Статті в журналах з теми "Non regular contact dynamics"

This paper addresses the problem of modeling biped dynamics and the use of such models for the control of walking, running and jumping robots. We describe two approaches to dynamic modeling: the basic Lagrange approach and the non-regular dynamic approach. The new non-regular dynamic approach takes into account discontinuities due to rigid contact between punctual feet and the ground without computing the exact impact time. The contact is close to the physical situation given by non-linear laws (impenetrability, non-smooth contact and real friction cone). Contact dynamics can be well managed with an accurate dynamic model that respects energy consistency during all the phases encountered during a step (0, 1 or 2 contacts). With this model, we can first study the equilibrum of a biped standing on one foot by a linearisation method. In the second stage, the unified modelized equation is used to establish a general control frame based on non-regular dynamical decoupling. A comparison is made and some simulation results are given with a two degree of freedom planar biped robot.

Abstract We extend the recently developed discrete geometric singular perturbation theory to the non-normally hyperbolic regime. Our primary tool is the Takens embedding theorem, which provides a means of approximating the dynamics of particular maps with the time-1 map of a formal vector field. First, we show that the so-called reduced map, which governs the slow dynamics near slow manifolds in the normally hyperbolic regime, can be locally approximated by the time-1 map of the reduced vector field which appears in continuous-time geometric singular perturbation theory. In the non-normally hyperbolic regime, we show that the dynamics of fast-slow maps with a unipotent linear part can be locally approximated by the time-1 map induced by a fast-slow vector field in the same dimension, which has a nilpotent singularity of the corresponding type. The latter result is used to describe (i) the local dynamics of two-dimensional fast-slow maps with non-normally singularities of regular fold, transcritical and pitchfork type, and (ii) dynamics on a (potentially high-dimensional) local center manifold in n-dimensional fast-slow maps with regular contact or fold submanifolds of the critical manifold. In general, our results show that the dynamics near a large and important class of singularities in fast-slow maps can be described via the use of formal embedding theorems which allow for their approximation by the time-1 map of a fast-slow vector field featuring a loss of normal hyperbolicity.

Objective We aimed to use mathematical models of SARS-COV-2 to assess the potential efficacy of non-pharmaceutical interventions on transmission in the parcel delivery and logistics sector. Methods We devloped a network-based model of workplace contacts based on data and consultations from companies in the parcel delivery and logistics sectors. We used these in stochastic simulations of disease transmission to predict the probability of workplace outbreaks in this settings. Individuals in the model have different viral load trajectories based on SARS-CoV-2 in-host dynamics, which couple to their infectiousness and test positive probability over time, in order to determine the impact of testing and isolation measures. Results The baseline model (without any interventions) showed different workplace infection rates for staff in different job roles. Based on our assumptions of contact patterns in the parcel delivery work setting we found that when a delivery driver was the index case, on average they infect only 0.14 other employees, while for warehouse and office workers this went up to 0.65 and 2.24 respectively. In the LIDD setting this was predicted to be 1.40, 0.98, and 1.34 respectively. Nonetheless, the vast majority of simulations resulted in 0 secondary cases among customers (even without contact-free delivery). Our results showed that a combination of social distancing, office staff working from home, and fixed driver pairings (all interventions carried out by the companies we consulted) reduce the risk of workplace outbreaks by 3-4 times. Conclusion This work suggests that, without interventions, significant transmission could have occured in these workplaces, but that these posed minimal risk to customers. We found that identifying and isolating regular close-contacts of infectious individuals (i.e. house-share, carpools, or delivery pairs) is an efficient measure for stopping workplace outbreaks. Regular testing can make these isolation measures even more effective but also increases the number of staff isolating at one time. It is therefore more efficient to use these isolation measures in addition to social distancing and contact reduction interventions, rather than instead of, as these reduce both transmission and the number of people needing to isolate at one time.

Abstract The moving contact line paradox discussed in the famous paper by Huh and Scriven has lead to an extensive scientific discussion about singularities in continuum mechanical models of dynamic wetting in the framework of the two-phase Navier–Stokes equations. Since the no-slip condition introduces a non-integrable and therefore unphysical singularity into the model, various models to relax the singularity have been proposed. Many of the relaxation mechanisms still retain a weak (integrable) singularity, while other approaches look for completely regular solutions with finite curvature and pressure at the moving contact line. In particular, the model introduced recently in [A.V. Lukyanov, T. Pryer, Langmuir 33, 8582 (2017)] aims for regular solutions through modified boundary conditions. The present work applies the mathematical tool of compatibility analysis to continuum models of dynamic wetting. The basic idea is that the boundary conditions have to be compatible at the contact line in order to allow for regular solutions. Remarkably, the method allows to compute explicit expressions for the pressure and the curvature locally at the moving contact line for regular solutions to the model of Lukyanov and Pryer. It is found that solutions may still be singular for the latter model.

Structure objects are exposed to different natural influences resulting in long-term and catastrophic outcomes. In order to avoid them, regular monitoring is needed. Various approaches to control condition of a structure can be considered, one of them is the measurement by means of monitoring which can be performed in different ways, depending on responses – static or dynamic, or both simultaneously. Specifically, technological development has enabled to monitor not only static but also dynamic responses by non-contact geodetic methods. Due to their simplicity and reliability of results, geodetic methods are more and more useful in this area. Moreover, state-of-art instruments and additional programme equipment allows up to 100 readings per second with an almost constant frequency of sampling, which is a condition for calculation of a dynamic response according to Fourier’s transformation. The article presents non-contact geodetic method of RTS on a bridging object.

Enforcing solid boundary conditions is one of the most challenging parts of the Smoothed Particle Hydrodynamics (SPH) method and many different approaches have been recently developed. Better understanding of interaction forces between solid bodies is of great importance in the investigation of structural stability and armor layer displacement in breakwaters. In this study, performance of repulsive force and dynamic boundary conditions have been investigated and showed that non-physical results are presented in non-cohesive contact. In this paper, a non-cohesive contact model in multi-body hydrodynamic systems has been developed and validated against other common boundary conditions. Using the developed contact model, the effect of regular and irregular placement of cubic concrete armors has been investigated. Also, comparison has been made with Van Buchem (2009) experimental results and concluded that in the irregular case it is more possible that a unit moves toward instability.

Purpose – The primary objective of this study is to assess and compare the levels of organizational identification, employee engagement, organizational commitment, and perceptions of organizational support between contract-of-service and regular non-teaching employees in a state university in Iligan City. Aims(s) – This study investigates whether OI among contract-of-service and regular non-teaching employees mediates the relationships between OS, EE, and OC. Design/methodology/approach – This study used a cross-sectional quantitative research design. The respondents comprised 81 contract-of-service and 91 regular non-teaching employees from different offices in MSU-IIT using an online survey form. The collected data was analyzed using SmartPLS4 and Partial Least Square of Structural Equation Modeling (PLS-SEM) to test the hypotheses. Findings – The findings show that Organizational Identification (OI) significantly mediates the relationship between Organizational Support and Affective Commitment (AC), with stronger effects for contract-of-service employees. For contract-of-service and regular employees, OI is crucial in linking support and commitment. Regular non-teaching employees show stronger OI than temporary workers, enhancing their engagement and commitment. Limitations of the study and practical implications – Future research can also be conducted on a larger sample size, including other government higher educational institutions in Mindanao, to generalize the findings. One such limitation is the scope of this study, which is limited to a state university in Iligan City only. This work is limited to the MSU-IIT non-teaching employees; a cross-cultural study may be conducted to see if any variations occur in other cultural settings. A comparative study among the non-teaching employees of government and private higher educational institutions is also suggested. Originality - This research contributes to the broader understanding of employee dynamics, especially the non-teaching employees within the academic sector, specifically in the Philippine context, with implications for improving institutional performance and employee well-being.

