Fabrication and Characterization of Viton@FOX-7@Al Spherical Composite with Improved Thermal Decomposition Property and Safety Performance

To achieve a uniform distribution of the components and a better performance of aluminized composite explosives, Viton (dipolymers of hexafluoropropylene and vinylidene fluoride) @ FOX-7 (1,1-diamino-2,2-dinitroethylene) @Al microspheres and FOX-7/Viton@Al were synthesized by spray-drying strategy contrastively. Viton@FOX-7@Al owned porous and loose morphology and good sphericity with a retained crystal phase of FOX-7 and aluminum. The 23.56% fluorine content on Viton@FOX-7@Al surface indicated that Viton was completely coated on the surface of the particles. Nanosized aluminum (nAl) in Viton@FOX-7@Al had a certain catalytic activity on the thermal decomposition process of FOX-7 resulting in a depressed exothermic peak temperature and reduced apparent activation energy relative to nAl in FOX-7/Viton@Al. Because of the specific structure and the synergies between each individual component, Viton@FOX-7@Al showed reduced impact sensitivity and friction sensitivity than those of FOX-7/Viton@Al. In brief, Viton@FOX-7@Al with multilevel coating structure possessed comparatively low thermal decomposition energy requirement and improved safety performance.     

A Top-Down Approach and Thermal Characterization of Luminescent Hybrid BPA.DA-MMA@Ln2L3 Materials Based on Lanthanide(III) 1H-Pyrazole-3,5-Dicarboxylates

In this study, novel hybrid materials exhibiting luminescent properties were prepared and characterized. A top-down approach obtained a series of polymeric materials with incorporated different amounts (0.1; 0.2; 0.5; 1, and 2 wt.%) of dopants, i.e., europium(III) and terbium(III) 1H-pyrazole-3,5-dicarboxylates, as luminescent sources. Methyl methacrylate and bisphenol A diacrylate monomers were applied for matrix formation. The resulting materials were characterized using Fourier transform infrared spectroscopy (FTIR) and thermal analysis methods (TG-DTG-DSC, TG-FTIR) in air and nitrogen atmosphere, as well as by luminescence spectroscopy. The homogeneity of the resulting materials was investigated by means of optical microscopy. All obtained materials exhibited good thermal stability in both oxidizing and inert atmospheres. The addition of lanthanide(III) complexes slightly changed the thermal decomposition pathways. The main volatile products of materials pyrolysis are carbon oxides, water, methyl methacrylic acid and its derivatives, bisphenol A, 4-propylphenol, and methane. The luminescence properties of the lanthanide complexes and the prepared hybrid materials were investigated in detail.     

Thermal Hazard Evaluation of Tert-Butyl Peroxy-3,5,5-trimethylhexanoate (TBPTMH) Mixed with Acid-Alkali

Tert-butyl peroxy-3,5,5-trimethylhexanoate (TBPTMH), a liquid ester organic peroxide, is commonly used as an initiator for polymerization reactions. During the production process, TBPTMH may be exposed to acids and alkali, which may have different effects on its thermal hazard, so it is necessary to carry out a study on the thermal hazard of TBPTMH mixed with acids and alkali. In this paper, the effects of H₂SO₄ and NaOH on the thermal decomposition of TBPTMH were investigated by differential scanning calorimetry (DSC) and adiabatic calorimetry (Phi-TEC II). The “kinetic triple factors” were calculated by thermodynamic analysis. The results show that the three E_a are 132.49, 116.36, and 118.24 kJ/mol, respectively; thus, the addition of H₂SO₄ and NaOH increased the thermal hazard of TBPTMH. In addition, the characteristic parameters (time to maximum rate under adiabatic conditions, self-accelerated decomposition temperature) of its thermal decomposition were determined, and the control temperature (45, 40, and 40 °C) of TBPTMH under the action of acid-alkali were further received. This work is expected to provide some guidance for the safe storage, handling, production, and transportation of TBPTMH in the process industry.     

