Search results for: marketing theory and applications

Authors: Konesh Navsaria, Itumeleng Ramodumo

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The study explored university students’ perceptions of cannabis use on academic life at a higher education institution (HEI) in Nelson Mandela Bay, South Africa. Cannabis is described as the most commonly-used drug by youth, especially those who are in tertiary institutions. The use of cannabis has both negative and positive effects; this is evident in different areas of human functioning. Cannabis usage has been debated upon in courts regarding its legalization and decriminalization, and on the 18th of September 2018, the South African High Court decriminalized cannabis for personal use. Cannabis use has increased in academic settings, and this has raised concerns about how it affects the mental health of students. A qualitative approach was used for the study with an explorative, descriptive design. Purposive sampling was used to select 15 participants for the study. Data were collected using focused-group interviews, following ethical clearance from the HEI. The collected data were analyzed and interpreted using thematic analysis, and cognitive behavioural theory was used as the theoretical framework. The research findings indicated both positive and negative influences of cannabis use on mental health. Most participants who expressed positive effects have used cannabis before, whereas most participants with negative perspectives of cannabis use on mental health are non-cannabis users. The findings revealed that participants perceived that the quantity of cannabis smoked determined whether there was a positive or negative effect on mental health; that is, large doses of cannabis were perceived as having negative effects. The research findings also revealed that the legalization of cannabis is very likely to increase its use and also highlighted precautionary measures users take to avoid the substance’s negative effects on mental health.

Keywords: cannabis use, mental health, university students, legalization

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Authors: Hamed Hossein Afshari, Shahrzad Jalali, Amir Hossein Ghods, Bijan Raahemi

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This paper introduces an automated clustering solution that applies to WiFi/Bluetooth sensing data and is later used for traffic management applications. The paper initially summarizes a number of clustering approaches and thereafter shows their performance for noise removal. In this context, clustering is used to recognize WiFi and Bluetooth MAC addresses that belong to passengers traveling by a public urban transit bus. The main objective is to build an intelligent system that automatically filters out MAC addresses that belong to persons located outside the bus for different routes in the city of Ottawa. The proposed intelligent system alleviates the need for defining restrictive thresholds that however reduces the accuracy as well as the range of applicability of the solution for different routes. This paper moreover discusses the performance benefits of the presented clustering approaches in terms of the accuracy, time and space complexity, and the ease of use. Note that results of clustering can further be used for the purpose of the origin-destination estimation of individual passengers, predicting the traffic load, and intelligent management of urban bus schedules.

Keywords: WiFi-Bluetooth sensing, cluster analysis, artificial intelligence, traffic management

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Authors: Ahmed Deen

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The introduction of the mobile devices which were equipped with internet access and a camera, as well as the messaging services, has become a major inspiration for the use of the mobile devices in the growth in the reporting of news. Mobile journalism (MOJO) was a creation of modern technology, especially the use of mobile technology for video journalism purposes. MOJO, thus, is the process by which information is collected and disseminated to society, through the use of mobile technology, and even the use of the tablets. This paper seeks to better understand the ethics of Saudi mobile journalists towards news coverage. Also, this study aims to explore the relationship between minimizing harms and truth-seeking efforts among Saudi mobile journalists. Three main ethics were targeted in this study, which are seek truth and report it, minimize harm, and being accountable. Diffusion of innovation theory applied to reach this study’s goals. The non- probability sampling approach, ‘Snowball Sampling’ was used to target 124 survey participants, an online survey via SurveyMonkey that was distributed through social media platforms as a web link. The code of ethics of the Society of Professional Journalists has applied as a scale in this study. This study found that the relationship between minimizing harm and truth-seeking efforts is significantly moderate among Saudi mobile journalists. Also, it is found that the level journalistic experiences and using smartphones to cover news are weakly and negatively related to the perceptions of mobile journalism among Saudi journalists, while Saudi journalists who use their smartphone to cover the news between 1-3 years, were the majority of participants (55 participants by 51.4%).

Keywords: mobile journalism, Saudi journalism, smartphone, Saudi Arabia

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Authors: Pratham Madnur, Prathamkumar Shetty, Sneha Varur, Gouri Parashetti

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In order to overcome conventional obstacles, this research paper investigates novel approaches for cricket pitch and ball detection that make use of cutting-edge technologies. The research integrates OpenCV for pitch inspection and modifies the YOLOv8 model for cricket ball detection in order to overcome the shortcomings of manual pitch assessment and traditional ball detection techniques. To ensure flexibility in a range of pitch environments, the pitch detection method leverages OpenCV’s color space transformation, contour extraction, and accurate color range defining features. Regarding ball detection, the YOLOv8 model emphasizes the preservation of minor object details to improve accuracy and is specifically trained to the unique properties of cricket balls. The methods are more reliable because of the careful preparation of the datasets, which include novel ball and pitch information. These cutting-edge methods not only improve cricket analytics but also set the stage for flexible methods in more general sports technology applications.

