Oxidation Kinetics of Aluminum Powders in a Gas Fluidized Bed Reactor in the Potential Application of Surge Arresting Materials

In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general.

In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes

Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant challenge.In addition,the reaction mecha-nisms and origins of enhanced performance remain elusive.Here,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron micros-copy.We found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is size-dependent.Apparent expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized nanoflakes.The significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element analysis.Despite the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon depotassiation.In particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural integrity.This article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation dynamics.Moreover,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.

Exploration of Ideological and Political Materials for the Course of Inorganic and Analytical Chemistry for Environmental and Ecological Engineering Major

Integrating ideological and political theories teaching into the whole process of classroom teaching construction is a new requirement for implementing the fundamental task of cultivating people by virtue and playing the role of collaborative education.In order to realize the seamless integration of inorganic and analytical chemistry courses and ideological and political education,this paper summarizes the current situation of ideological and political research on inorganic and analytical chemistry courses in three major databases in China(VIP,CNKI and Wanfang),and sorts out the knowledge points,ideological and political elements and educational goals according to the content of the course chapters,to provide a basic guarantee for the ideological and political education construction of the course.

Fabrication of PMMA nanocomposite biomaterials reinforced by cellulose nanocrystals extracted from rice husk for dental applications

The primary objective of global studies is to develop the properties and durability of polymers for various applications.When it comes to dental disability,denture base materials must have sufficient mechanical and tribological performance in order to withstand the forces experienced in the mouth.This work aims to investigate the effects of the addition of low content of cellulose nanocrystals(CNC)on the mechanical and tribological performance of the polymethyl methacrylate(PMMA)nanocomposites.Different weight percent of CNC(0,0.2,0.4,0.6,and 0.8 wt%)were added to the PMMA matrix followed by ball milling to evenly distribute the nanoparticles reinforced phase in the matrix phase.The findings emphasize the significant impact of CNC integration on the performance of PMMA nanocomposites.By increasing the content of the CNC nanoparticles,the mechanical properties of PMMA were improved.In addition,the tribological outcomes demonstrated a significant reduction in the friction coefficient besides an enhancement in the wear resistance as the weight percentage of nanoparticles increased.The surface of the worn samples was investigated by utilizing SEM to identify the wear mechanisms corresponding to the different compositions.In addition,a finite elment model(FEM)was developed to ascertain the thickness of the worn layer and the generated stressed on the surfaces of the nanocomposite throughout the friction process.

Restorative Dental Materials

本书系牙科大学生用教科书,也供牙科医生继续教育参用。 作者简介: RobertG,CRAIG MS,PhD:1923年生。美国Michigan大学牙医学院生物学和材料科学系名誉教授。

Prospects of 3D Printing Technology in Dental Medicine

With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and future potential of 3D printing technology in dental medicine and to analyze its benefits and challenges.It first introduces the current state of 3D printing technology in dental implants,crowns,bridges,orthodontics,and maxillofacial surgery.It then discusses the potential applications of 3D printing technology in oral tissue engineering,drug delivery systems,personalized dental prosthetics,and surgical planning.Finally,it analyzes the benefits of 3D printing technology in dental medicine,such as improving treatment accuracy and patient comfort,and shortening treatment times,while also highlighting the challenges faced,such as costs,material choices,and technical limitations.This article aims to provide a reference for professionals in the field of dental medicine and to promote the further application and development of 3D printing technology in this area.

Pt-Al₂OM₃Composite Material Designed for Cyclic Production of Optical Glasses under High Temperature Conditions

The article considers one of the possible approaches to the solution of an urgent issue of metal consumption reduction, increase of operating life and maximum operating temperature as well as reduction of irrecoverable losses of platinum products and alloys when operating under high temperature conditions, particularly for glassblowing and single crystal growing crucibles. A two-layered composite material based on platinum-group metals and corundum plasma ceramics is thoroughly investigated. A successful experience of crucibles exploitation, designed for production of high temperature optical glasses from the composite and results of the research on composite material specimens are described.

