bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of affect on suboptimal strategy choice in the Monty Hall dilemma
Authors: Efendic Emir , Drace Sasa
Published: June 2015

The Monty Hall dilemma (MHD) presents an intriguing choice anomaly that
offers insight into human reasoning. It presents a specific subclass of
decision tasks that require the adequate use of Bayes theorem in order to
make optimal decisions. In the MHD, participants are presented with three
doors with only one door hiding the prize. After their initial choice of a
door, they are offered additional information. A different door (one that
does not hide the prize and one not chosen by the participant) is opened to
reveal nothing behind it. Afterwards, the participants are offered to stay
with their initial choice or to switch to the other remaining door. The
better strategy is to always switch; a counterintuitive one for most people.
We examine the notorious difficulty of the MHD from an affective perspective
while relying on the dual processing approach to thinking. We varied
participants? reliance on their affective reactions as opposed to a neutral
condition and hypothesized that the affective reactions associated with the
staying option contribute to worse performance on the task. Indeed, the
participants in the affective condition chose the staying option more often
than our control participants. Using the MHD as an appropriate paradigm of
conditional probability reasoning we show that, for this type of task, an
affective strategy is highly inefficient. We attribute these results to the
affective reactions associated with the staying option, with regret avoidance
associated with the switch option, and the conditional probability
construction of the dilemma.
The role of local framework luminance range in the simultaneous lightness contrast illusion with double increments
Authors: Economou Elias
Published: June 2015

In double increment Simultaneous Lightness Contrast two equiluminant squares
rest on darker backgrounds that differ in luminance. Research on such
displays has produced conflicting results as to whether an illusion is
observed. Anchoring theory of lightness predicts no illusion with double
increment displays. Here we test the hypothesis that an illusion can be
predicted if the framework containing the target and the darkest background
carries more weight in lightness computations. We tested two displays, one
with a general white and one with a general black background. An illusion was
obtained only in the first display. These results suggest that an illusion
can occur with double increment displays when the global value of the targets
differs from their local value, as these conditions allow different local
framework weighting to affect the targets? final lightness. We propose that
this parameter be added to the Anchoring Theory.
Selected Aircraft Throttle Controller With Support Of Fuzzy Expert Inference System
Authors: Żurek Józef , Grzesik Norbert , Kurpas Jakub
Published: June 2015

The paper describes Zlin 143Lsi aircraft engine work parameters control support method – hourly fuel flow as a main factor under consideration. The method concerns project of aircraft throttle control support system with use of fuzzy logic (fuzzy inference). The primary purpose of the system is aircraft performance optimization, reducing flight cost at the same time and support proper aircraft engine maintenance. Matlab Software and Fuzzy Logic Toolbox were used in the project. Work of the system is presented with use of twenty test samples, five of them are presented graphically. In addition, system control surface, included in the paper, supports system all work range analysis.
Uncharacteristic Circumferential TMF Cracking in a Heavy-duty Stationary Gas Turbine Engine Burner Outlet
Authors: Neidel A. , Ullrich Th. , Wallich S.
Published: June 2015

Burners are key components of turbomachinery with internal combustion. They allow for a particularly lean combustion in heavy-duty stationary gas turbine engines for power stations and thus contribute significantly to economical operation. Depending on their design, burners are often subject to thermomechanical stress. This failure analysis is concerned with thermal cycling cracks at the burner outlet. Circumferential cracking, parallel to the component surface, is untypical for this damage mechanism. Thermal cycling and thermal-mechanical fatigue cracks usually spread in a radial direction. Possible causes could be the special kind of centrifugal casting structure or the high thermal tension, which might have built up during burner operation.
Antimicrobial property and phytochemical study of ginger found in local area of Punjab, Pakistan
Authors: Riaz Humayun , Begum Almas , Raza Syed Atif , Khan Zia Mohy-Ud-Din , Yousaf Hamad , Tariq Ayesha
Published: June 2015

The aim of study is to identify the antimicrobial property of ginger. Phytochemical screening of chloroform plant extract showed presence of different chemicals. In this study we used Cultures of E. Coli, Bacillus subtilis, Staphylococcus aureus and Streptococcus faecalis to identify the antimicrobial strength. Effectiveness of ginger against different conditions attributed to its different constituents (volatile oils, shogaols, Gingerols and diarylheptanoids) that show their therapeutic efficacy by modulating the genetic or metabolic activities of our body. In this study, we performed phytochemical evaluation and antimicrobial assay of ginger root extract which were available in our local farms of Lahore. Ginger possesses a noticeable antimicrobial activity which was confirmed by checking the susceptibility of different strains of bacteria and fungus by measuring the zone of inhibition. In the light of several socioeconomic factors of Pakistan mainly poverty and poor hygienic condition, present study encourages the use of spices as alternative or supplementary medicine to reduce the burden of high cost, side effects and progressively increasing drug resistance of pathogens.International Current Pharmaceutical Journal, June 2015, 4(7): 405-409
‘On or about December 1910’: F. T. Marinetti's Onslaught on London and Recursive Structures in Modernism
Authors: Wood Jamie
Published: June 2015

