Determination of bile salt critical micellization concentration on the road to drug discovery

2014 ◽  
Vol 87 ◽  
pp. 62-81 ◽  
Author(s):  
Benedetto Natalini ◽  
Roccaldo Sardella ◽  
Antimo Gioiello ◽  
Federica Ianni ◽  
Alessandro Di Michele ◽  
...  
1949 ◽  
Vol 22 (1) ◽  
pp. 259-262
Author(s):  
J. F. Morley

Abstract These experiments indicate that softeners can influence abrasion resistance, as measured by laboratory machines, in some manner other than by altering the stress-strain properties of the rubber. One possible explanation is that the softener acts as a lubricant to the abrasive surface. Since this surface, in laboratory abrasion-testing machines, is relatively small, and comes repeatedly into contact with the rubber under test, it seems possible that it may become coated with a thin layer of softener that reduces its abrasive power. It would be interesting in this connection to try an abrasive machine in which a long continuous strip of abrasive material was used, no part of it being used more than once, so as to eliminate or minimize this lubricating effect. The fact that the effect of the softener is more pronounced on the du Pont than on the Akron-Croydon machine lends support to the lubrication hypothesis, because on the former machine the rate of wear per unit area of abrasive is much greater. Thus in the present tests the volume of rubber abraded per hr. per sq. cm. of abrasive surface ranges from 0.03 to 0.11 cc. on the du Pont machine and from 0.0035 to 0.0045 cc. on the Akron-Croydon machine. On the other hand, if the softener acts as a lubricant, it would be expected to reduce considerably the friction between the abrasive and the rubber and hence the energy used in dragging the rubber over the abrasive surface. The energy figures given in the right-hand columns of Tables 1 and 3, however, show that there is relatively little variation between the different rubbers. As a test of the lubrication hypothesis, it would be of interest to vary the conditions of test so that approximately the same amount of rubber per unit area of abrasive is abraded in a given time on both machines; this should show whether the phenomena observed under the present test conditions are due solely to the difference in rate of wear or to an inherent difference in the type of wear on the two machines. This could most conveniently be done by considerably reducing the load on the du Pont machine. In the original work on this machine the load was standardized at 8 pounds, but no figures are quoted to show how abrasion loss varies with the load. As an addition to the present investigation, it is proposed to examine the effect of this variation with special reference to rubbers containing various amounts and types of softener. Published data on the influence of softeners on the road wear of tire rubbers do not indicate anything like such large effects as are shown by the du Pont machine. This throws some doubt on the value of this machine for testing tire tread rubbers, a conclusion which is confirmed by information obtained from other workers.


Author(s):  
Jos A. Romero ◽  
Miguel Marti´nez ◽  
Alejandro Lozano

Friction between cargo and vehicle’s deck has been considered among the supplemental means for securing cargo. Although friction coefficients have been determined as a function of different influencing factors, such measurements have been performed under laboratory controlled conditions that simplify vehicle vibration and cargo-deck stiffness and contact characteristics. In this paper a methodology is proposed to quantify cargo-deck friction coefficients under realistic field conditions throughout the kinematical analysis of the stopping of the cargo-carrying vehicle by effects of dragging the cargo on the vehicle’s platform. The vehicle is located on an inclined road segment while the cargo is lashed to a fixed point on the road, in such a manner that the vehicle can travel a certain distance before the lashing becomes tensioned and the cargo starts stopping the vehicle. While average values for friction coefficients correlated well with those reported in the literature, standard deviations represented up to 33% of such average values.


Author(s):  
Daniil A. Loktev ◽  
Alexey A. Loktev ◽  
Alexandra V. Salnikova ◽  
Anna A. Shaforostova

This study is devoted to determining the geometric, kinematic and dynamic characteristics of a vehicle. To this purpose, it is proposed to use a complex approach applying the models of deformable body mechanics for describing the oscillatory movements of a vehicle and the computer vision algorithms for processing a series of object images to determine the state parameters of a vehicle on the road. The model of the vehicle vertical oscillations is produced by means of the viscoelastic elements and the dry friction element that fully enough represent the behavior of the sprung masses. The introduced algorithms and models can be used as a part of a complex system for monitoring and controlling the road traffic. In addition, they can determine both the speed of the car and its dynamic parameters and the driving behavior of the individual drivers.


Author(s):  
Чирков ◽  
E. Chirkov ◽  
Дорохин ◽  
S. Dorokhin ◽  
Скрыпников ◽  
...  

