Search results for: contact roller

Authors: Aleksandra Łochowicz, Daria Świętochowska, Loredano Pollegioni, Nazim Ocal, Franck Charmantray, Laurence Hecquet, Katarzyna Szymańska

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Multienzymatic cascade reactions are nowadays widely used in pharmaceutical, chemical and cosmetics industries to produce high valuable compounds. They can be carried out in two ways, step by step and one-pot. If two or more enzymes are in the same reaction vessel is necessary to work out the compromise to run the reaction in optimal conditions for each enzyme. So far most of the reports of multienzymatic cascades concern on usage of free enzymes. Unfortunately using free enzymes as catalysts of reactions accomplish high cost. What is more, free enzymes are soluble in solvents which makes reuse impossible. To overcome this obstacle enzymes can be immobilized what provides heterogeneity of biocatalyst that enables reuse and easy separation of the enzyme from solvents and reaction products. Usually, immobilization increase also the thermal and operational stability of enzyme. The advantages of using immobilized multienzymes are enhanced enzyme stability, improved cascade enzymatic activity via substrate channeling, and ease of recovery for reuse. The one-pot immobilized multienzymatic cascade can be carried out in mixed or coimmobilized type. When biocatalysts are coimmobilized on the same carrier the are in close contact to each other which increase the reaction rate and catalytic efficiency, and eliminate the lag time. However, in this type providing the optimal conditions both in the process of immobilization and cascade reaction for each enzyme is complicated. Herein, we examined immobilization of 3 enzymes: D-amino acid oxidase from Rhodotorula gracilis, commercially available catalase and transketolase from Geobacillus stearothermophilus. As a support we used silica monoliths with hierarchical structure of pores. Then we checked their stability and reusability in one-pot cascade of L-erythrulose and hydroxypuryvate acid synthesis.

Keywords: biocatalysts, enzyme immobilization, multienzymatic reaction, silica carriers

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Authors: Sina Modares Ahmadi, Mohamad Reza Ghazavi, Mandana Sheikhzad

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Squeeze film damper systems (SFD) are often used in machines with high rotational speed to reduce non-periodic behavior by creating external damping. These types of systems are frequently used in aircraft gas turbine engines. There are some structural parameters which are of great importance in designing these kinds of systems, such as oil film thickness, C, and outer race mass, mo. Moreover, there is a crucial parameter associated with manufacturing process, under the title of waviness. Geometric imperfections are often called waviness if its wavelength is much longer than Hertzian contact width which is a considerable source of vibration in ball bearings. In this paper, a system of a flexible rotor and two ball bearings with floating ring squeeze film dampers and consideration of waviness has been modeled and solved by a numerical integration method, namely Runge-Kutta method to investigate the dynamic response of the system. The results show that by increasing the number of wave lobes, which is due to inappropriate manufacturing, non- periodic and chaotic behavior increases. This result reveals the importance of manufacturing accuracy. Moreover, as long as C< 1.5×10-4 m, by increasing the oil film thickness, unwanted vibrations and non-periodic behavior of the system have been reduced, On the other hand, when C>1.5×10-4 m, increasing the outer oil film thickness results in the increasing chaotic and non-periodic responses. This result shows that although the presence of oil film results in reduction the non-periodic and chaotic behaviors, but the oil film has an optimal thickness. In addition, with increasing mo, the disc displacement amplitude increases. This result reveals the importance of utilizing light materials in manufacturing the squeeze film dampers.

Keywords: squeeze-film damper, waviness, ball bearing, bifurcation

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Authors: Tarek Hassan, Sanaa Abouras

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Some factors such as interaction of migration process, cultural identity have an impact in a way that may lead to cultural disinheritance. Even if migrants' culture would not be lost, it may be affected by the new society culture. Therefore, it is anticipated that migration of an ethnic group would impact the culture of that group. Nubians; an ethnic group originated in South Egypt, have experienced migration that took place in the sixties of the past century. Nubians were forced to leave their origin land and relocate to Kom Ombo; an Egyptian town to the north of Aswan. The effect of migration on national culture, social homogeneity or the interest of social contact influences the attitudes of natives towards migration. Hence, it is very important for societies to help migrants to adapt to the new culture and at the same time not to impede migrants' effort to maintain their own culture. This study aims to investigate the effect of internal migration on the culture of Egyptian Nubians in order to predict if Nubian can maintain their own culture after the migration. Research question: what is the cultural influence of Nubians' migration from Egyptian Nubia to their new destinations? The researchers' hypothesis: there is mutual influence between the two cultures of Nubians and non-Nubians in Egypt. Results supported researchers' hypothesis as they observed that the Nubians managed to reserve balance between the maintenance of their own culture and the adoption of some cultural features of the community of their new destination(s). Also, the study examined why Nubians adhere to their culture although they left their land forever. Questionnaire and interviews were used to collect data from 80 informants; 40 Nubians and 40 non-Nubians in Kom-Ombo and the two cities of Cairo and Alexandria. Results suggested that there is obvious mutual cultural impact between Nubians and non-Nubians. The findings of this study would trigger the researchers to conduct further research on minorities for the deeper understanding of the impact of/on the culture of minorities.

Keywords: culture change, culture influence, culture maintenance, minority migration

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Authors: Afifa Hafidh, Hedia Chaabane

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This work mainly focused on the synthetic strategies and biological activities associated with pyrazoles. Pyrazole derivatives have been successfully synthesized by simple and facile method and studied for their antibacterial activity. These compounds were prepared from pyrazolic difunctional compounds as starting materials, by reaction with salicylic acid, paracetamol and thiosemicarbazide respectively. Structure of all the prepared compounds confirmation were proved using (FT-IR), (1H-NMR) and (13C-NMR) spectra in addition to melting points. The screening of the antimicrobial activity of the pyrazolic derivatives was examined against different microorganisms in the present study. They were screened for their antimicrobial activities against gram positive bacteria, gram negative bacteria and Candida albicans. The synthesized compounds were found to exhibit high antibacterial and antifungal efficiency against several tested bacterial strains, using agar diffusion method and filter paper disc-diffusion method. Ampicillin was used as positive control for all strains except Candida albicans for which Nystatin was used. The obtained results reveal that the antibacterial activity of some pyrazolic derivatives is comparable to that observed for the control samples (Ampicilin and Nystatin), suggesting a strong antibacterial activity. The analysis of these results shows that synthesized products react on the surfaces cell walls that are disrupted. When these products are in contact with the bacteria, they damage the membrane, leading to the perturbation of different cellular processes and then leakage of cytoplasm, resulting in the death of the cells. The results will be presented in details. The obtained products constitute effective antibacterial agents and important compounds for biological systems.

