Search results for: loading units

Authors: Angelica Alvarez-Lee, Sergio Martinez-Diaz, Jose Luis Garcia-Corona, Humberto Lanz-Mendoza

Abstract:

World aquaculture is always looking for improvements to achieve productions with high yields avoiding the infection by pathogenic agents. The best way to achieve this is to know the biological model to create alternative treatments that could be applied in the hatcheries, which results in greater economic gains and improvements in human public health. In the last decade, immunomodulation in shrimp culture with probiotics, organic acids and different carbon sources has gained great interest, mainly in larval and juvenile stages. Immune priming is associated with a strong protective effect against a later pathogen challenge. This work provides another perspective about immunostimulation from spawning until hatching. The stimulation happens during development embryos and generates resistance to infection by pathogenic bacteria. Massive spawnings of white shrimp L. vannamei were obtained and placed in experimental units with 700 mL of sterile seawater at 30 °C, salinity of 28 ppm and continuous aeration at a density of 8 embryos.mL⁻¹. The immunostimulating effect of three death strains of non-pathogenic bacterial (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and a pathogenic strain for white shrimp (Vibrio parahaemolyticus) was evaluated. The strains killed by heat were adjusted to O.D. 0.5, at A 600 nm, and directly added to the seawater of each unit at a ratio of 1/100 (v/v). A control group of embryos without inoculum of dead bacteria was kept under the same physicochemical conditions as the rest of the treatments throughout the experiment and used as reference. The duration of the stimulus was 12 hours, then, the larvae that hatched were collected, counted and transferred to a new experimental unit (same physicochemical conditions but at a salinity of 28 ppm) to carry out a challenge of infection against the pathogen V. parahaemolyticus, adding directly to seawater an amount 1/100 (v/v) of the live strain adjusted to an OD 0.5; at A 600 nm. Subsequently, 24 hrs after infection, nauplii survival was evaluated. The results of this work shows that, after 24 hrs, the hatching rates of immunostimulated shrimp embryos with the dead strains of B. subtillis and V. parahaemolyticus are significantly higher compared to the rest of the treatments and the control. Furthermore, survival of L. vanammei after a challenge of infection of 24 hrs against the live strain of V. parahaemolyticus is greater (P < 0.05) in the larvae immunostimulated during the embryonic development with the dead strains B. subtillis and V. parahaemolyticus, followed by those that were treated with E. coli. In summary superficial antigens can stimulate the development cells to promote hatching and can have normal development in agreeing with the optical observations, plus exist a differential response effect between each treatment post-infection. This research provides evidence of the immunostimulant effect of death pathogenic and non-pathogenic bacterial strains in the rate of hatching and oversight of shrimp L. vannamei during embryonic and larval development. This research continues evaluating the effect of these death strains on the expression of genes related to the defense priming in larvae of L. vannamei that come from massive spawning in hatcheries before and after the infection challenge against V. parahaemolyticus.

Keywords: immunostimulation, L. vannamei, hatching, survival

Procedia PDF Downloads 146

Authors: Komal Rathore, Kiesha Pierre, Kyle Cogswell, Aaron Driscoll, Andres Tejada Martinez, Gita Iranipour, Luke Mulford, Aydin Sunol

Abstract:

Modeling of Biological Wastewater Treatment Plants requires several parameters for kinetic rate expressions, thermo-physical properties, and hydrodynamic behavior. The kinetics and associated mechanisms become complex due to several biological processes taking place in wastewater treatment plants at varying times and spatial scales. A dynamic process model that incorporated the complex model for activated sludge kinetics was developed using the BioWin software platform for an Advanced Wastewater Treatment Plant in Valrico, Florida. Due to the extensive number of tunable parameters, an experimental design was employed for judicious selection of the most influential parameter sets and their bounds. The model was tuned using both the influent and effluent plant data to reconcile and rectify the forecasted results from the BioWin Model. Amount of mixed liquor suspended solids in the oxidation ditch, aeration rates and recycle rates were adjusted accordingly. The experimental analysis and plant SCADA data were used to predict influent wastewater rates and composition profiles as a function of time for extended periods. The lumped dynamic model development process was coupled with Computational Fluid Dynamics (CFD) modeling of the key units such as oxidation ditches in the plant. Several CFD models that incorporate the nitrification-denitrification kinetics, as well as, hydrodynamics was developed and being tested using ANSYS Fluent software platform. These realistic and verified models developed using BioWin and ANSYS were used to plan beforehand the operating policies and control strategies for the biological wastewater plant accordingly that further allows regulatory compliance at minimum operational cost. These models, with a little bit of tuning, can be used for other biological wastewater treatment plants as well. The BioWin model mimics the existing performance of the Valrico Plant which allowed the operators and engineers to predict effluent behavior and take control actions to meet the discharge limits of the plant. Also, with the help of this model, we were able to find out the key kinetic and stoichiometric parameters which are significantly more important for modeling of biological wastewater treatment plants. One of the other important findings from this model were the effects of mixed liquor suspended solids and recycle ratios on the effluent concentration of various parameters such as total nitrogen, ammonia, nitrate, nitrite, etc. The ANSYS model allowed the abstraction of information such as the formation of dead zones increases through the length of the oxidation ditches as compared to near the aerators. These profiles were also very useful in studying the behavior of mixing patterns, effect of aerator speed, and use of baffles which in turn helps in optimizing the plant performance.

Keywords: computational fluid dynamics, flow-sheet simulation, kinetic modeling, process dynamics

Procedia PDF Downloads 215

Authors: Animesh Pan, Geoffrey D. Bothun

Abstract:

With the development of nanotechnology, research in multifunctional delivery systems has a new pace and dimension. An incipient challenge is to design an all-in-one delivery system that can be used for multiple purposes, including tumor targeting therapy, radio-frequency (RF-), near-infrared (NIR-), light-, or pH-induced controlled release, photothermal therapy (PTT), photodynamic therapy (PDT), and medical diagnosis. In this regard, various inorganic nanoparticles (NPs) are known to show great potential as the 'functional components' because of their fascinating and tunable physicochemical properties and the possibility of multiple theranostic modalities from individual NPs. Magnetic, luminescent, and plasmonic properties are the three most extensively studied and, more importantly biomedically exploitable properties of inorganic NPs. Although successful attempts of combining any two of them above mentioned functionalities have been made, integrating them in one system has remained challenge. Keeping those in mind, controlled designs of complex colloidal nanoparticle system are one of the most significant challenges in nanoscience and nanotechnology. Therefore, systematic and planned studies providing better revelation are demanded. We report a multifunctional delivery platform-based liposome loaded with drug, iron-oxide magnetic nanoparticles (MNPs), and a gold shell on the surface of liposomes, were synthesized using a lipid with polyelectrolyte (layersomes) templating technique. MNPs and the anti-cancer drug doxorubicin (DOX) were co-encapsulated inside liposomes composed by zwitterionic phophatidylcholine and anionic phosphatidylglycerol using reverse phase evaporation (REV) method. The liposomes were coated with positively charge polyelectrolyte (poly-L-lysine) to enrich the interface with gold anion, exposed to a reducing agent to form a gold nanoshell, and then capped with thio-terminated polyethylene glycol (SH-PEG2000). The core-shell nanostructures were characterized by different techniques like; UV-Vis/NIR scanning spectrophotometer, dynamic light scattering (DLS), transmission electron microscope (TEM). This multifunctional system achieves a variety of functions, such as radiofrequency (RF)-triggered release, chemo-hyperthermia, and NIR laser-triggered for photothermal therapy. Herein, we highlight some of the remaining major design challenges in combination with preliminary studies assessing therapeutic objectives. We demonstrate an efficient loading and delivery system to significant cell death of human cancer cells (A549) with therapeutic capabilities. Coupled with RF and NIR excitation to the doxorubicin-loaded core-shell nanostructure helped in securing targeted and controlled drug release to the cancer cells. The present core-shell multifunctional system with their multimodal imaging and therapeutic capabilities would be eminent candidates for cancer theranostics.

Keywords: cancer thernostics, multifunctional nanostructure, photothermal therapy, radiofrequency targeting

Procedia PDF Downloads 133

Authors: Jeronimo Cox, Tomonari Furukawa

Abstract:

Magnetometers have become more popular in inertial measurement units (IMU) for their ability to correct estimations using the earth's magnetic field. Accelerometer and gyroscope-based packages fail with dead-reckoning errors accumulated over time. Localization in robotic applications with magnetometer-inclusive IMUs has become popular as a way to track the odometry of slower-speed robots. With high-speed motions, the accumulated error increases over smaller periods of time, making them difficult to track with IMU. Tracking a high-speed motion is especially difficult with limited observability. Visual obstruction of motion leaves motion-tracking cameras unusable. When motions are too dynamic for estimation techniques reliant on the observability of the gravity vector, the use of magnetometers is further justified. As available magnetometer calibration methods are limited with the assumption that background magnetic fields are uniform, estimation in nonuniform magnetic fields is problematic. Hard iron distortion is a distortion of the magnetic field by other objects that produce magnetic fields. This kind of distortion is often observed as the offset from the origin of the center of data points when a magnetometer is rotated. The magnitude of hard iron distortion is dependent on proximity to distortion sources. Soft iron distortion is more related to the scaling of the axes of magnetometer sensors. Hard iron distortion is more of a contributor to the error of attitude estimation with magnetometers. Indoor environments or spaces inside ferrite-based structures, such as building reinforcements or a vehicle, often cause distortions with proximity. As positions correlate to areas of distortion, methods of magnetometer localization include the production of spatial mapping of magnetic field and collection of distortion signatures to better aid location tracking. The goal of this paper is to compare magnetometer methods that don't need pre-productions of magnetic field maps. Mapping the magnetic field in some spaces can be costly and inefficient. Dynamic measurement fusion is used to track the motion of a multi-link system with us. Conventional calibration by data collection of rotation at a static point, real-time estimation of calibration parameters each time step, and using two magnetometers for determining local hard iron distortion are compared to confirm the robustness and accuracy of each technique. With opposite-facing magnetometers, hard iron distortion can be accounted for regardless of position, Rather than assuming that hard iron distortion is constant regardless of positional change. The motion measured is a repeatable planar motion of a two-link system connected by revolute joints. The links are translated on a moving base to impulse rotation of the links. Equipping the joints with absolute encoders and recording the motion with cameras to enable ground truth comparison to each of the magnetometer methods. While the two-magnetometer method accounts for local hard iron distortion, the method fails where the magnetic field direction in space is inconsistent.

