Search results for: flow state

Authors: Gashin Shahsavari, Gilles Arnaud-Fassetta, Alberto Campisano, Roberto Bertilotti, Fabien Riou

Abstract:

Sewer deposits have been identified as a major cause of dysfunctions in combined sewer systems regarding sewer management, which induces different negative consequents resulting in poor hydraulic conveyance, environmental damages as well as worker’s health. In order to overcome the problematics of sedimentation, flushing has been considered as the most operative and cost-effective way to minimize the sediments impacts and prevent such challenges. Flushing, by prompting turbulent wave effects, can modify the bed form depending on the hydraulic properties and geometrical characteristics of the conduit. So far, the dynamics of the bed-load during high-flow events in combined sewer systems as a complex environment is not well understood, mostly due to lack of measuring devices capable to work in the “hostile” in combined sewer system correctly. In this regards, a one-episode flushing issue from an opening gate valve with weir function was carried out in a trunk sewer in Paris to understanding its cleansing efficiency on the sediments (thickness: 0-30 cm). During more than 1h of flushing within 5 m distance in downstream of this flushing device, a maximum flowrate and a maximum level of water have been recorded at 5 m in downstream of the gate as 4.1 m3/s and 2.1 m respectively. This paper is aimed to evaluate the efficiency of this type of gate for around 1.1 km (from the point -50 m to +1050 m in downstream from the gate) by (i) determining bed grain-size distribution and sediments evolution through the sewer channel, as well as their organic matter content, and (ii) identifying sections that exhibit more changes in their texture after the flush. For the first one, two series of sampling were taken from the sewer length and then analyzed in laboratory, one before flushing and second after, at same points among the sewer channel. Hence, a non-intrusive sampling instrument has undertaken to extract the sediments smaller than the fine gravels. The comparison between sediments texture after the flush operation and the initial state, revealed the most modified zones by the flush effect, regarding the sewer invert slope and hydraulic parameters in the zone up to 400 m from the gate. At this distance, despite the increase of sediment grain-size rages, D50 (median grain-size) varies between 0.6 mm and 1.1 mm compared to 0.8 mm and 10 mm before and after flushing, respectively. Overall, regarding the sewer channel invert slope, results indicate that grains smaller than sands (< 2 mm) are more transported to downstream along about 400 m from the gate: in average 69% before against 38% after the flush with more dispersion of grain-sizes distributions. Furthermore, high effect of the channel bed irregularities on the bed material evolution has been observed after the flush.

Keywords: bed-load evolution, combined sewer systems, flushing efficiency, sediments transport

Procedia PDF Downloads 403

Authors: C. S Lee, W. C. Hsu, H. Y. Liu, C. J. Lin, S. C. Yao, Y. T. Shen, Y. C. Lin

Abstract:

In₀.₁₈Al₀.₈₂N/AlN/GaN metal-oxide-semiconductor heterostructure field-effect transistors (MOS-HFETs) having Al₂O₃ gate-dielectric and backside metal-trench structure are investigated. The Al₂O₃ gate oxide was formed by using a cost-effective non-vacuum ultrasonic spray pyrolysis deposition (USPD) method. In order to enhance the heat dissipation efficiency, metal trenches were etched 3-µm deep and evaporated with a 150-nm thick Ni film on the backside of the Si substrate. The present In₀.₁₈Al₀.₈₂N/AlN/GaN MOS-HFET (Schottky-gate HFET) has demonstrated improved maximum drain-source current density (IDS, max) of 1.08 (0.86) A/mm at VDS = 8 V, gate-voltage swing (GVS) of 4 (2) V, on/off-current ratio (Ion/Ioff) of 8.9 × 10⁸ (7.4 × 10⁴), subthreshold swing (SS) of 140 (244) mV/dec, two-terminal off-state gate-drain breakdown voltage (BVGD) of -191.1 (-173.8) V, turn-on voltage (Von) of 4.2 (1.2) V, and three-terminal on-state drain-source breakdown voltage (BVDS) of 155.9 (98.5) V. Enhanced power performances, including saturated output power (Pout) of 27.9 (21.5) dBm, power gain (Gₐ) of 20.3 (15.5) dB, and power-added efficiency (PAE) of 44.3% (34.8%), are obtained. Superior breakdown and RF power performances are achieved. The present In₀.₁₈Al₀.₈₂N/AlN/GaN MOS-HFET design with backside metal-trench is advantageous for high-power circuit applications.

Keywords: backside metal-trench, InAlN/AlN/GaN, MOS-HFET, non-vacuum ultrasonic spray pyrolysis deposition

Procedia PDF Downloads 254

Authors: Abdulaziz F. Ettir, Ghait Bashir, Tarek S. Duzan

Abstract:

A proper well planning is very vital to achieve any successful drilling program on the basis of preventing, overcome all drilling problems and minimize cost operations. Since the hydraulic system plays an active role during the drilling operations, that will lead to accelerate the drilling effort and lower the overall well cost. Likewise, an improperly designed hydraulic system can slow drill rate, fail to clean the hole of cuttings, and cause kicks. In most cases, common sense and commercially available computer programs are the only elements required to design the hydraulic system. Drilling optimization is the logical process of analyzing effects and interactions of drilling variables through applied drilling and hydraulic equations and mathematical modeling to achieve maximum drilling efficiency with minimize drilling cost. In this paper, practical software adopted in this paper to define drilling optimization models including four different optimum keys, namely Opti-flow, Opti-clean, Opti-slip and Opti-nozzle that can help to achieve high drilling efficiency with lower cost. The used data in this research from vertical and horizontal wells were recently drilled in Waha Oil Company fields. The input data are: Formation type, Geopressures, Hole Geometry, Bottom hole assembly and Mud reghology. Upon data analysis, all the results from wells show that the proposed program provides a high accuracy than that proposed from the company in terms of hole cleaning efficiency, and cost break down if we consider that the actual data as a reference base for all wells. Finally, it is recommended to use the established Optimization calculations software at drilling design to achieve correct drilling parameters that can provide high drilling efficiency, borehole cleaning and all other hydraulic parameters which assist to minimize hole problems and control drilling operation costs.

