scholarly journals High-capacity stacking apparatus for thermoforming machine – Part II: Structural design of the adjustable stacker driving mechanism

2021 ◽  
Vol 13 (10) ◽  
pp. 168781402110524
Author(s):  
Marko Penčić ◽  
Maja Čavić ◽  
Dragana Oros ◽  
Dijana Čavić ◽  
Marko Orošnjak ◽  
...  

Part II presents the structural design of a high-capacity adjustable stacker mechanism for thermoforming machines which enables the receival, transport and stacking of cup-like products. It was previously established (please see Part I) that a four-bar linkage mechanism with a one-way clutch is the optimal solution for realizing the intermittent motion of the stacker conveyor. The main objective here is to enable the change of the stacker work parameters, with the goal of changing and adjusting the work stroke of the conveyor. Accordingly, there are two main requirements the solution needs to fulfill. The first is that of the regulation characteristic’s function – the relationship between the change of the work stroke and the change of the regulation parameter, must be linear, and the second is that it allows for regulation within a wide range. Due to this, the adopted solution proposed that two links have variable lengths. The input link should have discreet length values which correspond to different values of the conveyor work stroke, while the output link length should be continuously variable, within a narrow range thus ensuring linear regulation characteristic. Finally, it should be noted that this solution makes the stacker compatible with a wide array of products, which increases the productivity and flexibility, adjusting the stacker to receive a different product can be done quickly and easily and avoiding a halt in the production as it takes less time to adjust the stacker than the thermoforming machine.

2019 ◽  
Vol 19 (04) ◽  
pp. 1950018 ◽  
Author(s):  
XUHUI LIU ◽  
TIANTIAN GUO ◽  
JIAHAO ZHANG ◽  
GUANG YANG ◽  
LUCHAN SUN ◽  
...  

In this paper, a mathematical model of four-bar linkage mechanism is built to investigate the prosthetic knee joint, by means of the bar group method, and the motion of the prosthetic knee joint is simulated by motion analysis software. In the state of motion of the four linkage mechanism, to the moving component of the mechanism, the relationship between the moving displacement, velocity and acceleration are obtained. On the basis of the above investigation, dynamic statics analysis for the moving component of four-bar linkage mechanism are completed by the ‘D’Alembert principle. The research results show that, with the change of the rotating angle of the active part, the counter-force of rotating pair and the balance torque on active component are all changeable, which will provide a theoretical basis for the design of prosthetic knee joint mechanism with longer life and better damping effect.


2020 ◽  
Vol 10 (7) ◽  
pp. 2619 ◽  
Author(s):  
Giuseppe Carbone ◽  
Eike Christian Gerding ◽  
Burkard Corves ◽  
Daniele Cafolla ◽  
Matteo Russo ◽  
...  

This paper presents a novel exoskeleton mechanism for finger motion assistance. The exoskeleton is designed as a serial 2-degrees-of-freedom wearable mechanism that is able to guide human finger motion. The design process starts by analyzing the motion of healthy human fingers by video motion tracking. The experimental data are used to obtain the kinematics of a human finger. Then, a graphic/geometric synthesis procedure is implemented for achieving the dimensional synthesis of the proposed novel 2 degrees of freedom linkage mechanism for the finger exoskeleton. The proposed linkage mechanism can drive the three finger phalanxes by using two independent actuators that are both installed on the back of the hand palm. A prototype is designed based on the proposed design by using additive manufacturing. Results of numerical simulations and experimental tests are reported and discussed to prove the feasibility and the operational effectiveness of the proposed design solution that can assist a wide range of finger motions with proper adaptability to a variety of human fingers.


2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Theeraphong Wongratanaphisan ◽  
Matthew O. T. Cole

This paper presents the analysis of a gravity compensated four-bar linkage mechanism with zero-free-length linear spring suspension. The objective of the study is to seek the possibility of employing the four-bar linkage or similar mechanisms for assisting vertical planar motion of a load mass in a gravitational field. The analysis is based on the system potential energy framework. Firstly, an arrangement of springs for gravity compensation in a four-bar linkage mechanism is proposed. It is then shown that for a four-bar linkage with symmetric geometric and mass properties the potential energy of the system has interesting and useful characteristics near the configuration at which the middle link is horizontal: an ideal operating configuration. The study also covers more practical cases where there is asymmetry in the mass distribution. The potential use of the mechanism in these cases is validated through a study of the sensitivity of the system potential energy function around the equilibrium point. Finally, based on the results obtained a novel mechanism is proposed for achieving gravity compensated vertical plane motion of a load mass. The proposed mechanism can have a wide range of travel and has significant potential for use not only in low-speed mechanical systems but also in high-speed heavy automated systems, where operating accelerations are of the order of 1g or less.


