Search results for: behaviour change consultations

Authors: R. Naveen, E. Vanitha, S. Gayathri

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The use of Sandwich composite materials in aerospace and civil infrastructure application has been increasing especially due to their enormously low weight that leads to a reduction in the total weight and fuel consumption, high flexural and transverse shear stiffness, and corrosion resistance. The essential properties of sandwich materials vary according to the application area of the structure. The objectives of this study are to identify the mechanical behaviour and failure mechanisms of sandwich structures made of bamboo, V- board and metal (Aluminium as face sheet and Foam as Core material). The three-point bending test and UTM (Universal testing machine) experimental tests are done for three specimens for each type of sandwich composites. From the experiment results of three sandwich composites, bamboo shows high Young’s modulus of elasticity and low density.

Keywords: bamboo sandwich composite, metal sandwich composite, sandwich composite, v-board sandwich composite

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Authors: Samuel O. Akande

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The human-induced climate change is likely to have severe consequences on forest ecosystems in Nigeria. Recent discussions and emphasis on issues concerning the environment justify the need for this research which examined deforestation monitoring in Oban Forest, Nigeria using Remote Sensing techniques. The Landsat images from TM (1986), ETM+ (2001) and OLI (2015) sensors were obtained from Landsat online archive and processed using Erdas Imagine 2014 and ArcGIS 10.3 to obtain the land use/land cover and Normalized Differential Vegetative Index (NDVI) values. Ground control points of deforested areas were collected for validation. It was observed that the forest cover decreased in area by about 689.14 km² between 1986 and 2015. The NDVI was used to determine the vegetation health of the forest and its implications on agricultural sustainability. The result showed that the total percentage of the healthy forest cover has reduced to about 45.9% from 1986 to 2015. The results obtained from analysed questionnaires shown that there was a positive correlation between the causes and effects of deforestation in the study area. The coefficient of determination value was calculated as R² ≥ 0.7, to ascertain the level of anthropogenic activities, such as fuelwood harvesting, intensive farming, and logging, urbanization, and engineering construction activities, responsible for deforestation in the study area. Similarly, temperature and rainfall data were obtained from Nigerian Meteorological Agency (NIMET) for the period of 1986 to 2015 in the study area. It was observed that there was a significant increase in temperature while rainfall decreased over the study area. Responses from the administered questionnaires also showed that futile destruction of forest ecosystem in Oban forest could be reduced to its barest minimum if fuelwood harvesting is disallowed. Thus, the projected impacts of climate change on Nigeria’s forest ecosystems and environmental stability is better imagined than experienced.

Keywords: deforestation, ecosystems, normalized differential vegetative index, sustainability

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Authors: Jeremy Attard, Jordan François, Serge Lazzarini, Thierry Masson

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Gauge theories are the natural background for describing geometrically fundamental interactions using principal and associated fiber bundles as dynamical entities. The central notion of these theories is their local gauge symmetry implemented by the local action of a Lie group H. There exist several methods used to reduce the symmetry of a gauge theory, like gauge fixing, bundle reduction theorem or spontaneous symmetry breaking mechanism (SSBM). This paper is a presentation of another method of gauge symmetry reduction, distinct from those three. Given a symmetry group H acting on a fiber bundle and its naturally associated fields (Ehresmann (or Cartan) connection, curvature, matter fields, etc.) there sometimes exists a way to erase (in whole or in part) the H-action by just reconfiguring these fields, i.e. by making a mere change of field variables in order to get new (‘composite‘) fields on which H (in whole or in part) does not act anymore. Two examples: the re-interpretation of the BEHGHK (Higgs) mechanism, on the one hand, and the top-down construction of Tractor and Penrose's Twistor spaces and connections in the framework of conformal Cartan geometry, one the other, will be discussed. They have, of course, nothing to do with each other but the dressing field method can be applied on both to get a new insight. In the first example, it turns out, indeed, that generation of masses in the Standard Model can be separated from the symmetry breaking, the latter being a mere change of field variables, i.e. a dressing. This offers an interpretation in opposition with the one usually found in textbooks. In the second case, the dressing field method applied to the conformal Cartan geometry offer a way of understanding the deep geometric nature of the so-called Tractors and Twistors. The dressing field method, distinct from a gauge transformation (even if it can have apparently the same form), is a systematic way of finding and erasing artificial symmetries of a theory, by a mere change of field variables which redistributes the degrees of freedom of the theories.

Keywords: BEHGHK (Higgs) mechanism, conformal gravity, gauge theory, spontaneous symmetry breaking, symmetry reduction, twistors and tractors

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Authors: Mahima Shrivastava, Soumya Kar, B. Swetha Malika, Lalu Saheb, M. Muthu Kumar, P. V. Ponambala Moorthi

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Natural hazards and manmade destruction causes both economic and societal losses. Generalized pre-mitigation strategies introduced and adopted for prevention of disaster all over the world are capable of augmenting the resiliency and optimizing the life-cycle cost of facilities. In countries like India where varied topographical feature exists requires location specific mitigation measures and strategies to be followed for better enhancement by event-driven and code-driven approaches. Present state of vindication measures followed and adopted, lags dominance in accomplishing the required development. In addition, serious concern and debate over climate change plays a vital role in enhancing the need and requirement for the development of time bound adaptive mitigation measures. For the development of long-term sustainable policies incorporation of future climatic variation is inevitable. This will further assist in assessing the impact brought about by the climate change on life-cycle cost of facilities. This paper develops more definite region specific and time bound pre-mitigation measures, by reviewing the present state of mitigation measures in India and all over the world for improving life-cycle cost of facilities. For the development of region specific adoptive measures, Indian regions were divided based on multiple-calamity prone regions and geo-referencing tools were used to incorporate the effect of climate changes on life-cycle cost assessment. This study puts forward significant effort in establishing sustainable policies and helps decision makers in planning for pre-mitigation measures for different regions. It will further contribute towards evaluating the life cycle cost of facilities by adopting the developed measures.