Keywords: optimum keys, namely opti-flow, opti-clean, opti-slip and opti-nozzle

Procedia PDF Downloads 319

Authors: Mohamed Rajab Peer Mohamed, Thiruvenkatasamy Kannabiran

Abstract:

In the present investigation, the scour around a circular pier subjected to a steady current were studied numerically using two-dimensional MIKE21 Flow Model (FM) and Sand Transport (ST)Modulewhich is developed by Danish Hydraulic Institute (DHI), Denmark. The unstructured flexible mesh generated with rectangular flume dimension of 10 m wide, 1 m deep, and 30 m long. The grain size of the sand was d50 = 0.16 mm, sediment size, sediment gradation=1.16, pier diameter D= 30 mm and depth-averaged current velocity, U = 0.449 m/s are considered in the model. The estimated scour depth obtained from this model is validated and it is observed that the results of the model have good agreement with flume experimental results.In order to estimate the scour depth, several simulations were made for three cases viz., Case I:change in sediment transport model description in the numerical model viz, i) Engelund-Hansen model, ii) Engelund-Fredsøe model, and iii) Van Rijn model, Case II: change in current velocity for keeping constant pile diameter D=0.03 m and Case III:change in pier diameter for constant depth averaged current speed U=0.449 m/s.In case I simulations, the results indicate that the scour depth S/D is the order of 1.73 for Engelund-Hansen model, 0.64 for Engelund-Fredsøe model and 0.46 for VanRijn model. The scour depth estimates using Engelund-Hansen method compares well the experimental results.In case II, simulations show that the scour depth increases with increasing current component of the flow.In case III simulations, the results indicate that the scour depth increases with increase in pier diameter and it stabilize attains steady value when the Froude number> 2.71.All the results of the numerical simulations are clearly matches with reported values of the experimental results. Hence, this MIKE21 FM –Sand Transport model can be used as a suitable tool to estimate the scour depth for field applications. Moreover, to provide suitable scour protection methods, the maximum scour depth is to be predicted, Engelund-Hansen method can be adopted to estimate the scour depth in the steady current region.

Keywords: circular pier, MIKE21, numerical model, scour, sediment transport

Procedia PDF Downloads 317

Authors: Onifade Yemi Sikiru, Vwoke Eruya

Abstract:

An investigation has been made of the groundwater potentials of Erusu-Arigidi, Ondo State, Nigeria and using an electrical resistivity survey. This study was motivated to determine the electrical resistivity parameters of the area. This work aims to use the electrical resistivity method to explore the groundwater potentials of the study area. A total of ten vertical electrical soundings (VES) were conducted with a maximum electrode spacing of 150 m. The data was acquired using ABEM SAS 1000 Terrameter and processed using WINRESIST. The interpreted and analyzed results reveal four to six geoelectric layers. The VES curves obtained were QH, H, AAA, HKH, and HA. Findings from the study revealed that the geoelectric layer ranges from 3 to 5 layers. From the result, the Dar Zarrouk parameters longitudinal conductance (S) and transverse resistance (Tr), average longitudinal resistance (), transverse resistivity (), coefficient of anisotropy (λ), and reflection coefficient ranges from 0.22 to 1.45mhos, 67.12 to 4262.91 Ω/m², 8.81 to 76.12 Ω-m, 12.0 to 243.5 Ωm², 1.01 to 1.78, and 0.72 to 0.99 respectively. Deduction from S suggested that groundwater tends to be slightly vulnerable to surface contamination. Further findings from Dar Zarrouk parameters revealed that southwest parts of the study area tend to have high groundwater potential when compared to other parts of the study area. While hydraulic conductivity and transmissivity range from 0.003 to 0.051m/day, and 11.16 to 158.30m²/day, results obtained from H and T revealed northwest parts of the study area are considered to be aquiferous when compared to other parts of the research area.

Keywords: variation, isoresistivity, hydraulic conductivity, groundwater

Procedia PDF Downloads 77

Authors: Jay Gohel, Anant Parghi

Abstract:

A tuned liquid column damper (TLCD) is a modified passive system of tuned mass damper, where a liquid is used in place of mass in the structure. A TLCD consists of U-shaped tube with an orifice that produces damping against the liquid motion in the tube. This paper provides a state-of-the-art review on the vibration control of wind and earthquake excited structures using liquid dampers. Further, the paper will also discuss the theoretical background of TCLD, history of liquid dampers and existing literature on experimental, numerical, and analytical study. The review will also include different configuration of TLCD viz single TLCD, multi tuned liquid column damper (MTLCD), TLCD-Interior (TLCDI), tuned liquid column ball damper (TLCBD), tuned liquid column ball gas damper (TLCBGD), and pendulum liquid column damper (PLCD). The dynamic characteristics of the different configurate TLCD system and their effectiveness in reducing the vibration of structure will be discussed. The effectiveness of semi-active TLCD will be also discussed with reference to experimental and analytical results. In addition, the review will also provide the numerous examples of implemented TLCD to control the vibration in real structures. Based on the comprehensive review of literature, some important conclusions will be made and the need for future research will be identified for vibration control of structures using TLCD.

Keywords: earthquake, wind, tuned liquid column damper, passive response control, structures

Procedia PDF Downloads 208

Authors: Thuy Phan, Stephanie Luallin

Abstract:

Inclusive education policies have demonstrated benefits for students with and without disabilities in the US. There are several laws that relate to inclusive education, such as 'No Child Left Behind', 'The Individuals with Disabilities Education Act'. However, the application of these inclusive education laws and policies vary per state and school district. Classroom teachers in an inclusive classroom often experience confusion as to how to apply these policies in order to create appropriate inclusive learning environments that meet the abilities and needs of their diverse student population. The study aims to investigate teachers’ perspective of their capacities to create an appropriate learning environment for their diverse student population including students with disabilities. Qualitative method is implemented in this study, using open-end interview questions to investigate teachers’ perspective of their capacities to create an appropriate inclusive learning environment for all students based on current inclusive education laws and district policies in the state of Colorado, USA. These findings may indicate a lack of confidence in teachers’ capacity to create appropriate inclusive learning environments based on laws and district policies; including challenges that classroom teachers may experience in creating inclusive learning environments. The purpose of this study is to examine the adequate preparation of classroom teachers in creating inclusive classrooms with the intent of determining implications for developing policies in inclusive education.

