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An augmented Lagrangian preconditioner for implicitly-constituted non-Newtonian incompressible flow. (arXiv:2005.03150v1 [math.NA])

We propose an augmented Lagrangian preconditioner for a three-field stress-velocity-pressure discretization of stationary non-Newtonian incompressible flow with an implicit constitutive relation of power-law type. The discretization employed makes use of the divergence-free Scott-Vogelius pair for the velocity and pressure. The preconditioner builds on the work [P. E. Farrell, L. Mitchell, and F. Wechsung, SIAM J. Sci. Comput., 41 (2019), pp. A3073-A3096], where a Reynolds-robust preconditioner for the three-dimensional Newtonian system was introduced. The preconditioner employs a specialized multigrid method for the stress-velocity block that involves a divergence-capturing space decomposition and a custom prolongation operator. The solver exhibits excellent robustness with respect to the parameters arising in the constitutive relation, allowing for the simulation of a wide range of materials.




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Optimally Convergent Mixed Finite Element Methods for the Stochastic Stokes Equations. (arXiv:2005.03148v1 [math.NA])

We propose some new mixed finite element methods for the time dependent stochastic Stokes equations with multiplicative noise, which use the Helmholtz decomposition of the driving multiplicative noise. It is known [16] that the pressure solution has a low regularity, which manifests in sub-optimal convergence rates for well-known inf-sup stable mixed finite element methods in numerical simulations, see [10]. We show that eliminating this gradient part from the noise in the numerical scheme leads to optimally convergent mixed finite element methods, and that this conceptual idea may be used to retool numerical methods that are well-known in the deterministic setting, including pressure stabilization methods, so that their optimal convergence properties can still be maintained in the stochastic setting. Computational experiments are also provided to validate the theoretical results and to illustrate the conceptional usefulness of the proposed numerical approach.




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A Gentle Introduction to Quantum Computing Algorithms with Applications to Universal Prediction. (arXiv:2005.03137v1 [quant-ph])

In this technical report we give an elementary introduction to Quantum Computing for non-physicists. In this introduction we describe in detail some of the foundational Quantum Algorithms including: the Deutsch-Jozsa Algorithm, Shor's Algorithm, Grocer Search, and Quantum Counting Algorithm and briefly the Harrow-Lloyd Algorithm. Additionally we give an introduction to Solomonoff Induction, a theoretically optimal method for prediction. We then attempt to use Quantum computing to find better algorithms for the approximation of Solomonoff Induction. This is done by using techniques from other Quantum computing algorithms to achieve a speedup in computing the speed prior, which is an approximation of Solomonoff's prior, a key part of Solomonoff Induction. The major limiting factors are that the probabilities being computed are often so small that without a sufficient (often large) amount of trials, the error may be larger than the result. If a substantial speedup in the computation of an approximation of Solomonoff Induction can be achieved through quantum computing, then this can be applied to the field of intelligent agents as a key part of an approximation of the agent AIXI.




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Evaluation, Tuning and Interpretation of Neural Networks for Meteorological Applications. (arXiv:2005.03126v1 [physics.ao-ph])

Neural networks have opened up many new opportunities to utilize remotely sensed images in meteorology. Common applications include image classification, e.g., to determine whether an image contains a tropical cyclone, and image translation, e.g., to emulate radar imagery for satellites that only have passive channels. However, there are yet many open questions regarding the use of neural networks in meteorology, such as best practices for evaluation, tuning and interpretation. This article highlights several strategies and practical considerations for neural network development that have not yet received much attention in the meteorological community, such as the concept of effective receptive fields, underutilized meteorological performance measures, and methods for NN interpretation, such as synthetic experiments and layer-wise relevance propagation. We also consider the process of neural network interpretation as a whole, recognizing it as an iterative scientist-driven discovery process, and breaking it down into individual steps that researchers can take. Finally, while most work on neural network interpretation in meteorology has so far focused on networks for image classification tasks, we expand the focus to also include networks for image translation.




