bluuebunny/crossref_metadata_2025 huggingface dataset:
An Integrated Approach to Accurate Part Manufacture in Single Point Incremental Forming Using Feature Based Graph Topology
Authors: Behera Amar Kumar , Lauwers Bert , Duflou Joost R.
Published: February 2012

Previous studies have shown that optimized tool paths based on behavior of individual features and feature interactions can be used to improve the accuracy of features in parts produced by single point incremental forming. These tool paths are generated with compensated CAD files of the part, which result from a prediction of deviations of individual features. However, in order to improve the accuracy of an entire part, it is important to systematically look at behavior of all the individual features and all feasible interactions between features. In this paper, the authors present a graph topology approach to integrating the effects of the behavior of all features present in a part. For any given part, a conceptual graph is constructed representing all the features and connecting them based on their spatial locations with conceptual relations. Next, all possible feature interactions based on the generated graph are analyzed, and the deviations due to the feasible interactions in an uncompensated test are predicted. Depending on the feature types and interactions present, a comprehensive strategy for accurate part manufacture is generated. This strategy may be composed of a selection of one or more complementary tool path strategies for compensating the anticipated deviations on the part. Case studies illustrating improvement in accuracy of parts produced by this technique are discussed next to justify the use of the graph based approach.
Influence of Material Properties on Accuracy Response Surfaces in Single Point Incremental Forming
Authors: Behera Amar Kumar , Gu Jun , Lauwers Bert , Duflou Joost R.
Published: February 2012

The ability to manufacture accurate parts in single point incremental forming is dependent on the capability to properly predict accuracy response surfaces of individual features and feature interaction combinations formed using uncompensated tool paths. Recent studies show that the accuracy profiles obtained are dependent on the choice of material used for forming, in terms of magnitude, geometric shape and nature of errors (under forming and over forming). In this paper, an attempt is made to capture the effect of material properties on the accuracy response surfaces. The response surfaces are modeled using Multivariate Adaptive Regression Splines (MARS), which is a non-parametric multivariate regression technique that helps generating continuous response surfaces. The MARS functions are based on process and feature specific geometric parameters. A set of features and feature interactions for which the response surface dependence on material properties is well predicted is used to illustrate the applicability of the MARS method for predicting the accuracy. An in-process stereo camera system is used to measure the displacement fields for different materials using digital image correlation (DIC) and understand the material dislocation mechanism. Improvements in accuracy for different sheet metal materials based on the predicted response surfaces are then discussed.
On the Rapid Prototyping Technologies and Applications in Product Design and Manufacturing
Authors: Pandey Pulak M.
Published: February 2012

Material removal, forming, casting and joining are the established manufacturing approaches and processes based on these approaches are being practiced even in modern industries with appropriate automation. Layer by layer material deposition method to produce prototypes from a solid model is relatively new and was developed during last 10-15 years of 20th century. These processes were named as Rapid Prototyping (RP) or Solid Freeform Fabrication (SFF). Today there are many commercial RP system and most of these able to deposit liquid or solid/powder polymer based materials. Some systems are also able to deposit blends of polymer and metal or ceramic. Latest trend in this area is to deposit metals or alloys with variable composition and hence to produce functionally graded material. This paper describes in general the details related to RP processes, data preparation, and various commercial RP technologies. The article also discusses applications these processes.
Impact Extrusion of Aluminium Alloy Cans: Development of Ellipsoidal Cans as Storage Containers for Electrochemical Energy Systems
Authors: Mercy T.D. , Sharma Rahul , Kaladharan V.F. , Kamalakaran K.P. , Aravamuthan S. , Balachander G.
Published: February 2012

Aluminium alloy cans are generally used as containers for electrochemical energy systems like capacitors and advanced batteries. Packing efficiency of batteries depends upon their configuration. Containers in prismatic, cylindrical and elliptic-cylindrical shapes are generally used for battery applications. Elliptic-cylindrical shape has the advantage of better heat dissipation and good packing efficiency in battery assembly. Safety device to be provided in the cans requires material in the minimum half hard (H14) condition. In the present work, ellipsoidal cans of Al-Mn alloy were successfully realised by impact extrusion process. Mechanical properties of the cans were analysed through to ensure the adequacy of the process and it has been demonstrated that impact extrusion is a viable process for making cans for batteries with required mechanical properties, for the can in total and for the safety device in particular.
Effect of Rolling Speed on Microstructure of Al-33wt. % Cu Alloy Strip Prepared by Twin Roll Strip Casting
Authors: Sahoo Seshadev , Ghosh Sudipto
Published: February 2012

Microstructural evolutions of Al-33wt. % Cu alloy strip, prepared by twin roll strip casting (TRC) at different roll speed (100-500 rpm) were studied in the present investigation. The as cast sample were subjected to Scanning Electron Microscope (SEM) to study the effect of rolling speed on microstructure along the thickness of the strip. The microstructure shows that Al-33 wt. % Cu strip is a layered structure which consists of partly lamellar and wavy structure. The lamellar microstructure consists of alternating layers of well bonded α-Al phase and θ-Al2Cu phase.
Study of Shell Cracking Behavior and its Remedies in Investment Casting Process Using Quick Cast Rapid Prototype Polymer Patterns
Authors: Sharma Ankit , Acharya Mayukh , Agarwal Alok , Govind  , Sharma S.C. , Sreekumar K. , Sinha Parameshwar Prasad
Published: February 2012

