Continuous Contact Research Articles

Taf1 N-terminal domain 2 (TAND2) of TFIID promotes formation of stable and mobile unstable TBP-TATA complexes

In eukaryotes, TATA-binding protein (TBP) occupancy of the core promoter globally correlates with transcriptional activity of class II genes. Elucidating how TBP is delivered to the TATA box or TATA-like element is crucial to understand the mechanisms of transcriptional regulation. A previous study demonstrated that the inhibitory DNA binding (IDB) surface of human TBP plays an indispensable role during the two-step formation of the TBP-TATA complex, first assuming an unstable and unbent intermediate conformation, and subsequently converting slowly to a stable and bent conformation. The DNA binding property of TBP is altered by physical contact of this surface with TBP regulators. In the present study, we examined whether the interaction between Taf1 N-terminal domain 2 (TAND2) and the IDB surface affected DNA binding property of yeast TBP by exploiting TAND2-fused TBP derivatives. TAND2 promoted formation of two distinct types of TBP-TATA complexes, which we arbitrarily designated as complex I and II. While complex I was stable and similar to the well-characterized original TBP-TATA complex, complex II was unstable and moved along DNA. Removal of TAND2 from TBP after complex formation revealed that continuous contact of TAND2 with the IDB surface was required for formation of complex II but not complex I. Further, TFIIA could be incorporated into the complex of TAND2-fused TBP and the TATA box, which was dependent on the amino-terminal non-conserved region of TBP, implying that this region could facilitate the exchange between TAND2 and TFIIA on the IDB surface. Collectively, these findings provide novel insights into the mechanism by which TBP is relieved from the interaction with TAND to bind the TATA box or TATA-like element within promoter-bound TFIID.

A path planning method for compliant jointing of weakly rigid helicopter fuselage

PurposeThe purpose of this paper is to propose a strategy for the final assembly of helicopter fuselage with weak rigidity parts and mismatched jointing butt ends.Design/methodology/approachThe strategy is based on path planning methods. Compared with traditional path planning methods, the configuration-space and collision detection in the method are different. The obstacles in the configuration-space are weakly rigid and allow continuous contact with the robot. The collision detection is based on interference magnitudes, and the result is divided into no collision, weak collision and strong collision. Only strong collision is unacceptable. Then a compliant jointing path planning algorithm based on RRT is designed, combined with some improvements in search efficiency.FindingsA series of planning results show that the efficiency of this method is higher than original RRT under the same conditions. The effectiveness of the method is verified by a series of simulations and experiments on two sets of systems.Originality/valueThere are few reports on the automation technology of helicopter fuselage assembly. This paper analyzes the problem and provides a solution from the perspective of path planning. This method contains a new configuration-space and collision detection method adapted to this problem and could be intuitive for the jointing of other weakly rigid parts.

PLA-Mg film degradation under in vitro environments supplemented with glucose and/or ketone bodies

Materials used for the manufacture of implants may suffer alterations in their surface properties as a result of continuous contact with physiological fluids. Moreover, in biodegradable and bioabsorbable materials, such as polylactic acid (PLA), these changes may be more accentuated, and their biological response may be affected by the presence of proteins, enzymes or other compounds of an oxidizing character. This research proposes to study the degradation of PLA in a close-to-reality environment by supplementing the physiological buffer m-SBF with concentrations of glucose and ketone bodies of healthy individuals. To this end, parameters such as hydrophobicity, surface tension, topography and surface chemical composition of PLA films and PLA films doped with magnesium particles after degradation were evaluated to determine how these components influence these properties compared to degradation in standard buffer. The presence of glucose and/or ketone bodies in the degradation medium of PLA doped with magnesium particles altered the composition of the salt layers absorbed on the surface of the material due to the action of gluconate and/or hydroxybutyrate anions, which were able to coordinate with ions from the solution as well as Mg2+ cations from polymer degradation. The salt accumulation on polymeric films changes the surface mechanical response increasing the Young's modulus after degradation.

