Resolving Problems of Finding Surface Boundaries during Laser Machining

2016 ◽  
Vol 862 ◽  
pp. 66-71 ◽  
Author(s):  
Vladimír Pata ◽  
Libuše Sýkorová ◽  
Milena Kubišová ◽  
Martina Malachova
Keyword(s):  
Aluminum Alloy ◽  
Optical Microscopy ◽  
Surface Quality ◽  
Accurate Determination ◽  
Quality Parameters ◽  
Laser Machining ◽  
Basic Parameters ◽  
The Individual

During of aluminum alloy materials, it is possible to find three surface types which can be distinguish as primary, secondary and tertiary sections. In practice this is a big problem in case of finding the basic parameters of roughness and waviness as described by ISO 4288. According to our research, it is possible to use optical microscopy in the first step and subsequently to scan the surface in 3D in order to distinguish the type of. Another problem is how to determine the boundaries between the individual structures. The article describes methods to distinguish the boundaries in a more precise way by the cumulative functions, leading to more accurate determination of the surface quality parameters.

scholarly journals Visualizing the Bohr effect in hemoglobin: neutron structure of equine cyanomethemoglobin in the R state and comparison with human deoxyhemoglobin in the T state

2016 ◽  
Vol 72 (7) ◽  
pp. 892-903 ◽  
Author(s):  
Steven Dajnowicz ◽  
Sean Seaver ◽  
B. Leif Hanson ◽  
S. Zoë Fisher ◽  
Paul Langan ◽  
...  
Keyword(s):  
Structural Changes ◽  
Accurate Determination ◽  
Bohr Effect ◽  
Salt Bridges ◽  
Histidine Residues ◽  
Regions Of Stability ◽  
The Individual ◽  
T State

Neutron crystallography provides direct visual evidence of the atomic positions of deuterium-exchanged H atoms, enabling the accurate determination of the protonation/deuteration state of hydrated biomolecules. Comparison of two neutron structures of hemoglobins, human deoxyhemoglobin (T state) and equine cyanomethemoglobin (R state), offers a direct observation of histidine residues that are likely to contribute to the Bohr effect. Previous studies have shown that the T-state N-terminal and C-terminal salt bridges appear to have a partial instead of a primary overall contribution. Four conserved histidine residues [αHis72(EF1), αHis103(G10), αHis89(FG1), αHis112(G19) and βHis97(FG4)] can become protonated/deuterated from the R to the T state, while two histidine residues [αHis20(B1) and βHis117(G19)] can lose a proton/deuteron. αHis103(G10), located in the α1:β1dimer interface, appears to be a Bohr group that undergoes structural changes: in the R state it is singly protonated/deuterated and hydrogen-bonded through a water network to βAsn108(G10) and in the T state it is doubly protonated/deuterated with the network uncoupled. The very long-term H/D exchange of the amide protons identifies regions that are accessible to exchange as well as regions that are impermeable to exchange. The liganded relaxed state (R state) has comparable levels of exchange (17.1% non-exchanged) compared with the deoxy tense state (T state; 11.8% non-exchanged). Interestingly, the regions of non-exchanged protons shift from the tetramer interfaces in the T-state interface (α1:β2and α2:β1) to the cores of the individual monomers and to the dimer interfaces (α1:β1and α2:β2) in the R state. The comparison of regions of stability in the two states allows a visualization of the conservation of fold energy necessary for ligand binding and release.

The Influence of Laser Beam Technological Parameters on the Polymethyl Methacrylate Surface Quality

2018 ◽  
Vol 919 ◽  
pp. 190-198 ◽  
Author(s):  
Vladimír Pata ◽  
Libuše Sýkorová ◽  
Oldřich Šuba ◽  
Milena Kubišová
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Laser Beam ◽  
Surface Quality ◽  
Polymethyl Methacrylate ◽  
Quality Parameters ◽  
Technological Parameters ◽  
Detailed Statistical Analysis ◽  
Mathematical Relations

The paper is focused on the determination of the course and change of the surface quality parameters obtained by the laser engraving of the material known under commercial name polymethyl methacrylate. The paper aims to find mathematical relations based on regression analysis for amplitudes parameters Ra and Rz. For this purpose, a sample of variable technology parameters will be machined followed by the surface measuring and evaluation using the Talysurf CLI 500 3D Surface Scanner. Thus the data obtained will be subjected to the detailed statistical analysis to check homoscedasticity, the presence of outliers, and multidimensional normality testing.