Keywords: salicylic acid, antimicrobial activities, antioxidant activity, paracetamol, pyrazole, thiosemicarbazide

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Authors: Mukhtari Hussaini Muhammad, Abba Adamu

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The paper will examine the approaches and solutions that will be offered by Senior Secondary School II Students (Demonstration Secondary School, Azare Bauchi State Northern Nigeria – Hausa/ Fulani predominant area) toward solving exercises related to the circle theorem. The angle that an arc of a circle subtends at the center is twice that which it subtends at any point on the remaining part of the circumference. The Students will be divided in to 2 groups by given them numbers 1, 2; 1, 2; 1, 2, then all 1s formed group I and all 2s formed group II. Group I will be considered as control group in which the traditional method will be applied during instructions. Thus, the researcher will revise the concept of circle, state the theorem, prove the theorem and then solve examples. Group II, experimental group in which the concept of circle will be revised to the students and then the students will be asked to draw different circles, mark arcs, draw angle at the center, angle at the circumference then measure the angles constructed. The students will be asked to explain what they can infer/deduce from the angles measured and lastly, examples will be solved. During the next contact day, both groups will be subjected to solving exercises in the classroom related to the theorem. The angle that an arc of a circle subtends at the center is twice that which it subtends at any point on the remaining part of circumference. The solution to the exercises will be marked, the scores compared/analysed using relevant statistical tool. It is expected that group II will perform better because of the method/ technique followed during instructions is more learner-centered. By exploiting the talents of the individual learners through listening to the views and asking them how they arrived at a solution will really improve learning and understanding.

Keywords: circle theorem, control group, experimental group, traditional method

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Authors: Meva Apaydin, Fatih Apaydin

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Role of education in the development of society is great. Teaching and training started with the beginning of the history and different methods and techniques which have been applied as the time passed and changed everything with the aim of raising the level of learning. In addition to the traditional teaching methods, technology has been used in recent years. With the beginning of the use of internet in education, some problems which could not be soluted till that time has been dealt and it is inferred that it is possible to educate the learners by using contemporary methods as well as traditional methods. As an advantage of technological developments, distance education is a system which paves the way for the students to be educated individually wherever and whenever they like without the needs of physical school environment. Distance education has become prevalent because of the physical inadequacies in education institutions, as a result; disadvantageous circumstances such as social complexities, individual differences and especially geographical distance disappear. What’s more, the high-speed of the feedbacks between teachers and learners, improvement in student motivation because there is no limitation of time, low-cost, the objective measuring and evaluation are on foreground. In spite of the fact that there is teaching beneficences in distance education, there are also limitations. Some of the most important problems are that : Some problems which are highly possible to come across may not be solved in time, lack of eye-contact between the teacher and the learner, so trust-worthy feedback cannot be got or the problems stemming from the inadequate technological background are merely some of them. Courses are conducted via distance education in many departments of the universities in our country. In recent years, giving lectures such as Turkish Language, English, and History in the first grades of the academic departments in the universities is an application which is constantly becoming prevalent. In this study, the application of Turkish Language course via distance education system by analyzing advantages and disadvantages of the distance education system which is based on internet.

Keywords: distance education, Turkish language, motivation, benefits

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Authors: Kebede Gamo Sebehanie, Olu Emmanuel Femi, Alberto Velázquez Del Rosario, Abubeker Yimam Ali, Gudeta Jafo Muleta

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Water pollution is one of the most serious worldwide issues today. Among water pollution, heavy metals are becoming a concern to the environment and human health due to their non-biodegradability and bioaccumulation. In this study, a magnetite-cellulose nanocomposite derived from renewable resources is employed for hexavalent chromium elimination by adsorption. Magnetite nanoparticles were synthesized directly from iron ore using solvent extraction and co-precipitation technique. Cellulose nanofiber was extracted from sugarcane bagasse using the alkaline treatment and acid hydrolysis method. Before and after the adsorption process, the MNPs-CNF composites were evaluated using X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transform infrared (FTIR), and Vibrator sample magnetometer (VSM), and Thermogravimetric analysis (TGA). The impacts of several parameters such as pH, contact time, initial pollutant concentration, and adsorbent dose on adsorption efficiency and capacity were examined. The kinetic and isotherm adsorption of Cr (VI) was also studied. The highest removal was obtained at pH 3, and it took 80 minutes to establish adsorption equilibrium. The Langmuir and Freundlich isotherm models were used, and the experimental data fit well with the Langmuir model, which has a maximum adsorption capacity of 8.27 mg/g. The kinetic study of the adsorption process using pseudo-first-order and pseudo-second-order equations revealed that the pseudo-second-order equation was more suited for representing the adsorption kinetic data. Based on the findings, pure MNPs and MNPs-CNF nanocomposites could be used as effective adsorbents for the removal of Cr (VI) from wastewater.

