bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaporation from Water Surfaces in Arid and Semi-Arid Areas in Algeria
Authors: Fekih Malika , Bourabaa Abdenour , Saighi Mohamed
Published: January 2014

The evaporation from open water remains a difficult process to measure or estimate. The major source of difficulty is the fact that the required meteorological parameters are rarely measured over the water. In this study, we calculate the evaporation rate from the pan using the energy budget method which is widely considered to be the most accurate method of estimating evaporation and A CFD-based methodology to estimate monthly evaporation for the two dams. The evaporation rates calculated with the energy budget and the application of CFD were in good agreement with monthly evaporation measurements in dams located in areas of different climates in Algeria.
Asymptotic Analysis of Non-Newtonian Fluid Flow in a Microchannel under a Combination of EO and MHD Micropumps
Authors: Escandón J.P. , Bautista O.E. , Santiago F. , Méndez Federico
Published: January 2014

Asymptotic solution for the shear stress distributions and velocity profiles of steady electroosmotic (EO) and magnetohydrodynamic (MHD) flows are obtained in a parallel flat plate microchannel. A fully-developed flow is considered and the fluid obeys a constitutive relation based in a simplified Phan-Thien-Tanner model. The effect of the following dimensionless parameters on the fluid flow control is predicted: the viscoelastic parameter and the Hartmann number. The momentum equation, boundary conditions and the constitutive rheological model are combined to formulating a nonlinear differential equation to solve the shear stress, which is expanded in a regular expansion series in powers of small Hartmann numbers. This limit of small Hartmann numbers and low electrical conductivity in the buffer solution correspond to the range where the electric and magnetic effects can be used to move a charged solution in the flow control and sample handling in biomedical and chemical analysis.
Thermal Field of Twin Variably Elevated Tandem Jets in Crossflow
Authors: Radhouane Amina , Mahjoub Said Nejla , Mhiri Hatem , Le Palec Georges , Bournot Philippe
Published: January 2014

Consideration is given to twin inline elliptical fume jets issuing within an oncoming cooler environmental crossflow. Jets are emitted from similar nozzles, characterized by a variable injection height. Such a configuration is found at large scale, in the industrial urban zones, and more particularly in multiple chimney power plants. It is found at small scale as well like in cooling in electronic devices. The present study is carried out numerically by means of the finite volume method together with the Reynolds Stress Model (RSM) second order turbulent closure model and non uniform grid system particularly refined around the emitting nozzles. Emphasis is put on the temperature distribution around the emitting nozzles in order to highlight the joint effect of the jets elevation and temperature. It was mainly found that both parameters are complementary and help straitening the discharged jets, leading their thermal mixing away from the injection ground.
Nomenclature
Impingement Cooling of a Semi-Spherical Concave Surface Covered by Porous Medium with a Jet Trapping Hole
Authors: Wu Pey Shey , Lin Yi Hung , Jhuo Yue Hua , Chan Hsiao Ying
Published: January 2014

Impingement heat transfer between a circular jet and a semi-spherical concave surface with or without coverage of porous material is investigated experimentally and numerically. For cases with coverage of the porous material on the target plate, a trapping hole for the jet fluid is fabricated. Measured local Nusselt number distributions along a meridian are documented. The flow and temperature fields at the conditions similar to that of experiments were computed with CFD software to support the experimental results and help to explain the physics. Varying parameters include Reynolds number, nozzle-to-plate distance, relative curvature, and a target surface with or without the covered porous material. Results show that the attachment of a porous material increases Nusselt number, with more influence at the stagnation zone than the far field. Increasing Reynolds number usually increases Nusselt number unless it is too high. Although an increase in the nozzle-to-plate distance decreases stagnation Nusselt number, the influence in heat transfer is small in the far field. The trapping-hole diameter should be the same as that of the jet diameter for best heat transfer enhancement.
Flow Boiling Heat Transfer Enhancement from Carbon Nanotube-Enhanced Surfaces
Authors: Pranoto I. , Yang C. , Zheng L.X. , Leong K.C. , Chan P.K.
Published: January 2014

This paper presents an experimental study of flow boiling heat transfer from carbon nanotube (CNT) structures in a two-phase cooling facility. Multi-walled CNT (MWCNT) structures of dimensions 80 mm × 60 mm were applied to a horizontal flow boiling channel. Two CNT structures with different properties viz. NC-3100 and MERCSD were tested with a dielectric liquid FC-72. The height of the CNT structures was fixed at 37.5 μm and tests were conducted at coolant mass fluxes of 35, 50, and 65 kg/m2·s under saturated flow boiling conditions. The experimental results show that the CNT structures enhance the boiling heat transfer coefficients by up to 1.6 times compared to the smooth aluminum surface. The results also show that the CNT structures increase significantly the Critical Heat Flux (CHF) of the smooth aluminum surface from 66.7 W/cm2 to 100 W/cm2.
Experiments on Inverse Method to Illumination by Optimization Technique IMIbyOPTIM with Fixed Light Source Power
Authors: Rodrigues Letícia Jenisch , Andriotty Tiago Haubert , Schneider Paulo Smith , França Francis Henrique Ramos
Published: January 2014

