Search results for "CNC"
showing 10 items of 38 documents
Fermented Milk Consumption and Common Infections in Children Attending Day-Care Centers: A Randomized Trial
2016
Supplemental Digital Content is available in the text
Green Nanocomposites-Based on PLA and Natural Organic Fillers
2017
Over the past decades, many efforts have been carried out for the development of novel green nanocomposites based on biopolymers and natural organic nanofillers. Indeed, these nanocomposites could replace some oil-derived polymers and thus helping to overcome environmental problems. In this regard, poly (lactic acid) (PLA) as matrix and polysaccharide nanocrystals (cellulose, chitin, and starch) as bio-based nanoreinforcements are the most promising components to obtain high-performance green nanocomposites. This chapter covers the basic features of PLA and polysaccharide nanocrystals derived from biomass-based raw materials such as cellulose, chitin, and starch. In particular, this chapter…
Theoretical and Experimental Researches Regarding Multilayer Materials Used for Incremental Forming
2014
Although this represents a relatively recent development in the industry, the composite multilayer sheets are currently encountered in almost all industrial domains, due to the density, mechanical strength and energy absorption properties that are higher than those of the blanks realised from a single material. These materials are useful especially in domains such a the automotive industry, where the vehicles must fulfil simultaneously conditions of increased passenger safety, increased comfort, increase of the loading capacity in conditions of a reduced energy consumption. First of all the paper shows the types of multilayer sheets and their areas and areas of use, then the paper analyzes …
Brāķēto detaļu skaita samazināšanas metāla apstrādes uzņēmumā "Exigum"
2022
Bakalaura darbā ar inženiertehnisko projektu ir pētīta metālapstrādes uzņēmuma SIA “Exigum” ražošanas process un tā laikā radušās brāķētās detaļas ar mērķi noteikt šo problēmu rašanās iemeslus un ieviest atbilstošus uzlabojumus ražošanas procesā, lai samazinātu brāķēto detaļu rašanās iespējamību. Pētījums ietver informācijas avotu analīzi par biežākajiem iemesliem brāķētajām detaļām metāla detaļu ražošanā izmantojot CNC iekārtas, uzņēmuma statistikas analīzi par brāķētajām detaļām, piemērotāko ražošanas procesu uzlabojumu izvēli, pamatojoties uz uzņēmuma specifiku, šo uzlabojumu ieviešanu uzņēmuma ražošanas procesā uz noteiktu laiku un statistikas salīdzināšanu pirms un pēc uzlabojumu ievie…
An Efficient NURBS Path Generator for a Open Source CNC
2014
In this paper a NURBS path generator (on the plane XY) is proposed to be developed for those CNC machine tools and robot which are Open Source or Opening Architecture. The goal is to use simple and efficient techniques to manufacture geometries which are very complex, whose main feature is the presence of free-form surfaces and contours. To reach this goal, the NURBS path generator has been optimized in order to enable the user to select among three different options to generate the tool path, using a specific parameter. The three options are respectively called “NURBS interpolation with constant increments of u parameter” (NICU), “NURBS interpolation with constant displacement increments b…
Search for flavor-changing neutral current and lepton-flavor violating decays of D-0 -> l(+)l(-)
2004
We report on a search for the flavor-changing neutral current decays $\Dz\to e^+e^-$ and $\Dz\to\mu^+\mu^-$, and the lepton-flavor violating decay $\Dz\to e^\pm\mu^\mp$. The measurement is based on $122 {fb}^{-1}$ of data collected by the \babar detector at the PEP-II asymmetric $e^+e^-$ collider. No evidence is found for any of the decays. The upper limits on the branching fractions, at the 90 % confidence level, are $1.2\times 10^{-6}$ for $\Dz\to e^+e^-$, $1.3\times 10^{-6}$ for $\Dz\to\mu^+\mu^-$, and $8.1\times 10^{-7}$ for $\Dz\to e^\pm\mu^\mp$.
Primary small cell neuroendocrine carcinoma of the breast: The histogenetic diatribe
2013
The article entitled “Primary small cell neuroendocrine carcinoma of the breast: a report of two cases and review of the literature” by Spinelli et al. [1]. The authors stated that “the histogenesis is still unclear because the presence of neuroendocrine cells in normal breast has not been proved conclusively”. Moreover they reported two histogenetic hypotheses, the first one stating that “small cell neuroendocrine carcinoma (SCNC) is a variant of metaplastic carcinoma arising from a lobular or ductal carcinoma”, the second one claiming that “it is a distinct type of breast carcinoma different from the usual type”. We appreciate this case report and we agree with the authors on the histogen…
Minimal Flavour Violation and Multi-Higgs Models
2010
We propose an extension of the hypothesis of Minimal Flavour Violation (MFV) to general multi-Higgs models without the assumption of Natural Flavour Conservation (NFC) in the Higgs sector. We study in detail under what conditions the neutral Higgs couplings are only functions of V-CKM and propose a MFV expansion for the neutral Higgs couplings to fermions
The Role of Eucalyptus Species on the Structural and Thermal Performance of Cellulose Nanocrystals (CNCs) Isolated by Acid Hydrolysis
2022
Cellulose nanocrystals (CNCs) are attractive materials due to their renewable nature, high surface-to-volume ratio, crystallinity, biodegradability, anisotropic performance, or available hydroxyl groups. However, their source and obtaining pathway determine their subsequent performance. This work evaluates cellulose nanocrystals (CNCs) obtained from four different eucalyptus species by acid hydrolysis, i.e., E. benthamii, E. globulus, E. smithii, and the hybrid En × Eg. During preparation, CNCs incorporated sulphate groups to their structures, which highlighted dissimilar reactivities, as given by the calculated sulphate index (0.21, 0.97, 0.73 and 0.85, respectively). Although the impact o…
2013
Abstract. As part of the CLACE-6 campaign we performed size-resolved CCN measurements for a~supersaturation range of S = 0.079 % to 0.66% at the high-alpine research station Jungfraujoch, Switzerland, in March~2007. The derived effective hygroscopicity parameter κ describing the influence of particle composition on CCN activity was on average 0.23–0.30 for Aitken (50–100 nm) and 0.32–0.43 for accumulation mode particles (100–200 nm). The campaign average value of κ = 0.3 is similar to the average value of κ for other continental locations. When air masses came from southeasterly directions crossing the Po Valley in Italy, particles were much more hygroscopic (κ ≈ 0.42) due to…