Many accounts of the formative years of English modernism rely on Futurism's own questionable record of F. T. Marinetti's visit to London in the spring of 1910 as the catalyst for an avant-garde revolution in Anglo-American literature that led through Roger Fry's revolutionary Post-Impressionist exhibition to Imagism, and onto Vorticism. New evidence presented here, however, supports the position advanced by a number of scholars that Marinetti did not visit until after Fry's exhibition. We can now quite precisely date Marinetti's important ‘Futurist Speech to the English’ to Tuesday 13 December 1910, rather than to the spring of that year as previously thought. Close examination of the content and context of this lecture, to an audience of Suffragettes at the Lyceum Club for Women, highlights the sheer extent of Marinetti's propaganda drive between 1908 and 1910, as he attempted to garner support for his movement and neutralise the satirical attitude of the mainstream English press. Moreover, Futurism, it appears, actively altered the historical record in order to genealogically prioritise itself. Such a process finds itself recursively working back into modernist studies, through a process in which theories of British historical and cultural decline or inferiority, alongside a presupposition of the continental avant-garde's guiding influence, tend to unconsciously take root in studies of literature of this period. In contrast and as illustration, we can find in one of Wyndham Lewis's early essays – previously considered imitative of, but now clearly an influence upon, Marinetti – the extent to which ‘on or about December 1910’ British society and culture was already in the process of radicalizing itself.
‘Prey to Communications’: Samuel Beckett and the Simulation of Psychosis
Authors: Gaedtke Andrew
Published: June 2015

This article examines Beckett's prolonged inquiry into the phenomenological conditions of mental illness. If psychosis initially manifests as an explicit thematic concern in Murphy, it later becomes a formal principle that shapes Beckett's experiments with alternative narrative structures and electronic media. In radio, Beckett finds resources to reproduce for his audience the phenomenological conditions of auditory hallucination and ‘thought transmission’ that his earlier novelistic simulations of madness could only describe. While offering a rationale for the series of formal transformations that structured Beckett's career, this article also examines the convergence of electronic media and psychopathology and their ethical consequences for clinical conceptions of disability and the human.
George Barker in the 1930s: Narcissus and the Autodidact
Authors: Mellor Leo
Published: June 2015

This article traces the complex and potent role of classical mythology in the poet George Barker's work of the 1930s. Noting Geoffrey Grigson's rage about ‘narcissism’ when reviewing Barker in 1935 it shows why this barb was more perceptive and apposite – in acknowledging an obsession with both a figure and an overtly classical precedent – than the acclamation given to Barker at the time, from T. S. Eliot among others. Central to the article is an exploration of Barker's heterodox version of a common modernist urge: encountering and reworking of fractured myths. For the radical and ever-present notions of uncertainty with which classical tales and Gods are treated in Barker's work is also revelatory of the autodidactic process – incomplete, unstable, and without class-annotated cultural authority – by which he gained such knowledge. The article thus situates Barker within a cultural matrix, and draws renewed attention to the pluralities of poetry within 1930s Britain.
Aux marges du domaine de Neptune : quelques évolutions géopolitiques récentes des littoraux maritimes (At the margins of Neptun's area : some recent geopolitical evolutions of maritime coasts)
Authors: Sanguin André-Louis , Marchand Hélène
Published: June 2015

Abstract. - The new Law of the Sea, generated by the Montego Bay Convention (1982), significantly strenghtened the geopolitical role of maritime coastlines. Henceforth, these latter are used as pins for the 200 miles zone's demarcation. This new context is generating some major consequences which are scrutinized within this paper. There is a contradiction of extended coastal juridiction on the one hand and the need for even greater international cooperation in ocean matter on the other.
Un exemple d'organisation géopolitique à l'échelle européenne : l'Arc Manche (A new euroregion in the new Europe : the Arc Manche)
Authors: Chable Eric
Published: June 2015

Résumé. - L'Arc Manche cherche à faire revivre l'aventure du royaume anglo-normand. Il s'inscrit parmi les projets transfrontaliers favorisés par l'intégration européenne. Il donne à chaque littoral, l'espace stratégique pour se dégager de l'emprise des deux capitales.
La géomorphologie des origines à nos jours : une science jeune arrivée à maturité (Geomorphology from the origin to the present time)
Authors: Battiau-Queney Yvonne
Published: June 2015

Résumé. - La géomorphologie est apparue dans la deuxième moitié du XIXe siècle comme une branche de la géologie. Elle devint, avec Davis, une discipline géographique fondée sur un modèle d'évolution du relief à valeur universelle. De la seconde guerre mondiale aux années 70, la géomorphologie bénéficia d'un renouvellement méthodologique et conceptuel, avec l'apparition simultanée d'une géomorphologie climatique, d'une géomorphologie quantitative et d'une géomorphologie dynamique. La France participe activement au premier courant, un peu moins aux deux autres qui connaissent un succès foudroyant au Royaume-Uni. A partir des années 80, la géomorphologie s 'affirme comme une science autonome, une science de la nature avec un objet et des méthodes propres. Ses liens avec la géologie et la géographie restent plus ou moins étroits selon les pays. On assiste à une explosion de travaux de géomorphologie dynamique, à la généralisation de l 'approche systémique, au renouveau d'une géomorphologie structurale influencée par la Tectonique des Plaques. Science utile à l'homme dans ses relations avec son environnement, elle est étroitement liée à l'approche géographique, mais par les dimensions temporelles et spatiales de son domaine d'étude, et la nature scientifique de ses méthodes d'analyse, elle déborde largement le champ de la géographie.
Plastid primers for angiosperm phylogenetics and phylogeography
Authors: Prince Linda M.
Published: June 2015

Premise of the study:

PCR primers are available for virtually every region of the plastid genome. Selection of which primer pairs to use is second only to selection of the genic region. This is particularly true for research at the species/population interface.

