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The nursing profession is faced with various challenges, and the work of nurses and technicians has become extremely responsible and demanding. Sometimes such a way of working can have negative consequences on mental health. The goal was to examine the differences in suicidality between nurses/technicians and nursing students, the association of suicidality with sociodemographic variables and loneliness in nursing students and nurses/technicians, and the contribution of variables to suicidality in nurses/technicians and nursing students. Subjects and methods: A cross-sectional study was conducted on the population of nurses and technicians and nursing students. A total of 144 respondents participated in the online survey conducted in February and March 2023. One hundred and thirteen (78.5%) employed nurses and technicians who are not studying and 31 (21.5%) nursing students participated in the research, the mean age of the respondents was 31.26 (SD=11.62). Sociodemographic data were collected. The presence of suicidal thoughts was tested with the attribute scale of suicidal ideation. Loneliness was tested with the scale of social and emotional loneliness. Results: Significantly higher levels of suicidality were found in nursing students compared to nurses/technicians (Mann-Whitney test; p=0.047). The results showed that in nursing students there is a significant moderate positive association between suicidality and family loneliness (Spearman's correlation; p=0.018) and a moderate negative association with the assessment of financial status (Spearman's correlation; p=0.019). In nurses/technicians, the results showed that suicidality is moderately positively associated with social (Spearman correlations; p

The outpatient clinic provides a special institutional service for psychiatric patients who need treatment in an environment similar to a hospital but allows them to return home and integrate into everyday life after therapy. This form of treatment is suitable for patients who do not require hospitalization, but who need a more intensive therapeutic program that includes active treatment. Objective: To examine the differences in mature, immature and neurotic defense mechanisms before and after treatment in the Outpatient Clinic of Psychiatry. Respondents and methods: The research was conducted in 2023. Ninety-two patients treated in the Outpatient Clinic of Psychiatry participated in the research, of which 18 (56.5%) were female and 74 (80.4%) were male, and the mean age of the subjects was M=52.45 (range from 27 to 74; SD=10.34). Demographic Questionnaire and Defense Style Questionnaire (DSQ-40) were used in the research. Results: Overall, looking at defense mechanisms, the results showed that the neurotic defense mechanisms were significantly lower after treatment (t-test; p=0.039). Individually looking at mature defense mechanisms, after treatment the subjects used sublimation significantly less (ttest; p=0.049) while they used humor significantly more (t-test; p=0.008). In the case of neurotic defense mechanisms, after treatment, subjects used pseudo-altruism (t-test; p=0.038) and idealization (t-test; p=0.003) significantly less, while they used reactive formation significantly more t-test; p=0.035); while with immature defense mechanisms after treatment, they used acting out (t-test; p=0.006), denial (t-test; p=0.012) and splitting (t-test; p=0.014) significantly less, while they used passive aggression significantly more (t-test; p=0.002). Conclusion: Despite the relatively short duration of treatment, these findings suggest that even relatively short-term therapeutic procedures can have a significant impact on reducing maladaptive defense mechanisms. These results emphasize the importance of therapeutic interventions in promoting adaptive defense mechanisms and reducing dysfunctional defense strategies. Although further research is needed to understand the long-term effects of therapy on defense mechanisms, these preliminary findings suggest that therapists can successfully intervene in reducing unhealthy defense patterns in their patients even in a relatively short period of time.

In this paper, we employ the finite element method based on non-uniform rational B-splines function approximation to solve the nonlinear Brinkman-Forcheimer-Darcy equation in a simply connected and bounded Lipschitz domain Ω. We provide both theoretical and numerical studies of the Dirichlet boundary problem. Utilizing a stream function formulation, we demonstrate the well-posedness of the weak form. Furthermore, we approximate the velocity and pressure fields by linearizing the nonlinear terms, resulting in an algebraic system. This Non-uniform rational B-splines method is more effective in terms of the exact representation of the geometry and the good approximation of the solution compared to the virtual element method. To validate the effectiveness of the non-uniform rational B-splines Finite Element Method, we conduct numerical simulations of fluid flow in porous media.

