Search results for: adverse light condition

Authors: J. L. Chukwuneke, C. H. Achebe, S. N. Omenyi

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This research work presents the surface thermodynamics approach to M-TB/HIV-Human sputum interactions. This involved the use of the Hamaker coefficient concept as a surface energetics tool in determining the interaction processes, with the surface interfacial energies explained using van der Waals concept of particle interactions. The Lifshitz derivation for van der Waals forces was applied as an alternative to the contact angle approach which has been widely used in other biological systems. The methodology involved taking sputum samples from twenty infected persons and from twenty uninfected persons for absorbance measurement using a digital Ultraviolet visible Spectrophotometer. The variables required for the computations with the Lifshitz formula were derived from the absorbance data. The Matlab software tools were used in the mathematical analysis of the data produced from the experiments (absorbance values). The Hamaker constants and the combined Hamaker coefficients were obtained using the values of the dielectric constant together with the Lifshitz equation. The absolute combined Hamaker coefficients A132abs and A131abs on both infected and uninfected sputum samples gave the values of A132abs = 0.21631x10-21Joule for M-TB infected sputum and Ã132abs = 0.18825x10-21Joule for M-TB/HIV infected sputum. The significance of this result is the positive value of the absolute combined Hamaker coefficient which suggests the existence of net positive van der waals forces demonstrating an attraction between the bacteria and the macrophage. This however, implies that infection can occur. It was also shown that in the presence of HIV, the interaction energy is reduced by 13% conforming adverse effects observed in HIV patients suffering from tuberculosis.

Keywords: absorbance, dielectric constant, hamaker coefficient, lifshitz formula, macrophage, mycobacterium tuberculosis, van der waals forces

Procedia PDF Downloads 276

Authors: Iman Kamranfar, Gang-Ping Xue, Salma Balazadeh, Bernd Mueller-Roeber

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Adverse environmental conditions such as salinity stress, high temperature and drought limit plant growth and typically lead to precocious tissue degeneration and leaf senescence, a process by which nutrients from photosynthetic organs are recycled for the formation of flowers and seeds to secure reaching the next generation under such harmful conditions. In addition, abiotic stress affects developmental patterns that help the plant to withstand unfavourable environmental conditions. We discovered an NAC (for NAM, ATAF1, 2, and CUC2) transcription factor (TF), called RAF in the following, which plays a central role in abiotic drought stress-triggered senescence and the control of developmental adaptations to stressful environments. RAF is an ABA-responsive TF; RAF overexpressors are hypersensitive to abscisic acid (ABA) and exhibit precocious senescence while knock-out mutants show delayed senescence. To explore the RAF gene regulatory network (GRN), we determined its preferred DNA binding sites by binding site selection assay (BSSA) and performed microarray-based expression profiling using inducible RAF overexpression lines and chromatin immunoprecipitation (ChIP)-PCR. Our studies identified several direct target genes, including those encoding for catabolic enzymes acting during stress-induced senescence. Furthermore, we identified various genes controlling drought stress-related developmental changes. Based on our results, we conclude that RAF functions as a central transcriptional regulator that coordinates developmental programs with stress-related inputs from the environment. To explore the potential agricultural applications of our findings, we are currently extending our studies towards crop species.

Keywords: abiotic stress, Arabidopsis, development, transcription factor

Procedia PDF Downloads 195

Authors: Nirjhar Dhang, S. Vinay Kumar

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Concrete is a non-homogeneous mix of coarse aggregates, sand, cement, air-voids and interfacial transition zone (ITZ) around aggregates. Adoption of these complex structures and material properties in numerical simulation would lead us to better understanding and design of concrete. In this work, the mesoscale model of concrete has been prepared from X-ray computerized tomography (CT) image. These images are converted into computer model and numerically simulated using commercially available finite element software. The mesoscale models are simulated under the influence of compressive displacement. The effect of shape and distribution of aggregates, continuous and discrete ITZ thickness, voids, and variation of mortar strength has been investigated. The CT scan of concrete cube consists of series of two dimensional slices. Total 49 slices are obtained from a cube of 150mm and the interval of slices comes approximately 3mm. In CT scan images, the same cube can be CT scanned in a non-destructive manner and later the compression test can be carried out in a universal testing machine (UTM) for finding its strength. The image processing and extraction of mortar and aggregates from CT scan slices are performed by programming in Python. The digital colour image consists of red, green and blue (RGB) pixels. The conversion of RGB image to black and white image (BW) is carried out, and identification of mesoscale constituents is made by putting value between 0-255. The pixel matrix is created for modeling of mortar, aggregates, and ITZ. Pixels are normalized to 0-9 scale considering the relative strength. Here, zero is assigned to voids, 4-6 for mortar and 7-9 for aggregates. The value between 1-3 identifies boundary between aggregates and mortar. In the next step, triangular and quadrilateral elements for plane stress and plane strain models are generated depending on option given. Properties of materials, boundary conditions, and analysis scheme are specified in this module. The responses like displacement, stresses, and damages are evaluated by ABAQUS importing the input file. This simulation evaluates compressive strengths of 49 slices of the cube. The model is meshed with more than sixty thousand elements. The effect of shape and distribution of aggregates, inclusion of voids and variation of thickness of ITZ layer with relation to load carrying capacity, stress-strain response and strain localizations of concrete have been studied. The plane strain condition carried more load than plane stress condition due to confinement. The CT scan technique can be used to get slices from concrete cores taken from the actual structure, and the digital image processing can be used for finding the shape and contents of aggregates in concrete. This may be further compared with test results of concrete cores and can be used as an important tool for strength evaluation of concrete.