Nanosilica is widely used in various applications, with its market expected to grow over USD 5 billion by 2025. The fluidized bed technology, owing to its intimate contact and efficient mixing of phases, is ideally suited for the large scale processing of powders. However, the bulk processing and dispersion of ultrafine nanosilica using the fluidized bed technology are critically affected by the interparticle forces, such that the hydrophilic nanosilica shows agglomerate bubbling fluidization (ABF), while the hydrophobic nanosilica undergoes agglomerate particulate fluidization (APF). This study carried out a detailed investigation into the fluidization hydrodynamic of the hydrophobic nanosilica by monitoring the region-wise dynamics of the fluidized bed subjected to a regular step change of fixed duration in the gas velocity. The gas flow was controlled using a mass controller operated with an analog output signal from a data acquisition system. The analog input data were acquired at the sampling rate of 100 Hz and analyzed in both time and temporal frequency domains. The effect of velocity transients on the bed dynamics was quickly mitigated and appeared as lower frequency events, especially in regions away from the distributor. Despite the apparent particulate nature of the fluidization, strong hysteresis was observed in both pressure drop and bed expansion. Moreover, the fully fluidized bed’s pressure drop was less than 75% of the theoretical value even though the bed appeared to free from non-homogeneities. Key fluidization parameters, e.g., minimum fluidization velocity (Umf) and the agglomerate size, were evaluated, which can be readily used in the large scale processing of nanosilica powders using fluidized bed technology.

Dynamic displacement measurement of objects can be challenging due to the limitations of conventional methods and pricey instrumentation of unconventional methods, such as laser scanners. In this research, Close Range Photogrammetry (CRP) is used as an affordable non-contact method to measure 3D dynamic displacements. It is proposed as a reliable alternative to traditional dynamic deformation measurement methods such as displacement sensors or accelerometers. For this purpose, dynamic displacements of a three-dimensional one-story building frame model on a one-dimensional shake table are determined by using the traditional method of attached accelerometer and CRP. The results of the CRP method are compared with the results of the traditional methods as well as numerical models. The results show a good agreement which evidences the reliability of the CRP with regular cameras.

The COVID-19 outbreak has brought to the forefront the importance of predicting and controlling an epidemic outbreak with policies such as vaccination or reducing social contacts. This paper studies an SIHR epidemic model characterized by susceptible (S), non-seriously infected (I), hospitalized (H), and recovered (R) subpopulations, and dynamic vaccination; vaccination itself and H are fed back, and its dynamics are also determined by a free-design time-dependent function and parameters. From a theoretical analysis, the well-posedness of the model is demonstrated; positivity and the disease-free (Pdf) and endemic (Pee) equilibrium points are analyzed. The controlled reproduction number (Rc) is proved to be a threshold for the local asymptotic stability of Pdf and the existence Pee; when Rc<1 (Rc>1), then Pdf is (not) locally asymptotically stable and Pee does not (does) exist. Simulations have been carried out with data concerning COVID-19 where the importance of keeping Rc<1 to prevent the disease spreading and future deaths is highlighted. We design the control input, since it can be easily adapted to match the user specification, to obtain impulsive and regular vaccination and fulfill the condition Rc<1.

Background. Most ice hockey injuries are contact, but about 15% are non-contact musculoskeletal injuries and lower body injuries account for 30-45% of all injuries in ice hockey players. It is believed that proprioception and balance training can improve neuromuscular control, improve its ability to synchronise the muscle joint to improve dynamic stability and improve human performance, so balance and proprioception are suggested exercises as a regular part of training. The aim. To determine the effects of a 6-week balance and proprioception training exercises on balance and lower extremity injury risk in ice hockey players. Material and methods. 20 men were randomly divided into experimental and control groups. Six weeks were applied to the research group balance and proprioception exercises, twice a week for 45 minutes next to their regular training. The control group continued with regular training. Before and after the study, static balance was assessed by the flamingo test, dynamic balance and lower extremity injury risk by the modified star excursion test, and injury risk assessment using the Functional Movement Assessment. Results. In the intervention group after 6 weeks the static balance of the right and left leg improved statistically significantly (p<0,05), the dynamic balance of the right and left leg in the front, posteromedial, posterolateral directions (p<0,05), but functional movement patterns did not change statistically significantly (p>0,05). A statistically significant difference was found between the groups in the dynamic balance of the left and right leg in the front, posteromedial, and posterolateral directions (p<0,05) and the static balance of the right leg (p<0,05). The results of the intervention group were better compared to the control group. Conclusions. After the application of balance and proprioception training exercises, the static and dynamic balance of ice hockey players improved and the risk of injury in ice hockey players decreased. Recommendations. Balance and proprioception exercises should be included in hockey physical training to improve static and dynamic balance and reduce the risk of injury. When performing balance and proprioception exercises, we recommend incorporating a variety of specific movements that are similar to those performed by athletes during training and competition. In order to determine the cause of injuries and their risk, it is very important to carry out regular tests, store them and analyse them. Keywords: balance, proprioception, hockey, injury risk

The paper reports the sequence of the definition of bearings resource in a crank gear of heatengines. A brief description is given regarding the procedure for the computation of bearing hydromechanical properties in terms of hydrodynamic theory of lubrication and that of the procedure for the definition of an area of contact interaction. The input equations for the computation of dynamics and lubrication are: the equation for the field of hydrodynamic pressures in a lubrication layer separating random loaded surfaces (Reynolds equation); the equations set of plane motion of a shaft journal center; the heatbalance equation manifesting the equality of heat values mean in a cycle of load disseminated in a lubrication layer of a bearing and heat removed by lubricant flowing out in its faces. The procedure for the determination of an area of a contact interaction is developed in accordance with a molecular-mechanical theory of friction and a fatigue theory of wear according to I.V. Kragelsky. The extension of the area of a contact interaction (an area of the violation of a hydrodynamic mode of lubrication) in a slider bearing was defined in terms of the computation of the de-pendence of a minimum thickness in a lubrication layer of a bearing of a connecting rod upper head upon a rotation angle of a crankshaft. At the same time there were taken into account: the non-Newton’s properties of a lubricant; the presence of oil feeding sources on friction surfaces; possible deviations of friction surfaces from a regular form. The procedures presented at the given stage can be used for a comparative assessment of tribocouplings life in heatengines at an initial stage of designing.

The concept of process intensification is applied to a CSTR polymerization reactor, where bulk reactions take place via styrene free-radicals, connected to a semi-flooded horizontal condenser; the aim is to operate the system in a safe and efficient way. The results obtained show that the developed model was able to reproduce the major dynamic characteristics, even with the presence of non-condensable gases. The existence of such gases prevents the reactor from ever reaching a steady-state, as they accumulate in the system, increasing the condenser pressure and the reactor temperature and reducing the contact area and the mass of liquid in the condenser. To overcome this problem, the control strategy of this work proposes a regular purge of the condenser gases in order to avoid a collapse of the system. In this context, different control algorithms were also analyzed and it was concluded that a fast and reliable control of the reactor is only possible when advanced controllers are used.

