bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Different In-Process and Building Materials with Varying Hardness on Impact Sensitivity of the Matchhead Composition
Authors: Sivapirakasam S.P. , Phanindra K. Harisivasri , Surianarayanan Mahadevan , Balasubramanian K.R.
Published: August 2019

The objective of this research work is to study the influence of different in-process contact materials (steel, aluminium and brass) and building contact materials (concrete and wood), and its hardness on the impact sensitivity of matchhead composition. The BAM fall hammer was used for measurement of impact sensitivity. The result demonstrated that the in-process and building contact materials, and its hardness imparted variation to the sensitivity between 3.33J and 15.892J. The least LIE was found at 3.33J for the steel at 115 HRB and 117 HRB; 3.72J for aluminium at 53 HRB; 4.7J for brass at 82 HRB; 12.16J for concrete at 35 RHN, and 13.14J for wood at 16 HRB. The limited impact energy was lowest when there was contact between steel and steel as in-process material and contact between concrete and concrete as building contact material. The impact sensitivity was higher for material with higher hardness for all building and in-process contact materials. Brass and wood is suggested to be used as process and building materials in order to reduce the risk of explosions due to impact sensitivity.
Effect of Soaking Time on Evolution of Microstructure and Hardness during Annealing of EN-47 Spring Steel
Authors: Kumar S. Ramesh , Kumaran S. Senthil , Ramesh G. , Sree Arravind M. , Venkateswarlu D.
Published: August 2019

The study presents the results of the examination on the effect of soaking time on the Microstructure, Grain shape and hardness properties of annealed EN-47 Spring Steel. The EN-47 Spring Steel samples were heated at 860 °C for soaking times of 60, 120, 240, 480 minutes. Optical Microscopy and Rockwell Hardness were carried out to determine the morphology, grain shape and hardness of the material with increasing soaking time. EN-47 Spring Steel samples showed up a decreased value in hardness with the extent of soaking time. Pearlite colonies expand with the increase in soaking time. The linear relationship between the soaking time and other factors were also observed. Keywords: EN-47, Annealing, Microstructure, Rockwell Hardness.
Fullerene (PCBM) Modulated MEH-PPV Photoactive Material for Plastic Solar Cells
Authors: Naik Ishwar , Bhajantri Rajashekhar , Patil B.S. , Bhat Vinayak
Published: August 2019

Abstract.Plastic solar cells are promising devices in looking for low cost and flexible energy storing devices. Low efficiency is the main drawback of these cells in comparison with inorganic solar cells and hence the search for an efficient plastic solar cell has become a globally demanded research problem. In the present work we have used the modified fullerene [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) as N type modulating probe on P type semiconducting polymer Poly[2-methoxy-5-(2’-ethylhexyloxy)-phenylenevinylene] (MEH-PPV). The donor MEH-PPV polymer matrix is modulated by adding PCBM in the weight ratio 1:3, 1:1 and 3:1 in Chloro-Benzene(CB) as the common solvent and glass-coated samples are prepared by solution cast method. Samples are analyzed by UV-VISIBLE spectroscopy by JASCO UV Vis NIR V 670 spectrometer. The effect of PCBM content on MEH-PPV is to broaden the spectral response of MEH-PPV. In other words the acceptor PCBM has tuned the band gap (energy difference between HOMO & LUMO) of the donor MEH-PPV. Spectral analysis revealed that 1:3 blend of MEH-PPV with PCBM has a wide spectral sensitivity for absorption. The band gap for each blend is determined using Tauc’s plot. Increased Fullerene content has decreased the band gap of the host polymer. We conclude that modified fullerene can effectively modulate the donor polymer matrix and 1:3 MEH-PPV: PCBM can act as a good photoactive material for solar cells. Absorption can be further enhanced by either dye sensitization or by metal oxide nanoparticle doping without increasing the thickness of the film. We have doped the optimized 1:3 blend with 20%, 40% & 60% of TiO2 nanoparticles wherein the absorption is enhanced with doping level. The increased absorption is attributed to the photocatalytic activity of the nanaoparticles embedded in the polymer matrix
An Investigation on the Suitability of Al-Mg Binary Hypo-Eutectic and Eutectic Aluminium Alloys as a Metal Matrix for Polymer Reinforced Composites and Lightweight Applications
Authors: Kumaran D. , Rajadurai A. , Sivam S.P. Sundar Singh
Published: August 2019

This research work reports on the investigation on the suitability of prepared Al-Mg binary alloys of hypo-eutectic and eutectic compositions, for making metal matrix composites for light weight applications. Commercial pure aluminium, and magnesium blocks were used for the purpose of making binary alloys of Al-Mg, with the Mg in weight percentages 15%, 20%, 25%, 30%, and 37%. composition prepared by stir-casting under Argon cover gas. The cast Al-Mg alloys were cut to standard specimens to investigate its microstructure and mechanical properties. Test results revealed that the Vicker’s Hardness Number (VHN) of the alloys increases with the increased weight percentage of Mg and Ultimate Tensile Strength (UTS) were also increasing with increasing Mg content. The SEM images revealed the presence of micro-voids in alloys of higher Mg contents. The test values indicates the suitability of hypo-eutectic alloys as candidates for metal matrix composites for light weight applications.
Investigating the Effect of Friction Stir Welding on Microstructure and Corrosion Behaviour of Al-Zn-Mg Alloy
Authors: Sharma Chaitanya , Upadhyay Vikas
Published: August 2019

