scholarly journals THEORETICAL AND EXPERIMENTAL SUBSTANTIATION FOR EFFORT CHANGES IN SUPPORTS OF BOOM SELF-PROPELLED CRANE

2020 ◽  
Vol 2020 (2) ◽  
pp. 43-52
Author(s):  
Pavel Grigor'ev ◽  
Lyubov' Sladkova ◽  
Vadim Krylov

In the paper on the basis of the Rostechnadzor report data there is revealed the topicality of the work connected with stability loss of boom self-propelled cranes during the work on weak load-bearing soils. The fulfilled out theoretical investigations of effort distribution in supports depending upon the angle of a boom pitch (boom extension), the angle of boom rotation in a horizontal plane and the weight of the load to be lifted allowed offering a practical realization of measures for boom self-propelled cranes updating at the expense of the introduction of underlying mechanisms allowing not only the assurance of surface horizontal positioning, but the change of soil bearing capacity (supporting surface). For the determination of the effectiveness of the device offered ensuring a table work on weak load-bearing soils there was developed a procedure for the fulfillment of experimental investigations consisting of two stages. At the first stage there were defined efforts in crane supports depending upon a weight of the load to be lifted and sp-acial boom position. At the second stage there was carried out an estimate of crane support subsidence into soil of different state for basic and updated machines. The investigation results are confirmed with confidence probability of 0.95 by Cochran, Student and Fisher criteria. As a result of experimental investigation carrying out there was defined that the application of an updated design allows increasing self-propelled crane stability by 1.41… 2.27 times.

2019 ◽  
Vol 70 (2) ◽  
pp. 242-262
Author(s):  
David Gibbs-Kneller ◽  
Derek Whayman

The determination of the scope of the fiduciary duty of loyalty, when created by contract, is not a unitary process. It is raised following a multi-factorial enquiry, which considers the nature of the engagement, in a first stage. Here, no single factor is conclusive. It is then, in a separate, second stage, reduced by qualifying contractual terms, which are applied almost strictly logically. This second stage uses the contractual doctrines of interpretation and implication. However, since it is a form of the fiduciary doctrine of authorisation, those contractual doctrines are modified according to fiduciary principles. We argue this follows from the underlying nature of the fiduciary obligation as a way of resolving its internal tensions. While this division has not yet been fully recognised in the cases, the courts have been inching towards it. However, not fully recognising this inevitable division and eliding the two stages has led to defective reasoning and outcomes.


2020 ◽  
Vol 21 (4) ◽  
pp. 408-416
Author(s):  
S. V. Bobkov ◽  
O. V. Uvarova

The article provides the results of the experiments on determination of optimal parameters for obtaining isolated proteins from grains of cultivated and wild pea for use in breeding for quality. The flour of pea varieties Sophia, Rodnik and wild accession k-3370 (Pisum sativum L. ssp. Elatius) were used in the experiment. Isolated pea proteins were obtained based on alkaline extraction and isoelectric precipitation. The experiments were carried out with the use of complete and fractional factorial plans with two levels of factors. Extraction and precipitation of protein were conducted in two stages. One hundred grams of flour were used for extraction. Influence of factors (variety, pH, duration of extraction) on the yield of isolated protein, extraction efficiency, crude protein and fat content in protein isolates was studied. All isolates were characterized by high content of crude protein (90.2-93.1 %). It was determined that increase of pH higher than eight led to enhancement of protein yield and decrease of crude protein content. The results obtained raise the possibility of effective extraction at decreased level of pH that prevents the formation of toxic chemicals. Increase of pH promoted fat accumulation in protein isolate especially at the second stage of extraction. Thus, obtaining protein isolates for evaluation of pea genetic resources should be conducted during a single cycle of extraction and precipitation. The experiments have not revealed significant differences between cultivated and wild pea as to the technology of extraction. The results of the studies are important for evaluation of pea genetic resources according to functional properties of protein isolates.


2020 ◽  
Vol 313 ◽  
pp. 00002
Author(s):  
Michal Polák ◽  
Tomáš Plachý ◽  
Adam Čítek ◽  
Karolína Berková ◽  
Petra Hájková ◽  
...  