Keywords: OpenCV, YOLOv8, cricket, custom dataset, computer vision, sports

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Authors: B. J. Sonani, J. K. Ratnadhariya, Srinivas Palanki

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Cryogenic engineering is the fast growing branch of the modern technology. There are various applications of the cryogenic engineering such as liquefaction in gas industries, metal industries, medical science, space technology, and transportation. The low-temperature technology developed superconducting materials which lead to reduce the friction and wear in various components of the systems. The liquid oxygen, hydrogen and helium play vital role in space application. The liquefaction process is produced very low temperature liquid for various application in research and modern application. The air liquefaction system for oxygen plants in gas industries is based on the Claude cycle. The effect of process parameters on the overall system is difficult to be analysed by manual calculations, and this provides the motivation to use process simulators for understanding the steady state and dynamic behaviour of such systems. The parametric study of this system via MATLAB simulations provide useful guidelines for preliminary design of air liquefaction system based on the Claude cycle. Every organization is always trying for reduce the cost and using the optimum performance of the plant for the staying in the competitive market.

Keywords: cryogenic, liquefaction, low -temperature, oxygen, claude cycle, optimization, MATLAB

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Authors: A. Altomi, A. Alhebshi, M. Rasm, B. Osman

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This study explored the application of chitin nanocrystals (ChiNCs), derived from a renewable and environmentally friendly material, as stabilizers for oil-in-water (O/W) emulsions. O/W emulsions are commonly used in various applications but are prone to instability and degradation over time. Instability can occur due to factors such as flocculation, coalescence, and gravitational separation, including creaming and sedimentation, either independently or simultaneously. To produce ChiNCs, chitin powder underwent acid hydrolysis. Transmission electron microscopy (TEM) analysis revealed that ChiNCs exhibited a needle-like morphology, with lengths ranging from 200 to 800 nm and widths ranging from 20 to 80 nm. The surface charge of ChiNCs was negative at pH values above 7 and positive at pH values below 7. The rheological properties of O/W emulsions stabilized by ChiNCs were compared to those stabilized by synthetic surfactants, namely Tween 80 and CTAB. The emulsions stabilized by ChiNCs demonstrated higher yield stress and lower shear viscosity compared to those stabilized by synthetic surfactants. This indicates that ChiNC-stabilized emulsions are more stable and less prone to breakdown. Based on these findings, ChiNCs show promise as an alternative to synthetic surfactants for stabilizing O/W emulsions.

Keywords: chitin nanocrystals, colloidal pickering, emulsion rheology, oil-in-water, synthetic surfactant

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Authors: Avichal Malhotra, Jerome Frisch, Christoph van Treeck

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The utilization of semantic, cadastral and topological data from geographic information systems (GIS) has exponentially increased for building and urban-scale energy performance simulations. Urban planners, simulation scientists, and researchers use virtual 3D city models for energy analysis, algorithms and simulation tools. For dynamic energy simulations at city and district level, this paper provides an overview of the available GIS data models and their levels of detail. Adhering to different norms and standards, these models also intend to describe building and construction industry data. For further investigations, CityGML data models are considered for simulations. Though geographical information modelling has considerably many different implementations, extensions of virtual city data can also be made for domain specific applications. Highlighting the use of the extended CityGML models for energy researches, a brief introduction to the Energy Application Domain Extension (ADE) along with its significance is made. Consequently, addressing specific input simulation data, a workflow using Modelica underlining the usage of GIS information and the quantification of its significance over annual heating energy demand is presented in this paper.

Keywords: CityGML, EnergyADE, energy performance simulation, GIS

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Authors: Joao Ferreira Do Rosario, Nuno Gustavo, Ana Machado, Lurdes Calisto, Luisa Carvalho, Georgette Andraz

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Currently, tourism small and medium enterprises (TSMEs) face serious economic and financial problems, making recovery efforts difficult. How the pandemic will affect tourists' behavior is still to be known. Will tourists be even more cautious regarding their choices or, on the contrary, will they be more adventurers with an enormous desire to travel in search of the lost freedom? Tourists may become even more demanding when traveling, more austere, or less concerned and eager to socialize. Adjusting to this "new tourist" is an added challenge for tourism service providers. Generation Z made up of individuals born in 1995 and following years, currently tends to assume a particular role and meaning in the present and future economic and social context, considering that we are facing the youngest workforce as well as tomorrow's consumers. This generation is distinguished from others as it is the first generation to combine a high level of education and technological knowledge and to fully experience the digital world. These young people are framed by a new value system that can explain new behaviours and consumption, namely, in the context of tourism. All these considerations point to the importance of investigating this target group as it is essential to understand how these individuals perceive, understand, act, and can be involved in a new environment built around a society regulated by new priorities and challenges of a sustainable nature. This leads not only to a focus on short-term market choices but mainly to predict future choices from a longer-term perspective. Together with the social background of a person, values are considered a stable antecedent of behavior and might therefore predict not just immediate, but also future choices. Furthermore, the meaning attributed to travel has a general connotation and goes beyond a specific travel choice or experience. In other words, values and travel's meaning form a chain of influences on the present and future travel behavior. This study explores the social background and values of Generation Z travelers vs the meaning these tourists give to travel. The aim is to discover in their present behavior cues to predict travel choices so that the future of tourism can be secured. This study also provides data for predicting the tourism choices of youngsters in the more immediate future. Methodologically, a quantitative approach was adopted based on the collection of data through a survey. Since academic research on Generation Z of tourists is still scarce, it is expected to contribute to deepening scientific knowledge in this area. Furthermore, it is expected that this research will support tourism professionals in defining differentiated marketing strategies and adapted to the requirements of this target, in a new time.

