Search results for: economic conditions

Authors: Hanna Salminen

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Due to the large societal changes in working life, such as retirement reforms, globalization and technological changes, careers are becoming longer, more varied and unpredictable than before. Similar to other new career concepts, such as protean and boundaryless career, a sustainable career concept emphasizes an individual’s active role and agency in managing his/her own career in changing working life. However, the sustainable career concept also underlines the importance of safeguarding and developing human capital over time and thereby fostering continuity. Especially, the theoretical discussion around sustainable careers stresses flexible career choices that meet an individual’s own personal needs, allow work-family balance and promotes continuous learning. Although sustainable careers concern employees at all ages, this study focuses on older employees (aged 50+). So far, the changing nature of careers has been mainly investigated among younger generations, and the changing and prolonging late career phase has received less attention among career scholars. In other words, there is lack of knowledge regarding what constitutes a sustainable career in the late career phase and how the individual, organizational, and societal levels of sustainable career ecosystem are interconnected. The theoretical discussion around sustainable careers is closely linked to the sustainable management of human resources in organizations. In the field of human resource management (HRM), sustainable HRM has received more attention in recent years and it has been seen as a step forward from strategic HRM approach. As a concept, sustainable HRM stresses the long-term focus on organizations’ social, economic, and ecological resources, and the benefits of HRM practices for employees, organizations, and the society at large. However, some HRM scholars argue that the ecological and financial matters have overshadowed the social aspect of sustainability. In this study, the sustainable career and sustainable HRM literature are combined. As a result of an integrative literature review, this study provides new insight, how sustainable late career phase has been understood and conceptualized in sustainable career and sustainable HRM literature.

Keywords: sustainability, career, human resource management, ageing

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Authors: Adnan A. E. Darwish

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The predatory potential and preference of both larvae and adult of seven-spot ladybird, Coccinella septempunctata Linnaeus and the eleven-spot ladybird, Coccinella undecimpunctata Linnaeus to the green peach aphid, Myzus persicae (Sulzer), the cotton aphid, Aphis gossypii Glover, the bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus) and onion thrips, Thrips tabaci Lindeman were investigated under laboratory conditions at varying prey densities at faculty of Agriculture, Damanhour university, Egypt. There were significant differences between the consumed numbers of the four different species by the two different lady beetle species. The most consumed prey by C. septempunctata was the A. gossypii followed by R. padi then M. persicae and finally T. tabaci and these results were repeated in case of C. undecimpunctata. As the grubs of C. septempunctata and C. undecimpunctata developed from 1st to 4th larval instars, the consumption rate from aphid species and thrips increased. The consumption rate of M. persicae, A. gossypii, R. padi and T. tabaci significantly increased with the advancement in the larval stage of the predator. The forth larval instar of C. septempunctata and C. undecimpunctata exhibited the highest predatory potential comparing to the first, second and third larval instars. The number of prey eaten by adult stage or different instars of larvae of the two predators increased significantly with prey density, reaching the maximum value when 150 preys were provided compared with 50 and 100 preys.

Keywords: predatory potential, Coccinella septempunctata, Coccinella undecimpunctata, Thrips tabaci, Myzus persicae, Aphis gossypii, Rhopalosiphum padi

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Authors: Hyunjoo Park, Taehyun Kim, Taehyun Kim

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The government that declared 'de-nuclearization' pushes up renewable energy policies such as solar power and wind power as an alternative to nuclear power generation. However, local residents who are concerned about the development and natural disasters have been hit by opposition, and related businesses around the country are experiencing difficulties. There is also a voice saying that installing a large wind power generator will cause landslides, low frequencies and noise, which will have a bad influence. Renewal is only a harmful and disgusting facility for the residents. In this way, it is expected that extreme social conflicts will occur in the decision making process related to the locally unwanted land-use (LULU). The government's efforts to solve this problem have been steadily progressing, but the systematic methodology for bringing in active participation and opinion gathering of the residents has not yet been established except for the simple opinion poll or referendum. Therefore, it is time to identify the factors that concern the local residents about the wind power generation facilities, and to find ways to make policy decision-making possible. In this study, we analyze the perception of people about offshore and onshore wind power facilities through questionnaires or interviews, and examine quantitative and qualitative precedent studies to analyze them. In addition, the study evaluates what factors affect the local acceptance of wind power facilities. As a result of the factor analysis of the questionnaire items, factors affecting the residents' acceptance of the wind power facility were extracted from four factors such as environmental, economic, risk, social, and management factor. The study also found that the influence of the determinants of local acceptance on the regional acceptability differs according to the demographic characteristics such as gender and income level. This study will contribute to minimizing the conflict on the installation of wind power facilities through communication among the local residents.

Keywords: factor analysis, local acceptance, locally unwanted land-use, LULU, wind power generation facilities

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Authors: Quoc Van Nguyen, Behzad Fatahi, Aslan S. Hokmabadi

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Performance based seismic design is a modern approach to earthquake-resistant design shifting emphasis from “strength” to “performance”. Soil-Structure Interaction (SSI) can influence the performance level of structures significantly. In this paper, a fifteen storey moment resisting frame sitting on a shallow foundation (footing) with different sizes is simulated numerically using ABAQUS software. The developed three dimensional numerical simulation accounts for nonlinear behaviour of the soil medium by considering the variation of soil stiffness and damping as a function of developed shear strain in the soil elements during earthquake. Elastic-perfectly plastic model is adopted to simulate piles and structural elements. Quiet boundary conditions are assigned to the numerical model and appropriate interface elements, capable of modelling sliding and separation between the foundation and soil elements, are considered. Numerical results in terms of base shear, lateral deformations, and inter-storey drifts of the structure are compared for the cases of soil-structure interaction system with different foundation sizes as well as fixed base condition (excluding SSI). It can be concluded that conventional design procedures excluding SSI may result in aggressive design. Moreover, the size of the foundation can influence the dynamic characteristics and seismic response of the building due to SSI and should therefore be given careful consideration in order to ensure a safe and cost effective seismic design.

