bluuebunny/crossref_metadata_2025 huggingface dataset:
THE INTERNATIONALIZATION OF SMALL AND MEDIUM ENTERPRISES AND HUMAN CAPITAL / MAŽŲ IR VIDUTINIŲ ĮMONIŲ INTERNACIONALIZACIJA IR ŽMOGIŠKASIS KAPITALAS
Authors: Godelytė Laura , Korsakiene Renata
Published: June 2015

Small and medium enterprises (SME’s) are generally recognised as a factor, which influences economic growth and impacting competitiveness of country. In the context of globalization the impact of internationalization of SME’s is increasing and determines development of new technologies. The internationalization of SME’s is determined to a large extent by the human capital of entrepreneurs/managers. The aim of this article is to analyse and summarise elements of human capital, that are discussed in scientific literature and to distinguish the most important for SME’s internationalization. The research is based on the evaluation of human capital in scientific literature and analysis and synthesis of questions of SME’s internationalization. Mažos ir vidutinės įmonės yra visuotinai pripažįstamos kaip ekonominį augimą lemiantis veiksnys, turintis poveikį šalies konkurencingumo didinimui. Globalizacijos kontekste didėja MVĮ internacionalizacijos vaidmuo, lemiantis naujų technologijų plėtojimą. MVĮ internacionalizaciją stipriai įtakoja savininkų / vadovų turimas žmogiškasis kapitalas. Šiame straipsnyje siekiama išanalizuoti ir apibendrinti mokslinėje literatūroje aptinkamus žmogiškojo kapitalo elementus bei išskirti svarbiausius MVĮ internacionalizacijai. Atliktas tyrimas yra pagrįstas mokslinės literatūros žmogiškojo kapitalo vertinimo ir MVĮ internacionalizacijos klausimais analize bei sinteze.
LITHUANIAN POPULATION AGING FACTORS ANALYSIS / LIETUVOS GYVENTOJŲ SENĖJIMĄ LEMIANČIŲ VEIKSNIŲ ANALIZĖ
Authors: Garlauskaitė Agnė , Zabarauskaitė Rasa
Published: June 2015

The aim of this article is to identify the factors that determine aging of Lithuania’s population and to assess the influence of these factors. The article shows Lithuanian population aging factors analysis, which consists of two main parts: the first describes the aging of the population and its characteristics in theoretical terms. Second part is dedicated to the assessment of trends that influence the aging population and demographic factors and also to analyse the determinants of the aging of the population of Lithuania. After analysis it is concluded in the article that the decline in the birth rate and increase in the number of emigrants compared to immigrants have the greatest impact on aging of the population, so in order to show the aging of the population, a lot of attention should be paid to management of these demographic processes.
Darbo tikslas – nustatyti, kokie veiksniai lemia Lietuvos gyventojų senėjimą ir įvertinti tų veiksnių įtaką. Straipsnyje atliekamą Lietuvos gyventojų senėjimą lemiančių veiksnių analizę sudaro dvi pagrindinės dalys: pirmoji skirta apibūdinti gyventojų senėjimą ir jo rodiklius teoriniu aspektu. Antroji skirta įvertinti gyventojų senėjimą ir jį lemiančias demografinių veiksnių tendencijas bei gyventojų senėjimą ir jį lemiančius veiksnius Lietuvoje. Atlikus analizę, straipsnyje daroma išvada, kad gyventojų senėjimą labiausiai įtakoja gimstamumo mažėjimas ir emigrantų skaičiaus didėjimas imigrantų atžvilgiu, todėl, siekiant pristabdyti gyventojų senėjimą, didžiausias dėmesys turėtų būti skiriamas šių demografinių procesų valdymui.
INFLUENCE OF PERSONAL INCOME TAX ON THE MUNICIPALITIES’ INCOME / GYVENTOJŲ PAJAMŲ MOKESČIO ĮTAKA SAVIVALDYBIŲ PAJAMOMS
Authors: Slavinskaitė Neringa , Kreizaitė Orinta , Stonytė Monika
Published: June 2015

The article analyzes the impact of Lithuanian Republic personal income tax changes on municipality budget and the factors influ -encing that change. This area of Lithuanian practice is evaluated, applied methodical positions are discussed, an overview of other countries’ practical experience and theoretical work is presented. Personal income tax in European countries is one of the main taxes, but the existing framework of personal income tax and the taxation policies, as defined in each country, influence the policy of personal income tax in various European countries. The study showed that the total amount of collected personal income taxes increases each year (2009 – 2,411 millions Lt., in 2013 – 3,723 millions Lt.). The analysis showed that the personal income tax collection is influenced by the average wage (correlation coefficient – 0.72), number of employees (correlation coefficient – 0.87) and tax­exempt income (ratio or correlation – 0.72). Straipsnyje yra analizuojama Lietuvos Respublikos gyventojų pajamų mokesčio pokyčio įtaka savivaldybių biudžeto pajamoms bei šiam pokyčiui įtaką darantys veiksniai. Vertinama šios srities Lietuvos praktika, aptariamos taikomos metodinės nuostatos, apžvelgiama kitų valstybių praktinė patirtis ir teoriniai darbai. Gyventojų pajamų mokestis Europos valstybėse yra vienas iš pagrindinių mokesčių, tačiau atskirų šalių gyventojų pajamų apmokestinimo politiką lemia galiojanti gyventojų pajamų apmokestinimo sistema bei apmokestinimo politikos gairės, kurias apibrėžia kiekviena šalis. Tyrimo metu nustatyta, kad gyventojų pajamų mokesčio surinkimo suma didėja kiekvienais metais (2009 m. – 2,411 mln. Lt, o 2013 m. – 3,723 mln. Lt.). Atlikta analizė parodė, kad gyventojų pajamų mokesčio surinkimui įtaką daro vidutinis darbo užmokestis (koreliacijos koeficientas – 0,72), dirbančiųjų skaičius (koreliacijos koeficientas – 0,87) ir neapmokestinamosios mokestinės pajamos (koreliacijos – 0,72).
GLOBAL COMPETITIVENESS OF EXPORTING BUSINESS: THE CASE STUDY OF LITHUANIA / PASAULINIS EKSPORTUOJANČIŲ GAMINTOJŲ KONKURENCINGUMAS: LIETUVOS ATVEJO ANALIZĖ
Authors: Zacharevič Greta , Dzemyda Ignas
Published: June 2015

