Correct Mode Research Articles

Adaption of active boundary conditions in structural fire testing

Purpose This paper aims to investigate the need for active boundary conditions during fire testing of structural elements, review existing studies on hybrid fire testing (HFT), a technique that would ensure updating of boundary conditions during a fire test, and propose a compensation scheme to mitigate instabilities in the hybrid testing procedure. Design/methodology/approach The paper focuses on structural steel columns and starts with a detailed literature review of steel column fire tests in the past few decades with varying axial and rotational end restraints. The review is followed with new results from comparative numerical analyses of structural steel columns with various end constraints. HFT is then discussed as a potential solution to be adapted for fire testing of structural elements. Challenges in contemporary HFT procedures are discussed, and application of stiffness updating approaches is demonstrated. Findings The reviewed studies indicate that axial and rotational restraints at the boundaries considerably influence the fire response of steel columns. Equivalent static spring technique for simulating effect of surrounding frame on an isolated column behavior does not depict accurate buckling and post-buckling response. Additionally, numerical models that simulate fire performance of a column situated in a full-frame do follow the trends observed in actual test results up until failure occurs, but these simulations do not necessarily capture post-failure performance accurately. HFT can be used to capture proper boundary conditions during testing of isolated elements, as well as correct failure modes. However, existing studies showed cases with instabilities during HFT. This paper demonstrates that a different stiffness updates calculated from the force-displacement response history of test specimen at elevated temperature can be used to resolve stability issues. Originality/value The paper has two contributions: it suggests that the provision of active boundary conditions is needed in structural fire testing, as equivalent static spring does not necessarily capture the effect of surrounding frame on an isolated element during a fire test, and it shows that force-displacement response history of test specimen during HFT can be used in the form of a stiffness update to ensure test stability.

Lack of awareness among surgeons regarding safe use of electrosurgery. A cross sectional survey of surgeons in Pakistan.

ObjectiveTo assess our surgeons perceptive regarding the safe usage of electrosurgical devices.Methodology: This cross sectional survey was carried out at two hospitals, A cancer hospital and a public sector general hospital. Consultants, fellows and senior residents (Resident year 3rd and year 4th) on the surgical floor were requested to fill up the questionnaire. Calculations were performed with Statistical Package for the Social Sciences (SPSS 20) for Windows version 20 statistical software. Data was described using median with minimum and maximum value for quantitative variables. For categorical variables, number of observations and percentages were reported. The study is complied with hospital guidelines on research involving human subjects.ResultsOut of 80 questionnaires 52 were filled and returned. 12 consultants, 16 fellows/Senior registrars and 24 senior residents filled their questionnaires. For the sake of anonymity no information was obtained regarding the level of training and experience. Total 12 questions were asked. An expert level was set for a score above 10/12. A moderate level was set at 8/12. A score of less than 8 was considered unsafe for using electrosurgical devices. Only 6 (11.5%) participants had an expert level of understanding. 16 (30.7%) had moderate understanding. 30 (57.7%) were considered unsafe regarding use of electrosurgical devices. 85% participants were not aware of the correct mode of current to use for coagulating vessels. 69% of surgeons would use electrocautery to control staple line bleeds. 67% participants weren't aware of the correct placement of dispersive electrode. 60% couldn't identify a safe device for use in patients with a pacemaker. 46% of surgeons would cut a dispersive electrode to fit it on a child. 69% believed that harmonic scalpel was a bipolar cautery. 61% couldn't differentiate between RFA and Microwave Ablation. 63% didn't know how to handle an operating room fire.ConclusionIn these two hospitals, high level of ignorance noticed regarding the procedure and indications of basic electrosurgical equipment which needs raising awareness and further training.

Global trends in myopia management attitudes and strategies in clinical practice – 2019 Update

PurposeA survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later. MethodsA self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies. ResultsOf the 1336 respondents, concern was highest (9.0 ± 1.6; p < 0.001) in Asia and lowest (7.6 ± 2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ± 2.3; p < 0.001), the North American practitioners being the least active (6.3 ± 2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ± 21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %). ConclusionsWhile practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future.

