Cast Structure Research Articles

Corrosion behavior of Ti-0.3Mo-0.8Ni (TA10) alloy in proton exchange membrane fuel cell environment: Experimental and theoretical studies

The Ti-0.3Mo-0.8Ni (TA10) alloy is a titanium-based material known for its favorable corrosion resistance, making it a promising candidate for PEMFC bipolar plates. In order to investigate the electrochemical behavior of the TA10 alloy in a simulated PEMFC environment, the microstructure of the alloy was characterized using scanning electron microscopy and X-ray diffraction. The corrosion resistance was evaluated through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests in the simulated PEMFC cathode environment. Based on the experimental characterization, the mechanism underlying the improved corrosion resistance of the TA10 alloy in the PEMFC environment was revealed using first-principles calculations. The research findings demonstrate that the cast structure of the TA10 alloy comprises a predominant white α-phase matrix and a minor proportion of gray-black layered β-phase. The α-phase is composed solely of 100 wt% Ti, while the β-phase contains 90.4 wt% Ti and 9.6 wt% Ni. Under the simulated PEMFC environment, the corrosion potentials of TA1 and TA10 were observed to be − 0.424 V and − 0.228 V, respectively, in the anode environment, and − 0.382 V and − 0.234 V, respectively, in the cathode environment, representing an increase of approximately 38.7–46.2 % compared to the TA1 alloy. Importantly, the corrosion current density of the TA10 alloy was reduced by approximately 20.5–36.9 % compared to TA1, indicating enhanced corrosion resistance and chemical stability due to the higher corrosion potential and lower corrosion current density exhibited by the TA10 alloy. Furthermore, electrochemical impedance spectroscopy (EIS) measurements demonstrated a significant increase in the capacitive arc radius of TA10 compared to TA1, with an Rfb value of 7.166 kΩ cm2 for TA10, approximately 13 times higher than the corresponding value of 0.529 kΩ/cm2 for TA1. This substantial increase in the Rfb value signifies the improved corrosion resistance of TA10 compared to TA1. Theoretical calculations revealed that the presence of Mo and Ni elements in the TA10 alloy effectively reduces the overpotential on the Ti surface. Specifically, the overpotential was found to be 0.734 eV for Ti-Mo, 0.569 eV for Ti-Ni, and when Mo and Ni were co-doped, the overpotential further decreased to 0.512 eV. This reduction in overpotential enhances the rate of the cathodic hydrogen evolution reaction and facilitates the formation of an anodic passivation film, thereby significantly improving the corrosion resistance of the TA10 alloy. In conclusion, our study provides comprehensive insights into the electrochemical performance of the TA10 alloy in a PEMFC environment, highlighting its potential as a corrosion-resistant material for bipolar plates in PEMFC applications.

Bulleh Shah’s Anti-Orthodox Views on Self-Purification and Their Implications for Social Reforms in Punjabi Society

Bulleh Shah is regarded as a social critic and reformer, though he was not a conventional preacher, but he was a true critic of his contemporary society. Sufis aimed at ethical character reformation of the society. This article discusses the moral and ethical situation in Punjabi society of Bulleh Shah’s time and his Sufi philosophy for social reforms. Bulleh Shah reflected on the social situation of his time in his poetry. This article relates Bulleh Shah’s views regarding social reforms to the concurrent social issues in Punjabi society. Bulleh Shah focused on the real character and criticized hypocrisy and duality in pursuit of social, political, and religious aims. Punjab remained a gateway for the invading forces in India. So, the social structure in Punjab remained complex with a clear distinction between the privileged and underprivileged classes. The exploitative social order inspired pride and hollow show among the upper elite and inferiority sentiments among the least privileged classes. Bulleh Shah’s philosophy for self-purification and salvation focuses on the negation of self-pride to achieve harmony with nature and humanity in general. Punjab was not a land of homogeneous class structure, race, and religion. Here was a merger of various cultures, and people belonged to different religions. These differences were so obvious that it was difficult to extract the uniform principle on which the Punjabi identity could be constructed. Religion, caste structure, sect, and biradari all played important roles in constructing Punjabi identity. These were the critical issues of concern for the intelligentsia of that time.

