San Francisco Space Saving Bike Rack

Large cities like San Francisco can experience congested streets and crowded sidewalks. Increasing bike ridership has been shown to alleviate some of these pains, but they are currently being undersupported. In order to properly account for the growing cyclist population, more efficient bike storage solutions need to be made available. Current bike racks take up too much space, are not reasonably theft resistant, and are not adaptable to a variety of both indoor and outdoor spaces. In this paper, we designed and constructed a bike rack to take advantage of vertical space in order to reduce the footprint that storing a bike takes. Our experiments showed that by reorienting the bike in an upright position and allowing it to travel along a main column, we were able to significantly reduce the footprint of the bike and bike rack system. Additionally, by using a simple hand wheel and pulley system, we would be able to reduce the amount of force the user would need to exert to hoist the bike upwards with a few modifications. By recognizing that the vertical space above traditional bike racks is often wasted and made unusable, we were able to design a system that maximizes its efficiency to decrease the amount of floor space required to store bikes. Our new and innovative design is a viable solution for crowded cities like San Francisco where square footage is both expensive and limited. With our data showing a possible reduction in footprint of up to 92%, implementing a vertical bike rack design has the potential to drastically change the way people get around the city and secure their individual modes of transportation

Comparison of isoflurane and propofol sedation in critically ill COVID-19 patients-a retrospective chart review

Purpose In this retrospective study, we compared inhaled sedation with isoflurane to intravenous propofol in invasively ventilated COVID-19 patients with ARDS (Acute Respiratory Distress Syndrome). Methods Charts of all 20 patients with COVID-19 ARDS admitted to the ICU of a German University Hospital during the first wave of the pandemic between 22/03/2020 and 21/04/2020 were reviewed. Among screened 333 days, isoflurane was used in 97 days, while in 187 days, propofol was used for 12 h or more. The effect and dose of these two sedatives were compared. Mixed sedation days were excluded. Results Patients’ age (median [interquartile range]) was 64 (60–68) years. They were invasively ventilated for 36 [21–50] days. End-tidal isoflurane concentrations were high (0.96 ± 0.41 Vol %); multiple linear regression yielded the ratio (isoflurane infusion rate)/(minute ventilation) as the single best predictor. Infusion rates were decreased under ECMO (3.5 ± 1.4 versus 7.1 ± 3.2 ml∙h−1; p < 0.001). In five patients, the maximum recommended dose of propofol of 4 mg∙hour−1∙kg−1ABW was exceeded on several days. On isoflurane compared to propofol days, neuro-muscular blocking agents (NMBAs) were used less frequently (11% versus 21%; p < 0.05), as were co-sedatives (7% versus 31%, p < 0.001); daily opioid doses were lower (720 [720–960] versus 1080 [720–1620] mg morphine equivalents, p < 0.001); and RASS scores indicated deeper levels of sedation (− 4.0 [− 4.0 to − 3.0] versus − 3.0 [− 3.6 to − 2.5]; p < 0.01). Conclusion Isoflurane provided sufficient sedation with less NMBAs, less polypharmacy and lower opioid doses compared to propofol. High doses of both drugs were needed in severely ill COVID-19 patients

HyPLC: Hybrid Programmable Logic Controller Program Translation for Verification

Programmable Logic Controllers (PLCs) provide a prominent choice of implementation platform for safety-critical industrial control systems. Formal verification provides ways of establishing correctness guarantees, which can be quite important for such safety-critical applications. But since PLC code does not include an analytic model of the system plant, their verification is limited to discrete properties. In this paper, we, thus, start the other way around with hybrid programs that include continuous plant models in addition to discrete control algorithms. Even deep correctness properties of hybrid programs can be formally verified in the theorem prover KeYmaera X that implements differential dynamic logic, dL, for hybrid programs. After verifying the hybrid program, we now present an approach for translating hybrid programs into PLC code. The new tool, HyPLC, implements this translation of discrete control code of verified hybrid program models to PLC controller code and, vice versa, the translation of existing PLC code into the discrete control actions for a hybrid program given an additional input of the continuous dynamics of the system to be verified. This approach allows for the generation of real controller code while preserving, by compilation, the correctness of a valid and verified hybrid program. PLCs are common cyber-physical interfaces for safety-critical industrial control applications, and HyPLC serves as a pragmatic tool for bridging formal verification of complex cyber-physical systems at the algorithmic level of hybrid programs with the execution layer of concrete PLC implementations.Comment: 13 pages, 9 figures. ICCPS 201