Morphological and cellular organization of green microalgae to cope with cold stress in subarctic environment

Microalgae are one of the most widely dispersed living organisms on Earth and can be found even in extreme environments. Especially in such habitats, the microalgal cell wall plays an essential role as it is the first barrier in continuous contact with the surrounding and changing environment. In cold conditions microalgae can show changes in their morphology, also known as phenotypic plasticity which is the ability of an organism to show different phenotypes when exposed to different environmental conditions. In addition, presence or absence of algaenan is thought to be responsible for increase/decrease permeability and stiffness of the cell wall. The aim of this work was to evaluate and compare how microalgae cells can modify their cell wall components and cellular morphology under low-temperature conditions (5 °C) and differ during the exponential and stationary phases. Four microalgae species were studied: Coelastrella sp. 3–4, Chlorella vulgaris sp. 13–1, Haematococcus pluvialis, and Scenedesmus sp. B2–2, which were isolated from subarctic locations.Using a histochemical approach in conjunction with light microscopy, cell features such as size, organization and cell wall ornamentation were evaluated. Staining procedures showed changes in biochemical components such as pectins and presence or absence of exopolysaccharides and lipids. Results showed that Coelastrella cultures did not grow under low-temperature conditions. However, Chlorella vulgaris, Haematococcus pluvialis and Scenedesmus species demonstrated a slower growth rate, bigger and rounded cell-shape during cold condition. Furthermore, the latter microalgal strain also showed modification in algaenan presence as one of the main components in cell wall architecture, which can be related to the permeability of cell wall. Changes in other features such as cell organization and cell wall ornamentation were investigated.

Molybdenum powder coating on steel substrate to study three body wear resistance

Steel rollers are most commonly used in conveyor system across different industries like mining and construction. In the conveyor rollers used in mining industry, the steel specimen of the roller is in continuous contact with another metal of the same or different material rolling and sliding on that surface. In this motion of the roller, the third body i.e., the sand, grits and dust of various sizes may be entrapped in the interface of the roller material. The third body induced causes the wear due to its abrading action. To reduce this abrading action, a layer of molybdenum coating is developed on the steel substrate to improve its wear resistance by using the plasma spray technique, a thermal spray method. The experimental procedures were performed according to standard ASTM G65 method. The results were compared and tabulated in full factorial method. The SEM and EDAX results were obtained. The average specific wear rate [Ks] of the coated specimen is reduced by 30% when compared with the uncoated specimen.

Byzantine Translations from Arabic into Greek: Old and New Historiography in Confluence and in Conflict

Scholarly demand to re-evaluate underappreciated cultures has grown since the 1980s. This generated a call to re-write the nineteenth-century narrative on the transmission of knowledge from the ancient Near East to the Graeco-Roman, Islamic, Western medieval, and early modern European world. The paper surveys the modern study of Byzantine translations from Arabic into Greek in order to propose a new narrative frame, no longer linear but attentive to continuous and bi-directional contact between medieval civilisations. The paper offers the contact between Byzantium and various parts of the Islamic world as an example. It discusses the presumed insularity of Byzantine literary culture and its relationship with ancient Greek literary heritage. Problems of dating, localising, and socially contextualising the translations (through information on their authors and patrons) are also examined.

Periodic Contact Problems for a Wedge with Friction Forces

Periodic contact problems for a three-dimensional elastic wedge (a dihedral angle, a half-space and a quarter of space are particular cases), taking into account the Coulomb friction forces in unknown contact areas are considered. One face of the wedge is rigidly fixed, and the other face interacts with an infinite rectilinear chain of identical rigid dies, the axis of the chain is parallel to the edge of the wedge. Friction forces perpendicular or parallel to the edge of the wedge are taken into account. Integral equations are derived in which the series generated by the Cerruti components of the contribution of friction forces are summed exactly. Problems are solved using the method of nonlinear integral equations, which makes it possible to simultaneously determine the contact area and contact pressures. The mechanical characteristics are calculated, the transition from a discrete to a continuous contact area of infinite length is studied.