The inclusion of memory-dependent derivatives (MDD) in constitutive models improves the ability to predict and analyze time-dependent responses of materials, providing a more detailed depiction of their mechanical properties and structural changes. In this paper, a new thermoelasticity model is created that combines the Moore-Gibson-Thompson (MGT) equation with higher-order memory-dependent derivatives (MDD), any optional kernel function, and time delay. The objective of this model is to provide a more accurate mathematical depiction of the thermal and mechanical reactions of materials, particularly those that exhibit complex behaviors over time. A theoretical study was conducted to provide additional clarification of the proposed concept. For this purpose, thermal-mechanical waves were studied in a semi-infinite region, surrounded by a magnetic field, and exposed to a direct heat source uniformly distributed on its outer surface. To solve the coupled partial differential equations governing the system, the Laplace transform methodology was used. The effects of different kernel functions, time delays, and higher-order (HO) derivatives on the behavior of thermoelastic materials are discussed and illustrated using figures and tables.

Open surgical repair of abdominal aortic aneurysm (AAA) is often regarded as a near-permanent operation with little long-term complications. Reported herein is a case of delayed rupture of an enlarging AAA sac after open repair requiring re-exploration in a patient presenting with flank pain and ipsilateral hydronephrosis. The natural history of a large, excluded aneurysm sac after open AAA repair, hypothesized etiology for this rare occurrence, and proposed diagnostic and therapeutic algorithm are described.

Abstract There has been increasing practical and scholarly interest in the engagement of universities with the Sustainable Development Goals (SDGs). However, there has been limited examination of international university collaborations focusing on the SDGs and how they become embedded within universities. Addressing this need, this article explores the experiences of three members of the Reach Alliance a consortium of eight higher education institutions from around the globe. Reach supports students and faculty mentors to study how critical interventions can be made accessible to those who are the hardest to reach. This work aligns with SDG 4 (Quality Education), as well as SDG 17 (Partnership for the Goals) and the Goal’s second universal value of leave no one behind. This commitment to connecting education and societal engagement resonates with Goddard et al.’s work on the civic university as both “globally competitive and locally engaged” (2012: 43). This article focuses on University College London (UK), Ashesi University (Ghana), and Tecnológico de Monterrey (Mexico), selected for their diverse structures and geographies. For each case, we examine how the Reach Alliance initiative has been institutionally embedded, as well as the role of local and global partnerships in making the case for supporting Reach. We find that Reach’s organisation as an international network has encouraged its adoption by host institutions. The initiative’s emphasis on both local concerns as well as the global goal and networks has also resonated with host institutions. This article will be of interest to those working in sustainability and higher education when considering strategies for introducing or increasing SDG-focussed research and teaching.

Abstract Accurately characterizing the thermomechanical parameters of nanoscale systems is essential for understanding their performance and building innovative nanoscale technologies due to their distinct behaviours. Fractional thermal transport models are commonly utilized to correctly depict the heat transfer that occurs in these nanoscale systems. The current study presents a novel mathematical thermoelastic model that incorporates a new fractional differential constitutive equation for heat conduction. This heat equation is useful for understanding the effects of thermal memory. An application of a fractional-time Atangana–Baleanu (AB) derivative with a local and non-singular kernel was utilized in the process of developing the mathematical model that was suggested. To deal with effects that depend on size, nonlocal constitutive relations are introduced. Furthermore, in order to take into consideration, the viscoelastic behaviour of the material at the nanoscale, the fractional Kelvin–Voigt model is utilized. The proposed model is highly effective in properly depicting the unusual thermal conductivity phenomena often found in nanoscale devices. The study also considered the mechanical deformation, temperature variations, and viscoelastic characteristics of the functionally graded (FG) nanostructured beams. The consideration was made that the material characteristics exhibit heterogeneity and continuous variation across the thickness of the beam as the nanobeam transitions from a ceramic composition in the lower region to a metallic composition in the upper region. The complicated thermomechanical features of simply supported viscoelastic nanobeams that were exposed to harmonic heat flow were determined by the application of the model that was constructed. Heterogeneity, nonlocality, and fractional operators are some of the important variables that contribute to its success, and this article provides a full study and illustration of the significance of these characteristics. The results that were obtained have the potential to play a significant role in pushing forward the design and development of tools, materials, and nanostructures that have viscoelastic mechanical characteristics and graded functions.

