Contact Situations Research Articles

Swept area modeling and cutter wear study in turn-milling

In turn-milling machining, we found the cutter wear concentrated on a small section around the corner of the cutter and affect the cutter life. In this paper, the idea of swept area is proposed firstly based on the analyses for cutter wear, and it can indicate the cutter wear. Balance of swept area will lead to balanced wear along cutting edge, and expressions of swept areas of infinitesimal elements on the cutting edge are given. Secondly, the cutting depth and cutting angle, which are the key parameters in calculating the swept area, are analyzed based on different contact situations between the cutter and workpiece, and the detailed calculating method is given. Then, the optimization model to balance swept areas along the cutting edge is established, and the cutting parameters including cutter offset and machining length are optimized. Finally, the orthogonal turn-milling machining experiments with different cutting parameters are conducted; the result shows that turn-milling with optimized parameters can actually balance the cutter wear and increase the cutter life.

슬라이더-디스크 접촉 영역에서의 마찰열에 의한 영향 연구

In HDD industry, many technologies have been developed and investigated as means to increase the areal density of drives. Thermal flying-height control has been considered and widely applied in current HDD. When contact occur between TFC slider and disk, the slider has a friction heating induced by highly rotated disk. Moreover, because of the friction heating, additional protrusion of slider can occur. The additional protrusion in contact situation can be a severe effect on head part of slider and disk. Therefore, in this paper, we analyze the friction heating and additional protrusion in contact situation.

Multiscale tool–fabric contact observation and analysis for composite fabric forming

This paper provides measurements and analysis at the meso and microscopic scales of the real contact area between twill carbon fabric and a flat glass counterface. The mesoscopic contact area associated with tow contacts is about 55–75% of the nominal area. However, the total real contact length within the tow contacts, associated with microscopic contact at the fibre level, is only 4–8% of the idealised contact conditions with parallel touching fibres, for a nominal contact pressure of around 2kPa. The dependence of real contact area on fabric shear angle is also investigated. The estimated real contact pressure is 15,000 times higher than the nominal contact pressure. Models or experiments of friction in composites forming which do not take into account the real contact situation, which is very far from an idealised packing arrangement, may fail to capture the essential tribological mechanisms.

A contact layer element for large deformations

In many contact situations the material behavior of one contact member strongly influences the force acting between the two bodies. Unfortunately standard friction models cannot reproduce all of these material effects at the contact layer and often continuum interface elements are used instead. These elements are intrinsically tied to the fixed grid and hence cannot be used in large sliding simulations. Due to the shortcomings of the standard contact formulations and of the interface elements a new type of a contact layer element is developed in this work. The advantages of this element are the direct implementation of continuum models into the contact formulation and the application to arbitrary large deformations. Showing a relation between continuum and contact kinematics based on the solid-shell concept the new contact element is at the end a natural extension of the standard contact formulations into 3D. Two examples show that the continuum behavior can be exactly reproduced at the contact surface even in large sliding situations using this contact layer element. For the discretization of the new contact element the Mortar method is chosen exemplary, but it can be combined with all kinds of contact formulations.

Give-Constructions in Heritage Ambon Malay in the Netherlands

The domains where languages show variable syntax are often vulnerable in language contact situations. This paper investigates one such domain in Ambon Malay: the variable encoding of give-events. We study give-expressions in the Ambon Malay variety spoken by heritage speakers in the Netherlands, and compare the responses of heritage speakers with those of homeland speakers in Ambon, Indonesia. We report that heritage Ambon Malay shows an innovative higher incidence of do constructions compared to the homeland variety, and a significant decrease in the frequency of ‘two predicate’ constructions. The change that heritage Ambon Malay is undergoing is thus not categorical, but rather involves a change in frequency of certain constructions. We argue that this ‘restructuring by changing frequency’ is due to a combination of factors: influence from Dutch, universal tendencies in language acquisition, and the language history of individual speakers. Apart from a quantitative difference, we also observe a qualitative difference between the give-constructions of heritage and homeland speakers of Ambon Malay: both groups use different prepositions in the prepositional object construction, a reflection of their different social histories.

Biblical Metaschematism as a Device for Religious Transfer - Paul’s Communicative Strategy in a Situation of Religious Contact

Paul’s use of the concept of metaschematism in the First and Second Letter to the Corinthians, and in the Letter to the Philippians can be examined as a significant example of religious transfer in the form of negotiation of schemata on the level of object language that tries to establish a meta-language through negotiation of schemata. By metaschematizing, mental and behavioral dispositions become interfaces linking different systems together, though in an asymmetrical manner. By taking into account the role of metaschematic processes in medicinal and philosophical contexts, the article intends to scrutinize the role of metaschematism in schematic interaction.

