A mixed lubrication analysis of a thrust bearing with fractal rough surfaces

Fractal descriptions of rough surfaces are widely used in tribology. The fractal dimension, D, is an important parameter which has been regarded as instrument and scale independent, although recent findings bring this into question. A thrust bearing is analyzed in the mixed lubrication regime while considering the fractal nature. Surface data obtained from a thrust bearing surface are characterized and used to calculate the fractal dimension value by the roughness-length method. Then these parameters are used to generate different rough surfaces via a filtering algorithm. By comparing the predicted performance between the measured surface and generated fractal surfaces, it is found that the fractal dimension must be used carefully when characterizing the tribological performance of rough surfaces, and other parameters need to be found

Secondary Teachers’ Beliefs About Teaching Writing to Typically Achieving and Struggling Adolescent Writers

Writing is a critical component of many secondary classrooms, but little is known about teachers’ beliefs and assumptions surrounding their teaching of writing at the secondary level (particularly including the beliefs of special educators) and teaching writing to students with disabilities. Yet, teachers’ beliefs impact their own perceptions and judgments, which can then affect their behavior (i.e., instructional decisions) within their classrooms. The purpose of this study was to describe middle and high school general and special educators’ beliefs about writing. Results of this study demonstrated that secondary teachers (a) felt somewhat self-efficacious about teaching writing and somewhat less self-efficacious about effecting change in students’ writing, (b) moderately emphasized explicitly teaching writing, (c) were less likely to make adaptations for struggling writers across several writing practices, and (d) placed less emphasis on teaching basic transcription skills. Although limitations related to sample size preclude further disaggregated analyses, this study offers an early examination of teachers’ writing beliefs across several content domains. Changing writing practices in secondary classrooms will necessitate instructional methods that are individualized to meet students’ needs as well as a personal examination of one’s own beliefs to ensure that what one believes is not inhibiting the delivery of effective instructional writing practices

Refractive lensing of scintillating FRBs by sub-parsec cloudlets in the multi-phase CGM

We consider the refractive lensing effects of ionized cool ($T \sim 10^4\,{\rm K}$) gas cloudlets in the circumgalactic medium (CGM) of galaxies. In particular, we discuss the combined effects of lensing from these cloudlets and scintillation from plasma screens in the Milky Way interstellar medium (ISM). We show that, if the CGM comprises a mist of sub-parsec cloudlets with column densities of order $10^{17}\,{\rm cm}^{-2}$ (as predicted by McCourt et al. (2018)), then FRBs whose sightlines pass within a virial radius of a CGM halo will generically be lensed into tens of refractive images with a $\sim 10\,{\rm ms}$ scattering timescale. These images will be resolved by scintillating screens in the Milky Way ISM, and therefore are expected to suppress scintillation. From this, we argue that positive detections of FRB scintillation can constrain the properties of these cool-gas cloudlets, with current scintillation observation disfavouring the cloudlet model. We propose that sheet-like geometries for the cool gas in the CGM can reconcile quasar absorption measurements (from which we infer the presence of the cool gas with structure on sub-parsec scales) and the unexpected lack of lensing signals from this gas thus far observed

Rolling Back Transparency in China\u27s Courts

Despite a burgeoning conversation about the centrality of information management to governments, scholars are only just beginning to address the role of legal information in sustaining authoritarian rule. This Essay presents a case study showing how legal information can be manipulated: through the deletion of previously published cases from China’s online public database of court decisions. Using our own dataset of all 42 million cases made public in China between January 1, 2014, and September 2, 2018, we examine the recent deletion of criminal cases from the China Judgements Online website. We find that the deletion of cases likely results from a range of overlapping, often ad hoc, concerns: the international and domestic images of Chinese courts, institutional relationships within the Chinese Party-State, worries about revealing negative social phenomena, and concerns about copycat crimes. Taken together, the decision(s) to remove hundreds of thousands of unconnected cases shape a narrative about the Chinese courts, Chinese society, and the Chinese Party-State. Our findings also provide insight into the interrelated mechanisms of censorship and transparency in an era in which data governance is increasingly central. We highlight how courts seek to curate a narrative that protects the courts from criticism and boosts their standing with the public and within the Party-State. Examining how Chinese courts manage the removal of cases suggests that how courts curate and manage information disclosure may also be central to their legitimacy and influence

Liability Beyond Law: Conceptions of Fairness in Chinese Tort Cases

Empirical work consistently finds that Chinese courts resolve civil cases by finding a compromise solution. But beyond this split-it-down-the-middle tendency, when and how do Chinese courts arrive at decisions that feel “fair and just” in cases in which they invoke those ideas? Drawing on a data set of 9,485 tort cases, we find that Chinese courts impose liability on two types of parties with ethical, but not legal, obligation to victims: (1) participants in a shared activity and (2) those who control a physical space. In these cases, Chinese courts stretch the law to spread losses through communities and to acknowledge traumatic harm. Considering fairness, then, returns Chinese courts to their longstanding role as managers of communities who respond to misfortune by assigning legal responsibility to relationships that range from intimate to surprisingly tenuous

Overexpression of a Prefoldin β subunit gene reduces biomass recalcitrance in the bioenergy crop Populus.