The article aims to study global competitiveness of exporting business of Lithuania. In the article theoretical aspects of international trade challenges and global competitiveness of exporting business, international trade tendencies in Lithuania in the period of 2004–2013 are studied, Lithuanian structure of international trade in 2008–2013, Lithuanian international trade partners in 2013 are explored, global competitiveness of Lithuania is evaluated. The results of research indicates that it is important to achieve global competitiveness of Lithuanian exporting companies in order to prepare international trade specialists properly. Highly educated and appropriately qualified people could be the main factor for the development of exports of high value­added products and services of Lithuania.
Straipsniu siekiama ištirti pasaulinį eksportuojančių gamintojų konkurencingumą Lietuvoje. Straipsnyje nagrinėjami teoriniai tarptautinės prekybos iššūkiai eksportuojantiems gamintojams ir globalus eksportuojančių gamintojų konkurencingumas, tarptautinės prekybos tendencijos Lietuvoje 2013–2014 m., Lietuvos tarptautinės prekybos struktūra 2008–2013 m., Lietuvos Tarptautinės prekybos partneriai 2013 metais, taip pat vertintas globalus Lietuvos konkurencingumas. Tyrimo rezultatai parodo, kad siekiant globalaus Lietuvos eksportuojančių įmonių konkurencingumo, labai svarbu tinkamai paruošti tarptautinės prekybos specialistus. Tinkamos kvalifikacijos žmonės su aukštuoju išsilavinimu gali stipriai prisidėti vystant aukštos pridėtinės vertės Lietuvos produktus ir paslaugas.
Zionstheologische Konzepte im Sacharjabuch zwischen Abgrenzung und universaler Öffnung anhand von Sach 2
Authors: Mentemeier Christina
Published: June 2015

Qu’est-ce qui constitue une identité qui, après les expériences de l’exil, est associée à Jérusalem ou bien à Sion ? Zac 2 montre la relation à YHWH comme facteur décisif, fondateur d’identité. YHWH laisse entrevoir qu’il sera de nouveau accessible en son lieu choisi et qu’il participe à l’aménagement de cet espace vital pour son peuple de manière nouvelle et rassurante. Suivant Zac 2,15s, un élargissement et une ouverture de l’entité en principe exclusive du peuple sont possibles sans que cela mette en danger son identité particulière. Des fils multiples s’entremêlent dans les récits des visions et les promesses de salut en Zac 2 et décrivent les rapports respectifs entre YHWH, Jérusalem/Sion et les hommes.
Une philosophie de l’Europe
Authors: Ferry Jean-Marc
Published: June 2015

L’idée d’Europe est-elle morte ? Une modernité marquée du sceau de la raison instrumentale, du désenchantement du monde, et de l’individualisme possessif en a-t-elle eu raison ? Ce n’est pas l’explication que l’on donne aujourd’hui du « malaise européen », plutôt lié au désenchantement survenu cinquante ans après le lancement d’un projet visant paix, prospérité et justice. Face à l’impression d’une « perte de sens », seule la construction d’une Philosophie de l’Europe peut permettre de dépasser les apories nées des difficultés pratiques liées à la gestion de la réalité actuelle du continent.
Spectral-Domain OCT Analyses of Macular Changes After Ranibizumab Therapy for Type 1 Retinopathy of Prematurity
Authors: Erol Muhammet Kazim , Coban Deniz Turgut , Özdemir Özdemir , Tunay Zuhal Özen , Bilgin Ahmet Burak , Dogan Berna
Published: June 2015

Purpose:

To investigate the clinical and macular spectral-domain optical coherence tomography (SD-OCT) findings after intravitreal ranibizumab treatment for type 1 retinopathy of prematurity (ROP).

Methods:

Eighteen eyes of 10 premature infants with type 1 ROP were retrospectively studied. All eyes were treated with intravitreal ranibizumab as monotherapy. Macular SD-OCT was performed before and after intravitreal ranibizumab therapy using a portable SD-OCT machine; the follow-up images were taken 1 day, 1 week, 1 month, and 2 months after therapy.

Results:

Among the 10 infants, there were six males and four females. Mean central foveal thickness before and 2 months after intravitreal ranibizumab was 292.5 ± 61.4 and 171.6 ± 21.7 µm, respectively. Differences were statistically significant (
P
= .01). Sixteen eyes of eight patients had macular edema before treatment. Two eyes of two patients developed a crack in the outer hyperreflective line on SD-OCT corresponding with retinal pigment epithelium with serous retinal detachment 1 day after treatment. Macular edema regressed in all patients 2 months after intravitreal ranibizumab therapy. Mean follow-up time was 11.4 ± 1.5 months. No recurrence was seen except in both eyes of one patient treated with intravitreal ranibizumab monotherapy.