Investment casting has emerged as the foremost casting process for manufacturing of intricate parts where better dimensional accuracy is required. Use of rapid prototyping polymer patterns is one of the major advancements in investment casting process. Elimination of die making step as required in the traditional wax process makes it quicker and a cost effective process. The direct conversion of 3D CAD data into rapid prototyping pattern decreases development time, chances of costly mistakes, minimizes sustaining engineering changes and extend product lifetime by adding necessary features and eliminating redundant features early in the design.
Microstructural and Mechanical Characterization of Friction Stir Processed 5086 Aluminum Alloy
Authors: Pradeep Shivanna , Sharma Sumit Kumar , Pancholi Vivek
Published: February 2012

In the present investigation friction stir processing (FSP) is carried out by single and multipass FSP on a 5086 aluminum alloy to modify microstructure and mechanical properties. The processing is carried out at constant rotation speed of 1025 rpm and at a traverse speed of 30 mm/min. Inhomogeneous microstructural distribution was observed across the processed zone. EBSD analysis has been done to evaluate the microstructure. Overlapping passes is showing same grain size as in single pass FSPed material. Material processed using multi pass FSP at 30 mm/min is showing higher mechanical strength as compared to base material. The bulk material produced due to multipass seems to be good for superplastic forming applications.
Grain Refinement in OFHC Cu Subjected to Repetitive Upsetting Extrusion (RUE) Process
Authors: Balasundar I. , Ravi K.R. , Raghu T.
Published: February 2012

Repetitive Upsetting Extrusion (RUE) is a relatively new severe plastic deformation (SPD) process in which two conventional metal forming operations such as upsetting and extrusion has been combined to impart large plastic strain. Though originally invented to process powder materials for bulk mechanical alloying, a more recent study on the process has revealed that by suitably modifying the die design, the process can be used to impart large deformations in bulk materials as well. Using this new die, oxygen free high conductivity (OFHC) copper has been subjected up to 10 cycles of RUE. Microstructures across the cross-section of the RUE processed samples were evaluated using optical, scanning and transmission electron microscope to ascertain the deformation behaviour and the mechanism of grain refinement. The results obtained are presented and discussed.
Fabrication and Characterization of Short Carbon Fiber Reinforced AZ91 Mg Alloy Composites
Authors: Ajukumar Kodappully Anilan , Ajith Kumar Kumaraswamy Kaliamma , Ravikumar Kuriakkattil Kunjayyappan , Rajan Thazhavilai Ponnu Deva , Pillai Uma Thanu Subramonia , Pai Bellambettu Chandrasekhara
Published: February 2012

Short carbon ﬁber reinforced AZ91 magnesium alloy matrix composites have been made by stir casting technique. The microstructure and the fibre matrix interfacial region of the composites characterized using optical and scanning electron microscopes reveal uniform distribution of fiber in the matrix and good interfacial bonding respectively. Increase in compressive strength values are observed with increase in fiber content where as the room and high temperature (150°C) strength properties are found to decrease marginally. The microfractograph of the tensile fractured surface reveals mixed type of fracture.
Structure and Defect Formation during DC Casting of Aluminium Alloys
Authors: Katgerman Laurens , Eskin Dmitry G.
Published: February 2012

Research activities on aluminium production technology focus on the successive steps in the production chain of aluminium wrought products. Direct-chill casting of aluminium alloys is a well-developed technology with a long history. But only in the last 20 years, the development of computer modelling offered a means of better understanding of the physical phenomena involved in solidification. The main scientific challenge is to obtain a fundamental insight into the processing of aluminium alloys and to establish quantitative relationships between materials, processes, and performance. A systems approach is employed, covering theoretical and experimental studies on processing into semi-finished products. Special emphasis is placed on experimental verification and industrial applicability with the availability of pilot scale experimental facilities at M2i-TUD. This facilitates the design of process conditions as desired for experimental validation studies. In this paper we will consider main mechanisms of structure and defect formation during solidification of DC cast billets, mostly based in the results obtained in cooperation between Delft University of Technology and Materials Innovation Institute (M2i).
Effect of Tempering Temperature on Strength and Fracture Toughness of 0.3C-CrMoV(ESR) Steel
Authors: Saravanan K. , Suresh Kumar R. , Sharma V.M.J. , Sivakumar D. , Ramkumar P. , Ramesh Narayanan P. , Sreekumar K. , Sinha Parameshwar Prasad
Published: February 2012