An Improved Free Energy Perturbation FEP+ Sampling Protocol for Flexible Ligand-Binding Domains

Recent improvements to the free energy perturbation (FEP) calculations, especially FEP+ , established their utility for pharmaceutical lead optimization. Herein, we propose a modified version of the FEP/REST (i.e., replica exchange with solute tempering) sampling protocol, based on detail studies on several targets by probing a large number of perturbations with different sampling schemes. Improved FEP+ binding affinity predictions for regular flexible-loop motions and considerable structural changes can be obtained by extending the prior to REST (pre-REST) sampling time from 0.24 ns/λ to 5 ns/λ and 2 × 10 ns/λ, respectively. With this new protocol, much more precise ∆∆G values of the individual perturbations, including the sign of the transformations and decreased error were obtained. We extended the REST simulations from 5 ns to 8 ns to achieve reasonable free energy convergence. Implementing REST to the entire ligand as opposed to solely the perturbed region, and also some important flexible protein residues (pREST region) in the ligand binding domain (LBD) has considerably improved the FEP+ results in most of the studied cases. Preliminary molecular dynamics (MD) runs were useful for establishing the correct binding mode of the compounds and thus precise alignment for FEP+ . Our improved protocol may further increase the FEP+ accuracy.

Nonlinear Embedding Model-Based Continuous Class E/F Power Amplifier

This letter presents the design of a continuous class E/F power amplifier (PA) using model-based nonlinear embedding. The theoretically calculated continuous class E/F loads defined at the current source reference plane (CRP) may not guarantee feasible loads at the extrinsic package reference plane (ERP) due to nonlinear parasitic. Hence, a design space is analyzed to map the correct mode of the class E/F continuum over broadband to obtain feasible loads. A scheme is presented to assign fundamental current component ( $\phi$ ) to various frequencies over the band to obtain a tradeoff between best bandwidth and feasibility of a passive matching network. A nonlinear embedding model is used to project the loads from CRP to ERP. As a proof of concept, a continuous class E/F PA is designed using CGH27015F. The prototype developed has measured a drain efficiency of 60.2%–76.5% from 1.5 to 2.9 GHz which corresponds to 63.6% fractional bandwidth.

ESTIMATION OF EFFICIENCY OF OSTEOPATHIC CORRECTION OF FUNCTIONAL STATE OF STUDENT ORGANISM UNDER INCREASED PSYCHO-EMOTIONAL LOADS

Introduction. The social changes happening in the country for the last 25 years negatively affected the state of health of citizens, mainly younger generation. It is expressed in the gain in the morphological and functional of deviations, the general incidence of teenagers, deterioration in psychosomatic health of youth as a result of high compensatory and adaptive exertion up to nervous breakdowns. Purpose. To estimate efficiency of correction of a functional condition of an organism of students by means of osteopathic influence at the raised psychological and emotional loads during exams. Material and methods. 15 almost healthy students of pedagogical higher education institution, at the age of 22.4±0.7 under increased psychological and emotional exertion during exams acted as examinees. Changes of indices of the osteopathic status and a functional condition of the central nervous system of students directly before osteopathic correction, right after influence and also in 3 weeks were estimated. Results. The osteopathic correction was established to promote a significant improvement in students according to values of indices of functional mobility of nervous processes in the cerebral cortex; a mental state on nosological and syndromologic scales; - indices of the osteopathic status Conclusion. Single osteopathic correction leads to optimization of the mental status, mobility, and steadiness of nervous processes, and also to reduction of processes of excitement in a cerebral cortex both right after influence and in 3 weeks after its carrying out. Also improvement of attention and memory in students in 3 weeks after an influence, and right after carrying out correction - decrease in an uneasiness index in them and the general functional status is noted. Results of research revealed need of carrying out further research on the development of the modes of correction for the purpose of the introduction it in educational process.