Prefoldin (PFD) is a group II chaperonin that is ubiquitously present in the eukaryotic kingdom. Six subunits (PFD1-6) form a jellyfish-like heterohexameric PFD complex and function in protein folding and cytoskeleton organization. However, little is known about its function in plant cell wall-related processes. Here, we report the functional characterization of a PFD gene from Populus deltoides, designated as PdPFD2.2. There are two copies of PFD2 in Populus, and PdPFD2.2 was ubiquitously expressed with high transcript abundance in the cambial region. PdPFD2.2 can physically interact with DELLA protein RGA1_8g, and its subcellular localization is affected by the interaction. In P. deltoides transgenic plants overexpressing PdPFD2.2, the lignin syringyl/guaiacyl ratio was increased, but cellulose content and crystallinity index were unchanged. In addition, the total released sugar (glucose and xylose) amounts were increased by 7.6% and 6.1%, respectively, in two transgenic lines. Transcriptomic and metabolomic analyses revealed that secondary metabolic pathways, including lignin and flavonoid biosynthesis, were affected by overexpressing PdPFD2.2. A total of eight hub transcription factors (TFs) were identified based on TF binding sites of differentially expressed genes in Populus transgenic plants overexpressing PdPFD2.2. In addition, several known cell wall-related TFs, such as MYB3, MYB4, MYB7, TT8 and XND1, were affected by overexpression of PdPFD2.2. These results suggest that overexpression of PdPFD2.2 can reduce biomass recalcitrance and PdPFD2.2 is a promising target for genetic engineering to improve feedstock characteristics to enhance biofuel conversion and reduce the cost of lignocellulosic biofuel production

Nanoscale probing of electron-regulated structural transitions in silk proteins by near-field IR imaging and nano-spectroscopy

Silk protein fibres produced by silkworms and spiders are renowned for their unparalleled mechanical strength and extensibility arising from their high-β-sheet crystal contents as natural materials. Investigation of β-sheet-oriented conformational transitions in silk proteins at the nanoscale remains a challenge using conventional imaging techniques given their limitations in chemical sensitivity or limited spatial resolution. Here, we report on electron-regulated nanoscale polymorphic transitions in silk proteins revealed by near-field infrared imaging and nano-spectroscopy at resolutions approaching the molecular level. The ability to locally probe nanoscale protein structural transitions combined with nanometre-precision electron-beam lithography offers us the capability to finely control the structure of silk proteins in two and three dimensions. Our work paves the way for unlocking essential nanoscopic protein structures and critical conditions for electron-induced conformational transitions, offering new rules to design protein-based nanoarchitectures.National Science Foundation (U.S.) (1563422)National Science Foundation (U.S.) (1562915

Zero-Shot Multi-View Indoor Localization via Graph Location Networks

Indoor localization is a fundamental problem in location-based applications. Current approaches to this problem typically rely on Radio Frequency technology, which requires not only supporting infrastructures but human efforts to measure and calibrate the signal. Moreover, data collection for all locations is indispensable in existing methods, which in turn hinders their large-scale deployment. In this paper, we propose a novel neural network based architecture Graph Location Networks (GLN) to perform infrastructure-free, multi-view image based indoor localization. GLN makes location predictions based on robust location representations extracted from images through message-passing networks. Furthermore, we introduce a novel zero-shot indoor localization setting and tackle it by extending the proposed GLN to a dedicated zero-shot version, which exploits a novel mechanism Map2Vec to train location-aware embeddings and make predictions on novel unseen locations. Our extensive experiments show that the proposed approach outperforms state-of-the-art methods in the standard setting, and achieves promising accuracy even in the zero-shot setting where data for half of the locations are not available. The source code and datasets are publicly available at https://github.com/coldmanck/zero-shot-indoor-localization-release.Comment: Accepted at ACM MM 2020. 10 pages, 7 figures. Code and datasets available at https://github.com/coldmanck/zero-shot-indoor-localization-releas