A new classification of solvents based on chemometric empirical scale of parameters

1990 ◽  
Vol 55 (3) ◽  
pp. 644-652 ◽  
Author(s):  
Oldřich Pytela

The paper presents a classification of 51 solvents based on clustering in three-dimensional space formed by the empirical scale of PAC, PBC, and PPC parameters designed for interpretation of solvent effect on a model with cross-terms. For the classification used are the clustering methods of the nearest neighbour, of the furthest neighbour, of average bond, and the centroid method. As a result, the solvents have been divided into 8 classes denoted as: I - nonpolar-inert solvents (aliphatic hydrocarbons), IIp - nonpolar-polarizable (aromatic hydrocarbons, tetrachloromethane, carbon disulphide), IIb - nonpolar-basic (ethers, triethylamine), IIIp - little polar-polarizable (aliphatic halogen derivatives, substituted benzenes with heteroatom-containing substituents), IIIb - little polar-basic (cyclic ethers, ketones, esters, pyridine), IVa - polar-aprotic (acetanhydride, dialkylamides, acetonitrile, nitromethane, dimethyl sulfoxide, sulfolane), IVp - polar-protic (alcohols, acetic acid), and V - exceptional solvents (water, formamide, glycol, hexamethylphosphoric triamide). The information content of the individual parameters used for the classification has been determined. The classification is based primarily on solvent polarity/acidity (PAC), less on polarity/basicity (PBC), and the least on polarity/polarizability (PPC). Causal relation between chemical structure of solvent and its effect on the process taking place therein has been established.

1993 ◽  
Vol 155 ◽  
pp. 44-44
Author(s):  
O.S. Yatsyk

Intensities of the observed spectral lines, radio fluxes and Hβ fluxes are used for the classification of planetary nebulae by centroid method of taxonomical analysis. Two variants of classification are proposed. The first one– in the three–dimensional space of relation of intensity of spectral lines He II λ 4686/HeI λ 4471, [OIII] λ 4959+5007/[OII] λ 3726+29, [OIII] λ 4959+5007/[OIII] 4363. The second variants is the classification in the three-dimensional space with cooordinates being radio flux, Hβ flux and [OIII] λ 4959+5007 intensity. The membership of classes (taxons) are presented. In the diagram joining the planetary nebula descriptors pairwise there are regions of complete (or predominant) of nebulae belonging to the same taxon, but there are also some regions of overlap. The corresponding taxons are not isolated but merge continuously into one another.


2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.


i-com ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 67-85
Author(s):  
Matthias Weise ◽  
Raphael Zender ◽  
Ulrike Lucke

AbstractThe selection and manipulation of objects in Virtual Reality face application developers with a substantial challenge as they need to ensure a seamless interaction in three-dimensional space. Assessing the advantages and disadvantages of selection and manipulation techniques in specific scenarios and regarding usability and user experience is a mandatory task to find suitable forms of interaction. In this article, we take a look at the most common issues arising in the interaction with objects in VR. We present a taxonomy allowing the classification of techniques regarding multiple dimensions. The issues are then associated with these dimensions. Furthermore, we analyze the results of a study comparing multiple selection techniques and present a tool allowing developers of VR applications to search for appropriate selection and manipulation techniques and to get scenario dependent suggestions based on the data of the executed study.


2001 ◽  
Vol 43 (6) ◽  
pp. 135-135 ◽  
Author(s):  
J.-U. Kreft ◽  
J. W. Wimpenny

We have simulated a nitrifying biofilm with one ammonia and one nitrite oxidising species in order to elucidate the effect of various extracellular polymeric substance (EPS) production scenarios on biofilm structure and function. The individual-based model (IbM) BacSim simulates diffusion of all substrates on a two-dimensional lattice. Each bacterium is individually simulated as a sphere of given size in a continuous, three-dimensional space. EPS production kinetics was described by a growth rate dependent and an independent term (Luedeking-Piret equation). The structure of the biofilm was dramatically influenced by EPS production or capsule formation. EPS production decreased growth of producers and stimulated growth of non-producers because of the energy cost involved. For the same reason, EPS accumulation can fall as its rate of production increases. The patchiness and roughness of the biofilm decreased and the porosity increased due to EPS production. EPS density was maximal in the middle of the vertical profile. Introduction of binding forces between like cells increased clustering.


2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Samuel T. Leitkam ◽  
Tamara Reid Bush

Detection and quantification of changes in hand function are important for patients with loss of function and clinicians who are treating them. A recently developed model, the weighted fingertip space (WFS) quantifies the hand function of individuals in three-dimensional space and applies kinematic weighting parameters to identify regions of reachable space with high and low hand function. The goal of this research was to use the WFS model to compare and contrast the functional abilities of healthy individuals with the abilities of individuals with reduced functionality due to arthritis (RFA). Twenty two individuals with no reported issues with hand function and 21 individuals with arthritis affecting the hand were included in the research. Functional models were calculated from the ranges of motion and hand dimension data for each individual. Each model showed the volume of reachable space for each fingertip of each hand, the number of ways to reach a point in space, the range of fingertip orientations possible at each point, and the range of possible force application directions (FADs) at each point. In addition, two group models were developed that showed how many individuals in both the healthy and RFA groups were able to reach the same points in space. The results showed differences between the two groups for the range of motion (ROM) measurements, the individual model calculations, and the group models. The ROM measurements showed significant differences for the joints of the thumb, extension of the nonthumb metacarpophalangeal (MCP) joints, and flexion of the distal interphalangeal (DIP) joints. Comparing the models, the two groups qualitatively showed similar patterns of functional measures in space, but with the RFA group able to reach a smaller volume of space. Quantitatively, the RFA group showed trends of smaller values for all of the calculated functional weighting parameters and significantly smaller reachable volume for all of the fingers. The group models showed that all healthy individuals were able to reach an overlapping space, while 18 of 21 RFA individuals were able to reach similar spaces. Combined, the results showed that the WFS model presents the abilities of the hand in ways that can be quantitatively and qualitatively compared. Thus, the potential of this hand model is that it could be used to assess and document the changes that occur in hand function due to rehabilitation or surgery, or as a guide to determine areas most accessible by various populations.