In this work, Friction Stir Welding (FSW) of alloy 7039 was carried out in T4 temper and resulting microstructure and corrosion behaviour of developed weld were studied. FSW transformed the starting microstructure of base metal and formed stirred zone (SZ) and heat affected zone (HAZ) with varying microstructure and precipitate morphology. The observed zones in welded joints exhibited decreased protection to corrosion resistance than base metal. Dissolution of secondary precipitates in SZ and occurrence of precipitate free zones (PFZs) in HAZ enhanced susceptibility to corrosion of HAZ and weld nugget zone (WNZ) than base metal.
Parameter Optimization for Laser Welding of High Strength Dissimilar Materials
Authors: Anuradha M. , Das Vemulapalli Chittaranjan , Venkateswarlu D. , Cheepu Muralimohan
Published: August 2019

Dissimilar joining of high strength tensile steels are joined using laser beam welding. The selection of the welding conditions for joining of dissimilar materials is highly required to satisfy the quality of the joints. In the present investigation, optimization technique were used to determine the optimal welding conditions. Initially welding conditions were optimized for weld geometry and formation of different zones in the weldment. The metallurgical and mechanical properties of the welds are greatly influenced by the geometry of the welds. The surface response methodology design is carried out for the experimental design by the development of regression equations. Analysis of variance (ANOVA) was used to check the validity of the model. The output of the welding conditions were compared with the predicted values to identify the accuracy of the model. The obtained results from response surface methodology were compared with the experimental results and validated.
Investigation of a Hollow Shaft to Determine the Maximum Angular Velocity Regarding the FGM Properties
Authors: Torabnia Shams , Hemati Mohammadreza , Aghajani Sepideh
Published: August 2019

To determine the maximum velocity of a rotating hollow shaft it is mandatory to understand the effects of material & geometrical properties variations. In this paper, mechanical behavior & maximum rotational speed of a hollow FGM shaft in elastic zone is investigated. The analysis is based on small deformation in plane-strain state. Young's modulus, density & yield stress are assumed to vary as a power-law function of radial coordinate. Introducing dimensionless parameters, the equilibrium equation has been analytically solved. For the case of equal exponent parameters, numerical results compared the effect of density & yield stress variation on displacement, strain & stress elements. The results are compared with a homogeneous shaft & a variable material properties case. It shows material properties’ variation may have a considerable effect on the stress & strain components & radial displacement & causes yielding onset from the inner radius of the shaft.
Metal Joining Technique of SA 213 Tube and SA 387 Tube Plate Grade Materials Using Backing Block by Clearance Fit Condition
Authors: Kumaran S. Senthil , Srinivasan Narayanan , Kumar S. Ramesh , Sekarapandian N. , Venkateswarlu D.
Published: August 2019

This work, Seamless Austenitic 213 tube is welded with Seamless Austenitic 387 tube plate through friction welding of tube to tube plate using an external tool (FWTPET) method in presence of backing block by using clearance fit method. Further, the analysis of microstructural features on the interface of weld exhibit that the FWTPET is able to generate flawless welds. In all nine various work specimen which welded under the various circumstances, the hardness value, tensile strength have taken. In this work, two type of specimen has taken where one kind is the tube which contains no hole and another one is with the hole in the circumference. 806.28 MPa and 746.5 MPa were the optimum strength for the workpiece which is not a having a hole and having the hole on the circumference.
TIG Arc Welding - Brazing of Dissimilar Metals - An Overview
Authors: Venukumar S. , Cheepu Muralimohan , Vijaya Babu T. , Venkateswarlu D.
Published: August 2019

Tungsten inert gas (TIG) arc welding–brazing has been recently developed and is being increasingly implemented in various industrial applications. Nowadays, this process gains much attention in joining of dissimilar metal combinations. This review paper explains the principles underlying TIG arc welding – brazing of dissimilar metal combinations and highlights the above benefits in a number of practical applications. The process mechanism of TIG brazing is different from the conventional welding processes and it will bridge the gap between the two substrates by the addition of fillers under the concentrated heat source of TIG electrode. TIG brazing technique is one of the best alternative process among the other joining process for effective joining of dissimilar metals, which have various melting temperatures and physical properties. It is very important to understand the process mechanism and its compatibility with the various dissimilar materials joining. The present study focuses on the addressing of progress of TIG brazing process in modern days and its applications in the various industries, and to bring the awareness to the manufacturers about the importance of this process from this review report. Keywords: Tungsten inert gas (TIG) arc welding–brazing, Dissimilar metals, Microstructures, Mechanical properties.
Elucidation on the Microstructural and Mechanical Properties of Tailored VAL12 Hybrid Composites with ZrO2 Dispersoids Fabricated by Squeeze Casting Technique
Authors: Srinivasan S.A. , Kumaresh Babu S.P. , Gaurav Vivek
Published: August 2019