Keywords: concrete, image processing, plane strain, interfacial transition zone

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Authors: Fernando Miguel Campos, Carlos Ferreira, João Pestana, Pedro Campos, Nils Ehrenberg, Wojciech Hydzik

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The current trend of organizations offering their workers open-office spaces and co-working offices has been primed for stimulating teamwork and collaboration. However, this is not always valid as these kinds of spaces bring other types of challenges that compromise workers productivity and creativity. We present an approach for improving creativity and productivity at the workspace by redesigning an office chair that incorporates subtle technological elements that help users focus, relax and being more productive and creative. This sheds light on how we can better design interactive furniture for such popular contexts, as we develop this new chair through a multidisciplinary approach using ergonomics, interior design, interaction design, hardware and software engineering and psychology.

Keywords: creativity, co-working, ergonomics, human-computer interaction, interaction, interactive furniture, productivity

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Authors: Imam Uddin, Imtiaz Ahmed Memon

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This paper analyzes the ideological contextuality of market oriented strategy language used by Industry leaders to envision the future of Islamic financial Institutions (IFIs) in the light of Wittgenstein language-games and Foucault’s power-discourse framework. The analysis infers that the explicit market orientation of strategy language and modern knowledge of finance now defines various concepts related of Islamic finance, let alone Islamic finance theory itself. Theorizing and practicing Islamic finance therefore under the dominant influence of modern strategy discourse and modern knowledge of finance has significant implications for developing an ethical and spiritual orientation of Islamic banks. The concerned academia and scholarship therefore need to review such trends and work around the possible degradation to the public image of IFIs and resulting disappointments of religiously inspired customers.

Keywords: Islamic finance discourse, strategy discourse, language games, strategic intent, productive misunderstanding

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Authors: Win-Jin Chang, Haw-Long Lee, Yu-Ching Yang

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In this study, we use the atomic-scale finite element method to investigate the mechanical behavior of the armchair- and zigzag-structured nanoporous graphene sheets with the clamped-free-free-free boundary condition under tension and shear loadings. The effect of porosity on Young’s modulus and shear modulus of nanoporous graphene sheets is obvious. For the armchair- and zigzag-structured nanoporous graphene sheets, Young’s modulus and shear modulus decreases with increasing porosity. Young’s modulus and shear modulus of zigzag graphene are larger than that of armchair one for the same porosity. The results are useful for application in the design of nanoporous graphene sheets.

Keywords: graphene, nanoporous, Young's modulus, shear modulus

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Authors: Ragy Raafat Gaber Attaalla

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For cardiovascular illness, oral P2Y12 inhibitors including clopidogrel, prasugrel, and ticagrelor are frequently recommended. Each of these medications has advantages and disadvantages. In the absence of genotyping, it has been demonstrated that the stronger platelet aggregation inhibitors prasugrel and ticagrelor are superior than clopidogrel at preventing significant adverse cardiovascular events following an acute coronary syndrome and percutaneous coronary intervention (PCI). Both, nevertheless, come with a higher risk of bleeding unrelated to a coronary artery bypass. As a prodrug, clopidogrel needs to be bioactivated, principally by the CYP2C19 enzyme. A CYP2C19 no function allele and diminished or absent CYP2C19 enzyme activity are present in about 30% of people. The reduced exposure to the active metabolite of clopidogrel and reduced inhibition of platelet aggregation among clopidogrel-treated carriers of a CYP2C19 no function allele likely contributed to the reduced efficacy of clopidogrel in clinical trials. Clopidogrel's pharmacogenetic results are strongest when used in conjunction with PCI, but evidence for other indications is growing. One of the most typical examples of clinical pharmacogenetic application is CYP2C19 genotype-guided antiplatelet medication following PCI. Guidance is available from expert consensus groups and regulatory bodies to assist with incorporating genetic information into P2Y12 inhibitor prescribing decisions. Here, we examine the data supporting genotype-guided P2Y12 inhibitor selection's effects on clopidogrel response and outcomes and discuss tips for pharmacogenetic implementation. We also discuss procedures for using genotype data to choose P2Y12 inhibitor therapies as well as any unmet research needs. Finally, choosing a P2Y12 inhibitor medication that optimally balances the atherothrombotic and bleeding risks may be influenced by both clinical and genetic factors.