Tissue engineering approaches for dental pulp regeneration:The development of novel bioactive materials using pharmacological epigenetic inhibitors

The drive for minimally invasive endodontic treatment strategies has shifted focus from technically complex and destructive root canal treatments towards more conservative vital pulp treatment.However,novel approaches to maintaining dental pulp vitality after disease or trauma will require the development of innovative,biologicallydriven regenerative medicine strategies.For example,cell-homing and cell-based therapies have recently been developed in vitro and trialled in preclinical models to study dental pulp regeneration.These approaches utilise natural and synthetic scaffolds that can deliver a range of bioactive pharmacological epigenetic modulators(HDACis,DNMTis,and ncRNAs),which are cost-effective and easily applied to stimulate pulp tissue regrowth.Unfortunately,many biological factors hinder the clinical development of regenerative therapies,including a lack of blood supply and poor infection control in the necrotic root canal system.Additional challenges include a need for clinically relevant models and manufacturing challenges such as scalability,cost concerns,and regulatory issues.This review will describe the current state of bioactive-biomaterial/scaffold-based engineering strategies to stimulate dentine-pulp regeneration,explicitly focusing on epigenetic modulators and therapeutic pharmacological inhibition.It will highlight the components of dental pulp regenerative approaches,describe their current limitations,and offer suggestions for the effective translation of novel epigenetic-laden bioactive materials for innovative therapeutics.

A Review: On Smart Materials Based on Some Polysaccharides;within the Contextual Bigger Data, Insiders, “Improvisation” and Said Artificial Intelligence Trends

Smart Materials are along with Innovation attributes and Artificial Intelligence among the most used “buzz” words in all media. Central to their practical occurrence, many talents are to be gathered within new contextual data influxes. Has this, in the last 20 years, changed some of the essential fundamental dimensions and the required skills of the actors such as providers, users, insiders, etc.? This is a preliminary focus and prelude of this review. As an example, polysaccharide materials are the most abundant macromolecules present as an integral part of the natural system of our planet. They are renewable, biodegradable, carbon neutral with low environmental, health and safety risks and serve as structural materials in the cell walls of plants. Most of them are used, for many years, as engineering materials in many important industrial processes, such as pulp and papermaking and manufacture of synthetic textile fibres. They are also used in other domains such as conversion into biofuels and, more recently, in the design of processes using polysaccharide nanoparticles. The main properties of polysaccharides (e.g. low density, thermal stability, chemical resistance, high mechanical strength…), together with their biocompatibility, biodegradability, functionality, durability and uniformity, allow their use for manufacturing smart materials such as blends and composites, electroactive polymers and hydrogels which can be obtained 1) through direct utilization and/or 2) after chemical or physical modifications of the polysaccharides. This paper reviews recent works developed on polysaccharides, mainly on cellulose, hemicelluloses, chitin, chitosans, alginates, and their by-products (blends and composites), with the objectives of manufacturing smart materials. It is worth noting that, today, the fundamental understanding of the molecular level interactions that confer smartness to polysaccharides remains poor and one can predict that new experimental and theoretical tools will emerge to develop the necessary understanding of the structure-property-function relationships that will enable polysaccharide-smartness to be better understood and controlled, giving rise to the development of new and innovative applications such as nanotechnology, foods, cosmetics and medicine (e.g. controlled drug release and regenerative medicine) and so, opening up major commercial markets in the context of green chemistry.

Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

Technical Note and Brief Overview of the Materials Science and Technology along with Designing Aspects for Development of Spintronic Devices with Optimum Efficiency

One of the major challenges in designing and fabricating Spintronic devices is the choice of both, Materials and the Technology, along with understanding the intricacies of the Designing aspects. In this communication, we have attempted to briefly discuss these factors, with an aim to draw the attention of the Materials Scientists and Technologists to this serious challenge, in the direction of which, though a lot of research and development work has been done, still needs more concerted efforts to be made in order to make the Spintronic devices that can offer good efficiency for maximizing their usefulness.

