Search

This article introduces and elaborates on the themes of PCE2021: 'Tihei mauri ora – Contact, culture, and context'. It provides the background to the organizers' thinking about these themes, and especially their focus on bicultural engagement in the context of life and therapeutic practice in Aotearoa New Zealand and, as such, offers an introduction to this special issue of papers from that conference. [ABSTRACT FROM AUTHOR]

The main work of this paper is to investigate two kinds of generalized focal surfaces and two kinds of evolutes generated by spacelike curve γ lying in lightlike surfaces in Minkowski three‐space. Applying the method of unfolding theory in singularity theory to our study, it is shown that there exist the cuspidal edge and the swallowtail types of singularities in each of two classes of generalized focal surfaces under certain conditions; the only cusps will appear in each of evolutes. Two new geometric invariants are presented to classify the singularities of generalized focal surfaces and evolutes. Much more importantly, we reveal the correspondence among the geometric invariants, the types of singularities on generalized focal surfaces and evolutes, the singularities of two kinds of evolutes, and the contact of γ with the osculating spheres. Finally, several examples are presented to demonstrate the correctness of the theoretical results. [ABSTRACT FROM AUTHOR]

This communication describes a simple method for printing aqueous solutions with millimeter-scale patterns on a variety of substrates using an easily fabricated, paper-based microfluidic device (a paper-based “stamp”) as a contact printing device. The device is made from inexpensive materials, and it is easily assembled by hand; this method is thus accessible to a wide range of laboratories and budgets. A single device was used to print over 2500 spots in less than three minutes at a density of 16 spots per square centimeter. This method provides a new tool to pattern biochemicals—reagents, antigens, proteins, and DNA—on planar substrates. The accuracy of the volume of fluid delivered in simple paper-to-paper printing is low, and although the pattern transfer is rapid, it is better suited for qualitative than accurate, quantitative work. By patterning the paper to which the transfer occurs using wax printing or an equivalent technique, accuracy increases substantially., Chemistry and Chemical Biology

Attitudes toward and contact with lesbian women and gay men were assessed through questionnaires in a 2-year follow-up study in a cohort of 511 Norwegian participants, 19 years of age at first data collection. A substantial proportion reported negative attitudes at baseline (between 39 and 63%) and two years later (between 32 and 59%), females being more positive than males. A majority reported having no contact with lesbian women or gay men either at 19 years of age (66–79%) or 2 years later (51–62%). Longitudinally, the measures were moderately stable (Pearson's r 0.43–0.73), and contact change was positively related to attitude change. Also, attitude change positively predicted contact change. The findings imply that efforts to reduce stigma associated with homosexuality are still needed among young people in Norway. Copyright © 2002 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper contributes to international feminist debates on shared parenting and family violence via reforms to Canada's Divorce Act, in force since 2021. Looking backwards, it reviews parliamentary debates and early judicial discussions. The documentary review reads the reforms as an unstable compromise between calls from feminist voices and experts on family violence and from groups representing fathers. Family violence is now defined broadly and declared relevant to children's welfare. But language in the statute may undermine its seriousness. Exposing the tensions underlying these reforms is useful for Canadian participants in family justice and for scholars, practitioners, and policymakers elsewhere, exemplifying the promise and perils of reform in this area. Looking ahead, the paper offers recommendations to higher courts. Appellate judges should read rules on contact with both parents and parental cooperation in the light of the new recognition of family violence, taking the latter as an overarching objective of the statute. [ABSTRACT FROM AUTHOR]

This work is devoted to the mathematical and numerical study of a framework handling a system of coupled variational inequalities. We prove both the existence and the uniqueness of a weak solution to the problem. Then, we introduce a convergent iterative scheme. Using this latter, we decouple the problem into further subproblems and derive their corresponding minimization problems. As a practical application of this class of coupled abstract variational inequalities, we consider a class of problems that model an electroelastic body coming into frictional contact with a rigid electrically conductive foundation. Both electrical and mechanical contacts are of Signorini type. In other words, our model prescribes the mechanical response produced by the foundation and the outflow of the free charges across the contact zone. The last part of this paper is mainly reserved for the numerical resolution of the problem at hand. For this purpose, we have developed an alternating direction method of multipliers and convex dualities to compute and illustrate the solutions. [ABSTRACT FROM AUTHOR]