The effect of ZrO2 (2, 4, 6 and 8 wt%) dispersoids with 1 wt% graphite on the microstructural, mechanical properties on squeeze cast VAL12 matrix hybrid composite is investigated in the present study. The hybrid composites were characterized using advanced characterization techniques to reveal its microstructural and physical properties. The microscopic examinations using optical and SEM technique reveal that the addition of dispersoids accelerates the nucleation kinetics, thus attaining fine, equiaxial grains in hybrid composites. The squeeze cast composites show almost nil porosity, defects and owing to it, the actual density of the composites are found to be more than 95% as that of the theoretical density values. The hardness values and tensile values increase with respect to the increase in percentage addition of ZrO2. The tensile results show that there is an appreciable increase in the UTS values of composites without much loss in its ductility as the addition of graphite improves the self-lubricating property and provides wettability during the casting. Fractographic studies on tensile tested specimen reveal that the crack occurs in both matrix and particles showing the good interface between matrix and dispersoids. Machinability studies reveal the formation of continuous chips in hybrid composites with a lower percentage of reinforcement (up to 4% ZrO2 + 1%Gr) and segmented chips in case of the composite with 8% ZrO2 + 1%Gr, as the increase in the percentage of dispersoids improve the chip breakability of the composites. On an overall, the hybrid aluminium matrix composites with 1%Gr and 6 % ZrO2 unveiled better optimal results.
Optimization of Friction Stir Processing Parameters for the Development of Cu-W Surface Composite
Authors: Naik Ramavath Bheekya , Reddy G. Madhusudhan , Subbu S. Kanmani , Kumar R. Arockia
Published: August 2019

The present work focusses on improving the surface wear resistance of commerical pure copper by reinforcing tungsten particles through friction stir processing. Particularly this work adopts Taguchi’s experimental design to achieve minimum wear rate for Copper-Tungsten surface composite by optimizing the process parameters. The rotational and traverse speeds of tool and volume fraction of reinforcement (i.e. tungsten) are the chosen parameters for minimizing the wear rate. Taguchi L9 orthogonal array was used to design the experiments. The surfaces of the processed specimens were investigated by optical microscopy for the distribution of tungsten particles and sliding wear behavior was studied by conducting pin-on-disc method. It was observed from the optical micrographs that the reinforcement evenly dispersed in the processed zone. The measured hardness was 85% higher than the base metal for the specimen exhibited minimum wear rate. The effects of all three parameters on wear rate were studied. The minimum wear rate was achieved by using rotational and traverse speeds of tool, 1200rpm and 60mm/min, respectively. The amount of reinforcement required to achieve maximum wear resistance was 10%. Variance analysis showed that amount of reinforcement played a key role in determining the properties than the other parameters. Keywords: Cu-W composite, high strength high conductivity alloy, friction stir processing, Taguchi optimization
Recent Studies on the Fabrication of Magnesium Based Metal Matrix Nano-Composites by Using Ultrasonic Stir Casting Technique - A Review
Authors: Kumar Dinesh , Thakur Lalit
Published: August 2019

This paper presents the recent studies on the fabrication of magnesium based metal matrix nanocomposites (MMMC) by using ultrasonic assisted stir casting technique. The pure metal and alloys, due to their limited mechanical properties are not suitable for various engineering applications. It has been observed that the addition of suitable reinforcements into metallic matrix improves the specific strength, ultimate tensile strength, porosity and wear properties as compared to the conventional and monolithic engineering materials for aerospace and automotive applications. The effects of ultrasonic vibrations and the resulting uniform dispersion of reinforcements on the mechanical and tribological properties of magnesium based MMCs are specifically highlighted in this paper.
Properties of Three Phase Magneto-Electro-Thermo-Elastic Composites
Authors: Patel Hardik , Penumakala Pavan Kumar , Patel Dhruv
Published: August 2019

Three phase composites that consists of piezoelectric and piezomagnetic fibers embedded inan elastic matrix phase exhibits new product properties such as magnetoelectric effect, pyroelectric andpyromagnetic effect, which are absent in individual phases. In this work, simple analytical expressionsare developed based on strength of materials approach to find these effective coupling coefficients. In amicro scale rectangular representative volume element (RVE) of a layered type three phase composite,series connectivity is assumed between fiber and matrix layers along transverse direction and parallelconnectivity is assumed along longitudinal direction. The analytical model is validated with otherhomogenisation methods and effective property variation of BaTiO3-CoFe2O4-Epoxy composite andLiNbO3-CoFe2O4- Epoxy composite are discussed.
Numerical Analysis of Constrained Groove Pressing and Mechanical Behaviour of Processed 316L Stainless Steel
Authors: Singh Rahul , Rajan Gaurav , Kumar B. Kranthi , Verma Raviraj , Singh Dharmendra , Rao P. Nageswara , Jayaganthan R. , Kumar Abhishek
Published: August 2019

