Self-sorting in two-dimensional assemblies of simple chiral molecules

Structural modification of adsorbed overlayers by means of external factors is an important objective in the fabrication of stimuli-responsive materials with adjustable physicochemical properties. In this contribution we present a coarse-grained Monte Carlo model of the confinement-induced chiral self-sorting of hockey stick-shaped enantiomers adsorbed on a triangular lattice. It is assumed that the adsorbed overlayer consists of "normal" molecules that are capable of adopting any of the six planar orientations imposed by the symmetry of the lattice and molecular directors having only one permanent orientation, that reflect the coupling of these species with an external directional field. Our investigations focus on the influence of the amount fraction of the molecular directors, temperature and surface coverage on the extent of the chiral segregation. The simulated results demonstrate that the molecular directors can have a significant effect on the ordering in enantiopure overlayers, while for the corresponding racemates their role is largely diminished. These findings can be helpful in designing strategies to improve methods of fabrication of homochiral surfaces and enantioselective adsorbents.Comment: 10 pages, 8 figure

High dispersion observations of Venus during 1972. The CO2 band at 7820 angstrom

Photographic plates of Venus which show the spectrum of the carbon dioxide band at 7820A were obtained at Table Mountain Observatory in September-October 1972. These spectra showed a semi-regular 4-day variation in the CO2 abundance over the disk of the planet. Evidence for temporal variations in the rotational temperature of this band and temperature variations over the disk was found. The two quantities, CO2 abundance and temperature, do not show any obvious relationship; however, an increase in the temperature usually is accompanied by a decrease in the abundance of CO2. The average temperature, found from a curve of growth analysis assuming a constant CO2 line of width, is 249 plus or minus 1.4 K (one standard deviation)

High-dispersion spectroscopic observations of Venus during 1968 and 1969 II. The carbon-dioxide band at 8689A

Thirty well-exposed photographic plates showing the spectrum of the carbon dioxide band at 8689A in the atmosphere of Venus were obtained during 1968 and 1969. All spectra were obtained at a dispersion of 2 A/mm for Venus phase angles varying from 10 deg. to 126 deg. Rotational temperatures ranging from 236 K to 274 K were found. The average value of the rotational temperature is 246 + or - 1 K (one standard deviation); for 1967 observations, the rotational temperatures ranged from 222 to 248 K, with an average value of 238 + or - 4 K. The variation of the equivalent width of the 8689A band, with Venus phase angle, was very similar for the two sets of observations (53 plates). The temporal variations, of approximately 30 percent, were comparable with the phase variations over this limited range of phase angle

Własności monady i diady w "Theologumena arithmeticae" przypisywanej Jamblichowi z Chalkis

The paper presents characteristics of the monad and dyad which might be found in aritmological treatise attributed to Iamblichus Chalcidensis. The treatise deals with the nature of and relation between principles of numbers — the monad and dyad. It contains mathematical analyses linked with traditional Greek theology, and ontological characteristics of the principles are derived even from etymological arguments. The treatise presents many problems, final solutions of which, for historical reasons, needs to remain guesswork. It is probable that Iamblichus, because of his attention for Pythagoreism, addressing the claism of Nicomachus, Antonius and “the ancients”, was in fact presenting also fragment of his own teaching concerning numbers and principles which organise the universe

Open, sesame! Introducing access control to voice services

Personal voice assistants (VAs) are shown to be vulnerable against record–and–replay, and other acoustic attacks which allow an adversary to gain unauthorized control of connected devices within a smart home. Existing defenses either lack detection and management capabilities or are too coarse-grained to enable flexible policies on par with other computing interfaces. In this work, we present Sesame, a lightweight framework for edge devices which is the first to enable fine-grained access control of smart-home voice commands. Sesame combines three components: Automatic SpeechRecognition, Natural Language Understanding (NLU) and a Policymodule. We implemented Sesame on Android devices and demonstrate that our system can enforce security policies for both Alexa and Google Home in real-time (362ms end-to-end inference time), with a lightweight (<25MB) NLU model which exhibits minimal accuracy loss compared to its non-compact equivalent

Koncepcja monopsychizmu a wymiary bytowania w "Enneadach" Plotyna

The paper deals with the relation between the individual soul and the Soul taken as the hypostasis. This relation is the crucial element of Plotinus’ psychology and anthropology. It enables the explanation of the possibility of crossing the connection of a man with his body and finding the beyond-individual realms of being. In this way Plotinus presents various levels of self-knowledge of the self as different levels of its identity, from the level of body and senses, through the noetic dimension, to unio mystica

From C/Mrkos to P/Halley: 30 years of cometary spectroscopy

An Atlas of Cometary Spectra was compiled, as a sequel to the well-known Atlas published by Swings and Haser in 1956. The new atlas comprises some 400 reproductions of cometary spectra secured in the world's largest observatories during the three decades or so from the passage of comet Mrkos 1957 V, for which the very first high-dispersion spectrum was obtained, to the return of Halley's comet. The illustrations refer to 40 different comet apparitions; they are grouped into a set of 186 loose 11 x 14 in. plates, while the texts, comments, and relevant data are given in a separate booklet. The main purpose of this atlas is to show in detail the tremendous progress which was achieved in cometary spectroscopy during the period covered, essentially thanks to the use of high-resolution coude spectrographs and large telescopes, the considerable extension of the observed wavelength range, and the advent of electronic detectors. It is divided into two parts. Part 1, which contains about two-thirds of the selected material, presents photographic spectra, while electronically recorded spectra covering the vacuum ultraviolet, through the optical, infrared, and radio regions appear in Part 2

O filozofii, która stała się matematyką. Recenzja książki Bogdana Dembińskiego: „Późny Platon i Stara Akademia.” Kęty: Wydawnictwo Marek Derewiecki, 2010

Recenzja książki Bogdana Dembińskiego: „Późny Platon i Stara Akademia.” Kęty: Wydawnictwo Marek Derewiecki, 201

Problem antywartości w filozofii Plotyna

Jedną z wyróżniających cech filozofii starożytnej jest jedność dociekań ontologicznych i etyczno-aksjologicznych1. Nierozdzielność i wzajemna komplementarność tych perspektyw, znamionująca refleksję Greków, znajduje wyraz już w jej najwcześniejszych postaciach, wyrażając tym samym pierwotne doświadczenie ładu kosmicznego, którego uczestnik — człowiek — doświadcza zarazem jako doskonałości i dobroci. Filozofia Plotyna nie stanowi wyjątku od nakreślonego paradygmatu myślenia, a nawet może być postrzegana jako zwieńczenie długiej tradycji poszukiwania transcendentnego ugruntowania jedności bytu i dobra2. Plotyńska teoria Jedna-Dobra jako pryncypium określoności, poznawalności i dobroci stanowi właściwie rozwinięcie podstawowej intuicji Platońskiej wyrażonej między innymi w paradygmatycznym wartościowaniu, obecnym w słynnej metaforze jaskini z Państwa (515 b—518 d), w której perspektywa epistemologiczna i perspektywa ontologiczna zbiegają się wyraźnie z imperatywem etycznym i wskazaniami społecznymi3. Jedno-Dobro, które jest źródłem bytowości, poznawalności, uporządkowania duszy i państwa (sc. duszy w skali makrokosmicznej), odsłania zarazem teleologiczną perspektywę ludzkiego życia