Keywords: motion tracking, sensor fusion, magnetometer, state estimation

Procedia PDF Downloads 88

Authors: E. A. Krasikov

Abstract:

As the service life of an operating nuclear power plant (NPP) increases, the potential misunderstanding of the degradation of aging components must receive more attention. Integrity assurance analysis contributes to the effective maintenance of adequate plant safety margins. In essence, the reactor pressure vessel (RPV) is the key structural component determining the NPP lifetime. Environmentally induced cracking in the stainless steel corrosion-preventing cladding of RPV’s has been recognized to be one of the technical problems in the maintenance and development of light-water reactors. Extensive cracking leading to failure of the cladding was found after 13000 net hours of operation in JPDR (Japan Power Demonstration Reactor). Some of the cracks have reached the base metal and further penetrated into the RPV in the form of localized corrosion. Failures of reactor internal components in both boiling water reactors and pressurized water reactors have increased after the accumulation of relatively high neutron fluences (5´1020 cm–2, E>0,5MeV). Therefore, in the case of cladding failure, the problem arises of hydrogen (as a corrosion product) embrittlement of irradiated RPV steel because of exposure to the coolant. At present when notable progress in plasma physics has been obtained practical energy utilization from fusion reactors (FR) is determined by the state of material science problems. The last includes not only the routine problems of nuclear engineering but also a number of entirely new problems connected with extreme conditions of materials operation – irradiation environment, hydrogenation, thermocycling, etc. Limiting data suggest that the combined effect of these factors is more severe than any one of them alone. To clarify the possible influence of the in-service synergistic phenomena on the FR structural materials properties we have studied hydrogen-irradiated steel interaction including alternating hydrogenation and heat treatment (annealing). Available information indicates that the life of the first wall could be expanded by means of periodic in-place annealing. The effects of neutron fluence and irradiation temperature on steel/hydrogen interactions (adsorption, desorption, diffusion, mechanical properties at different loading velocities, post-irradiation annealing) were studied. Experiments clearly reveal that the higher the neutron fluence and the lower the irradiation temperature, the more hydrogen-radiation defects occur, with corresponding effects on the steel mechanical properties. Hydrogen accumulation analyses and thermal desorption investigations were performed to prove the evidence of hydrogen trapping at irradiation defects. Extremely high susceptibility to hydrogen embrittlement was observed with specimens which had been irradiated at relatively low temperature. However, the susceptibility decreases with increasing irradiation temperature. To evaluate methods for the RPV’s residual lifetime evaluation and prediction, more work should be done on the irradiated metal–hydrogen interaction in order to monitor more reliably the status of irradiated materials.

Keywords: hydrogen, radiation, stability, structural steel

Procedia PDF Downloads 276

Authors: Mangala. Sadasivan, Mary Hughes, Bryan Kelly

Abstract:

Medical Education must focus on bridging the gap between teaching and learning when training pre-clinical year students in skills needed to keep up with medical knowledge and to meet the demands of health care in the future. The authors were interested in showing that a 3-S Model (building strength, developing stamina, and increasing speed) using a bridged curriculum design helps connect teaching and learning and improves students’ retention of basic science and clinical knowledge. The authors designed three learning modules using the 3-S Model within a systems course in a pre-clerkship medical curriculum. Each module focused on a bridge (concept map) designed by the instructor for specific content delivered to students in the course. This with-in-subjects design study included 304 registered MSU osteopathic medical students (3 campuses) ranked by quintile based on previous coursework. The instructors used the bridge to create self-directed learning exercises (building strength) to help students master basic science content. Students were video coached on how to complete assignments, and given pre-tests and post-tests designed to give them control to assess and identify gaps in learning and strengthen connections. The instructor who designed the modules also used video lectures to help students master clinical concepts and link them (building stamina) to previously learned material connected to the bridge. Boardstyle practice questions relevant to the modules were used to help students improve access (increasing speed) to stored content. Unit Examinations covering the content within modules and materials covered by other instructors teaching within the units served as outcome measures in this study. This data was then compared to each student’s performance on a final comprehensive exam and their COMLEX medical board examinations taken some time after the course. The authors used mean comparisons to evaluate students’ performances on module items (using 3-S Model) to non-module items on unit exams, final course exam and COMLEX medical board examination. The data shows that on average, students performed significantly better on module items compared to non-module items on exams 1 and 2. The module 3 exam was canceled due to a university shut down. The difference in mean scores (module verses non-module) items disappeared on the final comprehensive exam which was rescheduled once the university resumed session. Based on Quintile designation, the mean scores were higher for module items than non-module items and the difference in scores between items for Quintiles 1 and 2 were significantly better on exam 1 and the gap widened for all Quintile groups on exam 2 and disappeared in exam 3. Based on COMLEX performance, all students on average as a group, whether they Passed or Failed, performed better on Module items than non-module items in all three exams. The gap between scores of module items for students who passed COMLEX to those who failed was greater on Exam 1 (14.3) than on Exam 2 (7.5) and Exam 3 (10.2). Data shows the 3-S Model using a bridge effectively connects teaching and learning

Keywords: bridging gap, medical education, teaching and learning, model of learning

Procedia PDF Downloads 65

Authors: N. C. Shahi, Anupama Singh, E. Kate

Abstract:

Drying is practiced to enhance the storage life, to minimize losses during storage, and to reduce transportation costs of agricultural products. Drying processes range from open sun drying to industrial drying. In most of the developing countries, use of fossil fuels for drying of agricultural products has not been practically feasible due to unaffordable costs to majority of the farmers. On the other hand, traditional open sun drying practiced on a large scale in the rural areas of the developing countries suffers from high product losses due to inadequate drying, fungal growth, encroachment of insects, birds and rodents, etc. To overcome these problems a middle technology dryer having low cost need to be developed for farmers. In case of mechanical dryers, the heated air is the main driving force for removal of moisture. The air is heated either electrically or by burning wood, coal, natural gas etc. using heaters. But, all these common sources have finite supplies. The lifetime is estimated to range from 15 years for a natural gas to nearly 250 years for coal. So, mankind must turn towards its safe and reliable utilization and may have undesirable side effects. The mechanical drying involves higher cost of drying and open sun drying deteriorates the quality. The solar tunnel dryer is one of promising option for drying various agricultural and agro-industrial products on large scale. The advantage of Solar tunnel dryer is its relatively cheaper cost of construction and operation. Although many solar dryers have been developed, still there is a scope of modification in them. Therefore, an attempt was made to develop Solar tunnel dryer and test its performance using highly perishable commodity i.e. leafy vegetables (spinach). The effect of air velocity, loading density and shade net on performance parameters namely, collector efficiency, drying efficiency, overall efficiency of dryer and specific heat energy consumption were also studied. Thus, the need for an intermediate level technology was realized and an effort was made to develop a small scale Solar Tunnel Dryer . A dryer consisted of base frame, semi cylindrical drying chamber, solar collector and absorber, air distribution system with chimney and auxiliary heating system, and wheels for its mobility were the main functional components. Drying of fenugreek was carried out to analyze the performance of the dryer. The Solar Tunnel Dryer temperature was maintained using the auxiliary heating system. The ambient temperature was in the range of 12-33oC. The relative humidity was found inside and outside the Solar Tunnel Dryer in the range of 21-75% and 35-79%, respectively. The solar radiation was recorded in the range of 350-780W/m2 during the experimental period. Studies revealed that total drying time was in range of 230 to 420 min. The drying time in Solar Tunnel Dryer was considerably reduced by 67% as compared to sun drying. The collector efficiency, drying efficiency, overall efficiency and specific heat consumption were determined and were found to be in the range of 50.06- 38.71%, 15.53-24.72%, 4.25 to 13.34% and 1897.54-3241.36 kJ/kg, respectively.

Keywords: overall efficiency, solar tunnel dryer, specific heat consumption, sun drying

Procedia PDF Downloads 316

Authors: Sergey A. Lurie, Yury O. Solyaev, Dmitry B. Volkov-Bogorodsky, Alexander V. Volkov

Abstract:

The media with voids is considered and the method of the analytical estimation of the effective mechanical properties in the theory of elastic materials with voids is proposed. The variational model of the porous media is discussed, which is based on the model of the media with fields of conserved dislocations. It is shown that this model is fully consistent with the known model of the linear elastic materials with voids. In the present work, the generalized model of the porous media is proposed in which the specific surface properties are associated with the field of defects-pores in the volume of the deformed body. Unlike typical surface elasticity model, the strain energy density of the considered model includes the special part of the surface energy with the quadratic form of the free distortion tensor. In the result, the non-classical boundary conditions take modified form of the balance equations of volume and surface stresses. The analytical approach is proposed in the present work which allows to receive the simple enough engineering estimations for effective characteristics of the media with free dilatation. In particular, the effective flexural modulus and Poisson's ratio are determined for the problem of a beam pure bending. Here, the known voids elasticity solution was expanded on the generalized model with the surface effects. Received results allow us to compare the deformed state of the porous beam with the equivalent classic beam to introduce effective bending rigidity. Obtained analytical expressions for the effective properties depend on the thickness of the beam as a parameter. It is shown that the flexural modulus of the porous beam is decreased with an increasing of its thickness and the effective Poisson's ratio of the porous beams can take negative values for the certain values of the model parameters. On the other hand, the effective shear modulus is constant under variation of all values of the non-classical model parameters. Solutions received for a beam pure bending and the hydrostatic loading of the porous media are compared. It is shown that an analytical estimation for the bulk modulus of the porous material under hydrostatic compression gives an asymptotic value for the effective bulk modulus of the porous beam in the case of beam thickness increasing. Additionally, it is shown that the scale effects appear due to the surface properties of the porous media. Obtained results allow us to offer the procedure of an experimental identification of the non-classical parameters in the theory of the linear elastic materials with voids based on the bending tests for samples with different thickness. Finally, the problem of implementation of the Saint-Venant hypothesis for the transverse stresses in the porous beam are discussed. These stresses are different from zero in the solution of the voids elasticity theory, but satisfy the integral equilibrium equations. In this work, the exact value of the introduced surface parameter was found, which provides the vanishing of the transverse stresses on the free surfaces of a beam.

