Search results for: Hail Region

Authors: S. Wakim, M. Nemer, B. Zeghondy, B. Ghannam, C. Bouallou

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Designing the optimal heat exchanger is still an essential objective to be achieved. Parametrical optimization involves the evaluation of the heat exchanger dimensions to find those that best satisfy certain objectives. This method contributes to an enhanced design rather than an optimized one. On the contrary, topology optimization finds the optimal structure that satisfies the design objectives. The huge development in metal additive manufacturing allowed topology optimization to find its way into engineering applications especially in the aerospace field to optimize metal structures. Using topology optimization in 3d heat and mass transfer problems requires huge computational time, therefore coupling it with CFD simulations can reduce this it. However, existed CFD models cannot be coupled with topology optimization. The CFD model must allow creating a uniform mesh despite the initial geometry complexity and also to swap the cells from fluid to solid and vice versa. In this paper, a porous media approach compatible with topology optimization criteria is developed. It consists of modeling the fluid region of the heat exchanger as porous media having high porosity and similarly the solid region is modeled as porous media having low porosity. The switching from fluid to solid cells required by topology optimization is simply done by changing each cell porosity using a user defined function. This model is tested on a plate and fin heat exchanger and validated by comparing its results to experimental data and simulations results. Furthermore, this model is used to perform a material reallocation based on local criteria to optimize a plate and fin heat exchanger under a constant heat duty constraint. The optimized fin uses 20% fewer materials than the first while the pressure drop is reduced by about 13%.

Keywords: computational methods, finite element method, heat exchanger, porous media, topology optimization

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Authors: Anil Sharma, Ajay Kumar Mahur, R. G. Sonkawade, A. C. Sharma, R. Prasad

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In coal fired thermal power stations, large amount of fly ash is produced after burning of coal. Fly ash is spread and distributed in the surrounding area by air and may be deposited on the soil of the region surrounding the power plant. Coal contains increased levels of these radionuclides and fly ash may increase the radioactivity in the soil around the power plant. Radon atoms entering into the pore space from the mineral grain are transported by diffusion and advection through this space until they in turn decay or are released into the atmosphere. In the present study, Soil samples were collected from the region around a Kasimpur Thermal Power Plant, Kasimpur, Aligarh (U.P.). Radon activity, radon surface exhalation and mass exhalation rates were measured using “sealed can technique” using LR 115-type II nuclear track detectors. Radon activities vary from 92.9 to 556.8 Bq m-3 with mean value of 279.8 Bq m-3. Surface exhalation rates (EX) in these samples are found to vary from 33.4 to 200.2 mBq m-2 h-1 with an average value of 100.5 mBq m-2 h-1 whereas, Mass exhalation rates (EM) vary from 1.2 to 7.7 mBq kg-1 h-1 with an average value of 3.8 mBq kg-1 h-1. Activity concentrations of radionuclides were measured in these samples by using a low level NaI (Tl) based gamma ray spectrometer. Activity concentrations of 226Ra 232Th and 40K vary from 12 to 49 Bq kg-1, 24 to 49 Bq kg-1 and 135 to 546 Bq kg-1 with overall mean values of 30.3 Bq kg-1, 38.5 Bq kg-1 and 317.8 Bq kg-1, respectively. Radium equivalent activity has been found to vary from 80.0 to 143.7 Bq kg-1 with an average value of 109.7 Bq kg-1. Absorbed dose rate varies from 36.1 to 66.4 nGy h-1 with an average value of 50.4 nGy h-1 and corresponding outdoor annual effective dose varies from 0.044 to 0.081 mSv with an average value of 0.061 mSv. Values of external and internal hazard index Hex, Hin in this study vary from 0.21 to 0.38 and 0.27 to 0.50 with an average value of 0.29 and 0.37, Respectively. The results will be discussed in light of various factors.

Keywords: natural radioactivity, radium equivalent activity, absorbed dose rate, gamma ray spectroscopy

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Authors: Nour Mohamad Fayad

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Complex and extensively researched, the impact of corruption on economic growth seems to be intricate. Many experts believe that corruption reduces economic development. However, counterarguments have suggested that corruption either promotes growth and development or has no significant impact on economic performance. Clearly, there is no consensus in the economics literature regarding the possible relationship between corruption and economic development. Corruption's complex and clandestine nature, which makes it difficult to define and measure, is one of the obstacles that must be overcome when investigating its effect on an economy. In an attempt to contribute to the ongoing debate, this study examines the impact of corruption on economic growth in the Middle East and North Africa (MENA) region between 2000 and 2021 using a Customized Corruption Index-CCI and panel data on MENA countries. These countries were selected because they are understudied in the economic literature, and despite the World Bank's recent emphasis on corruption in the developing world, the MENA countries have received little attention. The researcher used Cobb-Douglas functional form to test corruption in MENA using a customized index known as Customized Corruption Index-CCI to track corruption over almost 20 years, then used the dynamic panel data. The findings indicate that there is a positive correlation between corruption and economic growth, but this is not consistent across all MENA nations. First, the relatively recent lack of data from MENA nations. This issue is related to the inaccessibility of data for many MENA countries, particularly regarding the returns on resources, private malfeasance, and other variables in Gulf countries. In addition, the researcher encountered several restrictions, such as electricity and internet outages, due to the fact that he is from Lebanon, a country whose citizens have endured difficult living conditions since the Lebanese crisis began in 2019. Demonstrating a customized index known as Customized Corruption Index-CCI that suits the characteristics of MENA countries to peculiarly measure corruption in this region, the outcome of the Customized Corruption Index-CCI is then compared to the Corruption Perception Index-CPI and Control of Corruption from World Governance Indicator-CC from WGI.

Keywords: corruption, economic growth, corruption measurements, empirical review, impact of corruption

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Authors: Pilly Kagosi, Cherestino Balama

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Beekeeping plays major role in improving biodiversity, increasing household income, and crop production through pollination. Tobacco farming is also the main source of household income for smallholder farmers. In Kigoma, production of Tobacco has increased and is perceived to threaten honey quality. The study explored the perception of the community on quality of honey in tobacco and non tobacco growing areas. The study was conducted in Kigoma Region, Tanzania. District and Villages were purposively sampled based on large numbers of people dealing with beekeeping activities and tobacco farming. Socioeconomic data were collected and analysed using Statistical Package for Social Sciences and content analysis. The perception of stakeholders on honey quality was analysed using Likert scale. Majority of the respondents agreed that tobacco farming greatly affects honey quality because honey from beehives near tobacco farms test bitter and sometimes irritating, which was associated with nicotine content and agrochemicals applied to tobacco crops. Though they cannot differentiate honey bitterness from agrochemicals and bee fodders. Furthermore, it was revealed that chemicals applied to tobacco and vegetables have negative effect on the bees and honey quality. Respondents believe that setting bee hives near tobacco farms might contaminate honey and therefore affect its quality. Beekeepers are not aware of the nicotine content from other bee fodders like miombo of which do not have any effect on human beings. Actually, tobacco farming does not affect beekeeping activities in issue of quality when farmers follow proper management of tobacco flowers and proper handling of honey. Though, big challenge in tobacco farming is chemically applied to the crops and harvest bee fodders for curing tobacco. The study recommends training to community on proper management of tobacco and proper handling of bee products.

