TOJSAT - Volume 11 - Issue 1 - January 2021

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A NOVEL ACTIVATED CARBON FROM NON LIVING LICHEN CETRARIA ISLANDICA (L.) ACH

Hülya Koyuncu, Ali Rıza Kul

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Abstract:

Activated carbons obtained from different sources are used for a wide variety of purposes. For example, they are frequently used in wastewater treatment, energy storage, gas purification, catalysis support materials and removal of environmental pollutants. As far as we know, lichens are rarely used in activated carbon production. However, it is more economical and sustainable to produce activated carbon from lichens. Lichens, which can be found in many regions of the world and have a wide variety of species, are organisms consisting of symbiotic combination of fungi and algae. In this study, activated carbon was produced using Cetraria islandica (L.) Ach. lichen (LCI) collected from Çankırı region in Turkey. Chemical activation was performed with ZnCl2. Carbonization was carried out in an ash furnace under nitrogen atmosphere at 768 oC for 1 hour. The surface area and pore size distribution of the ACCI and LCI were determined by BET analysis. Physicochemical properties of both the ACCI and LCI were examined by FTIR and TGA analysis. Morphological properties were analysed by XRD and SEM techniques. The BET surface area of the ACCI and LCI was found as 394.417 m2g-1 and 1.103 m2g-1, respectively. While the LCI had a heterogeneous surface morphology, the synthesized ACCI had a homogeneous and porous surface structure. It was found that activation and carbonization processes caused very significant changes in the LCI molecular structure and surface morphology. As a result, a novel activated carbon with relatively high surface area was successfully synthesized.

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AN EXPERIENCE OF IMPLEMENTING ICONIX, A SOFTWARE DEVELOPMENT METHODOLOGY, IN A SOFTWARE DEVELOPMENT CLASS DICTATED IN A PRIVATELY MANAGED UNIVERSITY FROM ARGENTINA, VIRTUALLY, DUE TO THE QUARANTINE

Rodrigo DE LATORRE, Marcelo VAQUERO, Guillermo LEALE, Alejandro SARTORIO

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Due to the mandatory quarantine implemented in most countries, and especially where this investigation is taking place, Argentina, most Academic organizations, either public or privately managed, needed to reinvent themselves in order to be able to teach courses in a completely remote environment. In this context, one class, which has the objective of develop a specific software and where this research took place, will use ICONIX, a software development methodology that is one of the latest technology standards used in the software industry, and flipped classroom, where instead of professors teaching students, they provide them with all the necessary information so they can study them before the class takes place. Given that this class has been always taught face-to-face and under other software development methodologies, the purpose of this paper is to evaluate the experience and take relevant data, measurable, about the degree of acceptance of both students and professors, in order to conclude if this virtual experience can be replicated after the quarantine period ends, replacing, if possible, the classroom teaching for a more up-to-date approach, taking advantage of the latest tools that have been developed for communicating, creating, distributing, grading assignments and sharing files and knowledge between teachers and students. 

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EFFECT ON BENDING RIGIDITY OF TOWEL SAMPLES WITH DIFFERENT FIBER CONTENT

Gülşah SUSURLUK, Erkan TÜRKER, Yüksel İKİZ

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Recently, there have been significant developments in investigating the quality perception and aesthetic behavior of the towel fabrics due to the developments in objective evaluation techniques in parallel with the technology. When bending properties are evaluated especially in terms of towel fabric comfort and towel quality perception, it is the main parameter that affects the selection of raw material, design and appearance of the textile material. In this study, towel samples with different fiber content (cotton, modal, bamboo, tencel, polyester etc.), yarn structure (carded, combed, open-end), yarn count, pile height, weight values were collected. By measuring the bending rigidity of towel samples, the effects of towel samples with different fiber content on both quality perception and bending rigidity were investigated.

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ON THE CONCEPT OF TIME IN EVERYDAY LIFE AND BETWEEN PHYSICS AND MATHEMATICS

Paolo DI SIA

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In this paper I consider the concept of time in a general way as daily human time and then within physics with relation to mathematics. I consider the arrow of time and then focus the attention on quantum mechanics, with its particular peculiarities, examining important concepts like temporal asymmetry, complexity, decoherence, irreversibility, information theory, chaos theory. In conclusion I consider the notion of time connected to a new theory in progress, called “Superfluid Dynamic Space” theory, based on a time-invariant universe that overcomes the Big Bang model and is connected on the so called “bijective physics”.

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PREPARATION OF TRANSDERMAL FILMS FOR CONTROLLED RELEASE OF DONEPEZIL HCL

Yasemin ACAR, Emel AKYOL

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Transdermal drug delivery systems, also known as “patches” have been attracted a great deal of attention for the past few decades since it delivers the drug through the skin in a predetermined and controlled. Transdermal delivery is a viable alternative to conventional oral therapy and provides a controlled drug release by increasing patient compliance and avoiding first-pass metabolism. Donepezil Hydrochloride is an active pharmaceutical ingredient for Alzheimer’s disease (AD) It has been widely used by oral route. But this type of treatment may have some disadvantages when a chronic neurological disorder is present because of the patient’s unwillingness to swallow and forgeting to take or carry pills in the day. So, transdermal patches can be used as an alternative treatment for AD.  
The aim of this study was to develop a transdermal drug delivery system for controlled release of Donepezil HCl. For this purpose, hydroxyethyl cellulose/sodium alginate/gelatin combined with polyvinylpyrrolidone (PVP) and PEG-400 in the formulation of transdermal patches. Transdermal patches were prepared by Franz diffusion cell method. Hydroxyethyl cellulose, sodium alginate and gelatine as matrix-forming agent and transcutol as plasticizer was in the transdermal films. Fourier transform infrared (FT-IR) spectroscopy) was used to characterize the films. In vitro drug release studies were performed for donepezil hydrochloride-loaded hydrogels at 7.4. To study the release kinetics, data obtained from in-vitro drug release studies were plotted in various kinetic models which include zero order, first order, Higuchi and Korsmeyer-Peppas. The results in the present investigation confirm the controlled release of Donepezil HCl and sodium alginate content of transdermal patch can extend the release of donepezil. The study demonstrates that the fabricated transdermal system of Donepezil HCl can be considered as a suitable alternative of the oral route. Also studies have shown promising results, further studies are needed for pharmacokinetic evaluation.

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THE ACCURACY AND REPEATABILITY OF UV-DAD-HPLC METHOD FOR DETERMINATION OF CHOLESTEROL CONTENT IN MILK

Lukáš KOLARIČ, Peter ŠIMKO

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This paper is a report on the determination of the accuracy and repeatability of the proposed UV-DAD-HPLC method for the analysis of cholesterol content in milk sample. The accuracy and repeatability of the method are important values in the validation process and refer to the suitability of the method for given purpose. The sample preparation consisted of the saponification and extraction process. The conditions of saponification were as follows: time of saponification 15 min, the concentration of methanolic KOH solution 1 mol/L with a volume of 12 mL. The extraction of unsaponified residue was done two times with the mixture of n-hexane:chloroform (1:1, v:v). The samples were analyzed by HPLC chromatography with UV-DAD detector, C18 stationary phase, and with mobile phase consisted of an isocratic mixture of acetonitrile:methanol (60:40, v:v). In these conditions, the accuracy of method varied from 97.3 to 105.8%. The repeatability referred to the precision was evaluated from the relative standard deviation with the values ranging from 1.34 to 2.37%. From the results, it can be concluded that proposed HPLC method showed great accuracy and repeatability, and thus it could be suitable for the appropriate determination of cholesterol content in milk samples.  

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