Two additional solutions of new shear-horizontal surface acoustic waves (SH-SAWs) are found in this theoretical report. The SH-SAW propagation is managed by the free surface of a solid when it has a direct contact wit...Two additional solutions of new shear-horizontal surface acoustic waves (SH-SAWs) are found in this theoretical report. The SH-SAW propagation is managed by the free surface of a solid when it has a direct contact with a vacuum. The studied smart solid represents the transversely isotropic piezoelectromagnetic (magnetoelectroelastic or MEE) medium that pertains to crystal symmetry class 6 mm. In the developed theoretical treatment, the solid surface must be mechanically free. Also, the magnetic and electrical boundary conditions at the common interface between a vacuum and the solid surface read: the magnetic and electrical displacements must continue and the same for the magnetic and electrical potentials. To obtain these two new SH-SAW solutions, the natural coupling mechanisms such as eμ-hα and εμ-α2 present in the coefficient of the magnetoelectromechanical coupling (CMEMC) can be exploited. Based on the obtained theoretical results, it is possible that a set of technical devices (filters, sensors, delay lines, lab-on-a-chip, etc.) based on smart MEE media can be developed. It is also blatant that the obtained theoretical results can be helpful for the further theoretical and experimental studies on the propagation of the plate SH-waves and the interfacial SH-waves in the MEE (composite) media. The most important issue can be the influence of the magnetoelectric effect on the SH-wave propagation. One must also be familiar with the fact that the surface, interfacial, and plate SH-waves can frequently represent a common tool for nondestructive testing and evaluation of surfaces, interfaces, and plates, respectively.展开更多
Introduction: The incidence of lesions of sensory and motor nerves associated with oral and maxillofacial surgery is often underestimated, representing around 32.0% of all lesions, and orthognathic surgery contributes...Introduction: The incidence of lesions of sensory and motor nerves associated with oral and maxillofacial surgery is often underestimated, representing around 32.0% of all lesions, and orthognathic surgery contributes 12.3% to these lesions. Thus, the use of piezosurgery (PiZCi) has been indicated in several procedures within oral and maxillofacial surgery due to a number of advantages over conventional drill and saw techniques. Objective: to analyze the main literature on the use of the piezoelectric device in relation to the use of drills and to orthognathic surgery in dentistry. Methods: A total of 41 articles were found involving Orthognathic Surgery, Piezoelectric Device, Drills Device, Saws Device, and Efficiency. Initially, it was held the exclusion existing title and duplications following the interest described this work. After this process, the summaries were evaluated, and a new exclusion was held. 29 articles were included and discussed in this study. Initially, the keywords were determined by searching the DeCS tool (Descriptors in Health Sciences, BIREME base) and later verified and validated by MeSh system (Medical Subject Headings, the US National Library of Medicine). Results and conclusion: It was concluded that the piezoelectric device has excelled with an effective surgical technique, being able to be indicated in the most diverse areas of the oral surgery, providing accurate, clean and minimally traumatic osteotomies for the soft tissues, intraoperative bleeding, when compared to conventional surgery using drills and/or saws.展开更多
In the primary processing of cotton, it is important to increase the productivity of ginning and reduce the wear of working bodies. The working body of the genie is the working chamber, the saw cylinder and the rib gr...In the primary processing of cotton, it is important to increase the productivity of ginning and reduce the wear of working bodies. The working body of the genie is the working chamber, the saw cylinder and the rib grate. The main wear is on the saw cylinder shaft and saw teeth. The wear of these parts leads to additional material costs, as well as to a decrease in the quality of the fiber. The wear of the shaft is affected by the number of saws and the mass of raw cotton in the working chamber of the gin. To prevent wear of the saw cylinder, the article determines the optimal static load on the shaft by calculating saw gins consisting of 90, 100, 110, 120, 130 saws. An analysis of tables shows that maximum value to bending shows 120 and 130 saws cylinder, because shaft bending angles along the length appear. This leads to a 2% - 3% reduction in the distance between the saws, serves for the premature wear of the saw, the exit of short fibers.展开更多