Keywords: community, honey, perceptions, tobacco

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Authors: A. D. Rao, Sachiko Mohanty, R. Gayathri, V. Ranga Rao

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Modeling on coupled physical and biogeochemical processes of coastal waters is vital to identify the primary production status under different natural and anthropogenic conditions. About 7, 500 km length of Indian coastline is occupied with number of semi enclosed coastal bodies such as estuaries, inlets, bays, lagoons, and other near shore, offshore shelf waters, etc. This coastline is also rich in wide varieties of ecosystem flora and fauna. Directly/indirectly extensive domestic and industrial sewage enter into these coastal water bodies affecting the ecosystem character and create environment problems such as water quality degradation, hypoxia, anoxia, harmful algal blooms, etc. lead to decline in fishery and other related biological production. The present study is focused on the southeast coast of India, starting from Pulicat to Gulf of Mannar, which is rich in marine diversity such as lagoon, mangrove and coral ecosystem. Three dimensional Massachusetts Institute of Technology general circulation model (MITgcm) along with Darwin biogeochemical module is configured for the western Bay of Bengal (BoB) to study the biogeochemistry over this region. The biogeochemical module resolves the cycling of carbon, phosphorous, nitrogen, silica, iron and oxygen through inorganic, living, dissolved and particulate organic phases. The model domain extends from 4°N-16.5°N and 77°E-86°E with a horizontal resolution of 1 km. The bathymetry is derived from General Bathymetric Chart of the Oceans (GEBCO), which has a resolution of 30 sec. The model is initialized by using the temperature, salinity filed from the World Ocean Atlas (WOA2013) of National Oceanographic Data Centre with a resolution of 0.25°. The model is forced by the surface wind stress from ASCAT and the photosynthetically active radiation from the MODIS-Aqua satellite. Seasonal climatology of nutrients (phosphate, nitrate and silicate) for the southwest BoB region are prepared using available National Institute of Oceanography (NIO) in-situ data sets and compared with the WOA2013 seasonal climatology data. The model simulations with the two different initial conditions viz., WOA2013 and the generated NIO climatology, showed evident changes in the concentration and the evolution of the nutrients in the study region. It is observed that the availability of nutrients is more in NIO data compared to WOA in the model domain. The model simulated primary productivity is compared with the spatially distributed satellite derived chlorophyll data and at various locations with the in-situ data. The seasonal variability of the model simulated primary productivity is also studied.

Keywords: Bay of Bengal, Massachusetts Institute of Technology general circulation model, MITgcm, biogeochemistry, primary productivity

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Authors: Merih Welay Welesilassie

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Language is a potent instrument that does not only serve the purpose of communication but also plays a pivotal role in shaping our cultural practices and identities. The right to choose one's language is a fundamental human right that helps to safeguard the integrity of both personal and communal identities. Language holds immense significance in Ethiopia, a nation with a diverse linguistic landscape that extends beyond mere communication to delineate administrative boundaries. Consequently, depriving Ethiopians of their linguistic rights represents a multifaceted punishment, more complex than food embargoes. In the aftermath of the civil war that shook Ethiopia in November 2020, displacing millions and resulting in the loss of hundreds of thousands of lives, concerns have been raised about the preservation of the indigenous Tigrayan language and culture. This is particularly true following the annexation of western Tigray into the Amhara region and the implementation of an Amharic-only language and culture education policy. This scholarly inquiry explores the intricacies surrounding the Amhara regional state's prohibition of Tigrayans' indigenous language and culture and the subsequent adoption of a monolingual and monocultural Amhara language and culture in western Tigray. The study adopts the linguistic genocide conceptual framework as an analytical tool to gain a deeper insight into the factors that contributed to and facilitated this significant linguistic and cultural shift. The research was conducted by interviewing ten teachers selected through a snowball sampling. Additionally, document analysis was performed to support the findings. The findings revealed that the push for linguistic and cultural assimilation was driven by various political and economic factors and the desire to promote a single language and culture policy. This process, often referred to as ‘Amharanization,’ aimed to homogenize the culture and language of the society. The Amhara authorities have enacted several measures in pursuit of their objectives, including the outlawing of the Tigrigna language, punishment for speaking Tigrigna, imposition of the Amhara language and culture, mandatory relocation, and even committing heinous acts that have inflicted immense physical and emotional suffering upon members of the Tigrayan community. Upon conducting a comprehensive analysis of the contextual factors, actions, intentions, and consequences, it has been posited that there may be instances of linguistic genocide taking place in the Western Tigray region. The present study sheds light on the severe consequences that could arise because of implementing monolingual and monocultural policies in multilingual areas. Through thoroughly scrutinizing the implications of such policies, this study provides insightful recommendations and directions for future research in this critical area.

Keywords: linguistic genocide, linguistic human right, mother tongue, Western Tigray

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Authors: Aslihan Caliskan

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The term Mediterranean comes from the Latin “mediterraneus” (Medius, "middle" plus Terra, "land, earth"). For the ancient Romans, the Mediterranean was the center of the earth as they knew it. The desire to gain control of the Mediterranean has led to disputes between many nations throughout history, some of which continue to this day. The recent major natural gas discoveries in the Mediterranean have aggravated ongoing tensions in some neighboring countries. The sea border dispute between Turkey and Greece & Greek-Cypriot side is one of the most critical conflicts in the Mediterranean Sea region. This unresolved dispute has many implications for all countries involved, as well as for third parties that have direct or indirect interests in the region. The research question of this context is what are the implications of this controversial sea border problem on the maritime security of Turkey and its military spending. In this paper, the quantitative method is used. Records from the Turkish Defense Ministry, data from the Turkish naval forces have been obtained. In addition, literature research and the United Nations Convention on the Law of the Sea (UNCLOS) application cases were evaluated, and an incident analysis was carried out. This research shows that the sea border dispute issue has a significant impact on the Turkish military both in terms of the structures required to ensure maritime and border security, as well as rising military costs and its macroeconomic implications. The paper begins with a brief overview of relevant principles and methods applied for delimiting th esea borders. The paper continues with a brief description and a background of the sea border dispute between Turkey and Greece & Greek-Cypriot side in the light of the United Nations Convention on the Law of the Sea (UNCLOS). An analysis of the implications of the dispute on Turkey’s maritime security and its military spending is provided in the following chapters. The paper ends with concluding remarks of the author, including suggestions for the way forward.