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Electricity-Aware Heat Unit Commitment: A Bid-Validity Approach. (arXiv:2005.03120v1 [eess.SY])

Coordinating the operation of combined heat and power plants (CHPs) and heat pumps (HPs) at the interface between heat and power systems is essential to achieve a cost-effective and efficient operation of the overall energy system. Indeed, in the current sequential market practice, the heat market has no insight into the impacts of heat dispatch on the electricity market. While preserving this sequential practice, this paper introduces an electricity-aware heat unit commitment model. Coordination is achieved through bid validity constraints, which embed the techno-economic linkage between heat and electricity outputs and costs of CHPs and HPs. This approach constitutes a novel market mechanism for the coordination of heat and power systems, defining heat bids conditionally on electricity market prices. The resulting model is a trilevel optimization problem, which we recast as a mixed-integer linear program using a lexicographic function. We use a realistic case study based on the Danish power and heat system, and show that the proposed model yields a 4.5% reduction in total operating cost of heat and power systems compared to a traditional decoupled unit commitment model, while reducing the financial losses of each CHP and HP due to invalid bids by up-to 20.3 million euros.




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Deep Learning for Image-based Automatic Dial Meter Reading: Dataset and Baselines. (arXiv:2005.03106v1 [cs.CV])

Smart meters enable remote and automatic electricity, water and gas consumption reading and are being widely deployed in developed countries. Nonetheless, there is still a huge number of non-smart meters in operation. Image-based Automatic Meter Reading (AMR) focuses on dealing with this type of meter readings. We estimate that the Energy Company of Paran'a (Copel), in Brazil, performs more than 850,000 readings of dial meters per month. Those meters are the focus of this work. Our main contributions are: (i) a public real-world dial meter dataset (shared upon request) called UFPR-ADMR; (ii) a deep learning-based recognition baseline on the proposed dataset; and (iii) a detailed error analysis of the main issues present in AMR for dial meters. To the best of our knowledge, this is the first work to introduce deep learning approaches to multi-dial meter reading, and perform experiments on unconstrained images. We achieved a 100.0% F1-score on the dial detection stage with both Faster R-CNN and YOLO, while the recognition rates reached 93.6% for dials and 75.25% for meters using Faster R-CNN (ResNext-101).




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Eliminating NB-IoT Interference to LTE System: a Sparse Machine Learning Based Approach. (arXiv:2005.03092v1 [cs.IT])

Narrowband internet-of-things (NB-IoT) is a competitive 5G technology for massive machine-type communication scenarios, but meanwhile introduces narrowband interference (NBI) to existing broadband transmission such as the long term evolution (LTE) systems in enhanced mobile broadband (eMBB) scenarios. In order to facilitate the harmonic and fair coexistence in wireless heterogeneous networks, it is important to eliminate NB-IoT interference to LTE systems. In this paper, a novel sparse machine learning based framework and a sparse combinatorial optimization problem is formulated for accurate NBI recovery, which can be efficiently solved using the proposed iterative sparse learning algorithm called sparse cross-entropy minimization (SCEM). To further improve the recovery accuracy and convergence rate, regularization is introduced to the loss function in the enhanced algorithm called regularized SCEM. Moreover, exploiting the spatial correlation of NBI, the framework is extended to multiple-input multiple-output systems. Simulation results demonstrate that the proposed methods are effective in eliminating NB-IoT interference to LTE systems, and significantly outperform the state-of-the-art methods.




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Robust Trajectory and Transmit Power Optimization for Secure UAV-Enabled Cognitive Radio Networks. (arXiv:2005.03091v1 [cs.IT])

Cognitive radio is a promising technology to improve spectral efficiency. However, the secure performance of a secondary network achieved by using physical layer security techniques is limited by its transmit power and channel fading. In order to tackle this issue, a cognitive unmanned aerial vehicle (UAV) communication network is studied by exploiting the high flexibility of a UAV and the possibility of establishing line-of-sight links. The average secrecy rate of the secondary network is maximized by robustly optimizing the UAV's trajectory and transmit power. Our problem formulation takes into account two practical inaccurate location estimation cases, namely, the worst case and the outage-constrained case. In order to solve those challenging non-convex problems, an iterative algorithm based on $mathcal{S}$-Procedure is proposed for the worst case while an iterative algorithm based on Bernstein-type inequalities is proposed for the outage-constrained case. The proposed algorithms can obtain effective suboptimal solutions of the corresponding problems. Our simulation results demonstrate that the algorithm under the outage-constrained case can achieve a higher average secrecy rate with a low computational complexity compared to that of the algorithm under the worst case. Moreover, the proposed schemes can improve the secure communication performance significantly compared to other benchmark schemes.




