Corrosion Behavior in Saline Medium for a Cu-Zn Casting Alloy

2015 ◽  
Vol 660 ◽  
pp. 68-74 ◽  
Author(s):  
Mirabela Georgiana Minciună ◽  
Petrică Vizureanu ◽  
Dragoş Cristian Achiţei ◽  
Ramona Cimpoeşu
Keyword(s):  
Quantitative Analysis ◽  
Structural Modification ◽  
Casting Alloy ◽  
Cast State ◽  
Structural Modifications ◽  
Corrosive Liquid ◽  
Corrosion Studies ◽  
Cuzn Alloy ◽  
Spectrometer Type ◽  
Saline Medium

The paper present aspects about the structural modification of CuZn alloy obtained by casting and used to manufacture the housing which works in corrosive liquid mediums. The analyzed alloy has a chemical composition determine by spectral quantitative analysis, with an optic spectrometer type Foundry Masters, using cooper analysis base. The structural modifications, both in cast state, also after corrosion studies, have highlighted by SEM, at 500x and 2000x magnitude. The experiments were made on samples, with specific dimensions for each analysis.

scholarly journals The Effect of Inner Reinforcing Cores on Natural Frequencies of the Lathe Tool Body

2013 ◽  
Vol 21 (Special-Issue) ◽  
pp. 186-192 ◽  
Author(s):  
Ladislav Rolník ◽  
Milan Naď
Keyword(s):  
Material Properties ◽  
Machine Tools ◽  
Structural Modification ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Geometrical Parameters ◽  
Structural Modifications ◽  
Modal Properties ◽  
Machine Productivity ◽  
Lathe Tool

Abstract The contribution is mainly focused on research and development of structural modification of machine tools, lathes in particular. The main aim of the modification is to change the modal properties (mode shapes, natural frequencies) of the lathe tool. The main objective of the contribution will be to formulate, mathematical analyse and evaluate the proposed methods and procedures for structural modifications of the tool, represented by beam body. A modification of modal properties by insertion of beam cores into beam body is studied in this paper. In this paper, the effect of material properties and geometrical parameters of reinforcing cores on natural frequencies of beam body is presented. The implementation will bring benefit on machine productivity, decreasing the machine tool wear and in many cases it will lead to better conditions in the cutting process.

scholarly journals Peptide location fingerprinting reveals modification-associated biomarkers of ageing in human tissue proteomes

2020 ◽  
Author(s):  
Matiss Ozols ◽  
Alexander Eckersley ◽  
Kieran T Mellody ◽  
Venkatesh Mallikarjun ◽  
Stacey Warwood ◽  
...  
Keyword(s):  
Structural Modification ◽  
Protein Structures ◽  
Cytoskeletal Proteins ◽  
Structural Modifications ◽  
Location Fingerprinting ◽  
Age Related ◽  
Analysis Technique ◽  
Key Factor ◽  
Aged Skin ◽  
Novel Biomarkers

AbstractAlthough dysfunctional protein homeostasis (proteostasis) is a key factor in many age-related diseases, the untargeted identification of structural modifications in proteins remains challenging. Peptide location fingerprinting is a proteomic analysis technique capable of identifying structural modification-associated differences in mass spectrometry (MS) datasets of complex biological samples. A new webtool (Manchester Peptide Location Fingerprinter), applied to photoaged and intrinsically aged skin proteomes, can relatively quantify peptides (spectral counting) and map statistically significant differences to regions within protein structures. New photoageing biomarkers were identified in multiple proteins including matrix components (collagens and proteoglycans), oxidation and protease modulators (peroxiredoxins and SERPINs) and cytoskeletal proteins (keratins). Crucially, for many extracellular biomarkers, structural modification-associated differences were not correlated with relative abundance (by ion intensity). By applying peptide location fingerprinting to published MS datasets, (identifying biomarkers including collagen V and versican in ageing tendon) we demonstrate the potential of the MPLF webtool to discover novel biomarkers.