Among several existing and well established severe plastic deformation techniques, constrained groove pressing (CGP) is one of the prominent and trusted routes for producing ultrafine grained materials. In the present work medical grade 316L austenitic stainless steel sheet of 3 mm thickness was subjected to CGP up to two cycles. Samples obtained as a result of processing were investigated both experimentally and numerically through finite element (FE) analysis using DEFORM-3D software. XRD study revealed the transformation of austenitic phase to martensitic phase. Tensile and hardness tests were conducted to see the effect of processing on mechcanical properties. The ultimate tensile strength increases with the number of CGP passes from 767 (solution annealed) to 1162 MPa (after 2 cycles), similarly, yield strength increases from 269 (as received) to 328 MPa (after 2 cycles). Finite element analysis showed an imposed strain of 2.30 with standard deviation of 0.31 after two cycle of CGP is in coordination with experimental measured strain of 2.32.
High Entropy Based Composites - An Overview
Authors: Ram Prabhu T. , Chodancar Yash , Arivarasu M. , Arivazhagan N. , Mishra R.K.
Published: August 2019

High entropy alloy (HEA) is a new class of alloy that has a different alloy design concept over the conventional dilute alloys. In this alloy, the alloying elements have an equi-atomic ratio that helps to increase the entropy of the alloy to stabilize the simple solid solution (BCC, FCC and HCP) over the intermetallics. The stabilization of solid solution improves the paradoxial properties such as strength and toughness. High thermal stability, excellent creep and fatigue properties, outstanding corrosion resistance are the attractive features of HEA. Recently, the HEA is explored as a matrix or particle in the metal matrix composites. Research studies on HEA based composites are plenty and scattered. In this work, we attempt to collate essential information in the HEA based composites. The overview covers (1) processing techniques, (2) microstructure characterization and (3) the mechanical properties in detail. A short note on the potential applications of HEA based composites is also proposed.
Emtricitabine-induced pure red cell aplasia
Authors: Manickchund Nithendra , Du Plessis Camille , John Melanie-Anne A. , Manzini Thandekile C. , Gosnell Bernadett I. , Lessells Richard J. , Moosa Yunus S.
Published: August 2019

Introduction: Anemia is common in HIV. Parvo B19 infection is a well-recognised cause of red cell aplasia. Other causes of persistent pure red cell aplasia (PRCA) include anti-retroviral drugs such as zidovudine and lamivudine. We describe a case of PRCA that strongly implicates emtricitabine as the probable cause.Patient presentation: Patient was HIV positive and on treatment with a fixed drug combination consisting of tenofovir, emtricitabine and efavirenz for 3 months when she developed severe transfusion dependent anemia. The anemia, attributed to PRCA, was persistent and transfusion dependent for about one year.Management and outcome: Replacement of emtricitabine with abacavir resulted in a prompt, complete and lasting resolution of the anaemia, suggesting an etiologic role of emtricitabine in the PRCA.Conclusion: Emtricitibine is a rare cause of pure red cell aplasia.
The sup-norm problem for GL(2) over number fields
Authors: Blomer Valentin , Harcos Gergely , Maga Péter , Milićević Djordje
Published: August 2019

We solve the sup-norm problem for spherical Hecke–Maaß newforms of square-free level for the group GL(2) over a number field, with a power saving over the local geometric bound simultaneously in the eigenvalue and the level aspect. Our bounds feature a Weyl-type exponent in the level aspect, they reproduce or improve upon all known special cases, and over totally real fields they are as strong as the best known hybrid result over the rationals.
Dissolved organic nutrients dominate melting surface ice of the Dark Zone (Greenland Ice Sheet)
Authors: Holland Alexandra T. , Williamson Christopher J. , Sgouridis Fotis , Tedstone Andrew J. , McCutcheon Jenine , Cook Joseph M. , Poniecka Ewa , Yallop Marian L. , Tranter Martyn , Anesio Alexandre M. ,   The Black & Bloom Group
Published: August 2019

Abstract. Glaciers and ice sheets host abundant and dynamic communities of
microorganisms on the ice surface (supraglacial environments). Recently, it
has been shown that Streptophyte glacier algae blooming on the surface ice
of the south-western coast of the Greenland Ice Sheet are a significant
contributor to the 15-year marked decrease in albedo. Currently, little is
known about the constraints, such as nutrient availability, on this
large-scale algal bloom. In this study, we investigate the relative
abundances of dissolved inorganic and dissolved organic macronutrients (N
and P) in these darkening surface ice environments. Three distinct ice
surfaces, with low, medium and high visible impurity loadings, supraglacial
stream water and cryoconite hole water, were sampled. Our results show a
clear dominance of the organic phase in all ice surface samples containing
low, medium and high visible impurity loadings, with 93 % of the total
dissolved nitrogen and 67 % of the total dissolved phosphorus in the
organic phase. Mean concentrations in low, medium and high visible impurity
surface ice environments are 0.91, 0.62 and 1.0 µM for dissolved inorganic nitrogen (DIN), 5.1, 11 and 14 µM for dissolved organic nitrogen (DON), 0.03, 0.07 and 0.05 µM for dissolved inorganic phosphorus (DIP) and 0.10, 0.15 and 0.12 µM for dissolved organic phosphorus
(DOP), respectively. DON concentrations in all three surface ice samples are
significantly higher than DON concentrations in supraglacial streams and
cryoconite hole water (0 and 0.7 µM, respectively). DOP
concentrations are higher in all three surface ice samples compared to
supraglacial streams and cryoconite hole water (0.07 µM for both).
Dissolved organic carbon (DOC) concentrations increase with the amount of
visible impurities present (low: 83 µM, medium: 173 µM and
high: 242 µM) and are elevated compared to supraglacial streams and
cryoconite hole water (30 and 50 µM, respectively). We
speculate that the architecture of the weathering crust, which impacts on
water flow paths and storage in the melting surface ice and/or the
production of extracellular polymeric substances (EPS), containing both N
and P in conjunction with C, is responsible for the temporary retention of
DON and DOP in the melting surface ice. The unusual presence of measurable DIP
and DIN, principally as NH4+, in the melting surface ice
environments suggests that factors other than macronutrient limitation are
controlling the extent and magnitude of the glacier algae.
HETEROFOR 1.0: a spatially explicit model for exploring the
response of structurally complex forests to uncertain future
conditions. II. Phenology and water cycle
Authors: de Wergifosse Louis , André Frédéric , Beudez Nicolas , de Coligny François , Goosse Hugues , Jonard François , Ponette Quentin , Titeux Hugues , Vincke Caroline , Jonard Mathieu
Published: August 2019