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AVAC: A Machine Learning based Adaptive RRAM Variability-Aware Controller for Edge Devices. (arXiv:2005.03077v1 [eess.SY])

Recently, the Edge Computing paradigm has gained significant popularity both in industry and academia. Researchers now increasingly target to improve performance and reduce energy consumption of such devices. Some recent efforts focus on using emerging RRAM technologies for improving energy efficiency, thanks to their no leakage property and high integration density. As the complexity and dynamism of applications supported by such devices escalate, it has become difficult to maintain ideal performance by static RRAM controllers. Machine Learning provides a promising solution for this, and hence, this work focuses on extending such controllers to allow dynamic parameter updates. In this work we propose an Adaptive RRAM Variability-Aware Controller, AVAC, which periodically updates Wait Buffer and batch sizes using on-the-fly learning models and gradient ascent. AVAC allows Edge devices to adapt to different applications and their stages, to improve computation performance and reduce energy consumption. Simulations demonstrate that the proposed model can provide up to 29% increase in performance and 19% decrease in energy, compared to static controllers, using traces of real-life healthcare applications on a Raspberry-Pi based Edge deployment.




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Guided Policy Search Model-based Reinforcement Learning for Urban Autonomous Driving. (arXiv:2005.03076v1 [cs.RO])

In this paper, we continue our prior work on using imitation learning (IL) and model free reinforcement learning (RL) to learn driving policies for autonomous driving in urban scenarios, by introducing a model based RL method to drive the autonomous vehicle in the Carla urban driving simulator. Although IL and model free RL methods have been proved to be capable of solving lots of challenging tasks, including playing video games, robots, and, in our prior work, urban driving, the low sample efficiency of such methods greatly limits their applications on actual autonomous driving. In this work, we developed a model based RL algorithm of guided policy search (GPS) for urban driving tasks. The algorithm iteratively learns a parameterized dynamic model to approximate the complex and interactive driving task, and optimizes the driving policy under the nonlinear approximate dynamic model. As a model based RL approach, when applied in urban autonomous driving, the GPS has the advantages of higher sample efficiency, better interpretability, and greater stability. We provide extensive experiments validating the effectiveness of the proposed method to learn robust driving policy for urban driving in Carla. We also compare the proposed method with other policy search and model free RL baselines, showing 100x better sample efficiency of the GPS based RL method, and also that the GPS based method can learn policies for harder tasks that the baseline methods can hardly learn.




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Learning, transferring, and recommending performance knowledge with Monte Carlo tree search and neural networks. (arXiv:2005.03063v1 [cs.LG])

Making changes to a program to optimize its performance is an unscalable task that relies entirely upon human intuition and experience. In addition, companies operating at large scale are at a stage where no single individual understands the code controlling its systems, and for this reason, making changes to improve performance can become intractably difficult. In this paper, a learning system is introduced that provides AI assistance for finding recommended changes to a program. Specifically, it is shown how the evaluative feedback, delayed-reward performance programming domain can be effectively formulated via the Monte Carlo tree search (MCTS) framework. It is then shown that established methods from computational games for using learning to expedite tree-search computation can be adapted to speed up computing recommended program alterations. Estimates of expected utility from MCTS trees built for previous problems are used to learn a sampling policy that remains effective across new problems, thus demonstrating transferability of optimization knowledge. This formulation is applied to the Apache Spark distributed computing environment, and a preliminary result is observed that the time required to build a search tree for finding recommendations is reduced by up to a factor of 10x.




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CovidCTNet: An Open-Source Deep Learning Approach to Identify Covid-19 Using CT Image. (arXiv:2005.03059v1 [eess.IV])

Coronavirus disease 2019 (Covid-19) is highly contagious with limited treatment options. Early and accurate diagnosis of Covid-19 is crucial in reducing the spread of the disease and its accompanied mortality. Currently, detection by reverse transcriptase polymerase chain reaction (RT-PCR) is the gold standard of outpatient and inpatient detection of Covid-19. RT-PCR is a rapid method, however, its accuracy in detection is only ~70-75%. Another approved strategy is computed tomography (CT) imaging. CT imaging has a much higher sensitivity of ~80-98%, but similar accuracy of 70%. To enhance the accuracy of CT imaging detection, we developed an open-source set of algorithms called CovidCTNet that successfully differentiates Covid-19 from community-acquired pneumonia (CAP) and other lung diseases. CovidCTNet increases the accuracy of CT imaging detection to 90% compared to radiologists (70%). The model is designed to work with heterogeneous and small sample sizes independent of the CT imaging hardware. In order to facilitate the detection of Covid-19 globally and assist radiologists and physicians in the screening process, we are releasing all algorithms and parametric details in an open-source format. Open-source sharing of our CovidCTNet enables developers to rapidly improve and optimize services, while preserving user privacy and data ownership.




