Test Stand for Durability Tests of Rotating Elements of Office Chairs

2014 ◽  
Vol 223 ◽  
pp. 155-162 ◽  
Author(s):  
Andrzej Zbrowski ◽  
Krzysztof Matecki
Keyword(s):  
Test Stand ◽  
Point Of View ◽  
Static Loads ◽  
Certification Tests ◽  
Test Conditions ◽  
Present Test ◽  
Normative Requirements ◽  
Design And Construction

This paper presents the purpose, concept, principles of functioning, design and construction of a stand intended for testing the durability of rotational elements of office chairs. It shows the use of the stand for certification tests in accordance with the PN-EN 1335:2009 standard. It also discusses how tests on swivelling and the durability of wheels and the base of office chairs should be conducted using the developed stand. The authors present test conditions and discuss the instrumentation necessary to induce static loads during the investigations. They also identify the possibilities to perform other tests on the stand by introducing to the existing research instruments additional instrumentation necessary from the point of view of the above listed standard. The possibility of adjusting the stand to the prospective changes in normative requirements and the needs of individual users are also described.

scholarly journals An overview and a WBS template for construction planning of mid-rise buildings

2020 ◽  
Vol 1 (2) ◽  
pp. 18-25 ◽  
Author(s):  
Jean Pierre Lukongo Ngenge ◽  
Fatemeh Nouban
Keyword(s):  
Point Of View ◽  
Construction Planning ◽  
Work Breakdown Structure ◽  
High Rise ◽  
Construction Step ◽  
Period Estimation ◽  
Proper Performance ◽  
Design And Construction

The construction of small houses was started many years before Christ, and the development of this field has led many architects and engineers to a higher level of buildings. Mainly the buildings in terms of height are classified into three types: low-, medium- and high-rise buildings. In this particular study, medium or med-rise buildings are investigated. Reaching the fully finished building stage is not easy, and it requires many steps. Taking into account the step-by-step tasks for proper performance completion, economical point of view, performance period estimation and other considerations, it is essential to organise (plan) the work before it starts accurately; that is why a work breakdown structure (WBS) template is vital in the planning, design and construction of buildings. In this paper, an overview and a WBS template for construction planning of the med-rise buildings are submitted. It was seen that for the successful construction of a mid-rise building, 14 steps are required prior completion, and among all steps, construction step takes more time for completion.

scholarly journals Modern preschool building: design and construction practice

2019 ◽  
Vol 135 ◽  
pp. 03030
Author(s):  
Natalia Norina ◽  
Svetlana Golovina ◽  
Veniamin Norin
Keyword(s):  
Structural Design ◽  
Building Design ◽  
Comprehensive Analysis ◽  
Point Of View ◽  
Design Solution ◽  
Structural Element ◽  
Educational Establishment ◽  
The City ◽  
Construction Practice ◽  
Design And Construction

The paper presents a comprehensive analysis of the design solution of the building of a preschool educational establishment in the city of Guastalla (Italy) with the aim of the possibility of adapting such a project to the conditions of Russian cities. A set of basic requirements for preschool buildings according to Russian building codes and rules is presented. They are grouped into four main groups: compliance with sanitary- hygienic and psychological requirements, safety, durability, cost-effectiveness, good appearance. A detailed analysis of the structural design of buildings based on a glued laminated frame with curved sections is presented from an environmental point of view. The conclusion is made about the inadmissibility of the use of glued laminated frames as a structural element of the preschool buildings. It is emphasized that the preschool building must in a special way satisfy the physiological needs of a small person. If this requirement is not met, no other advantages of the building will make it suitable for a comfortable and safe stay of children. The paper also presents a comparison of the development trends in the architecture of modern preschool buildings in the Russian and foreign practice of design and construction.

