Search results for: brake specific fuel consumption

Authors: Franziska Köhler-Dauner, Inka Mayer, Lara Hart, Ute Ziegenhain, Jörg M. Fegert

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Preventive isolation and social distancing strategies during the SARS-CoV-2 pandemic have confronted families with a variety of different restrictions and stresses. Especially during this stressful time, children need a stable parental home to avoid developmental disorders. Additional risk factors such as maternal childhood abuse and neglect (CM) experiences may influence mothers' psychosomatic health (pG) and children's physical well-being (kW) during times of increased stress. Our aim was to analyse the interaction between maternal CM, maternal pG and children's kW during the pandemic. Mothers from a well-documented birth cohort to study transgenerational transmission of CM, were included in an online 'pandemic' survey assessing maternal pG and children's physical health during the pandemic. Our mediation analysis showed a significant positive association between the extent of maternal CM experiences, mothers' psychosomatic symptoms and their children's kW. Maternal psychosomatic symptoms significantly mediate the interaction between CM and children's kW; the direct effect remains non-significant when maternal psychosomatic symptoms are included as mediators. Maternal CM appears to be a relevant risk factor for maternal pG and children's kW during the pandemic. Maternal CM experiences seem to influence the way parents cope with stressful situations and increase the risk of suffering from depressive symptoms. The latter also affect their children's kW. Our findings underline the importance of carefully assessing the specific situation of families with children and offering individually adapted help to help families survive the pandemic.

Keywords: pandemic, maternal health, child health, abuse, neglect, maternal experiences

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Authors: Ahmed Tahsin Shams

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The right to dissent through any form of art has been facing challenges through various strict legal measures, particularly since 2018 when the Government of Bangladesh passed the Digital Security Act 2018 (DSA). Therefore, the references to ‘popular’ culture mostly include mainstream religious and national festivals and exclude critical intellectual representation of specific political allusions in any form of storytelling: whether wall art or fiction writing, since the post-DSA period in Bangladesh. Through inductive quantitative and qualitative methodological approaches, this paper aims to study the pattern of censorship, detention or custodial tortures against artists and the banning approach by the Bangladeshi government in the last five years, specifically against static visual arts, i.e., cartoon and wall art. The pattern drawn from these data attempts to redefine the popular notion of ‘pop culture’ as an unorganized folk or mass culture. The results also hypothesize how the post-DSA period forcefully constructs ‘pop culture’ as a very organized repetitive deception of enlightenment or entertainment. Thus the argument theorizes that this censoring trend is a fascist approach making the artists subaltern. So, in this socio-political context, these two similar and overlapping elements: culture and art, are vastly separated in two streams: the former being appreciated by the power, and the latter is a fearful concern for the power. Therefore, the purpose of art also shifts from entertainment to an act of rebellion, adding more layers to the new postmodern definition of ‘pop culture.’

Keywords: popular culture, visual arts, censoring trend, fascist approach, subaltern, digital security act

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Authors: Timo Avikainen, Tuukka Verho

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The use of natural fibers as reinforcements is growing increasingly in polymers which are involved in e.g. structural, vibration, and acoustic applications. The use of bio composites is being investigated as lightweight materials with specific properties like the ability to dissipate vibration energy and positive environmental profile and are thus considered as potential replacements for synthetic composites. The macro-level mechanical properties of the biocomposite material depend on several parameters in the detailed architecture and morphology of the reinforcing fiber structure. The polymer matrix phase is often applied to remain the fiber structure in touch. A big role in the packaging details of the fibers is related to the used manufacturing processes like extrusion, injection molding and treatments. There are typically big variances in the detailed parameters of the microstructure fibers. The study addressed the question of how the multiscale simulation methodology works in bio composites with short pulp fibers. The target is to see how the vibro – acoustic performance of thin–walled panels can be controlled by the detailed characteristics of the fiber material. Panels can be used in sound-producing speakers or sound insulation applications. The multiscale analysis chain is tested starting from the microstructural level and continuing via macrostructural material parameters to the product component part/assembly levels. Another application is the dynamic impact type of loading, exposing the material to the crack type damages that is in this study modeled as the Charpy impact tests.

Keywords: bio composite, pulp fiber, vibration, acoustics, impact, FEM

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Authors: Chris George, Adam Hamlin, Lily Pereg, Richard Charlesworth, Gal Winter

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Background: According to the ‘hygiene hypothesis’ the current rise in allergies and autoimmune diseases stems mainly from reduced microbial exposure due, amongst other factors, to urbanisation and distance from soil. However, this hypothesis is based on epidemiological and not biological data. Useful insights into the underlying mechanisms of this hypothesis can be gained by studying our interaction with soil. Soil microbiota may be directly ingested or inhaled by humans, enter the body through skin-soil contact or using plants as vectors. This study aims to examine the ability of soil microbiota to colonise the gut, study the interaction of soil microbes with the immune system and their potential protective activity. Method: The nutrition of the rats was supplemented daily with fresh or autoclaved soil for 21 days followed by 14 days of no supplementations. Faecal samples were collected throughout and analysed using 16S sequencing. At the end of the experiment rats were sacrificed and tissues and digesta were collected. Results/Conclusion: Results showed significantly higher richness and diversity following soil supplementation even after recovery. Specific soil microbial groups identified as able to colonise the gut. Of particular interest was the mucosal layer which emerged as a receptive host for soil microorganisms. Histological examination revealed innate and adaptive immune activation. Findings of this study reinforce the ‘hygiene hypothesis’ by demonstrating the ability of soil microbes to colonise the gut and activate the immune system. This paves the way for further studies aimed to examine the interaction of soil microorganisms with the immune system.