Keywords: soil-structure-interaction, seismic response, shallow foundation, abaqus, rayleigh damping

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Authors: A. Jéglot, F. Plauborg, M. K. Schnorr, R. S. Sørensen, L. Elsgaard

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Artificial wetlands such as woodchip bioreactors are efficient tools to remove nitrate from agricultural wastewater with a minimized environmental impact. However, the temperature dependence of the microbiological nitrate removal prevents the woodchip bioreactors from being an efficient system when the water temperature drops below 8℃. To quantify and describe the temperature effects on nitrate removal efficiency, we studied nitrate-reducing enrichments from a woodchip bioreactor in Denmark based on samples collected in Spring and Fall. Growth was quantified as optical density, and nitrate and nitrous oxide concentrations were measured in time-course experiments to compare the growth of the microbial population and the nitrate conversion efficiencies at different temperatures. Ammonia was measured to indicate the importance of dissimilatory nitrate reduction to ammonia (DNRA) in nitrate conversion for the given denitrifying community. The temperature responses observed followed the increasing trend proposed by the Arrhenius equation, indicating higher nitrate removal efficiencies at higher temperatures. However, the growth and the nitrous oxide production observed at low temperature provided evidence of the psychrotolerance of the microbial community under study. The assays conducted showed higher nitrate removal from the microbial community extracted from the woodchip bioreactor at the cold season compared to the ones extracted during the warmer season. This indicated the ability of the bacterial populations in the bioreactor to evolve and adapt to different seasonal temperatures.

Keywords: agricultural waste water treatment, artificial wetland, denitrification, psychrophilic conditions

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Authors: Fourar Ali, Fourar Fatima Zohra

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Knowledge of sediment characteristics is fundamental to understanding their sedimentary functioning: sedimentation, settlement, and erosion processes of cohesive sediments are controlled by complex interactions between physical, chemical, and biological factors. Sediment transport is of primary importance in river hydraulics and river engineering. Indeed, the displacement of sediments can lead to lasting modifications of the bed in terms of its elevation, slope and roughness. The protection of a bank, for example, is likely to initiate a local incision of the river bed, which, in turn, can lead to the subsidence of the bank. The flows in the natural environment occur in general with heterogeneous boundary conditions because of the distribution of the roughnesses of the fixed or mobile bottoms and of the important deformations of the free surface, especially for the flows with a weak draft considering the irregularity of the bottom. Bedforms significantly influence flow resistance. The arrangement of particles lining the bottom of the stream bed or experimental channel generates waveforms of different sizes that lead to changes in roughness and consequently spatial variability in the turbulent characteristics of the flow. The study which is focused on the laws of friction in alluvial beds, aims to analyze the characteristics of flows and materials constituting the natural channels. Experimental results were obtained by simulating these flows on a rough bottom in an experimental channel at the Hydraulics Laboratory of the University of Batna 2. The system of equations governing the problem is solved using the program named: CLIPPER.5 and ACP.

Keywords: free surface flow, heterogeneous sand, moving bottom bed, friction coefficient, bottom roughness

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Authors: Birendra Kumar Jha, Mingma L. Sherpa, Binod Kumar Dahal

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Background: The metabolic syndrome is emerging as a major public health concern in the world. Urbanization, surplus energy uptake, compounded by decreased physical activities, and increasing obesity are the major factors contributing to the epidemic of metabolic syndrome worldwide. However, prevalence of metabolic syndrome and its risk factors are little studied in Terai region of Nepal. The objectives of this research were to estimate the prevalence and to identify the risk factors of metabolic syndrome among adults in Terai region of Nepal. Method: We used a community based cross sectional study design. A total of 225 adults (age: 18 to 80 years) were selected from three district of Terai region of Nepal using cluster sampling by camp approach. IDF criteria (central obesity with any two of following four factors: triglycerides ≥ 150 mg/dl or specific treatment for lipid abnormality, reduced HDL, raised blood pressure and raised fasting plasma glucose or previously diagnosed type 2 diabetes) were used to assess metabolic syndrome. Interview, physical and clinical examination, measurement of fasting blood glucose and lipid profile were conducted for all participants. Chi-square test and multivariable logistic regression were employed to explore the risk factors of metabolic syndrome. Result: The overall prevalence of metabolic syndrome was 70.7%. Hypertension, increased fasting blood sugar, increased triglycerides and decreased HDL were observed in 50.7%, 32.4%, 41.8% and 79.1% of the subjects respectively. Socio-economic and behavioral risk factors significantly associated with metabolic syndrome were gender male (OR=2.56, 955 CI: 1.42-4.63; p=0.002), in service or retired from service (OR=3.72, 95% CI: 1.72-8.03; p=0.001) and smoking (OR= 4.10, 95% CI: 1.19-14.07; p=0.016). Conclusion: Higher prevalence of Metabolic syndrome along with presence of behavioral risk factors in Terai region of Nepal likely suggest lack of awareness and health promotion activities for metabolic syndrome and indicate the need to promote public health programs in this region to maintain quality of life.

Keywords: metabolic syndrome, Nepal, prevalence, risk factors, Terai

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Authors: Hamza Hadj Abdallah, Brahim Belabdi

