Equal Force Research Articles

A Multichamber Pulsating-Flow Device With Optimized Spatial Shear Stress and Pressure for Endothelial Cell Testing.

Design and analysis are presented for a new device to test the response of endothelial cells to the simultaneous action of cyclic shear stresses and pressure fluctuations. The design consists of four pulsatile-flow chambers connected in series, where shear stress is identical in all four chambers and pressure amplitude decreases in successive chambers. Each flow chamber is bounded above and below by two parallel plates separated by a small gap. The design of the chamber planform must ensure that cells within the testing region experience spatially uniform time-periodic shear stress. For conditions typically encountered in applications, the viscous unsteady flow exhibits order-unity values of the associated Womersley number. The corresponding solution to the unsteady lubrication problem, with general nonsinusoidal flowrate, is formulated in terms of a stream function satisfying Laplace's equation, which can be integrated numerically to determine the spatial distribution of shear stresses for chambers of general planform. The results are used to optimize the design of a device with a hexagonal planform. Accompanying experiments using particle tracking velocimetry (PTV) in a fabricated chamber were conducted to validate theoretical predictions. Pressure readings indicate that intrachamber pressure variations associated with viscous pressure losses and acoustic fluctuations are relatively small, so that all cells in a given testing region experience nearly equal pressure forces.

Music support for gender equality campaigns

Can music be a force for gender equality? With the development of time, people’s attention to gender equality has gradually increased, and many efforts have been made to change the various kinds of discrimination that have existed for a long time. What role does music play in these efforts? This thesis explores the role of music in promoting gender equality, gives examples of musicians and musical works that have had a significant impact on gender equality, and analyses how these examples have challenged and changed gender stereotypes. Through case studies and literature analysis, the paper also explores the role of music education in fostering gender equality awareness, analysing in-depth the various parts of the music industry from a number of perspectives, including creation, performance, advocacy and education. It is found that music not only reflects social change, but also positively contributes to the process of gender equality. These findings are intended to inform future research and practice and to promote the further development of the potential of music as a tool for social change.

A rigid and compact piezoelectric motor with high output efficiency.

We introduce a novel piezoelectric stepper motor featuring high compactness, rigidity, and any direction operability. Here, not only is the structure of high novelty but also the working principle very simple. The piezo stacks unit is sandwiched between two spring finger pieces, with almost equal clamping forces applied between the top of the piezo stacks' unit and the spring finger piece. Applying individual driving signals to each of the five piezo stack pairs, causing deformation one by one in the same direction, followed by simultaneous recovery in the reverse direction, enables movement of the frame part. The optimized clamping force of the piezoelectric stack units and spring fingers ensures maximum output force. The motor's operational capability at low threshold voltages, specifically 8V for downward movement and 10V for upward movement, confirmed its efficacy in both vertical and horizontal directions. The motor's operational capability at a low threshold voltage of 10V confirmed its efficacy in both vertical and horizontal directions. At room temperature, step size ranges from 0.3 to 7.4 µm at 20Hz frequency and varying driving voltage from 10 to 180V. It has a maximum travel range of about 5mm and can lift a maximum load of 220g in an upward direction, so the maximum output force generated by this motor is 2.2 N. The compact and rigid design is capable of building an atomically resolved scanning probe microscope, and its working ability has the potential to use the cleavage of different types of samples in limited space environments, such as the small-bore superconducting magnet and low temperature.

Tricortical versus bicortical anchorage in a double-screw tandem skeletal expander and a single-screw maxillary anchorage rapid palatal expander: A finite element analysis.