Caste Identities and Structures of Threats: Stigma, Prejudice and Social Representation in Indian universities

Caste is a complex ontological construction. Despite several anti-caste movements and constitutional provisions, caste exists in the Indian psyche as part of everyday life. Even in the advent of globalization, caste continues to foster social and economic inequalities and exclusion in newer forms and perpetuates violence. The available research on caste-based stigma and humiliation provides a limited understanding as it deals with Dalits only; and ignores caste-Hindus (upper-caste) agency. Based largely on qualitative data collected at an intense three-day workshop, including two Focus Group Discussions and a year-long ethnography, this article illustrates the micro processes of everyday life experiences of caste-based stigma and humiliation among university students, academic staff and administrative staff. It explores subtle and overt caste discrimination, prejudices and stereotypes existing in the spatial morphologies of Indian higher education, its perpetuation on campuses and its impact on students’ psyche. It highlights the dearth of scholarship in this area of caste identity and stigma; and proposes nuanced questions for future research to understand why universities in India are turning into places of social defeat for Dalit and OBC students. The article argues the basis of caste discrimination and humiliation in universities is not the same as it exists in other social institutions. Instead of asserting conclusions on this matter we set out justifiable lines of inquiry. There are two issues that this article examines: first, how students in Indian higher education evolve strategies for coping with threatened identities. Second, what structural repair in higher education is required to heal the wounded (caste) psyche?

Contesting the mainstream transwoman figurations: The question of caste and precarity in Udalaazham

ABSTRACT Udalaazham (Body Deep), the 2018 Malayalam film directed by Unnikrishnan Avala, intrigues into the precarious dimensions of gender liminality in unprecedented ways by being the first film to discuss the life of a gender-liminal belonging to a tribal (Paniya) community in Kerala. The paper engages in a close reading and analysis of the film-text Udalaazham by placing it in juxtaposition to figurations of transgender subjectivities in contemporary Malayalam films, with an aim to contest the acclaimed progressive disposition of these mainstream representations. It employs the framework of intersectionality to focus on the protagonist Gulikan’s lived experiences enmeshed within the structures of tribal caste, ethnicity and gender characterized by multiple interlocking dimensions of precarity. His body, identity and desires are open to threat, violence, mutilations and perpetual questioning due to lack of socio-cultural capital and support network. The relevance of this film is in opening up the discussions on caste and liminal gender identity and thereby urging the dire need to re-write the formula of identity politics in the region and its popular culture. Reading Udalaazham in this context provides a more liberating yet disturbing space to discuss the regressive operations of identity categories and their limitations in conceptualizing regional queer identities in India.

IMPACT OF HIGHER EDUCATION AND DEVELOPMENT OF BACKWARD CLASSES: A CASE STUDY IN CHITTOOR DISTRICT ANDHRA PRADESH

In traditional India different castes formed a hierarchy of social precedence. Each position in the caste structure was dened in terms of in purity or pollution relative to others, whilst those who are least pure i.e. the Panchamas, sometimes called the 'out castes' or 'Untouchables' are inferior to all other castes. In the traditional system is generally conceptualized in terms of the four-fold Varnas, which in addition to the Brahmins at the top included the Kshatriyas, or warriors, the Vaishyas, or traders, and the Shudras, or servants and labourers, in that order. Thus, in a class society members typically believe that mobility is easily available and secured on merit. Andhra Pradesh (AP) is a relatively newly formed state; it was carved out of an erstwhile statewith the same name that was divided into AP and Telangana in 2014. The participation of educationally disadvantaged communities such as Scheduled Castes (SCs), Scheduled Tribes (STs), and Other Backward Classes (OBCs), has been increasing over the years at all stages except senior secondary. This could be attributed to several factors, one of which is the lack of accessibility to the seinstitutions, especially for students from disadvantaged. India is one the oldest societies on earth. Also known as Bharat and Hindustan and condently termed as the 'Republic of India', it is the largest liberal social equality of the world. India is divided into 29 states and 7 union territories. India is also the land of the Vedas the oldest scriptures in the world. It is divided in four-volumes and is gaze at as the storehouse of coast-to-coast thoughts. Today, India is the world's seventh largest country in terms of area and second in terms of populaces. The sights, the ancient temples and the lush paddy elds make the country unique and amazing. It has 22 major languages with 844 dialects, making this country and its people culturally diverse. The secular nature of India has attracted philosophers and researchers from across the globe to explore India

