Research on Dynamic Response of Slopes With Weak Interlayers Under Mining Blasting Vibration

As blasting technology starts to be used in a wide range of areas, blast loading has led to an increasing number of geological disasters such as slope deformation, collapses, and soil slippage. Slopes with weak interlayers are more likely to be deformed and damaged under the influence of blast loading. It is of great importance to study the evolution for the deformation of slopes with weak interlayers during blasting excavation. This study constructed a slope model with a weak interlayer to investigate the influence of different factors of blasting, including explosive charge, blast radius, blast origin, and multi-hole blasting, on the internal dynamic response. The deformation mechanism of slopes with weak interlayers under the influence of blast loading was analyzed. Test results show that each layer of the model had a different displacement response (uncoordinated dynamic response) to blasting with various factors. Explosive energy and the pattern of dynamic response of each layer varied depending on different settings of blasting factors such as explosive charge, blast radius, blast origin, and detonation initiation method. When the explosive energy produced under the influence of various factors was small, the change in the uncoordinated dynamic response between layers was significant, and the change gradually became less significant as the explosive energy increased. Therefore, this study has proposed the concept of critical explosive energy, and it is speculated that when the explosive energy produced with various factors is less than critical explosive energy, the dynamic response is mainly affected by the internal structure of the slope (property difference induced geologic layers). In other words, the uncoordinated motion of material’s particles in each layer is caused by different limitations and the degree of movement of the particles, which leads to the uncoordinated dynamic response and uncoordinated deformation of each layer. If the explosive energy is greater than the critical value, the dynamic response of each layer is mainly affected by the explosive energy. The differences in the internal structure of the slope are negligible, and the incoordination of dynamic responses between layers gradually weakens and tends to synchronize.

Striving for Freedom. Some Notes about Fichte’s Idealism

Moving from Fichte’s assumption that “the essence of the I is its activity”, this paper tries to analyze the meaning and implications of the idea of “activity” [Tathandlung] in order to explicate the peculiarities of Fichte’s critical, transcendental, and moral idealism. Fichte’s idea of activity will be examined with reference to such basic concepts as collision [Anstoss], interaction [Wechselwirkung], inter-determination [Wechselbestimmung], and striving [Streben]. However, it is freedom which frames and connects the core components of Fichte’s thinking and sets up the goal of his philosophy of action. What freedom accounts for, can be identified both at the transcendental level, in the internal dynamic of infinity and finitude constituting the subjectivity of the I, and at the moral and social levels of Fichte’s thought, as the goal of the human action in history and in the society. In assuming the unitary character of Fichte’s philosophical system, concluding remarks are developed concerning the moral meaning of the act of striving for freedom and, conversely, the immorality of attitudes and feelings such as fear, resignation, and fatigue.

COMPUTATIONAL AND EXPERIMENTAL METHOD FOR ESTIMATING THE RESIDUAL LIFE OF GEARS BASED ON VIBRATION MONITORING DATA

A computational and experimental method for estimating the residual life of gears in the inter-repair period is proposed. The method is based on the main provisions of the theory of vibration-pulse diagnostics of spur gears, developed at the OIM of the National Academy of Sciences of Belarus. The main performance criteria are the contact and bending endurance of the teeth. Accounting for changes in the value of the coefficient of internal dynamic load in the gearing during the operation of gears is carried out on the basis of vibration analysis during their vibration monitoring. The proposed method makes it possible to estimate the residual life of the gear mechanism at any stage of operation, providing the opportunity to organize the transition from planned preventive maintenance of machines to maintenance according to the actual condition. An example of estimating the residual life of a gear pair that limits the reliability of a two-row planetary gear motor-wheel of a heavy-duty dump truck is given. Keywords: gear transmission; vibration monitoring; residual life; inter-repair period; internal dynamic load in engagement