This study aims to employ finite element method (FEM) analysis to compare the differences between bicortical and tricortical anchorage of the posterior miniscrews in a single-screw miniscrew-assisted rapid palatal expansion (MARPE) and a double-screw tandem skeletal expander (TSE) under open and closed suture conditions. A cone beam computed tomography of the human skull of a 21.5-year-old female was utilized as a model for creating a FEM analysis. Simulations involved the insertion of four palatal miniscrews: two anterior ones with bicortical anchorage and two posterior ones (one with bicortical and another with tricortical anchorage), under open and closed suture conditions in a single-screw MARPE and double-screw TSE, resulting in a total of eight different simulation configurations. Evaluation parameters include total deformation (mm), Von Mises stress (MPa), and strain for each miniscrew body. Tricortical anchorage of the posterior miniscrews provides greater anchorage, higher stress, and deformation on the anterior miniscrews in single-screw MARPE. Tricortical anchorage combined with a double-screw TSE promotes a more even distribution of force and stress on miniscrews under open suture conditions, leading to a parallel midpalatal suture opening along its entire length and height. FEM analysis revealed favorable midpalatal suture opening with equal force distribution and less stress when posterior tricortical anchorage in conjunction with double-screw TSE is applied.

Characterising applied forces during positive pressure ventilation: a randomised cross-over simulation study

ObjectiveTo characterise applied force on the face and head during simulated mask ventilation with varying mask, device and expertise level.DesignRandomised cross-over simulation study.SettingA quiet, empty room in the children’s hospital.ParticipantsNeonatal...

Design, modelling and evaluation of a variable inertance bypass fluid inerter

The inerter emerged as a mechanical analogy to the electrical capacitor, completing the force-current analogy. It operates as a one-port, two terminal device, where the equal and opposite forces at its terminals correlate with the relative acceleration between them. This relationship is governed by ‘inertance’, a quantity that bears the unit of mass, allowing inerters to exert inertial forces. Inerters have gained considerable traction, particularly in vibration control applications. Derived from their passive counterparts, variable inertance inerters enable active control of their inertance through integrated control mechanisms. This work presents the design, modelling and evaluation of a variable inertance inerter prototype dubbed the ‘Variable Inertance Bypass Fluid Inerter’ (VIBFI). An experimental prototype of the concept was designed, constructed and tested. Simultaneously, an effort to develop and validate a mathematical model of the VIBFI is thoroughly documented. Experimental results demonstrate the controllability of performance parameters of the device, including inertance and damping coefficients, through modulating the flow restriction of the bypass channel. The mathematical models derived for the device can serve as an estimate for its performance parameters, though further refinement is required.

African Liveliness as a Secular Moral Theory: Problems and Prospects

Abstract An important belief in African Traditional Religion holds that everything, both animate and inanimate objects, are imbued with an imperceptible energy known as life force. Since life force is the greatest value, it is the grounds of morality. However, it is undertheorized in contemporary African ethics, with work on personhood and harmonious relationships taking centerstage. I seek to fill this gap in the literature by further developing an entirely secular and naturalistic moral theory of life force that avoids metaphysical controversies and is known as liveliness, which was first gestured at by Thaddeus Metz (2012, 2022). I demonstrate that while a series of objections that Metz levels against liveliness affect teleological versions, they do not apply with equal force to deontological versions. Liveliness, particularly deontological versions, ought to be considered as a contender for the best African moral theory alongside those that focus on personhood or harmonious relationships.

Modernism as Liberation: J. Max Bond Jr. at Mississippi’s Mary Holmes College

Abstract From early in his career, J. Max Bond Jr. (1935–2009) brought the civil rights movement to bear on architecture, insisting that modernism live up to its promise to build a better world. Exemplary of this effort was the first completed work of Bond Ryder Associates, the Neigh Dormitory (1968–70) at Mary Holmes College in West Point, Mississippi. This article offers a close reading of this overlooked project in the context of Bond’s own encounters with modern architecture as an African American, the realities of Mississippi in the 1960s, and the experiences of the students who made this dorm their home. It contends that Bond Ryder shaped a liberatory modernism here especially focused on the freedom and self-determination of the dorm’s Black residents amid ongoing racial violence. In doing so, the article provides a novel perspective on the role that architecture played as a force for racial equality and that, in turn, the long civil rights movement played in shaping architectural modernism. While modern architecture had caused much harm by midcentury, this dorm’s history reveals an unexpected source for the rejuvenation of modernism’s social promise: the long struggle for racial justice.