Keywords: magnetite-cellulose nanocomposite, hexavalent chromium, adsorption, sugarcane bagasse

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Authors: Ines Cherif, Ghassen Kharroubi, Leila Bouabid, Adel Gharbi, Aicha Boukthir, Margaret Mccarron, Nissaf Ben Alaya, Afif Ben Salah, Jihene Bettaieb

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Healthcare workers' flu vaccination prevents influenza disease among both patients and caregivers. We aimed in this study to assess influenza vaccine (IV) coverage in 2018-2019 among Tunisian physicians and to determine factors associated with IV receipt. A cross sectional study was carried out in Tunisian primary and secondary health care facilities in the 2018-2019 influenza season. Physicians with direct patient contact were recruited according to a self-weighted multistage sampling. Data were collected through a face to face questionnaire containing questions on knowledge, attitudes, and practices regarding IV. Bivariate analysis was used in order to determine factors associated with IV receipt. A total of 167 physicians were included in the study with a mean age of 48.2 ± 7.7 years and a sex-ratio (M: F) of 0.37. Among participants, 15.1% (95% CI: [9.7%-20.3%]) were vaccinated against influenza in the 2018-2019 influenza season. Bivariate analysis revealed that previous flu immunization in the four years preceding the 2018-2019 influenza season (OR=32.3; p < 10-3), belief that vaccinating healthcare workers may reduce work absenteeism (OR=4.7, p=0.028), belief that flu vaccine should be mandatory to healthcare workers (OR=3.3, p=0.01) and high confidence towards IV efficacy in preventing influenza among caregivers (OR= 4.5, p=0.01) were associated with a higher IV receipt in 2018-2019 among physicians. Less than one fifth of Tunisian physicians were vaccinated against influenza in 2018-2019. Higher vaccine uptake was related to a higher belief in vaccine efficacy in preventing influenza disease among both patients and caregivers. This underscores the need for periodic educational campaigns to raise physicians' awareness about IV efficacy. The switch to an IV mandatory policy should also be considered.

Keywords: influenza vaccine, physicians, Tunisia, vaccination uptake

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Authors: Duvert A. Puentes T., Javier A. Maldonado E., Ivan Quintero., Diego F. Villegas

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Mechanical Computation is a great tool to study the performance of complex models. An example of it is the study of the human body structure. This paper took advantage of different types of software to make a 3D model of the glenohumeral joint and apply a finite element analysis. The main objective was to study the change in the biomechanical properties of the joint when it presents an injury. Specifically, a BANKART lesion, which consists in the detachment of the anteroinferior labrum from the glenoid. Stress and strain distribution of the soft tissues were the focus of this study. First, a 3D model was made of a joint without any pathology, as a control sample, using segmentation software for the bones with the support of medical imagery and a cadaveric model to represent the soft tissue. The joint was built to simulate a compression and external rotation test using CAD to prepare the model in the adequate position. When the healthy model was finished, it was submitted to a finite element analysis and the results were validated with experimental model data. With the validated model, it was sensitized to obtain the best mesh measurement. Finally, the geometry of the 3D model was changed to imitate a BANKART lesion. Then, the contact zone of the glenoid with the labrum was slightly separated simulating a tissue detachment. With this new geometry, the finite element analysis was applied again, and the results were compared with the control sample created initially. With the data gathered, this study can be used to improve understanding of the labrum tears. Nevertheless, it is important to remember that the computational analysis are approximations and the initial data was taken from an in vitro assay.

Keywords: biomechanics, computational model, finite elements, glenohumeral joint, bankart lesion, labrum

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Authors: Suresh Kumar Reddy Narala, Rakesh Kumar Gunda

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In modern industry, mechanical parts are subjected to friction and wear, leading to heat generation, which affects the reliability, life and power consumption of machinery. To overcome the tribological losses due to friction and wear, a significant portion of lubricant with high viscous properties allows very smooth relative motion between two sliding surfaces. Advancement in modern tribology has facilitated the use of applying solid lubricants in various industrial applications. Solid lubricant additives with high viscous thin film formation between the sliding surfaces can adequately wet and adhere to a work surface. In the present investigation, an attempt has been made to investigate and evaluate the tribological studies of various solid lubricants like MoS¬2, graphite, and boric acid at different sliding conditions. The base oil used in this study was SAE 40 oil with a viscosity of 220 cSt at 400C. The tribological properties were measured on pin-on-disc tribometer. An experimental set-up has been developed for effective supply of solid lubricants to the pin-disc interface zone. The results obtained from the experiments show that the friction coefficient increases with increase in applied load for all the considered environments. The tribological properties with MoS2 solid lubricant exhibit larger load carrying capacity than that of graphite and boric acid. The present research work also contributes to the understanding of the behavior of film thickness distribution of solid lubricant using potential contact technique under different sliding conditions. The results presented in this research work are expected to form a scientific basis for selecting the best solid lubricant in various industrial applications for possible minimization of friction and wear.

Keywords: friction, wear, temperature, solid lubricant

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Authors: Ibrahim Rassoul, E-K. Si Ahmed

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The growth, deformation, and detachment of fluid droplets adherent to solid substrates is a problem of fundamental interest with numerous practical applications. Specific interest in this proposal is the problem of a droplet on a fibrous, hydrophobic substrate subjected to body or external forces (gravity, convection). The past decade has seen tremendous advances in proton exchange membrane fuel cell (PEMFC) technology. However, there remain many challenges to bring commercially viable stationary PEMFC products to the market. PEMFCs are increasingly emerging as a viable alternative clean power source for automobile and stationary applications. Before PEMFCs can be employed to power automobiles and homes, several key technical challenges must be properly addressed. One technical challenge is elucidating the mechanisms underlying water transport in and removal from PEMFCs. On the one hand, sufficient water is needed in the polymer electrolyte membrane or PEM to maintain sufficiently high proton conductivity. On the other hand, too much liquid water present in the cathode can cause 'flooding' (that is, pore space is filled with excessive liquid water) and hinder the transport of the oxygen reactant from the gas flow channel (GFC) to the three-phase reaction sites. The aim of this work is to investigate the stability of a liquid water droplet emerging form a GDL pore, to gain fundamental insight into the instability process leading to detachment. The approach will combine analytical and numerical modeling with experimental visualization and measurements.

