bluuebunny/crossref_metadata_2025 huggingface dataset:
Cold Metal Transfer (CMT) Welding of Dissimilar Materials: An Overview
Authors: Venukumar S. , Cheepu Muralimohan , Vijaya Babu T. , Venkateswarlu D.
Published: August 2019

In recent years, the continuous growth in manufacturing industries such as light weight structures, demands in increasing of its performance and functionality enhance the use of different materials for producing hybrid structures and thus the requirements for joining of dissimilar joints. The physical and metallurgical properties of the materials are utilised to get combined properties to achieve the product performance. On the other hand the joining methods are continuously challenging for joining of dissimilar materials. The present study reviews and describes the effective welding method of cold metal transfer for joining of dissimilar materials and its state of the art research in various materials joining. Cold metal transfer joining mechanism, capabilities of joining of dissimilar metals and their performance are reviewed. The current and emerging techniques of cold metal transfer welding method are reviewed. Methods and other technological parameters selection are described and future challenges for improving research methods on joining of dissimilar metals using cold metal transfer. Keywords: Cold Metal Transfer, MIG welding, Dissimilar materials, Mechanical properties.
Remediation Technologies - A Comparative Study
Authors: Mittal Ayush , Shukla Shalinee
Published: August 2019

Contaminated land is a legacy of industrial revolution as a result of rapid growth of industries. Since long back, the disposal of liquid and solid wastes on land though undesirable, has been in practice. The leachate generated out from these hazardous wastes infiltrates into the ground and causes multiple problems viz., ground water pollution, soil pollution, loss of nutrition value of soil and thereby severe damage to plantation growth, changes in the soil behavior (excessive swell/shrink) depending on the nature of waste. It also causes serious distress to the existing structures such as pavements, foundations, underground pipelines and culverts. The changes in the soil behaviour caused by ground contamination can lead to structural failures. The present paper describes various physical, chemical, biological, thermal and solidification/stabilization methods of soil and ground water remediation and their comparison on the basis of applicability, time and cost.
Experimental Investigation of Sunflower Oil as Dielectric Fluid in Die Sinking Electric Discharge Machining Process
Authors: Reddy G.Gowtham , Singaravel B. , Shekar K.Chandra
Published: August 2019

Electric Discharge Machining (EDM) is used to machine complex geometries of difficult to cut materials in the area of making dies, mould and tools. Currently, hydrocarbon based dielectric fluids are used in EDM and which plays major role for material removal and it emits harmful emission. In this work, vegetable oil is attempted as dielectric fluid and their performance are studied during processing of AISI P20 steel. The effect of pulse on time (Pon) , pulse off time (Poff), and current (A) on Material Removal Rate (MRR), Tool wear rate (TWR) and surface roughness (SR) are analyzed. The result showed that vegetable oils are given good machining performance than conventional dielectric fluids. These proposed dielectric fluids are biodegradable eco friendly and enhance sustainability in EDM process.
Processing of Nickel-Copper Coated Carbon Fibre Rods Reinforced Al6082/4% Al2O3/2%Gr Matrix Composites
Authors: Srinivasu Marise , Suresh R. , Shivaramu L.
Published: August 2019

Aluminum metal matrix with carbon fibre reinforcement composites are potential materials for automotive, aerospace and electronics industries. The interaction between Al matrix and carbon fibre reinforcement, plays vibrant role to decide the properties of the Metal Matrix Composites (MMC’s). However, interaction between Al alloy matrix and carbon fibre is forming an Aluminum Carbide (Al4C3) at higher temperature (>650°C). This consequence degrades the mechanical properties and promotes corrosion. To overcome corrosion problem and improve the composite properties, metallic coating on carbon rod is very vital. In the present study, aluminum metal matrix composites (Al6082/4%Al2O3+2%Gr) were developed with coated carbon fibre rod using stir casting process. Carbon fibre rods of 3 mm diameter is coated with nickel by electro less process and then copper coating done by electrolytic process. The bonding between matrix and reinforcement was observed in SEM and EDAX analysis. The results indicates the absent of Al4C3 formation.
Investigation on Effects of Cutting and Jet Parameters in Turning of AISI 4140 Hardened Alloy Steel
Authors: Mane Sandip , Kumar Sanjay
Published: August 2019

Turning of hardened alloy steel (Hard turning) is a replacement for grinding operation. The heat generation and temperature during hard turning at the cutting zone and due to the friction at tool-chip-workpiece interface are significant parameters which influence chip formation mechanism, tool wear, tool life, surface integrity and hence the machining quality. Cutting fluid performs key role in metal cutting due to its cooling and lubrication action. Flood cooling is a common method of cutting fluid application, in which large quantity of cutting fluid is applied at the cutting zone. Due to environmental, health and safety concerns, the usage of cutting fluid in abundant quantity is being restricted. Most of the researchers have varied the cutting parameters like cutting speed, feed rate and depth of cut to machine different work materials with different cutting tools and studied its effects on cutting force and cutting temperature. It is thus essential to study the combine effect of cutting and jet parameters in machining. This research article focusses on study and optimization of cutting and jet parameters on tool-chip interface temperature and cutting forces during turning hardened alloy steel AISI 4140 steel of 50 HRC using Finite Element Analysis and Taguchi’s Technique. Three levels of cutting speed, feed rate, depth of cut, jet angle and jet velocity are chosen. A suitable L27 Orthogonal array is selected based on Taguchi’s Design of Experiments (DoE) and the output quality characteristics such as tool-chip interface temperature and cutting forces are analyzed by Signal-to-Noise (S/N) ratio. Analysis of Variance is performed to determine the most contributing factor, which shows that the feed and depth of cut are the most prominent contributing parameter followed by cutting speed, jet impingement angle and jet velocity.
Electrical Discharge Machining Characteristics of ECAP Copper Electrode
Authors: Gopal R. , Thangadurai K.R. , Thirunavukkarasu K.
Published: August 2019