Methods:

Primer pairs for 130 regions of the chloroplast genome were evaluated in 12 species distributed across the angiosperms. Likelihood of amplification success was inferred based upon number and location of mismatches to target sequence. Intraspecific sequence variability was evaluated under three different criteria in four species.

Results:

Many published primer pairs should work across all taxa sampled, with the exception of failure due to genomic reorganization events. Universal barcoding primers were the least likely to work (65% success). The list of most variable regions for use within species has little in common with the lists identified in prior studies.

Discussion:

Published primer sequences should amplify a diversity of flowering plant DNAs, even those designed for specific taxonomic groups. “Universal” primers may have extremely limited utility. There was little consistency in likelihood of amplification success for any given publication across lineages or within lineage across publications.
Next‐generation sampling: Pairing genomics with herbarium specimens provides species‐level signal in Solidago (Asteraceae)
Authors: Beck James B. , Semple John C.
Published: June 2015

Premise of the study:

The ability to conduct species delimitation and phylogeny reconstruction with genomic data sets obtained exclusively from herbarium specimens would rapidly enhance our knowledge of large, taxonomically contentious plant genera. In this study, the utility of genotyping by sequencing is assessed in the notoriously difficult genus Solidago (Asteraceae) by attempting to obtain an informative single‐nucleotide polymorphism data set from a set of specimens collected between 1970 and 2010.

Methods:

Reduced representation libraries were prepared and Illumina‐sequenced from 95 Solidago herbarium specimen DNAs, and resulting reads were processed with the nonreference Universal Network‐Enabled Analysis Kit (UNEAK) pipeline. Multidimensional clustering was used to assess the correspondence between genetic groups and morphologically defined species.

Results:

Library construction and sequencing were successful in 93 of 95 samples. The UNEAK pipeline identified 8470 single‐nucleotide polymorphisms, and a filtered data set was analyzed for each of three Solidago subsections. Although results varied, clustering identified genomic groups that often corresponded to currently recognized species or groups of closely related species.

Discussion:

These results suggest that genotyping by sequencing is broadly applicable to DNAs obtained from herbarium specimens. The data obtained and their biological signal suggest that pairing genomics with large‐scale herbarium sampling is a promising strategy in species‐rich plant groups.
Properties of PTFE tape as a semipermeable membrane in fluorous reactions
Authors: Parsons Brendon A , Smith Olivia Lin , Chae Myeong , Dragojlovic Veljko
Published: June 2015

In a PTFE tape phase-vanishing reaction (PV-PTFE), a delivery tube sealed with PTFE tape is inserted into a vessel which contains the substrate. The reagent diffuses across the PTFE tape barrier into the reaction vessel. PTFE co-polymer films have been found to exhibit selective permeability towards organic compounds, which was affected by the presence of solvents. In this study, we attempted to establish general trends of permeability of PTFE tape to different compounds and to better describe the process of solvent transport in PV-PTFE bromination reactions. Though PTFE tape has been reported as impermeable to some compounds, such as dimethyl phthalate, solvent adsorption to the tape altered its permeability and allowed diffusion through channels of solvent within the PTFE tape. In this case, the solvent-filled pores of the PTFE tape are chemically more akin to the adsorbed solvent rather than to the PTFE fluorous structure. The solvent uptake effect, which was frequently observed in the course of PV-PTFE reactions, can be related to the surface tension of the solvent and the polarity of the solvent relative to the reagent. The lack of pores in bulk PTFE prevents solvents from altering its permeability and, therefore, bulk PTFE is impermeable to most solvents and reagents. However, bromine, which is soluble in liquid fluorous media, diffused through the bulk PTFE. A better understanding of the PTFE phase barrier will make it possible to further optimize the PV-PTFE reaction design.
MODEL OF EMPLOYEES MOTIVATION THROUGH GAMIFICATION OF INFORMATION SYSTEM / DARBUOTOJŲ MOTYVAVIMO ŽAIDYBINIMO PRIEMONĖMIS INFORMACINĖJE SISTEMOJE MODELIS
Authors: Kostecka Jolanta , Davidavičienė Vida
Published: June 2015

In this article the problem of motivation of employees, who are working with information system and whose work environment is full of monotonous, boring and repetitive tasks, is analyzed. On the basis of literature, theoretical aspects of work motivation are analyzed and it is suggested to use gamification in order to solve this problem. On the basis of literature, theoretical and practical aspects of motivation of gamers and gamification are analyzed. After all, it is suggested to use model which joins main aspects of employee needs and gamification. Through example of accounting specialists the offered model is used in practice. Based on the results of the research, opportunities of motivating accounting specialists through gamification of information system are evaluated. Šiame darbe yra nagrinėjama darbuotojų, kurie dirba su informacinėmis sistemomis ir kurių darbo aplinka yra monotoniška ir perkrauta nuobodžiais, pasikartojančiais veiksmais, motyvavimo problematika. Remiantis užsienio ir Lietuvos autorių literatūra, išanalizuojami teoriniai darbo motyvavimo aspektai ir pasiūloma šią problemą spręsti žaidybinimo priemonėmis. Žaidybinimas yra palyginus naujas reiškinys, todėl remiantis užsienio autorių literatūra, išanalizuojami teoriniai žaidėjų motyvavimo ir žaidybinimo aspektai. Remiantis darbuotojų poreikių ir žaidybinimo pagrindiniais aspektais, pasiūlomas modelis. Praktinis modelio pritaikymas demonstruojamas pasitelkiant buhalterinės apskaitos specialistų pavyzdį. Remiantis tyrimo rezultatais, įvertinamos buhalterinės apskaitos specialistų motyvavimo žaidybinimo priemonėmis informacinėje sistemoje galimybės.
Helmut Thielicke, théologien du compromis
Authors: Greiner Dominique
Published: June 2015