Design and construction of hardware and software for autonomous observations of Transient Luminous Events

2021 ◽  
Vol 16 (12) ◽  
pp. T12016
Author(s):  
S. Amrich ◽  
Š. Mackovjak ◽  
I. Strhárský ◽  
J. Baláž ◽  
M. Hančikovský
Keyword(s):  
Deep Neural Networks ◽  
Astronomical Observatory ◽  
Uniform Method ◽  
Point Of View ◽  
Cmos Camera ◽  
Small Power ◽  
Power Efficient ◽  
Transient Luminous Events ◽  
Observation Network ◽  
Design And Construction

Abstract Transient luminous events (TLE) are phenomena which are currently on the rise in terms of sightings. However, there is no widespread uniform method of their observation and subsequent image processing. Therefore, our project focuses on the design and construction of hardware that can record TLE. It consists of a low gain, colour, CMOS camera with a bright, wide lens connected to a small, power-efficient single board computer. The project also includes writing software to control the hardware. The software decides whether to capture or not and at what orientation there is the biggest chance to capture a TLE. The software can process and classify the created photos based on deep neural networks. As a final product, we have developed the whole apparatus from a hardware and software point of view and installed it at the Astronomical Observatory at Kolonica Saddle in Slovakia, Central Europe. The plan for the future is to make similar apparatuses to spread the observation network.

Preservation of the Large Timber Roof of the Porta Nuova Railway Station in Torino

2013 ◽  
Vol 778 ◽  
pp. 951-958 ◽  
Author(s):  
Clara Bertolini-Cestari ◽  
Stefano Invernizzi ◽  
Tanja Marzi ◽  
Steni Rolla
Keyword(s):  
Cultural Heritage ◽  
Point Of View ◽  
Timber Structure ◽  
Structural Assessment ◽  
Railway Station ◽  
Roof Structure ◽  
Maintenance Program ◽  
Bearing Structure ◽  
Important Structure ◽  
Design And Construction

Torino, in 1861, was the first capital of the just unified Reign of Italy. In the same year, Eng. A. Mazzucchetti was charged for the design of the railway station of Porta Nuova in Torino, in correspondence of the arrival of the railway connecting Genova. The original conception resembles the bilateral scheme of the King Cross station in London, which is few years older. The design and construction of the station deserved contributions from the most outstanding scientists of that time, including R. Sephenson who provided the details of the lateral roof structures of the station, and the young Eng. A. Castigliano who defended his thesis on the design of the great steel vault above the rails. The two main branches were conceived with masonry bearing structure and a wide span timber roof covered with stone plates. The station, during the years, was object of several interventions, including restorations, dismantling of parts, and changes in the destination of use. Nowadays, the roof structure needs for important maintenance interventions due to the water leaking which caused the deterioration of the beneath timber structure. The present holders are considering the replacement of the entire roof. This solution is not respectful for conservation criteria, nor is affordable from an economical point of view. The present study describes the correct and sustainable approach for the structural assessment, restoration and maintenance program for the preservation of this important structure belonging to cultural heritage.

Detailed Heat Transfer Distributions and Pressure Drop Measurements for a Rotating Parallelogram Channel With Radially Outward Flow

2011 ◽  
Author(s):  
S. W. Chang ◽  
T.-M. Liou ◽  
T.-H. Lee
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Test Channel ◽  
Transfer Data ◽  
Performance Factors ◽  
Nusselt Numbers ◽  
Test Conditions ◽  
Present Test ◽  
First Time ◽  
Rotating Channel

This experimental study examines the pressure drop coefficients (f) and the detailed Nusselt numbers (Nu) distributions over two opposite leading and trailing walls roughened by 45° ribs for a rotating parallelogram channel with radially outward flow. For the first time the isolated effects of Reynolds (Re), rotation (Ro) and buoyancy (Bu) numbers on local and area averaged Nusselt numbers (Nu and Nu) measured from the infrared thermography method were successfully examined at the parametric conditions of 5000≤Re≤15000, 0≤Ro≤0.3 and 0.001≤Bu≤0.23 for the single-pass parallelogram channel. A set of selected heat transfer data illustrates the Coriolis and rotating-buoyancy effects on the detailed Nu distributions and the area-averaged heat transfer performances of the rotating parallelogram channel. With the consideration of the f data generated at the isothermal conditions, the thermal performance factors (η) for this radially rotating channel were evaluated. The Nusselt numbers obtained from the leading and trailing walls of the rotating test channel fall in the respective ranges of 0.78–1.34 and 1.09–1.38 times of the stationary levels; while the η factors are in the range of 0.979–1.575 for the present test conditions.

