High-speed data acquisition for the Princeton University Dynamic Model Track

Real time analysis of data can reduce the time involved in exploring dynamic systems. The failure of the data acquisition system at the Princeton Dynamic Model Track prompted its replacement with a real time data acquisition system. Data can be obtained from an experiment and analyzed during and immediately following a data run. The new system employs high speed analog to digital conversion and a small computer to collect data. Sampling rates of 1000 hertz over 44 channels (44,000 words/sec) are obtainable. The data can be accessed as it enters the computer's environment where it may be displayed or stored for later processing. The system was tested on a helicopter rotor steep descent experiment. The data collected compares with previous data from a similar experiment

OSL chronologies for Aeolian activity in the context of lake-level fluctuations, drainage reorganization and glacial retreat, North-Central Minnesota

Journal ArticleDunes and stratified eolian sedi-ments are a significant component of the postglacial landscape across the mid-continent. During the 1970s, a benchmark study in north-central Minne-sota inferred a period of eolian activity 8,000 ? 5,000 years ago (i.e., the Altithermal Hypsithermal periods), based upon radiocarbon dates on charcoal and organic material preserved within paleosols developed in dunes [1]. We revisited a classic local-ity at Lake Winnibigoshish (N 47?27'; W 94?12'), and sample other dune-forms to hypothesis-test whether eolian landform development occurred dur-ing the middle Holocene. Optical luminescence techniques can better resolve Minnesota's eolian chronologies by directly dating the emplacement of bed forms; sediments are typically oxidized and lack preserved organic materials suitable for 14C dating

On hereditary irreducibility of some monomial matrices over local rings

We consider monomial matrices over a commutative local principal ideal ring $R$ of type $M(t,k,n)=\Phi\left(\begin{smallmatrix}I_k&0\\0\,\,&tI_{n-k}\end{smallmatrix}\right)$, $0<k<n$, where $t$ is a generating element of Jacobson radical $J(R)$ of $R$, $\Phi$ is the companion matrix to $\lambda^n-1$ and $I_k$ is the identity $k\times k$ matrix. In this paper, we indicate a criterion of the hereditary irreducibility of $M(t,k,n)$ in the case $t^{\left[\frac{k\cdot(n-k)}{n}\right]+1}\not=0$

Free n-dinilpotent doppelsemigroups

A doppelalgebra is an algebra defined on a vector space with two binary linear associative operations. Doppelalgebras play a prominent role in algebraic K-theory. In this paper we consider doppelsemigroups, that is, sets with two binary associative operations satisfying the axioms of a doppelalgebra. We construct a freen-dinilpotent doppelsemigroup and study separately freen-dinilpotentdoppelsemigroups of rank 1. Moreover,we characterize the least n-dinilpotent congruence on a free doppelsemigroup, establish that the semigroups of the freen-dinilpotentdoppelsemigroup are isomorphic and the automorphism group of the freen-dinilpotent doppelsemigroup is isomorphic to the symmetric group. We also give different examples of doppelsemigroups andprove that a system of axioms of a doppelsemigroup is independent

ОРТОГОНАЛЬНОЕ ПРЕДСТАВЛЕНИЕ СОБСТВЕННОГО ПРЕОБРАЗОВАНИЯ ПЕРСИММЕТРИЧНОЙ МАТРИЦЫ НА ОСНОВЕ ОПЕРАТОРОВ ВРАЩЕНИЯ

The mathematical substantiation of the algorithm for synthesis of the proper transformation and finding the eigenvalue formulae of a persymmetric matrix of dimension N = 2 k ( k =1, 4 ) based on orthogonal rotation operators is given. The proposed algorithm made it possible to improve the author's approach to calculating eigenvalues based on numerical examples for the maximal dimension of matrices 64×64, resulting the possibility to obtain analytical relations for calculating the eigenvalues of the persymmetric matrix. It is shown that the proper transformation has a factorized structure in the form of a product of rotation operators, each of which is a direct sum of elementary Givens and Jacobian rotation matrices. Приводится математическое обоснование алгоритма синтеза собственного преобразования и нахождения формулы собственных значений персимметричной матрицы размерности N = 2 k ( k =1, 4 ) на основе ортогональных операторов вращения. Предложенный алгоритм позволил усовершенствовать разработанный автором подход к вычислению собственных значений на основе численных примеров для максимальной размерности матриц 64 ´ 64, в результате чего удалось получить аналитические соотношения для вычисления собственных значений персимметричной матрицы. Показывается, что собственное преобразование имеет факторизованную структуру в виде произведения операторов вращения, каждый из которых является прямой суммой элементарных матриц вращения Гивенса и Якоби.