Enormous research work has done on the electrode wear in spark erosion machining such as hybrid electrical discharge machining process, introducing various methods such as ultrasonic vibration in electrode, rotating the electrode, developing new electrode material (alloys and composites) and surface coated electrode etc,. Equal Channel Angular pressing is one such technique which makes tool material harder through grain refinement and ultimately enhances the tool life. The work material is AISI H13. For this research work, two copper electrodes are prepared, out of which one copper electrode has undergone equal channel angular pressing process. The most influencing parameters of spark machining like current, pulse on time and pulses off time are chosen for this study. The experiments are conducted using bare copper electrode and equal channel angular pressed copper electrode based on the box Behnken approach. The observations are analyzed for the machining characteristics in terms of rate of machining, rate of tool erosion and surface coarseness. Finally, it is found that ECAP processed copper electrode has lesser wear rate and better surface finish than bare copper electrode.
Parametric Studies on TIG Welding of 316L Stainless Steel by RSM and TLBO
Authors: Moi Subhas Chandra , Rudrapati Ramesh , Bandyopadhyay Asish , Pal Pradip Kumar
Published: August 2019

Present study is planned to analyze the effects of welding process parameters on quality characteristics of TIG welded 316L austenitic stainless steels (ASS). The input parameters considered in the study are: welding current, speed and gas flow rate. Butt-joints of ASS sheets have been made as per Box-Behnken design of response surface methodology (RSM). After welding operation, tensile tests have been conducted on welded samples and observations of ultimate tensile strength (UTS) has been noted. Mathematical modeling has been made to relate the input parameters and output response by RSM. Teaching leaning-based optimization (TLBO) approach has been used to optimize the UTS. The influences of input welding parameters on UTS has been studied and analyzed through contour plots. Confirmatory tests have been conducted to validate the predicted parametric condition obtained by integrated RSM and TLBO. From the study, it is found that RSM and TLBO is efficient to maximize UTS in TIG welding operation.
Optimization of Process Parameters in the Turning Operation of Inconel 625
Authors: Vasudevan Hari , Rajguru Ramesh , Shaikh Moeiz , Shaikh Arsalan
Published: August 2019

Many difficult to machine materials, such as Inconel 625Ni-based super alloy, are uncommon class of metallic materials with exceptional combination of greater thermal strength, toughness and resistance to deterioration. They have extensive applications in the manufacturing of new aero-engines, besides its enormous uses in marine, chemical and oil & petrochemical industries. In the context of its wide range of applications, there is a need for efficiently processing better methods in the manufacturing of such difficult to machine materials. This study consists of the turning operation of Ni-based super alloy Inconel 625 without coolant, carried out by physical vapour deposition (PVD) coated carbide inserts. The response parameters, such as surface roughness and material removal rate were evaluated in terms of cutting speed, feed rate and depth of cut. Sixteen experiments were carried out, based on Taguchi's Design of Experiments using orthogonal array. The resulting analysis was done based on response graph. The experimental results revealed that the feed rate was the most influential factor, followed by the depth of cut and cutting speed. The optimal parameters achieved were cutting speed of 90 m/min, the feed rate of 0.35 mm/rev and the depth of cut 0.2 mm.
Multi-Objective Optimization of Machining Process Parameters in Wire-Cut Electric Discharge Machining of Inconel X750 Alloy by Combinatorial Approach
Authors: Kumar G. Venkata Ajay , Shilpa M. , Purander Udagave Shital , Madhoo G. , Asokan V.
Published: August 2019

Difficult-to-cut materials, generally high hardness, strength and toughness, are generally difficult to machine in conventional machining. Also tool wear is high in conventional machining processes. Wire Cut Electric Discharge (WEDM) machining is particularly used for machining complex profiles, demanding very high accuracy. The current work focuses on the optimization of roughness of a surface that is machined using WEDM; the process parameters considered for optimization are pulse-on-time (Pon), pulse-off time (Poff), wire feedrate (WFR) and spark gap voltage (SGV). One of the surface integrity aspect is considered as surface roughness (SR) and other related to machining output considered as material removal rate (MRR) for the output responses. The paper presents, a multi-criteria decision making technique, with Grey Relational Analysis (GRA) integrated with Particle Swarm Optimization (PSO) for optimizing the process parameters. Further, confirmation tests that were conducted also validated the improvement in SR and MRR.
Effect of Grain Refiners and/or Modifiers on the Microstructure and Mechanical Properties of Al-Si Alloy (LM6)
Authors: Prema Satya , Chandrashekharaiah T.M. , Begum P. Farida
Published: August 2019