An investigation of corrosion in dehumidification bubble caps in a gas refinery

One of the severe challenges in the oil, gas and petrochemical industry is associated with reducing the costs of corrosion damages by removing oil fluid moisture and humidity in facilities. An essential component of moisture absorption towers in the dehumidification section is the bubble cap, which loses its efficiency in a short time due to continuous contact with steam. In the present work, the causes of the destruction of a piece of bubble cap were investigated thoroughly by employing visual and microstructural observation, chemical composition study using a quantometer, energy-dispersive X-ray spectroscopy and X-ray diffraction assessments and corrosion behavior study by polarization and electrochemical impedance spectrometry analysis. The mechanism and type of corrosion that occurred in the bubble cap and its capability against the corrosion were assessed. The results showed that the corrosion products after service were iron (II,III) oxide (Fe3O4), iron (III) oxide (Fe2O3), iron (III) hydroxide (Fe(OH)3) and iron (II) carbonate (FeCO3), which decreased the microhardness from 121.3 to 99.3 HV. The corrosion rate was found to be 0.03116 mm/year in saline solution. The poor performance of the material against corrosion was attributed to casting defects and ineffective microstructural phases, formed due to deficient alloying elements. According to the results, some recommendations and solutions, as effective preventive ways, are proposed to hinder corrosion and lead to higher durability and lower replacement costs.

연속 접촉 헬리컬 기어펌프의 수치해석 연구: 모델 개발 및 적용

연속 접촉 헬리컬 기어펌프의 수치해석 연구: 모델 개발 및 적용

Wearable Foot Pressure Sensing System for Fallen Arch Analysis

The main purpose of this research is to distinguish the extent of fallen arch by analyzing the center of foot pressure when people are walking. Fallen arch is often called the flatfoot. There are two types of flatfoot, the rigid flatfoot and the acquired flatfoot. The rigid flatfoot is because of bones formation, and people often get rigid flatfoot when they are young. The acquired flatfoot occurs usually on adults because of the walking postures, shoe types, weight and so on. Since these reasons, it is possible that we can improve or prevent the acquired flatfoot through wearing orthotic insoles or changing the walking posture. That’s the reason why our research is focusing on the acquired flatfoot. In this research, we develop a wearable foot pressure sensing system, consist of wireless Bluetooth transmit module and sensing insoles. The wireless Bluetooth transmit module helps to accomplish our measuring system as a wearable device. The sampling rate of wireless Bluetooth transmit module is one thousand samples per second. As a result, we can get a very detailed track on the walking motions. The sensing insoles are made of triboelectric nanogenerator (TENG) technology. The working principle of TENG is based on the coupling of triboelectric effect and electrostatic induction. Depending on the property of triboelectric generation of different materials and through continuous contact and separation, there is an electrostatic induction and current flow between the triboelectric layers and the electrodes, thus causing the potential difference. By detecting the potential differences, we can get the signals of pressure, so we can calculate the center of foot pressure and compare with the standard to check which walking posture we can apply to improve the fallen arch and find out where the center of foot pressure should be placed. Using this system, we can get the real-time foot pressure information and collect the information anytime and anywhere, accomplishing the smart medical.

Sentencing and the over-representation of people with cognitive disability in the Australian criminal justice system

ABSTRACT People with Cognitive Disability (PWCD) are over-represented in Australian and International Criminal Justice Systems (CJS). Research has focused on the disadvantages experienced by PWCD which bring them into earlier and more continuous contact with the CJS than the general population. There has been little empirical analysis of how sentencing might contribute to over-representation. This article reports on a project which investigated: (1) the characteristics of PWCD who appeared before Queensland courts to be sentenced; and (2) the factors that judges considered during the sentencing of PWCD. An inductive thematic analysis of 34 sentencing remarks transcripts from Queensland’s Supreme and District Courts provided a descriptive overview to address the first component. Themes addressing the second component included: difficulties and disadvantages; capabilities; and the subjectivities of defendants. Interpreted using critical sociological perspectives on punishment, these themes demonstrated how judges navigated a tension between responding to defendants’ needs and protecting the community from a ‘dangerous other’. The community was often prioritised, contributing to the enmeshment of PWCD in the CJS. This adds to over-representation and raises the dilemma of how to respond to community safety concerns while meeting the potentially complex needs of PWCD without drawing them more deeply into the CJS.