Relevance of the reaction of a manganese(III) chelate with hydroxide ion to photosynthesis: Reaction of hydroxide ion with 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)porphinatomanganese(III) in ligating and nonligating solvents

The reaction of HO^- with 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)porphinatomanganese(III) chloride [(TMP)Mn^III(Cl)] in ligating solvents (CH₃CN, dimethyl sulfoxide, pyridine) results in formation of (TMP)Mn^II (≈10⁶ M^-1·s^-r), which in a slower reaction is converted to a product whose structure is suggested to be that of a porphyrin manganese(III) peroxo dimer. Admittance of O₂ at any time during these reactions leads to formation of the manganese(III) peroxide (TMP)Mn^III(O₂)^-. In nonligating solvents [CH₂Cl₂, (CH₃)₂CO], the reaction of HO^- with (TMP)Mn^III(Cl) yields (TMP)Mn^IV(OH)₂.     

The Use of Nanoscale Montmorillonite (MMT) as Reinforcement for Polylactide Acid (PLA) Prepared by Fused Deposition Modeling (FDM)—Comparative Study with Biocarbon and Talc Fillers

The subject of the presented research focuses on a comparative assessment of three types of polymer fillers used to modify highly crystalline poly(lactic acid) PLA intended for the FDM technique. The aim of the presented work was to determine the performance of the developed materials. The key aspect of the work was the use of polymer fillers of three different types. Nano-sized montmorillonite (MMT), biobased biocarbon (BC) and mineral talc. The several types of composites were prepared using extrusion technique. The maximum content for BC and talc filler was limited to 20 wt%, while for MMT it was 5 wt%. Prepared samples were subjected to detailed material analysis including mechanical tests (tensile, flexural, Charpy), thermal analysis (DSC, DMTA), HDT/Vicat tests and structure analysis. The results of the test confirmed that even relatively small amount of nano-type filler can be more efficient than micrometric particles. The used type of matrix was highly crystalline PLA, which resulted in a significant nucleation effect of the crystalline structure. However, thermomechanical tests revealed no improvement in thermal resistance. Microscopic survey confirmed that for MMT and talc filler the structure anisotropy was leading to more favorable properties, especially when compared to structures based on spherical BC particles.     

Comparative Evaluation of Tensile Bond Strength of Poly Ether Ether Ketone (PEEK) and Zirconia Copings Using Resin Cement with or without Adhesive: An In Vitro Study

This in vitro research aimed to evaluate the Tensile Bond Strength of Poly Ether Ether Ketone and Zirconia copings using resin cement with or without Visio.link adhesive. From commercially available Zirconia and PEEK, blocks were machined milled using (CAD)/(CAM) to obtain 20 Zirconia and 20 PEEK copings. These specimens were sandblasted using 110 μm of alumina. The two main groups (20 Zirconia and 20 PEEK copings) were divided further into 4 subgroups, GROUP 1 (n = 10) PEEK substructure with self-adhesive resin cement without pretreatment, and GROUP 2 (n = 10) PEEK substructure with self-adhesive resin cement pre-treated with Visio.link adhesive. GROUP 3 (n = 10) Zirconia copings with self-adhesive resin cement without pretreatment. GROUP 4 (n = 10) Zirconia copings with self-adhesive resin cement pre-treated with Visio.link adhesive. Universal testing machine was used to evaluate the tensile bond strength of these copings. The results were analyzed using SPSS software Version 25.0 (SPSS Inc., Chicago, IL, USA). One-way ANOVA and independent t-test were used to compare the mean scores. Statistically significant increase was observed in Tensile Bond Strength of samples when Visio.link adhesive was used. Tensile Bond Strength of PEEK copings and Zirconia copings with Visio.link adhesive is considerably greater than PEEK copings and Zirconia copings without adhesive. The mean Tensile Bond Strength of Zirconia (with or without adhesive) is less as compared to Tensile Bond Strength of PEEK (with or without adhesive), but the difference is not statistically significant.     

