陶瓷焊补技术在玻璃窑炉热态维修中最新研究进展

运用360°回旋自感应陶瓷焊补枪对玻璃窑炉小炉侧墙及平碹采用锆质陶瓷焊补料维修,并对维修前后做了对比分析。     

Epoxy coating destruction as a result of sulphuric acid aqueous solution action

Destruction of epoxy coatings was examined under the influence of ageing with sulphuric acid aqueous solutions (3, 10 and 20%). The ageing caused oxidation, blistering and porosity increase of examined coatings as well as their surface roughness increase.     

Current Progress in Bioactive Ceramic Scaffolds for Bone Repair and Regeneration

Bioactive ceramics have received great attention in the past decades owing to their success in stimulating cell proliferation, differentiation and bone tissue regeneration. They can react and form chemical bonds with cells and tissues in human body. This paper provides a comprehensive review of the application of bioactive ceramics for bone repair and regeneration. The review systematically summarizes the types and characters of bioactive ceramics, the fabrication methods for nanostructure and hierarchically porous structure, typical toughness methods for ceramic scaffold and corresponding mechanisms such as fiber toughness, whisker toughness and particle toughness. Moreover, greater insights into the mechanisms of interaction between ceramics and cells are provided, as well as the development of ceramic-based composite materials. The development and challenges of bioactive ceramics are also discussed from the perspective of bone repair and regeneration.     

Eco-Sustainable Silk Fibroin/Pomegranate Peel Extract Film as an Innovative Green Material for Skin Repair

Skin disorders are widespread around the world, affecting people of all ages, and oxidative stress represents one of the main causes of alteration in the normal physiological parameters of skin cells. In this work, we combined a natural protein, fibroin, with antioxidant compounds extracted in water from pomegranate waste. We demonstrate the effective and facile fabrication of bioactive and eco-sustainable films of potential interest for skin repair. The blended films are visually transparent (around 90%); flexible; stable in physiological conditions and in the presence of trypsin for 12 days; able to release the bioactive compounds in a controlled manner; based on Fickian diffusion; and biocompatible towards the main skin cells, keratinocytes and fibroblasts. Furthermore, reactive oxygen species (ROS) production tests demonstrated the high capacity of our films to reduce the oxidative stress induced in cells, which is responsible for various skin diseases.     

Heat Treatments as a Method of Protection for a Ceramic Fiber—Glass Matrix Composite

Thermal exposure in air has been shown to embrittle a ceramic fiber-glass matrix composite by the infiltration of oxygen to the fiber-matrix interface. Samples exposed at sufficiently high temperatures demonstrate less embrittlement and less strength loss than samples exposed at intermediate temperatures, because of a material flow which seals the surface. It is shown that the protection against embrittlement provided by a short, high-temperature thermal treatment remains in force for materials subsequently exposed to intermediate temperatures under both loaded and unloaded conditions.     

Gel-tape casting as a novel method for the production of flexible fine-grained alumina sheets

The paper reports on the development of a new aqueous gel-tape casting method for processing nanosized powders into thin fine-grained sheets with a high relative density after sintering. The method was based on casting a low-viscosity slurry into a tape, using the doctor-blade method and gelling the slurry after the casting. The gelled tape was removed from the tape carrier without any solvent evaporation and the drying of the gelled tape was performed later in a climate box under controlled temperature and humidity. The epoxy-based ceramic slurry could be prepared with a solid loading of 42 vol.%. Ceramic sheets with flat and smooth surfaces were prepared in a thickness range from 0.08 to 0.4 mm after sintering. The sintered sheets reached a relative density of 99.4%, with an average grain size of about 1.1 μm. The strength and flexibility of alumina sheets were investigated and discussed.     