Conclusions:

Intravitreal ranibizumab injection is effective for the treatment of type 1 ROP as a monotherapy agent; however, macular changes not seen with indirect ophthalmoscope may develop.

[
J Pediatr Ophthalmol Strabismus.
2015;52(3):152–158.]
Goniotomy for Steroid-Induced Glaucoma: Clinical and Tonographic Evidence to Support Therapeutic Goniotomy
Authors: Choi Eun Young , Walton David S.
Published: June 2015

Purpose:

To report the surgical results of goniotomy for corticosteroid-induced glaucoma and to provide evidence to support its use as initial surgical therapy.

Methods:

The medical records of 5 patients with a history of goniosurgery for steroid-induced glaucoma were reviewed. Preoperative and postoperative clinical findings were reviewed, including the topical use of steroids, tonometric and gonioscopic findings, goniosurgery, and postoperative results. In addition, tonography was performed on one patient to document the improved facility of outflow following successful goniosurgery.

Results:

Surgical success was achieved in all patients, with intraocular pressures less than 18 mm Hg without the use of medication for an average follow-up period of 11.5 years (range: 9 months to 30 years). A normal postoperative facility of outflow (C = 0.30 mm
3
/min/mm Hg) was determined in one patient. No complications of surgery were experienced.

Conclusion:

Goniotomy is an effective procedure for persistent steroid-induced glaucoma, and should be considered for initial surgical treatment.

[
J Pediatr Ophthalmol Strabismus.
2015;52(3):183–188.]
Comparison of the Efficacy of Medial Rectus Recession and Lateral Rectus Resection for Treatment of Divergence Insufficiency
Authors: Breidenstein Brenda G. , Robbins Shira L. , Granet David B. , Acera Erika C.
Published: June 2015

Purpose:

Surgical approaches for divergence insufficiency esotropia include medial rectus recession and lateral rectus resection. A retrospective chart review compared the efficacy of each.

Methods:

Eighteen patients older than 50 years with divergence insufficiency esotropia who were operated on between 2005 and 2012 by two surgeons were reviewed.

Results:

Nine patients underwent medial rectus recession and nine underwent lateral rectus resection. The average distance esotropia decreased from 19.75 to 3.2 prism diopters in the medial rectus recession group (
P
= .001) and from 17.7 to 2.6 prism diopters in the lateral rectus resection group (
P
= .0002). The disparity between distance and near alignment decreased from 7.3 to 3.4 in the medial rectus recession group (
P
= .019) and from 9 to 5.4 prism diopters in the lateral rectus resection group (
P
= .004).

Conclusions:

Both medial rectus recession and lateral rectus resection are effective treatment for divergence insufficiency, with both decreasing distance-near disparity.

[
J Pediatr Ophthalmol Strabismus.
2015;52(3):173–176.]
Mechanical and Cure Characteristics of Natural Rubber Composites with Caryota Fibre Incorporated in Dry Stage and Latex Stage
Authors: John Sajeev , Joseph Rani , Issac Jeoju M.
Published: June 2015

In conventional method of coagulation acetic acid or formic acid is used. A novel method is reported in which yeast is used for the coagulation. Short Caryota fibres of 10mm size were used for making composites of natural rubber (NR) and samples were prepared by two methods. In the first method fibres were added at the dry stage while compounding and in the second method fibres were added directly to the latex and cure characteristics and mechanical properties were studied. Tensile modulus@300% elongation, tear strength and abrasion resistance were found to be better in latex stage processing.
Contact Stress Analysis of a Helical Gear
Authors: Devaraj R.
Published: June 2015

The main factors that cause the failure of gears are the bending stress and contact stress of the gear tooth. Out of these, failure of gears due to contact stress is high compared to bending stress. Stress analysis has been a key area of research to minimize failure and optimize design. This paper gives a finite element model for introspection of the stresses in the tooth during the meshing of gears. Specifically, helix angle is important for helical gears. Using modeling software, 3-D models for different helix angles in helical gears were generated, and the simulation was performed using ANSYS 12.0 to estimate the contact stress. The Hertz equation and AGMA standard was used to calculate the contact stress. The results of the theoretical contact stress values, using Hertz and AGMA are compared with the stress values from the FEA for different helix angles and the results are tabulated and discussed.
Acoustical Failure Diagnosis of Bush in a Domestic Mixer
Authors: Charles S. , Vijaya D. Joslin
Published: June 2015

Many of the machines and systems having rotating components are designed for operation at high speeds, and hence, it is obvious that only these elements are damaged initially and becomes the root cause of a defect in any machine. Using on line, continuous monitoring techniques, any defect in a rotating part can be detected at its initial stage itself and the user could be alerted before it leads to a catastrophic failure. In this experimental work of the acoustical failure diagnosis, three domestic mixers, the first one in healthy condition, the next mixer about to fail and the last with completely damaged bush were analyzed, with a Type-1 and Delta ohm HD2010 Model sound level meter (SLM). The acoustical readings of the three mixers were measured and tabulated in decibel, using Delta Ohm Noise Studio software. Graphs were drawn for different sets of readings and by analyzing the graphs of the three mixers, the threshold value of the initiation of the defect was found to be 80 decibel, at which failure starts.
Performance Combustion and Emission Characteristics of DI Diesel Engine with Use of Alternate Mechanism
Authors: Arumugam K. , Senthilkumaar J.S. , Umanath K. , Sai Praveen M.
Published: June 2015

