Chempak


Not only can the inclination (relative to vertical) of a well be changed, but also the azimuth at which it is being drilled. The azimuth refers to the compass bearing relative to magnetic north. The well path can be turned to the right or to the left . Obviously it is essential to know at all times were the bit is. Therefore a number of directional surveying techniques are employed to monitor the progress of the hole. Essentially compass readings and inclination measurements are taken at intervals and relayed to the drill floor either via surface read outs or on film to be retrieved by wireline.  [c.49]

The authors thank the german research community (DFG) for the support of the presented investigations whieh were realized inside the Special Research Area 326, named, J rocess Integrated Quality Control with Quality Information System for Metallic Parts in Mechanical Engineering, and special thanks to the scientific bilateral project between Brazil and Germany supported by the CNPq, KFA and DLR to realize the presented investigations in advanced radioscopy and tomography.  [c.17]

Personal Computer COMPAQ 590  [c.77]

These effects were recorded in Greece around 2500 years ago and not long afterwards Democritus proposed an atomic structure for all matter. The magnetic compass seems to have taken another 1500 years to appear and magnetic theory a further half century.  [c.270]

Similarly, the identical expression holds for a liquid that completely fails to wet the capillary walls, where there will be an angle of contact between the liquid and the wall of 180°, a convex meniscus and a capillary depression of depth h.  [c.12]

Lovett R 1995 Can a solid be turned into a gas without passing through a first order phase transition Observation, Prediction and Simuiation of Phase Transitions in Compiex Fiuids vol 460 NATO ASi Series O ed M Baus, L F Rull and J-P Ryckaert (Dordrecht Kluwer) pp 641-54  [c.2285]

Larson R G 1999 The Structure and Rheoiogy of Compiex Fiuids (New York Oxford University Press)  [c.2691]

Newell A C 1989 Compiex Systems ed D Stein (New York Addison-Wesley)  [c.3074]

Given the pair and surface potentials, the weights are then constructed by solving the convex bound constrained quadratic program  [c.216]

The following is one of the simplest ways of fluting a filter-paper. First make four folds in the paper so that the latter is divided into eight equal sectors (Fig. 7(a)), the two halves of the paper on each occasion being folded forwards so that all the folds tend to be concave. Now take each segment in turn (e.., aOb, Fig. 7(b)) and fold the points a and b backwards until they meet, so that a new convex fold Ox is made between them continue in this way making new folds Oy, O2, etc. around the paper. When the complete fluted paper (Fig. 7(c)) is placed in the ordinary conical funnel, it will possess a series of regular corrugations, and only the edges of the folds Oa, Ob, Oc, etc., will be in contact with the funnel.  [c.13]

The simplest form of apparatus consists of a small porcelain evaporating dish covered with a filter paper which has been perforated with a number of small holes a watch glass of the same size, convex side uppermost, is placed on the filter paper. The substance is placed inside the dish, and the latter heated with a minute flame on a wire gauze or sand bath. The sublimate collects in the Fig. II, 45, 1. watch glass, and the filter paper below prevents the sublimate from falling into the residue. The watch glass may be kept cool by covering it with several pieces of damp filter  [c.154]

The element forms an alloy with osmium which is used for tipping pens and compass bearings.  [c.139]

The first clear cormection between an electric current and magnetism was observed in the early 1800 s here in Copenhagen. Hans Christian Oersted noticed that a current flowing in a wire affected a compass nearby. It was a direct current so magnetism rather than eddy currents was being created but it seems to be the first time the notion of a field of force was postulated, at least one created by an electric current. We now know that eddy currents would have been created as the electric current in the conductor increased and decreased on switching on and off Soon afterwards Ampere demonstrated that the magnetic fields from equal and opposite currents flowing in adjacent wires cancel each other out. Ever since that time engineers have carefully twisted wires together to reduce problems of radiation and pick-up. Not too tightly of course or the impedance would increase, although that had not been discovered at that time. In 1824 Arago discovered that a magnetic needle was affected by metal plates being rotated in its vicinity. Was this the first demonstration of eddy currents Efforts to track down Arago have so far met with no success, the only references found relate to a Monsieur Arago  [c.270]

This criterion resumes all the a priori knowledge that we are able to convey concerning the physical aspect of the flawed region. Unfortunately, neither the weak membrane model (U2 (f)) nor the Beta law Ui (f)) energies are convex functions. Consequently, we need to implement a global optimization technique to reach the solution. Simulated annealing (SA) cannot be used here because it leads to a prohibitive cost for calculations [9]. We have adopted a continuation method like the GNC [2].  [c.332]

The method has been extended to mixtures of hard spheres, to hard convex molecules and to hard spherocylinders that model a nematic liquid crystal. For mixtures m. subscript) of hard convex molecules of the same shape but different sizes. Gibbons [38] has shown that the pressure is given by  [c.482]

Kino G S and Xiao G Q 1990 Real time scanning optical microscope Confocai Microscopy ed T Wilson (New York Academic)  [c.1673]

