scholarly journals Technical solutions for working elements of machines for efficient compaction of soil

2018 ◽  
Vol 230 ◽  
pp. 01006
Author(s):  
Kazimir Glavatsky ◽  
Volodymyr Cherkudinov ◽  
Olexandr Posmitiuha
Keyword(s):  
Soil Compaction ◽  
Structural Elements ◽  
Initial State ◽  
Modular Units ◽  
Wide Range ◽  
Combined Action ◽  
The Creation ◽  
Technical Solutions ◽  
The Impact ◽  
Light Medium

The modernization of machines for compaction of soil on a modular basis has the following advantages: some of their structural elements (working equipment and working elements) can be performed as unified modular units, from which, depending on the technological requirements, it is possible to assemble the required configuration of the sealing machine; the initial state of the machine does not deteriorate, to which it is easy to return; the nomenclature of structural elements and machines in general decreases, as the machine can be completed with variable modules, which leads to an improvement in their quality. When consolidating the soil massive use static, dynamic and combined action on the soil in the form of rollers, vibro-and ramboards. Machines of the boottype are classified into light, medium and heavy, which determines the order of its application. It is obvious that the reduction of technology for the process of soil compaction is possible due to the creation of machines that can change the intensity of the impact on the soil in a wide range.

On the Calculation of Pair Creation by Fast Charged Particles and the Effect of Screening

1935 ◽  
Vol 31 (3) ◽  
pp. 394-406 ◽  
Author(s):  
H. J. Bhabha
Keyword(s):  
Impact Parameter ◽  
Momentum Space ◽  
Minimum Distance ◽  
Rest Mass ◽  
Charged Particles ◽  
The Other ◽  
Initial State ◽  
Special Cases ◽  
The Creation ◽  
The Impact

In a recent paper I developed a method for calculating the probability of the creation of an electron pair in the collision of two charged particles moving with a relative velocity very near that of light. I showed there that under certain conditions it is legitimate to treat one of the colliding particles, say the heavier one of charge Z2 and rest mass M2, which we shall call the particle 2, as fixed at the origin of coordinates, and the other, of charge Z1 and rest mass M1, which we shall call the particle 1, as moving classically along a straight line with uniform velocity V in the direction of the z-axis, passing the other particle 2 at a minimum distance of approach (impact parameter) b. I developed expressions (given by (18) to (22) of A) giving the probability of the transition of an electron from an initial state of negative energy E0 and momentum p0 lying in an element of momentum space dp0 to a final state of energy E and momentum p lying in an element of momentum space dp, under the combined perturbing influence of the two colliding particles when they pass at a minimum distance b. The initial state of the electron, left vacant after the transition, appears as a positron of momentum p+ = − p0. To get the differential effective cross-section for the creation of the above pair, we must integrate this probability over all values of the impact parameter b, and this integration can be performed easily as shown in A. The final result can be written as a sum of a finite number of doubly infinite integrals (A, (24)). The purpose of this paper is to carry through the evaluation of these integrals for certain special cases, and to consider the effects of screening. The results have already been communicated in A.

scholarly journals Properties of Structural Lightweight Aggregate Concrete Based on Sintered Fly Ash and Modified with Exfoliated Vermiculite

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5922
Author(s):  
Patrycja Przychodzień ◽  
Jacek Katzer
Keyword(s):  
Fly Ash ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Structural Elements ◽  
Ordinary Concrete ◽  
Wide Range ◽  
Actual Use ◽  
Structural Lightweight Aggregate Concrete ◽  
The Impact

Despite the undoubted advantages of using lightweight concrete, its actual use for structural elements is still relatively small in comparison to ordinary concrete. One of the reasons is the wide range of densities and properties of lightweight aggregates available on the market. As a part of the research, properties of concrete based on sintered fly ash were determined. The ash, due to its relatively high density is suitable to be used as a filler for structural concretes. Concrete was based on a mixture of sintered fly ash and exfoliated vermiculite aggregate also tested. The purpose of the research was to determine the possibility of using sintered fly ash as alternative aggregate in structural concrete and the impact of sintered fly ash lightweight aggregate on its physical, mechanical and durability properties. Conducted tests were executed according to European and Polish standards. Created concretes were characterized by compressive strength and tensile strength ranging from 20.3 MPa to 54.2 MPa and from 2.4 MPa to 3.8 MPa, respectively. The lightest of created concretes reached the apparent density of 1378 kg/m3.

scholarly journals Regularities in aerodynamic efficiency control for gas cooler fans

2021 ◽  
Vol 6 ◽  
pp. 76-86
Author(s):  
Nikolai V. Makarov ◽  
Keyword(s):  
Aerodynamic Resistance ◽  
Structural Elements ◽  
Impeller Blade ◽  
Aerodynamic Efficiency ◽  
Wide Range ◽  
Efficiency Control ◽  
Specific Speed ◽  
The Impact ◽  
Aerodynamic Quality