0.3C-CrMoV(ESR) steel is an ultra-high strength low alloy steel indigenously developed by ISRO for space applications. The steel is used in the form of rings of 2.8 m diameter also. In this paper, the effect of tempering temperature on ring rolled steel for the best combination of fracture toughness and strength properties is studied. The tensile properties and fracture toughness of the steel were evaluated in the as quenched and tempered conditions through the specimens drawn in radial direction of the ring segment. Five tempering temperatures were used in the study: 200, 450, 475, 500 and 510°C. Tensile strength of the steel showed continuous decrease with increasing tempering temperature, but yield strength increased reaching maximum when tempered at 450°C and further decreased with increasing tempering temperature. The elongation was higher for higher tempering temperature. The strain hardening exponent decreased with increasing tempering temperature. The fracture toughness test results showed that tempering between 475 and 510°C exhibited better combination of fracture toughness and strength.
Aging Behavior in 15-5 PH Precipitation Hardening Martensitic Stainless Steel
Authors: Anil Kumar V. , Karthikeyan M.K. , Gupta Rohit Kumar , Gino Prakash F. , Ram Kumar P.
Published: February 2012

15-5 PH stainless steel is strengthened by precipitation of copper rich phases in a low carbon body centred cubic (b.c.c) lath martensitic matrix. Microstructures developed in aerospace grade 15-5PH precipitation-hardened stainless steel with different aging heat treatments have been studied. An attempt has been made to correlate the microstructural observations with the mechanical properties in different aging regimes. The overaging treatment imparts excellent ductility with a compromise in strength in peak aged condition to overaged condition the tune of 300 MPa in both tensile and yield strength. Hardness and tensile strength showed a similar decreasing trend with increase in aging temperature.
Type Certification of 18 Ni Maraging Steels for Landing Gears
Authors: Kumar Ashok , Balaji Y. , Prasad N. Eswara
Published: February 2012

Maraging steels exhibit unique properties, such as high strength with excellent fracture toughness, ease of machining and above all distortion free thermal processing. These attractive properties and advantages of maraging steel do not outweigh the initial cost resulting from high alloy content and especially in certain structural components where in much of the forging is machined as swarf. However, with the constant drive to prove the technology when maximum strength and stiffness per unit volume becomes the major criteria, the choice of material may overwhelmingly become maraging steel. Above requirements necessiate a landing gear material for Indian fighter aircraft to have a combination of high strength, sufficient stiffness, excellent fatigue strength, utmost cleanliness, resistance to micro-structural degradation, freedom from surface anomalies, good corrosion & stress corrosion resistance and superior toughness to meet the current damage tolerant design criteria. M/s Midhani in consultation with airworthiness authorities took up the task to develop & manufacture this steel to the laid down type test schedule. The steel has satisfactorily met all the requirements and landing gear has been successfully forged, machined and fitted to the prototype. This paper describes the metallurgical aspects that are relevant for developing the maraging steel along with a brief note on the properties - chemical, microstructural and mechanical. An attempt is made in the presentation to show that the indigenously developed and produced maraging steel is indeed at par with aeronautical grade materials, including maraging steels of international sources.
Effect of Cold Working and Heat Treatment on Recrystallization, Mechanical Properties and Microstructure of High Strength Ti15V3Al3Cr3Sn (Ti-Beta) Alloy
Authors: Muneshwar Pravin , Singh Satish Kumar , Kumar K. Naresh , Pant Bhanu , Sreekumar K.
Published: February 2012

Ti15V3Al3Cr3Sn (Ti-15-3-3-3) alloy is a highly cold formable metastable beta alloy and attains very high strength by proper selection of cold working and heat treatment cycles. Due to the presence of softer BCC beta phase at ambient temperature in solution treated condition, this alloy is highly cold workable; to as much as 90% without need of any intermediate annealing. In the present work, cold working up to 83% was imparted to the sheet. Subsequently, cold worked sheet was solution annealed at various temperatures. Cold worked and solution annealed samples were provided with two types of aging cycles: 482°C/16hrs/AC (STA-1) and 538°C/8hrs/AC (STA-2). Hardness measurement, tensile property and microstructural evaluation in cold worked (CW), CW plus solution annealed (CWSA) and CWSA plus aged conditions were carriedout. Recrystallization temperature has been observed to be dependent on extent of cold working. Tensile properties are higher for STA-1 cycle as compared to STA-2 cycle. Hardness values in cold worked condition are higher than solution annealed samples whereas for cold worked and STA samples, an increase in hardness w.r.t. to annealed values has been observed. Corresponding volume fraction of alpha precipitates is found to be more with STA-1 cycle than STA-2 cycle. Also, distribution of the precipitates with STA-1 cycle is observed to be more uniform than STA-2 cycle. The present paper discusses the effect of cold working on recrystallization, mechanical properties and microstructure in Ti-15-3-3-3 beta alloy.
Age Hardening Behavior in Al-8Zn-2Mg-2Cu Wrought Aluminum Alloy
Authors: Anil Kumar V. , Bhat Raghavendra R. , Sharma Romesh C.
Published: February 2012

