement in the nanosheets’ height adjustable from 2 to 20 nm has a decisive impact on their electronic properties. This is demonstrated by their use as conduction channel in a field effect transistor [2]. Recently we also showed that especially thin nanosheets show a high carrier multiplication (CM) efficiency [3] which could make them, through the confinement induced band gap and high photoconductivity, very attractive for application in photovoltaic devices. We are already able to manufacture photovoltaic devices out of single nanosheets which show promising results.

Keywords: physical sciences, chemistry, materials, chemistry, colloids, physics, condensed-matter physics, semiconductors, two-dimensional materials

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Authors: Jeong Min Baik

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We present that the electroluminescence (EL) properties and electrical output power of flexible N-face p-type GaN thin films can be tuned by strain-induced piezo-potential generated across the metal-semiconductor-metal structures. Under different staining conditions (convex and concave bending modes), the transport properties of the GaN films can be changed due to the spontaneous polarization of the films. The I-V characteristics with the bending modes show that the convex bending can increase the current across the films by the decrease in the barrier height at the metal-semiconductor contact, increasing the EL intensity of the P-N junction. At convex bending, it is also shown that the flexible p-type GaN films can generate an output voltage of up to 1.0 V, while at concave bending, 0.4 V. The change of the band bending with the crystal polarity of GaN films was investigated using high-resolution photoemission spectroscopy. This study has great significance on the practical applications of GaN in optoelectronic devices and nanogenerators under a working environment.

Keywords: GaN, flexible, laser lift-off, nanogenerator

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Authors: Mitali Saha, Soma Das

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The fabrication of nanoscale materials for use in chemical sensing, biosensing and biological analyses has proven a promising avenue in the last few years. Cholesterol has aroused considerable interest in recent years on account of its being an important parameter in clinical diagnosis. There is a strong positive correlation between high serum cholesterol level and arteriosclerosis, hypertension, and myocardial infarction. Enzyme-based electrochemical biosensors have shown high selectivity and excellent sensitivity, but the enzyme is easily denatured during its immobilization procedure and its activity is also affected by temperature, pH, and toxic chemicals. Besides, the reproducibility of enzyme-based sensors is not very good which further restrict the application of cholesterol biosensor. It has been demonstrated that carbon nanotubes could promote electron transfer with various redox active proteins, ranging from cytochrome c to glucose oxidase with a deeply embedded redox center. In continuation of our earlier work on the synthesis and applications of carbon and metal based nanoparticles, we have reported here the synthesis of carbon nanotubes (CCNT) by burning coconut oil under insufficient flow of air using an oil lamp. The soot was collected from the top portion of the flame, where the temperature was around 6500C which was purified, functionalized and then characterized by SEM, p-XRD and Raman spectroscopy. The SEM micrographs showed the formation of tubular structure of CCNT having diameter below 100 nm. The XRD pattern indicated the presence of two predominant peaks at 25.20 and 43.80, which corresponded to (002) and (100) planes of CCNT respectively. The Raman spectrum (514 nm excitation) showed the presence of 1600 cm-1 (G-band) related to the vibration of sp2-bonded carbon and at 1350 cm-1 (D-band) responsible for the vibrations of sp3-bonded carbon. A nonenzymatic cholesterol biosensor was then fabricated on an insulating Teflon material containing three silver wires at the surface, covered by CCNT, obtained from coconut oil. Here, CCNTs worked as working as well as counter electrodes whereas reference electrode and electric contacts were made of silver. The dimensions of the electrode was 3.5 cm×1.0 cm×0.5 cm (length× width × height) and it is ideal for working with 50 µL volume like the standard screen printed electrodes. The voltammetric behavior of cholesterol at CCNT electrode was investigated by cyclic voltammeter and differential pulse voltammeter using 0.001 M H2SO4 as electrolyte. The influence of the experimental parameters on the peak currents of cholesterol like pH, accumulation time, and scan rates were optimized. Under optimum conditions, the peak current was found to be linear in the cholesterol concentration range from 1 µM to 50 µM with a sensitivity of ~15.31 μAμM−1cm−2 with lower detection limit of 0.017 µM and response time of about 6s. The long-term storage stability of the sensor was tested for 30 days and the current response was found to be ~85% of its initial response after 30 days.