The present work has carried out to enhance the engine performance with use of supercharger and exhaust gas recirculation (EGR). Experiments were conducted on a single cylinder DI diesel engine. Effects of EGR and supercharger on combustion and emissions of a diesel engine were investigated. Tests were performed on diesel engine under different load conditions. Results show that cooled EGR is an effective to reduce NOX, because it lowers the flame temperature and oxygen concentration in the combustion chamber. Increase the inlet mass flow rate of air with aid of supercharger increases the NOX formation and reduces the CO emission considerably. Increase of inlet air temperature with use of EGR has contrary effects on combustion and emission. Diesel engine with EGR at constant pressure is a way to drastically reduce the NOX. Meanwhile increase in CO and hydrocarbon emissions.
A Case Study on Scrap Reduction of Transfer Pump in Common Rail Fuel Pump
Authors: S Lakshmi Sankar , Manoj Kumar A. , Joel Henry K.
Published: June 2015

The aim of the paper is to reduce the Scrap in Transfer Pump Tightening Assembly in Common rail Pump. Low Torque rejection phenomenon was considered as it was of more rejection in past 6 months and it was having average per month scrap cost to be excessive. The objective of the work was to reduce the scrap quantity of TPC Tightening Assembly phenomenon from 3% of total scrap quantity of CR – Pump assembly to an accepted level. Due to this more rejection quantity, Loss of production and quality, High scrap cost and utilization of more man power were noticed in CR-Pump Assembly. To solve these problems seven problem Solving tools were attempted. To reduce the scrap cost and increase productivity and quality were targets with good usage of man power.
Entropy Generation Analysis of 10Wp Photovoltaic Thermal Hybrid System
Authors: Vijayalakshmi M.M. , Rekha L. , Natarajan E.
Published: June 2015

The entropy generation of any thermodynamic system provides a useful measure of extent of irreversibility. The irreversibility causes the loss of useful work (exergy) in the system and it has to be minimized. Thermal radiation, coming from the sun is rich in exergy. Entropy generation is one of the parameter that quantifies the loss of exergy. It is a unique parameter to measure the strength of irreversibility of thermodynamic process. The criterion for the optimal thermodynamic operation of a collector is used in terms of Entropy Generation Number (Ns) and Mass Flow Number (M). In this paper, the performance of a 10 Wp photovoltaic thermal (PVT) system is analyzed. The range of mass flow rates to be used for testing is obtained by entropy minimization method. The maximum electrical, thermal and exergy efficiency of 10.9, 23.5, 14.8 % is obtained at the mass flow rate of 0.008 kg/s.
Innovative Approach in Introducing Lean Manufacturing Tools in Maintenance of Aircraft
Authors: Kolanjiappan S.
Published: June 2015

Lean manufacturing was initially introduced successfully in Japan to enhance the production standard of cars in Toyota Company. These lean principles were initially known as Toyota Production system (TPS)[2]. Lean seeks to eliminate all forms of waste in the manufacturing process—including waste in the maintenance operation [1]. This present study about lean principles if could be introduced in maintenance of aircraft the standard of maintenance process could be significantly improved. Hence study of experimental research was carried out on pre-matured failure of lifed hydraulic components of ten aircrafts. The failure rate of each component was studied in-depth to adopt remedial measures for improving its life and in turn to reduce the period of “Aircraft on Grounds”. Aircraft on ground mean unserviceable aircraft will be on ground and not suitable for flying. In addition, a deep study was made on each component to fix a Time Between Overhaul (TBO) by analyzing the failure trend of each component to determine a common and effective TBO for enhancing the serviceability rate of aircrafts. It also prevents sudden failure of components thus improving the serviceability status. In order to enhance the standard of serviceability a “Root Cause Analysis” was carried out on those defective components to suggest remedial measures to those maintenance personnel to modify the maintenance process and reduce the TBO for effective reduction in time of occurrence of the defects. These suggestive measures were implemented by the users of the ten aircrafts on trial basis. Occurrence of such defects was minimized showing significant improvement in the subsequent maintenance of aircrafts. Further, the remedial measures have a great impact on the development of a high degree of aircraft maintenance. The final results of this research study are prepared and suggested measures are forwarded for implementation to manufactures, overhaul agency and operators.
Solving Multi Objective Job Shop Scheduling Problems Using Artificial Immune System Shifting Bottleneck Approach
Authors: Gopinath S. , Arumugam C. , Page Tom , Chandrasekaran M.
Published: June 2015

Scheduling problems are usually solved using heuristics to get optimal or near optimal solutions because problems found in practical applications cannot be solved to optimality using reasonable resources in many cases. Scheduling problems vary widely according to specific production tasks but most are NP-hard problems. Optimization of three practical performance measures mean job flow time, mean job tardiness and makespan are considered in this work. The Artificial Immune System Shifting Bottleneck Approach is used for finding optimal makespan, mean flow time, mean tardiness values of two benchmark problems. In this Artificial Immune System Shifting Bottleneck Approach (AISSB), initial sequences are generated with Artificial Immune System Algorithm (AIS) and Shifting Bottleneck Algorithm (SB) is used for finding final solutions. The results show that the AISSB Approach is effective algorithm that gives better results than literature results. The proposed AISSB Approach is an efficient problem-solving technique for multi objective job shop scheduling problem.
Experimental Investigation on Mechanical Properties of Hemp-Banana-Glass Fiber Reinforced Composites
Authors: Bhoopathi R. , Deepa C. , Sasikala G. , Ramesh M.
Published: June 2015