Abstract. Climate change affects forest growth in numerous and sometimes opposite ways and the resulting trend is often difficult to predict for a given site. Integrating and structuring the knowledge gained from the monitoring and experimental studies into process-based models is an interesting approach to predict the response of forest ecosystems to climate change. While the first generation of such models operates at stand level, we need now individual-based and spatially-explicit approaches in order to account for structurally complex stands whose importance is increasingly recognized in the changing environment context. Among the climate-sensitive drivers of forest growth, phenology and water availability are often cited as crucial elements. They influence, for example, the length of the vegetation period during which photosynthesis takes place and the stomata opening, which determines the photosynthesis rate. In this paper, we describe the phenology and water balance modules integrated in the tree growth model HETEROFOR and evaluate them on six Belgian sites. More precisely, we assess the ability of the model to reproduce key phenological processes (budburst, leaf development, yellowing and fall) as well as water fluxes. Three variants are used to predict budburst (Uniforc, Unichill and Sequential), which differ regarding the inclusion of chilling and/or forcing periods and the calculation of the coldness or heat accumulation. Among the three, the Sequential approach is the least biased (overestimation of 2.46 days) while Uniforc (chilling not considered) best accounts for the interannual variability (Pearson’s R = 0.68). For the leaf development, yellowing and fall, predictions and observation are in accordance. Regarding the water balance module, the predicted throughfall is also in close agreement with the measurements (Pearson’s R = 0.856, bias = −1.3 %) and the soil water dynamics across the year is well-reproduced for all the study sites (Pearson’s R comprised between 0.893 and 0.950, and bias between −1.81 and −9.33 %). The positive results from the model assessment will allow us to use it reliably in projection studies to evaluate the impact of climate change on tree growth and test how diverse forestry practices can adapt forests to these changes.
Urban pluvial flood risk assessment – data resolution and spatial scale when developing screening approaches on the micro scale
Authors: Löwe Roland , Arnbjerg-Nielsen Karsten
Published: August 2019

Abstract. Urban development models typically provide simulated building areas in an aggregated form. When using such outputs to parametrize pluvial flood risk simulations in an urban setting, we need to identify ways to characterize imperviousness and flood exposure. We develop data-driven approaches for establishing this link, and we focus on the data resolutions and spatial scales that should be considered. We use regression models linking aggregated building areas to total imperviousness, and models that link aggregated building areas and simulated flood areas to flood damages. The data-resolutions used for training regression models are demonstrated to have a strong impact on identifiability, with too fine data resolutions preventing the identification of the link between building areas and hydrology, and too coarse resolutions leading to uncertain parameter estimates. The optimal data resolution for modelling imperviousness was identified to be 400 m in our case study, while an aggregation of the data to at least 1000 m resolution is required when modelling flood damages. In addition, regression models for flood damages are more robust when considering building data with coarser resolutions of 200 m than for finer resolutions. The results suggest that aggregated building data can be used to derive realistic estimations of flood risk in screening simulations. Future work needs to focus on training regression approaches where different degrees of flood-awareness in landuse management can be considered.
Representaciones de género en las publicaciones periódicas de Nicaragua (1950-1979): un análisis hemerocrítico
Authors: Rojas Icabalzeta Nohemí
Published: August 2019