Keywords: coconut oil, CCNT, cholesterol, biosensor

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Authors: Hamid Merzouk, Dajhida Talantikite, Amel Tounsi

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Thin films of ZnS have been deposited by chemical route into acidic medium. The deposition time fixed at 5 hours, and the bath temperature varied from 80° C to 95°C with an interval of 5°C. The X-ray diffraction (XRD), UV/ visible spectrophotometry, Fourier Transform Infrared spectroscopy (FTIR) have been used to study the effect of temperature on the structural and optical properties of ZnS thin films. The XRD spectrum of the ZnS layer obtained shows an increase of peaks intensity of ZnS with increasing bath temperature. The study of optical properties exhibit good transmittance (60–80% in the visible region), and the band gap energy of the ZnS thin film decrease from 3.71 eV to 3.64 eV while the refractive index (n) increase with increasing temperature bath. The FTIR analyze confirm our studies and show characteristics bands of vibration of Zn-S.

Keywords: ZnS thin films, XRD spectra, optical gap, XRD

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Authors: Amina Aquil, Abdeljalil El Got

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Background: Sleep quality is one of the most important indicators related to the quality of life of patients suffering from cancer. Many factors could affect this quality of sleep and then be considered as associated predictors. Methods: The aim of this study was to assess the prevalence of sleep disorders and the associated factors with impaired sleep quality in Moroccan women with gynecological cancer. A cross-sectional study was carried out within the oncology department of the Ibn Rochd University Hospital, Casablanca, on Moroccan women who had undergone radical surgery for gynecological cancer (n=100). Translated and validated Arabic versions of the following international scales were used: Pittsburgh sleep quality index (PSQI), Hospital Anxiety and Depression Scale (HADS), Rosenberg's self-esteem scale (RSES), and Body image scale (BIS). Results: 78% of participants were considered poor sleepers. Most of the patients exhibited very poor subjective quality, low sleep latency, a short period of sleep, and a low rate of usual sleep efficiency. The vast majority of these patients were in poor shape during the day and did not use sleep medication. Waking up in the middle of the night or early in the morning and getting up to use the bathroom were the main reasons for poor sleep quality. PSQI scores were positively correlated with anxiety, depression, body image dissatisfaction, and lower self-esteem (p < 0.001). Conclusion: Sleep quality and its predictors require a systematic evaluation and adequate management to prevent sleep disturbances and mental distress as well as to improve the quality of life of these patients.

Keywords: body image, gynecological cancer, self esteem, sleep quality

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Authors: Tarek S. Jamil, H. A. Abbas, Rabab A. Nasr, Eman S. Mansor, Rose-Noëlle Vannier

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The citrate manner (Pechini method) was utilized in elaboration of a novel Nano-sized BaFe(1-x)CuxO3 (x=0.01, 0.05 and 0.10). The prepared photocatalysts were characterized by x-ray diffraction, diffuse reflectance, TEM and the surface area. The prepared samples have a mixture of cubic perovskite structure (main) and orthorhombic phases. The effect of different loads of copper as dopant on the structural properties as well as the photocatalytic activity was demonstrated. The lattice parameter and the unit cell volume of the prepared materials are given. Doping with copper increased the photocatalytic activity of BaFeO3 several times in abstraction of hazardous atrazine that causes acute problems in drinking water treatment facilities. This may be reasoned to low band gap energy of copper doped BaFe(1-x)CuxO3 attributed to oxygen vacancies formation.

Keywords: photocatalysis, nano-sized, BaFeO3, copper doping, atrazine

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Authors: Soroush Mokallaei

Abstract:

Since ancient times, urbanization engineers have always thought of creating green spaces along with urbanization. Athens and Rome have attempted to construct public gardens around streets and palaces. Since then developing green space has become a part of urban civilization. In medieval ages, all Western cities had palaces and houses with internal gardens. In different sources green belt is defined as a green band of trees and bushes around the cities which has multiple functions. It is said that green belts are not only around the mountains, cities, and rivers but also around houses, subways, and highways. Constructing green belt around cities has different advantages such as: protecting cities against pollution, purifying air, screening dust, being a place for recreation, buffer zone of city internal lands, confronting the phenomenon of heat island, increasing agricultural products, helping to prevent illegal city development, confronting deforestation, preventing flood and increasing subterranean water resources.