Keywords: inhibitors, cardiovascular events, coronary intervention, pharmacogenetic implementation

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Authors: Hyun Ji Hyun, Hyo Sun Suh, Min Kook Kim, Yong Chan Kwon, Byung-Mu Lee

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Scope: This study is focused on the effect of myristic acid on LPS-induced inflammation in RAW 264.7 macrophage cells. Methods and results: For the experiment, RAW 264.7 mouse macrophage cell line was used. Results showed that treatment with myristic acid can attenuate LPS-induced inflammation. Moreover, myristic acid significantly suppressed expression of inflammatory mediators and down-regulating UVB-induced intracellular ROS generation. Furthermore, myristic acid reduced the expression of NF-κB by inhibiting degradation of IκB-α and ERK, JNK, and p38 pathways by inhibiting phosphorylation in RAW 264.7 macrophage cells. Conclusion: Overall, these data suggest that the myristic acid could reduce LPS-induced inflammation. Acknowledgment: This research was supported by the Ministry of Trade, Industry & Energy(MOTIE), Korea Institute for Advancement of Technology(KIAT) through the Encouragement Program for The Industries of Economic Cooperation Region

Keywords: anti-inflammation, myristic acid, ROS, ultraviolet light

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Authors: Hossein Arzani, Masoud Jafari Shalamzari, Z. Arzani

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This paper follows FAO model of suitability analysis. Influential factors affecting extensive grazing were determined and converted into a model. Taleghan rangelands were examined for common types of grazing animals as an example. Advantages and limitations were elicited. All range ecosystems’ components affect range suitability but due to the time and money restrictions, the most important and feasible elements were investigated. From which three sub-models including water accessibility, forage production and erosion sensitivity were considered. Suitable areas in four levels of suitability were calculated using GIS. This suitability modeling approach was adopted due to its simplicity and the minimal time that is required for transforming and analyzing the data sets. Managers could be benefited from the model to devise the measures more wisely to cope with the limitations and enhance the rangelands health and condition.

Keywords: range suitability, land-use, extensive grazing, modeling, land evaluation

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Authors: H. A. Erdogan

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Historical masonry arch bridges built centuries ago have fulfilled their function until recent decades. However, from the beginning of 20th century, these bridges have remained inadequate as a result of increasing speed, size and capacity of the means of transport. Although new bridges have been built in many places, masonry bridges located within the city limits still need to be used. When the size and transportation loads of modern vehicles are taken into account, it is apparent that historical masonry arch bridges would be exposed to greater loads than their initial design loads. Because of that, many precautions taken either remain insufficient or damage these bridges. In this study, the history of Debbaglar Bridge, one of the historic bridges located in the city center of Aksaray/Turkey is presented and its existing condition is evaluated. Structural analysis of the bridge under present conditions and loads is explained. Moreover, the retrofit and restoration application prepared considering the analysis data is described.

Keywords: adaptive re-use, Aksaray debbaglar bridge, masonry bridge, reconstruction

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Authors: He Li Wen, Meng Qing Xiang, Li De Yong, Zhang Ya Wei, Ren Li Ping

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Stress always exerts some extent adverse effects on the animal production, food safety and quality concerns. Stress is commonly-seen in livestock industry, but there is rare literature focusing on the effects of nutrition stress. What’s more, the research always concentrates on the effect of single stress additionally, there is scarce information about the stress effect on waterfowl like goose as they are commonly thought to be tolerant to stress. To our knowledge, it is not always true. The object of this study was to evaluate the response of growing Greylag geese offered different fiber sources to the comprehensive stress, primarily involving the procedures of fasting, transport, capture, etc. The birds were randomly selected to rear with the diets differing in fiber source, being corn straw silage (CSS), steam-exploded corn straw (SECS), steam-exploded wheat straw (SEWS), and steam-exploded rice straw (SERS), respectively. Blood samples designated for the determination of stress status were collected before (pre-stress ) and after (post-stress ) the stressors carried out. No difference (P>0.05) was found on the pre-stress blood parameters of growing Greylags fed alternative fiber sources. Irrespective of the dietary differences, the comprehensive stress decreased (P<0.01) the concentration of SOD and increased (P<0.01) that of CK. Between the dietary treatments, the birds fed CSS had a higher (P<0.05)post-stress concentration of MDA than those offered SECS, along with a similarity to those fed the other two fiber sources. There was no difference (P>0.05) found on the stress response of the birds fed different fiber sources. In conclusion, SOD and CK concentration in blood may be more sensitive in indicating stress status and dietary fiber source exerted no effect on the stress response of growing Greylags. There is little chance to improve the stress status by ingesting different fiber sources.

