无机陶瓷膜澄清食醋工艺研究

应用无机陶瓷膜微滤技术对老陈醋进行除浊除茵试验研究.通过探讨无机陶瓷膜平均孔径、跨膜压差、膜面流速、操作温度、料液浓缩比等操作参数对过滤效果的影响,确定了适宜的工艺分离条件.无机陶瓷膜澄清食醋工艺在最佳操作条件(常温,采用平均孔径为0.1μm无机陶瓷膜,跨膜压差0.14 MPa、膜面流速2.0 m/s、最大浓缩倍数9)下,平均膜渗透通量可达40 L/(m2·h);过滤后的食醋不仅感观、理化和卫生指标符合国家标准,而且放置两年后无返浑现象.     

疏水陶瓷膜脱除油中水分的研究

对采用平均孔径50nm、表面疏水的陶瓷膜脱除油中水分的过程进行了研究,考察了跨膜压差、膜面流速、原料液水含量对膜渗透通量及水截留率的影响.结果表明,采用疏水陶瓷膜脱除异辛烷中水分可得到较好的分离效果;增大跨膜压差或减小原料液水含量可以增加膜稳定通量,而随着膜面流速的增加,膜稳定通量先升后降.实验得出适宜的操作参数为跨膜压差0.1MPa、膜面流速1.67m/s,获得的水截留率均在98%以上.基于所用陶瓷膜稳定的亲油疏水表面,渗透侧水含量在不同的操作条件下变化很小.     

螺旋形中空纤维超滤膜处理高浓度废水时Dean旋流对膜污染阻力的削弱作用

根据DeaIl旋流原理.以洗毛废水为高浓度废水,用螺旋形中空纤维超滤膜研究透膜压差、膜面流速、料液浓度、Dean参数等对膜污染阻力的影响.结果表明:在50℃,透膜压差△P为80 kPa,膜面流速V为0.68 m/s,螺距6为5 mm,螺径dc为25 mm,处理水质为CODCr46 365 ng/L、羊毛脂12 g/L、pH=8.0、总固体浓度20 158 mg/L时,螺旋形膜透过液通量,是直形膜的1.6～1.96倍,阻力Rf比直形膜降低60%以上.在Dean参数的构成中,提高试验温度和减小螺距对膜污染阻力的削弱效果最为显著.     

混凝和微滤膜组合工艺处理稠油污水的研究

以辽河油田某稠油污水处理厂外排水为对象,采用混凝与微滤膜(MF)处理相结合的方法.从操作压差、膜孔径、混凝处理等多个角度对稠油污水膜分离及组合工艺进行条件优化和效果分析.确定选择0.5 μm孔径膜、0.25 MPa操作压差为膜最佳操作运行条件;通过常规的混凝和膜分离联合处理方法可有效去除稠油废水中悬浮性及部分可溶性有机污染物,处理后出水COD平均浓度86～97 mg/L,去除率达到43.4 %;且膜清洗通量能够恢复96.8%.结果表明该工艺远优于传统工艺,可以作为稠油污水二级处理保障工艺.     

陶瓷微滤膜滤除骨架镍催化剂微粒的研究

提出用陶瓷微滤膜脱除骨架镍催化剂微粒的方法,研究了操作压差、膜面流速、温度和料液浓度等操作条件对膜通量的影响,确定了简单而有效的膜清洗方法与合适的操作条件.结果表明,在本实验中膜的污染现象不严重,主要的膜过滤阻力来自形成的滤饼层,采用平均孔径0.2μm的陶瓷膜,在合适的操作条件下,膜稳定通量为1050L/(m2·h),渗透液中镍含量小于3mg/L,截留率满足了化工产品质量要求.     

高锰酸钾强化混凝/砂滤/超滤组合工艺处理松花江水试验研究

进行中试试验考察了高锰酸钾对混凝/砂滤/超滤组合工艺去除松花江水中污染物的强化效能及对膜渗透性能的影响.结果表明,高锰酸钾可以强化对水中污染物的去除,DOC去除率由21.4%提高到33.4%,UV254去除率由14.2%提高到28.0%,膜出水浊度低于0.1NTU,大于2μm颗粒物少于10个/mL;此外,高锰酸钾可以改善膜渗透性能,延缓了膜通量的降低速率,提高了膜通量.     

超声在陶瓷膜微滤中药口服液过程中的应用研究

研究了在线超声技术在无机陶瓷膜微滤中药口服液中的应用.以膜渗透通量、膜污染阻力分布等为指标,考察了在线连续超声与正常微滤在口服液微滤中的差异,进而对操作条件进行优化.结果表明,超声能显著增强膜的渗透通量,增液口服液、黄芪精口服液的通量提高率分别为26.6%和44.6%.超声波还能有效控制膜表面污染.采用超声强化陶瓷膜微滤中药口服液能有效的减少膜污染、提高膜的利用效率.     

聚合物强化陶瓷膜处理低浓度重金属废水

采用三种孔径分别为200 nm、50 nm和20 nm的陶瓷膜,以聚丙烯酸为络合剂,含Cu2+废水作为模拟废水,研究聚合物强化膜分离处理低浓度重金属废水的过程.重点考察运行时间、跨膜压差、聚合物/金属离子质量浓度比P∶M值及pH对渗透通量和重金属离子截留率的影响.研究表明,控制合适的条件,陶瓷微滤膜和超滤膜对Cu2+均达到99.8%的截留率,且能得到较高的渗透通量.     

陶瓷膜澄清苦丁茶提取液

针对苦丁茶丰富的药用价值及其成分比较复杂难以分离纯化的特点,本文主要研究陶瓷膜对苦丁茶提取液的过滤澄清过程,通过模型计算与实验的方法分析研究了膜孔孔径和操作条件(如操作压差、膜面流速、操作温度和苦丁荼质量浓度等)对过滤过程的影响.结果表明,模型计算结果与实验结果有较好的吻合,陶瓷膜过滤苦丁茶提取液有较好的澄清效果,提取液中固体悬浮物截留率在90%以上,渗透液静置15天仍保持澄清且渗透液中有效成分得到较好的保留,同时确定了以孔径为500 nm的膜管在3 m/s的膜面流速、40℃的操作温度和0.18 MPa的操作压差条件下过滤苦丁茶提取液能获得较好的过滤澄清效果,渗透通量达到400 L/(m2·h).     

膜技术处理含油废水的研究

介绍了膜技术在含油废水处理中的特点和应用前景,针对含油废水的性质,探讨了膜类型的选择、操作压差、膜面流速、操作温度、膜污染及清洗等因素对膜技术处理含油废水的影响.通常情况下,操作压力过大时,膜通量随压力变化较小,而低于该压力时,膜通量随操作压力的增大而提高;膜面流速和温度对膜通量的影响和操作压力的影响类似;膜经过合适的清洗可以基本恢复膜通量.还介绍了膜技术在油田含油废水处理中的实例和存在的问题,并进一步指出今后的发展方向是研究开发经济、高效的污水处理技术,尤其是膜技术和微生物法结合处理油田含油废水的技术.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.