Aluminum alloys based on Al-Zn-Mg-Cu system classified under high strength light alloys, find a large scale application in aerospace sector. In the present study, heat treatment of an Aluminum alloy with Al-8Zn-2Mg-2Cu wt.% (AA7449) was carried out. Heat treatment parameters were optimized based on hardness and conductivity measurements. The mechanisms of strengthening in primary and secondary aged states are explained using hardness and conductivity measurements. Conductivity generally showed an increasing trend with increase in aging time, which could be attributed to decrease in the lattice distortion of the Aluminum matrix with increase in aging time. The dissolution of GP zones and formation of other metastable phases like η’ and stable phase like η were found to reduce the supersaturation in the matrix as the precipitation growth and coarsening processes are completed during overaging. Transmission electron microscopy (TEM) study was carried out to confirm the peak-aging regime. Selected Area Diffraction (SAD) patterns were recorded where GP zones and η’ precipitates were observed in the bright field images to establish their nature. The mechanical properties were correlated with the TEM observations and was suggested that a critical distribution of GP zones and η’ precipitates is essential to achieve peak strength in Al-Zn-Mg alloys.
Age-Hardening Characteristics of Cu-3Ag-0.5Zr Alloy
Authors: Krishna S. Chenna , Thomas Tharian K. , Pant Bhanu , Kottada Ravi S.
Published: February 2012

Among the copper alloys, the Cu-3Ag-0.5Zr alloy is one of the potential candidates for combustion chamber of liquid rocket engine because of its optimum combination of high strength with thermal conductivity. The present study is a detailed characterization of microstructure, strength, and electrical conductivity during the aging treatment. The aging cycle for Cu-3Ag-0.5Zr alloy after the solution treatment (ST) was optimized to obtain higher hardness without compromising on electrical conductivity. The precipitates responsible for strengthening in aged samples are identified as nanocrystalline Ag precipitates with an average diameter of 9.0±2.0 nm.
Metallurgical Studies on Explosive Welded Aluminium Alloy-Stainless Steel Bimetallic Plates
Authors: Muneshwar Pravin , Singh Satish Kumar , Kumar K. Naresh , Pant Bhanu , Sreekumar K.
Published: February 2012

Aluminium alloys and austenitic stainless steels are often used for construction of cryogenic pressure vessels owing to their attractive properties at cryogenic temperatures. Indian space programme requires AA2219/ICSS1218-SS321 bimetallic components which are machined from explosive welded plates. Pure aluminium sheet is used as an interlayer between aluminium alloy and steel to achieve a satisfactory bond. Internal soundness of the joint is evaluated through ultrasonic testing (UT). The present paper discusses bonding trials carried out by varying the explosive parameters using facilities and expertise of Terminal Ballistic Research Laboratory (TBRL), Chandigarh and M/s Giridhari Explosives Private Limited (GEPL), Hyderabad. The welded joint is extensively characterised with respect to Lap Shear and Ultimate Tensile Strength at ambient temperature and for metallographic analysis.
Assessment of Failure Modes of Components in High Capacity Pumps due to Synergistic Effects of Erosion and Corrosion – A Case Study in Lignite Mines
Authors: Kumarasamy M. , Natarajan S. , Kumaresh Babu S.P. , Santhanam S. , Veerabalu P. , Chokkuvel Murugan S.
Published: February 2012

Neyveli Lignite Corporation Ltd., Neyveli (aNavaratnaPublic Sector of Government of India), Tamil Nadu, India, operates three open cast lignite mines of total capacity 24 million tones per annum (mtpa) with ‘three pit head power stations’ of capacity 2490MW. The Mine operations are influenced by the aquifers and high monsoon that necessitated huge pumping of water before excavation of lignite. Hence a network of system of pumping was established for both ground water control (GWC) and storm water Control (SWC). As the volume of water to be handled is high capacity mining pumps of capacity 1.5m3/s and 180m Head are operated. These pumps in most of the occasions handle acidic water pH less than 3.5 and sand particles loaded up to 15% and experience variety of failures including erosion corrosion problems. The ‘Mean Time Between Failures’ was less than 100 hours in Mine-I and replacement and reconditioning of units are challenging jobs for maintenance crew.
The Role of Nanostructured Active Support Materials in Electrocatalysis of Direct Methanol Fuel Cell Reactions
Authors: Chellasamy Velu , Manoharan Ramasamy
Published: February 2012

The necessity for developing oxidation–resistant noncarbon catalyst support materials for use in the electrode/electrolyte interface of proton exchange membrane (PEM) based direct methanol fuel cells (DMFCs) is emphasized. A great deal of attention is currently being paid to nanostructured catalytic and support materials for electrocatalysing both anodic methanol oxidation reaction (MOR) and cathodic oxygen reduction reaction (ORR). The performances of various nanostructured transition metal oxides have been reviewed. Mn3O4 nanorods have been synthesized by us and their performances for electrocatalysing the MOR with Pd catalyst are discussed. A model explaining how nanostructured active support materials can extract active oxygen atoms required for complete oxidation of methanol from the electrolyte and supply to the adjacent catalytic sites has been proposed.
Role of Substrate Temperature in the Pulsed Laser Deposition of Zirconium Oxide Thin Film
Authors: Mittra Joy , Abraham Geogy Jiju , Kesaria Manoj , Bahl Sumit , Gupta Aman , Shivaprasad Sonnada M. , Viswanadham Chebolu Subrahmanya , Kulkarni Ulhas Digambar , Dey Gautam Kumar
Published: February 2012