Keywords: educator’s capacity, inclusive education, inclusive learning environment, policy

Procedia PDF Downloads 170

Authors: Jonghyuk Yoon, Hyoungwoon Song

Abstract:

Recently, there are lots of increasing interest in a smart farming that represents application of modern Information and Communication Technologies (ICT) into agriculture since it provides a methodology to optimize production efficiencies by managing growing conditions of crops automatically. In order to obtain high performance and stability for smart greenhouse, it is important to identify the effect of various working parameters such as capacity of ventilation fan, vent opening area and etc. In the present study, a 3-dimensional CFD (Computational Fluid Dynamics) simulation for single-span greenhouse was conducted using the commercial program, Ansys CFX 18.0. The numerical simulation for single-span greenhouse was implemented to figure out the internal thermal and flow characteristics. In order to numerically model solar radiation that spread over a wide range of wavelengths, the multiband model that discretizes the spectrum into finite bands of wavelength based on Wien’s law is applied to the simulation. In addition, absorption coefficient of vinyl varied with the wavelength bands is also applied based on Beer-Lambert Law. To validate the numerical method applied herein, the numerical results of the temperature at specific monitoring points were compared with the experimental data. The average error rates (12.2~14.2%) between them was shown and numerical results of temperature distribution are in good agreement with the experimental data. The results of the present study can be useful information for the design of various greenhouses. This work was supported by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through Advanced Production Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA)(315093-03).

Keywords: single-span greenhouse, CFD (computational fluid dynamics), solar radiation, multiband model, absorption coefficient

Procedia PDF Downloads 136

Authors: Osaretin Rosemary Uyi, A. O. Ogungbemi

Abstract:

Female involvement in policy making and partnership in a man-driven-world is fast gaining international recognition. The Nigeria commercial real estate is one of the sectors of the economy that has a significant number of the male in the business. This study was conducted to assess the participation of females in estate management in Lagos state, Nigeria. Lagos is the commercial nerve center of Nigeria having the highest number of real estate practitioners and investors. The population due to the daily influx of people has made real estate business to continue to grow in this part of Nigeria. A structured questionnaire duly pre-tested and validated was used to elicit information from the respondents. The data collected were presented using tables and charts and were analyzed using descriptive statistical tools such as frequency counts, percentages, were used to test the hypothesis. The results also indicated that most females that participated in commercial real estate business are educated (80%), fell within 31-40 years of age (75%) and of high income status (88%) earn above ₦800,000 per year, while 10% are real estate investors and 82% of the female in the sector are employee. The study concluded that the number of female participating in various aspect of commercial real estate business in the study area was moderate while the numbers of female investors are low when compared to male. This might be due to the problems associated with rent collection, land disputes and other issues that are associated with property management in Nigeria. It is therefore recommended that females in real estate should be empowered and encouraged to match with their male counterpart.

Keywords: commercial real estate, empowerment, female, participation, property management

Procedia PDF Downloads 332

Authors: A. Douka, S. Vouyiouka, L. M. Papaspyridi, D. Korres, C. Papaspyrides

Abstract:

A "green" process was studied for the preparation of partially renewable aliphatic polyesters based on 1,4-butanediol and 1,8-octanediol with various diacids and derivatives, namely diethyl succinate, adipic acid, sebacic acid, 1,12-dodecanedioic acid and 1,14-tetradecanedioic acid. A first step of enzymatic prepolymerization was carried out in the presence of two different solvents, toluene and diphenylether, applying molecular sieves and vacuum, respectively, to remove polycondensation by-products. Poly(octylene adipate) (PE 8.6), poly(octylene dodecanate)(PE 8.12) and poly(octylene tetradecanate) (PE 8.14) were firstly enzymatically produced in toluene using molecular sieves giving however, low-molecular-weight products. Thereafter, the synthesis of PE 8.12 and PE 8.14 was examined under optimized conditions using diphenylether as solvent and a more vigorous by-product removal step, such as application of vacuum. Apart from these polyesters, the optimized process was also implemented for the production of another long-chain polyester-poly(octylene sebacate) (PE 8.10) and a short-chain polyester-poly(butylene succinate) (PE 4.4). Subsequently, bulk post-polymerization in the melt or solid state was performed. SSP runs involved absence of biocatalyst and reaction temperatures (T) in the vicinity of the prepolymer melting point (Tm-T varied between 15.5 up to 4oC). Focusing on PE 4.4 and PE 8.12, SSP took place under vacuum or flowing nitrogen leading to increase of the molecular weight and improvement of the end product physical appearance and thermal properties.

Keywords: aliphatic polyester, enzymatic polymerization, solid state polymerization, Novozym 435

Procedia PDF Downloads 324

Authors: P. O. Fatoki, R. S. Olaleye, B. O. Adeniji

Abstract:

The study investigated farmers’ perception of the effects of climate change on rice production in Nasarawa State, Nigeria. Multi-stage sampling technique was used in selecting a total of 248 rice farmers from the study area. Data for the study were collected through the use of interview schedule. The data were analysed using both descriptive and inferential statistics. Results showed that majority (71.8%) of the respondents were married and the mean age of the respondents was 44.54 years. The results also showed that most adapted strategies for mitigating the effects of climate change on rice production were change of planting and harvesting date (67.7%), movement to another site (63.7%) and increased or reduced land size (58.5%). Relationship between the roles of extension agents in mitigating climate change effects on rice production and farmers’ perception were significant as revealed Chi-Square analysis from the study ; Dissemination of information ( = 2.16, P < 0.05) and use of demonstration methods ( = 2.15, P < 0.05). Poisson regression analysis revealed that educational status, farm size, experience and yield had significant relationship with the perception of the effects of climate change at 0.01 significance level while household size was as well significant at 0.05. It is recommended that some of the adaptive strategies and practices for mitigating the effects of climate change in rice production should be improved, while the extension outfits should be strengthened to ensure adequate dissemination of relevant information on climate change with a view to mitigate its effects on rice production.