Keywords: gut microbiota, hygiene hypothesis, microbiome, soil

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Authors: Shafag Dadashova

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The study discusses relativity of perception and interpretation of power, its interdependence with conformity level of an individual. It describes an autobiography as a form of epiphany. It is suggested that life-writing helps the author analyze the past and define the borders of his personal power and sources of empowerment. As all life-writings deal with behaviors, values, attitudes, relationships and emotions, their investigation requires qualitative methods to understand social norms, gender roles, religion, and their role in empowerment and disempowerment of the author. The study consists of two parts. The first part is theoretical and interrogates the notion of personal power and how writing the own life can bring to conscious empowerment. The second part presents two autobiographies by female authors from two different Muslim cultures who negotiate between the larger nationalist agenda and their own personal concerns. These autobiographies (Tehmina Durrani, Pakistani author ‘My Feudal Lord’, Banine, Azerbaijani writer 'Caucasian days' and 'Parisian days') are the end of their authors’ long silence, their revolt against the conventional norms, their decision to have an agency to confess and protest. These autobiographies are the authors’ attempts to break the established matrix of perceptions, imposed norms, and gain power to build the real picture of their identity. The study sums up with the conclusion that in spite of very similar motifs of female authors to get empowered through self-analysis, different cultures and time create specific subjectivities associated with particular historical events and geographical location.

Keywords: conformity level, empowerment, female autobiography, self-identity

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Authors: Bhawna Devi, Girishwar Misra, Rajni Sahni

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Menarche and menstruation is a nearly universal experience in adolescent girls’ lives, yet based on several observations it has been found that it is rarely explicitly talked about, and remains poorly understood. By menarche, girls are likely to have been influenced not only by cultural stereotypes about menstruation, but also by information acquired through significant others. Their own expectations about menstruation are likely to influence their reports of menarcheal experience. The aim of this study is to examine how girls construct meaning around menarche and menstruation in social interactions and specific contexts along with conceptualized experiences which is ‘owned’ by individual girls. Twenty adolescent girls from New Delhi (India), between the ages of 12 to 19 years (mean age = 15.1) participated in the study. Semi-structured interviews were conducted to capture the nuances of menarche and menstrual experiences of these twenty adolescent girls. Thematic analysis was used to analyze the data. From the detailed analysis of transcribed data main themes that emerged were- Menarche: A Trammeled Sky to Fly, Menarche as Flashbulb Memory, Hidden Secret: Shame and Fear, Hallmark of Womanhood, Menarche as Illness. Therefore, the finding unfolds that menarche and menstruation were largely constructed as embarrassing, shameful and something to be hidden, specifically within the school context and in general when they are outside of their home. Menstruation was also constructed as illness that programmed ‘feeling of weaknesses’ into them. The production and perpetuation of gender-related difference narratives was also evident. Implications for individuals, as well as for the subjugation of girls and women, are discussed, and it is argued that current negative representations of, and practices in relation to, menarche and menstruation need to be challenged.

Keywords: embarrassment, gender-related difference, hidden secret, illness, menarche and menstruation

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Authors: Kumar Shashvat, Amol P. Bhondekar

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In the midst of the five senses, odor is the most reminiscent and least understood. Odor testing has been mysterious and odor data fabled to most practitioners. The delinquent of recognition and classification of odor is important to achieve. The facility to smell and predict whether the artifact is of further use or it has become undesirable for consumption; the imitation of this problem hooked on a model is of consideration. The general industrial standard for this classification is color based anyhow; odor can be improved classifier than color based classification and if incorporated in machine will be awfully constructive. For cataloging of odor for peas, trees and cashews various discriminative approaches have been used Discriminative approaches offer good prognostic performance and have been widely used in many applications but are incapable to make effectual use of the unlabeled information. In such scenarios, generative approaches have better applicability, as they are able to knob glitches, such as in set-ups where variability in the series of possible input vectors is enormous. Generative models are integrated in machine learning for either modeling data directly or as a transitional step to form an indeterminate probability density function. The algorithms or models Linear Discriminant Analysis and Naive Bayes Classifier have been used for classification of the odor of cashews. Linear Discriminant Analysis is a method used in data classification, pattern recognition, and machine learning to discover a linear combination of features that typifies or divides two or more classes of objects or procedures. The Naive Bayes algorithm is a classification approach base on Bayes rule and a set of qualified independence theory. Naive Bayes classifiers are highly scalable, requiring a number of restraints linear in the number of variables (features/predictors) in a learning predicament. The main recompenses of using the generative models are generally a Generative Models make stronger assumptions about the data, specifically, about the distribution of predictors given the response variables. The Electronic instrument which is used for artificial odor sensing and classification is an electronic nose. This device is designed to imitate the anthropological sense of odor by providing an analysis of individual chemicals or chemical mixtures. The experimental results have been evaluated in the form of the performance measures i.e. are accuracy, precision and recall. The investigational results have proven that the overall performance of the Linear Discriminant Analysis was better in assessment to the Naive Bayes Classifier on cashew dataset.

Keywords: odor classification, generative models, naive bayes, linear discriminant analysis

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Authors: Muhammad Shahid, Muhammad Mansoor

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Increasing demands of contemporary applications for high strength and lightweight materials prompted the development of metal-matrix composites (MMCs). After the discovery of carbon nanotubes (CNTs) in 1991 (revealing an excellent set of mechanical properties) became one of the most promising strengthening materials for MMC applications. Additionally, the relatively low density of the nanotubes imparted high specific strengths, making them perfect strengthening material to reinforce MMCs. In the present study, aluminum-multiwalled carbon nanotubes (Al-MWCNTs) composite was prepared in an air induction furnace. The dispersion of the nanotubes in molten aluminum was assisted by inherent string action of induction heating at 790°C. During the fabrication process, multifunctional fluxes were used to avoid oxidation of the nanotubes and molten aluminum. Subsequently, the melt was cast in to a copper mold and cold rolled to 0.5 mm thickness. During metallographic examination using a scanning electron microscope, it was observed that the nanotubes were effectively dispersed in the matrix. The mechanical properties of the composite were significantly increased as compared to pure aluminum specimen i.e. the yield strength from 65 to 115 MPa, the tensile strength from 82 to 125 MPa and hardness from 27 to 30 HV for pure aluminum and Al-CNTs composite, respectively. To recognize the associated strengthening mechanisms in the nanocomposites, three foremost strengthening models i.e. shear lag model, Orowan looping and Hall-Petch have been critically analyzed; experimental data were found to be closely satisfying the shear lag model.