scholarly journals Anthocyanin Pigments: Beyond Aesthetics

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5500
Author(s):  
Bindhu Alappat ◽  
Jayaraj Alappat
Keyword(s):  
Defense Mechanisms ◽  
Structural Modification ◽  
Synthetic Methods ◽  
Isolation And Identification ◽  
Polyphenol Compounds ◽  
Structural Modifications ◽  
New Gene ◽  
The Stability ◽  
Vegetables And Fruits

Anthocyanins are polyphenol compounds that render various hues of pink, red, purple, and blue in flowers, vegetables, and fruits. Anthocyanins also play significant roles in plant propagation, ecophysiology, and plant defense mechanisms. Structurally, anthocyanins are anthocyanidins modified by sugars and acyl acids. Anthocyanin colors are susceptible to pH, light, temperatures, and metal ions. The stability of anthocyanins is controlled by various factors, including inter and intramolecular complexations. Chromatographic and spectrometric methods have been extensively used for the extraction, isolation, and identification of anthocyanins. Anthocyanins play a major role in the pharmaceutical; nutraceutical; and food coloring, flavoring, and preserving industries. Research in these areas has not satisfied the urge for natural and sustainable colors and supplemental products. The lability of anthocyanins under various formulated conditions is the primary reason for this delay. New gene editing technologies to modify anthocyanin structures in vivo and the structural modification of anthocyanin via semi-synthetic methods offer new opportunities in this area. This review focusses on the biogenetics of anthocyanins; their colors, structural modifications, and stability; their various applications in human health and welfare; and advances in the field.

Persistent functional and structural retinal anomalies in newborn rats exposed to hyperoxia

1999 ◽  
Vol 77 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Pierre Lachapelle ◽  
Olga Dembinska ◽  
Luz Marina Rojas ◽  
Julie Benoit ◽  
Guillermina Almazan ◽  
...  
Keyword(s):  
Structural Modification ◽  
Histological Analysis ◽  
Plexiform Layer ◽  
Oscillatory Potentials ◽  
Newborn Rats ◽  
Sprague Dawley ◽  
Structural Modifications ◽  
Retina Development ◽  
Sprague Dawley Rats ◽  
Retinal Disorder

Previous studies have shown that newborn rats exposed postnatally to hyperoxia will develop a permanent impairment of the retinal function as determined with the electroretinogram (ERG). The purpose of our study was to examine whether postnatal hyperoxia equally alters the light- and dark-adapted ERGs and oscillatory potentials (OPs) as well as leads to permanent structural modification of the retina. During the first 14 days of life, cohorts of Sprague-Dawley rats were exposed to a hyperoxic environment, and ERGs were recorded at mean ages of approximately 25 and 55 days. Our results indicate that both light- and dark-adapted ERGs and OPs are already significantly altered within a few days following exposure to hyperoxia. None of the ERG and (or) OP parameters, with the exception of the a-wave, returned to normal values by 55 days of age. In fact some dark-adapted OPs were completely abolished following postnatal O2 exposure. Histological analysis revealed that the retina of rats exposed to hyperoxia failed to develop an outer plexiform layer and had a reduced count of horizontal cells, consistent with the permanent postreceptoral anomalies seen in the ERG responses. Our results suggest that postnatal hyperoxia causes a generalized retinal disorder leading to permanent structural modifications of the retinal cytoarchitecture and lasting anomalies of the rod and cone functions.Key words: rods, cones, electroretinography, oscillatory potentials, hyperoxia, retina, development.