Unendlichkeit (Infinity)

This entry argues that, in his poetic as well as theoretical and scientific writings, Goethe adopts a dialectical position vis-à-vis one of the dominant philosophical concepts of the modern age: infinity (Unendlichkeit). While the concept of infinity came to be embraced by the end of the eighteenth century in literature and philosophy, as well as in the powerful tool of infinitesimal calculus, Goethe consistently emphasized the need for a dialectic between the finite and the infinite in which the internal force driving humans and nature beyond all limits must be balanced or counteracted by an equal force drawing them back towards the world of finitude. Goethe depicts this dialectic as both an inherent law of nature and an ethical and existential feature of humanity.

Semi-active inerters: a review of the literature

The inerter was introduced as a mechanical counterpart to the electrical capacitor, completing the force-current analogy. This is a one-port, two-terminal device in which the equal and opposite forces exerted at its terminals are proportional to the relative acceleration between them. Within this relationship, the “inertance” is the coefficient of proportionality and carries the unit of mass. This implies that the inerter can exert an inertial force at its terminals, effectively representing a virtual mass. Due to these properties, inerters have gained popularity, finding applications as components of vibration control systems and energy harvesters. Derived from passive inerters, semi-active inerters are integrated with active control systems to regulate their inertance. Since their introduction, semi-active inerters have been pivotal in situations demanding active monitoring of natural frequency or control force, generally outperforming their passive counterparts. While numerous significant reviews on passive inerters and their applications have been published in respected journals, dedicated literature reviews on semi-active inerters remain scarce. This review seeks to bridge this gap, offering a comprehensive literature review on semi-active inerters and highlighting research challenges and opportunities. Given the novelty of semi-active inerters, they present a fascinating area of study.

Development of an adaptive two-phalanx grip model for robotic manipulators

The purpose of this work is to study the problem of uniform grip at the points of contact of a round or spherical object (fruits and vegetables) with the grip. The research methodology uses pressure sensors mounted on the “fingers” of the handle. At a certain force value in the contact zone, the “fingers” of the handle stop. The grip must create equal forces at the points of contact of all “fingers” for an even grip. To explore these issues, phalangeal graspers adapting to the fetal surface are analyzed here. The flat model shows the general patterns of the relationship between the forces of the “fingers” of the grip and the round object to be grasped. The flat model shows the general patterns of the relationship between the forces of the “fingers” of the grip and the round object to be grasped. We examined the 3D model of this gripper and calculated the parameters of the 3D model. Conclusions and practical consequences are the values of stresses and elastic displacements at the points of the contact lines of the teeth of the 3D models of the gripper and the object being grabbed. The distribution of forces on a flat diagram and the values of von Mises stresses in the 3D model demonstrate a certain similarity in the uniformity of distribution of these parameters. Color scales with the values of the corresponding parameters are also presented; the calculation was carried out using the finite element modeling method in inventor.

Blackness in the Black Legend: How narratives of race and slavery in the Amistad affair shaped anti-Hispanicism and "American Exceptionalism"

Abstract: This article examines Steven Spielberg's 1997 film Amistad, which depicts a slave rebellion and mutiny on a Cuban slave ship in 1839, as a lens through which to view the origins of the Black Legend. The Black Legend emerged in 1830s in the U.S. to depict Latin American instability as the result of Spanish oppression, violence, cultural inferiority and Catholicism. The narrative served to benefit the ideology of white supremacy and the myth of American (read U.S.) "exceptionalism" by drawing global attention away from the maintenance of slavery in the U.S. and highlighting Spanish and Cuban involvement in the clandestine slave trade in the nineteenth century. The article analyzes a variety of secondary and primary sources that place blackness at the center of the construction of the Black Legend, from contemporary accounts of the Amistad revolt to subsequent references to blackness in histories of U.S.-Latin American relations in the 1830s and 1840s. The article shows how Spielberg inserts Christianity as a force for racial equality and holds up the judicial branch of the U.S. government as a model for Latin America to follow, echoing the inherent contradictions of the Black Legend in the late twentieth century. Ultimately, the article argues that U.S. history must be examined in relation to the history of Latin America, and narratives of blackness in the Atlantic world shaped national mythos and identities in similar ways. Examining the African Diaspora in the Americas, as well as the subsequent national narratives of race and national identities, helps to deconstruct narratives of exceptionalism and reveal political motivations and contradictions in the Black Legend narrative.