Thermal Characterization of Medium-Temperature Phase Change Materials (PCMs) for Thermal Energy Storage Using the T-History Method

To reduce energy consumption and increase energy efficiency in the building sector, thermal energy storage with phase change materials (PCMs) is used. The knowledge of the thermophysical properties and the characteristics of PCMs (like their enthalpy changes and the distribution of stored energy over a specified temperature range) is essential for proper selection of the PCM and optimal design of the latent thermal energy store (LHTES). This paper presents experimental tests of the thermophysical properties of three medium-temperature PCMs: OM65, OM55, RT55, which can be used in domestic hot water installations and heating systems. Self-made test chambers with temperature control using Peltier cells were used to perform measurements according to the T-history method. In this way the temperature range of the phase transition, latent heat, specific heat capacity, enthalpy and the distributions of stored energy of the three PCMs were determined. The paper also presents measurements of the thermal conductivity of these PCMs in liquid and solid state using a self-made pipe Poensgen apparatus. The presented experimental tests results are in good agreement with the manufacturers’ data and the results of other researchers obtained with the use of specialized instruments. The presented research results are intended to help designers in the selection of the right PCM for the future LHTES co-working with renewable energy systems, waste heat recovery systems and building heating systems.     

Decomposition Characteristics of the TTIP (Tetraisopropyl Orthotitanate) Precursor for Atomic Layer Deposition

The decomposition of tetraisopropyl orthotitanate (TTIP), a representative precursor used in the atomic layer deposition (ALD) of titanium dioxide (TiO₂) film, and the resulting changes in the thin film properties of the TiO₂ film were investigated. TTIP was evaluated after exposure to thermal stress in an enclosed container. The vapor pressure results provide reasonable evidence that impurities are generated by the decomposition of TTIP under thermal stress. These impurities led to changes in the thermal properties of TTIP and changes in the growth rate, morphology, and composition of the thin film; in particular, these impurities increased the unstable oxidation states of Ti²⁺ (TiO) content in the TiO₂ film. The changes in the properties of the TiO₂ film resulting from the changes in the physical properties of TTIP led to a change in the properties of the device. We proved that the thermal stability of the precursor is a factor that can determine the reliability of the ALD process and the resulting thin film. Additionally, systematic evaluation of the precursor can provide useful information that can improve the development of the precursor and the consistency of the process.     

Comparative study of the fecundity and fertility of Biomphalaria glabrata (Say, 1818) and Biomphalaria straminea (Dunker, 1848) in a laboratory through self-fertilization and cross-fertilization

The aim of this study was to compare the fecundity and fertility of B. glabrata and B. straminea by cross- and self-fertilization. To attain this objective, laboratory-raised strains of B. glabrata and B. straminea were used. The former originated from natural breeding grounds in the municipality Paulista, state of Pernambuco, Brazil. The latter originated from irrigation ditches in the municipality of Petrolandia, in the same state. Snail populations of B. glabrata and B. straminea were maintained for 240 days in laboratory. Their fecundity was evaluated by noting the number of egg-masses, eggs and eggs per mass. Their fertility was evaluated by the number of viable eggs and the hatching rate. B. straminea was markedly more fecund than B. glabrata through cross- and self-fertilization, namely: greater egg-mass; higher egg production and more eggs per mass. Regarding fertility, there seemed to be no preferential period for occlusion to occur or a trend in the rhythm of producing viable eggs.     