This study aimed to measure the total arsenic content deposited in the ovaries of three consecutive generations of mice. The animals were treated with two different concentrations to determine whether histological changes were caused in the ovaries. The control group of mice received tap water, whereas the experimental groups were given different concentrations of dissolved arsenic (III)-oxide. The arsenic content in the ovaries in both experimental groups increased with each generation. The highest content was recorded in the third generation of the second experimental group. Between the two experimental groups in each generation, significant differences in the average number of corpora lutea and ovarian follicles were identified. Arsenic caused structural changes in the ovaries in both experimental groups in all three consecutive generations.

The structure verification of 5′-oxospiro-(fluorene-9,4′-imidazolidine)-2′-thione by NMR is reported. Toward this aim, 2D NMR techniques including 1H-1H COSY, HMQC, and HMBC experiments were used to assist with the assignment of the 1H and 13C chemical shifts for the corresponding structure. The mutual interpretation of the 1D and 2D NMR spectra ensured a complete and accurate 1H and 13C NMR data assignment for 5′-oxospiro-(fluorene-9,4′-imidazolidine)-2′-thione.

Imagery has become one of the main data sources for investigating seascape spatial patterns. This is particularly true in deep-sea environments, which are only accessible with underwater vehicles. On the one hand, using collaborative web-based tools and machine learning algorithms, biological and geological features can now be massively annotated on 2D images with the support of experts. On the other hand, geomorphometrics such as slope or rugosity derived from 3D models built with structure from motion (sfm) methodology can then be used to answer spatial distribution questions. However, precise georeferencing of 2D annotations on 3D models has proven challenging for deep-sea images, due to a large mismatch between navigation obtained from underwater vehicles and the reprojected navigation computed in the process of building 3D models. In addition, although 3D models can be directly annotated, the process becomes challenging due to the low resolution of textures and the large size of the models. In this article, we propose a streamlined, open-access processing pipeline to reproject 2D image annotations onto 3D models using ray tracing. Using four underwater image datasets, we assessed the accuracy of annotation reprojection on 3D models and achieved successful georeferencing to centimetric accuracy. The combination of photogrammetric 3D models and accurate 2D annotations would allow the construction of a 3D representation of the landscape and could provide new insights into understanding species microdistribution and biotic interactions.

Abstract Our study is dedicated to a mixture composed of a dipolar elastic medium and a viscous Moore–Gibson–Thompson (MGT) material. The mixed problem with initial and boundary data, considered in this context, is approached from the perspective of the existence of a solution to this problem as well as the uniqueness of the solution. Considering that the mixed problem is very complex, both from the point of view of the basic equations and that of the initial conditions and the boundary data, the classical methods become difficult. That is why we preferred to transform it into a problem of Cauchy type on a conveniently constructed Hilbert space. In this way, we immediately proved both the existence and uniqueness of the solution, with techniques from the theory of semigroups of linear operators.

A combination of 1D and 2D NMR techniques, including HMQC, HSQC, 1H-1H COSY and HMBC, was used to provide completely assigned 1H and 13C NMR data for the structures of three 3-[substituted methylidene]-1H,3H-naphtho[1,8-cd]-pyran-1-ones—3-[(4-methoxyphenyl)methylidene]-1H,3H-naphtho[1,8-cd]-pyran-1-one, 3-[(4-fluorophenyl)methylidene]-1H,3H-naphtho-[1,8-cd]-pyran-1-one and 3-[(thiophen-3-yl)methylidene]-1H,3H-naphtho[1,8-cd]-pyran-1-one. The heteronuclear coupling constants 1–4JCF and 3–4JHF were correspondingly determined. Additionally, IR and Raman spectral data were provided in support of the assigned structures.

This paper presents a more general method to study the dynamic behavior of a planar mechanism with joints. To do this, Graph Theory is used. A topological description is presented based on which a corresponding graph is attached to any mechanism. This method can be used for both kinematic and dynamic study in the same model, and many of the descriptors used in kinematic analysis can also be used for dynamic analysis. As a final result, the motion equations of the studied mechanical system can be obtained. An application is made to a flap and wing control system of a light sport aircraft. The graph associated with the mechanism first used to determine the field of velocities and accelerations of the mechanism elements is then used to obtain the motion equation for the control system. In this way, Graph Theory proves useful for the parallel study of both the kinematic and dynamic study of such problems.