Keywords: blood parameter, fiber source, Greylag goose, stress

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Authors: E. Popov, N. Yorino, Y. Zoka, Y. Sasaki, H. Sugihara

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This paper discusses the performance of critical trajectory method (CTrj) for power system transient stability analysis under various loading settings and heavy fault condition. The method obtains Controlling Unstable Equilibrium Point (CUEP) which is essential for estimation of power system stability margins. The CUEP is computed by applying the CTrjto the boundary controlling unstable equilibrium point (BCU) method. The Proposed method computes a trajectory on the stability boundary that starts from the exit point and reaches CUEP under certain assumptions. The robustness and effectiveness of the method are demonstrated via six power system models and five loading conditions. As benchmark is used conventional simulation method whereas the performance is compared with and BCU Shadowing method.

Keywords: power system, transient stability, critical trajectory method, energy function method

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Authors: Paul Dallyn, Ashraf El-Hamalawi, Alessandro Palmeri, Bob Knight

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In order to better understand the long term implications of the grout wear failure mode in large-diameter plain-sided grouted connections, a numerical model has been developed and calibrated that can take advantage of existing operational plant data to predict the wear accumulation for the actual load conditions experienced over a given period, thus limiting the need for expensive monitoring systems. This model has been derived and calibrated based on site structural condition monitoring (SCM) data and supervisory control and data acquisition systems (SCADA) data for two operational wind turbine generator substructures afflicted with this challenge, along with experimentally derived wear rates.

Keywords: grouted connection, numerical model, offshore structure, wear, wind energy

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Authors: Sibel Aydogan, Ceyda Aysuna

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Religion is a social superstructure institution. Religious beliefs and practices are undeniable phenomena in the simplest and / or most complex societies and communities. All individuals in the society are not devout, but yet they are affected by religion one way or another. This study aims to identify the relationship between religion and country reputation. The uniqueness of the study lies in the fact that in the literature there is no study aimed to examine this relationship. Because of this reason the findings of the study can have important implications to fill this literature gap. Beyond examining this relationship, in the study also different religious oriented people’s opinions of country reputation was analyzed. The results of the analysis of data consisting of 985 respondents reveal that there is a significant relationship between religion and people’s opinions on country reputation. Another important finding of the study is people with different religious orientations have different opinions about a country’s reputation. The findings of the reputation may be important for people and organizations who are responsible for increasing a country’s reputation. Also the findings may shed light on country branding activities.

Keywords: religion, religiosity, religious orientation, country reputation, Turkey

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Authors: Mohamed A. Baba, Gazy Rodowan, Brigita Abakevičienė, Sigitas Tamulevičius, Bartlomiej Lemieszek, Sebastian Molin, Tomas Tamulevičius

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Solid oxide fuel cells (SOFC) efficiently convert hydrogen to energy without producing any disturbances or contaminants. The core of the cell is electrolyte. For improving the performance of electrolyte-supported cells, it is desirable to extend the available exchange surface area by micro-structuring of the electrolyte with laser-based micromachining. This study investigated the electrochemical performance of cells micro machined using a femtosecond laser. Commercial ceramic SOFC (Elcogen, AS) with a total thickness of 400 μm was structured by 1030 nm wavelength Yb: KGW fs-laser Pharos (Light Conversion) using 100 kHz repetition frequency and 290 fs pulse length light by scanning with the galvanometer scanner (ScanLab) and focused with a f-Theta telecentric lens (SillOptics). The sample height was positioned using a motorized z-stage. The microstructures were formed using a laser spiral trepanning in Ni/YSZ anode supported membrane at the central part of the ceramic piece of 5.5 mm diameter at active area of the cell. All surface was drilled with 275 µm diameter holes spaced by 275 µm. The machining processes were carried out under ambient conditions. The microstructural effects of the femtosecond laser treatment on the electrolyte surface were investigated prior to the electrochemical characterisation using a scanning electron microscope (SEM) Quanta 200 FEG (FEI). The Novo control Alpha-A was used for electrochemical impedance spectroscopy on a symmetrical cell configuration with an excitation amplitude of 25 mV and a frequency range of 1 MHz to 0.1 Hz. The fuel cell characterization of the cell was examined on open flanges test setup by Fiaxell. Using nickel mesh on the anode side and au mesh on the cathode side, the cell was electrically linked. The cell was placed in a Kittec furnace with a Process IDentifier temperature controller. The wires were connected to a Solartron 1260/1287 frequency analyzer for the impedance and current-voltage characterization. In order to determine the impact of the anode's microstructure on the performance of the commercial cells, the acquired results were compared to cells with unstructured anode. Geometrical studies verified that the depth of the -holes increased linearly according to laser energy and scanning times. On the other hand, it reduced as the scanning speed increased. The electrochemical analysis demonstrates that the open circuit voltage OCV values of the two cells are equal. Further, the modified cell's initial slope reduces to 0.209 from 0.253 of the unmodified cell, revealing that the surface modification considerably decreases energy loss. Plus, the maximum power density for the cell with the microstructure and the reference cell respectively, are 1.45 and 1.16 Wcm⁻².