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Evaluating text coherence based on the graph of the consistency of phrases to identify symptoms of schizophrenia. (arXiv:2005.03008v1 [cs.CL])

Different state-of-the-art methods of the detection of schizophrenia symptoms based on the estimation of text coherence have been analyzed. The analysis of a text at the level of phrases has been suggested. The method based on the graph of the consistency of phrases has been proposed to evaluate the semantic coherence and the cohesion of a text. The semantic coherence, cohesion, and other linguistic features (lexical diversity, lexical density) have been taken into account to form feature vectors for the training of a model-classifier. The training of the classifier has been performed on the set of English-language interviews. According to the retrieved results, the impact of each feature on the output of the model has been analyzed. The results obtained can indicate that the proposed method based on the graph of the consistency of phrases may be used in the different tasks of the detection of mental illness.




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Fault Tree Analysis: Identifying Maximum Probability Minimal Cut Sets with MaxSAT. (arXiv:2005.03003v1 [cs.AI])

In this paper, we present a novel MaxSAT-based technique to compute Maximum Probability Minimal Cut Sets (MPMCSs) in fault trees. We model the MPMCS problem as a Weighted Partial MaxSAT problem and solve it using a parallel SAT-solving architecture. The results obtained with our open source tool indicate that the approach is effective and efficient.




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What “Friday Night Tykes” Can Teach Us About Youth Football

Why do some parents and coaches think it's okay to let 9-year-old kids get hit in the head over and over in football practices and games?




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Chronic Traumatic Encephalopathy (CTE) in Amateur Athletes

A new study suggests that vulnerability to CTE is not limited to professional athletes.




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5 Magnificent Examples of Websites That Convert Visitors into Customers

Need some inspiration to build a high converting website? Websites that convert persuade visitors to become customers. These websites drive more revenue, so if you want to increase your site’s revenue, use these examples of websites that convert as inspiration! We’ll go over what makes for the best converting websites and five examples of websites […]

The post 5 Magnificent Examples of Websites That Convert Visitors into Customers appeared first on WebFX Blog.




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Community Solar: The Utility of the Future

By Timothy Schoechle Courtesy of Solar Today A Colorado community is developing a community-based clean energy economy. Boulder, Colorado, sits at the foot of the Rocky Mountains a half-hour drive northwest of Denver. It is a city, but still small … Continue reading




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What’s New With Node? Interview With Bethany Griggs, Node.js Technical Steering Committee

Node.js 14 is available now. We wanted to get more context and details about the state of Node, and why developers should care about Node.js 14. We talked with Bethany Griggs, Node.js Technical Steering Committee member and Open-source Engineer at IBM, to find out more. 

Bethany has been a Node Core Collaborator for over two years. She contributes to the open-source Node.js runtime and is a member of the Node.js Release Working Group where she is involved with auditing commits for the long-term support (LTS) release lines and the creation of releases. 





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The Innovia Foundation's former president has finally won his three-year battle to stop the organization from donating to a racist website

There's one thing the Innovia Foundation can never say: That it hadn't been told.…



  • News/Local News

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The cruelest part of the coronavirus: It's cut us off from community and solace

There’s a cliche that always follows a big tragedy — something we say after natural disasters, economic collapses, school shootings, acts of terrorisms.…



  • Comment/Columns & Letters

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Rationing Protective Gear Means Checking on Coronavirus Patients Less Often. This Can Be Deadly

Low on essential supplies and fearing they’ll get sick, doctors and nurses told ProPublica in-person care for coronavirus patients has been scaled back. In some cases, it’s causing serious harm. By Joshua Kaplan, Lizzie Presser and Maya Miller, ProPublica Every morning, between 7 and 8, at Long Island Jewish Medical Center in Queens, several coronavirus patients are pronounced dead.…