Keywords: Generation Z, travel behavior, travel meaning, Generation Z Values

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Authors: Lucyna Kapka-Skrzypczak, Barbara Sochanowicz, Magdalena Matysiak-Kucharek, Magdalena Czajka, Krzysztof Sawicki, Marcin Kruszewski

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Due to the strong antimicrobial activity silver nanoparticles (AgNPs) are widely used in various medical and general applications, among others, in cosmetics, odour resistant textiles, etc. The aim of this study was to compare effect of AgNPs and gold NPs (AuNPs) on histones posttranslational modifications. Histone molecule posttranscriptional modifications are responsible for chromatin compaction and repackaging. In this study, BALB/c mice were inoculated with murine mammary carcinoma 4T1 cells and treated with AgNPs coated with citrate (AgNPs(cit) or PEG (AgNPs(PEG), or AuNPs. Thereafter the histone H3 acetylation on Lys9 and H3 methylation on Lys4, Lys9, Lys29 was investigated. All NPs tested decreased H3 methylation, while no effect was observed for H3 acetylation. Modification of histone H3 methylation dependent on type of NPs used its coating, site of methylation and treatment used. Conclusion, epigenetic effects of nanomaterials depend on nanomaterial composition, its coating, and way of application. This work was supported by National Science Centre grant No. 2014/15/B/NZ7/01036 (MK, LKS, MMK, MC, KS), statutory funding for INTC (BS).

Keywords: gold nanoparticles, histone, methylation, silver nanoparticles

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Authors: Bharti Bhandari, Bharati Mehta, Sabyasachi Sircar

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Medical education is advancing in India, with its advancement newer innovations are being incorporated in teaching and assessment methodology. Our study focusses on a teaching innovation that is more student-centric than teacher-centric and is the need of the day. The teaching innovation was carried out in 1st year MBBS students of our institute. Students were assigned control and test groups. Priming was done for the students in the test group with an open-book MCQ based test in a particular topic before delivering formal didactic lecture on that topic. The control group was not assigned any such exercise. This was followed by formal didactic lecture on the same topic. Thereafter, both groups were assessed on the same topic. The marks were compiled and analysed using appropriate statistical tests. Students were also given questionnaire to elicit their views on the benefits of “self-priming”. The mean marks scored in theory assessment by the test group were statistically higher than the marks scored by the controls. According to students’ feedback, the ‘self-priming “process was interesting, helped in better orientation during class-room lectures and better understanding of the topic. They want it to be repeated for other topics with moderate difficulty level. Better performance of the students in the primed group validates the combination of student-centric priming model and didactic lecture as superior to the conventional, teacher-centric methods alone. If this system is successfully followed, the present teacher-centric pedagogy should increasingly give way to student-centric activities where the teacher is only a facilitator.

Keywords: medical education, open-book test, pedagogy, priming

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Authors: Shib Shankar Banerjeea, Andreas Ferya, Gert Heinricha, Amit Das

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Recently, the growing need for the development of soft robots consisting of highly deformable and compliance materials emerge from the serious limitations of conventional service robots. However, one of the main challenges of soft robotics is to develop such compliance materials, which facilitates the design of soft robotic structures and, simultaneously, controls the soft-body systems, like soft artificial muscles. Generally, silicone or acrylic-based elastomer composites are used for soft robotics. However, mechanical performance and long-term reliabilities of the functional parts (sensors, actuators, main body) of the robot made from these composite materials are inferior. This work will present the development and characterization of robust super-soft programmable elastomeric materials from crosslinked natural rubber that can serve as touch and strain sensors for soft robotic arms with very high elastic properties and strain, while the modulus is altered in the kilopascal range. Our results suggest that such soft natural programmable elastomers can be promising materials and can replace conventional silicone-based elastomer for soft robotics applications.

Keywords: elastomers, soft materials, natural rubber, sensors

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Authors: Fabio Fabris, Alex A. Freitas

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Hierarchical classification is a special type of classification task where the class labels are organised into a hierarchy, with more generic class labels being ancestors of more specific ones. Meta-learning for classification-algorithm recommendation consists of recommending to the user a classification algorithm, from a pool of candidate algorithms, for a dataset, based on the past performance of the candidate algorithms in other datasets. Meta-learning is normally used in conventional, non-hierarchical classification. By contrast, this paper proposes a meta-learning approach for more challenging task of hierarchical classification, and evaluates it in a large number of bioinformatics datasets. Hierarchical classification is especially relevant for bioinformatics problems, as protein and gene functions tend to be organised into a hierarchy of class labels. This work proposes meta-learning approach for recommending the best hierarchical classification algorithm to a hierarchical classification dataset. This work’s contributions are: 1) proposing an algorithm for splitting hierarchical datasets into new datasets to increase the number of meta-instances, 2) proposing meta-features for hierarchical classification, and 3) interpreting decision-tree meta-models for hierarchical classification algorithm recommendation.