Due to desirable properties and its role of natural and manmade fibers reinforced composite materials are growing in a faster rate in the field of engineering and technology. Now-a-days the treated natural composites are serves better in terms of corrosive resistance, and other desirable properties when compared to the traditional materials. The main aim of this experimental study is to fabricate and investigate the mechanical properties such as tensile strengths, flexural strengths and impact strengths of NaOH treated and hemp-banana-glass fibers reinforced hybrid composites. From the experimental results, it has been noted that the treated hemp-banana-glass fibers reinforced hybrid epoxy composites exhibited superior properties and used as an alternate material for synthetic fiber reinforced composite materials. Morphological studies are carried out to analyze the interfacial characteristics, internal structures, fiber failure mode and fractured surfaces by using scanning electron microscopy (SEM) analysis.
Investigation of Flexural Characteristics of Flax and Abaca Hybrid Epoxy Composites
Authors: Vijaya Ramnath B. , Elanchezhian C. , Jayakumar C.V. , Manickavasagam V.M. , Aswin U.S. , Eashwar H. , Kavirajan P. , Murugan D.
Published: June 2015

Recent growth in the field of engineering demands specialised composite materials to meet various industrial needs. Composite materials are emerging as the most promising new materials. This paper deals with the fabrication and analysis of flexural characteristics of flax and Abaca hybrid epoxy composite. The show that GFRP + Flax +Abaca based hybrid composite has a higher ultimate stress which is much greater than GFRP + Flax composite and GFRP + Abaca composites. The inner filament breakage and crack propagation are studied using scanning electron microscope.
Processing and Mechanical Property Evaluation of Kenaf-Glass Fiber Reinforced Polymer Composites
Authors: Ramesh M. , Nijanthan S. , Palanikumar K.
Published: June 2015

The development of high-performance engineering products made from natural resources is increasing worldwide, due to renewable and environmental issues. Among the many different types of natural resources, kenaf plants have been extensively exploited over the past few years. Kenaf-glass fibers reinforced composites are manufactured by compression moulding and the tensile, flexural and impact tests are conducted. From the experiment it is found that the processing conditions have little effect on properties except for pressurization which increased tensile and flexural strength at low fiber volume fractions. Examinations using a scanning electron microscopy showed that all the laminates failed due to mechanical loading and the way of fracture of the materials.
Synthesis and Characterization of Multi Wall Carbon Nanotube (MWCNT) Filled Hybrid Banana-Glass Fiber Reinforced Composites
Authors: Rajmohan T. , Mohan K. , Palanikumar K.
Published: June 2015

Natural Fiber Reinforced Composite (NFRC) are used by replacing Synthetic Fiber Reinforced Composites (SFRC) because of its poor reusability, recycling, bio degradability. Even though NFRC are lack in thermal stability, strength degradation, water absorption and poor impact properties. The hybridization and nanoparticles mixed in different polymers are used to improve mechanical and wear properties of the polymer composites. In the present investigation Multi wall carbon nanotubes (MWCNT) dispersed in Epoxy resin using ultrasonic bath sonicator are used as matrix face for hybrid banana-Glass Fiber Reinforced Plastics composite materials which is manufactured by compression molding processes. As per ASTM standards tensile, compression tests are carried out by using Universal Testing Machine. Microstructure of samples are investigated by scanning electron microscope (SEM) with Energy dispersive X-ray (EDS). SEM shows the homogeneous distribution of the fiber in the modified polymer matrix. The results indicated that the increase in weight % of MWCNT improves the mechanical properties of MWCNT filled hybrid natural fiber composites.
A Study on Dry Sliding Wear Behaviour of Hybrid Metal Matrix Composites at Room Temperature
Authors: Siddeshkumar N.G. , Shiva Shankar G.S. , Basavarajappa S.
Published: June 2015

An attempt has been made to study the dry sliding wear behaviour of Aluminium based hybrid composites in room temperature.Al 2219 is used as base material with B4C and MoS2 as reinforcements. The hybrid composite were prepared by conventional stir casting technique. The dry sliding wear test were carried out for various parameters like sliding distance, applied load and sliding speed. The Optical Microscope and SEM results showed the presence of B4C and MoS2, which are fairly uniform and randomly dispersed on matrix material.XRD analysis, shown the presence of B4C and MoS2 phases in the prepared composites.The incorporation of reinforcement particles B4C and MoS2 reduces the specific wear rate of composites. The addition of MoS2 as a secondary reinforcement has significant effect on reducing specific wear rate of prepared composites. By using SEM worn surface of hybrid composites were studied.
Evaluation of Mechanical Properties of Aluminium Alloy 7075 Reinforced with SiC and Al2O3 Hybrid Metal Matrix Composites
Authors: Pugalethi P. , Jayaraman M. , Natarajan A.
Published: June 2015

