Search

Temperature has a significant effect on the performance of elastohydrodynamic lubrication (EHL), and this topic has been extensively covered in many studies. These studies are focused on how temperature affects lubrication performance, without considering the effect of temperature on the deformation and the subsurface stress of the contact bodies. However, there will be a significant rise in temperature in the contact area under such conditions as high speeds, heavy loads, and high slide-roll ratios. This will generate significant thermal stress inside the solid, thus inhibiting the elastic deformation of the contact surface and impairing the lubrication performance in the contact area. In such cases, it is essential to consider the effects of solid thermal stress and thermal expansion on thermal elastohydrodynamic lubrication (TEHL). In this paper, a TEHL model that consider solid thermal expansion and thermal stress to solve point contact problems is developed. The effects of solid thermal expansion and thermal stress on pressure, film thickness, temperature, and subsurface stress are investigated. The results show that solid thermal expansion partially inhibits the elastic deformation of the contact surface, resulting in a decrease in film thickness and an increase in pressure. It is also found that solid thermal stress causes the subsurface von Mises stress of the upper contact body to increase and that of the lower contact body to decrease.

As a common phenomenon in elastohydrodynamic lubrication, cavitation has an effect on the completeness of the oil film in the contact area. Many studies have therefore been conducted on cavitation. Experimental researches on cavitation usually rely on optical interference observation, which offers a limited resolution and observation range. In this paper, an infrared thermal camera is used to observe the cavity bubbles on a ball-on-disc setup under sliding/rolling conditions. The results show that the cavity length increases with an increases of the entrainment speed and the viscosity of the lubricants. These observations are explained by a numerical model based on Elrod's algorithm. Effects of entrainment speed and lubricant viscosity on the breakup of cavitation bubbles and the cavitation states are investigated. Both the simulation and experimental results show that a negative pressure area is present behind the Hertzian contact area. The ambient pressure plays a role in maintaining cavitation state 1. The cavitation pressure is close to the vacuum pressure when the entrainment speed is low and to the ambient pressure instead when the entrainment speed is high.

Purpose The cleaning of food production equipment using cleaning detergents may contaminate the lubricant of the bearings, thereby reducing the bearing service life. The purpose of this paper is to investigate the cause and mechanism of such damage of bearings lubricated by cleaning detergent/water-in-oil emulsions. Design/methodology/approach The emulsion was prepared by adding a mixture of cleaning detergent and water in one base oil. A self-designed ball-on-disc optical interference test rig was applied to examine the effect of emulsion on lubrication and wear of bearing contacts under pure sliding conditions. Findings The emulsion reduced lubricating film thickness at a relatively low-sliding speed but only when the water concentration (20%) in emulsion was high. Water droplets were trapped around the ball-on-disc contact area under static conditions because of a high capillary force. The emulsion can induce damages on the soft surface in the startup mainly due to the presence of water around the contact. Originality/value The basic lubrication behaviour of water/oil emulsions containing cleaning detergent under pure sliding was experimental studied and the mechanism of bearing damage in food production equipment was investigated. Based on the study, the solution to avoid such damage was proposed.

Background. Regional analgesia for tubeless, uniport, thoracoscopic wedge resection of benign peripheral nodules is generally performed by intercostal nerve block (INB). We examined the effectiveness of thoracic paravertebral block (PVB), in comparison to the traditional intercostal blocks, for the procedure. Methods. Between July 2016 and December 2016, 20 consecutive patients with solitary benign peripheral lung nodules underwent tubeless uniport thoracoscopic wedge resection using thoracic PVB (PVB group). The clinical outcomes were compared with those of 20 other consecutive patients who underwent the same procedure under the conventional INB, between January 2016 and July 2016 (INB group). In both groups, the procedures were performed without endotracheal intubation, urinary catheterization, or chest tube drainage. Results. The clinical data of patients in both groups were comparable in terms of demographic and baseline characteristics, operative and anesthetic characteristics, puncture-related complications, and postoperative anesthetic adverse events. No puncture-related complications occurred during the perioperative period in either group. The threshold values for mechanical pain at postoperative hours 4 and 8 were significantly higher in the PVB group than in the INB group. Furthermore, the incidence of nausea or vomiting in the PVB group was significantly less than that in the INB group. None of the patients required reintervention or readmission to our hospital. Conclusions. Tubeless uniportal thoracoscopic wedge resection for solitary benign peripheral lung nodules using thoracic PVB for regional analgesia is a feasible and safe procedure. Moreover, we found that thoracic PVB is less painful than INB.

