Fabrication of dye-sensitized solar modules based on a prototyping pilot line and their integration into energy storage microsystems

We successfully developed a prototyping pilot line for dye-sensitized solar modules up to 23 × 23 cm². Dedicated ceramic materials were studied for large area application: we formulated a lead-free glass frit sealant with low softening point based on the ternary system Bi₂O₃-B₂O₃-ZnO and a TiO₂ anatase screen-printable paste for semi-transparent photoanodes. Alongside traditional screen-printing, specific machines among which a thermal press, a dye injection equipment and an automatic electrolyte filler were designed and realized. A silver-free layout was adopted and the solar modules reached an efficiency close to 2%. Photovoltaic glass panels composed by interconnected DSSC modules were interfaced with custom integrated circuits to realize energy storage microsystems for two self-powered prototypes: a USB solar table for recharging of portable devices and a novel LED glass parapet for active night lighting are here presented.     

Can we restore the colour of long-term discoloured resin composites by noninvasive methods?

The aim of this study is to investigate the effect of toothbrushing and paste repolishing on the colour restitution of long-term coffee discoloured prefabricated and direct resin composites. One prefabricated (Componeer-Coltène) and three direct resin composites (Brilliant Ever Glow-Coltène, Essentia-GC, Harmonize-Kerr) were tested. Componeer samples were prepared with and without polishing while the other groups were all polished. After baseline colour-measurement, the specimens were immersed in coffee for 3-month and colour-measurement was repeated, then a simulation of 1-year of toothbrushing (Toothbrush Simulation ZM-3.4-SD Mechatronics) with Pro-Expert Professional Protection-Ipana, 3D White Luxe Perfection-Ipana, and White Ruscello-GC toothpaste was performed. Colour-changes (ΔE) after toothbrushing and repolishing with polishing paste (Enamelize, Cosmodent) were calculated. The discolouration occurred after prolonged exposure to a coffee solution was above the clinically acceptable level of ΔE = 2 in all groups, except Componeer polished group. The lowest discoloured group was Componeer polished (ΔE = 1.66 ± 0.32) while the highest was Essentia group (ΔE = 4.30 ± 0.48). The samples toothbrushed with White Ruscello exhibited the greatest colour restitution (ΔE = 2.06 ± 0.75) (P < .05). After paste repolishing, slight colour restitution was observed among all the groups, but the differences between them remained the same as after the toothbrushing procedure. Prolonged exposure to coffee solution affects the colour of the resin composites and noninvasive methods can provide colour restitution below the critical value for visual perception (ΔE = 3.3). Noninvasive procedures such as toothbrushing with a whitening toothpaste or repolishing with a polishing paste may ensure the colour restitution of direct resin composite restorations until a clinically acceptable level.     

Effect of degree of ethoxilation on the viscosity depressancy properties of fatty acid ethoxilates used in PVC paste formulations

Plastisols of poly (vinylchloride) (PVC) are important commercial products. The rheological properties especially the viscosity of the paste plays an important role in PVC paste applications. Viscosity depressants are usually added to paste formulations in order to obtain desired paste viscosities. In this work, viscosity depressant effects of various fatty acid/ethylene oxide condensates containing 2 to 12 moles ethylene oxide per mole are investigated by Brookfield rotational viscometric method. The effectivenesses of the viscosity depressants are determined at 1.3 sec^?1 shear rates and a relationship between ethylene oxide content and viscosity reduction is found. This relationship between effectiveness and degree of ethoxilation gives way to prediction of viscosity reduction of paste by simply determining the ethylene oxide content. The effect on 24 h aging is also studied. The results showed improvements in short term aging properties of the PVC paste.     