A Passive Polycentric Mechanism to Improve Active Mediolateral Balance in Prosthetic Walking.

Prosthetic legs are typically passive systems without active ankle control, restricting mediolateral balancing to a hip strategy. Resulting balance control impairments for persons with a lower extremity amputation may be mitigated by increasing hip strategy effectiveness, in which relatively small hip moments of force are adequate for mediolateral balancing. To increase hip strategy effectiveness we have developed a prosthetic leg prototype based on the Peaucellier mechanism, the Sideways Balance Mechanism (SBM). This polycentric mechanism adds a frontal plane degree of freedom, reducing mediolateral body displacements. Adding a passive joint alone introduces instability, in which mediolateral body rotation leads to CoM height loss, ultimately resulting in a fall. The SBM however provides stability typically absent by lengthening under rotation, thereby compensating for CoM height loss. By allowing for both foot rotation (in-/eversion), and increased mediolateral ground reaction force the SBM increases hip strategy effectiveness. We aimed to provide proof of principle that the SBM can improve active mediolateral balance control in prosthetic walking by increasing hip strategy effectiveness compared to a typical set-up. Comparison between a typical set-up and the SBM showed an increased mediolateral ground reaction force at equal hip moments of force for a 2D forwards dynamics computer simulation, and a reduced hip moment of force at equal mediolateral ground reaction force for a case study. Results validate increased hip strategy effectiveness of the SBM compared to a typical set-up, providing proof of principle that adding an SBM to a prosthetic set-up improves mediolateral balance control in prosthetic walking.

Австрийская конституционная модель разграничения компетенции между Федерацией и землями

The constitutional development of the Austrian state at the turn of the XIX – early XX centuries was characterized by a combination of centralist and federalist tendencies. One of the controversial issues during the monarchy, and later in the First Austrian Republic, was the issue of the division of competence between the central government and its constituent parts. The Austrian half of the monarchy (Cisleithania), despite the long tradition of separate crown lands, was a unitary state, although decentralized. The division of competence between the center and the lands was based on the February Patent of 1861 and the December Constitution of 1867. At the same time, the issue of the correlation of different types of laws has not received certain regulation. In constitutional practice, there is an indisputable doctrine about the equal force of the imperial laws and the laws of the lands. After the collapse of the Austro-Hungarian Empire, the state of German Austria was created, which, according to Austrian legal historians, arose as a decentralized unitary state. The constitutional processes took place with the active participation of political parties. In the coalition agreement concluded on October 17, 1919 between the Social Democrats and the Christian Socialists, it was stated that the constitution should be adopted as soon as possible. By the beginning of the work of the Subcommittee of the Constitutional Committee in July 1920, agreement had been reached on a significant part of the constitutional text. At the same time, the issues of the division of competence between the Federation and the lands, as well as the relationship between federal law and land law, remained controversial. The Federal Constitutional Law, adopted on October 1, 1920 by the Constituent National Assembly, establishes a complex model for dividing competence between the federation and the lands. The theoretical justification for this approach to the regulation of the division of competence was presented in the first commentary to the Federal Constitutional Law, co-authored by Hans Kelsen (Professor at the University of Vienna, member of the Constitutional Court), Georg Froelich (Adviser to the Minister of the Federal Chancellery) and Adolf Merkle (Professor at the University of Vienna) (1922). The Austrian model of the division of competence between the federation and the lands remains unique, theoretically grounded, and characterized by political and institutional continuity.