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Respiratory disease is a dominant pathology in cattle. It causes mortality and especially morbidity and irreversible damage. Although the dairy herd is affected, it is essentially the lactating herd and especially young cattle either nursing or fattening that undergo the greatest economic impact. The objective of this study is to establish a microbiological diagnosis of bovine respiratory inffections from lung presented with gross lesions at the slaughter of Batna. A total of 124 samples (pharyngeal and nasal swabs and lung fragments) from 31 seven months old calves, with lung lesions was collected to determine possible correlations between etiologic agents and lesion types. The hépatisation injury (or consolidation) was the major lesion (45.17%) preferentially localized in the right apical lobe. A diverse microbial flora (15 genera and 291 strains was isolated. The bacteria most frequently isolated are the Enterobacteriaceae (49.45%), Staphylococci (25.1%) followed by non Enterobacteriaceae bacilli represented by Pseudomonas (5.83%) and finally, Streptococcus (13.38 %). The pneumotropic bacteria (Pasteurellaaerogenes and Pasteurellapneumotropica) were isolated at a rate of 0.68%. The study of the sensitivity of some germs to antibiotics showed a sensitivity of 100% for ceftazidime. A very high sensitivity was also observed for kanamycin, Ciprofloxacin, Imepinem, Cefepime, Tobramycin and Gentamycin (between 90% and 97%). Strains of E. coli showed a sensitivity of 100% for Imepinem, while only 55.9% of the strains were sensitive to Ampicillin. The isolated Pasteurella exhibited excellent sensitivity (100%) for the antimicrobials used with the exception of Colistin and Ticarcillin-Clavulanic acid association which showed a sensitivity of 50%.This survey has demonstrated the strong spread of atypical pneumonia in cattle population (bulls) at the slaughterhouse of Batna justifying stunting and losses in cattle farms in the region.Thus, it was considered urgent to establish a profile of sensitivity of different germs to antibiotics isolated to limit this increasingly dreadful infection.

Keywords: Pasteurella, enterobacteria, bacteriology, pneumonia

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Authors: Karthika Durairaj, Buvaneswari G., Gowdham M., Gilles M., Velmurugan G.

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Background: Hyperglycaemia is the primary cause of metabolic illness. Recently, researchers focused on the possibility that chemical exposure could promote metabolic disease. Hyperglycaemia causes a variety of metabolic diseases dependent on its etiologic conditions. According to animal and population-based research, individual chemical exposure causes health problems through alteration of endocrine function with the influence of microbial influence. We were intrigued by the function of gut microbiota variation in high fat and chemically induced hyperglycaemia. Methodology: C57/Bl6 mice were subjected to two different treatments to generate the etiologic-based diabetes model: I – a high-fat diet with a 45 kcal diet, and II - endocrine disrupting chemicals (EDCs) cocktail. The mice were monitored periodically for changes in body weight and fasting glucose. After 120 days of the experiment, blood anthropometry, faecal metagenomics and metabolomics were performed and analyzed through statistical analysis using one-way ANOVA and student’s t-test. Results: After 120 days of exposure, we found hyperglycaemic changes in both experimental models. The treatment groups also differed in terms of plasma lipid levels, creatinine, and hepatic markers. To determine the influence on glucose metabolism, microbial profiling and metabolite levels were significantly different between groups. The gene expression studies associated with glucose metabolism vary between hosts and their treatments. Conclusion: This research will result in the identification of biomarkers and molecular targets for better diabetes control and treatment.

Keywords: hyperglycaemia, endocrine-disrupting chemicals, gut microbiota, host metabolism

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Authors: Ren Moses, Emmanuel Kidando, Eren Ozguven, Yassir Abdelrazig

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This study applied traffic speed and occupancy to develop clustering models that identify different traffic conditions. Particularly, these models are based on the Dirichlet Process Mixture of Generalized Linear regression (DML) and change-point regression (CR). The model frameworks were implemented using 2015 historical traffic data aggregated at a 15-minute interval from an Interstate 295 freeway in Jacksonville, Florida. Using the deviance information criterion (DIC) to identify the appropriate number of mixture components, three traffic states were identified as free-flow, transitional, and congested condition. Results of the DML revealed that traffic occupancy is statistically significant in influencing the reduction of traffic speed in each of the identified states. Influence on the free-flow and the congested state was estimated to be higher than the transitional flow condition in both evening and morning peak periods. Estimation of the critical speed threshold using CR revealed that 47 mph and 48 mph are speed thresholds for congested and transitional traffic condition during the morning peak hours and evening peak hours, respectively. Free-flow speed thresholds for morning and evening peak hours were estimated at 64 mph and 66 mph, respectively. The proposed approaches will facilitate accurate detection and prediction of traffic congestion for developing effective countermeasures.

Keywords: traffic congestion, multistate speed distribution, traffic occupancy, Dirichlet process mixtures of generalized linear model, Bayesian change-point detection

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Authors: Siqin Wang, Jonathan Corcoran, Yan Liu, Thomas Sigler

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Australia is a quintessentially immigrant nation with 28 percent of its residents being foreign-born. By 2011, People’s Republic of China (PRC) overtook the United Kingdom to become the largest source country in Australia. Significantly, the profile of PRC-born migrants has changed to mirror broader global shifts towards high-skilled labour, education-related, and investment-focussed migration, all of which reflect an increasing trend in the mobility of wealthy and/or educated cohorts. Together, these coalesce to form a more complex pattern of migrant settlement –both spatially and socio-economically. This paper focuses on the PRC-born migration, redresses these lacunae, with regard to the settlement outcomes of PRC migrants to Australia, with a particular focus on spatial evolution and residential mobility at both the metropolitan and national scales. By drawing on Census Data and migration Micro Datasets, the aim of this paper is to examine the shifting dynamics of PRC-born migrants in Australian capital cities to unveil their socioeconomic characteristics, residential patterns and change of spatial concentrations during their transition into the new host society. This paper finds out three general patterns in the residential evolution of PRC-born migrants depending on the size of capital cities where they settle down, as well as the association of socio-economic characters with the formation of enclaves. It also examines the residential mobility across states and cities from 2001 to 2011 indicating the rising status of median-size Australian capital cities for receiving PRC-born migrants. The paper concludes with a discussion of evidences for policy formation, facilitates the effective transition of PRC-born populations into the mainstream of host society and enhances social harmony to help Australia become a more successful multicultural nation.