Keywords: sea border security, mediterranean sea, greece-turkey dispute, limitation of sea, united nations convention on the law of the sea (UNCLOS)

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Authors: Benhammadi Hocine, Fehdi Chemseddine, Chaffai Hicham

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The study site is the plateau Cheria, a city in south eastern Algeria (Tebessa) thanks to its structure perched syncline is the region of Tebessa a real water tower. Special rates provided by some boreholes and wells around the city Cheria have long been led to believe that the reserves were virtually limitless. The investigations carried out in this region have located karstified limestone areas at depth of 100 meters of the carbonate formation. During the last two decades a rainfall deficit has increased the effect of drought has caused an increase in flow from this aquifer. The effect on water resources is a significant and progressive reduction of the static level of the karst aquifer. The qualitative aspect has also been marked by degradation. This climate variability marked by the decade of drought (1990/2000) has had the effect on the local population, a forced change of their activity primarily agricultural. Abandoning agro pastoral mode due to prolonged drought, populations chose agriculture maraichère consumer a lot of water, this increasing the depletion of water resources. This change in activity was accompanied by a rural exodus to urban areas. The result has led to an increase in population in the urban areas, this has resulted in an increase in water demand and an increase in emissions (waste water). Uncontrolled discharges contribute to pollute a little more groundwater. The second consequence is type Geotechnical, it is the appearance of sinkholes, results of the alternating periods of drought and violent floods. Sinkholes are a real concern for the management and urban development. An interdisciplinary contribution (geology, hydrology, climatology and management) is essential to reduce or avoid impacts in different sectors.

Keywords: aquifer, carbonate formation, drought, exodus, resources, chéria, Algéria

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Authors: Atinder Pal Kaur

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A central characteristic of people is their apparent movement from one station to other for their sustenance. Human migration has become one of the most challenging issues faced by the world today. Migration represents an important dimension in world-wide setting; and remittances received by families constitute a major agent in integrating societies in the all over the world, both economically and socially. This paper is an attempt to explore the impact of male migration and remittances upon the family system. This paper brings out how the women play the role of head of the household and take all the economic decisions, but still faces discrimination in the family, that bring loneliness and emotional breakdown on their personal front. For the purpose of this study, data was collected using 30 interviews and 10 case studies in the Doaba region of Punjab. The respondents were classified into two age groups 20-35 years and above 40 years aged women whose husbands migrated abroad. The findings of this study revealed that even though the women were taking some of the economic decisions, but in majority of the cases the patriarchal structure still existed and power remained in the hands of their husbands or in-laws. It was found that women of different age groups reported differently in terms of authority that they have regarding remittances and its consequences in their emotional well-being. The distinction related to their participation in public and private spheres still exists and public spheres are mostly dominated by male members of the family. It can be concluded that freedom of women to take decision on their own is still restricted and they are subjugated to follow their husband or in-law’s opinion in matters related to both public and private spheres. However, old age group women enjoyed more independence and freedom to take decision in comparison to young age women. Loneliness and depression were more common in the young age respondent’s group than in old age women.

Keywords: gender discrimination, migration, patriarchal structure, remittances

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Authors: Ayla Hoeta, Holly Winton

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Maramataka is an ancestral lunar environmental knowledge system based on environmental tohu (signs, observations or indicators), that continues to impart maatauranga (knowledge) to tangata whenua, people of the land after thousands of years. Maramataka is the mauri (energy) flow between whenua (land), moana (water) and rangi (sky), experienced through tirotiro (observing), connecting and attuning to the natural environment. Tohu serve as guidance to practises of kaiawhina (protection) a key value driving Aotearoa New Zealand led research in Antarctica. Recent developments recognise the importance of including and integrating indigenous knowledge and perspectives such as maatauranga Maaori which can provide insights into the conservation of Antarctica. We use an ancient kaupapa Maaori framework of weaving, wayfinding and attunement to navigate complexities using Hautu Waka. We investigate and weave together learnings from Antarctic and western science and indigenous Maaori maatauranga and tohu of moana, whenua and rangi to provide an indigenous perspective of Antarctica taiao and Maramataka. Drawing on past and present knowledge of environmental calendars contained in maatauranga Maaori and paleoclimate knowledge bases, field observations, interviews and whakataukii (proverbs), we aim to provide a conceptual Maramataka of the southwestern Ross Sea region and area of Antarctica. A key area of interest are the tohu related to the marama which are connected to all three interweaving spheres of moana, rangi, whenua. Maatauranga Maramataka in Aotearoa has been developed over millennia and we acknowledge the mana and sacredness of this tupuna knowledge and that this conceptual Maramataka serves as the starting point of a journey to shine light on indigenous perspectives using Maaori methods and frameworks in a dominant western science paradigm.

Keywords: Maramataka, Antarctica, Aotearoa, Maaori, tohu, moon, lunar calendar

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Authors: Xuerui Niu, Bolin Wang, Xinchuang Zhang, Xiaohua Ma, Bin Hou, Ling Yang

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The application of discrete GaN-based power switches requires the collaboration of silicon-based peripheral circuit structures. However, the packages and interconnection between the Si and GaN devices can introduce parasitic effects to the circuit, which has great impacts on GaN power transistors. GaN-based monolithic power integration technology is an emerging solution which can improve the stability of circuits and allow the GaN-based devices to achieve more functions. Complementary logic circuits consisting of GaN-based E-mode p-channel heterostructure field-effect transistors (p-HFETs) and E-mode n-channel HEMTs can be served as the gate drivers. E-mode p-HFETs with recessed gate have attracted increasing interest because of the low leakage current and large gate swing. However, they suffer from a poor interface between the gate dielectric and polarized nitride layers. The reliability of p-HFETs is analyzed and discussed in this work. In circuit applications, the inverter is always operated with dynamic gate voltage (VGS) rather than a constant VGS. Therefore, dynamic electrical stress has been simulated to resemble the operation conditions for E-mode p-HFETs. The dynamic electrical stress condition is as follows. VGS is a square waveform switching from -5 V to 0 V, VDS is fixed, and the source grounded. The frequency of the square waveform is 100kHz with the rising/falling time of 100 ns and duty ratio of 50%. The effective stress time is 1000s. A number of stress tests are carried out. The stress was briefly interrupted to measure the linear IDS-VGS, saturation IDS-VGS, As VGS switches from -5 V to 0 V and VDS = 0 V, devices are under negative-bias-instability (NBI) condition. Holes are trapped at the interface of oxide layer and GaN channel layer, which results in the reduction of VTH. The negative shift of VTH is serious at the first 10s and then changes slightly with the following stress time. However, different phenomenon is observed when VDS reduces to -5V. VTH shifts negatively during stress condition, and the variation in VTH increases with time, which is different from that when VDS is 0V. Two mechanisms exists in this condition. On the one hand, the electric field in the gate region is influenced by the drain voltage, so that the trapping behavior of holes in the gate region changes. The impact of the gate voltage is weakened. On the other hand, large drain voltage can induce the hot holes generation and lead to serious hot carrier stress (HCS) degradation with time. The poor-quality interface between the oxide layer and GaN channel layer at the gate region makes a major contribution to the high-density interface traps, which will greatly influence the reliability of devices. These results emphasize that the improved etching and pretreatment processes needs to be developed so that high-performance GaN complementary logics with enhanced stability can be achieved.