Spontaneous ventilation video-assisted thoracic surgery (SV-VATS) is reported to have superior or equal efficacy on postoperative recovery to mechanical ventilation VATS (MV-VATS). However, perioperative safety of the SV-VATS blebectomy is not entirely demonstrated.We performed a noninferiority, randomized controlled trial (No. NCT03016858) for primary spontaneous pneumothorax patients aged 16 to 50 years undergoing a SV-VATS and the MV-VATS procedure. The trial was conducted at 10 centers in China from April 2017 to January 2019. The primary outcome was the comparison of intra- and postoperative complications between SV-VATS and MV-VATS procedures. Secondary outcomes included total analgesia dose, change of vital sign during surgery, procedural duration, recovery time, postoperative visual analog pain scores, and hospitalization length.In this study, 335 patients were included. There was no significant difference between the SV-VATS group and the MV-VATS group in the intra- and postoperative complication rates (17.90% vs 22.09%; relative risk, 0.81; 95% confidence interval, 0.52-1.26; P = .346). The SV-VATS group was associated with significantly decreased total dose of intraoperative opioid agents; that is, sufentanil (11.37 μg vs 20.92 μg; P .001) and remifentanil (269.78 μg vs 404.96 μg; P .001). The SV-VATS procedure was also associated with shorter extubation time (12.28 minutes vs 17.30 minutes; P .001), postanesthesia care unit recovery time (25.43 minutes vs 30.67 minutes; P = .02) and food intake time (346.07 minute vs 404.02 minutes; P = .002). Moreover, the SV-VATS procedure deceased the anesthesia cost compared with the MV-VATS ($297.81 vs $399.81; P .001).SV-VATS was shown to be noninferior to MV-VATS in term of complication rate and in selected patients undergoing blebectomy for primary spontaneous pneumothorax.

Many fast growing cities have designated greenbelts but have failed to maintain them. This is often attributed to weak planning regulations, but there is little understanding of the underlying impacts of greenbelts on the interactions among land use control, transport supply and economic activities. This paper presents a counterfactual analytical model to examine the greenbelts’ impacts on consumers’ utility, producers’ productivity, and their locational choices. The model establishes historic-what-if scenarios and compares what historically happened with what could have happened under alternative levels of greenbelt interventions. The model is applied to Beijing, which intended to establish two greenbelts in 1994, but large parts of the greenbelts have disappeared under fast urban expansion. The model compares the economic impacts of the greenbelts as they stood with hypothetical fully-enforced greenbelts and no-greenbelt scenarios from 1990 to 2010. The modelling results show that the two greenbelts, if fully enforced, would have decreased consumer surplus by $202 million in Beijing in 2010. To fulfil the policy aim of decentralisation, transport improvements between the city and new towns are crucial. For a more effective implementation of greenbelts in the future, development constraints could be carefully removed from non-ecologically sensitive sites which are served with good transport conditions., Cambridge Overseas Trust China Scholarship Council special fund of Key Laboratory of Eco Planning & Green Building, Ministry of Education (Tsinghua University), China Capco Future Cities Fellowship, Cambridge Real Estate Research Centre The Cambridge-UC Berkeley-National University of Singapore University Alliance project ’Smart Design’

The development and training of innovative and entrepreneurial talents is the basic support for enhancing the national core competitiveness, and the training of innovative and entrepreneurial talents has become an important mission of higher education. From the perspective of maker culture, the cultivation of college students’ innovation and entrepreneurship ability has the dilemma of deviation of educational concept, weakened educational carrier, and inefficient evaluation of quality,To this end, build an information network, innovate the education system, and create a cultivation ecology of educational atmosphere, in order to cultivate more campus makers.

Greenspaces at the city scale, like greenbelts, green-wedges or green-grids, have become well-known instruments for shaping urban economic activity and land use. The economic impacts of such instruments are complex and hard to measure. This article addresses one of the rarely studied problems of measuring the economic impacts of alternative greenspace configurations in fast growing cities. In such cities, there is an uncertain basis for making such greenspace related decisions, for example the assumptions about the cities’ total population and economic activity. Decision makers have few tools to measure and predict the potential economic costs and benefits of alternative greenspace configurations. We present a new model that allows tracking over time of both non-divisible land use decisions and a multitude of gradual adaptations made by businesses and consumers. The model is applied to Greater Beijing, one of the fast growing cities that is actively exploring alternative greenspace configurations to control urban expansion. The modelling results suggest that compared with the trend-development scenario of no greenspace intervention, a strict greenbelt would decrease the overall consumer surplus in Beijing by US$3.3 billion, while an adaptive mix of green-wedges and green-grid would increase consumer surplus by US$3.6 billion per year in 2030. The adaptive configuration also reduces car journeys by 11% in Beijing. More generally, modelling results show that a flexible design of strategic greenspaces and careful siting of new development around metro stations within the designated greenspaces could benefit consumers and promote sustainable travel.