Keywords: climate change, geo-referencing tools, life-cycle cost, multiple-calamity prone regions, pre-mitigation strategies, sustainable policies

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Authors: Rishabh Shukla, Achin Agrawal, Anupam Saxena, S. Mandal

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The existence of a crack, affects the mechanical behaviour and various properties of a structure to a great degree. This paper focuses on recognizing the parameters that gets changed due to the formation of cracks and have a great impact on the performance of the structure. Spalling is a major concern as it leaves the reinforcement bars more susceptible to environmental attacks. Beams of cross section 300 mm × 500 mm are designed and for a calculated area of steel, two different arrangements of reinforced bars are analysed. Results are prepared for different stages of cracking for each arrangement of rebars. The parameters for both arrangements are then compared. The Finite Element Analysis (FEA) is carried out and changes in the properties like flexural strength, Elasticity and modal frequency are reported. The conclusions have been drawn by comparing the results.

Keywords: cracks, elasticity, spalling, FEA

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Authors: Anupama Purohit

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The paper is a study on the inevitable cross-linguistic effect found in the early multilingual learners. The cross-linguistic behaviour like code-mixing, code-switching, foreign accent, literal translation, redundancy and syntactic manipulation effected due to other languages on the English language output of a non-native pre-school child are discussed here. A case study method is adopted in this paper to support the claim of the title. A simultaneously tetra lingual pre-school child’s (within 1;3 to 4;0) language behaviour is analysed here. The sample output data of the child is gathered from the diary entries maintained by her family, regular observations and video recordings done since her birth. She is getting the input of her mother tongue, Sambalpuri, from her grandparents only; Hindi, the local language from her play-school and the neighbourhood; English only from her mother and occasional visit of other family friends; Odia only during the reading of the Odia story book. The child is exposed to code-mixing of all the languages throughout her childhood. But code-mixing, literal translation, redundancy and duplication were absent in her initial stage of multilingual acquisition. As the child was more proficient in English in comparison to her other first languages and had never heard code-mixing in English language; it was expected from her input pattern of English (one parent, English language) that she would maintain purity in her use of English while talking to the English language interlocutor. But with gradual increase in the language proficiency in each of the languages of the child, her handling of the multiple codes becomes deft cross-linguistically. It can be deduced from the case study that after attaining certain milestone proficiency in each language, the child’s linguistic faculty can operate at a metalinguistic level. The functional use of each morpheme, their arrangement in words and in the sentences, the supra segmental features, lexical-semantic mapping, culture specific use of a language and the pragmatic skills converge to give a typical childlike multilingual output in an intelligible manner to the multilingual people (with the same set of languages in combination). The result is appealing because for expressing the same ideas which the child used to speak (may be with grammatically wrong expressions) in one language, gradually, she starts showing cross-linguistic effect in her expressions. So the paper pleads for the separatist view from the very beginning of the holophrastic phase (as the child expresses in addressee-specific language); but development of a metalinguistic ability that helps the child in communicating in a sophisticated way according to the linguistic status of the addressee is unique to the multilingual child. This metalinguistic ability is independent of the mode if input of a multilingual child.

Keywords: code-mixing, cross-linguistic effect, early multilingualism, literal translation

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Authors: Ujjal Chattaraj, M. Raviteja, Chaitanya Aemala

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Over the years vehicular traffic has been given priority over pedestrian traffic. With the increase of population in cities, pedestrian traffic is increasing day by day. Pedestrian safety has become a matter of concern for the Traffic Engineers. Pedestrian comfort is primary important for the Engineers who design different pedestrian facilities. Pedestrian comfort and safety can be measured in terms of different level of service (LOS) of the facilities. In this study video data on pedestrian movement have been collected from different railway foot over bridges (FOB) in India. The level of service of those facilities has been analyzed. A cellular automata based model has been formulated to mimic the route choice behaviour of the pedestrians on the foot over bridges.

Keywords: cellular automata model, foot over bridge, level of service, pedestrian

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Authors: Iva Dvornik, Sandro Božić, Žana Božić Brkić

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System-dynamic simulating modelling is one of the most appropriate and successful scientific methods of the complex, non-linear, natural, technical and organizational systems. In the recent practice its methodology proved to be efficient in solving the problems of control, behavior, sensitivity and flexibility of the system dynamics behavior having a high degree of complexity, all these by computing simulation i.e. “under laboratory conditions” what means without any danger for observed realities. This essay deals with the research of the gas turbine dynamic process as well as the operating pump units and transformation of gas energy into hydraulic energy has been simulated. In addition, system mathematical model has been also researched (gas turbine- centrifugal pumps – pipeline pressure system – storage vessel).