The present work reports an experimental procedure designed to validate a particular solution for the distribution of artificial light sources in the sealing of an enclosure obtained by the inverse method IMIbyOPTIM. An illumination design assuming the free placement of purely diffuse light sources aims to generate a uniform illumination field on a work plane. A reduced scale enclosure is built to validate the method effectiveness, by comparing the experimental results to an illuminance target. An equally non-optimized light source distribution is placed on the enclosure and measurements confirm the hypothesis of distortion of the illumination field, already predicted by simulations. After the optimization of the light sources distribution, the measured illumination field becomes closer to the dimensionless unitary target, with a standard deviation of less than 0.021. This particular experiment verifies IMIbyOPTIM predictions and allows continuing the validation process of the method for a broad variety of design combinations.
Intermolecular Study of Adansonia Digitata (AnD) Binary Liquid Mixture
Authors: Phadke Sushil , Ujle Suneel Kumar , Shrivastava Bhaktdarshan , Mishra Ashutosh , Dagaonkar Nagesh
Published: January 2014

The resistance of a liquid to flow and the molecules of a liquid exhibit intermolecular attraction for each another and are called its viscosity and surface tension. Surface tension is measured as the energy required to increase the surface area of a liquid by a unit of area. Viscosity is governed by the strength of intermolecular forces and especially by the shapes of the molecules of a liquid. The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules. The change in free energy during a reaction, it is a direct measure of the amount disorder that is created in the universe when the reaction occurs. A thermo-dynamic quantity combining enthalpy and entropy into a single value is called the Gibbs free energy ΔG. The value of ΔG for a reaction is a direct measure of how far the reaction is from equilibrium. The large negative value for ATP hydrolysis in a cell merely reflects the fact that cells keep the ATP hydrolysis reaction as much as 10 orders of magnitude away from the equilibrium. The change of free energy is equal to the sum of its enthalpy plus the product of the temperature and entropy of the system. The characteristic time for a system to reach an equilibrium condition after a disturbance is called relaxation time. Adansonia Digitata (AnD) fruit collected from Mandav District Dhar (M.P.). The entire chemical used in this study analytical grade.
Numerical Study of the Effect of the Relative Depth on the Overtopping Wave Energy Converters According to Constructal Design
Authors: dos Santos Elizaldo Domingues , Machado Bianca Neves , Zanella Marcos Moisés , Gomes Mateus das Neves , Souza Jeferson Avila , Isoldi Liércio André , Rocha Luiz Alberto Oliveira
Published: January 2014

The conversion of wave energy in electrical one has been increasingly studied. One example of wave energy converter (WEC) is the overtopping device. Its main operational principle consists of a ramp which guides the incoming waves into a reservoir raised slightly above the sea level. The accumulated water in the reservoir flows through a low head turbine generating electricity. In this sense, it is performed a numerical study concerned with the geometric optimization of an overtopping WEC for various relative depths: d/λ = 0.3, 0.5 and 0.62, by means of Constructal Design. The main purpose is to evaluate the effect of the relative depth on the design of the ramp geometry (ratio between the ramp height and its length: H1/L1) as well as, investigate the shape which leads to the highest amount of water that insides the reservoir. In the present simulations, the conservation equations of mass, momentum and one equation for the transport of volumetric fraction are solved with the finite volume method (FVM). To tackle with water-air mixture, the multiphase model Volume of Fluid (VOF) is used. Results showed that the optimal shape, (H1/L1)o, has a strong dependence of the relative depth, i.e., there is no universal shape that leads to the best performance of an overtopping device for several wave conditions.
Constructal Design of Y-Shaped Conductive Pathways for Cooling a Heat-Generating Body
Authors: dos Santos Horbach Cristina , dos Santos Elizaldo Domingues , Isoldi Liércio André , Rocha Luiz Alberto Oliveira
Published: January 2014