Method for calculating dynamic yield stress of fresh cement pastes using a coaxial cylinder system

The calculation of the rheological parameters of fresh cement pastes plays a key role in understanding the rheology of cement-based mixes. Because cement paste is not a simple Bingham fluid, a suitable nonlinear model must be found for characterizing its flow. A test system in which the rotational speed or shear rate can be changed in multiple steps is regarded as a suitable rheological test protocol because the paste reaches a steady state. Furthermore, theoretical derivations show that the solution of the Couette inverse problem corresponding to the modified Bingham model and the Herschel–Bulkley (H-B) model is complex. However, a comparative analysis revealed that the yield stress of fresh paste could easily be obtained through a calculation process based on a Parabolic model. This study presents the complete calculation procedure for this model. The influence of the plug flow is considered, and test points with low minimum shear stress (τ_min) are excluded. Finally, the accuracy of the proposed method is verified through comparisons with the results obtained using mini-cone slump tests. These results show that the dynamic yield stress calculated using the expression of the Couette inverse problem based on the Parabolic model in consideration of the plug flow is very close to the yield stress obtained using the mini-cone slump flow test. This proves that the proposed method could precisely characterize the dynamic yield stress of cement pastes.     

Separation and quantitation of nitrocellulose,nitroglycerin, diethylphthalate,and centralite in double-base powder

A method is described which makes possible a direct determination of nitrocellulose in double-base powder and powder paste after separation from low-molecular components by gel permeation chromatography and subsequent integration of the nitrocellulose peak. It is also possible to determine nitroglycerin and stabilizers in the same sample by collecting the components in the low-molecular peak and subsequent injection into a reversed-phase chromatography system. The procedure is exemplified on a powder paste containing nitrocellulose, nitroglycerin, centralite I, and diethylphthalate. The whole quantitation procedure will take less than an hour.     

聚氯乙烯糊树脂制品消光方法

概述了使用物理方法、表面涂覆处理、高速增塑糊配方,应用多羟基醇以及消光专用糊树脂以得到表面消光制品的方法,并介绍了交联型、非交联型消光专用糊树脂的配方及生产工艺。     

Properties of polytetrafluoroethylene (PTFE) paste extrudates

In this work, we have studied the effects of extrusion die design, resin molecular structure, and lubricant concentration on the properties of PTFE paste extrudates by performing macroscopic extrusion pressure measurements, Raman spectroscopy, differential scanning calorimetry and mechanical testing on the extrudates. Five resins of different molecular structures were tested. We have found that a balance between fibril quantity and quality (in terms of fibril orientation and continuousness) is necessary to ensure acceptable products, as illustrated through the effects of the operating variables on the extrudate tensile strength. The number of fibrils formed during extrusion can be increased by extruding the paste through a die of larger reduction ratio or by decreasing the lubricant content in the paste, thereby increasing the extrusion pressure. However, excessive pressure will cause fibril breakage. By using a die of larger entrance angle, the extent of fibrillation is also increased, although the quality of the fibrils is somewhat compromised. Increasing the die aspect (L/D) ratio does not increase the extent of fibrillation. However, it increases the degree of fibril orientation and ensures smoother extrudate. Finally, we have found that extrudates obtained using a paste of higher molecular weight are mechanically superior.     

卤水侵蚀对水泥粉煤灰浆体微结构影响

采用XRD、29Si和27Al MAS NMR测试技术,研究了粉煤灰掺量和侵蚀龄期对卤水侵蚀下水泥-粉煤灰浆体水化产物相组成、含铝相产物迁移与转变、C-S-H凝胶微结构变化的影响规律.研究结果表明:卤水侵蚀导致浆体Ca (OH)2含量降低,AFm和TAH向AFt转变,同时生成大量Friedel盐,C-S-H凝胶中Al[4]脱出;随粉煤灰掺量增加,浆体中AFt、AFm和TAH生成量降低,C-S-H的MCL和Al[4]/Si增大,Friedel盐生成量先增后减;侵蚀早期,水泥-粉煤灰浆体结构疏松,AFt生成量较纯水泥高,后期浆体致密性提高,抑制卤水侵蚀,AFt生成量较少,C-A-S-H脱铝作用减弱.     

