Search results for: peak ground velocity

Authors: Rohit Shrivastava, Stefan Luding

Abstract:

A mechanical wave is propagation of vibration with transfer of energy and momentum. Studying the energy as well as spectral energy characteristics of a propagating wave through disordered granular media can assist in understanding the overall properties of wave propagation through inhomogeneous materials like soil. The study of these properties is aimed at modeling wave propagation for oil, mineral or gas exploration (seismic prospecting) or non-destructive testing for the study of internal structure of solids. The study of Energy content (Kinetic, Potential and Total Energy) of a pulse propagating through an idealized one-dimensional discrete particle system like a mass disordered granular chain can assist in understanding the energy attenuation due to disorder as a function of propagation distance. The spectral analysis of the energy signal can assist in understanding dispersion as well as attenuation due to scattering in different frequencies (scattering attenuation). The selection of one-dimensional granular chain also helps in studying only the P-wave attributes of the wave and removing the influence of shear or rotational waves. Granular chains with different mass distributions have been studied, by randomly selecting masses from normal, binary and uniform distributions and the standard deviation of the distribution is considered as the disorder parameter, higher standard deviation means higher disorder and lower standard deviation means lower disorder. For obtaining macroscopic/continuum properties, ensemble averaging has been used. Interpreting information from a Total Energy signal turned out to be much easier in comparison to displacement, velocity or acceleration signals of the wave, hence, indicating a better analysis method for wave propagation through granular materials. Increasing disorder leads to faster attenuation of the signal and decreases the Energy of higher frequency signals transmitted, but at the same time the energy of spatially localized high frequencies also increases. An ordered granular chain exhibits ballistic propagation of energy whereas, a disordered granular chain exhibits diffusive like propagation, which eventually becomes localized at long periods of time.

Keywords: discrete elements, energy attenuation, mass disorder, granular chain, spectral energy, wave propagation

Procedia PDF Downloads 267

Authors: Yun Chen, Qihang Liu, Catherine Ticehurst, Chandrama Sarker, Fazlul Karim, Dave Penton, Ashmita Sengupta

Abstract:

The application of ICESAT-2 altimetry data in river hydrology critically depends on the accuracy of the mean water surface elevation (WSE) at a virtual station (VS) where satellite observations intersect with water. The ICESAT-2 track generates multiple VSs as it crosses the different water bodies. The difficulties are particularly pronounced in large river basins where there are many tributaries and meanders often adjacent to each other. One challenge is to split photon segments along a beam to accurately partition them to extract only the true representative water height for individual elements. As far as we can establish, there is no automated procedure to make this distinction. Earlier studies have relied on human intervention or river masks. Both approaches are unsatisfactory solutions where the number of intersections is large, and river width/extent changes over time. We describe here an automated approach called “auto-segmentation”. The accuracy of our method was assessed by comparison with river water level observations at 10 different stations on 37 different dates along the Lower Murray River, Australia. The congruence is very high and without detectable bias. In addition, we compared different outlier removal methods on the mean WSE calculation at VSs post the auto-segmentation process. All four outlier removal methods perform almost equally well with the same R2 value (0.998) and only subtle variations in RMSE (0.181–0.189m) and MAE (0.130–0.142m). Overall, the auto-segmentation method developed here is an effective and efficient approach to deriving accurate mean WSE at river VSs. It provides a much better way of facilitating the application of ICESAT-2 ATL13 altimetry to rivers compared to previously reported studies. Therefore, the findings of our study will make a significant contribution towards the retrieval of hydraulic parameters, such as water surface slope along the river, water depth at cross sections, and river channel bathymetry for calculating flow velocity and discharge from remotely sensed imagery at large spatial scales.

Keywords: lidar sensor, virtual station, cross section, mean water surface elevation, beam/track segmentation

Procedia PDF Downloads 47

Authors: Kassahun Tilahun Dessie

Abstract:

The purpose of this study was to explore the awareness of teachers and the attitude they have to the curriculum they implement as well as to assess the actual and desired magnitude of teachers' participation in curriculum development process. It also aimed at investigating the factors that affect teachers' level of conception and perception towards the new higher education curriculum. The study was carried out in Debre Birhan University. Teachers, course coordinators, team leaders and presidents were included in the study as research subjects. Teachers were proportionally selected from each department (of the six faculties) based on available sampling technique. Accordingly, a total of 103 teachers were chosen as a subject of the study. In order to collect first hand data from the teachers, a questionnaire with four parts was developed by the researcher. To this end, scales were designed for measuring the extent of teachers' awareness and attitude. Each of the scales encompasses 11 and 17 items respectively. An open ended questionnaire was also attached for the purpose of obtaining elaborated data on the issue. Information was also obtained from interviews with presidents, team leaders and course coordinators. The data obtained were analyzed qualitatively using descriptive statistical tools. The overall results of the analysis revealed that the awareness of teachers on the curriculum was low. The meager participation of teachers in the process of curriculum development and the deficiency of trainings on the concern were major factors. Teachers' perception towards the existence and implementation of the new curriculum was also inclined to the negative, though difficult to generalize. Lack of awareness, administrators poor approach and lack of facilitating appropriate incentives as well as absence of room for evaluating the curriculum etc plays big role in endangering teachers attitude while the up to datedness of the new curriculum, involvement of teachers in the curriculum development process, the wide ranging quality of the new curriculum etc laid a better ground to boost teachers attitude towards the curriculum. This may have implication to the university in that there is a need to facilitate workshops or awareness creation trainings, to have positive and cooperative administrators, and embracing committed teachers to implement the curriculum efficiently.

Keywords: conception, perception, curriculum, higher education, Ethiopia

Procedia PDF Downloads 482

Authors: Claudia Huerta, Pepijn Doornenbal, Walaa Elsiddig

Abstract:

Rising waves of nationalism around the world have led first-world migration receiving countries to exploit the ambiguity of international refugee law and establish asylum application processes that deter applications, allow for bureaucratic deniability, and violate human rights. This case study of Greek asylum application practices argues that the 'pre-application' asylum process in Greece violates the spirit of international law by making it incredibly difficult for potential asylum seekers to apply for asylum, in essence violating the human rights of thousands of asylum seekers. This study’s focus is on the Greek mainland’s asylum 'pre-application' process, which in 2016 began to require those wishing to apply for asylum to do so during extremely restricted hours via a basic Skype line. The average wait to simply begin the registration process to apply for asylum is 81 days, during which time applicants are forced to live illegally in Greece. This study’s methodology in analyzing the 'pre-application' process consists of hours of interviews with asylum seekers, NGOs, and the Asylum Service office on the ground in Athens, as well as an analysis of the Greek Asylum Service historical asylum registration statistics. This study presents three main findings: the delays associated with the Skype system in Greece are the result of system design, as proven by a statistical analysis of Greek asylum registrations, NGOs have been co-opted by the state to perform state functions during the process, and the government’s use of technology is both purposefully lazy and discriminatory. In conclusion, the study argues that such asylum practices are part of a pattern of first-world migration receiving countries policies’ which discourage asylum seekers from applying and fall short of the standards in international law.