Keywords: GaN-based E-mode p-HFETs, dynamic electric stress, threshold voltage, monolithic power integration technology

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Authors: Surajit Das Barman, Rakibuzzaman Shah, Apurv Kumar

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Bushfire is known as one of the ascendant factors to create pyrocumulus thundercloud that causes the ignition of new fires by pyrocumulonimbus (pyroCb) lightning strikes and creates major losses of lives and property worldwide. A conceptual model-based risk planning would be beneficial to predict the lightning striking zones on the surface of the earth underneath the pyroCb thundercloud. PyroCb thundercloud can generate both positive cloud-to-ground (+CG) and negative cloud-to-ground (-CG) lightning in which +CG tends to ignite more bushfires and cause massive damage to nature and infrastructure. In this paper, a simple line charge structured thundercloud model is constructed in 2-D coordinates using the method of image charge to predict the probable +CG lightning striking zones on the earth’s surface for two conceptual thundercloud charge configurations: titled dipole and conventional tripole structure with excessive lower positive charge regions that lead to producing +CG lightning. The electric potential and surface charge density along the earth’s surface for both structures via continuously adjusting the position and the charge density of their charge regions is investigated. Simulation results for tilted dipole structure confirm the down-shear extension of the upper positive charge region in the direction of the cloud’s forward flank by 4 to 8 km, resulting in negative surface density, and would expect +CG lightning to strike within 7.8 km to 20 km around the earth periphery in the direction of the cloud’s forward flank. On the other hand, the conceptual tripole charge structure with enhanced lower positive charge region develops negative surface charge density on the earth’s surface in the range |x| < 6.5 km beneath the thundercloud and highly favors producing +CG lightning strikes.

Keywords: pyrocumulonimbus, cloud-to-ground lightning, charge structure, surface charge density, forward flank

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Authors: T. Radu, R. Sreenivas, H. Albuflasa, A. Mustafa Khan, W. Aloqab

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The Kingdom of Bahrain, a small island country in the Gulf region, is experiencing fast economic growth resulting in a sharp increase in population and greater than ever amounts of waste being produced. However, waste management in the country is still very basic, with landfilling being the most popular option. Recycling is still a scarce practice, with small recycling businesses and initiatives emerging in recent years. This scenario is typical for other countries in the region, with similar amounts of per capita waste being produced. In this paper, we are reviewing current waste management practices in Bahrain by collecting data published by the Government and various authors, and by visiting the country’s only landfill site, Askar. In addition, we have performed a survey of the residents to learn more about the awareness and attitudes towards sustainable waste management strategies. A review of the available data on waste management indicates that the Askar landfill site is nearing its capacity. The site uses open tipping as the method of disposal. The highest percentage of disposed waste comes from the building sector (38.4%), followed by domestic (27.5%) and commercial waste (17.9%). Disposal monitoring and recording are often based on estimates of weight and without proper characterization/classification of received waste. Besides, there is a need for assessment of the environmental impact of the site with systematic monitoring of pollutants in the area and their potential spreading to the surrounding land, groundwater, and air. The results of the survey indicate low awareness of what happens with the collected waste in the country. However, the respondents have shown support for future waste reduction and recycling initiatives. This implies that the education of local communities would be very beneficial for such governmental initiatives, securing greater participation. Raising awareness of issues surrounding recycling and waste management and systematic effort to divert waste from landfills are the first steps towards securing sustainable waste management in the Kingdom of Bahrain.

Keywords: landfill, municipal solid waste, survey, waste management

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Authors: Majid Dashtgerd, Eisa Moradi Afrapoli

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The “Yemen War” is one of the longest wars of the recent century, which was launched on 26 March 2015 after the Saudi Arabia-led alliance's military intervention in Yemen. The war began with the aim of fighting Yemen's Houthis and preventing Iranian influence in the region, and Saudi leaders expected a quick victory; However, the “Yemen War” lasted about seven years and is still going on (May 2022), and Saudi Arabia has not been able to achieve its strategic objectives. This study seeks to examine some of the most important reasons for Saudi Arabia's protracted war and failure in Yemen.

Keywords: Saudi Arabia, yemen war, houthis, Iran

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Authors: Maria Francesca Scannone, Martina Bochicchio

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One of the major environmental problems today is hydrocarbon contamination. The promising sustainable technologies for the treatment of these contaminated sites involves the use of biological organisms. In Agri Valley (Basilicata Region) there is a living laboratory (natural oil seeps) where the selective pressure has enriched the environmental matrices with microorganisms, fungi and plant species able to use the hydrocarbons as a source of metabolic energy, to degrade or tolerate hydrocarbons. Observers visiting this area are fascinated by its unspoiled nature, and the condition of the ecosystem does not appear to has been damaged. The amazing resiliency observed in Tramutola site is of key importance to try to bring green remediation technologies, but no research has been done to identify high-performing native species. The aim of this research was to study how natural processes affect the fate of released oil or how individual species or communities of plants and animals are capable of dealing with the burden of otherwise toxic chemicals. The survey of vegetation was carried out, more than 60 species have been identified and divided into tree, shrub and herb layer. Plant data sheets have been completed only for the species that showed the most appropriate properties for phytoremediation. In general, members of the Salicales, Cyperales, Poales, Fagales, Cornales, Equisetales orders were the most commonly identified orders. They are pioneer plants with high adaptive capacity and vegetative propagation. The literature review has highlighted the existence of rhizosphere effect and a green liver model on selected plants. The study provides significant information on the environmental stress adaptation processes of many indigenous plants that are living and growing on a natural leak of crude oil and gas that migrates up through subsurface.