Los años 50, 60 y 70 marcan una coyuntura en la historia de Nicaragua y en el caso particular de la perspectiva de género. Por un lado, durante los años 50, la mujer conquistó el derecho a ejercer el sufragio, y por otro, el año 1979 recoge importantes datos respecto a la participación de las mujeres en la Revolución Popular Sandinista. En esta investigación se recogen estos y otros acontecimientos con relación a las representaciones de género manifiestasen las publicaciones periódicas de los dos diarios con mayor circulación a nivel nacional en la época: Novedades y La Prensa; el primero manejado por la familia somocista; y en consecuencia, el siguiente asumía un papel opositor en contra del gobierno imperante. El recorrido por las páginas de La Prensa y Novedades en el contexto de 1950 a 1979, ofrece un análisis integral en relación a la concepción de la mujer en aquella época. Esta visión de la mujer está manifiesta a través del estudio de categorías como los estereotipos de género que modelan patrones de comportamiento, las clases sociales impuestaspor la manipulación mediática, la concepción de belleza femenina y la recepción de los mensajes de la población de la época en estudio. Estos elementos están inmersos desde los medios de comunicación escritos como un eje totalizante a través de un enfoque holístico.
The Effectiveness of Teaching an Educational Unit According to the Learning Cycle-5 Es Model "Bybee" in the Development of Problem-Solving Skills and Academic Achievement in Geography Subject in Grade 9 in Jordan
Authors: Fattah Al Assaf Jamal Abdel
Published: August 2019

The aim of this study is to investigate the effectiveness of the learning cycle-5 Es model “Bybee ”in the developmentof problem-solving skills and academic achievement in Geography subject in the ninth graders in Jordan. The studyconsists of 60 students from the University Education Directorate in Amman in the second semester for the year2017/ 2018. The sample was distributed randomly into two groups; one of which is experimental of (30 students) andwas taught according to the Bybee model. The other was a control group, which consisted of (30) students and wastaught in the usual way. The study tools consisted of the cognitive achievement test and the capacity scale forproblem-solving.The results of the study showed that there were statistically significant differences in the average achievement of theninth-grade students in geography subject, due to the impact of the teaching strategy in favor of the experimentalgroup. Also, it showed statistically significant differences in the average achievement of ninth grade students ingeography, due to the teaching strategy of problem-solving skills and in favor of the experimental group.The researcher recommended the benefit of the learning model "Bybee" in teaching the geography subject at allstages of the upper stage.
Students’ Attitudes Towards Learning, A Study on Their Academic Achievement and Internet Addiction
Authors: Sert Ağır Meral
Published: August 2019

Examining attitudes of students towards learning, their academic achievements and internet addictions is the mainfocus of this study. With the institution permission obtained from the Provincial Directorate of National Education ofİstanbul Governorship dated: 21.04.2016 and No: 59090411-20-E.4519158, a descriptive study in relationalscreening model was conducted. By evaluating the data of 355 students (158 male and 176 female), from 370students studying in the 9th, 10th, and 11th grades attending public high schools in the region of Kadıköy, İstanbulduring 2015-2016 academic year the outcome results were obtained. "Personal Information Form", "AttitudesTowards Learning" and “Computer Addiction for Adolescents” scales were used in order to collect research data. Byanalyzing the data with t test, one-way variance analysis (ANOVA) and correlation statistical research techniques inthe SPSS 22.0 program, findings were obtained. A significance level of 0.05 was taken as the basis in the appliedstatistics. As per the findings, a difference was found in terms of internet addiction according to gender, academicachievement, homework habits, family activity frequency variables. Furthermore, a negative relationship was foundaccording to the correlation analysis result between students' attitudes towards learning and internet addiction. Inconclusion, in the light of the the research findings, it is possible to express that differentiation of students' attitudestowards learning can support effective and efficient use of information technologies. However, the negativedifferentiation of the attitudes towards learning can generate Internet addiction as a result of inefficient use of theinformation technologies.
Supporting Academic Growth of English Language Learners: Integrating Reading into STEM Curriculum
Authors: Maarouf Saoussan A.
Published: August 2019

English Language Learners (ELLs) in the U.S. have recently received growing attention in educational researchbecause of their struggle in academic performance, especially after the launch of the Common Core State Standards(CCSS) and assessments in 2009. Unfortunately, ELL students are required to take these standardized tests inEnglish language regardless of their proficiency level in reading. Despite increased focus and resources ofimplementing STEM (Science, Technology, Engineering, and Math) curriculum in K-12 education, there is a strongevidence that ELL students do not attain commensurate performance when compared to their nativeEnglish-speaking peers. The integration of Art into STEM disciplines has evolved STEM into STEAM. Lately, therehas been much discussion in the educational field that the acronym STEAM should be further evolved into STREAMby integrating Reading. The purpose of this study is to investigate the efficacy of integrating STEM and Readingcurriculum in K-12 education to reduce the achievement gap between ELL and non-ELL students. Practicalclassroom strategies for classroom teaching and instruction are discussed.
Performance based design of buildings to assess damage and downtime and implement a rating system
Authors: Mayes Ronald , Wetzel Nicholas , Weaver Ben , Tam Ken , Parker Will , Brown Andrew , Pietra Dario
Published: August 2019

The Christchurch earthquakes have highlighted the mismatch in expectations between the engineering profession and society regarding the seismic performance of buildings. While most modern buildings performed as expected, many buildings have been, or are to be, demolished. The ownership, occupancy, and societal costs of only targeting life-safety as the accepted performance standard for building design are now apparent in New Zealand.

