Plant growth, yield and quality of potato crop in relation to potassium fertilization

The present work evaluated the effect of soil (S) and foliage (F) applied potassium on the growth, yield, and quality of potato plants. Potassium was added in soil at the recommended rate for all the treatments combining mineral fertilizers with K-feldspar and biofertilizers, while foliar spraying included the application of potassium citrate (PC), potassium silicate (PS), and monopotassium phosphate (MP). The obtained results showed that plant height was highest following treatment with 100% mineral potassium fertilizer under the foliar application of MP, while the content of P, K, and total carbohydrates in leaves also increased with the same fertilization treatment. On the other hand, the highest values for number of stems and fresh and dry weight per plant, as well as the highest nitrogen content in leaves, were obtained after the addition of mineral potassium fertilizer and the foliar spraying of PC, regardless of the growing season. Yield parameters were positively affected by the combination of mineral potassium fertilizers (100% or 80% K2SO4 + 20% K-feldspar + biofertilizer) and the foliar spraying of MP, while the total nitrogen, protein, amino acids, potassium, phosphorus, and starch content of tubers were positively affected by the same mineral fertilizer treatments combined with foliar spraying of MP or CP. In conclusion, the application of mineral potassium fertilizer with foliar spraying of MP or CP increased most of the plant growth-and tuber chemical composition-related parameters. These results highlight the importance of potassium fertilizer regimes for achieving high tuber yields and improving the quality of tubers in a sustainable and cost-effective manner. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Spectrally efficient DMT transmission over 40 km SMF using an electrically packaged silicon photonic intensity modulator

We demonstrate a record-high spectral efficiency (5b/s/Hz) DMT transmission by using a fully electrically-packaged silicon photonic intensity modulator. We transmit over a 40-km single mode fibre link at a rate of 49.6 Gb/s without the need for any dispersion compensation.</p

The political economy of greek policing:Between neo-liberalism and the sovereign state

This article interrogates historical developments, modern structures and future trends in Greek policing from the viewpoint of contemporary neo-liberal policing and social theory. We argue throughout this article that although neo-liberal thinking has indeed recently crept into the rhetoric and logics of Greek governance, the particular social, geographical and political history of the Hellenic Republic has muted these tendencies significantly for policing. Rather than reflecting changes toward post-Keynesian or postmodern policing, Greece (and Greek policing) is confronted by the basic modernist dilemma of ensuring state integrity both physically in the material military security of its borders and vast coastline, and ideologically in the battle for establishing public trust in the efficiency and effectiveness of government. This article analyzes relevant statutes and offers data on the growth of the Greek police and the relatively small private security sector. We conclude that while it is tempting to point to Greece as an exception to the general theoretical maxim that the provision of policing is fragmenting and de-centring as the state is shrinking, there are more and more examples of the recrudescence, re-emergence and continuing central relevance of the state for security provision in other national contexts

Explorer of Enceladus and Titan (E2T): investigating ocean worlds' evolution and habitability in the solar system

Titan, with its organically rich and dynamic atmosphere and geology, and Enceladus, with its active plume, both harbouring global subsurface oceans, are prime environments in which to investigate the habitability of ocean worlds and the conditions for the emergence of life. We present a space mission concept, the Explorer of Enceladus and Titan (E2T), which is dedicated to investigating the evolution and habitability of These Saturnian satellites. E2T is proposed as a medium-class mission led by ESA in collaboration with NASA in response to ESA's M5 Cosmic Vision Call. E2T proposes a focused payload that would provide in-situ composition investigations and high-resolution imaging during multiple flybys of Enceladus and Titan using a solar-electric powered spacecraft in orbit around Saturn. The E2T mission would provide high-resolution mass spectrometry of the plume currently emanating from Enceladus' south polar terrain and of Titan's changing upper atmosphere. In addition, highresolution infrared (IR) imaging would detail Titan's geomorphology at 50-100 m resolution and the temperature of the fractures on Enceladus' south polar terrain at meter resolution. These combined measurements of both Titan and Enceladus would enable the E2T mission scenario to achieve two major scientific goals: 1) Study the origin and evolution of volatile-rich ocean worlds; and 2) Explore the habitability and potential for life in ocean worlds. E2T's two high-resolution time-of-flight mass spectrometers would enable resolution of the ambiguities in chemical analysis left by the NASA/ESA/ASI Cassini-Huygens mission regarding the identification of low-mass organic species, detect high-mass organic species for the first time, further constrain trace species such as the noble gases, and clarify the evolution of solid and volatile species. The high-resolution IR camera would reveal the geology of Titan's surface and the energy dissipated by Enceladus' fractured south polar terrain and plume in detail unattainable by the Cassini mission

Unified State Model theory and application in astrodynamics

The Unified State Model is a method for expressing orbits using a set of seven elements. The elements consist of a quaternion and three parameters based on the velocity hodograph. A complete derivation of the original model is given in addition to two proposed modifications. Both modifications reduce the number of state elements from seven to six by replacing the quaternion with either modified Rodrigues parameters or the Exponential Map. Numerical simulations comparing the original Unified StateModel, the Unified State Model with modified Rodrigues parameters, and the Unified State Model with Exponential Map, with the traditional Cartesian coordinates have been carried out. The Unified StateModel and its derivatives outperform the Cartesian coordinates for all orbit cases in terms of accuracy and computational speed, except for highly eccentric perturbed orbits. The performance of the Unified State Model is exceptionally better for the case of orbits with continuous lowthrust propulsion with CPU simulation time being an order of magnitude lower than for the simulation using Cartesian coordinates. This makes the Unified State Model an excellent state propagator for mission optimizations.Aerospace Engineerin