Keywords: Australia, Chinese migrants, residential mobility, spatial evolution

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Authors: Seember Susan Aondoakura

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This paper examines the international legal framework established to address the challenges women and girls experience in situations of violent conflict. The United Nations (UN) women, peace, and security agenda (hereafter WPS agenda, the Agenda) aspire to make wars safer for women. It recognizes women's agency in armed conflict and their victimization and formulates measures for their protection. The Agenda also acknowledges women's participation in conflict transformation and post-conflict reconstruction. It also calls for the involvement of women in conflict transformation, encourages the protection of women from sex and gender-based violence (SGBV), and provides relief and recovery from conflict-related SGBV. Using Third World Critical Feminist Theory, this paper argues that the WPS agenda overly focus on the protection of women from SGBV occurring in the less developed and conflict-ridden states in the global south, obscures the complicity of western states and economies to the problem, and silences the privileges that such states derive from war economies that continue to fuel conflict. This protectionist approach of the UN also obliterates other equally pressing problems in need of attention, like the high rates of economic degradation in conflict-ravaged societies of the global south. Prioritising protection also 'others' the problem, obliterating any sense of interconnections across geographical locations and situating women in the less developed economies of the global south as the victims and their men as the perpetrators. Prioritising protection ultimately situates western societies as saviours of Third World women with no recourse to their role in engendering and sustaining war. The paper demonstrates that this saviour mentality obliterates chances of any meaningful coalition between the local and the international in framing and addressing the issue, as solutions are formulated from a specific lens—the white hegemonic lens.

Keywords: conflict, protection, security, SGBV

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Authors: Mustafa Al-Yaseen, Haider Mohammed Mahdi, Haider Ali Al–Zahid, Nazar S. Haddad

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Background: Early diagnosis of musculoskeletal infections is of vital importance to avoid devastating complications. There is no single laboratory marker which is sensitive and specific in diagnosing these infections accurately. White blood cell count, erythrocyte sedimentation rate, and C-reactive protein are not specific as they can also be elevated in conditions other than bacterial infections. Materials Culture and sensitivity is not a true gold standard due to its varied positivity rates. Serum Procalcitonin is one of the new laboratory markers for pyogenic infections. The objective of this study is to assess the value of PCT in the diagnosis of soft tissue, bone, and joint infections. Patients and Methods: Patients of all age groups (seventy-four patients) with a diagnosis of musculoskeletal infection are prospectively included in this study. All patients were subjected to White blood cell count, erythrocyte sedimentation rate, C-reactive protein, and serum Procalcitonin measurements. A healthy non infected outpatient group (twenty-two patients) taken as a control group and underwent the same evaluation steps as the study group. Results: The study group showed mean Procalcitonin levels of 1.3 ng/ml. Procalcitonin, at 0.5 ng/ml, was (42.6%) sensitive and (95.5%) specific in diagnosing of musculoskeletal infections with (positive predictive value of 87.5% and negative predictive value of 48.3%) and (positive likelihood ratio of 9.3 and negative likelihood ratio of 0.6). Conclusion: Serum Procalcitonin, at a cut – off of 0.5 ng/ml, is a specific but not sensitive marker in the diagnosis of musculoskeletal infections, and it can be used effectively to rule in the diagnosis of infection but not to rule out it.

Keywords: procalcitonin, infection, labratory markers, musculoskeletal

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Authors: Hadeer E. Eliwa, Naglaa S. Bazan, Ebtissam A. Darweesh, Nagwa A. Sabri

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Background: Generic substitution of brand ivabradine prescriptions can reduce drug expenditures and improve adherence. However, the distrust of generic medicines by practitioners and patients due to doubts regarding their quality and fear of counterfeiting compromise the acceptance of this practice. Aim: The goal of this study is to compare the therapeutic equivalence of brand product versus the generic product of ivabradine in adult patients with chronic heart failure with reduced ejection fraction (≤ 40%) (HFrEF). Methodology: Thirty-two Egyptian patients with chronic heart failure with reduced ejection fraction (HFrEF) were treated with branded ivabradine (Procrolan ©) and generic (Bradipect ©) during 24 (2x12) weeks. Primary outcomes were resting heart rate (HR), NYHA FC, Quality of life (QoL) using Minnesota Living with Heart Failure (MLWHF) and EF. Secondary outcomes were the number of hospitalizations for worsening HFrEF and adverse effects. The washout period was not allowed. Findings: At the 12th week, the reduction in HR was comparable in the two groups (90.13±7.11 to 69±11.41 vs 96.13±17.58 to 67.31±8.68 bpm in brand and generic groups, respectively). Also, the increase in EF was comparable in the two groups (27.44 ±4.59 to 33.38±5.62 vs 32±5.96 to 39.31±8.95 in brand and generic groups, respectively). The improvement in NYHA FC was comparable in both groups (87.5% in brand group vs 93.8% in the generic group). The mean value of the QOL improved from 31.63±15.8 to 19.6±14.7 vs 35.68±17.63 to 22.9±15.1 for the brand and generic groups, respectively. Similarly, at end of 24 weeks, no significant changes were observed from data observed at 12th week regarding HR, EF, QoL and NYHA FC. Only minor side effects, mainly phosphenes, and a comparable number of hospitalizations were observed in both groups. Conclusion: The study revealed no statistically significant differences in the therapeutic effect and safety between generic and branded ivabradine. We assume that practitioners can safely interchange between them for economic reasons.

Keywords: bradipect©, heart failure, ivabradine, Procrolan ©, therapeutic equivalence

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Authors: Charlene N. T. Mfangnia, Henri Tonnang, Berge Tsanou, Jeremy Herren

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The Microsporidia MB found in the populations of anopheles is a recently discovered symbiont responsible for the Plasmodium transmission blocking. From early studies, it was established that the symbiont can be transmitted vertically and horizontally. The present study uses compartmental mathematical modelling approach to investigate the dynamics of Microsporidia transmission in the mosquito population with the mindset of establishing a mechanism for use to control malaria. Data and information obtained from laboratory experiments are used to estimate the model parameters with and without temperature dependency of mosquito traits. We carry out the mathematical analysis focusing on the equilibria states and their stability for the autonomous model. Through the modelling experiments, we are able to assess and confirm the contribution of vertical and horizontal transmission in the proliferation of Microsporidia MB in the mosquito population. In addition, the basic and target reproductions are computed, and some long-term behaviours of the model, such as the local (and global) stability of equilibrium points, are rigorously analysed and illustrated numerically. We establish the conditions responsible for the low prevalence of the symbiont-infected mosquitoes observed in nature. Moreover, we identify the male death rate, the mating rate and the attractiveness of MB-positive mosquitoes as mosquito traits that significantly influence the spread of Microsporidia MB. Furthermore, we highlight the influence of temperature in the establishment and persistence of MB-infected mosquitoes in a given area.