Keywords: effective properties, scale effects, surface defects, voids elasticity

Procedia PDF Downloads 424

Authors: Andrew N. Saylor, James R. Peters

Abstract:

Scoliosis is a complex 3D deformity of the thoracic and lumbar spines, clinically diagnosed by measurement of a Cobb angle of 10 degrees or more on a coronal X-ray. The Cobb angle is the angle made by the lines drawn along the proximal and distal endplates of the respective proximal and distal vertebrae comprising the curve. Traditionally, Cobb angles are measured manually using either a marker, straight edge, and protractor or image measurement software. The task of measuring the Cobb angle can also be represented by a function taking the spine geometry rendered using X-ray imaging as input and returning the approximate angle. Although the form of such a function may be unknown, it can be approximated using artificial neural networks (ANNs). The performance of ANNs is affected by many factors, including the choice of activation function and network architecture; however, the effects of these parameters on the accuracy of scoliotic deformity measurements are poorly understood. Therefore, the objective of this study was to systematically investigate the effect of ANN architecture and activation function on Cobb angle measurement from the coronal X-rays of scoliotic subjects. The data set for this study consisted of 609 coronal chest X-rays of scoliotic subjects divided into 481 training images and 128 test images. These data, which included labeled Cobb angle measurements, were obtained from the SpineWeb online database. In order to normalize the input data, each image was resized using bi-linear interpolation to a size of 500 × 187 pixels, and the pixel intensities were scaled to be between 0 and 1. A fully connected (dense) ANN with a fixed cost function (mean squared error), batch size (10), and learning rate (0.01) was developed using Python Version 3.7.3 and TensorFlow 1.13.1. The activation functions (sigmoid, hyperbolic tangent [tanh], or rectified linear units [ReLU]), number of hidden layers (1, 3, 5, or 10), and number of neurons per layer (10, 100, or 1000) were varied systematically to generate a total of 36 network conditions. Stochastic gradient descent with early stopping was used to train each network. Three trials were run per condition, and the final mean squared errors and mean absolute errors were averaged to quantify the network response for each condition. The network that performed the best used ReLU neurons had three hidden layers, and 100 neurons per layer. The average mean squared error of this network was 222.28 ± 30 degrees2, and the average mean absolute error was 11.96 ± 0.64 degrees. It is also notable that while most of the networks performed similarly, the networks using ReLU neurons, 10 hidden layers, and 1000 neurons per layer, and those using Tanh neurons, one hidden layer, and 10 neurons per layer performed markedly worse with average mean squared errors greater than 400 degrees2 and average mean absolute errors greater than 16 degrees. From the results of this study, it can be seen that the choice of ANN architecture and activation function has a clear impact on Cobb angle inference from coronal X-rays of scoliotic subjects.

Keywords: scoliosis, artificial neural networks, cobb angle, medical imaging

Procedia PDF Downloads 134

Authors: Salwa Mohamed Salah Eldin, Howida Kamal Ibrahim

Abstract:

Introduction: Major depressive disorder affects high proportion of the world’s population presenting cost load in health care. Extended release venlafaxine is more convenient and could reduce discontinuation syndrome. The once daily dosing also reduces the potential for adverse events such as nausea due to reduced Cmax. Venlafaxine is an effective first-line agent in the treatment of depression. A once daily formulation was designed to enhance patient compliance. Complexing with a resin was suggested to improve loading of the water soluble drug. The formulated systems were thoroughly evaluated in vitro to prove superiority to previous trials and were compared to the commercial extended release product in experimental animals. Materials and Methods: Venlafaxine-resinates were prepared using Dowex®50WX4-400 and Dowex®50WX8-100 at drug to resin weight ratio of 1: 1. The prepared resinates were evaluated for their drug content, particle shape and surface properties and in vitro release profile in gradient pH. The release kinetics and mechanism were evaluated. Venlafaxine-Dowex® resinates were encapsulated using O/W solvent evaporation technique. Poly-ε-caprolactone, Poly(D, L-lactide-co-glycolide) ester, Poly(D, L-lactide) ester and Eudragit®RS100 were used as coating polymers alone and in combination. Drug-resinate microcapsules were evaluated for morphology, entrapment efficiency and in-vitro release profile. The selected formula was tested in rabbits using a randomized, single-dose, 2-way crossover study against Effexor-XR tablets under fasting condition. Results and Discussion: The equilibrium time was 30 min for Dowex®50WX4-400 and 90 min for Dowex®50WX8-100. The percentage drug loaded was 93.96 and 83.56% for both resins, respectively. Both drug-Dowex® resintes were efficient in sustaining venlafaxine release in comparison to the free drug (up to 8h.). Dowex®50WX4-400 based venlafaxine-resinate was selected for further encapsulation to optimize the release profile for once daily dosing and to lower the burst effect. The selected formula (coated with a mixture of Eudragit RS and PLGA in a ratio of 50/50) was chosen by applying a group of mathematical equations according to targeted values. It recorded the minimum burst effect, the maximum MDT (Mean dissolution time) and a Q24h (percentage drug released after 24 hours) between 95 and 100%. The 90% confidence intervals for the test/reference mean ratio of the log-transformed data of AUC0–24 and AUC0−∞ are within (0.8–1.25), which satisfies the bioequivalence criteria. Conclusion: The optimized formula could be a promising extended release form of the water soluble, short half lived venlafaxine. Being a multiple unit formulation, it lowers the probability of dose dumping and reduces the inter-subject variability in absorption.

Keywords: biodegradable polymers, cation-exchange resin, microencapsulation, venlafaxine hcl

Procedia PDF Downloads 400

Authors: B. Ozarisoy, E. Ampatzi, G. Z. Lancaster

Abstract:

This research project is undertaken in the Turkish Republic of Northern Cyprus (T.R.N.C). The study focuses on identifying refurbishment activities capable of diagnosing and detecting the underlying problems alongside the challenges offered by the buildings’ typology in addition to identifying the correct construction materials in the refurbishment process which allow for the maximisation of expected energy savings. Attention is drawn to, the level of awareness and understanding of refurbishment activity that needs to be raised in the current construction process alongside factors that include the positive environmental impact and the saving of energy. The approach here is to look at buildings that have been built by private construction companies that have already been refurbished by occupants and to suggest additional control mechanisms for retrofitting that can further enhance the process of renewal. The objective of the research is to investigate the occupants’ behaviour and role in the refurbishment activity; to explore how and why occupants decide to change building components and to understand why and how occupants consider using energy-efficient materials. The present work is based on data from this researcher’s first-hand experience and incorporates the preliminary data collection on recent housing sector statistics, including the year in which housing estates were built, an examination of the characteristics that define the construction industry in the T.R.N.C., building typology and the demographic structure of house owners. The housing estates are chosen from 16 different projects in four different regions of the T.R.N.C. that include urban and suburban areas. There is, therefore, a broad representation of the common drivers in the property market, each with different levels of refurbishment activity and this is coupled with different samplings from different climatic regions within the T.R.N.C. The study is conducted through semi-structured interviews to identify occupants’ behaviour as it is associated with refurbishment activity. The interviews provide all the occupants’ demographic information, needs and intentions as they relate to various aspects of the refurbishment process. This research paper presents the results of semi-structured interviews with 70 homeowners in a selected group of 16 housing estates in five different parts of the T.R.N.C. The people who agreed to be interviewed in this study are all residents of single or multi-family housing units. Alongside the construction process and its impact on the environment, the results point out the need for control mechanisms in the housing sector to promote and support the adoption of retrofit strategies and minimize non-controlled refurbishment activities, in line with diagnostic information of the selected buildings. The expected solutions should be effective, environmentally acceptable and feasible given the type of housing projects under review, with due regard for their location, the climatic conditions within which they were undertaken, the socio-economic standing of the house owners and their attitudes, local resources and legislative constraints. Furthermore, the study goes on to insist on the practical and long-term economic benefits of refurbishment under the proper conditions and why this should be fully understood by the householders.

Keywords: construction process, energy-efficiency, refurbishment activity, retrofitting

Procedia PDF Downloads 329

Authors: Javed Iqbal

Abstract:

The growing need for energy by the human society and depletion of conventional energy sources demands a renewable, safe, infinite, low-cost and omnipresent energy source. One of the most suitable ways to solve the foreseeable world’s energy crisis is to use the power of the sun. Photovoltaic devices are especially of wide interest as they can convert solar energy to electricity. Recently the best performing solar cells are silicon-based cells. However, silicon cells are expensive, rigid in structure and have a large timeline for the payback of cost and electricity. Organic photovoltaic cells are cheap, flexible and can be manufactured in a continuous process. Therefore, organic photovoltaic cells are an extremely favorable replacement. Organic photovoltaic cells utilize sunlight as energy and convert it into electricity through the use of conductive polymers/ small molecules to separate electrons and electron holes. A major challenge for these new organic photovoltaic cells is the efficiency, which is low compared with the traditional silicon solar cells. To overcome this challenge, usually two straightforward strategies have been considered: (1) reducing the band-gap of molecular donors to broaden the absorption range, which results in higher short circuit current density (JSC) of devices, and (2) lowering the highest occupied molecular orbital (HOMO) energy of molecular donors so as to increase the open-circuit voltage (VOC) of applications devices.8 Keeping in mind the cost of chemicals it is hard to try many materials on test basis. The best way is to find the suitable material in the bulk. For this purpose, we use computational approach to design molecules based on our organic chemistry knowledge and determine their physical and electronic properties. In this study, we did DFT calculations with different options to get high open circuit voltage and after getting suitable data from calculation we finally did synthesis of a novel D–π–A–π–D type low band-gap small molecular donor material (ZOPTAN-TPA). The Aarylene vinylene based bis(arylhalide) unit containing a cyanostilbene unit acts as a low-band- gap electron-accepting block, and is coupled with triphenylamine as electron-donating blocks groups. The motivation for choosing triphenylamine (TPA) as capped donor was attributed to its important role in stabilizing the separated hole from an exciton and thus improving the hole-transporting properties of the hole carrier.3 A π-bridge (thiophene) is inserted between the donor and acceptor unit to reduce the steric hindrance between the donor and acceptor units and to improve the planarity of the molecule. The ZOPTAN-TPA molecule features a low HOMO level of 5.2 eV and an optical energy gap of 2.1 eV. Champion OSCs based on a solution-processed and non-annealed active-material blend of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and ZOPTAN-TPA in a mass ratio of 2:1 exhibits a power conversion efficiency of 1.9 % and a high open-circuit voltage of over 1.0 V.