Research relevance. The paper establishes the regularities in the impact the geometry and structural elements of a fan system piping have on the fan system’s aerodynamic efficiency in a wide range of the specific speed variation. Objectives and methods of research. A mathematical model has been obtained for the dependence of fan system’s geometry and kinematic parameters and the aerodynamic efficiency on the specific speed. Results. It has been proved that in order to reach higher aerodynamic efficiency of fan systems, in view of the increasing specific speed of fan systems, the aerodynamic quality of the impeller blade profiles should be increased and the aerodynamic resistance of the piping elements should be reduced. It has been shown that it is possible to create a gas cooler fan system with at least 400 specific speed and at least 0.85 efficiency if the impeller profiles aerodynamic quality is more than 25, and piping drag coefficient doesn’t exceed 0.2.

scholarly journals Innovative approaches to the formation of competitive tourism products (services): foreign and domestic experience

2021 ◽  
pp. 108-113
Author(s):  
Vitalii Okhota
Keyword(s):  
Tourism Industry ◽  
International Tourist ◽  
Wide Range ◽  
Complete Set ◽  
The Creation ◽  
In The Beginning ◽  
Cultural Routes ◽  
The Impact ◽  
The Given ◽  
Innovative Approaches

Purpose. The aim of the article is systematization of innovative approaches to the formation of competitive tourism products (services), provided by foreign and domestic experience. Methodology of research. The following methods are used to achieve the above goal: a systematic approach – to establish a complete set of innovative solutions; generalizations and unifications that allow to establish the most optimal and acceptable approaches to the formation of competitive tourism products (services). Findings. Based on the study of domestic and foreign experience in the formation of competitive tourism products (services) systematization of innovative approaches in this area: the approach associated with the formation of tourism products (services) depending on their connection with certain values, opportunities to solve problems as internal nature (at the level of tour operators) and external (socially significant); an approach based on the orientation of products (services) on international tourist cultural routes; institutional innovative approach related to the focus on the involvement of institutions, objects of different infrastructure for the creation and provision of competitive tourism products (services); approach to the creation of products (services) in the tourism industry, based on the virtualization of travel (virtualized approach); virtualized approach based on visualization and virtualization of travel (virtualized visualized approach). It is determined that the given universal systematization can be adapted to modern conditions of development in this sphere, in particular, challenges and threats of epidemiological character which have arisen in the beginning of 2020 in the world. It is proved that the virtualized visualized approach proposed in the study can be implemented for a wide range of types of tourism, but its implementation requires the development of new knowledge, skills, strong potential to attract new consumers who are focused on purchasing travel remotely. Originality. For the first time, promising areas for the development of competitive positions of tourism entities, tourism industries, based on the current realities of the spread of epidemiological threats; possible features of management of creation and the organization of introduction of tourist products (services) developed in the context of the virtualized visualized approach are formulated. Practical value. The results of the study can be used by domestic tourism entities to find and implement innovative approaches to the formation of products (services) in terms of the impact of the spread of epidemiological threats. Key words: innovative approaches, tourist products (services), competitive positions, threats of epidemiological character, virtualized visualized approach, remote mode, values, international tourist cultural routes.

Biscogniauxia (Hypoxylon) Canker or Dieback in Trees

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Claudia Paez ◽  
Jason A. Smith
Keyword(s):  
Water Stress ◽  
Tree Species ◽  
Soil Compaction ◽  
Urban Areas ◽  
Root Disease ◽  
Poor Health ◽  
Green Spaces ◽  
Opportunistic Pathogens ◽  
Wide Range ◽  
Quercus Spp

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009).  Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).

Influence of the distribution of the shear walls on the seismic response of the buildings

2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui
Keyword(s):  
Structural Analysis ◽  
Seismic Response ◽  
Natural Frequency ◽  
Structural Design ◽  
Structural Response ◽  
Shear Walls ◽  
Structural Elements ◽  
Analysis Software ◽  
Ansys Apdl ◽  
The Impact

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.

Comparative study of the impact of two mechanical perforation densities on the behavior of a sandy soil

2012 ◽  
Vol 8 (1) ◽  
pp. 37-48
Author(s):  
S. Chehaibi ◽  
K. Abrougui ◽  
F. Haouala
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Water Infiltration ◽  
Cone Penetration ◽  
Initial State ◽  
Soil Water Infiltration ◽  
Good Improvement ◽  
The Impact ◽  
Positive Effect ◽  
Resistance To Penetration