Assessment, Monitoring, and Awareness of Garment Workers Regarding the Prevalence of Tuberculosis in Savar, Dhaka

The study was conducted to evaluate the awareness regarding Tuberculosis (TB) in the middle of the export-oriented garment workers in Savar, Dhaka. Data were calmed by face to face talk to using a semi-structured questionnaire. A gross of 110 garment workers was talked to, in the middle of them, 51.8% were male and rests of 48.2% were female. Maximum 30.9% participants age was between 20-22 years and 28.2% of respondent’s ages were more than 28 years. 58.2% of respondents had secondary education, 22.7% of respondents had primary education, and 14.5% of respondents had HSC and above education. Out of 110 participants, 60.0% resided in a nuclear family, 39.1% have resided in a joint family, and 34.5 % were at their own house, 3.6 % were at slum and 57.3% were at the colony. The majority had heard about TB (72.7%) by listening to Television, Radio, Newspaper, and 27.3% were family members, offices, doctors, or hospitals. only 25.5% perceived it to be an infectious disease, (30.0%) were did not perceive and the highest number 44.5 % were didn’t know. The correct mode of conveyance i.e. airborne (coughing) was familiar to 66.7% research subjects. The majority (62.4%) knew cough as a symptom. Maximum (71.8%) participants thought TB to be a curable disease, in the middle of the majority (52.0 %) were of the viewpoint to avert the TB by a cover on the mouth at coughing, 8.1% were said BCG (Bacillus Calmette-Guérin) vaccination and 35.8 % was no smoking. Most of the respondents (96.4%) said TB is a treatable disease, in the middle of them, 75.5% said by Anti TB antibiotics. 62.7% of participants perceive TB is a totally curable disease. This work shows (74.5%) garments workers have deficient awareness and (25.5%) have adequate awareness.

MPC-Based Coordinated Voltage Regulation for Distribution Networks With Distributed Generation and Energy Storage System

This paper presents a model predictive control (MPC)-based coordinated voltage control scheme for distribution networks with high penetration of distributed generation (DG) and energy storage. In this scheme, the DG units, energy storage devices, and on-load tap changer are optimally coordinated to maintain all bus voltages in the network within a permissible range. To better coordinate the economical operation and voltage regulation, two control modes are designed according to the operating conditions. In the preventive mode, the DG units operate in the maximum power point tracking mode. State-of-charge of energy storage system (ESS) units and power outputs of DG and ESS units are optimized while maintaining the voltages within the feasible range. In the corrective mode, active power curtailment of DG units is also used as a necessary method to correct the severe voltage deviations. The voltage sensitivity coefficients with respect to the power injections and tap changes are updated in real time using an analytical sensitivity calculation method to improve the computation efficiency. A test system consisting of two 20-kV feeders fed from the same substation based on a real distribution network was used to validate the proposed coordinated voltage control scheme under both normal and large-disturbance conditions.

The role of hydration effects in 5-fluorouridine binding to SOD1: insight from a new 3D-RISM-KH based protocol for including structural water in docking simulations.

Misfolded Cu/Zn superoxide dismutase enzyme (SOD1) shows prion-like propagation in neuronal cells leading to neurotoxic aggregates that are implicated in amyotrophic lateral sclerosis (ALS). Tryptophan-32 (W32) in SOD1 is part of a potential site for templated conversion of wild type SOD1. This W32 binding site is located on a convex, solvent exposed surface of the SOD1 suggesting that hydration effects can play an important role in ligand recognition and binding. A recent X-ray crystal structure has revealed that 5-Fluorouridine (5-FUrd) binds at the W32 binding site and can act as a pharmacophore scaffold for the development of anti-ALS drugs. In this study, a new protocol is developed to account for structural (non-displaceable) water molecules in docking simulations and successfully applied to predict the correct docked conformation binding modes of 5-FUrd at the W32 binding site. The docked configuration is within 0.58Å (RMSD) of the observed configuration. The docking protocol involved calculating a hydration structure around SOD1 using molecular theory of solvation (3D-RISM-KH, 3D-Reference Interaction Site Model-Kovalenko-Hirata) whereby, non-displaceable water molecules are identified for docking simulations. This protocol was also used to analyze the hydrated structure of the W32 binding site and to explain the role of solvation in ligand recognition and binding to SOD1. Structural water molecules mediate hydrogen bonds between 5-FUrd and the receptor, and create an environment favoring optimal placement of 5-FUrd in the W32 binding site.