Keywords: system dynamics, modelling, centrifugal pump, turbine, gases, continuous and discrete simulation, heuristic optimisation

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Authors: Usman Mahmood, Khawaja M. U. Suleman

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A peer-to-peer storage system has challenges like; peer availability, data protection, churn rate. To address these challenges different redundancy, replacement and repair schemes are used. This paper presents a hybrid scheme of redundancy using replication and erasure coding. We calculate and compare the storage, access, and maintenance costs of our proposed scheme with existing redundancy schemes. For realistic behaviour of peers a trace of live peer-to-peer system is used. The effect of different replication, and repair schemes are also shown. The proposed hybrid scheme performs better than existing double coding hybrid scheme in all metrics and have an improved maintenance cost than hierarchical codes.

Keywords: erasure coding, P2P, redundancy, replication

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Authors: A. Sathiya Susuman, N. Wilson

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Background: The sexual behaviour of youths is believed to play an important role in the spread of sexually transmitted infections (STIs). Method: The data from the Malawi Demographic and Health Survey 2010 and a sample of 16,217 youth’s age 15 to 24 years (with each household 27.2% female and 72.8% male) was the basis for analysis. Bivariate and logistic regression analysis was performed. Results: The result shows married youth were not interested in condom use (94.2%, p<0.05). Those who were living together were 69 times (OR=1.69, 95% CI, 1.26–2.26) more likely to be involved in early sexual activity compared to those who were not living together. Conclusion: This scientific paper will help other researchers, policy makers, and planners to create strategies to encourage these youths to make use of contraception.

Keywords: sexually transmitted infections (STIs), reproductive tract infections (RTIs), condom use, sexual partners, early sexual debut, youths

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Authors: Zohra Mhedhbi, Meheret Gaston, Sinda Haoues-Jouve, Julia Hidalgo, Pierre Mazzega

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In the current context of climate change, supporting national and local stakeholders to make climate-smart decisions is necessary but still underdeveloped in many countries. To overcome this problem, the Global Frameworks for Climate Services (GFCS), implemented under the aegis of the United Nations in 2012, has initiated many programs in different countries. The GFCS contributes to the development of Climate Services, an instrument based on the production and transfer of scientific climate knowledge for specific users such as citizens, urban planning actors, or agricultural professionals. As cities concentrate on economic, social and environmental issues that make them more vulnerable to climate change, the New Urban Agenda (NUA), adopted at Habitat III in October 2016, highlights the importance of paying particular attention to disaster risk management, climate and environmental sustainability and urban resilience. In order to support the implementation of the NUA, the World Meteorological Organization (WMO) has identified the urban dimension as one of its priorities and has proposed a new tool, the Integrated Urban Services (IUS), for more sustainable and resilient cities. In the southern countries, there’s a lack of development of climate services, which can be partially explained by problems related to their economic financing. In addition, it is often difficult to make climate change a priority in urban planning, given the more traditional urban challenges these countries face, such as massive poverty, high population growth, etc. Climate services and Integrated Urban Services, particularly in African cities, are expected to contribute to the sustainable development of cities. These tools will help promoting the acquisition of meteorological and socio-ecological data on their transformations, encouraging coordination between national or local institutions providing various sectoral urban services, and should contribute to the achievement of the objectives defined by the United Nations Framework Convention on Climate Change (UNFCCC) or the Paris Agreement, and the Sustainable Development Goals. To assess the state of the art on these various points, the Web of Science metadatabase is queried. With a query combining the keywords "climate*" and "urban*", more than 24,000 articles are identified, source of more than 40,000 distinct keywords (but including synonyms and acronyms) which finely mesh the conceptual field of research. The occurrence of one or more names of the 514 African cities of more than 100,000 inhabitants or countries, reduces this base to a smaller corpus of about 1410 articles (2990 keywords). 41 countries and 136 African cities are cited. The lexicometric analysis of the metadata of the articles and the analysis of the structural indicators (various centralities) of the networks induced by the co-occurrence of expressions related more specifically to climate services show the development potential of these services, identify the gaps which remain to be filled for their implementation and allow to compare the diversity of national and regional situations with regard to these services.

Keywords: African cities, climate change, climate services, integrated urban services, lexicometry, networks, urban planning, web of science

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Authors: Man-Yu Wong, Siyu Zhou, Zhiqiang Cao

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In quality of life, health service utilization is an important determinant of medical resource expenditures on Colorectal cancer (CRC) care, a better understanding of the increased utilization of health services is essential for optimizing the allocation of healthcare resources to services and thus for enhancing the service quality, especially for high expenditure on CRC care like Hong Kong region. In assessing the association between the health-related quality of life (HRQOL) and health service utilization in patients with colorectal neoplasm, count data models can be used, which account for over dispersion or extra zero counts. In our data, the HRQOL evaluation is a self-reported measure obtained from a questionnaire completed by the patients, misreports and variations in the data are inevitable. Besides, there are more zero counts from the observed number of clinical consultations (observed frequency of zero counts = 206) than those from a Poisson distribution with mean equal to 1.33 (expected frequency of zero counts = 156). This suggests that excess of zero counts may exist. Therefore, we study tests for detecting zero-inflation in models with measurement error in covariates. Method: Under classical measurement error model, the approximate likelihood function for zero-inflation Poisson regression model can be obtained, then Approximate Maximum Likelihood Estimation(AMLE) can be derived accordingly, which is consistent and asymptotically normally distributed. By calculating score function and Fisher information based on AMLE, a score test is proposed to detect zero-inflation effect in ZIP model with measurement error. The proposed test follows asymptotically standard normal distribution under H0, and it is consistent with the test proposed for zero-inflation effect when there is no measurement error. Results: Simulation results show that empirical power of our proposed test is the highest among existing tests for zero-inflation in ZIP model with measurement error. In real data analysis, with or without considering measurement error in covariates, existing tests, and our proposed test all imply H0 should be rejected with P-value less than 0.001, i.e., zero-inflation effect is very significant, ZIP model is superior to Poisson model for analyzing this data. However, if measurement error in covariates is not considered, only one covariate is significant; if measurement error in covariates is considered, only another covariate is significant. Moreover, the direction of coefficient estimations for these two covariates is different in ZIP regression model with or without considering measurement error. Conclusion: In our study, compared to Poisson model, ZIP model should be chosen when assessing the association between condition-specific HRQOL and health service utilization in patients with colorectal neoplasm. and models taking measurement error into account will result in statistically more reliable and precise information.