scholarly journals On phenomena relating to the spectra of hydrogen and helium

1916 ◽  
Vol 93 (646) ◽  
pp. 27-28
Keyword(s):  
Accurate Determination ◽  
Principal Series ◽  
Black Body ◽  
Black Body Radiation ◽  
Balmer Series ◽  
Mean Values ◽  
Carbon Arc ◽  
The Mean ◽  
The Individual

In a previous paper the structure of broadened spectrum lines was investigated by a method involving the use of a neutral-tinted wedge as an accessory to the spectroscope. The present communication deals with a method for the accurate determination of the photographic intensities of spectrum lines and the reduction of such intensities to absolute values by comparison with the continuous black-body radiation of the carbon arc. These methods have been applied to a study of the relative intensity distribution in the spectra of helium and hydrogen under different conditions of excitation. It has been found that under certain specified conditions there is a transfer of energy from the longer to the shorter wave-lengths in any given series, and that, under such conditions, the associated series, and in particular the Diffuse series, are relatively enhanced at the expense of the Principal series. It has also been found that the distribution of intensity found in certain celestial spectra can be approximately reproduced in the laboratory. In any attempt to interpret the phenomena observed in connection with the Balmer series of hydrogen, it is necessary to know the particular type to which this series belongs. In order to decide this point a study has been made of the separations of the components of lines of the Balmer series of hydrogen, and the mean values of the separations of the doublets constituting the lines H a and H β have been found to be respectively 0.132 Å.U. and 0.033 Å.U. These values are consistent with the separations appropriate to a Principal series, and the first is in precise agreement with the value deduced by Buisson and Fabry. These results have been obtained by crossing a Lummer Gehrcke plate with the neutral wedge, and submitting the contours obtained to mathematical analysis, by means of which the distribution of intensity in the individual components, and the separation of the components, can be determined.

scholarly journals Discussion on the structure of atomic nuclei

1929 ◽  
Vol 123 (792) ◽  
pp. 373-390 ◽  
Keyword(s):  
Accurate Determination ◽  
Essential Point ◽  
Whole Numbers ◽  
Atomic Nuclei ◽  
Whole Number ◽  
Nuclear Atom ◽  
The Individual ◽  
The Masses ◽  
Made In

Sir Ernest Rutherford: It was on March 19, 1914, that the Royal Society held its last discussion on the constitution of the atom—just fifteen years ago. I had the honour to open the discussion on that occasion, and the other speakers were Mr. Moseley, Profs. Soddy, Nicholson, Hicks, Stanley Allen, S. P. Thomp­son. In my opening remarks I put forward the theory of the nuclear atom and the evidence in support of it, while Mr. Moseley gave an account of his X-ray investigations, which defined the atomic numbers of the elements, and showed how many gaps were present between hydrogen number 1 and uranium number 92. Prof. Soddy drew attention to the existence of isotopes in the radioactive series, and also to a remarkable observation by Sir Joseph Thomson and Dr. Aston, who had obtained two parabolas in the positive ray spectrograph of neon, and he suggested that possibly the ordinary elements might also consist of mixture of isotopes. I think you will find that the remarks and suggestions made in this discussion fifteen years ago have a certain pertinence to-day. In particular Hicks and Stanley Allen drew attention to the importance of taking into account the magnetic fields in the nucleus, although at that time we had very little evidence on that point, and even to-day our information is very scanty. What has been accomplished in the intervening period ? On looking back we see that three new methods of attack on this problem have been developed. The first, and in some respects the most important, has been the proof of the isotopic constitution of the ordinary elements, and the accurate determination of the masses or weights of the individual isotopes, mainly due to the work of Dr. Aston. This has led in a sense to an extension of the original ideas of Moseley. The experiments of the latter fixed the number of possible nuclear charges, while Aston has shown that there are a large number of species of atoms each defined by its nuclear charge, although their masses and their nuclear constitution may be different. The essential point brought out in the earlier work of Dr. Aston was that the masses of the elements are approxi­mately expressed by whole numbers, where oxygen is taken as 16—with the exception of hydrogen itself. But the real interest, as we now see it, is not the whole number rule itself, but rather the departures from it.