Grande figure de l’Allemagne d’après-guerre, le théologien luthérien Helmut Thielicke accorde une place importante à la catégorie de compromis dans sa monumentale Ethique théologique . Elle permet, selon lui, de faire le pont entre la normativité des commandements divins et le devenir historique de l’homme, sans tomber dans le relativisme. Après une présentation du projet théologique de Thielicke dans le champ de l’éthique, cet article analyse son interprétation théologique du compromis qui tente de maintenir la radicalité des exigences divines telles qu’elles sont exprimées dans le Sermon sur la montagne.
Revision and Psychometric Testing of the Incivility in Nursing Education (INE) Survey: Introducing the INE-R
Authors: Clark Cynthia M. , Barbosa-Leiker Celestina , Gill Larecia Money , Nguyen Danh
Published: June 2015

Background:

Academic incivility is a serious challenge for nursing education, which needs to be empirically measured and fully addressed.

Method:

A convenience sample of nursing faculty and students from 20 schools of nursing in the United States participated in a mixed-methods study to test the psychometric properties of the Incivility in Nursing Education-Revised (INE-R) Survey.

Results:

A factor analysis and other reliability analyses support the use of the INE-R as a valid and reliable measurement of student and faculty perceptions of incivility in nursing education.

Conclusion:

The INE-R is a psychometrically sound instrument to measure faculty and student perceptions of incivility; to examine differences regarding levels of nursing education, program type, gender, age, and ethnicity; to compare perceptions of incivility between and among adjunct, clinical, teaching, and research faculty; and to conduct pre- and postassessments of the perceived levels of faculty and student incivility in nursing programs to inform evidence-based interventions. [
J Nurs Educ.
2015;54(6):306–315.]
Effects of a Community-Based Hospice Experience on Attitudes and Self-Perceived Competencies of Baccalaureate Senior Nursing Students
Authors: Gilliland Irene
Published: June 2015

Background:

Educational programs preparing nurses have devoted little time in the curricula to the care of the dying patient and the grieving family.

Method:

An experimental design was used to determine the effects of a 2-day hospice experience on the attitudes and competencies of 61 baccalaureate nursing students enrolled in their final semester. Measures included an end-of-life attitudes survey, an end-of-life competency survey, and student reflections.

Results:

Mean scores changed significantly after the hospice experience, suggesting a positive attitude change as a result of the intervention. Although mean scores in competency changed, these were not statistically significant. Student reflections supported attitude changes about end-of-life care and improved competencies.

Conclusion:

Although the experience seemed to make a difference, larger samples and longer exposure to the care of the dying are needed to more accurately assess the impact of a hospice experience on student attitudes and competencies related to end-of-life care. [
J Nurs Educ
. 2015;54(6):335–338.]
Axial Globe Length in Congenital Ptosis
Authors: Takahashi Yasuhiro , Kang Hyera , Kakizaki Hirohiko
Published: June 2015

Purpose:

To compare axial globe length between affected and unaffected sides in patients with unilateral congenital ptosis.

Methods:

This prospective observational study included 37 patients (age range: 7 months to 58 years). The axial globe length, margin reflex distance-1 (MRD-1), and refractive power were measured. The axial globe length difference was calculated by subtracting the axial globe length on the unaffected side from that of the affected side. The relationships among axial globe length differences, MRD-1 on the affected sides, and patient ages were analyzed using multiple regression analysis.

Results:

No significant differences were found in the axial globe length between sides (
P
= .677). The axial globe length difference was 0.17 ± 0.30 mm (mean ± standard deviation), and two patients (5.4%), aged 32 to 57 years, showed axial globe length more than 0.67 mm longer (corresponding to a refractive power of 2 diopters) on the affected side compared to the unaffected side. The multiple regression model between axial globe length difference, patient age, and MRD-1 on the affected sides was less appropriate (Y
AGL
= 0.003X
AGE
−0.048X
MRD-1
+0.112;
r
= 0.338; adjusted
r
2
= 0.062;
P
= .127). The cylindrical power was greater on the affected side (
P
= .046), although the spherical power was not different between sides (
P
= .657).

Conclusions:

No significant difference was identified in the axial globe length between sides, and only 5% of non-pediatric patients showed an axial globe length more than 0.67 mm longer on the affected side. Congenital ptosis may have little effect on axial globe length elongation, and the risk of axial myopia-induced anisometropic amblyopia may be low in patients with unilateral congenital ptosis.

[
J Pediatr Ophthalmol Strabismus
. 2015;52(3):177–182.]
En Face Optical Coherence Tomography for Visualization of the Choroid
Authors: Savastano Maria Cristina , Rispoli Marco , Savastano Alfonso , Lumbroso Bruno
Published: June 2015

BACKGROUND AND OBJECTIVE:

To assess posterior pole choroid patterns in healthy eyes using en face optical coherence tomography (OCT).

PATIENTS AND METHODS:

This observational study included 154 healthy eyes of 77 patients who underwent en face OCT. The mean age of the patients was 31.2 years (standard deviation: 13 years); 40 patients were women, and 37 patients were men. En face imaging of the choroidal vasculature was assessed using an OCT Optovue RTVue (Optovue, Fremont, CA). To generate an appropriate choroid image, the best detectable vessels in Haller’s layer below the retinal pigment epithelium surface parallel plane were selected.