Keywords: high open circuit voltage, donor, triphenylamine, organic solar cells

Procedia PDF Downloads 243

Authors: Nanteza Rachel

Abstract:

Background: Worldwide, there were 36.7 million people living with Human Immunodeficiency Virus (HIV) in 2015, up from 35 million at the end of 2013. Wakiso district is one of the hotspots for the Human Immunodeficiency Virus (HIV)/ Acquired Immune Deficiency Syndrome (AIDS) infection in Uganda, with the prevalence of 8.1 %. Herbal medicine has gained popularity among Human Immunodeficiency Virus (HIV)/ Acquired Immune Deficiency Syndrome (AIDS) patients as adjuvant therapy to reduce the adverse effects of ART. Regardless of the subsidized and physical availability of the Anti-Retroviral Therapy (ART), majority of Africans living with Human Immunodeficiency Virus (HIV)/ Acquired Immune Deficiency Syndrome (AIDS) resort to adding to their ART traditional medicine. Result found out from a pilot observation made by the PI that indicate 13 out of 30 People Living with AIDS(PLWA) who are attending Human Immunodeficiency Virus (HIV) clinics in Wakiso district reported to be using herbal preparations despite the fact that they were taking Anti Retro Viral (ARVs) this prompted this study to be done. Purpose of the study: To determine the prevalence and factors associated with concurrent use of herbal medicine and anti-retroviral therapy among HIV/AIDS patients attending selected HIV clinics in Wakiso district. Methodology: This was a cross sectional study with both quantitative data collection (use of a questionnaire) and qualitative data collection (key informants’ interviews). A mixed method of sampling was used, that is, purposive and random sampling. Purposive sampling was based on the location in the district and used to select 7 health facilities basing on the 7 health sub districts from Wakiso. Simple random sampling was used to select one HIV clinic from each of the 7 health sub districts. Furthermore, the study units were enrolled in to the study as they entered into the HIV clinics, and 105 respondents were interviewed. Both manual and computer packages (SPSS) were used to analyze the data Results: The prevalence of concurrent use of herbal medicine and ART was 38 (36.2%). Commonly HIV symptom treated with herbs was fever 27(71.1%), diarrhea 3(7.9%) and cough 2(5.3%). Commonly used herbs for fever (Omululuza (Vernonica amydalina), Ekigagi (Aloe sp), Nalongo (Justicia betonica Linn) while for diarrhea was Ntwatwa. The side effects also included; too much pain, itchy pain of HIV, aneamia,felt sick, loss/gain appetite, joint pain and bad dreams. Herbs used to sooth the side effects were; for aneamia was avocado leaves Parea Americana mill The significant factors associated with concurrent use of herbal medicine were being familiar with herbs and conventional medicine for management HIV symptoms being expensive. The other significant factor was exhibiting hostility to patients by health personnel providing HIV care. Conclusion: Herbal medicine is widely used by clients in HIV/AIDS care. Patients being familiar with herbs and conventional medicine being expensive were associated with concurrent use of herbal medicine and ART. The exhibition of hostility to the HIV/AIDS patients by the health care providers was also associated with concurrent use of herbal medicine and ART among HIV/AIDS patients.

Keywords: HIV patients, herbal medicine, antiretroviral therapy, factors associated

Procedia PDF Downloads 103

Authors: Monisha Elumalai, Joana Guerreiro, Joana Carvalho, Marta Prado

Abstract:

DNA biosensors popularity has been increasing over the past few years. Traditional analytical techniques tend to require complex steps and expensive equipment however DNA biosensors have the advantage of getting simple, fast and economic. Additionally, the combination of DNA biosensors with nanomaterials offers the opportunity to improve the selectivity, sensitivity and the overall performance of the devices. DNA biosensors are based on oligonucleotides as sensing elements. These oligonucleotides are highly specific to complementary DNA sequences resulting in the hybridization of the strands. DNA biosensors are not only an advantage in the clinical field but also applicable in numerous research areas such as food analysis or environmental control. Zebra Mussels (ZM), Dreissena polymorpha are invasive species responsible for enormous negative impacts on the environment and ecosystems. Generally, the detection of ZM is made when the observation of adult or macroscopic larvae's is made however at this stage is too late to avoid the harmful effects. Therefore, there is a need to develop an analytical tool for the early detection of ZM. Here, we present a portable plasmonic biosensor for the detection of environmental DNA (eDNA) released to the environment from this invasive species. The plasmonic DNA biosensor combines gold nanoparticles, as transducer elements, due to their great optical properties and high sensitivity. The detection strategy is based on the immobilization of a short base pair DNA sequence on the nanoparticles surface followed by specific hybridization in the presence of a complementary target DNA. The hybridization events are tracked by the optical response provided by the nanospheres and their surrounding environment. The identification of the DNA sequences (synthetic target and probes) to detect Zebra mussel were designed by using Geneious software in order to maximize the specificity. Moreover, to increase the optical response enzyme amplification of DNA might be used. The gold nanospheres were synthesized and characterized by UV-visible spectrophotometry and transmission electron microscopy (TEM). The obtained nanospheres present the maximum localized surface plasmon resonance (LSPR) peak position are found to be around 519 nm and a diameter of 17nm. The DNA probes modified with a sulfur group at one end of the sequence were then loaded on the gold nanospheres at different ionic strengths and DNA probe concentrations. The optimal DNA probe loading will be selected based on the stability of the optical signal followed by the hybridization study. Hybridization process leads to either nanoparticle dispersion or aggregation based on the presence or absence of the target DNA. Finally, this detection system will be integrated into an optical sensing platform. Considering that the developed device will be used in the field, it should fulfill the inexpensive and portability requirements. The sensing devices based on specific DNA detection holds great potential and can be exploited for sensing applications in-loco.

Keywords: ZM DNA, DNA probes, nicking enzyme, gold nanoparticles

Procedia PDF Downloads 251

Authors: Lee Tasker, Ali Karrech, Jeffrey Shragge, Matthew Josh

Abstract:

Monitoring for the deterioration of concrete infrastructure is an important assessment tool for an engineer and difficulties can be experienced with monitoring for deterioration within an infrastructure. If a failure crack, or fluid seepage through such a crack, is observed from the surface often the source location of the deterioration is not known. Geophysical methods are used to assist engineers with assessing the subsurface conditions of materials. Techniques such as Ground Penetrating Radar (GPR) provide information on the location of buried infrastructure such as pipes and conduits, positions of reinforcements within concrete blocks, and regions of voids/cavities behind tunnel lining. This experiment underlines the application of GPR as an infrastructure-monitoring tool to highlight and monitor regions of possible deterioration within a concrete test wall due to an increase in the generation of fractures; in particular, during a time period of applied load to a concrete wall up to and including structural failure. A three-point load was applied to a concrete test wall of dimensions 1700 x 600 x 300 mm³ in increments of 10 kN, until the wall structurally failed at 107.6 kN. At each increment of applied load, the load was kept constant and the wall was scanned using GPR along profile lines across the wall surface. The measured radar amplitude responses of the GPR profiles, at each applied load interval, were reconstructed into depth-slice grids and presented at fixed depth-slice intervals. The corresponding depth-slices were subtracted from each data set to compare the radar amplitude response between datasets and monitor for changes in the radar amplitude response. At lower values of applied load (i.e., 0-60 kN), few changes were observed in the difference of radar amplitude responses between data sets. At higher values of applied load (i.e., 100 kN), closer to structural failure, larger differences in radar amplitude response between data sets were highlighted in the GPR data; up to 300% increase in radar amplitude response at some locations between the 0 kN and 100 kN radar datasets. Distinct regions were observed in the 100 kN difference dataset (i.e., 100 kN-0 kN) close to the location of the final failure crack. The key regions observed were a conical feature located between approximately 3.0-12.0 cm depth from surface and a vertical linear feature located approximately 12.1-21.0 cm depth from surface. These key regions have been interpreted as locations exhibiting an increased change in pore-space due to increased mechanical loading, or locations displaying an increase in volume of micro-cracks, or locations showing the development of a larger macro-crack. The experiment showed that GPR is a useful geophysical monitoring tool to assist engineers with highlighting and monitoring regions of large changes of radar amplitude response that may be associated with locations of significant internal structural change (e.g. crack development). GPR is a non-destructive technique that is fast to deploy in a production setting. GPR can assist with reducing risk and costs in future infrastructure maintenance programs by highlighting and monitoring locations within the structure exhibiting large changes in radar amplitude over calendar-time.