Keywords: asylum, European Union, governance, Greece, irregular, migration, policy, refugee, Skype

Procedia PDF Downloads 111

Authors: Rahman Davtalab

Abstract:

Florida is one of the most vulnerable states to natural disasters among the 50 states of the USA. The state exposed by tropical storms, hurricanes, storm surge, landslide, etc. Besides, the mentioned natural phenomena, global warming, sea-level rise, and other anthropogenic environmental changes make a very complicated and unpredictable system for decision-makers. In this study, we tried to highlight the effects of climate change and sea-level rise on surface water and groundwater systems for three different geographical locations in Florida; Main Canal of Jacksonville Beach (in the northeast of Florida adjacent to the Atlantic Ocean), Grace Lake in central Florida, far away from surrounded coastal line, and Mc Dill in Florida and adjacent to Tampa Bay and Mexican Gulf. An integrated hydrologic and hydraulic model was developed and simulated for all three cases, including surface water, groundwater, or a combination of both. For the case study of Main Canal-Jacksonville Beach, the investigation showed that a 76 cm sea-level rise in time horizon 2060 could increase the flow velocity of the tide cycle for the main canal's outlet and headwater. This case also revealed how the sea level rise could change the tide duration, potentially affecting the coastal ecosystem. As expected, sea-level rise can raise the groundwater level. Therefore, for the Mc Dill case, the effect of groundwater rise on soil storage and the performance of stormwater retention ponds is investigated. The study showed that sea-level rise increased the pond’s seasonal high water up to 40 cm by time horizon 2060. The reliability of the retention pond is dropped from 99% for the current condition to 54% for the future. The results also proved that the retention pond could not retain and infiltrate the designed treatment volume within 72 hours, which is a significant indication of increasing pollutants in the future. Grace Lake case study investigates the effects of climate change on groundwater recharge. This study showed that using the dynamically downscaled data of the groundwater recharge can decline up to 24% by the mid-21st century.

Keywords: groundwater, surface water, Florida, retention pond, tide, sea level rise

Procedia PDF Downloads 165

Authors: L. L. Tundisi, A. Pessoa Jr., E. B. Tambourgi, E. Silveira, P. G. Mazzola

Abstract:

L-asparaginase (L-ASNase) is the gold standard treatment for acute lymphoblastic leukemia that mainly affects pediatric patients; treatment increases survival from 20% to 90%. The characterization of other L-Asparaginases, apart from the most used from Escherichia coli and Erwinia chrysanthemi, has been reported, but the choice of the most appropriate is still under debate. This choice should be based on its pharmacokinetics, immune hypersensitivity, doses, prices, pharmacodynamics. The main factors influencing the antileukemic activity of ASNase are enzymatic activity, Km, glutaminase activity, clearance of the enzyme and development of resistance. However, most of the commercialized enzyme present an intrinsic glutaminase activity, which is responsible for some side effects. In this study, glutaminase free asparaginase produced from Aspergillus oryzae was precipitated in different percentages of ethanol (0–80%), until optimum ethanol concentration of 60% (w/w) was found. Following, precipitation of crude L-ASNase was performed in a single step, using 60% (w/w) ethanol, under constant agitation and temperature. It presented activity of 135.45 U/mg and after gel filtration chromatography with Sephadex G-the enzymatic activity was 322.02 U/mg. The apparent molecular mass of the purified L-ASNase fraction was estimated by 10% SDS-PAGE. Proteins were stained with Coomassie Brilliant Blue R-250. The molar mass range was from 10 kDa to 250 kDa. L-ASNase from Aspergillus oryzae was characterized aiming possible therapeutic use. Four different buffers (phosphate-citrate buffer pH 2.6 to 5.8; phosphate buffer pH 5.8 to 7.4; Tris - HCl pH 7.4 to 9.0; and carbonate buffer pH 9.8 to 10.6) were used to measure the optimum pH for L-ASNase activity. The optimum temperature for enzyme activity was measured at optimal pH conditions (Tris-HCl and phosphate buffer, pH 7.4) at different temperatures ranging from 5 to 55°C. All activities were calculated by quantifying the free ammonia, using the Nessler reagent. The kinetic parameters calculation, e.g. Michaelis-Menten constant (Km), maximum velocity (Vmax) and Hills coefficient (n), were performed by incubating the enzyme in different concentrations of the substrate at optimum conditions of pH and fitted on Hill’s equation. This glutaminase free asparaginase showed a low Km (3.39 mM and 3.81 mM) and enzymatic activity of 135.45 U/mg after precipitation with ethanol. After gel filtration chromatography it rose to 322.02 U/mg. Optimum activity was found between pH 5.8 - 9.0, best activity results with phosphate buffer pH 7.4 and Tris-HCl pH 7.4 and showed activity from 5°C to 55°C. These results indicate that L-ASNase from A. oryzae has the potential for human use.

Keywords: biopharmaceuticals, bioprocessing, bioproducts, biotechnology, enzyme activity, ethanol precipitation

Procedia PDF Downloads 276

Authors: Francisco Liaño-Carrera, José Isaac Ramírez-Macías, David Salas-Monreal, Mayra Lorena Riveron-Enzastiga, Marcos Rangel-Avalos, Adriana Andrea Roldán-Ubando

Abstract:

The construction of most coastal infrastructure developments around the world are usually made considering wave height, current velocities and river discharges; however, little effort has been paid to surveying sediment transport during dredging or the modification to currents outside the ports or marinas during and after the construction. This study shows a complete survey during the construction of one of the largest ports of the Gulf of Mexico. An anchored Acoustic Doppler Current Velocity profiler (ADCP), a towed ADCP and a combination of model outputs were used at the Veracruz port construction in order to describe the hourly sediment transport and current modifications in and out of the new port. Owing to the stability of the system the new port was construction inside Vergara Bay, a low wave energy system with a tidal range of up to 0.40 m. The results show a two-current system pattern within the bay. The north side of the bay has an anticyclonic gyre, while the southern part of the bay shows a cyclonic gyre. Sediment transport trajectories were made every hour using the anchored ADCP, a numerical model and the weekly data obtained from the towed ADCP within the entire bay. The sediment transport trajectories were carefully tracked since the bay is surrounded by coral reef structures which are sensitive to sedimentation rate and water turbidity. The survey shows that during dredging and rock input used to build the wave breaker sediments were locally added (< 2500 m²) and local currents disperse it in less than 4 h. While the river input located in the middle of the bay and the sewer system plant may add more than 10 times this amount during a rainy day or during the tourist season. Finally, the coastal line obtained seasonally with a drone suggests that the southern part of the bay has not been modified by the construction of the new port located in the northern part of the bay, owing to the two subsystem division of the bay.

Keywords: Acoustic Doppler Current Profiler, construction around coral reefs, dredging, port construction, sediment transport monitoring,

Procedia PDF Downloads 213

Authors: Prem, Norhaya, Vwrene C., Mohammad Harris A., Amarjit, Fazir M.