The current work aims to investigate the interaction between thermal, magnetic, and elastic phenomena in a homogeneous and unbounded material that includes a spherical cavity. A laser beam with a Gaussian distribution was used to expose the solid thermal medium, thereby bringing a source of heat into the system. The study is grounded in the expanded theory of thermoelasticity without energy dissipation, which considers the interconnection between thermal, elastic, and magnetic phenomena. This theoretical framework serves as a basis for understanding the interactions and behaviors of thermal and mechanical processes within an elastic material. The system was analyzed using a direct approach, employing the Laplace transformation method to provide solutions for the system's equations. This methodology enables the computation and presentation of precise equations for several domains of concern, such as displacement, temperature, and thermal stresses. The discussion and analysis focused on a copper-based material, and graphical representations were used to demonstrate the behavior of the researched physical fields. These graphical representations aid in comprehending the development of displacement, temperature, and thermal stresses within the material caused by the laser beam and the interplay between thermal, magnetic, and elastic processes. The results demonstrate that the laser pulse parameters have a significant impact on the temperature and thermal stress distribution, thereby influencing the thermo-mechanical reactions of the solid medium. Ultimately, this study enhances our comprehension of the intricate behavior and interplay of thermal, magnetic, and elastic phenomena in thermoelastic materials.

Within the framework of the Thaenae archaeological field-school, excavations were carried out from 2017 to 2022 by a Tunisian-French team in the vicinity of the Tacape Gate in order to contribute to the study of the urban evolution of the city, marked, in Late Antiquity, by the construction of a wall whose area is larger than that of the Early Imperial city. On the basis of cross-referenced field and laboratory data (coins, ceramics and radiocarbon), it has been shown that this wall was built in the first half of the 4th century (perhaps as early as the first quarter of the century) by including the funerary spaces and craft workshops, which were then moved outside the new wall. The monumental character of this wall and the care taken in its construction argue in favour of a prestigious operation testifying to the economic and political vitality of the city of Thaenae in the years preceding or following the advent of the Constantinian dynasty.

Abstract The study of multibody systems with elastic elements involves at the moment the reevaluation of the classical methods of analysis offered by analytical mechanics. Modeling this system with the finite element method requires obtaining the motion equation for an element in the circumstances imposed by a multibody system. The paper aims to present the main analysis methods used by researchers, to make a comparative analysis, and to show the advantages or disadvantages offered by different methods. For the presentation of the main methods (namely Lagrange’s equations, Gibbs–Appell’s equations, Maggi’s formalism, Kane’s equations, and Hamilton’s equations) a unified notation is used. The paper provides a critical evaluation of the studied applications that involved some of these methods, highlighting the reason why it was decided to use them. Also, the paper identifies potential research areas to explore.

In this paper, we implement the finite detail technique primarily based on T-Splines for approximating solutions to the linear elasticity equations in the connected and bounded Lipschitz domain. Both theoretical and numerical analyses of the Dirichlet and Neumann boundary problems are presented. The Reissner–Mindlin (RM) hypothesis is considered for the investigation of the mechanical performance of a 3D cylindrical shell pipe without and with preformed hole problems under concentrated and compression loading in the linear elastic behavior for trimmed and untrimmed surfaces in structural engineering problems. Bézier extraction from T-Splines is integrated for an isogeometric analysis (IGA) approach. The numerical results obtained, particularly for the displacement and von Mises stress, are compared with and validated against the literature results, particularly with those for Non-Uniform Rational B-Spline (NURBS) IGA and the finite element method (FEM) Abaqus methods. The obtained results show that the computation time of the IGA based on the T-Spline method is shorter than that of the IGA NURBS and FEM Abaqus/CAE (computer-aided engineering) methods. Furthermore, the highlighted results confirm that the IGA approach based on the T-Spline method shows more success than numerical reference methods. We observed that the NURBS IGA method is very limited for studying trimmed surfaces. The T-Spline method shows its power and capability in computing trimmed and untrimmed surfaces.