Keywords: 4D GPR, engineering geophysics, ground penetrating radar, infrastructure monitoring

Procedia PDF Downloads 181

Authors: Vikas Kumar, Kailash Chandra, Kaomud Tyagi

Abstract:

The insect order Thysanoptera includes small insects commonly called thrips. As insect vectors, only thrips are capable of Tospoviruses transmission (genus Tospovirus, family Bunyaviridae) affecting various crops. Currently, fifteen species of subfamily Thripinae (Thripidae) have been reported as vectors for tospoviruses. Frankliniella schultzei, which is reported as act as a vector for at least five tospovirses, have been suspected to be a species complex with more than one species. It is one of the historical unresolved issues where, two species namely, F. schultzei Trybom and F. sulphurea Schmutz were erected from South Africa and Srilanaka respectively. These two species were considered to be valid until 1968 when sulphurea was treated as colour morph (pale form) and synonymised under schultzei (dark form) However, these two have been considered as valid species by some of the thrips workers. Parallel studies have indicated that brown form of schultzei is a vector for tospoviruses while yellow form is a non-vector. However, recent studies have shown that yellow populations have also been documented as vectors. In view of all these facts, it is highly important to have a clear understanding whether these colour forms represent true species or merely different populations with different vector carrying capacities and whether there is some hidden diversity in 'Frankliniella schultzei species complex'. In this study, we aim to study the 'Frankliniella schultzei species complex' with molecular spectacles with DNA data from India and Australia and Africa. A total of fifty-five specimens was collected from diverse locations in India and Australia. We generated molecular data using partial fragments of mitochondrial cytochrome c oxidase I gene (mtCOI) and 28S rRNA gene. For COI dataset, there were seventy-four sequences, out of which data on fifty-five was generated in the current study and others were retrieved from NCBI. All the four different tree construction methods: neighbor-joining, maximum parsimony, maximum likelihood and Bayesian analysis, yielded the same tree topology and produced five cryptic species with high genetic divergence. For, rDNA, there were forty-five sequences, out of which data on thirty-nine was generated in the current study and others were retrieved from NCBI. The four tree building methods yielded four cryptic species with high bootstrap support value/posterior probability. Here we could not retrieve one cryptic species from South Africa as we could not generate data on rDNA from South Africa and sequence for rDNA from African region were not available in the database. The results of multiple species delimitation methods (barcode index numbers, automatic barcode gap discovery, general mixed Yule-coalescent, and Poisson-tree-processes) also supported the phylogenetic data and produced 5 and 4 Molecular Operational Taxonomic Units (MOTUs) for mtCOI and 28S dataset respectively. These results of our study indicate the likelihood that F. sulphurea may be a valid species, however, more morphological and molecular data is required on specimens from type localities of these two species and comparison with type specimens.

Keywords: DNA barcoding, species complex, thrips, species delimitation

Procedia PDF Downloads 131

Authors: Seungsik Yu, Minho Kang

Abstract:

As the threat of terrorism to nuclear facilities is increasing globally after the attacks of September 11, we are striving to recognize the physical protection system and strengthen the emergency response system. Since 2015, Korea has implemented physical protection security exercise for nuclear facilities. The exercise should be carried out with full cooperation between the operator and response forces. Performance testing of the physical protection system should include appropriate exercises, for example, force-on-force exercises, to determine if the response forces can provide an effective and timely response to prevent sabotage. Significant deficiencies and actions taken should be reported as stipulated by the competent authority. The IAEA(International Atomic Energy Agency) is also preparing force-on-force exercise program documents to support exercise of member states. Currently, ROK(Republic of Korea) is implementing exercise on the force-on-force exercise evaluation system which is developed by itself for the nuclear power plant, and it is necessary to establish the exercise procedure considering the use of the force-on-force exercise evaluation system. The purpose of this study is to establish the work procedures of the three major organizations related to the force-on-force exercise of nuclear power plants in ROK, which conduct exercise using force-on-force exercise evaluation system. The three major organizations are composed of licensee, KINAC (Korea Institute of Nuclear Nonproliferation and Control), and the NSSC(Nuclear Safety and Security Commission). Major activities are as follows. First, the licensee establishes and conducts an exercise plan, and when recommendations are derived from the result of the exercise, it prepares and carries out a force-on-force result report including a plan for implementation of the recommendations. Other detailed tasks include consultation with surrounding units for adversary, interviews with exercise participants, support for document evaluation, and self-training to improve the familiarity of the MILES (Multiple Integrated Laser Engagement System). Second, KINAC establishes a force-on-force exercise plan review report and reviews the force-on-force exercise plan report established by licensee. KINAC evaluate force-on-force exercise using exercise evaluation system and prepare training evaluation report. Other detailed tasks include MILES training, adversary consultation, management of exercise evaluation systems, and analysis of exercise evaluation results. Finally, the NSSC decides whether or not to approve the force-on-force exercise and makes a correction request to the nuclear facility based on the exercise results. The most important part of ROK's force-on-force exercise system is the analysis through the exercise evaluation system implemented by KINAC after the exercise. The analytical method proceeds in the order of collecting data from the exercise evaluation system and analyzing the collected data. The exercise application process of the exercise evaluation system introduced in ROK in 2016 will be concretely set up, and a system will be established to provide objective and consistent conclusions between exercise sessions. Based on the conclusions drawn up, the ultimate goal is to complement the physical protection system of licensee so that the system makes licensee respond effectively and timely against sabotage or unauthorized removal of nuclear materials.

Keywords: Force-on-Force exercise, nuclear power plant, physical protection, sabotage, unauthorized removal

Procedia PDF Downloads 144

Authors: Salma Akter, Md. Kamal Uddin

Abstract:

This study aims to demonstrate how top-down shelter policy and its resultant dwelling environment leads to ‘everyday compromise’ by the grassroots according to subjective (satisfaction) and objective (physical design elements and physical environmental elements) indicators, which are measured across three levels of the settlement; macro (Community), meso (Neighborhood or shelter/built environment) and micro (family). Ashrayan Prakalpa is a resettlement /housing project of Government of Bangladesh for providing shelters and human resources development activities like education, microcredit, and training programme to landless, homeless and rootless people. Despite the integrated nature of the shelter policies (comprises poverty alleviation, employment opportunity, secured tenure, and livelihood training), the ‘quality of life’ issue at the different levels of settlements becomes questionable. As dwellers of shelter units (although formally termed as ‘barracks’ rather shelter or housing) remain on the receiving end of government’s resettlement policies, they often involve with spatial-physical and socio-economic negotiation and assume curious forms of spatial practice, which often upholds contradiction with policy planning. Thus, policy based shelter force dwellers to persistently compromise with their provided built environments both in overtly and covertly. Compromising with prescribed designed space and facilities across living places articulated their negotiation with the quality of allocated space, built form and infrastructures, which in turn exert as less quality of life. The top-down shelter project, Dakshin Chandani Mahal Ashrayan Prakalpa at Dighalia Upazila, the study area located at the Eastern fringe area of Khulna, Bangladesh, is still in progress to resettle internally displaced and homeless people. In terms of methodology, this research is primarily exploratory and adopts a case study method, and an analytical framework is developed through the deductive approach for evaluating the quality of life. Secondary data have been obtained from housing policy analysis and relevant literature review, while key informant interview, focus group discussion, necessary drawings and photographs and participant observation across dwelling, neighborhood, and community level have also been administered as primary data collection methodology. Findings have revealed that various shortages, inadequacies, and negligence of policymakers force to compromise with allocated designed space, physical infrastructure and economic opportunities across dwelling, neighborhood and mostly community level. Thus, the outcome of this study can be beneficial for a global-level understating of the compromising the ‘quality of life’ under top-down shelter policy. Locally, for instance, in the context of Bangladesh, it can help policymakers and concerned authorities to formulate the shelter policies and take initiatives to improve the well-being of marginalized.

Keywords: Ashrayan Prakalpa, compromise, displaced people, quality of life

Procedia PDF Downloads 155

Authors: Dila Ram Bhandari

Abstract:

Throughout the 20th century, new governments were created where identities such as ethnic, religious, linguistic, caste, communal, tribal, and others played a part in the development of constitutions and the legal system of victim and criminal justice. Acute issues with extremism, poverty, environmental degradation, cybercrimes, human rights violations, crime against, and victimization of both individuals and groups have recently plagued South Asian nations. Everyday massive number of crimes are steadfast, these frequent crimes have made the lives of common citizens restless. Crimes are one of the major threats to society and also for civilization. Crime is a bone of contention that can create a societal disturbance. The old-style crime solving practices are unable to live up to the requirement of existing crime situations. Crime analysis is one of the most important activities of the majority of intelligent and law enforcement organizations all over the world. The South Asia region lacks such a regional coordination mechanism, unlike central Asia of Asia Pacific regions, to facilitate criminal intelligence sharing and operational coordination related to organized crime, including illicit drug trafficking and money laundering. There have been numerous conversations in recent years about using data mining technology to combat crime and terrorism. The Data Detective program from Sentient as a software company, uses data mining techniques to support the police (Sentient, 2017). The goals of this internship are to test out several predictive model solutions and choose the most effective and promising one. First, extensive literature reviews on data mining, crime analysis, and crime data mining were conducted. Sentient offered a 7-year archive of crime statistics that were daily aggregated to produce a univariate dataset. Moreover, a daily incidence type aggregation was performed to produce a multivariate dataset. Each solution's forecast period lasted seven days. Statistical models and neural network models were the two main groups into which the experiments were split. For the crime data, neural networks fared better than statistical models. This study gives a general review of the applied statistics and neural network models. A detailed image of each model's performance on the available data and generalizability is provided by a comparative analysis of all the models on a comparable dataset. Obviously, the studies demonstrated that, in comparison to other models, Gated Recurrent Units (GRU) produced greater prediction. The crime records of 2005-2019 which was collected from Nepal Police headquarter and analysed by R programming. In conclusion, gated recurrent unit implementation could give benefit to police in predicting crime. Hence, time series analysis using GRU could be a prospective additional feature in Data Detective.

