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The problem of corrosion and its influence on spring performance is possibly even more vital than any other component in the field of engineering. This may seem to be an overstatement until the peculiar position of springs in engineering is fully understood. A spring is a device for storing and releasing energy, either at a definite time cycle, of which motor‐car or aero valve springs are a good example, or in continuous but out‐of‐phase timing, as typified for instance in the oscillating of the coil suspension of motor‐cars. Again, this unique engineering component may be called on to operate only at intervals, such springs including those found in electric light switches, return mechanisms and the like. Thus coil springs can be quite fairly said to be some of the most ubiquitous components in industry.

The purpose of this paper is to explore the applications and technological details of common components – rings and springs.

The characteristics and applications of compression springs and then extension springs are investigated, and various finishing techniques are reported. Rings ranging from flat washers to snap‐rings, push‐on rings and Smalley rings are presented.

The humble spring may be surprisingly high‐tech, with applications in fuel injection, pacemakers and insulin delivery systems. Springs fulfill shock absorption duties as well as securing tasks, and can pre‐load fixtures to withstand thermal expansion and vibration. Retaining rings are used in heavy duty lifting gear and wind turbines, whilst simple washers elegantly combine wear protection with insulation in securing circuit boards.

The paper highlights the continuing development and surprising strengths of some simple components.

A SPRING is defined as a device for storing and retaining energy. This definition is very much a simplification and every designer should have some idea of what is involved in selection of springs and the design of them where necessary. This article only covers springs made from metallic materials, although mention must be made of the fact that springs may be devised from such materials as glass fibre reinforced plastics, rubber, air and other fluids.

The purpose of this paper is to examine the impact of social movements engendered by the Arab Spring crisis on the relationship between corporate social responsibility disclosure (CSRD) and corporate governance attributes, particularly board composition, considering the importance of governance after the Arab Spring event.

Content analysis was used to examine the extent and nature of CSRD in annual reports of Jordanian companies listed on the Amman Stock Exchange covering the period 2009–2016. A dynamic regression model using panel data is then undertaken for a sample of 114 listed companies over the period to analyse the potential impact of board composition on the level of CSRD.

The results reveal that there was a significant increase in the level of CSRD post-the Arab Spring crisis; and that governance appears to be a key driver. Specifically, board age, directors educated in business and/or accounting-related fields and foreign members are found to have a significant positive relationship with CSRD.

Looking at the Arab region pre- and after the Arab Spring helps to complete the global picture of how company governance can lead to improved CSR performance. Specifically, this region has been behind in developing rules and codes that include CSR. The results show that having a diverse board, with directors with expertise specific to the context, increases the effectiveness of stakeholder management through CSRD. The results, therefore, offer valuable insights for companies, policymakers and for the development of regulations.

This study aimed to develop a method to calculate the mattress indentation for further estimating spinal alignment.

A universal indentation calculation model is derived based on the system theory, and the deformation characteristics of each component are analyzed by the finite element (FE) model of a partial air-spring mattress under the initial air pressure of 0.01–0.025 MPa. Finally, the calculation error of the model is verified.

The results indicate that the indentation calculation model could describe the stain of a mattress given the load and the constitutive model of each element. In addition, the FE model of a partial air-spring mattress can be used for further simulation analysis with an error of 1.47–3.42 mm. Furthermore, the deformation of the series system is mainly contributed by the air spring and the components directly in contact with it, while the top component is mainly deflection deformation. In addition, the error of the calculation model is 2.17–5.59 mm on the condition of 0.01–0.025 MPa, satisfying the engineering application. Finally, the supine spinal alignment is successfully extracted from the mattress indentation.

The limitation of this study is that it needs to verify the practicality of the indentation calculation model for the Bonnier spiral spring mattress. The main feature of the Bonnier spring mattress is that all springs are connected, so the mattress deflection and neighborhood effect are more significant than those of the air-spring mattress. Therefore, the applicability of the model needs to be tested. Moreover, it is worth further research to reduce the deformation error of each component.