While the structural system has a significant effect on the seismic performance of the entire building, including the contents, it is only about 20% of the total building cost. Hence, structural engineers should view the seismic performance in a wider context, looking at all the systems of the building rather than just the damage to structural items and life-safety.

The next generation of performance-based seismic design procedures, outlined in the FEMA P-58 document, provide engineers with the tools to express the seismic performance of the entire building in terms of the future life loss, facility repair cost and repair time. This paper will outline the FEMA P-58 procedure and present the results of a comparative study of six different structural systems for a three storey commercial and laboratory building: moment frame; buckling restrained braced frame; viscously damped moment frame; Pres-Lam timber coupled-walls; cast-in-place reinforced concrete shear wall; and base isolated braced frame. Each system was analysed as a fully non-linear structure and the calculated drifts and floor accelerations were input into the FEMA P-58 PACT tool to evaluate the overall building performance. The PACT tool performs loss calculations for the expected casualties, repair cost, and repair time from which a QuakeStar or SEAONC rating for the building can be obtained.
Evaluation of numerical pounding models with experimental validation
Authors: Khatiwada S. , Chouw N. , Butterworth J.W.
Published: August 2019

Pounding damage in major earthquakes has been observed frequently in the form of aesthetic, minor or major structural cracks and collapse of buildings. These observations have attracted many numerical and experimental studies that led to analytical models for simulating seismic pounding. This study considers pounding between two steel portal frames without a seismic gap. The first frame has a constant natural period while the second frame has variable stiffness and mass values. Five different ground motions are applied to eight combinations of adjacent frames using a shake table. Numerical simulations for the same configurations are carried out with five pounding force models, viz. linear viscoelastic model, modified linear viscoelastic model, nonlinear viscoelastic model, Hertzdamp model and modified Hertzdamp model. The contact element stiffness and coefficient of restitution for numerical models are determined experimentally. The amplification of maximum displacement of the first frame predicted by the numerical simulations is compared with the shake table results. It was found that the Hertzdamp model always overestimated the responses while the other four models also frequently overestimated the amplifications. The predictions from the four models were not significantly different. Since the linear viscoelastic model requires substantially less computation, compared with the other models this model is more suitable for numerical modelling of pounding responses. However, more study is required to refine the numerical models before building pounding can be modelled with enough confidence.
Ground motions and damage observations in the Marlborough region from the 2013 Lake Grassmere earthquake
Authors: Morris Gareth J. , Bradley Brendon A. , Walker Adam , Matuschka Trevor
Published: August 2019

This paper presents various aspects of the preliminary damage observations caused by ground motions in the Marlborough region following the Mw6.6 Lake Grassmere earthquake on 16 August 2013. To emphasize the severity of the ground shaking, the observed pseudo-acceleration response spectra are compared to those from the 21 July 2013 Mw6.5 Cook Strait earthquake and the NZS1170.5:2004 design spectrum. The near-source damage to State Highway 1 roads, bridges and buildings is presented within. Stainless steel wine storage tanks showed various damage states that were consistent with observations from previous earthquake events. The performance of wine tanks and other winemaking infrastructure are discussed with future design considerations. Eleven water storage dams within 12 kilometres of the earthquake source were inspected and preliminary observations are discussed. A 250,000 cubic metre dam located 10 kilometres southwest of Seddon suffered moderate damage following the 21 July event while significant further damage was sustained following the 16 August event and emergency earthworks were undertaken to reduce the risk of dam failure (to those living downstream). The performance of residential housing in rural townships of Seddon and Ward was satisfactory with respect to preserving life safety however there was moderate levels of damage which are presented within. Post-earthquake business disruption was minimal as commercial buildings in the Blenheim central business district sustained either minor or no damage.
Sources, ground motion and structural response characteristics in Wellington of the 2013 Cook Strait earthquakes
Authors: Holden C. , Kaiser A. , Van Dissen R. , Jury R.
Published: August 2019

The Cook Strait earthquake sequence occurred in a region of known high seismicity. However, this was the strongest shaking felt in decades for the Wellington region and the top of the South Island. The location and size of the earthquake meant that the ground shaking was of rather short duration and moderate intensity, except for the epicentral region of the Lake Grassmere earthquake where a PGA of 0.7g was recorded, and for part of the Wellington foreshore where up to 0.2g was recorded in both earthquakes. The level of shaking in terms of response spectra was, in general, moderate except for very high “spiked” response at particular Wellington sites (WNKS and VUWS) at periods of 0.4-0.5 seconds. Amplification and polarization in the NE-SW direction at approximately ~1 s period at many Wellington stations is likely due to basin resonance effects, whereas dominant polarization in the NW-SE direction at shorter periods is consistent with a directivity effect, and is particularly evident in the Lake Grassmere earthquake. The earthquakes were not only a real-life test on the level of preparedness for the population but also on the behaviour of recently-built structures in the Wellington region that had not yet experienced a moderate earthquake. The ability to measure, analyse and understand the intensity and characteristics of the ground shaking coupled with well-documented damage to the buildings and building array recordings will hopefully foster collaboration across earthquake engineering disciplines.
Landslides and liquefaction generated by the Cook Strait and Lake Grassmere earthquakes
Authors: Van Dissen R. , McSaveney M. , Townsend D. , Hancox G. , Little T.A. , Ries W. , Perrin N. , Archibald G. , Dellow G. , Massey C. , Misra S.
Published: August 2019