Abstract:

Upper limb surgery is a common orthopedic procedure. After surgery, it is necessary to raise the patient's arm to reduce limb swelling and promote recovery. After an injury or surgery, swelling (edema) in the limbs is common. This swelling can be painful, cause stiffness, and affect movement and ability to do daily activities. One of the easiest ways to manage swelling is to elevate the swollen limb. The goal is to elevate the swollen limb slightly above the level of the heart. This helps the extra fluid move back towards the heart for circulation to the rest of the body. Conventional arm sling or pillows are usually placed under the arm to raise it, but in this way the arm cannot be fixed well and easily slide down, without ideal raising effect. Conventional arm sling need experience to tie the sling and this delay in the application process. To reduce the waiting time and cost, modified Norhaya upper limb elevation sling was designed and made readily available. The sling is made from calico fabric, readily available in the ward. Measurements of patients’ arm lengths are obtained, and fabric sizes are cut into the average arm lengths, as well as 1 size above and below. The cut calico fabric is then sewn together with thick sewing threads. Its application is easy and junior most staff or doctor will be able to apply it on patient. The time taken to set up the sling is also reduced. Feedback gathered from ground staff regarding ease of setting up the sling was tremendous and patient also feel comfort in the modified Norhaya sling. The device can freely adjust the raising height of the affected limb and effectively fix the affected limb to reduce its swelling, thus promoting recovery. This device is worthy to be clinically popularized and applied. The Modified Norhaya upper limb elevation sling is the quickest to set up and the delay in elevating the patient’s hand is significantly reduced. Moreover, it is reproducible and there is also significant cost savings.

Keywords: elevate, effective, sling, timely

Procedia PDF Downloads 174

Authors: Christina Peristeri, Tobias Berg, Domenico Caridi, Paul Hutcheson, Robert Winstanley

Abstract:

In recent years the demand for rapid innovations in the automotive industry has led to the need for accelerated simulation procedures while retaining a detailed representation of the simulated phenomena. The project’s aim is to create a fast transient workflow for external aerodynamic CFD simulations of road vehicles. The geometry used was the SAE Notchback Closed Cooling DrivAer model, and the simulation results were compared with data from wind tunnel tests. The meshes generated for this study were of two types. One was a mix of polyhedral cells near the surface and hexahedral cells away from the surface. The other was an octree hex mesh with a rapid method of fitting to the surface. Three different grid refinement levels were used for each mesh type, with the biggest total cell count for the octree mesh being close to 1 billion. A series of steady-state solutions were obtained on three different grid levels using a pseudo-transient coupled solver and a k-omega-based RANS turbulence model. A mesh-independent solution was found in all cases with a medium level of refinement with 200 million cells. Stress-Blended Eddy Simulation (SBES) was chosen for the transient simulations, which uses a shielding function to explicitly switch between RANS and LES mode. A converged pseudo-transient steady-state solution was used to initialize the transient SBES run that was set up with the SIMPLEC pressure-velocity coupling scheme to reach the fastest solution (on both CPU & GPU solvers). An important part of this project was the use of FLUENT’s Multi-GPU solver. Tesla A100 GPU has been shown to be 8x faster than an Intel 48-core Sky Lake CPU system, leading to significant simulation speed-up compared to the traditional CPU solver. The current study used 4 Tesla A100 GPUs and 192 CPU cores. The combination of rapid octree meshing and GPU computing shows significant promise in reducing time and hardware costs for industrial strength aerodynamic simulations.

Keywords: CFD, DrivAer, LES, Multi-GPU solver, octree mesh, RANS

Procedia PDF Downloads 98

Authors: Sarchil H. Qader, Andrew Harfoot, Mathias Kuepie, Sabrina Juran, Attila Lazar, Andrew J. Tatem

Abstract:

The need for high-quality, reliable, and timely population data, including demographic information, to support the achievement of the sustainable development goals (SDGs) in all countries was recognized by the United Nations' 2030 Agenda for sustainable development. However, many low and middle-income countries lack reliable and recent census data. To achieve reliable and accurate census and survey outputs, up-to-date census enumeration areas and digital national sampling frames are critical. Census enumeration areas (EAs) are the smallest geographic units for collection, disseminating, and analyzing census data and are often used as a national sampling frame to serve various socio-economic surveys. Even for countries that are wealthy and stable, creating and updating EAs is a difficult yet crucial step in preparing for a national census. Such a process is commonly done manually, either by digitizing small geographic units on high-resolution satellite imagery or walking the boundaries of units, both of which are extremely expensive. We have developed a user-friendly tool that could be employed to generate draft EA boundaries automatically. The tool is based on high-resolution gridded population and settlement datasets, GPS household locations, building footprints and uses publicly available natural, man-made and administrative boundaries. Initial outputs were produced in Burkina Faso, Paraguay, Somalia, Togo, Niger, Guinea, and Zimbabwe. The results indicate that the EAs are in line with international standards, including boundaries that are easily identifiable and follow ground features, have no overlaps, are compact and free of pockets and disjoints, and the boundaries are nested within administrative boundaries.

Keywords: enumeration areas, national sampling frame, gridded population data, preEA tool

Procedia PDF Downloads 122

Authors: E. A. Amao, O. D. Amao, Z. O. Buzari, T. M. Adelegan, W. A. Tiamiyu, M. O. Yunus

Abstract:

Signals from in vivo as well as in vitro studies shows that botanicals play notable roles in the treatment, prevention and management of diseases. Use of natural compounds in botanicals has been suggested as potential alternative to conventional therapeutic options. Therefore this study aimed to evaluate the effect of varying levels of turmeric powder (Curcuma longa) on semen characteristics and haematological indices of cocks. Turmeric (C. longa) was obtained from a local market in Saki in Oyo State, Nigeria, in March 2023. The rhizomes were washed, its skin scraped and air-dried for about 10 h, and further oven-dried at 40◦C for 12 h. afterwards, the dried turmeric was ground into powder using a blender. The product was kept in an air-tight container until the period of usage. The experimental material was drenched in cocks (60 cocks assigned into four treatments with three replicates) at 0.0g (T1), 0.05g (T2), 1.00g (T3) and 1.5g (T4) after 2 weeks of acclimatization. Semen volume, sperm cell progressive motility, sperm cell liveability, acrosome integrity, sperm cell concentration and normal sperm cell were evaluated for semen characteristics. Haematological parameters measured were: PCV, RBC, WBC Hb, MCV, MCH and MCHC. Data obtained were subjected to one-way analysis of variance. Semen volume (0.34 – 0.37ml), sperm cell progressive motility (68.33 – 80%), sperm cell liveability (46.66 – 85.00%), acrosome integrity (50.00 – 85%) and normal sperm cell (66.66 – 90%) shows significant difference (p<0.05) in favour cocks on higher level of turmeric powder. While sperm cell concentration (28.33 -40.00 X109/ml) shows no significant difference (p>0.05). PCV (36.00 – 40.33%), RBC (3.55 – 3.74 X106/ml), WBC (19.01 – 19.71 X109/ml), Hb (11.66 – 13.00 dl), MCV (100.53 – 109.53 ⴄ), MCH (32.57 – 35.31pg) and MCHC (32.00 – 32.37%) shows no significant difference (p>0.05). all serum biochemical indices showed significant difference (p<0.05) with animals on the test ingredient showed higher values in respect of the increase in turmeric powder.