This paper applies constructal design to obtain numerically the configuration that facilitates the access of the heat that flows through Y-shaped pathways of a high-conductivity material embedded within a square-shaped heat-generating medium of low-conductivity to cooling this finite-size volume. The objective is to minimize the maximal excess of temperature of the whole system, i.e., the hot spots, independent of where they are located. The total volume and the volume of the material of high thermal conductivity are fixed. Results show that there is no universal optimal geometry for the Y-shaped pathways for every value of high conductivity investigated here. For small values of high thermal conductivity material the best shape presented a well defined format of Y. However, for larger values of high thermal conductivity the best geometry tends to a V-shaped (i.e., the length of stem is suppressed and the bifurcated branches penetrates deeply the heat-generating body towards the superior corners). A comparison between the Y-shaped pathway configuration with a simpler I-shaped blade and with X-shaped configuration was also performed. For constant values of area fraction occupied with a high-conductivity material and the ratio between the high thermal conductivity material and low conductivity of the heat-generating body (φ = 0.1 and = 100) the Y-shaped pathways performed 46% and 13% better when compared to I-shaped and X-shaped pathway configuration, respectively. The best thermal performance is obtained when the highest temperatures (hot spots) are better distributed in the temperature field, i.e., according to the constructal principle of optimal distribution of imperfections.
Evaluation of the Structural Integrity of the Jet Pumps of a Boiling Water Reactor under Hydrodynamic Loading
Authors: Cuahquentzi Noel M. , Gómez Luis H.H. , López Pablo R. , Urriolagoitia-Calderón Guillermo , Beltrán-Fernández Juan Alfonso , Urriolagoitia-Sosa G. , Cuamatzi Enrique F. , Ramírez Arturo O. , Ángeles Beatriz R.
Published: January 2014

The structural integrity of a jet pump assembly of a boiling water reactor (BWR) under hydrodynamic loading was evaluated. This arrangement, which has a riser joined with a couple of jet pumps by the transition piece, is part of the reactor recirculation system. It is submerged in water under pressure. The main function is to induce forced flow through the core of the reactor. A dynamic structural analysis was carried out with the finite element method. The first ten modes of vibration and their natural frequencies were calculated. The first five natural frequencies are in the range between 25 Hz and 40 Hz. In this analysis, it was considered that the jet pump assembly is supported at the riser brace. The restrainer bracket keeps together the riser with the two jet pumps and there is free movement at the slip joints.
3D Thermosolutal Convection within Porous Media
Authors: Amel Kacem , Fakhreddine Oueslati , Bennacer Rachid , Afif Elcafsi
Published: January 2014

The present work aims to study convection and heat transfer and mass in a porous cubic cavity. The configuration considered is a cavity cube with vertical walls left and right are subjected to temperatures required while others are impermeable and adiabatic. We realized that the results depend on several characteristic parameters, and general correlations are established for the calculation of heat and mass transfer, according to various studied parameters. The study focuses on the influence of the control parameters on the structure of the flow, heat and mass transfer.
The Roles of CFD in Enhancing Teaching and Learning Process and its Potentials in Solving Real Engineering Issues
Authors: Asmuin Norzelawati , Ismail A.
Published: January 2014

Computational fluid dynamics (CFD) is able to enhance unseen problems using numerical methods and algorithms in solving fluid dynamics which is related to real engineering life. Implementations through experiments are very costly. However, due to constraint in space problem, time and money, CFD is economic for engineers, especially young employer in current trends of teaching and industries globally. This research is focusing on CFD education that contributes to solve real engineering issues. A few strategies are projected in CFD for teaching and learning by validation and comparison analysis. The performance of experimental validation are different from traditional experiments and testing. Some variables such as Reynolds number, turbulence kinetic energy, coefficient of variation and cavitations number are parameters which can be detected in a CFD approach. The results from CFD are validated by experiments or real world and by comparison with other software.
An Efficient Technique of Linearization towards Fourth Order Finite Differences for Numerical Solution of the 1D Burgers Equation
Authors: Cruz M.M. , Campos M.D. , Martins J.A. , Romão E.C.
Published: January 2014

This work aims to solve the 1D Burgers equation, which represents a simplification of the Navier-Stokes equation, supposing the yielding only at x-direction and without pressure gradient. For such a solution, an implicit scheme (Cranck-Nicolson method) with a fourth order precision in space is utilized. The main contribution of this work is the application of a linearization technique of the non-linear term (advective term), and then, towards the analytical and numerical results from literature, validate and demonstrate it as being highly satisfactory.
Multiphase Flow and Heat Transfer in Risers
Authors: Sarmento Lígia Rafaely Barbosa , Pereira Filho G.H.S. , de Lima Antônio Gilson Barbosa , de Farias Neto Severino Rodrigues , Barbosa E.S. , de Lima Cunha A.
Published: January 2014

Multiphase flows commonly occur in the production and transportation of oil, natural gas and water. In this type of flow, the phases can flow in different spatial configurations disposed inside the pipe, so called multiphase flow patterns. The identification of flow patterns and the determination of the pressure drop along the pipe lines for different volumetric flows are important parameters for management and control of production. In this sense, this work proposes to numerically investigate the non-isothermal multiphase flow of a stream of ultraviscous heavy oils containing water and natural gas in submerged risers (catenary) via numerical simulation (ANSYS CFX 11.0). Results of the pressure, volumetric fractions and temperature distributions are presented and analyzed. Numerical results show that the heat transfer was more pronounced when using the largest volume fraction of gas phases.
Numerical Analysis of Heat Transfer of a Flow Confined by Wire Screen in Lithium Bromide Absorption Process
Authors: Mve Herbert Obame , Rullière Romuald , Goulet Rémi , Haberschill Phillippe
Published: January 2014