Does averaging overestimate or underestimate population growth? It depends

When a matrix population model is nonautonomous, i.e., when it represents a set of single-time-step ("annual") PPMs, L(t), t = 0, 1, …, T – 1, each corresponding to a fixed life cycle graph, then each of the annual matrices generates its own set of model results to characterize the population. In particular, λ1(t), the asymptotic growth rate, varies with t and may result in alternating predictions of population viability. A logical way to characterize the population over the total period of observations is to average the given set of T PPMs, and I have proved the correct mode of averaging to be the pattern-geometric average. It means finding a matrix, G, such that its Tth power equals the product of T annual matrices (in the chronological order), while its pattern does correspond to the given life cycle graph. In practical cases however, the mathematical problem of pattern-geometric average has no exact solution for a fundamental mathematical reason. Nevertheless, the approximate solutions have revealed a fair precision of approximation in recent case studies of alpine short-lived perennials (Eritrichium caucasicum and Androsace albana), resulting in quite certain predictions of population viability by means of λ1(G), the dominant eigenvalue of the average matrix.An alternative approach to estimate the viability leades to the concept of stochastic environment (represented by the given PPMs to be chosen at random) and the ensuing stochastic growth rate, λS. In the case studies, the λSs have been estimated by a direct method of Monte Carlo simulations, all the E. caucasicum estimates having unambiguously been less than λ1(G), whereas those for A. albana being certainly greater than λ1(G). There should be a general mathematical reason for this, too, thus a challenge to the theory of nonnegative matrices.

Fragment Binding Pose Predictions Using Unbiased Simulations and Markov-State Models.

Predicting the costructure of small-molecule ligands and their respective target proteins has been a long-standing problem in drug discovery. For weak binding compounds typically identified in fragment-based screening (FBS) campaigns, determination of the correct binding site and correct binding mode is usually done experimentally via X-ray crystallography. For many targets of pharmaceutical interest, however, establishing an X-ray system which allows for sufficient throughput to support a drug discovery project is not possible. In this case, exploration of fragment hits becomes a very laborious and consequently slow process with the generation of protein/ligand cocrystal structures as the bottleneck of the entire process. In this work, we introduce a computational method which is able to reliably predict binding sites and binding modes of fragment-like small molecules using solely the structure of the apoprotein and the ligand's chemical structure as input information. The method is based on molecular dynamics simulations and Markov-state models and can be run as a fully automated protocol requiring minimal human intervention. We describe the application of the method to a representative subset of different target classes and fragments from historical FBS efforts at Boehringer Ingelheim and discuss its potential integration into the overall fragment-based drug discovery workflow.

The effect of nursing program propaganda strategy on the knowledge, attitude and practice of breast cancer patients with PICC catheter

Objective To analyze the influence of nursing program propaganda strategy on the knowledge, attitude and practice of breast cancer patients with indweled PICC catheter, and to provide a premise for quality diagnosis and treatment by accumulating evidence-based data. Methods Using computers as the medium of selection, 94 breast cancer patients with PICC catheterization admitted by the hospital from September 2012 to August 2017 were divided into study group and control group by random number table, with 47 cases each.The cognition, beliefs and behaviors of patients in the two groups before catheterization and after the third chemotherapy cycle were evaluated, and the maintenance status, occurrence of adverse events and nursing satisfaction were recorded. Results The cognitive, attitude and behavior scores of the patients in the study group were higher than those in the control group, and the difference was statistically significant (P<0.05). The proportion of adverse events, delayed maintenance and delayed maintenance times of the study group was lower than that of the control group, and the difference was statistically significant(P<0.05). The satisfaction of the study group was higher than the control group, and the difference was statistically significant (P<0.05). Conclusions Application of nursing program propaganda strategy in breast cancer patients with indwent PICC catheter can improve their cognition and belief level and help them consciously form correct behavior mode. Key words: Nursing procedure; Mission strategy; PICC lien; Breast cancer; Knowledge, attitude and practice

An Integrated Single-Stage Converter fed Sensor-less Motor Drive

This paper details an Integrated Single-stage converter fed sensor-less BLDC motor drive. The drive speed is regulated by altering the DC voltage of the inverter that drives the motor. The switches of the inverter are operated at the line frequency, thereby reducing the inverter switching stresses and enhancing the overall drive system efficiency. The converter works in Dual-discontinuous Current Mode (D-DCM) for Power Factor Correction (PFC) and better power quality at the supply mains. DC voltage control is used adjust the duty ratio of the converter switch. Fast voltage regulation, zero current switching at turn-on and enhanced power factor for a broad range of speeds are the advantages of this converter configuration. The necessity of Hall-Effect position sensors is eliminated by employing a sensor-less technique for brushless dc motor commutation. This reduces the dimensions, volume and expenditure of the motor drive and upgrades its overall efficiency. Drive performance is assessed over an extensive span of speeds. A power factor approximating to unity, and enhanced power quality indicators which are adequately within the sanctioned cap of IEC standard 61000-3-2 are obtained.