Keywords: electrochemical performance, electrolyte-supported cells, laser micro-structuring, solid oxide fuel cells

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Authors: M. Nuhu, M. S. Amina, A. H. Aminu, A. J. Abbas, N. Salahudeen, A. Z. Yusuf

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Transesterification of jatropha methyl ester (JME) with the common polyol, trimethylolpropane (TMP) produced the TMP based ester which exhibits improved temperature properties. This paper discusses the physic-chemical properties of jatropha bio-lubricant base oil applicable for ISO VG32 and VG46 requirement. The catalyst employed for the JME was CaO synthesized in National Research Institute for Chemical Technology (NARICT) that gives 100% conversion. The molar ratio of JME to TMP was 3.5:1 and the catalyst (NaOCH3) loading were found to be 0.8% of the weight of the total reactants. The final fractionated jatropha bio-lubricant base was found to contain 11.95% monoesters, 43.89% diesters and 44.16% triesters (desired product). In addition, it was found that the bio-lubricant base oil produced is comparable to the ISO VG46 commercial standards for light and industrial gears applications and other plant based bio-lubricant.

Keywords: biodegradability, methyl ester, pour point, transesterification, viscosity index

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Authors: Sharon Diaz Ruiz

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The population of Latinx adult English language learners (ELLs) in the United States will increase in the next few years and become even more racially and linguistically diverse. Our classrooms reflect these demographic changes; therefore, there will always be the need to identify language teaching practices that would allow educators to meet this linguistic diversity. This qualitative study explores Latinx adult English language learners' perceptions of culturally responsive teaching strategies. Participants in this study will be enrolled in an English developmental course for the Fall of 2022. The data collection process will consist of overt observation during five presentations/activities, including culturally inclusive readings and student reflections. The teaching materials selected will align with the course module's goals and objectives. The result of this investigation will shed light on the gap in the literature documenting the application of culturally responsive pedagogy to Latino adult language learners.

Keywords: emergent bilinguals, adult learners, Latinx learners, ELL

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Authors: N. Kaewpraek, W. Assawinchaichote

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This paper considers an H_∞ TS fuzzy state-derivative feedback controller for a class of nonlinear dynamical systems. A Takagi-Sugeno (TS) fuzzy model is used to approximate a class of nonlinear dynamical systems. Then, based on a linear matrix inequality (LMI) approach, we design an H_∞ TS fuzzy state-derivative feedback control law which guarantees L₂-gain of the mapping from the exogenous input noise to the regulated output to be less or equal to a prescribed value. We derive a sufficient condition such that the system with the fuzzy controller is asymptotically stable and H_∞ performance is satisfied. Finally, we provide and simulate a numerical example is provided to illustrate the stability and the effectiveness of the proposed controller.

Keywords: h-infinity fuzzy control, an LMI approach, Takagi-Sugano (TS) fuzzy system, the photovoltaic systems

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Authors: Gurcan A. B., Baker T. N.

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Due to economic and environmental requirements, it is becoming increasingly important to reduce vehicle weight. The first approach consisted in using light materials with high thermal conductivity, such as aluminium alloys. This choice allowed significant mass reduction and lower temperature but required recourse to ventilated discs. Among aluminium alloys, Al 6xxx series alloys enjoy the highest strength-to-weight ratio and, therefore, have found wide applications in the automobile and aerospace industries. However, these alloys lose their high strength rapidly when they are exposed to elevated temperatures. This rapid decline in the strength is directly related to the coarsening of very fine precipitates which are then not as effective in obstructing the dislocations. The incorporation of micro-scale and nano-scale particulates in aluminium systems can greatly enhance their mechanical characteristics.

Keywords: mechanical and tribological behaviour, scanning electron microscope, optical test, mechanical properties test, experimental test

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Authors: Y. T. Boon, M. N. Naim, R. Zakaria, N. F. Abu Bakar, N. Ahmad, I. W. Lenggoro

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In this study, encapsulation of agarwood oil with non-ionic surfactant, Tween 80 was prepared at critical micelle concentration of 0.0167 % v/v to produce the most stable nano-emulsion in aqueous. The encapsulation has minimized the bioactive compounds degradation in various pH conditions thus prolong their shelf life and maintained its initial oil grade. The oil grading of the prepared samples were conducted using the gel electrophoresis instead of using common analytical industrial grading such as gas chromatography- mass spectrometry (GC- MS). The grading method was chosen due to their unique zeta potential value after the encapsulation process. This paper demonstrates the feasibility of applying the electrophoresis principles to separate the encapsulated agarwood oil or grading of the emulsified agarwood oil. The results indicated that the grading process are potential to be further investigate based on their droplet size and zeta potential value at various pH condition when the droplet were migrate through polyacrylamide gel.