Keywords: perception, rice farmers, climate change, mitigation, adaptive strategies

Procedia PDF Downloads 357

Authors: Mairo Musa Galadima

Abstract:

This paper examines the impact of Mother tongue interference on students’ performance in English Language in Bauchi State. It is observed that the students of Bauchi district share the same problem with Hausa native speakers of Kano dialect which is the standard form. It is observed that there are some phonemes which are present in English but absent in Hausa so the Hausa speakers of Bauchi district also replace these sounds with similar ones present in Hausa. Students in Bauchi district fail English language because they transfer features of their mother tongue (MT) into English. The data is obtained through unobtrusive observation of the English speech of about fifty Hausa native speakers of Bauchi district which is similar to Kano dialect from Abubakar Tatari Ali Polytechnic, Bauchi since only those who have had some good background of secondary education are used because uneducated Nigeria English of whatever geographical location is more likely to be unintelligible as cockney or uneducated African-American English. For instance /Ə:/ is absent in Hausa so the speakers find it difficult to distinguish between such pairs of words as /bƏ:d / and /bΛst/, /fa:st/ and /fƏ:st / hence /a:/ is generally used wherever /Ə:/ is present regardless of the spelling, that is why words like ‘work’, ‘first’ and ‘person’ all have / a:/. In Hausa most speakers use /P/ in place of, or in alternation with /f/, e.g. ‘few’ is pronounced as ‘pew’, or ‘pen’, as ‘fen’, /b/ for /v/, /s/ for /z/ and /z/ for /ᵹ/. Also the word vision/visn/ is pronounced as /vidzn/. Therefore, there is confusion in spellings and pronunciation of words. One solution out of the problem is having constant practice with a qualified consistent staff and making use of standard textbooks in the learning process.

Keywords: English, failure, mother tongue, interference, students

Procedia PDF Downloads 220

Authors: B. O. Diyaolu

Abstract:

Viability and competency during competition is the dream of every team sports so as to have a good result. But it seems factors abound which deter the performance of even a good sports team. Different individuals with different state of mind all come together to perform in team sports with different degree of satisfaction. This study investigated the role of satisfaction on performance among Afe Babalola University team sports. Descriptive survey research design was used and the population consists of all male and female athletes in the team sports that participated in the last 2019 Ekiti State Higher Institution games (ESHIGA). Total enumeration technique was used for the three team sports; football (44), basketball (24) and volleyball (24). A total of 92 participants were involved in the research. The instrument used for the study was a modified Athlete Satisfaction Scale (ASS). The questionnaire was divided into two sections. The Cronbach’s Alpha reliability coefficient of 0.71 was obtained. The hypotheses were tested at 0.05 significant levels. The completed questionnaire was collated, coded, and analyzed using descriptive statistics of frequency counts and percentage and inferential statistics of chi-square (X²). Findings of this study revealed that satisfaction significantly influences team sports performance among Athletes of Afe Babalola University. The responsibility of satisfying athlete lies on the coaches, fans, sports administrators as well as organizers of such event, as it is not only financial reward that gives satisfaction. The performance of a team sports is quiet important and its being determined by the degree of satisfaction of each individual that make up the team. All effort must be made to satisfy athlete in order to guarantee optimum performance.

Keywords: athlete satisfaction, optimum achievement, optimum performance, sports performance and team sports

Procedia PDF Downloads 149

Authors: Iwuchukwu J. C., Mbah C.

Abstract:

There seems to be dearth on information on how oil bean is being exploited, processed and conserved locally. This gap stifles initiatives on the evaluation of the suitability of the methods used and the invention of new and better methods. The study; therefore, assesses activities of processors in domestication/conservation and processing of oil bean (Pentaclethra macrophylla) Enugu State, South East Nigeria. Three agricultural zones, three blocks, nine circles and seventy-two respondents that were purposively selected made up the sample for the study. Data were presented in percentage, chart and mean score. The result shows that processors of oil bean in the area were middle-aged, married with relatively large household size and long years of experience in processing. They sourced oil bean they processed from people’s farmland and sourced information on processing of oil bean from friends and relatives. Activities involved in processing of oil bean were boiling, dehulling, washing, sieving, slicing, wrapping. However, the sequence of these activities varies among these processors. Little or nothing was done by the processors towards the conservation of the crop while poor storage and processing facilities and lack of knowledge on modern preservation technique were major constraints to processing of oil bean in the area. The study concluded that efforts should be made by governments and processors through cooperative group in provision of processing and storage facility for oil bean while research institute should conserve and generate improved specie of the crop to arouse interest of the farmers and processors on the crop which will invariably increase productivity.

Keywords: conservation, domestication, oil bean, processing

Procedia PDF Downloads 308

Authors: Abdul Hadi Butt, Asfandyar Arshad

Abstract:

The purpose of this paper is to study the thrust variation in different configurations of clustered nozzles. It involves the design and analysis of clustered configuration of nozzles using Ansys fluent. Clustered nozzles with different configurations are simulated and compared on basis of effective exhaust thrust. Mixing length for the flow interaction is also calculated. Further clustered configurations are analyzed over different altitudes. An optimum value of the thrust among different configurations is proposed at the end of comparisons.

