BILSAT: Advancing Smallsat Capabilities

Small spacecraft technologies and capabilities are evolving to the point where the BILSAT 120kg spacecraft will this year demonstrate capabilities and performance similar to the 320kg UoSAT-12 mission launched in 1999. Over the past few years, the design of small satellites has evolved from simple curiosities to effective, high performance systems, capable of competing with much bigger and much more expensive spacecraft. Within the framework of an agreement between SSTL and TUBITAK-BILTEN (The Information Technologies and Electronics Research Institute), a non-profit government laboratory located in Ankara, Turkey, a Technology Transfer Program was started in August 2001. This program includes the design, manufacture and launch of one Enhanced SSTL microsatellite platform, one engineering model for use in Turkey and the training of engineers in all aspects of the spacecraft design. Detailed design began using the Enhanced SSTL microsatellite platform as the starting point. The end product that will be launched in the summer of 2003, is the most advanced spacecraft ever designed by SSTL, carrying two advanced payloads developed by TUBITAK-BILTEN. The spacecraft is a highly optimised satellite, with a mass of 120kg and including 14 cameras (in several imager arrangements), a 10m/s class resistojet propulsion system, VHF/UHF and S-band RF systems, tried and tested OBDH units in parallel with newly designed mass data storage and processing units, all this topped by a high performance AODCS subsystem, including two star trackers, GPS receiver (for both orbit and attitude determination), rate gyros, four momentum/reaction wheels, and what will be the first operational use of Control Momentum Gyros on a small spacecraft, to perform high agility manoeuvres. These units will be used to achieve the missions specified for this project, mainly full imaging of Turkey, stereoscopic imaging of selected targets, a Digital Elevation Map of Turkey, and communications. The present paper discusses briefly the technical characteristics of the spacecraft, but focuses on the mission aspects and how the different subsystems (namely the new subsystems and payloads) will be used to accomplish the mission. The operational modes of the spacecraft are discussed and the interaction of the AODCS subsystem with the OBDH and Imaging system is described in detail

Jovanka kommt an! Stadtgestaltung für einen inklusiven Campus Lichtwiese. Städtebaulicher Entwurf im Sommersemester 2017.

Der TU Darmstadt Campus Lichtwiese wird sich in den nächsten Jahrzehnten stark entwickeln. Zur Debatte stehen eines neues Mobilitätskonzept, die Neuordnung der Freiflächen und Nachverdichtung durch studentisches Wohnen. In Rahmen des Entwurfs sollen in Zusammenarbeit mit Studierenden mit eingeschränkter Mobilität, Seh- oder Höreinschränkung, und Newcomern in Darmstadt Konzepte entwickelt werden, die Zugänglichkeit und Aufenthaltsqualität des Campus (für eine der Gruppen) im Sinne des Universal Design und des Access for All erhöhen

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Getting the most out of macroeconomic information for predicting excess stock returns

This paper documents the fact that the factors extracted from a large set of macroeconomic variables contain information that can be useful for predicting monthly US excess stock returns over the period 1975–2014. Factor-augmented predictive regression models improve upon benchmark models that include only valuation ratios and interest rate related variables, and possibly individual macro variables, as well as the historical average excess return. The improvements in out-of-sample forecast accuracy are significant, both statistically and economically. The factor-augmented predictive regressions have superior market timing abilities, such that a mean–variance investor would be willing to pay an annual performance fee of several hundreds of basis points to switch from the predictions offered by the benchmark models to those of the factor-augmented models. One important reason for the superior performance of the factor-augmented predictive regressions is the stability of their forecast accuracy, whereas the benchmark models suffer from a forecast breakdown during the 1990s