1,073 research outputs found
Nanocellulose Fragmentation Mechanisms and Inversion of Chirality from the Single Particle to the Cholesteric Phase
Understanding how nanostructure and nanomechanics influence physical material
properties on the micro- and macroscale is an essential goal in soft condensed
matter research. Mechanisms governing fragmentation and chirality inversion of
filamentous colloids are of specific interest because of their critical role in
load-bearing and self-organizing functionalities of soft nanomaterials. Here we
provide a fundamental insight into the self-organization across several length
scales of nanocellulose, an important bio-colloid system with wide-ranging
applications as structural, insulating and functional material. Through a
combined microscopic and statistical analysis of nanocellulose fibrils at the
single particle level, we show how mechanically and chemically induced
fragmentation proceed in this system. Moreover, by studying the bottom-up
self-assembly of fragmented carboxylated cellulose nanofibrils into cholesteric
liquid crystals, we show via direct microscopic observations, that the
chirality is inverted from right-handed at the nanofibril level to left-handed
at the level of the liquid crystal phase. These results improve our fundamental
understanding of nanocellulose and provide an important rationale for their
application in colloidal systems, liquid crystals and nanomaterials
NEW METHODS OF PRODUCT CLASSIFICATION FOR COMPUTER AIDED PROCESS PLANNING SYSTEMS
Classification of engineering parts is a very demanding activity especially in process planning. It is one of the important methods utilised in the group technology approach to computer aided process planning. This paper deals with a new method of classification, which extends the possibility of engineering part classification, especially for the process planning of non-cutting processes (forging, casting, etc.
Mjerenje desorpcije iz polikristalnog sloja TiO2 u nitnim žaruljama
The pressure increase due to the desorption was measured in closed vacuum systems of incandescent lamps with tungsten filament. The inside surface of the glass bulbs was covered with light diffusing layer of TiO2. Pressure differences were measured in clear lamps and lamps frosted with TiO2. Desorption was stimulated by increasing the temperature for fixed intervals of time. Pressure was determined from the filament I-V characteristics that were transformed to a linear plot. At 210 °C, desorption was approximately four times higher in TiO2 coated lamps than in clear lamps.Povećanje tlaka zbog desorpcije mjereno je u zatvorenim vakuumskim žarulja s volframovom niti. Unutarnja strana stijenki bila je prekrivena svjetlo-difuznim slojem TiO2. Uspoređivale su se prozirne i ’bijele’ žarulje. Desorpcija je stimulirana zagrijavanjem tijekom određenog intervala vremena. Tlak se mjerio određivanjem I −V karakteristika žarne niti. Pri 210 ◦C ustanovljeno je da je desorpcija iz žarulja s TiO2 oko četiri puta veća nego u prozirnim žaruljama
VALIDATION OF THE SERVICEABILITY OF THE MANUFACTURING SYSTEM USING SIMULATION
This article discusses the creation and use of known algorithms in production that uses a flow-shop system to monitor and verify its operability. It also describes the input data, which must be further opportunities for decision entered into the system. In the next section are described in detail the different parts of this procedure. Than it describes the sequential problems that are not yet at a practical level, few addressed, but thus methods shorten the processing time. The conclusion focuses on the validation of the serviceability of the manufacturing system using knowledge mentioned and their embedding and verification by simulation
Rastlinske združbe visokih steblik in trav razreda Mulgedio-Aconitetea v subalpinskem pasu gorovja Krivánska Malá Fatra (Slovaška)
The following paper reports the results of phytosociological research of tall-herb and tall-herb plant communities within the class Mulgedio-Aconitetea in the subalpine belt of the Krivánska Malá Fatra Mts. The data set of 209 relevés was sampled and analysed using numerical classification and ordination. Major ecological gradients were interpreted using Ellenberg’s indicator values and the Shannon-Wiener diversity index. Ten associations within five alliances were distinguished and characterised: Aconitetum firmi, Digitali ambiguae-Calamagrostietum arundinaceae, Helianthemo grandiflorae-Calamagrostietum arundinaceae, Potentillo aurei-Calamagrostietum arundinaceae, Allio victorialis-Calamagrostietum villosae, Festucetum carpaticae, Adenostylo alliariae-Athyrietum alpestris, Aconito firmi-Adenostyletum alliariae, Geranio robertiani-Delphinietum elati and Aconito firmi-Rumicetum alpini. Relationships between the floristic composition of the communities and environmental variables were analysed by canonical correspondence analysis.V članku so prikazani rezultati fitocenološke raziskave rastlinskih združb visokih steblik in trav razreda Mulgedio- Aconitetea v subalpinskem pasu gorovja Krivánska Malá Fatra. Podatkovni niz sestavlja 209 popisov, ki smo jih analizirali z numerično klasifikacijo in ordinacijo. Glavne ekološke gradiente smo interpretirali z Ellenbergovimi indikacijskimi vrednostmi in Shannon-Wienerjevim indeksom diverzitete. Ločili smo deset asociacij znotraj petih zvez in jih opisali: Aconitetum firmi, Digitali ambiguae-Calamagrostietum arundinaceae, Helianthemo grandiflorae-Calamagrostietum arundinaceae, Potentillo aurei-Calamagrostietum arundinaceae, Allio victorialis-Calamagrostietum villosae, Festucetum carpaticae, Adenostylo alliariae-Athyrietum alpestris, Aconito firmi-Adenostyletum alliariae, Geranio robertiani-Delphinietum elati in Aconito firmi-Rumicetum alpini. Povezavo med vrstno sestavo rastlinskih združb in rastiščnimi dejavniki smo analizirali s kanonično korespondenčno analizo
Effective ecological and cheap heating of dwelling spaces
The sustainability of human civilization depends largely on green energy management. This work represents one way to achieve this goal. The work is devoted to converting microwave radiation to heat. The article analyses different ways of heating residential and utility areas. Materials suitable for converting microwave radiation to heat from ceramic composites, concretes, fire clays, and bauxite with water glass are enclosed. For all materials we have measured DTA/TG (Differential Thermal Analysis/Thermogravimetric Analysis) curves, XRD (X-Ray Diffraction) patterns, chemical composition of samples, the specific heat capacity c(p) [J/kg.K], thermal conductivity k [W/m.K] and diffusivity alpha [m(2)/s(-1)]. The cooling curves of these materials after microwave heating are characterized in detail. The paper also presents a description and construction of a microwave reactor together with the parameters of the living space heating.Web of Science121art. no. 5
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