Synthesis and properties of high-entropy CoCrFeNiMnWx alloys

Compact samples and coatings from CoCrFeNiMnWx high entropy alloys (HEAs) powders synthesized by mechanical alloying followed by plasma spheroidization (PS) were obtained by directed energy dssssseposition (DED). The microstructure of CoCrFeNiMnWx samples obtained by DED represents a cast dendritic structure. The phase composition of all samples represents a solid solution with FCC lattice. The increase in the lattice parameter in the samples by 0.33–0.47% compared to the spheroidized powder is characteristic of all obtained alloys after DED. The lattice parameter of CoCrFeNiMnWx samples increases with increasing W content, which is associated with the formation of a highly entropic solid replacement solution. The hardness of the samples increased by 4.6% and 12.9% with the addition of W in amounts of 0.125 and 0.25 at. % to the CoCrFeNiMn HEA, respectively. Tungsten-doped alloy coatings have a higher bending strength than the CoCrFeNiMn alloy. With relatively similar ductility values, the CoCrFeNiMn alloy has a lower strength, which is insufficient to resist cracking when bent to an angle above 20–45°, depending on the bending direction.

Microstructure evolution and constitutive modeling of as-cast A356 aluminum alloy in semi-solid deformation regime

The present work deals with the semi-solid deformation behavior of A356 aluminum alloys with an emphasis on microstructure evolution and constitutive modeling. The main idea of this research is based on investigating the semi-solid deformation behavior starting with primary dendritic cast structure, instead the conventional approach in which a feedstock is prepared through the various spheroidization process. Toward this end, hot compression tests in the semi-solid temperature range (580, 590, and 600 °C) under different strain rates (0.001, 0.01, 0.1 s−1) and different initial holding times (1, 7, and 14 min) have been conducted. Compared with the thixotropic deformation in which the solid globules slide within the liquid matrix through lubricated flow mechanisms, in the present case, the strain compensation through the deformation of solid grains was increased. The higher portion of the solid-grains from the applied strain provided a proper condition for substructure development and dynamic recrystallization in the semisolid temperature range. The penetration of the liquid phase along the newly developed boundaries was introduced as another factor influencing on the softening behavior of the material. Under these conditions, the specimens were deformed up to the high strain level (>0.5) without creating cracks or tearing under very low stresses less than 2 MPa. A phenomenological-physical constitutive equation was also developed considering deformation parameters (temperature, strain rate, and strain) and material's parameters (grain size, strain rate sensitivity, viscosity) which was capable of predicting the semisolid flow stress behavior of the material.

Study on the composition, microstructure and properties of new W-Al alloyed ethylene cracking furnace tube under 1100 ℃ carburising test conditions

ABSTRACT The carburising tests were carried out at 1100 ℃ for 50 h, 100 h, 150 h and 200 h for a new type of tungsten-aluminium alloyed ethylene cracking furnace tube. The composition, microstructure transformation and performance of furnace tubes were analysed. The results showed that the average carbon content within 1 mm of the inner wall increased with the prolongation of carburising time. The thickness of carburised layer increased from 0.3 mm to 1.5 mm. The carbides in as cast structure were mainly massive (Cr, Fe, W)23C6 on the outside and fishbone (Cr, Fe, W)7C3 on the inside. During carburising process, the external (Cr, Fe, W)23C6 carbides coarsened and transformed into (Cr, Fe)7C3, and then gradually transformed into (Cr, Fe, W)7C3. Carbide coarsening mainly occurred in internal (Cr, Fe, W)7C3 during carburising. The carbide precipitation and transformation also led to Vickers hardness value of furnace tube increased.