The propagation of nonstationary disturbances in a plane-parallel layer of infinite extent, which arise as a result of normal dynamic loading of one of its surfaces when the other surface is stationary, is investigated. The material of the layer is assumed to be functionally graded and, at the same time, viscoelastic. The hereditary properties of such a material are taken into account using linear integral Boltzmann–Volterra relations with regular kernels in the form of partial sums of the Prony's series. The peculiarity of this work is that here the parameters of the relaxation kernels are considered continuous functions of the transverse coordinate in the same way as other physical and mechanical characteristics. A method was used for the study, which consists in replacing a functionally graded material with an approximating layered homogeneous structure with continuity conditions at the contact of homogeneous layers. The solution of the nonstationary dynamic linear viscoelasticity problem for a package of plane homogeneous viscoelastic layers is presented in a special form, which greatly simplifies its numerical implementation, especially with a large number of layers with different hereditary properties. This made it possible to successfully apply this method and carry out a series of calculations using an efficient algorithm. Transient wave processes are investigated in the case when the parameters of a functionally graded material are non-monotonic functions of the transverse coordinate, symmetrical with respect to the middle surface of the layer. A comparison of transient wave processes for different types of these functions is carried out. The convergence of the calculation results with an increase in the number of approximating homogeneous layers with a continuous dependence of the external load on time is confirmed. The significant influence of both heterogeneity and viscosity of the material on nonstationary wave processes has been established.

The modern world is very fast and dynamic. Consumer requirements rise to every commodity part of their everyday life - food, clothing, cosmetics, and medical devices. Eye care and eye health are also part of them. Companies producing contact lenses work daily to improve the safety and comfort of wearing, as well as on the technical characteristics of the material (type of material, wear time, module, Dk / t etc.). Silicon hydrogel contact lenses (SiHy) were introduced almost two decades ago. At that time it was estimated that there are about 70 million contact lenses all over the world. Since then, their number has doubled and a significant majority now have silicone-hydrogel contact lenses, resulting in a steady and noticeable reduction in the number of regular hydrogel lenses. When the first one-day silicon-hydrogel contact lenses were introduced in 2008, they were announced as breakthroughs in technology. When they were introduced to the market, they were presented in spherical, toric and multifocal designs, which led to a significant increase in the use / prescription of silicon-hydrogel daily disposable contact lenses. A survey conducted in 2014 by the International Consortium illustrates this point. Although, according to this study, the use of SiHy contact lenses varies widely across the world. In the United States, Canada, Australia and the United Kingdom, four to six times more patients were fitted with silicone-hydrogel CLs compared to hydrogels in 2014 and in each country, daily disposable SiHy contact lenses were prescribed with a larger frequency compared to daily disposable hydrogel lenses. It is important to make a good fit to ensure and increase the comfort of wearing contact lenses. In addition to some of the standard fitting techniques such as: keratometry and choice of base curve of the lens; size and eccentricity; an assessment of the mobility of a lens placed in the eye - look positions, mobility, push up test, can be added and the wetting of the contact lens. Even in perfect fit, if the lens does not interact well with the tear film, it would lead to complaints and discomfort in the patient. The degree of wetting is determined by the balance between adhesive and cohesive forces acting on the surface of the lens. CLs, which can support full wetting, allow a tight coating of the tear film, a smooth recovery of the tear layer after eyelid opening and good visual acuity. The interaction between CL, eye surface and tear film is vital to their successful fit. It has long been known that both the organic and inorganic components of the tear film and anterior surface of the eye can deposit deposits on the contact lenses. There are various non-invasive methods for assessing the tear film and, above all, the lipid layer. Some of these are Non invasive breakup time (NIBUT) and specular biomicroscopy. In the present work we will look at daily disposable silicone-hydrogel contact lenses that have been tested in vivo for good wetting, stability and good regeneration of the tear film.

Depending on the phase of the menstrual cycle, different values of running kinematic variables can be obtained. The aim of this study is to analyze whether there are changes in the kinematic variables in running throughout the menstrual cycle and to relate them to running performance and injury prevention. Eight regular female runners and triathletes performed a maximal treadmill test, as well as a submaximal test (6′ stages at 50%, 60% and 80% of maximal aerobic speed) in each of the phases of the menstrual cycle: menstruation phase (day 2.4 ± 0.7), follicular phase (day 10.4 ± 2.2) and luteal phase (day 21.8 ± 2.1). Running dynamics were measured using RunScribe. For parametric data, a general linear model of repeated measures was applied, with two intrasubject independent variables, menstrual cycle phases (with three levels: Menstruation, Follicular, and Luteal) and running intensity (with four levels relative to the maximum speed reached in the test: 100%, 80%, 60%, and 50%). For variables with non-normal distributions, Friedman tests were performed with Wilcoxon post-tests adjusted for significance according to Bonferroni. The maximum stance velocity from foot strike to the point of maximum pronation (°/s) was higher in the menstruation phase than in the follicular and luteal phases (p = 0.008), the step rate (s/min) was higher in the follicular phase than in the menstruation and luteal phases (p = 0.049), the vertical velocity (m/s) was lower in the follicular phase than in the menstruation (p = 0.004) and luteal phases (p = 0.003), and the contact time (ms) was lower in the luteal phase than in the menstruation and follicular phases. These results suggest that training at high intensities could be a factor in greater risk of injury in female athletes, especially in the menstruation phase, finding in the luteal phase and at an intensity of 80% a greater efficiency in the running.

Purpose This paper aims to develop a numerical model of bead spreading architecture of a viscous polymer in fused filament fabrication (FFF) process with different nozzle geometry. This paper also focuses on the manufacturing feasibility of the nozzles and 3D printing of the molten beads using the developed nozzles. Design/methodology/approach The flow of a highly viscous polymer from a nozzle, the melt expansion in free space and the deposition of the melt on a moving platform are captured using the FLUENT volume of fluid (VOF) method based computational fluid dynamics code. The free surface motion of the material is captured in VOF, which is governed by the hydrodynamics of the two-phase flow. The phases involved in the numerical model are liquid polymer and air. A laminar, non-Newtonian and non-isothermal flow is assumed. Under such assumptions, the spreading characteristic of the polymer is simulated with different nozzle-exit geometries. The governing equations are solved on a regular stationary grid following a transient algorithm, where the boundary between the polymer and the air is tracked by piecewise linear interface construction (PLIC) to reconstruct the free surface. The prototype nozzles were also manufactured, and the deposition of the molten beads on a flatbed was performed using a commercial 3D printer. The deposited bead cross-sections were examined through optical microscopic examination, and the cross-sectional profiles were compared with those obtained in the numerical simulations. Findings The numerical model successfully predicted the spreading characteristics and the cross-sectional shape of the extruded bead. The cross-sectional shape of the bead varied from elliptical (with circular nozzle) to trapezoidal (with square and star nozzles) where the top and bottom surfaces are significantly flattened (which is desirable to reduce the void spaces in the cross-section). The numerical model yielded a good approximation of the bead cross-section, capturing most of the geometric features of the bead with a reasonable qualitative agreement compared to the experiment. The quantitative comparison of the cross-sectional profiles against experimental observation also indicated a favorable agreement. The significant improvement observed in the bead cross-section with the square and star nozzles is the flattening of the surfaces. Originality/value The developed numerical algorithm attempts to address the fundamental challenge of voids and bonding in the FFF process. It presents a new approach to increase the inter-bead bonding and reduce the inter-bead voids in 3D printing of polymers by modifying the bead cross-sectional shape through the modification of nozzle exit-geometry. The change in bead cross-sectional shape from elliptical (circular) to trapezoidal (square and star) cross-section is supposed to increase the contact surface area and inter-bead bonding while in contact with adjacent beads.