Following both the Cook Strait earthquake (Mw 6.6; 21 July, 2013) and the Lake Grassmere earthquake (Mw 6.6; 16 August, 2013) reconnaissance visits were made of the epicentral regions to document the general distribution and extend of landslides, liquefaction, and other ground damage effects generated by these earthquakes. The extent of landsliding generated in central New Zealand by these two earthquakes was at the lower end of the expected range for shallow earthquakes of these magnitudes. Liquefaction effects generated by the Cook Strait and Lake Grassmere earthquakes in central New Zealand were substantially less than those generated by the 2010-2011 Canterbury earthquakes in the Christchurch area, despite the fact that the Cook Strait and Lake Grassmere earthquakes were of comparable size and proximity, and impacted grossly similar geological settings. There is no evidence of primary ground-surface fault rupture during the Lake Grassmere earthquake.
Reviewer Acknowledgements for International Journal of Business and Management, Vol. 14 No. 9
Authors: Lee Stephen
Published: August 2019

Reviewer Acknowledgements for International Journal of Business and Management, Vol. 14 No. 9, 2019
On Generalized Gamma Distribution and Its Application to Survival Data
Authors: J Kiche , Ngesa Oscar , Orwa George
Published: August 2019

The generalized gamma distribution is a continuous probability distribution with three parameters. It is a generalization of the two-parameter gamma distribution. Since many distributions commonly used for parametric models in survival analysis (such as the Exponential distribution , the Weibull distribution and the Gamma distribution) are special cases of the generalized gamma, it is sometimes used to determine which parametric model is appropriate for a given set of data. Generalized gamma distribution is one of the distributions used in frailty modeling. In this study , it is shown that generalized gamma distribution has three sub-families and its application to the analysis of a survival data has also been explored. The parametric modeling approach has been carried out to find the expected results.
Grain Quality and Yield of Rice in the Main and Ratoon Harvests in the Southern U.S.
Authors: Cai Haiya , Tabien Rodante E. , Xu Deze , Harper Chersty L. , Samford Jason , Yang Yuanyuan , You Aiqing , Samonte Stanley Omar P. B. , Holgate Leon , Jiao Chunhai
Published: August 2019

The ratoon rice system is an energy-saving, high-efficiency cultivation method. Harvests from a two-year field trial with a main crop (MC) and a ratoon crop (RC) were used to evaluate milled grain quality traits and yield performance. The results indicated that chalkiness was significantly lower in the RC than in the MC. Chalkiness ranged from 1.90 to 15.01%, with an average of 6.46%, in the MC and from 0.66 to 3.28%, with an average of 1.50%, in the RC across two years. In addition, nearly all of the RC of the test entries had lower white vitreous (higher translucency) than the MC of the same entry. In 6 of the 20 entries, the MC had longer or wider milled grain than the RC in 2017. The milled rice recovery for the MC was higher in both years, but there was no difference in head rice recovery within the same year. The average total yield (MC+RC) in the two years was 12.6 and 13.0 t/ha, and the two-year average RC yields were 47.5 and 37.3% those of the MC. Our results revealed that the RC milled grains showed better appearance quality than the MC grains, and several genotypes had comparable or even better milled grain quality and yield compared with the check entries that were suitable for the ratoon rice system.
Reactive Natural Phosphate in Safflower Fertilization in Cerrado Oxisol
Authors: Bonfim-Silva Edna Maria , Dourado Luana Glaup Araújo , Soares Denise César , Santos Túlio Martinez , Silva Tonny José Araújo da , Fenner William
Published: August 2019

Fertilizer management has a direct influence on crop productivity, especially phosphorus, which is most limiting to the development of crops in tropical soils due to the genesis of these soils. In this sense, it is necessary to use nutrient sources that are agronomically efficient at reduced costs compared to conventional sources. Thus, the objective of the present study was to evaluate the effects of reactive natural phosphate as a source of phosphorus on the development, growth, and yield of safflower in Cerrado Oxisol. The experiment was carried out in a greenhouse at the Federal University of Mato Grosso, Campus of Rondonópolis. The completely randomized design consisted of the following treatments: 0, 100, 200, 400 and 600 mg dm-3 of reactive natural phosphate (Bayóvar reactive phosphate), with 6 replicates, consisting by pots with 2 dm3 of capacity. To the Oxisol used to fill the plots was incorporated dolomitic limestone to increase base saturation to60%. Safflower cultivar used was IMA 0213 with a final population of three plants per plot. Plant height, number of leaves and chlorophyll index were evaluated at 15, 30, 45 and 55 days after emergence. In the last evaluation plants were cut and the number and diameter of the chapters, shoot and chapters dry mass, volume and root dry mass were also evaluated. The results were submitted to analysis of variance and regression up to 10% probability. In general, safflower crop shows a positive response to application of reactive natural phosphate. Doses between 389 and 600 mg dm-3 promoted best results for development and safflower production in an Oxisol.