Mechanical properties and electrical conductivity of Al–Y–Sс–Er cold worked alloy

Aluminum alloys alloyed with rare earth and transition metal are promising materials for electric energy transportation due to their high properties of strength, thermal stability, and electrical conductivity. The features of strengthening, their mechanical properties and electrical conductivity of Al–0.2Y–0.2Sc–0.3Er alloy after cold rolling have been established. The alloy as a cast structure is presented by aluminum solid solution (Al) and dispersed eutectics with τ2 (Al75-76Er11-17Y7-14) phase upon complete dissolution of scandium in (Al), and a content of yttrium and erbium at the level of 0.2–0.3 % each. Cold rolling the ingot accelerates strengthening upon annealing at 270 and 300 °C, reducing the time of achieving peak hardness. The maximum strengthening due to precipitation of L12 dispersoid of Al3(Sc,Y,Er) phase with the average particle size up to 10 nm is achieved after 7 h of annealing at 300 °C after cold rolling. This shows the prevailing heterogeneous mechanism of nucleation due to defects accumulated during cold rolling which stimulates strengthening. The eutectic particles are located mainly along the boundaries, elongated in the rolling direction. Irrespective of the mode of sheet fabrication, the alloy demonstrates high thermal stability up to 400 °C. During annealing of the sheets to 450 °C, their non-recrystallized structure is retained. Ingot annealing at t = 300 °C in 7 h and cold rolling with subsequent annealing under the same conditions provide a high level of mechanical properties and electrical conductivity: σ0.2 = 194 MPa, σu = 210 MPa, δ = 12.1 % and IACS – 60,1 %. The alloy has demonstrated high yield stress up to 100 h of annealing at t = 300 °C.

Structure and strain state of aluminum bars at the initial phase of extrusion

The structure of insufficiently deformed areas at the non-steady phase of extrusion was studied. The tests at Kamensk Uralsky Metallurgical Works using a 120 MN press and 800 mm dia. container, in order to extrude a 355.6 mm dia. Bar was performed. The bar material is the Al–Mg–Si AD33 aluminum alloy (GOST 4784), similar to ASTM 6061. The percentage reduction was 80 %, and the reduction ratio was 5.06. After that, the macrostructure, microstructure, and average grain size along the radius, mechanical properties at room and elevated temperatures were investigated. It was found that the extruded bar macrostructure is fine-grained, homogeneous, and dense, with no nonmetallic or intermetallic inclusions. The cross-section contained several structures. The central part is weakly deformed preserving the dendritic cell structure inherited from the casting. At the circumference, a streaked structure is formed. Its components are crushed and uniformly distributed. We measured the strength at elevated temperatures and compared the results to the data available in the literature. The tested material strength almost doubled, thus indicating its incomplete softening. The ductility was also performed. The DEFORM-2D software, in order to simulate the low reduction of extrusion was used. The metal at the circumference is exposed to a greater strain from the extrusion beginning. A step-by-step analysis indicated that at the first step, the strain is localized near the die hole. In the second step, a rigid area is formed in the vicinity of the die/container liner interface. The circumference layer of metal with a 1.75–2.00 reduction of area is formed. At the bar center, this range is 0.75–1.00 (half of the circumference value). In the third step, the circumference layer with an elevated strain has a wedge-like shape. In the fourth step, the circumference layer (with elevated strain) has an equal thickness along the extrusion axis. This indicates the steady phase. The plastic strain at the bar front end is higher at the circumference than in the center. This confirms the structural analysis results. They show that the central part of the bar may retain its cast structure, while the circumference is deformed. If the bar central part is required to have some specific properties, the bar has to undergo another manufacturing operation to increase the accumulated strain. Re-extrusion processes the areas insufficiently deformed during the first extrusion.