In this paper, a semi-analytical calculation model for the coefficient of friction (COF) of single spherical protrusions is presented. It allows the prediction of the deformative friction part (μdef) and adhesive friction part (μadh) of the friction pairings steel ∣ polyethylene with ultra-high molecular weight (PE-UHMW) and polyoxymethylene (POM) ∣ PE-UHMW. The experimental studies included unlubricated friction tests, which served to determine the total COF (μtot), as well as tests being lubricated with silicone oil, from which μdef is obtained. Based on the verification tests, it could be shown that both states of lubrication result in the same deformation and that the relationship between the rear angle (ω) and μdef postulated in the calculation model is valid. Therefore, friction tests with segmented spheres were carried out, which allow a specific variation of the ω. It can be concluded that for both pairings the μdef is generally of minor significance (approx. 1/3 μtot) and the influence of the μadh predominates (approx. 2/3 μtot) the friction process. Furthermore the μtot decreases with increasing contact pressure especially in the low pressure range and depends on the form of motion (continuous and discontinuous). [ABSTRACT FROM AUTHOR]

This paper examines variation in six features of Spanish, testing the hypothesis that outcomes of language and dialect contact are shaped by the differing social meaning of linguistic variables. Two of the study's variables are strongly associated with aspects of identity and style. Four others are poorer signals of social meaning, despite constituting sites of crosslinguistic and/or dialectal difference. In the speech of life-long residents of the contact setting (Boston, MA), the weak features have converged with English grammatical norms. In contrast, the strong features show persistence of dialectal and crosslinguistic differences, suggesting that socially weaker variables are more susceptible to reconfiguration by bilingual optimization strategies. The effect of contact on strong variables, by comparison, is to amplify their already powerful links to ideologies of personal and group style. While strong variables are not immune to contact-induced change, modification in their use is primarily social, rather than cognitive, in nature. [ABSTRACT FROM AUTHOR]

There is a well-known variety of contact paradoxes which are significantly linked to topology. The aim of this paper is to present a new paradox concerning contact with bodies composed of a denumerable infinity of parts. This paradox establishes the logical necessity, in a Newtonian context, of contact forces (herein called "phantom forces") that violate what is probably our most basic causal intuition, embodied in what I call the Principle of Influence: any force exerted on a body B induces (causes) change of movement of B or (inclusive disjunction) the emergence of internal forces in B. However, the above paradox can be made strictly compatible with a Newtonian framework by introducing phantom forces as ideal elements in the Hilbert sense, though it will be seen that this does not solve all the problems. [ABSTRACT FROM AUTHOR]

The clinician who adopts a psychoanalytic approach in a psychiatric context often regards the encounter between two individuals as an interplay of subjectivities, whose mode of being-in-the-world is shaped by their unique historical experiences. Despite some psychoanalytic authors exploring the concept of "contact", it has often been reduced to its similarity with transference and countertransference, with little attention given to its distinctive qualities. This limits psychoanalysis in its ability to conceptualize an unmediated, preverbal encounter between two individuals. In this article, we argue that the dimension of "contact" cannot be equated with transference, and that it constitutes a vital tool for diagnosing and guiding therapy for various clinical conditions commonly encountered in psychiatry. This article is based on theoretical considerations. We first worked on the history of the concept of contact, then of Praecox Gefühl in the works of H.C. Rümke, to which we added the findings of current studies on the relevance of Praecox Gefühl in the diagnosis of schizophrenia and the study of the works of the great phenomenological psychiatrists. In so doing, we aimed to show that contact could be a tool of great use for psychiatric diagnosis, insofar that it allows for a typification of the forms of existence of different patients. H.C. Rümke's investigation of the concept of Praecox Gefühl highlights the unique mode of contact observed in schizophrenia. It is distinct from the feeling of strangeness and involves an intuitive observation of a perceived distance within the clinical relationship. Given that many psychiatric pathologies can cause patients to withdraw from the shared world, we suggest that the notion of Praecox Gefühl , beyond its original designation of the clinician's experience of schizophrenic dissociation and the particularities of the schizophrenic mode of being-in-the-world, may be applicable to other pathologies studied in psychiatric phenomenology. We propose four main forms of contact: the loss of vitality in schizophrenia, the untraceable authenticity of the hysteric, the impossible fluidity in the melancholic, and the failure of anchorage in mania. By approaching contact as a fractal form that reveals the entire mode of the subject's being-in-the-world, this typifying approach goes beyond a purely semiological or etiological reflection and can be diagnostically useful in guiding therapeutic efforts to enhance the subject's capacity to truly engage with others. Our paper focuses on the relationship between contact and what clinicians commonly refer to as an "encounter." It is important to recognize that contact is not always equivalent to an encounter, and that assuming otherwise risks overlooking the possibility that certain relational modalities could actively prevent such an encounter from taking place. These "anti-contact" modalities, exemplified by the Praecox Gefühl , necessitate a focus on the very possibility of being in a therapeutic relationship with the clinician. Therefore, we suggest that clinicians should work to establish the possibility of being in a relation with the patient, prior to attempting to create an encounter. This approach allows for a more nuanced understanding of the ways in which patients can either facilitate or hinder the development of an encounter, and highlights the importance of working on establishing the possibility of a real encounter and being-with the clinician. This paper has sought to challenge the prevailing assumption among psychoanalytically oriented clinicians that contact is merely a sub-dimension of the transferential dynamic. Instead, we have argued that contact warrants specific attention as a tool for both diagnosis and therapy in psychiatry. By examining the example of the Praecox Gefülh , we have proposed a typifying approach that could be applied to the most common clinical entities encountered in psychiatry, based on the clinician's perception of specific modalities of contact within the therapeutic consultation. This reflection on contact and anti-contact is a necessary and contemporary contribution to the psychiatric field, which is increasingly embracing a dimensional approach to psychological pathologies. By prioritizing the dimension of contact, we can deepen our understanding of the nuances of the therapeutic relationship and can enhance our ability to help patients overcome barriers to connection and encounter. [ABSTRACT FROM AUTHOR]

