Empty bus

Surreal. Disconcerting. But most of all--lonely. Riding a bus to and back from Cheney, a bus so often overcrowded it was difficult to find room to stand--had suddenly, and with a quiet severity, transformed into a reminder of the fragility of society, and how quickly, the daily norms and what can be expected, unravels.https://dc.ewu.edu/covid/1002/thumbnail.jp

Biogeochemical Changes During Bio-cementation Mediated by Stimulated and Augmented Ureolytic Microorganisms.

Microbially Induced Calcite Precipitation (MICP) is a bio-mediated cementation process that can improve the engineering properties of granular soils through the precipitation of calcite. The process is made possible by soil microorganisms containing urease enzymes, which hydrolyze urea and enable carbonate ions to become available for precipitation. While most researchers have injected non-native ureolytic bacteria to complete bio-cementation, enrichment of native ureolytic microorganisms may enable reductions in process treatment costs and environmental impacts. In this study, a large-scale bio-cementation experiment involving two 1.7-meter diameter tanks and a complementary soil column experiment were performed to investigate biogeochemical differences between bio-cementation mediated by either native or augmented (Sporosarcina pasteurii) ureolytic microorganisms. Although post-treatment distributions of calcite and engineering properties were similar between approaches, the results of this study suggest that significant differences in ureolysis rates and related precipitation rates between native and augmented microbial communities may influence the temporal progression and spatial distribution of bio-cementation, solution biogeochemical changes, and precipitate microstructure. The role of urea hydrolysis in enabling calcite precipitation through sustained super-saturation following treatment injections is explored

Method for continuous camlobe phasing

A method of attaining a desired engine performance comprises the steps of changing the angular position of a variable camlobe (or cam) member relative to a fixed camlobe (or cam) member from a first angular position to a second angular position. In changing from the first to the second angular position, the variable camlobe (or cam) member moves in a predetermined direction relative to the direction of rotation of a camshaft. The predetermined direction and the magnitude of the angular movement of the variable camlobe (or cam) member is dependent at least in part upon at least one desired operating condition of the engine. The method further comprises changing the angular position of both camlobe (or cam) members relative to a reference point of a drive pulley. This change in the angular position of both of the camlobe (or cam) members relative to the reference point involves movement of the camlobes (or cams) in a direction relative to the direction of rotation of a camshaft. The direction and magnitude of this movement is based at least in part upon at least one desired operating condition of the engine

Dual-acting apparatus for variable valve timing and the like

An apparatus and method effects the cyclical actuation of an actuation member. The apparatus can be driven by a crankshaft and has at least one dual-acting phasing apparatus with at least three rotatable mounted internally splined members and at least a first rotatably mounted, externally splined, flexible member having a portion thereof rotatably disposed within each of at least two of the internally splined members. One inner splined member can be connected nonrotatably to a first rotatable member such as an inner shaft, which is rotatably disposed within an outer shaft of a concentric camshaft. Another internally splined member can be nonrotatably connected to the outer shaft. Yet another internally splined member can be nonrotatably connected to a pulley wheel driven by the crankshaft. A fourth internally splined member can be connected to one of the other three internally splined members. A second externally splined, flexible member can be disposed with a portion thereof rotatably disposed within each of at least two of either the three or four internally splined members. Various configurations of cam members and camlobe members can be disposed as integral portions of the inner shaft and the outer shaft. The cam members can be fixed or variable, full width cam members or splittable cam members. More than one concentric camshaft can be controlled by a single dual-acting phasing mechanism. More than one dual-acting phasing mechanism can be used to control two camshafts, concentric or conventional