Structural modification of zolpidem led to potent antimicrobial activity in imidazo[1,2-a]pyridine/pyrimidine-1,2,3-triazoles

2019 ◽  
Vol 43 (41) ◽  
pp. 16281-16299 ◽  
Author(s):  
Rajkumar Reddyrajula ◽  
Udaya Kumar Dalimba
Keyword(s):  
Antimicrobial Activity ◽  
Structural Modification ◽  
Parent Compound ◽  
Antitubercular Activity ◽  
Structural Modifications

New imidazo[1,2-a]pyridine/pyrimidine-1,2,3-triazoles (IPTs) designed by specific structural modifications of zolpidem exhibited superior antitubercular activity than the parent compound.

The limits of the law and the mutability of the judicial system

2016 ◽  
pp. 11-27
Author(s):  
DAN CLAUDIU DĂNIȘOR
Keyword(s):  
Legal System ◽  
Liberal Democracy ◽  
Structural Modification ◽  
Legal Order ◽  
Judicial System ◽  
Social Changes ◽  
Structural Modifications ◽  
The Law ◽  
Political Economic ◽  
Structural Conflict

In a liberal democracy, the sphere of law cannot be unlimited. The first category of its limits results from the necessity to temper the mutability of the legal system. Firstly, the law must not be perishable. The passage of time should not, in itself, affect the legal system. Thus, the law must limit the desire for change only for the sake of change and the desire to turn regulations into a performance. The limitation of such tendencies is not legally effective under any circumstances, meaning that the choice of regulatory methods must take into account formal principles and the context of their application as well. Secondly, law cannot be receptive to all changes. It must shift only under certain circumstances, commensurate with the magnitude of social changes. Any social conflict, change of ideological orientation, or political, economic or structural modification should not determine modifications with respect to the legal order. Thirdly, the mutability of the legal system may be determined by systemic dysfunctions. However, any structural conflict within the legal order should not bring about systemic changes. Basically, only certain dysfunctions can be classified as systemic, and the reaction towards them should be limited to drawing up structural modifications.

Structural Modification of Disc Brake Judder Using Finite Element Analysis

2012 ◽  
Vol 165 ◽  
pp. 68-72
Author(s):  
Matthias Edric Bengsoon ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Modification ◽  
Brake Disc ◽  
Disc Brake ◽  
Baseline Model ◽  
Element Analysis ◽  
Structural Modifications ◽  
Long Period ◽  
Commercial Software Package

Brake judder is a phenomenon of noise which its vibration can be felt physically by the driver of a vehicle. If this vibration is exposed to the driver for a long period it can lead to tiredness during driving. There are two types of judder which is cold judder and hot judder. This paper will be focusing on the hot judder. As a disc surface heats up during braking it causes both sides of the disc distort and hence produce a sinusoidal waviness around its edges. In this paper finite element analysis of hot judder is performed using a commercial software package, ABAQUS. An existing brake disc design is simulated and will be used as a baseline model. Various structural modifications made on the disc are proposed in an attempt to reduce brake judder in a disc brake assembly.

Emission Spectrographic Method For Quantitative Analysis Of Corrosion Products

CORROSION ◽  
1965 ◽  
Vol 21 (2) ◽  
pp. 62-68 ◽  
Author(s):  
G. M. SHIFLETT ◽  
M. LIEBERMAN
Keyword(s):  
Quantitative Analysis ◽  
Barium Carbonate ◽  
Internal Standard ◽  
Germanium Dioxide ◽  
Corrosion Products ◽  
Corrosion Studies ◽  
Piping Systems ◽  
Lead Magnesium ◽  
Spectrographic Method ◽  
Corrosion Deposits

Abstract Corrosion studies of metals, piping systems, steam generators, etc., often require knowledge of chemical nature of corrosion products formed. As amounts of such products are sometimes very small, wet chemical analysis may be difficult. Therefore, a direct arc emission spectrographic method has been developed for quantitatively determining 13 elements, many of which are known to be present in water systems as the result of corrosion, scaling or fouling. Using high purity graphite as diluent, germanium dioxide as buffer, and barium carbonate as internal standard, it was found that an element concentration of 0.3 percent provided the spectral line densities suitable for quantitative analysis. The 13 elements yielding satisfactory results were aluminum, calcium, chromium, cobalt, iron, lead, magnesium, manganese, nickel, silicon, tin, titanium and vanadium. Method was applied to carbonates, oxides and silicates of these elements with results indicating accuracy of ±15 percent and precision of approximately 12 percent. Corrosion deposits, scales, slags and oxides can be analyzed routinely by this method.