1万t/a PVC糊树脂装置扩产5 kt/a技改总结

通过对 1万t/aPVC糊树脂装置的状况及各主要工序 (包括化学品配制与分散工序、聚合工序、干燥干序和粉碎包装工序 )能力的分析后 ,确定扩产 5kt/a的技改方案。该方案需要增加聚合釜、放料罐、分离器等设备 ,工程总投资 180 0万元 ,于 2 0 0 0年 11月 6日一次试车成功 ,2 0 0 1年 1～ 6月共生产PVC糊树脂 70 0 5 .4t ,产品合格率达到 98.5 %以上 ,文中提到产量没有达到装置规模的原因是粉碎机的能力不够 ,还需对其完善 ,尽快实现达产达标的目的     

Self-cementitious properties of fly ashes from CFBC boilers co-firing coal and high-sulphur petroleum coke

Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler co-firing coal and high-sulphur petroleum coke (CPFA) were investigated. CPFA was self-cementitious which was affected by its fineness and chemical compositions, especially the contents of SO₃ and free lime (f-CaO). Higher contents of SO₃ and f-CaO were beneficial to self-cementitious strength; the self-cementitious strength increases with a decrease of its 45 μm sieve residue. The expansive ratio of CPFA hardened paste was high because of generation of ettringite (AFt), which was influenced by its water to binder ratio (W/A), curing style and grinding of the ash. The paste cured in water had the highest expansive ratio, and grinding of CPFA was beneficial to its volume stability. The hydration products of CPFA detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM) were portlandite, gypsum, AFt and hydrated calcium silicate (C-S-H).     

Quality assurance of Chinese herbal medicines: Procedure for single‐herb extraction

A procedure for herbal extraction has been developed for producing a Chinese herbal medicine (CHM) with consistent quality regardless of the source of the herb. The quality assurance (QA) procedure is based on a model which accounts for the physicochemical phenomena governing herbal extraction. With this model and the companion experiments for determining the relevant model parameters, the amount of each herb needed from different herb quality classes to produce a CHM decoction with consistent quality can be determined. The procedure was illustrated by the extraction of Danshen and that of Gegen. For both examples, the experimental chemical marker concentrations fell within ± 10% of the specified concentrations by using the amount of herb from each herb class as predicted. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4241–4254, 2013     

球磨粉的特点及其对炭素制品性能的影响

研究了球磨粉的特点和普通球磨粉与超细粉的差别,并根据不同粒度焦炭的吸附性计算出其粘结剂的最佳需要量。结果表明,-0.075mm球磨粉需要粘结剂量是2～1mm焦炭需要粘结剂量的3.8倍,是4～2mm焦炭需要粘结剂量的4.2倍。同时还计算了由不同粒度焦炭构成的糊料的真密度,-0.075mm球磨粉构成糊料的真密度低于0.5～0.15mm及0.15～0.075mm焦炭构成糊料的真密度,但明显高于4～2mm焦炭构成糊料的真密度。-0.075mm球磨粉的含量对炭素制品的性能有明显的影响,其含量适宜时,炭素制品的体积密度、抗折强度及弹性模量最高,电阻率最低。     

高温条件下G级油井水泥原浆及加砂水泥的水化和硬化

利用X射线衍射仪和扫描电子显微镜研究了80～240℃温度范围内温度、硅砂对G级油井水泥水化硬化的影响,检测和分析了硬化体的水化产物、微观结构和强度,揭示了水化产物组成、微观结构及硬化体抗压强度的变化特点.结果表明:当养护温度超过110℃时,不添加硅砂的水泥原浆的主要水化产物由CSH(Ⅱ),C2SH2,C3S2H3转变为C2SH,硬化体微观结构由三维网络状结构转变为板快状或团块状结构,原浆水泥石抗压强度随温度升高而降低;在相对较高的温度条件下,添加硅砂的水泥主要水化产物则分别转变为C5S6H5,C6S6H(>150℃),C5S5A0.5H5.5,C3.2S2H0.8及其他类型的水化硅酸钙晶体,硬化体的微观结构相应地变为纤维网状、粗框架、短平行针状及团块状,在温度为100～150℃范围时,添加硅砂的水泥硬化体抗压强度随温度升高而增加,而在温度为150～240℃范围时.抗压强度随温度升高而降低.对于温度超过120℃的深井,合理的硅砂加量为30%～40%.     