This article describes the relevance of road transport under current conditions in the region of a transport hub. Established transit factor, let-conductive to determine the optimal value of the extra-urban transit from the total intensity-sti movement. Submitted economic calculations of the cost of work on transportation, taking into account speed limits. Recommended cost performance of all modes of transport that are formed on the main roads


1883 ◽  
Vol 10 (5) ◽  
pp. 199-205 ◽  
Author(s):  
T. G. Bonney

In my brief paper published in this Magazine for 1880 (Decade II. Vol. VII. p. 404), I mentioned that pebbles of felstone were not uncommon in the Bunter conglomerate on the northern part of Cannock Chase. Since that time, as opportunity has occurred, I have been making a more special study of these pebbles, and think it may be worth while publishing a description of some of the commoner varieties, as a contribution to the lithology of this interesting deposit and a help to the determination of the question of the origin of its material. I believe that I have observed most of the varieties, which commonly occur in the district, but do not pretend (for circumstances have not allowed of this) to have made anything like a complete collection. Many of my specimens have been derived from the broken materials spread upon some roads newly made over the portion of the Chase in the vicinity of Rugeley, but several of them were obtained in a large pit in the Bunter itself, by the side of the railway on the road to Hednesford, and I was able by a careful search in it to identify most of the varieties that I had collected elsewhere. I cannot say that erratics are absolutely unknown in this district, but they are extremely rare, and there is practically no danger of making a mistake as to the source of the pebbles. These pebbles of felstone (to use an inclusive term) appear to be by no means rare. I think one could hardly search a couple of square yards of a newly “metalled” road without picking up a fragment. Now and then specimens are found with a dark ground-mass, and occasionally one which seems to be an indurated felspathic breccia; but in the majority there is a certain common character, though there are many varietal differences. These have a compact ground-mass, varying from a pale brick-red (the commonest) to some tint of pinkish-grey.


2014 ◽  
Vol 13 (1) ◽  
pp. 339-347
Author(s):  
Vitalii Naumov ◽  
Natalia Vnukova ◽  
Ganna Zhelnovach

The analysis of problems and of approaches for ensuring the environmental safety of roads in Ukraine has been performed. The proposed mathematical model on the basis of neural networks allows numerical evaluation of quality of road area in the conditions of incomplete and fuzzy information. The proposed approach allows the determination of roads’ environmental safety level, the indica­tion of necessity for arrangement of environmental monitoring stations, and allows the development of a number of activities for environmental protection on the road sections as well.


Author(s):  
Jozef Gnap ◽  
Jana Kupculjakova ◽  
Stefania Semanova

The paper deals with the issue of delays of public transport vehicles at the signal controlled junctions. Based on the road traffic survey results, the average values of vehicle delays were determined. By using those values, it is possible to define time savings for the vehicles and mainly for passengers that are transported. The time savings were determined based on the relationships and coefficients defined in this paper.


Author(s):  
Nataliia Semchenko ◽  

The work is devoted to the actual problem of determining the parameters of dense traffic flows on the road cities network, which can be used when introducing automated traffic control systems. The subject of the study is to determine the parameters of traffic flows in the central part of the city. The purpose of the work is to develop methods for determining the parameters of traffic flows of the street and road network on the basis of empirical and analytical modeling to reduce the number of peripheral measuring devices in the automated traffic control system. Methodology. In the given thesis there was solved the applied scientific problem of short-term operational forecasting of the traffic flow intensity on the transport network using the empirical-analytical approach, in which the measurement of traffic flow parameters at the entrances to the area of traffic flow management is carried out by transport detectors, internal local objects are determined by modeling. The proposed model is based on the determination of intensities at approaches to stop lines of internal crossroads of the management area using recurrent sequences. Experimental researches of traffic flows on the network and on the crossings were carried out using video filming during periods of maximum load. A comparative analysis of the simulation results with the experimental data showed that the relative error on a network with an area of 50-60 hectares does not exceed 3%, which indicates the adequacy of the model and the possibility of using it for management tasks. Practical implications. Implementation of the empirical-analytical method in automated traffic management systems will make it possible to reduce the number of detectors by 43-46% depending on the area of traffic management and obtain a sufficient economic effect. The regularities of the movement of dense traffic flows of high specific intensity on short hauls, typical for the central parts of cities, have been investigated. Value/originality. According to experimental results there were obtained approximating models of parameters of the logarithmic normal probabilistic law of time intervals distribution in dense traffic flows, the specific intensity of which exceeds 600 vph; the changes in basic characteristics of the vehicles group in the traffic flow when driving through the road crossing taking into account its intensity and the distance from the group forming object are determined.


Sign in / Sign up

Export Citation Format

Share Document