scholarly journals Different Structural Modification Methods of the Patch for Reducing the Size of An Microstrip Patch Antenna

2018 ◽  
Vol 7 (4.1) ◽  
pp. 86
Author(s):  
Nayla Ferdous ◽  
Goh Chin Hock ◽  
Saidatul Hamidah A. Hamid ◽  
Mohamad Nazri Abdul Raman ◽  
Tiong Sieh Kiong ◽  
...  
Keyword(s):  
Patch Antenna ◽  
Structural Modification ◽  
Return Loss ◽  
Side Lobe ◽  
Substrate Material ◽  
Microstrip Patch Antenna ◽  
Side Lobe Level ◽  
Original Design ◽  
Structural Modifications ◽  
Microstrip Patch

The aim of this paper is to present a simulation and analysis of a rectangular microstrip patch antenna with three different structural modifications to reduce the size of the antenna. We have tried to decrease the size of the antenna by inducing three different shaped slits inside the patch of the antenna. All these models have been designed and analyzed using CST Microwave Studio software. For designing the antennas, Flame Retardant 4 (FR-4 lossy) has been used as the substrate material with a dielectric constant of Ԑr=4.3. The antenna works at the frequency of 2.4 GHz. Performance characteristics such as return loss S11 parameter<-10 dB, directivity, side lobe level, gain and bandwidth of each of the modified designs are obtained and compared with the original design. We were able to reduce the size by maximum 18% and minimum 7% by only inducing the slits, while maintain the performance. 

scholarly journals In vitro evaluation of the effect of C-4 substitution on methylation of 7,8-dihydroxycoumarin: metabolic profile and catalytic kinetics

2018 ◽  
Vol 5 (1) ◽  
pp. 171271 ◽  
Author(s):  
Yang-Liu Xia ◽  
Tong-Yi Dou ◽  
Yong Liu ◽  
Ping Wang ◽  
Guang-Bo Ge ◽  
...  
Keyword(s):  
Structural Modification ◽  
Metabolic Stability ◽  
Electronic Effects ◽  
Pharmacological Activities ◽  
Oh Groups ◽  
Structural Modifications ◽  
Catalytic Kinetics ◽  
Relationship Of

Daphnetin (7,8-dihydroxycoumarin (7,8-DHC)) and its C-4 derivatives have multiple pharmacological activities, but the poor metabolic stability of these catechols has severely restricted their application in the clinic. Methylation plays important roles in catechol elimination, although thus far the effects of structural modifications on the metabolic selectivity and the catalytic efficacy of human catechol- O -methyltransferase (COMT) remain unclear. This study was aimed at exploring the structure–methylation relationship of daphnetin and its C-4 derivatives, including 4-methyl, 4-phenyl and 4-acetic acid daphnetin. It was achieved by identifying the methylated products generated and by careful characterization of the reaction kinetics. These catechols are selectively metabolized to the corresponding 8- O -methyl conjugates, and this regioselective methylation could be elucidated by flexible docking, in which all the 8-OH groups of these catechols are much closer than the 7-OH groups to catalytic residue LYS144 and methyl donor AdoMet. The results of the kinetic analyses revealed that the Cl int values of the compounds could be strongly affected by the C-4 substitutions, which could be partially explained by the electronic effects of the C-4 substituents and the coordination modes of 7,8- dihydroxycoumarins in the active site of COMT. These findings provide helpful guidance for further structural modification of 7,8-DHCs to improve metabolic stability.

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