Keywords: algorithm recommendation, meta-learning, bioinformatics, hierarchical classification

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Authors: Yan-Wen Wang, Chu-Yang Chou, Jen-Cheng Wang, Min-Sheng Liao, Hsuan-Hsiang Hsu, Cheng-Ying Chou, Chen-Kang Huang, Kun-Chang Kuo, Joe-Air Jiang

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Performance-related parameters of high concentration photovoltaic (HCPV) modules (e.g. current and voltage) are required when estimating the maximum power point using numerical and approximation methods. The maximum power point on the characteristic curve for a photovoltaic module varies when temperature or solar radiation is different. It is also difficult to estimate the output performance and maximum power point (MPP) due to the special characteristics of HCPV modules. Based on the p-n junction semiconductor theory, a brand new and simple method is presented in this study to directly evaluate the MPP of HCPV modules. The MPP of HCPV modules can be determined from an irradiated I-V characteristic curve, because there is a non-linear relationship between the temperature of a solar cell and solar radiation. Numerical simulations and field tests are conducted to examine the characteristics of HCPV modules during maximum output power tracking. The performance of the presented method is evaluated by examining the dependence of temperature and irradiation intensity on the MPP characteristics of HCPV modules. These results show that the presented method allows HCPV modules to achieve their maximum power and perform power tracking under various operation conditions. A 0.1% error is found between the estimated and the real maximum power point.

Keywords: energy performance, high concentrated photovoltaic, maximum power point, p-n junction semiconductor

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Authors: Adekunle Saheed Ajisebiyawo

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This paper examines the influence of identity politics on the development of electoral democracy in Nigeria. The paper was anchored on a theory of African democracy adopted the qualitative methodology and deployed data from secondary sources to evaluate the 2023 presidential election, and found that ethnicity, religion, and regional sentiments played a major role in the election. The practical implications of this paper are that while Nigeria’s democracy is tending towards consolidation, if the unexpected does not happen, e.g., military takeover, religious and ethnic identities can mar the country’s development as competent candidates that have good policies will be voted out based on religious and ethnic sentiments. Thus, there is a need to de-emphasize religion and ethnicity in the Nigerian polity. Candidates and parties that campaign based on racial or religious narratives should be barred from contesting elective positions. The paper concluded that identity politics is inimical to Nigeria’s democratization process as well as efforts aimed at uniting and integrating the country; it, therefore, recommended that to establish a sound electoral democracy and a strong united country, the menace of ethnic, religious, and regional cleavages should be addressed. To achieve this, efforts should be intensified towards providing a set of principles for nation-building which should be included in the constitution. In addition, the paper urges the media to support the formation of an inclusive government, cutting across tribes and religions in the country to reduce the negative impact of ethnicity and religion in the country.

Keywords: cleavages, democracy, ethnicity, election, identity politics, religion

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Authors: Houria Hamitouche, Abdellah Khelifa

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Quaternary ammonium salts (QACs) are the most common cationic surfactants of natural or synthetic origin usually. They possess one or more hydrophobic hydrocarbon chains and hydrophilic cationic group. In fact, the hydrophobic groups are derived from three main sources: petrochemicals, vegetable oils, and animal fats. These QACs have attracted the attention of chemists for a long time, due to their general simple synthesis and their broad application in several fields. They are important as ingredients of cosmetic products and are also used as corrosion inhibitors, in emulsion polymerization and textile processing. Within biological applications, QACs show a good antimicrobial activity and can be used as medicines, gene delivery agents or in DNA extraction methods. The 2004 worldwide annual consumption of QACs was reported as 500,000 tons. The petroleum product is considered a true reservoir of a variety of chemical species, which can be used in the synthesis of quaternary ammonium salts. The purpose of the present contribution is to synthesize the quaternary ammonium salts by Menschutkin reaction, via chloromethylation/quaternization sequences, from Algerian petroleum products namely: reformate, light naphtha and kerosene and characterize.

Keywords: quaternary ammonium salts, reformate, light naphtha, kerosene

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Authors: Nor Diana Ahmad, Eric Atwell, Brandon Bennett

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Text processing techniques for English have been developed for several decades. But for the Malay language, text processing methods are still far behind. Moreover, there are limited resources, tools for computational linguistic analysis available for the Malay language. Therefore, this research presents the use of natural language processing (NLP) in processing Malay translated Qur’an text. As the result, a new language resource for Malay translated Qur’an was created. This resource will help other researchers to build the necessary processing tools for the Malay language. This research also develops a simple question-answer prototype to demonstrate the use of the Malay Qur’an resource for text processing. This prototype has been developed using Python. The prototype pre-processes the Malay Qur’an and an input query using a stemming algorithm and then searches for occurrences of the query word stem. The result produced shows improved matching likelihood between user query and its answer. A POS-tagging algorithm has also been produced. The stemming and tagging algorithms can be used as tools for research related to other Malay texts and can be used to support applications such as information retrieval, question answering systems, ontology-based search and other text analysis tasks.