Grain refinement is one of the most important and popular melt treatment process for Al-Si alloy casting. Microstructure and mechanical properties of commercially available Aluminium Silicon alloy LM6 can be improved with the addition of grain refiners and modifiers as these provide technical and economic advantages. This paper is an effort to study the effects of addition of grain refiners and modifiers to the eutectic Al – Si alloy LM6. Commercially available Al - Si alloy LM6 (eutectic = 12% Si) is grain refined with Al-5Ti-1B and Al-3B; and modified with Al-10Sr master alloys. These were added individually and then tested for its unique mechanical properties such as ultimate tensile strength, hardness and wear; which are co-related with the machining tests such as turning, surface roughness and drilling. The test results are compared with microstructure of the samples observed through SEM.The mechanical properties of this alloy can be altered after addition of master alloys, which in turn alter the grain size. Thus the results conclude that the mechanical properties of Al-Si alloys in general are controlled by a number of principal microstructural features. A fine grain size is desirable, leading to improvement of mechanical properties.
Fracture Behaviour of Fibre Reinforced Rubcrete
Authors: RAJ ANAND , Usman Arshad P.J. , Nagarajan Praveen , Shashikala A.P.
Published: August 2019

Fracture energy (Gf) studies provide us with means to assess the variation in ductility of concrete. This paper presents the results of fracture energy studies conducted on 18 mixes of M60 Grade concrete consisting of rubcrete (0%, 5%, 10%, 15% of crumb rubber), steel fibre reinforced rubcrete (0.25%, 0.5%, 0.75%, 1% steel fibres and 0% and 15% crumb rubber) and polypropylene fibre reinforced rubcrete (0.1%, 0.2%, 0.3% polypropylene fibres and 0% and 15% crumb rubber) using three-point bend beam tests on 60 × 100 × 500 mm specimens as per TC 50 FMC (1985). Results indicated an enhancement of fracture energy with an increase in rubber content.
Effect of Various Welding Parameters on the Mechanical Behaviour of 316L Stainless Steel-Galvanized Steel Weld
Authors: Shreyas P. , Panda Bijayani , Kumar Rakesh
Published: August 2019

Several case studies have shown that welding of stainless steel to galvanized steel leads to evolution of zinc which can penetrate through the steel and result in cracking, the present study focuses on determination of the effect of zinc on the mechanical behaviour of such weld joints. Welding was carried out using two shielding gas combinations. The other variations in parameters were heat input and presence or absence of zinc coating at the weld location. Tensile tests showed that the ductility of weld specimen improved when the coating was stripped off the samples prior to welding. Impact strength of weld specimens also followed similar trend. The impact strength was found to be improved when welding was done using Ar+2%He+2%O2 as shielding gas. The compressive strength was found to be similar. To explain the mechanical behaviour of the welded specimen, microstructural characterization of the weld region was carried out.
Finite Element Modeling of Back-to-Back Built-Up CFS Un-Lipped Channels under Axial Compression
Authors: Roy Krishanu , Ting Tina Chui Huon , Ho Lau Hieng , Bhatnagar Shashank , Lim James B.P.
Published: August 2019

A finite element model is described in this paper, which investigates the behavior of CFS built-up un-lipped channel sections, connected back to back with the help of intermediate web fasteners, subjected to axial load. Finite element package ABAQUS was used to develop the model for built-up columns, which were validated against the test results reported by the authors recently on another paper. Material non-linearity and initial imperfections were included in the FEA model. A parametric study was conducted using the validated FEA model to investigate the effect of screw spacing on axial strength. Axial strengths obtained from the FEA model were compared against the AISI&AS/NZS design strengths; obtained comparisons showed that the AISI&AS/NZS standards were un-conservative for stub and short columns which failed by local buckling whereas the standards were over-conservative for columns failed through overall buckling.
A Review on Fabrication of Surface Composites on Magnesium Alloys by Friction Stir Processing
Authors: Surya P.R. , Ram Prabhu , Arivarasu M. , Rozario P.L. , Mishra R.K.
Published: August 2019

Friction stir processing (FSP) is emerging as a singular solid-state surface engineering technique to fabricate surface composites (SC) since its adaption from Friction Stir Welding (FSW) from the early 90s. FSP is a promising technique to overcome the barrier of magnesium being a poor material in terms of wear and corrosion resistant without adding much on the processing cost and thus, widen its applications.The targeted property enhancement by forming surface composites via FSP are strength, ductility, hardness, wear resistance, toughness, fatigue life, formability, corrosion resistance, etc. Although, a decade of research work has been carried out on FSP for different metal alloys, the advantages of the process particularly on magnesium alloys is yet to be understood clearly. The present review is focused on understanding the response of magnesium alloys for friction stir processing to fabricate surface composites. The available literatures have been thoroughly reviewed to present the microstructure evolution during processing and the mechanism of strengthening; the works on magnesium has been summarized to understand the effect of various processing parameters such as tool speed (rotation and traverse), number of passes, etc. and the tool geometry on the resulting properties. Also, details regarding the selection of suitable tool material and reinforcing particles to achieve optimum properties for specific magnesium alloys is included. Important suggestions and scope for further research regarding fabrication of surface composites on magnesium alloy are provided.
Scale down Approach to Solve Distortion Problem in Case of Wind Turbine Tower Fabrication
Authors: Sarfudeen M. , Prabhu Pradnyesh R. , Muthukumaran S.
Published: August 2019