Keywords: CD nozzle, cluster, thrust, fluent, ANSYS

Procedia PDF Downloads 401

Authors: Kudrat-E-Khuda Babu

Abstract:

Rohingya refugees are the most marginalized and persecuted section of people in the world. The heinous brutality of Myanmar has forced the Muslim minority community to flee themselves to their neighboring country, Bangladesh for quite a few times now. The recent atrocity of the Buddhist country has added insult to injury on the existing crisis. In lieu of protection, the rights of the Rohingya community in Myanmar are being violated through exclusion from citizenship and steamroller of persecution. The mass influx of Rohingya refugees to Bangladesh basically took place in 1978, 1992, 2012, and 2017. At present, there are around one million Rohingyas staying at Teknaf, Ukhiya of Cox’s Bazar, the southern part of Bangladesh. The country, despite being a poverty-stricken one, has shown unprecedented generosity in sheltering the Rohingya people. For sheltering half of the total refugees in 2017, the Prime Minister of Bangladesh, Sheikh Hasina is now being regarded as the lighthouse of humanity or the mother of humanity. Though Bangladesh is not a ratifying state of the UN Refugee Convention, 1951 and its Additional Protocol, 1967, the country cannot escape its obligation under international human rights jurisprudence. Bangladesh is a party to eight human rights instruments out of nine core instruments, and thus, the country has an indirect obligation to protect and promote the rights of the refugees. Pressure from international bodies has also made Bangladesh bound to provide refuge to Rohingya people. Even though the demographic vulnerability and socio-economic condition of the country do not suggest taking over extra responsibility, the principle of non-refoulment as a part of customary international law reminds us to stay beside those persecuted or believed to have well-founded fear of persecution. In the case of HM Ershad v. Bangladesh and Others, 7 BLC (AD) 67, it was held that any international treaty or document after signing or ratification is not directly enforceable unless and until the parliament enacts a similar statute howsoever sweet the document is. As per Article 33(2) of the 1951 Refugee Convention, there are even exceptions for a state party in case of serious consequences like threat to national security, apprehension of serious crime and danger to safeguard state population. Bangladesh is now at a cross-road of human rights and national interest. The world community should come forward to resolve the crisis of the persecuted Rohingya people through repatriation, resettlement, and reintegration.

Keywords: Rohingya refugees, human rights, Bangladesh, Myanmar

Procedia PDF Downloads 188

Authors: Abdullah Abdulsalam, Adamu Balami, Olajide Olubanji Olowe, Maryam Abdu Abdulkadir

Abstract:

The development and persistence of low back pain may be influenced by several factors which include lifestyle factors, previous pain symptoms, psychological factors, workplace factors as well as socio-demographic variables. The focus of this study was to determine the socio-demographic and work related variables as a predictor of persistence of back pain and disability among civil servants receiving physiotherapy in tertiary health institutions in Kano, Nigeria. One hundred and twenty nine newly referred low back pain patients for physiotherapy participated in the study. This study was a cross sectional study involving patients that were newly diagnosed of back pain, referred and received physiotherapy. The convenience sampling technique was used to select the patients based on the inclusion criteria. The data obtained was analysed using simple percentage and multiple regression for stated hypothesis at 0.05 level of significance. The findings reveal that all the variables are not significant predictor of persistence of back pain and disability. The study recommended that determinants of low back pain recovery by clinician should include other clinical factors not only reduction in pain intensity.

Keywords: socio-demographic, work related variables, Kano state, back pain and disability

Procedia PDF Downloads 301

Authors: Inikpi Ameh, Grace Kia, A. K. B. Sackey, Joy Atawodi, Richard Whittington

Abstract:

Ranaviruses are belonging to the viral Family Iridoviridae, are a group of globally emerging pathogens recognized as major viral pathogens of cold-blooded vertebrates. They cause systemic infection in fishes, amphibians, and reptiles. Ranaviruses have been associated with numerous disease outbreaks in natural and cultured populations of fish, amphibians, and reptiles. To investigate the presence of the ranavirus in fish and edible frogs sourced from dams and ponds in Zaria, Kaduna State, Nigeria. A total of 425 frogs (Rana spp.) and fishes (n=215 and n=200, respectively) were randomly collected based on consent and availability. Liver, kidney, and spleen tissue samples from each animal were pooled and homogenized. The samples were screened for ranavirus using the Indirect Enzyme linked Immunosorbent assay (ELISA). An overall prevalence of 46.1% (196/425) was obtained from the study. Frogs had a prevalence of 51.2% (110/215) while fish had 43% (86/200). This is the first study on ranavirus in fish and edible frogs in Nigeria. This study has established that edible frogs (Rana spp) and fishes sold in Zaria, Nigeria were infected with ranavirus which may have great economic importance to the nation’s aquaculture. In view of occasional massive economic losses observed in fishery industry due to deaths of unknown origin, this preliminary investigation is useful in directing veterinarians, policy makers and researchers on need to survey for ranavirus and also enlighten the relevant stakeholders on its prevention and control in Nigeria.

Keywords: fish, frogs, Nigeria, Ranavirus

Procedia PDF Downloads 360

Authors: Aminu Alhaji Bala

Abstract:

The Jama’atu Izalatil Bid’ah Wa-Iqamatis Sunnah is a Da’wah organization and reform movement launched in Jos - Nigeria in 1978 as a purely reform movement under the leadership of late Shaykh Ismai’la Idris. The organization started a full fledge preaching sessions at National, State and Local Government levels immediately after its formation. The contributions of this organization to da'wah activities in Nigeria are paramount. The organization conducted its preaching under the council of preaching with the help of the executives, elders and patrons of the movement. Teaching and preaching have been recognized as the major programs of the society. Its preaching activities are conducted from ward, local, state and national levels throughout the states of Nigeria and beyond. It also engaged itself in establishing Mosques, schools and offers sermons during Friday congregation and Eid days throughout its mosques where its sermon is translated into vernacular language, this attracted many Muslims who don’t understand Arabic to patronize the its activities. The organization however split into two faction due to different approaches to Da’wah methodology and some seemingly selfish interests among its leaders. It is upon this background that this research was conducted using analytical method to compare and contrast the da’wah methodology applied by the two factions of the organization. The research discussed about the formation, Da’wah activities of the organization. It also compared and contrast the Da’wah approach and methodology of the two factions. The research finding reveals that different approach and methods applied by these factions is one of the main reason of their split in addition to other selfish interest among its leaders.