Keywords: language resource, Malay translated Qur'an, natural language processing (NLP), text processing

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Authors: Karen Odendaal

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Accounting transactions are becoming more complex, and more extensive accounting guidance is provided on a continuous basis. It is widely perceived that conceptual teaching of accounting contributes to lifelong learning. Such a conceptual teaching approach also contributes to effective accounting problem-solving. This framework-based approach is rooted in educational psychologies such as constructivism and Ausubel’s subsumption theory. This study aimed at investigating the ability of students to solve complex accounting problems by using only concepts underlying the Conceptual Framework. An assignment was administered to pre-graduate students at a South African university and this study made use of an interpretative research design which implemented multiple research instruments to investigate the ability of students to solve complex accounting problems using only concepts underlying the Conceptual Framework. Student perceptions were analysed and were aided by a related reflective questionnaire. The importance of the study indicates the necessity of Accounting educators to enhance a conceptual understanding among students as a mechanism for problem-solving of accounting issues. The results indicate that the ability of students to solve accounting problems effectively using only the Conceptual Framework depends on the complexity of the scenario and the students’ familiarity with the problem. The study promotes a balanced and more conceptual (rather than only technical) preference to the problem-solving of complex accounting problems. The study indubitably promotes considerable emphasis on the importance of the Conceptual Framework in accounting education and the promotion of life-long learning in the subject field.

Keywords: accounting education, conceptual teaching, constructivism, framework-based, problem-solving

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Authors: Saleh Gorji, Sahil Gulati, Ana Pakzad

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Continuous electron diffraction tomography, also known as microcrystal electron diffraction (MicroED) or three-dimensional electron diffraction (3DED), is a powerful technique, which in combination with cryo-electron microscopy (cryo-ED), can provide atomic-scale 3D information about the crystal structure and composition of different classes of crystalline materials such as proteins, peptides, and small molecules. Unlike the well-established X-ray crystallography method, 3DED does not require large single crystals and can collect accurate electron diffraction data from crystals as small as 50 – 100 nm. This is a critical advantage as growing larger crystals, as required by X-ray crystallography methods, is often very difficult, time-consuming, and expensive. In most cases, specimens studied via 3DED method are electron beam sensitive, which means there is a limitation on the maximum amount of electron dose one can use to collect the required data for a high-resolution structure determination. Therefore, collecting data using a conventional scintillator-based fiber coupled camera brings additional challenges. This is because of the inherent noise introduced during the electron-to-photon conversion in the scintillator and transfer of light via the fibers to the sensor, which results in a poor signal-to-noise ratio and requires a relatively higher and commonly specimen-damaging electron dose rates, especially for protein crystals. As in other cryo-EM techniques, damage to the specimen can be mitigated if a direct detection camera is used which provides a high signal-to-noise ratio at low electron doses. In this work, we have used two classes of such detectors from Gatan, namely the K3® camera (a monolithic active pixel sensor) and Stela™ (that utilizes DECTRIS hybrid-pixel technology), to address this problem. The K3 is an electron counting detector optimized for low-dose applications (like structural biology cryo-EM), and Stela is also a counting electron detector but optimized for diffraction applications with high speed and high dynamic range. Lastly, data collection workflows, including crystal screening, microscope optics setup (for imaging and diffraction), stage height adjustment at each crystal position, and tomogram acquisition, can be one of the other challenges of the 3DED technique. Traditionally this has been all done manually or in a partly automated fashion using open-source software and scripting, requiring long hours on the microscope (extra cost) and extensive user interaction with the system. We have recently introduced Latitude® D in DigitalMicrograph® software, which is compatible with all pre- and post-energy-filter Gatan cameras and enables 3DED data acquisition in an automated and optimized fashion. Higher quality 3DED data enables structure determination with higher confidence, while automated workflows allow these to be completed considerably faster than before. Using multiple examples, this work will demonstrate how to direct detection electron counting cameras enhance 3DED results (3 to better than 1 Angstrom) for protein and small molecule structure determination. We will also show how Latitude D software facilitates collecting such data in an integrated and fully automated user interface.

Keywords: continuous electron diffraction tomography, direct detection, diffraction, Latitude D, Digitalmicrograph, proteins, small molecules

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Authors: Shannen Lorraine, Paul Maragh, Tara Dasgupta, Kamaluddin Abdur-Rashid

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(R)-(4,4',6,6'-tetramethoxybiphenyl-2,2'-diyl)bis(diphenylphosphine) (R-Ph-Garphos), and (S)-(4,4',6,6'-tetramethoxybiphenyl-2,2'-diyl)bis(diphenylphosphine) (S-Ph-Garphos) are novel, nucleophilic, chiral atropisomeric ligands. The research explored the synthesis of chiral transition metal complexes containing these ligands and their applications in various asymmetric catalytic transformations. Herein, the transition metal complexes having ruthenium(II), rhodium(I) and iridium(I) metal centres will be discussed. These are air stable complexes and were characterized by CHN analysis, 1H, 13C, and 31P NMR spectroscopy, and polarimetry. Currently, there is an emphasis on 'greener' catalysts and the need for 'green' solvents in asymmetric catalysis. As such, the Ph-Garphos ligands were demethylated thereby introducing hydroxyl moieties unto the ligand scaffold. The facile tunability of the biaryl diphosphines led to the preparation of the (R)-(4,4',6,6'-tetrahydroxybiphenyl-2,2'-diyl)bis(diphenylphosphine) (R-Ph-Garphos-OH), and (S)-(4,4',6,6'-tetrahydroxybiphenyl-2,2'-diyl)bis(diphenylphosphine) (S-Ph-Garphos-OH) ligands. These were successfully characterized by CHN analysis, 1H, 13C, and 31P NMR spectroscopy, and polarimetry. The use of the Ph-Garphos and Ph-Garphos-OH ligands and their transition metal complexes in asymmetric hydrogenations will be reported. Additionally, the scope of the research will highlight the applicability of the Ph-Garphos-OH ligand and its transitional metal complexes as 'green' catalysts.