Keywords: polymer electrolyte fuel cell, water droplet, gas diffusion layer, contact angle, surface tension

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Authors: Veruska C. Dutra, Mary L. G. S. Senna, Afonso R. Aquino

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Tourists bring many benefits to a local community, encouraging it to be involved in that activity; however, it may also have detrimental effects like garbage, noise, violence, external culture and the damaging of the natural environment among others, which may promote community dissatisfaction. The contact between the tourist and the local community is a concern, especially when the community is located near protected areas. In this case, the community must know the tourist destination well, so it can collaborate in the tourism development without harming the environment. In this context, the present article aims to demonstrate the results of a research study conducted as part of a doctorate program in Sciences from the University of Sao Paulo, Brazil. It had as an objective to elaborate a methodology proposal to measure the local community satisfaction indicator, with applicability on a case study in the Mateiros community located in the surrounding area of the Parque Estadual do Jalapão –PEJ conservation unit in the state of Tocantins, Brazil. This is a study of an interdisciplinary nature that had the deductive method as its guide. The indicator result is going to be presented in this study. It pointed out as negative factors: there is no involvement between the local community and the tourism sector, and there is also dissatisfaction with regard to the town’s basic services. The study showed as positive the local community knowledge about the various attractions in the surrounding area and that the group recognizes the importance of the tourism for the town and life. Concerning the methodology that was used, the results showed that it can collaborate in seeking actions of improvement and involvement of the community in the planning and development of the local tourism. It comes out as an efficient analysis tool, thus enabling the perceiving of the local community point of view.

Keywords: satisfaction indicator, tourism, community, Jalapão

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Authors: Lucile Soudani, Hervé Illy, Rémi Bouchié

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Mould growth in living environments has been widely reported for decades all throughout the world. A higher level of moisture in housings can lead to building degradation, chemical component emissions from construction materials as well as enhancing mould growth within the envelope elements or on the internal surfaces. Moreover, a significant number of studies have highlighted the link between mould presence and the prevalence of respiratory diseases. In recent years, the proportion of biobased materials used in construction has been increasing, as seen as an effective lever to reduce the environmental impact of the building sector. Besides, bio-based materials are also hygroscopic materials: when in contact with the wet air of a surrounding environment, their porous structures enable a better capture of water molecules, thus providing a more suitable background for mould growth. Many studies have been conducted to develop reliable models to be able to predict mould appearance, growth, and decay over many building materials and external exposures. Some of them require information about temperature and/or relative humidity, exposure times, material sensitivities, etc. Nevertheless, several studies have highlighted a large disparity between predictions and actual mould growth in experimental settings as well as in occupied buildings. The difficulty of considering the influence of all parameters appears to be the most challenging issue. As many complex phenomena take place simultaneously, a preliminary study has been carried out to evaluate the feasibility to sadopt a reliability approach rather than a deterministic approach. Both epistemic and random uncertainties were identified specifically for the prediction of mould appearance and growth. Several studies published in the literature were selected and analysed, from the agri-food or automotive sectors, as the deployed methodology appeared promising.

Keywords: bio-based materials, mould growth, numerical prediction, reliability approach

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Authors: Sharjeel Abid, Tanveer Hussain, Ahsan Nazir, Abdul Zahir, Nabyl Khenoussi

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Localized application of drug has various advantages and fewer side effects as compared with other methods. Burn patients suffer from swear pain and the major aspects that are considered for burn victims include pain and infection management. Nano-fibers (NFs) loaded with drug, applied on local wound area, can solve these problems. Therefore, this study dealt with the fabrication of drug loaded NFs for better pain management. Two layers of NFs were fabricated with different drugs. Contact layer was loaded with Gabapentin (a nerve painkiller) and the second layer with acetaminophen. The fabricated dressing was characterized using scanning electron microscope, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and UV-Vis Spectroscopy. The double layered based NFs dressing was designed to have both initial burst release followed by slow release to cope with pain for two days. The fabricated nanofibers showed diameter < 300 nm. The liquid absorption capacity of the NFs was also checked to deal with the exudate. The fabricated double layered dressing with dual drug loading and release showed promising results that could be used for dealing pain in burn victims. It was observed that by the addition of drug, the size of nanofibers was reduced, on the other hand, the crystallinity %age was increased, and liquid absorption decreased. The combination of fast nerve pain killer release followed by slow release of non-steroidal anti-inflammatory drug could be a good tool to reduce pain in a more secure manner with fewer side effects.

Keywords: pain management, burn wounds, nano-fibers, controlled drug release

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Authors: Mona Hassan Aburahma, Alaa Hamed Salama

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Ufasomes “unsaturated fatty acids liposomes” are unique nano-sized self-assembled bilayered vesicles that can be easily created from the readily available unsaturated fatty acid. Ufasomes are formed due to weak associative interaction of the fully ionized and unionized fatty acids into bilayers structures. In the ufasomes constructs, the fatty acid molecules are oriented with their hydrocarbon tails directed toward the membrane interior and the carboxyl groups are in contact with water. Although ufasomes can be employed as a safe vesicular carrier for drugs, the extreme instability of their aqueous dispersions hinders their effective use in drug delivery field. Accordingly, in our study, lyophilized gels containing ufasomes were prepared using a simple assembling technique form the readily available oleic acid to overcome the colloidal instability of the ufasomes dispersions and convert them into accurate unit dosage forms. The influence of changing cholesterol percentage relative to oleic acid on the ufasomes vesicles were investigated using factorial design. The optimized oleic acid ufasomes comprised nanoscaled spherical vesicles. Scanning electron micrographs of the lyophilized gels revealed that the included ufasomes were intact, non-aggregating, and preserved their spherical morphology. Rheological characterization (viscosity and shear stress versus shear rate) of reconstituted ufasomal lyophilized gel ensured the ease of application. The capability of the ufasomes, included in the gel, to penetrate deep through the mucosa layers was illustrated using ex-vivo confocal laser imaging, thereby, highlighting the feasibility of stabilizing ufasomes using lyophilized gel platforms.