The present study deals with the numerical analysis of heat transfer inside a lithium bromide solution flowing down between finely meshed plastic wire screens. These screens confine the flow through capillary action while allowing the water vapor transfer inside an innovative absorber technology. The complex menisci shape formed on the confinement grid level, where the surface tension forces are of first importance, are reconstructed by a volume of fluid (VOF) model. A continuum surface force model is used to account for the surface tension force. A static contact angle is used to define the wall adhesion. A new algorithm, consisting to set an unique constant temperature at the liquid/vapour interface and to determine the evolution of heat transfer characteristics over the simulation domain, has been implemented and validated by analytical solutions. A parametric study has been conducted to determine the effect of the inlet velocity and the geometrical parameters (wire diameter and the number of divisions).
Hydrodynamics of Oil-Water with Leakage by CFD
Authors: Sarmento Lígia Rafaely Barbosa , Leite B.E. , de Farias Neto Severino Rodrigues , de Lima Antônio Gilson Barbosa
Published: January 2014

The oil industry has sought to minimize the environmental impact from mining activities and oil transportation. The oil transportation by pipeline is subject to failures and leaks that cause financial losses and environmental damage, often irreparable. In this sense, the aim of this study is to evaluate the influence of the leak diameter in the behavior of the two-phase flow (oil and water) in a pipe. A transient and incompressible multiphase flow mathematical model based on the particle model was used here. Oil is the dispersed phase while water is the continuous phase. To model the turbulence effect it was used the standard k-ε model. All simulations were carried out using the Ansys CFX® commercial code. Results of the pressure, velocity and volumetric fraction of the phases are presented and discussed. The results confirm the difficulty to detect leakage with small diameters.
Evaluation of Multiphase Flow in the Presence of Leak in Oil Pipelines: Modeling and Simulation
Authors: Tavares Daniela Passos Simões de Almeida , Vasconcellos Morgana A. , de Farias Neto Severino Rodrigues , de Lima Antônio Gilson Barbosa
Published: January 2014

The transport of oil and its derivates is mainly done through pipelines linking the oil fields, refineries and distribution networks to consumers. They are considered the best, safe and economical way to fluids transportation over long distances. Despite significant advances in the development of lighter and stronger materials for the construction of pipelines and the growing number of gas and oil pipelines, many problems of leaks have been observed, which has encouraged the development of reliable techniques to inspect and detect quickly and accurately possible leaks along these pipelines. The goal is to eliminate or minimize damage to the oil industry and mainly to the environment. In this context, this paper aims to study the thermo-fluid dynamics of a transient three-phase flow (oil, water and gas) in a horizontal pipe in the presence of a leakage at different positions. Herein it was applied a 3D Eulerian-Eulerian model, including the transient turbulent model (RNG k-ε), using the ANSYS CFX® 12.1 commercial package to perform all simulations. Numerical results of velocity, pressure and volume fraction fields of the involved phases are presented and discussed.
Gas-Solid Suspension Flow near Walls: Particle Statistical Mechanics Model and Particle Force Balance Equation
Authors: Aydın Mahmut , Günaydınoğlu Erkan , Aydın Murat , Miguel Antonio Ferreira
Published: January 2014

We address the problem of estimating the particle distribution in the suspension flow near solid walls which is of considerable interested in science and technology. The present paper focuses on the methodology that can be used to study the dynamics of moving particles. A statistical-mechanics based analytical model is developed for the particle concentration distributions (Eulerian approach). The performance of this approach is compared with a standard force balance model on moving particles that treats particles as a discrete phase (Lagrangian approach). The attractive properties of these approaches are demonstrated in the simulation of a gas-solid suspension flow above solid surfaces with a rebound effect. Results shows that our model can effectively predict particle concentration distributions and both approaches are complementary descriptions for simulating aerosol flows.
Dynamical Study of a Molten Boundary Layer Ejected by Laminar Gas Flow
Authors: Aggoune Samia , Amara El Hachemi
Published: January 2014

We consider in the present work the fusion laser cutting of stainless steel sheets under a nitrogen laminar gas jet. The molten metal is treated as a laminar and steady viscous incompressible fluid. The mathematical model describing our problem is set in terms of Navier-Stokes equations, solved numerically using the finite differences method, where the effect of the gas jet velocity on the molten boundary layer is considered. The generated shear stress occurring on the gas-liquid interface and its contribution in the momentum is carried out, and it is found that when the skin friction and the shear stress decrease, the thickness and the velocity at the edge of the molten boundary layer increase along the kerf surface. The layer thickness reduces when the assisting gas velocity is increased.
Diffusion Phenomenon of a Pollutant Flowing into a Lagoon
Authors: Corral Bustamante R. Leticia , Corral Evelyn M. Rodríguez , Magdaleno José Nino Hernández , Chávez Gilberto Irigoyen
Published: January 2014