Keywords: green liver, hydrocarbon degradation, oil seeps, phytoremediation

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Authors: Ayalew Yimam Ali

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The Y-shaped microchannel system is used to mix up low or high viscosities of different fluids, and the laminar flow with high-viscous water-glycerol fluids makes the mixing at the entrance Y-junction region a challenging issue. Acoustic streaming (AS) is time-average, a steady second-order flow phenomenon that could produce rolling motion in the microchannel by oscillating low-frequency range acoustic transducer by inducing acoustic wave in the flow field is the promising strategy to enhance diffusion mass transfer and mixing performance in laminar flow phenomena. In this study, the 3D trapezoidal Structure has been manufactured with advanced CNC machine cutting tools to produce the molds of trapezoidal structure with the 3D sharp edge tip angles of 30° and 0.3mm spine sharp-edge tip depth from PMMA glass (Polymethylmethacrylate) and the microchannel has been fabricated using PDMS (Polydimethylsiloxane) which could be grown-up longitudinally in Y-junction microchannel mixing region top surface to visualized 3D rolling steady acoustic streaming and mixing performance evaluation using high-viscous miscible fluids. The 3D acoustic streaming flow patterns and mixing enhancement were investigated using the micro-particle image velocimetry (μPIV) technique with different spine depth lengths, channel widths, high volume flow rates, oscillation frequencies, and amplitude. The velocity and vorticity flow fields show that a pair of 3D counter-rotating streaming vortices were created around the trapezoidal spine structure and observing high vorticity maps up to 8 times more than the case without acoustic streaming in Y-junction with the high-viscosity water-glycerol mixture fluids. The mixing experiments were performed by using fluorescent green dye solution with de-ionized water on one inlet side, de-ionized water-glycerol with different mass-weight percentage ratios on the other inlet side of the Y-channel and evaluated its performance with the degree of mixing at different amplitudes, flow rates, frequencies, and spine sharp-tip edge angles using the grayscale value of pixel intensity with MATLAB Software. The degree of mixing (M) characterized was found to significantly improved to 0.96.8% with acoustic streaming from 67.42% without acoustic streaming, in the case of 0.0986 μl/min flow rate, 12kHz frequency and 40V oscillation amplitude at y = 2.26 mm. The results suggested the creation of a new 3D steady streaming rolling motion with a high volume flow rate around the entrance junction mixing region, which promotes the mixing of two similar high-viscosity fluids inside the microchannel, which is unable to mix by the laminar flow with low viscous conditions.

Keywords: nano fabrication, 3D acoustic streaming flow visualization, micro-particle image velocimetry, mixing enhancement

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Authors: Ashneel Ajay Singh, Naoki Suzuki, Kazumi Sakuramoto, Swastika Roshni, Paras Nath, Alok Kalla

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Albacore tuna (Thunnus alalunga) is one of the commercially important species of tuna in the North Pacific region. Despite the long history of albacore fisheries in the Pacific, its ecological characteristics are not sufficiently understood. The effects of changing climate on numerous commercially and ecologically important fish species including albacore tuna have been documented over the past decades. The objective of this study was to explore and elucidate the relationship of environmental variables with the stock parameters of albacore tuna. The relationship of the North Pacific albacore tuna recruitment (R), spawning stock biomass (SSB) and recruits per spawning biomass (RPS) from 1970 to 2012 with the environmental factors of sea surface temperature (SST), Pacific decadal oscillation (PDO), El Niño southern oscillation (ENSO) and Pacific warm pool index (PWI) was construed. SST and PDO were used as independent variables with SSB to construct stock reproduction models for R and RPS as they showed most significant relationship with the dependent variables. ENSO and PWI were excluded due to collinearity effects with SST and PDO. Model selections were based on R2 values, Akaike Information Criterion (AIC) and significant parameter estimates at p<0.05. Models with single independent variables of SST, PDO, ENSO and PWI were also constructed to illuminate their individual effect on albacore R and RPS. From the results it can be said that SST and PDO resulted in the most significant models for reproducing North Pacific albacore tuna R and RPS time series. SST has the highest impact on albacore R and RPS when comparing models with single environmental variables. It is important for fishery managers and decision makers to incorporate the findings into their albacore tuna management plans for the North Pacific Oceanic region.

Keywords: Albacore tuna, El Niño southern oscillation, Pacific decadal oscillation, sea surface temperature

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Authors: Amr A. El Hanafy, Muhammad I. Qureshi, Jamal Sabir, Mohamed Mutawakil, Mohamed M. Ahmed, Hassan El Ashmaoui, Hassan Ramadan, Mohamed Abou-Alsoud, Mahmoud Abdel Sadek

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β-Lactoglobulin (β-LG) is the dominant non-casein whey protein found in bovine milk and of most ruminants. The amino acid sequence of β-LG along with its 3-dimensional structure illustrates linkage with the lipocalin superfamily. Preliminary studies in goats indicated that milk yield can be influenced by polymorphism in genes coding for whey proteins. The aim of this study is to identify and evaluate the incidence of functional polymorphisms in the exonic and intronic portions of β-LG gene in native Saudi goat breeds (Ardi, Habsi, and Harri). Blood samples were collected from 300 animals (100 for each breed) and genomic DNA was extracted using QIAamp DNA extraction Kit. A fragment of the β-LG gene from exon 7 to 3’ flanking region was amplified with pairs of specific primers. Subsequent digestion with Sac II restriction endonuclease revealed two alleles (A and B) and three different banding patterns or genotypes i.e. AA, AB and BB. The statistical analysis showed that β-LG AA genotype had higher milk yield than β-LG AB and β-LG BB genotypes. Nucleotide sequencing of the selected β-LG fragments was done and submitted to GenBank NCBI (Accession No. KJ544248, KJ588275, KJ588276, KJ783455, KJ783456 and KJ874959). Two already established SNPs in exon 7 (+4601 and +4603) and one fresh SNP in the 3’ UTR region were detected in the β-LG fragments with designated AA genotype. The polymorphisms in exon 7 did not produce any amino acid change. Phylogenetic analysis on the basis of nucleotide sequences of native Saudi goats indicated evolutional similarity with the GenBank reference sequences of goat, Bubalus bubalis and Bos taurus.

