scholarly journals Innovative Method for Coating of Natural Corrosion Inhibitor Based on Artemisia vulgaris

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2234
Author(s):  
Daniel Alejandro Pineda Hernández ◽  
Elisabeth Restrepo Parra ◽  
Pedro José Arango Arango ◽  
Belarmino Segura Giraldo ◽  
Carlos Daniel Acosta Medina

In this work, the production of a novel methodology for the application of natural corrosion inhibitors on steel, using an autoclave is presented. Tests were carried out using Artemisia vulgaris. The inhibitor was produced with a simple soxhlet extraction process using 15 g of Artemisia vulgaris and 260 mL of Ether. Once the inhibitor was produced, the steel was immersed in it, to form a coating that protects the material against corrosion. Thermogravimetry analyzes (TGA) were performed on the inhibitor, to determine the degradation temperature; it was observed that, at 321 °C, the loss of organic mass begins. After applying the inhibitor to the steel, the Fourier Transform Infrared Spectroscopy (FTIR) technique was used to determine the vibrational bands and the difference between the spectra for the steels before and after the coating was applied. For the evaluation of the method efficiency, Electrochemical Impedance Spectroscopy (EIS) and polarization resistance tests were performed, where Nyquist diagrams and Tafel curves were obtained, for steels with and without treatment. In this case, an increase of 93% in the corrosion resistance, and an 88% decrease in the corrosion rate were observed, proving that this methodology can be used to protect steel against corrosion and extend the steel’s useful life.

2018 ◽  
Vol 12 (12) ◽  
pp. 119
Author(s):  
Carlos A. Díaz V ◽  
William F. Garzón M ◽  
Juan C. Higuita V ◽  
Elisabeth. Restrepo-Parra

In this work, a study of samples that contained cocaine camouflaged inside unidentified polymers was performed. Samples were seized at the Dorado International airport in Colombia. Cocaine was adsorbed or occluded within the matrix. The objective of this research was to extract cocaine from the matrices using soxhlet extraction method. Thereafter matrices were analyzed to determine the surface morphology before and after the extraction. Several morphological differences were exhibited between samples including both adsorbed and occluded cocaine. Moreover, changes in the surface morphology were also observed before and after cocaine extraction. The chemical elemental composition of matrices was also studied using energy dispersive spectroscopy, observing that the alkaloid was totally removed in almost all samples after the extraction process. On the other hand, Thermo gravimetric analysis also allows comparing the results obtained for the samples with patterns of pure cocaine and other polymers as CMC, PVA and HEC, finding several similarities of structural type.


Author(s):  
R.A. Herring

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.


1979 ◽  
Vol 42 (04) ◽  
pp. 1332-1339 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Takeshi Motomiya ◽  
Minoru Sonoda ◽  
Noboru Miyagawa

SummaryChanges in platelets in 48 patients with uterine myoma before and after hysterectomy with and without ovariectomy were examined. Bilateral ovariectomy in 25 cases (ovariec-tomized group) and unilateral or non-ovariectomy in 23 cases (control group) were performed at the hysterectomy. Platelet count and an appearance rate of secondary aggregation decreased at one day after and increased at one week after the operation, similarly in both the ovariectomized and the control group. The appearance rate of secondary aggregation was reflected in an intensity of aggregation at 5 min after the addition of reagent to PRP. At one month after the operation, the appearance rate of secondary aggregation induced by 3 μM ADP showed a statistically significant decrease in comparison with the preoperation value (P <0.05) and the enhancement of 5-min aggregation was still observed in the control group, while ceased in the ovariectomized group. The difference between the two groups was significant (P < 0.05). There was almost no change in the speed and intensity of primary and secondary aggregation during the observation period. No significant differences in collagen-induced aggregation were noted between the two groups. The results suggest that ovarian hormones, mainly estrogen, facilitate platelet activation which is mediated by the so-called secondary aggregation.