Keywords: time series analysis, forecasting, ARIMA, machine learning

Procedia PDF Downloads 168

Authors: Dianelys Vega, Carlos Magluta, Ney Roitman

Abstract:

The simulation of loads induced by walking people in civil engineering structures is still challenging It has been the focus of considerable research worldwide in the recent decades due to increasing number of reported vibration problems in pedestrian structures. One of the most important key in the designing of slender structures is the Human-Structure Interaction (HSI). How moving people interact with structures and the effect it has on their dynamic responses is still not well understood. To rely on calibrated pedestrian models that accurately estimate the structural response becomes extremely important. However, because of the complexity of the pedestrian mechanisms, there are still some gaps in knowledge and more reliable models need to be investigated. On this topic several authors have proposed biodynamic models to represent the pedestrian, whether these models provide a consistent approximation to physical reality still needs to be studied. Therefore, this work comes to contribute to a better understanding of this phenomenon bringing an experimental validation of a pedestrian walking model and a Human-Structure Interaction model. In this study, a bi-dimensional bipedal walking model was used to represent the pedestrians along with an interaction model which was applied to a prototype footbridge. Numerical models were implemented in MATLAB. In parallel, experimental tests were conducted in the Structures Laboratory of COPPE (LabEst), at Federal University of Rio de Janeiro. Different test subjects were asked to walk at different walking speeds over instrumented force platforms to measure the walking force and an accelerometer was placed at the waist of each subject to measure the acceleration of the center of mass at the same time. By fitting the step force and the center of mass acceleration through successive numerical simulations, the model parameters are estimated. In addition, experimental data of a walking pedestrian on a flexible structure was used to validate the interaction model presented, through the comparison of the measured and simulated structural response at mid span. It was found that the pedestrian model was able to adequately reproduce the ground reaction force and the center of mass acceleration for normal and slow walking speeds, being less efficient for faster speeds. Numerical simulations showed that biomechanical parameters such as leg stiffness and damping affect the ground reaction force, and the higher the walking speed the greater the leg length of the model. Besides, the interaction model was also capable to estimate with good approximation the structural response, that remained in the same order of magnitude as the measured response. Some differences in frequency spectra were observed, which are presumed to be due to the perfectly periodic loading representation, neglecting intra-subject variabilities. In conclusion, this work showed that the bipedal walking model could be used to represent walking pedestrians since it was efficient to reproduce the center of mass movement and ground reaction forces produced by humans. Furthermore, although more experimental validations are required, the interaction model also seems to be a useful framework to estimate the dynamic response of structures under loads induced by walking pedestrians.

Keywords: biodynamic models, bipedal walking models, human induced loads, human structure interaction

Procedia PDF Downloads 135

Authors: Andre Pastori D'Aurea, Lauriston Bertelli Feranades, Luis Eduardo Ferreira, Leandro Dias Pinto, Fabiana Ayumi Shiozaki

Abstract:

The aim of this study was to improve the production of beef cattle on tropical pasture without harming this environment. On tropical pastures, cattle's live weight gain is lower than feedlot, and forage production is seasonable, changing from season to season. Thus, concerned with sustainable livestock production, the Premix Company has developed strategies to improve the production of beef cattle on tropical pasture to ensure sustainability of welfare and production. There are two important principles in this productivity system: 1) increase individual gains with use of better supplementation and 2) increase the productivity units with better forage quality like corn silage or other forms of forage conservations, actually used only in winter, and adding natural additives in the diet. This production system was applied from June 2017 to May 2018 in the Research Center of Premix Company, Patrocínio Paulista, São Paulo State, Brazil. The area used had 9 hectares of pasture of Brachiaria brizantha. 36 steers Nellore were evaluated for one year. The initial weight was 253 kg. The parameters used were daily average gain and gain per area. This indicated the corrections to be made and helped design future fertilization. In this case, we fertilized the pasture with 30 kg of nitrogen per animal divided into two parts. The diet was pasture and protein-energy supplements (0.4% of live weight). The supplement used was added with natural additive Fator P® – Premix Company). Fator P® is an additive composed by amino acids (lysine, methionine and tyrosine, 16400, 2980 and 3000 mg.kg-1 respectively), minerals, probiotics (Saccharomyces cerevisiae, 7 x 10E8 CFU.kg-1) and essential fatty acids (linoleic and oleic acids, 108.9 and 99g.kg-1 respectively). Due to seasonal changes, in the winter we supplemented the diet by increasing the offer of forage, supplementing with maize silage. It was offered 1% of live weight in silage corn and 0.4% of the live weight in protein-energetic supplements with additive Fator P ®. At the end of the period, the productivity was calculated by summing the individual gains for the area used. The average daily gain of the animals were 693 grams per day and was produced 1.005 kg /hectare/year. This production is about 8 times higher than the average of Brazilian meat national production. To succeed in this project, it is necessary to increase the gains per area, so it is necessary to increase the capacity per area. Pasture management is very important to the project's success because the dietary decisions were taken from the quantity and quality of the forage. We, therefore, recommend the use of animals in the growth phase because the response to supplementation is greater in that phase and we can allocate more animals per area. This system's carbon footprint reduces emissions by 61.2 percent compared to the Brazilian average. This beef cattle production system can be efficient and environmentally friendly to the natural. Another point is that bovines will benefit from their natural environment without competing or having an impact on human food production.

Keywords: cattle production, environment, pasture, sustainability

Procedia PDF Downloads 154

Authors: Ruchira Das

Abstract:

The major Metropolises of India are resultant of Colonial manifestation of Production, Consumption and Sustenance. These cities grew, survived, and sustained on the basic whims of Colonial Power and Administrative Agendas. They were symbols of power, authority and administration. Within them some Colonial Towns remained as small towns within the close vicinity of the major metropolises and functioned as self–sufficient units until peripheral development due to tremendous pressure occurred in the metropolises. After independence huge expansion in Judiciary and Administration system resulted City Oriented Employment. A large number of people started residing within the city or within commutable distance of the city and it accelerated expansion of the cities. Since then Budgetary and Planning expenditure brought a new pace in Economic Activities. Investment in Industry and Agriculture sector generated opportunity of employment which further led towards urbanization. After two decades of Budgetary and Planning economic activities in India, a new era started in metropolitan expansion. Four major metropolises started further expansion rapidly towards its suburbs. A concept of large Metropolitan Area developed. Cities became nucleus of suburbs and rural areas. In most of the cases such expansion was not favorable to the relationship between City and its hinterland due to absence of visualization of Compact Sustainable Development. The search for solutions needs to weigh the choices between Rural and Urban based development initiatives. Policymakers need to focus on areas which will give the greatest impact. The impact of development initiatives will spread the significant benefit to all. There is an assumption that development integrates Economic, Social and Environmental considerations with equal weighing. The traditional narrower and almost exclusive focus on economic criteria as the determinant of the level of development is thus re–described and expanded. The Social and Environmental aspects are equally important as Economic aspect to achieve Sustainable Development. The arrangement of opportunities for Public, Semi – Public facilities for its citizen is very much relevant to development. It is responsibility of the administration to provide opportunities for the basic requirement of its inhabitants. Development should be in terms of both Industrial and Agricultural to maintain a balance between city and its hinterland. Thus, policy is to formulate shifting the emphasis away from Economic growth towards Sustainable Human Development. The goal of Policymaker should aim at creating environments in which people’s capabilities can be enhanced by the effective dynamic and adaptable policy. The poverty could not be eradicated simply by increasing income. The improvement of the condition of the people would have to lead to an expansion of basic human capabilities. In this scenario the suburbs/rural areas are considered as environmental burden to the metropolises. A new living has to be encouraged in the suburban or rural. We tend to segregate agriculture from the city and city life, this leads to over consumption, but this urbanism model attempts both these to co–exists and hence create an interesting overlapping of production and consumption network towards sustainable Rurbanism.

Keywords: socio–economic progress, sustainability, social equity, urbanism

Procedia PDF Downloads 309

Authors: X. King, E. Nazarzadeh, J. Reboud, J. Cooper

Abstract:

Pulmonary diseases, such as asthma, are generally treated by the inhalation of aerosols that has the advantage of reducing the off-target (e.g., toxicity) effects associated with systemic delivery in blood. Effective respiratory drug delivery requires a droplet size distribution between 1 and 5 µm. Inhalation of aerosols with wide droplet size distribution, out of this range, results in deposition of drug in not-targeted area of the respiratory tract, introducing undesired side effects on the patient. In order to solely deliver the drug in the lower branches of the lungs and release it in a targeted manner, a control mechanism to produce the aerosolized droplets is required. To regulate the drug release and to facilitate the uptake from cells, drugs are often encapsulated into protective liposomes. However, a multistep process is required for their formation, often performed at the formulation step, therefore limiting the range of available drugs or their shelf life. Using surface acoustic waves (SAWs), a pulmonary drug delivery platform was produced, which enabled the formation of defined size aerosols and the formation of liposomes in situ. SAWs are mechanical waves, propagating along the surface of a piezoelectric substrate. They were generated using an interdigital transducer on lithium niobate with an excitation frequency of 9.6 MHz at a power of 1W. Disposable silicon superstrates were etched using photolithography and dry etch processes to create an array of cylindrical through-holes with different diameters and pitches. Superstrates were coupled with the SAW substrate through water-based gel. As the SAW propagates on the superstrate, it enables nebulisation of a lipid solution deposited onto it. The cylindrical cavities restricted the formation of large drops in the aerosol, while at the same time unilamellar liposomes were created. SAW formed liposomes showed a higher monodispersity compared to the control sample, as well as displayed, a faster production rate. To test the aerosol’s size, dynamic light scattering and laser diffraction methods were used, both showing the size control of the aerosolised particles. The use of silicon superstate with cavity size of 100-200 µm, produced an aerosol with a mean droplet size within the optimum range for pulmonary drug delivery, containing the liposomes in which the medicine could be loaded. Additionally, analysis of liposomes with Cryo-TEM showed formation of vesicles with narrow size distribution between 80-100 nm and optimal morphology in order to be used for drug delivery. Encapsulation of nucleic acids in liposomes through the developed SAW platform was also investigated. In vitro delivery of siRNA and DNA Luciferase were achieved using A549 cell line, lung carcinoma from human. In conclusion, SAW pulmonary drug delivery platform was engineered, in order to combine multiple time consuming steps (formation of liposomes, drug loading, nebulisation) into a unique platform with the aim of specifically delivering the medicament in a targeted area, reducing the drug’s side effects.