Keywords: activities, Da’wah, methodology, organization

Procedia PDF Downloads 223

Authors: K. Mondal, S. Talapatra, M. Terrones, S. Pokhrel, C. Frizzel, B. Sumpter, V. Meunier, A. L. Elias

Abstract:

Worldwide energy independence is reliant on the ability to leverage locally available resources for fuel production. Recently, syngas produced through gasification of carbonaceous materials provided a gateway to a host of processes for the production of various chemicals including transportation fuels. The basis of the production of gasoline and diesel-like fuels is the Fischer Tropsch Synthesis (FTS) process: A catalyzed chemical reaction that converts a mixture of carbon monoxide (CO) and hydrogen (H₂) into long chain hydrocarbons. Until now, it has been argued that only transition metal catalysts (usually Co or Fe) are active toward the CO hydrogenation and subsequent chain growth in the presence of hydrogen. In this paper, we demonstrate that carbon nanotube (CNT) surfaces are also capable of hydro-deoxygenating CO and producing long chain hydrocarbons similar to that obtained through the FTS but with orders of magnitude higher conversion efficiencies than the present state-of-the-art FTS catalysts. We have used advanced experimental tools such as XPS and microscopy techniques to characterize CNTs and identify C-O functional groups as the active sites for the enhanced catalytic activity. Furthermore, we have conducted quantum Density Functional Theory (DFT) calculations to confirm that C-O groups (inherent on CNT surfaces) could indeed be catalytically active towards reduction of CO with H₂, and capable of sustaining chain growth. The DFT calculations have shown that the kinetically and thermodynamically feasible route for CO insertion and hydro-deoxygenation are different from that on transition metal catalysts. Experiments on a continuous flow tubular reactor with various nearly metal-free CNTs have been carried out and the products have been analyzed. CNTs functionalized by various methods were evaluated under different conditions. Reactor tests revealed that the hydrogen pre-treatment reduced the activity of the catalysts to negligible levels. Without the pretreatment, the activity for CO conversion as found to be 7 µmol CO/g CNT/s. The O-functionalized samples showed very activities greater than 85 µmol CO/g CNT/s with nearly 100% conversion. Analyses show that CO hydro-deoxygenation occurred at the C-O/O-H functional groups. It was found that while the products were similar to FT products, differences in selectivities were observed which, in turn, was a result of a different catalytic mechanism. These findings now open a new paradigm for CNT-based hydrogenation catalysts and constitute a defining point for obtaining clean, earth abundant, alternative fuels through the use of efficient and renewable catalyst.

Keywords: CNT, CO Hydrodeoxygenation, DFT, liquid fuels, XPS, XTL

Procedia PDF Downloads 347

Authors: Eisa Y. Adam, Anas A. Fadlelmula, Ali E. Ali

Abstract:

Sorghum head bug is a key insect pest of sorghum, and it is important to pay attention to the peak time of the pest abundance. The objective of this study was to study the effect of planting date on head bugs population. Field experiment was conducted during 2007/08 – 2008/09 and 2013/14 - 2014/15 cropping seasons at the Damazine Research Station Farm, Blue Nile State to determine sorghum head bugs incidence and abundance through the sowing date. Different sowing dates (early, mid and late sowing) and a susceptible sorghum variety known as Wad Ahmed variety were used the experiment. The experimental design used was randomized complete block design (RCBD). Data were collected on the number of head bug adults and nymphs/panicle, damage percent, coloration and a puncture due to bug feeding and oviposition, 1000 seeds weight and yield. The results showed that significantly (P<0.05) higher number of bugs and damage percent were recorded on the late sowing date for the four seasons followed by the mid sowing, while the early sowing gave low number of bugs, damage percent and high1000 weight. There were significant differences between protected and unprotected heads. The late sowing (August) is a critical sorghum planting time because it coincided with highest numbers of the head bugs.

Keywords: abundance, damage, headbugs, panicle

Procedia PDF Downloads 261

Authors: Naveed Ahmad Fazili

Abstract:

More than 20 human diseases involve the fibrillation of a specific protein/peptide which forms pathological deposits at various sites. Hereditary lysozyme amyloidosis is a systemic disorder which mostly affects liver, spleen and kidney. This conformational disorder is featured by lysozyme fibril formation. In vivo lysozyme fibrillation was simulated under in vitro conditions using a strong denaturant GdHCl at 3M concentration. Sharp decline in the ANS fluorescence intensity compared to the partially unfolded states, almost 20 fold increase in ThT fluorescence intensity, increase in absorbance at 450 nm suggesting turbidity, negative ellipticity peak in the far-UVCD at 217 nm, red shift of 50 nm compared to the native state in congo red assay and appearance of a network of long rope like fibrils in TEM analysis suggested HEWL fibrillation. Anti-fibrillation potency of baicalein against the preformed fibrils of HEWL was investigated following ThT assay in which there was a dose dependent decrease in ThT fluorescence intensity compared to the fibrillar state of HEWL with the maximum effect observed at 150 μM baicalein concentration, loss of negative ellipticity peak in the far-UVCD region, dip in the Rayleigh scattering intensity and absorbance at 350 nm and 450 nm respectively together with a reduction in the density of fibrillar structure in TEM imaging. Thus, it could be suggested that baicalein could prove to be a positive therapeutics for hereditary human lysozyme amyloidosis.

