A topic network analysis of the system turn in the environmental sciences

Scientometrics - The concept of Earth system science denotes a shift in the scientific discourse from disciplinary accounts of isolated components of the global environment towards the holistic and...     

Brominated flame retardants in Belgian home-produced eggs: levels and contamination sources

The extent and the sources of contamination with brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), in home-produced eggs from free-foraging chicken of Belgian private owners were investigated. Various factors, such as seasonal variability, exposure of chickens through diet (kitchen waste) and soil, and elimination of BFRs through eggs and faeces were assessed. PBDEs were more important than HBCD in terms of concentrations and detection frequency. Concentrations of PBDEs and HBCD in Belgian home-produced eggs were relatively low and comparable with reported levels from other European countries and the US. The concentrations of PBDEs (sum of 13 congeners, including BDE 209) ranged between not detected and 32 ng/g lipid weight (lw), with medians of 3.0 and < 2.0 ng/g lw for the autumn 2006 and spring 2007 campaigns, respectively. When present, BDE 209 was the major PBDE congener (45% of sum PBDEs). When BDE 209 was not detected, the PBDE profile was composed of PentaBDE (BDE 99 and BDE 47), with, in some cases, higher contribution of OctaBDE (BDE 183 and BDE 153). HBCD was also detected (< 0.4 and 2.9 ng/g lw for the autumn 2006 and spring 2007 campaigns, respectively), but at lower detection frequency. The highest HBCD value was 62 ng/g lw. The similarity between profiles and seasonal variations in the concentrations of BFRs in soil and eggs indicate that soil is an important source, but not the sole source, for eggs laid by free-foraging chicken. The contamination of eggs with PBDEs and HBCD appears to be of low concern for public health and the contribution of eggs to the total daily intake of PBDEs appears to be limited (10% for chicken owners and 5% for the average Belgian consumer).     

Achievable working range for solid all-desiccant air-conditioning systems under specific space comfort requirements

Solid desiccant air-conditioning systems present a promising solution, in terms of performance level and environmental protection, pointing out their potential to be coupled with thermal solar or waste heat energy source. Nevertheless, these systems are characterized by constraints to the load they can satisfy, through the trade-off between the dehumidification cooling capacity and the latent load of the conditioned space. On that level, one has to note that, for steady environmental conditions, the conditioned space does not present unique value of load, but range of load, corresponding to an array of acceptable temperature and (usually relative) humidity values. In this work a methodology is proposed for the definition of the system's achievable working range under specific set of space (comfort) requirements. Through this approach, the systems present greater potential for covering the space requirements, thus presenting more possibilities on a design basis, and more flexible control strategies, as well. The proposed methodology is presented and discussed through the case study of a solar desiccant air-conditioning system coupled to a typical residential building.     

激光跟踪仪在起落架收放型架研制中的应用

根据飞机起落架现代数字化工艺装备的研制需要,通过自主学习,掌握了激光跟踪仪测量技术及数字量传递法以及最大投影面原则、3-2-1原则等设计原则,顺利完成了某型飞机起落架收放型架研制。通过完成该型架安装检测,计量检测人员熟练掌握了激光测量技术在型架制造、检验中的应用技能,积累了飞机起落架型架研制经验。     

Progress and prospects of the human–robot collaboration

Recent technological advances in hardware design of the robotic platforms enabled the implementation of various control modalities for improved interactions with humans and unstructured environments. An important application area for the integration of robots with such advanced interaction capabilities is human–robot collaboration. This aspect represents high socio-economic impacts and maintains the sense of purpose of the involved people, as the robots do not completely replace the humans from the work process. The research community’s recent surge of interest in this area has been devoted to the implementation of various methodologies to achieve intuitive and seamless human–robot-environment interactions by incorporating the collaborative partners’ superior capabilities, e.g. human’s cognitive and robot’s physical power generation capacity. In fact, the main purpose of this paper is to review the state-of-the-art on intermediate human–robot interfaces (bi-directional), robot control modalities, system stability, benchmarking and relevant use cases, and to extend views on the required future developments in the realm of human–robot collaboration.