Keywords: carbon nanotubes, induction melting, strengthening mechanism, nanocomposite

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Authors: Olumide Simeon Ogunnusi, Shukor Abd Razak, Michael Kolade Adu

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Inter-agent communication manager facilitates communication among mobile agents via message passing mechanism. Until now, all Foundation for Intelligent Physical Agents (FIPA) compliant agent systems are capable of exchanging messages following the standard format of sending and receiving messages. Previous works tend to secure messages to be exchanged among a community of collaborative agents commissioned to perform specific tasks using cryptosystems. However, the approach is characterized by computational complexity due to the encryption and decryption processes required at the two ends. The proposed approach to secure agent communication allows only agents that are created by the host agent server to communicate via the agent communication channel provided by the host agent platform. These agents are assumed to be harmless. Therefore, to secure communication of legitimate agents from intrusion by external agents, a 2-phase policy enforcement system was developed. The first phase constrains the external agent to run only on the network server while the second phase confines the activities of the external agent to its execution environment. To implement the proposed policy, a controller agent was charged with the task of screening any external agent entering the local area network and preventing it from migrating to the agent execution host where the legitimate agents are running. On arrival of the external agent at the host network server, an introspector agent was charged to monitor and restrain its activities. This approach secures legitimate agent communication from Man-in-the Middle and Replay attacks.

Keywords: agent communication, introspective agent, isolation of agent, policy enforcement system

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Authors: Lucy Patricia Onundo, Wilfred Njoroge Mwema

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The tidal power potential available for electricity generation from Mombasa and Lamu sites in Kenya will be examined. Several African countries in the Western Indian Ocean endure insufficiencies in the power sector, including both generation and distribution. One important step towards increasing energy security and availability is to intensify the use of renewable energy sources. The access to cost-efficient hydropower is low in Mombasa and Lamu hence Ocean energy will play an important role. Global-Level resource assessments and oceanographic literature and data have been compiled in an analysis between technology-specific requirements for ocean energy technologies (salinity, tide, tidal current, wave, Ocean thermal energy conversion, wind and solar) and the physical resources in Lamu and Mombasa. The potential for tide and tidal current power is more restricted but may be of interest at some locations. The theoretical maximum power produced over a tidal cycle is determined by the product of the forcing tide and the undisturbed volumetric flow-rate. The extraction of the maximum power reduces the flow-rate, but a significant portion of the maximum power can be extracted with little change to the tidal dynamics. Two-dimensional finite-element, numerical simulations designed and developed agree with the theory. Temporal variations in resource intensity, as well as the differences between small-scale and large-scale applications, are considered.

Keywords: energy assessment, marine tidal power, renewable energy, tidal dynamics

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Authors: Maria Sofia Palagonia, Doriano Brogioli, Fabio La Mantia

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In the last decade, lithium has become an important raw material in various sectors, in particular for rechargeable batteries. Its production is expected to grow more and more in the future, especially for mobile energy storage and electromobility. Until now it is mostly produced by the evaporation of water from salt lakes, which led to a huge water consumption, a large amount of waste produced and a strong environmental impact. A new, clean and faster electrochemical technique to recover lithium has been recently proposed: electrochemical ion pumping. It consists in capturing lithium ions from a feed solution by intercalation in a lithium-selective material, followed by releasing them into a recovery solution; both steps are driven by the passage of a current. In this work, a new configuration of the electrochemical cell is presented, used to study and optimize the process of the intercalation of lithium ions through the hydrodynamic condition. Lithium Manganese Oxide (LiMn₂O₄) was used as a cathode to intercalate lithium ions selectively during the reduction, while Nickel Hexacyano Ferrate (NiHCF), used as an anode, releases positive ion. The effect of hydrodynamics on the process has been studied by conducting the experiments at various fluxes of the electrolyte through the electrodes, in terms of charge circulated through the cell, captured lithium per unit mass of material and overvoltage. The result shows that flowing the electrolyte inside the cell improves the lithium capture, in particular at low lithium concentration. Indeed, in Atacama feed solution, at 40 mM of lithium, the amount of lithium captured does not increase considerably with the flux of the electrolyte. Instead, when the concentration of the lithium ions is 5 mM, the amount of captured lithium in a single capture cycle increases by increasing the flux, thus leading to the conclusion that the slowest step in the process is the transport of the lithium ion in the liquid phase. Furthermore, an influence of the concentration of other cations in solution on the process performance was observed. In particular, the capturing of the lithium using a different concentration of NaCl together with 5 mM of LiCl was performed, and the results show that the presence of NaCl limits the amount of the captured lithium. Further studies can be performed in order to understand why the full capacity of the material is not reached at the highest flow rate. This is probably due to the porous structure of the material since the liquid phase is likely not affected by the convection flow inside the pores. This work proves that electrochemical ion pumping, with a suitable hydrodynamic design, enables the recovery of lithium from feed solutions at the lower concentration than the sources that are currently exploited, down to 1 mM.