Preparation of Chamottes as a Raw Material for Low‐Cost Ceramic Membranes

Low‐cost ceramic membranes are usually prepared from a mixture of natural raw materials and some organic porogen agent such as starch. The fact that porogen must be completely eliminated during firing, leaving an interconnected porous structure, impose large firing times, increasing the final price. A study about the synthesis of porous chamottes as an alternative to organic pore formers was conducted to reduce firing costs. Chamottes were obtained from mixtures of clay and starch. Different starches were used and the influence of the composition and processing variables were studied. The viability of the porous chamottes was demonstrated.     

Particle-particle coating in a cyclomix impact mixer

Dry particle coating can be used to create new-generation materials by combining different powders exhibiting different physical and/or chemical properties. In such processes relatively large particles (host particles) are mechanically coated with fine particles (guest particles), without using solvents and subsequent drying, to create new functionalities or to improve initial characteristics. The coating of a host powder by guest particles can be performed in many different ways ranging from simple stirring of two components, to high energy impact coating.The purpose here is to examine the use of a Cyclomix high shear mixer granulator for the surface modification of silica particles by dry coating with magnesium stearate, and of cornstarch dry coated with hydrophilic or hydrophobic fume silica. Several powder characterisation methods have been used to study the physico-chemical properties of the coated particles. These include: Observation by environmental scanning electron microscopy (ESEM), Characterization of cohesion and flowability by tap density measurements, Determination of wettability by measurements of the contact angle between the coated particles and water. Measurement of moisture adsorption-desorption isotherms of uncoated and coated particles, and Tribo-electrification characteristics of the powders. The results show that the surface properties of the two host particles are changed, and that the Cyclomix can be used for dry particle coating to modify the properties of silica gel and cornstarch powders.     

耐碱玻璃纤维原料用锆英砂中二氧化锆（铪）含量测定方法的探讨

探讨了EDTA快速测定锆英砂中二氧化锆（铪）含量的方法,对试验酸度、滴定温度和Fe3＋对测定的影响进行了研究,着重选用简便的标定物Zr标准溶液对操作步骤进行简化,通过4种锆英砂样品进行方法验证以及加标回收试验,结果表明, Zr标准物质标定结果与基准试剂标定结果吻合,二氧化锆（铪）测定结果与重量法测的值比对绝对差均不大于0．18%,加标回收率达到98%以上。     

DNA Repair Genes as Drug Candidates for Early Breast Cancer Onset in Latin America: A Systematic Review

The prevalence of breast cancer in young women (YWBC) has increased alarmingly. Significant efforts are being made to elucidate the biological mechanisms concerning the development, prognosis, and pathological response in early-onset breast cancer (BC) patients. Dysfunctional DNA repair proteins are implied in BC predisposition, progression, and therapy response, underscoring the need for further analyses on DNA repair genes. Public databases of large patient datasets such as METABRIC, TCGA, COSMIC, and cancer cell lines allow the identification of variants in DNA repair genes and possible precision drug candidates. This study aimed at identifying variants and drug candidates that may benefit Latin American (LA) YWBC. We analyzed pathogenic variants in 90 genes involved in DNA repair in public BC datasets from METABRIC, TCGA, COSMIC, CCLE, and COSMIC Cell Lines Project. Results showed that reported DNA repair germline variants in the LA dataset are underrepresented in large databases, in contrast to other populations. Additionally, only six gene repair variants in women under 50 years old from the study population were reported in BC cell lines. Therefore, there is a need for new approaches to study DNA repair variants reported in young women from LA.     

SmPO4-coated Li1.2Mn0.54Ni0.13Co0.13O2 as a cathode material with enhanced cycling stability for lithium ion batteries

SmPO₄ coated Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ cathode materials were prepared by the precipitation method and calcined at 450 °C. The crystal structures and electrochemical properties of the pristine and coated samples are studied by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, electron diffraction spectroscopy, galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). It has been found that the electrochemical performances of the Li-rich cathode material have been substantially improved by SmPO₄ surface coating. Especially, the 2 wt% SmPO₄-coated sample demonstrates the best cycling performance, with capacity retention of 88.4% at 1 C rate after 100 cycles, which is much better than that of 72.3% in the pristine sample. The improved electrochemical properties have been ascribed to the SmPO₄ coating layer, which not only stabilizes the cathode structure by decreasing the loss of oxygen, but also protects the Li-rich cathode material from side reaction with the electrolyte and increases the Li⁺ migration rate at the cathode interface.     