As the size of advanced technology nodes keeps scaling down, IC manufacturers continue to push the active die area to the wafer edge. Defects originating from the wafer edge can result in substantial yield loss. Etching and cleaning bevel films and particles is increasingly critical in improving wafer yield performance near the wafer edge. Even though backside center dispense spin (BCS) and bevel nozzle dispense spin (BVS) methods have been developed and employed as two main wet bevel cleaning techniques in high volume manufacturing, the comparison of cut width accuracy between different wet bevel cleaning techniques has not been fully studied. The goal of this study is to investigate and understand the effects of fluid dynamics on cut width accuracy in different wet bevel cleaning techniques (i.e. BCS and BVS). In this study, computational fluid dynamics (CFD) numerical models were developed to study the chemical liquid flow in wet bevel cleaning processes. In the BCS process, the chemical liquid is dispensed through a nozzle below the center of wafer backside while the wafer is spinning. In order to characterize the cut width profile after BCS process, the liquid flow was modeled under the coordinate system of the rotating wafer instead of the regular stationary coordinate system. This special type of model allows understanding how the liquid is distributed on the wafer surface with respect to the rotating wafer, which will be more straightforward to be compared with the measurement of cut width profile. For the BCS process, the simulation results of liquid flow on the wafer backside surface are shown in Fig. 1. Due to the increasing centrifugal force towards the wafer edge, the liquid flow starts to develop some branching patterns. The liquid velocity (Fig. 1(a)) and liquid film thickness (Fig. 1(b)) are not axisymmetric anymore. Fig. 2 shows a vertical cross section of liquid flow at the wafer edge. The frontside etching in BCS relies on this liquid wrap-around flow. Due to the inertia and capillary force effects, the liquid first climbs from wafer backside to frontside as shown in Fig. 2(a). The liquid volume keeps increasing as liquid accumulates around the wafer edge as shown in Fig. 2(b). When the liquid volume at wafer bevel is greater than a certain threshold, the extra liquid will be stripped from the continuous liquid film as shown in Fig. 2(c). Because this wrap-around flow is unstable and periodic, the leading edge of the liquid on wafer frontside always fluctuates during BCS process as shown in Fig. 3. The non-axisymmetric backside flow leads to non-axisymmetric wrap-around flow on the wafer frontside. Because the liquid wrap-around flow is spatially non-axisymmetric and temporally unstable, the cut width profile over the whole perimeter of wafer bevel region can be quite non-uniform as shown in Fig. 4(a). In the BVS process, the chemical liquid is dispensed through a nozzle above the frontside bevel region as shown in Fig. 5. After the liquid jet lands on the rotating wafer, the liquid will develop into a stable circular flow along the wafer edge as shown in Fig. 5(a). A vertical cross section of the liquid film flow is plotted in Fig. 5(b). The inner cut position of the liquid film flow dictates the cut width in the BVS process. Because this circular liquid flow during BVS process is more stable, the cut width profile is more uniform in the BVS process as shown in Fig. 4(b). In practice, the cut width profile after the BCS process is also dependent on the properties of wafer surface such as wafer surface wettability. If the wafer surface is hydrophobic, the liquid flow on the wafer backside surface can break up, which results in very limited wrap-around flow and limited etching at the wafer edge. Therefore it can be difficult to use the BCS technique to etch the hydrophobic bevel films. On the other hand, the circular liquid flow in the BVS process is less affected by the properties of wafer surface because the liquid is directly dispensed over the bevel region. It is much easier to achieve the cut width target using the BVS technique by adjusting operation conditions such as the nozzle position. Since the numerical model developed in this study can accurately represent the flow physics in the BVS process, this CFD model can be adopted as a digital twin of the BVS tool to optimize the BVS process conditions based on the film material properties (e.g., contact angle) to meet the cut width target. Figure 1

Introduction: Giant cell tumors of the bone are aggressive and potentially malignant lesions. Juxtaarticular giant cell tumors of the lower end radius are common and is a challenge for reconstruction after tumor excision. Several reconstructive procedures like vascularized and non-vascularized fibular graft, osteoarticular allograft, ceramic prosthesis, and megapros thesis are in use for substitution of the defect in the distal radius following resection. Here, we have analyzed the results of aggressive benign Giant cell tumor of the distal radius treated by en bloc excision and reconstruction using autogenous non-vascularized fibular graft along with brachytherapy. Material and Methods: Eleven patients with either Campanacci Grade II or III histologically proven giant cell tumors of lower end radius were treated with en bloc excision and reconstruction with ipsilateral non-vascularized proximal fibular autograft. Host graft junction was fixed with low contact dynamic compression plate (LC-DCP) in all cases. Fixation of the head of the fibula with carpal bones and distal end of the ulna, if not resected, using K-wires at graft host junction was done. Brachytherapy was given in all 11 cases. Routine radiographs and clinical assessments regarding pain, instability, recurrence, hand grip strength, and functional status were done using Mayo modified wrist score at regular intervals. Results: The follow-up ranged from 12 to 15 months. At last follow-up, the average combined range of motion was 76.1%. The average union time was 19 weeks. Out of 11 patients, two patients had good results, five patients had fair results, and four patient had poor results. There was no case of graft fracture, metastasis, death, local recurrence, or significant donor site morbidity. Conclusion: En bloc resection of giant cell tumors of the lower end radius is a widely accepted method. Reconstruction with non-vascularized fibular graft and internal fixation with LC-DCP along with brachytherapy minimizes the problem and gives satisfactory functional results with no recurrence. Keywords: GCT, brachytherapy, en bloc resection, recurrence

BACKGROUND Ankle fractures are among the most common injuries encountered by orthopaedic surgeons. An ankle is considered unstable when the loss of normal constraints around the ankle permits the talus to move in a non-physiologic pattern. Under such circumstances, the dynamic joint surface contact area within the ankle is diminished, which predisposes to articular cartilage damage and premature degeneration. In today’s time, many modalities are available for surgical fixation of bimalleolar fractures. Such interventions restore anatomy and biomechanics of the ankle joint. Even though there are plethora of foreign studies on similar matter, deficiency of such analysis has been depicted in literature from developing countries, particularly from South-East Asian region. In this study, we wanted to assess various methods of internal fixation in ankle fracture & evaluate their clinical and radiological outcome post-operatively. METHODS 26 ankle fracture patients in the age group of 18 - 60 years were included in this study. Fractures were classified pre-operatively based on Lauge-Hansen classification. Patients were followed up at regular intervals of 1st, 2nd, 3rd, 6th & 12 month after surgery and assessed by Baird and Jackson scoring system based on subjective, objective and radiographic criteria. Complications like infection, arthritis, stiffness & implant failure were assessed on regular follow-up. RESULTS Variety of methods (including k-wires, plates & screws) were used for surgical fixation. Majority of fractures resulted from road traffic accident (RTA). Patients were evaluated using Baird & Jackson scoring system during follow-up at 1st, 2nd , 3 rd, 6th & 12 month. All patients had poor scores for initial 3 months. Patients showed good to excellent result on final follow-up at 9 to 12 months after surgery. Complications were observed in 19 % cases with arthritis being most common. CONCLUSIONS Open reduction and internal fixation restores the articular congruity of the ankle joint. The operative result was satisfactory with good clinical outcome. KEYWORDS Ankle, Fracture, Anatomy, Modalities