Thin films of zirconium oxide have been deposited using pulsed laser deposition on Zr-base alloy substrates, held at 300 K, 573 K and 873 K, in order to understand the effect of substrate temperature on the deposited film. In this study, a KrF excimer laser having 30 ns pulse width and 600 mJ energy at source has been used for depositing the films from a sintered ZrO2 target using a laser fluence of 5 J.cm-2. After visual observation, deposited thin films were examined using Raman Spectroscopy (RS) and X-ray Photo-electron Spectroscopy (XPS). It has been found that the oxide deposited at 300 K temperature does not show good adherence with the substrate. The oxide films deposited at 573 K and 873 K are found to be adherent with the substrate and lustrous black in appearance. Thin films of zirconia, deposited using pulsed laser on the Zr-base metallic substrate are initially in amorphous state and possibly little deficient in oxygen. The substrate temperature and the duration of holding at high temperature are responsible for the evolution of nanocrystals in the deposited thin films. The stoichiometry of the amorphous oxide film supports its crystallization, below 573 K, into monoclinic and tetragonal phases and not into cubic phase.
Developing New Sol-Gel Surface Treatments Formulation for Bonded Repair of Aircraft
Authors: Sim Ze Rong , Tan Willy C.K. , Ng L.L. , Cheung Prislin
Published: February 2012

Over the years, Sol-gel has been widely used in aerospace industry for surface treatment process in preparation of adhesive bonded repair to aircraft. It plays a crucial role in the process of bonded repair of aircraft as a chemical linkage between adhesive bonded repair and damaged metallic structure of aircraft. As a chemical linkage, it produces strong and durable bond between metal and organic adhesive (Thermoplastics) which improves the overall strength in adhesive bonded repair to aircraft. In this paper, both conventional and newly formulated sol-gel will be subjected under Wedge Test (ASTM D 3762-03) to examine its durability. This would be a crucial milestone if the durability of the newly formulated sol-gel is higher than conventional sol-gel. Cost of repair would be able to reduce as serviceability of the aircraft increase. Keywords: Sol Gel, Chemical linkage, Bonding Strength, Shear strength
Laminated Microstructure and Toughness Mechanism of Abalone Shell
Authors: Chen Bin , Yin Da Gang , Wang Jian Guo , Yuan Quan , Fan Jing Hong
Published: February 2012

SEM observation on an abalone shell shows that the shell is a kind of bioceramic composite consisting of inorganic aragonite sheets and organic collagen protein matter. The aragonite sheets possess long and thin shape and are divided by the collagen protein matter, which compose a kind of laminated microstructure of the shell. The fracture surface energy of the laminated microstructure is investigated and compared with non-laminated microstructure based on its representative model. It shows that the fracture surface energy of the laminated microstructure is markedly larger than that of the non-laminated microstructure and endows the shell with high fracture toughness.
Athermal Martensites, Temperature-Time-Transformation Diagrams and Thermal Hysteresis: Monte Carlo Simulations of Strain Pseudospins
Authors: Shankaraiah N , Murthy K.P.N. , Lookman Turab , Shenoy S.R.
Published: February 2012

We explore the kinetics of a three-state strain pseudospin model for a square/rectangle ferroelastic transition, described by a temperature dependent hamiltonian without quenched disorder, using temperature quench Monte Carlo simulations. The model hamiltonian includes power law anisotropic long range interactions, which lock the domain walls in a symmetry breaking diagonal direction. In athermal parameter regime, there are fast conversions at the athermal transition temperature, but with delay tails above it, as in experiment. The conversion delay tails have a Vogel-Fulcher divergence at transition to austenite. The incubation delays and their insensitivity to elastic energy scales are attributed to entropy barriers. Temperature cycling shows hysteretic behavior in physical quantities.
Investigating the Thermoelectric and Structural Properties of Bismuth Telluride Thin Films for Harvesting Energy from Waste Heat
Authors: Leong Marcus Chiang Mun , Chun Fabian Chiang Mun , Wei Jae Lee Kai , Zhen Peng Qi , San Ye Ko , Ezhilvalavan Santhiagu , Hoon Heng Hui , Ma Jan
Published: February 2012

Recently, thermoelectric thin films have been gaining attention as potential thermoelectric generators that can be used to power external devices. Such films can recover electrical energy from waste heat and are environmentally friendly. Micro fabrication of thin films is achieved by sputtering on silicon films. In this study, the sputtering of Bismuth Telluride (N-type, P-type) films was investigated. Research has verified the efficiency of Bismuth Telluride films, but little is known about how the sputtering process affects the film's quality. Thus, the focus of this study explores how sputtering parameters of discontinuous sputtering intervals, exposure to normal atmospheric conditions and in situ annealing affect the thickness, thermoelectric properties, and microstructure of films. This will bring about a better understanding of the relationship between the sputtering process and the properties of the produced film for both N and P type materials. Recommendations based on this study can contribute to the production of more efficient thin films suitable for energy harvest application.
Effect of Sputtering Process Parameters on the Thermoelectric Properties of P and N-Type Bi2Te3 Films
Authors: Arina  , Hui Fan Shermin Chow , Shamira Banu Abdul Bari , Chia Ai Lin , San Ye Ko , Khong Samuel , Sim Jonathan , Ezhilvalavan Santhiagu , Ma Jan , Hoon Heng Hui
Published: February 2012