Variable valve actuating apparatus

An actuating apparatus, which can be used to perform variable valve timing of the intake or exhaust valves of an internal combustion engine, includes a hollow shaft with at least one slot defined through a cylindrical wall. A movable cam member is disposed to project through the slot and is rotatable relative to the hollow shaft in a channel defined in the interior surface of the hollow shaft. A base circle band extends circumferentially around the outer surface of the hollow shaft between the endwalls of the slot. The exterior surface of the hollow shaft can define grooves which receive front or back ear members of the cam member. The exterior surface of the hollow shaft also can define recesses, which in some embodiments have bottom surfaces and in other embodiments have partial bottom surfaces or no bottom surface. The recesses can receive tongue members formed on the cam member. The cam member can be engaged by a cam follower that has a roller to engage the cam surface. When the length of the roller exceeds the width of the cam surface, base circle arcuate sections can be provided on the exterior surface of the hollow shaft to carry the roller across the exposed portion of the slot that exists between the endwall of the slot and the free end of the cam member. An inner shaft extends through an opening defined transversely through the cam member and nonrotatably engages same. The nose portion of the cam member can be defined by a rotatable roller. Twin cam members having identical cam surface profiles can be disposed side-by-side, with one cam member projecting through the slot and the other cam member secured to the outer surface of the hollow shaft. A single follower such as a tappet defining a circular cylindrical surface can be provided to engage both cam members and can be held nonrotatably

Fault-Tolerant Quantum Memory using Low-Depth Random Circuit Codes

Low-depth random circuit codes possess many desirable properties for quantum error correction but have so far only been analyzed in the code capacity setting where it is assumed that encoding gates and syndrome measurements are noiseless. In this work, we design a fault-tolerant distillation protocol for preparing encoded states of one-dimensional random circuit codes even when all gates and measurements are subject to noise. This is sufficient for fault-tolerant quantum memory since these encoded states can then be used as ancillas for Steane error correction. We show through numerical simulations that our protocol can correct erasure errors up to an error rate of $2\%$. In addition, we also extend results in the code capacity setting by developing a maximum likelihood decoder for depolarizing noise similar to work by Darmawan et al. As in their work, we formulate the decoding problem as a tensor network contraction and show how to contract the network efficiently by exploiting the low-depth structure. Replacing the tensor network with a so-called ''tropical'' tensor network, we also show how to perform minimum weight decoding. With these decoders, we are able to numerically estimate the depolarizing error threshold of finite-rate random circuit codes and show that this threshold closely matches the hashing bound even when the decoding is sub-optimal

Overlap of heritable influences between Cannabis Use Disorder, frequency of use and opportunity to use cannabis: Trivariate twin modelling and implications for genetic design

Background: The genetic component of Cannabis Use Disorder may overlap with influences acting more generally on early stages of cannabis use. This paper aims to determine the extent to which genetic influences on the development of cannabis abuse/dependence are correlated with those acting on the opportunity to use cannabis and frequency of use. Methods: A cross-sectional study of 3303 Australian twins, measuring age of onset of cannabis use opportunity, lifetime frequency of cannabis use, and lifetime DSM-IV cannabis abuse/dependence. A trivariate Cholesky decomposition estimated additive genetic (A), shared environment (C) and unique environment (E) contributions to the opportunity to use cannabis, the frequency of cannabis use, cannabis abuse/dependence, and the extent of overlap between genetic and environmental factors associated with each phenotype. Results: Variance components estimates were A = 0.64 [95% confidence interval (CI) 0.58–0.70] and E = 0.36 (95% CI 0.29–0.42) for age of opportunity to use cannabis, A = 0.74 (95% CI 0.66–0.80) and E = 0.26 (95% CI 0.20–0.34) for cannabis use frequency, and A = 0.78 (95% CI 0.65–0.88) and E = 0.22 (95% CI 0.12–0.35) for cannabis abuse/dependence. Opportunity shares 45% of genetic influences with the frequency of use, and only 17% of additive genetic influences are unique to abuse/dependence from those acting on opportunity and frequency. Conclusions: There are significant genetic contributions to lifetime cannabis abuse/dependence, but a large proportion of this overlaps with influences acting on opportunity and frequency of use. Individuals without drug use opportunity are uninformative, and studies of drug use disorders must incorporate individual exposure to accurately identify aetiology