Southern Brazilian Journal of Chemistry - Southern Brazilian Journal of Chemistry, Volume 28, No. 28, 2020
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Published By Periodico Tche Quimica

0104-5431

Author(s):  
Ana Carla PESSUTTO ◽  
JONKO Eliena

Background: Aluminum stands out for being a light, corrosion-resistant, and recyclable metal, achieving wide coverage in the market. When incorporated into alloying elements, it is possible to acquire other desirable characteristics. Alloy 6063, intended for architectural purposes, has aesthetic, structural, and strength functions. Anodized finishing is performed through an electrolytic process, ensuring a more resistant aluminum oxide film than that formed naturally. For decorative purposes, the anodic film coloration can be performed by several methodologies, in this case, for the coloration by organic adsorption, with the use of aniline, and the electrolytic coloration, composed of tin sulfate salts, both for obtaining the black color. Aim: Compare of two different staining methods on the surface of anodized profiles of aluminum alloy 6063. Methods: Profile samples were collected and tests were carried out to measure the thickness of the anodic layer, immersion tests with 3,5 percent sodium chloride, for 1000 hours, and neutral saline mist, for 600 hours. Results and Discussion: Both methodologies proved to be resistant to immersion tests with sodium chloride, as well as with neutral saline mist, and these tests are quite aggressive and provide corrosion of the material when not well treated. Corrosion points were only seen at the intersections performed, and in the rest of thearea, no points were detected. Conclusions: The result of both methodologies was positive, considering tht there was no corrosion in the tested samples, except in the intersections performed, as well as the maintenance of the color in both tested methodologies, which was not expected in the literature. For future work, it is suggested to deepen the study to perform electrochemical impedance spectroscopy tests for exaluate the strength of the anodic film and perform anodizing with the same parameters, however, with different anilines to analyze their behavior.


Author(s):  
SHARBA Intisar Razzaq ◽  
AL-DUJAILI Arshad Noori

Background: β-thalassemia is a blood disorder in which the body does not make hemoglobin normally. Aim: To assess serum sclerostin in female patients with beta-thalassemia and compare with the healthy controls and to predict its complication associated with the bone pathophysiology, for designed improvement the lifestyle goodliness for these patients. Material and methods: Sixty-nine female beta-thalassemia (βT) patients (54 βT major and 15 βT Intermedia), aged 8-40 years who dependent on transfused blood, and 20 healthy controls were evaluated serum sclerostin, and was examined the relationship with hematological parameters RBC, Hb, PCV, WBC, PLT, BMI, splenic status, iron, and ferritin levels. The information of beta-thalassemia patients was collected and records by the questioner. Results: A significantly increased serum sclerostin level (mean 26.80±0.91) pg/ml was showed in βT patients compared with the healthy controls (10.03±0.68, p  smaller than  0.001) pg/ml. Furthermore, a significant decrease (p smaller than 0.05) of the sclerostin level was observed in β-thalassemia major compared to intermedia β-thalassemia patients. Serum sclerostin level revealed a significant increase in progress age; it is highest in the age group (30-40) year as compared with age group (8-18) and (19-29) year respectively. Sclerostin showed no associations with the RBC, Hb, PCV, and significantly positively correlated (p smaller than 0.05) with serum iron, ferritin levels, WBC, and PLT count. Significantly higher sclerostin levels in splenectomized and underweight groups were observed compared to unsplenectomized and normal-weight groups (p smaller than 0.05) of βT patients. Conclusions: Sclerostin plays an important role in beta-thalassemia patients and can serve as a biomarker associated with the bone pathophysiology and indicator to prevent the continuation of such serious diseases caused by iron overload in these patients.


Author(s):  
Aye Taiwo AJIBOYE ◽  
Jaye Femi OPADIJI ◽  
Adebimpe Ruth AJAYI

Background: MQ-series gas sensors belong to the metal oxide semiconductor (MOS) family of sensors that can sense the presence of many gases. These sensors find their application in gas alarm systems as key components. While necessary sensor circuit output voltage value for alarm point in a stand-alone gas alarm system is desirable, but what exact combination of the sensor circuit parameters is required? Hitherto, the determination of these circuit parameters has not been given much attention in the research community. Aim: the purpose of this work is to explore a structured graphical approach of determination of MQ series gas sensor circuit parameters for a stand-alone gas alarm system that yields desired sensor circuit output voltage value for the alarm point; the main objective of the study was to develop mathematical model equations that relate the: (i) sensor resistance (RS) with the gas concentration (x) and the sensor resistance at standard calibration concentration of the sensor base gas in the clean air (Ro) and (ii) sensor circuit output voltage (VRL), load resistance (RL) and sensor resistance (RS). It is expected from the model equations developed that graphical correlations of the sensor circuits parameters will be generated. Using these graphs for a particular case of an MQ-4 gas sensor under the influence of LPG, the parameters that yield desired sensor circuit output voltage of 2V for 1000 ppm of LPG alarm point will be determined. Methods: Model equations were developed for the sensor dynamics, and based on these model equations, graphs for the determination of required sensor parameters were plotted for a case of MQ-4 gas sensor response to LPG. Results and Discussion: The results yielded optimal values for R_O,R_S and R_L of 20 kΩ, 30 kΩ and 20 kΩ respectively, for alarm settings of 1000 ppm and a desired sensor circuit output voltage of 2 V. Based on determined parameters, the calibration equation for determination of best concentration value for a given value of emulated LPG concentration was developed. Using the method proposed in this study makes the process of determining the MQ-series gas sensor circuit parameters less cumbersome as their value can easily be obtained from the resulting graphs. Conclusions: a structured graphical approach for determination of MQ-series gas sensor circuit parameters for alarm points in a stand-alone gas alarm system showed that using MQ-4 gas sensor and LPG as the target gas, and for a sensor circuit output voltage of 2 V for alarm point at 1000 ppm of LPG, the corresponding value of R_O, R_S and R_L obtained were 20 kΩ, 30 kΩ, and 20 kΩ respectively. Hence, a structured graphical approach is suitable for determining MQ series gas sensor circuit parameters for a stand-alone gas alarm system under the influence of its associated gases.