Photoreduction of 4-Nitrobenzenethiol on Au by Hot Electrons Plasmonically Generated from Ag Nanoparticles: Gap-Mode Surface-Enhanced Raman Scattering Observation

Hot electrons generated plasmonically from a Ag substrate can reduce 4-nitrobenzenethiol (4-NBT) to 4-aminobenzenethiol (4-ABT). In order to evaluate the effectiveness of hot electrons, we have carried out a surface-enhanced Raman scattering (SERS) study by forming a nanogap system composed of a planar Au substrate and an Ag-coated micrometer-sized silica bead, wherein 4-NBT was adsorbed first onto the Au substrate, and then Ag-coated silica beads, derivatized with 1-alkanethiols, were spread over the 4-NBT layer: the distance between 4-NBT and a nanostructured Ag substrate was varied by the chain length of alkanethiol molecules. Although the planar Au substrate itself was ineffective in the reduction of 4-NBT, hot electrons usable in the reduction of 4-NBT were generated from the Ag-coated silica beads. The hot electrons generated by 514.5 nm radiation were more effective in the reduction of 4-NBT to 4-ABT than those generated by 632.8 nm radiation, although the nanogap was more SERS-active with the excitation at 632.8 nm than at 514.5 nm. The photoreduction efficiency of hot electrons nonetheless decreased exponentially with the distance they traveled from the Ag surface: the reduction capability at a distance of 2 nm apart is about one-fourth of that in contact situations.

Conceptualising Linguistic and Cultural Mediation

This editorial discusses some issues associated with the definition of ‘language and culture mediation’, in order to contextualise the reflections found in this special issue. This expression, rather controversial in some countries, is often used to describe activities of assistance to foreigners, mainly migrants, similar to or coinciding with public service interpreting. A component of mediation is also recognised in the translator’s profession as s/he mediates between the source text and the final readers, and between the relevant cultures. But language and culture mediation can be interpreted more broadly, to refer also to situations of cultural contact involving a process of culture learning and synthesis. In this interpretation, rather than specific professional profiles, it designates various activities and situations involving mediation between cultures, e.g. in tourism communication, or in the promotion of culturally relevant products for export. Hence, it is argued that many problems surrounding the denomination ‘language and culture mediation’ are due to its use in specific contexts, while, if used as a superordinate, this expression can embrace various actions, activities and professional profiles having the common property of granting mutual accessibility to languages and cultures.

Experimental Study on Wave Propagation Across a Rock Joint with Rough Surface

Joints are an important mechanical feature of rock masses. Their effect on wave propagation is significant in characterizing dynamic behaviors of discontinuous rock masses. An experimental study on wave propagation across artificial rock joint was carried out to reveal the relation between the transmission coefficient and the contact situation of the joint surface. The modified split Hopkinson pressure bar apparatus was used in this study while all the bars and specimens were norite cored from the same site. One surface of the specimens with a number of notches was adopted to simulate the artificial rough joint. Two strain gauges were mounted on each pressure bar at a specific spacing. The incident, reflected and transmitted waves across the joints were obtained using a wave separation method. Comparisons of the transmission coefficients were made under two different conditions: with the same joint thickness but different contact area ratios, and with the same contact area ratio but different joint thicknesses. The results show the effects of contact area ratio and thickness of joints on wave transmission.

Contextualizing Intergroup Contact

This article examines intergroup contact effects in different political contexts. We expand on previous efforts of social psychologists by incorporating the messages of political parties as a contextual trigger of group membership awareness in contact situations. We argue that the focus among political parties on us-them categorizations heightens the awareness of group memberships. This focus in turn enhances the positive intergroup contact effect by stimulating majority members to perceive contacted persons as prototypical outgroup members. A multilevel analysis of 22 countries and almost 37,000 individuals confirms that the ability of intergroup contact to reduce antiforeigner sentiment increases when political parties focus intensively on immigration issues and cultural differences. Specifically, both workplace contact and interethnic friendship become more effective in reducing antiforeigner sentiment when intergroup relations are politicized. These findings demonstrate the need for widening the scope of the intergroup contact theory in order to cover macro-political conditions.

Connessione e contatto. Connettivi italiani nel ladino fassano parlato

This paper investigates a peculiar language contact situation, namely the Ladin area in Trentino-South Tyrol, in order to verify the presence and distribution of Italian discourse markers and connectives in a bilingual context. Based on a bilingual speech corpus , I will point out how Ladin speakers distinguishes between the pragmatic and semantic level of connection, using Italian forms in the first case and Ladin ones in the latter. In conclusion, I will focus on Italian connectives perche ‘because’ and allora ‘then, therefore’ and their equivalent Ladin forms , i.e. percheche / ajache and enlouta / donca.