In this paper it is presented a mathematical model in the context of physics/transport/diffusion/dispersion about a contaminant that is a product of wood fiber cooking in a pulp cellulose plant, which is currently being thrown in a lagoon that does not have any water treatment process. The objective is improving the environmental conditions prevailing according to an environmental technology program of water treatment process required by the Government of Mexico through regulations and certifications in water treatment industries, and the prediction of the involvement of the contaminant in fishes from the Lagoon.
The Role of the Thermodynamic Factor in Hydrogen Diffusion in Metal and Alloy Membranes
Authors: Flanagan Ted B.
Published: January 2014

The role of the thermodynamic factor in determining the magnitude of Ficks diffusion constant, DH, for H in metals and alloys is discussed using mainly Pd and its fcc alloys as examples because data are available for some of these systems over a wide range of H contents. Procedures are given for obtaining DH*, the concentration-independent diffusion constant, from DH under permeation conditions where the H concentration varies through the membrane; which is the common situation for H2purification membranes where pupstream>> pdownstream. The role of the thermodynamic factor in H diffusion through multi-layer membranes will also be discussed.
E and Id Proteins Influence Invariant NKT Cell Sublineage Differentiation and Proliferation
Authors: D’Cruz Louise M. , Stradner Martin H. , Yang Cliff Y. , Goldrath Ananda W.
Published: January 2014

Disease outcome is known to be influenced by defined subsets of invariant NKT (iNKT) cells residing in distinct locations within peripheral tissue. However, the factors governing the development of these unique iNKT sublineages during thymic development are unknown. In this study we explored the mechanism by which E protein transcription factors and their negative regulators, the Id proteins, control the development of iNKT sublineages after positive selection. We found that E proteins directly bound the promyelocytic leukemia zinc finger (PLZF) promoter and were required for expression of this lineage-defining transcription factor and for the maturation and expansion of thymic iNKT cells. Moreover, expression of the negative regulators of E proteins, Id2 and Id3, defined distinct iNKT cell sublineages. Id3 was expressed in PLZFhigh NKT2 cells and loss of Id3 allowed for increased thymic iNKT cell expansion and abundance of the PLZF+ NKT2 sublineage. Id2 was expressed in T-BET+ NKT1 cells, and both Id proteins were required for the formation of this sublineage. Thus, we provide insight into E and Id protein regulation of iNKT cell proliferation and differentiation to specific sublineages during development in the thymus.
Overweight and obesity profiles in Niger Delta Region, Nigeria
Authors: Idung Alphhonsus U. , Abasiubong Festus , Udoh Sunday B. , Ekanem Uwemedimbuk S.
Published: January 2014

Introduction: Overweight and obesity are global public health problems because of their effect on individuals, families and communities. The objective of this study was to describe the profile of overweight and obesity amongst adult out patients in Uyo in the Niger Delta region of Nigeria.Method: This was a cross-sectional descriptive study done between October 2011 and March 2012. Using a systematic sampling technique, 584 subjects aged 18–65 years were recruited; data were collected with a structured questionnaire. Subjects were measured for height, weight, waist and hip circumferences. Body mass index (BMI) and waist–hip ratio (WHR) were calculated. Subjects with a BMI of 25.0 kg/m2 – 29.9 kg/m2 were regarded as being overweight whilst a BMI of > 30.0 kg/m2 was regarded as obese. Subjects with a WHR of > 0.90 for men or > 0.85 for women were regarded as having abnormal WHR.Results: Of the 584 subjects, 196 (36.6%) were men and 388 (66.4%) women. The mean age for men and women was 43.3 ± 17.8 years and 50.2 ± 13.6 years, respectively. The prevalence of overweight amongst men was 39.8% versus 31.7% for women; obesity in men was 28.0% versus 52.0% in women. Overweight and obesity were more prevalent in subjects aged 25–54 years and amongst married subjects. There was a significant relationship between obesity and television viewing (p = 0.003). Hypertension (p = 0.008) and osteoarthropathies (p = 0.043) were more prevalent amongst the obese than the non-obese subjects.Conclusion: Overweight and obesity are now common in our environment. There is therefore a need for more public education about the health consequences of big body size.
Experience with peroneus brevis muscle flaps for reconstruction of distal leg and ankle defects
Authors: Bajantri Babu , Bharathi Ravindra , Ramkumar Sanjai , Latheef Latheesh , Dhane Smitha , Sabapathy S. Raja
Published: January 2014