Extracorporeal life support in COVID-19-related acute respiratory distress syndrome: A EuroELSO international survey

Extracorporeal life support (ECLS) is a means to support patients with acute respiratory failure. Initially, recommendations to treat severe cases of pandemic coronavirus disease 2019 (COVID-19) with ECLS have been restrained. In the meantime, ECLS has been shown to produce similar outcomes in patients with severe COVID-19 compared to existing data on ARDS mortality. We performed an international email survey to assess how ECLS providers worldwide have previously used ECLS during the treatment of critically ill patients with COVID-19. A questionnaire with 45 questions (covering, e.g., indication, technical aspects, benefit, and reasons for treatment discontinuation), mostly multiple choice, was distributed by email to ECLS centers. The survey was approved by the European branch of the Extracorporeal Life Support Organization (ELSO); 276 ECMO professionals from 98 centers in 30 different countries on four continents reported that they employed ECMO for very severe COVID-19 cases, mostly in veno-venous configuration (87%). The most common reason to establish ECLS was isolated hypoxemic respiratory failure (50%), followed by a combination of hypoxemia and hypercapnia (39%). Only a small fraction of patients required veno-arterial cannulation due to heart failure (3%). Time on ECLS varied between less than 2 and more than 4 weeks. The main reason to discontinue ECLS treatment prior to patient’s recovery was lack of clinical improvement (53%), followed by major bleeding, mostly intracranially (13%). Only 4% of respondents reported that triage situations, lack of staff or lack of oxygenators, were responsible for discontinuation of ECLS support. Most ECLS physicians (51%, IQR 30%) agreed that patients with COVID-19-induced ARDS (CARDS) benefitted from ECLS. Overall mortality of COVID-19 patients on ECLS was estimated to be about 55%. ECLS has been utilized successfully during the COVID-19 pandemic to stabilize CARDS patients in hypoxemic or hypercapnic lung failure. Age and multimorbidity limited the use of ECLS. Triage situations were rarely a concern. ECLS providers stated that patients with severe COVID-19 benefitted from ECLS

Einfluss von Transportprozessen und Grenzflächenreaktionen in porösen Zink- und Zink-Aluminium-Spritzüberzügen auf die Kinetik der Korrosion in wässrigen Medien

The economic interest in thermal spraying has been increasing in different industrial sectors, in particular due to the intensified process development in recent decades. Thermal sprayed coatings based on zinc and zinc in combination with aluminium, especially with an aluminium content of 15 w.%, are known for their good corrosion protection properties and are already used in the fields of bridges and offshore wind energy devices. The mechanical layer adhesion to the substrate, the lamellar layer structure and the porosity, which can be significantly changed by spraying process, spraying parameters and spraying materials are characteristic for such coatings. Many investigations clearly show that thermally sprayed coatings are subject to an external as well as an internal corrosion attack, whereby the current corrosion models consider the influence of the porosity insufficiently. Investigating this was the aim of this work. For this purpose the porosity and its structural properties were characterized depending on the alloy composition and the layer thickness, their influences on the transport processes were investigated and correlated with the results of corrosion investigations. The influence of porosity on the corrosion behavior of thermally sprayed Zn and ZnAl15 coatings was determined on mechanically uncompressed and mechanically compressed coatings, and the influence of substrate was investigated on coatings with different thicknesses on a steel substrate as well as on isolated coatings. The results of this work contributed to a mathematical model which describes the durability of sprayed Zn and ZnAl15 coatings on steel structures considering the porosity

Oktaventechnik : für Pianoforte / von Eduard Mertke.

119 p. ; 34 cm. I. Abt.: Vorübungen. II. Abt.: 20 Oktaven - Etüden von Kleinmichel, Czerny, Clementi, Schwalm, Kessler, Raff, Chopin. III. Abt.: 153 Zitate aus Meisterwerken