Ozonation as a Post-Treatment Step for Tannery Wastewater to Reduce Foam Formation in a River

Foam formation in a transboundary river, accompanied by protests of local stakeholders, made it necessary to investigate measures to quantify and reduce foam formation. It was previously reported that 80% of the occurring foam formation was provided by three tanneries. Therefore, laboratory-scale experiments were run with wastewater from the three tanneries for six months to investigate the influence of ozonation and biological post-treatment on foam formation. Ozonation with biological post-treatment showed a significant positive effect, with up to 50% additional COD reduction and the elimination of > 70% of the foam formation on river catchment scale. Biological post-treatment alone did not show any effect on the foam formation. The new legal standards for tannery wastewater can be kept at the investigated tanneries through ozonation and biological post-treatment.     

Iron incorporated rice husk silica as a sorbent for hexavalent chromium attenuation in aqueous system

An environmentally benign metal oxide, Fe, was incorporated into silica derived from rice husk via the sol gel route and the physiognomies of both the modified (IRS) and raw rice husk derived silica (RHS) were studied via FTIR and XRD analysis and pH_PZC and surface area determinations. The stability of the Fe incorporated into the silica matrix, determined via the toxicity characteristic leaching procedure, showed that the integrity of the sorbent was intact only in basic medium but got vitiated in acidic medium. The sorption process conformed to the pseudo second order model than reversible first order and pseudo first order kinetic models and the rate of sorption of Cr(VI) onto either sorbents was determined by film diffusion. Process variables optimization showed that the amount of Cr(VI) removed per gram of sorbent reduced with increase in initial solution pH and the negative impact of the anionic interference was more in the presence of SO₃²⁻ than NO₃²⁻ and Cl⁻. The predicted Langmuir monolayer sorption capacity (mg/g) of the IRS (63.69) was higher than that of the RHS (61.35). The value of the mean free energy (kJ/mol) of sorption, obtained for IRS (267.26) and RHS (100.00), and the significant changes in the peak positions of specific functional groups on the Cr(VI) laden sorbents showed that chemisorption was the dominant mechanism of Cr(VI) uptake.     

利用纤维原料在串联式生物反应器中协同酶解发酵乳酸

采用廉价的纤维素原料代替粮食发酵生产乳酸,具有重要的社会意义和经济价值。在串联式生物反应器中,将纤维原料酶水解与固定化乳酸杆菌发酵相耦联,纤维素的酶解产物葡萄糖被有效转化成乳酸,纤维素对乳酸的转化率和乳酸产率分别为70.3%和0.713g?(L?h)?1。在酶解体系中添加纤维二糖酶可以提高酶解得率。将酶解罐、固定化纤二糖酶柱和固定化细胞柱相串联,可有效消除纤维二糖积累所造成的反馈抑制作用,纤维素对乳酸的转化率和乳酸产率分别提高到90.6%和0.986g?(L?h)?1。串联式生物反应器性能稳定,在重复分批发酵工艺中,连续10批纤维素对乳酸的转化率平均为89.6%。采用分批添料工艺,纤维底物的终浓度可增加到200g?L?1,发酵终点的乳酸浓度达105.2g?L?1,乳酸产率为1.315g?(L?h)?1。对等量底物而言,反应时间明显缩短,同时纤维素酶的利用率也得到了有效提高。     

Investigation into Paraffin Wax and Ethylene Vinyl Acetate Blends for Use as a Carrier Vehicle in Ceramic Injection Molding