Objective: Peroneus brevis is a muscle in the leg which is expendable without much functional deficit. The objective of this study was to find out its usefulness in coverage of the defects of the lower leg and ankle. Patients and Methods: A retrospective analysis of the use of 39 pedicled peroneus brevis muscle flaps used for coverage of defects of the lower leg and ankle between November 2010 and December 2012 was carried out. The flaps were proximally based for defects of the lower third of the leg in 12 patients and distally based for reconstruction of defects of the ankle in 26 patients, with one patient having flaps on both ankles. Results: Partial flap loss in critical areas was found in four patients requiring further flap cover and in non-critical areas in two patients, which were managed with a skin graft. Three of the four critical losses occurred when we used it for covering defects over the medial malleolus. There was no complete flap loss in any of the patients. Conclusion: This flap has a unique vascular pattern and fails to fit into the classification of the vasculature of muscles by Mathes and Nahai. The unusual feature is an axial vessel system running down the deep aspect of the muscle and linking the perforators from the peroneal artery and anterior tibial artery, which allows it to be raised proximally or distally on a single perforator. The flap is simple to raise and safe for the reconstruction of small-to moderate-sized skin defects of the distal third of the tibia and all parts of the ankle except the medial malleolus, which is too far from the pedicle of the distally based flap. The donor site can be closed primarily to provide a linear scar. The muscle flap thins with time to provide a good result aesthetically at the primary defect.
Tadalafil significantly reduces ischemia reperfusion injury in skin island flaps
Authors: Kayiran Oguz , Cuzdan Suat S. , Uysal Afsin , Kocer Ugur
Published: January 2014

Introduction: Numerous pharmacological agents have been used to enhance the viability of flaps. Ischemia reperfusion (I/R) injury is an unwanted, sometimes devastating complication in reconstructive microsurgery. Tadalafil, a specific inhibitor of phosphodiesterase type 5 is mainly used for erectile dysfunction, and acts on vascular smooth muscles, platelets and leukocytes. Herein, the protective and therapeutical effect of tadalafil in I/R injury in rat skin flap model is evaluated. Materials and Methods: Sixty epigastric island flaps were used to create I/R model in 60 Wistar rats (non-ischemic group, ischemic group, medication group). Biochemical markers including total nitrite, malondialdehyde (MDA) and myeloperoxidase (MPO) were analysed. Necrosis rates were calculated and histopathologic evaluation was carried out. Results: MDA, MPO and total nitrite values were found elevated in the ischemic group, however there was an evident drop in the medication group. Histological results revealed that early inflammatory findings (oedema, neutrophil infiltration, necrosis rate) were observed lower with tadalafil administration. Moreover, statistical significance (P < 0.05) was recorded. Conclusions: We conclude that tadalafil has beneficial effects on epigastric island flaps against I/R injury.
Microvascular free flap reconstruction for head and neck cancer in a resource-constrained environment in rural India
Authors: Trivedi Nirav P. , Trivedi Pravin , Trivedi Harish , Trivedi Saroj , Trivedi Nirali
Published: January 2014

Introduction: Reconstruction with free flaps has significantly changed the outcome of patients with head and neck cancer. Microsurgery is still considered a specialised procedure and is not routinely performed in the resource-constrained environment of certain developing parts of India. Materials and Methods: This article focuses on the practice environment in a cancer clinic in rural India. Availability of infrastructure, selection of the case, choice of flap, estimation of cost and complications associated with treatment are evaluated and the merits and demerits of such an approach are discussed. Results: We performed 22 cases of free flaps in a six-month period (2008-2009). Majority (17) of the patients had oral cancer. Seven were related to the tongue and eight to the buccal mucosa. Radial forearm free flap (RFF: 9) and anterolateral thigh flap (ALT: 9) were the most commonly used flaps. A fibula flap (1) was done for an anterior mandible defect, whereas a jejunum free flap (1) was done for a laryngopharyngectomy defect. There were six complications with two re-explorations but no loss of flaps. Conclusion: Reconstruction with microvascular free flaps is feasible in a resource-constrained setup with motivation and careful planning.
Life threatening deep scald burns in a neonate: A rare case report
Authors: Bhatia Vijay Y. , Mishra Susant , Menon Pramod A. , Nanavati Nidhish
Published: January 2014

Domestic burns in neonate are rare in literature. Neonates are high risk for burns because of their thin and fragile skin, fluid overload or dehydration as the fluid balance range is small and immature immune system leading to septicaemia. Neonates are not small adults, owing to their different physiological response makes the management of neonates challenging as the clinical signs are different from the adults and the resuscitation protocols or end points are also different. We present a case of 11 days old neonate, who sustained 51% scald burns when the hot water bag being used by her mother accidentally burst, the youngest reported case of domestic scald burns with such high percentage. The baby was managed by fluid resuscitation, antibiotics, dressings, ventilatory support for septicaemia and subsequently homograft application. The neonate was discharged with completely healed areas after 35 days of burns and is on regular follow up and no complications have been observed.
Retrograde vascularisation of fibula free flap in composite oro-mandibular reconstruction
Authors: Nambi G.I. , Dhiwakar M.
Published: January 2014