With the development of minimally invasive thoracoscopic and anesthesia control techniques, intravenous anesthesia with spontaneous ventilation video-assisted thoracic surgery (SV-VATS) has been increasingly employed in management of pleural effusion, bullectomy for pneumothorax, mediastinal biopsy, thymectomy and thymomectomy, wedge lung resections, anatomical lung resections for radical treatment of lung cancer and even more complex surgical procedures including tracheal resection and sleeve lobectomy (1-7) This changes in surgical strategies have been applied in the believe that SV-VATS can avoid adverse effects of mechanical ventilation and the residual effects of muscle relaxants, can achieve a faster recovery of respiratory muscle function and lower operative morbidity (7,8).

An electrohydrodynamic lubrication (EHL) model in point contacts with consideration of surface coating is presented. The disturbance displacement caused by the coating on the surfaces is calculated using the finite element method (FEM). The effects of coating’s hardness and thickness on oil film pressure, thickness, and subsurface von Mises stresses are investigated. The results show that hard coating causes a significant increase in the oil film pressure, while soft coating has the opposite effect. A significant stress concentration occurs at the subsurface when there is a hard coating. And when the thickness of the coating reaches a certain value, the subsurface stress reaches its maximum. While when there is a soft coating, the maximum stress on the subsurface is slightly reduced.

With the popularization and application of chemical process safety management (PSM) systems in the chemical industry, the use of such systems in China has become the focus of a large volume of research. In this article, 12 elements included in the current Chinese PSM system are divided into four stages from a structural point of view. This division will be helpful in the follow-up analysis. After a careful analysis of the evaluation results for one PSM pilot study in Nanjing, some correlations have been found between the results of the elemental evaluation. Small- and medium-sized chemical plants make up a large proportion of Chinese chemical plants and many chemical accidents take place in these plants, so a simplified PSM system in practical operation need to be found. Based on a previous PSM structural analysis, the secondary elements of the PSM system can be removed. This allows researchers to avoid the traditional method of analyzing PSM elements individually. In the concrete analysis process, a theoretical analysis of the correlation degree between elements can be combined with the results of accident investigations. The simplified Chinese PSM system consists of four core elements: Process safety information, process hazard analysis, training, and emergency management. Based on the current applications of these four core elements in China, a consideration of correlations between these elements is used to make several suggestions for improving China's PSM systems. © 2017 American Institute of Chemical Engineers Process Saf Prog, 2017

The high level of reactive oxygen species and up-regulation of mitochondrial fission protein dynamin-related protein-1, both of which involved in pulmonary artery smooth muscle cells (PASMCs) apoptosis, have been detected in the lungs of rodent pulmonary arterial hypertension models. However, the regulatory mechanisms between ROS and DRP1 are poorly understood. In this study, ROS inhibitor, hypoxic rodent PAH models, small interfering RNA, polymerase chain reaction, Western blot, flow cytometry, immunohistochemistry and immunofluorescence were used. We determined that ROS, mainly derive from mitochondria, mediate mitochondria fission of PASMCs contributing to pulmonary vascular remodeling. Meanwhile, we also observed that hypoxia-induced DRP1 expression depends on ROS generation, especially mitochondrial ROS (mROS). Moreover, the levels of ROS and mROS evoked by hypoxia were regulated by DRP1. Furthermore, we verified the apoptosis suppression of PASMCs under hypoxia due to the interaction between ROS/mROS and DRP1. Our study reveals a novel mechanism of hypoxia-induced pulmonary vascular remodeling, suggesting a new therapeutic strategy which is targeting on the positive feedback of ROS/mROS-DRP1 for the treatment of PAH.