Thermoelectric is an ever evolving field that serves many critical needs (cooling and power generation) in the industry. The key objective of this work is to fabricate Bismuth Telluride (Bi2Te3) thin-films by varying the various process parameters using a radio-frequency (RF) magnetron sputtering disposition technique. Characterization methods such as four point probe resistivity, surface profiler, atomic force microscopy (AFM), X-ray diffraction (XRD), Seebeck coefficient and thermal diffusivity are performed on the N and P-type Bi2Te3films. The samples are analysed for their electrical properties in relation to the evolved microstructures, for how the process parameters of sputtering and annealing affect these changes. The results demonstrate that N-Type film (S2) processed using sputtering parameters of 7mT, 100W, 50sccm of argon flow under room temperature for 30mins with no annealing and the P-Type film processed using sputtering parameters of 7mT, 100W, 60sccm under room temperature for 30mins with institute annealing at 200°C for 2h exhibit desirable thermoelectric properties suitable for cooling application in microelectronic and optoelectronic devices, optimizing their performance and reliability.
Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens
Authors: Petzer Inge-Marie , Karzis Joanne , Van der Schans Theodorus J. , Watermeyer Johanna C. , Mitchell-Innes Norman , Eloff Stephanie , Fosgate Geoffrey T.
Published: February 2012

The aim of this study was to compare the effects of cryopreservation at approximately -196 °C in liquid nitrogen (N) and freezing at approximately -20 °C in a freezer, on the viability and survival of eight different mastitogenic bacteria inoculated in milk. Bacteria were frozen at approximately -20 °C in a freezer and cryopreserved at approximately -196 °C in liquid nitrogen. An effective preservation method was needed for follow-up samples from cows identified in the South African National Milk Recording Scheme (NMRS) with somatic cell counts above 250 000 cells/mL milk. The organisation responsible for sample collection of the NMRS milk samples also provides producers with liquid nitrogen for their semen flasks at the collection sites. This existing mode of storage and transport could therefore be utilised.Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH) (phage type lytic group III) or Sta. aureus (STA) (phage typed, other than lytic group III). Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation.Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds.
Analyzing precipitationsheds to understand the vulnerability of rainfall dependent regions
Authors: Keys P. W. , van der Ent R. J. , Gordon L. J. , Hoff H. , Nikoli R. , Savenije H. H. G.
Published: February 2012

Abstract. It is well known that rivers connect upstream and downstream ecosystems within watersheds. Here we describe the concept of precipitationsheds to show how upwind terrestrial evaporation source areas contribute moisture for precipitation to downwind sink regions. We illustrate the importance of upwind land cover in precipitationsheds to sustain precipitation in critically water stressed downwind areas, specifically dryland agricultural areas. We first identify seven regions where rainfed agriculture is particularly vulnerable to reductions in precipitation, and then map their precipitationsheds. We then develop a framework for qualitatively assessing the vulnerability of precipitation for these seven agricultural regions. We illustrate that the sink regions have varying degrees of vulnerability to changes in upwind evaporation rates depending on the extent of the precipitationshed, source region land use intensity and expected land cover changes in the source region.
Inferring snow pack ripening and melt out from distributed ground surface temperature measurements
Authors: Schmid M.-O. , Gubler S. , Fiddes J. , Gruber S.
Published: February 2012

Abstract. The seasonal snow cover and its melting are heterogeneous both in space and time. Describing and modelling this variability are important because it affects divers phenomena such as runoff, ground temperatures or slope movements. This study investigates the derivation of melting characteristics based on spatial clusters of temperature measurements. Results are based on data from Switzerland where ground surface temperatures were measured with miniature loggers (iButtons) at 40 locations, referred to as footprints. At each footprint, ten iButtons have been distributed randomly few cm below the ground surface over an area of 10 m × 10 m. Footprints span elevations of 2100–3300 m a.s.l. and slope angles of 0–55°, as well as diverse slope expositions and types of surface cover and ground material. Based on two years of temperature data, the basal ripening date and the melt-out date are determined for each iButton, aggregated to the footprint level and further analysed. The date of melt out could be derived for nearly all iButtons, the ripening date could be extracted for only approximately half of them because it requires ground freezing below the snow pack. The variability within a footprint is often considerable and one to three weeks difference between melting or ripening of the points in one footprint is not uncommon. The correlation of mean annual ground surface temperatures, ripening date and melt-out date is moderate, making them useful intuitive complementary measured for model evaluation.
Afro and Indigenous Life-Visions in/and Politics. (De)colonial Perspectives in Bolivia and Ecuador
Authors: Walsh Catherine
Published: February 2012

Ancestral cosmologies or “life visions” are increasingly visible today, both within the realm of Afro and Indigenous community-based struggles, and within the frame of State constitutions, rights, and politics. This article looks at what happens when ancestral life–visions are positioned as central principles of State and of State politics and public policies. Can these philosophies, rationalities and logics otherwise guide the remaking or re–founding of society and State, and how, particularly when the authority, organization, and practice of politics and State remain bound to Western frames and capitalist interests?
HUMAN CAPITAL HETEROGENEITY AND ORGANIZATIONAL PERFORMANCE ANALYSIS: AN EMPIRICAL STUDY ABOUT INTERNATIONAL HOTEL CHAINS IN TURKEY
Authors: Halici Ali , Aktaş Ramazan , Kasimoglu Murat , Gruber Ahu Genis
Published: February 2012