RESULTS:

Images of diverse choroidal vessel patterns at the posterior pole were observed and recorded with en face OCT. Five different patterns of Haller’s layer with different occurrences were assessed. Pattern 1 (temporal herringbone) represented 49.2%, pattern 2 (branched from below) and pattern 3 (laterally diagonal) represented 14.2%, pattern 4 (doubled arcuate) was observed in 11.9%, and pattern 5 (reticular feature) was observed in 10.5% of the reference plane.

CONCLUSION:

In vivo assessment of human choroid microvasculature in healthy eyes using en face OCT demonstrated five different patterns. The choroid vasculature pattern may play a role in the origin and development of neuroretinal pathologies, with potential importance in chorioretinal diseases and circulatory abnormalities.

[
Ophthalmic Surg Lasers Imaging Retina
. 2015;46:561–565.]
Strategic Behavior of Firms in Differentiated Oligopoly
Authors: Rao T.V.S. Ramamohan
Published: June 2015

In the context of differentiated oligopoly each firm attempts to pursue a predefined goal (such as price-cost margins, market share, dominant product line etc) and endeavors to achieve it through a specific strategy (price, advertising or any other aspect of its supply chain). That is, each firm attempts to achieve a monopoly and operate in its own niche. Contemporary studies of monopoly power concentrate on the consequences of strategic choices alone. The present study offers an algorithmic approach from a behavioral perspective to the identification of non-price strategies and objectives of individual firms that confer it a monopoly. “And as regards practically all the finished products and services of industry and trade, it is clear that every grocer, every filling station, every manufacturer of gloves or shaving cream or handsaws has a small and precarious market of his own which he tries – must try – to build up and to keep by price strategy, quality strategy – ‘product differentiation' – and advertising” – Schumpeter (1950, p. 79).
Indexing Musical Sequences in Large Datasets Using Relational Databases
Authors: Charapko Aleksey , Chuan Ching-Hua
Published: June 2015

This paper proposes and tests models that provide quick searching and retrieval of continuations and the longest repeated suffix for data sequences, particularly musical data, using relational databases. The authors extend existing interactive music-generation systems by focusing on large input sequences. Algorithms for indexing prefix trees and factor oracles in relational databases are also proposed. Experiments using textual and musical data provide satisfactory performance results for the models using the two indexing methods.
A Combination of Spatial Pyramid and Inverted Index for Large-Scale Image Retrieval
Authors: Nguyen Vinh-Tiep , Ngo Thanh Duc , Tran Minh-Triet , Le Duy-Dinh , Duong Duc Anh
Published: June 2015

Large-scale image retrieval has been shown remarkable potential in real-life applications. The standard approach is based on Inverted Indexing, given images are represented using Bag-of-Words model. However, one major limitation of both Inverted Index and Bag-of-Words presentation is that they ignore spatial information of visual words in image presentation and comparison. As a result, retrieval accuracy is decreased. In this paper, the authors investigate an approach to integrate spatial information into Inverted Index to improve accuracy while maintaining short retrieval time. Experiments conducted on several benchmark datasets (Oxford Building 5K, Oxford Building 5K+100K and Paris 6K) demonstrate the effectiveness of our proposed approach.
Effect of Silicon Carbide (SiC) on Stir Cast Aluminium Metal Matrix Hybrid Composites – A Review
Authors: Velavan K. , Palanikumar K.
Published: June 2015

Nowadays, the usage of metal matrix composites is increased in aero space, automotive, marine, electronic and manufacturing industries. Aluminum metal matrix composites have attained significant attention due to their good mechanical properties like strength, stiffness, abrasion and impact resistant, corrosion resistance. When compared to the conventional materials Aluminum Silicon Carbide (AlSiC) hybrid materials available in minimum cost. In the present study, based on the literature review, the individual Silicon Carbide with aluminum and combined influence of Silicon Carbide with graphite reinforcements Aluminium Metal Matrix Composites and Silicon Carbide with mica reinforcement Aluminum is studied. The monolithic composite materials are combined in different compositions by stir casting fabrication techniques, to produce composite materials. The literature review framework in this paper provides a clear overview of the usage of Graphite and Mica as a reinforcing agent in different composition matrices along with its distinctive performances.
Hybrid Nanocomposites – A Review
Authors: Koilraj T. Thomas , Kani Kalaichelvan
Published: June 2015

Since the last ten years, research happenings in the field of nanomaterials have been increased dramatically. Materials scientists and researchers have realized that the mechanical properties of materials can be altered at the fundamental level, i.e. at the atomic-scale. Carbon nanotubes have been well recognized as nanostructural materials that can be used to modify mechanical, thermal and electrical properties of polymer-based composite materials, because of their excellent properties and perfect atom arrangement. In geneal, scientific research related to the nanotubes and their co-related polymer based composites can be distinguished into four particular scopes: (i) production of high purity and well-regulated nanotubes, in terms of their size, length and chiral arrangement; (ii) enhancement of interfacial bonding strength between the nanotubes and their surrounding matrix; (iii) control of the dispersion properties and alignment of the nanotubes in nanotube/polymer composites and (iv) applications of the nanotube in real life. Research shows that addition of resin with nanoclays permits to retain stiffness without losing toughness, and also improving barrier and thermal properties. Dynamic Mechanical Analysis (DMA) studies revealed that filling the carbon nanotube into epoxy can produce a 90% enhancement in storage modulus and a 22°C increase in Tg. Addition of nanoclay and epoxy with nanotubes forms a hybrid nanocomposite.
Laser Assisted Brazing of Ceramic and Titanium Alloy Using Cu-Ag Filler Material
Authors: Mohan H.S. , Bharathesh T.P. , Sreenivas Rao K.V. , Beeranur Ravikumar
Published: June 2015

