以钾长石为原料制备的白榴石对牙科玻璃陶瓷性能的影响

实验采用了化工原料来合成SiO2-Al2O3-K2O系统玻璃陶瓷,结果发现合成的玻璃陶瓷主要为玻璃相,只有很少量的白榴石晶体;在玻璃相陶瓷中添加白榴石后,其显微结构表明白榴石晶体呈柱状或颗粒状与玻璃相基质紧密结合,并均匀地分布于玻璃相基质中;添加白榴石可明显提高玻璃陶瓷的强度。     

Studies on tableting properties of lactose

The consolidation and compaction behaviour of sieve fractions of crystalline -lactose monohydrate were studied. From mercury porosimetry measurements tablet pore surface areas were derived. At a certain compaction load it appeared that tablets compressed from small particles were generally stronger and showed a larger surface area than compacts prepared from coarse sieve fractions. By plotting compact strength against pore surface area, a unique linear relationship was obtained. From these results it can be concluded that the actual tablet surface area, being a function of both the initial particle size and applied compaction pressure, is responsible for the compact strength.     

Predicting Compressive and Splitting Tensile Strengths of Silica Fume Concrete Using M5P Model Tree Algorithm

Compressive strength (CS) and splitting tensile strength (STS) are paramount parameters in the design of reinforced concrete structures and are required by pertinent standard provisions. Robust prediction models for these properties can save time and cost by reducing the number of laboratory trial batches and experiments needed to generate suitable design data. Silica fume (SF) is often used in concrete owing to its substantial enhancements of the engineering properties of concrete and its environmental benefits. In the present study, the M5P model tree algorithm was used to develop models for the prediction of the CS and STS of concrete incorporating SF. Accordingly, large databases comprising 796 data points for CS and 156 data records for STS were compiled from peer-reviewed published literature. The predictions of the M5P models were compared with linear regression analysis and gene expression programming. Different statistical metrics, including the coefficient of determination, correlation coefficient, root mean squared error, mean absolute error, relative squared error, and discrepancy ratio, were deployed to appraise the performance of the developed models. Moreover, parametric analysis was carried out to investigate the influence of different input parameters, such as the SF content, water-to-binder ratio, and age of the specimen, on the CS and STS. The trained models offer a rapid and accurate tool that can assist the designer in the effective proportioning of silica fume concrete.     

Evaluation of Moisture Damage Potential in Hot Mix Asphalt Using Polymeric Aggregate Treatment

To enhance the moisture damage performance of hot mix asphalt (HMA), treating the aggregate surface with a suitable additive was a more convenient approach. In this research, two types of aggregate modifiers were used to study the effect of moisture damage on HMA. Three different aggregate sources were selected based on their abundance of use in HMA. To study the impact of these aggregate modifiers on moisture susceptibility of HMA, the indirect tensile strength test and indirect tensile modulus test were used as the performance tests. Moisture conditioning of specimens was carried out to simulate the effect of moisture on HMA. The prepared samples’ tensile strength ratio (TSR) and stiffness modulus (Sm) results indicated a decrease in the strength of the HMA after moisture conditioning. After treating the aggregate surface with additives, an improvement was seen in dry and wet strength and stiffness. Moreover, an increasing trend was observed for both additives. The correlation between TSR and strength loss reveals a strong correlation (R² = 0.7219). Also, the two additives indicate increased wettability of asphalt binder over aggregate, thus improving the adhesion between aggregate and asphalt binder.     

Experimental Investigation on Mechanical Properties of Geocell Strips at Low Temperature

Geocell is widely used in the treatment of poor roadbed, which can restrain soil laterally and improve the stability of soil. In cold area engineering, a change in temperature can influence the mechanical properties of geocell of different materials. To study the mechanical response of geocell at low temperatures, three types of geocell strips commonly used in engineering, namely the polyethylene (HDPE), polypropylene (PP), and polyester (PET), were studied via the uniaxial tensile test at the ambient temperatures of −5 °C, −20 °C, and −35 °C, respectively. Meanwhile, the tensile strength, fracture mode, and temperature sensitivity of geocell specimens were compared. It is concluded that: (1) at low temperatures, the tensile strengths of HDPE and PET geocell strips are significantly improved, while that of the PP geocell strip is less sensitive to the temperature. (2) The PP geocell is subject to a brittle failure at all ambient temperatures. The PET geocell strip experiences a hard-ductile failure at normal temperatures of −5 °C and −20 °C. While in the tensile test at −35 °C, it is prone to brittle failure and hard-ductile failure. The HDPE geocell strip suffers from ductile failure at all ambient temperatures. (3) At low temperatures, overall, the tensile properties of the PET geocell strip is better than those of the PP and HDPE geocell strips.     