Keywords: semen volume, total protein, packed cell volume, turmeric powder, albumin

Procedia PDF Downloads 33

Authors: Yakubu Adamu, Baba Alfa, Salahudeen Adamu Gene

Abstract:

As the drive towards clean, renewable and sustainable energy generation is gradually been reshaped by renewable penetration over time, energy storage has thus, become an optimal solution for utilities looking to reduce transmission and capacity cost, therefore the need for capacity resources to be adjusted accordingly such that renewable energy storage may have the opportunity to substitute for retiring conventional energy systems with higher capacity factors. Considering the Nigeria scenario, where Over 80% of the current Nigerian primary energy consumption is met by petroleum, electricity demand is set to more than double by mid-century, relative to 2025 levels. With renewable energy penetration rapidly increasing, in particular biomass, hydro power, solar and wind energy, it is expected to account for the largest share of power output in the coming decades. Despite this rapid growth, the imbalance between load and resources has created a hindrance to the development of energy storage capacity, load and resources, hence forecasting energy storage capacity will therefore play an important role in maintaining the balance between load and resources including supply and demand. Therefore, the degree to which this might occur, its timing and more importantly its sustainability, is the subject matter of the current research. Here, we forecast the future energy storage capacity rating and thus, evaluate the load and resource scenario in Nigeria. In doing so, We used the scenario-based International Energy Agency models, the projected energy demand and supply structure of the country through 2030 are presented and analysed. Overall, this shows that in high renewable (solar) penetration scenarios in Nigeria, energy storage with 4-6h duration can obtain over 86% capacity rating with storage comprising about 24% of peak load capacity. Therefore, the general takeaway from the current study is that most power systems currently used has the potential to support fairly large penetrations of 4-6 hour storage as capacity resources prior to a substantial reduction in capacity ratings. The data presented in this paper is a crucial eye-opener for relevant government agencies towards developing these energy resources in tackling the present energy crisis in Nigeria. However, if the transformation of the Nigeria. power system continues primarily through expansion of renewable generation, then longer duration energy storage will be needed to qualify as capacity resources. Hence, the analytical task from the current survey will help to determine whether and when long-duration storage becomes an integral component of the capacity mix that is expected in Nigeria by 2030.

Keywords: capacity, energy, power system, storage

Procedia PDF Downloads 19

Authors: Samuel O. Akande

Abstract:

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

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

Procedia PDF Downloads 172

Authors: Amiya Kumar Pati, Spandan Sahu, Kishanjit Kumar Khatua

Abstract:

River is our main source of water which is a form of open channel flow and the flow in the open channel provides with many complex phenomena of sciences that needs to be tackled such as the critical flow conditions, boundary shear stress, and depth-averaged velocity. The development of society, more or less solely depends upon the flow of rivers. The rivers are major sources of many sediments and specific ingredients which are much essential for human beings. A river flow consisting of small and shallow channels sometimes divide and recombine numerous times because of the slow water flow or the built up sediments. The pattern formed during this process resembles the strands of a braid. Braided streams form where the sediment load is so heavy that some of the sediments are deposited as shifting islands. Braided rivers often exist near the mountainous regions and typically carry coarse-grained and heterogeneous sediments down a fairly steep gradient. In this paper, the apparent shear stress formulae were suitably modified, and the Energy Concept Method (ECM) was applied for the prediction of discharges at the junction of a two-flow braided compound channel. The Energy Concept Method has not been applied for estimating the discharges in the braided channels. The energy loss in the channels is analyzed based on mechanical analysis. The cross-section of channel is divided into two sub-areas, namely the main-channel below the bank-full level and region above the bank-full level for estimating the total discharge. The experimental data are compared with a wide range of theoretical data available in the published literature to verify this model. The accuracy of this approach is also compared with Divided Channel Method (DCM). From error analysis of this method, it is observed that the relative error is less for the data-sets having smooth floodplains when compared to rough floodplains. Comparisons with other models indicate that the present method has reasonable accuracy for engineering purposes.

Keywords: critical flow, energy concept, open channel flow, sediment, two-flow braided compound channel

Procedia PDF Downloads 115

Authors: Gabrielle Peck, Ryan Hayes

Abstract:

Four façade systems were tested using a reduced height BS 8414-2 (5 m) test rig. An L-shaped masonry test wall was clad with three types of insulation and an aluminum composite panel with a non-combustible filling (meeting Euroclass A2). A large (3 MW) wooden crib was ignited in a recess at the base of the L, and the fire was allowed to burn for 30 minutes. Air velocity measurements and gas samples were taken from the main ventilation duct and also a small additional ventilation duct, like those in an apartment bathroom or kitchen. This provided a direct route of travel for smoke from the building façade to a theoretical room using a similar design to many high-rise buildings where the vent is connected to (approximately) 30 m³ rooms. The times to incapacitation and lethality of the effluent were calculated for both the main exhaust vent and for a vent connected to a theoretical 30 m³ room. The rainscreen façade systems tested were the common combinations seen in many tower blocks across the UK. Three tests using ACM A2 with Stonewool, Phenolic foam, and Polyisocyanurate (PIR) foam. A fourth test was conducted with PIR and ACM-PE (polyethylene core). Measurements in the main exhaust duct were representative of the effluent from the burning wood crib. FEDs showed incapacitation could occur up to 30 times quicker with combustible insulation than non-combustible insulation, with lethal gas concentrations accumulating up to 2.7 times faster than other combinations. The PE-cored ACM/PIR combination produced a ferocious fire, resulting in the termination of the test after 13.5 minutes for safety reasons. Occupants of the theoretical room in the PIR/ACM A2 test reached a FED of 1 after 22 minutes; for PF/ACM A2, this took 25 minutes, and for stone wool, a lethal dose measurement of 0.6 was reached at the end of the 30-minute test. In conclusion, when measuring smoke toxicity in the exhaust duct, there is little difference between smoke toxicity measurements between façade systems. Toxicity measured in the main exhaust is largely a result of the wood crib used to ignite the façade system. The addition of a vent allowed smoke toxicity to be quantified in the cavity of the façade, providing a realistic way of measuring the toxicity of smoke that could enter an apartment from a façade fire.