Submerged arc welding (SAW) process is extensively used in major industrial application such as wind turbine towers and ship building industries for joining of larger thickness (~10 to 50mm) of similar and dissimilar materials. However, other joining processes are not popular to weld larger thickness compared to SAW. In welding, one of the major problems is distortion, which destroys the dimensional stability of the component, a major concern in manufacturing. Simulation of larger thickness component will increase the simulation time. Therefore, an attempt has been made to evaluate a 3 - dimensional finite element analysis (FEA) using SYSWELD to study the effect of the joining of two similar shells of High Strength Low Alloy (HSLA) steel through scale down model in the ratio of 10:1. To reduce the simulation time, the two shells of steel having 400mm diameter and 2mm thickness are modelled and simulated with single pass GMAW process using eight different welding sequences as per welding procedure specification (WPS) using SYSWELD. Results show the simulated welding sequence no. 4 has a considerable amount of reduction in distortion of 1.526 mm compared to that of other sequences. Welding sequence no. 4 is then followed by actual windmill tower fabrication, which resulted in reduced distortion level of 5 mm.
Thermal Analysis of Dissimilar Materials Diffusion Bonding Using Finite Element Method
Authors: Kumar S. Suresh , Ravisankar Balasubramanian , Sheriff F. Mohammed Ajmal , Silvister Raju M.J.
Published: August 2019

Finite element method (FEM) is employed to study an effect of diffusion bonding strength between aluminium and its copper material and optimized parameters. The diffusion bonding soundness was estimated at different processing parameters such as temperature, pressure and time. The coefficients of linear thermal expansion (CTE) of the metals induce thermal stress at the bonded area. This phenomenon motivated the study of the stress distribution along with maximum and minimum stress values, while bonding of two dissimilar metals at particular bonding process parameters. The incompatible thermal stress at the bonded area plays a vital role in better bond soundness. Thus, it is required to estimate the bonding interface in dissimilar joints. This study was performed using the FEM and the analysis was carried out using the commercial software package Ansys V12.0
High-Temperature Wear Behavior of the ZE41 Mg Alloy
Authors: Chiranth B.P. , Siddaraju C. , Mishra R.K. , Sasikumar R. , Sathiskumar R. , Ram Prabhu T.
Published: August 2019

High-temperature wear and friction properties of ZE41 alloy were evaluated using a pin on disc tribometer. The microstructure of the alloy has the equiaxed grains of 72±20µm decorated with the rare earth rich precipitates. Result shows that wear rate decreases upto 100°C and then increases until 250°C for all the loading conditions. The wear mechanism study revealed that the underlying thin oxide tribolayer minimizes the wear rate upto 100°C. Above 100°C, thickening of oxide layer due to enhanced oxidation rate results in breakage of the layer. Further, the increase of temperature softens the alloy which deforms and fractures in the subsurface at low critical load resulting in more delamination wear. The combined effects of oxidation and delamination wear are accentuated with the increase of load and temperature resulting in the increase of the wear rate. Comparing the influence of load and temperature on the wear rate, contact load is more.
Fabrication of Light Weight Metal Matrix Nanocomposites Using Ultrasonic Cavitation Process: A State of Review
Authors: Madhukar Pagidi , Selvaraj N. , Rao C.S.P. , Mishra S.K.
Published: August 2019

Fabrication of nanocomposites is a highly challenging task because of the particles need to be disseminated across the molten liquid due to broad surface area, poor wettability. Homogeneous dispersion is tough in traditional stirring methods leads to cluster and agglomeration formation in high viscous molten metals. In such attempts, the ultrasonic vibration process exhibits the better dispersion and distribution of nanocomposites with enhanced material properties as compared to other fabrication processes. This paper deals with the fabrication process, probe design and effective process parameters of sonication process to the uniform dispersion of nanoparticles.
Pyruvic acid in the boreal forest: first measurements and impact on
radical chemistry
Authors: Eger Philipp G. , Schuladen Jan , Sobanski Nicolas , Fischer Horst , Karu Einar , Williams Jonathan , Riva Matthieu , Zha Qiaozhi , Ehn Mikael , Quéléver Lauriane L. J. , Schallhart Simon , Lelieveld Jos , Crowley John N.
Published: August 2019

Abstract. Pyruvic acid, CH3C(O)C(O)OH, is an organic acid of biogenic origin that plays a crucial role in plant metabolism, is present in tropospheric air in both gas-phase and aerosol-phase and is implicated in the formation of secondary organic aerosols (SOA). Up to now, only a few field studies have reported mixing ratios of gas-phase pyruvic acid and its tropospheric sources and sinks are poorly constrained. We present the first gas-phase measurements of pyruvic acid in the boreal forest as part of the IBAIRN (Influence of Biosphere–Atmosphere Interactions on the Reactive Nitrogen budget) field campaign in Hyytiälä, Finland, in September 2016. The mean pyruvic acid mixing ratio during IBAIRN was 96 pptv, with a maximum value of 327 pptv. From our measurements we derived the overall pyruvic acid source strength and quantified the contributions of isoprene oxidation and direct emissions from vegetation in this monoterpene-dominated, forested environment. Further, we discuss the relevance of gas-phase pyruvic acid for atmospheric chemistry by investigating the impact of its photolysis on acetaldehyde and peroxy radical production rates. Our results show that, based on our present understanding of its photo-chemistry, pyruvic acid is an important source of acetaldehyde in the boreal environment, exceeding ethane/propane oxidation by factors of ~ 10 and ~ 20.
Exploratory what-if analysis of some debated canister failure modes in the review of a licence application for the construction and operation of a spent nuclear fuel repository in Sweden
Authors: Strömberg Bo , Sonnerfelt Lena , Öberg Henrik
Published: August 2019