This work demonstrates deformation in hygrothermoelastic medium with an overlying non-viscous fluid of uniform thickness. A constant mechanical force is applied along the fluid-layer. The normal-mode analysis technique is applied to solve the governing equations of the medium. The analytical expressions of displacement, moisture concentration, temperature distribution, and stresses are obtained for the hygrothermoelastic medium and depicted graphically for different values of fluid-layer depth. The finding of this work is that the values of the aforementioned physical quantities decrease with an increase in the fluid-layer, which justifies the decaying nature of waves with depth. The novelty of the problem is that no research has been carried out so far for analyzing hygrothermoelastic medium subjected to thermoelastic deformation.

Abstract GPCRs are master regulators of cell signaling by transducing extracellular stimuli into the cell via selective coupling to intracellular G-proteins. Here we present a computational analysis of the structural determinants of G-protein-coupling repertoire of experimental and predicted 3D GPCR-G-protein complexes. Interface contact analysis recapitulates structural hallmarks associated with G-protein-coupling specificity, including TM5, TM6 and ICLs. We employ interface contacts as fingerprints to cluster Gs vs Gi complexes in an unsupervised fashion, suggesting that interface residues contribute to selective coupling. We experimentally confirm on a promiscuous receptor (CCKAR) that mutations of some of these specificity-determining positions bias the coupling selectivity. Interestingly, Gs-GPCR complexes have more conserved interfaces, while Gi/o proteins adopt a wider number of alternative docking poses, as assessed via structural alignments of representative 3D complexes. Binding energy calculations demonstrate that distinct structural properties of the complexes are associated to higher stability of Gs than Gi/o complexes. AlphaFold2 predictions of experimental binary complexes confirm several of these structural features and allow us to augment the structural coverage of poorly characterized complexes such as G12/13.

In this paper, we bring into light, study the polygonal structure of Fibonacci polynomials that are placed clockwise on these by a number corresponding to each vertex. Also, we find the relation between the numbers with such vertices. We present a relation for obtained sequence in an n-gon yielding the m-th term formed at k vertices. Also, we apply these situations to Lucas polynomials and find new recurrence relations. Then, the numbers obtained by writing the coefficients of these polynomials in step form are shown in OEIS.

Abstract This paper introduces size-dependent modeling and investigation of the transverse vibrational behavior of rotating thermoelastic nanobeams by means of nonlocal elasticity theory. In the formulation, a model of thermal conductivity with two-phase delays (DPL) was utilized. By incorporating the interactions between phonons and electrons, this model took into account microstructural influences. Also, we have employed the state-space approach and Laplace transform approach to solve the governing equations, which were developed in the context of the nonlocal Eringen model. The nanobeam material is subjected to a changeable temperature field produced by the graphene tape attached to the nanobeam and connected to an electrical source. In addition, the nanobeam material is fully encompassed by an axially applied magnetic field. It has been revealed how coefficients such as the rotational angular velocity of the nanobeam, nonlocal coefficient, voltage, electrical resistance, and applied magnetic field influence its behavior.

Background: This study aims to evaluate PD-L1 expression in colorectal carcinomas (CRCs) by using the tumor proportion score (TPS) and the combined positive score (CPS), and to investigate whether there is a correlation with clinicopathologic features. Methods: A cross-sectional study was conducted that included samples from patients with colorectal adenocarcinoma treated with colon resection and rectal resection after neoadjuvant radio- and chemotherapy at the Department of Abdominal Surgery at Požega Hospital in the period from 2017 to 2022. The study included 102 tumor tissue samples from patients after resection and the pathohistological diagnosis of adenocarcinoma. Results: In our study, the PD-L1 positivity rate after the TPS was 42 (41%) samples, and after the CPS, 97 (95%) of them (p < 0.001). The positive expression of PD-L1 in tumor cells using the TPS method showed a statistically significant association with adenocarcinoma (TPS ≥ 10–50% and ≥50%). There were significantly more that were moderately differentiated, with TPS ≥ 50%, and those poorly differentiated had values ≥ 10–50%. There were significantly more patients with a status of more than one positive lymph node with TPS values ≥ 10–50%. Patients without metastases in the lymph nodes are significantly more likely to have CPS values > 50%, compared with other lymph node statuses. Conclusions: These results suggest that the total number of PD-L1-expressing cells, including tumor and immune cells, is a more sensitive biomarker than the number of PD-L1-expressing tumor cells alone in CRC.