Aluminium based Metal Matrix Composites (MMCs) with Aluminium matrix and non-metallic reinforcements are finding extensive applications in automotive, aerospace and defence fields because of their high strength-to-weight ratio, high stiffness, hardness, wear-resistance, high-temperature resistance, etc. Composite materials are frequently chosen for structural applications because they have desirable combinations of mechanical characteristics. Development of hybrid metal matrix composites has become an important area of research interest in Material Science. In this work, the Aluminium alloy is reinforced with 3,5,7,9 wt. % of Al2O3 and 2 wt. % of SiC to prepare the hybrid composite. The present study is aimed at evaluating the physical properties of aluminium 7075 in the presence of silicon carbide, aluminium oxide and its combinations. The compositions are added up to the ultimate level and stir casting method is used for the fabrication of aluminium metal matrix composites. The mechanical behaviours of metal matrix composites like tensile strength, and hardness test are investigated by conducting laboratory experiments. Mechanical properties like micro hardness and tensile strength of Al7075 alloy increase with the addition of SiC and Al2O3 reinforcements.
The Mechanical Characterization of Al2O3 Reinforced AL6061 Metal Matrix Composite
Authors: Mohan P. , Kathirvel M. , Azhagesan N. , Sivapragash M.
Published: June 2015

The aluminium based composites are increasingly being used in the transport, aerospace, marine, automobile and mineral processing industries. The widely used reinforcing materials for these composites are silicon carbide, aluminium oxide and graphite in the form of particles or whiskers. In this study Al6061-6 & 4wt% Al2O3 based metal matrix composite were produced by mechanical stir casting process. The obtained cast metal matrix composite is carefully machined to prepare the test specimens for hardness, tensile as well as fracture toughness studies as per ASTM standards. The hardness, tensile strength and fracture toughness properties of Al6061-Al2O3 composites are explored experimentally. Finally compare the material characterization with heat treatment process sample and compare the fracture toughness of sample with mathematical approach, experimental and finite element method.
Tribological Performance and Microstructural Analysis of an Aluminium Alloy Based Hybrid Composite Produced by P/M
Authors: Karthik N , Prabhu S. , Santosh Sahil , Singh Ashutosh
Published: June 2015

In the field of material science and engineering, there is a great impact ever since the invention of composites materials. High strength to weight ratio provides the attractive combination that moves composite materials into new era. The conventional materials like cast iron, steel, and aluminium alloy are replaced by the composite materials due to its superficial properties and could be applied in aerospace and automotive applications. Powder metallurgy fabrication technique is one of the best and attractive methods for producing metal matrix composites because of its better distribution of particles and reliability and cost in manufacturing. In this paper, composites based on aluminium alloy (Al 2024) reinforced with 10% weight fraction of hard ceramics like Aluminium oxide (Al2O3) and 10% weight fraction of Aluminium oxide (Al2O3) with 5% graphite particles is produced by Powder metallurgy method. Hardness and wear test are conducted for the Al 2024, Al-10%Al2O3, and Al-10% Al2O3-5% Graphite. In addition the surfaces of the composite are analyzed by SEM to study the wear of the composites.
Effect of Abrasive Grain Size of the AWJM Performance on AA(6351)-SiC-B4C Hybrid Composite
Authors: Thirumalai Kumaran S. , Uthayakumar Marimuthu , Mathiyazhagan P. , Krishna Kumar K. , Muthu Kumar P.
Published: June 2015

In this work, Abrasive Water Jet Machining (AWJM) on aluminum based hybrid composite with Silicon Carbide (SiC) and Boron Carbide (B4C) reinforcement particles are investigated. Two different abrasive grain sizes of 80 mesh and 120 mesh are selected to carry out the experiments. The cutting parameters namely pressure, standoff distance (SOD) and traverse speed are assessed in terms of the kerf angle, Material Removal Rate (MRR) and Surface Roughness (Ra). The result shows that the coarse abrasive particle has a favorable effect on the MRR, while the fine grained abrasive particle produced minimum kerf angle and good surface finish.
Investigations on Wear and Frictional Characteristic of Hybrid Polymer
Authors: Babu G. Rama Kishore , Revanthkumar J. , Anandh P. , Venkatachalam G. , Prabaharan Graceraj P.
Published: June 2015

This study targets on wear and frictional characteristics of hybrid polymer. Experiments are carried out on hybrid polymers using reciprocating wear testing machine by sliding against mating steel plate. General purpose resin is blended with Cashew nut shell is used as test specimen. The values of frictional force, frictional coefficient and wear were measured to study the influence of accelerated wear.
Experimental Study on Mechanical Properties of PA66 Blended with MWNTs
Authors: Koilraj T. Thomas , Kalaichelvan K.
Published: June 2015

A composite material is a macroscopic consolidation of two or more materials, having a detectable interface between them. A nanocomposite is the one which consists of two or more nanosized materials which are dispersed in a matrix in order to perk up the properties of the primary material. Polymer composites are prepared by dispersing strengthening fibres in the polymer matrix. A polymer nanocomposite consists of a polymer matrix with nanosized filler. CNTs are one of the most encouraging fillers because of their extraordinary properties and large aspect ratio. A microscopic amount of CNT can have an inquisitively large impact on the properties of a composite. CNTs have been well documented as nanostructural materials that can be used to alter mechanical properties of polymer-based composite materials because of their superior properties. In this research the properties, both elastic modulus and strength of Nylon-66 is improved by the selective addition of CNT. The main objectives include the study of the effect of CNTs content on the mechanical properties of Nylon 66. The composite is to be prepared at various compositions of CNT and material will be analysed by testing the mechanical properties using various test facilities. The finite element modelling of the test specimens were made and a Representative Volume Element (RVE) approach of finite element modelling is used to model the specimen. Mathematical calculations were performed to find out the modelling and RVE. The results are then compared and concluded.
Characterization of Al-17wt.%Si Using Centrifugal Casting
Authors: Harish N. , Hamritha S. , Aithal S. Kiran
Published: June 2015