Keywords: desalination battery, electrochemical ion pumping, hydrodynamic, lithium

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Authors: Kimberly Samaha

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In order to attract new types of investors into the emerging Bio-Economy, a new set of metrics and measurement system is needed to better quantify the environmental, social and economic impacts of circular zero-waste design. The Bio-Hub Ecosystem model was developed to address a critical area of concern within the global energy market regarding the use of biomass as a feedstock for power plants. Lack of an economically-viable business model for bioenergy facilities has resulted in the continuation of idled and decommissioned plants. In particular, the forestry-based plants which have been an invaluable outlet for woody biomass surplus, forest health improvement, timber production enhancement, and especially reduction of wildfire risk. This study looked at repurposing existing biomass-energy plants into Circular Zero-Waste Bio-Hub Ecosystems. A Bio-Hub model that first targets a ‘whole-tree’ approach and then looks at the circular economics of co-hosting diverse industries (wood processing, aquaculture, agriculture) in the vicinity of the Biomass Power Plants facilities. It proposes not only models for integration of forestry, aquaculture, and agriculture in cradle-to-cradle linkages of what have typically been linear systems, but the proposal also allows for the early measurement of the circularity and impact of resource use and investment risk mitigation, for these systems. Typically, life cycle analyses measure environmental impacts of different industrial production stages and are not integrated with indicators of material use circularity. This concept paper proposes the further development of a new set of metrics that would illustrate not only the typical life-cycle analysis (LCA), which shows the reduction in greenhouse gas (GHG) emissions, but also the zero-waste circularity measures of mass balance of the full value chain of the raw material and energy content/caloric value. These new measures quantify key impacts in making hyper-efficient use of natural resources and eliminating waste to landfills. The project utilized traditional LCA using the GREET model where the standalone biomass energy plant case was contrasted with the integration of a jet-fuel biorefinery. The methodology was then expanded to include combinations of co-hosts that optimize the life cycle of woody biomass from tree to energy, CO₂, heat and wood ash both from an energy/caloric value and for mass balance to include reuse of waste streams which are typically landfilled. The major findings of both a formal LCA study resulted in the masterplan for the first Bio-Hub to be built in West Enfield, Maine. Bioenergy facilities are currently at a critical juncture where they have an opportunity to be repurposed into efficient, profitable and socially responsible investments, or be idled and scrapped. If proven as a model, the expedited roll-out of these innovative scenarios can set a new standard for circular zero-waste projects that advance the critical transition from the current ‘take-make-dispose’ paradigm inherent in the energy, forestry and food industries to a more sustainable bio-economy paradigm where waste streams become valuable inputs, supporting local and rural communities in simple, sustainable ways.

Keywords: bio-economy, biomass energy, financing, metrics

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Authors: Mahlet Nigussie Worku

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The main purpose of this study was to examine the effects of different leadership styles on employee engagement in Ethiopian Airlines headquarters located in Addis Ababa. Specific objectives of the study were stated to examine the effects of five leadership styles, namely transformational, transactional, democratic, lassies fair and autocratic leadership styles on employees’ engagement. The study was conducted on 288 sample sizes, and a simple random sampling technique was employed. The quantitative findings were presented and analyzed by table, ANOVA, bivariate correlation and regression model through SPSS software version 23. Out of 288 total distributed questionnaires, 280 were returned, and 8 of the returned were rejected due to missing data, while the remaining 280 responses were used for data analysis. Data was analyzed using the Statistical Package for Social Sciences (SPSS). The study employed both descriptive and explanatory research design. Correlation and regression were used to analyze the relationship and its effect between leadership Style and employee engagement. The regression results showed that transformational, transactional and democratic leadership Styles have significant contributions to employee engagement. Similarly, the transformational, transactional land democratic leadership style had a positive and strong correlation with employee engagement. However, lassies-fair and autocratic leadership styles showed a negative and insignificant effect on employee engagement. Finally, based on the findings, workable recommendations and implications for further studies were forwarded.

Keywords: leadership, autocratic leadership style, democratic leadership style, employee engagement

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Authors: Ia Kurashvili, Giorgi Darsavelidze, Giorgi Chubinidze, Marina Kadaria

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Boron-doped Czochralski (CZ) silicon of p-type, widely used in the photovoltaic industry is suffering from the light-induced-degradation (LID) of bulk electrophysical characteristics. This is caused by specific metastable B-O defects, which are characterized by strong recombination activity. In this regard, it is actual to suppress B-O defects in CZ silicon. One of the methods is doping of silicon by different isovalent elements (Ge, C, Sn). The present work deals with the investigations of the influence of germanium doping on the internal friction and shear modulus amplitude dependences in the temperature interval of 600-800⁰C and 0.5-5 Hz frequency range in boron-containing monocrystalline silicon. Experimental specimens were grown by Czochralski method (CZ) in [111] direction. Four different specimens were investigated: Si+0,5at%Ge:B (5.1015cm-3), Si+0,5at%Ge:B (1.1019cm-3), Si+2at%Ge:B (5.1015cm-3) and Si+2at%Ge:B (1.1019cm-3). Increasing tendency of dislocation density and inhomogeneous distribution in silicon crystals with high content of boron and germanium were revealed by metallographic studies on the optical microscope of NMM-80RF/TRF. Weak increase of current carriers-holes concentration and slight decrease of their mobility were observed by Van der Pauw method on Ecopia HMS-3000 device. Non-monotonous changes of dislocation origin defects mobility and microplastic deformation characteristics influenced by measuring temperatures and boron and germanium concentrations were revealed. Possible mechanisms of changes of mechanical characteristics in Si-Ge experimental specimens were discussed.

Keywords: dislocation, internal friction, microplastic deformation, shear modulus

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Authors: Karolina Pietras, Joanna Fryt, Aleksandra Gronostaj, Tomasz Smolen

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Young women and men differ from their parents in preferred values. Those differences enable their adaptability to a new socio-cultural context and help with fulfilling developmental tasks specific to young adulthood. At the same time core values, with special importance to family members, are transmitted within families. Intergenerational similarities in values may thus be both an effect of value transmission within a family and a consequence of sharing the same socio-cultural context. These processes are difficult to separate. In our study we assessed similarities and differences in values within four intergenerational family dyads (mothers-daughters, fathers-daughters, mothers-sons, fathers-sons). Sixty Polish young adults (30 women and 30 men aged 19-25) along with their parents (a total of 180 participants) completed the Schwartz’ Portrait Value Questionnaire (PVQ-21). To determine which values may be transmitted within families, we used a correlation analysis and pseudo dyad analysis that allows for the estimation of a baseline likeness between all tested subjects and consequently makes it possible to determine if similarities between actual family members are greater than chance. We also assessed whether different strategies of measuring similarity between family members render different results, and checked whether resemblances in family dyads are influenced by child’s and parent’s gender. Reported similarities were interpreted in light of the evolutionary and the value salience perspective.