Keywords: ufasomes, lyophilized gel, confocal scanning microscopy, rheological characterization, oleic acid

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Authors: Bekan Bogale, Tsegaye Girma Asere, Tilahun Yai, Fekadu Melak

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Aims: To study photocatalytic degradation of methylene blue dye on cuprous oxide/graphene nanocomposite. Background: Cuprous oxide (Cu2O) nanoparticles are among the metal oxides that demonstrated photocatalytic activity. However, the stability of Cu2O nanoparticles due to the fast recombination rate of electron/hole pairs remains a significant challenge in their photocatalytic applications. This, in turn, leads to mismatching of the effective bandgap separation, tending to reduce the photocatalytic activity of the desired organic waste (MB). To overcome these limitations, graphene has been combined with cuprous oxides, resulting in cuprous oxide/graphene nanocomposite as a promising photocatalyst. Objective: In this study, Cu2O/graphene nanocomposite was synthesized and evaluated for its photocatalytic performance of methylene blue (MB) dye degradation. Method: Cu2O/graphene nanocomposites were synthesized from graphite powder and copper nitrate using the facile sol-gel method. Batch experiments have been conducted to assess the applications of the nanocomposites for MB degradation. Parameters such as contact time, catalyst dosage, and pH of the solution were optimized for maximum MB degradation. The prepared nanocomposites were characterized by using UV-Vis, FTIR, XRD, and SEM. The photocatalytic performance of Cu2O/graphene nanocomposites was compared against Cu2O nanoparticles for cationic MB dye degradation. Results: Cu2O/graphene nanocomposite exhibits higher photocatalytic activity for MB degradation (with a degradation efficiency of 94%) than pure Cu2O nanoparticles (67%). This has been accomplished after 180 min of irradiation under visible light. The kinetics of MB degradation by Cu2O/graphene composites can be demonstrated by the second-order kinetic model. The synthesized nanocomposite can be used for more than three cycles of photocatalytic MB degradation. Conclusion: This work indicated new insights into Cu2O/graphene nanocomposite as high-performance in photocatalysis to degrade MB, playing a great role in environmental protection in relation to MB dye.

Keywords: methylene blue, photocatalysis, cuprous oxide, graphene nanocomposite

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Authors: Ansah Iris Baffour, Dong-Ho Kim, Sung-Gyu Park

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The ongoing COVID-19 pandemic, caused by the SARS-CoV-2 virus and is gradually shifting to an endemic phase which implies the outbreak is far from over and will be difficult to eradicate. Global cooperation has led to unified precautions that aim to suppress epidemiological spread (e.g., through travel restrictions) and reach herd immunity (through vaccinations); however, the primary strategy to restrain the spread of the virus in mass populations relies on screening protocols that enable rapid on-site diagnosis of infections. Herein, we employed surface enhanced Raman spectroscopy (SERS) for the rapid detection of SARS-CoV-2 lysate on an Au-modified Au nanodimple(AuND)electrode. Through in situone-pot Au electrodeposition on the AuND electrode, Au-lysate nanocomposites were synthesized, generating3D internal hotspots for large SERS signal enhancements within 30 s of the deposition. The capture of lysate into newly generated plasmonic nanogaps within the nanocomposite structures enhanced metal-spike protein contact in 3D spaces and served as hotspots for sensitive detection. The limit of detection of SARS-CoV-2 lysate was 5 x 10-2 PFU/mL. Interestingly, ultrasensitive detection of the lysates of influenza A/H1N1 and respiratory syncytial virus (RSV) was possible, but the method showed ultimate selectivity for SARS-CoV-2 in lysate solution mixtures. We investigated the practical application of the approach for rapid on-site diagnosis by detecting SARS-CoV-2 lysate spiked in normal human saliva at ultralow concentrations. The results presented demonstrate the reliability and sensitivity of the assay for rapid diagnosis of COVID-19.

Keywords: label-free detection, nanocomposites, SARS-CoV-2, surface-enhanced raman spectroscopy

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Authors: Authors: A. Lakhal, M. Bahalou, A. Khattabi

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Introduction: Tuberculosis is one of the world's deadliest infectious diseases. In Morocco, a total of 30,636 cases of Tuberculosis, all forms combined, were reported in 2015, representing an incidence of 89 cases per 100,000 population. The number of deaths from tuberculosis (TB) was 656 cases. In the prefecture of Meknes, its incidence remains high compared to the national level. The objective of this work is to describe the epidemiological profile of tuberculosis in the prefecture of Meknes. Methods: It is a descriptive analysis of TB cases reported between 2016 and 2020 at the regional diagnostic center of tuberculosis and respiratory diseases. We performed analysis by using Microsoft Excel and EpiInfo 7. Results: Epidemiological data from 2016 to 2020 report a total of 4100 new cases of all forms of tuberculosis, with an average of 820 new cases per year. The median age is 32 years. There is a clear male predominance, on average 58% of cases are male and 42% female. The incidence rate of bacteriologically confirmed tuberculosis per 100,000 inhabitants has increased from 35 cases per 100,000 inhabitants in 2016 to 39.4 cases per 100,000 inhabitants in 2020. The confirmation rate for pulmonary tuberculosis decreased from 84% in 2016 to 75% in 2020. Pulmonary involvement predominates by an average of 46%, followed by lymph node involvement 29%and pleural involvement by an average of 10%. Digestive, osteoarticular, genitourinary, and meningeal involvement occurs in 8% of cases. Primary tuberculosis infection occurs in an average of 0.5% of cases. The proportion of HIV-TB co-infections was 2.8 in 2020. Conclusion: The incidence of tuberculosis in Meknes remains high compared to the national level. Thus, it is imperative to reinforce the earlier detection; improve the contact tracing, detection methods of cases for their confirmation and treatment, and to reduce the proportion of the lost to follow up as well.

Keywords: tuberculosis, epidemiological profile, meknes, morocco

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Authors: Shabnam Etemadi

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Background: Infertility is one of the most important issues in any society due to its psychological, medical and economic consequences that can greatly influence overall health and life. This study aims to assess the relationship between inhalation or exposing workplace pollution and dysfunction of the male reproductive system. Semen samples are male employees in south of Iran who exposed to work environmental pollutants for long hours. Method: Due to descriptive-analytical, the analysis of all interviews of all male patients of Bu Ali Medical Center and Pasteur Laboratory are conducted within 6 months. Random sampling numbered and patients signed informed consent. To analyze the data, Miller's fertility motivation questionnaires and the Miller-Smith lifestyle assessment inventory are used and Working Conditions Survey is developed. For analyzing the collecting data SPSS is used. Findings: Although sperm motility and volume had no statistically significant relationship with any of the lifestyle components, the weak relationship between sperm movement and work environment conditions (P = 0.07) lead to other factors to be investigated. * Among the factors of Working Environment Condition, smoking, work in the open environment and presence of more than 6 hours in the work environment with sperm mobility, smoking, contact with chemicals and radioactive with sperm volume at a level less than 0.05 had a statistically significant relationship. Conclusion: Finding revealed the environment pollution is one of the important factors in male infertility and strengthens this hypothesis. Working Environmental pollutants in the field of metropolitan pollution should be considered as a unifying hypothesis, possibly could interfere with male reproductive function.