As part of the series of studies on the intelligent air-spring mattress, the indentation-based evaluation method of spinal alignment in sleep postures will be studied for hardness and intelligent regulation based on this study.

The results of this research are ultimately used for the intelligent adjustment of air-spring mattresses, which automatically adjusts the hardness according to the user's sleep postures and spinal alignment, thus maintaining optimal spinal biomechanics. The successful application of this result could improve the sleep health of the general public.

Based on the series system theory, an indentation calculation model for mattresses with arbitrary structure is proposed, overcoming the dependence of parameters on materials and their combinations when fitting the Burgers model. Further, the spinal alignment in supine posture is extracted from the indentation, laying a theoretical foundation for further recognition and adjustment of the spinal alignment of the intelligent mattress.

After reviewing the literature focused on real-world course–client marketing projects as well as the literature regarding teaching entrepreneurial marketing (EM), the current paper assesses a census population (N = 106) of course–client projects selected by the current author via Riipen – an online course–project matching hub – for marketing courses taught from Spring 2018 through Spring 2023. The purpose of this paper is to uncover and explore the degree of EM teaching relevance of said course projects over the five-year span indicated.

All Riipen-sourced course–client projects selected by the current author for marketing courses taught from Spring 2018 through Spring 2023 (N = 106) were reviewed so that broad project-level and firm-level characteristics and trends – especially EM relevance – could be excavated and assessed over the five-year/10-semester span. In addition, an in-depth qualitative primacy-recency/bookend approach was taken with regards to the first semester (Spring 2018) and the most recent semester (Spring 2023).

The main finding is that Riipen-sourced course–client projects exhibited an increasingly high degree of EM relevance between Spring 2018 through Spring 2023. Project representatives at the founder/co-founder level or the equivalent made up only 20% of the pool in Spring 2018 yet constituted slightly over 94% of the pool by Spring 2023. Similarly, whereas only 33% of firms sourced and selected in Spring 2018 were in startup mode, fully 100% of firms selected in Spring 2023 were in startup mode.

The population of 106 Riipen-sourced-and-selected course–client projects do not represent a statistically valid basis for “apples-to-apples” comparisons because: the population of projects was spread across multiple courses and across multiple semesters over a five-year span where many shifts and trends were ongoing – including impacts to course-delivery modality due to COVID-19, and it is likely that unconscious idiosyncratic biases of the current author were operant during selection. Moving forward, researchers are encouraged to pursue questions such as the following: are there statistically significant EM-related learning outcomes that differ for students paired to projects that vary across the preliminary project taxonomy detailed?

Many practical teaching recommendations regarding effective ways to source, select and integrate high-EM course–client projects into otherwise standard-issue marketing courses are made. The paper also serves as something of a primer on how best to source and adapt Riipen marketing projects. Cautionary teaching notes and recommendations based on the current author’s observations are also shared.

Over the course of the five-period (Spring 2018 through Spring 2023), it was observed that a rapidly increasing percentage of firms on the Riipen platform self-identified as female-owned, minority-owned and/or LGBTQ-owned. Similarly, a moderately increasing percentage of marketing projects with “social entrepreneurship” and/or “social impact” and/or “environmental impact” elements were posted to the platform.

To the best of the author’s knowledge, this is the first peer-reviewed journal article to explore the EM value of real-world course–client marketing projects sourced via Riipen.

In the current manuscript, the authors examine the Belleville spring with the variable thickness. The thickness is assumed to be variable along the meridional and parallel coordinates of conical coordinate system. The calculation of the Belleville springs includes the cases of the free gliding edges and the edges on cylindric curbs, which constrain the radial movement. The equations developed here are based on common assumptions and are simple enough to be applied to the industrial calculations.

In the current manuscript, the authors examine the Belleville spring with the variable thickness. The calculation of the Belleville springs investigates the free gliding edges and the edges on cylindric curbs with the constrained radial movement. The equations developed here are based on common assumptions and are simple enough to be applied to the industrial calculations.