Abstract. Regulatory review of the licence application for construction and
operation of a spent fuel repository at the Forsmark site in Sweden involves
detailed assessment of both expected and hypothetical failure modes of the
copper canister. The copper canister, which is supported by the bentonite
buffer and the surrounding crystalline rock in the KBS-3 concept, is
expected to provide complete containment of radioactive elements for very
long timescales. Detailed assessment shows that there is a small probability
on such timescales of canister failure due to corrosion following loss of
buffer as well as mechanical failure due to large earthquakes. During the
regulatory review process, it was proposed that canisters might also fail
due to: (i) corrosion in anoxic oxygen gas free water, (ii) pitting corrosion,
(iii) stress corrosion cracking, (iv) creep brittle failure, (v) hydrogen
embrittlement. We here provisionally accept a number of alternative
assumptions related to these processes as a basis for what-if analysis of
their implications. The focus is not to determine the merit or to estimate
probability of these cases, but rather to explore their potential
significance in the context of the available knowledge about the repository
environment. Simplified estimates are made of the consequences in terms of
number and timing of canister failures as well as radiological impact. It is
judged that poor creep ductility of copper would have larger potential
consequences compared to localised corrosion phenomena. Potential corrosion
failures are expected to be associated with the small fraction of deposition
holes that are most extensively exposed to corrodants.
Growth, Gas Exchanges and Maize Productivity Under Potassic Fertilizer Management and Residual Response on Bean
Authors: Ribeiro João Everthon da Silva , Neto Manoel Felix da Silva , Júnior José Marcelino da Silva , Albuquerque Manoel Bandeira de , Podestá Guilherme Silva de , Mielezrski Fábio
Published: August 2019

Potassium (K) is the second nutrient of greater absorption by plants, and it is of fundamental importance for the development of the cultures and acts in the activation of enzymes that participate in the photosynthetic processes. However, there are still doubts about its residual effect on crop succession. Therefore, the objective of the research was to evaluate the effect of K doses on growth, gas exchange and maize yield and its residual effect on bean culture. The experiment was a randomized complete block design, in a 5x2 factorial scheme, totaling 10 treatments, with five K doses (0, 50, 100, 150 and 200 kg ha-1) and two fertilization periods (seeding and V5 stadium) in maize plants. Growth parameters, gas exchange and yield were evaluated in maize plants, and growth was evaluated in Bean plants in an experimental area belonging to the Department of Plant Science and Environmental, Federal University of Paraíba in Northeast Brazil. For the analysis of the data, we performed the analysis of variance, according to the design adopted. Subsequently, the data were submitted to regression analysis, with curve fitting, according to the parameters evaluated. Results revealed that, K fertilization influenced the growth of maize plants in the two fertilization periods (seeding and V5 stadium) at 45 and 75 days after planting, as well as in gas exchange and productivity. Fertilization at the V5 stadium in maize presented higher values compared to fertilization at seeding, in which the dose of 150 kg ha-1 presented the best results at both planting times. In relation to the residual effect of K on bean growth, it was verified that, there was influence of the doses on the growth of plants, in which the dose of 200 kg ha-1 recorded the highest values. The results showed that there is the residual response of K on bean cultivation in succession with maize. For the greater development of maize, it is recommended to use the dose of 150 kg ha-1 at the V5 stage of plants.
Evaluation of Morphological Properties of Avenue Tree Species and Concentrations of Pollutants Under and Outside Their Canopies in Port Harcourt, Nigeria
Authors: Chima Uzoma Darlington , Opara Miriam Ugochi
Published: August 2019

We evaluated the morphological attributes of three major avenue tree species (Delonix regia, Gmelina arborea and Terminalia mantaly) and the concentrations of pollutants under and outside their canopies at four locations reflecting different levels of anthropogenic activities that contribute to pollution, in Port Harcourt, Rivers State, Nigeria. The sites are: Shell Petroleum Development Company (SPDC) Agbada (II) Flow Station, Aluu; LNG Seaport (LNG), Trans-Amadi; Isaac Boro Park (IBP), Mile 1; and Rivers State University (RSU), Nkporlu. Three trees belonging to each of the three species were randomly selected at each site and measurements of their total height (THT), diameter at breast height (DBH), crown diameter (CD), and basal area (BA), were taken. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), ammonia (NH3), methane (CH4), sulphur dioxide (SO2), and particulate matter (PM) under and 50 m outside their canopies, were also measured. One-way Analysis of Variance (ANOVA) was used to test for significant difference (p ≤ 0.05) in tree attributes and the concentrations of pollutants under canopies of each tree species among sites, while t-test was used to test for significant difference (p ≤ 0.05) in the concentrations of the pollutants under and 50 m outside tree canopies at each site. THT, DBH, CD and BA of the three tree species varied significantly at the four sites with highest and lowest mean values recorded for RSU and LNG, respectively, except for D. regia where DBH and BA were highest and lowest at IBP and LNG, respectively. The concentration of pollutants under tree canopies at different sites did not vary significantly (p > 0.05) in most cases (except PM) despite the significant differences in tree growth/morphological attributes. There was no significant difference between the concentrations of pollutants under and 50 m outside tree canopies in all the sites. Higher concentrations of CO and PM were recorded under trees at LNG Seaport while NO2, SO2 and CH4 were higher under trees at SPDC, indicating that the level of pollutants at each site reflected the nature of the activities associated with the sites and not differences in tree morphological attributes. However, concentrations of the pollutants, except CH4, were below recommended exposure limits under and outside tree canopies, at all the locations.
Las fuentes para la interpretación del Valle de Sébaco como subregión histórica
Authors: Balladares N. Sagrario
Published: August 2019