Keywords: count data, measurement error, score test, zero inflation

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Authors: Fatemeh Khalili Varnamkhasti

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Numerous nations have recognized the critical ought to address natural issues, such as discuss contamination, squander transfer, worldwide warming, and common asset consumption, through the application of green innovation. The rise of cleverly advances has driven mechanical basic changes that will offer assistance accomplish carbon decrease. Manufactured insights (AI) innovation is an imperative portion of digitalization, giving unused mechanical apparatuses and bearings for the moo carbon advancement of endeavors. Quickening the brilliantly change of fabricating industry is an critical vital choice to realize the green advancement change. The reason why fabricating insights can advance the advancement of green advancement execution is that fabricating insights is conducive to the generation of "innovation advancement impact" and "fetched decrease impact" so as to advance green innovation advancement, at that point viably increment the alluring yields and essentially diminish the undesirable yields. AI improvement will boost GTI as it were when the escalated of natural direction and organization environment is over a certain edge esteem. In any case, the AI improvement spoken to by mechanical robot applications still has no self-evident impact on GTI, indeed, when the R&D venture surpasses a certain edge.

Keywords: greenhouse gas emissions, green infrastructure, artificial intelligence, environmental protection

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Authors: D. Suman, B. Nikitha, J. Sarvani, V. Archana

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Histological slides provide clinical diagnostic information about the subjects from the ancient times. Even with the advent of high resolution imaging cameras the image tend to have some background noise which makes the analysis complex. A study of the histological slides is done by using a nonlinear transfer function based image enhancement method. The method processes the raw, color images acquired from the biological microscope, which, in general, is associated with background noise. The images usually appearing blurred does not convey the intended information. In this regard, an enhancement method is proposed and implemented on 50 histological slides of human tissue by using nonlinear transfer function method. The histological image is converted into HSV color image. The luminance value of the image is enhanced (V component) because change in the H and S components could change the color balance between HSV components. The HSV image is divided into smaller blocks for carrying out the dynamic range compression by using a linear transformation function. Each pixel in the block is enhanced based on the contrast of the center pixel and its neighborhood. After the processing the V component, the HSV image is transformed into a colour image. The study has shown improvement of the characteristics of the image so that the significant details of the histological images were improved.

Keywords: HSV space, histology, enhancement, image

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Authors: Shimony Agrawal

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In this continually evolving world, change is the most imperative component of our identity. The term alteration alludes to degree by which an individual adapts to inward strains, needs, clashes and can bring coordination between his internal requests and those forced by the external world. Adjustment is a way of managing various demands of life. . Entering school is a defining moment for school first year recruits in their adulthood. The progress from school to school can be rationally and in addition physically troubling. Students deal with a unique amount of stressors when they enter college. Introductory months of school are loaded with apprehension and attempting to fit in the new condition. Colleges and schools should ensure their understudies are balanced in the new condition by giving help at whatever point vital.. The main objective of the study was a comparative analysis of adjustment level with respect to overall adjustment level, gender and living environment. This research has been conducted using Adjustment Inventory for College Students (AICS). The total population is comprised of 240 college-going students. The data majority of the population scored poorly on Emotional Adjustment. Also, female students faced more adjustment problems as compared to male students. However, no significant change was noticed in living environment of the students.

Keywords: adjustment, college students, freshmen year, senior year

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Authors: E.K.K. Agyeman, P. Mousseau, A. Sarda, D. Edelin

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The uniform and controlled cooling of hot metals by the circulation of water in canals remains a challenge due to the phase change of the water and the high heat fluxes associated with the phase change. This is because, during the cooling process, the phases are not uniformly distributed along the canals with the liquid phase dominating at the entrances of the canals and the gaseous phase dominating towards the exits. The difference in thermal properties between both phases leads to a heterogeneous temperature distribution in the part being cooled. Slowing down the cooling process is also a challenge due to the high heat fluxes associated with the phase change of water. This study investigates the use of multiple water jets for the controlled and homogenous cooling of hot metal parts and the effect of gravity on the effectiveness of the cooling process with a potential application in the cooling of composite forming moulds. A hole is bored at the centre of a steel block along its length. The jets are generated from the holes of a perforated steel pipe which is placed along the centre of the hole bored in the steel block. The evolution of the temperature with respect to time on the external surface of the steel block is measured simultaneously by thermocouples and an infrared camera. Different jet positions are tested in order to identify the jet placement configuration that ensures the most homogenous cooling of the block while the cooling speed is controlled by an intermittent impingement of the jets. In order to study the effect of gravity on the cooling process, a scenario where the jets are oriented in the opposite direction to that of gravity is compared to one where the jets are aligned in the same direction as gravity. It’s observed that orienting the jets in the direction of gravity reduces the effectiveness of the cooling process on the face of the block facing the impinging jets. This is due to the formation of a deeper pool of water due to the effect gravity and of the curved surface of the canal. This deeper pool of water influences the boiling regime characterized by a slower bubble evacuation when compared to the scenario where the jets are opposed to gravity.