Keywords: smoke toxicity, large-scale testing, BS8414, FED

Procedia PDF Downloads 43

Authors: Edvard Kokanyan, Narine Babajanyan, Ninel Kokanyan, Marco Bazzan

Abstract:

Lithium niobate (LN) crystals, renowned for their exceptional nonlinear optical, electro-optical, piezoelectric, and photorefractive properties, stand as foundational materials in diverse fields of study and application. While they have long been utilized in frequency converters of laser radiation, electro-optical modulators, and holographic information recording media, LN crystals doped with rare earth ions represent a compelling frontier for modern compact devices. These materials exhibit immense potential as key components in infrared lasers, optical sensors, self-cooling systems, and radiation balanced laser setups. In this study, we present the successful synthesis of Ho-doped lithium niobate (LN:Ho) thin films on sapphire substrates employing the Sol-Gel technique. The films exhibit a strong crystallographic orientation along the perpendicular direction to the substrate surface, with X-ray diffraction analysis confirming the predominant alignment of the film's "c" axis, notably evidenced by the intense (006) reflection peak. Further characterization through Raman spectroscopy, employing a confocal Raman microscope (LabRAM HR Evolution) with exciting wavelengths of 532 nm and 785 nm, unraveled intriguing insights. Under excitation with a 785 nm laser, Raman scattering obeyed selection rules, while employing a 532 nm laser unveiled additional forbidden lines reminiscent of behaviors observed in bulk LN:Ho crystals. These supplementary lines were attributed to luminescence induced by excitation at 532 nm. Leveraging data from anti-Stokes Raman lines facilitated the disentanglement of luminescence spectra from the investigated samples. Surface scanning affirmed the uniformity of both structure and luminescence across the thin films. Notably, despite the robust orientation of the "c" axis perpendicular to the substrate surface, Raman signals indicated a stochastic distribution of "a" and "b" axes, validating the mosaic structure of the films along the mentioned axis. This study offers valuable insights into the structural properties of Ho-doped lithium niobate thin films, with the observed luminescence behavior holding significant promise for potential applications in optoelectronic devices.

Keywords: lithium niobate, Sol-Gel, luminescence, Raman spectroscopy

Procedia PDF Downloads 37

Authors: Abhisek Dash

Abstract:

This study had three neural networks, one for number segmentation, one for number detection and one for number recognition all of which are coupled to one another. All networks were trained on the MNIST dataset and were convolutional. It was assumed that the images had lighter background and darker foreground. The segmentation network took 28x28 images as input and had sixteen outputs. Segmentation training starts when a dark pixel is encountered. Taking a window(7x7) over that pixel as focus, the eight neighborhood of the focus was checked for further dark pixels. The segmentation network was then trained to move in those directions which had dark pixels. To this end the segmentation network had 16 outputs. They were arranged as “go east”, ”don’t go east ”, “go south east”, “don’t go south east”, “go south”, “don’t go south” and so on w.r.t focus window. The focus window was resized into a 28x28 image and the network was trained to consider those neighborhoods which had dark pixels. The neighborhoods which had dark pixels were pushed into a queue in a particular order. The neighborhoods were then popped one at a time stitched to the existing partial image of the number one at a time and trained on which neighborhoods to consider when the new partial image was presented. The above process was repeated until the image was fully covered by the 7x7 neighborhoods and there were no more uncovered black pixels. During testing the network scans and looks for the first dark pixel. From here on the network predicts which neighborhoods to consider and segments the image. After this step the group of neighborhoods are passed into the detection network. The detection network took 28x28 images as input and had two outputs denoting whether a number was detected or not. Since the ground truth of the bounds of a number was known during training the detection network outputted in favor of number not found until the bounds were not met and vice versa. The recognition network was a standard CNN that also took 28x28 images and had 10 outputs for recognition of numbers from 0 to 9. This network was activated only when the detection network votes in favor of number detected. The above methodology could segment connected and overlapping numbers. Additionally the recognition unit was only invoked when a number was detected which minimized false positives. It also eliminated the need for rules of thumb as segmentation is learned. The strategy can also be extended to other characters as well.

Keywords: convolutional neural networks, OCR, text detection, text segmentation

Procedia PDF Downloads 140

Authors: Sheraz Ahmad, Li Yiming, Li XiangFang, Xia Wei, Zeen Chen

Abstract:

Holding CO₂ at massive scale in the enclathrated solid matter called hydrate can be perceived as one of the most reliable methods for CO₂ sequestration to take greenhouse gases emission control measures and global warming preventive actions. In this study, a dynamically coupled mass and heat transfer mathematical model is developed which elaborates the unsteady behavior of CO₂ flowing into a porous medium and converting itself into hydrates. The combined numerical model solution by implicit finite difference method is explained and through coupling the mass, momentum and heat conservation relations, an integrated model can be established to analyze the CO₂ hydrate growth within P-T equilibrium conditions. CO₂ phase transition, effect of hydrate nucleation by exothermic heat release and variations of thermo-physical properties has been studied during hydrate nucleation. The results illustrate that formation pressure distribution becomes stable at the early stage of hydrate nucleation process and always remains stable afterward, but formation temperature is unable to keep stable and varies during CO₂ injection and hydrate nucleation process. Initially, the temperature drops due to cold high-pressure CO₂ injection since when the massive hydrate growth triggers and temperature increases under the influence of exothermic heat evolution. Intermittently, it surpasses the initial formation temperature before CO₂ injection initiates. The hydrate growth rate increases by increasing injection pressure in the long formation and it also expands overall hydrate covered length in the same induction period. The results also show that the injection pressure conditions and hydrate growth rate affect other parameters like CO₂ velocity, CO₂ permeability, CO₂ density, CO₂ and H₂O saturation inside the porous medium. In order to enhance the hydrate growth rate and expand hydrate covered length, the injection temperature is reduced, but it did not give satisfactory outcomes. Hence, CO₂ injection in vacated natural gas hydrate porous sediment may form hydrate under low temperature and high-pressure conditions, but it seems very challenging on a huge scale in lengthy formations.

Keywords: CO₂ hydrates, CO₂ injection, CO₂ Phase transition, CO₂ sequestration

Procedia PDF Downloads 119

Authors: Hatice Idil Gorgen

Abstract:

Turkey has been investing in its national defence industrial base since the 1980s. State’s role in defence industry showed differences in Turkey. Parallel with this, ruling group’s attitude toward companies in defence sector varied. These changes in policies and behaviors of the state have occurred throughout such milestones as political and economic turmoil in domestic and international level. Hence, it is argued that state’s role, relations with private companies in defense sector and its policies towards the defense industry has shown differences due to the international system, political institutions, ideas and political coalitions in Turkey since the 1980s. Therefore, in order to see changes in the role of the state in defence sector, this paper aims to indicate first, history of state’s role in production and defence industry in the post-1980s era. Secondly, to comprehend the changes in the state’s role in defence industry, Stephan Haggard’s sources of policy change will be provided in the theoretical ground. Thirdly, state cooperated, and joint venture defence firms, state’s actions toward them will be observed. The remaining part will explore the underlying reasons for the changes in the role of the state in defence industry, and it implicitly or explicitly impacts on state business relations. Major findings illustrate that targeted idea of self-sufficient or autarky Turkey to attract domestic audience and to raise the prestige through defence system; ruling elites can regard defence industry and involved business groups as a mean for their ends. State dominant value, sensitive perception which has been ever since Ottoman Empire, prioritizes business groups in defence industry compared to others and push the ruling elites to pursue hard power in defence sectors. Through the globally structural transformation in defence industry, integration of Turkey to liberal bloc deepened and widened interdependence among states. Although it is a qualitative study, it involves the numerated data and descriptive statistics. Data will be collected by searching secondary sources from the literature, examining official documents of ministry of defence, and other appropriate ministries.