Present work is focused on Horizontal centrifugal casting process, by which a wear resistant material with considerable strength can be designed. A material of heterogeneous microstructure designed in which a high volume fraction of hard particles is dispersed at the inner surface, where better wear properties are needed, and a gradually decreasing lower volume fraction of hard particles at the outer surface. By this, a better strength and ductility will be achieved at the desired surfaces. The present work is focused on the preparation of cylinder liners using centrifugal casting for Al-17wt%Si. These cylinder liners are characterized for Microstructure, Hardness, Tensile strength and Wear.
Formability Analysis of AA6061 Sheet in T6 Condition
Authors: Vijayananth Suyamburajan , Jayaseelan V. , Shivasubbramanian G.
Published: June 2015

Formability of a material is defined as its ability to deform into desired shape without being fracture. There will always be a need for formability tests, a larger number of tests have been used in an effort to measure the formability of sheet materials. Aluminium Alloy 6061 is a magnesium and silicon alloy of aluminium. It is also called as marine material as it has high corrosion resistance to seawater. In this paper Formability test of AA6061 sheet is done by Forming Limit Diagram (FLD) Analysis. FLD or Forming Limit Curve (FLC) for the forming processes of AA6061 sheets is obtained by Experimental method and FEM. Experimental method involves Deep drawing test of the sheet and ANSYS software is used for FEM.
Experimental Investigation of Solar Paraffin Wax Melting Unit Integrated with Phase Change Heat Energy Storage by Using Phase Change Material
Authors: Saikrishnan V. , Jagadeesh P.S. , Jayasuriyaa K.R.
Published: June 2015

An Experimental study on phase change heat energy storage system (PCHES) using Erythritol as a phase change material (PCM) has been carried out. Simple and popularly used domestic solar thermal applications make use of direct radiation energy of the sun for cooking, liquid heating, drying and many others as it is the remarkable potential renewable energy source. Effective utilization of such energy can be made with the development of economically operating phase change heat energy storage (PCHES) which is elemental in spanning the gap between supply and demand of energy. PCHES that stores the latent heat of fusion of phase change materials is provocative because of its huge storage density. An integrated Solar wax melting unit with phase change thermal energy storage using ethylene glycol as heat transfer fluid(HTF) to transfer the heat from parabolic dish collector to the wax melting unit is investigated. In this experimental setup, the paraffin wax container is kept in an insulated heat retrieval unit. Heat stored during the daytime by the PCHES is utilized in the off sunshine hours.
Effect of Spillway Materials in Air-Water Interactions
Authors: Senthilkumar G.
Published: June 2015

The spillway system allows stabilization of the water free level and avoids variation in free level of water along the flow passage as a function of flow rate. The main problem in the spillway is the profiling of weir crest. The criteria that need to be satisfied are there should be no flow separation from the crest and there should be uniform circumferential flow to avoid flow asymmetry in the flow passage. Separation of flow leads to large impact velocity of the falling water, which would lead to the large-scale entrainment of air in water. This paper describes the effect of spillway materials by coating over the weir and changing the profile on air entrainment characteristics in the downstream.
Applications of Cellular Materials – An Overview
Authors: Prabhu S. , Raja V.K. Bupesh , Nikhil Rajan
Published: June 2015

The research in material science had led to the discovery of new materials; but the real challenge lies in finding suitable application for those materials to be used in various engineering fields. Finding application for a new material is very difficult. Cellular materials have the most promising applications and proved to be satisfactory for its applicability due to their high stiffness-to-weight ratio, better crash energy absorption, fire resistance, non-toxicity, low thermal conductivity, magnetic permeability and lower density. Along with drastic weight reduction and material savings in the case of cellular structures, there are other application-specific benefits like noise and energy absorption, mechanical damping and filtration effects. Various materials exist where weight reduction is the only parameter to be considered but if low weight combined with good energy absorption characteristics or heat resistance is required, then metal foams could be preferred. Possible applications are seen in areas like light weight construction, crash energy absorption, noise control, transport industry, building industry, heat exchangers, purifiers, decoration and arts, etc,. The use of foams can satisfy the demand for light-weighing parts of several branches of industry.
Study of Composite Helical Spring Using Glass Fibre with Araldite LY556 and XY54
Authors: Krishnamoorthy A. , Karthik R.
Published: June 2015

This paper titled “Study of composite helical spring using glass fibre with Araldite LY556 and XY54”. Currently, the composite materials in the automobile sector are used for construction of the body, interiors, chassis, hoods, electrical components etc...these components are in simplest form and also they are regular in shape and easy to manufacture. However the design of suspension system and complicated structures in the automobile are quite difficult to bring out the same shape and performance. The most important no gap of steel springs suspension are limited corrosion resistance, long-lasting manufacturing process and weight. This paper brings out incredibly a simple method to prepare the composite helical spring for any dynamic application. The glass fibre and resin mixed with 70:30 ratio and it is tested by compression testing machine as per ASTM. The mechanical properties, such as maximum load carrying capacity, deflection, stiffness Youngs’modulus, Shear stress and strain energy are determined using compression testing machine. The objective of this study is to reduce the weight of the spring, to obtain good surface finish, similar to steel spring, novel manufacturing methodology and identification of failure point rather than the maximum load.
Micro Cantilever CO2 Gas Sensor Based on Mass
Authors: Subhashini S. , Vimala Juliet A.
Published: June 2015