Author(s):  
Tingting Wang ◽  
Lizhong Xu ◽  
Jichun Xing

In this paper, the structural design and driving mechanism of a non-contact piezoelectric motor modulated by electromagnetic force are introduced. The equations of the electromagnetic force and torque of the electromagnetic modulation mechanism for the motor are deduced. Based on the piezoelectric constitutive equation and torque balance equations of the driving system, the equation of the piezoelectric driving torque is also obtained. Using these equations, the influences of the related parameters on the relationship between electromagnetic torque and angle difference between pole and rotor are studied. The influences of the main parameters and signal frequency on piezoelectric driving torques are analyzed. Based on them, the torque optimization of the motor is completed and the load-carrying ability of the motor is increased by about 50 times. A prototype of the motor is developed. Its output torque is tested and compared with calculated one which illustrates the theoretical model here.


2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.


2012 ◽  
Vol 6 (1-3) ◽  
pp. 243-259 ◽  
Author(s):  
Yohan Yoo

This article demonstrates the need for the iconic status and function of Buddhist scripture to receive more attention by illuminating how lay Korean Buddhists try to appropriate the power of sutras. The oral and aural aspects of scripture, explained by Wilfred Cantwell Smith, provide only a limited understanding of the characteristics of scripture. It should be noted that, before modern times, most lay people, not only in Buddhist cultures but also in Christian and other traditions, neither had the chance to recite scriptures nor to listen to their recitations regularly. Several clear examples demonstrate contemporary Korean Buddhists’ acceptance of the iconic status of sutras and their attempt to appropriate the power and status of those sacred texts. In contemporary Korea, lay Buddhists try to claim the power of scriptures in their daily lives by repeating and possessing them. Twenty-first century lay believers who cannot read or recite in a traditional style have found new methods of repetition, such as internet programs for copying sacred texts and for playing recordings of their recitations. In addition, many Korean Buddhists consider the act of having sutras in one’s possession to be an effective way of accessing the sacred status and power of these texts. Hence, various ways of possessing them have been developed in a wide range of products, from fancy gilded sutras to sneakers embroidered with mantras.


2018 ◽  
Vol 35 (4) ◽  
pp. 62-64
Author(s):  
Nazar Ul Islam Wani

Pilgrimage in Islam is a religious act wherein Muslims leave their homes and spaces and travel to another place, the nature, geography, and dispositions of which they are unfamiliar. They carry their luggage and belongings and leave their own spaces to receive the blessings of the dead, commemorate past events and places, and venerate the elect. In Pilgrimage in Islam, Sophia Rose Arjana writes that “intimacy with Allah is achievable in certain spaces, which is an important story of Islamic pilgrimage”. The devotional life unfolds in a spatial idiom. The introductory part of the book reflects on how pilgrimage in Islam is far more complex than the annual pilgrimage (ḥajj), which is one of the basic rites and obligations of Islam beside the formal profession of faith (kalima); prayers (ṣalāt); fasting (ṣawm); and almsgiving (zakāt). More pilgrims throng to Karbala, Iraq, on the Arbaeen pilgrimage than to Mecca on the Hajj, for example, but the former has received far less academic attention. The author expands her analytic scope to consider sites like Konya, Samarkand, Fez, and Bosnia, where Muslims travel to visit countless holy sites (mazarāt), graves, tombs, complexes, mosques, shrines, mountaintops, springs, and gardens to receive the blessings (baraka) of saints buried there. She reflects on broader methodological and theoretical questions—how do we define religion?—through the diversity of Islamic traditions about pilgrimage. Arjana writes that in pilgrimage—something which creates spaces and dispositions—Muslim journeys cross sectarian boundaries, incorporate non-Muslim rituals, and involve numerous communities, languages, and traditions (the merging of Shia, Sunni, and Sufi categories) even to “engende[r] a syncretic tradition”. This approach stands against the simplistic scholarship on “pilgrimage in Islam”, which recourses back to the story of the Hajj. Instead, Arjana borrows a notion of ‘replacement hajjs’ from the German orientalist Annemarie Schimmel, to argue that ziyārat is neither a sectarian practice nor antithetical to Hajj. In the first chapter, Arjana presents “pilgrimage in Islam” as an open, demonstrative and communicative category. The extensive nature of the ‘pilgrimage’ genre is presented through documenting spaces and sites, geographies, and imaginations, and is visualized through architectural designs and structures related to ziyārat, like those named qubba, mazār (shrine), qabr (tomb), darih (cenotaph), mashhad (site of martyrdom), and maqām (place of a holy person). In the second chapter, the author continues the theme of visiting sacred pilgrimage sites like “nascent Jerusalem”, Mecca, and Medina. Jerusalem offers dozens of cases of the ‘veneration of the dead’ (historically and archaeologically) which, according to Arjana, characterizes much of Islamic pilgrimage. The third chapter explains rituals, beliefs, and miracles associated with the venerated bodies of the dead, including Karbala (commemorating the death of Hussein in 680 CE), ‘Alawi pilgrimage, and pilgrimage to Hadrat Khidr, which blur sectarian lines of affiliation. Such Islamic pilgrimage is marked by inclusiveness and cohabitation. The fourth chapter engages dreams, miracles, magical occurrences, folk stories, and experiences of clairvoyance (firāsat) and the blessings attached to a particular saint or walī (“friend of God”). This makes the theme of pilgrimage “fluid, dynamic and multi-dimensional,” as shown in Javanese (Indonesian) pilgrimage where tradition is associated with Islam but involves Hindu, Buddhist and animistic elements. This chapter cites numerous sites that offer fluid spaces for the expression of different identities, the practice of distinct rituals, and cohabitation of different religious communities through the idea of “shared pilgrimage”. The fifth and final chapter shows how technologies and economies inflect pilgrimage. Arjana discusses the commodification of “religious personalities, traditions and places” and the mass production of transnational pilgrimage souvenirs, in order to focus on the changing nature of Islamic pilgrimage in the modern world through “capitalism, mobility and tech nology”. The massive changes wrought by technological developments are evident even from the profusion of representations of Hajj, as through pilgrims’ photos, blogs, and other efforts at self documentation. The symbolic representation of the dead through souvenirs makes the theme of pilgrimage more complex. Interestingly, she then notes how “virtual pilgrimage” or “cyber-pilgrimage” forms a part of Islamic pilgrimage in our times, amplifying how pilgrimage itself is a wide range of “active, ongoing, dynamic rituals, traditions and performances that involve material religions and imaginative formations and spaces.” Analyzing religious texts alone will not yield an adequate picture of pilgrimage in Islam, Arjana concludes. Rather one must consider texts alongside beliefs, rituals, bodies, objects, relationships, maps, personalities, and emotions. The book takes no normative position on whether the ziyāratvisitation is in fact a bid‘ah (heretical innovation), as certain Muslim orthodoxies have argued. The author invokes Shahab Ahmad’s account of how aspects of Muslim culture and history are seen as lying outside Islam, even though “not everything Muslims do is Islam, but every Muslim expression of meaning must be constituting in Islam in some way”. The book is a solid contribution to the field of pilgrimage and Islamic studies, and the author’s own travels and visits to the pilgrimage sites make it a practicalcontribution to religious studies. Nazar Ul Islam Wani, PhDAssistant Professor, Department of Higher EducationJammu and Kashmir, India