Keywords: cooling speed, gravity, homogenous cooling, jet impingement

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Authors: Tomas Makaras

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Sticklebacks (Gasterosteiformes) are increasingly used in ecological and evolutionary research and become well-established role as model species for biologists. However, ecotoxicology studies concerning behavioural effects in sticklebacks regarding stress responses, mainly induced by chemical mixtures, have hardly been addressed. Moreover, although many authors in their studies emphasised the similarity between three-spined and nine-spined stickleback in morphological, neuroanatomical and behavioural adaptations to environmental changes, several comparative studies have revealed considerable differences between these species in and their susceptibility and resistance to variousstressors in laboratory experiments. The hypothesis of this study was that three-spined and nine-spined stickleback species will demonstrate apparent differences in response patterns and sensitivity to metal-based chemicals stimuli. For this purpose, we investigated the swimming behaviour (including mortality rate based on 96-h LC50 values) of two ecologically similar three-spined (Gasterosteusaculeatus) and nine-spined sticklebacks (Pungitiuspungitius) to short-term (up to 24 h) metal mixture (MIX) exposure. We evaluated the relevance and efficacy of behavioural responses of test species in the early toxicity assessment of chemical mixtures. Fish exposed to six (Zn, Pb, Cd, Cu, Ni and Cr) metals in the mixture were either singled out by the Water Framework Directive as priority or as relevant substances in surface water, which was prepared according to the environmental quality standards (EQSs) of these metals set for inland waters in the European Union (EU) (Directive 2013/39/EU). Based on acute toxicity results, G. aculeatus found to be slightly (1.4-fold) more tolerant of MIX impact than those of P. pungitius specimens. The performed behavioural analysis showed the main effect on the interaction between time, species and treatment variables. Although both species exposed to MIX revealed a decreasing tendency in swimming activity, these species’ responsiveness to MIX was somewhat different. Substantial changes in the activity of G. aculeatus were established after 3-h exposure to MIX solutions, which was 1.43-fold lower, while in the case of P. pungitius, 1.96-fold higher than established 96-h LC50 values for each species. This study demonstrated species-specific differences in response sensitivity to metal-based water pollution, indicating behavioural insensitivity of P. pungitiuscompared to G. aculeatus. While many studies highlight the usefulness and suitability of nine-spined sticklebacks for evolutionary and ecological research, attested by their increasing popularity in these fields, great caution must be exercised when using them as model species in ecotoxicological research to probe metal contamination. Meanwhile, G. aculeatus showed to be a promising bioindicator species in the environmental ecotoxicology field.

Keywords: acute toxicity, comparative behaviour, metal mixture, swimming activity

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Authors: Michel Pons, Anthony Delahaye, Laurence Fournaison

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Secondary refrigeration consists of splitting large-size direct-cooling units into volume-limited primary cooling units complemented by secondary loops for transporting and distributing cold. Such a design reduces the refrigerant leaks, which represents a source of greenhouse gases emitted into the atmosphere. However, inserting the secondary circuit between the primary unit and the ‘users’ heat exchangers (UHX) increases the energy consumption of the whole process, which induces an indirect emission of greenhouse gases. It is thus important to check whether that efficiency loss is sufficiently limited for the change to be globally beneficial to the environment. Among the likely secondary fluids, phase change slurries offer several advantages: they transport latent heat, they stabilize the heat exchange temperature, and the formerly evaporators still can be used as UHX. The temperature level can also be adapted to the desired cooling application. Herein, the slurry {ice in mono-propylene-glycol solution} (melting temperature Tₘ of 6°C) is considered for food preservation, and the slurry {mixed hydrate of CO₂ + tetra-n-butyl-phosphonium-bromide in aqueous solution of this salt + CO₂} (melting temperature Tₘ of 13°C) is considered for air conditioning. For the sake of thermodynamic consistency, the analysis encompasses the whole process, primary cooling unit plus secondary slurry loop, and the various properties of the slurries, including their non-Newtonian viscosity. The design of the whole process is optimized according to the properties of the chosen slurry and under explicit constraints. As a first constraint, all the units must deliver the same cooling power to the user. The other constraints concern the heat exchanges areas, which are prescribed, and the flow conditions, which prevent deposition of the solid particles transported in the slurry, and their agglomeration. Minimization of the total energy consumption leads to the optimal design. In addition, the results are analyzed in terms of exergy losses, which allows highlighting the couplings between the primary unit and the secondary loop. One important difference between the ice-slurry and the mixed-hydrate one is the presence of gaseous carbon dioxide in the latter case. When the mixed-hydrate crystals melt in the UHX, CO₂ vapor is generated at a rate that depends on the phase change kinetics. The flow in the UHX, and its heat and mass transfer properties are significantly modified. This effect has never been investigated before. Lastly, inserting the secondary loop between the primary unit and the users increases the temperature difference between the refrigerated space and the evaporator. This results in a loss of global energy efficiency, and therefore in an increased energy consumption. The analysis shows that this loss of efficiency is not critical in the first case (Tₘ = 6°C), while the second case leads to more ambiguous results, partially because of the higher melting temperature.The consequences in terms of greenhouse gases emissions are also analyzed.

