Strategie zur festigkeitsmäßigen Auslegung von Druckbehälterkomponenten

Safety of equipment destined for the chemical and power generation industries is still mandatory. Structural changes in the equipment manufacturing industry and the current switch‐over to European and international standards harbour potential dangers which can ultimately manifest themselves in plant safety. Items of equipment used in process engineering are generally not mass produced articles with a generally valid safety standard. In contrast, they are subjected to specified loads and in this respect each one to be regarded as one of a kind. Strength testing is a mandatory requirement. This article considers a number of general points demanding attention in design work and future trends affecting design practice. The gap between research and everyday practice has to be bridged by applications‐orientated presentation of results. The paper presents a number of illustrative examples.     

Mikroverfahrenstechnik: Komponenten – Anlagenkonzeption – Anwenderakzeptanz – Teil 2

Microtechnology: Components – Plant Concepts – User Acceptance Many activities over the last five or so years have focussed on the thus far underdeveloped field of carrying out reactions on small scales. Due to the rapid development of new components, this paper touches on recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous size difference between the microchannels and the fluid periphery of possible components this is not just a technical question, it touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development, are questions that are addressed here with respect to the big industrial interest in microreactors.     

Sicherheits‐ und Rückhalteeinrichtungen für Mehrzweckanlagen. Teil 2 – Rückhalteeinrichtungen

Fine chemicals and products of the pharmaceutical industry are produced predominantly in multi‐purpose plants. Characteristically, they comprise of many recipes and very different processes. The challenge is often to adapt a certain process to a given plant. At first the sizing scenarios must be identified by means of a systematic risk analysis. Secondly, the process operation must be bounded to fulfill the requirements of the existing protection concept of the plant. This includes proper limits of the process control interlocks and the proper operation of safety devices and following disposal systems. The sizing of cyclone separators and quenches for emergency relief systems are presented and recommendations for proper industrial application of the devices are given. Short cut methods are presented to recalculate the cyclone separator and the quench in case of a change of a product in the multipurpose plant.     

Sicherheits‐ und Rückhalteeinrichtungen für Mehrzweckanlagen. Teil 1 – Sicherheitskonzept und Schutzeinrichtungen

Fine chemicals and products of the pharmaceutical industry are produced predominantly in multi‐purpose plants. Characteristically, they comprise of many recipes and very different processes. The challenge is often to adapt a certain process to a given plant. At first the sizing scenarios must be identified by means of a systematic risk analysis. Secondly, the process operation must be bounded to fulfill the requirements of the existing protection concept of the plant. This includes proper limits of the process control interlocks and the proper operation of safety devices and following disposal systems. A general concept is presented for the safe operation of multi‐purpose plants. Starting with the identification of hazardous potentials an evaluation by means of critically classes is demonstrated. A sizing procedure is given for recalculating an existing safety device according to ISO 4126 part 10. It is based on a concept of energy specific valve seat areas. About 60 typical solvents are applied to the concept.     

基于COM的压力容器辅助设计系统研究

依照复用思想为核心的软件开发技术,把压力容器辅助设计系统分解为设备计算,零部件计算,材料数据库等组件,选用COM技术开发各组件,完成各组件的组装,建立基于COM组件的压力容器辅助设计系统;用户可根据需要编写增加组件,或修改已有的组件,这样增加与修改的组件越多,系统的功能就越丰富,价格低廉,应用就越广泛。     

Ga2S3‐Sb2S3‐CsI chalcohalide glasses for mid‐infrared applications

In this study, a new chalcohalide glass system, Ga₂S₃‐Sb₂S₃‐CsI, is reported. It has a glass‐forming domain composed of ~0‐35 mol% Ga₂S_3, ~15‐95 mol% Sb₂S₃, and ~0‐55 mol% CsI. The glasses have a wide transparent window of ~0.7‐13.5 μm, high third‐order nonlinear refractive indices of ~1.7‐8.7×10^?14 cm²/W @ 1.55 μm, and relatively short zero group‐velocity‐dispersion wavelengths of 3.8‐5.15 μm. The glasses can dissolve more than 2 mol% active ions (e.g., Dy³⁺), and the doped glasses show intense emissions in the mid‐infrared. These superior properties demonstrate their good potentials for mid‐infrared applications such as thermal imaging, nonlinear photonics and lasers.     