An experimental study into paraffin wax and ethylene vinyl acetate-28 blends has been undertaken to investigate the potential for their use as carrier vehicles for ceramic injection molding applications. Carrier systems are critical for the fabrication of this type of molded component, making their properties at all stages of the process of great importance. Paraffin wax and ethylene vinyl acetate-28, in most circumstances, combine to form stable homogeneous blends, which experience relatively small changes in the melting and solidification phase transition behavior. However, these blends exhibit notable viscosity shifts and flexural strength performance changes with increasing ethylene vinyl acetate-28 content. The melt flow behavior of the blends at shear rates of 100 s^?1 varies from 0.01 Pa.s for paraffin wax to 10 Pa.s for the composition by weight of 50% paraffin wax and 50% ethylene vinyl acetate-28, which suggests the upper viscosity limit for successful carrier systems. All paraffin wax/ethylene vinyl acetate-28 blends experience shear thinning behavior with increasing shear rate, which can be modeled with reasonable accuracy using the Cross and Carreau models. Increasing the ethylene vinyl acetate-28 content in a blend causes the initiation of shear thinning at progressively lower shear rates and also forms a blend with an increasing elastic character at typical injection temperature. Yield stress is not developed for blends containing less than 50 wt% ethylene vinyl acetate-28. The addition of ethylene vinyl acetate-28 significantly alters the mechanical properties of the blends, modifying the brittle nature of paraffin wax to develop increasing flexible and plastic properties. Although with less than 25 wt% ethylene vinyl acetate-28 in a blend fracture failure still results, greater ethylene vinyl acetate-28 content represses the failure mechanisms, developing the increasing degrees of plastic deformation.     

Use of MS2 Coliphage as a Surrogate for Enteric Viruses in Surface Waters Disinfected with Ozone

The purpose of this study was to determine the relative inactivation of MS2 coliphage (American Type Culture Collection strain 15597-B1) and heterotrophic plate count bacteria using raw surface water under a variety of naturally occurring conditions. It was found that the applied ozone dose and dissolved organic carbon had the most impact on ozone disinfection of MS2 coliphage and HPC bacteria. The dissolved organic carbon was found to compete for the ozone and significantly reduce the inactivation of both the coliphage and the bacteria. Furthermore, it was observed that the presence of any ozone residual inactivated greater than 4 logs MS2 coliphage and 2 logs heterotrophic plate count bacteria within a 30 second contact time. Ozone residuals greater than 0.20 mg/L inactivated greater than 5 logs MS2 coliphage and 3 logs heterotrophic plate count bacteria also within 30 second contact time. Comparison of inactivation studies indicate that MS2 coliphage is probably more sensitive to ozone than enteric viruses. It was concluded that the regulatory agencies should reevaluate their recommendations for using MS2 coliphage as an ozone disinfection indicator of enteric viruses.     

Molybdenum as a Potential Biocompatible and Resorbable Material for Osteosynthesis in Craniomaxillofacial Surgery—An In Vitro Study

Titanium and stainless steel are commonly known as osteosynthesis materials with high strength and good biocompatibility. However, they have the big disadvantage that a second operation for hardware removal is necessary. Although resorbable systems made of polymers or magnesium are increasingly used, they show some severe adverse foreign body reactions or unsatisfying degradation behavior. Therefore, we started to investigate molybdenum as a potential new biodegradable material for osteosynthesis in craniomaxillofacial surgery. To characterize molybdenum as a biocompatible material, we performed in vitro assays in accordance with ISO Norm 10993-5. In four different experimental setups, we showed that pure molybdenum and molybdenum rhenium alloys do not lead to cytotoxicity in human and mouse fibroblasts. We also examined the degradation behavior of molybdenum by carrying out long-term immersion tests (up to 6 months) with molybdenum sheet metal. We showed that molybdenum has sufficient mechanical stability over at least 6 months for implants on the one hand and is subject to very uniform degradation on the other. The results of our experiments are very promising for the development of new resorbable osteosynthesis materials for craniomaxillofacial surgery based on molybdenum.