We present a case of composite oromandibular reconstruction with fibula free flap in which the vascularity to the flap was established in a retrograde direction through the distal end of the peroneal pedicle vessels. The flap was initially designed in such a way so as to anastomose with superior thyroid artery. However after initial good flow, the superior thyroid artery flow became insufficient. Therefore, an attempt was made to vascularise the flap by anastomosing the distal end of peroneal vessels with the facial artery and a tributary of the internal jugular vein so that the flap was perfused in a retrograde direction. This was successful and the retrograde flow was adequate to ensure flap survival. We believe this to be the first successful case of reverse vascular flow reported for composite oromandibular reconstruction with the fibula free flap.
Management of bi-canalicular block: A novel technique
Authors: Meena Manju , Naik Milind , Honavar Santosh
Published: January 2014

Medial canthal dystopia with canalicular obstruction is a common presentation following injury to the medial canthal region. Conjunctivodacryocystorhinostomy with Lester′s Jones tube is considered as the standard treatment in such cases. Alternatively, these patients can be managed by retrograde intubation dacryocystorhinostomy with medial canthoplasty. We herein describe the modification of retrograde bicanalicular intubation, combined with medial canthoplasty (monopedicle flap) which gives good cosmetic results.
Kinetics of Dengue Non-Structural Protein 1 Antigen and IgM and IgA Antibodies in Capillary Blood Samples from Confirmed Dengue Patients
Authors: Matheus Séverine , Pham Thai Binh , Labeau Bhetty , Huong Vu Thi Que , Lacoste Vincent , Deparis Xavier , Marechal Vincent
Published: January 2014

Large-scale epidemiological surveillance of dengue in the field and dengue patient management require simple methods for sample collection, storage, and transportation as well as effective diagnostic tools. We evaluated the kinetics of three biological markers of dengue infection—non-structural protein 1 (NS1) antigen, immunoglobulin M (IgM), and IgA—in sequential capillary blood samples collected from fingertips of confirmed dengue patients. The overall sensitivities and specificities of the tests were 96% and 100%, respectively, for NS1, 58.1% and 100%, respectively, for IgM, and 33% and 100%, respectively, for IgA. During the acute phase of the disease, NS1 was the best marker of dengue infection, with a sensitivity of 98.7%, whereas from day 5, all three markers exhibited relevant levels of sensitivity. This first descriptive study of the kinetics of biological markers of dengue in capillary blood samples confirms the usefulness of this biological compartment for dengue diagnosis and argues for its exploitation in community-level and remote settings.
Determination of monomethylmercury from seawater with ascorbic acid‐assisted direct ethylation
Authors: Munson Kathleen M. , Babi Diana , Lamborg Carl H.
Published: January 2014

We developed a technique to measure monomethylmercury (MMHg) concentrations from small volumes (180 mL) of seawater at low femtomolar concentrations using direct ethylation derivitization, decreasing the required volume by 90% from current methods while maintaining a 5 fM detection limit. In this method, addition of ascorbic acid before derivitization of MMHg allows for full recovery of MMHg from the seawater matrix without the need for sample distillation or extraction. The small sample size and relative ease of detection are ideal both for shipboard as well as shore‐based measurements of preserved MMHg samples. Combined with shipboard determination of dimethylmercury (DMHg) and elemental mercury (Hg(0)), this method can be used to determine full marine mercury speciation.
Correcting CDOM fluorescence measurements for temperature effects under field conditions in freshwaters
Authors: Watras Carl J , Morrison Ken A. , Mather Jeff , Milewski Paul , Hanson Paul C.
Published: January 2014

A method recently proposed by Ryder et al. (2012) as the preferred way to compensate for temperature quenching of CDOM fluorescence is mathematically equivalent to the prior method that they claim to improve upon.
The syntactic analysis of the Dutch absentive construction
Authors: Broekhuis Hans
Published: January 2014

This squib discusses Dutch absentive constructions like Jan is vissen ‘Jan is off fishing’. The literature on this construction so far has mainly paid attention to the meaning of the construction. This paper focuses on the syntactic analysis; two competing approaches will be compared according to which the verb zijn is, respectively, a copular verb and an auxiliary verb. It will be shown that the latter approach is the correct one.
De integratie van Engels in Vlaamse jongerentaal kwantitatief en kwalitatief bekeken: das wel nice! :p
Authors: De Decker Benny , Vandekerckhove Reinhild
Published: January 2014

The paper focuses on the presence of English in a written chat corpus produced by Flemish adolescents in their late teens whose native language is (a variety of) Dutch. Topics include the relative presence of lexemes and word categories, the effect on the target language (Dutch) and the way the loans are integrated into the chatspeak of the teenagers, i.e. (g)localisation processes. In quantitative terms, the impact of English on the informal ‘speech’ of Flemish teenagers appears to be considerable, but the borrowing process is not a ‘copy-and-paste’ practice. In many cases the teenagers transform the English words graphematically, morphologically and/or semantically. By using an extensive and reliable corpus and by quantifying and categorizing the English tokens in several ways, this paper offers a representative case study for the appropriation of English by a generation whose socialization process partly proceeds via electronic media.
Feiten en fictie - Taalvariatie in Vlaamse televisiereeksen vroeger en nu
Authors: Van Hoof Sarah , Vande kerckhove Bram
Published: January 2014