Author(s):  
Niken Setyaningrum ◽  
Andri Setyorini ◽  
Fachruddin Tri Fitrianta

ABSTRACTBackground: Hypertension is one of the most common diseases, because this disease is suffered byboth men and women, as well as adults and young people. Treatment of hypertension does not onlyrely on medications from the doctor or regulate diet alone, but it is also important to make our bodyalways relaxed. Laughter can help to control blood pressure by reducing endocrine stress andcreating a relaxed condition to deal with relaxation.Objective: The general objective of the study was to determine the effect of laughter therapy ondecreasing elderly blood pressure in UPT Panti Wredha Budhi Dharma Yogyakarta.Methods: The design used in this study is a pre-experimental design study with one group pre-posttestresearch design where there is no control group (comparison). The population in this study wereelderly aged over> 60 years at 55 UPT Panti Wredha Budhi Dharma Yogyakarta. The method oftaking in this study uses total sampling. The sample in this study were 55 elderly. Data analysis wasused to determine the difference in blood pressure before and after laughing therapy with a ratio datascale that was using Pairs T-TestResult: There is an effect of laughing therapy on blood pressure in the elderly at UPT Panti WredhaBudhi Dharma Yogyakarta marked with a significant value of 0.000 (P <0.05)


2020 ◽  
Vol 22 (3) ◽  
pp. 341-361
Author(s):  
Gonzalo Grau-Pérez ◽  
J. Guillermo Milán

In Uruguay, Lacanian ideas arrived in the 1960s, into a context of Kleinian hegemony. Adopting a discursive approach, this study researched the initial reception of these ideas and its effects on clinical practices. We gathered a corpus of discursive data from clinical cases and theoretical-doctrinal articles (from the 1960s, 1970s and 1980s). In order to examine the effects of Lacanian ideas, we analysed the difference in the way of interpreting the clinical material before and after Lacan's reception. The results of this research illuminate some epistemological problems of psychoanalysis, especially the relationship between theory and clinical practice.


1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.


1979 ◽  
Vol 7 (1) ◽  
pp. 31-39
Author(s):  
G. S. Ludwig ◽  
F. C. Brenner

Abstract An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.


2017 ◽  
Vol 13 (2) ◽  
pp. 4640-4647
Author(s):  
A. M. Abdelghany ◽  
M.S. Meikhail ◽  
S.I. Badr ◽  
A. S. Momen

Thin film samples of pristine polyvinyl chloride (PVC), poly vinyldine fluoride (PVDF) in combination with their blend in addition to samples containing factorial mass fraction of multi wall carbon nano-tubes (MWCNTs) in the dopant level were prepared via routine casting technique using tetrahydrofurane (THF) as a common solvent. X-ray diffraction and transmission electron microscopy (TEM) depict the nano-scale (15-25 nm) of functionalized MWCNTs with no surface damage results from functionalization process.X-ray diffraction (XRD) shows a semi-crystalline nature of PVDF with evidence for more than one phase namely a and b phases. The fraction of b phase was calculated and correlated to the dopant content. FTIR optical absorption spectra revels a preservation of the main vibrational bands before and after addition of MWCNTs in the doping level with a presence of new small band 1151 cm-1 assigned for the interaction and complexation between constituents.


Author(s):  
I Ketut Widana

The working practice of the engineering students is part of the learning process that is irreducible and indispensable. The composition of  lecturing between theoretical and practical one is 40% to 60%. With this condition, the students spend more time at the laboratory. Generally, the students perform in the laboratory work by standing position. The design of research is observational cross-sectional. The method applied is observation, interview and measuring. The subjects of research are practicing students amounting to 21 students. Referring to the analysis of statistical test or Wilcoxon signed ranks test, the difference of effect of work position is significant, namely p < 0.05 towards musculoskeletal disorders (MSDs) before and after working. The quantity of the average complaint after working is score 44.62 ± 9.47. The result of Wilcoxon signed rank test shows that there is significant different effects of standing work position, namely p < 0.05 towards fatigue generally before and after working. The degree of the working pulse is on the average of 110.78  ± 17.80 bpm (beats per minutes) which can be categorized into the medium workload. Using paired t-test, the result is p < 0.05.


1979 ◽  
Vol 44 (12) ◽  
pp. 3632-3643 ◽  
Author(s):  
Karel Mach ◽  
Igor Janovský ◽  
Karel Vacek

Total yields of paramagnetic species, their optical bleaching and thermal annealing in acetic, propionic, a-butyric, isobutyric, and pivalic acid γ-irradiated at 77 K were followed by ESR spectroscopy. Radical anions, always found after irradiation, disappear during optical bleaching without formation of any paramagnetic product. During thermal annealing they are converted almost quantitatively into the α-radicals of the respective acid, with the exception of pivalic acid. Amounts of radical anions were estimated from the difference of integrated ESR spectra taken before and after optical bleaching. The results show that approximately equal amounts of the reduction and oxidation paramagnetic products of the γ-irradiation can be detected.


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