Search results for "SAW"
showing 10 items of 204 documents
Sulfur-free pulping of hot-water-extracted spruce sawdust
2016
Softwood (Picea abies) sawdust was hot-water-extracted with two multi-phase processes (160-180°C, 100-280 min, and liquor-to-wood ratio 5 l/kg) corresponding to P-factors of ~780 (yield 80.0%) and ~4580 (yield 72.4%). The pre-treated materials were then pulped with the soda-AQ cooking (170°C, NaOH charge 20%, AQ charge 0.1%, 30-150 min, and liquor-to-wood ratio 5 l/kg), resulting in a yield range of 36.1-61.4% (for reference cooks without pre-extraction 47.9-60.0%). It was observed that the pre-extraction under moderate conditions enhanced the dissolution especially of large-molar-mass lignin during cooking, and the total amount of the dissolved lignin was also higher than that removed from…
Developing Online Collaborative Games for e-Learning Environments
2014
Based on our experience, we believe that games, competition and teamwork offer a pleasant and active way of learning. This is much more efficient when the learner has a smile on his face, when he is astonished and curious about next levels and finds the game sufficiently challenging and fun to try again. Our application proposal has the purpose of implementing an e-Learning platform for improving the teaching and learning process in somewhat abstract domains, such as computer architecture or object oriented programming, with the help of games. These games are time-dependent and are able to support collaboration between groups. To this date there are two learning games implemented: a crosswo…
Algorithms for permutability in finite groups
2013
In this paper we describe some algorithms to identify permutable and Sylow-permutable subgroups of finite groups, Dedekind and Iwasawa finite groups, and finite T-groups (groups in which normality is transitive), PT-groups (groups in which permutability is transitive), and PST-groups (groups in which Sylow permutability is transitive). These algorithms have been implemented in a package for the computer algebra system GAP.
The Inverse Seesaw Family: Dirac And Majorana
2021
After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking "$\mu$-terms". These models can be tested both in colliders and with the observation of lepton flavour violating processes.
Gravitational footprints of massive neutrinos and lepton number breaking
2020
We investigate the production of primordial Gravitational Waves (GWs) arising from First Order Phase Transitions (FOPTs) associated to neutrino mass generation in the context of type-I and inverse seesaw schemes. We examine both "high-scale" as well as "low-scale" variants, with either explicit or spontaneously broken lepton number symmetry $U(1)_L$ in the neutrino sector. In the latter case, a pseudo-Goldstone majoron-like boson may provide a candidate for cosmological dark matter. We find that schemes with softly-broken $U(1)_L$ and with single Higgs-doublet scalar sector lead to either no FOPTs or too weak FOPTs, precluding the detectability of GWs in present or near future measurements.…
Reloading the Axion in a 3-3-1 setup
2020
We generalize the idea of the axion to an extended electroweak gauge symmetry setup. We propose a minimal axion extension of the Singer-Valle-Schechter (SVS) theory, in which the standard model fits in $\mathrm{SU(3)_L\otimes U(1)_X}$, the number of families results from anomaly cancellation, and the Peccei-Quinn (PQ) solution to the strong-CP problem is implemented. Neutrino masses arise from a type-I Dirac seesaw mechanism, suppressed by the ratio of SVS and PQ scales, suggesting the existence of new physics at a moderate SVS scale. Novel features include an enhanced axion coupling to photons when compared to the DFSZ axion, as well as flavour-changing axion couplings to quarks.
Income and expenses of Jan Karol Chodkiewicz (1686–1712), starost of Veliuona, Zabłudów, Baisogala and Daugeliskis, relating to his schooling in Wars…
2021
Postać Jana Karola Chodkiewicza (1686–1712) z linii supraskiej nie doczekała się do tej pory swojego opracowania choćby w postaci noty biograficznej. Artykuł niniejszy przybliża więc wybrany fragment z życiorysu wyżej wymienionego bohatera, który w latach 1700–1705 przebywał na naukach w szkole jezuickiej w Warszawie. Okres nauk stanowił ważne wydarzenie w życiu młodych magnatów, którzy w ich ramach przygotowywali się do służby państwowej i funkcjonowania w społeczeństwie szlacheckim. Nie inaczej było w przypadku Jana Karola, dziedzica ogromnej fortuny chodkiewiczowskiej, który resztę swojego krótkiego życia spędził później na sporach o dobra ojczyste. Młody starosta pobierał nauki w trudny…
Analysis of dust exposure during chainsaw forest operations
2017
Abstract: In 1999, the European Union proclaimed hardwood dust carcinogenic based on the classification of the International Agency for Research on Cancer (IARC) issued in 1995. The operational exposure limit (OEL) for inhalable wood dust has been set to 5 mg m-3 by EU directives, though in different countries the OEL ranges from 1 to 5 mg m-3. The objective of this study was to determine the exposure to wood dust of forest workers in chainsaw cutting and processing and suggest possible countermeasures. The study took into consideration different silvicultural treatments (coppice clear cut, conifer thinning, conifer pruning, and sanitary cut) and chainsaw fuel (normal two-stroke gasoline mi…
"Agezylausz" jako "Agis Spartańczyk" : nieznany odpis dramatu Juliusza Słowackiego
2016
Agis Spartańczyk (Agis the Spartan), classified in catalogues, bibliographies, and digital libraries, as an original play by Ksawery Godebski, proves to be a copy of Agezylausz Agesilaus), a late play by Juliusz Słowacki, which remained unpublished during the poet’s lifetime. The copy is not even made with Godebski’s hand, and bears no marks proving that it has been in fact written by him. It is, however, apparent, that it has been based on Słowacki’s own manuscript, as it copies its layout, which has been subject to modification in subsequent editions. At the same time it also introduces changes to the text, which at times appear to be mistakes of the copyist, while in other cases appear a…
Działalność Zagranicznego Komitetu Odbudowy Zamku Królewskiego w Warszawie (1967–1972)
2018
Zdecydowana większość emigracyjnych elit politycznych zajęła negatywne stanowisko w sprawie zbiórki pieniędzy na restytucję Zamku Królewskiego w Warszawie. W 1. połowie lat 70. XX w. na całym świecie działało jednak kilkadziesiąt komitetów i organizacji polonijnych wspierających ową inicjatywę, najwięcej w Stanach Zjednoczonych, Australii, we Francji i w Kanadzie. Chronologicznie pierwszy tego typu komitet zawiązał się jeszcze w czerwcu 1967 r. w Londynie, na kilka lat przed decyzją władz PRL w sprawie podniesienia z ruin byłej siedziby królewskiej. Przewodniczącym Zagranicznego Komitetu Odbudowy Zamku Królewskiego w Warszawie został Ignacy Czaykowski. W skład komitetu weszły osoby, które w…