The developed equations demonstrate that the shift of the inversion point to the inside edge does not influence the bending of the cone. On the contrary, the character of the extensional deformation (circumferential strain) of the middle surface alternates significantly. The extension of the middle surface of free gliding spring occurs outside the inversion. The middle surface of the free gliding spring squeezes inside the inversion point. Contrarily, the complete middle surface of the disk spring on the cylindric curb extends. This behavior influences considerably the function of the spring.

A slotted disk spring consists of two segments: a disk segment and a number of lever arm segments. Currently, the calculation of slotted disk spring is based on the SAE formula (SAE, 1996). This formula is limited to a straight slotted disk spring with freely gliding inner and outer edges.

The equations developed here are based on common assumptions and are simple enough to be applied to the industrial calculations. The developed method is applicable for disk springs with radially constrained edges. The vertical displacements of a disk spring result from an axial load uniformly distributed on inner and outer edges. The method could be directly applied for calculation of slotted disk springs.

The nonlinear governing equations for the of Belleville spring centres were derived. The equations describe the deformation and stresses of thin and moderately thick washers. The variation method is applicable for the disc springs with free gliding and rigidly constrained edges. The developed method is applicable for Belleville spring with radially constrained edges. The vertical displacements of a disc spring result from an axial load uniformly distributed on inner and outer edges.

The purpose of this paper is to conduct a survey on research in fabric and cloth simulation using mass spring model. Also in this paper some of the common methods in process of fabric simulation in mass spring model are discussed and compared.

This paper reviews and compares presented mesh types in mass spring model, forces applied on model, super elastic effect and ways to settle the super elasticity problem, numerical integration methods for solving equations, collision detection and its response. Some of common methods in fabric simulation are compared to each other. And by using examples of fabric simulation, advantages and limitations of each technique are mentioned.

Mass spring method is a fast and flexible technique with high ability to simulate fabric behavior in real time with different environmental conditions. Mass spring model has more accuracy than geometrical models and also it is faster than other physical modeling.

In the edge of digital, fabric simulation technology has been considered into many fields. 3D fabric simulation is complex and its implementation requires knowledge in different fields such as textile engineering, computer engineering and mechanical engineering. Several methods have been presented for fabric simulation such as physical and geometrical models. Mass spring model, the typical physically based method, is one of the methods for fabric simulation which widely considered by researchers.

The spring‐assisted gantry robots, described in this paper, were designed primarily for the rapid transfer of lightweight objects from one point to another, e.g. to pick objects from a conveyor belt and to place them in a box. The average amount of work required for pick‐and‐place operations carried out by a conventional gantry robot was decided. Springs were added to conserve the kinetic energy of the main bar, which slides in the X‐direction and the work of the same pick‐and‐place operation was decided. A theoretical study showed that when the spring constant was optimized the required motor work of the spring‐assisted robots were 42–95 percent less than the required work of the conventional robot. The conceptual robot exists in mathematical models in Matlab and SIMULINK.

The purpose of this paper is to provide sound understanding of the mutual interactions of the major leaf spring design parameters and their effects on both the stress behavior of the designed leaf and the steering behavior of the vehicle.

Finite elements analyses have been performed referring to the design of a high performance monoleaf spring used for the suspension of the front axle of a serial heavy truck. Design parameters like eye type, eye lever, spring rate and arm rate difference have been parametrically examined regarding the stress performance and their influence on the wheel joint kinematics. The effect of each design parameter is exhibited both qualitatively and quantitatively.

Eye lever and eye type affect significantly the wheel joint kinematics and therewith the steering behavior of the vehicle. Spring rate and arm rate difference affect solely the stress performance of the leaf spring.

Design engineers may use the outcomes of this research as a guide to achieve optimal leaf spring design ensuring its operational strength in conjunction with accurate steering performance of the vehicle.

The international literature contains only few, mostly qualitative data regarding the effect of single design parameters on the leaf spring and the corresponding axle kinematics. The present work contains a comprehensive and systematic study of all major leaf spring design parameters, and reveals their effect on both the stress behavior and the steering behavior of the vehicle qualitatively and quantitatively.