Today, workforce diversity is not only a legal requirement for organizations, but it is also a must to survive in a highly competitive business environment. The prime motive for this study is to investigate the relationship between workforce diversity and perception of discrimination. The basic hypothesis of the study is that as the workforce diversity increases, the perception of discrimination decreases. In order to test the hypothesis, a survey is carried out international hotel chains in Istanbul. There are 19 international hotel chains in Turkey. In this study research is designed to understand human capital heterogeneity pattern of international chains of hotel industry and how this contribute organizational culture strategically that help to manage organizational performance much more efficiently with cross sectional data. Globalization of markets, changing demographics in the labor market, new business strategies requiring team work and the shift from a manufacturing to a service economy are the prime reasons for human capital heterogeneity (HCH). HCH improves the organizational capabilities in terms of flexibility, creativity, problem solving and competitive advantage. Especially in the service sector, in order to gain competitive advantage, organizations need a diverse workforce for both understanding the diverse needs of customers and answering to these needs in a prompt and proper way.
The Rise of a Local Opera form in east China, up to 1920
Authors: Stock Jonathan P. J.
Published: February 2012

Scholars of Shanghai opera accord their tradition, huju, a history of some two centuries or more, typically describing its rise in terms of a development from local traditions of folk song to balladry, and from ballad-singing to staged and costumed opera (in the 1920s). This chapter begins with a brief summary of the history of opera in China to provide initial orientation for the subsequent evaluation of how huju relates to and contrasts with other dramatic forms. The analysis draws on surviving primary and secondary source materials, such as the memoirs of old singers, to assess the question as to how much huju changed as it gained acceptance in the city of Shanghai. The data suggests that the generally cited model of development through stages of folk song-ballad-local opera is in need of revision, and new models are generated.
Ethnomusicological Research in an Urban Setting
Authors: Stock Jonathan P. J.
Published: February 2012

This chapter argues that ethnomusicology is unevenly theorized. Despite the amount of research now carried out on large-scale, mass-mediated, transnational, and professional traditions, theoretical-methodological literature has tended to emphasize models more appropriate to the research of small-scale traditions and those in which the researcher can gain direct experience as one of the performance group. Reyes Schramm noted twenty years ago that the urban environment offers a challenge to existing conceptions of research. It is shown that this challenge still applies and, through a consideration of researching huju in Shanghai, to spell out some aspects of it more explicitly.
In the Beginning: Origins and Originating Questions
Authors: Moorey P. R. S.
Published: February 2012

This chapter discusses terracottas and Old Testament study and looks at two paradigm shifts in recent scholarship in the origins of Israelite religion and in cognitive archaeology. It next turns to examine some conceptual hazards with regard to toys, magic and fertility. Finaly clay and cuneiform texts in terms of inscribed terracottas in ancient Mesopotamia are discussed and the value of broad and extended perspectives are given. Finally the chapter looks at contrasting terracotta repertories in the areas of Canaan, Israel and Judah.
Introduction
Authors: Haskell Yasmin Annabel
Published: February 2012

From antiquity, to the Middle Ages, to the Renaissance, and to the early modern period, a genre of poetry flourished in the West that has fallen out of favour in the recent times. This is didactic poetry, poetry of instruction in astronomy, hunting, farming, philosophy, and in all fields of sciences, arts, and recreational activities. In the seventeenth and eighteenth centuries, Jesuits produced a great quantity of Latin didactic poems. These poems revealed of the early modern Jesuits, local literary fashions, classical traditions, contemporary events and inventions, scientific developments, cultural knowledge, and social mores. Didactic poetry was the best literary genre for the cultivation of the Jesuits, the modern teaching order par excellence. The majority of Jesuit didactic poems were written by teachers, most of whom were writing in a radically transformed world of print and science, and in the scholarly language of Latin that was facing its gradual decline in the eighteenth century. Most of these poems were initially written for their fellow Jesuits and not for the proper literary classes of humanities and rhetoric. By the turn of the eighteenth century, didactic poems began to take a special place among the Jesuits, and a consciousness of contributions to the Jesuit tradition and microtradition ensued wherein the didactic poems took a special part.
Gentle Labour: Jesuit Georgic in the Age of Louis XIV
Authors: Haskell Yasmin Annabel
Published: February 2012