The paper presents an experimental dynamic analysis of the existing footbridge across the Berounka River in Dobřichovice town, Czech Republic. The experiment was realized in two stages. The main purpose of the first one was the vibration response determination of the footbridge induced by pedestrians. At first, the natural frequencies and mode shapes of its horizontal load-bearing structure were measured and then the footbridge was loaded by different groups of pedestrians. The response was observed and dynamic behaviour of the footbridge was evaluated. In the course of the second stage of the experiment, the dynamic response of the footbridge deck to pedestrian traffic was measured by two different methods using radar interferometry and classical approach realized by piezoelectric accelerometers. Basic objectives of the second stage were to evaluate the fundamental modal characteristics of the footbridge and to verify new approach to dynamic response measurement – radar interferometry realized by two synchronized radars.


2021 ◽  
Author(s):  
Natalia Remez ◽  
◽  
Viktor Boiko ◽  
Alina Dychko ◽  
Tetiana Hrebeniuk ◽  
...  

In this work, seismic-explosive waves are investigated on the basis of mathematical simulation of short-delayed explosion of a system of charges and effective and seismic-safe schemes are calculated. Numerical simulation of the explosion of a group of charges of cylindrical symmetry in a rock mass is carried out. During the development of the explosion, two stages are distinguished. At the first stage, the explosion of a cylindrical explosive charge in an unlimited soil mass is considered. The principle of superposition of fields is used in the study of explosions of two or more charges, while the influence of the intervals of deceleration and distribution of masses of charges within a group on the parameters of seismic-explosion waves is investigated. It is established that approximately the same stress state is achieved in the soil mass in the near and middle zones of the explosion, which is necessary for the destruction of the rock. The efficiency of application of the proposed schemes for mining in quarries is proved. At the second stage of solving the problem, an assessment of the total action of a short-delayed explosion of a system of cylindrical charges is made. The results of theoretical studies on the determination of the optimal short-delay detonation schemes depending on the distribution of masses within the group and the deceleration intervals are presented. The development of the method for calculating seismic vibrations based on mathematical modeling of a short-delayed explosion of a system of charges, which makes it possible to calculate wave parameters depending on the distribution of masses of charges within a group of deceleration intervals, is made and proved its effectiveness.


Author(s):  
M. M. Ganbarov ◽  
M. M. Ataev ◽  
K. K. Gazvini

The kinetics of the process of using phosphorus-containing mineral compounds by their decomposition, which are actual problems, has been studied. At beginning of the it have been notified that the process takes place in two stages. These stages of the process are differed from each another mainly by rate of process realization, because a rate of the first stage is much more that a rate of the second stage. This fact is a reason of the deep research of kinetic of given process. Apart from that a detailed study of these processes connect with some problems of enter prices. All these question are analizied in the work, also the information by methodical carry out of experiments. Regime parameters correlation of components, concentrations of components, a time requite for realization of process are presented. The dependence of degree by different mass correlation of components from the time realization of process are also shown. In the work the types existence of precipitate, monitite brush it are shown. On base of received date a dissolubility of the base received product are graphically presented. In the work an influence of mass correlation of CaO?P2O5 and time of process realization on precipitation is studied. It have been determined that by 650C temperature a mass correlation of the base components must be equal to one, by that a time being used on neutralization process don’t play the practical role, because its increase and decrease don’t influence practically on process indices. The results shown that by equality of components CO?P2O5=1 correlation during four hours the precipitation degree makes up to 90,66 % and during 1 hour this index is 78,2 % for duringthe remaining three during this index is increased on 12 %. By using of these received data these is a possibility determination of the optimum technological conditions for given process. it is shown that there are opportunities to achieve processivization, to increase the use of raw materials and to obtain an environmentally friendly product with the introduction of regime parameters and component ratios in the absolute state.


1991 ◽  
Vol 7 (3) ◽  
pp. 229-281 ◽  
Author(s):  
Vladimir M. Zatsiorsky ◽  
Nikolai Yakunin

Despite relatively numerous studies, the biomechanics of rowing remains poorly understood. Much of the data is contradictory and, worse still, there appears to be a lack of consensus on the mechanical background of rowing, which leads to different approaches to the measurement of a number of parameters known by the same terms. This makes direct comparison impossible. For this reason, the present review divides the discussion of relevant biomechanical problems into two stages. The first stage involves the construction of mechanical models of the rowing element under consideration, compilation of equations, and determination of parameters used in these equations. In the second stage, experimentally obtained empirical data on these parameters are discussed.