Precision and traceable measurement of small forces have become increasingly important due to the rapid change in technology and miniaturization of devices. In this paper, we have discussed the design, development and metrological aspects of double bending beam force transducer for low-force measurements. To achieve this task, elastic spring element is designed and machined for fabricating the force transducer and virtually tested through the finite element analysis (FEA) method to validate its load capacity and to understand its mechanical behaviour. The metrological capability of spring element is determined with the application of small forces, sensing the applied forces through contact and non-contact methods. In the contact method, strain gauges are employed for the detection of induced strain on the spring element. For this, the maximum and minimum strain values and their distribution are found to get the optimum normalized output in the electrical unit of mV/V. In the non-contact method, a pair of light-emitting diode (LED) and light-dependent resistor (LDR) is utilized for the detection of the bending caused by the applied force. The optimal detectable deflection is found in the spring element through FEA. The experimental characterization results of the force transducers showed that the developed force transducers have good metrological capability in terms of high linearity and repeatability in the range of 0.3–3 N. [ABSTRACT FROM AUTHOR]

Analytical solutions of some contact problems are infinite functional series according to the system of basic functions. When constructing such solutions, it becomes necessary to represent the kernels of integral equations describing the process of interaction in the form of two-dimensional series on a given basis. Often the kernels have a rather complex appearance, therefore, the process of finding the decomposition coefficients is a rather complex and labor-intensive process, on which the accuracy and speed of obtaining final results depend. The paper proposes a calculation method that allows calculating the coefficients of decomposition of the kernels of plane contact problems according to a special orthonormal basis that takes into account the features of contacting bodies. Other approximate formulas are also derived for the special case when coating characteristics are constant. Based on the received presentation, conclusions and recommendations are formulated. [ABSTRACT FROM AUTHOR]

This paper discusses an approach to estimating the parameters of the cohesive zone model (CZM) by mode II by extruding the bushing along the lug axis. This method of evaluation requires small samples, which is particularly relevant when investigating short fiber-reinforced polymers (SFRPs) with additively manufactured embedded elements. Adhesion is investigated on the example of 30% carbon fiber-reinforced polyamide-6 molded to Ti-6Al-4V (VT6) selective laser-melted (SLM) alloy bushing in cases of a roughness Ra = 2.66 μm (vibratory finishing), Ra = 8.79 μm (sandblasting), and Ra = 10.02 (directly from SLM). The values of the maximum equivalent tangential contact stress were in a range from 1.1 MPa to 9.5 MPa, while the critical fracture energy for tangential slip was estimated at 15 N/mm for all cases. Experimental validation of the obtained CZM mode II was carried out by evaluating the load-carrying capacity of the lugs with different bushings. In both the experiment and the calculation, greater bushing roughness provides greater lug load-bearing capacity. The ribbed bushings added significant strength in the experiments, which confirmed the importance of considering the tangential mode in the contact model. The presented models can be used for the preliminary evaluation of short fiber-reinforced polyamide-6 parts with titanium-embedded elements bearing capacity. [ABSTRACT FROM AUTHOR]