DFCT: A New Data Forwarding Algorithm Based on Cumulative Performance and Transient Performance in DTNs

Delay Tolerant Networks (DTNs) are lack of end-to-end links. In order to overcome the frequent link interrupt, DTNs are often the store-carry-forwarding mechanism. Most routing forwarding algorithm only consider cumulative contact situation between network node and destination node, but in DTNs the frequent change of network topology can cause a lot of transient contact situation between network node and destination node. In order to make the fullest use of these transient contact situations, this paper proposes a new data forwarding algorithm based on cumulative performance and transient performance. It combines the cumulative performance and transient conditions between network node and destination node. We can choose a better relay node, so as to more efiectively improve the network performance. Then we use a realistic trace flle for simulation experiment, and compared with the two classic routing algorithms of Epidemic and Label. The experimental results show that the proposed algorithm can obviously reduce the network overhead compared with Epidemic algorithm and Label algorithm, and is close to the maximum delivery rate obtained by Epidemic algorithm.

Religion and language variation in a convergence area: The view from the border town of Kupwar post-linguistic reorganisation of Indian states

The study focuses on the contemporary ethnolinguistic situation in Kupwar at the Maharashtra-Karnataka border. Gumperz and Wilson (1971)'s classic study of language contact in this village predicted that multilingualism would be maintained as long as the ethnic (i.e. religious) separateness of home life remained important in the contact situation. This paper examines the influence of religion and regional identity on language choices, especially among the newly created linguistic minority communities. The paper suggests that Kupwar is characterised today by both accentuated religious differentiation and growing linguistic assimilation. Present-day patterns of language choice are interpreted in the light of the changed ethno-social context and the perceived role of religious identity in the region.

The effect of Italo-Romance contact on the Greek cluster vɣ in Corsica and the implications for sound change in Italiot Greek in Southern Italy

In this study we describe a change in the phonotactic structure of Corsican or Cargese Greek, involving the historical cluster /vɣ/, and relate it to contact with local Italo-Romance (Corsican). While the change in Cargese is seen to be very limited in scope, it provides a useful key to a better understanding of a similar but more complex series of changes in Greek dialects spoken in another Italo-Romance contact situation some distance away in Southern Italy. It also shows how a small change leads not to immediate replacement of an earlier structure, but to increased variation over time. We also motivate the change in question to show that it is related to very specific phonotactic and frequency features of /ɡw/ in Italo-Romance.

Should it be Omanhenes, Amanhenes or Amanhene? - or are they in free variation?

ABSTRACTThis article will look at the varying plural noun forms found in Akan. The focus will be on Akan nouns referring to persons, and the paper will discuss how these forms appear in Ghanaian English. It argues that in an intense language contact situation, such as pertains in (urban) Ghana, the question as to what is a code-switched item and what is a lexical borrowing is not clear, as many transferred items exhibit either Akan or English plurals and at times a confounding of the two. Some lexical items of obvious ethno-cultural significance cannot easily be classified as of either transfer category, and so code-switching and lexical borrowing might not be as clearly distinguishable as suggested by, for instance, Poplack and Sankoff (1984). It will be argued that the varying plural forms might be best explained in terms of a style-shift using Bell's (1999; 2001) Audience Design framework.

The management of academic discourse acquisition

AbstractThis article applies the Language Management Theory (LMT) in the context of overseas students participating in university study in an English-speaking context and who are developing their academic discourse while at the same time undertaking disciplinary studies. It draws upon data from a number of previous studies and examines central aspects of the theory, including kinds of management, stages of the management process, and simple and organized management, showing how the latter are sometimes interconnected in various ways. In the article, I consider issues relating to the start of the management process and analyze how power is exercised and by whom in these contact situations. Finally, consideration is given to methodological procedures which help us to identify the occurrence of management, in particular, follow-up (stimulated recall) interviews and interaction interviews.

Chinese IT terminology management in Hong Kong

AbstractThis article discusses IT terms and terminology management in Hong Kong from the perspective of Language Management Theory (Jernudd and Neustupný 1987, 1991; Jernudd and Nekvapil 2012; Nekvapil 2012). The noting, evaluating, adjusting and implementing of IT terms are examined in the context of lexical innovation (through translation) in the contact situation that Hong Kong represents. It describes the management of Chinese IT terms by agencies in Hong Kong and also discusses the efficacy of standardization of terminology as an agency goal in view of the potential of noting inadequacies of terminology in actual discourse.