Keywords: catalysis, asymmetric hydrogenation, diphosphine transition metal complexes, Ph-Garphos ligands

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Authors: S. Nandal, R. Bhargava

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The paper contains a numerical study of the unsteady magneto-hydrodynamic natural convection flow of nanofluids within a symmetrical wavy walled trapezoidal enclosure. The length and height of enclosure are both considered equal to L. Two-phase nanofluid model is employed. The governing equations of nanofluid flow along with boundary conditions are non-dimensionalized and are solved using one of Meshfree technique (EFGM method). Meshfree numerical technique does not require a predefined mesh for discretization purpose. The bottom wavy wall of the enclosure is defined using a cosine function. Element free Galerkin method (EFGM) does not require the domain. The effects of various parameters namely time t, amplitude of bottom wavy wall a, Brownian motion parameter Nb and thermophoresis parameter Nt is examined on rate of heat and mass transfer to get a visualization of cooling and heating effects. Such problems have important applications in heat exchangers or solar collectors, as wavy walled enclosures enhance heat transfer in comparison to flat walled enclosures.

Keywords: heat transfer, meshfree methods, nanofluid, trapezoidal enclosure

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Authors: Qijiao He

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MicroElectrical-Mechanical System (MEMS) is one of the most rapidly developing frontier research field both in theory study and applied technology. Micro-channel is a very important link component of MEMS. With the research and development of MEMS, the size of the micro-devices and the micro-channels becomes further smaller. Compared with the macroscale flow, the flow characteristics of gas in the micro-channel have changed, and the rarefaction effect appears obviously. However, for the rarefied gas and microscale flow, Navier-Stokes-Fourier (NSF) equations are no longer appropriate due to the breakup of the continuum hypothesis. A Nonlinear Coupled Constitutive Model (NCCM) has been derived from the Boltzmann equation to describe the characteristics of both continuum and rarefied gas flows. We apply the present scheme to simulate continuum and rarefied gas flows in a micro-channel structure. And for comparison, we apply other widely used methods which based on particle simulation or direct solution of distribution function, such as Direct simulation of Monte Carlo (DSMC), Unified Gas-Kinetic Scheme (UGKS) and Lattice Boltzmann Method (LBM), to simulate the flows. The results show that the present solution is in better agreement with the experimental data and the DSMC, UGKS and LBM results than the NSF results in rarefied cases but is in good agreement with the NSF results in continuum cases. And some characteristics of both continuum and rarefied gas flows are observed and analyzed.

Keywords: continuum and rarefied gas flows, discontinuous Galerkin method, generalized hydrodynamic equations, numerical simulation

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Authors: Ebrahim Tilahun, Erkan Sahinkaya, Bariş Calli̇

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Raw biogas is a valuable renewable energy source however it usually needs removal of the impurities. The presence of hydrogen sulfide (H2S) in the biogas has detrimental corrosion effects on the cogeneration units. Removal of H2S from the biogas can therefore significantly improve the biogas quality. In this work, a conventional bioscrubber (CBS), and a dense membrane bioscrubber (DMBS) were comparatively evaluated in terms of H2S removal efficiency (RE), CH4 enrichment and alkaline consumption at gas residence times ranging from 5 to 20 min. Both bioscrubbers were fed with a synthetic biogas containing H2S (1%), CO2 (39%) and CH4 (60%). The results show that high RE (98%) was obtained in the DMBS when gas residence time was 20 min, whereas slightly lower CO2 RE was observed. While in CBS system the outlet H2S concentration was always lower than 250 ppmv, and its H2S RE remained higher than 98% regardless of the gas residence time, although the high alkaline consumption and frequent absorbent replacement limited its cost-effectiveness. The result also indicates that in DMBS when the gas residence time increased to 20 min, the CH4 content in the treated biogas enriched upto 80%. However, while operating the CBS unit the CH4 content of the raw biogas (60%) decreased by three fold. The lower CH4 content in CBS was probably caused by extreme dilution of biogas with air (N2 and O2). According to the results obtained here the DMBS system is a robust and effective biotechnology in comparison with CBS. Hence, DMBS has a better potential for real scale applications.