Keywords: β-Lactoglobulin, Saudi goats, PCR-RFLP, functional polymorphism, nucleotide sequencing, phylogenetic analysis

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Authors: David B. Tsuanyo, Didier Aussel, Yao Azoumah, Pierre Neveu

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An innovative concept called “Flexy-Energy”is developing at 2iE. This concept aims to produce electricity at lower cost by smartly mix different available energies sources in accordance to the load profile of the region. With a higher solar irradiation and due to the fact that Diesel generator are massively used in sub-Saharan rural areas, PV/Diesel hybrid systems could be a good application of this concept and a good solution to electrify this region, provided they are reliable, cost effective and economically attractive to investors. Presentation of the developed approach is the aims of this paper. The PV/Diesel hybrid system designed consists to produce electricity and/or heat from a coupling between Diesel gensets and PV panels without batteries storage, while ensuring the substitution of gasoil by bio-fuels available in the area where the system will be installed. The optimal design of this system is based on his technical performances; the Life Cycle Cost (LCC) and Levelized Cost of Energy are developed and use as economic criteria. The Net Present Value (NPV), the internal rate of return (IRR) and the discounted payback (DPB) are also evaluated according to dual electricity pricing (in sunny and unsunny hours). The PV/Diesel hybrid system obtained is compared to the standalone Diesel gensets. The approach carried out in this paper has been applied to Siby village in Mali (Latitude 12 ° 23'N 8 ° 20'W) with 295 kWh as daily demand. This approach provides optimal physical characteristics (size of the components, number of component) and dynamical characteristics in real time (number of Diesel generator on, their load rate, fuel specific consumptions, and PV penetration rate) of the system. The system obtained is slightly cost effective; but could be improved with optimized tariffing strategies.

Keywords: investments criteria, optimization, PV hybrid, sizing, rural electrification

Procedia PDF Downloads 441

Authors: Marcin Jakiel, Maria Kurek, Karolina Gutkowska, Sylwia Sanakiewicz, Dominika Stolarczyk, Jakub Batko, Rafał Jakiel, Mateusz K. Hołda

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The geometry of RVOT is extremely complicated. It is an irregular block with an ellipsoidal cross-section, whose dimensions decrease toward the pulmonary valve and measure 33.82 (IQR 30,51-39,36), 28.82 (IQR 26,11-32,22), 27.95 ± 4,11 for width [mm] and 33.41 ± 6,14, 26.99 ± 4,41, 26.91 ± 4,00 [mm] for depth, in the basal, middle and subpulmonary parts, respectively. In a sagittal section view, the RVOT heads upward and slightly backward. Its anterior perimeter has an average length of 41.96 mm and inclines to the transverse plane at an angle of 50.77° (IQR 46,53°-58,70°). In the posterior region, the RVOT is shorter (18.17mm) and flexes anteriorly. Therefore, the slope of the upper part of the rear wall to the transverse plane is an acute angle (open toward the rear) of 44,58° (IQR 37,30°-51,25°), while in the lower part it is an angle close to a right angle of 94,30°±15,44°. In addition, the thickness of the RVOT wall in the diastolic phase, at the posterior perimeter at the base, in the middle of the length and subpulmonary measure 3,80 mm ± 0,88 mm, 3,56 mm ± 0,73 mm, 3,56 mm ± 0,65 mm, respectively. In frontal cross-section, the RVOT rises on the interventricular septum, which makes it possible to distinguish the septal and supraseptal parts on its left periphery. The angles (facing the vertices to the right) of the inclination of these parts to the transverse plane are 75.5° (IQR 66,44°-81,11°) and 107.01° (IQR 99,09 – 115,23°), respectively, which allows us to conclude that the direction of the RVOT long axis changes from left to right. The above analysis shows that there is no single RVOT axis. Two axes can be distinguished, the one for the upper RVOT being more backward and leftward. The aforementioned forward deflection of the posterior wall and the RVOT's elevation over the interventricular septum, suggest that access to the subpulmonary region may be difficult. It should be emphasized that this area is often the target for ablation of ventricular arrhythmias. The small thickness of the RVOT posterior wall, with its difficult geometry, may favor its perforation into the pericardium or ascending aorta.

Keywords: angle, geometry, operation access, position, RVOT, shape

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Authors: A. Ribeiro, N. Valério, C. Vilarinho, J. Araujo, J. Carvalho

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Res2ValHUM project involves institutions from the Spanish Autonomous Region of Galicia and the north of Portugal (districts of Porto and Braga) and has as overall objectives of promotion of composting as an process for the correct managing of organic waste, valorization of compost in different fields or applications for the constitution of products with high added value, reducing of raw materials losses, and reduction of the amount of waste throw in landfills. Three main actions were designed to achieve the objectives: development of a management tool to improve collection and residue channeling for composting, sensibilization of the population for composting and characterization of the chemical and biological properties of compost and humic and fulvic substances to envisage high-value applications of compost. Here we present the cooperative activity of Galician and northern Portuguese institutions to valorize organic waste in both regions with common socio-economic characteristics and residue management problems. Results from the creation of the resource manage tool proved the existence of a large number of agricultural wastes that could be valorized. In the North of Portugal, the wastes from maize, oats, potato, apple, grape pomace, rye, and olive pomace can be highlighted. In the Autonomous Region of Galicia the wastes from maize, wheat, potato, apple, and chestnuts can be emphasized. Regarding the isolation and identification of microbial consortia from compost samples, results proved microorganisms belong mainly to the genus Bacillus spp. Among all the species identified in compost samples, Bacillus licheniformis can be highlighted in the production of humic and fulvic acids.

Keywords: agricultural wastes, Bacillus licheniformis, Bacillus spp., humic-acids, fulvic-acids

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Authors: Dehni Abdellatif, Lounis Mourad

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The new approach of applied spatial geostatistics in materials sciences, agriculture accuracy, agricultural statistics, permitted an apprehension of managing and monitoring the water and groundwater qualities in a relationship with salt-affected soil. The anterior experiences concerning data acquisition, spatial-preparation studies on optical and multispectral data has facilitated the integration of correction models of electrical conductivity related with soils temperature (horizons of soils). For tomography apprehension, this physical parameter has been extracted from calibration of the thermal band (LANDSAT ETM+6) with a radiometric correction. Our study area is Oran region (Northern West of Algeria). Different spectral indices are determined such as salinity and sodicity index, the Combined Spectral Reflectance Index (CSRI), Normalized Difference Vegetation Index (NDVI), emissivity, Albedo, and Sodium Adsorption Ratio (SAR). The approach of geostatistical modeling of electrical conductivity (salinity), appears to be a useful decision support system for estimating corrected electrical resistivity related to the temperature of surface soils, according to the conversion models by substitution, the reference temperature at 25°C (where hydrochemical data are collected with this constraint). The Brightness temperatures extracted from satellite reflectance (LANDSAT ETM+) are used in consistency models to estimate electrical resistivity. The confusions that arise from the effects of salt stress and water stress removed followed by seasonal application of the geostatistical analysis in Geographic Information System (GIS) techniques investigation and monitoring the variation of the electrical conductivity in the alluvial aquifer of Es-Sénia for the salt-affected soil.