An Integrated Single-Stage Converter Fed Sensor-Less Motor Drive

This paper details an Integrated Single-stage converter fed sensor-less BLDC motor drive. The drive speed is regulated by altering the DC voltage of the inverter that drives the motor. The switches of the inverter are operated at the line frequency, thereby reducing the inverter switching stresses and enhancing the overall drive system efficiency. The converter works in Dual-discontinuous Current Mode (D-DCM) for Power Factor Correction (PFC) and better power quality at the supply mains. DC voltage control is used adjust the duty ratio of the converter switch. Fast voltage regulation, zero current switching at turn-on and enhanced power factor for a broad range of speeds are the advantages of this converter configuration. The necessity of Hall-Effect position sensors is eliminated by employing a sensor-less technique for brushless dc motor commutation. This reduces the dimensions, volume and expenditure of the motor drive and upgrades its overall efficiency. Drive performance is assessed over an extensive span of speeds. A power factor approximating to unity, and enhanced power quality indicators which are adequately within the sanctioned cap of IEC standard 61000-3-2 are obtained.

Aberration-corrected focused ion beam for time-of-flight secondary neutral mass spectrometry

A chromatic and spherical aberration corrector with liquid Ga ion metal source was developed. The aberration corrector reduced the ion probe diameter to ∼1.5 times smaller for the 69Ga+ beam in aberration correction mode compared with the corrector in non-aberration correction mode. The probe current at a given probe size is approximately two times larger in aberration correction mode than in non-aberration correction mode. The aberration-corrected focused ion beam yields higher lateral resolutions and higher sensitivities with lower acceleration voltage for the same acquisition time down to 10 nm with a current of 1 pA.

Behaviour and modelling of cross-laminated timber panels with boundary connections subjected to blast loads

This paper presents the experimental findings from a research program investigating the blast performance of cross-laminated timber (CLT) panels with idealized and realistic boundary conditions. A total of twenty-seven static and simulated blast tests were undertaken on 5-ply CLT panels with the aim to quantify the high strain-rate effects in the connections. Two types of CLT end connections were tested, namely a relatively thin off-the-shelf angle and a thicker in-house manufactured angle, both of which used screw fasteners. Component-level testing was conducted on the connections in order to quantify their behaviour in isolation prior to incorporating them into full-scale CLT assemblies. A statistically significant dynamic increase factor (DIF) was obtained for the connections in which the failure mode consisted mainly of wood crushing and angle bending, whereas no DIF was observed for the connections where yielding and rupturing of the steel screw fasteners were the predominant failure modes. The highly-deformable thin angle connection was found to be greatly affected by axial restraint. A two-degree-of-freedom blast analysis software that was developed and validated using the experimental results, showed reasonable ability to predict the response of the CLT assemblies. The software was able to predict the displacement as well as the correct failure mode when proper modelling inputs were utilized.

Refinining the Drift Model of a Strapdown ESG for Orbital Spacecraft

Refinement of the electrostatic gyroscope (ESG) drift model aboard an orbital maneuverable satellite for remote sensing of the Earth’s surface is considered. Some changes of the drift model also hold for the ESG ground-based applications. The paper also analyzes the quasi-continuous correction mode of the ESG-based strapdown inertial attitude reference system (SIARS) using raw (unsmoothed) data from the star tracker and the extended Kalman filter (EKF) algorithm. A special feature of solving the problem of SIARS output data correction and the calibration problem in this mode is rejection of incorrect measurements. The algorithm for this problem solution is described. The ESG drift model is given both for the SIARS calibration mode in order to ensure an adequate prediction of ESG drifts over a long time interval and for the quasi-continuous correction mode under spacecraft maneuvering conditions. The results of data processing of the flight tests of the SIARS and the star tracker aboard one of the spacecraft are discussed.