High-Speed Fracture in Rubber

1959 ◽  
Vol 32 (1) ◽  
pp. 13-20
Author(s):  
Peter Mason
Keyword(s):  
Energy Consumption ◽  
Boundary Conditions ◽  
Crack Propagation ◽  
Elastic Waves ◽  
High Speed ◽  
Fracture Propagation ◽  
Smooth Surfaces ◽  
Test Conditions ◽  
Present Test ◽  
Slow Propagation

Abstract Cinematographic observations have been made of crack propagation under well-defined boundary conditions in rubbers at speeds up to 30 m/sec. The fracture-markings showed resemblances to those obtained with metals, plastics, and glass, and could be related directly to the corresponding speed of fracture-propagation. In close analogy with Schardin's observations on glass, a non-crystallizing rubber (GR-S) showed a mode of crack propagation in which the fractured surfaces were visually smooth and the speed was about one quarter of the speed of longitudinal elastic waves. A crystallizing rubber (natural rubber) did not show this mode of propagation under the present test conditions. It is suggested that the modes of solid fracture can be usefully classified in three categories: (i) slow propagation, generally with smooth surfaces, obtained by careful control of the boundary conditions; (ii) propagation at intermediate rates with rough surfaces, involving correspondingly greater energy consumption; and (iii) fast propagation with smooth surfaces, the rate of propagation being limited by the speed of elastic waves in the material in accord with Mott's theory.

Hydrodynamic journal bearing lubricated with a ferrofluid

2017 ◽  
Vol 69 (5) ◽  
pp. 754-760 ◽  
Author(s):  
Nimeshchandra S. Patel ◽  
Dipak Vakharia ◽  
Gunamani Deheri
Keyword(s):  
Design Methodology ◽  
Journal Bearing ◽  
Magnetic Bearing ◽  
Point Of View ◽  
Content Type ◽  
Test Conditions ◽  
Hydrodynamic Journal Bearing ◽  
Bearing Design ◽  
Set Up ◽  
Bearing System

Purpose This paper aims to investigate the performance of a ferrofluid-based hydrodynamic journal bearing system. Design/methodology/approach This paper presents a new design of ferrofluid-based hydrodynamic journal bearing. An experimental set-up consisting of a magnetic shaft along with a brass bearing was modified and developed. A permanent magnet was used to make the selected shaft material magnetic. The load and speed were varied to conduct the analyses for different test conditions. Findings The paper provides information about a design of ferrofluid-based journal bearing and its improved performances. For moderate to higher loads at different shaft speeds, it was found that because of the magnetization effect, the maximum film pressure in case of a ferrofluid lubricant increased up to approximately 60 per cent, compared with that of the conventional lubricant-based journal bearing system. Besides, the temperature rise was found smaller for ferrofluid lubricants, thus making the system cooler while running. Originality/value This paper offers a new design of magnetic bearing system for the experimental analysis by utilizing a magnetic shaft with a non-magnetic bearing. The present ferrofluid-based bearing design is less complicated from manufacturing point of view.

scholarly journals Projeto de bancadas didáticas para laboratório de instalações elétricas

2019 ◽  
Vol 40 ◽  
pp. 48
Author(s):  
Angélico Loreto Teixeira ◽  
Lucas Giuliani Scherer ◽  
Ana Alice Timm Gorretti
Keyword(s):  
Higher Education ◽  
University Students ◽  
Civil Engineering ◽  
Electrical Engineering ◽  
Point Of View ◽  
Private Companies ◽  
Public And Private ◽  
Teaching Learning ◽  
Important Form ◽  
Design And Construction