The Effect of Englishisation on Language Use among the Ewe of Southern Volta in Ghana

The contact of English language with other languages in the world has significant impacts on language use in different domains. The coexistence of English with Ghanaian indigenous languages in Ghana, for example, has resulted to different language varieties in the country. Thus, presently, Ghana has three different language varieties: Unmixed-English, Unmixed-Ghanaian Language(s), and Mixed-English. The use of any of these varieties, as observed by Owusu-Ansah (1997) is, however, largely constrained by multiple domains of language use in Ghana. This paper, accordingly, discusses the extent at which the contact of English with Ewe language affects language use in the informal domain among the Ewe of Southern Volta. It highlights the use, and the domains of use of these varieties in contact situations, but focuses more on the informal domains such as homes, streets, recreational centres, markets and shops. The data were collected from 120 participants from different age groups, gender and different educational groups through participant observation and interview. The study has shown that the informal domains: homes, streets, shops, markets and recreational centres among the Aŋlɔ-Ewe are highly dominated by the use of English and Mixed-Ewe English varieties. This suggests that the Aŋlɔ-Ewe do not restrict themselves to language specific domains in Ghana, but manipulate the choice available to them to fulfill their communicative purposes; they choose the variety they feel most comfortable with. This finding thus contradicts Owusu-Ansah (1997). It nevertheless, contributes to the on-going discussion on language situation in Ghana, and also helps the Aŋlɔ-Ewe to work towards maintaining the Unmixed-Ewe variety so as to avoid its death.

Measurement and Observation of Elementary Transition Boiling Process after Sudden Contact of Liquid with Hot Surface

A Fast response surface temperature measurement technique has been developed to investigate transient transition boiling phenomena after ethanol droplet impact on a nickel hot surface. Our motivation is to make clear the mechanism of boiling transition between nucleate and film boiling which is closely related the recovery of wetting on the hot surface being higher than the Leidenfrost temperature. In this study transient boiling phenomena during sudden contact of an ethanol sessile droplet on a hot solid surface has been investigated to understand what governs whether the solid surface keeps wet or not. The droplet impact boiling system is very simple and easier to observe but it includes the elementary transition boiling process. Since the transient transition took place within a couple ten milliseconds, observation with high speed video system and fast response surface temperature measurement technique are essential for better understanding of the transition boiling phenomena.The experiments were conducted for single and multiple droplet impacts. The multiple droplet impacts simulates liquid and solid contact situations on a hot surface during spray or laminar jet quench. The nickel disk of 50mm in diameter and 5mm in thickness was used as the hot surface. The hot surface was inclined from 0 deg (horizontal) to 40 deg. The fast-response film thermocouple with a typical minimum response time of 80 microseconds was developed and fabricated on the nickel disk at the depth of 3 micrometers from the surface. The temperature histories just beneath the surface were recorded at the sampling frequency of 200kHz. The boiling phenomena beneath a sessile droplet impacted on the hot surface were observed by using a microscope equipped with the high speed video camera at the maximum frame rate of 22.5 kfps. The surface temperature and surface heat flux were estimated with 1D inverse heat conduction analysis. Histories of local surface temperature and local heat flux were compared with the boiling video image. The experiments were done for different initial wall temperatures up to 250°C, different liquid subcoolings from 33 to 53K. The multiple impact frequency was changed from 280 to 840Hz.In case of the single droplet impact tests, the observation results showed that wetting situation was maintained for very short time even though the surface temperature was beyond the liquid superheat limit temperature. We defined the vapor film generation time as the characteristic boiling transition time scale from wetted nucleation boiling regime to dry film boiling regime. The film generation time were measured for the extensive initial surface temperature range, different subcoolings and different impact velocities. As the initial surface temperature increased, the film generation time decreased to order of microsecond and film boiling situation seemed to be established via spontaneous nucleation (vapor explosion) process. In case of the multiple droplets impact tests, film generation times were evaluated every droplet impact during continuous cooling from the initial solid temperature. As long as the generation time was less than 1 millisecond and much shorter than the impact period, stable film boiling was observed. Then the film generation time increased with the droplet impact times and approached to the droplet impact period as the cooling time elapsed. This region was recognized as the transition boiling region. After the generation time reached to the droplet impact period and then stable wetted situation, namely nucleate boiling was observed. As compared with the single impact tests, the generation time for the multiple impact became shorter than that for the single droplet impact at same initial surface temperature and the lower limit surface temperature observed vapor film generation was reduced. This fact may imply the effect of transient heat conduction on the wetting temperature shifts to higher wall superheat temperature beyond liquid superheat limit temperature during quenching with jets or sprays.

The management of language and power in intercultural contact situations in Japan

AbstractThis article examines how participants in intercultural contact situations in Japan manage deviations relating to language and power in their daily life interactions. Based on the management summaries of eight plurilingual residents of Japan, this study investigates how deviations relating to language and power are noted and evaluated and what adjustment strategies are implemented in such cases. The results suggest that the management of language and power is complex and a number of interests may be in conflict. Deviations relating to power may be evaluated both positively and negatively and a lack of language proficiency can actually be used as a powerful tool. It is argued that speaker identity is a crucial issue that influences how interactional problems will be managed.