A Comparative Study of Additive and Subtractive Manufacturing Techniques for a Zirconia Dental Product: An Analysis of the Manufacturing Accuracy and the Bond Strength of Porcelain to Zirconia

This study was aimed at preparing zirconia samples via additive manufacturing (AM) and subtractive manufacturing (SM) and testing the following aspects: (1) the manufacturing accuracy of the zirconia samples and (2) the bond strength of porcelain to zirconia to evaluate the applicability of the zirconia fabricated by AM in dental clinics. We used three milling machines for SM (AR, K5, and UP) and a 3D printer for AM (AO). The manufacturing accuracy of the zirconia specimen in the internal and marginal areas was evaluated by superimposing techniques to calculate the root mean square (RMS) values. The bond strengths of porcelain to zirconia prepared via SM and AM were measured using a universal testing machine. The internal and marginal RMS values of the zirconia prepared by AM (AO) were within the range of those of the zirconia prepared by SM (AR, K5, and UP). Moreover, the bond strength value of the zirconia prepared by AM (35.12 ± 4.09 MPa) was significantly higher than that of the zirconia prepared by SM (30.26 ± 5.20 MPa). Therefore, AM technology has significant potential for applications in dentistry.     

Experimental Study on the Development of Fly Ash Foam Concrete Containing Phase Change Materials (PCMs)

Phase change materials (PCMs) have the ability to absorb and release a large amount of energy during the process of transforming physical properties (i.e., phase transition process). PCMs are suitable for thermal energy storage and reducing energy consumption in buildings. The aim of the study is to assess the basic material properties and thermal behavior of fly ash foam concrete mixed with two different types of microencapsulated PCMs (PCM6D and PCM18D). We made five different varieties of fly ash foam concrete by replacing the equivalent unit weight of cement with PCM 0%, PCM 10% and PCM 30%. The results show that using a new type of mixer, the microencapsulated PCMs kept their spherical shapes without any cracks or damage in the foam concrete matrix. Differential scanning calorimetry analysis showed that PCM18D-30% had a latent heat capacity of 19.2 °C and 44.7 J/g, in liquid and solid phase with melting and freezing temperatures of 9.46 °C and 41.7 J/g respectively. Additionally, thermocycle analysis showed that it had maintained the temperature for 8 h within the phase change range. In conclusion, PCMs can reduce indoor temperature fluctuations and exhibit the potential for enhancing energy savings and thermal comfort of buildings.     

肾脏病患者脂蛋白（a）异常的初步研究

采用恒电位暂态和旋转盘环电极等方法研究了α、α＋β以及β黄铜在硫酸钠、硫酸以及氯化钠的稀溶液中的阳极溶解过程，结果表明，在黄铜阳极溶解的初始阶段测得的ｉ－ｔ曲线遵循抛物线定律，求得ｉ－ｔ＾－１／２为一通过坐标原点的直线，证明了黄铜中锌的选择性溶解受固相扩散控制，计算出在上述溶液中黄铜中锌的扩散系数值在１０＾１５～１０＾－１３ｃｍ＾２．Ｓ＾－１数量级，介质成分和微量合金元素砷对扩散系值有明显的影响。     

九项生化试验对弧菌科10种致病菌鉴定的探讨

目前弧菌科(属种)的鉴定,主要依靠生化性状的试验。本文根据Rypka等(1967)报道的选择最佳鉴别性状的推理方法,从众多的生化试验项目中进行统计学分析优选出九项(即精氨酸、赖氨酸、V-P、阿拉伯糖、甘露糖、蔗糖、无盐胨水、6％盐胨水、10％盐胨水等),组成生化鉴定系统与常规生化试验(11～16项)对疑似弧菌科细菌318株进行鉴定,符合率可达100％;试验结果表明,用最少的生化试验项目,达到了对弧菌科临床常见弧菌的鉴定,既节省了时间,又节约了经费。本次试验将九项生化试验培养基制成后分装安瓿,做成生化鉴定药盒,操作简单,使用方便,对基层实验室有推广价值。     