Author(s):  
GALIASSI Gabriela Regina Rosa ◽  
RAMIREZ Maribel Valverde

Background: Heat treatment is one of the most used methods to preserve food, such as orange juices, which are an excellent source of ascorbic acid. To avoid vitamin C degradation and reduce loss, fast heating is recommended. However, little is known about heat transfer during juice pasteurization. Aim: Therefore, this work aimed to determine the vitamin C content and the convective heat transfer coefficient in the pasteurization of orange juice. Methods: To perform the experiment, in the juice container, two regions were analyzed: the central region and near the wall. For the time-temperature control, thermometers were installed in the two regions mentioned. Every 120 seconds, the temperature was measured. The vitamin C content in the juice was evaluated before and after pasteurization using the iodometric method. The convective coefficient was evaluated using the method of dimensionless numbers and the experimental method. Results and Discussion: In pasteurization, the solution was heated to 80 °C, where heating lasted 3000 seconds and cooling for 2520 seconds. The graph showing the relationship of the convective heat transfer coefficient and temperature follows the same trend of the literature. The convective coefficient is higher in the region near the wall. As time passes and temperature decreases, the central region tends to equilibrium, and the coefficient becomes more constant. The vitamin C content remained constant before and after pasteurization. The values of the dimensionless numbers used in the calculations are in the same order of magnitude as the literature. Conclusions: The pasteurization did not cause ascorbic acid degradation since the heating step was fast in the heat treatment. The graphic showed that there is a dependence of the dimensionless of temperature with the dimensionless Biot and Fourier. It was noted that studying the thermal behavior in the cooling of orange juice is extremely important to ensure its quality.


Author(s):  
Andrey SEVBITOV ◽  
Aleksey DOROFEEV ◽  
Sergey MIRONOV ◽  
Samer AL-KHOURY ◽  
Anton TIMOSHIN

Background: Despite innovations in orthopedic dentistry, the manufacture of removable dentures belongs to the most popular orthopedic care category. Removable dentures are combined stimuli that affect the mucous membrane and neuro-receptor apparatus. Acrylic plastic prostheses, widely used in prosthetic dentistry, have a negative side mechanical, chemical-toxic, sensitizing, and thermal insulating effect on oral tissue and prosthetic impression area. This is often complicated by a violation of the biocenosis of the oral cavity, the growth of pathogenic microflora that releases toxins, especially an increase in the number of yeast colonies that irritate the oral mucosa and prosthetic stomatitis. According to the WHO, one-fifth of the world s population suffers or has suffered various candidiasis forms at least once. The worldwide increase in the incidence of the disease is primarily related to the fact that this infection is opportunistic, more than half of the world s population is a carrier of fungi of this kind, i.e., in most cases, it is an endogenous infection, which makes candidiasis different from other opportunistic mycoses. Aims: The purpose of this study was to study the prevalence of candidiasis in patients using removable dentures and to evaluate the effectiveness and prevention of candidiasis treatment. Methods: 100 patients with oral candidiasis of various age groups from 45 to 65 years were observed. Of these, 60 patients with removable plate prostheses; 40 patients with partially removable prostheses. Results and Discussion: Chronic forms of candidiasis were diagnosed in 40 patients and with exacerbation of chronic forms of candidiasis-60 people. The number of untreated carious cavities and poor hygienic condition of the oral cavity directly affects the severity of candidiasis. Acute forms of candidiasis were observed mainly in patients with high DMF and PMA indices. The severity of candidiasis depends on the degree and duration of wearing dentures and hygienic conditions - the most severe forms of invasive candidiasis were observed in the presence of removable plate prostheses, the complete absence of teeth, and the use of a prosthesis for more than 10-15 years. A combined lesion of the oral mucosa and the red border of the lips was observed mainly in patients older than 60 years. Conclusions: The presence of candidiasis in the oral cavity in patients with removable plate prostheses leads to a statistically significant change in the indicators of local immunity of the oral cavity: an increase in the concentration of serum IgG and IgA and the values of the coefficient of the balance of local immunity factors.