Sensors had gained importance in all fields of science and technology and development of real time small devices with high sensitivity for in situ measurements at low cost has gained momentum. Micromachined cantilever provides a solution to this hunt. MEMS cantilever are the simplest of all the other mechanical structures and hence is considered for the ease of fabrication. Here a chemical CO2 sensor is considered with the metal oxide layer as receptor to adsorb the CO2 molecules leading to an increase in mass and microcantilever as the transducer part converting the change in mass to change in natural frequency. The sensitive SnO2 layer increases the mass and hence decreases the resonant frequency. The inherent natural frequency of the cantilever is altered by the sensitive coating on top of the beam and the residual stresses present on the structure. In this paper, we investigate the SiO2 cantilever with SnO2 deposited on the top surface. Initially the microcantilever is analytically modelled and then is fabricated and characterized experimentally. Finally the error % is analysed between the analytical model and experimental results.
Dry Sliding Wear Behaviour of Al2O3 Coatings for AISI 410 Grade Stainless Steel
Authors: Girisha K.G. , Durga Prasad C. , Anil K.C. , Sreenivas Rao K.V.
Published: June 2015

The wear and corrosion resistance of working surfaces can be improved by applying suitable coatings using thermal spray techniques. In the present work air plasma spray deposition technique (PSD) was used to coat Al2O3 ceramic powder on AISI 410 grade stainless steel. The steel substrate was primarily coated with Ni/Cr which acts as a bond coat for good fastening. Surface morphology of Al2O3 particulates of the coating was examined by scanning electron microscope (SEM). Uniform distribution of the Al2O3 particles on Ni/Cr pre-coated steel substrate was observed. Sliding wear tests under dry condition were conducted for different sliding velocity by keeping applied normal load and sliding distance constant. The results indicate significant improvement in the wear resistance of Al2O3 coated stainless steel substrate using PSD. The micro hardness of Al2O3 coated surface was found to be higher than that of the base metal.
Effect of Plasma Spray Process on TiO2 Coating over Mild Steel Substrate
Authors: Arul Raj I. , Ramachandran S.
Published: June 2015

Coatings are applied for protection of mild steel against corrosion. The paper deals at development of TiO2 coatings onto mild steel substrate by Atmospheric plasma spraying. The coating thickness was taken as 250μm. Surface characterization was analysed by Scanning Electron Microscope. The surface roughness was determined by Atomic Force Microscope. The average roughness was found to be 459.009 nm.
Performance Study on Copper Coated Tool Using Powder Mixed EDM of Monel 400
Authors: Ramesh R. , Roseline V. Anusha , Purushothaman D. , Jeeva N.T.
Published: June 2015

The Electric Discharge Machining (EDM) is one of the most widely used new techniques to machining. In this work the literature available for improving the performance measures of EDM by using suspended powders in a dielectric medium. The Powder Mixed EDM (PMEDM) is improving the material removal rate, reducing the tool wear rate and improving the surface quality of the work piece. In this work the Monel 400 has been chosen as the work material and copper coated tool as an electrode, kerosene-servotherm as dielectric fluid and silicon, graphite as suspended powders in dielectric. EDS analysis and surface topography studies are carried out to identify the performance of the tool.
Investigation of Morphological and Mechanical Features of Polyurea
Authors: Arunkumar T. , Ramachandran S.
Published: June 2015

Polyurea coatings are very reactive and fast curing even at very low temperatures with exceptional mechanical properties, chemical resistance and durability. Polyurea spray coating technology is used to overcome the initial problems in surface coating such as substrate wetting,mixing and surface finish. The study deals with the analysis of morphology and tensile properties of polyurea coating. The polyurea sample is characterized by using SEM, FTIR and XRD in addition to EDAX to determine the microstructure and chemical composition. Finally Tensile Test was carried out to examine the ultimate tensile strength and young’s modulus of Polyurea using UTM.
A Review on Surface Engineering of Ti6Al4V Titanium Alloy Using Gas and Laser Nitriding Techniques
Authors: Deepak J.R
Published: June 2015

Nitriding is the most common surface engineering technique that is being used in Titanium alloys for improving their surface properties, viz hardness, wear resistance, etc. Ti6Al4V (Grade 5) Titanium Alloy is a super alloy that exhibits excellent mechanical strength; it is highly resistance to creep at very high temperatures which maintains good surface stability. It is resistant to corrosion and oxidation. The main objective of this review paper is to study the recent research works carried on Nitriding of Ti6Al4V alloy by using, viz gas Nitriding and laser Nitriding. This process is used in the surface hardening of machine parts such as aircraft engine parts, crank pins, valve seats, gears, bush, aero engine cylinders, aero crank shafts. Gas Nitriding is a diffusional technique in which the nitrogen atoms are diffused into the surface of the metal to obtain hard surface. By Laser Nitriding is a diffusional technique by which the surface properties of the titanium alloy is enhanced. Laser nitriding process comprises of various stages, viz, transport of heat, melting effect, diffusion and convection effect. By Nitriding technique the surface hardness of super alloys like Titanium Alloy Ti6Al4V Grade 5 can be increased by increasing the hardness on the surface there by its scope of application is widened. In this paper a literature survey is carried out and the recent research works on surface engineering of Ti6Al4V alloy using gas and laser Nitriding technique is summarized.