Garment buttons from a Hallstatt period tumulus

Abstract A Hallstatt period burial mound (tumulus) in Schandorf, Burgenland, Austria, was opened and archaeologically investigated in 2021. Not only numerous pottery fragments, but also some garment buttons were found, one of which was provided for metallographic examinations, aiming at identifying the method of manufacture: soldering, riveting, casting? Prior to the metallographic examinations, micro-computed tomography (μm CT) was carried out at a resolution of 5 μm. The Figures show that large areas are oxidized. It was, however, found that metallic portions still existed. The overall appearance suggests investment casting as the manufacturing method. Analytical measurements revealed that the material is tin bronze. Despite severe corrosion, the metallographic sections still exhibit a clearly recognizable cast structure. There are presumably two types of corrosion: first, high temperature corrosion, which resulted in the formation of bronze oxides in the grain boundary areas during the cremation, and, second, corrosion in an aqueous environment, during which malachite formed. So far, no comparable studies can be found in the literature.

Low cycle fretting and fretting corrosion properties of low carbon CoCrMo and additively manufactured CoCrMoW alloys for dental and orthopedic applications.

Additive manufacturing (AM) of CoCrMo metallic implants is growing in the orthopedic and dental fields. This is due to the traditional alloy's excellent corrosion resistance and mechanical properties. AM processes like selective laser melting (SLM) require less time, materials, and waste than casting or subtractive manufacturing complex-geometry structures (bridges, partial dentures, etc.). The objective of this work was to investigate the low cycle tribological and tribocorrosion characteristics of AM CoCrMoW alloys compared to wrought LC CoCrMo (ASTM F-1537) to assess this AM alloy's performance. Fretting and tribocorrosion testing was performed in air (wear only), PBS (wear + corrosion), and PBS with 10 mM H2 O2 (wear + corrosion + inflammation) by a single diamond asperity. No variation between alloys in volume of material removed (p = .12), volume of plastic deformation (p = .13), and scratch depth (p = .84) showed that AM was substantially similar in wear resistance to LC in air and PBS. AM exhibited significantly higher fretting currents (p < .01) at loads up to 100 mN ( = 57 nA and = 49 nA) than LC CoCrMo ( = 30 nA) and ( = 29 nA). In PBS, wear track depth linearly correlates to fretting current, averaged over 100 cycles. Additionally, fretting currents of both alloys were significantly lower in simulated inflammatory conditions compared to PBS alone. AM alloy has generally similar wear and tribocorrosion resistance to wrought LC CoCrMo and would be ideal for patient specific dentistry or orthopedics where precise, complex geometries are required.

Lead isotope reveals the mineral source change of late Bronze Age bronze mirrors excavated in Hunan Province, Southern China

The late Bronze Age was the first golden period for bronze mirror production in ancient China. In this paper, scientific analysis and research were carried out on 28 late Bronze Age bronze mirrors excavated in Hunan Province, Southern China. All bronze mirrors are Cu-Sn-Pb materials, and their lead isotope data are in line with the characteristics of common lead. Among them, 4 bronze mirrors containing metal bodies all show bronze casting structures with high tin features, and there are some differences in the elemental composition distribution range between them and previously tested bronze mirrors. This paper significantly reveals that the lead mineral source of Hunan bronze mirrors underwent two obvious changes during the late Bronze Age. The Warring States bronze mirrors excavated in Hunan mainly used lead ore from the Nanling region and Northern Hunan region, and Changsha should be the center of mirror-production and mirror-circulation in Southern Chu Kingdom. However, the lead ore consumed by the Western Han bronze mirrors excavated in Hunan primarily came from the East Qinling region, which was close to the core region under the rule of the Western Han government. In the middle and late Eastern Han Dynasty, with the frequent metal production activities in the Nanling region and the prosperity of private mirror-casting industry in Southern China, lead ore from the Nanling region was re-introduced in the production of Hunan bronze mirrors.