Keywords: biogas, bioscrubber, desulfurization, PDMS membrane

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Authors: Ayesha Ashfaq, Muhammad Ajmal Ashfaq

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It has been assumed that metaphorical and symbolic contests are waged with metaphors, captions, and signs in political cartoons that play a significant role in image construction of political actors, situations or events in the political arena. This paper is an effort to explore the metaphorical devices in political cartoons related to the political confrontation in Pakistan between the ruling party Pakistan Muslim League Nawaz (PMLN) and opposition parties especially after Panama leaks. For this purpose, political cartoons sketched by five renowned political cartoonists on the basis of their belongings to the most highly circulated mainstream English newspapers of Pakistan and their professional experiences in their genre, were selected. The cartoons were analyzed through the Barthes’s model of Semiotics under the umbrella of the first level of agenda setting theory ‘framing’. It was observed that metaphorical devices in political cartoons are one of the key weapons of cartoonists’ armory. These devices are used to attack the candidates and contribute to the image and character building. It was found that all the selected political cartoonists used different forms of metaphors including situational metaphors and embodying metaphors. Not only the physical stature but also the debates and their activities were depicted metaphorically in the cartoons that create the scenario of comparison between the cartoons and their real political confrontation. It was examined that both forms of metaphors shed light on cartoonist’s perception and newspaper’s policy about political candidates, political parties and particular events. In addition, it was found that zoomorphic metaphors and metaphors of diminishments were also predominantly used to depict the conflict between two said political actors.

Keywords: metaphor, Panama leaks, political cartoons, political communication

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Authors: Liang-Hsuan Chen, Sheng-Shing Nien

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This study aims to develop approaches to formulate intuitionistic fuzzy regression (IFR) models for many decision-making applications in the fuzzy environments using intuitionistic fuzzy observations. Intuitionistic fuzzy numbers (IFNs) are used to characterize the fuzzy input and output variables in the IFR formulation processes. A mathematical programming problem (MPP) is built up to optimally determine the IFR parameters. Each parameter in the MPP is defined as a couple of alternative numerical variables with opposite signs, and an intuitionistic fuzzy error term is added to the MPP to characterize the uncertainty of the model. The IFR model is formulated based on the distance measure to minimize the total distance errors between estimated and observed intuitionistic fuzzy responses in the MPP resolution processes. The proposed approaches are simple/efficient in the formulation/resolution processes, in which the sign of parameters can be determined so that the problem to predetermine the sign of parameters is avoided. Furthermore, the proposed approach has the advantage that the spread of the predicted IFN response will not be over-increased, since the parameters in the established IFR model are crisp. The performance of the obtained models is evaluated and compared with the existing approaches.

Keywords: fuzzy sets, intuitionistic fuzzy number, intuitionistic fuzzy regression, mathematical programming method

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Authors: Eman Alzahrani

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Efficient extraction of proteins by removing interfering materials is necessary in proteomics, since most instruments cannot handle such contaminated sample matrices directly. In this study, chitosan-coated magnetic nanoparticles (CS-MNPs) for purification of myoglobin were successfully fabricated. First, chitosan (CS) was prepared by a deacetylation reaction during its extraction from shrimp-shell waste. Second, magnetic nanoparticles (MNPs) were synthesised, using the coprecipitation method, from aqueous Fe2+ and Fe3+ salt solutions by the addition of a base under an inert atmosphere, followed by modification of the surface of MNPs with chitosan. The morphology of the formed nanoparticles, which were about 23 nm in average diameter, was observed by transmission electron microscopy (TEM). In addition, nanoparticles were characterised using X-ray diffraction patterns (XRD), which showed the naked magnetic nanoparticles have a spinel structure and the surface modification did not result in phase change of the Fe3O4. The coating of MNPs was also demonstrated by scanning electron microscopy (SEM) analysis, energy dispersive analysis of X-ray spectroscopy (EDAX), and Fourier transform infrared (FT-IR) spectroscopy. The adsorption behaviour of MNPs and CS-MNPs towards myoglobin was investigated. It was found that the difference in adsorption capacity between MNPs and CS-MNPs was larger for CS-MNPs. This result makes CS-MNPs good adsorbents and attractive for using in protein extraction from biological samples.

Keywords: chitosan, magnetic nanoparticles, coprecipitation, adsorption

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Authors: Cristina Isabrl de Oliveira SAntos

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The study aims to investigate how transferrable and effective career conversations could be, in the context of general track Portuguese secondary schools, with the view of improving students’ career competencies. It does so by analysing: 1) the extent to which students’ perceptions of career conversations relate with their existing career competencies, 2) the extent to which each of the parameters; perceptions of career conversations and student career competencies, relate with student situational and personal characteristics, 3) how patterns in perceptions of headteachers and of teachers at a school, regarding the implementation of career conversations, correlate to the views of students regarding career conversations and to school contextual characteristics. Data were collected from 27 secondary schools out of 32 in the same district of Aveiro, in Portugal. Interviews were performed individually, with 27 headteachers, and in groups, with a total of 10 teacher groups and 11 student groups. Survey responses were also collected from742 studentsand 310 teachers. Interview responses were coded and analysed using grounded theory principles. Data from questionnaires is currently beingscrutinised through descriptive statistics with SPSS, and Structural Equation Modelling (SEM). Triangulation during different stages of data analysis uses the principles of retroduction and abduction of the realist evaluation framework. Conclusions from the pilot-study indicate that student perceptions scores on content and relationship in career conversations change according to their career competencies and the type of school. Statistically significant differences in perceptions of career conversations were found for subgroups based on gender and parent educational level.

