Investigation of inhibition processes at sand-deposited surfaces

CO2 corrosion of carbon steel in the presence of deposits is a major concern in the oil and gas industry as the deposits impair effective corrosion inhibition and promote localized corrosion. This study shows that the extent of corrosion is affected by the nature of the mineral deposit. Chukanovite and siderite were identified as corrosion products formed at sand-deposited carbon steels. Sulphur-containing organic compounds showed low affinity for sand and effectively inhibited general corrosion at sand-deposited steels

Synchrotron infrared microspectroscopy study of the orientation of an organic surfactant on a microscopically rough steel surface

The performance of organic surfactants as corrosion inhibitors is influenced by the mechanism of adsorption and the resulting molecular orientation on the substrate. The molecular orientation of 1-dodecylpyridinium chloride (DPC) deposited on non-corroded 1030 mild steel and after corrosion in a carbon dioxide environment has been investigated using synchrotron infrared microspectroscopy. DPC mitigates the corrosion process by adsorbing at the steel surface and forming a protective layer. Infrared spectra analogous to polarized grazing angle spectra were obtained from a microscopically rough surface using a synchrotron source. The appearance of negative and positive absorption bandsin the spectra, when using synchrotron radiation, is discussed in terms of the optical system used. The presence of the DPC surfactant at the steel surface is shown by the CH2 and CH3 infrared absorption bands of the aliphatic chain of the DPC molecule. The infrared spectra provide direct evidence on the orientation of DPC at the steel substrate. The aliphatic chain of the surfactant is tilted orthogonally, but not perpendicular to the substrate plane. The absence of significant absorption bands characteristic of the pyridinium ring of DPC indicates its orientation parallel to the substrate plane, and an adsorption mechanism involving pi-bonding with the steel. This study demonstrates the applicability of synchrotron infrared microspectroscopy to the investigations of thin organic films on microscopically rough steel surfaces, and can facilitate further investigations of thin films on metallic surfaces and monolayer studies in general

Expression and Function of Cannabinoid Receptors CB1 and CB2 and Their Cognate Cannabinoid Ligands in Murine Embryonic Stem Cells

Background: Characterization of intrinsic and extrinsic factors regulating the self-renewal/division and differentiation of stem cells is crucial in determining embryonic stem (ES) cell fate. ES cells differentiate into multiple hematopoietic lineages during embryoid body (EB) formation in vitro, which provides an experimental platform to define the molecular mechanisms controlling germ layer fate determination and tissue formation. Methods and Findings: The cannabinoid receptor type 1 (CB1) and cannabinoid receptor type 2 (CB2) are members of the G-protein coupled receptor (GPCR) family, that are activated by endogenous ligands, the endocannabinoids. CB1 receptor expression is abundant in brain while CB2 receptors are mostly expressed in hematopoietic cells. However, the expression and the precise roles of CB1 and CB2 and their cognate ligands in ES cells are not known. We observed significant induction of CB1 and CB2 cannabinoid receptors during the hematopoietic differentiation of murine ES (mES)-derived embryoid bodies. Furthermore, mES cells as well as ES-derived embryoid bodies at days 7 and 14, expressed endocannabinoids, the ligands for both CB1 and CB2. The CB1 and CB2 antagonists (AM251 and AM630, respectively) induced mES cell death, strongly suggesting that endocannabinoids are involved in the survival of mES cells. Treatment of mES cells with the exogenous cannabinoid ligand $\Delta^9$-THC resulted in the increased hematopoietic differentiation of mES cells, while addition of AM251 or AM630 blocked embryoid body formation derived from the mES cells. In addition, cannabinoid agonists induced the chemotaxis of ES-derived embryoid bodies, which was specifically inhibited by the CB1 and CB2 antagonists. Conclusions: This work has not been addressed previously and yields new information on the function of cannabinoid receptors, CB1 and CB2, as components of a novel pathway regulating murine ES cell differentiation. This study provides insights into cannabinoid system involvement in ES cell survival and hematopoietic differentiation

Covalent Inhibitors of Human Monoacylglycerol Lipase: Ligand-Assisted Characterization of the Catalytic Site by Mass Spectrometry and Mutational Analysis