Keywords: amyloid fibrils, baicalein, congo red, negative ellipticity, therapeutics

Procedia PDF Downloads 294

Authors: Syed Hammad Ali, Rijan Bhakta Kayastha, Danial Hashmi, Richard Armstrong, Ahuti Shrestha, Iram Bano, Javed Hassan

Abstract:

This paper presents the results of a semi-distributed modified positive degree-day model (MPDDM) for estimating snow and ice melt contributions to discharge from the glacierized Hunza River basin, Pakistan. The model uses daily temperature data, daily precipitation data, and positive degree day factors for snow and ice melt. The model is calibrated for the period 1995-2001 and validated for 2002-2013, and demonstrates close agreements between observed and simulated discharge with Nash–Sutcliffe Efficiencies of 0.90 and 0.88, respectively. Furthermore, the Weather Research and Forecasting model projected temperature, and precipitation data from 2016-2050 are used for representative concentration pathways RCP4.5 and RCP8.5, and bias correction was done using a statistical approach for future discharge estimation. No drastic changes in future discharge are predicted for the emissions scenarios. The aggregate snow-ice melt contribution is 39% of total discharge in the period 1993-2013. Snow-ice melt contribution ranges from 35% to 63% during the high flow period (May to October), which constitutes 89% of annual discharge; in the low flow period (November to April) it ranges from 0.02% to 17%, which constitutes 11 % of the annual discharge. The snow-ice melt contribution to total discharge will increase gradually in the future and reach up to 45% in 2041-2050. From a sensitivity analysis, it is found that the combination of a 2°C temperature rise and 20% increase in precipitation shows a 10% increase in discharge. The study allows us to evaluate the impact of climate change in such basins and is also useful for the future prediction of discharge to define hydropower potential, inform other water resource management in the area, to understand future changes in snow-ice melt contribution to discharge, and offer a possible evaluation of future water quantity and availability.

Keywords: climate variability, future discharge projection, positive degree day, regional climate model, water resource management

Procedia PDF Downloads 290

Authors: Nikoloz Jalabadze, Roin Chedia, Lili Nadaraia, Levan Khundadze

Abstract:

Nanocrystalline materials in powder condition can be manufactured by a number of different methods, however manufacture of composite materials product in the same nanocrystalline state is still a problem because the processes of compaction and synthesis of nanocrystalline powders go with intensive growth of particles – the process which promotes formation of pieces in an ordinary crystalline state instead of being crystallized in the desirable nanocrystalline state. To date spark plasma sintering (SPS) has been considered as the most promising and energy efficient method for producing dense bodies of composite materials. An advantage of the SPS method in comparison with other methods is mainly low temperature and short time of the sintering procedure. That finally gives an opportunity to obtain dense material with nanocrystalline structure. Graphene has recently garnered significant interest as a reinforcing phase in composite materials because of its excellent electrical, thermal and mechanical properties. Graphene nanoplatelets (GNPs) in particular have attracted much interest as reinforcements for ceramic matrix composites (mostly in Al2O3, Si3N4, TiO2, ZrB2 a. c.). SPS has been shown to fully densify a variety of ceramic systems effectively including Al2O3 and often with improvements in mechanical and functional behavior. Alumina consolidated by SPS has been shown to have superior hardness, fracture toughness, plasticity and optical translucency compared to conventionally processed alumina. Knowledge of how GNPs influence sintering behavior is important to effectively process and manufacture process. In this study, the effects of GNPs on the SPS processing of Al2O3 are investigated by systematically varying sintering temperature, holding time and pressure. Our experiments showed that SPS process is also appropriate for the synthesis of nanocrystalline powders of alumina-graphene composites. Depending on the size of the molds, it is possible to obtain different amount of nanopowders. Investigation of the structure, physical-chemical, mechanical and performance properties of the elaborated composite materials was performed. The results of this study provide a fundamental understanding of the effects of GNP on sintering behavior, thereby providing a foundation for future optimization of the processing of these promising nanocomposite systems.

Keywords: alumina oxide, ceramic matrix composites, graphene nanoplatelets, spark-plasma sintering

Procedia PDF Downloads 376

Authors: Soumya Bhattacharjya, Avinandan Sahoo, Gaurav Datta

Abstract:

Wind fragility analysis of chimney is often carried out disregarding temperature effect. However, the combined effect of wind and temperature is the most critical limit state for chimney design. Hence, in the present paper, an efficient fragility analysis for concrete chimney is explored under combined wind and temperature effect. Wind time histories are generated by Davenports Power Spectral Density Function and using Weighed Amplitude Wave Superposition Technique. Fragility analysis is often carried out in full Monte Carlo Simulation framework, which requires extensive computational time. Thus, in the present paper, an efficient adaptive metamodelling technique is adopted to judiciously approximate limit state function, which will be subsequently used in the simulation framework. This will save substantial computational time and make the approach computationally efficient. Uncertainty in wind speed, wind load related parameters, and resistance-related parameters is considered. The results by the full simulation approach, conventional metamodelling approach and proposed adaptive metamodelling approach will be compared. Effect of disregarding temperature in wind fragility analysis will be highlighted.

Keywords: adaptive metamodelling technique, concrete chimney, fragility analysis, stochastic extreme wind load, temperature effect

Procedia PDF Downloads 214

Authors: Mhenga Agneta, Li Zhaomin, Zhang Chao

Abstract:

When velocity is high enough, gas can entrain fluid and carry to the surface, but as time passes by, velocity drops to a critical point where fluids will start to hold up in the tubing and cause liquid loading which prevents gas production and may lead to the death of the well. Foam injection is widely used as one of the methods to unload liquid. Since wells have different characteristics, it is not guaranteed that foam can be applied in all of them and bring successful results. This research presents a technology to optimize the efficiency of foam to unload liquid by air compression. Two methods are used to explain optimization; (i) mathematical formulas are used to solve and explain the myth of how density and critical velocity could be minimized when air is compressed into foaming agents, then the relationship between flow rates and pressure increase which would boost up the bottom hole pressure and increase the velocity to lift liquid to the surface. (ii) Experiments to test foam carryover capacity and stability as a function of time and surfactant concentration whereby three surfactants anionic sodium dodecyl sulfate (SDS), nonionic Triton 100 and cationic hexadecyltrimethylammonium bromide (HDTAB) were probed. The best foaming agents were injected to lift liquid loaded in a created vertical well model of 2.5 cm diameter and 390 cm high steel tubing covered by a transparent glass casing of 5 cm diameter and 450 cm high. The results show that, after injecting foaming agents, liquid unloading was successful by 75%; however, the efficiency of foaming agents to unload liquid increased by 10% with an addition of compressed air at a ratio of 1:1. Measured values and calculated values were compared and brought about ± 3% difference which is a good number. The successful application of the technology indicates that engineers and stakeholders could bring water flooded gas wells back to production with optimized results by firstly paying attention to the type of surfactants (foaming agents) used, concentration of surfactants, flow rates of the injected surfactants then compressing air to the foaming agents at a proper ratio.