El presente artículo ha sido elaborado con el propósito de compartir con los lectores una selección de fuentes para la interpretación de la Dinámica Social del valle de Sébaco como una sub región histórica durante el periodo entre los siglos XVI y XIX. Para ello se emprendió una búsqueda de fuentes primarias, tales como las evidencias arqueológicas recuperadas en trabajos anteriores en la región, documentos históricos que se encuentran en los archivos parroquiales y archivos administrativos coloniales dentro y fuera del país, en este caso, en el Archivo General de Centroamérica nde Guatemala (AGCA), además, de los testimonios y descripciones dejadas por cronistas, visitas pastorales, viajeros; así como algunas entrevistas de líderes y actores claves de las actuales comunidades indígenas de Sébaco y Matagalpa.También se han considerado otras fuentes secundarias, como las de tipo antropológicas, etnográficas, estadísticas, económicas, ecológicas, entre otras.Se espera que los resultados del análisis de datos procedentes de estas fuentes sirvan para inferir desde una perspectiva histórica, la dinámica social desarrollada en el valle de Sébaco durante el periodo propuesto.
Deshumanización del trabajo y necesidad colectiva: consideraciones acerca del trabajo informal
Authors: Solís Narváez Norling
Published: August 2019

El comercio informal en los espacios urbanos suele ser la salida para sustentar la necesidad inmediata de sobrevivencia entre muchos obreros y campesinos que migran hacia la ciudad en busca de “mejores oportunidades”. El trabajo en su expresión básica, es una implicancia práctica del movimiento humano. El ser humano en su cotidianidad ejerce trabajo, porque emplea su cuerpo, sus manos, sus pies, sus sentidos, buscando la satisfacción de necesidad de movimiento, alimentación, hidratación, etc. En ese sentido, el trabajo no debería ser un problema mayor, sin embargo, bajo la lógica del sistema capitalista, el trabajo adquiere otra dimensión, esclaviza, explota. Este ensayo aborda el comercio informal, como un hecho laboral donde convergen relaciones sociales de poder. Se busca evidenciar que los mercados, en contextos urbanos, son espacio de conflictos, pugnas de poder provocados por la necesidad de sobrevivencia. El proceso metodológico utilizado se basa en las observaciones y notas de campo1, diarios de campo, así como la sistematización de la experiencia teórica y documental sobre el tema. Es un aporte a la discusión sobre los conflictos que con frecuencia se suscitan en estos mercados populares.
Iran and Future European Union Gas Supply: Sociolinguistic Element of Iranian Gas Export Media Debate
Authors: Singh Rajdeep
Published: August 2019

While Iran possesses one of the biggest gas reserves in the world, Iranian media debate about gas export has been concentrated around the gas pipe line strategy. On the other hand, Iran is not even yet a gas export country despite having such big gas reserves and this begs the question as to why Iran has not been successful in providing European Union with gas. Our research deals with this question and explains the future prospect of Iran-European Union cooperation in energy sector. Our main hypothesis in this research is then formulated as follows: Iranian media has been mostly captured by pro-pipe line officials who see great fortune in the possible economic benefits for them in this. However, for petroleum products, as long as Iran enjoys good relationship with Europe, it can play an important role in the oil sector. In fact, we will show that the linguistic aspect is vital as it help depict a different picture for the general public, bringing about different expectation among the youth and nationalists. Finally, we also discuss the LNG gas export possibility and the economic reasoning behind its future exploitation in Iran.
An Analysis of Coaches’ Unethical Behaviors in terms of Sociodemographic Variables
Authors: Tanyeri Levent
Published: August 2019

In addition to physical struggle, sports are also closely related to moral behaviors and attitudes. The will to succeedand win which plays a central role in sports also brings about various ethical questions. In this respect, the presentstudy aims to analyze coaches’ unethical behaviors in terms of socio-demographic variables. To this aim, a total of173 students comprised of 100 male students and 73 female students were invited to participate in the present study.“Athlete Perception Scale about Coaches’ Unethical Behaviors” developed by Güven and Öncü (2012) and a“personal information form” developed by the researcher was used data collection tools in the present study, and thefindings indicate a normal data distribution. No significant differences were found among scale scores in terms ofgender, sports branch and level of sportsmanship. However, it was also demonstrated that years of athletic experiencehad a significant effect on students’ views on coaches’ unethical behaviors.
The impact of the Canterbury Earthquake Sequence on the earthquake engineering profession in New Zealand
Authors: Brunsdon Dave , Hare John , Stannard Mike , Berryman Kelvin , Beattie Graeme , Traylen Nick
Published: August 2019

Professional engineers have provided a range of inputs into the responses to the Canterbury Earthquake Sequence and the recovery process that has followed. This earthquake sequence has been unique in many respects, including the intensity of shaking produced in the Christchurch CBD by each of the major aftershocks in February, June and December 2011. For engineers, the heavy workload has been continuous from the response to the original 4 September 2010 Darfield earthquake, and will extend for several years to come.