This article presents a comparative corpus analysis of the language variation in Flemish TV fiction series broadcast around 1980 and in the late 2000s, in order to assess the oftenheard claim that the use of Standard Dutch in TV fiction has decreased in favor of so-called tussentaal, an ‘intermediate’ variety. Using mixed-effects logistic regression, we assessed the effect of period on the use of 7 tussentaal markers in 21 old and recent series. Because these markers do not uniquely identify tussentaal but can also indicate dialect use, we included estimates of the speakers’ dialect use as a covariate. Rather than evidencing a straightforward decrease of the use of Standard Dutch in favour of tussentaal, our results indicate that the linguistic spectrum in TV fiction has been reduced over a period of 30 years time. Whereas language use around 1980 ranged from Standard Dutch to dialect, in present-day series a ‘cleaned up’ variety of tussentaal, differing maximally from both Standard Dutch and dialect, prevails.
Football wordt voetbal - De vroegste geschiedenis van voetbalvocabulair in het Nederlands – lexicologie, fonologie, morfologie
Authors: Zonneveld Wim
Published: January 2014

Football (soccer), the current number one sport practised in the Netherlands, was introduced into Dutch sports and educational culture in the final two decades of the 19th century, as one of the manifestations of a continental literary, cultural and political ‘anglomania’. This event implied new vocabulary, the introduction of which into Dutch is traced in this article. Investigating previous turn of the century football vocabulary in loanword research is motivated by the conveniently large size of the new lexicon. Moreover, differently from other sports, football quickly started to lose its elite character, implying a relatively wide range of speakers, of sociolinguistically diverse backgrounds. The new (2010) online ‘Royal Library’ newspaper website is used as a source of considerably extended and improved lexicological data of Dutch. Phonological and morphological patterns of foreign vocabulary introduction are outlined, showing that and where adopting loanwords may have been beneficial to Dutch phonotactics, and how creative morphology was applied in developing native variants.
Het nieuwe Brabants. Een onderzoek naar diversiteit in taal en cultuur onder jongeren in Noordoost-Brabant
Authors: Swanenberg Jos , Meulepas Jolijn
Published: January 2014

This paper aims at mapping out and analyzing language variation and the underlying social structures of adolescents in a part of the province North Brabant, The Netherlands. It presents the findings of a study that was conducted in 2010 at two Dutch high schools, in a large college in the town of Uden and in a much smaller school in the peripheral village of Mill. Twelve video recordings were made of Brabantish boys and girls aged 15 and 16, who were having spontaneous conversations in their spare time at school. Additionally a written survey was made of social and cultural characteristics. We sketched profiles of our 38 informants, consisting of features such as locality, ethnicity, language use, language attitude, cultural behavior, and political opinion. We could form only one cluster of three informants that shared relating characteristics. Diversity and variability seems to reach such a degree that stereotypes are not or hardly applicable.
De historische wortels van de rode en groene volgorde in het Nederlands
Authors: Coussé Evie , De Sutter Gert
Published: January 2014

A typical characteristic of Dutch (and other Continental West Germanic languages such as German and Frisian) is that verbs (both finite and infinite) appear together at the end of the subordinate clause in a so-called verb cluster. The ordering of the verbs within these verb clusters
is not fixed in most historical stages of the Dutch language. This article studies the variable placement within verb clusters consisting of two verbs using a text corpus spanning most of the written history of the Dutch language (i.e. from 1250 until 2000). The verb order of more than six
thousand verb clusters is described in the study, taking into account factors such as period, region and type of verb cluster.
Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone
Authors: Squire O. J. , Archibald A. T. , Abraham N. L. , Beerling D. J. , Hewitt C. N. , Lathière J. , Pike R. C. , Telford P. J. , Pyle J. A.
Published: January 2014

Abstract. Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to explore a range of potential future (2095) changes in isoprene emissions caused by changes in climate (including natural land use changes), land use, and the inhibition of isoprene emissions by CO2. From the present-day (2000) value of 467 Tg C yr−1, we find that the combined impact of these factors could cause a net decrease in isoprene emissions of 259 Tg C yr−1 (55%) with individual contributions of +78 Tg C yr−1 (climate change), −190 Tg C yr−1 (land use) and −147 Tg C yr−1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally, all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present-day. At the surface, decreases in ozone of 6–10 ppb are calculated over the oceans and developed northern hemispheric regions, due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4–6 ppb are calculated in the continental tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario consists of cropland expansion, which is most pronounced in the tropics. The tropics are also where land use change causes the greatest increases in ozone. As such there is potential for increased crop exposure to harmful levels of ozone. However, we find that these ozone increases are still not large enough to raise ozone to such damaging levels.