Keywords: microsporidia MB, vertical transmission, horizontal transmission, compartmental modelling approach, temperature-dependent mosquito traits, malaria, plasmodium-transmission blocking

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Authors: Hamil Uribe, Cristian Arancibia

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In Chile, the water for irrigation and hydropower generation is delivery essentially through unlined channels on earth, which have high seepage losses. Traditional seepage-abatement technologies are very expensive. The goals of this work were to quantify water loss in unlined channels and select reaches to evaluate the use of linear anionic polyacrylamide (LA-PAM) to reduce seepage losses. The study was carried out in Maule Region, central area of Chile. Water users indicated reaches with potential seepage losses, 45 km of channels in total, whose flow varied between 1.07 and 23.6 m³ s⁻¹. According to seepage measurements, 4 reaches of channels, 4.5 km in total, were selected for LA-PAM application. One to 4 LA-PAM applications were performed at rates of 11 kg ha⁻¹, considering wet perimeter area as basis of calculation. Large channels were used to allow motorboat moving against the current to carry-out LA-PAM application. For applications, a seeder machine was used to evenly distribute granulated polymer on water surface. Water flow was measured (StreamPro ADCP) upstream and downstream in selected reaches, to estimate seepage losses before and after LA-PAM application. Weekly measurements were made to quantify treatment effect and duration. In each case, water turbidity and temperature were measured. Channels showed variable losses up to 13.5%. Channels showing water gains were not treated with PAM. In all cases, LA-PAM effect was positive, achieving average loss reductions of 8% to 3.1%. Water loss was confirmed and it was possible to reduce seepage through LA-PAM applications provided that losses were known and correctly determined when applying the polymer. This could allow increasing irrigation security in critical periods, especially under drought conditions.

Keywords: canal seepage, irrigation, polyacrylamide, water management

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Authors: M. O. Adeniyi, R. T. Akinnubi

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The parameterization of turbulent heat fluxes is needed for modeling land-atmosphere interactions in Global Climate Models (GCMs). However, current GCMs still have difficulties with producing reliable turbulent heat fluxes for humid tropical regions, which may be due to inadequate parameterization of the roughness lengths for momentum (z0m) and heat (z0h) transfer. These roughness lengths are usually expressed in term of excess resistance factor (κB^(-1)), and this factor is used to account for different resistances for momentum and heat transfers. In this paper, a more appropriate excess resistance factor (〖 κB〗^(-1)) suitable for low wind speed condition was developed and incorporated into the aerodynamic resistance approach (ARA) in the GCMs. Also, the performance of various standard GCMs κB^(-1) schemes developed for high wind speed conditions were assessed. Based on the in-situ surface heat fluxes and profile measurements of wind speed and temperature from Nigeria Micrometeorological Experimental site (NIMEX), new κB^(-1) was derived through application of the Monin–Obukhov similarity theory and Brutsaert theoretical model for heat transfer. Turbulent flux parameterizations with this new formula provides better estimates of heat fluxes when compared with others estimated using existing GCMs κB^(-1) schemes. The derived κB^(-1) MBE and RMSE in the parameterized QH ranged from -1.15 to – 5.10 Wm-2 and 10.01 to 23.47 Wm-2, while that of QE ranged from - 8.02 to 6.11 Wm-2 and 14.01 to 18.11 Wm-2 respectively. The derived 〖 κB〗^(-1) gave better estimates of QH than QE during daytime. The derived 〖 κB〗^(-1)=6.66〖 Re〗_*^0.02-5.47, where Re_* is the Reynolds number. The derived κB^(-1) scheme which corrects a well documented large overestimation of turbulent heat fluxes is therefore, recommended for most regional models within the tropic where low wind speed is prevalent.

Keywords: humid, tropic, excess resistance factor, overestimation, turbulent heat fluxes

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Authors: Yohanes Kambaru Windi, Loetfia Dwi Rahariyani, Dyah Wijayanti, Eko Rustamaji

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Surabaya, the second largest city in Indonesia, has been struggling for years with waste production and its management. Nearly 11,000 tons of waste are generated daily by domestic, commercial and industrial areas. It is predicted that approximately 1,300 tons of waste overflew the Benowo Landfill daily in 2013 and projected that the landfill operation will be critical in 2015. The Super Depo Sutorejo (SDS) is a pilot project on waste management launched by the government of Surabaya in March 2013. The project is aimed to reduce the amount of waste dumped in landfill by sorting the recyclable and organic waste for composting by employing waste pickers to sort the waste before transported to landfill. This study is intended to assess the capacity of SDS to process and reduce waste and its complementary benefits. It also overviews the benefits of the project to the waste pickers in term of satisfaction to the job. Waste processing data-sheets were used to assess the difference between input and outputs waste. A survey was distributed to 30 waste pickers and interviews were conducted as a further insight on a particular issue. The analysis showed that SDS enable to reduce waste up to 50% before dumped in the final disposal area. The cost-benefits analysis using cost differential calculation revealed the economic benefit is considerable low, but composting may substitute tangible benefits for maintain the city’s parks. Waste pickers are mostly satisfied with their job (i.e. Salary, health coverage, job security), services and facilities available in SDS and enjoyed rewarding social life within the project. It is concluded that SDS is an effective and efficient model for sustainable waste management and reliable to be developed in developing countries. It is a strategic approach to empower and open up working opportunity for the poor urban community and prolong the operation of landfills.