Determination of atomistic deformation of tricalcium silicate paste with high-volume fly ash

We examined the effect of incorporating high-volume fly ash on the atomic arrangement and interatomic deformation behavior of calcium silicate hydrates in tricalcium silicate paste upon exposure to external forces. The interatomic structural changes and strains under compressive load were assessed using synchrotron in situ high-energy X-ray scattering-based atomic pair distribution function analysis. Three different types of strains, which were (a) macroscopic strains from gauges on the surfaces of specimen, (b) strains in a reciprocal space (Bragg peak shift), and (c) strains in real space (PDF peak shift), were compared to each other. All monitored and calculated strains for tricalcium silicate-fly ash (50 wt% fly ash) paste were compared with the counterparts of the pure tricalcium silicate paste. Pair distribution function analysis in the range of r < 10 Å indicated that the atomic arrangement of tricalcium silicate-fly ash was similar to that of synthetic calcium silicate hydrates followed by that of pure tricalcium silicate paste. Moreover, the pair distribution function refinement results revealed that the calcium silicate hydrate structure in tricalcium silicate-fly ash paste was similar to tobermorite 11 Å, unlike that in pure tricalcium silicate paste. The interatomic strain of tricalcium silicate-fly ash in the real space (r < 20 Å) was smaller than that of tricalcium silicate under compression, which suggested that the incompressibility of calcium silicate hydrates at atomistic scale was enhanced by the incorporation of fly ash into it. This was likely to be caused by the increased silicate polymerization of calcium silicate hydrates, which was attributed to the increase in the amount of silicate in their structure via the addition of fly ash.     

Oxidative Stability of Pistachio (Pistacia vera L.) Paste and Spreads

In this study, pistachio (Pistacia vera L.) spread was prepared using pistachio paste, icing sugar, and red palm oil. Pistachio paste, pistachio spread without emulsifier, and pistachio spread with 1.5 % monoglycerides (Dimodan HP‐M, Danisco, Malaysia) were investigated to determine their oxidative stability by subjecting them to accelerated autoxidation conditions (60 °C). Pistachio paste and pistachio spread exhibit a great susceptibility to lipid oxidation due to their high‐fat content. However, it was found that the high oleic and palmitic contents of the oil increase its stability. In all the pistachio products examined, Totox values were higher than 10 (the maximum permitted level) after 25 days of storage. In none of the products was (E,E)‐2,4‐decadienal detected on day 0. After 25 days of storage, however, the peak area percentages rose to 0.13, 0.19, and 0.18 in pistachio paste, pistachio spread without emulsifier, and pistachio spread with emulsifier, respectively. Based on color investigations, the a value (i.e., less greenish) was increased in all the pistachio samples at the end of the storage period. Based on the results obtained from sensory evaluations as well as GC–MS, free fatty acid (FFA), and color measurements, it may be concluded that the shelf life of pistachio products is 20 days at 60 °C.     

Rheological behavior of cement pastes under Large Amplitude Oscillatory Shear

Cement pastes exhibit virtually all the rheological features of complex fluids. Thus, several rheological methods and setups have been used in the literature to characterize these materials. In the present investigation Large Amplitude Oscillatory Shear (LAOS) is for the first time exploited for cement pastes. LAOS can be used to characterize all the rheological properties within a single procedure. This technique is tested in the case of three different cement mixes: a Portland cement paste, nanoclay blended cement paste and a cement paste containing a hydro-soluble polymer. These mixes were selected in order to get rheological properties that are different both quantitatively and qualitatively. Indeed, addition of a low amount of nanoclay increased significantly the yield stress and the shear-thinning/thixotropic aspects of the cement paste, whereas addition of cellulose ether led to the decrease of yield stress and thixotropy. These non-linear rheological properties are discussed within the framework of LAOS.     

EVA对硫铝酸盐水泥净浆微观结构和力学性能的影响

研究了乙烯-醋酸乙烯酯(EVA)对硫铝酸盐水泥(CSA)净浆抗压强度、凝结时间、干燥收缩、质量损失及浆体内部温度的影响规律,并通过XRD、FTIR、SEM及EDS等测试手段对6 h、28 d龄期时的水化产物及微观结构进行分析。结果表明：掺入EVA后CSA净浆的凝结时间显著缩短,6 h的抗压强度升高,而1 d、3 d、28 d的抗压强度降低;CSA净浆的干燥收缩和质量损失率随着EVA掺量的增加逐渐减小;EVA的掺入提高了CSA净浆内部温度曲线的峰值,加快了峰值出现的时间。微观分析表明：EVA对CSA净浆6 h的水化具有促进作用,使其生成了更多的钙矾石,而对其28 d的水化具有抑制作用,水化产物有所减少。     