The joining of ceramic to structural alloys has received much attention in recent years because of its potentially attractive properties. In the present investigation alumina which is a ceramic has been brazed with titanium alloy (Ti6Al4V) using KM72(Ag/Cu) filler material.The study has been carried out using CO2 laser gas in argon inert atmosphere. Uniformity of the brazed joints has been observed in scanning electron micrographs. The elements and phases present at the joint interface have been characterized by EDX and XRD spectra analysis. As per the experimental observation, the phases present in the Ti6Al4V/KM72/alumina joint are Cu3TiO4, Cu3Ti2,CuO, Ti2Cu, CuTi, and Cu4Ti3. The effect of brazing process parameters on the shear strength of the brazed joint has been studied and maximum shear strength observed at brazing power of 330 watts and speed 300 mm/min is 4±0.5MPa. Micro-hardness values of the brazed interface indicate that the interface is softer than the substrate.
Roundness Error Evaluation in Drilling of Glass Fiber Reinforced Polypropylene (GFR/PP) Composites Using Box Behnken Design (BBD)
Authors: Srinivasan T. , Palanikumar K. , Rajagopal K.
Published: June 2015

In this paper, the damage of drilling parameters on roundness error is investigated in drilling of Glass Fiber Reinforced Polypropylene (GFR/PP) matrix composites with ‘Brad and Spur’ drill bit. The experiment is carried out using Solid Carbide drill bit and L27 orthogonal array is used to analyze the effect of spindle speed, feed rate and drill diameter. A complete and in-detail evaluation and optimization of cutting parameter using Box-Behnken Design (BBD) technique is carried out. The design is contributed for quality and productivity equally and analysis of the drilling parameters. The roundness error is determined using response surface methodology (RSM) and Analysis of variance (ANOVA) which is used for analyzing the output results. One of the most important ovalty damage to be controlled on a cylindrical drilled part is the roundness error. The Co-ordinate Measuring Machine (CMM) is the general metrological equipment used for inspection of roundness error which is normally performed in a quality room. The results indicated that the model can be effectively used for predicting the response variable by means of which roundness error can be controlled. 3-D response surface graphs are developed to study the effect of drilling parameters with roundness error and presented in detail.
An Investigation of the Influences of EDM Parameters and Tool Geometries on Radial Overcut for Monel 400 Material with Tungsten Copper Electrode
Authors: Padmini P. , Senthamilperarasu S. , Shanmuganathan B. , Anbusagar N.R.R. , Sengottuvel P.
Published: June 2015

Electrical-discharge Machining (EDM) is a nonconventional machining process utilizing an electric spark discharge from the electrode (-) towards the work piece (+) through the dielectric fluid. The Dimensional accuracy in this is very important consideration for the accuracy of the finished product. The objective of this experimental study is to determine parameters that offer the best dimensional accuracy in electrical discharge machining (EDM). Discharge current (A), Pulse On Time (Ton), Pulse Off Time (Toff ) and Circle,Rectangle,Triangle and Square Tool Geometrical Shapes (Geo) are taken as machining parameters. The experimental investigations are carried out on Monel 400 material using Tungsten copper electrode. The response of ROC is considered for improving the machining efficiency. Optimal combination of parameters was obtained Taguchi Optimization technique. The confirmation experiments results shows that the significant improvement in Radial Overcut was obtained. ANOVA have been used to analyze the contribution of individual parameters on ROC. The experimental result demonstrates that the Taguchi method satisfies the practical requirements
A Study of N-Isopropyl Acrylamide (NIPAM)-Based Polymer Gel Dosimeter by Using Raman Spectroscopy
Authors: Adenan Mohd Zulfadli , Ahmad Mansor , Mohd Noor Noramaliza , Saion Elias
Published: June 2015

Polymer gel is a kind of radiation dosimetry system that has been applied widely in radiotherapy treatment. In this study, the samples of NIPAM-based polymer gel which posses a good potential as 3D radiation dosimetry are synthesized. The samples of polymer gel were irradiated up to 20 Gy by using gamma cell instrument with 60Co sources at a constant dose rate. Upon irradiation, then the chemical changes in polymer gel were characterized by using Raman spectroscopy. The polymerization was referred to an increment in Raman intensity at 815 cm-1, assigned for C-C stretching mode of NIPAM polymer gel, as the dose increased. The consumptions of the co-monomers were referred to a decrement in Raman intensities at 1025 cm-1 and 2353 cm-1 assigned for C=C stretching modes of NIPAM and BIS respectively, as the dose increased. Result shows that the amount of carbon single bonds increases while the amount of carbon covalent bonds decreases following irradiation.
Characterizations and Morphology of MWCNTs-SiC Nanoparticles Reinforced PLA/NR/LENR Composites
Authors: Tarawneh Mou'ad A. , Ahmad Sahrim Haji , Hassan Ibrahim N. , Chen Ruey Shan , Al-Banawi O.
Published: June 2015