SummaryThe active site of recombinant hexa-histidine-tagged human monoacylglycerol lipase (hMGL) is characterized by mass spectrometry using the inhibitors 5-((biphenyl-4-yl)methyl)-N,N-dimethyl-2H-tetrazole-2-carboxamide (AM6701), and N-arachidonylmaleimide (NAM) as probes. Carbamylation of Ser129 by AM6701 in the putative hMGL catalytic triad demonstrates this residue's essential role in catalysis. Partial NAM alkylation of hMGL cysteine residues 215 and/or 249 was sufficient to achieve ∼80% enzyme inhibition. Although Cys215 and/or Cys249 mutations to alanine(s) did not affect hMGL hydrolytic activity as compared with nonmutated hMGL, the C215A displayed heightened NAM sensitivity, whereas the C249A evidenced reduced NAM sensitivity. These data conclusively demonstrate a sulfhydryl-based mechanism for NAM inhibition of hMGL in which Cys249 is of paramount importance. Identification of amino acids critical to the catalytic activity and pharmacological modulation of hMGL informs the design of selective MGL inhibitors as potential drugs

DeepQ Residue Representation of Moving Object Images using YOLO in Video Surveillance Environment

The IAEA photo evaluation software does have functions for scene-alternate recognition, black photo detection, and deficient scene analysis, even though its capabilities are not at their highest. The current workflows for detecting safeguards-relevant activities heavily rely on inspectors' laborious visual examination of surveillance videos, which is a time-consuming and error-prone process. The paper proposes using item-based totally movement detection and deep gadget learning to identify fun items in video streams in order to improve method accuracy and reduce inspector workload. An attitude transformation model is used to estimate historical movements, and a deep learning classifier trained on manually categorized datasets is used to identify shifting applicants within the history subtracted image. Through optical glide matching, we identify spatio-temporal tendencies for each and every shifting item applicant and then prune them solely based on their movement patterns in comparison to the past. In order to improve the temporal consistency of the various candidate detections, a Kalman clear out is performed on pruned shifting items. A UAV-derived video dataset was used to demonstrate the rules. The results demonstrate that our set of rules can effectively target small UAVs with limited computing power

Psychophysical study of brain with intermittent photic stimulation using magnetoencephalography (MEG)

Dynamic visual stimulation also called as intermittent photic stimulation is used in psychophysical studies of brain to an intermittently flickering light. Brain’s response to this type of stimulus has long been applied in epilepsy studies with Electroencephalography(EEG). Magnetoencephalography(MEG) is a sophisticated technology having ability to detect magnetic brain signals within milliseconds range. In this study, we will use MEG to study the response of brain to a dynamic photic stimulation that has been recently shown to possess great potential as therapeutic approach due to its ability to entrain brain oscillations. Three experiments covering the study of illusion effect, variation in signal with age and entrainment of gamma waves are present in this report. Factors influencing the psychophysical response such as age, frequency of stimulation are taken into consideration. A novel photic stimulator that is compatible to function inside MEG setup is used. This stimulator uses a fiber optic cable to deliver light inside the MEG shielding room and can be readily connected to the main MEG acquisition system. All the results pertaining to each of the experiment and the established findings are discussed along with their potentials in taking the study forward using image processing tools like MNE Python, Brainstorm and in-built MEG tools.​Master of Science (Biomedical Engineering

Analysis of crystalline perfection of pure and Modoped KTP crystals on different growth planes by high-resolution X-ray diffraction

Single crystals of pure and molybdenum (Mo)-doped potassium titanyl phosphate (KTP) crystals were grown by the high-temperature solution growth technique. The presence of dopant ions in the grown crystal was confirmed by energy-dispersive X-ray analysis. Grown crystals, cut along various growth planes such as (100), (011) or (201), were analysed for crystalline perfection using high-resolution X-ray diffraction (HRXRD). Although the HRXRD study showed that the crystalline perfection of most of the crystals was quite good without any structural defects, structural grain boundaries were observed in some of the crystals chosen for study. The observed structural defects are probably due to mechanical or thermal fluctuations occurring during the growth process