Keywords: defense industry, state and business relations, public private relations, arm industry

Procedia PDF Downloads 297

Authors: Chitra Rajagopal, Indra Deo Kumar, Ila Chauhan, Ruchi Joshi, Binoy Bhargavan

Abstract:

Reliability and safety are essential for the success of mission-critical and safety-critical defense systems. Humans are part of the entire life cycle of defense systems development and deployment. The majority of industrial accidents or disasters are attributed to human errors. Therefore, considerations of human performance and human reliability are critical in all complex systems, including defense systems. Defense systems are operating from the ground, naval and aerial platforms in diverse conditions impose unique physical and psychological challenges to the human operators. Some of the safety and mission-critical defense systems with human-machine interactions are fighter planes, submarines, warships, combat vehicles, aerial and naval platforms based missiles, etc. Human roles and responsibilities are also going through a transition due to the infusion of artificial intelligence and cyber technologies. Human operators, not accustomed to such challenges, are more likely to commit errors, which may lead to accidents or loss events. In such a scenario, it is imperative to understand the human factors in defense systems for better systems performance, safety, and cost-effectiveness. A case study using Task Analysis (TA) based methodology for assessment and reduction of human errors in the Air and Missile Defense System in the context of emerging technologies were presented. Action-oriented task analysis techniques such as Hierarchical Task Analysis (HTA) and Operator Action Event Tree (OAET) along with Critical Action and Decision Event Tree (CADET) for cognitive task analysis was used. Human factors assessment based on the task analysis helps in realizing safe and reliable defense systems. These techniques helped in the identification of human errors during different phases of Air and Missile Defence operations, leading to meet the requirement of a safe, reliable and cost-effective mission.

Keywords: defence systems, reliability, risk, safety

Procedia PDF Downloads 116

Authors: Amol Rakhunde, Namdeo Hedaoo

Abstract:

Cold bituminous emulsion mixes (CBEM) are preferred due to their low cost for the construction of low volume roads in India. Due to the low strength of CBEM’s, the strength is generally increased by the addition of Ordinary Portland Cement (OPC) and hydrated lime. To improve the performance of CBEM’s, the use of industrial waste material is also an alternative. Steel slag is by product of steel industry which is sustainable construction material. Due to limited modes of practice of utilization steel slag, huge amount of steel slag dumped in yards of each steel industry and engaging of important agricultural land and gave pollution to whole environment. The effective use of steel slag as additives in CBEM’s has ultimate benefits such improvement in strength of CBEM’s, waste disposal steel slag, saving natural aggregate and lowering cost of roadways. Studies carried out in the past have shown a significant improvement in the strength of CBEM’s prepared with the replacement of natural aggregate with industrial waste materials such as fly ash and ground granulated blast furnace slag. In this study, effect of modified mix which is mixes prepared with steel slag compared with the control mix and the mixes prepared with OPC. Experimental work was carried out on the sample of control mix, OPC mix, and modified mix. For modified mix, aggregate was replaced with steel slag by 10%, 20%, 30% and 40% of weight of aggregate of same size as of steel slag in aggregate gradation. For OPC mix, filler was replaced by 1%, 2% and 3% of weight of total aggregate with OPC. Optimum emulsion content of each mix obtained by using Marshall stability test and comparison of stability values were carried out. Marshall stability, indirect tensile strength test, and retained stability tests are performed on control mixes, OPC mixes and modified mixes. Significant improvement in Marshall stability retained stability and indirect tensile strength of modified mix compared to control mix and OPC mix.

Keywords: CBEM, indirect tensile strength test, Marshall stability test, OPC, optimum emulsion content, retained stability test, steel slag

Procedia PDF Downloads 138

Authors: Daniel Schwarz, Jan Fivaz, Alessia Neuroni

Abstract:

Although digitization is a buzzword in almost every election campaign, the political parties leave voters largely in the dark about their specific positions on digital issues. In the run-up to the 2019 elections in Switzerland, the ‘Digitization Monitor’ project (DMP) was launched in order to change this situation. Within the framework of the DMP, all 4,736 candidates were surveyed about their digital policy positions and values. The DMP is designed as a digital policy supplement to the existing ‘smartvote’ voting advice application. This enabled a direct comparison of the digital policy attitudes according to the DMP with the topics of the ‘smartvote’ questionnaire which are comprehensive in content but mainly related to conventional policy areas. This paper’s main research goal is to analyze and visualize possible differences between conventional and digital policy areas in terms of response patterns between and within political parties. The analysis is based on dimensionality reduction methods (multidimensional scaling and principal component analysis) for the visualization of inter-party differences, and on standard deviation as a measure of variation for the evaluation of intra-party unity. The results reveal that digital issues show a lower degree of inter-party polarization compared to conventional policy areas. Thus, the parties have more common ground in issues on digitization than in conventional policy areas. In contrast, the study reveals a mixed picture regarding intra-party unity. Homogeneous parties show a lower degree of unity in digitization issues whereas parties with heterogeneous positions in conventional areas have more united positions in digital areas. All things considered, the findings are encouraging as less polarized conditions apply to the debate on digital development compared to conventional politics. For the future, it would be desirable if in further countries similar projects to the DMP could emerge to broaden the basis for conclusions.

Keywords: comparison of political issue dimensions, digital awareness of candidates, digital policy space, party positions on digital issues

Procedia PDF Downloads 166

Authors: Asrat Agalu Abejew

Abstract:

Background: Antimicrobial resistance (AMR) is a silent tsunami and one of the top global threats to health care and public health. It is one of the common agendas globally and in Ethiopia. Emerging AMR will be a double burden to Ethiopia, which is facing a series of problems from infectious disease morbidity and mortality. In Ethiopia, although there are attempts to document AMR in healthcare institutions, comprehensive and all-inclusive analysis is still lacking. Thus, this study is aimed to determine trends in AMR from 2016-2021. Methods: A retrospective analysis of secondary data recorded in the Amhara Public Health Institute (APHI) from 2016 to 2021 G.C was conducted. Blood, Urine, Stool, Swabs, Discharge, body effusions, and other Microbiological specimens were collected from each study participants, and Bacteria identification and Resistance tests were done using the standard microbiologic procedure. Data was extracted from excel in August 2022, Trends in AMR were analyzed, and the results were described. In addition, the chi-square (X2) test and binary logistic regression were used, and a P. value < 0.05 was used to determine a significant association. Results: During 6 years period, there were 25143 culture and susceptibility tests. Overall, 265 (46.2%) bacteria were resistant to 2-4 antibiotics, 253 (44.2%) to 5-7 antibiotics, and 56 (9.7%) to >=8 antibiotics. The gram-negative bacteria were 166 (43.9%), 155 (41.5%), and 55 (14.6%) resistant to 2-4, 5-7, and ≥8 antibiotics, respectively, whereas 99(50.8%), 96(49.2% and 1 (0.5%) of gram-positive bacteria were resistant to 2-4, 5-7 and ≥8 antibiotics respectively. K. pneumonia 3783 (15.67%) and E. coli 3199 (13.25%) were the most commonly isolated bacteria, and the overall prevalence of AMR was 2605 (59.9%), where K. pneumonia 743 (80.24%), E. cloacae 196 (74.81%), A. baumannii 213 (66.56%) being the most common resistant bacteria for antibiotics tested. Except for a slight decline during 2020 (6469 (25.4%)), the overall trend of AMR is rising from year to year, with a peak in 2019 (8480 (33.7%)) and in 2021 (7508 (29.9%). If left un-intervened, the trend in AMR will increase by 78% of variation from the study period, as explained by the differences in years (R2=0.7799). Ampicillin, Augmentin, ciprofloxacin, cotrimoxazole, tetracycline, and Tobramycin were almost resistant to common bacteria they were tested. Conclusion: AMR is linearly increasing during the last 6 years. If left as it is without appropriate intervention after 15 years (2030 E.C), AMR will increase by 338.7%. A growing number of multi-drug resistant bacteria is an alarm to awake policymakers and those who do have the concern to intervene before it is too late. This calls for a periodic, integrated, and continuous system to determine the prevalence of AMR in commonly used antibiotics.