The high cost of assembling laboratories for higher education is a challenge when there is a contingency of resources. An alternative to overcome the high cost in the development of the basic structures of the teaching laboratories, is the designing and implementation of laboratory workbenches, built with the help of teachers, technicians and university students. In this work will be approached the project of didactic workbenches for the laboratory of electrical installations, capable of attending the most varied menus, as well as courses such as Electrical Engineering, Civil Engineering, Architecture and Urbanism, among others. Analyzing from a financial point of view, there is an economy above 90%, compared to commercial didactic workbenches in market. In addition, taking into account the teaching-learning aspect of the students, the benefits are greater, since the very design, design and construction of the benches represent an important form of practical learning. In addition, the workbench aims to increase the degree of complexity of the tasks compared to the existing equipment in the market, since it encompasses more concepts. For the acquisition of materials, it is suggested the use of institutional resources or partnership with public and private companies.

scholarly journals Autonomy: a Matter of Content

2008 ◽  
Author(s):  
Raffaela Giovagnoli
Keyword(s):  
Moral Agency ◽  
Practical Reasoning ◽  
Personal Autonomy ◽  
Point Of View ◽  
Individual Choice ◽  
Important Distinction ◽  
Normative Requirements ◽  
Autonomous Agency ◽  
The Right

Autonomy is the core of a lively debate on moral and political philosophy, where many competing perspectives and conceptual distinctions are presented. Several authors tend to override the metaphysical questions of determinism and free will: this is the right step for emphasizing the dimensions of individual choice as well as the role of socialization in developing capacities for critical reflection. In this context, the most important distinction is between "moral" autonomy and "personal" autonomy. Generally speaking, the theorists of personal autonomy try to give an account of autonomy that is conceived not only as moral agency. This move allows the consideration of several patterns of practical reasoning that imply several kinds of reasons for acting. The argumentation considers the discussion between "procedural" and "substantive" theories. Procedural theories emphasize the structural conditions of the process of "identification" with one's own motives. Even if these conditions are relevant, substantive theories rightly point to the role of the content of our reasons for autonomous agency. This perspective requires substantive standards according to which we can recognize and criticize oppressive norms. The main theoretical proposal of this work is to show the normative requirements for autonomy. An intersubjective model is promising if we consider socialization from the point of view of the process through which we develop the cognitive and moral capacities necessary for autonomy. The "scorekeeping" model, (an original variant of Wittgenstein's linguistic game as proposed by Robert Brandom) seems to offer the deontic structure of discursive practices in which the agents have the possibility of discussing and criticizing their own and others' reasons.

A Dynamic Rubber-Cord Composite Adhesion and Fatigue Test

1974 ◽  
Vol 47 (1) ◽  
pp. 171-187 ◽  
Author(s):  
P. P. Langevin ◽  
R. J. Payne ◽  
C. S. Shephard
Keyword(s):  
Fatigue Test ◽  
Fatigue Tests ◽  
Point Of View ◽  
Rubber Compound ◽  
Dynamic Tests ◽  
Dynamic Conditions ◽  
Test Conditions ◽  
Single Station ◽  
Steel Cord ◽  
Static And Dynamic Tests

Abstract Dynamic adhesion and fatigue tests can be conducted on the Firestone Flexometer, where the hysteresis effect of the rubber compound can be brought to bear on the rubber-cord interface. Only minor modifications of equipment need to be made to run this test under a range of different conditions. Although the test is designed for single-station testing, several samples can be run at once, and test conditions can be adjusted to prevent cycle-life from becoming excessive. Rubber-steel cord composites have been studied under dynamic conditions, and indications are that other cord types and dips can also be evaluated with this method. Thus, the study of adhesion can be approached from a different point of view than that which is provided by current static and dynamic tests.

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