Keywords: electrophoretic mobility, essential oil, nanoemulsion, polyacrylamide gel electrophoresis, tween 80, zeta potential

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Authors: Keyvanl Yahya

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This paper aims to find a algorithmic structure that affords to predict and explain economic choice behaviour particularly under uncertainty (random policies) by manipulating the prevalent Actor-Critic learning method that complies with the requirements we have been entrusted ever since the field of neuroeconomics dawned on us. Whilst skimming some basics of neuroeconomics that might be relevant to our discussion, we will try to outline some of the important works which have so far been done to simulate choice making processes. Concerning neurological findings that suggest the existence of two specific functions that are executed through Basal Ganglia all the way down to sub-cortical areas, namely 'rewards' and 'beliefs', we will offer a modified version of actor/critic algorithm to shed a light on the relation between these functions and most importantly resolve what is referred to as a challenge for actor-critic algorithms, that is lack of inheritance or hierarchy which avoids the system being evolved in continuous time tasks whence the convergence might not emerge.

Keywords: neuroeconomics, choice behaviour, decision making, reinforcement learning, actor-critic algorithm

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Authors: Kyung Hwa Hong

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The objective of this study was to evaluate the ability of spent coffee extract to enhance the antioxidant and antimicrobial properties of cotton fabrics. The emergence and spread of infectious diseases has raised a global interest in the antimicrobial substances. The safety of chemical agents, such as antimicrobials and dyes, which may irritate the skin, cause cellular and organ damage, and have adverse environmental impacts during their manufacturing, in relation to the human body has not been established. Nevertheless, there is a growing interest in natural antimicrobials that kill microorganisms or stop their growth without dangerous effects on human health. Spent coffee is the by-product of coffee brewing and amounted to 96,000 tons worldwide in 2015. Coffee components such as caffeine, melanoidins, and chlorogenic acid have been reported to possess multifunctional properties, including antimicrobial, antioxidant, and anti-inflammatory activities. Therefore, the current study examined the possibility of applying spent coffee in functional textile finishing. Spent coffee was extracted with 60% methanol solution, and the major components of the extract were quantified. In addition, cotton fabrics treated with spent coffee extract through a pad-dry-cure process were investigated for antioxidant and antimicrobial activities. The cotton fabrics finished with the spent coffee extract showed an increase in yellowness, which is an unfavorable outcome from the fabric finishing process. However, the cotton fabrics finished with the spent coffee extract exhibited considerable antioxidant activity. In particular, the antioxidant ability significantly increased with increasing concentrations of the spent coffee extract. The finished cotton fabrics showed antimicrobial ability against S. aureus but relatively low antimicrobial ability against K. pneumoniae. Therefore, further investigations are needed to determine the appropriate concentration of spent coffee extract to inhibit the growth of various pathogenic bacteria.

Keywords: spent coffee grounds, cotton, natural finishing agent, antioxidant activity, antimicrobial activity

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Authors: Mehmet Bozca

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Singular value decomposition based optimisation of geometric design parameters of a 5-speed gearbox is studied. During the optimisation, a four-degree-of freedom torsional vibration model of the pinion gear-wheel gear system is obtained and the minimum singular value of the transfer matrix is considered as the objective functions. The computational cost of the associated singular value problems is quite low for the objective function, because it is only necessary to compute the largest and smallest singular values (µmax and µmin) that can be achieved by using selective eigenvalue solvers; the other singular values are not needed. The design parameters are optimised under several constraints that include bending stress, contact stress and constant distance between gear centres. Thus, by optimising the geometric parameters of the gearbox such as, the module, number of teeth and face width it is possible to obtain a light-weight-gearbox structure. It is concluded that the all optimised geometric design parameters also satisfy all constraints.

Keywords: Singular value, optimisation, gearbox, torsional vibration

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Authors: Masoumeh Ghasemi, Afshin Farahbakhsh, Arman Farahbakhsh, Ali Asghar Safari

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In this study, lipase production has been investigated using submerge fermentation by Aspergillus niger in Kilka fish oil as main substrate. The Taguchi method with an L9 orthogonal array design was used to investigate the effect of parameters and their levels on lipase productivity. The optimum conditions for Kilka fish oil concentration, incubation temperature and pH were obtained 3 gr./ml 35°C and 7, respectively. The amount of lipase activity in optimum condition was obtained 4.59IU/ml. By comparing this amount with the amount of productivity in the olive oil medium based on the cost of each medium, it was that using Kilka fish oil is 84% economical. Therefore Kilka fish oil can be used as an economical and suitable substrate in the lipase production and industrial usages.