Keywords: infertility, lifestyle, workplace pollution, male infertility

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Authors: Jing Niu, Jun X. Wang

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Arterial stiffness predicts mortality and morbidity, independently of other cardiovascular risk factors. And it is a major risk factor for age-related morbidity and mortality. The non-invasive industry gold standard measurement system of arterial stiffness utilizes pulse wave velocity method. However, the desktop device is expensive and requires trained professional to operate. The main objective of this research is the proof of concept of the proposed non-invasive method which uses measurement of magnetic flux disturbance and electrocardiogram (ECG) signal for measuring arterial stiffness. The method could enable accurate and easy self-assessment of arterial stiffness at home, and to help doctors in research, diagnostic and prescription in hospitals and clinics. A platform for assessing arterial stiffness through acquisition and analysis of radial artery pulse waveform and ECG signal has been developed based on the proposed method. Radial artery pulse waveform is acquired using the magnetic based sensing technology, while ECG signal is acquired using two dry contact single arm ECG electrodes. The measurement only requires the participant to wear a wrist strap and an arm band. Participants were recruited for data collection using both the developed platform and the industry gold standard system. The results from both systems underwent correlation assessment analysis. A strong positive correlation between the results of the two systems is observed. This study presents the possibility of developing an accurate, easy to use and affordable measurement device for arterial stiffness assessment.

Keywords: arterial stiffness, electrocardiogram, pulse wave velocity, Magnetic Flux Disturbance

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Authors: Miroslava Rysová, Zdena Syrová, Tomáš Zajíc, Petr Exnar

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Currently, attention of tissue engineers has been attracted to novel nanofibrous materials having advanced properties and ability to mimic extracellular matrix (ECM) by structure which makes them interesting candidates for application in regenerative medicine as scaffolding and/or drug delivering material. Throughout the last decade, more than 200 synthetic and natural polymers have been successfully electrospun leading to the formation of nanofibres with a wide range of chemical, mechanical and degradation properties. In this family, inorganic nanofibres represent very specific group offering an opportunity to manufacture inert to body, well degradable and in properties tunable material. Aim of this work, was to reveal unique properties of silica (SiO2, CAS 7631-86-9) nanofibres and their potential in field of regenerative medicine. Silica nanofibres were prepared by sol-gel method from tetraethyl orthosilicate (TEOS, CAS 78-10-4) as a precursor and subsequently manufactured by needleless electrospinning on NanospiderTM device. Silica nanofibres thermally stabilized under 200°C were confirmed to be fully biodegradable and soluble in several simulated body fluids. In vitro cytotoxicity tests of eluate (ES ISO 10993-5:1999) and in direct contact (ES ISO 10993-5:2009) showed no toxicity - e.g. cell viabilities reached values exceeding 80%. Those results were obtained equally from two different cell lines (Vero, 3T3). Non-toxicity of silaca nanofibres´ eluate was additionally confirmed in real time by testing on xCelligence (ACEA Biosciences, Inc.) device. Both cell types also showed good adhesion to material. To conclude, all mentioned results lead to resumption that silica nanofibres have a potential as material for regenerative medicine which opens door to further research.

Keywords: cytotoxicity, electrospinning, nanofibres, silica, tissue engineering

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Authors: N. Valderrama, W. Albarracín, N. Algecira

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It was studied the effect of the inclusion of thyme and rosemary essential oils into chitosan films, as well as the microbiological and physical properties when storing chitosan film with and without the mentioned inclusion. The film forming solution was prepared by dissolving chitosan (2%, w/v), polysorbate 80 (4% w/w CH) and glycerol (16% w/w CH) in aqueous lactic acid solutions (control). The thyme (TEO) and rosemary (REO) essential oils (EOs) were included 1:1 w/w (EOs:CH) on their combination 50/50 (TEO:REO). The films were stored at temperatures of 5, 20, 33°C and a relative humidity of 75% during four weeks. The films with essential oil inclusion did not show an antimicrobial activity against strains. This behavior could be explained because the chitosan only inhibits the growth of microorganisms in direct contact with the active sites. However, the inhibition capacity of TEO was higher than the REO and a synergic effect between TEO:REO was found for S. enteritidis strains in the chitosan solution. Some physical properties were modified by the inclusion of essential oils. The addition of essential oils does not affect the mechanical properties (tensile strength, elongation at break, puncture deformation), the water solubility, the swelling index nor the DSC behavior. However, the essential oil inclusion can significantly decrease the thickness, the moisture content, and the L* value of films whereas the b* value increased due to molecular interactions between the polymeric matrix, the loosing of the structure, and the chemical modifications. On the other hand, the temperature and time of storage changed some physical properties on the chitosan films. This could have occurred because of chemical changes, such as swelling in the presence of high humidity air and the reacetylation of amino groups. In the majority of cases, properties such as moisture content, tensile strength, elongation at break, puncture deformation, a*, b*, chrome, ΔE increased whereas water resistance, swelling index, L*, and hue angle decreased.