Keywords: AMR, trend, pattern, MDR

Procedia PDF Downloads 57

Authors: Asim Quddus

Abstract:

A miniaturized three dimensional co-planar waveguide (CPW) two-port MIMO antenna, exhibiting high isolation and WLAN band-notched characteristics is presented in this paper for ultrawideband (UWB) communication applications. The microstrip patch antenna operates as a single UWB antenna element. The proposed design is a cuboid-shaped structure having compact size of 35 x 27 x 45 mm³. Radiating as well as decoupling structure is placed around cuboidal polystyrene sheet. The radiators are 27 mm apart, placed Face-to-Face in vertical direction. Decoupling structure is placed on the side walls of polystyrene. The proposed antenna consists of an oval shaped radiating patch. A rectangular structure with fillet edges is placed on ground plan to enhance the bandwidth. The proposed antenna exhibits a good impedance match (S11 ≤ -10 dB) over frequency band of 2 GHz – 10.6 GHz. A circular slotted structure is employed as a decoupling structure on substrate, and it is placed on the side walls of polystyrene to enhance the isolation between antenna elements. Moreover, to achieve immunity from WLAN band distortion, a modified, inverted crescent shaped slotted structure is etched on radiating patches to achieve band-rejection characteristics at WLAN frequency band 4.8 GHz – 5.2 GHz. The suggested decoupling structure provides isolation better than 15 dB over the desired UWB spectrum. The envelope correlation coefficient (ECC) and gain for the MIMO antenna are analyzed as well. Finite Element Method (FEM) simulations are carried out in Ansys High Frequency Structural Simulator (HFSS) for the proposed design. The antenna is realized on a Rogers RT/duroid 5880 with thickness 1 mm, relative permittivity ɛr = 2.2. The proposed antenna achieves a stable omni-directional radiation patterns as well, while providing rejection at desired WLAN band. The S-parameters as well as MIMO parameters like ECC are analyzed and the results show conclusively that the design is suitable for portable MIMO-UWB applications.

Keywords: 3-D antenna, band-notch, MIMO, UWB

Procedia PDF Downloads 286

Authors: Jovana Petrovic, Biljana Pajin, Ivana Loncarevic, Aleksandar Fistes, Antun Jozinivic, Durdica Ackar, Drago Subaric

Abstract:

Recovery of food wastes and their conversion to economically viable products will play a vital role for the management strategies in the years to come. Apple pomace may be considered as wastes, but they contain considerable amounts of high value reusable materials. Apple pomace, the by-product of apple juice and cider production, is a good source of fibre, particularly insoluble one. The remaining apple pulp contains 12% dry residue, which is half dietary fibre. Another remarkable aspect is its richness in polyphenols, components with antioxidant activity. Apple pomace could be an interesting alternative source for fibre and polyphenols in extruded corn meals. The extruded corn meals with the addition of finely ground apple pomace were prepared (the ratio of corn meal: apple pomace was 85:15 and 70:30). Characterization of the extrudates in terms of determining the chemical composition and colour was performed. The color of samples was measured by MINOLTA Chroma Meter CR-400 (Minolta Co., Ltd., Osaka, Japan) using D 65 lighting, a 2º standard observer angle and an 8-mm aperture in the measuring head. The following CIELab color coordinates were determined: L* – lightness, a* – redness to greenness and b* – yellowness to blueness. Protein content decreased significantly from 7.91% to 5.19% with increase in pomace from 0% to 30%, while total fibre content increase from 3.39% to 16.62%. The apple pomace addition produced extrudates with a significantly lower L* value and significantly higher a* value. This study has been fully supported by the Provincial Secretariat for High Education and Scientific Research of the Government of Autonomous Province of Vojvodina, Republic of Serbia, project 142-451-2483/2017 and the Ministry of Science and Technological Development of the Republic of Serbia (Project no. 31014).

Keywords: apple pomace, chemical composition, colour, extruded corn snack products, food waste recovery

Procedia PDF Downloads 207

Authors: M. J. Gibbons, A. J. Robinson

Abstract:

Increasing expectations on small form factor electronics to be more compact while increasing performance has driven conventional cooling technologies to a thermal management threshold. An emerging solution to this problem is electrospray (ES) cooling. ES cooling enables two phase cooling by utilising Coulomb forces for energy efficient fluid atomization. Generated charged droplets are accelerated to the grounded target surface by the applied electric field and surrounding gravitational force. While in transit the like charged droplets enable plume dispersion and inhibit droplet coalescence. If the electric field is increased in the cone-jet regime, a subsequent increase in the plume spray angle has been shown. Droplet segregation in the spray plume has been observed, with primary droplets in the plume core and satellite droplets positioned on the periphery of the plume. This segregation is facilitated by inertial and electrostatic effects. This result has been corroborated by numerous authors. These satellite droplets are usually more densely charged and move at a lower relative velocity to that of the spray core due to the radial decay of the electric field. Previous experimental research by Gomez and Tang has shown that the number of droplets deposited on the periphery can be up to twice that of the spray core. This result has been substantiated by a numerical models derived by Wilhelm et al., Oh et al. and Yang et al. Yang et al. showed from their numerical model, that by varying the extractor potential the dispersion radius of the plume also varies proportionally. This research aims to investigate this dispersion density and the role it plays in the local heat transfer coefficient profile (h) of ES cooling. This will be carried out for different extractor – target separation heights (H2), working fluid flow rates (Q), and extractor applied potential (V2). The plume dispersion will be recorded by spraying a 25 µm thick, joule heated steel foil and by recording the thermal footprint of the ES plume using a Flir A-40 thermal imaging camera. The recorded results will then be analysed by in-house developed MATLAB code.