Impact of high strength steels over large ships fore peak structure

The fore area of the ships in extreme conditions is commonly subjected to external impact pressures such as bottom slamming and bow impact. The phenomenon combined with a poor design can lead to local structural damage (cracks, dents, buckling of plate panels) and malfunction to the installations on-board of the ship. In the present article, a comparison study between different steel material grades is performed for a VLCC fore peak structure subjected to external and internal dynamic pressures under the Harmonized Common Structural Rules for Bulk Carriers and Oil Tankers (H-CSR). Three steel grades generally used in the shipbuilding industry, one normal strength and two higher strength, are subjected for the assessment. The hull structure is built based on the benchmark crude oil carrier KVLCC2 surface developed by KRISO (Korea Research Institute for Ships and Ocean Engineering, and modelled with plate finite elements in FEMAP software. The study targets an optimization process to minimize the steel weight of the structural members by plate elements thickness reduction.

ESO-Based Vibration Control for All-Clamped Plate Using an Electrodynamic Inertial Actuator

This paper proposes a disturbance rejection method with extended state observer (ESO) and a tracking differentiator (TD) to realize vibration suppression of all-clamped plate structure in the presence of lumped disturbance, i.e. internal dynamic uncertainties, unknown external forces and accelerometer measurement noises. First, the structure is modeled as two degrees of freedom system based on vibration characteristics. Second, an ESO is employed to ensure the vibration suppression performance by estimating the lumped disturbances and compensating these disturbances via real-time feedforward mechanism. Meanwhile, a TD is introduced to eliminate the influence of the measurement noises. Moreover, the stability of the closed-loop system is discussed in detail. Finally, the proposed controller is verified on the hardware-in-loop plat-form based on NI PCIe-6343 data acquisition card. Theoretical analysis and experimental results show that the proposed method possesses good vibration suppression performance.

The Subcooling Effect of the Flue Gas Flow Mixture Internal Dynamic and Heating Capacity

Growing environmental restrictions in energy production industry calls for greater efficiency and cleaner fuel burning processes. Biomass (wood chips) as a fuel is in great demand for boiler and power plants as it is considered widely available and relatively clean. While combining woodfuel flue gas and condensing economizers significantly raises the efficiency and makes it even more viable solution for energy production although the biomass fuel usage still has reservations in waste heat, which could be utilized. The calculation algorithm is presented for evaluation of subcooled biomass flue gas components concentration values which determine the leftover heat energy value carried by flue gas flow. Several cases of biomass quality (regarding moisture w=45%, 50%, 55% and 60%) and combustion process quality (regarding air excess value λ=1,2; 1,5; 1,8) in the flue gas temperature range of 50 to 20°C and effects for flue gas internal dynamic were examined. It was determined that water vapour amount depends only on temperature, while every other component concentration change with different air excess and temperature values. It was observed that further usage of biomass flue gas could result in up to 13% additional heat energy recovery for 1MW of fuel input, system combination together with condensing economizers could result in up to 31% of heat energy recovery.

Kinetic and macroscopic models for active particles exploring complex environments with an internal navigation control system

A large number of biological systems — from bacteria to sheep — can be described as ensembles of self-propelled agents (active particles) with a complex internal dynamic that controls the agent’s behavior: resting, moving slow, moving fast, feeding, etc. In this study, we assume that such a complex internal dynamic can be described by a Markov chain, which controls the moving direction, speed, and internal state of the agent. We refer to this Markov chain as the Navigation Control System (NCS). Furthermore, we model that agents sense the environment by considering that the transition rates of the NCS depend on local (scalar) measurements of the environment such as e.g. chemical concentrations, light intensity, or temperature. Here, we investigate under which conditions the (asymptotic) behavior of the agents can be reduced to an effective convection–diffusion equation for the density of the agents, providing effective expressions for the drift and diffusion terms. We apply the developed generic framework to a series of specific examples to show that in order to obtain a drift term three necessary conditions should be fulfilled: (i) the NCS should possess two or more internal states, (ii) the NCS transition rates should depend on the agent’s position, and (iii) transition rates should be asymmetric. In addition, we indicate that the sign of the drift term — i.e. whether agents develop a positive or negative chemotactic response — can be changed by modifying the asymmetry of the NCS or by swapping the speed associated to the internal states. The developed theoretical framework paves the way to model a large variety of biological systems and provides a solid proof that chemotactic responses can be developed, counterintuitively, by agents that cannot measure gradients and lack memory as to store past measurements of the environment.