Keywords: chitosan, food additives, modified films, polymers

Procedia PDF Downloads 366

Authors: N. G. Vepkhvadze, T. Enukidze

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Anthrax is a fatal disease caused by strains of Bacillus anthracis, a spore-forming gram-positive bacillus that causes the disease anthrax in animals and humans. Anthrax is a zoonotic disease that is also well-recognized as a potential agent of bioterrorism. Infection in humans is extremely rare in the developed world and is generally due to contact with infected animals or contaminated animal products. Testing of this zoonotic disease began in 1907 in Georgia and is still being tested routinely to provide accurate information and efficient testing results at the State Laboratory of Agriculture of Georgia. Each clinical sample is analyzed by RT-PCR and bacteriology methods; this study used Real-Time PCR assays for the detection of B. anthracis that rely on plasmid-encoded targets with a chromosomal marker to correctly differentiate pathogenic strains from non-anthracis Bacillus species. During the period of 2015-2022, the State Laboratory of Agriculture (SLA) tested 250 clinical and environmental (soil) samples from several different regions in Georgia. In total, 61 out of the 250 samples were positive during this period. Based on the results, Anthrax cases are mostly present in Eastern Georgia, with a high density of the population of livestock, specifically in the regions of Kakheti and Kvemo Kartli. All laboratory activities are being performed in accordance with International Quality standards, adhering to biosafety and biosecurity rules by qualified and experienced personnel handling pathogenic agents. Laboratory testing plays the largest role in diagnosing animals with anthrax, which helps pertinent institutions to quickly confirm a diagnosis of anthrax and evaluate the epidemiological situation that generates important data for further responses.

Keywords: animal disease, baccilus anthracis, edp, laboratory molecular diagnostics

Procedia PDF Downloads 87

Authors: Mohammad Derakhshani, Saeed Reza Allahkaram, Michael Isakani-Zakaria, Masoud Samadian, Hojat Sharifi Rasaey

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Dynamic stray currents tend to change their magnitude and polarity with time at their source which will create anodic and cathodic spots on a nearby interfered structure. To date, one of the biggest known dynamic stray current sources are DC traction systems. Laboratory simulation is a suitable method to apply theoretical principles in order to identify effective parameters in dynamic stray current influenced corrosion. Simulation techniques can be utilized for various mitigation methods applied in a small scales for selection of the most efficient method with regards to field applications. In this research, laboratory simulation of potential fluctuations caused by dynamic stray current on a cathodically protected structure was investigated. A lab model capable of generating DC static and dynamic stray currents and simulating its effects on cathodically protected samples were developed based on stray current induced (contact-less) polarization technique. Stray current pick-up and discharge spots on an influenced structure were simulated by inducing fluctuations in the sample’s stationary potential. Two mitigation methods for dynamic stray current interference on buried structures namely application of sacrificial anodes as preferred discharge point for the stray current and potentially controlled cathodic protection was investigated. Results showed that the application of sacrificial anodes can be effective in reducing interference only in discharge spot. But cathodic protection through potential controlling is more suitable for mitigating dynamic stray current effects.

Keywords: simulation, dynamic stray current, fluctuating potentials, sacrificial anode

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Authors: Karla Hrbackova, Anna Petr Safrankova, Jakub Hladik

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Machiavellianism as social phenomenon reveals certain methods of communication that man puts in contact with other people in both personal and working life (and work with clients). Especially at the helping-profession students is honesty, openness or low motivation for personal benefit important part of the profession. The aim of a study is to expose intercultural differences influence of Machiavellianism between Czech and Slovak university students and to determine whether these differences manifest themselves differently among students focusing on management and social profession (by helping degrees). The research involved 1120 university students from the Czech Republic and the Slovak Republic. The measurement of Machiavellianism used a test Mach IV. The test contained 20 statements divided into four central dimensions of Machiavellianism: flattery, deception and falsehood, immorality and cynicism. We found out, that Czech and Slovak's student expressed a similar attitude toward Machiavellianism as a means of manipulation in the interpersonal relationship, but this is not true in all dimensions. Czech and Slovak's students perceive differently flattery, deception and falsehood and cynicism too. In addition to specific features of cultural conditionality, we found out differences depending on the helping profession. Students focusing on managerial occupation (lower level of helping) tend towards greater acceptance of the use flattery as a means of communication than students specializing in the social profession (high-grade assisting). If they are an intercultural and interdisciplinary influences combined and effect on the perception of Machiavellianism together, then their significant importance for the perception of flattery and cynicism. The result will help us to reveal certain specific traits that students apply communication and with whom we can continue to work during their training.

Keywords: use of manipulative strategies, Machiavellianism, helping-profession students, professional training of students

Procedia PDF Downloads 383

Authors: Kechnit Djamel, Ammarri Abdelhadi, Raphael Tshimang, Mark Trrig

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One of the most important aspects of monitoring rivers is navigation. The variation of discharge in the river generally produces a change in available draft for a vessel, particularly in the low flow season, which can impact the navigable water path, especially when the water depth is less than the normal one, which allows safe navigation for boats. The water depth is related to the bathymetry of the channel as well as the discharge. For a seasonal update of the navigation maps, a daily discharge value is required. Many novel approaches based on earth observation and remote sensing have been investigated for large rivers. However, it should be noted that most of these approaches are not currently able to directly estimate river discharge. This paper discusses the application of remote sensing tools using the analysis of the reflectance value of MODIS imagery and is combined with field measurements for the estimation of discharge. This approach is applied in the lower reach of the Congo River (Pool Malebo) for the period between 2019 and 2021. The correlation obtained between the observed discharge observed in the gauging station and the reflectance ratio time series is 0.81. In this context, a Discharge Reflectance Model (DRM) was developed to express discharge as a function of reflectance. This model introduces a non-contact method that allows discharge monitoring using earth observation. DRM was validated by field measurements using ADCP, in different sections on the Pool Malebo, over two different periods (dry and wet seasons), as well as by the observed discharge in the gauging station. The observed error between the estimated and measured discharge values ranges from 1 to 8% for the ADCP and from (1% to 11%) for the gauging station. The study of the uncertainties will give us the possibility to judge the robustness of the DRM.