Icing on wind turbine blades in cold and humid weather has become a detrimental factor limiting their efficient operation, and traditional methods for detecting blade icing have various limitations. Therefore, this paper proposes a non-contact ice volume estimation method based on binocular vision and improved image processing algorithms. The method employs a stereo matching algorithm that combines dynamic windows, multi-feature fusion, and reordering, integrating gradient, color, and other information to generate matching costs. It utilizes a cross-based support region for cost aggregation and generates the final disparity map through a Winner-Take-All (WTA) strategy and multi-step optimization. Subsequently, combining image processing techniques and three-dimensional reconstruction methods, the geometric shape of the ice is modeled, and its volume is estimated using numerical integration methods. Experimental results on volume estimation show that for ice blocks with regular shapes, the errors between the measured and actual volumes are 5.28%, 8.35%, and 4.85%, respectively; for simulated icing on wind turbine blades, the errors are 5.06%, 6.45%, and 9.54%, respectively. The results indicate that the volume measurement errors under various conditions are all within 10%, meeting the experimental accuracy requirements for measuring the volume of ice accumulation on wind turbine blades. This method provides an accurate and efficient solution for detecting blade icing without the need to modify the blades, making it suitable for wind turbines already in operation. However, in practical applications, it may be necessary to consider the impact of illumination and environmental changes on visual measurements.

The article considers a new method for producing glassy carbon microspheres in solutions containing furfuryl alcohol, ethylene glycol, iso-octylphenol decaethylene glycol (OP-10) and sulfuric acid. The morphology of the microspheres is presented, as well as the results of their electrochemical testing in a solution of 0.1 M KCl, 0.005 M K3[Fe(CN)6], 0.005 M K4[Fe(CN)6]. Using a non-contact thermometer, the dependence of the solution temperature during synthesis (the heat released during the polycondensation reaction) on the volume of added acid was established. The polymer microspheres obtained in the solution were washed, dried, and calcined at 900 °C. The obtained materials were investigated using scanning electron microscopy and X-ray fluorescence elemental analysis. The elemental analysis showed that the materials contained about 98 % carbon, as well as less than 2 % potassium, copper, oxygen, sulfur, and iron. Scanning electron microscopy revealed that the microspheres had a regular spherical shape, well-developed surface and a diameter ranging from 0.5 to 10 microns. On the basis of the data summarizing the characteristic sizes of the microspheres determined by dynamic light scattering, the dependences of their sizes on the ratio of reagents during synthesis were constructed. The microspheres were used for preparation of the paste for an electrode with a mass ratio of microspheres : vacuum oil = 80 : 10. This mixture was stirred into a homogeneous paste and stuffed into a tubular electrode with the 3 mm diameter. The peak current and peak potential values of the electrode with pure microspheres were determined using cyclic voltammetry, with addition of barium hexaferrite as an electrochemical catalyst for the best sample. Among the nineteen solutions studied during synthesis, the most promising is the solution containing 100 mL of ethylene glycol, 5 mL of furfuryl alcohol, 5 mL of OP-10, and 50 m> of sulfuric acid.

Gestational diabetes mellitus is characterized by an increased risk of fetal macrosomia and obstetric complications during childbirth, as well as the development of type 2 diabetes in the mother after pregnancy. Timely diagnosis and treatment of hyperglycemia during pregnancy reduces adverse pregnancy outcomes. The first step towards tight glucose control during pregnancy is self-monitoring of glycemia. Aim: to evaluate the effectiveness of regular glycemic control using a Satellite express glucometer calibrated on capillary whole blood in patients with gestational diabetes mellitus (GDM) in outpatient practice. Material and methods. The 96-week prospective observational non-interventional study included 150 patients with GDM. In women with confirmed GDM, blood glucose was measured using a satellite express glucometer. At each visit, further tactics for the treatment of GDM were determined based on the results of glycemia (data from the self-monitoring diary). Until the 34th week of pregnancy, an endocrinologist was consulted with a frequency of 1 time in 2 weeks in the form of a medical appointment and telephone contact. After 34 weeks of pregnancy, consultation of an endocrinologist with a frequency of 1 time per week. 6–12 weeks after delivery, an oral glucose tolerance test and consultation with an endocrinologist were performed to assess the degree of carbohydrate metabolism disorder. Results. The participation of 138 (92%) patients in the study ended in childbirth, 12 (8%) patients dropped out of the study ahead of schedule. Spontaneous abortions were noted in patients who performed self-monitoring of glycemia 0–1 times a day, independent births were more often observed in patients who performed self-monitoring 3–4 times a day, and these patients also had more stable glycemic indices. 9 patients out of 138 gave birth to children weighing 4000 g or more. The weight of the rest of the children at birth did not exceed 3500 g. Conclusion. A well-controlled course of GDM, adequate self-monitoring and dynamic observation of women allows delivery to be carried out within the generally accepted terms without worsening its outcomes.

Abstract Introduction: Patients with locally advanced, triple-negative breast cancer (TNBC) typically receive neoadjuvant systemic therapy (NAST). However, the response of TNBC to NAST is varied and a prognostic marker is still lacking. Since angiogenesis plays an important role in cancer progression, the quantification of changes in the tumor vasculature during treatment has the potential to provide useful information for characterizing the treatment response. We have recently developed a method to quantify changes in tumor-associated vasculature through a novel analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In this study, we investigated its ability to monitor the response of TNBC to NAST. Methods: Dynamic contrast-enhanced (DCE) MRI was acquired in TNBC patients (N = 50; 25 pathological complete response (pCR), 25 non-pCR) before, after 2 and 4 cycles of Adriamycin/Cyclophosphamide (A/C), as part of the ARTEMIS trial (NCT02276433). Using DCE-MRI, we identified the tumor-associated vessels via a breast vasculature analysis. Specifically, the difference between pre- and post-contrast DCE-MRI images was enhanced by a histogram-based intensity transfer function. The 3D vasculature in the breast was then segmented by applying a Hessian filter. Given the vasculature segmented by the algorithms and the tumor masks segmented by radiologists, a lowest-cost tracking algorithm was used to automatically detect the vessels that are most likely to contact the tumor. These vessels are defined as tumor-associated vessels (TAV). The number of TAVs per patient was tabulated and the Wilcoxon rank sum test compared the TAV values before (V1), after 2 cycles (V2), and after 4 cycles of NAST (V3). Additionally, we compared the percent change of TAV from V1 to V3 between the pCR patients and non-pCR patients. Statistical significance was defined as P &lt; 0.05. Results: A significant decrease in the number of TAVs was observed during the NAST. In particular, the number of TAVs has a median (interquartile range) of 15 (7 - 24), 7 (3 - 14), and 2 (0 - 8) at V1, V2, V3, respectively, which are (pair-wise) significantly different (P &lt; 0.01). Moreover, pCR patients showed a significantly greater decrease in the number of TAVs as compared to non-pCR patients. The percent changes in the number of TAVs from V1 to V3 have a median (range) of -88.89% (-100.00% - -60.00%) and -66.67% (-87.85% - -40.88%) in the pCR and non-pCR patients, respectively (P &lt; 0.05). Conclusion: These preliminary results demonstrate that tumor-associated vasculature may be a valuable imaging biomarker for monitoring the response of TNBC to NAST. Ongoing efforts include additional investigation of the TAVs beyond their number, as well as applying the analysis to more patients. Citation Format: Chengyue Wu, Casey E. Stowers, Zhan Xu, Ernesto A. B. F. Lima, Clinton Yam, Jong Bum Son, Jingfei Ma, Gaiane M. Rauch, Thomas E. Yankeelov. Quantification of tumor-associated vasculature as an imaging biomarker for monitoring the response of triple-negative breast cancer to neoadjuvant chemotherapy. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5569.