Keywords: exergy, hydrates, optimization, phase change material, thermodynamics

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Authors: Zied Guidara, Alexander Morgenstern, Aref Younes Maalej

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In this paper, a desiccant solar unit for air conditioning and desalination is presented first. Secondly, a dynamic modelling study of the desiccant wheel is developed. After that, a simulation study and an experimental investigation of the behaviour of desiccant wheel are developed. The experimental investigation is done in the chamber of commerce in Freiburg-Germany. Indeed, the variations of calculated and measured temperatures and specific humidity of dehumidified and rejected air are presented where a good agreement is found when comparing the model predictions with experimental data under the considered range of operating conditions. Finally, the study of the compartments of desalination and water condensation shows that the unit can produce an acceptable quantity of water at the same time of the air conditioning operation.

Keywords: air conditioning, desalination, condensation, design, desiccant wheel

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Authors: Viera Zatkalíková, Lenka Markovičová, Aneta Tor-Swiatek

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The effect of molybdate addition to chloride environment on resistance of AISI 316Ti stainless steel to pitting corrosion was studied. Potentiodynamic polarisation tests were performed in 1 M and 0.1 M chloride acidified solutions with various additions of sodium molybdate at room temperature. The presented results compare the effect of molybdate anions on quality of passive film (expressed by the pitting potential) in both chloride solutions. The pitting potential increases with the increase inhibitor concentration. The inhibitive effect of molybdate ions is stronger in chloride solution of lower aggressiveness (0.1M).

Keywords: AISI 316Ti steel, molybdate inhibitor, pitting corrosion, pitting potential, potentiodynamic polarisation

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Authors: Salim H. Al Salmani, Kevin Tansey, Mohammed S. Ozigis

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The study of the growth of built-up areas and settlement expansion is a major exercise that city managers seek to undertake to establish previous and current developmental trends. This is to ensure that there is an equal match of settlement expansion needs to the appropriate levels of services and infrastructure required. This research aims at demonstrating the potential of satellite image processing technique, harnessing the utility of single feature probability-object based image analysis technique in assessing the urban growth dynamics of the Muscat Governorate in Oman for the period 1990, 2002 and 2013. This need is fueled by the continuous expansion of the Muscat Governorate beyond predicted levels of infrastructural provision. Landsat Images of the years 1990, 2002 and 2013 were downloaded and preprocessed to forestall appropriate radiometric and geometric standards. A novel approach of probability filtering of the target feature segment was implemented to derive the spatial extent of the final Built-Up Area of the Muscat governorate for the three years period. This however proved to be a useful technique as high accuracy assessment results of 55%, 70%, and 71% were recorded for the Urban Landcover of 1990, 2002 and 2013 respectively. Furthermore, the Normalized Differential Built – Up Index for the various images were derived and used to consolidate the results of the SFP-OBIA through a linear regression model and visual comparison. The result obtained showed various hotspots where urbanization have sporadically taken place. Specifically, settlement in the districts (Wilayat) of AL-Amarat, Muscat, and Qurayyat experienced tremendous change between 1990 and 2002, while the districts (Wilayat) of AL-Seeb, Bawshar, and Muttrah experienced more sporadic changes between 2002 and 2013.

Keywords: urban growth, single feature probability, object based image analysis, landcover change

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Authors: Ntandoyenkosi Moyo

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Majority of rural Eastern Cape villages of South Africa households do not have access to safe water supply. Due to changes in climatic conditions for example higher temperatures, these sources become not reliable in supplying adequate and safe water to the population. These rural populations due to the drying up of water resources have to find other alternative ways to get water. Climate change has an impact on the reliability of water resources and this has an impact on rural communities. This study seeks to establish what alternative ways do people use when affected by unfavorable conditions like less rainfall and increased temperatures. The study also seeks to investigate any local and provincial intervention in the provision of water to the village. Interventions can be in the form of programmes or initiatives that involve water supply strategies. The community should participate fully in making sure that their place is serviced. The study will identify households with improved sources (JOJO tanks) and those with unimproved sources (rivers) and investigate what alternatives they resort to when their sources dry up. The study also investigates community views on whether they have any challenges of water supply (reliability and adequacy) as required by section 27(1) (b) of the constitution which states that everyone should have access to safe and clean water.

Keywords: rural water resources, temperature, improved sources, unimproved sources

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Authors: R. Berglund, T. Backström, M. Bellgran

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This study explores how management addresses psychosocial risks in seven teams of engineers and technicians in the midst of the fourth industrial revolution. The sample is from an ongoing quasi-experiment about psychosocial risk management in a manufacturing company in Sweden. Each of the seven teams belongs to one of two clusters: a positive cluster or a negative cluster. The positive cluster reports a significantly positive change in psychosocial risk levels between two time-points and the negative cluster reports a significantly negative change. The data are collected using semi-structured interviews. The results of the computer aided thematic analysis show that there are more differences than similarities when comparing the risk treatment actions taken between the two clusters. Findings show that the managers in the positive cluster use more enabling actions that foster and support formal and informal relationship building. In contrast, managers that use less enabling actions hinder the development of positive group processes and contribute negative changes in psychosocial risk levels. This exploratory study sheds some light on how management can influence significant positive and negative changes in psychosocial risk levels during a risk management process.