THE SUPPRESSION OF VITRINITE REFLECTANCE IN SOME NORTH WEST SHELF WELLS: BARROW-1, JUPITER-1 AND FLAMINGO-1

1992 ◽  
Vol 32 (1) ◽  
pp. 300 ◽  
Author(s):  
R.W.T. Wilkins ◽  
J.R. Wilmshurst ◽  
G. Hladky ◽  
M.V. Ellacott ◽  
C.P. Buckingham
Keyword(s):  
Organic Matter ◽  
Vitrinite Reflectance ◽  
Accurate Determination ◽  
Petroleum Exploration ◽  
Thermal Maturity ◽  
North West ◽  
The North ◽  
The Individual ◽  
Reflectance Data

The sediments of the North West Shelf pose several problems for the accurate determination of thermal maturity by vitrinite reflectance. There are some serious discrepancies between the results of different workers; in some wells there is a surprisingly small increase of reflectance with depth, and it is sometimes difficult to honour these data in thermal maturity modelling. There appear to be two major sources of error in the reflectance data. These are firstly, the effect known as 'suppression' of vitrinite reflectance, and secondly, the difficulty of identifying the vitrinite population in dispersed organic matter.These problems may be addressed by the fluorescence alteration technique which is closely related to vitrinite reflectance but has two special advantages. Firstly, it depends on an analysis of the fluorescence alteration response of a small representative population of organic matter in which the individual macerals need not be identified. Secondly, anomalous vitrinites with suppressed vitrinite reflectance are readily characterized, and the corrected equivalent reflectances determined.The technique has been tested on three North West Shelf petroleum exploration wells, Barrow-1, Jupiter-1 and Flamingo-1. Major discrepancies between measured and equivalent vitrinite reflectance appear to originate in part from the difficulty of identifying the vitrinite population in dispersed organic matter from marine sediments. There is also evidence of suppression of vitrinite reflectance in most samples from Barrow-1, in the Flamingo Group and Plover Formation of Flamingo-1, and in the upper part of the Mungaroo Formation of Jupiter-1.A model is proposed to facilitate the assessment of measured vitrinite reflectance data from Carnarvon or Bonaparte Basin wells. Suppression effects are likely to have influenced measured vitrinite reflectance results from wells for which the strongest data are obtained from the Lower Cretaceous fluvio-deltaic Barrow Group sediments or their equivalents.

Determination of Mechanical Properties for Microhardness Mapping in a 5052 Aluminum Alloy Welded by Mig Process

2018 ◽  
Vol 930 ◽  
pp. 356-361
Author(s):  
José Costa de Macêdo Neto ◽  
Juarez Viégas Silva ◽  
Guilherme dos Santos Moreira ◽  
João Evangelista Neto ◽  
Flavio Silveira ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Tensile Test ◽  
Mechanical Strength ◽  
Optical Microscopy ◽  
Weld Pool ◽  
Gas Flow ◽  
Filler Metal ◽  
Welded Joint ◽  
Transfer Mode

Aluminum alloys are widely used in shipbuilding, it is a material with good mechanical strength, high corrosion resistance and good conformation. In this study we used the filler metal 5183 aluminum alloy, groove angle 80°, root opening 0,5mm, stick-out 12 a 14mm, voltage 23V, torch 99,99%Ar, transfer mode Pulsed, current 220A, wire speed 30cm/min, gas flow 25l/min. The aim of this study was to research the mechanical strength in a welded joint naval 5052 aluminum alloy welded by Metal Inert Gas-MIG process using a mapping microhardness and software images. They were also carried out the tensile test, chemical analysis of the studied alloy and optical microscopy. The results of microhardness showed that the weld pool showed lower values. Optical microscopy showed that the weld pool had bubbles and the tensile test was presented fracture in the welded joint.

scholarly journals Clinical Aspects of Trace Elements: Zinc in Human Nutrition - Assessment of Zinc Status

1996 ◽  
Vol 10 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Michelle M Pluhator ◽  
Alan Br Thomson ◽  
Richard N Fedorak
Keyword(s):  
Accurate Determination ◽  
Clinical Aspects ◽  
Zinc Status ◽  
Uncertain Process ◽  
Zinc Tolerance ◽  
Acceptable Method ◽  
Zinc Levels ◽  
The Many ◽  
The Individual