<Session 2: Fish Telemetry II>Expanding from creeks to hydroelectric diversion facilities - Construction and in situ evaluation of large half-duplex PIT tag antennas to evaluate fish entrainment at high velocity water diversions

19–22 May 2020 Kyoto, JapanThe implementation of Passive Integrated Transponder (PIT) technology for monitoring fish has historically required small detection areas in either creeks or constricted openings. Advancements in PIT technology have evolved to allow for much broader applications and larger monitoring areas. Custom fabricated large-scale PIT tag readers were used to estimate entrainment in two diversion tunnels (up to 3.8 m x 4.4 m) that experienced discharge as high as 31.1 cubic meters per second and operated in water depths of up to 6.4 m. The PIT arrays, consisting of three separate antennas stacked one on top of the other, were hand-molded from fiberglass into a hydrodynamic 'wing' shape. This design enabled the antennas to withstand high flows, while simultaneously detecting fish over the entire monitoring area of the diversion tunnels. This also allowed for the diversions to operate at full capacity and not be constrained to a modified smaller detection area. The antenna arrays and tag detection systems achieved optimal performance throughout the duration of the study. The antennas operated continuously for over a year, and monitored upwards of 99.0 percent of all diverted flows through the tunnels due to minimal required maintenance. A total of 220 unique detection events representing 58 fish were observed at the two diversion tunnels and equated to performance efficiency greater than 90 percent. The continuous operation and high detection efficiency achieved by the relatively large-scale PIT arrays confirms the success of this innovative deployment of PIT tag technology that was previously limited to small creeks and monitoring areas

POTENTIAL OF INTERNATIONAL COOPERATION OF UKRAINE IN THE GEOECONOMIC SPACE OF THE TOURIST INDUSTRY

The article defines the dominant criteria for the functional symbiosis of macro-regional and local-regional systems with a large number of producers of tourism products. A macroeconomic model was developed for calculating the integrated index of international cooperation of the country in the European geoeconomic space of the tourism industry based on standardized variable indicators. A detailed analysis of the development of the tourism industry in Ukraine was carried out, with the determination of the scope of tourist flows in the pre-war period and during the war period. The forecast dynamics of the development of the potential of international cooperation of Ukraine in the geo-economic space of macro-regional systems of Europe are provided

Electrochemical Activation of Graphene at Low Temperature: The Synthesis of Three-Dimensional Nanoarchitectures for High Performance Supercapacitors and Capacitive Deionization

An electrochemical technique is developed to activate graphene oxide (GO) at relatively low temperature and assemble it into porous electrodes. The activation process is carried out in molten KOH by switching the polarity between 2 symmetrical GO electrodes. The electrochemically activated graphene (ECAG) showed a specific surface area as high as 2170 m² g^–1 and nanometer-sized pore created at a temperature as low as 450 °C. The ECAG electrode shows a significant enhancement in the electrochemical activity and thus improved electrochemical performance when being used as electrodes in supercapacitors and capacitive deionization (CDI) cells. A specific capacitance of 275 F g^–1 is obtained in 6 M KOH electrolyte, and 189 F g^–1 in 1 M NaCl electrolyte, which maintains 95% after 5000 cycles. The desalination capacity of the electrodes was evaluated by a batch mode electrosorption experiment. The ECAG electrode was able to remove 14.25 mg of salts per gram of the active materials and satisfy a high adsorption rate of 2.01 mg g^–1 min^–1. The low energy consumption of the CDI system is demonstrated by its high charge efficiency, which is estimated to be 0.83