There have been many post-earthquake challenges for seismologists and geotechnical and structural engineers, commencing with urban search and rescue responses and rapid building evaluations, and extending through the more detailed assessments and repair specifications during the recovery phase. Engineers are required to interface with owners, regulatory authorities and insurers, and face many challenges in meeting the objectives of these different sectors, which are rarely aligned.

Adding to the technical demands has been the requirement for many scientists and engineers to provide input into the Canterbury Earthquakes Royal Commission of Inquiry and other investigations. The Royal Commission was set up to investigate the failure of buildings that led to the loss of 185 lives in the 22 February 2011 aftershock, and has placed close scrutiny on many aspects of engineering activities, particularly those undertaken following the 4 September 2010 earthquake. The prominent public reporting of the Royal Commission hearings has placed additional pressure on many engineers, including those who volunteered their services following the original earthquake into a role for which they had received only limited prior training. Interpreting and communicating ‘safety’ in relation to the re-occupancy (or continued occupancy) of commercial buildings continues to be a challenge in the face of liability concerns.

A more comprehensive understanding of the technical and process guidance required by engineers and authorities has resulted from the work undertaken in response to this earthquake sequence. Much of this guidance has now been produced, and will be of considerable benefit for future major earthquake events.

This paper reflects on the range of work undertaken by scientists and engineers during the response and recovery stages. The scope and implications of the various official inquiries are summarised, and the potential impacts on engineers involved in the response to and recovery from future major earthquakes are briefly discussed.
Horizontal Versus Vertical Coopetition: The Tunisian Manufacturing Industry
Authors: Zgarni Asma
Published: August 2019

By opting for coopetition strategy, some companies prefer the horizontal one while others opt for the vertical. Furthermore, some coopetitions are rather aggressive, while others are rather cooperative. Nevertheless, the reasons for using one or the other of these strategies remain still ambiguous.

This article aims to explain the reasons, both internal and external, for the use of each type of coopetition and its nature. By adopting a quantitative hypothetico-deductive approach, and through a sample of Tunisian industrial companies, this study confirms that the need for strategic capabilities holds the strongest weight that the competitive intensity in the explanation of the coopetition type and its nature.
A Review of the Study on Father Involvement in Child Rearing
Authors: Liu Xiaohong
Published: August 2019

A large number of studies have proved that fathers have irreplaceable important value to the growth of young children. While in reality, there is a large number of "father missing" phenomenon in China. Previous studies have focused on the influence of father involvement on children development and the influence factors of father involvement in child rearing. Fathers’ participation has various degrees of influence on children’s development of personality, social ability, cognition, intelligence and academic achievement, gender roles, morality and emotion, as well as physical development. Family, society, fathers’ characters and children’s personalities all affect fathers’ participation in child rearing to some extent. There are the following deficiencies in the studies of father involvement: first, the number of research on fathers’ participation is very insufficient; second, the research scope of father involvement is narrow and interdisciplinary research is insufficient; third, the research depth needs to be improved urgently; Fourth, the research paradigm is mainly speculative and quantitative, and the qualitative research needs to be strengthened.
Reviewer Acknowledgements for English Language Teaching Vol 12 No 9
Authors: Yu Gavin
Published: August 2019

Reviewer acknowledgements for English Language Teaching, Vol. 12, No. 9, 2019
Reviewer Acknowledgements for Higher Education Studies, Vol. 9, No. 3
Authors: Lin Sherry
Published: August 2019

Higher Education Studies wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal are greatly appreciated.

Higher Education Studies is recruiting reviewers for the journal. If you are interested in becoming a reviewer, we welcome you to join us. Please find the application form and details at http://recruitment.ccsenet.org and e-mail the completed application form to hes@ccsenet.org.

Reviewers for Volume 9, Number 3

Antonina Lukenchuk, National Louis University, USA

Arbabisarjou Azizollah, Zahedan University of Medical Sciences, Iran

Arwa Aleryani, Saba University, Yemen

Ausra Kazlauskiene, Siauliai University, Lithuania

Donna.Smith, The Open University, UK

Evrim Ustunluoglu, Izmir University of Economics, Turkey

Firouzeh Sepehrianazar, Orumieh University, Iran

Gregory S. Ching, Fu Jen Catholic University, Taiwan

Hüseyin Serçe, Selçuk University, Turkey

John Cowan, Edinburgh Napier University, United Kingdom

Kartheek R. Balapala, University Tunku Abdul Rahman, Malaysia

Laith Ahmed Najam, Mosul University, Iraq

Lung-Tan Lu, Fo Guang University, Taiwan

Mei Jiun Wu, Faculty of Education, University of Macau, China

Najia Sabir, Indiana University Bloomington, USA

Nicos Souleles, Cyprus University of Technology, Cyprus

Prashneel Ravisan Goundar, Fiji National University, Fiji

Sumita Chowhan, Jain University, India

Tuija A. Turunen, University of Lapland, Finland

Zahra Shahsavar, Shiraz University of Medical Sciences, Iran
Reviewer Acknowledgements for International Journal of Statistics and Probability, Vol. 8, No. 5
Authors: Smith Wendy
Published: August 2019

International Journal of Statistics and Probability wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated.