Keywords: discharge monitoring, navigation, MODIS, empiric, ADCP, Congo River

Procedia PDF Downloads 91

Authors: Thomas Schalow

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It is commonly recognized that our present curriculum is not preparing students to function in the 21st century. This is particularly true in regard to communication needs across cultures - both human and non-human. In this paper, a comprehensive theory of communication-based on communication with non-human cultures and intelligences is presented to meet the following three imminent contingencies: communicating with sentient biological intelligences, communicating with extraterrestrial intelligences, and communicating with artificial super-intelligences. The paper begins with the argument that we need to become much more serious about communicating with the non-human, intelligent life forms that already exists around us here on Earth. We need to broaden our definition of communication and reach out to other sentient life forms in order to provide humanity with a better perspective of its place within our ecosystem. The paper next examines the science and philosophy behind CETI (communication with extraterrestrial intelligences) and how it could prove useful even in the absence of contact with alien life. However, CETI’s assumptions and methodology need to be revised in accordance with the communication theory being proposed in this paper if we are truly serious about finding and communicating with life beyond Earth. The final theme explored in this paper is communication with non-biological super-intelligences. Humanity has never been truly compelled to converse with other species, and our failure to seriously consider such intercourse has left us largely unprepared to deal with communication in a future that will be mediated and controlled by computer algorithms. Fortunately, our experience dealing with other cultures can provide us with a framework for this communication. The basic concepts behind intercultural communication can be applied to the three types of communication envisioned in this paper if we are willing to recognize that we are in fact dealing with other cultures when we interact with other species, alien life, and artificial super-intelligence. The ideas considered in this paper will require a new mindset for humanity, but a new disposition will yield substantial gains. A curriculum that is truly ready for the 21st century needs to be aligned with this new theory of communication.

Keywords: artificial intelligence, CETI, communication, language

Procedia PDF Downloads 364

Authors: Sima Majnooni

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This paper discusses the Green Climate Fund's environmental and social management framework (GCF). The environmental and social management framework ensures the accredited entity considers the GCF's accreditation standards and effectively implements each of the GCF-funded projects. The GCF requires all accredited entities to meet basic transparency and accountability standards as well as environmental and social safeguards (ESMS). In doing so, the accredited entity sets up different independent units. One of these units is called the Grievance Mechanism. When allegations of environmental and social harms are raised in association with GCF-funded activities, affected parties can contact the entity’s grievance unit. One of the most challenging things about the accredited entity's grievance unit is the lack of available information and resources on the entities' websites. Many AEs have anti-corruption or anti-money laundering unit, but they do not have the environmental and social unit for affected people. This paper will argue the effectiveness of environmental and social grievance mechanisms of AEs by using a qualitative approach to indicate how many of AEs have a poor or an effective GRM. Some ESMSs seem highly effective. On the other hand, other mechanisms lack basic requirements such as a clear, transparent, uniform procedure and a definitive timetable. We have looked at each AE mechanism not only in light of how the website goes into detail regarding the process of grievance mechanism but also in light of their risk category. Many mechanisms appear inadequate for the lower level risk category entities (C) and, even surprisingly, for many higher-risk categories (A). We found; in most cases, the grievance mechanism of AEs seems vague.

Keywords: grievance mechanism, vague environmental and social policies, green climate fund, international climate finance, lower and higher risk category

Procedia PDF Downloads 124

Authors: Syed Qasim Gilani, Muhammad Umair, Muhammad Noman, Syed Bilawal Shah, Aqib Abbasi, Muhammad Waheed

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Cardiovascular Diseases(CVD's) are the major cause of death in the world. The main reason for these deaths is the unavailability of first aid for heart failure. In many cases, patients die before reaching the hospital. We in this paper are presenting innovative online health service for Cardiac Patients. The proposed online health system has two ends. Users through device developed by us can communicate with their doctor through a mobile application. This interface provides them with first aid.Also by using this service, they have an easy interface with their doctors for attaining medical advice. According to the proposed system, we developed a device called Cardiac Care. Cardiac Care is a portable device which a patient can use at their home for monitoring heart condition. When a patient checks his/her heart condition, Electrocardiogram (ECG), Blood Pressure(BP), Temperature are sent to the central database. The severity of patients condition is checked using Artificial Intelligence Algorithm at the database. If the patient is suffering from the minor problem, our algorithm will suggest a prescription for patients. But if patient's condition is severe, patients record is sent to doctor through the mobile Android application. Doctor after reviewing patients condition suggests next step. If a doctor identifies the patient condition as critical, then the message is sent to the central database for sending an ambulance for the patient. Ambulance starts moving towards patient for bringing him/her to hospital. We have implemented this model at prototype level. This model will be life-saving for millions of people around the globe. According to this proposed model patients will be in contact with their doctors all the time.

Keywords: cardiovascular disease, classification, electrocardiogram, blood pressure

Procedia PDF Downloads 184

Authors: R. Periyasamy, Deepak Joshi, Sneh Anand

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Foot posture assessment is important to evaluate foot type, causing gait and postural defects in all age groups. Although different methods are used for classification of foot arch type in clinical/research examination, there is no clear approach for selecting the most appropriate measurement system. Therefore, the aim of this study was to develop a system for evaluation of foot type as clinical decision-making aids for diagnosis of flat and normal arch based on the Arch Index (AI) and foot pressure distribution parameter - Power Ratio (PR) data. The accuracy of the system was evaluated for 27 subjects with age ranging from 24 to 65 years. Foot area measurements (hind foot, mid foot, and forefoot) were acquired simultaneously from foot pressure intensity image using portable PedoPowerGraph system and analysis of the image in frequency domain to obtain foot pressure distribution parameter - PR data. From our results, we obtain 100% classification accuracy of normal and flat foot by using the linear discriminant analysis method. We observe there is no misclassification of foot types because of incorporating foot pressure distribution data instead of only arch index (AI). We found that the mid-foot pressure distribution ratio data and arch index (AI) value are well correlated to foot arch type based on visual analysis. Therefore, this paper suggests that the proposed system is accurate and easy to determine foot arch type from arch index (AI), as well as incorporating mid-foot pressure distribution ratio data instead of physical area of contact. Hence, such computational tool based system can help the clinicians for assessment of foot structure and cross-check their diagnosis of flat foot from mid-foot pressure distribution.

Keywords: arch index, computational tool, static foot pressure intensity image, foot pressure distribution, linear discriminant analysis

Procedia PDF Downloads 499