This paper reports on the mechanical and morphological properties of polylactic acid (PLA)/Natural rubber (NR) composite reinforced by multi-walled carbon nanotubes (MWCNTs) and nano-silicon carbide (SiC) particles. Their properties in relation to optimal particle content are discussed. The pure composite is a blend of PLA/NR and liquid epoxidised natural rubber (LENR), which is used as a compatibilizer at a percentage of volume ratios 60:30:10 respectively. The nanocomposites were with various MWCNTs-SiC compositions. The results extracted from flexural test showed that the bending modulus and bending strength of a 3wt % MWCNTs reinforced sample increase as compared with the pure PLA/NR sample and other nanocomposites. The improved dispersion properties was due to altered interparticle interactions, MWCNTs, SiC and MWCNTs-SiC networks that combined to generate a synergistic effect that is shown by SEM micrographs.
Complex Impedance Spectroscopy Studies of BaTiO3 Ceramic with 10% BaFe12O19 Substitution
Authors: Zalita Zainuddin , Anuar S.N. , Shamsudin Roslinda , Idris M.N.
Published: June 2015

Barium titanate with 10% barium ferrite substitution (BaTiO3-BaFe12O19) has been synthesized by the solid state reaction route. Formation of the BaFe12O19 phase confirmed its existence in the composite. Impedance spectroscopy study of the composite sample was performed at different temperatures of 25, 40, 80, 120 and 160 °C. BaFe12O19 substituted sample shows a single semicircle at lower temperature and two overlapped arcs at 120 and 160 °C due to grain and grain boundary. The impedance plots were fitted based on a parallel R-CPE circuit. The grain boundary resistance behaves like the positive temperature coefficient of resistivity (PTCR) for donor-doped BaTiO3 semiconductor. The highest capacitance is contributed by the grain boundary at 80 °C.
Effects of Acid Modified SiO2 on Ionic Conductivity and Blend Properties of LiBF4 Doped PMMA/ENR 50 Electrolytes
Authors: Sharil Fadli Mohamad Zamri , Famiza Abdul Latiff
Published: June 2015

Previously, it was found that the addition of SiO2 filler can improve the homogeneity and enhance the ionic conductivity of lithium tetrafluoroborate (LiBF4) doped polymethyl methacrylate/50 % epoxidized natural rubber (PMMA/ENR 50) blend from 6.21 x 10-7 Scm-1 to 5.26 x 10-6 Scm-1. Unfortunately, this SiO2 filler tend to agglomerates thus obstructing the smoothness in the transportation of lithium ion in the polymer blend matrix. This unruly phenomenon was due to the formation of hydrogen bonding between the oxygen atom of SiO2 and the hydrogen atom from the moisture. Therefore, in this study, this SiO2 filler was modified using hydrochloric acid (HCl) to reduce the formation of hydrogen bonding between SiO2 and moisture. It was found that the modification was able to reduce the hydrogen bond in SiO2 filler. The CHNS analysis shows that the percentage of hydrogen reduces as concentration of acid increased. This was further confirmed from the FT-IR analysis in which the peak corresponding to Si-OH was reduces meanwhile the peaks corresponding to Si-O-Si increases as HCl concentration increased. As a result, the homogeneity of the blends was further improved. However, the ionic conductivity of the system was found slightly reduce by few magnitudes. Temperature dependence ionic conductivity of LiBF4 doped PMMA/ENR 50 filled HCl-SiO2 electrolytes shows nonlinear trend indicates that the system not obeys Arrhenius equation.
Effects of Bu3MeNTf2N Ionic Liquid Addition on Conductivity of PVC-NH4Tf Polymer Electrolytes
Authors: Yahaya Subhan Ri Hanum , Deraman S.K. , Mohamed Nor Sabirin
Published: June 2015

Solid polymer electrolytes (SPEs) with poly (vinyl) chloride (PVC) doped with a fixed amount of ammonium trifluoro methane sulfonate (NH4Tf) and with varying concentrations of ionic liquid butyltrimethyl ammonium bis (trifluoromethyl sulfonyl) imide (Bu3MeNTf2N) were synthesised via solution cast technique. PVC-NH4Tf-Bu3MeNTf2N-based SPEs with 15 weight % Bu3MeNTf2N exhibit conductivity of 1.56 x 10-4 Scm-1 at room temperature. The ionic conductivity is attributed to the dissociation of NH4Tf facilitated by Bu3MeNTf2N. Results of XRD indicate that the most amorphous film has the highest conductivity and this is corroborated by the results of DSC. FTIR spectra revealed that Bu3MeNTf2N has weak interaction suggesting that it acts mainly as a lubricant to facilitate polymer segmental motion.
Effects of Different Concentration in (w/v)% of Carboxymethyl Iota-Carrageenan Based Green Polymer Electrolyte
Authors: Jumaah Fatihah Najirah , Ahmad Azizan , Hanibah Hussein , Mobarak Nadhratun Naiim , Ghani M.A.
Published: June 2015