We study the dynamics of overdamped systems in a symmetric periodic potential against an external load. Using numerical and analytical methods, we show that a symmetric driving signal cannot rectify these systems while an asymmetric one can rectify them, causing its unidirectional rotation. We consider the case where the driving signal is multiharmonic. We find that the mean velocity of the system increases to get the highest value, by appropriate tuning of parameters.

A new class of contact manifolds (carring a global non-vanishing timelike vector field) is introduced to establish a relation between spacetime manifolds and contact structures. We show that odd dimensional strongly causal (in particular, globally hyperbolic) spacetimes can carry a regular contact structure. As examples, we present a causal spacetime with a non regular contact structure and a physical model [Gödel Universe] of Homogeneous contact manifold. Finally, we construct a model of 4-dimensional spacetime of general relativity as a contact CR-submanifold.

Abstract Introduction Increasing incidences of wound healing disorders are a growing problem in our aging society. Moreover, the survival rate of the elderly is diminished when it comes to extensive high-grade burn injuries. Here, we characterized the systemic and local reactions towards burn injuries in young, middle aged and aged rats. Additionally, we provide a comparison in wound healing progression between burn wounds and full-thickness wounds of the same sizes. Methods For this study, 54 male Wistar rats from three different age groups (11; 27; and 56 weeks) either received high-grade contact burns, full-thickness skin wounds (2x2 wounds, Ø 10 mm each) or served as unwounded controls. Throughout the study regular wound documentation and non-invasive imaging methods were performed. Blood was sampled from the tail vein to detect differences in plasma cytokine concentrations. Moreover, body weight and food intake were measured daily. On the final study day (day 7), tissue biopsies were collected from the wound and control areas and were analyzed on a histological and molecular level. Mainly inflammatory markers (interleukins, TGFb, TNFa etc.) and markers for tissue perfusion (VEGFa, HIF1a) were quantified by qPCR. Repeated measures analysis of variance was performed to compare the means among groups. Results We found that epidermal thickness of unwounded skin declined with age and was lowest in 56-weeks-old rats. On day 4 after wounding, tissue perfusion was significantly impaired in 27- and 56-weeks-old rats compared to 11-weeks-old rats (p &lt; 0.001). Histological scores for the immune response showed an age-dependent effect in both burns and excisional wounds. Neutrophil and lymphocyte counts were highest in the 27-weeks-old rats (11 weeks vs. 27 weeks: p &lt; 0.001). Eosinophil counts, however, were significantly increased in burn wounds compared to excisional wounds (p = 0.013), regardless of age. We did not detect any age-dependent effects in wound sizes on the final day, nor in the animals’ weight loss after wounding. Conclusions Although there are significant age-related differences in the thickness of the epidermis, the angiogenic potential of the skin and the local immune response, these differences do not seem to affect healing. It is reasonable to assume that decreased wound healing progression occurs only when additional factors, such as impaired perfusion, diabetes etc are involved. Applicability of Research to Practice We believe the precise knowledge of processes involved in wound healing is crucial for the development of new therapeutic strategies and to support healing after burns. Our results might challenge the paradigm of impaired healing in aged individuals and draw attention to the necessity to dig for other influential factors. However, as skin morphology and healing dynamics differ between rodents and humans, we plan to implement a translational approach using human abdominal skin flaps of donors from different age groups.