Keywords: air compression, foaming agents, gas well, liquid loading

Procedia PDF Downloads 135

Authors: Sunil Mekale, Debasish Chowdhury, Sanchita Patnaik, Amitav Das, Ashok Agarwal

Abstract:

Background: Odisha is a low HIV prevalence state in India (ANC-HIV positivity of 0.42% as per HIV sentinel surveillance 2010-2011); however, it is an important source migration state with 3.2% of male migrants reporting to be PLHIV. USAID Public Health Foundation of India -PIPPSE project is piloting a source-destination corridor programme between Odisha and Gujarat. In Odisha, the focus has been on developing a comprehensive strategy to reach out to the out migrants and their spouses in the place of their origin based on their availability. The project has made concerted attempts to identify vulnerable districts with high out migration and high positivity rate. Description: 48 out of 97 ICTCs were selected from nine top high out migration districts through multistage sampling. A retrospective descriptive analysis of HIV positive male migrants and their spouses for two years (April 2013-March 2015) was conducted. A total of 3,645 HIV positive records were analysed. Findings: Among 34.2% detected HIV positive in the ICTCs, 23.3% were male migrants and 11% were spouses of male migrants; almost 50% of total ICTC attendees. More than 70% of the PLHIV male migrants and their spouses were less than 45 years old. Conclusions: Couple HIV testing approach may be considered for male migrants and their spouses. ICTC data analysis could guide in identifying the locations with high HIV positivity among male migrants and their spouses.

Keywords: HIV testing, migrants, spouse of migrants, Integrated Counselling and Testing Centre (ICTC)

Procedia PDF Downloads 379

Authors: Maryam Ghoreishi, Christian Larsen

Abstract:

In this paper, we investigate the effect of stochastic inputs on problem of joint optimal pricing and lot-sizing decisions where the inventory cycle is divided into advance and spot sales periods. During the advance sales period, customer can make reservations while customer with reservations can cancel their order. However, during the spot sales period customers receive the order as soon as the order is placed, but they cannot make any reservation or cancellation during that period. We assume that the inter arrival times during the advance sales and spot sales period are exponentially distributed where the arrival rate is decreasing function of price. Moreover, we assume that the number of cancelled reservations is binomially distributed. In addition, we assume that deterioration process follows an exponential distribution. We investigate two cases. First, we consider two-state case where we find the optimal price during the spot sales period and the optimal price during the advance sales period. Next, we develop a generalized case where we extend two-state case also to allow dynamic prices during the spot sales period. We apply the Markov decision theory in order to find the optimal solutions. In addition, for the generalized case, we apply the policy iteration algorithm in order to find the optimal prices, the optimal lot-size and maximum advance sales amount.

Keywords: inventory control, pricing, Markov decision theory, advance sales system

Procedia PDF Downloads 324

Authors: S. A. Al-Qallaf, S. A. Al-Mawsawi, A. Haider

Abstract:

Among all FACTS devices, the unified power flow controller (UPFC) is considered to be the most versatile device. This is due to its capability to control all the transmission system parameters (impedance, voltage magnitude, and phase angle). With the growing interest in UPFC, the attention to develop a mathematical model has increased. Several models were introduced for UPFC in literature for different type of studies in power systems. In this paper a novel comparison study between two dynamic models of UPFC with their proposed control strategies.

Keywords: FACTS, UPFC, dynamic modeling, PWM, fundamental frequency

Procedia PDF Downloads 346

Authors: Godwin Dennison, C. E. Boulind, O. Gould, B. de Lacy Costello, J. Allison, P. White, P. Ewings, A. Wicaksono, N. J. Curtis, A. Pullyblank, D. Jayne, J. A. Covington, N. Ratcliffe, N. K. Francis

Abstract:

Background: Colorectal symptoms are common but only infrequently represent serious pathology, including colorectal cancer (CRC). A large number of invasive tests are presently performed for reassurance. We investigated the feasibility of urinary volatile organic compound (VOC) testing as a potential triage tool in patients fast-tracked for assessment for possible CRC. Methods: A prospective, multi-centre, observational feasibility study was performed across three sites. Patients referred on NHS fast-track pathways for potential CRC provided a urine sample which underwent Gas Chromatography Mass Spectrometry (GC-MS), Field Asymmetric Ion Mobility Spectrometry (FAIMS) and Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) analysis. Patients underwent colonoscopy and/or CT colonography and were grouped as either CRC, adenomatous polyp(s), or controls to explore the diagnostic accuracy of VOC output data supported by an artificial neural network (ANN) model. Results: 558 patients participated with 23 (4.1%) CRC diagnosed. 59% of colonoscopies and 86% of CT colonographies showed no abnormalities. Urinary VOC testing was feasible, acceptable to patients, and applicable within the clinical fast track pathway. GC-MS showed the highest clinical utility for CRC and polyp detection vs. controls (sensitivity=0.878, specificity=0.882, AUROC=0.884). Conclusion: Urinary VOC testing and analysis are feasible within NHS fast-track CRC pathways. Clinically meaningful differences between patients with cancer, polyps, or no pathology were identified therefore suggesting VOC analysis may have future utility as a triage tool. Acknowledgment: Funding: NIHR Research for Patient Benefit grant (ref: PB-PG-0416-20022).

Keywords: colorectal cancer, volatile organic compound, gas chromatography mass spectrometry, field asymmetric ion mobility spectrometry, selected ion flow tube mass spectrometry

Procedia PDF Downloads 91