Numerical modeling of rock failure under dynamic loading with polygonal elements

SummaryPolygonal finite elements are gaining an increasing attention in the computational mechanics literature, but their application in rock mechanics is very rare. This paper deals with numerical modeling of rock failure under dynamic loading based on polygonal finite elements. For this end, a damage‐viscoplastic constitutive model for rock based on the Mohr‐Coulomb criterion with the Rankine criterion as a tensile cutoff is employed and implemented with the polygonal finite element method. Moreover, the mineral mesostructure or rock is described by randomly mapping groups of polygonal elements representing the constituent minerals into a global mesh and assigning these groups with the corresponding mineral material properties. The performance of the polygonal elements is compared with that of the linear and quadratic triangular and bilinear quadrilateral elements in numerical simulations of controlled shear band formation under uniaxial compression and lateral splitting failure in the dogbone tension test. Numerical simulations of uniaxial tension and compression tests as well as dynamic Brazilian disc test under increasing loading rates demonstrate that the present approach predicts the correct failure modes as well as the dynamic increase in strength of rock.

Organizational and financial and economic instruments of management democratization and regulation of social and cultural enterprises development in Ukraine

The subject of the study is theoretical and practical aspects of democratization of management and regulation of the development of enterprises of the socio-cultural sphere of Ukraine with the use of organizational and financial-economic instruments and mechanisms. The purpose of the work is to identify and address the challenges and problems of developing the socio-cultural sphere to improve the management and regulation of its enterprises and institutions on the basis of democratization in conditions of decentralization of power, European integration influences and using organizational and financial and economic instruments. Methodological basis of the article became as general scientific, and special methods of scientific knowledge. Were used methods: dialectical, monographic, historical, system-structural analysis and synthesis, problem and program-target approaches. Results of work. The article reveals that the decentralization of power in Ukraine and the pursuit of European standards of life place new demands on development, hence the management of national socio-cultural space. It has been established that the management of enterprises and organizations in the socio-cultural sphere should be based on the consistent democratization of the entire management system. To this end, the expediency of introducing the public-public model into the system of management of them, the involvement of social entrepreneurship instruments and social responsibility has been substantiated. The challenges and positive trends of the socio-cultural sphere development are revealed. New effective mechanisms, methods and tools for management, related to forecasting, designing and implementation of innovations, program-target planning in the mode of constant correction of goals and tasks and monitoring of socio-cultural space are proposed. The field of application of results. Conclusions and results of the article can be used in the educational-scientific process of the economic faculties of higher educational institutions. It is expedient to transfer them for practical use in the management of cultural and artistic institutions, enterprises of social infrastructure in the countryside. They also represent a practical interest in the work of rural communities and the development of rural areas. Conclusions. Democratization of the management of enterprises of socio-cultural sphere is carried out on the principles of decentralization of power, gradual formation of civil society, in accordance with the processes of European integration and in response to internal and external socio-economic challenges. At the same time, the latest methods, mechanisms and instruments of management and regulation should be applied. In their totality, the comprehensive implementation deserves programming and planning activities. It means the development of specific programs with a scientifically developed conceptual framework for the development of financially sustainable socio-cultural enterprises or activities. In the future, it is also necessary to develop criteria that will allow an assessment of the effectiveness of the implementation of these programs, provide options for their adverse development and remedial action in such cases. Executive activities in this context should include the creation of regulatory and legal networks and organizational structures that will allow for the unification of constructive processes of self-organization and specific management measures, the introduction of new mechanisms for the implementation of the potential of a program that forms relevant logistical, labor and financial and economic resources, information bases and innovations.

Rate dependent mode II traction separation law for S-2 glass/epoxy interface using a microdroplet test method

This paper presents a methodology to determine unique Mode II rate dependent traction separation law for composite interfaces by simulating all of the physically observed mechanisms in S glass fiber/epoxy microdroplet experiments conducted over a wide range of loading rates (1 µm/s to 1 m/s). A unique set of traction separation laws were determined for each loading rate by narrowing down the range of traction law parameters that accurately predicts interfacial shear strength (IFSS) with the correct failure mode for different droplet sizes (75 to 125 um). Peak traction and the fracture energy increase with the increase in the rate of loading by a factor of 1.9 and 3, respectively. The simulation provides insight into the importance of accurate rate dependent peak traction stress and resin yield stress as this ratio governs the failure mechanisms associated with IFSS and energy absorption during the debonding process.