Design and development of low density, high strength ZrNbAlVTi high entropy alloy for high temperature applications

Superior high temperature strength, better thermodynamic stability and good workability are some of the desirable attributes of structural materials for next generation nuclear reactors. In this regard, the present study involves the development of a low density, equiatomic ZrNbVTiAl High Entropy Alloy (HEA) for nuclear applications. The alloy was designed using a combination of thermodynamic simulations and first principle techniques and later synthesized using levitation melting to ensure better purity and compositional homogeneity. The melted alloy possessed lower density (5.76 g/cm3) and higher hardness (5.7 GPa) in comparison to conventional structural materials like austenitic steel. Detailed characterization of the alloy showed the presence of bcc type phase along with small fractions of Al- Zr type intermetallics in as-solidified condition. The mechanical properties of the equiatomic ZrNbVTiAl alloy were studied using compression testing at room temperature and up to 1000 °C. The alloy exhibited superior specific yield strength as well as dynamic recrystallization at high temperatures resulting in the breaking of cast structure, thereby reflecting its appreciable workability. The alloy also showed a satisfactory elastic modulus (128 GPa) when measured using ultrasonic technique. The experimentally measured values of elastic moduli of alloy were compared with the values obtained through Density Functional Theory (DFT) simulations and the results matched within acceptable range. Results from the present study indicates that the equiatomic ZrNbVTiAl alloy could be a suitable candidate for light weight, high temperature and high strength structural applications.

A Study on Manufacturing Technique and Corrosion Characteristics of Bronze Dirk, Bronze Sword, Bronze Mirror in Early Iron Age Excavated from the Osong Site in Cheongju

Metallography, SEM-EDS, and Raman Micro-Spectroscopy analysis were conducted on bronze dirk, bronze sword, and bronze mirror excavated from the pit tomb No. 1-1 at 12th Point of Osong Site in Cheongju to study the manufacturing techniques and corrosion properties. The bronze dirk, bronze sword and bronze mirror are judged to be binary alloys of Cu(79.16∼79.89 wt%)-Sn (19.12∼20.34 wt%). The microstructure is a cast structure composed of δ phase and (α+δ) eutectoid, and no heat treatment was performed. As a result of classifying the corrosion characteristics, it was confirmed that the bronze dirk, bronze sword, bronze mirror were Type I. As a result of EDS analysis in subsurface area, tin oxide is located as a selective corrosion of (α+δ) eutectoid, and as a result of Raman Micro-Spectroscopy analysis, corrosion products of Cassiterite and Malachite were identified for the bronze dirk and Cassiterite for bronze sword and bronze mirror. The secondary metallic copper was mainly present in the hole left by corrosion of Pb particles and on the (α+δ) eutectoid, and was found to be 100.00 wt% of Cu as a result of the analysis, confirming that all of them were high-purity copper.

The Influence of Microstructure Quality on the Efficiency of Bucket Teeth of Career Excavators

The mining industry is the main base of the country's industrial potential, a significant part of which is the development and production of various rocks and minerals. The main type of machines used in open pit mining are powerful excavators, who make up the bulk of the equipment fleet of mining enterprises. Operating enterprises incur large losses due to wear and destruction of excavator bucket teeth, therefore, improving the quality of the tooth material is an urgent task. This article discusses the influence of the casting quality, including the cast structure of the material, on the performance of the excavator teeth. The object of research was the teeth of the buckets of Cat-391 and VOLVO-350 mining excavators made of 30Cr2Si2MnMo steel after long-term operation. The actual condition of the bucket teeth of mining excavators after operation was examined and microstructure, hardness and worn surfaces of the teeth was analyzed. The study showed that the efficiency of excavator bucket teeth is determined by the level of unevenness of the microstructure and microhardness and the presence of defects, hot and cold cracks. It has been established that the main reason for the accelerated failure of the teeth of open-pit excavator buckets is the superposition of various microstructural defects connected with unevenness of the metal microstructure and imperfection of the casting process. Main directions of increasing efficiency of mining excavators’ teeth bucket were identified.

