The control of paracetamol particle size and surface morphology through crystallisation in a spray dryer

The parameters governing the crystallisation of paracetamol using various conventional techniques has been extensively studied, however the factors influencing the drug crystallisation using spray drying is not as well understood. The aim of this work was to investigate the crystallisation of an active pharmaceutical ingredient through evaporative crystallisation using a spray dryer to study the physicochemical properties of the drug and to use semi-empirical equations to gain insight into the morphology and particle size of the dried powder. Paracetamol solutions were spray dried at various inlet temperatures ranging from 60 °C to 120 °C and also from a series of inlet feed solvent compositions ranging from 50/50% v/v ethanol/water to 100% ethanol and solid-state characterisation was done. The size and morphology of the dried materials were altered with a change in spray drying parameters, with an increase in inlet temperature leading to an increase in particle Sauter mean diameter (from 3.0 to 4.4 µm) and a decrease in the particle size with an increase in ethanol concentration in the feed (from 4.6 to 4.4 µm) as a result of changes in particle density and atomised droplet size. The morphology of the dried particles consisted of agglomerates of individual crystallites bound together into larger semi-spherical agglomerates with a higher tendency for particles having crystalline ridges to form at higher ethanol concentrations of the feed.     

Hybrid-triggered fault detection filter design for networked Takagi–Sugeno fuzzy systems subject to persistent heavy noise disturbance

In the network environment, the single time-triggered scheme wastes limited bandwidth resources due to all the sampled data are transmitted to the networks, and the single event-triggered scheme may increase system error because of ignoring factors such as changes in network utilization. To reduce the design conservatism, this paper is concerned with the hybrid-triggered L₁ fault detection filter design for a class of nonlinear networked control systems (NCSs) described by Takagi–Sugeno (T-S) fuzzy model. Taking the effects of time-triggered scheme and event-triggered scheme into consideration simultaneously, we construct a fuzzy fault detection system. New results on stability and L₁ performance are proposed for fuzzy fault detection system by exploiting the Lyapunov–Krasovskii functional and by means of the integral inequality method. Specially, attention is focused on the design of fault detection filter that guarantees a prescribed L₁ noise attenuation level . Finally, two examples are presented to demonstrate the effectiveness of the proposed method.     

用神经网络综合预测水力旋流器性能

将人工神经网络用作水力旋流器的性能预测模型，实现了对其性能的全面预测，并探讨了结构及工艺参数对其性能的综合影响，弥补了以往数学模型预测的某些不足，为水力旋流器性能的综合预测提出了一个有效而简单的新手段。     

BKDZ型矿用隔爆型真空馈电开关保护性能的可靠性探讨

针对BKDZ矿用隔爆型智能真空馈电开关保护性能存在的不足之处,在短路保护、检漏取样电路及智能整定电路等进行重点技术探索,以提高开关保护性能的可靠性。     

SXJ4261型香蕉筛的动态特性分析

介绍了SXJ4261型香蕉筛的技术特征、工作原理。利用三维建模软件对振动筛进行实体建模,采用有限元软件计算出了筛体结构的固有频率、固有振型和应力分布,为振动筛的大型化设计提供了理论指导。     

Is activity-based working impacting health,work performance and perceptions? A systematic review

ABSTRACT

Numerous claims have been made about the benefits of activity-based working (ABW) on workers’ health and work performance. Yet, it is unclear if these claims are proven. This systematic review aims to establish whether there is an evidence base for the effects of ABW on health, work performance and perceptions of the work environment. Eight databases were searched in September 2016. Three reviewers independently screened titles and abstracts and assessed the studies and extracted the data. Seventeen studies involving 36,039 participants were included. The study designs varied in rigorousness from qualitative studies to pre–post-trials and in sample size ranging from 12 to 11,799. This review found that ABW has positive merits in the areas of interaction, communication, control of time and space, and satisfaction with the workspace; however, it is unfavourable for concentration and privacy. For physical and mental health, the evidence is equivocal. ABW seems to be a promising concept that can be implemented and promoted based on some benefits for work performance and perceptions of the work environment when it is coupled with appropriate management support and organization. More high-quality research is needed to strengthen the evidence base further and establish its health effects.     

浅议SMC轻质内隔墙板在工程中的应用

阐述了SMC隔墙板组成材料及主要技术性能指标，介绍了SMC轻质内隔墙板在工程中的工艺流程及安装要点，提出具体的质量要求，指出SMC隔墙板质轻、隔音、性能稳定，有广泛的应用前景。     

钢绞线压花锚锚固性能试验与分析

以宁波招宝山大桥西引桥A、B匝道后张法预应力连续箱梁采用钢绞线压花锚锚固技术的工程实例,叙述了压花锚锚固性能试验中试块尺寸、测点布置、实验装置及加载方法,并作了试验结果分析。     

阳泉地区软土的特征及地基勘察探讨

叙述了阳泉地区分布在桃河Ⅰ级阶地上的软土特征及工程性能。介绍应如何进行地基勘察 ,同时提出对软土地区进行建筑规划设计及环境等方面应采取的措施     

水性树脂体系中二氧化硅消光剂的评价及应用

在几个水性树脂体系中,对典型的气相二氧化硅消光剂和沉淀法二氧化硅消光剂的消光性能进行了评价实验,结合物性分析和消光原理对实验结果和二氧化硅消光剂的应用技术进行了探讨,结论对于二氧化硅消光剂的选择和应用具有指导意义。