Mechanism of Anti-tumor Effects of Viola Medicinal Materials Based on Network Pharmacology and Molecular Docking

[Objectives]To explore the relationship between anti-tumor components,targets,and pathways involved in Viola medicinal materials,study its main active components,and evaluate its inhibitory activity.[Methods]Through network pharmacological analysis,molecular docking simulation experiments and in vitro experiments,the main components and corresponding targets of Viola were screened out,and their anti-tumor signaling pathways were confirmed.MTT colorimetric assay was used to investigate the inhibitory effect of different extraction layers of Viola on the growth of tumor cells.[Results]18 anti-tumor active components such as 2α,19α-Dihydroxyursolic acid,Corlumine,Madolin U,Trifolirhizin and etc.,and 52 action targets such as PTGS2,PTGS1,P2RX7,MMP1,and GABRB3,and anti-tumor signaling pathways were confirmed.The results of molecular docking showed that all the selected Viola compounds had good binding activity.The results of MTT colorimetric assay showed that the petroleum ether layer and n-butanol layer had a good inhibitory effect on the growth of tumor cell lines.[Conclusions]Viola medicinal materials have the potential of anti-tumor,triterpenoids and flavonoids may be the main active components,and the petroleum ether layer and n-butanol layer have better inhibitory effect on the growth of tumor cells.

Augmenting the Heat Sink for Better Heat Dissipation

Heat sinks were invented to absorb heat from an electronic circuit conduct, and then to dissipate or radiate this heat to the surrounding supposedly, ventilated space, at a rate equal to or faster than that of its buildup. Ventilation was not initially recognized as an essential factor to thermal dispersion. However, as electronic circuit-boards continued to heat up, circuit failure became a problem, forcing the inclusion of miniaturized high speed fans. Later, heat sinks with fins and quiet fans were incorporated in most manufactured circuits. Now heat sinks come in the form of a fan with fans made to function as fins to disperse heat. Heat sinks absorb and radiate excess heat from circuit-boards in order to prolong the circuit’s life span. The higher the thermal conductivity of the material used the more efficient and effective the heat sink is. This paper is an attempt to theoretically design a heat sink with a temperature gradient lower than that of the circuit board’s excess heat.

Biomaterials and tissue engineering in traumatic brain injury:novel perspectives on promoting neural regeneration

Traumatic brain injury is a serious medical condition that can be attributed to falls, motor vehicle accidents, sports injuries and acts of violence, causing a series of neural injuries and neuropsychiatric symptoms. However, limited accessibility to the injury sites, complicated histological and anatomical structure, intricate cellular and extracellular milieu, lack of regenerative capacity in the native cells, vast variety of damage routes, and the insufficient time available for treatment have restricted the widespread application of several therapeutic methods in cases of central nervous system injury. Tissue engineering and regenerative medicine have emerged as innovative approaches in the field of nerve regeneration. By combining biomaterials, stem cells, and growth factors, these approaches have provided a platform for developing effective treatments for neural injuries, which can offer the potential to restore neural function, improve patient outcomes, and reduce the need for drugs and invasive surgical procedures. Biomaterials have shown advantages in promoting neural development, inhibiting glial scar formation, and providing a suitable biomimetic neural microenvironment, which makes their application promising in the field of neural regeneration. For instance, bioactive scaffolds loaded with stem cells can provide a biocompatible and biodegradable milieu. Furthermore, stem cells-derived exosomes combine the advantages of stem cells, avoid the risk of immune rejection, cooperate with biomaterials to enhance their biological functions, and exert stable functions, thereby inducing angiogenesis and neural regeneration in patients with traumatic brain injury and promoting the recovery of brain function. Unfortunately, biomaterials have shown positive effects in the laboratory, but when similar materials are used in clinical studies of human central nervous system regeneration, their efficacy is unsatisfactory. Here, we review the characteristics and properties of various bioactive materials, followed by the introduction of applications based on biochemistry and cell molecules, and discuss the emerging role of biomaterials in promoting neural regeneration. Further, we summarize the adaptive biomaterials infused with exosomes produced from stem cells and stem cells themselves for the treatment of traumatic brain injury. Finally, we present the main limitations of biomaterials for the treatment of traumatic brain injury and offer insights into their future potential.