The effects of mechanical perforation densities by extracting soil cores through an aerator Vertidrain with a working width of 1.6 m and equipped with hollow tines spaced of 65 mm, were studied on a sandy soil of a grassy sward in the Golf Course El Kantaoui in Sousse (Tunisia). The mechanical aeration was performed at two densities: 250 and 350 holes/m2. The cone penetration resistance and soil water infiltration were measured. These parameters were performed at initial state before aeration (E0) and then on the 10th, 20th and 30th day after aeration. These results showed that perforation density of 350 holes/m2 had a positive effect on the soil by reducing its cone resistance to penetration compared to the initial state (Rp = 14.8 daN/cm2). At 5 cm depth the decrease in resistance to penetration was 34% and 43% on the 10th and 20th day after aeration, respectively. However, on the 30th day after aeration the soil resistance to penetration tended to grow and its value compared to the initial state decreased only by 21 and 26%, respectively, at 5 and 15 cm of depth only by 10% and 9% with 250 holes/m2 density. The soil water infiltration made a good improvement after aeration compared to the initial state. This parameter increased from 4.8 cm/h to 8.3, 10.9 and 13.1 cm/h with 250 holes/m2 density and to 10, 12.9 and 14.8 cm/h with 350 holes/m2 density on the 10th, 20th and 30th day following the aeration.

THE IMPACT OF LEADERSHIP PRACTICES TO TEAM MEMBERS’ SATISFACTION

2009 ◽  
Vol 8 (1) ◽  
Author(s):  
Chalimah .
Keyword(s):  
Conflict Resolution ◽  
Leadership Practices ◽  
Hotel Industry ◽  
Leader Behavior ◽  
Team Leader ◽  
Shop Floor ◽  
Team Members ◽  
Top Executives ◽  
Wide Range ◽  
The Impact

eamwork is becoming increasingly important to wide range of operations. It applies to all levels of the company. It is just as important for top executives as it is to middle management, supervisors and shop floor workers. Poor teamwork at any level or between levels can seriously damage organizational effectiveness. The focus of this paper was therefore to examine whether leadership practices consist of team leader behavior, conflict resolution style and openness in communication significantly influenced the team member’s satisfaction in hotel industry. Result indicates that team leader behavior and the conflict resolution style significantly influenced team member satisfaction. It was surprising that openness in communication did not affect significantly to the team members’ satisfaction.

Stress, anxiety, depression and burnout in frontline health care workers during COVID-19 pandemic: a brief systematic review and new data from Russia

2021 ◽  
Author(s):  
Ekaterina Mosolova ◽  
Dmitry Sosin ◽  
Sergey Mosolov
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Female Gender ◽  
Assessment Tools ◽  
Care Workers ◽  
Younger Age ◽  
Wide Range ◽  
Associated Risk Factors ◽  
Anxiety Depression ◽  
The Impact

During the COVID-19 pandemic, healthcare workers (HCWs) have been subject to increased workload while also exposed to many psychosocial stressors. In a systematic review we analyze the impact that the pandemic has had on HCWs mental state and associated risk factors. Most studies reported high levels of depression and anxiety among HCWs worldwide, however, due to a wide range of assessment tools, cut-off scores, and number of frontline participants in the studies, results were difficult to compare. Our study is based on two online surveys of 2195 HCWs from different regions of Russia during spring and autumn epidemic outbreaks revealed the rates of anxiety, stress, depression, emotional exhaustion and depersonalization and perceived stress as 32.3%, 31.1%, 45.5%, 74.2%, 37.7% ,67.8%, respectively. Moreover, 2.4% of HCWs reported suicidal thoughts. The most common risk factors include: female gender, nurse as an occupation, younger age, working for over 6 months, chronic diseases, smoking, high working demands, lack of personal protective equipment, low salary, lack of social support, isolation from families, the fear of relatives getting infected. These results demonstrate the need for urgent supportive programs for HCWs fighting COVID-19 that fall into higher risk factors groups.

Trading faces: Complete AI face doubles avoid the uncanny valley

2020 ◽  
Author(s):  
Christopher Welker ◽  
David France ◽  
Alice Henty ◽  
Thalia Wheatley
Keyword(s):  
Artificial Intelligence ◽  
Sexual Orientation ◽  
Uncanny Valley ◽  
Torture Survivors ◽  
The Uncanny ◽  
The Creation ◽  
Full Face ◽  
The Impact

Advances in artificial intelligence (AI) enable the creation of videos in which a person appears to say or do things they did not. The impact of these so-called “deepfakes” hinges on their perceived realness. Here we tested different versions of deepfake faces for Welcome to Chechnya, a documentary that used face swaps to protect the privacy of Chechen torture survivors who were persecuted because of their sexual orientation. AI face swaps that replace an entire face with another were perceived as more human-like and less unsettling compared to partial face swaps that left the survivors’ original eyes unaltered. The full-face swap was deemed the least unsettling even in comparison to the original (unaltered) face. When rendered in full, AI face swaps can appear human and avoid aversive responses in the viewer associated with the uncanny valley.

Sign in / Sign up

Export Citation Format

Share Document