Keywords: cost-benefits, integration, satisfaction, waste management

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Authors: Hanjong Kim, Changwan Han, Seonghun Park

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Heat exchanger manifolds in aircraft play an important role in evenly distributing the fluid entering through the inlet to the heat transfer unit. In order to achieve this requirement, the manifold should be designed to have a light weight by withstanding high internal pressure. Therefore, this study aims at minimizing the weight of the heat exchanger manifold through topology optimization. For topology optimization, the initial design space was created with the inner surface extracted from the currently used manifold model and with the outer surface having a dimension of 243.42 mm of X 74.09 mm X 65 mm. This design space solid model was transformed into a finite element model with a maximum tetrahedron mesh size of 2 mm using ANSYS Workbench. Then, topology optimization was performed under the boundary conditions of an internal pressure of 5.5 MPa and the fixed support for rectangular inlet boundaries by SIMULIA TOSCA. This topology optimization produced the minimized finial volume of the manifold (i.e., 7.3% of the initial volume) based on the given constraints (i.e., 6% of the initial volume) and the objective function (i.e., maximizing manifold stiffness). Weight of the optimized model was 6.7% lighter than the currently used manifold, but after smoothing the topology optimized model, this difference would be bigger. The current optimized model has uneven thickness and skeleton-shaped outer surface to reduce stress concentration. We are currently simplifying the optimized model shape with spline interpolations by reflecting the design characteristics in thickness and skeletal structures from the optimized model. This simplified model will be validated again by calculating both stress distributions and weight reduction and then the validated model will be manufactured using 3D printing processes.

Keywords: topology optimization, manifold, heat exchanger, 3D printing

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Authors: Gabi N. Nehme, Saeed Ghalambor

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The use of titanium fluoride and iron fluoride (TiF3/FeF3) catalysts in combination with polutetrafluoroethylene (PTFE) in plain zinc dialkyldithiophosphate (ZDDP) oil is important for the study of engine tribocomponents and is increasingly a strategy to improve the formation of tribofilm and to provide low friction and excellent wear protection in reduced phosphorus plain ZDDP oil. The influence of surface roughness and the concentration of TiF3/FeF3/PTFE were investigated using bearing steel samples dipped in lubricant solution @100°C for two different heating time durations. This paper addresses the effects of water drop contact angle using different surface finishes after treating them with different lubricant combination. The calculated water drop contact angles were analyzed using Design of Experiment software (DOE) and it was determined that a 0.05 μm Ra surface roughness would provide an excellent TiF3/FeF3/PTFE coating for antiwear resistance as reflected in the scanning electron microscopy (SEM) images and the tribological testing under extreme pressure conditions. Both friction and wear performance depend greatly on the PTFE/and catalysts in plain ZDDP oil with 0.05% phosphorous and on the surface finish of bearing steel. The friction and wear reducing effects, which was observed in the tribological tests, indicated a better micro lubrication effect of the 0.05 μm Ra surface roughness treated at 100°C for 24 hours when compared to the 0.1 μm Ra surface roughness with the same treatment.

Keywords: scanning electron microscopy, ZDDP, catalysts, PTFE, friction, wear

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Authors: Raoul Ouambo Tobou, Alexis Kuitche, Marcel Edoun

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The FWM (Finite Window Method) is a new numerical meshfree technique for solving problems defined either in terms of PDEs (Partial Differential Equation) or by a set of conservation/equilibrium laws. The principle behind the FWM is that in such problem each element of the concerned domain is interacting with its neighbors and will always try to adapt to keep in equilibrium with respect to those neighbors. This leads to a very simple and robust problem solving scheme, well suited for transfer problems. In this work, we have applied the FWM to an unsteady scalar convection-diffusion equation. Despite its simplicity, it is well known that convection-diffusion problems can be challenging to be solved numerically, especially when convection is highly dominant. This has led researchers to set the scalar convection-diffusion equation as a benchmark one used to analyze and derive the required conditions or artifacts needed to numerically solve problems where convection and diffusion occur simultaneously. We have shown here that the standard FWM can be used to solve convection-diffusion equations in a robust manner as no adjustments (Upwinding or Artificial Diffusion addition) were required to obtain good results even for high Peclet numbers and coarse space and time steps. A comparison was performed between the FWM scheme and both a first order implicit Finite Volume Scheme (Upwind scheme) and a third order implicit Finite Volume Scheme (QUICK Scheme). The results of the comparison was that for equal space and time grid spacing, the FWM yields a much better precision than the used Finite Volume schemes, all having similar computational cost and conditioning number.

Keywords: Finite Window Method, Convection-Diffusion, Numerical Technique, Convergence

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Authors: Yue Wang, Fan Chen

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After the economic reform in 1978, the urbanization in China has grown fast. It urged cities to expand in an unprecedented high speed. Villages around were annexed unprepared, and it turned out to be a new type of community called 'village in city.' Two things happened here. First, the locals gave up farming and turned to secondary industry and tertiary industry, as a result of losing their land. Secondly, attracted by the high income in cities and low rent here, plenty of migrants came into the community. This area is important to a city in rapid growth for providing a transitional zone. But thanks to its passivity and low development, 'village in city' has caused lots of trouble to the city. Densities of population and construction are both high, while facilities are severely inadequate. Unplanned and illegal structures are built, which creates a complex mixed-function area and leads to a bad residential area. Besides, the locals have a strong property right consciousness for the land. It holds back the transformation and development of the community. Although the land capitalization can bring significant benefits, it’s inappropriate to make a great financial compensation to the locals, and considering the large population of city migrants, it’s important to explore the relationship among the 'village in city,' city immigrants and the city itself. Taking the example of Hangzhou, this paper analyzed the developing process, functions spatial distribution, industrial structure and current traffic system of 'village in city.' Above the research on the community, this paper put forward a common method to make urban planning through the following ways: adding city functions, building civil facilities, re-planning functions spatial distribution, changing the constitution of local industry and planning new traffic system. Under this plan, 'village in city' finally can be absorbed into cities and make its own contribution to the urbanization.