Effects of nonionic surfactants and external factors on stability of latex in cement paste

To clarify why different surfactants affect stability of latex in cement paste and why many latexes qualified in standard stability test still coagulate when mixed with cement, several kinds of nonionic surfactants with different structures were selected to improve stability of latex and the interactions among cement, latex, and surfactant were discussed. Results show that a higher affinity of surfactant to polymer contributes to a higher stability of latex in cement paste. When surfactants have similar hydrophilic group with each other, surfactants with phenyl in hydrophobic group can more effectively improve stability of styrene–acrylate (SA) latex in cement paste than that with n‐alkyl. With the same hydrophobic group (octyl phenyl) in molecules, surfactants with shorter hydrophilic group show better stabilization effect on SA latex. The combined action of high Ca²⁺ concentration, high solid concentration, and mechanical shear during agitation process of cement paste is the decisive factor causing coagulation of latex. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45946.     

Reagentless Hydrogen Peroxide and L-Lactate Sensors Based on Carbon Paste Electrodes modified with different peroxidases and lactate oxidases

Reagentless amperometric hydrogen peroxide and L -lactate electrodes based on bienzyme modified carbon pastes were tested and compared. The behaviour of 7 peroxidases and two lactate oxidases immobilized in carbon pastes were investigated amperometrically under flow injection conditions. By the combination of recombinant lactate oxidase from Aerococcus viridans (RLOD) and lactate oxidase from Pedicoccus sp. with (LOD) horseradish peroxidase, peroxidase form Arthromyces ramosus, microperoxidases MP-8 and MP-11 sensitive carbon paste electrodes were prepared to detect H₂O₂ and L -lactate. The selectivity with respect to several redox active substances and substrates of the peroxidases is slightly influenced by the selection of the heme containing peroxidase. The operational stability of both the hydrogen peroxide and the L -lactate sensors could be improved by electrochemical deposition of o-phenylenediamine onto bienzyme modified carbon paste electrodes. Despite microperoxidases have a considerably lower electro-catalytical efficiency per molecule, especially MP-8 can be used to modify carbon paste electrodes for sensitive H₂O₂ detection. Both MP-8 and MP-11 can be coimmobilized with LOD and RLOD to detect L -lactate.     

Thermal,mechanical, and surface properties of poly(vinyl alcohol) (PVA) polymer modified cementitious composites for sustainable development

This study aimed to investigate the effect of poly(vinyl alcohol) (PVA) polymer on the thermal, mechanical, and surface properties on cementitious composites for sustainable development. Thermal properties of the PVA‐modified cement paste, including thermal insulation and energy absorption ability, were first studied and correlated with the porosity and microstructures. The experimental results indicated that the thermal conductivity of cement paste can be greatly reduced by 42.9% with 2.0 wt % addition of PVA due to the more porous structure. However, at the same time, more thermal energy can be captured and concentrated at the surface of cement paste with the increasing amount of PVA, causing an increased thermal load and a negative effect on thermal insulating efficiency of cement paste. The contradictory effect of PVA on thermal properties of cement paste should be balanced before it is used as a foaming modifier to fabricate cementitious composites with thermal insulation. In addition, the contact angle measurement revealed that PVA can be used as an effective additive to improve the hydrophobicity of cement‐based materials. Only 3.0% PVA can turn the surface nature from hydrophilicity to hydrophobicity for cement paste, which benefited to the development of self‐cleaning cementitious composites. Finally, the mechanical properties of the PVA‐modified cement paste, especially for the tensile strength that has been rarely reported, were investigated and correlated with its thermal and surface properties. Due to the compensative effects of irregular packing, formation of PVA films and microcracks, tensile strength of cement paste can be improved by 23.5% with a small scarifying of the compressive strength by adding 2.0% of PVA. In conclusion, the PVA‐modified cement‐based materials with lower thermal conductivity, hydrophobic surface nature and enhanced mechanical properties have a great potential to satisfy the high requirements in developing sustainable infrastructure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46177.