Keywords: lipase, Aspergillus niger, Kilka fish oil, submerge fermentation method

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Authors: Luis A. Anchordoqui, Jorge F. Soriano, Diego F. Torres

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Auger data show evidence for a correlation between ultrahigh-energy cosmic rays (UHECRs) and nearby starburst galaxies. This intriguing correlation is consistent with data collected by the Telescope Array, which have revealed a much more pronounced directional 'hot spot' in arrival directions not far from the starburst galaxy M82. In this work, we assume starbursts are sources of UHECRs, and we investigate the prospects to use the observed distribution of UHECR arrival directions to constrain galactic magnetic field models. We show that if the Telescope Array hot spot indeed originates on M82, UHECR data would place a strong constraint on the turbulent component of the galactic magnetic field.

Keywords: galactic magnetic field, Pierre Auger observatory, telescope array, ultra-high energy cosmic rays

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Authors: Mary Oo, Thet Oo

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Mandalay is home to the last dynasty of Myanmar and is rich in cultural heritage. In Mandalay, cultural heritage is still being seen today, in not only intangible but also many tangible heritages. Intangible heritage, a religious structure such as mosques, churches, stupas, temples, Buddha libraries and monasteries, comprise over 80%. Among these religious structures, the authors aim to study the wooden monasteries built in the 19th century and then propose heritage management for them. Although some of the wooden monasteries are being conserved by the government, NGOs or inhabitants in those buildings, because of the unsystematic management plan and some of the inappropriate traditional methods, even their authentic architectural values have been lost today. In this paper, four aspects are explored: 1) the architectural features of 19th-century wooden monasteries 2) the condition of the problems and challenges, 3) the analysis of the problems of them and finally, based on these above analyses, recommend the appropriate heritage management proposal.

Keywords: Mandalay, wooden monasteries, challenges, problems, heritage management proposal

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Authors: Mohammad Mohammadi, Mohammad Pashmchi

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Background: Malnutrition commonly develops and worsens following gastric cancer surgery, particularly after discharge, which is associated with adverse outcomes. Former studies have primarily focused on patients during their hospital stay period, and there is limited evidence regarding the recommendation of nutritional interventions for patients after discharge from the hospital following gastric cancer surgery. This review is aimed to evaluate the efficiency of post-discharge dietary counseling with oral nutritional supplements (ONS), and dietary counseling alone on post-surgical nutritional outcomes in patients undergoing gastric cancer surgery. Methods: The four databases of Embase, PubMed, web of science, and google scholar were searched up to November 2022 for relevant randomized controlled trials. The Cochrane Collaboration’s assessment tool for randomized trials was used to evaluate the quality of studies. Results: Compared to patients who only received dietary counseling, patients who received both dietary counseling and ONS had considerably higher SMI, BMI, and less weight loss and sarcopenia occurrence rate. The patients who had received dietary counseling and ONS had significantly lower risk of chemotherapy intolerance. No differences in the readmission rate between the two groups was found. In terms of the quality of life, concomitant dietary advice and ONS significantly was associated with lower appetite loss and fatigue rate, but there was no difference in the other outcomes between the two groups. Conclusions: Post-discharge dietary advice with ONS following gastric cancer surgery may improve skeletal muscle maintenance, nutritional outcomes, quality of life variables, and chemotherapy tolerance. This evidence supports the recommendation of post-discharge dietary advice with ONS for patients who underwent gastric cancer surgery.

Keywords: gastric cancer surgery, oral nutritional supplements, malnutrition, gastric cancer

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Authors: L. P. Gomes, G. F. Araújo, Y. M. L. Cordeiro, C. T. Andrade, E. M. Del Aguila, V. M. F. Paschoalin

Abstract:

The application of nanoscale materials and nanostructures is an emerging area, these since materials may provide solutions to technological and environmental challenges in order to preserve the environment and natural resources. To reach this goal, the increasing demand must be accompanied by 'green' synthesis methods. Chitosan is a natural, nontoxic, biopolymer derived by the deacetylation of chitin and has great potential for a wide range of applications in the biological and biomedical areas, due to its biodegradability, biocompatibility, non-toxicity and versatile chemical and physical properties. Chitosan also presents high antimicrobial activities against a wide variety of pathogenic and spoilage microorganisms. Ultrasonication is a common tool for the preparation and processing of polymer nanoparticles. It is particularly effective in breaking up aggregates and in reducing the size and polydispersity of nanoparticles. High-intensity ultrasonication has the potential to modify chitosan molecular weight and, thus, alter or improve chitosan functional properties. The aim of this study was to evaluate the influence of sonication intensity and time on the changes of commercial chitosan characteristics, such as molecular weight and its potential antibacterial activity against Gram-negative bacteria. The nanoparticles (NPs) were produced from two commercial chitosans, of medium molecular weight (CS-MMW) and low molecular weight (CS-LMW) from Sigma-Aldrich®. These samples (2%) were solubilized in 100 mM sodium acetate pH 4.0, placed on ice and irradiated with an ultrasound SONIC ultrasonic probe (model 750 W), equipped with a 1/2" microtip during 30 min at 4°C. It was used on constant duty cycle and 40% amplitude with 1/1s intervals. The ultrasonic degradation of CS-MMW and CS-LMW were followed up by means of ζ-potential (Brookhaven Instruments, model 90Plus) and dynamic light scattering (DLS) measurements. After sonication, the concentrated samples were diluted 100 times and placed in fluorescence quartz cuvettes (Hellma 111-QS, 10 mm light path). The distributions of the colloidal particles were calculated from the DLS and ζ-potential are measurements taken for the CS-MMW and CS-LMW solutions before and after (CS-MMW30 and CS-LMW30) sonication for 30 min. Regarding the results for the chitosan sample, the major bands can be distinguished centered at Radius hydrodynamic (Rh), showed different distributions for CS-MMW (Rh=690.0 nm, ζ=26.52±2.4), CS-LMW (Rh=607.4 and 2805.4 nm, ζ=24.51±1.29), CS-MMW30 (Rh=201.5 and 1064.1 nm, ζ=24.78±2.4) and CS-LMW30 (Rh=492.5, ζ=26.12±0.85). The minimal inhibitory concentration (MIC) was determined using different chitosan samples concentrations. MIC values were determined against to E. coli (106 cells) harvested from an LB medium (Luria-Bertani BD™) after 18h growth at 37 ºC. Subsequently, the cell suspension was serially diluted in saline solution (0.8% NaCl) and plated on solid LB at 37°C for 18 h. Colony-forming units were counted. The samples showed different MICs against E. coli for CS-LMW (1.5mg), CS-MMW30 (1.5 mg/mL) and CS-LMW30 (1.0 mg/mL). The results demonstrate that the production of nanoparticles by modification of their molecular weight by ultrasonication is simple to be performed and dispense acid solvent addition. Molecular weight modifications are enough to provoke changes in the antimicrobial potential of the nanoparticles produced in this way.

Keywords: antimicrobial agent, chitosan, green production, nanoparticles

Procedia PDF Downloads 326

Authors: Noor Ul Ain Bhatti, M. Junaid Khan, Javed Ahmad, Murtaza Saleem, Shahid M. Ramay, Saadat A. Siddiqi

Abstract:

Manganese oxide is being recently used as electrode material for rechargeable batteries. In this study, Al incorporated Mn₂O₃ compositions were synthesized to study the effect of Al doping on electrochemical performance of host material. Structural studies were carried out using X-ray diffraction analysis to confirm the phase stability and explore the lattice parameters, crystallite size, lattice strain, density and cell volume. Morphology and composition were analyzed using field emission scanning electron microscope and energy dispersive X-ray spectroscopy, respectively. Dynamic light scattering analysis was performed to observe the average particle size of the compositions. FTIR measurements exhibit the O-Al-O and O-Mn-O and Al-O bonding and with increasing the concentration of Al, the vibrational peaks of Mn-O become sharper. An enhanced electrochemical performance was observed in compositions with higher Al content.

Keywords: Mn2O3, electrode materials, energy storage and conversion, electrochemical performance

Procedia PDF Downloads 367

Authors: Minjeong Kim, Seungchul Lee, Iman Janghorban Esfahani, Jeong Tai Kim, ChangKyoo Yoo

Abstract:

A trajectory of set-point of ventilation control systems plays an important role for efficient ventilation inside subway stations since it affects the level of indoor air pollutants and ventilation energy consumption. To maintain indoor air quality (IAQ) at a comfortable range with lower ventilation energy consumption, the optimal trajectory of the ventilation control system needs to be determined. The concentration of air pollutants inside the station shows a diurnal variation in accordance with the variations in the number of passengers and subway frequency. To consider the diurnal variation of IAQ, an iterative dynamic programming (IDP) that searches for a piecewise control policy by separating whole duration into several stages is used. When outdoor air is contaminated by pollutants, it enters the subway station through the ventilation system, which results in the deteriorated IAQ and adverse effects on passenger health. In this study, to consider the influence of outdoor air quality (OAQ), a new performance index of the IDP with the passenger health risk and OAQ is proposed. This study was carried out for an underground subway station at Seoul Metro, Korea. The optimal set-points of the ventilation control system are determined every 3 hours, then, the ventilation controller adjusts the ventilation fan speed according to the optimal set-point changes. Compared to manual ventilation system which is operated irrespective of the OAQ, the IDP-based ventilation control system saves 3.7% of the energy consumption. Compared to the fixed set-point controller which is operated irrespective of the IAQ diurnal variation, the IDP-based controller shows better performance with a 2% decrease in energy consumption, maintaining the comfortable IAQ range inside the station.

Keywords: indoor air quality, iterative dynamic algorithm, outdoor air information, ventilation control system

Procedia PDF Downloads 501