Many authors, regardless of whether International Journal of Statistics and Probability publishes their work, appreciate the helpful feedback provided by the reviewers.

Reviewers for Volume 8, Number 5

Abdullah A. Smadi, Yarmouk University, Jordan

Carla J. Thompson, University of West Florida, USA

Chin-Shang Li, School of Nursing, USA

Encarnación Alvarez-Verdejo, University of Granada, Spain

Felix Almendra-Arao, UPIITA del Instituto Politécnico Nacional , México

Gabriel A. Okyere, Kwame Nkrumah University of Science and Technology, Ghana

Gane Samb Lo, University Gaston Berger, SENEGAL

Gennaro Punzo, University of Naples Parthenope, Italy

Gerardo Febres, Universidad Simón Bolívar, Venezuela

Ivair R. Silva, Federal University of Ouro Preto – UFOP, Brazil

Mingao Yuan, North Dakota State University, USA

Philip Westgate, University of Kentucky, USA

Qingyang Zhang, University of Arkansas, USA

Sajid Ali, Quaid-i-Azam University, Pakistan

Sohair F. Higazi, University of Tanta, Egypt

Subhradev Sen, Alliance University, India

Vyacheslav Abramov, Swinburne University of Technology, Australia

Wei Zhang, The George Washington University, USA

Yuvraj Sunecher, University of Technology Mauritius, Mauritius

Zaixing Li, China University of Mining and Technology (Beijing), China

 

Wendy Smith

On behalf of,

The Editorial Board of International Journal of Statistics and Probability

Canadian Center of Science and Education
Seed Technology of Myrcianthes pungens (Berg) Legr: An Approach to Biometry and Germination
Authors: Griebeler Adriana Maria , Araujo Maristela Machado , Rorato Daniele Guarienti , Turchetto Felipe , Tabaldi Luciane Almeri , Barbosa Felipe Manzoni , Berghetti Álvaro Luis Pasquetti
Published: August 2019

Myrcianthes pungens, native fruit with medicinal, ornamental and ecological potential, lacks information on biometry and technology for seed germination. Thus, the aim of this study was to characterize the fruits and seeds of M. pungens, determining the appropriate substrate for laboratory tests, as well as to evaluate the effect of different concentrations of gibberellic acid (GA3) on the germination of the species. In the biometry, the mensuration of the fruits and seeds was made with the aid of a digital caliper. In the laboratory, three substrates (between filter paper, between vermiculite and between sand) were used, with five concentrations of GA3 (0; 125; 250; 375 and 500 mg L-1) and the tests were conducted in a germination chamber. The percentage of germination, hard seeds, germination speed index and seedling length root and shoot were evaluated. The average fruit length and width were 17.38 and 16.05 mm, respectively. The fruits presented one or two seeds with 8.10; 9.56 and 6.49 mm in length, width and thickness. The germination test is more efficient between fine sand, and vermiculite may also be used. The wetting of the substrate with gibberellin in the concentration of 125 to 274 mg L-1 optimizes the percentage and speed of germination.
Relationship Between Spatio-Temporal Leaf Area Index and Crop Coefficient When Monitoring Coffee Plots in Brazil Using the Sentine-2
Authors: Jaramillo-Giraldo Carolina , Ferreira Williams Pinto Marques , Fonseca Humberto Paiva , Ribeiro Marcelo de Freitas , Silva Laís Maria Rodrigues , Fernandes Raphael Bragança Alves
Published: August 2019

Robust monitoring techniques for perennial crops have become increasingly possible due to technological advances in the area of Remote Sensing (RS), and the products are available through the European Space Agency (ESA) initiative. RS data provides valuable opportunities for detailed assessments of crop conditions at plot level using high spatial, spectral, and temporal resolution. This study addresses the monitoring of coffee at the plot level using RS, analyzing the relationship between the spatio-temporal variability of the Leaf Area Index (LAI) and the crop coefficient (Kc); the Kc being a biophysical variable that integrates the potential hydrological characteristics of an agroecosystem compared to the reference crop. Daily and one-year Kc were estimated using the relation of crop evapotranspiration and reference. ESA Sentinel-2 images were pre-analyzed and atmospherically corrected, and Top-of-the-Atmosphere (TOA) reflections converted to Top-of-the-Canopy (TOC) reflectance. The TOCs resampled at the 10m resolution, and with the angles corresponding to the directional information at the time of the acquisition, the LAI was estimated using the trained neural network available in the Sentinel Application Platform (SNAP). During 75% of the monitored days, Kc ranged between 1.2 and 1.3 and, the LAI analyzed showed high spatial and temporal variability at the plot level. Based on the relationship between the biophysical variables, the LAI variable can substitute the Kc and be used to monitor the water conditions at the production area as well as analyze spatial variability inside that area. Sentinel-2 products could be more useful in monitoring coffee in the farm production area.