Observation of a gravitational Aharonov-Bohm effect

Gravitational interference The Aharonov-Bohm effect is a quantum mechanical effect in which a magnetic field affects the phase of an electron wave as it propagates along a wire. Atom interferometry exploits the wave characteristic of atoms to measure tiny differences in phase as they take different paths through the arms of an interferometer. Overstreet et al . split a cloud of cold rubidium atoms into two atomic wave packets about 25 centimeters apart and subjected one of the wave packets to gravitational interaction with a large mass (see the Perspective by Roura). The authors state that the observed phase shift is consistent with a gravitational Aharonov-Bohm effect. —ISO

EXPERIMENTAL STUDY OF THE MECHANICAL EFFECT OF BIO-LOADS ON PVC RECYCLING

With the increase in plastic waste, recycling becomes an urgent necessity to reduce and revalue it. PVC is one of the most widely used types of plastic in the world, and indeed it is among the most recycled. The effect of recycling on PVC or any other type of material is to reduce these characteristics, which also depends on the method by which it is recycled. Finding a way to increase the recyclability number of PVC by improving the mechanical characteristics will be an addition at the level of scientific research as well as at the industrial level. The addition of a bio-loading in the form of cow horns, coconut or chicken feathers on the rigid and flexible PVC with an experimental study of the results obtained allow to deduce the most adequate bio-loaded material to improve the mechanical characteristics after recycling. The experiments carried out on rigid and flexible PVC demonstrated the evolutions brought to PVC with and without loading after recycling The results obtained showed an improvement in the mechanical properties of rigid and flexible PVC with a natural bio-loading with the three fibers of coconut, cow horns and chicken feathers which enhance the environment, are very light and can be collected. directly from the waste with a large amount.

Study on the Release of Muscle Passive Force by Ultrasonic Mechanical Effect and its Related Mechanism

Background: Excessive muscle force impedes physical movement and relaxing passive muscle force substantially improves movement impairment. Ultrasound is an energy carrier with the characteristics of repetitive mechanical stimulation, which may be a feasible method to relieve muscle tension.Methods: We performed stress relaxation experiments on soleus muscle and combine the obtained results with the standard linear solid model to extract information of viscoelastic effect of ultrasound on muscle, and calculated muscle fibril content by histological analysis.Results: Ultrasound can accelerate muscle stress relaxation; the viscosity and elasticity coefficient of the ultrasound group was higher than that of the control group, and there was no significant difference between the three ultrasound intensities; H&E staining showed that muscle fibrillar content decreased and the matrix substance increased.Conclusion: We considered that ultrasound can change the microstructure of muscle, and the matrix substance plays a significant role in the relaxation process. In this paper, the relationship between muscle viscoelasticity and passive muscle force is obtained. The results provide an important theoretical basis and a feasible method for monitoring muscle functional characteristics by measuring muscle viscoelasticity.

Obesity and Bone: A Complex Relationship

There is a large literature on the relationship between obesity and bone. What we can conclude from this review is that the increase in body weight causes an increase in BMD, both for a mechanical effect and for the greater amount of estrogens present in the adipose tissue. Nevertheless, despite an apparent strengthening of the bone witnessed by the increased BMD, the risk of fracture is higher. The greater risk of fracture in the obese subject is due to various factors, which are carefully analyzed by the Authors. These factors can be divided into metabolic factors and increased risk of falls. Fractures have an atypical distribution in the obese, with a lower incidence of typical osteoporotic fractures, such as those of hip, spine and wrist, and an increase in fractures of the ankle, upper leg, and humerus. In children, the distribution is different, but it is not the same in obese and normal-weight children. Specifically, the fractures of the lower limb are much more frequent in obese children. Sarcopenic obesity plays an important role. The authors also review the available literature regarding the effects of high-fat diet, weight loss and bariatric surgery.

STRENGTH OF MULTILAYER POLYMER PIPE TAKING INTO ACCOUNT CHANGE IN PHYSICAL AND MECHANICAL PROPERTIES OF THE MATERIAL

Strength if a multilayer polymer pipe under the action of the system if external loads is studied taking into account the change in physical and mechanical properties of the material. Mechanical effect, the dependence of joint deformability of several polymer materials on the character of change if their physical and chemical properties was established. Occurrence and dependence of physical and chemical properties of the material and also breaking stresses between the layer determining adhesive strength of layered polymer pipe was established.