Ternary Blends for Self-Compacting Mortars Production Composed by Electric Arc Furnace Dust and Other Industrial by-Products

This study is framed within the circular economy model through the valorisation of industrial by-products. This research shows the results of producing self-compacting mortars (SCMs) with electric arc furnace dust (EAFD) and other industrial by-products such as fly ash, conforming (FA) or not conforming (NcFA), from coal-fired power plants, or recovery filler (RF) from hot-mix asphalt plants. Three batches of SCMs, each with one industrial-by product (FA, NcFA, or RF), and three levels of EAFD ratio incorporation (0%, 10%, 20%), were tested. An extra batch with a greater amount of FA was manufactured. When the incorporation ratio of EAFD rose, the mechanical strength decreased, due to the presence of a calcium zinc hydroxide dihydrate phase; nevertheless, this decrease diminished over time. All SCM mixes, except the 40C 40FA 20 EAFD mix, were above 20 MPa at 28 days. All mixes named 70C and 40C reached 40 and 30 MPa, respectively, at 90 days. Mixes with EAFD showed less capillarity and no difference in water absorption by immersion with respect to mixes without EAFD after 91 days. The SCMs designed proved to be stable in terms of leaching of the heavy metals contained in EAFD, where all the hardened SCMs were classified as inert.     

Omega-9 Modifies Viscoelasticity and Augments Bone Strength and Architecture in a High-Fat Diet-Fed Murine Model

The influence of diet on the development of osteoporosis is significant and not fully understood. This study investigated the effect of diets of varying lipid profiles and ω-3, ω-6 and ω-9 composition on the structural and mechanical properties of bone. The hypothesis studied was that a diet high in saturated fat would induce osteoporosis and produce an overall increased detrimental bony response when compared with a diet high in unsaturated ω-6, or ω-9. Male C57BL/6J mice were fed either a control diet, 50:50 mix (saturated:unsaturated) high in ω-9 (HFD^50:50), a diet high in saturated fat (HSF) or a polyunsaturated fat diet high in ω-6 (PUFA) over an 8-week duration. Tibiae were retrieved and evaluated using DMA, 3-point-bending, histomorphometry, and microCT. Mice fed a HSF diet displayed key features characteristic of osteoporosis. The loss tangent was significantly increased in the HFD^50:50 diet group compared with control (p = 0.016) and PUFA-fed animals (p = 0.049). HFD^50:50-fed mice presented with an increased viscous component, longer tibiae, increased loss modulus (p = 0.009), and ultimate stress, smaller microcracks (p < 0.001), and increased trabecular width (p = 0.002) compared with control animals. A diet high in ω-9 resulted in an overall superior bone response and further analysis of its role in bone health is warranted.     

羧甲基大豆多糖性能研究

用氯乙酸作为羧甲基化试剂合成了羧甲基大豆多糖，测定了羧甲基大豆多糖，褐藻胶，褐藻胶－羧甲基大豆多糖合金膜的机构强度，溶解性，并对其肠溶性，抑菌性也作了探讨，实验表明：羧甲基大豆多糖可改进褐藻胶膜的柔韧性和抗冲击强度，与褐藻胶一样具有肠溶性，并对蜡样芽孢杆菌和枯草杆菌生长繁殖有抑制作用。     

4种粘结材料在氧化锆陶瓷与牙本质间的粘结剪切强度比较

目的探讨氧化锆陶瓷与牙本质间合适的粘结材料。方法将烧结后的氧化锆陶瓷片分为4组,每组6片,分别选用PanaviaTMF、Multilink Sprint、RelyXTMLuting、Fuji plus 4种粘结材料将经过纳米硅涂层表面改性的氧化锆陶瓷片与牙本质进行粘结,水浴24 h后测试其粘结剪切强度,数据用SAS6.12软件进行统计学分析。结果PanaviaTMF的粘结抗剪强度最高,与RelyXTMLuting和Fuji plus差别有高度统计学意义（P〈0.01）,与MultilinkSprint的差异无统计学意义（P〉0.05）。结论含磷酸单体MDP的树脂粘结剂,配合适当的表面处理方式可以使氧化锆陶瓷获得较好的粘结效果。     

Effect of water storage on fluoride release and mechanical properties of a polyacid-modified composite resin （compomer）

We evaluated the effect of water storage on fluoride release and mechanical properties of compomer restorative material.Fluoride release was recorded using a specific fluoride electrode.Flexural properties and fracture toughness were measured using a universal testing machine.Vickers hardness was measured using a micro-hardness tester.There was initial burst of fluoride release up to 1 w,which was diminished to a low level in 1 mon and remained relatively constant over 6 mon.Flexural strength and hardness w...