Co-continuous Composite Material Design Using the Volumetric Distance Field Based on Analytic Shape Functions

An effective and simple design method for co-continuous composite material construction is proposed by using a hybrid methodology with triply periodic minimal surface( TPMS) cellular topology and the volumetric distance field( VDF). After generating a set of VDF-based features for the given exterior shape and desired internal core structure,a series of simple modifications in distance fields enabled us to obtain an arbitrarily-shaped complex co-continuous composite material computational model. Design results and manufactured prototypes through 3 D printing technology show that the proposed methodology has the potential to open a new paradigm for producing multifunctional next generation co-continuous composite materials which are impossible to design and manufacture using traditional CAD and CAM.

Evaluation of the Functional Impression Technique with Various Impression Materials on the Surface Topography of Dental Stone Casts and Their Effect on Retention

Background: The accuracy of the final prosthesis is affected by the final impression technique and master cast production. The aim of the present study was to evaluate the effect of the functional impression technique with various impression materials on the surface characteristic of dental stone casts and their clinical effect on the retention of complete dentures. Method: Specimens of three impression materials/stone casts were fabricated. The specimens of the impression materials/stone casts were divided into three equal groups (I, II, and III). The impression materials used were as follows: tissue conditioner group (I), zinc oxide (ZEO) (group II) and poly (vinyl siloxane) (PVS) (group III). Cylindrical split aluminium moulds were designed to receive the impression materials and the stone mixture. The surface roughness of the stone cast specimens of the three groups (I, II, and III) was measured with a surface profilometer and analyzed by a scanning electron microscope. A clinical study included five severely resorbed mandibular edentulous alveolar ridges and edentulous maxillary arches. Each subject received three heat-cured acrylic resin dentures, fabricated using the functional impression technique. The three dentures were identical except for the different impression materials used from Groups I, II and III. The retentive force of each denture for each subject was measured. Result: The results of this study revealed that the mean value of surface roughness of the stone cast surface of group I was higher than group II and group III. A statistically significant difference was observed in surface roughness and the retentive dislodging force between the three studied groups. Although using a tissue conditioner as a functional impression material led to a high level of surface roughness and good retention, it could not produce the same smooth surface quality of PVS or ZEO. These data were supported by SEM analysis. The complete dentures for these patients require important oral and denture hygiene care. Conclusion: Complete dentures made using functional impression technique with PVC as a final impression material are more comfortable, retentive and stable.

Exposure to Hyaluronan and Radon-Containing Water during the Treatment of Periodontal Pockets

Hyaluronic acid (HA) preparations have emerged as pivotal components in contemporary dentistry, gaining widespread recognition for their multifaceted roles in various biological functions. Extensive literature underscores the significance of HA in maintaining tissue water balance, fostering cell proliferation, promoting rapid cell migration, influencing cell differentiation during organism development, and facilitating tissue regeneration. Notably, HA’s interactions with cell surface receptors contribute to the viscosity of synovial fluid, activate the immune system, and enhance cartilage elasticity. Beyond these established functions, HA has also been investigated for its potential involvement in determining and studying the hormetic effects of radon water, adding a novel dimension to its applications in dental research. A thorough exploration of existing studies reveals a nuanced understanding of how HA interventions impact the outcomes of dental procedures. The comprehensive scope of these investigations allows for a more accurate assessment of the potential effectiveness of specific interventions and provides valuable insights into post-procedural prognoses for individual patients. This synthesis of literature serves as the foundation for elucidating the intricate interplay between HA, radon exposure, and their relevance in modern dental practices.