Keywords: group process model, risk treatment, risk management, psychosocial

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Authors: Muhammad Afzal, Shahbaz Mushtaq, Duc-Anh-An-Vo, Kathryn Reardon Smith, Thanh Ma

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Climate change has become one of the most challenging environmental issues in the 21st century. Climate change-induced natural disasters, especially floods, are the major factors of livelihood vulnerability, impacting millions of individuals worldwide. Evaluating and mitigating the effects of floods requires an in-depth understanding of the relationship between vulnerability and livelihood capital assets. Using an integrated approach, sustainable livelihood framework, and system thinking approach, the study developed a conceptual model of a generalized livelihood system in District Rajanpur, Pakistan. The model visualizes the livelihood vulnerability system as a whole and identifies the key feedback loops likely to influence the livelihood vulnerability. The study suggests that such conceptual models provide effective communication and understanding tools to stakeholders and decision-makers to anticipate the problem and design appropriate policies. It can also serve as an evaluation technique for rural livelihood policy and identify key systematic interventions. The key finding of the study reveals that household income, health, and education are the major factors behind the livelihood vulnerability of the rural poor of District Rajanpur. The Pakistani government tried to reduce the livelihood vulnerability of the region through different income, health, and education programs, but still, many changes are required to make these programs more effective especially during the flood times. The government provided only cash to vulnerable and marginalized families through income support programs, but this study suggests that along with the cash, the government must provide seed storage facilities and access to crop insurance to the farmers. Similarly, the government should establish basic health units in villages and frequent visits of medical mobile vans should be arranged with advanced medical lab facilities during and after the flood.

Keywords: livelihood vulnerability, rural communities, flood, sustainable livelihood framework, system dynamics, Pakistan

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Authors: Tomáš Vyčítal

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In a simulation model of a railway system it is important, besides other crucial algorithms, to have correct behaviour of train overtaking in stochastic conditions. This problem is being addressed in many simulation tools focused on railway traffic, however these are not very human-realistic. The goal of this paper is to create a more human-realistic overtaking decision support system for the use in railway traffic simulations. A fuzzy system has been chosen for this task as fuzzy systems are well-suited for human-like decision making. The fuzzy system designed takes into account timetables, train positions, delays and buffer times as inputs and provides an instruction to overtake or not overtake.

Keywords: decision-making support, fuzzy systems, simulation, railway, transport

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Authors: Cai J. T. Ladd, Mollie F. Duggan-Edwards, Tjeerd J. Bouma, Jordi F. Pages, Martin W. Skov

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Salt marshes are valued for their role in coastal flood protection, carbon storage, and for supporting biodiverse ecosystems. As a biogeomorphic landscape, marshes evolve through the complex interactions between sea level rise, sediment supply and wave/current forcing, as well as and socio-economic factors. Climate change and direct human modification could lead to a global decline marsh extent if left unchecked. Whilst the processes of saltmarsh erosion and expansion are well understood, empirical evidence on the key drivers of long-term lateral marsh dynamics is lacking. In a GIS, saltmarsh areal extent in 25 estuaries across Great Britain was calculated from historical maps and aerial photographs, at intervals of approximately 30 years between 1846 and 2016. Data on the key perceived drivers of lateral marsh change (namely sea level rise rates, suspended sediment concentration, bedload sediment flux rates, and frequency of both river flood and storm events) were collated from national monitoring centres. Continuous datasets did not extend beyond 1970, therefore predictor variables that best explained rate change of marsh extent between 1970 and 2016 was calculated using a Partial Least Squares Regression model. Information about the spread of Spartina anglica (an invasive marsh plant responsible for marsh expansion around the globe) and coastal engineering works that may have impacted on marsh extent, were also recorded from historical documents and their impacts assessed on long-term, large-scale marsh extent change. Results showed that salt marshes in the northern regions of Great Britain expanded an average of 2.0 ha/yr, whilst marshes in the south eroded an average of -5.3 ha/yr. Spartina invasion and coastal engineering works could not explain these trends since a trend of either expansion or erosion preceded these events. Results from the Partial Least Squares Regression model indicated that the rate of relative sea level rise (RSLR) and availability of suspended sediment concentration (SSC) best explained the patterns of marsh change. RSLR increased from 1.6 to 2.8 mm/yr, as SSC decreased from 404.2 to 78.56 mg/l along the north-to-south gradient of Great Britain, resulting in the shift from marsh expansion to erosion. Regional differences in RSLR and SSC are due to isostatic rebound since deglaciation, and tidal amplitudes respectively. Marshes exposed to low RSLR and high SSC likely leads to sediment accumulation at the coast suitable for colonisation by marsh plants and thus lateral expansion. In contrast, high RSLR with are likely not offset deposition under low SSC, thus average water depth at the marsh edge increases, allowing larger wind-waves to trigger marsh erosion. Current global declines in sediment flux to the coast are likely to diminish the resilience of salt marshes to RSLR. Monitoring and managing suspended sediment supply is not common-place, but may be critical to mitigating coastal impacts from climate change.