Because the limiting and vulnerable zinc pool has not been identified, it becomes a challenge to determine which of the many zinc pools is most susceptible to deficiency. As a consequence, defining and assessing zinc status in the individual patient is a somewhat uncertain process. Laboratory analysis of zinc status is difficult because no single biochemical criterion can reliably reflect zinc body stores. Many indexes have been examined in the hopes of discovering a method for the assessment of zinc nutriture. None of the methods currently used can be wholeheartedly recommended because they are fraught with problems that affect their use and interpretation. However, these methods remain in use for clinical and research purposes, though their benefits and drawbacks must always be acknowledged. Until an acceptable method of analysis is discovered, clinicians must rely for confirmation of zinc deficiency on a process of supplementing with zinc and observing the patient’s response. The main indexes (plasma/serum, erythrocyte, leukocyte, neutrophil, urine, hair and salivary zinc levels, taste acuity and oral zinc tolerance tests, and measurement of metallothionein levels) are reviewed. Measurement of plasma or erythrocyte metallothionein levels shows promise as a future tool for the accurate determination of zinc status.

scholarly journals The civil liability of the consortium members for the individual mistake of one member

2018 ◽  
Vol 7 (2.13) ◽  
pp. 272
Author(s):  
Ahmed M. Elsawi
Keyword(s):  
Accurate Determination ◽  
Civil Liability ◽  
Separate Entity ◽  
Major Question ◽  
Legal Implications ◽  
Specific Determination ◽  
Contractual Agreements ◽  
The Individual ◽  
Personal Liability

Nowadays, the various forms of contractual agreements have spread between the different contracting companies for the purpose of executing the huge international contracts which require the synergy of all efforts. This has led to the appearance of new forms of cooperation between the international contractors, called the "Consortium Agreement", which is a kind of special partnership entered into for the purpose of executing a certain project, and ends at the completion of this project, without the constitution of a separate entity for the parties of this consortium. Nonetheless, many and various legal implications result from this consortium, some of which may be attributed to the subordination relationship between this agreement and the international contract of construction; while other legal implications might be attributed to the Consortium Agreement itself. The main problem in this regard may arise, if the consortium members did not agree on the accurate determination of the civil liability for each party, whether it was during the pre-contractual stage, or during the contract's execution; as well as the specific determination of the consortium members' liability towards the employer for the individual mistake of one member, especially in light of the multiple parties and the unity of purpose. In this regard, the liability may take one of the following two forms: first, to consider all members of the consortium as joint partners before the employer; second, to adopt the personal liability of each member separately, thus, each member shall be liable only for the part assigned to him. Hence, we will try here to answer a major question regarding the liability of the consortium members for the individual error of one member towards each other or towards the employer, taking into consideration the special nature of the Consortium Agreement.  

scholarly journals Determination of Chlorophyll and Carotenoids Present in the Seeds of the Plant Family Apiaceae and the Impact on Seed Quality

2018 ◽  
Vol 66 (4) ◽  
pp. 859-869 ◽  
Author(s):  
Marie Grulichová ◽  
Peter Mendel ◽  
Václav Trojan ◽  
Tomáš Vyhnánek
Keyword(s):  
Seed Quality ◽  
Seedling Emergence ◽  
Quality Parameters ◽  
Standard Laboratory ◽  
Plant Family ◽  
Pigment Contents ◽  
The Individual ◽  
The Impact ◽  
Β Carotene

In this study, we assessed the content of chlorophyllaandb, β-carotene and lutein in seeds of carrot, celery, dill, parsley and parsnip commercial varieties by spectrophotometric method. It was determined that the content of chlorophyllawas higher than chlorophyllband both differed significantly between plant species and varieties. The highest amounts of chlorophylla, chlorophyllb, β-carotene and lutein were detected in parsley “Olomoucka dlouha”. The lowest amounts of chlorophylla, chlorophyllb, β-carotene and no lutein were detected in celery “Nuget”, however, very low amount of lutein was detected in the parsley cultivars “Atika” and “Orbis”. The content of β-carotene was higher than that of lutein in most varieties. The individual pigment contents were compared to seed quality parameters such as standard laboratory germination and seedling emergence. Negative correlation between energy of germination and pigments and positive correlation between seedling emergence and pigments in the parsnip and parsley varieties was observed. Determination the content of pigments and correlations observed the possibility to use spectrophotometry to evaluate the pigments present in the seeds as an indicator of seed quality.

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