Keywords: China, city immigrant, urbanization, village in city

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Authors: L. A. Bosnea, T. Moschakis, C. Biliaderis

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Two probiotic strains of Lactobacillus paracasei subsp. paracasei (E6) and Lactobacillus paraplantarum (B1), isolated from traditional Greek dairy products, were microencapsulated by complex coacervation using whey protein isolate (WPI, 3% w/v) and gum arabic (GA, 3% w/v) solutions mixed at different polymer ratio (1:1, 2:1 and 4:1). The effect of total biopolymer concentration on cell viability was assessed using WPI and GA solutions of 1, 3 and 6% w/v at a constant ratio of 2:1. Also, several parameters were examined for optimization of the microcapsule formation, such as inoculum concentration and the effect of ionic strength. The viability of the bacterial cells during heat treatment and under simulated gut conditions was also evaluated. Among the different WPI/GA weight ratios tested (1:1, 2:1, and 4:1), the highest survival rate was observed for the coacervate structures made with the ratio of 2:1. The protection efficiency at low pH values is influenced by both concentration and the ratio of the added biopolymers. Moreover, the inoculum concentration seems to affect the efficiency of microcapsules to entrap the bacterial cells since an optimum level was noted at less than 8 log cfu/ml. Generally, entrapment of lactobacilli in the complex coacervate structure enhanced the viability of the microorganisms when exposed to a low pH environment (pH 2.0). Both encapsulated strains retained high viability in simulated gastric juice (>73%), especially in comparison with non-encapsulated (free) cells (<19%). The encapsulated lactobacilli also exhibited enhanced viability after 10–30 min of heat treatment (65oC) as well as at different NaCl concentrations (pH 4.0). Overall, the results of this study suggest that complex coacervation with WPI/GA has a potential to deliver live probiotics in low pH food systems and fermented dairy products; the complexes can dissolve at pH 7.0 (gut environment), releasing the microbial cells.

Keywords: probiotic, complex coacervation, whey, encapsulation

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Authors: Monika Szpringer, Mariola Wojciechowska, Robert Dutkiewicz, Grażyna Nowak-Starz, Marzena Olędzka

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The main aim of this article is to determine the phenomenon of stress among academic teachers as well as to identify the extent to which the teachers experience work-related psychological risks. It is also important to support academic teachers trade unions in scope of stress-oriented activities, including psychological dangers in the assessment of risk in the workplace (college). The authors used a method of a diagnostic survey with a polling as a technique and authors’ questionnaire as a tool. The survey was conducted between September and December of 2013 and it comprised 1890 academic teachers from five voivodeships. The study reveals that 84.0% of the respondents found the work of an academic teacher to be borne with a considerable stress. The percentage values of the most frequent causes of stress are as follows: frequent changes of both organisational and didactic matters as well as overwhelming bureaucracy (77.8 %), time pressure regarding professional development and related risk of losing job (68.2 %), difficult working conditions (45.4%), conflicts and rivalry between teachers (44.1%), excessive amount of duties as well as increasing requirements and demanding attitude of students (33.7%). Work-related stress affects or significantly affects the private life of 69 % and 66.4 % of the respondents respectively. The majority of the people surveyed deals with stress by undertaking various activities, with 40% pointing at using various substances, mostly cigarettes and alcohol (p > 0,05) Physical ailments were experienced by 81% of the respondents, in 9% they were rare and 8 % of the respondents had never experienced such disorders. The entire group of the surveyed people (100 %) claimed that they have no possibility of contacting a psychologist at their workplace (p > 0.05), and they stated that the need of contacting specialists does exist.

Keywords: stress, academic teachers, psychological risks, work-related

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Authors: Latif Apaassongo Ibrahim, Owusu-Addo Ebenezer, Isaac Bonuedo

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Structural barriers - including inadequate infrastructure, poor market linkages, and limited access to financial and extension services - have been the major constraints to improved welfare in the semi-arid regions of Ghana; food insecurity and malnutrition are persistent. The effects of infrastructural improvements as countermeasures are often misdirected by confounding effects of other economic, social, and environmental variables. This study applies Directed Acyclic Graphs (DAGs) to map the causal pathways between infrastructure development and household welfare, identifying key mediators and confounders for one such initiative in Ghana. Then, using Generalized Propensity Score (GPS) and Doubly Robust Estimation (IPWRA), this study evaluates the differential roles of government-supported infrastructure improvements in access and intensity of commercial relative to public infrastructure, on household food security and women’s nutritional diversity given three major value-chain improvements. The main findings suggest that these infrastructure improvements positively impact food security and nutrition, with women’s empowerment and nutritional education acting as key mediators. Market access emerged as a stronger causal mechanism relative to productivity gains in linking infrastructure to improved welfare. Membership in Farmer-Based Organizations (FBOs) and participation in agribusiness linkages further amplified these impacts. However, the effects of infrastructure improvements were less clear when combined with the adoption of climate resilience practices, suggesting potential trade-offs.

Keywords: food security, nutrition, infrastructure, market access, women's empowerment, farmer-based organizations, climate resilience, Ghana

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Authors: Christiana Frimpong, Mpundu Makasa, Lungowe Sitali, Charles Michelo

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Background: Toxoplasmosis is a neglected zoonotic disease which is prevalent among pregnant women especially in Africa. This study aimed to determine the seroprevalence and determinants of the disease among pregnant women attending the antenatal clinic at the University Teaching Hospital (UTH). Method: A cross-sectional study was employed where 411 pregnant women attending the antenatal clinic at UTH were interviewed using closed-ended questionnaires. Their blood was also tested for Toxoplasma gondii IgG and IgM antibodies using the OnSite Toxo IgG/IgM Combo Rapid Test cassettes by CTK Biotech, Inc, USA. Result: The overall seroprevalence of the infection (IgG) was 5.87%. There was no seropositive IgM result. Contact with cats showed 7.81 times the risk of contracting the infection in the pregnant women and being a farmer/being involved in construction work showed 15.5 times likelihood of contracting the infection. Socio-economic status of the pregnant women also presented an inverse relationship (showed association) with the infection graphically. However, though there were indications of the association between contact with cats, employment type as well as the socioeconomic status of the pregnant women with the infection, there was not enough evidence to suggest these factors as significant determining factors of Toxoplasma gondii infection in our study population. Conclusion: There is a low prevalence of Toxoplasma gondii infection among pregnant women in Lusaka, Zambia. Screening for the infection among pregnant women can be done once or twice during pregnancy to help protect both mother and child from the disease. Health promotion among women of child bearing age on the subject is of immense importance in order to help curb the situation. Further studies especially that of case-control and cohort studies should be carried out in the country in order to better ascertain the extent of the condition nationwide.