  • News/Nation & World

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Someone's dead and everyone's a suspect in the slight but engaging all-star whodunit Knives Out

[IMAGE-1] Watching Rian Johnson's Knives Out, I was reminded of my middle school English teacher Mrs. Soderbergh, who loved Agatha Christie books almost as much as she loved diagramming sentences. There was a week when she brought in a box stacked high with her own Christie paperbacks, set it down in front of the classroom and had each of us pick a book based solely on the plot summary on the back.…



  • Film/Film News

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As The Rise of Skywalker readies to put a bow on a chapter in Star Wars lore, the franchise's omnipresence has shifted its fandom

With all due respect to Greta Thunberg and Billie Eilish, nobody had a better 2019 than Baby Yoda. The real star of the Disney+ flagship Star Wars series The Mandalorian, the little green puppeteering/CGI marvel (aka "the Child") might be the most adorable creature ever created.…



  • Film/Film News

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Spokane musician Eliza Johnson brought her quirky style — and tinned fish — to American Idol Sunday night. Watch the clip

Back in November, we wrote about local singer-songwriter Eliza Johnson's musical project Eliza Catastrophe and her new album You, which she released on pre-loaded MP3 players. One thing we weren't able to mention in our interview — for contractual reasons — is that she had only a couple months prior auditioned for American Idol, and her performance finally aired on the ABC reality competition show Sunday night.…



  • Music/Music News

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In reimagining a beloved novel, Emma understands what made Jane Austen so special in the first place

[IMAGE-1] Before smartphones and Instagram, there were influencers, and they could be as shallow, overconfident and pejorative as they are today. This new adaptation of Jane Austen's Emma — the feature debuts of photographer and music-video director Autumn de Wilde and Man Booker Prize-winning novelist turned screenwriter Eleanor Catton — brings that sort of modern frisson to its retelling of the tale of a very rich young woman who amuses herself by interfering in the romantic lives of those around her.…



  • Film/Film News

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It's no Pixar classic, but Onward continues the studio's penchant for intelligent, original animated entertainment

What am I supposed to say here?…



  • Film/Film News

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CONCERT ANNOUNCEMENT: Wilco and Sleater-Kinney's co-headlining tour hits Spokane Aug. 6

Earlier this morning, Sleater-Kinney announced on Twitter that they're hitting the road on a co-headlining tour with Wilco this summer. Great news!…




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With a new compilation from his label CorpoRAT Records, Kris Martin gives his roster of local rockers a sonic platform

When he was putting together the latest compilation CD for his label CorpoRAT Records, Kris Martin had intended to hand out promotional discs at Boise's Treefort Music Festival, where several artists from the Spokane label were scheduled to perform, and then officially release the album in April for Record Store Day.…




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New music we love: Fiona Apple's thrilling Fetch the Bolt Cutters is a rush of lacerating lyrics and swirling sonics

You don't have to wander around the internet long before bumping into a rave review of Fiona Apple's new record Fetch the Bolt Cutters: It has inspired breathless acclaim, has already been labeled a masterwork and is notably the first new album in nearly a decade that Pitchfork has assigned a perfect 10/10 rating.…




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White House projects COVID-19 death toll of 3,000 people per day, Washington casinos weigh reopening, and other headlines

ON INLANDER.COM WORLD: Roughly two weeks after Canada's deadliest mass shooting, Prime Minister Justin Trudeau introduced an immediate ban on what he called “military-style assault weapons.”…




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Trump administration models predict near doubling of daily death toll by June

By The New York Times The New York Times Company As President Donald Trump presses for states to reopen their economies, his administration is privately projecting a steady rise in the number of cases and deaths from the coronavirus over the next several weeks, reaching about 3,000 daily deaths June 1, according to an internal document obtained by The New York Times, nearly double from the current level of about 1,750.…



  • Nation & World

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‘You’re 5 years old. Wow!’ Child stopped on highway headed for California

By Johnny Diaz The New York Times Company…



  • Nation & World

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Local distilleries are relying on curbside bottle sales - and small batches of hand sanitizer - to stay afloat

Drink Local In tumultuous times, one thing remains true: People still want their spirits.…



  • Food/Food News

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Live stream the University of Idaho's short film festival on Friday evening