Keywords: intergenerational differences in values, gender differences, pseudo dyad analysis, transmission of values

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Authors: S. Z. A. Zaidi, A. Crosky

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Biocomposites is a field that has gained much scientific attention due to the current substantial consumption of non-renewable resources and the environmentally harmful disposal methods required for traditional polymer composites. Research on natural fiber reinforced polyhydroxyalkanoates (PHAs) has gained considerable momentum over the past decade. There is little work on PHAs reinforced with unidirectional (UD) natural fibers and little work on using epoxidized natural rubber (ENR) as a toughening agent for PHA-based biocomposites. In this work, we prepared polyhydroxybutyrate-co-valerate (PHBV) biocomposites reinforced with UD 30 wt.% flax fibers and evaluated the use of ENR with 50% epoxidation (ENR50) as a toughening agent for PHBV biocomposites. Quasi-unidirectional flax/PHBV composites were prepared by hand layup, powder impregnation followed by compression molding.  Toughening agents – polybutylene adiphate-co-terephthalate (PBAT) and ENR50 – were cryogenically ground into powder and mechanically mixed with main matrix PHBV to maintain the powder impregnation process. The tensile, flexural and impact properties of the biocomposites were measured and morphology of the composites examined using optical microscopy (OM) and scanning electron microscopy (SEM). The UD biocomposites showed exceptionally high mechanical properties as compared to the results obtained previously where only short fibers have been used. The improved tensile and flexural properties were attributed to the continuous nature of the fiber reinforcement and the increased proportion of fibers in the loading direction. The improved impact properties were attributed to a larger surface area for fiber-matrix debonding and for subsequent sliding and fiber pull-out mechanisms to act on, allowing more energy to be absorbed. Coating cryogenically ground ENR50 particles with PHBV powder successfully inhibits the self-healing nature of ENR-50, preventing particles from coalescing and overcoming problems in mechanical mixing, compounding and molding. Cryogenic grinding, followed by powder impregnation and subsequent compression molding is an effective route to the production of high-mechanical-property biocomposites based on renewable resources for high-obsolescence applications such as plastic casings for consumer electronics.

Keywords: natural fibers, natural rubber, polyhydroxyalkanoates, unidirectional

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Authors: Jihye Hwang, Eun Hwa Choi, Su Youn Baek, Bia Park, Gyeongmin Kim, Chorong Shin, Joon Ha Lee, Jae-Sam Hwang, Ui Wook Hwang

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White-spotted flower chafers are widely distributed in Asian countries and traditionally used for the treatment of chronic fatigue, blood circulation, and paralysis in the oriental medicine field. The evolution and development of insect wings and metamorphosis remain under-discovered subjects in arthropod evolutionary researches. Gene expression abundance analyses along with developmental stages based on the large-scale RNA-seq data are also still rarely done. Here we report the de novo assembly of a Protestia brevitarsis seulensis transcriptome along four different developmental stages (egg, larva, pupa, and adult) to explore its development and evolution of wings and metamorphosis. The de novo transcriptome assembly consists of 23,551 high-quality transcripts and is approximately 96.7% complete. Out of 8,545 transcripts, 5,183 correspond to the possible orthologs with Drosophila melanogaster. As a result, we could found 265 genes related to wing development and 19 genes related to metamorphosis. The comparison of transcript expression abundance with different developmental stages revealed developmental stage-specific transcripts especially working at the stage of wing development and metamorphosis of P. b. seulensis. This transcriptome quantification along the developmental stages may provide some meaningful clues to elucidate the genetic modulation mechanism of wing development and metamorphosis obtained during the insect evolution.

Keywords: white-spotted flower chafers, transcriptomics, RNA-seq, network biology, wing development, metamorphosis

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Authors: H. Fekhar

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Design and implementation acquisition system using radio frequency (RF) ASK module and micro controllers PIC is proposed in this work. The paper includes hardware and software design. The design tools are divided into two units , namely the sender MCU and receiver.The system was designed to measure temperatures of two furnaces and pressure pneumatic process. The wireless transmitter unit use the 433.95 MHz band directly interfaced to micro controller PIC18F4620. The sender unit consists of temperatures-pressure sensors , conditioning circuits , keypad GLCD display and RF module.Signal conditioner converts the output of the sensors into an electric quantity suitable for operation of the display and recording system.The measurements circuits are connected directly to 10 bits multiplexed A/D converter.The graphic liquid crystal display (GLCD) is used . The receiver (RF) module connected to a second microcontroller ,receive the signal via RF receiver , decode the Address/data and reproduces the original data . The strategy adopted for establishing communication between the sender MCU and receiver uses the specific protocol “Header, Address and data”.The communication protocol dealing with transmission and reception have been successfully implemented . Some experimental results are provided to demonstrate the effectiveness of the proposed wireless system. This embedded system track temperatures – pressure signal reasonably well with a small error.

Keywords: microcontrollers, sensors, graphic liquid cristal display, protocol, temperature, pressure

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Authors: Claude Alavoine, Ferkan Kaplanseren

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Negotiation is a specific form of interaction based on communication in which the parties enter into deliberately, each with clear but different interests or goals and a mutual dependency towards a decision due to be taken at the end of the confrontation. Consequently, negotiation is a complex activity involving many different disciplines from the strategic aspects and the decision making process to the evaluation of alternatives or outcomes and the exchange of information. While gender differences can be considered as one of the most researched topic within negotiation studies, empirical works and theory present many conflicting evidences and results about the role of gender in the process or the outcome. Furthermore, little interest has been shown over gender differences in the definition of what is negotiation, its essence or fundamental elements. Or, as differences exist in practices, it might be essential to study if the starting point of these discrepancies does not come from different considerations about what is negotiation and what will encourage the participants in their strategic decisions. Some recent and promising experiments made with diverse groups show that male and female participants in a common and shared situation barely consider the same way the concepts of power, trust or stakes which are largely considered as the usual driving forces of any negotiation. Furthermore, results from Human Resource self-assessment tests display and confirm considerable differences between individuals regarding essential behavioral dimensions like capacity to improvise and to achieve, aptitude to conciliate or to compete and orientation towards power and group domination which are also part of negotiation skills. Our intention in this paper is to confront these dimensions with negotiation’s usual driving forces in order to build up new paths for further research.