Rail grinding with abrasive belt is increasingly applied in daily rail maintenance due to its high efficiency and high quality. The contact between rail and abrasive belt largely determines grinding efficiency and grinding quality, but the influences of grinding process and contact wheel’s parameters on the contact behaviour are obscure. To explore the influences, a finite element model of the wheelrail contact was established. The simulation results showed that the grinding angle significantly affected the shape of contact spot. The contact spot gradually became narrower as the grinding angle increased. Similarly, the reduction of the contact wheel radius significantly increased the contact stress. But when the ratio of the thickness of rubber layer to wheel radius increased above 60 %, it had little effect on the size of contact spot and maximum contact stress. This study provides the basis for the selection of grinding process and contact wheel’s parameters. In the actual grinding process, grinding process and contact wheel should be selected according to grinding requirements. (Received in April 2022, accepted in June 2022. This paper was with the authors 2 weeks for 1 revision.) [ABSTRACT FROM AUTHOR]

Friction is often accompanied by local fracture at the boundary of the contacting bodies. The gap between the bodies usually contains moving particles of different origin ("third body"), a change in the effective friction conditions may be associated with some changes in the structure of the third body. This paper presents a new series of experiments in which the process of rearrangement of intermediate layer particles interacting with various elastic materials (glass-rubber and steel) is modeled at different scale levels. A technique for visualizing the effect of mutual influence that occurs when two balls are pressed into a layer of rubber is proposed. It is the mutual influence that causes the effect of convergence or separation of the balls or particles during reciprocating frictional loading. The velocity of these processes depends on humidity and, in case of contact with the rubber layer, on the thickness of the layer. At high humidity, the configuration of the particles changes faster, and the friction force decreases. Replacing sand with an abrasive leads to an increase in the coefficient of friction and wear with a change in the microrelief of the surface. The minimum roughness is obtained for a humidity of 30%. [ABSTRACT FROM AUTHOR]

At present, there are very few vibration test designs for compressor stator blades in damped blade test research, and there is a lack of consideration of the holding ring structure of the blade installation. In recent years, compressor designs have become more elaborate, and their structures have become more compact. For improving compressor stator blade design, it is necessary to study the blade vibration response considering contact and friction. In this paper, a compressor stator blade vibration test system with a holding ring structure is designed and built. The composition of the system and the flow of vibration are tested. Then, the nonlinear vibration rules of the model stator blades are experimentally studied through the built test bench. The experimental conditions include excitation forces of 1 N, 2 N, 3 N and 4 N, respectively. At the same time, the normal load of the outer holding ring and the blade contact surface includes 10 N, 20 N, 30 N and 40 N working conditions. The nonlinear vibration law of the test model blade considering contact friction is analyzed using a numerical method and experimental data. The experimental data agree well with the numerical analysis results, and the relative error of measurement is basically less than 5%. It is concluded that the damping vibration rule of the test model blade is related to the exciting force applied by the exciter and the contact surface normal load applied by the adjusting bolt. When these two parameters change, the movement behavior of the contact surface will switch between macro-slip, fretting slip and even a viscous state. Therefore, the amplitude of the blade will change and show nonlinear vibration characteristics. The experimental data in this paper can provide a reference for research on stator ring vibration safety in compressors. [ABSTRACT FROM AUTHOR]

The present paper examines the tactile suitability of 3D printed materials with visually impaired people. The 3D printed materials are produced using two different printers, working with FFF and ColorJet technologies. The used material for the FFF technology is PLA, and for the ColorJet technology it is gypsum material, which is treated with different stages of finishing coating. By using the mentioned 3D printed materials, different models of animals, Egyptian symbols, cars, the Braille alphabet, screwdrivers, etc. are printed. To achieve the aims and objectives of the present paper, a group of 5 blind, 4 visually impaired people were examined by touching the pre-specified 3D printed test models. The results are original and they have not been published in other editions. [ABSTRACT FROM AUTHOR]