Background: Spontaneous ventilation VATS (SV-VATS) is reported to be associated with faster recovery and fewer complications than mechanical ventilation video-assisted thoracic surgery (MV-VATS). This study aimed to evaluate the effect of SV-VATS for patients with spontaneous pneumothorax. Methods: We performed a randomized controlled trial at 10 medical centers by recruiting primary pneumothorax patients undergoing SV-VATS and MV-VATS. Participants were randomly assigned (1:1), to receive non-intubated spontaneous ventilation (SV-VATS) or intubated mechanical one lung ventilation (MV-VATS). The primary outcome was the intraoperative surgery/anesthesia related accident rate, which was assessed according to incedences of intraoperative hypoxia, conversion to open surgery, conversion to intubation and other intraoperative adverse events that could happen in both groups. Other study outcomes included changes of vital signs, total analgesic dose, recovery time, post-operative complication rates, cost-effectiveness evaluation, etc. Findings: The trial began on Apr 10, 2017, and ended on Jan 03, 2019. During this time, 355 patients were assessed. After evaluation and randomization, 325 eligible patients were assigned to receive an SV-VATS (n=162) or MV-VATS (n=163) procedure. In the intention-to-treat analysis, there was no difference between the intraoperative accident rate of the SV-VATS (1.23%) and MV-VATS (1.23%) group (P=0.995). The SV-VATS group was associated with significantly decreased total dosage of both sufentanil (11.37 μg vs 20.92 μg; p

The expression and function of long noncoding RNAs (lncRNAs) in the development of hypoxic pulmonary hypertension, especially in the proliferation of pulmonary artery smooth muscle cells (PASMCs) are largely unknown. Here, we characterized the expression of lncRNA-maternally expressed gene 3 (lncRNA-MEG3) was significantly increased and primarily located in the cytoplasm of PASMCs by hypoxia. LncRNA-MEG3 knockdown by lung-specific delivery of small interfering RNAs (siRNAs) significantly prevented the development of hypoxic pulmonary hypertension in vivo. Silencing of lncRNA-MEG3 by siRNAs and gapmers attenuated PASMC responses to hypoxia in vitro. Mechanically, we found that lncRNA-MEG3 acts as a molecular sponge of microRNA-328 (miR-328); upon hypoxia, lncRNA-MEG3 interacts and sequesters miR-328, leading to the upregulation of insulin-like growth factor 1 receptor (IGF1R). Additionally, higher expression of lncRNA-MEG3 and IGF1R, and lower expression of miR-328 were observed in PASMCs of iPAH patients. These data provide insight into the contribution of lncRNA-MEG3 in hypoxia pulmonary hypertension. Upregulation of lncRNA-MEG3 sequesters cytoplasmic miR-328, eventually leading to the expression of IGF1R, revealing a regulatory mechanism by lncRNAs in hypoxia-induced PASMC proliferation.

Supplemental material, USJ770115_Supplementary_material for Economic impacts of alternative greenspace configurations in fast growing cities: The case of Greater Beijing by Mingfei Ma, Ying Jin in Urban Studies

The growth of the main built-up area of Beijing is characterised by a pancake like expansion, from 100 km2 in 1950 to 1210 km in 2005 in successive waves. The approach to future urban expansion will require careful consideration, as economic, environmental and social conflicts at the urban fringe have intensified. Two successive greenbelts have been designated to contain expansion and engender more compact growth. However, the first greenbelt has not been achieved successfully and many areas designated as the second greenbelt is facing implementation challenges. This paper builds on existing research into greenbelt policy implementation and investigates the impacts of alternative urban growth boundary proposals under a systematic modelling framework. It reviews the theoretical insights into growth at the urban fringe, and puts forward a methodology that links development at the urban fringe to the functioning of the entire metropolitan area. It outlines six alternative development scenarios that encompass the existing planning proposals for the urban fringe: trend growth, densification, stringent greenbelt, loose greenbelt, hybrid controls, and green wedges. We use a prototypical spatial equilibrium model to quantify the performance of the development scenarios in terms of production costs, consumer welfare, wages, floorspace rents, and commuting times. The analyses suggest that the physical forms of fringe area development do significantly affect the economic performance of the whole municipality. Alternative proposals, including those that have rarely considered in the past, should be investigated carefully in this light, in conjunction with related studies on social and environmental impacts of urban fringe development. 2

Primary spontaneous pneumothorax (PSP) has an estimated incidence ranging from 17–24/100,000 and 1–6/100,000 among males and females, respectively (1,2). It usually occurs in tall thin individuals between 10–30 years of age, especially smokers (3).