Keywords: negotiation, gender, trust, power, stakes, strategies

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Authors: A. Myrzabekova, D. Nurmukhamed, K. Nurumov, A. Zhulbarissova

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It is widely believed that stress can affect teachers’ intention to change the workplace. While existing research primarily focuses on the intrinsic sources of stress stemming from the school climate, the current attempt analyzes educational policies as one of the determinants of teacher’s intention to leave schools. In this respect, Kazakhstan presents a unique case since the country endorsed several educational policies which directly impacted teaching and administrative practices within schools. Using Teaching and Learning International Survey 2018 (TALIS) data with the country specific questionnaire, we construct a statistical measure of stress caused by the implementation of educational policies and test its impact on teacher’s intention to leave through the logistic regression. In addition, we control for sociodemographic, professional, and students related covariates while considering the intrinsic dimension of stress stemming from the school climate. Overall, our results suggest that stress caused by the educational policies has a statistically significant positive effect on teachers’ intentions to transfer between schools. Both policy makers and educational scholars could find these results beneficial. For the former careful planning and addressing the negative effects of the educational policies is critical for the sustainability of the educational process. For the latter, accounting for exogenous sources of stress can lead to a more complete understanding of why teachers decide to change their schools.

Keywords: educational policies, Kazakhstani teachers, logistic regression factor analysis, sustainability education TALIS, teacher turnover intention, work stress

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Authors: M. Bortolini, E. Ferrari, F. G. Galizia, C. Mora

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In the last decades, an increasing set of companies adopted lean philosophy to improve their productivity and efficiency promoting the so-called continuous improvement concept, reducing waste of time and cutting off no-value added activities. In parallel, increasing attention rises toward green practice and management through the spread of the green supply chain pattern, to minimise landfilled waste, drained wastewater and pollutant emissions. Starting from a review on contributions deepening lean and green principles applied to supply chain management, the most relevant drivers to measure the performance of industrial processes are pointed out. Specific attention is paid on the role of cost because it is of key importance and it crosses both lean and green principles. This analysis leads to figure out an original reference framework for integrating lean and green principles in designing and managing supply chains. The proposed framework supports the application, to the whole value chain or to parts of it, e.g. distribution network, assembly system, job-shop, storage system etc., of the lean-green integrated perspective. Evidences show that the combination of the lean and green practices lead to great results, higher than the sum of the performances from their separate application. Lean thinking has beneficial effects on green practices and, at the same time, methods allowing environmental savings generate positive effects on time reduction and process quality increase.

Keywords: environmental sustainability, green supply chain, integrated framework, lean thinking, supply chain management

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Authors: Jain Jyoti, Jain Shorab, Sinha Shishir

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In the field of material engineering, composites are in great concern for their nonbiodegradability and their cost. In order to reduce its cost and weight, plant derived fibers witnessed miraculous triumph. Plant fibers can be of different types like seed fibers, blast fibers, leaf fibers, etc. Composites can be reinforced with exclusively one type of natural fiber or also can be combined with two or more different types of natural or synthetic fibers to boost up their specific properties. Among all natural fibers, wheat straw, bagasse, kenaf, pineapple leaf, banana, coir, ramie, flax, etc. pineapple leaf fibers have very good mechanical properties. Being hydrophilic in nature, pineapple leaf fibers have very less affinity towards all types of polymer matrixes like HDPE, LDPE, PET, epoxy, etc. Surface treatments like alkaline treatment in different concentrations were conducted to improve its adhesion and compatibility towards hydrophobic polymer matrix i.e. epoxy resin. Pineapple leaf fiber epoxy composites have been prepared using hand layup method. Effect of fiber loading and surface treatments have been studied for different mechanical properties i.e. tensile strength, flexural strength and impact properties of pineapple leaf fiber composites. Analysis of fiber morphology has also been studied using FTIR, XRD. Scanning electron microscopy has also been used to study and compare the morphology of untreated and treated fibers. Also, the fracture surface has been reviewed comparing the reported literature of other eminent researchers of this field.

Keywords: composite, mechanical, natural fiber, pineapple leaf fiber

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Authors: Saeed Wahass

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Objective: Obesity is epidemic, affecting all societies and cultures. Most serious medical illnesses are attributed to obesity. For this reason, all healthcare systems worldwide have focused on obesity for both intervention and prevention. However, there is scientific evidence supporting that obesity is treatable through implementing different modalities of interventions. They include biological interventions like medications and bariatric surgeries and behavioral interventions. It seems healthcare professionals may suggest the quick and the easiest interventions for obesity like surgery, ignoring other modesties that might require efforts from their sides and patients as well. Searching on the onset, progression and prevention, behavior plays a major role. As a result, psychological interventions have become increasingly core for intervention and prevention of obesity. They are effective and cost effective in dealing with obesity. Methods: A questionnaire describing the role of behavior on obesity and the way it can be prevented and treated was distributed to a group of health professionals who are dealing with obesity e.g. bariatric surgeons, bariatric physicians, psychologists, health educators, nurses and social workers. Results: 88% of healthcare professionals believed that behavior plays a major role on the onset and progression of obesity, 95% of them recognized that obesity can be prevented with consideration for behavior factors. A major proportion (87%) of the respondents see that psychological interventions are effective and cost effective in treating obesity. Conclusions: It optimistically appears that the majority of healthcare professionals believe that behavior is a key component in understanding, preventing and treating obesity. This outcome may help in developing specific training courses for healthcare professionals, who are dealing with obesity concerning the way they can treat patients behaviorally and, moreover, educating the community.