To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs)...To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural concrete.In our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and 0.33.The effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were analyzed.The experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 MPa.Low W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs concrete.Through the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of concrete.SPFAs exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.展开更多
文摘Two additional solutions of new shear-horizontal surface acoustic waves (SH-SAWs) are found in this theoretical report. The SH-SAW propagation is managed by the free surface of a solid when it has a direct contact with a vacuum. The studied smart solid represents the transversely isotropic piezoelectromagnetic (magnetoelectroelastic or MEE) medium that pertains to crystal symmetry class 6 mm. In the developed theoretical treatment, the solid surface must be mechanically free. Also, the magnetic and electrical boundary conditions at the common interface between a vacuum and the solid surface read: the magnetic and electrical displacements must continue and the same for the magnetic and electrical potentials. To obtain these two new SH-SAW solutions, the natural coupling mechanisms such as eμ-hα and εμ-α2 present in the coefficient of the magnetoelectromechanical coupling (CMEMC) can be exploited. Based on the obtained theoretical results, it is possible that a set of technical devices (filters, sensors, delay lines, lab-on-a-chip, etc.) based on smart MEE media can be developed. It is also blatant that the obtained theoretical results can be helpful for the further theoretical and experimental studies on the propagation of the plate SH-waves and the interfacial SH-waves in the MEE (composite) media. The most important issue can be the influence of the magnetoelectric effect on the SH-wave propagation. One must also be familiar with the fact that the surface, interfacial, and plate SH-waves can frequently represent a common tool for nondestructive testing and evaluation of surfaces, interfaces, and plates, respectively.
文摘Introduction: The incidence of lesions of sensory and motor nerves associated with oral and maxillofacial surgery is often underestimated, representing around 32.0% of all lesions, and orthognathic surgery contributes 12.3% to these lesions. Thus, the use of piezosurgery (PiZCi) has been indicated in several procedures within oral and maxillofacial surgery due to a number of advantages over conventional drill and saw techniques. Objective: to analyze the main literature on the use of the piezoelectric device in relation to the use of drills and to orthognathic surgery in dentistry. Methods: A total of 41 articles were found involving Orthognathic Surgery, Piezoelectric Device, Drills Device, Saws Device, and Efficiency. Initially, it was held the exclusion existing title and duplications following the interest described this work. After this process, the summaries were evaluated, and a new exclusion was held. 29 articles were included and discussed in this study. Initially, the keywords were determined by searching the DeCS tool (Descriptors in Health Sciences, BIREME base) and later verified and validated by MeSh system (Medical Subject Headings, the US National Library of Medicine). Results and conclusion: It was concluded that the piezoelectric device has excelled with an effective surgical technique, being able to be indicated in the most diverse areas of the oral surgery, providing accurate, clean and minimally traumatic osteotomies for the soft tissues, intraoperative bleeding, when compared to conventional surgery using drills and/or saws.
文摘In the primary processing of cotton, it is important to increase the productivity of ginning and reduce the wear of working bodies. The working body of the genie is the working chamber, the saw cylinder and the rib grate. The main wear is on the saw cylinder shaft and saw teeth. The wear of these parts leads to additional material costs, as well as to a decrease in the quality of the fiber. The wear of the shaft is affected by the number of saws and the mass of raw cotton in the working chamber of the gin. To prevent wear of the saw cylinder, the article determines the optimal static load on the shaft by calculating saw gins consisting of 90, 100, 110, 120, 130 saws. An analysis of tables shows that maximum value to bending shows 120 and 130 saws cylinder, because shaft bending angles along the length appear. This leads to a 2% - 3% reduction in the distance between the saws, serves for the premature wear of the saw, the exit of short fibers.
基金Funded by the National Natural Science Foundation of China(No.52378213)the Technology Development Project(No.20201902977180010) of CABR Technology Co.,Ltd。
文摘To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural concrete.In our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and 0.33.The effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were analyzed.The experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 MPa.Low W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs concrete.Through the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of concrete.SPFAs exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.