EFFECT OF ULTRAVIOLET - C LIGHT IRRADIATION ON THE BIOBURDEN OF HOSPITAL CONTACT SURFACES

Microbial species replicate and propagate on every surface. Contact surfaces have become inevitable in hospitals as they are for convenience of staff and visitors. These hospital contact surfaces are microbial reservoirs, which play a leading role in the spread of nosocomial infections. Cleaning and disinfection of these surfaces deplete its bioburden, however, paucity of fund occasioned by lean healthcare budget has impacted on the continuous Cleaning and disinfection of these surfaces. We used a sterile swab moistened in normal saline to collect 600 samples in duplicate from various contact surfaces of 20 randomly selected hospitals before and after ultraviolet – c light irradiation. Standard microbiological assay were used to identify and characterize the isolated microbes. The mean of the pre-exposure bioburden in cfu/square swabbed surface was significantly higher than that of the post-exposure bioburden in cfu/square swabbed contact surface with (p ˂ 0.005). This result shows that ultraviolet – c light irradiation if effective in depleting the bioburden of hospital contact surfaces, we therefore, suggest the deployment of ultraviolet – c light irradiation in the integrated and continuous hospital contact surfaces disinfection regime

Micro/nano incremental material removal mechanisms in high-frequency ultrasonic vibration-assisted cutting of 316L stainless steel

Although the intermittent contact by the ultrasonic vibration-assisted cutting explained the machinability advantages, there exists a research gap in concentrating the effects of high-frequency ultrasonic vibration-assisted cutting (HFUVAC). This work clarified the differences of the micro/nano incremental material removal mechanisms between conventional cutting (CC) and high-frequency ultrasonic vibration-assisted cutting of 316 L stainless steel. The machinability advantages and microstructure features were compared and analyzed through the ultra-precision cutting experiments. Compared with the continuous contact mode of the conventional cutting, the incremental effect of the high-frequency ultrasonic vibration-assisted cutting achieved superior machinability, which included cutting force decreasing, tool wear reduction, surface defects suppression, and chips undergoing from discontinuous quasi-shear state to continuous multiple-shear state. As the nominal cutting speed increased in the high-frequency ultrasonic vibration-assisted cutting, the surface defects and surface roughness showed an increasing trend, which was indispensable to control the normal cutting speeds below 5 m/min, or the cutting stroke in each vibration cycle less than 800 nm to obtain the defect-free surface. The grain refinement and severe elongation deformation were observed at the chip bottom and machined surface of the conventional cutting due to strong mechanical friction loads. While the microstructure features of chips and the machined surface in the local deformation layer were the results of friction reduction, dynamic recrystallization, and twinning/stacking formation induced by the incremental effects of the high-frequency ultrasonic vibration-assisted cutting. The results help to improve surface quality and optimize the ratio of cutting speed to vibration frequency to enhance the efficiency.

DETERMINATION OF THE CONDITIONS FOR THE IMPLEMENTATION OF THE DEFORMED DRILLING LAYOUT ROTATION IN THE MODE OF STABILIZATION OF THE BOREHOLE DIRECTION