脂蛋白(a)与其他脂蛋白和载脂蛋白相关性研究

目的探讨冠心病患者血浆脂蛋白(a)与HDL-C、LDL-C、载脂蛋白(apo)A-Ⅰ、apoB的相关性,评价血脂异常与冠心病的相关性。方法选择因胸痛入院的患者1011例,经冠状动脉造影确诊为冠心病患者613例作为冠心病组,非冠心病患者398例作为对照组。测定脂蛋白(a)、apoA-Ⅰ、apoB、HDL-C和LDL-C,进行相关性分析,并计算apoB/apoA-Ⅰ比值。结果冠心病组的脂蛋白(a)、LDL-C及apoB水平较对照组明显升高(P=0.000);冠心病组脂蛋白(a)水平与LDL-C、apoB呈显著正相关(r=0.135、r=0.168,P0.01),与HDL-C、apoA-Ⅰ无相关性。对照组脂蛋白(a)与LDL-C、apoB呈显著正相关(r=0.201、r=0.236,P0.01),与HDL-C、apoA-Ⅰ无相关性。apoB/apoA-Ⅰ是诊断冠心病最显著的独立危险因素(OR=31.577,95% CI:8.324～11 9.788,P=0.000),其次为脂蛋白(a)(OR=19.446,95% CI:3.831～98.716,P=0.000)。结论脂蛋白(a)与LDL-C、apoB呈正相关,提示三者均为动脉粥样硬化的危险因素;apoB/apoA-Ⅰ和脂蛋白(a)为冠心病的独立危险因素。     

Longitudinal Study of Lipoprotein(a) in Peripubertal Children with Insulin-dependent Diabetes

We aimed to examine the longitudinal relationship between lipoprotein(a) and haemoglobin A_1c, albumin excretion rate, and puberty in peripubertal children with insulin-dependent diabetes. A total of 114 patients aged 11.5 ± 3.6 years (mean (SD)) were followed prospectively for 15.2 ± 2.8 months. Lipoprotein(a), apolipoproteinB-100, haemoglobin A_1c, mean overnight albumin excretion rate and Tanner stage were determined at the beginning and end of the study period. Lipoprotein(a) and apolipoproteinB-100 were measured using nephelometry. This method was correlated with radioimmunoassay and there was no significant change in mean bias during the study. Lipoprotein(a) fell significantly over time (214, (152, 276); 160 (84, 236) mg I^?1 geometric mean (0.95 confidence intervals), p < 0.001); apolipoproteinB-100 did not change. Lipoprotein(a) and apolipoproteinB-100 did not differ in 233 cross-sectional controls of similar age. The change in lipoprotein(a) did not correlate with a small fall in haemoglobin A_1c or with overnight albumin excretion rate, Tanner stage or insulin dose. Separate analysis of male and female patients and prepubertal and pubertal patients continued to show a significant fall in lipoprotein(a) independent of change in haemoglobin A_1c or albumin excretion rate. Likewise, 53 patients with a change in haemoglobin A_1c of greater than 1%, and 20 patients who progressed from normal albumin excretion rate to albumin excretion rate above the 95th centile, showed no relationship between lipoprotein(a) and haemoglobin A_1c or albumin excretion rate. In conclusion, longitudinal changes in lipoprotein(a) do not relate to metabolic control or early changes in albuminuria in young patients with insulin-dependent diabetes.     

单纯温血灌注与C_(93)温血灌注对心肌保护的电镜比较观察

本文应用体外循环心脏手术动物模型，实验犬随机分为对照组、温血组和C93加温血组。评估主动脉阻断前、阻断60＇末和再灌注60＇期间的心肌水肿、线粒体的形态和立体定量分析，以反映心肌保护的效果。结果表明：温血灌注对心肌的保护作用优于低温灌注，而C93可以增强温血灌注的心肌保护作用。     

Numerical Analysis of Experimental Research in a Lightweight Floor System (LFS) with Heat Diffuser