Patient satisfaction is a crucial measure of the quality of healthcare, especially with regard to nursing services in hospital settings. Understanding and increasing patient satisfaction with nursing care is critical to improving overall healthcare and ensuring positive patient experiences during their hospital stay. The aim of this research was to evaluate the psychometric properties of the Croatian version of the Satisfaction with Nursing Care Quality Questionnaire (PSNCQQ), test the reliability and validity of the tool after translation, and investigate differences in patient satisfaction based on demographic variables, as well as their contribution to satisfaction with the quality of nursing care. After translation and adaptation, the Croatian version of the PSNCQQ was applied to 350 hospitalized patients (average age 51.19 years (range: 18–87)), of whom 194 (55.4%) were men and 156 (44.6%) were women. The results showed high internal consistency (Cronbach’s α = 0.977) and confirmed the one-factor structure of the questionnaire, explaining 70.64% of the total variance. Confirmatory factor analysis supported the unidimensional model, showing strong fit indices (χ2 = 583.047, df = 149, p < 0.001, GFI = 0.861, AGFI = 0.818, NFI = 0.936, TLI = 0.946, CFI = 0.955, RMSEA = 0.080, PCLOSE < 0.001). In conclusion, the validation of the PSNCQQ in the Croatian language increases resources for evaluating and improving the quality of nursing care. This research lays the foundation for future studies and practical applications aimed at improving patient satisfaction and nursing care outcomes in Croatia, but there are also limitations to this study, including its one-institution scope, the possible influence of factors outside the current treatment on satisfaction, and the lack of comparison with objective clinical indicators.

The purpose of this research was to examine whether demographic variables, personality traits, and workplace variables (working in shifts, job tenure, and perceived organizational justice) contribute the most to the prediction of job satisfaction in nurses. The survey included 161 nurses. The instruments used in this research were as follows: the Demographic Data Questionnaire, the Perceived Organizational Justice Scale, the Job Satisfaction Scale, and the NEO five-factor inventory. The study findings indicated that age, health status, distributive justice, and procedural justice positively contribute to job satisfaction among nurses, while neuroticism contributes negatively. Older nurses, those in better health, those who are satisfied with the organization’s decision-making process, and those who feel adequately rewarded for their contributions tend to be more satisfied with their jobs. Conversely, nurses with a higher level of the neuroticism personality trait tend to be less satisfied with their job. The strongest predictors of job satisfaction among nurses were found to be health status, the personality trait of neuroticism, and distributive and procedural justice, with the age of nurses being slightly less powerful but still significant.

In this paper, the three-phase-lag model of fractional analysis on the reflection of two-dimensional problem of p-waves with initial stress, temperature-dependent, and magnetic field is investigated. The formulation of the problem for an isotropic homogeneous medium based on a three phase-lag theory. The boundary conditions applied on the surface for the stresses and thermal insulation. The numerical solution presented as well as the graphical representation of the impact of analysis considering the external parameters. Also, the modified elastic waves reflected under the action of the magnetic field, initial stress, fractional degree coefficient, and temperature to determine the more exact nature of the reflection of these waves, particularly seismic waves. A comparison has been made between the results obtained and the previous results obtained by others and already published and are in agreement with these, when external parameters considered in the present investigation neglected. The results obtained indicate that the new external parameters have new impact on the waves reflection and applicable in diverse fields as engineering, earthquakes, volcanos, geophysics, acoustics, and astronomy.

The systemic administration of glucocorticoids has not only strong beneficial anti-inflammatory and immunosuppressive effects but also numerous adverse health effects. Therefore, this study aimed to investigate the stereological and ultrastructural characteristics and distribution of gastrin-producing G cells in rat antral mucosa after 12 days of intraperitoneal administration of 2 mg/kg dexamethasone (DEX). In both groups of rats (DEX and control), the G cells were located at the base of the antral mucosal crypts, but in the DEX-treated rats, they were also found near the gastric lumen and showed an altered morphology compared to the basal cells. There were significant differences in the number of G cells per unit area and unit volume of antral mucosa between the groups studied. In the DEX-treated rats, the modified morphology and position of the antral G cells within the gastric units indicate their modified activity and possible impaired regulation of gastric acid production.