2017 ◽  
Vol 26 (12) ◽  
pp. 1750075
Author(s):  
Dana Rowland

A book representation of a graph is a particular way of embedding a graph in three-dimensional space so that the vertices lie on a circle and the edges are chords on disjoint topological disks. We describe a set of operations on book representations that preserves ambient isotopy, and apply these operations to [Formula: see text], the complete graph with six vertices. We prove there are exactly 59 distinct book representations for [Formula: see text], and we identify the number and type of knotted and linked cycles in each representation. We show that book representations of [Formula: see text] contain between one and seven links, and up to nine knotted cycles. Furthermore, all links and cycles in a book representation of [Formula: see text] have crossing number at most four.


Author(s):  
Roscoe C. Bowen ◽  
Rami Seliktar ◽  
Tariq Rahman ◽  
Michael Alexander ◽  
Mena Scavina

A number of neuropathologies such as Duchenne’s muscular dystrophy (DMD), cause disability in the upper extremity due to the loss of muscle strength. This will eventually prevent the individual from moving their arms in three-dimensional space so it has been proposed that a robotic orthosis could support and augment movement. This orthosis would need to accommodate the movement capabilities of the user. To accomplish this, knowledge of how movements are formed and controlled in the presence of neuromuscular disease needs to be determined. While the arm was supported in a floatation device, DMD subjects were asked to make pointing movements to several targets in the transverse plane. This was done from two start positions while torso movement was constrained and unconstrained. The hand trajectories formed while the torso was constrained were essentially straight but at a cost to the uni-modality of the hand velocity profile. In this configuration the velocity profile contains several phases of acceleration and deceleration producing a multi-modal profile. However, the additional degrees of freedom introduced in the unconstrained torso configuration were employed is such a manner as to produce a smooth uni-modal hand velocity profile.


Neurosurgery ◽  
2006 ◽  
Vol 59 (5) ◽  
pp. 1001-1010 ◽  
Author(s):  
Stefan Wolfsberger ◽  
André Neubauer ◽  
Katja Bühler ◽  
Rainer Wegenkittl ◽  
Thomas Czech ◽  
...  

Abstract OBJECTIVE Virtual endoscopy (vE) is the navigation of a camera through a virtual anatomical space that is computationally reconstructed from radiological image data. Inside this three-dimensional space, arbitrary movements and adaptations of viewing parameters are possible. Thereby, vE can be used for noninvasive diagnostic purposes and for simulation of surgical tasks. This article describes the development of an advanced system of vE for endoscopic transsphenoidal pituitary surgery and its application to teaching, training, and in the routine clinical setting. METHODS The vE system was applied to a series of 35 patients with pituitary pathology (32 adenomas, three Rathke's cleft cysts) operated endoscopically via the transsphenoidal route at the Department of Neurosurgery of the Medical University Vienna between 2004 and 2006. RESULTS The virtual endoscopic images correlated well with the intraoperative view. For the transsphenoidal approach, vE improved intraoperative orientation by depicting anatomical landmarks and variations. For planning a safe and tailored opening of the sellar floor, transparent visualization of the pituitary adenoma and the normal gland in relation to the internal carotid arteries was useful. CONCLUSION According to our experience, vE can be a valuable tool for endoscopic transsphenoidal pituitary surgery for training purposes and preoperative planning. For the novice, it can act as a simulator for endoscopic anatomy and for training surgical tasks. For the experienced pituitary surgeon, vE can depict the individual patient's anatomy, and may, therefore, improve intraoperative orientation. By prospectively visualizing unpredictable anatomical variations, vE may increase the safety of this surgical procedure.


2021 ◽  
Vol 2091 (1) ◽  
pp. 012073
Author(s):  
A V Belov ◽  
N N Trufanov ◽  
D V Churikov ◽  
O V Kravchenko

Abstract The preliminary processing of the signal coming from the vibration sensor is performed. Spectral analysis methods allow identifying the distinctive zones corresponding to three parameters: the average amplitude of vibrations, the average value of the spectrum, and the complex parameter of the vibration density obtained using interpolation methods. Hence, the vector contains the listed parameters as components produce a vector space, and the equations of separating surfaces in three-dimensional space and classification errors are calculated.


2020 ◽  
Vol 12 (22) ◽  
pp. 3757
Author(s):  
Hyunsoo Kim ◽  
Changwan Kim

Conventional bridge maintenance requires significant time and effort because it involves manual inspection and two-dimensional drawings are used to record any damage. For this reason, a process that identifies the location of the damage in three-dimensional space and classifies the bridge components involved is required. In this study, three deep-learning models—PointNet, PointCNN, and Dynamic Graph Convolutional Neural Network (DGCNN)—were compared to classify the components of bridges. Point cloud data were acquired from three types of bridge (Rahmen, girder, and gravity bridges) to determine the optimal model for use across all three types. Three-fold cross-validation was employed, with overall accuracy and intersection over unions used as the performance measures. The mean interval over unit value of DGCNN is 86.85%, which is higher than 84.29% of Pointnet, 74.68% of PointCNN. The accurate classification of a bridge component based on its relationship with the surrounding components may assist in identifying whether the damage to a bridge affects a structurally important main component.


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