Link for citation: Buglov N.A., Pushmin P.S. Determination of the conditions for the implementation of the deformed drilling layout rotation in the mode of stabilization of the borehole direction. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр.17-25.In Rus. The relevance of the study is caused by the need to create a general methodology for determining the eccentricity of the inertia center of the core set cross-section, which will significantly reduce the irrational material and energy costs of drilling wells drilled in conditions of natural curvature of their trunks, as well as optimize the technical and economic indicators of drilling operations. Objective: to increase the productivity of geological exploration when working in conditions of natural curvature of boreholes. Objects: drilling well, column set, drilling shell, drill string, natural curvature of the borehole, the trajectory of the borehole. Methods: analysis of literature sources on the research topic; processing data of production organizations; graphoanalytic method. Results. To eliminate some of the shortcomings currently available in the issue of maintaining the trajectory of the borehole drilled in conditions of natural curvature, a general technique is proposed that ensures minimization of the deflecting force on the rock-breaking tool during the deepening. The proposed technique is divided into two components: the use of pre-deformed core sets; the creation of a direct precession with continuous contact of the half-wave crest with the well wall during rotation of the arrangement. To implement the first case, the paper presents a method for determining the value of residual or preliminary deformation of a rectilinear core pipe. Practically, the proposed technique is implemented by sequentially performing three basic operations: the plane of deformation of the core set is determined during drilling; the parameters of the core set are adjusted by its residual deformation by the calculated value; the well is drilled with a pre-deformed core set. To implement the second case, the paper presents a method for determining the magnitude of the eccentricity of the inertia center of the column set cross-section. In this case, in order to implement the method, it is necessary: to make a rational arrangement of the lower part of the drill string; to carry out the drilling process at the maximum possible rotation frequencies of the drill shaft; to use emulsion washing fluids; to reduce the amount of bending moment due to the operation of diamond crowns that work effectively at low axial forces. Both proposed methods are justified and supported by the results of experimental work. Conclusions. The conducted research allowed us to present and justify a fundamentally new method of reducing the curvature of boreholes based on the use of pre-deformed core sets, as well as to obtain a dependence for determining the optimal value of their residual initial bending, which guarantees a deflection force close to zero on a rock-breaking tool. The magnitude of the eccentricity of the stabilizing arrangement, which guarantees the operation of the guide section in the mode of direct precession: is directly proportional to the force of its interaction with the walls of the well; is inversely proportional to its mass and rotational speed; is directly proportional to the coefficient of sliding friction.

Standard Lithuanian

The Lithuanian language, together with Latvian, belongs to the Baltic branch of the Indo-European language family and to the group of Eastern Baltic languages. The two surviving Baltic languages have many common features of phonemic inventories: opposition of long and short vowels, an abundance of diphthongs, a system of pitch accent. They have also developed substantial differences, e.g. Latvian has fixed stress and a set of palatal consonants, while Lithuanian has free (distinctive) stress and a phonological opposition between palatalized and non-palatalized consonants (Poliakovas 2008: 9, 42; Dini 2019: 577; Jaroslavienė et al. 2019: 263; Gelumbeckaitė & Pakerys 2020). In contrast to other Indo-European languages, the Baltic languages have lost j between a consonant and a front vowel, and have preserved m, rather than assimilated it, before the dental consonants d, t, which has not become n1 (Endzelynas 1957: 8). Lithuanian has preserved the manner of articulation of Indo-European plosive consonants (Bonfante 2008: 40). As a result of the continuous and long-lasting contact of Baltic with Slavic languages, these language groups also share common linguistic features (discussed later).

Continuous frequent contact detection over moving objects

Continuous frequent contact detection over moving objects

Continuous contact problem of interaction between two arbitrarily positioned flat stamps on the thermoelectric material

Continuous contact problem of interaction between two arbitrarily positioned flat stamps on the thermoelectric material

A Method for Analysis of Nonlinear Deformation, Buckling, and Vibrations of Thin Elastic Shells with Inhomogeneous Structures