Keywords: environment, garden cities, green belt, metropolises

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Authors: Rupali Mane

Abstract:

Cadmium sulfide (Cds) thin films were chemically deposited at room temperature, from aqueous ammonia solution using CdCl₂ (Cadmium chloride) as a Cd²⁺ and CS(NH₂)₂ (Thiourea) as S² ion sources. ‘as-deposited’ films were uniform, well adherent to the glass substrate, secularly reflective and yellowish in color. The ‘as-deposited ’Cds layers grew with nano-crystalline in nature and exhibit cubic structure, with blue-shift in optical band gap. The films were annealed in air atmosphere for two hours at different temperatures and further characterized for compositional, structural, morphological and optical properties. The XRD and SEM studies clearly revealed the systematic changes in morphological and structural form of Cds films with an improvement in the crystal quality. The annealed films showed ‘red-shift’ in the optical spectra after thermal treatment. The Thiourea modified CdS film could be good to provide solar cell application.

Keywords: cadmium sulfide, thin films, nano-crystalline, XRD

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Authors: M. Ashok Williams, T. V. Lakshmi Kumar

Abstract:

The life cycle of Black carbon aerosols depends on their physical removal processes from the atmosphere during the precipitation events. Black Carbon (BC) mass concentration has been analysed during rainy and non-rainy days of Northeast (NE) Monsoon months of the years 2015 and 2017 over a semi-urban environment near Chennai (12.81 N, 80.03 E), located on the east coast of India. BC, measured using an Aethalometer (AE-31) has been related to the atmospheric boundary layer height (BLH) obtained from the ERA Interim Reanalysis data during rainy and non-rainy days on monthly mean basis to understand the wet removal of BC over the study location. The study reveals that boundary layer height has a profound effect on the BC concentration on rainy days and non rainy days. It is found that the BC concentration in the night time is lower on rainy days compared to non rainy days owing to wash out on rainy days and the boundary layer height remaining nearly the same on rainy and non rainy days. On the other hand, in the daytime, it is found that the BC concentration remains nearly the same on rainy and non rainy days whereas the boundary layer height is lower on rainy days compared to non rainy days. This reveals that in daytime, lower boundary layer heights compensate for the wet removal effect on BC concentration on rainy days. A quantitative relation is found between the product of BC and BLH during rainy and non-rainy days which indicates the extent of redistribution of BC during non-rainy days when compared to the rainy days. Further work on the wet removal processes of the BC is in progress considering the individual rain events and other related parameters like wind speed.

Keywords: black carbon aerosols, atmospheric boundary layer, scavenging processes, tropical coastal location

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Authors: Nuray Ocakli

Abstract:

19th century was the era of changes and transformations for the Ottoman Empire. The first sultan of this century, Mahmud II (1808-1839), was the architect of Ottoman modernization and fundamental changes. The most radical of these was abolishing the Janissary corps and the traditional Ottoman military band, Mehteran. Mahmud II introduced modernized military corps as well as western style royal and military music. Mahmut II invited the Italian composer Giuseppe Donizetti to establish a modern military band for the new army and to compose the Sultan’s royal anthem. In 1828, Donizetti composed the first western-style Ottoman anthem, Mahmudiyye anthem. During the 19th and early 20th century, four other western style Ottoman anthems (Aziziyye, Mecidiyye, Hamidiyye, and Resadiyye) were composed but the last anthem adopted in the reign of Mehmet VI (r. 1918-1922) was again Mahmudiyye anthem. This paper aims to analyze the Mahmudiyye anthem composed as royal anthem in 1828 but adopted as national anthem in 1918. Research questions of this paper are as follows: What were the characteristics of the Mahmudiyye anthem making it the best choice of the last sultan for the last national anthem? Are there specific reasons of the last sultan to adopt Mahmudiyye anthem or not to adopt any of the other four anthems? The musical characteristics of the anthem are analyzed based on the Cerulo’s empirical research. Cerulo examined the musical structures of 124 western style anthems from 150 countries in the 1580-1976 period. Cerulo’s research categorizes musical codes of the anthems as basic and embellished related with the level of sociopolitical control. Musical analysis of the anthem indicates that the basic musical code of the anthem implies a high level of socio-political control during the reign of both Mahmut II and Mehmet VI. Historical analysis of each sultans’ reign shows that both sultans were autocratic. Mahmut II designed authoritarian government policies to suppress possible reactions against his reforms. On the other hand, authoritarian policies of Mehmet VI are related with the domestic and international political conditions following the World War I. Historical analysis of the research questions show that compared to the other western style Ottoman anthems, Mahmudiyye anthem remained the only neutral anthem symbolizing modernization and westernization of the empire. Other anthems were all the symbols of failed ideologies such as Ottomanism, pan-Islamism, and pan-Turkism. In the early 20th century, there were a few common things remained among the diverse communities of the Ottoman Empire: The land they shared as homeland and the idea of modernization to save the homeland. For this reason, the last sultan Mehmet VI adopted Mahmudiyye anthem as the memory of a unified empire under the rule of a powerful and modernist sultan. The last sultan’s reign lasted just for four years, and the Ottoman Empire disintegrated in 1922, but his adaptation of the Mahmudiyye anthem indicates his unifying policies, his attitudes to save the empire and the caliphate.

Keywords: Mahmudiyye anthem, musical code, national anthem, Ottoman Empire, royal anthem

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Authors: Mohammad Derakhshani, Saeed Reza Allahkarama, Michael Isakhani-Zakaria, Masoud Samadian, Hojjat Sharifi Rasaey

Abstract:

In order to investigate the effects of stray current from DC traction systems (subway) on cathodically protected gas pipelines, the subway and the gas network maps in the city of Tehran were superimposed and a comprehensive map was prepared. 213 intersections and about 100150 meters of parallel sections of gas pipelines were found with respect to the railway right of way which was specified for field measurements. The potential measurements data were logged for one hour in each test point. 24-hour potential monitoring was carried out in selected test points as well. Results showed that dynamic stray current from subway on pipeline potential appears as fluctuations in its static potential that is visible in the diagrams during night periods. These fluctuations can cause the pipeline potential to exit the safe zone and lead to corrosion or overprotection. In this study, a maximum potential shift of 100 mv in the pipe-to-soil potential was considered as a criterion for dynamic stray current effective presence. Results showed that a potential fluctuation range between 100 mV to 3 V exists in measured points on pipelines which exceeds the proposed criterion and needs to be investigated. Corrosion rates influenced by stray currents were calculated using coupons. Results showed that coupon linked to the pipeline in one of the locations at region 1 of the city of Tehran has a corrosion rate of 4.2 mpy (with cathodic protection and under influence of stray currents) which is about 1.5 times more than free corrosion rate of 2.6 mpy.

Keywords: stray current, DC traction, subway, buried Pipelines, cathodic protection list

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Authors: Y. Sefir, Z. Aziz, S. Cherid, Z. F. Meghoufel, F. Bendahama, S. Terkhi, B. Bouadjemi. A. Zitouni S. Bentata

Abstract:

This work is to study the effect of the variation of structural parameters on the band structure in the quasiperiodic Fibonacci superlattices AlxGa1-xAs/GaAs using the formalism of the transfer matrix and Airy function. Our results show that increasing the width of Fibonacci’s wells of allows to the confinement of subminibands with a widening of minigaps, this causes a consistent and coherent fragmentation. The barrier thickness of Fibonacci bf acts on the width of subminibands by controlling the interaction force between neighboring eigenstates. Its increase gives rise to singularly extended states. The barrier height Fibonacci Vf permit to control the degree of structural disorder in these structures. The variation of these parameters permits the design of laser with modulated wavelength.

Keywords: transmission coefficient – Quasiperiodic superlattices- singularly localized and extended states- structural parameters- Laser with modulated wavelength

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