Urban greenbelt are considered a key instrument for preventing excessive urban expansion. This paper puts greenbelt configurations in the context of the entire metropolitan area and aims to understand the long-term implications of this type of urban land use control. In particular, we are interested in understanding the economic implications that arise from both the success and failure in implementing greenbelts, through a comparison of London and Beijing. This comparative study is expected to uncover the key differences in the approaches to urban expansion, greenbelt policies, and land use outcomes. We first investigate the ongoing debate regarding greenbelt policies and their role in managing urban expansion. Based on the theoretical framework, we outline the urban expansion history of London (from 1890 to 1940) and Beijing (from 1950 to 2000). A comparison from the perspective of land use-transport interactions follows revealing the differences in greenbelt policy designs which resulted in different policy performances. The analyses suggest that transportation-led development, self-contained new towns, and adaptive greenbelt configurations led to the success of London’s Greenbelt, whilst inadequate transportation links, isolated new towns, and rigid planning caused Beijing’s persistent difficulties. This study aims to contribute to new insights into Beijing’s future greenbelt design.

Abnormal pulmonary arterial smooth muscle cells (PASMCs) proliferation is an important pathological process in hypoxic pulmonary arterial hypertension. Mitochondrial dynamics and quality control have a central role in the maintenance of the cell proliferation–apoptosis balance. However, the molecular mechanism is still unknown. We used hypoxic animal models, cell biology, and molecular biology to determine the effect of mitofusin 1 (Mfn1) on hypoxia-mediated PASMCs mitochondrial homeostasis. We found that Mfn1 expression was increased in hypoxia, which was crucial for hypoxia-induced mitochondrial dysfunction and smooth muscle cell proliferation as well as hypoxia-stimulated cell-cycle transition from the G0/G1 phase to S phase. Subsequently, we studied the role of microRNAs in mitochondrial function associated with PASMC proliferation under hypoxic conditions. The promotive effect of Mfn1 on pulmonary vascular remodeling was alleviated in the presence of miR-125a agomir, and miR-125a antagomir mimicked the hypoxic damage effects to mitochondrial homeostasis. Moreover, in vivo and in vitro treatment with miR-125a agomir protected the pulmonary vessels from mitochondrial dysfunction and abnormal remodeling. In the present study, we determined that mitochondrial homeostasis, particularly Mfn1, played an important role in PASMCs proliferation. MiR-125a, an important underlying factor, which inhibited Mfn1 expression and decreased PASMCs disordered growth during hypoxia. These results provide a theoretical basis for the prevention and treatment of pulmonary vascular remodeling.

As an innovative design for high performance computing, Intel Xeon Phi coprocessor based on Intel Many Integrated Core (Intel MIC) architecture relies heavily on its SIMD (single instruction multiple data) unit. However, performance of non-contiguous memory access has become the memory wall towards efficient utilization of SIMD unit on Intel Xeon Phi coprocessors due to gather/scatter overhead. Existing vectorization techniques in the optimization of gather/scatter overhead have been focusing on extracting data parallelism from inter-loop and intra-loop in a decoupled means. In this paper, we propose a novel inter-intra-hybrid vectorization technique which further exploits SIMD efficiency. In this technique, we generate optimized SIMD code for loops requesting non-contiguous memory. Additional strategies are also presented to improve SIMD unit parallelism through data padding and redundant computation. To evaluate our technique, the two major functions from Sandia's miniMD benchmark, i.e., LJ force calculation and neighbor list build, are taken for experiments which show that our proposed method achieves a performance gain of 25%-40% compared with Intel compiler auto vectorized code and outperforms the existing methods. Our optimization method can be further applied to other highly parallel workloads with frequent non-contiguous memory access, which is very common in real-world scientific applications.

Zhongshan Municipality is located in the delta of Pearl River. Industries in townships comprise the main components of Zhongshan’s economy, which is termed Zhongshan Development Pattern. Industries in townships started relatively early and at that time, the policy system was not completely built up and the labour force was relatively cheap. Therefore townships had a better economic system compared to the central city. However, with the industrial type transformation in China, development patterns of municipalities require change and promotion. Meanwhile, bottleneck effects in township industries of Zhongshan have emerged in the perspective of efficiency and land supplement. The municipality has been challenged by deficient market demands and deficient developmental motivation. It is becoming more and more important to coordinate the development of townships with the central city. The article uses scenario analysis to simulate the relationship between townships’ development and the city’s development, in order to find an approach to enhance the competitiveness for the municipality.