湿H_2S环境下压力容器设计中应注意的问题

结合自己的工作经验从材料、结构、工艺三方面分析了湿H2S环境下压力容器设计中应注意的问题。     

Enantioselective Synthesis of 4H‐Pyrans Through Organocatalytic Asymmetric Formal [3+3] Cycloadditions of 2‐(1‐Alkynyl)‐2‐alken‐1‐ones with β‐Keto Esters

4H‐Pyran units are frequently present in molecules with significant biological and pharmaceutical activities. Herein, we present the first enantioselective formal [3+3] cycloaddition between 2‐(1‐alkynyl)‐2‐alken‐1‐ones and β‐keto esters catalyzed by a cyclohexyldiamine‐based thiourea‐tertiary amine bifunctional catalyst. Under the mild and eco‐friendly conditions, a wide range of polysubstituted 4H‐pyrans were obtained in moderate yields with good enantioselectivities.

     

Design of active NiCo2O4‐δ spinel catalyst for abatement of CO‐CH4 emissions from CNG fueled vehicles

Increasing number of CNG vehicles on road emits considerable amount of CO, a poisonous gas and CH₄, a greenhouse‐gas. Highly active and oxygen‐deficient NiCo₂O_4‐δ spinel and its individual metal‐oxides were synthesized by calcination of precipitated/co‐precipitated basic‐carbonates followed by calcination under different strategies of stagnant air(s), flowing air(f) and reactive calcination(RC) for total oxidation of CO‐CH₄ mixture. The catalysts were characterized by XRD, XPS, BET surface‐area, SEM‐EDX and TEM. The performance order of the catalysts for the oxidation of CO‐CH₄ mixture was as follows: NiCo_RC>NiCo_f>NiCo_s>Co_RC>Co_f>Co_s>Ni_RC> Ni_f>Ni_s. The pairing of Ni and Co in spinel‐structure together with RC produced catalyst was oxygen‐deficient highly active for total oxidation of the mixture at the lowest temperature of 350°C. The NiCo_RC was found stable under reaction‐conditions for 50h at 350°C and after four successive heating (350°C)‐cooling (35°C) cycles besides accelerated‐aging tests up to 600°C. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2632–2646, 2018     

Stabilization of Telomeric I‐Motif Structures by (2′S)‐2′‐Deoxy‐2′‐C‐Methylcytidine Residues

G‐quadruplexes and i‐motifs are tetraplex structures present in telomeres and the promoter regions of oncogenes. The possibility of producing nanodevices with pH‐sensitive functions has triggered interest in modified oligonucleotides with improved structural properties. We synthesized C‐rich oligonucleotides carrying conformationally restricted (2′S)‐2′‐deoxy‐2′‐C‐methyl‐cytidine units. The effect of this modified nucleoside on the stability of intramolecular i‐motifs from the vertebrate telomere was investigated by UV, CD, and NMR spectroscopy. The replacement of selected positions of the C‐core with C‐modified residues induced the formation of stable intercalated tetraplexes at near‐neutral pH. This study demonstrates the possibility of enhancing the stability of the i‐motif by chemical modification.     

Generation of 4‐Cyanoisoquinolines and 4‐Amidylisoquinolines via a Palladium‐Catalyzed Cyanative Reaction of 2‐Alkynylbenzaldimines with Isocyanides

An efficient route to 4‐cyanoquinolines via a palladium‐catalyzed cyanative reaction of 2‐alkynylbenzaldimines with isocyanides has been developed. The transformation proceeds through 6‐endo cyclization, isocyanide insertion, and cyanation. 4‐Amidylisoquinolines can be generated as well if water is involved in the reaction.

     

Phosphine‐Catalyzed Asymmetric [4+2] Annulation of Vinyl Ketones with Oxindole‐Derived α,β‐Unsaturated Imines: Enantioselective Syntheses of 2′,3′‐Dihydro‐1′H‐spiro[indoline‐3,4′‐pyridin]‐2‐ones

A novel asymmetric [4+2] annulation of vinyl ketones with oxindole‐derived α,β‐unsaturated imines has been developed in the presence of a multifunctional thiourea‐phosphine catalyst derived from a natural amino acid, providing the first phosphine‐catalyzed enantioselective synthesis of 2′,3′‐dihydro‐1′H‐spiro[indoline‐3,4′‐pyridin]‐2‐ones in good yields with excellent stereoselectivities under mild conditions.