In our present study, we approach a linear theory for the thermoelasticity of type III for Cosserat media. At the beginning we introduce the equations and conditions, specific for a mixed problem in this context, namely the motion and energy equations, the initial condition and boundary relations. After that, we establish two results regarding the solution unique to the problem and two results on the continuous dependence of solutions, for the same mixed problem. Both problems that we address in our paper (uniqueness and continuous dependence) are not based on the material symmetries of the medium. Moreover, our results concern the theory of type III thermoelasticity for Cosserat media in their most general form, namely anisotropic.

Abstract This paper deals with the linear theory of thermoelastic Cosserat bodies. At the beginning, we formulate the mixed initial-boundary value problem in this context and obtain new theorems of reciprocity in the thermodynamics theory of these media. Then we prove that these new reciprocity relations imply the uniqueness of solution of the mixed problem. Based on the same reciprocal relations, we establish a minimum variational principle, which generalizes those from the theory of classical thermoelasticity.

In this paper, the authors propose the application of the Gibbs–Appell equations to obtain the equations of motion in the case of a mechanical system that has elements with a micro-polar structure, containing voids. Voids can appear as a result of the processing or manufacturing of the parts, or can be intentionally introduced. This research involves a model of the considered solid material containing voids. To determine the dynamic behavior of such a system, the Gibbs–Appell (GA) method is used to obtain the evolution equations, as an alternative to Lagrange’s classical description. The proposed method can be applied to any mechanical system consisting of materials with a micro-polar structure and voids. The study of such systems is interesting because the literature shows that even a reduce number of small voids can produce significant variations in physical behavior. The proposed method requires a smaller number of mathematical operations. To apply this method, the acceleration energy is calculated, which is then used to derive the equations. The method comes with advantages in the application to multibody systems having the mentioned properties and, in particular, in the study of robots and manipulators. Using the GA method, it is necessary to do a fewer differentiation operations than applying the Lagrange’s equations. This leads to a reduced amount of computation for obtaining the evolution equations.

The aim of this study is to solve a practical problem encountered in the automotive industry, especially the failure of a cracked lower control arm made of al 6062 T6 material during static and crash physical tests, and to characterize the behavior of cracked parts made of aluminum materials using the fracture mechanics parameters. As a first step, we carried out a numerical study and simulation using Abaqus/CAE 2020 software and the finite element method to determine the stress concentration and load limit capacity for different car weight cases. The von Mises stress variation shows crack initiation and propagation to be in the area of the lower control arm’s attachment to the vehicle platform, where stress is concentrated. These numerical results are consistent with the experimental test results found by automotive manufacturers. Also, we find that the mechanical load that can support this part is below 4900 N for good performance. In the second step, we use the results of the first section to simulate the failure of a lower control arm with a crack defect. This paper investigates the stress intensity factor KI in mode I for different lengths (L) and depths (a) of the crack in the lower control arm using the extended finite element method (XFEM) under Abaqus/CAE. For crack failure initiation and progression, we relied on the traction separation law, specifically the maximum principal stress (MAXPS) criterion. The KI factor was evaluated for the materials steel and Al 6062 T6. The results obtained from the variation of the KI coefficient as a function of crack depth (a) and the thickness (t) show that the crack remains stable even when a depth ratio (a/t = 0.8) is reached for the steel material. However, the crack in the Aluminum 6062 T6 material becomes unstable at depth (a/t = 0.6), with a high risk of total failure of the lower control arm.

In this study, the identification of thermoelastic mass diffusion was examined on a homogeneous isotropic microstretch thermoelastic diffusion (HIMTD) solid due to normal force on the surface of half space. In the framework of Cartesian symmetry, the components of displacement, stresses, temperature change, and microstretch as well as couple stress were investigated with and without microstretch and diffusion. The expression of the field functions was obtained using the Laplace and Fourier transforms. So as to estimate the nature of the components of displacement, stresses, temperature change, and microstretch as well as couple stress in the physical domain, an efficient approximate numerical inverse Laplace and Fourier transform technique and Romberg’s integration technique was adopted. It was meticulously considered and graphically illustrated how mass diffusion and microstretch affect thermoelastic deformation. Our objective was to address the inquiry regarding the impact of thermoelastic mass diffusion and microstretch on the field functions in the presence of a mass concentration source within the medium. Specifically, we aimed to investigate how these phenomena amplify the aforementioned effect.