Keywords: geostatistical modelling, landsat, brightness temperature, conductivity

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Authors: L. C. Ansanelli, P. Alfredini

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The article presents the evaluation of the effectiveness of two groins located at Gonzaguinha and Milionários Beaches, situated on the southeast coast of Brazil. The effectiveness of these coastal defense structures is evaluated in terms of sedimentary dynamics, which is one of the most important environmental processes to be assessed in coastal engineering studies. The applied method is based on the implementation of the Delft3D numerical model system tools. Delft3D-WAVE module was used for waves modelling, Delft3D-FLOW for hydrodynamic modelling and Delft3D-SED for sediment transport modelling. The calibration of the models was carried out in a way that the simulations adequately represent the region studied, evaluating improvements in the model elements with the use of statistical comparisons of similarity between the results and waves, currents and tides data recorded in the study area. Analysis of the maximum wave heights was carried to select the months with higher accumulated energy to implement these conditions in the engineering scenarios. The engineering studies were performed for two scenarios: 1) numerical simulation of the area considering only the two existing groins; 2) conception of breakwaters coupled at the ends of the existing groins, resulting in two “T” shaped structures. The sediment model showed that, for the simulated period, the area is affected by erosive processes and that the existing groins have little effectiveness in defending the coast in question. The implemented T structures showed some effectiveness in protecting the beaches against erosion and provided the recovery of the portion directly covered by it on the Milionários Beach. In order to complement this study, it is suggested the conception of further engineering scenarios that might recover other areas of the studied region.

Keywords: coastal engineering, coastal erosion, Sao Vicente bay, Delft3D, coastal engineering works

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Authors: Koyar Rane

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Nano- to submicron size particles of narrow particle size distribution of semi-conducting TiO₂, ZnO, NiO, CuO, Fe₂O₃ have been synthesized by novel hydrazine method and tested for their gas sensing, photocatalytic and bactericidal activities and the behavior found to be enhanced when the oxides in the thin film forms, that obtained in a specially built spray pyrolysis reactor. Hydrazine method is novel in the sense, say, the UV absorption edge of the white pigment grade wide band gap (~3.2eV) TiO₂ and ZnO shifted to the visible region turning into yellowish particles, indicating modification occurring the band structure. The absorption in the visible region makes these oxides visible light sensitive photocatalysis in degrading pollutants, especially the organic dyes which otherwise increase the chemical oxygen demand of the drinking water, enabling the process feasible not under the harsh energetic UV radiation regime. The electromagnetic radiations on irradiation produce electron-hole pairs Semiconductor + hν → e⁻ + h⁺ The electron-hole pairs thus produced form Reactive Oxygen Species, ROS, on the surface of the semiconductors, O₂(adsorbed)+e⁻ → O₂• - superoxide ion OH-(surface)+h⁺ →•OH - Hydroxyl radical The ROS attack the organic material and micro-organisms. Our antibacterial studies indicate the metal oxides control the Biological Oxygen Demand (BOD) of drinking water which had beyond the safe level normally found in the municipal supply. Metal oxides in the thin film form show overall enhanced properties and the films are reusable. The results of the photodegradation and antibactericidal studies are discussed. Gas sensing studies too have been done to find the versatility of the multifunctional metal oxides.

Keywords: hydrazine method, visible light sensitive, photo-degradation of dyes, water/airborne pollutant

Procedia PDF Downloads 163

Authors: A. R. Shakura, A. B. Elistina, M. S. Aini, S. Norhasmah, A. Fakhru’l-Razi

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Tsunami 2004 was an unforeseeable event that caught Malaysia of guard resulting with 68 losses of lives and with an estimated economic loss of about 55.15billion US dollar. Scientists predict that if the earthquake epicentre originates from the Andaman-Nicobar region, the coastal population of Penang will have about 30 minutes to evacuate to safety. Thus, a study was conducted to enhance resiliency of Penang community as the area was the worst affected region during 2004 tsunami disaster. This paper is intended to examine the factors that influence intention to prepare for future tsunami among the coastal residence in Penang. The differences in the level of intention to prepare were also examined between those who experience and did not experience the 2004 tsunami. This study utilized a cross-sectional research design using a survey method. A total of 503 respondents were chosen systematically and data gathered were analysed using SPSS. Both genders, male and female were equally represented with a mean age of 44 years. Data indicated that the level of intention to prepare for tsunami disaster was moderate (M=3.72) with no significant difference in intention to prepare between those who had experienced or had not experienced the 2004 tsunami. Subsequently, results from a multiple regression analysis found that sense of community to be the most influential factor followed by subjective norm, trust, positive outcome expectancy and risk perception, explaining the 57% variance in intention to prepare. These factors reflect the influence of the collectivistic culture in Malaysia whereby households plus communities have a central role in encouraging each other. Therefore, the findings highlights the potential of adopting a community based disaster risk management as recommended by the United Nations International Strategy Disaster Reduction (UNISDR) which encompasses the cooperation between the local community and relevant stakeholders in preparing for future tsunami disaster.

Keywords: disaster management, experience, intention to prepare, tsunami

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Authors: Noor Abdelhamid

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Almost half of Cairo’s growing population is housed in self-built, self-governed informal settlements serving as an alternative in the absence of government-provided public housing. These settlements emerged as the spatial expression of informal practices or activities operating outside regulated, formal frameworks. A comprehensive narrative of political events, administrative decisions, and urban policies set the stage for the growth of informal expression in Egypt. The purpose of this qualitative inquiry is to portray informal self-governance practiced by residents in the Cairo region. This research argues that informal spatial practices offer an alternative urban framework for bottom-up development in the absence of government provisions. In the context of this study, informal self-governance is defined as the residents’ autonomous control and use of public urban space in informal settlements. The case study for this research is Ard al-Liwa, a semi-formal settlement representing the majority of informal settlement typologies in Egypt, which consist of the formal occupation of land through an uncontrolled land subdivision, zoning, and construction. An inductive methodological approach is adopted to first study informal practices as singular activities and then as components of a larger environment. The collected set of empirical data consists of audiovisual material and observations obtained during regular site visits and interviews with residents native to the settlement. Methods of analysis are synthesized to identify themes in the data: the static and dynamic use of sidewalks, the urban traces of informal building allocation and construction, the de facto right to urban space, and the resultant spatial patterns. The paper concludes by positioning the research in the context of the current architectural practice, questioning the role, and responsibility, of designers in these self-governed urban regions.