The article presents the results of research on a lightweight floor system (LFS) with a heat diffuser made of metal lamellae. It differs from traditional layered floors in the absence of a screed layer, which reduces thermal inertia and predisposes it to be used with renewable energy sources. As part of the research, a real model of the floor, consisting of nine ceramic tiles, was made. Polyurethane adhesive was used to connect the individual layers of this composite. The model was subjected to a thermal action. It was constructed with the measuring equipment consisting of strain gauges. These were located at the boundaries of the composite layers and measured the material’s deformation. The measurement results were verified by numerical calculations. For this purpose, a computational model was made using FEM (finite element method). Comparable results of deformations were obtained (the differences did not exceed 6.1%), which made it possible to perform numerical calculations of light floor materials stresses. Additionally, the displacement of the tested model was measured and numerically verified. The results of these verifications can be useful not only in the heated/cooled LFS with aluminium lamellae, but also in other building partitions inside and outside the building.     

An Analysis of Kikuchi Lines Observed with a RHEED Apparatus for a TiO2-Terminated SrTiO3 (001) Crystal

In this study, electron diffraction patterns observed under high vacuum conditions for an SrTiO₃ surface were interpreted in detail while paying special attention to the features of inelastic effects. The surface of the SrTiO₂ was carefully prepared to enforce its termination with single domains of TiO₂ layers at the top. The inelastic patterns were interpreted using analytical models. Two types of Kikuchi lines are recognized in this paper: those which can be described with the Bragg law and those which appear due to surface wave resonance effects. However, we also discuss that there exists a formal connection between the two types of the Kikuchi lines observed.     

Comparison of the Masticatory Force (with 3D Models) of Complete Denture Base Acrylic Resins with Reline and Reinforcing Materials

The reinforcement of acrylic denture base remains problematic. Acrylic prosthesis fractures are commonly observed in prosthodontic practice and have not been reliably resolved. This study compared the resistance to masticatory force of acrylic bases of removable complete conventional prosthesis in 3D upper models. Forty acrylic base test specimens containing two types of reinforcement meshes (20 with glass fiber meshes (FIBER-FORCE^®- Synca, Bio Composants Médicaux^TM, Tullins, France), 20 with metal meshes (DENTAURUM^®-Ispringen, Germany)), 20 with a conventional PMMA acrylic base (LUCITONE 199^®-Dentsply Sirona, York, PA, USA), and 20 using a permanent soft reline material (MOLLOPLAST-B^®-DETAX GmbH & Co. KG, Ettlingen, Germany) were tested—a total of 80 specimens. Half of the specimens were made for a low alveolar ridge and half for a high alveolar ridge. The data were analysed using one-way analysis of variance and Student’s t-test for independent test specimens. In the high-alveolar-ridge group, the prosthesis reinforced with the glass fiber mesh was the most resistant to fracture, while in the low-alveolar-ridge group, the non-reinforced prosthesis showed the highest resistance masticatory force. Prostheses with the permanent soft reline material showed the lowest resistance to fracture in both high and low-alveolar-ridge groups. The results show that the selection of the right reinforcement material for each clinical case, based on the height of the alveolar ridge, may help to prevent prosthesis fractures.     

脑梗死病人血尿酸、脂蛋白(a)含量的研究

目的探讨脑梗死病人血尿酸(UA)、血清脂蛋白(a)[Lp(a)]含量的变化及其意义.方法对85例脑梗死病人测定其血总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)、脂蛋白(a)及血尿酸水平.并与对照组(40例)进行对比观察.结果脑梗死病人TC、TG、HDL-C水平与对照组相比无统计学意义(P＞0.05),UA、LDL-C、Lp(a)水平较对照组明显升高(P＜0.01);其中脑梗死合并糖尿病者较无糖尿病者血UA、Lp(a)亦有明显升高(P＜0.05),两组与正常对照组比较有统计学意义(P＜0.05).结论血尿酸、Lp(a)含量增高与脑梗死存在一定关系,是脑梗死的重要危险因素.