Keywords: lateral saltmarsh dynamics, sea level rise, sediment supply, wave forcing

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Authors: Fanny Desbiolles, Laure Malleret, Isabelle Laffont-Schwob, Christophe Tiliacos, Anne Piram, Mohamed Sarakha, Pascal Wong-Wah-Chung

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Pharmaceuticals in the environment have become a very hot topic in the recent years. This interest is related to the large amounts dispensed and to their release in urine or faeces from treated patients, resulting in their ubiquitous presence in water resources and wastewater treatment plants (WWTP) effluents. Thereby, many studies focused on the prediction of pharmaceuticals’ behaviour, to assess their fate and impacts in the environment. Carbamazepine is a widely consumed psychotropic pharmaceutical, thus being one of the most commonly detected drugs in the environment. This organic pollutant was proved to be persistent, especially with respect to its non-biodegradability, rendering it recalcitrant to usual biological treatment processes. Consequently, carbamazepine is very little removed in WWTP with a maximum abatement rate of 5 % and is then often released in natural surface waters. To better assess the environmental fate of carbamazepine in aqueous media, its photochemical transformation was undertaken in four natural waters (two French rivers, the Berre salt lagoon, Mediterranean Sea water) representative of coastal and inland water types. Kinetic experiments were performed in the presence of light using simulated solar irradiation (Xe lamp 300W). Formation of short-lifetime species was highlighted using chemical trap and laser flash photolysis (nanosecond). Identification of transformation by-products was assessed by LC-QToF-MS analyses. Carbamazepine degradation was observed after a four-day exposure and an abatement of 20% maximum was measured yielding to the formation of many by-products. Moreover, the formation of hydroxyl radicals (•OH) was evidenced in waters using terephthalic acid as a probe, considering the photochemical instability of its specific hydroxylated derivative. Correlations were implemented using carbamazepine degradation rate, estimated hydroxyl radical formation and chemical contents of waters. In addition, laser flash photolysis studies confirmed •OH formation and allowed to evidence other reactive species, such as chloride (Cl2•-)/bromine (Br2•-) and carbonate (CO3•-) radicals in natural waters. Radicals mainly originate from dissolved phase and their occurrence and abundance depend on the type of water. Rate constants between reactive species and carbamazepine were determined by laser flash photolysis and competitive reactions experiments. Moreover, LC-QToF-MS analyses of by-products help us to propose mechanistic pathways. The results will bring insights to the fate of carbamazepine in various water types and could help to evaluate more precisely potential ecotoxicological effects.

Keywords: carbamazepine, kinetic and mechanistic approaches, natural waters, photodegradation

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Authors: Zahrah Thamer Althagafi, Mohamed I. Awad

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A simple method for the fabrication of Au (111)-like electrode via controlled reductive desorption of a pre-adsorbed cysteine monolayer onto polycrystalline gold (poly-Au) electrode is introduced. Then, the voltammetric behaviour of dopamine (DA) and ascorbic acid (AA) on the thus modified electrode is investigated. Electrochemical characterization of the modified electrode is achieved using cyclic voltammetry and square wave voltammetry. For the binary mixture of DA and AA, the results showed that Au (111)-like electrode exhibits excellent electrocatalytic activity towards the oxidation of DA and AA. This allows highly selective and simultaneous determination of DA and AA. The effect of various experimental parameters on the voltammetric responses of DA and AA was investigated. The enrichment of the Au (111) facet of the poly-Au electrode is thought to be behind the electrocatalytic activity.

Keywords: gold electrode, electroanalysis, electrocatalysis, monolayers, self-assembly, cysteine, dopamine, ascorbic acid

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Authors: Rihab Belguith, Fathi Abid

Abstract:

The paper develops a system-based approach to investigate the dynamic adjustment of debt structure and investment policies of the Dow-Jones index. This approach enables the assessment of relations among sales, debt, and investment opportunities by considering the simultaneous effect of the market environmental change and future growth opportunities. We integrate the firm-specific sales variance to capture the industries' conditions in the model. Empirical results were obtained through a panel data set of firms with different sectors. The analysis support that environmental change does not affect equally the different industry since operating leverage differs among industries and so the sensitivity to sales variance. Including adjusted-specific variance, we find that there is no monotonic relation between leverage, sales, and investment. The firm may choose a low debt level in response to high sales variance but high leverage to attenuate the negative relation between sales variance and the current level of investment. We further find that while the overall effect of debt maturity on leverage is unaffected by the level of growth opportunities, the shorter the maturity of debt is, the smaller the direct effect of sales variance on investment.

Keywords: dynamic panel, investment, leverage decision, sales uncertainty

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Authors: Shaeel A. Al Thabaiti, Sulaiman N. Basahel, Salem M. Bawaked, Mohamed Mokhtar

Abstract:

Nanosheets for cobalt-layered double hydroxide (Co-Al-LDH)/GO were successfully synthesized with different Co:M g:Al ratios (0:3:1, 1.5:1.5:1, and 3:0:1). The layered double hydroxide structure and morphology were determined using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Temperature prgrammed reduction (TPR) of Co-Al-LDH showed reduction peaks at lower temperature which indicates the ease reducibility of this particular sample. The thermal behaviour was studied using thermal graviemetric technique (TG), and the BET-surface area was determined using N2 physisorption at -196°C. The C-C coupling reaction was carried out over all the investigated catalysts. The Mg–Al LDH catalyst without Co ions is inactive, but the isomorphic substitution of Mg by Co ions (Co:Mg:Al = 1.5:1.5:1) in the cationic sheet resulted in 88% conversion of iodobenzene under reflux. LDH/GO hybrid is up to 2 times higher activity than for the unsupported LDH.

Keywords: adsorption, co-precipitation, graphene oxide, layer double hydroxide

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