The effect of different concentrations in weight per volume percentage, (w/v)% of iota-carrageenan and carboxymethyl-iota carrageenan used as the green polymer electrolyte has been studied. The polymer electrolyte films were prepared by solution casting technique. Different concentration in the range from 1.0 – 6.0 (w/v)% were dissolved in fix volume of acetic acid which act as solvent. The films have been analyzed through attenuated Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) measurement and electrochemical impedance spectroscopy (EIS). The EIS results showed that the ionic conductivity increased as the concentration of the polymer increases. In comparison between iota-carrageenan and carboxymethyl iota-carrageenan, carboxymethyl-iota carrageenan showed better results due to the presence of more active site. The highest conductivity achieved by iota-carrageenan and carboxymethyl iota-carrageenan were 3.45 × 10-6 S cm-1 and 9.57 × 10-4 S cm-1 at the concentration 3.0 and 4.0 (w/v)% , respectively. From the FTIR spectra, it depicts that the intensity of significant peaks of ether and carboxylate group increases as the concentration of polymer increases. The XRD analysis showed that as the concentration of polymer increase, the amorphous region in the films would be enhanced. This study showed that the concentration play significant role in the ionic conductivity improvement.
Ionic Conductivity and Dielectric Properties of CMC Doped NH4SCN Solid Biopolymer Electrolytes
Authors: Noor N.A.M. , Isa M.I.N.
Published: June 2015

In this work, solid biopolymer electrolytes (SBE) containing carboxymethyl cellulose (CMC) doped with ammonium thiocyanate (NH4SCN) were prepared via solution casting method. The ionic conductivity and dielectric properties of CMC-NH4SCN system were investigated by electrical impedance spectroscopy in the temperature range of 303-353 K. The dc conductivity shows that the highest ionic conductivity of 6.48 x 10-5 Scm-1 at ambient temperature was obtained when 25 wt.% of NH4SCN was incorporated. The temperature dependence of ionic conductivity revealed that CMC-NH4SCN system was discovered to obey Arrhenius law where the regression value is almost unity (R2≈1). Activation energy of CMC-NH4SCN system was found to decrease with the increment of NH4SCN concentration. The dielectric behaviour of the CMC-NH4SCN system have been analyzed using dielectric permittivity (ε*) and electrical modulus (M*) spectra. Results from dielectric studies showed a non-Debye behaviour of CMC-NH4SCN system.
Fabrication and Electrical Properties of Strontium Doped Lanthanum Manganite Titanite Oxide
Authors: Mohd Hanif Siti Hashimah , Primus Walter Charles , Shaari Abdul H. , Hassan Jumiah
Published: June 2015

Composition of La0.7Sr0.3Mn0.4Ti0.6 O3 has been prepared using solid state reaction method where its crystal structure and electrical properties has been analyzed using X-ray Diffractometer (XRD) and Low frequency LCR meter, respectively. The result, shows that the sample has cubic perovskite structure with the existence of impurities phase. In electrical measurement, the frequency dependence of complex capacitance plot shows the sample have strong dispersion at lower frequency and the impedance plane plot shows a semicircle due to the grain effect. The sample electrical properties are also represented in equivalent electrical circuit which consists of a quasi d.c and in parallel with conductance.
Surface States and Band Gap Correlation in Silicon Nanoclusters
Authors: Ghoshal Sib Krishna , Sahar M.R. , Arifin R. , Rohani M.S. , Hamzah K.
Published: June 2015

Tuning the visible emission of Si nanomaterials by modifying their size and shape is one of the key issue in optoelectronics. The observed optical gain in Si-nanoclusters (NCs) has given further impulse to nanosilicon research. We develop a phenomenological model by combining the effects of surface passivation, exciton states and quantum confinement (QC). The size and passivation dependent band gap, oscillator strength, radiative lifetime and photoluminescence (PL) intensity for NCs with diameter ranging from 1.0 to 6.0 nm are presented. By controlling a set of fitting parameters, it is possible to tune the optical band gap, PL peak and intensity. In case of pure clusters, the band gap is found to decrease with increasing NC size. Furthermore, the band gap increases on passivating the surface of the cluster with hydrogen and oxygen respectively in which the effect of oxygen is more robust. Both QC and surface passivation in addition to exciton effects determine the optical and electronic properties of silicon NCs. Visible luminescence is due to radiative recombination of electrons and holes in the quantum-confined NCs. The role of surface states on the band gap as well as on the HOMO-LUMO states is also examined and a correlation is established. Our results are in conformity with other observations. The model can be extended to study the light emission from other nanostructures and may contribute towards the development of Si based optoelectronics.
Chemical Surface Modification of CNTs via Three Oxidative Acid Treatments
Authors: Gindana Bryan , Jamil Arvyvie Abie , Bernard Brian Brandon , Tan Florinna , Aishah M.A. Siti , Asik Jahimin A. , Idris Rubia
Published: June 2015

Carbon nanotubes are commonly used to create polymer-nanotube composite for various applications. To suffice the needs of the emerging interest in utilizing nanotube, a great concern in creating a stable dispersion of the nanotube in solvent emerged. There is a paramount need to enhance the adhesion between the polymer and carbon nanotube to give a homogenous and stable dispersion throughout the polymer matrix. Thus, oxidative acid treatments are often chosen to chemically functionalize carbon nanotube in order to give such dispersing ability to the nanomaterials. In this study, purified multi-walled carbon nanotubes (MWCNTs) is oxidized under the influence of three types of oxidants i) hydrogen peroxide, ii) citric acid monohydrate and iii) mixture of 3:1 sulphuric and nitric acid. All the MWCNTs suspensions ultrasonicated for 8 hours to create opening defects on the MWCNTs to allow the surface modification to occur. In this comparative study of chemically surface modification using oxidative acid treatments, FTIR was used to examine the formation of -OH, -COOH and -C=O groups on the surface of the MWCNTs, TGA and XRD used to determine the thermal behaviour and the crystal structure studies of the modified MWCNTs respectively.