Keywords: behavior, obesity, healthcare provider, psychological interventions

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Authors: Vasudha Chaturvedi, Mauro Guglielmin, Nicoletta Canone, Chiara Casiraghi, Francesco Griforni, Lorenzo Tonin, Silvia Piconne, Ilaria Bonfati, Filippo Caccia, Stefano Ponti

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The study explores the complex interplay between abiotic factors and methane emissions in Arctic environments. It highlights the challenges in understanding these relationships across different vegetation communities and seasons, considering the influence of multiple drivers. In the spring and early winter of 2023, we investigated net methane fluxes and 55 environmental parameters at three distinct sites in Alaska representing wet tundra, tussock, and dry heath using closed chamber techniques. Each site underwent three measurement cycles over consecutive days. Our findings reveal that tussock exhibited the highest methane emissions (ranging from 17 to 44 nmol m-2 s-1), followed by wet tundra (3 to 38 nmol m-2 s-1), while the dry heath consistently consumed methane across all seasons (-1.2 nmol m-2 s-1). Diurnal flux patterns at tussock sites peaked in the afternoon towards beginning of winter season, with correlations observed between fluxes and water content at 20 cm depth across all sites, and additionally with ground surface temperature (GST) temperature and water content at 0–60 cm depth at one site. Wet sites displayed higher correlations with GST up to 60 cm depth. These findings underscore the importance of considering site-specific dynamics and multiple environmental variables in understanding methane emissions from Arctic ecosystems.

Keywords: climate change, cryosphere, methane fluxes, soil, ground temperature

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Authors: Aliakbar Golshani, Seyyed Mehdi Poorhashemi, Mahsa Gharizadeh

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The under passing tunnels are strongly influenced by the soils around. There are some complexities in the specification of real soil behavior, owing to the fact that lots of uncertainties exist in soil properties, and additionally, inappropriate soil constitutive models. Such mentioned factors may cause incompatible settlements in numerical analysis with the obtained values in actual construction. This paper aims to report a case study on a specific tunnel constructed by NATM. The tunnel has a depth of 11.4 m, height of 12.2 m, and width of 14.4 m with 2.5 lanes. The numerical modeling was based on a 2D finite element program. The soil material behavior was modeled by hardening soil model. According to the field observations, the numerical estimated settlement at the ground surface was approximately four times more than the measured one, after the entire installation of the initial lining, indicating that some unknown factors affect the values. Consequently, the geotechnical parameters are accurately revised by a numerical back-analysis using laboratory and field test data and based on the obtained monitoring data. The obtained result confirms that typically, the soil parameters are conservatively low-estimated. And additionally, the constitutive models cannot be applied properly for all soil conditions.

Keywords: NATM tunnel, initial lining, laboratory test data, numerical back-analysis

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Authors: Cathy T. Mpanga Kowet, Aghaegbuna Obinna U. Ozumba

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This study examined and identified the inconsistencies, relationships, gaps and recurring themes in literature regarding the relationship between procurement strategies employed in the construction projects for sustainable buildings and realization of sustainability goals. A systematic literature review of studies on the relationship between various procurement strategies and attainment of sustainability outcomes was conducted. Using specific terms, papers published between 2002 and 2018 were identified and screened according to an inclusion and exclusion criteria. Current findings reveal that, although the attainment of sustainability goals is achievable with both traditional and contemporary procurement strategies, only projects delivered using modern procurement strategies are capable of meeting and exceeding targeted sustainability objectives. However, traditional procurement strategy remains the preferred method for most green building construction projects. The results suggest implications for decision makers in considering the impact of selected procurement strategies on targeted sustainability goals, in the early stages of sustainable building construction projects. The study shows that there is a gap between the reported appropriate procurement strategies and what is being practiced currently. Theoretically, the study expands on the literature on adoption and diffusion of contemporary procurement strategies, by consolidating existing studies to highlight the current gaps. While the study is at the literature review stage, deductions will serve as basis for field work involving empirical data.

Keywords: green buildings construction, procurement method, procurement strategy, sustainability objectives, sustainability outcomes

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Authors: B. Philip, J. Littlewood, R. Radford, N. Evans, T. Whyman, D. P. Jones

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UK buildings and energy infrastructures are heavily dependent on natural gas, a large proportion of which is used for domestic space heating. However, approximately half of the gas consumed in the UK is imported. Improving energy security and reducing carbon emissions are major government drivers for reducing gas dependency. In order to do so there needs to be a wholesale shift in the energy provision to householders without impacting on thermal comfort levels, convenience or cost of supply to the end user. Heat pumps are seen as a potential alternative in modern well insulated homes, however, can the same be said of older homes? A large proportion of housing stock in Britain was built prior to 1919. The age of the buildings bears testimony to the quality of construction; however, their thermal performance falls far below the minimum currently set by UK building standards. In recent years significant sums of money have been invested to improve energy efficiency and combat fuel poverty in some of the most deprived areas of Wales. Increasing energy efficiency of older properties remains a significant challenge, which cannot be achieved through insulation and air-tightness interventions alone, particularly when alterations to historically important architectural features of the building are not permitted. This paper investigates the energy demand of pre-1919 dwellings in a former Welsh mining village, the feasibility of meeting that demand using water from the disused mine workings to supply a district heat network and potential barriers to success of the scheme. The use of renewable solar energy generation and storage technologies, both thermal and electrical, to reduce the load and offset increased electricity demand, are considered. A wholistic surveying approach to provide a more accurate assessment of total household heat demand is proposed. Several surveying techniques, including condition surveys, air permeability, heat loss calculations, and thermography were employed to provide a clear picture of energy demand. Additional insulation can bring unforeseen consequences which are detrimental to the fabric of the building, potentially leading to accelerated dilapidation of the asset being ‘protected’. Increasing ventilation should be considered in parallel, to compensate for the associated reduction in uncontrolled infiltration. The effectiveness of thermal performance improvements are demonstrated and the detrimental effects of incorrect material choice and poor installation are highlighted. The findings show estimated heat demand to be in close correlation to household energy bills. Major areas of heat loss were identified such that improvements to building thermal performance could be targeted. The findings demonstrate that the use of heat pumps in older buildings is viable, provided sufficient improvement to thermal performance is possible. Addition of passive solar thermal and photovoltaic generation can help reduce the load and running cost for the householder. The results were used to predict future heat demand following energy efficiency improvements, thereby informing the size of heat pumps required.