Structural Foundation and Geometry of the Material Singularity (and Its Quantum Entanglement)

In this paper we develop and study, as the second part of one more general development, the energy transmutation equation for the material singularity, previously obtained through the symmetrisation of a wave packet, that is, we develop the correlation between the terms of this equation, which accounts for the formation of matter from a previous vibrational state, and the different possible energy species. These energetic species are ascribed, in a simplified form, to the equation E¯ω=E¯k+E¯f, which allows us, through its associated phase factor, to gain an insight into the wave character of the kinetic energy and thus to attain the basis of the matter-wave, and all sorts of related phenomenologies, including that concerning quantum entanglement. The formation of the matter was previously identified as an energetic process, analogous to the kinetic one, in which finally the inertial mass is consolidated as a mass in a different phase, now, in addition, the mass of the material singularity is identified as a volumetric density of waves of toroidal geometry created in the process of singularisation or energy transfer between species, which makes it possible to establish the real relation or correspondence between the corpuscular and photonic energy equation (E=mc2=hν), i.e. to explain through m the intimate sense of the first equivalence, which explains what νis in the second one.

Cycling performance of layered oxide cathode materials for sodium-ion batteries

Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity,high operating voltage,and simple synthesis.Cycling performance is an important criterion for evaluating the application prospects of batteries.However,facing challenges,including phase transitions,ambient stability,side reactions,and irreversible anionic oxygen activity,the cycling performance of layered oxide cathode materials still cannot meet the application requirements.Therefore,this review proposes several strategies to address these challenges.First,bulk doping is introduced from three aspects:cationic single doping,anionic single doping,and multi-ion doping.Second,homogeneous surface coating and concentration gradient modification are reviewed.In addition,methods such as mixed structure design,particle engineering,high-entropy material construction,and integrated modification are proposed.Finally,a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials.

Evaluating Acid Resistance Effect of Fluoride-Releasing Dental Materials Using Quantitative Light-Induced Fluorescence-Digital in Vitro

As erosion has become one of the serious oral health problems, some fluoride-releasing dental materials have been developed to protect enamel from demineralization. The purpose of this study was to evaluate the antidemineralization effect of PRG Barrier Coat® and FujiVII® (fluoride-releasing dental materials). Four square windows measuring 1 mm2 were prepared on the labial enamel surface of each bovine tooth using masking tape and nail varnish. The first and second windows were half covered by fluoride-releasing material and control material, respectively, whereas the third and fourth windows were left untreated. All windows were immersed into 0.1 M lactic acid and 6wt% CM-cellulose (pH 4.5) at 38℃ for 21 days. Subsequently, the first and second windows were covered with nail varnish after removal of the materials, and the third and fourth windows were immersed into ultrapure water at 38℃ for 28 days after being half covered with fluoride-releasing and control materials, respectively. The following procedure was performed separately during evaluations of the fluoride-releasing materials, PRG Barrier Coat, and FujiVII®, using eight and six bovine teeth, respectively. The first, second, third, and fourth windows were classified into DM-PRG;Demineralized-PRG or DM-FujiVII;Demineralized-FujiVII, DM-TCM;Demineralized-traditional cement or DM-TGIC;De-mineralized-traditional glass ionomer cement, RM-PRG;Remineralized-PRG or RM-FujiVII;Re-mineralized-FujiVII, and RM-TCM;Remineralized- traditional cement or RM-TGIC;Remineral-ized-traditional glass ionomer cement, respectively. After nail varnish was removed, △Q values (mean ± SD) of the windows were measured using QLF-D and were compared between DM-PRG and DM-TCM, RM-PRG and RM-TCM, DM-FujiVII and DM-TGIC, and RM-FujiVII and RM-TGIC groups. △Q values of RM-PRG (-60 ± 44) and RM-FujiVII (-5.0 ± 10) were significantly higher than that of RM-TCM (-315 ± 193) and RM-TGIC (-56 ± 43), respectively. The fluoride releasing materials provided remineralization effects to bovine enamel.