The formulation of the problem and the method of analysis of the stress-strain state, buckling and vibrations of elastic shells with inhomogeneous structure are considered. The modal analysis of the shells is performed at each stage of loading. The method allows one to study the behavior of shells with a complex shape of the middle surface, geometric features throughout the thickness, and a multilayer material structure under thermomechanical loading. We approximate a thin shell with one finite element (FE) over the entire thickness. At the same time, we use spatial FEs of the same type to model shell portions with stepwise-varying thickness. So we apply the universal finite element. It is based on an isoparametric 3D element with polylinear shape functions for coordinates and displacements and has additional parameters. The universal finite element can be transformed (modified) to accurately describe portions of the shell with stepped-variable thickness. This element can be eccentrically displaced relative to the average surface of the shell and change its own thickness. The side edges of neighboring FEs are in continuous contact, and the FE allows simulating sharp bends of the shell. The approach is modern and easy to implement, since it is based on the use of the relations of the three-dimensional geometrically nonlinear theory of thermoelasticity and the application of the moment finite-element scheme. The effectiveness of the method is demonstrated on classical test examples. The convergence, accuracy and reliability of the obtained solutions are investigated. Comparison of the results of calculations obtained by the moment finite-element scheme with the data of other authors shows a good agreement between the solutions.

The contact problem of a functionally graded layer under the effect of gravity

AbstractThis paper considers the continuous and discontinuous contact problems of a functionally graded (FG) layer under the effect of gravity. A finite distributed load is applied to the beam from the top and the beam is placed to the top of a rigid foundation. It is assumed that the shear modulus and mass density of the beam vary exponentially whereas Poisson's ratio remains constant. The problem is solved for both continuous and discontinuous cases. In each case, the governing equations and boundary conditions of the problem are reduced to an integral equation by the help of Fourier integral transform. In the continuous contact, the integral equation solved analytically and critical load that causes initial separation between the layer and the rigid foundation, separation distance and contact pressures are investigated for various non‐homogeneity parameters that presents the change in the shear modulus and density and loadings. The singular integral equation in case of discontinuous contact is numerically solved by using corresponding Gauss–Chebyshev quadrature and an iterative scheme. The effect of non‐homogeneity parameters and loading on the separation distance between the layer and the foundation and contact pressures are analyzed. All the results are shown in tables and figures. It is seen that increasing stiffness and decreasing density at the top of the layer reduce maximum pressures but increase separation distances. This study aims to fill the deficiency in the mechanical behavior of the coatings under gravity.

1831-PUB: Improving Accessibility of Patients with Type 1 Diabetes to Treatment by a Diabetes Nurse Practitioner

Background: Treatment of type 1 diabetes (T1D) is complex, requires therapeutic intensity and understanding patient needs. The COVID-19 pandemic has led to a rapid and dramatic increase in the use of telemedicine to maintain treatment continuum and response to patients. Dedicated software, developed to transfer data from patients’ glucose sensors and insulin pumps to the treating team, facilitates personalized therapeutic interventions. Diabetes Nurse Practitioners (DNPs) have the knowledge, treatment skills and expertise for analyzing patient data transferred by the software; hence, they are an essential resource for managing diabetes treatment in these patients. The lack of suitable infrastructure and staff members who specialize in T1D has led to the establishment of a dedicated DNP unit within a diabetes clinic in Israel. The unit’s services are provided by frontal and telemedicine sessions to patients aged 18-40 with T1D. Its aims include continuous and regular monitoring of patients, achieving glycemic control according to patients’ personal targets, and preventing acute and late complications. The DNP provides comprehensive advice and training, assesses, and evaluates the patients' conditions, adjusts their therapy and refers them to appropriate care providers based on their medical and emotional conditions. Each session lasts 30-45 minutes. The summary of each session is sent to the diabetes doctor and to the primary clinic’s team. Methods: Analysis of patient data treated by the dedicated DPN unit between January and July 2022. Results: A total of 143 patients underwent 537 sessions; 55% were frontal visits and 44.4% were telemedicine visits (online or by phone). improved glycosylated hemoglobin was noted in 61% of patients. One patient was hospitalized. Conclusions: DNPs are an important factor for improving the quality of care of patients with T1D by providing personalized care, continuous contact and better access to services through remote consultation. Disclosure O.Waizinger: None.