Keywords: heat demand, heat pump, renewable energy, retrofit

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Authors: Amanda Sheard, Garry Lee, Katherine Stockham

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Introduction: Health benefits associated with wine consumption have been well documented; these include anticancer, anti-inflammatory, and cardiovascular protection. The majority of these health benefits have been linked to polyphenols found within wine and grapes. Once consumed polyphenols exhibit free radical quenching capabilities. Environmental factors such as rainfall, temperature, CO2 levels and sunlight exposure have been shown to affect the polyphenol content of grapes. The objective of this work was to evaluate the effect of growing conditions on the antioxidant capacity of grapes obtained from a single plot vineyard in Perth. This was achieved through the analysis of samples using; oxygen radical antioxidant capacity (ORAC), cellular antioxidant activity (CAA) in human red blood cells, ICP-MS and ICP-OES, total polyphenols (PP’s), and total flavonoid’s (FLa). The data obtained was compared to observed climate data. The 14 Selected Vitis Vinefera L. cultivars included Cabernet franc, Cabernet Sauvignon, Carnelian, Chardonnay, Grenache, Melbec, Merlot, Orange muscat, Rousanne, Sauvignon Blanc, Shiraz, Tempernillo, Verdelho, and Voignier. Results: Notable variation’s between cultivars included results ranging from 125 mg/100 g-350 mg/100 g for PP’s, 93 mg/100 g–300 mg/100 g for FLa, 13 mM T.E/kg–33 mM T.E/kg for ORAC and 0.3 mM Q.E/kg–27 mM Q.E/kg CAA were found between red and white grape cultivars. No correlation was found between CAA and the ORAC obtained in this study; except that white cultivars were consistently lower than red. ICP analysis showed that seeds contained the highest concentration of copper followed by skins and flesh of the grape. A positive correlation between copper and ORAC was found. The ORAC, PP’s, and FLa in red grapes were consistently higher than white grape cultivars; these findings were supported by literature values. Significance: The cellular antioxidant activities of white and red wine cultivars were used to compare the bioactivity of these grapes against the chemical ORAC measurement. The common method of antioxidant activity measurement is the chemical value from ORAC analysis; however this may not reflect the activity within the human body. Hence, the measurements were also carried out using the cellular antioxidant activity to perform a comparison. Additionally, the study explored the influence of weather systems such as El Niño and La Niña on the polyphenol content of Australian wine cultivars grown in Perth.

Keywords: oxygen radical antioxidant activity, cellular antioxidant activity, total polyphenols, total flavonoids, wine grapes, climate

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Authors: Alexandra Doga, Andreas Lioumpas, Sotiris Petropoulos

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This paper assesses China-Greece relations since 2006, examining them as part of China’s Grand Strategy and Greece’s perception of them. Τhe first aim of the paper is to provide an overview of China-Greece relations in connection with its long- and short-term goals. In essence, it focuses on understanding whether a Chinese grand strategy towards Greece exists. Secondly, it aims to examine the perception of Greeks over China’s foreign policy towards Greece. The intended contribution of the paper is to illustrate the response of national discourses over China’s increased presence in both the global sphere and specific countries in particular. This paper is based on qualitative analysis of secondary data as well as a thorough primary research scheme based on semi-structured interviews. The study made use of official Chinese government documents as well as academic journal articles and books. Local news outlets like newspapers provide data, and news surrounding Greece’s perception of China-Greece relations were also included. Moreover, a number of interviews of Greek officials, academics, journalists, and businessmen were conducted. This paper concluded that the period that began with the 2006 Joint Communiqué between China and Greece on the Establishment of Comprehensive Strategic Partnership has been one of the rapid strengthening of bilateral economic and political relations and frequent high-level visits. There are diverging/opposing views on whether China’s strategic choices towards Greece form part of a broader strategic approach and on whether this strategy is closely connected to the BRI initiative and its priorities.

Keywords: China, Greece, Grand Strategy, BRI, COSCO, Piraeus Port, Mediterranean

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Authors: Eric Enongene Ekembe

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Recent calls on EFL teaching posit the centrality of context factors and argue for a correlation between effectiveness in teaching with the learners’ culture in the EFL classroom. Context is not everything; it is defined with indicators of learners’ cultural artifacts and stereotypes in meaningful interactions in the language classroom. In keeping with this, it is difficult to universalise pedagogic procedures given that appropriate procedures are context-sensitive- and contexts differ. It is necessary to investigate what counts as cultural specificities or stereotypes of specific learners to reflect on how different language learning contexts affect or are affected by English language teaching procedures, most especially in under-represented cultures, which have appropriated the English language. This paper investigates cultural stereotypes of EFL learners in the culturally diverse Cameroon to examine how they mediate teaching and learning. Data collected on mixed-method basis from 83 EFL teachers and 1321 learners in Cameroon reveal a strong presence of typical cultural artifacts and stereotypes. Statistical analysis and thematic coding demonstrate that teaching procedures in place were insensitive to the cultural artifacts and stereotypes, resulting in trending tension between teachers and learners. The data equally reveal a serious contradiction between the communicative goals of language teaching and learning: what teachers held as effective teaching was diametrically opposed to success in learning. In keeping with this, the paper argues for a ‘decentred’ teacher preparation in Cameroon that is informed by systemic learners’ feedback. On this basis, applied linguistics has the urgent task of exploring dimensions of what actually counts as contextualized practice in ELT.

Keywords: cultural stereotypes, EFL, implications, procedures

Procedia PDF Downloads 119