The ideal sintering process can be divided into tliree basic stages [74]. Initially, material is transported from convex particle surfaces to tire pore-grain boundary intersection to fonn necks between adjacent particles. As tliis occurs, grain boundaries grow to create a tliree-dimensional array of approximately cylindrical, interconnected (i.e. continuous) pore channels at tliree grain junctions tliroughout tlie compact. These pore channels slirink in diameter during intennediate-stage sintering. Ultimately, because of Rayleigh instability (i.e. tlie critical cylinder lengtli to diameter ratio), tlie channels pinch off to fonn approximately spherical, isolated (i.e. closed) pores at four grain junctions witliin tlie ceramic matrix. The radial slirinkage of closed pores and tlie growtli of larger grains at the expense of smaller ones constitute final-stage sintering.  [c.2769]

Deisenhofer J, Epp O, Miki K, Huber R and Michei H 1984 X-ray structure anaiysis of a membrane-protein compiex eiectron density map at 3 A resoiution and a modei of the chromophores of the photosynthetic reaction center from Rhode pseudomonas viridis J. Mol. Biol. 180 385-98  [c.2994]

In May 21 - 24, 1997 the Second International Symposium on Algorithms for Macromolecular Modelling was held in the new building of the Konrad Zuse Zentrum on the attractive Science Campus of the Free University of Berlin. Organizers of the symposium were the editors of this book, plus Bernie Brooks and Wilfred van Gunsteren. The event brought together computational scientists in fields like biochemistry, biophysics, physical chemistry, or statistical physics and numerical analysts as well as computer scientists working on the advancement of algorithms, for a total of over 120 participants from 19 countries. In the course of the symposium, it was agreed not to write traditional proceedings, but rather to produce a representative volume that combines survey articles and original papers (all refereed) that would give an account of the current state of the art of Molecular Dynamics (MD).  [c.497]

J. Gasteiger, P.A. Kollman, H.F. Schaefer III, P.R. Schreiner (Eds.), Wiley, Chichester, UK, 1998, pp. 1487-1496 htip lfunvw.mrw.intersdence.wiley. comfecc  [c.201]

J. Gasteiger, P.A. Kollman, H.F. Schaefer ITT, P.R. Schreiner (Eds.), Wiley, Chichester, 1998, pp. 2381-2402 http f/www.mra .interscience.wiley. comfecc  [c.201]

It Is cmphasi < cd that both versions of the generic structure query may include the parent compound and monochlorinated derivatives.  [c.253]

Show that the area under a parabolic arc that is convex upward is w(f(xi) -I- Af(xi+i) -I-/(v,+2)), where w is the width of the subinterval Xj+ - Xj.  [c.11]

Formation of an adsorption column. In order to obtain satisfactory results, the tube must be uniformly packed with the adsorbent. Uneven distribution leads to the formation of cracks and channels. If there is any doubt concerning the uniformity of the adsorbent powder, it should be sifted before use. The necessary support for the column (glass wool or cotton wool plug perforated porcelain plate, or sintered glass plate, with filter paper circle, etc.) is placed in the tube, the latter is clamped or held vertically, and the adsorbent added portionwise. The first portion should be about twice the size of those that follow. For tubes up to one cm. diameter, the individual portions are pressed down with a fiattened glass rod. For wider tubes, a cylindrical wooden pestle (walnut wood is recommended), slightly convex in the centre (Fig. II, 46, 6), is used the area of the conical end should be two thirds to three quarters of that of the tube. The adsorbent is pressed down by a short vigorous tapping from a height of 3 to 6 cm. With certain adsorbents, a slight vacuum is created as the pestle is raised and a cloud of fine powder may be formed this is avoided if a slight rotary movement is given to the pestle as it is raised, or by slightly turning the glass tube with the left hand each time the pestle is lifted. From one-fifth to one third of the tube should be left empty. The amount of adsorbent is usually generous compared with the quantity of material to be adsorbed.  [c.160]

Good teachers can have a great influence on their students. As I mentioned, besides the classics, humanities, history, and languages I also received a good education in mathematics and had some inspiring science teachers. I particularly remember my physics teacher, Jozsef Oveges, who I understand later introduced the first television science programs in Hungary, which made him well known and extremely popular. He was a very inspiring teacher who used simple but ingenious experiments to liven up his lectures. I must confess that I do not remember my chemistry teacher, who must have made less of an impression on me. When a friend received a chemistry set for Christmas one year, we started some experiments in the basement of his home. This was probably when I first experienced the excitement of some of the magic of chemistry. For example, we observed with fascination bubbles of carbon dioxide evolving when we dropped some sodium bicarbonate into vinegar or muriatic acid. Fittle did I expect to repeat  [c.44]


See pages that mention the term Chempak : [c.11]    [c.157]    [c.394]    [c.609]    [c.610]    [c.610]    [c.795]    [c.1651]    [c.1673]    [c.2484]    [c.2691]    [c.2768]    [c.2771]    [c.2845]    [c.2845]    [c.2994]    [c.3044]    [c.217]    [c.127]    [c.98]    [c.156]    [c.162]    [c.276]    [c.535]    [c.33]    [c.109]   
Applied Process Design for Chemical and Petrochemical Plants, Volume 2 (1997) -- [ c.240 ]