Bio-Fabrication and Experimental Validation of an Mg - 25Ca - 5Zn Alloy Proposed for a Porous Metallic Scaffold

This paper proposes the bio-fabrication of a porous scaffold from a selection procedure of elements taking into account biological behavior, using magnesium (Mg) alloyed with calcium (Ca) and zinc (Zn). The proposed scaffold could work as a treatment for specific pathologies in trauma and oncology, on the one hand, in addition to possible applications in osteosynthesis, through contributing to osseointegration and infection control through the release of drugs. Finally, another possible attribute of this alloy could be its use as a complementary treatment for osteosarcoma; this is due to the basification produced by oxidative degradation (attack on cancer cells). The evaluation of cell viability of an alloy of Mg - 25 wt% Ca + 5 wt% Zn will strengthen current perspectives on the use of Mg in the clinical evaluation of various treatments in trauma and oncology. Considerations on the preparation of an alloy of Mg - 25 wt% Ca + 5 wt% Zn and its morphological characterization will help researchers understand its applicability for the development of new surgical techniques and lead to a deeper investigation of alternative treatments. However, it is very important to bear in mind the mechanical effect of elements such as Ca and Zn on the degradation of the alloy matrix; the best alternative to predict the biological - mechanical potential starts with the selection of the essential - nutritional elements and their mechanical evaluation by micro-indentation due to the fragility of the matrix. Therefore, the morphological evaluation of the specimens of Mg - 25 wt% Ca + 5 wt% Zn will show the crystallinity of the alloy; these results together contribute to the design of biomedical alloys for use in treatments for various medical specialties. The results indicated that cell viability is not affected, and there are no morphological changes in the cells.

Study on the mechanical effect and wear behaviour of middle trough of a scraper conveyor based on DEM–MBD

Middle trough is the main-force portion of a scraper conveyor during transport, and its performance directly affects the reliability and service life of the scraper conveyor. To investigate the wear of a middle trough, a coupling-wear model of a middle trough was built to analyse the motion state and stress of a scraper, and the wear of the middle trough was analysed according to the wear morphology of the middle plate. The research results demonstrated that the simulation model based on coupling of the discrete element method and multi-body dynamics could effectively simulate the transport conditions of a scraper conveyor. The wear of the middle trough was mainly caused by three-body wear. Formation of three-body wear required that the coal particles between the scraper (chain) and middle plate must be in a certain position and posture, and the coal particles were subjected to the normal force of the scraper (chain) and middle plate. Constant fluctuation in the movement and force of the scraper (chain) resulted in uneven wear of the middle trough and random occurrence of three-body wear. This study provides a theoretical basis for wear prediction of the middle trough of a scraper conveyor and a simulation basis for further research on the wear resistance of a middle trough.

Electrostatic Self-Assembled Composite Abrasives for Chemical Mechanical Polishing of A-Plane Sapphire

Sapphire substrates with different orientations have wide applications due to their excellent physical, chemical and optical properties. However, the chemical mechanical polishing of sapphire is challenging due to its chemical inertness, extreme hardness and brittleness. Herein, chemical mechanical polishing of A- and C-plane sapphire was systematically studied using α-Al2O3 and silica abrasives and polishing mechanism was analyzed by X-ray photoemission spectroscopy (XPS) and nanoindentation meter. The high MRR selectivity for C-plane sapphire in α-Al2O3 slurry is the synergy of selective hydration of C-plane and stronger crystal structure of A-plane. The low MRR selectivity for C-plane sapphire in silica slurry can be attributed to the formation of Al2SiO5 on both planes which reduced the impact of strong mechanical effect of α-Al2O3 abrasives. To improve the MRR of A-plane sapphire, a new nanocomposite particle with alumina as the core and silica as the soft shell was prepared by an electrostatic self-assembly method. The new composite abrasives combined the mechanical effect of α-Al2O3 abrasives and chemical effect of silica abrasives and demonstrated substantially higher MRR for A-plane sapphire than pure alumina abrasives, pure silica abrasives and physical mixture of alumina+silica abrasives.

Evaluation of Stress Distribution of Isotropic, Composite, and FG Beams with Different Geometries in Nonlinear Regime via Carrera-Unified Formulation and Lagrange Polynomial Expansions

In this study, the geometrically nonlinear behaviour caused by large displacements and rotations in the cross sections of thin-walled composite beams subjected to axial loading is investigated. Newton–Raphson scheme and an arc length method are used in the solution of nonlinear equations by finite element method to determine the mechanical effect. The Carrera-Unified formulation (CUF) is used to solve nonlinear, low or high order kinematic refined structure theories for finite beam elements. In the study, displacement area and stress distributions of composite structures with different angles and functionally graded (FG) structures are presented for Lagrange polynomial expansions. The results show the accuracy and computational efficiency of the method used and give confidence for new research.