2021 ◽  
Vol 13 (3) ◽  
pp. 31-50
Author(s):  
L.A. Regush ◽  
E.V. Alekseeva ◽  
O.R. Veretina ◽  
A.V. Orlova ◽  
Ju.S. Pezhemskaya

The article presents the results of standardization of the questionary "Immersion Index in the Internet environment", intended for the adolescents aged 12 to 17 years. The questionary was based on theoretical analysis of the phenomenon of "immersion in the Internet environment", which allowed us to build its theoretical model and suggest that this phenomenon can be described through digital competence, digital consumption and emotional attitude to the digital environment. The standardization was carried out in two stages, with the participation of a total of 1142 teenagers from St. Petersburg. The first version of the questionnaire, tested for convergent validity, was adjusted in accordance with the results obtained. At the second stage, the questionnaire underwent the procedures of factorization, determination of reliability (Cronbach's Alpha coefficient), testing distribution normality, and age norms. The article presents a standardized version of the questionnaire "Immersion Index in the Internet environment" and instructions for processing the results.


2018 ◽  
Vol 4 (1) ◽  
pp. 67
Author(s):  
Silfia Ilma ◽  
Zulfadli Zulfadli ◽  
Superli Superli ◽  
Darius Rupa

Nepenthes is a unique carnivores plant that can be found in Padat Karya forest, Krayan at the North Kalimantan. The existence of these plants can be used as a media of learning so that learning activities become more contextual. The aims of this study are 1) to know the diversity of Nepenthes in Padat Karya forest, 2) to determine the feasibility of learning media in the form of poster developed from the results of the Nepenthes diversity research. This research consisted of two stages. The first was research stage which involved inventory, identification, and diversity index determination of Nepenthes. The second stage was development research i.e developing the results gained from the first stage into poster form. The research and development model employed in this study was the modified-Borg and Gall (2006) model. There were five steps conducted, namely (1) need analysis, (2) planning, (3) develop the preliminary form of product, (4) preliminary field testing, and (5) main product revision. The results showed that the diversity index value of Nepenthes was categorized as ‘medium’. In addition, based on the validation and response obtained, the poster developed was feasible to be utilized as a learning media in senior high school.


Author(s):  
Dale E. Bockman ◽  
L. Y. Frank Wu ◽  
Alexander R. Lawton ◽  
Max D. Cooper

B-lymphocytes normally synthesize small amounts of immunoglobulin, some of which is incorporated into the cell membrane where it serves as receptor of antigen. These cells, on contact with specific antigen, proliferate and differentiate to plasma cells which synthesize and secrete large quantities of immunoglobulin. The two stages of differentiation of this cell line (generation of B-lymphocytes and antigen-driven maturation to plasma cells) are clearly separable during ontogeny and in some immune deficiency diseases. The present report describes morphologic aberrations of B-lymphocytes in two diseases in which second stage differentiation is defective.


2020 ◽  
Vol 39 (6) ◽  
pp. 8139-8147
Author(s):  
Ranganathan Arun ◽  
Rangaswamy Balamurugan

In Wireless Sensor Networks (WSN) the energy of Sensor nodes is not certainly sufficient. In order to optimize the endurance of WSN, it is essential to minimize the utilization of energy. Head of group or Cluster Head (CH) is an eminent method to develop the endurance of WSN that aggregates the WSN with higher energy. CH for intra-cluster and inter-cluster communication becomes dependent. For complete, in WSN, the Energy level of CH extends its life of cluster. While evolving cluster algorithms, the complicated job is to identify the energy utilization amount of heterogeneous WSNs. Based on Chaotic Firefly Algorithm CH (CFACH) selection, the formulated work is named “Novel Distributed Entropy Energy-Efficient Clustering Algorithm”, in short, DEEEC for HWSNs. The formulated DEEEC Algorithm, which is a CH, has two main stages. In the first stage, the identification of temporary CHs along with its entropy value is found using the correlative measure of residual and original energy. Along with this, in the clustering algorithm, the rotating epoch and its entropy value must be predicted automatically by its sensor nodes. In the second stage, if any member in the cluster having larger residual energy, shall modify the temporary CHs in the direction of the deciding set. The target of the nodes with large energy has the probability to be CHs which is determined by the above two stages meant for CH selection. The MATLAB is required to simulate the DEEEC Algorithm. The simulated results of the formulated DEEEC Algorithm produce good results with respect to the energy and increased lifetime when it is correlated with the current traditional clustering protocols being used in the Heterogeneous WSNs.


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