Dialectics of War as a Natural Phenomenon: Existential Perspective

Due to natural processes of movements of opposites that interact with one another in equal forces, the universe is naturally considered an arena of conflicts. As the law of the universe continues to maintain everything in motion, each matter in the ecosystem strives to protect itself in given existential struggles within necessary conflicts. Therefore, the fundamental law of nature is the protection of life (self-preservation) which is often realized through self-defence. It then explains why humans engage themselves in conflicts; not necessarily to bring peace but to survive and maintain themselves in existence. Hence, war is motivated by the innate drive for self-defence and maintenance of self in existence guided by a natural instinct for survival. From conception to death, humans continue to struggle for survival and that entails overcoming conflicts and adversities of life. Thus, war can be considered as having a genetic foundation. This is evidenced in the works of evolutionary theorists. The Darwinian ethological theory tenaciously holds that humans, just like other organisms, struggle to survive, but this is influenced by natural selection which favours the stronger species against the weaker ones. While the stronger ones pass on their inheritable genes to the next generation for maintenance of their species in existence, the weaker ones die off. Hence, the survival of the fittest. This position was very much supported by the Malthusian theory of over-population alert against the limited human resources which demonstrates the constant fight for food in order to survive. The Nietzschean Superman, Marxian class struggle, Heraclitan notion of change, and so on, all cling to the idea that the universe is a violent arena. Consequently, the protection of life has an important moral value. By implication, self-defence is right and justified even if it involves war. Therefore, it is ethical to push through; to defeat the adversary.

EXPERIMENTAL STUDIES OF A DAMAGED BEAM REINFORCED WITH FIBER CONCRETE

The paper presents the results of a study of the load-bearing capacity of a beam damaged during hostilities, which was reinforced with steel fiber concrete. A beam with 20% damage in the compressed zone is considered. Before concreting, a foam liner was installed in the area of the planned damage, the shape and dimensions of which corresponded to the planned damage. After the concrete gained 70% of the brand strength, the liner was removed, and the resulting cavity was filled with a 2% mixture of fiber-reinforced concrete. This is one of the options for strengthening a beam in a comprehensive testing program for damaged beams, which involves studying a series of beams with different types of damage, damage zone (tension and compression) and its size, geometry and method of strengthening. The authors have developed a special stand for testing. Plane transverse bending of the loading of the beam under test is created using a hydraulic jack and a metal I-beam with a traverse that transmits two equal concentrated forces to the beam. The created load is controlled by an exemplary dynamometer of the Tokar system and a ring dynamometer, which acts as a support. Experimental studies have shown that a beam, the cross-section of which is 20% damaged in the middle compressed zone, and the shape of the damage is close to rectangular, has a load-bearing capacity of 93.6 kN, which is 95.0% of the load-bearing capacity of an undamaged beam (98.5 kN). Crack formation began on the 5th stage of loading, when the load value was 32.5 kN, that is, 34.7% of the load-bearing capacity of the damaged beam. In this case, 4 cracks formed in the pure bending zone. At the sixth stage, three more cracks appeared. At stages 9, 10 and 14 of loading, 7 more cracks formed. The maximum final crack opening width was 0.8 mm. throughout the testing process, the fiber-reinforced concrete liner worked with the beam as a single unit. It can be argued that strengthening a beam with 20% damage in the compressed zone using the method considered in the work makes it possible to achieve its load-bearing capacity, which is 95% of the load-bearing capacity of an undamaged beam.

Investigation of the mechanics of the grappling circuits of robotic manipulators for adaptive uniform gripping objects

There are many designs of robotic manipulator grippers. In this work, a study of adaptive gripping schemes for objects with a spherical shape was carried out. To evaluate the grip, pressure sensors are used, installed on the phalanges of the “fingers” of the grip, the values of which are preset in a certain range. However, there is no universal sensor that responds optimally to the entire range of pressures from very high to minimal values. Therefore, each such pressure sensor has its own range of values; they correspond to the nominal operating mode of the sensor. The European Union has established standards for fruits and vegetables. The shape of these products is approximately spherical, with some slight variations in shape in lemons and oblong tomatoes. The mechanical properties of apples, pears and tomatoes, etc. were also measured. That is, for each type of such product there must be a specific sensor with a specific small range of force changes. In addition, the gripper must, when in contact with the object with all its “fingers,” create equal forces for uniform grasping. To investigate this, grips with flexible traction elements, having several phalanges on the fingers and having an adaptation to the surface of the fetus in their structure, are analyzed here.