Keywords: Egypt, informal settlements, self-governance, urban framework

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Authors: Chakrit Chotamonsak

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This study was analyzed changes in temperature and precipitation extremes in northern Thailand for the period 1981-2011.The study includes an analysis of the average and trends of changes in temperature and precipitation using 22 climate indices, related to the intensity, frequency and duration of extreme climate events. The results showed that the averaged trend of maximum, minimum and mean temperature is likely to increase over the study area in rate of 0.5, 0.9 and 0.7 °C in last 30 years. Changes in temperature at nighttime, then rising at a rate higher daytime is resulting to decline of diurnal temperature range throughout the area. Trend of changes in average precipitation during the year 1981-2011 is expected to increase at an average rate of 21%. The intensity of extreme temperature events is increasing almost all station. In particular, the changes of the night were unusually hot has intensified throughout the region. In some provinces such as Chiang Mai and Lampang are likely be faced with the severity of hot days and hot nights in increasing rate. Frequency of extreme temperature events are likely to increase each station, especially hot days, and hot nights are increasing at a rate of 2.38 and 3.58 days per decade. Changes in the cold days and cold nights are declining at a rate of 0.82 and 3.03 days per decade. The duration of extreme temperature events is expected to increase the events hot in every station. An average of 17.8 days per decade for the number of consecutive cold winter nights likely shortens the rate of 2.90 days per decade. The analysis of the precipitation indices reveals the intensity of extreme precipitation is increasing almost across the region. The intensify expressed the heavy rain in one day (Rx1day) and very heavy rain accumulated in 5 days (RX5day) which is likely to increase, and very heavy rainfall is likely to increase in intensity. Frequency of extreme precipitation events is likely to increase over the station. The average frequency of heavy precipitation events increased xxx days per decade. The duration of extreme precipitation events, such as the consecutive dry days are likely to reduce the numbers almost all station while the consecutive wet days tends to increase and decrease at different numbers in different areas.

Keywords: climate extreme, temperature extreme, precipitation extreme, Northern Thailand

Procedia PDF Downloads 283

Authors: J. Chakwizira, P. Bikam, T. A. Adeboyejo

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This paper seeks to illustrate the impact of rapid urbanization (in terms of both increase in people and vehicles) in the Gauteng region (which includes Johannesburg, Pretoria and Ekurhuleni). The impact that existing transport systems and options place on the capacity of residents from low income areas to travel and conduct various socio-economic activities is discussed. The findings are drawn from a 2013 analysis of a random transport household survey of 1550 households carried out in Gauteng province. 91.4% of the study respondents had access to public transport, while 8.6% had no access to public transport. Of the 91.4% who used public transport, the main reason used to explain this state of affairs was that it was affordable (54.3%), convenient (15.9%), Accessible (11.9%), lack of alternatives (6.4%) and reliable at 4.1%. Recommendations advanced revolve around the need to reverse land use and transportation effects of apartheid planning, growing and developing a sustainable critical mass of public transport interventions supported by appropriate transport systems that are environmentally sustainable through proper governance. 38.5% of the respondents indicated that developing compact, smart and integrated urban land spaces was key to reducing travel challenges in the study area. 23.4% indicated that the introduction and upgrading of BRT buses to cover all areas in the study area was a step in the right direction because it has great potential in shifting travel patterns to favor public modes of transport. 15.1% indicated that all open spaces should be developed so that fragmentation of land uses can be addressed. This would help to fight disconnected and fragmented space and trip making challenges in Gauteng. 13.4% indicated that improving the metro rail services was critical since this is a mass mover of commuters. 9.6% of the respondents highlighted that the bus subsidy policy has to be retained in the short to medium term since the spatial mismatches and challenges created by apartheid are yet to be fully reversed.

Keywords: urbanisation, population, public, transport systems, Gauteng

Procedia PDF Downloads 287

Authors: Targba Aondowase

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Undocumented migration along Nigeria’s boarder with Cameroon, Chad and Niger is a key issue in tackling the human security challenges in the region as the security situation cannot be contained without proper boarder control. The paper adopts migration systems theory which asserts that migration alters the social, cultural, economic, and institutional conditions at both the sending and receiving ends to explain the influence of unregistered migrants on institutional changes as it affects the security situation in Northern Nigeria. It was found that undocumented migration is majorly influenced by poverty, illegal trade, wars and asylum. The study also discovers that Nigerian boarders are porous with over 250 footpaths that link directly to Cameroon, Chad and Niger, making the proliferation of small arms and light weapons a transnational organized crime in the region. These porous borders are unmanned by security operatives with limited government presence in the boarder communities. The study also found that undocumented immigrants are easily integrated into the northern communities due to common religious beliefs and race where they carry out normal and civic functions without obstruction. The paper concluded that the level of undocumented migration in Northern Nigeria is high due to unmanned and porous borders. The paper therefore recommended that the security agencies should be strengthened through adequate funding, innovative technology, sound policies and proficient processes that will help protect the country’s borders. The National Populations Commission and the National Identity Management Commission should be strengthened to have a good data base of the country’s citizens and there should be international cooperation between the neighbouring countries to tackle illegal migration and illegal trade along the borders. The findings and recommendations of this paper will serve as a guide towards curtailing the impact of undocumented migration on human security in Northern Nigeria.

Keywords: human security, impact, migration, undocumented

Procedia PDF Downloads 334

Authors: Mostafa Sefidgar, Kaamran Raahemifar, Hossein Bazmara, Madjid Soltani

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The computational methods provide condition for investigation related to the process of drug delivery, such as convection and diffusion of drug in extracellular matrices, and drug extravasation from microvascular. The information of this process clarifies the mechanisms of drug delivery from the injection site to absorption by a solid tumor. In this study, an advanced numerical method is used to solve fluid flow and solute transport equations simultaneously to show how capillary network structure induced by tumor affects drug delivery. The effect of heterogeneous capillary network induced by tumor on interstitial fluid flow and drug delivery is investigated by this multi scale method. The sprouting angiogenesis model is used for generating capillary network induced by tumor. Fluid flow governing equations are implemented to calculate blood flow through the tumor-induced capillary network and fluid flow in normal and tumor tissues. The Starling’s law is used for closing this system of equations and coupling the intravascular and extravascular flows. Finally, convection-diffusion-reaction equation is used to simulate drug delivery. The dynamic approach which changes the capillary network structure based on signals sent by hemodynamic and metabolic stimuli is used in this study for more realistic assumption. The study indicates that drug delivery to solid tumors depends on the tumor induced capillary network structure. The dynamic approach generates the irregular capillary network around the tumor and predicts a higher interstitial pressure in the tumor region. This elevated interstitial pressure with irregular capillary network leads to a heterogeneous distribution of drug in the tumor region similar to in vivo observations. The investigation indicates that the drug transport properties have a significant role against the physiological barrier of drug delivery to a solid tumor.

Keywords: solid tumor, physiological barriers to drug delivery, angiogenesis, microvascular network, solute transport

Procedia PDF Downloads 312