Keywords: electronic cooling, electrospray, electrospray plume dispersion, spray cooling

Procedia PDF Downloads 376

Authors: Haj Najafi Leila, Tehranizadeh Mohsen

Abstract:

Dependencies between diverse factors involved in probabilistic seismic loss evaluation are recognized to be an imperative issue in acquiring accurate loss estimates. Dependencies among component damage costs could be taken into account considering two partial distinct states of independent or perfectly-dependent for component damage states; however, in our best knowledge, there is no available procedure to take account of loss dependencies in story level. This paper attempts to present a method called "modal cost superposition method" for decoupling story damage costs subjected to earthquake ground motions dealt with closed form differential equations between damage cost and engineering demand parameters which should be solved in complex system considering all stories' cost equations by the means of the introduced "substituted matrixes of mass and stiffness". Costs are treated as probabilistic variables with definite statistic factors of median and standard deviation amounts and a presumed probability distribution. To supplement the proposed procedure and also to display straightforwardness of its application, one benchmark study has been conducted. Acceptable compatibility has been proven for the estimated damage costs evaluated by the new proposed modal and also frequently used stochastic approaches for entire building; however, in story level, insufficiency of employing modification factor for incorporating occurrence probability dependencies between stories has been revealed due to discrepant amounts of dependency between damage costs of different stories. Also, more dependency contribution in occurrence probability of loss could be concluded regarding more compatibility of loss results in higher stories than the lower ones, whereas reduction in incorporation portion of cost modes provides acceptable level of accuracy and gets away from time consuming calculations including some limited number of cost modes in high mode situation.

Keywords: dependency, story-cost, cost modes, engineering demand parameter

Procedia PDF Downloads 160

Authors: Pahirangan Sivapatham, Barbara Esser, Andreas Grimmel

Abstract:

In times of limited public funds and, in particular, an increased social, environmental awareness, as well as the limited availability of construction materials, sustainable and resource-saving pavement management system, is becoming more and more important. Therefore, the knowledge about the condition of the structural substances, particularly bearing capacity and its consideration while planning the maintenance measures of the subordinate network, i.e., state and municipal roads unavoidable. According to the experience, the recommended ride speed of the Traffic Speed Deflectometer (TSD) shall be higher than 40 km/h. Holding of this speed on the intra-urban roads is nearly not possible because of intersections and traffic lights as well as the speed limit. A sufficient background of experience for the evaluation of bearing capacity measurements with TSD in the range of lower speeds is not available yet. The aim of this study is to determine the possible lowest ride speed of the TSD while the bearing capacity measurement on the intra-urban roads. The manufacturer of the TSD used in this study states that the measurements can be conducted at a ride speed of higher than 5 km/h. It is well known that with decreasing ride speed, the viscous fractions in the response of the asphalt pavement increase. This must be taken into account when evaluating the bearing capacity data. In the scope of this study, several measurements were carried out at different speeds between 10 km/h and 60 km/h on the selected intra-urban roads with Pavement-Scanner of the University of Wuppertal, which is equipped with TSD. Pavement-Scanner is able to continuously determine the deflections of asphalt roads in flowing traffic at speeds of up to 80 km/h. The raw data is then aggregated to 10 m mean values so that, as a rule, a bearing capacity characteristic value can be determined for each 10 m road section. By means of analysing of obtained test results, the quality and validity of the determined data rate subject to the riding speed of TSD have been determined. Moreover, the data and pictures of the additional measuring systems of Pavement-Scanners such as High-Speed Road Monitor, Ground Penetration Radar and front cameras can be used to determine and eliminate irregularities in the pavement, which could influence the bearing capacity.

Keywords: bearing capacity measurement, traffic speed deflectometer, inter-urban roads, Pavement-Scanner, structural substance

Procedia PDF Downloads 212

Authors: D. M. Rey, V. Delgado, J. Zambrano Nájera

Abstract:

Increases in urbanization during XX century, has produced changes in natural dynamics of the basins, which has resulted in increases in runoff volumes, peak flows and flow velocities, that in turn increases flood risk. Higher runoff volumes decrease sewerage networks hydraulic capacity and can cause its failure. This in turn generates increasingly recurrent floods causing mobility problems and general economic detriment in the cities. In Latin America, especially Colombia, this is a major problem because urban population at late XX century was more than 70% is in urban areas increasing approximately in 790% in 1940-1990 period. Besides, high slopes product of Andean topography and high precipitation typical of tropical climates increases velocities and volumes even more, causing stopping of cities during storms. Thus, it becomes very important to know hydrological behavior of Andean Urban Watersheds. This research aims to determine the impact of urbanization in high sloped urban watersheds in its hydrology. To this end, it will be used as study area experimental urban watershed named Palogrande-San Luis watershed, located in the city of Manizales, Colombia. Manizales is a city in central western Colombia, located in Colombian Central Mountain Range (part of Los Andes Mountains) with an abrupt topography (average altitude is 2.153 m). The climate in Manizales is quite uniform, but due to its high altitude it presents high precipitations (1.545 mm/year average) with high humidity (83% average). It was applied HEC-HMS Hydrologic model on the watershed. The inputs to the model were derived from Geographic Information Systems (GIS) theme layers of the Instituto de Estudios Ambientales –IDEA of Universidad Nacional de Colombia, Manizales (Institute of Environmental Studies) and aerial photography taken for the research in conjunction with available literature and look up tables. Rainfall data from a network of 4 rain gages and historical stream flow data were used to calibrate and validate runoff depth using the hydrologic model. Manual calibration was made, and the simulation results show that the model selected is able to characterize the runoff response of the watershed due to land use for urbanization in high mountain watersheds.

Keywords: Andean watersheds modelling, high mountain urban hydrology, urban planning, hydrologic modelling

Procedia PDF Downloads 216

Authors: César Coelho, Nikolai Wiegand

Abstract:

The advancement of nanosatellite technology has opened new avenues for cost-effective and faster space missions. The NanoSat MO Framework (NMF) from the European Space Agency (ESA) provides a modular and simpler approach to the development of flight software and operations of small satellites. This paper presents a methodology using the NMF together with Docker for simulating constellations of satellites. By leveraging Docker containers, the software environment of individual satellites can be easily replicated within a simulated constellation. This containerized approach allows for rapid deployment, isolation, and management of satellite instances, facilitating comprehensive testing and development in a controlled setting. By integrating the NMF lightweight simulator in the container, a comprehensive simulation environment was achieved. A significant advantage of using Docker containers is their inherent scalability, enabling the simulation of hundreds or even thousands of satellites with minimal overhead. Docker's lightweight nature ensures efficient resource utilization, allowing for deployment on a single host or across a cluster of hosts. This capability is crucial for large-scale simulations, such as in the case of mega-constellations, where multiple traditional virtual machines would be impractical due to their higher resource demands. This ability for easy horizontal scaling based on the number of simulated satellites provides tremendous flexibility to different mission scenarios. Our results demonstrate that leveraging Docker containers with the NanoSat MO Framework provides a highly efficient and scalable solution for simulating satellite constellations, offering not only significant benefits in terms of resource utilization and operational flexibility but also enabling testing and validation of ground software for constellations. The findings underscore the importance of taking advantage of already existing technologies in computer science to create new solutions for future satellite constellations in space.

Keywords: containerization, docker containers, NanoSat MO framework, satellite constellation simulation, scalability, small satellites

Procedia PDF Downloads 18