Keywords: determinants, pregnant women, seroprevalence, toxoplasmosis, University Teaching Hospital (UTH), Zambia

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Authors: Arefeh Sabzipour

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In the present work, the effect of Lepidium meyenii on viability, motility, and sperm morphology in the treatment of infertility of adult male Wistar rats was evaluated. 21 male Wistar rats were adopted, fed and brought up in the same conditions to reach the weight of 230±5 g. after that, they were randomly divided into three groups, including two experimental groups and one control group, each group consisted of 7 rates. Lepidium meyenii was extracted and pulverized. Mice in the control group were treated with distilled water, and experimental groups were gavage with alcoholic juice extracted from Lepidium meyenii once a day for 10 consecutive days. After rates were killed, the testes were isolated. Different parameters includes semen volume in mice, sperm count, sperm motility, morphology, and viability, were evaluated. The results shows that sperm motility and sperm survival indices were significantly different between groups, and sperm count and sperm morphology indices were not significantly different. Sperm motility index in intervention group 1 was equal to 77.00±2.499 and was significantly higher than the one in intervention group two (70.14±3.579, P=0.018) and control group (69.43 ±7.323, P=0.018). Sperm survival index was 91.14 ± 2.410 in intervention group 1, 79.43± 5.062 in intervention group 2, and 76.71.6.651 in the control group (P<0.001). Based on the results of the present study, Lepidium meyenii had great effect on improving sperm indices of mice, especially sperm motility index and sperm survival index. Sperm count index and sperm morphology index, although increased, were not statistically significant.

Keywords: infertility, lepidium, sperm morphology, sperm survival

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Authors: Zahreddine Hafsi, Manoranjan Mishra , Sami Elaoud

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Ensuring the maximum recovery rate of oil from reservoir rocks is a challenging task that requires preliminary numerical analysis of different techniques used to enhance the recovery process. After conventional oil recovery processes and in order to retrieve oil left behind after the primary recovery phase, water flooding in one of several techniques used for enhanced oil recovery (EOR). In this research work, EOR via water flooding is numerically modeled, and hydrodynamic instabilities resulted from immiscible oil-water flow in reservoir rocks are investigated. An oil reservoir is a porous medium consisted of many fractures of tiny dimensions. For modeling purposes, the oil reservoir is considered as a collection of capillary tubes which provides useful insights into how fluids behave in the reservoir pore spaces. Equations governing oil-water flow in oil reservoir rocks are developed and numerically solved following a finite element scheme. Numerical results are obtained using Comsol Multiphysics software. The two phase Darcy module of COMSOL Multiphysics allows modelling the imbibition process by the injection of water (as wetting phase) into an oil reservoir. Van Genuchten, Brooks Corey and Levrett models were considered as retention models and obtained flow configurations are compared, and the governing parameters are discussed. For the considered retention models it was found that onset of instabilities viz. fingering phenomenon is highly dependent on the capillary pressure as well as the boundary conditions, i.e., the inlet pressure and the injection velocity.

Keywords: capillary pressure, EOR process, immiscible flow, numerical modelling

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Authors: Shishir Lamichhane, Saurav Dulal, Bibek Gautam, Madan Thapa Magar, Indraman Tamrakar

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Renewable energies such as wind turbines and solar photovoltaic have gained significance as a result of global environmental pollution and energy crises. These sources of energy are converted into electrical energy and delivered to end-users through the utility system. As a result of the widespread use of power electronics-based grid-interfacing technologies to accommodate renewable sources of energy, the prevalence of converters has expanded as well. As a result, the power system's rotating inertia is decreasing, endangering the utility grid's stability. The use of Virtual Synchronous Machine (VSM) technology has been proposed to overcome the grid stability problem due to low rotating inertia. The grid-connected inverter used in VSM can be controlled to emulate inertia, which replicates the external features of a synchronous generator. As a result, the rotating inertia is increased to support the power system's stability. A power angle control strategy is proposed in this paper and its model is simulated in MATLAB/Simulink to study the effects of parameter disturbances on the active power and frequency for a VSM. The system consists of a synchronous generator, which is modeled in such a way that the frequency drops to an unacceptable region during transient conditions due to a lack of inertia when VSM is not used. Then, the suggested model incorporating VSM emulates rotating inertia, injecting a controllable amount of energy into the grid during frequency transients to enhance transient stability.

Keywords: damping constant, inertia–constant, ROCOF, transient stability, distributed sources

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Authors: T. N. Girish, B. E. Pradeep, Ravi Parkash

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Insects from tropical wet or dry seasons are likely to cope starvation stress through seasonal phenotypic plasticity in energy metabolites. Accordingly, we analyzed such plastic changes in Zaprionus indianus flies reared under wet or dry season-specific conditions; and also after adult acclimation at 32℃ for 1 to 6 days; and to low (40% RH) or high (70% RH) humidity. Both thermal or humidity acclimation revealed significant accumulation of body lipids for wet season flies but low humidity acclimation did not change the level of body lipids in dry season flies. Developmental and adult acclimation showed sex specific differences i.e., starvation resistance and body lipids were higher in the males of dry season but in females of wet season. We found seasonal and sex specific differences in the relative level for body lipids at death; and in the rates of accumulation or utilization of energy metabolites (body lipids, carbohydrates and proteins). Body lipids constitute the preferred energy source under starvation for flies of both the seasons. However, utilization of carbohydrates (~20% to 30%) and proteins (~20% to 25%) was evident only in dry season flies. Higher starvation resistance after thermal or humidity acclimation is achieved by increased accumulation of lipids. Adult acclimation of wet or dry season flies revealed plastic changes in mean daily fecundity despite reduction in fecundity under starvation. Thus, thermal or humidity induced plastic responses in body lipids support starvation resistance under wet or dry seasons.

Keywords: heat or humidity acclimation, plastic changes in body lipids and starvation resistance, tropical drosophilid, Wet- or Dry seasons, Zaprionus indianus

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