‘Why Can’t Our Bhuta Have a Mask?’ Caste Contestations and Ritual Practice in Tulunadu

The paper describes caste contestations around the Bhutaradhane tradition in the Tulunadu region of coastal Karnataka. Bhutaradhane is a pantheistic tradition of spirit worship which has been a key site for the assertion of regional identity claims in Tulunadu. The Bhutas (spirits) are ranked along a graded hierarchy that reflects the caste structure of the region. Drawing on ethnographic fieldwork, the paper describes the interventions of a Dalit caste, the Mundalas, to rupture this hierarchical structure and challenge their low assigned status in the tradition and in society. It explores how they draw on narratives of the past to appropriate and reshape the Bhutaradhane tradition in line with their aspirations for upward mobility. The paper situates current contestations around the caste’s patron Bhuta within the growing socio-political consciousness of the Mundalas, who have challenged the hegemonic discourse of Bhuta heritage, laying bare the operations of caste within the ritual as well as caste inequalities and exclusions in the region.

Effect of hafnium on cast microstructure in alloy 1570

The issue is devoted to the study of the influence of hafnium on the structure and properties of alloy 1570. Ingots from alloy 1570 were cast into the steel coquille, including those with additives of hafnium 0.1, 0.2 and 0.5 %. To determine the size of the grain structure in the obtained ingots, an Axionovert-40 MAT optical microscope was used, chemical analysis of intermetallic particles was carried out using JEOL 6390A SEM. In addition, for the alloy 1570 and 1570–0.5Hf, the presence of nanoparticles with the L12 structure was studied using transmission electron microscope JEM-2100. Studies showed that hafnium additives make it possible to achieve a significant modification of the cast structure. For example, when introducing hafnium into the initial alloy in an amount of 0.5 % of the total weight, it was possible to achieve a reduction in the average grain size by 2 times. Scanning microscopy data showed that hafnium partially dissolves in particles containing scandium and zirconium as well. The addition of hafnium increases the number of large particles formed during crystallization. Transmission microscopy showed the presence of coherent aluminum matrix nanoparticles in alloy 1570 and having a superstructure of L12, which were most likely formed during intermittent decay during ingot cooling. When 0.5 % Hf was added, no nanoparticles with the L12 superstructure were detected. To explain the latter fact, it is necessary to study the surface of the liquidus of the Al–Hf–Sc system, as well as to study the effect of hafnium on the diffusion coefficient of scandium in aluminum.

Film and Caste Anxieties in Early Twentieth-Century India

Film was one of the new technological inventions of the ‘long nineteenth century’ that often instilled a fear of loss of the existing way of life and of disturbing existing social structures. In India, this manifested in a variety of ways, such as through the censorship of films by the government, but also by social codes which created major barriers for many to work in the film industry. In this article, I discuss film and its negotiations with caste in the twentieth century through close reading of the Indian Cinematograph Committee Report, film magazines, advertisements, audience responses and the speeches of nationalist leaders. I argue that rather than democratising desire by producing the universally desirable object of the star body, popular films in India produced desire that conformed to existing caste structures. The paper contributes to debates about early cinema and caste beyond the question of representation.

Vascular Cast to Program Antistenotic Hemodynamics and Remodeling of Vein Graft.

The structural stability of medical devices is established by managing stress distribution in response to organ movement. Veins abruptly dilate upon arterial grafting due to the mismatched tissue property, resulting in flow disturbances and consequently stenosis. Vascular cast is designed to wrap the vein-artery grafts, thereby adjusting the diameter and property mismatches by relying on the elastic fixity. Here, a small bridge connection in the cast structure serves as an essential element to prevent stress concentrations due to the improved elastic fixity. Consequently, the vein dilation is efficiently suppressed, healthy (laminar and helical) flow is induced effectively, and the heathy functions of vein grafting are promoted, as indicated by the flow directional alignment of endothelial cells with arterialization, muscle expansion, and improved contractility. Finally, collaborative effects of the bridge drastically suppress stenosis with patency improvement. As a key technical point, the advantages of the bridge addition are validated via the computational modeling of fluid-structure interaction, followed by a customized ex vivo set-up and analyses. The calculated effects are verified using a series of cell, rat, and canine models towards translation. The bridge acted like "Little Dutch boy" who saved the big mass using one finger by supporting the cast function.