Every spring, audiences in Moscow are typically congregating for the Kino Short Film Festival, an evening of shorts made by the University of Idaho's senior film students. Things being as they are, the Kenworthy Theater won't be open for this year's event, but the U of I will be streaming a virtual version this Friday, May 8, at 6 pm.…



  • Film/Film News

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National unemployment hits 14.7 percent, confusion surrounds Washington's reopening, and other headlines

ON INLANDER.COM NATION: For workers, there's no sign of what "normal is going to look like" in the pandemic economy.…



  • News/Local News

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Melissa Cole delves into new techniques at her Spokane studios

Sometimes when you're fairly well-known, especially for a particular style or product, it's tempting to stick with that style, especially if it's what pays the bills.…




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Shining a light on a lost literary legacy

When I first moved to Spokane just over five years ago, I had no idea what kind of literary hotbed I was making my new home.…




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Best Beer Bar: Community Pint

It's all right there in the name: "Community Pint."…




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Best of Nightlife

Best Sports Bar 24 TAPS BURGERS AND BREWS Welcoming.…




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REVIEW: The Commodores' funky, fun night at Northern Quest

One great thing about seeing "oldies" acts on tour is the vivid reminder you get that groups in the old days really knew how to serve their fans. Take the Commodores, for example, a group with a 52-year-history that swung by Northern Quest Resort & Casino Thursday night.…



  • Music/Music News

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Sugar, spice and everything nice, plus where to find it locally this Valentine's Day

Don't be caught empty-handed (or empty-hearted) this Valentine's Day, coming up Friday, Feb. 14.…



  • Food/Food News

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With ridership declining, we hop on the bus with one big question in mind: Where is the STA headed?

Before my car broke down, I didn't ride the bus.…



  • News/Local News

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Community leaders are feeding Spokane and supporting local restaurants at the same time

As soon as state Rep. Marcus Riccelli returned home from Olympia, he jumpstarted a community-wide effort to feed Spokane constituents deeply affected by the COVID-19 crisis.…



  • Food/Food News

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Unions promise to protect workers, and the coronavirus is demanding they prove it

New TV ads that started airing on morning shows throughout the Spokane region are aimed at grocery shoppers, but they're not hawking deals on cabbage or Cap'n Crunch.…



  • News/Local News

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'We obviously have a Camp Hope 2.0-type situation': photos from Thursday night's homeless camp police confrontation

At around 5:30 pm on Thursday, there were two camps of people set up in Coeur d'Alene Park in Browne's Addition.…



  • News/Local News

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Inland Northwest politicians put pressure on governors, health officials to accelerate reopening

Yesterday, Spokane Mayor Nadine Woodward and other local leaders urged Gov. Jay Inslee to allow Spokane County to open on a different schedule than the rest of the state.  Inslee, however, wouldn't budge.…



  • News/Local News

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Method for continuous production of nitrobenzene

The invention relates to a method for producing nitrobenzene, in which crude nitrobenzene is first produced by nitrating benzene and said crude nitrobenzene is then washed in succession in at least one acid wash, in at least one alkaline wash and in at least one neutral wash, at least one additional wash with an aqueous solution of a potassium salt being interposed between the last alkaline wash and the first neutral wash.




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Method for preparation of aryl poly(oxalkyl) quaternary ammonium compound

A method for preparation of an aryl poly(oxalkyl) quaternary ammonium compound is provided, said method comprising steps of: 1) reacting a phenol with a dihalopolyalkylene ether under the action of a phase transfer catalyst, to obtain an arylpoly(oxalkyl) halide; 2) reacting said arylpoly(oxalkyl) halide with an amination reagent under the action of a phase transfer catalyst, to obtain an arylpoly(oxalkyl) amine; 3) reacting said arylpoly(oxalkyl) amine with an alkylation reagent, to obtain an aryl poly(oxalkyl) quaternary ammonium compound; wherein R1 is H or a C1 to C16 alkyl group, located in the ortho, meta or para position; n is an integer of 2 to 6; R2 is H or a C1 to C16 alkyl group; R3 is H or a C1 to C16 alkyl group; R4 is a C1 to C16 alkyl group; X1 is Br or Cl; X is Cl, Br, or I. The preparation method according to the present invention requires low temperature and low pressure, the reaction time is short, and an overall yield can reach 75%. The operation is simple, the cost is low, and the product can be separated easily and have a purity of pharmaceutical grade, thereby facilitating the large-scale production.