The Improvement of Blade Element Momentum Theory in Horizontal Axis Wind Turbine Performance Analysis

The present work uses the blade element momentum theory method for evaluating the performance of horizontal axis wind turbine. The wind turbine performances are described in term of the thrust coefficient CT, torque coefficient CQ and the power coefficient CP. The blade element momentum theory (BEMT) represents the wind turbine performance prediction method as result of combining two methods, namely the blade element theory (BET) and the momentum theory (MT). Both theories are able to formulate the axial forces and torques which work on the blade. Equating axial force and torque formulated by BET is equal axial force and torque by MT, makes one allows the axial induction factor and the angular induction factor a^’, the unknown quantities, can be defined and furthermore the wind turbine performances can be evaluated. The BEMT method used here is the combination of BEMT. The implementation this method as the tool for predicting the wind turbine performances are work well. However, for wind turbine configuration need a little adjustment, especially in setting the hub radius rh where the blade element momentum theory starts to make calculation from the inner blade to the tip. The high pitch angle and a relatively a large chord length at rh, make the BEMT fail to converge. In addition to the present work found that the three wind turbine performance coefficients are formulated by using the momentum theory is less accurate compared with BET formulation.

The Legal Status of Armed Separatists in Cameroon: Terrorists or Secessionists

International Humanitarian Law (IHL) states that armed separatists are parties to the conflict. Hence, IHL applies to both armed separatists and government forces with equal force. Ambiguity comes in at the level of Cameroonian law, where armed separatists have been arrested and charged with the offences of terrorism and secession without consideration that there are parties to the conflict. The aim of this paper is to determine the status of armed separatist in NW and SW regions of Cameroon for the proper applicability of the law. This paper shall also examine whether the right to self -determination nullifies the offences of secession and terrorism within the context of the conflict in Cameroon. In order to attain the above objectives, doctrinal and analytical methodology has been adopted. The paper concludes that terrorism and secession are distinct offences under Cameroonian Law and the right to self-determination appears to be too abstract to shield these offences. To this end, it is recommended that they should be a clear line between secession, terrorism and self-determination. Equally, the law should clearly define the procedure for self-determination.

3-D printed meat alternatives based on pea and single cell proteins and hydrocolloids: Effect of paste formulation on process-induced fibre alignment and structural and textural properties

Extrusion-based 3D food printing can be used as an alternative structuring technique to traditional extrusion processing for creating meat-like structures. This study focused on 3-D food printing to generate structures analogous to meat by using various combinations of texturized pea protein fibrils, microbial Single Cell Protein (SCP) and hydrocolloids locust bean gum and/or sodium alginate. Simple moulding was utilized as benchmarking to better understand the 3D printing-induced structural effects. To gain understanding of the interactions between proteins of different origin (plant and SCP) and with hydrocolloids, structural, textural and rheological properties were analysed. Oscillatory stress sweeps of all printing pastes revealed elastic-dominant rheological behaviour (G′ 4000–6000 Pa) with a defined yield stress (25–60 Pa) explaining their printability and shape stability. X-ray microtomography of ion-crosslinked analogues showed a printing-induced preferential alignment of fibrils in the direction of nozzle movement, while moulding led to a random orientation. Textural characterization via bi-directional cutting tests demonstrated higher cutting force in transversal (FT) over longitudinal (FL) direction in 3D-printed samples and equal forces in moulded samples. The anisotropy index (AI = FT/FL) of printed samples ranged between 1.4 and 2.5, indicating anisotropic texture, and 0.8–1 for moulded samples indicating isotropic texture. This study demonstrated the applicability of paste-extrusion in generating anisotropic structures analogous to meat by process-induced fibril alignment. The results support further development of 3D food printing technology in design of sustainable meat alternatives resembling whole-muscle meat.