Keywords: acoustics, drug delivery, liposomes, surface acoustic waves

Procedia PDF Downloads 128

Authors: Mabel Y. C. Yau, Roy C. F. Lai, Hugo Y. H. Or

Abstract:

This study is a pilot surveillance of hygiene compliance and food microbial safety of both licensed and mobile vendors selling Chinese ready–to-eat snack foods in Hong Kong. The study reflects similar situations in running mobile food vending business on trucks. Hong Kong is about to launch the Food Truck Pilot Scheme by the end of 2016 or early 2017. Technically, selling food on the vehicle is no different from hawking food on the street or vending food on the street. Each type of business bears similar food safety issues and cast the same impact on public health. Present findings demonstrate exemplarily situations that also apply to food trucks. 9 types of Cantonese style snacks of 32 samples in total were selected for microbial screening. A total of 16 vending sites including supermarkets, street markets, and snack stores were visited. The study finally focused on a traditional snack, the steamed rice cake with red beans called Put Chai Ko (PCK). PCK is a type of classical Cantonese pastry sold on push carts on the street. It used to be sold at room temperature and served with bamboo sticks in the old days. Some shops would have them sold steam fresh. Microbial examinations on aerobic counts, yeast, and mould, coliform, salmonella as well as Staphylococcus aureus detections were carried out. Salmonella was not detected in all samples. Since PCK does not contain ingredients of beef, poultry, eggs or dairy products, the risk of the presence of Salmonella in PCK was relatively lower although other source of contamination might be possible. Coagulase positive Staphylococcus aureus was found in 6 of the 14 samples sold at room temperature. Among these 6 samples, 3 were PCK. One of the samples was in an unacceptable range of total colony forming units higher than 105. The rest were only satisfactory. Observational evaluations were made with checklists on personal hygiene, premises hygiene, food safety control, food storage, cleaning and sanitization as well as waste disposals. The maximum score was 25 if total compliance were obtained. The highest score among vendors was 20. Three stores were below average, and two of these stores were selling PCK. Most of the non-compliances were on food processing facilities, sanitization conditions and waste disposal. In conclusion, although no food poisoning outbreaks happened during the time of the investigation, the risk of food hazard existed in these stores, especially among street vendors. Attention is needed in the traditional practice of food selling, and that food handlers might not have sufficient knowledge to properly handle food products. Variations in food qualities existed among supply chains or franchise eateries or shops. It was commonly observed that packaging and storage conditions are not properly enforced in the retails. The same situation could be reflected across the food business. It did indicate need of food safety training in the industry and loopholes in quality control among business.

Keywords: cantonese snacks, food safety, microbial, hygiene, street food

Procedia PDF Downloads 307

Authors: Maryam Shahbazi, Amy B. Cerato

Abstract:

The importance of a systems’ natural frequency (fn) emerges when the vibration force frequency is equivalent to foundation's fn which causes response amplitude (resonance) that may cause irreversible damage to the structure. Several factors such as pile geometry (e.g., length and diameter), soil density, load magnitude, pile condition, and physical structure affect the fn of a soil-pile system; some of these parameters are evaluated in this study. Although experimental and analytical studies have assessed the fn of a soil-pile system, few have included individual and grouped helical piles. Thus, the current study aims to provide quantitative data on dynamic characteristics of helical pile-soil systems from full-scale shake table tests that will allow engineers to predict more realistic dynamic response under motions with variable frequency ranges. To evaluate the fn of single and grouped helical piles in dry dense sand, full-scale shake table tests were conducted in a laminar box (6.7 m x 3.0 m with 4.6 m high). Two different diameters (8.8 cm and 14 cm) helical piles were embedded in the soil box with corresponding lengths of 3.66m (excluding one pile with length of 3.96) and 4.27m. Different configurations were implemented to evaluate conditions such as fixed and pinned connections. In the group configuration, all four piles with similar geometry were tied together. Simulated real earthquake motions, in addition to white noise, were applied to evaluate the wide range of soil-pile system behavior. The Fast Fourier Transform (FFT) of measured time history responses using installed strain gages and accelerometers were used to evaluate fn. Both time-history records using accelerometer or strain gages were found to be acceptable for calculating fn. In this study, the existence of a pile reduced the fn of the soil slightly. Greater fn occurred on single piles with larger l/d ratios (higher slenderness ratio). Also, regardless of the connection type, the more slender pile group which is obviously surrounded by more soil, yielded higher natural frequencies under white noise, which may be due to exhibiting more passive soil resistance around it. Relatively speaking, within both pile groups, a pinned connection led to a lower fn than a fixed connection (e.g., for the same pile group the fn’s are 5.23Hz and 4.65Hz for fixed and pinned connections, respectively). Generally speaking, a stronger motion causes nonlinear behavior and degrades stiffness which reduces a pile’s fn; even more, reduction occurs in soil with a lower density. Moreover, fn of dense sand under white noise signal was obtained 5.03 which is reduced by 44% when an earthquake with the acceleration of 0.5g was applied. By knowing the factors affecting fn, the designer can effectively match the properties of the soil to a type of pile and structure to attempt to avoid resonance. The quantitative results in this study assist engineers in predicting a probable range of fn for helical pile foundations under potential future earthquake, and machine loading applied forces.

Keywords: helical pile, natural frequency, pile group, shake table, stiffness

Procedia PDF Downloads 137

Authors: Gheorghiţa Mitran, Adriana Urdă, Mihaela Florea, Octavian Dumitru Pavel, Florentina Neaţu

Abstract:

Oxidative dehydrogenation and hydrogenation reactions of L-malic acid are interesting ways for its transformation into valuable products, including oxaloacetic, pyruvic and malonic acids but also 1,4-butanediol and 1,2,4-butanetriol. Keto acids have a range of applicationsin many chemical syntheses as pharmaceuticals, food additives and cosmetics. 3-Hydroxybutyrolactone and 1,2,4-butanetriol are used for the synthesis of chiral pharmaceuticals and other fine chemicals, while 1,4-butanediol can be used for organic syntheses, such as polybutylene succinate (PBS), polybutylene terephthalate (PBT), and for production of tetrahydrofuran (THF). L-malic acid is a non-toxic and natural organic acid present in fruits, and it is the main component of wine alongside tartaric acid representing about 90% of the wine total acidity. Iron oxides dopped with cobalt (CoxFe3-xO4; x= 0; 0.05; 0.1; 0.15) were studied as catalysts in these reactions. There is no mention in the literature of non-noble transition metal catalysts for these reactions. The method used for catalysts preparation was coprecipitation, whileBET XRD, XPS, FTIR and UV-VIS spectroscopy were used for the physicochemical properties evaluation.TheXRD patterns revealed the presence of α-Fe2O3 rhombohedral hematite structure, with cobalt atoms well dispersed and embedded in this structure. The studied samples are highly crystalline, with a crystallite size ranged from 58 to 65 nm. The optical absorption properties were investigated using UV-Vis spectroscopy, emphasizing the presence of bands that correspond with the reported hematite nanoparticle. Likewise, the presence of bands corresponding to lattice vibration of hexagonal hematite structurehas been evidenced in DRIFT spectra. Oxidative dehydrogenation of malic acid was studied using as solvents for malic acid ethanol or water(2, 5 and 10% malic acid in 5 mL solvent)at room temperature, while the hydrogenation reaction was evaluated in water as solvent (5%), in the presence of 1% catalyst. The oxidation of malic acid into oxaloacetic acid is the first step, after that, oxaloacetic acid is rapidly decarboxylated to malonic acid or pyruvic acid, depending on the active site. The concentration of malic acid in solution, it, in turn, has an influence on conversionthis decreases when the concentration of malic acid in the solution is high. The spent catalysts after the oxidative dehydrogenation of malic acid in ethanol were characterized by DRIFT spectroscopy and the presence of oxaloacetic, pyruvic and malonicacids, along with unreacted malic acidwere observed on the surface. The increase of the ratio of Co/Fe on the surface has an influence on the malic acid conversion and on the pyruvic acid yield, while the yield of malonic acid is influenced by the percentage of iron on the surface (determined from XPS). Oxaloacetic acid yield reaches a maximumat one hour of reaction, being higher when ethanol is used as a solvent, after which it suddenly decreases. The hydrogenation of malic acid occurs by consecutive reactions with the production of 3-hydroxy-butyrolactone, 1,2,4-butanetriol and 1,4-butanediol. Malic acid conversion increases with cobalt loading increasing up to Co/Fe ratio of 0.1, after which it has a slight decrease, while the yield in 1,4-butanediol is directly proportional to the cobalt content.