The aim of the article is to provide answers to two research questions. Firstly, what in business practice is needed to convert a contact into beneficial relationship. And secondly, whether numerous personal contacts, the so-called “connections” are sufficient to achieve sustained success in creating business relationships. The authors responded the questions by using the results of research conducted among 419 companies. As a result they proposed a scheme of the development process from contact to a beneficial relationship. Introduction Relationships are formed between entities conducting business as an effect of repeated interactions. Although crucial to the business, the notion of relationships is often not entirely understood, due to the fact that relationships are not limited to formal relations between companies. In practice of running business, relationships are seen as a remedy for the lack of opportunities for the development of the company, ensuring the expansion and success of the business. This, in turn, promotes the belief in the need to establish numerous contacts, which then have to transform into relationships being the source of many benefits. But in practice the transformation of contacts into relationships is not so simple. Hence, two research questions arise, the answer to which will be given by this article. First, what in practice of doing business is needed to transform a contact into a beneficial relationship? Second, are numerous contacts, i.e. so-called “connections” sufficient to achieve sustainable success in building business relationships? This paper will present the results of the research conducted among 419 companies of different sizes in Poland. The research “The global and local dimension of business networks” was carried out from November 2014 to June 2015. The structure of the analysed companies corresponds to the general structure of companies in Poland – 87 percent of them are small and medium-sized companies (the remaining 13 percent are large entities) and 74 percent are private entities with national capital. In the survey, we asked the representatives of management of companies about the characteristics and benefits of relationships connecting their companies with their most important key customers and key suppliers. This enabled indication of the essential conditions necessary for the creation of beneficial relationships. The essence of relationships between companies A relationship is a phenomenon that is formed during a long time and is developed through repeated interactions between entities [Easton, 1992]. Thus, a relationship is defined as an interdependent process of continuous interaction and exchange between at least two entities within a business network [Holmund, Törnroos, 1997] or as a mutual orientation of two companies towards each other, which means that the companies are prepared to work together and expect such actions from each other [Johanson, Mattsson, 1987]. During the process of development of a relationship, the entities create strong and wide, social, economic, service, and technological bonds, in order to reduce total costs over time, and to increasethe added value, thus achieving mutual benefits [Anderson, Narus, 1991]. An important characteristic of relationships is the fact that they need a longer time to be formed. The emergence of a relationship takes time and effort on the part of both entities [Forsgren, et al., 2015, Håkansson, Ford, 2002, Szymura- Tyc, 2015]. A long-term nature can be described as a reciprocal expectation on the part of entities that the relationship will continue [Ratajczak-Mrozek, 2009], although unexpected events can always lead to its break. Another typical features describing the real relationships, as opposed to usual contacts, include trust, commitment, and also loyalty [Leszczyński, 2014, Morgan, Hunt, 1994, Farrelly, Quester, 2003]. These features are related to the concept of the quality of a relationship, taking into account that from the perspective of the company, not every relationship is equally important. Relationships are developed only with a limited number of entities [Håkansson, Waluszewski, 1992], and there is also the claim that an average company has ten important relationships [Håkansson, Henders, 1992], and a limited number of relationships stems from the investments that are required in order to develop them [Ford, Håkansson, 2006]. These investments involve commitment of resources, including financial resources, as well as time. The assumption concerning a limited number of important business relationships means that the interactions themselves may or may not lead to the development of a relationship [Blois, 1997]. Hence, more important is the question about the conditions of transferring individual interactions, embodied by the network of one-off contacts, into relationships that bring benefits. Key features and benefits of relationships between companies To answer the question on what is necessary to transform a contact into a beneficial relationship in practice of running the business, the answers obtained from 419 companies, as mentioned above, have been analysed. The method applied involved a survey delivered by post and via the Internet, with both questionnaires including the same research questions, and the companies could receive the questionnaire only once. The address list has been prepared on the basis of a nationwide company database Kompass Poland, and the sampling frame included companies from all around Poland, representing all sectors and all sizes of companies. The sample was selected at random. The return rate of 11.8 percent was obtained in the case of surveys by post, and 2.4 for Internet surveys, which led to the total of 419 responses. The questions about key relationships of companies were answered by the representatives of management, which was to provide representative opinions on important relationships from the perspective of the entire company. In the first phase, the characteristics of relationships have been analysed (see Figure 1), which enables identification of the most important areas distinguishing the relationships from all contacts of the company, and allows to indicate what is necessary to convert contacts into relationships. It is widely believed that the formation of relationships takes time. The presented research confirms this dependency. For a relationship to be established, it is essential to develop informal standards of cooperation and trust, and it usually takes time. What is more, the fact of building trust is proved not only by the duration of interactions, but also by the conviction about the long-term attitude of the partners towards joint activities. It must be emphasised that these conditions apply both to the relationships with customers, as well as with suppliers. Also the quality of what is going on in the course of cooperation is important. A relationship connected with routine assignments once in a while will not necessarily bring a wide spectrum of benefits. Among other things, the transformation of a contact into a relationship can be accelerated by a frequent and regular cooperation. Whereas, it is essential for this frequency to be related not only with keeping contacts, but with actual offering of benefits. The research conducted shows that each time 59 percent of relationships, both with key customers and suppliers, is based on the economic calculation (not excluding, however, at the same time, the importance of other factors), which indicates that the relationship is not only an idealistic vision of cooperation. Generally, the companies guided by maximising profits are looking for the most economical and financially beneficial solutions. Thus, the question arises, what might be the motives of the companies to maintain the remaining 40 percent of relationships? If in their case the most important is not the simple economic calculation, than they must be associated with other than strictly direct financial benefits. Relationships can bring not only financial benefits but also imply the improvement of flexibility and speed of operation, reduction of transaction costs, risks, and uncertainty by the creation of routine proceedings, unwritten principles of cooperation, trust and mutual adaptation. As a consequence, the closer the cooperation is, the more difficult it becomes to change the partner. On the other hand, if for almost 60 percent of the companies the economic factor plays an important role, in their case it can mean either the lack of place for other reasons to build relationships or the lack of differences in the perception of the existing key business partners. The latter creates a special market opportunity for those companies, that have already possessed the ability to build long-term business relationships based on non-financial factors, as it allows to stand out against the closest competitors. In this context, the research conducted showed the main benefits achieved by the companies thanks to relationships with key customers and suppliers, which is the second stage of the research (Figure 2). Apparently, there is a certain group of common benefits for all relationships, regardless of the type of a partner. They are related to the widely understood development (which may be supported in terms of economics, technology, competence, reputation), creation of new products, trust, and risk mitigation associated therewith. Moreover, in the case of key customer relationships, there are benefits associated with sales – directly, its growth and factors supporting it (recommendations and prestige). In turn, in the case of relationships with key suppliers, there are benefits related with the costs of operation (directly, reduction of costs, greater flexibility, and an increase in the margin). The broad range of benefits achieved by relationships at the same time indicates the key condition that must be satisfied to convert the contacts into relationships. If one of the parties does not achieve benefits, it means that there is no interest in the development of long-term and close relationships. In such a case, the relation is a rather forced contact (for example, due to the lack of alternatives in choosing a supplier, impossibility of allowing oneself to lose the customer providing revenues). Hence, for a contact to result in a relationship, it is necessary to appropriately identify and offer benefits sought by the other party. Speaking of relationships, the importance of having connections in the business is often emphasized. Meanwhile, the research conducted shows that the personal contacts are of a limited importance and in the absence of significant benefits, business relationships gradually erode. Bearing in mind the respondents’ answers, it should rather be stated that it is the effort made in the longer period to maintain mutually beneficial relationships, including frequent contacts with customers, that promotes the widening and deepening of the existing connections, which consequently sometimes also have the chance to be continued on the business and non-business grounds. In the above situation, contacts between people play a role in creating quality of the already existing relationships. It will be expressed in the way of communication, the depth and scope of cooperation, the distinguishing feature of which will be, in particular, the informal, direct and quick solving of emerging conflicts of interest or current problems. It should be remembered that the condition for this is the presence of benefits valued by both parties. Otherwise, the effort made sooner or later will begin to be perceived by one or the other side as unjustified. It is worth to note here that due to the dominant share of financial benefits in business relationships indicated in the research, the time horizon within which the parties assess the relationships, can be relatively short. And this in turn may affect the growth of their dynamics, and can cause their low resistance to changing conditions. Therefore, as indicated above, numerous contacts do not have to convert into numerous and durable relationships of the company at all. Wide personal contacts are good as a starting point, enable breaking through formal barriers associated with complex organisational structures or the lack of resources, and establishing the first contact between the companies, but not necessarily translate into real and beneficial relationships. On the other hand, business relationships do not have to be permanent, especially if they are based only on achieving financial benefits. The process of developing a contact into a beneficial relationship Building relationships takes time and requires orientation towards a long-term cooperation. For a contact to develop into a relationship, one needs to remember about the benefits that can be offered and which are important to the future or existing partner. But such benefits cannot be provided to all customers and suppliers, thus, it is important to be selective. It does not mean being closed to new contacts, on the contrary. It is important, however, to search for such contacts for which a high potential to build relationships based on mutual benefits can be indicated. Selectivity is not just a matter of choosing of those with whom direct contacts will be established, but relates also to the scope of time and effort necessary to be borne in order to transform particular contacts into established relationships. It may be considered that the expected benefits will be greater in the case of sustained involvement in several selected contacts and building business bonds with them, than in the case of blind devotion to establishing numerous contacts, and then making cursory attempts to “build relationships” with everybody. In this context, a considerable involvement of time and resources in building bonds with customers and suppliers that are guided only by the economic calculation (in this case the only criterion will always be a lower price), who, guided by undisclosed premises showed a lack of loyalty or turned out to be opportunist entities, who value immediate benefits more than long-term cooperation, may be found doubtful. Based on the survey, several key conditions necessary for the transformation of the established contact with a potential partner into a long-term beneficial relationship can be distinguished. They include the selectivity in relation to contacts, focusing on the target group (not – the more the better), discovering of this group and offering significant benefits to them, and then devoting time and keeping appropriate frequency of contacts. At the same time, these conditions are reflected in the process of developing relationships, which can be divided into four main stages, as shown in Figure 3. How might this process look like in practice, for example, in relation to a company providing B2B (business-tobusiness) services? The first stage can pose some difficulties, especially when one does not have extensive““connections”, and the target group, which can be offered the most benefits, while maximising one’s own, has not been precisely defined. After gaining interest in a potential partner that meets certain criteria, where the personal contacts can turn out to be helpful, the company oriented towards building longterm relationships will be more focused on awakening and increasing confidence than on maximising their financial benefits in the short-term. Due to the lack of previous experience in working together, and the risk associated therewith, the first contacts may be limited to rather small assignments. The development of the relationship at this stage will be promoted by considerable commitment, frequent contacts between people, ensuring that certain benefits have been achieved, which in turn should build trust, which will allow for the continuation of cooperation and obtaining new, possibly larger assignments. They will be an opportunity to strengthen cooperation, mutual matching, simplifying and making the operations more routine, which will greatly reduce the costs incurred and will improve the profitability of orders. In turn, a well-established cooperation will promote building relationships aiming at achieving objectives other than purely financial (Figure 2). Summary and managerial implications The suggestions presented in this article are not a guarantee of success and building beneficial, long-term relationships with every business partner. The results of the research indicate, however, that the orientation towards the simultaneous achievement of financial and nonfinancial benefits by both sides of the relationship is not common, and therefore, it may become a significant factor differentiating the company from others operating on the given market. Above all, however, this will require time, added value offered to the other partner, selection of and concentration on the most prospective partners, and effort spent on searching for mutually beneficial solutions and maintenance of proper daily contacts. Sometimes, despite the efforts undertaken, there may appear disappointment, frustration and discouragement. This is due to the fact that the assessment of the benefits arising from business relationships may change together with changing circumstances, and even despite the best efforts of one of the partners, the overall balance of benefits may lead the other party to decide to terminate or limit the existing relationship. Potential benefits of permanent business relationships, indicated by the surveyed respondents, however, are high enough to fully justify this effort. On the other hand, it may be so large that despite its efforts the entity will be able to create only few or one strong relationship with its business partner. It is, therefore, recommended for this partner to be significant or at least with a large development potential. It is important to recognise that a personal feeling and gaining a direct contact to a decision-maker of a potential business partner does not necessarily mean that there will be a commercial transaction completed, and even more, that one managed to establish a lasting business relationship. As shown in the article, there is still a long way to go, and requires crossing a number of stages of the defined process of developing the contact into the beneficial relationship.