René Rapin, the father of Jesuit georgic poetry, manoeuvred his intellectual life between the ancients and the moderns with an instinct for conciliation and compromise that made him an effective apostle to the world. He is best remembered for his Horti, a classical-style didactic poem in four books that celebrated the victory of the moderns over the ancients in horticultural art. His poem, which is secular in appearance, is motivated by (mildly concealed) religion and Jesuito-political impulses, and cultural and literary impulses, particularly those of Virgil. This chapter discusses some of the developments in the Italian Renaissance georgic poetry to better understand Rapin's contribution to the early modern Latin georgic. It considers the latter Latin poems on horticulture and sericulture, which bear resemblance to the ancient model yet are considerably shorter than Virgil's. These latter georgic poems predicated on a Nature that is mild and marvellous, and centred on the artistic manipulation of Nature. In the Italian Renaissance, the ‘recreational georgics’ were dominated by pastoral ease, which is ironic, given the prominent thematic of labour in the original georgics. While the georgics were poems that celebrated nature and labour in gardens, by the turn of the eighteenth century, French Jesuits had identified the didactic genre of georgics as a flexible medium for exhibiting their modern Latinity and advertising their honnêteté.
Marvellous Works: The Poetry of Wonder in Baroque Naples
Authors: Haskell Yasmin Annabel
Published: February 2012

This chapter examines how the French Jesuits influenced the didactic poetic practice of their Italian counterparts. It discusses Niccolò ‘Parthenius’ Giannettasio, an Italian Jesuit who, in spite of his admiration of Rapin, Fracastoro, and other French Jesuit contemporaries, opted to write Latin didactic poetry in a Neopolitan setting. The chapter also discusses Tommaso Strozzi, another Neopolitan Jesuit, who took inspiration from Girolamo Fracastoro's Syphlis. Fracastoro, who was the most famous Renaissance successor of Pontano, had a profound influence on the georgic poetry of his Tommaso, particularly his Praedium rusticum. The chapter also discusses Francesco Eulalio Savastano, a Neopolitan Jesuit didactic poet. His poems were a hybrid of French Jesuit and native Italian strains of neo-Latin georgic. Compared to Rapin and his Neopolitan colleagues, Savastano produced a didactic poem of more ambitious scientific pretensions. His Botanicorium, seu Institutionum rei herbariae libri iv sought to surpass the didactic poetry of Rapin. His Botanicorium was the harbinger of the more self-consciously difficult scientific poetry of the Jesuits working in Rome. It looks not only to Lucretius, Fracastoro, and Virgil but also to rivals such as Giannettasio and, above all, Rapin. This attempt to produce a scholarly difficult poetry was an opportunity for poetic, as well as competitive, display.
People and the contemporary environment
Authors: Eden Sally
Published: February 2012

Geographical approaches to human-environment relations have been diverse and dynamic over the last century. They have also been heavily influenced not only by academic disciplines outside geography but by popular and policy concerns outside academia. From an initial flurry of activity about how the environment influences society in the early part of the century, British geography then took a detour to other topics even as other disciplines discovered the environment as a topic of interest. This left geographers playing ‘catch-up’ in the late twentieth century, as the discipline sought to reoccupy the ground previously abandoned. This is not over yet: in the 1990s, research into ‘the environment’ and ‘nature’ was scattered across academia. This chapter examines the relationship between humans and the contemporary environment, focusing on environmental protection, environmental management and ecological science, environmental policy and management, environmentalism, and environment and history.
Unmasking the ‘personality’ of the state—Max Weber, Staatsrechtslehre, and the modern state
Authors: Kelly Duncan
Published: February 2012

This chapter examines Max Weber's rejection of an idea central to nineteenth-century Staatsrechtslehre. This is the notion that the state itself is a ‘personality’. After outlining some of the main tenets of this tradition, the chapter seeks to show how Weber, borrowing from the work of Georg Jellinek in particular, retains a conceptual understanding of the state that stresses its position at the apex of political life. He nevertheless rejected the formalism of Jellinek's modified legal-positivist argument, which had resulted in his famous two-sided (one legal, the other political-sociological) account of the state. Weber insisted that the state could only be properly discussed as a relationship of domination, and in an empirical-sociological and comparative manner at that.
Introduction
Authors: Constantine Mary-Ann , Porter Gerald
Published: February 2012

This introductory chapter discusses fragments of song, which is the main topic of the book. It defines fragments of song, and examines folk-song scholarship and the full narrative. The concept of the dislocated text is covered in one section of the chapter. The chapter concludes with a discussion of the folk-song scholarship and the minimal narrative.
Beating time: resistance and the subaltern voice in prison work songs
Authors: Constantine Mary-Ann , Porter Gerald
Published: February 2012

This chapter discusses resistance and the subaltern voice present in prison work songs. It shows that the songs that accompany work and follow its rhythm stand as a collective challenge to ideas of what makes a ‘complete’ or shapely song. The chapter presents excerpts of several prison songs, which show that these songs are full of breaks, have episodes that return to their starting-point, and that their leads are not followed up. These songs assume not only a world ‘out there’, but also a context of more or less indefinite variation.
Fragments and fringes: the view from the centre
Authors: Constantine Mary-Ann , Porter Gerald
Published: February 2012

This chapter discusses the assumption that certain groups — specifically inhabitants of ‘border’ areas — are prone to produce song fragments. It focuses on the act of perception and the material itself. The first section has a brief discussion on the concept of ‘Celtic’, its development and its effects on the study of literature and song. The chapter also presents a case-study that shows how the centre-to-margins pattern of perception evident in ‘outside’ dealings with the Celtic-speaking cultures can recur internally.