Keywords: malic acid, oxidative dehydrogenation, hydrogenation, oxaloacetic acid

Procedia PDF Downloads 187

Authors: Jonardan Koner, Avinash Purandare

Abstract:

In today’s globalized world international business is a very key area for the country's growth. Some of the strategic areas for holding up a country’s international business to grow are in the areas of connecting Ports, Road Network, and Rail Network. India’s International Business is booming both in Exports as well as Imports. Ports play a very central part in the growth of international trade and ensuring competitive ports is of critical importance. India has a long coastline which is a big asset for the country as it has given the opportunity for development of a large number of major and minor ports which will contribute to the maritime trades’ development. The National Economic Development of India requires a well-functioning seaport system. To know the comparative strength of Indian ports over South-east Asian similar ports, the study is considering the objectives of (I) to identify the key parameters of an international mega container port, (II) to compare the five selected container ports (JNPT, Chennai, Singapore, Dubai, and Colombo Ports) according to user of the ports and iii) to measure the growth of selected five container ports’ throughput over time and their comparison. The study is based on both primary and secondary databases. The linear time trend analysis is done to show the trend in quantum of exports, imports and total goods/services handled by individual ports over the years. The comparative trend analysis is done for the selected five ports of cargo traffic handled in terms of Tonnage (weight) and number of containers (TEU’s). The comparative trend analysis is done between containerized and non-containerized cargo traffic in the five selected five ports. The primary data analysis is done comprising of comparative analysis of factor ratings through bar diagrams, statistical inference of factor ratings for the selected five ports, consolidated comparative line charts of factor rating for the selected five ports, consolidated comparative bar charts of factor ratings of the selected five ports and the distribution of ratings (frequency terms). The linear regression model is used to forecast the container capacities required for JNPT Port and Chennai Port by the year 2030. Multiple regression analysis is carried out to measure the impact of selected 34 explanatory variables on the ‘Overall Performance of the Port’ for each of the selected five ports. The research outcome is of high significance to the stakeholders of Indian container handling ports. Indian container port of JNPT and Chennai are benchmarked against international ports such as Singapore, Dubai, and Colombo Ports which are the competing ports in the neighbouring region. The study has analysed the feedback ratings for the selected 35 factors regarding physical infrastructure and services rendered to the port users. This feedback would provide valuable data for carrying out improvements in the facilities provided to the port users. These installations would help the ports’ users to carry out their work in more efficient manner.

Keywords: throughput, twenty equivalent units, TEUs, cargo traffic, shipping lines, freight forwarders

Procedia PDF Downloads 134

Authors: Sandhya Parameswaran, Prajakta Dhuri

Abstract:

Despite great improvements in health care, the world oral health report states that dental problems still persist, particularly among underprivileged groups in both developing and developed countries. Dental caries and periodontal diseases are identified as the most important oral health problems globally. Acidic foods and beverages can affect natural teeth, and chronic exposure often leads to the development of dental erosion, abrasion, and decay. In recent years, there has been an increased interest toward essential oils. These are secondary metabolites and possess antibacterial, antifungal and antioxidant properties. Essential oils are volatile and chemically unstable in the presence of air, light, moisture and high temperature. Hence many novel methods like a liposomal encapsulation of oils have been introduced to enhance the stability and bioavailability. This research paper focuses on two essential oils, clove and cinnamon oil. Clove oil was obtained from Syzygium aromaticum Linn using clavengers apparatus. It contains eugenol and β caryophyllene. Cinnamon oil, from the barks of Cinnamomum cassia, contains cinnamaldehyde, The objective of the current research was to develop a liposomal carrier system containing clove and cinnamon oil and study their synergistic activity against dental pathogens when formulated as a gel. Methodology: The essential oil were first tested for their antimicrobial activity against dental pathogens, Lactobacillus acidophillus (MTCC No. 10307, MRS broth) and Streptococcus Mutans (MTCC No .890, Brain Heart Infusion agar). The oils were analysed by UV spectroscopy for eugenol and cinnamaldehyde content. Standard eugenol was linear between 5ppm to 25ppm at 282nm and standard cinnamaldehde from 1ppm to 5pmm at 284nm. The concentration of eugenol in clove oil was found to be 62.65 % w/w, and that of cinnamaldehyde was found to be 5.15%s w/w. The oils were then formulated into liposomes. Liposomes were prepared by thin film hydration method using Phospholipid, Cholesterol, and other oils dissolved in a chloroform methanol (3:1) mixture. The organic solvent was evaporated in a rotary evaporator above lipid transition temperature. The film was hydrated with phosphate buffer (pH 5.5).The various batches of liposomes were characterized and compared for their size, loading rate, encapsulation efficiency and morphology. The prepared liposomes when evaluated for entrapment efficiency showed 65% entrapment for clove and 85% for cinnamon oil. They were also tested for their antimicrobial activity against dental pathogens and their synergistic activity studied. Based on the activity and the entrapment efficiency the amount of liposomes required to prepare 1gm of the gel was calculated. The gel was prepared using a simple ointment base and contained 0.56% of cinnamon and clove liposomes. A simultaneous method of analysis for eugenol and cinnamaldehyde.was then developed using HPLC. The prepared gels were then studied for their stability as per ICH guidelines. Conclusion: It was found that liposomes exhibited spherical shaped vesicles and protected the essential oil from degradation. Liposomes, therefore, constitute a suitable system for encapsulation of volatile, unstable essential oil constituents.

Keywords: cinnamon oil, clove oil, dental caries, liposomes

Procedia PDF Downloads 196

Authors: Anele Horn, Amanda Van Eeden

Abstract:

The emphasis on the challenges posed by continued urbanisation, especially in developing countries has resulted in urban sprawl often researched and analysed in metropolitan urban areas, but rarely in small and medium towns. Consequently, there exists no comparative instrument between the proportional extent of urban sprawl in metropolitan areas measured against that of small and medium towns. This research proposes an Urban Sprawl Index as a possible tool to comparatively analyse the extent of urban sprawl between cities and towns of different sizes. The index can also be used over the longer term by authorities developing spatial policy to track the success or failure of specific tools intended to curb urban sprawl. In South Africa, as elsewhere in the world, the last two decades witnessed a proliferation of legislation and spatial policies to limit urban sprawl and contain the physical expansion and development of urban areas, but the measurement of the successes or failures of these instruments intending to curb expansive land development has remained a largely unattainable goal, largely as a result of the absence of an appropriate measure of proportionate comparison. As a result of the spatial political history of Apartheid, urban areas acquired a spatial form that contributed to the formation of single-core cities with far reaching and wide-spreading peripheral development, either in the form of affluent suburbs or as a result of post-Apartheid programmes such as the Reconstruction and Development Programme (1995) which, in an attempt to assist the immediate housing shortage, favoured the establishment of single dwelling residential units for low income communities on single plots on affordable land at the urban periphery. This invariably contributed to urban sprawl and even though this programme has since been abandoned, the trend towards low density residential development continues. The research area is the Western Cape Province in South Africa, which in all aspects exhibit the spatial challenges described above. In academia and popular media the City of Cape Town (the only Metropolitan authority in the province) has received the lion’s share of focus in terms of critique on urban development and spatial planning, however, the smaller towns and cities in the Western Cape arguably received much less public attention and were spared the naming and shaming of being unsustainable urban areas in terms of land consumption and physical expansion. The Urban Sprawl Index for the Western Cape (USIWC) put forward by this research enables local authorities in the Western Cape Province to measure the extent of urban sprawl proportionately and comparatively to other cities in the province, thereby acquiring a means of measuring the success of the spatial instruments employed to limit urban expansion and inefficient land consumption. In development of the USIWC the research made use of satellite data for reference years 2001 and 2011 and population growth data extracted from the national census, also for base years 2001 and 2011.

Keywords: urban sprawl, index, Western Cape, South Africa

Procedia PDF Downloads 333

Authors: Shailendra Kumar, Lokesh Kashyap, Puneet Khanna, Nishant Patel, Rakesh Kumar, Arshad Ayub, Kelika Prakash, Yudhyavir Singh, Krithikabrindha V.

Abstract:

Introduction: Spinal anesthesia is considered a standard anesthesia technique for caesarean delivery. The incidence of spinal hypotension during caesarean delivery is 70 -80%. Spinal hypotension may cause cerebral hypoperfusion in the mother, but physiologically cerebral autoregulatory mechanisms accordingly prevent cerebral hypoxia. Cerebral blood flow remains constant in the 50-150 mmHg of Cerebral Perfusion Pressure (CPP) range. Near-infrared spectroscopy (NIRS) is a non-invasive technology that is used to detect Cerebral Desaturation Events (CDEs) immediately compared to other conventional intraoperative monitoring techniques. Objective: The primary aim of the study is to correlate the change in cerebral oxygen saturation using NIRS with respect to a fall in mean blood pressure after spinal anaesthesia and to find out the effects of spinal hypotension on neonatal APGAR score, neonatal acid-base variations, and presence of Postoperative Delirium (POD). Methodology: NIRS sensors were attached to the forehead of all the patients, and their baseline readings of cerebral oxygenation on the right and left frontal regions and mean blood pressure were noted. Subarachnoid block was given with hyperbaric 0.5% bupivacaine plus fentanyl, the dose being determined by the individual anaesthesiologist. Co-loading of IV crystalloid solutions was given to the patient. Blood pressure reading and cerebral saturation were recorded every 1 minute till 30min. Hypotension was a fall in MAP less than 20% of the baseline values. Patients going for hypotension were treated with an IV Bolus of phenylephrine/ephedrine. Umbilical cord blood samples were taken for blood gas analysis, and neonatal APGAR was noted by a neonatologist. Study design: A prospective observational study conducted in a population of Thirty ASA 2 and 3 parturients scheduled for lower segment caesarean section (LSCS). Results: Mean fall in regional cerebral saturation is 28.48 ± 14.7% with respect to the mean fall in blood pressure 38.92 ± 8.44 mm Hg. The correlation coefficient between fall in saturation and fall in mean blood pressure is 0.057, and p-value {0.7} after subarachnoid block. A fall in regional cerebral saturation occurred 2±1 min before a fall in mean blood pressure. Twenty-nine out of thirty patients required vasopressors during hypotension. The first dose of vasopressor requirement is needed at 6.02±2 min after the block. The mean APGAR score was 7.86 and 9.74 at 1 and 5 min of birth, respectively, and the mean umbilical arterial pH of 7.3±0.1. According to DRS-98 (Delirium Rating Scale), the mean delirium rating score on postoperative day 1 and day 2 were 0.1 and 0.7, respectively. Discussion: There was a fall in regional cerebral oxygen saturation, which started before with respect to a significant fall in mean blood pressure readings but was statistically not significant. Maximal fall in blood pressure requiring vasopressors occurs within 10 min of SAB. Neonatal APGAR scores and acid-base variations were in the normal range with maternal hypotension, and there was no incidence of postoperative delirium in patients with post-spinal hypotension.

Keywords: cerebral oxygenation, LSCS, NIRS, spinal hypotension

Procedia PDF Downloads 73