Abstract The paper presents numerical modelling of the liquid film spreading dynamics of the R21 (mol. fraction: 0.9) and R114 refrigerants mixture. We considered an outer flow along a round vertical cylinder at Reynolds number of 104 and various contact angles. The simulation was performed in OpenFOAM software on the basis of the volume of fluid (VOF) method. We have shown that the wetting front deforms at wetting angles of 30 and 50 degrees, and regular jets form. At the same time, it was demonstrated that at the wetting angle of 10 degrees the spreading front has practically a flat shape, but one may see some regular thickenings of the liquid film along the contact line of the front.

Abstract We describe a method, based on contact topology, of showing the existence of semi-infinite trajectories of contact Hamiltonian flows which start on one Legendrian submanifold and asymptotically converge to another Legendrian submanifold. We discuss a mathematical model of non-equilibrium thermodynamics where such trajectories play a role of relaxation processes, and illustrate our results in the case of the Glauber dynamics for the mean field Ising model.

The phenomenon of droplet impact on moving surfaces is widely observed in fields such as transportation, rotating machinery, and inkjet printing. Droplets exhibit non-axisymmetric behavior due to the motion of solid surfaces which significantly determines core parameters such as contact time, maximum spreading radius, and bounding velocity, thereby affecting the efficiency of related applications. In this study, we focus on the kinetics and morphology of the non-axisymmetric bouncing behaviors for droplets impacting on a moving superhydrophobic surface (SHPS) within the normal (Wen) and tangential (Wet) Weber numbers. Considering the influences of the moving surface on the contact area and contact time, the previous scaling formula for the horizontal velocity of droplets has been improved. Based on the velocity superposition hypothesis, we establish a theoretical model for the ratio of the maximum spreading radius at both ends depending on Wen and Wet. This research provides both experimental and theoretical evidence for understanding and controlling the non-axisymmetric behavior of droplets impacting on moving surfaces.

Abstract Lung cancer has a high incidence rate and is the main cause of cancer-related deaths with 127,070 fatalities expected in the U.S. this year. Non-small cell lung cancer (NSCLC) accounts for an estimated 85% of all lung cancer cases and is typically diagnosed at an advanced disease stage, where outcomes are often poor and treatment options are limited. Targeted therapies are only available to a minority of NSCLC patients with identifiable tumor-driving mutations. Anti-programmed cell death protein 1 (anti-PD-1) immunotherapy has become a first-line treatment strategy for patients without tumor-driving gene mutations. However, only 15-20% of NSCLC patients exhibit a positive response to anti-PD-1 therapy. Moreover, patients who initially respond to anti-PD-1 therapy still face the risk of primary or acquired resistance, potentially leading to cancer progression. This study leverages a murine lung cancer cell line representative of NSCLC isolated from a genetically engineered mouse model expressing KrasG12D and P53−/flox oncogenic mutations in club cells, employing a cell type-specific promoter (Scgb1a1). After successfully establishing the oncogenic cell line, the cells were subcutaneously injected into immunocompetent C57BL/6 mice and subjected to anti-PD-1 therapy for 3 weeks post-injection. Tumor growth curves revealed a significant size reduction in anti-PD-1-treated tumors when compared to the IgG isotype control group, as confirmed by a paired t-test analysis (p &lt; 0.045). To evaluate the longitudinal dynamics of the tumor microenvironment, single-cell sequencing, and spatial transcriptomics were performed throughout effective anti-PD-1 treatment and following tumor relapse. Samples were collected at 2 time points during anti-PD-1 treatment, specifically at 1 and 3 weeks, as well as 3 weeks after the completion of the anti-PD-1 treatment. Subsequently, these samples underwent single-cell RNA sequencing and spatial transcriptomics using the 10x Genomics platform. Single-cell sequencing revealed modulations in immune recruitment throughout the treatment while relapsed tumors display elevated levels of myeloid gene expression and a shift to a highly fibrotic tumor phenotype post-anti-PD-1 therapy. These findings suggest that the established oncogenic cell line exhibits initial responsiveness to anti-PD-1 therapy in vivo before undergoing major changes within the tumor microenvironment. This study highlights the relevance and translational potential of our oncogenic cell line in advancing our understanding of NSCLC and its response to anti-PD-1 therapy. *This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-857319. Citation Format: Nicole F. Leon, Oscar A. Davalos, David Baliu-Rodriguez, Deepa K. Murugesh, Aimy Sebastian, Nicholas R. Hum. Assessing the longitudinal efficacy of anti-PD-1 therapy in a murine non-small cell lung cancer model using single-cell and spatial transcriptomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 579.

Dynamic properties of the air gauges performing in-process measurement are of the great importance because of dynamic error affecting the measurement results. The paper presents the analysis of the air gauges dynamics and some practical recommendation. The investigations proved the dependence of the time constants on the actually measured back-pressure. In practical solutions of in-process control, the air gauge must work in conditions of falling back-pressure since with the material removal dimensions of the machined workpiece go down. Thus, in the area of the smallest values of back-pressure within the measuring range, the time constant value is the largest. Worsening of the air gauge dynamic properties at the end stage of the machining must be considered when the dynamic characteristics of the projected air gauge are calculated.

Abstract The paper presents the results of investigations on the air gages dynamic characteristics in the measurement of the round profiles of motor cylinders. The principle of the measuring device is explained, and the analysis of the air gages dynamics is described. The results of dynamic calibration enabled to eliminate those configurations of air gages that may not meet the requirements of the measurement they were designed for. After the proper air gages were chosen, the entire system underwent the accuracy test and passed it successfully revealing the method accuracy better than 10% compared to the reference measurement.