Pyrolysis of Natural Gas: Effects of Process Variables and Reactor Materials on the Product Gas Composition

High‐temperature pyrolysis of natural gas is the basis of the standard method for the manufacture of acetylene. The study of methane pyrolysis was designed to find optimum process conditions that would produce high yields of acetylene with minimal carbon formation. High temperatures and short residence times enhanced the selectivity for acetylene, while hydrogen dilution was found to suppress the generation of carbonous products. Carbon formation on reactor surfaces over time may be mainly responsible for the misalignment of predicted and measured product gas compositions, as the mechanisms reported do not consider the surface chemistry. In essence, the pyrolysis system favors the highest possible temperature and shortest possible residence time, suggesting that the selection of reactor materials is the key for pyrolysis process optimization. The operating temperature is likely dictated by the physical properties of the reactor materials rather than the selection of optimal pyrolysis conditions.     

Auxiliary Diagnosis Based on the Knowledge Graph of TCM Syndrome

As one of the most valuable assets in China, traditional medicine has a long history and contains pieces of knowledge. The diagnosis and treatment of Traditional Chinese Medicine (TCM) has benefited from the natural language processing technology. This paper proposes a knowledge-based syndrome reasoning method in computerassisted diagnosis. This method is based on the established knowledge graph of TCM and this paper introduces the reinforcement learning algorithm to mine the hidden relationship among the entities and obtain the reasoning path. According to this reasoning path, we could infer the path from the symptoms to the syndrome and get all possibilities via the relationship between symptoms and causes. Moreover, this study applies the Term Frequency-Inverse Document Frequency (TF-IDF) idea to the computer-assisted diagnosis of TCM for the score of syndrome calculation. Finally, combined with symptoms, syndrome, and causes, the disease could be confirmed comprehensively by voting, and the experiment shows that the system can help doctors and families to disease diagnosis effectively.     

Landslide-susceptibility mapping in a semi-arid mountain environment: an example from the southern slopes of Sierra Nevada (Granada,Spain)

Landslide susceptibility is analysed in a semi-arid mountain environment, on the southern slope of Sierra Nevada. In a study area of 460 km², 252 landslides were inventoried, affecting 3.2% of the total surface area. These landslides were mainly slides and flows on phyllite, schist and marble units in the Inner Zone of the Betic Cordillera. The most relevant determining factors proved to be elevation, slope angle, slope aspect and lithology. Triggering factors include mainly short-term landslide generation during heavy rainfall, as well as sporadic earthquakes or long-term activation by land-use changes, river over-excavation, etc. Although landslide susceptibility, assessed by the GIS matrix method, is predominantly low, some 15% of the study area shows moderate to very high susceptibility, coinciding with the sites of public works in the region. The map drawn was validated by the degree-of-fit method, registering values above 83.2% for the zones of high and very high susceptibility.     

The porous composite BN@SHS made of boron nitride,silica hollow spheres and Si–O–B interface

Journal of Porous Materials - Calcined silica SiO2 hollow spheres (SHS), with a specific surface area of 523 m2 g?1, were used as porous scaffolds of ammonia borane (AB). AB is used...     

Surface modification of cellulose nanocrystals by grafting with poly(lactic acid)

The use of biopolymers obtained from renewable resources is currently growing and they have found unique applications as matrices and/or nanofillers in ‘green’ nanocomposites. Grafting of polymer chains to the surface of cellulose nanofillers was also studied to promote the dispersion of cellulose nanocrystals in hydrophobic polymer matrices. The aim of this study was to modify the surface of cellulose nanocrystals by grafting from L‐lactide by ring‐opening polymerization in order to improve the compatibility of nanocrystals and hydrophobic polymer matrices. The effectiveness of the grafting was evidenced by the long‐term stability of a suspension of poly(lactic acid)‐grafted cellulose nanocrystals in chloroform, by the presence of the carbonyl peak in modified samples determined by Fourier transform infrared spectroscopy and by the modification in C1s contributions observed by X‐ray photoelectron spectroscopy. No modification in nanocrystal shape was observed in birefringence studies and transmission electron microscopy. © 2013 Society of Chemical Industry     

Comparison of high protein and high fiber weight-loss diets in women with risk factors for the metabolic syndrome: a randomized trial

Background  

Studies have suggested that moderately high protein diets may be more appropriate than conventional low-fat high carbohydrate diets for individuals at risk of developing the metabolic syndrome and type 2 diabetes. However in most such studies sources of dietary carbohydrate may not have been appropriate and protein intakes may have been excessively high. Thus, in a proof-of-concept study we compared two relatively low-fat weight loss diets - one high in protein and the other high in fiber-rich, minimally processed cereals and legumes - to determine whether a relatively high protein diet has the potential to confer greater benefits.     

A property‐based approach to the synthesis of material conservation networks with economic and environmental objectives

This article presents a multiobjective optimization model for the recycle and reuse networks based on properties while accounting for the environmental implications of the discharged wastes using life‐cycle assessment. The economic objective function considers fresh sources and treatment costs, whereas the environmental objective function is measured through the eco‐indicator 99. The model considers constraints in the process sinks as well as in the environment based on stream properties such as pH, chemical oxygen demand, toxicity, density, and color, in addition to the composition of the waste streams. A global optimization procedure is developed by indirectly tackling properties through property operators and by segregating the process streams before treatment. Three examples are included, and the results show that it is possible to consider simultaneously the trade‐offs between the total annual costs and the overall environmental impact using the proposed methodology. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Controlling fibrillation – experiences of the dyeing and finishing of lyocell fibres

This review centres on the development of dyeing and finishing technologies for lyocell (TENCEL^®) fibres since they were introduced onto the market in 1992. Initially, it will look at the reason for starting manufacture of the fibre and its manufacturing technology. An overview of basic dyeing performance is followed by a critical assessment of the fibre's introduction into the commercial world and the problems that ensued from its fibrillation property. The review then outlines the pioneering process development efforts made in Japan. Dye machinery manufacturers also played an important role in developing processing routes, particularly, but not exclusively, Then, Thies, and Krantz. Courtaulds Tencel formed an alliance with Sir T & A Wardles of Courtaulds Textiles, setting up a project to demonstrate successful jet processing of lyocell fabrics. Investment in jet dyeing machines and personnel was critical: the review explains how it was done and results that were achieved. It also considers how to control fabric behaviour in relation to creasing and fibrillation. The latter phenomenon held the fibre back from knitted applications. Both Courtaulds and Lenzing developed non‐fibrillating versions of the fibres. This review covers these advances, as well as how new markets have been developed for the fibre, such as workwear and bed sheeting. It concludes by looking at the key market segments today and how Lenzing sees the lyocell market evolving.