Keywords: career conversations, career competencies, secondary education, teachers

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Authors: Abhishekkumar Ramasamy, Parameshwari

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Chitosan is the deacyelitated derivative of chitin, the second most abundant biopolymer just after cellulose. Without doubt, its biomedical usages have gained more importance among the vast variety of chitosan applications owing to its good biocompatibility and biodegradability. In recent years, particular interest has been devoted to chitosan hydrogels as a promising alternative in competition with conventional sutures or bioadhesives. Different parameters such as acid type and concentration, and degree of deacetylation (DD%) of chitosan, were altered to modify hydrogel properties including viscosity, pH, cohesive strength, and tissue bioadhesiveness. In the current work, we have investigated the effectiveness of chitosan hydrogel encapsulated with tanexamic acid to stop bleeding. Chitosan film was obtained with solubilization of chitosan powder in aqueous acidic media. In vivo experiments have been conducted on rat and rabbit models that provide a convenient way to evaluate the efficacy of prepared samples. The arteries vein was punctured on the hind limb of the rat and the gauze was been applied on the punchered area. Bioadhesive strength as well as irritant effects were discussed. Samples with higher degree of deacetylation, including Chs-16 and Chs-19 that were dissolved in lactic media showed best sealing effect.

Keywords: chitosan, biocomaptibility, biodegradability, bioadhersive, deacetylation

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Authors: B. Ravi Kumar, S. Gajanana, K. Hemachandra Reddy, K. Udayani

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Physically into various derived shapes and sizes under the effect of externally applied forces. The spinning process is an advanced plastic working technology and is frequently used for manufacturing axisymmetric shapes. Over the last few decades, Sheet metal spinning has developed significantly and spun products have widely used in various industries. Nowadays the process has been expanded to new horizons in industries, since tendency to use minimum tool and equipment costs and also using lower forces with the output of excellent surface quality and good mechanical properties. The automation of the process is of greater importance, due to its wider applications like decorative household goods, rocket nose cones, gas cylinders, etc. This paper aims to gain insight into the conventional spinning process by employing experimental and numerical methods. The present work proposes an approach for optimizing process parameters are mandrel speed (rpm), roller nose radius (mm), thickness of the sheet (mm). Forming force, surface roughness and strain are the responses.in spinning of Aluminum (2024-T3) using DOE-Response Surface Methodology (RSM) and Analysis of variance (ANOVA). The FEA software is used for modeling and analysis. The process parameters considered in the experimentation.

Keywords: FEA, RSM, process parameters, sheet metal spinning

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Authors: Hamid R. Chabok, Demetrios N. Christodoulides, Mercedeh Khajavikhan

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In recent years, acousto-optic (AO) lenses with tunable foci have emerged as a powerful tool for optical beam shaping, imaging, and particle manipulation. In most current AO lenses, the incident light that propagates orthogonally to a standing ultrasonic wave converts to a Bessel-like beam pattern due to the Raman-Nath effect, thus forming annular fringes that result in compromised focus response. Here, we report a new class of AO dynamic lensing based on generating a 3D-variable refractive index profile via a z-axis-scan ultrasound transducer. By utilizing the co- /counter propagation of light and acoustic waves that interact over a longer distance, the laser beam can be strongly focused in a fully controllable manner. Using this approach, we demonstrate AO lenses with instantaneous extended depth of field (DoF) and laterally localized dynamic focusing. This new light-sound interaction scheme may pave the way towards applications that require remote focusing, 3D micromanipulation, and deep tissue therapy/imaging.

Keywords: acousto-optic, optical beam shaping, dynamic lensing, ultrasound

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Authors: Aneela Sheikh

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Private higher education institutes are challenged for their resilience and competitive edge in the globalized knowledge-based economy in the 21st century. Faculty retention plays an important role as a catalyst for addressing the current mega-developmental phenomenon in higher education institutes faced by developing countries. This study intends to explore the influence of servant leadership practice on faculty retention through the intervening role of job satisfaction towards minimizing the high faculty turnover in private higher education institutes, with the mediating role of job satisfaction. A sample of 341 faculty members from ten private higher education institutes in Lahore city of Pakistan, was selected through a stratified proportionate random sampling technique. A descriptive survey research approach was employed to collect data from 341 faculty members by administering a close-ended questionnaire based on a seven-point Likert scale as a self-administered research instrument. The study was conducted under the domain of the Leader-Member Exchange (LMX) theory. The mediating role of job satisfaction was measured by bootstrapping technique. The results revealed that servant leadership has a statistically significant influence on faculty retention, with a statistically significant mediating role of job satisfaction, in private higher education institutes in Pakistan. Further, up to the best of the authors’ knowledge, this is the first systematic and empirical study on faculty retention conducted against the backdrop of servant leadership in an Eastern context, particularly in Pakistan.

Keywords: servant leadership, faculty retention, job satisfaction, higher education institutes

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