2019 ◽  
Vol 56 (5) ◽  
pp. 1800-1833 ◽  
Author(s):  
Steven Drake ◽  
Amy Auletto ◽  
Joshua M. Cowen

In July 2011, the State of Michigan adopted a broad set of teacher labor market reforms, including a high-stakes evaluation system designed in part to remove low-performing teachers. We examine the characteristics of teachers rated as “minimally effective” and “ineffective,” as well as their schools, and the relationship between low effectiveness ratings and later employment outcomes. Results suggest teachers of color across traditional and charter schools are more likely to receive low effectiveness ratings than their within-school peers. These low rating risks are higher for teachers of color working in comparatively White-faculty contexts. Male and novice teachers are also rated low more frequently, and important differences appear to exist in the usage of low ratings by traditional public and charter schools.


2021 ◽  
Vol 43 (1) ◽  
pp. 1-79
Author(s):  
Colin S. Gordon

Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a semilattice of effects grounds understanding of the essential issues and provides guidance when designing new effect systems. By contrast, sequential effect systems—where the order of effects is important—lack an established algebraic structure on effects. We present an abstract polymorphic effect system parameterized by an effect quantale—an algebraic structure with well-defined properties that can model the effects of a range of existing sequential effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that for most effect quantales, there is an induced notion of iterating a sequential effect; that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work; and that this induced notion of iteration is as precise as possible when defined. We also position effect quantales with respect to work on categorical semantics for sequential effect systems, clarifying the distinctions between these systems and our own in the course of giving a thorough survey of these frameworks. Our derived iteration construct should generalize to these semantic structures, addressing limitations of that work. Finally, we consider the relationship between sequential effects and Kleene Algebras, where the latter may be used as instances of the former.


2021 ◽  
pp. 1-8
Author(s):  
Paul Theo Zebhauser ◽  
Achim Berthele ◽  
Marie-Sophie Franz ◽  
Oliver Goldhardt ◽  
Janine Diehl-Schmid ◽  
...  

Background: Tau proteins are established biomarkers of neuroaxonal damage in a wide range of neurodegenerative conditions. Although measurement of total-Tau in the cerebrospinal fluid is widely used in research and clinical settings, the relationship between age and total-Tau in the cerebrospinal fluid is yet to be fully understood. While past studies reported a correlation between age and total-Tau in the cerebrospinal fluid of healthy adults, in clinical practice the same cut-off value is used independently of patient’s age. Objective: To further explore the relationship between age and total-Tau and to disentangle neurodegenerative from drainage-dependent effects. Methods: We analyzed cerebrospinal fluid samples of 76 carefully selected cognitively healthy adults and included amyloid-β 1–40 as a potential marker of drainage from the brain’s interstitial system. Results: We found a significant correlation of total-Tau and age, which was no longer present when correcting total-Tau for amyloid-β 1–40 concentrations. These findings were replicated under varied inclusion criteria. Conclusion: Results call into question the association of age and total-Tau in the cerebrospinal fluid. Furthermore, they suggest diagnostic utility of amyloid-β 1–40 as a possible proxy for drainage-mechanisms into the cerebrospinal fluid when interpreting biomarker concentrations for neurodegenerative diseases.


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