Co-Evaluation of Climate Services. An analysis of the CLARA experience

<p>This presentation aims to discuss some issues regarding the role of the economic evaluation of climate services in the context of the Horizon 2020 CLARA project. CLARA provides 14 innovative services based on a co-development approach involving service producers and specific final users. In this context, the first issue is the role of the evaluation in the co-development framework. Our understanding suggests that it cannot be one of the last steps in the process, but a preliminary evaluation should be presented in the co-design of the service. For this reason, we advise the use of the “maximum potential value” as a signal for both developers and users. It derives from a comparison between the values of two alternative knowledge sources (i.e. one other than the climate service and the other as a 100% skill climate service). The “maximum potential value” provides a benchmark against which to compare the final product. It gives insights to the producer how to improve the service, while the final user has a direct and understandable measure of likely benefits from climate service adoption. This directly supports a higher engagement of the final user, whose participation is essential in developing the service as well as in gathering information for the evaluation.</p><p>Moreover, the final user’s participation has a strong impact in assessing how the services enter the decision- making process that is sometimes an obscure issue in the internal dynamic of the organizations. Recognizing a benefit stimulate the discussion on how the tool may be used internally. This sometimes leads to changes in the service design to meet better the users’ requirements. Another critical issue is the final user’s ability to translate into actions the signals of the climate services as well as to predict and quantify costs and benefits of actions based on climate services forecasts.</p><p>All these issues are discussed presenting examples from the CLARA project, especially from a set of services related to renewable energy production and water management.</p>

Optimal supply chain performance

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings Companies can enhance their supply chain by combining data analytics and the digitization of activities. Manager focus on internal dynamic capabilities and effectiveness of data acquisition and utilization increases the possibility of improved operational and business performance. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

ALS-linked PFN1 variants exhibit loss and gain of functions in the context of formin-induced actin polymerization

Profilin-1 (PFN1) plays important roles in modulating actin dynamics through binding both monomeric actin and proteins enriched with polyproline motifs. Mutations in PFN1 have been linked to the neurodegenerative disease amyotrophic lateral sclerosis (ALS). However, whether ALS-linked mutations affect PFN1 function has remained unclear. To address this question, we employed an unbiased proteomics analysis in mammalian cells to identify proteins that differentially interact with mutant and wild-type (WT) PFN1. These studies uncovered differential binding between two ALS-linked PFN1 variants, G118V and M114T, and select formin proteins. Furthermore, both variants augmented formin-mediated actin assembly relative to PFN1 WT. Molecular dynamics simulations revealed mutation-induced changes in the internal dynamic couplings within an alpha helix of PFN1 that directly contacts both actin and polyproline, as well as structural fluctuations within the actin- and polyproline-binding regions of PFN1. These data indicate that ALS-PFN1 variants have the potential for heightened flexibility in the context of the ternary actin–PFN1–polyproline complex during actin assembly. Conversely, PFN1 C71G was more severely destabilized than the other PFN1 variants, resulting in reduced protein expression in both transfected and ALS patient lymphoblast cell lines. Moreover, this variant exhibited loss-of-function phenotypes in the context of actin assembly. Perturbations in actin dynamics and assembly can therefore result from ALS-linked mutations in PFN1. However, ALS-PFN1 variants may dysregulate actin polymerization through different mechanisms that depend upon the solubility and stability of the mutant protein.