Author(s):  
Georgy Georgievich KLASNER ◽  
Alexandr Maximovich SPIRIDONOV

The main vector of mechanization and automation of livestock farming at the present stage of technological development of producers is the improvement of resource-saving technologies and technical devices that enables agricultural producers to produce relatively expensive and high-quality equipment to improve conditions for the animals. This article was considered a method for effective fractionation of manure on pig farms to further obtain humus for soil fertilization. The optimal conditions for the performance of the presented gadget were identified, namely: the time spent by the manure mass in the rotor is 0.1, with a separation factor of 170 to 180, the partition for the filter is made of metal sheet with holes whose diameter varies from 0.8 to 1.5 mm and a thickness of no more than 1 mm. The device presented in the manuscript has several advantages in the form of automation, low energy consumption and cost, novelty, and high efficiency.


Author(s):  
Intisar Razzaq Sharba ◽  
Arshad Noori Al-Dujaili

E-selectin, as identified (CD62E), is expressed on endothelial cells after stimulation with inflammation cytokines. β-Thalassemia diseases (βT) and early diagnosis are of utmost significance in the entire world population. This study was performed in the Thalassemia Center of the Al-Zahraa Educational Hospital in Al-Najaf Province, Iraq, on sixty-nine with β-thalassemia (54 βT major and 15 βT Intermedia) aged 8-40 years who transfused blood. Compared to 20 healthy volunteers as a control group. In both βT patients and healthy groups were assessed serum E-selectin levels. It was investigated the relationship with RBC, Hb, PCV, WBC, PLT, BMI, splenic status, iron, and ferritin levels. The results revealed a significant (P<0.05) decreased values of HB, RBC, P.C.V, and BMI. In contrast, values of WBC, PLT, Iron, and Ferritin were significantly increased in βT patients as compared to the healthy control groups. A significant (P<0.05) increase in serum E- Selectin level in βT patients (20.55±0.47) ng/ml to compare with the healthy group (9.16±0.50) ng/ml. Furthermore, it was a significant decrease in groups of βT major (19.87±0.42) ng/ml more than in βT intermedia (23±1.42) ng/ml. E-Selectin revealed a significant increase (P<0.05) in progress age and associated with splenectomies and underweight groups compared to splenectomies and the normal weight groups, respectively. Also, E-Selectin levels significantly positively correlated with WBC, PLT value, iron, and Ferritin levels. However, it was no significant with RBC, PCV, Hb. As a conclusion from this study, E- Selectin is an important biomarker in β-thalassemia patients can be identified as the complications associated with iron overload, inflammatory process, and endothelial dysfunction in βT disease.


Author(s):  
Flávia Sapper DA ROSA ◽  
Andressa LHAMBY ◽  
Vinicyus Mourão Monteiro GUILLET ◽  
Marcos Antônio KLUNK ◽  
Nattan Roberto CAETANO

The ore beneficiation process uses little technology, but mining companies have high economic performance. As an energy source, firewood plays a fundamental role due to its simple storage, low cost, great availability of forests, and lack of processing. Thus, the present work aims to analyze the consumption of firewood as fuel and possible improvements in the process for the production of lime in terms of harnessing raw materials and costs. Calcium oxide is obtained from the thermal decomposition of calcium and magnesium carbonates obtained from dolomitic deposits of limestone (CaCO3 : CaMgCO3). After CaO extraction, it is subjected to a calcination process, removing carbon dioxide (CO2) in ovens that work at temperatures between 900 and 1200°C. The source of energy applied to the calcination furnaces in the analyzed area is wood. The wood has a calorific value between 2,250 and 2,700 Kcal/Kg, but the moisture content responsible for the thermal variation must be considered. The firewood burning process was carried out in a ravine type oven where the temperature at which operators are exposed to heat was evaluated. The results indicated that the cooking time dropped by 20% as the amount of wood is fed into the oven. This increase represents a significant gain in lime production, thus leading to a higher profit for the company.


Author(s):  
Jeans Wills RAMÍREZ ◽  
Marilia GUILLEN ◽  
Gerzon E. DELGADO

The extraction of naturally occurring compounds is one of the fastest-growing industries because of its benefits against its synthetic analogs. Environmental protection must require the use of natural products instead of chemicals to minimize pollution. Thus, this investigation studies the use of some natural product, as curcumin, as naturally occurring acid‐base indicators. Curcumin can be used as acid-base indicators since it was found that it possesses pH-dependent solubility. Curcumin, the major active component of turmeric, Curcuma longa (Zingiberaceae), is used as a spice in curry and as a coloring agent in yellow mustards, cosmetics, pharmaceuticals, and hair dyes. In this research, the main compound colored rhizome of turmeric (Curcuma longa) cultivated in Mérida, Venezuela, is extracted: Curcumin (C21H20O6) (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, in a yield of 3.42% after 8 hours of extraction using soxhlet extractor system with organic solvents (hexane and ethanol). The thin-layer chromatography and column performed separation and purification using a mobile phase, a mixture of chloroform-hexane 3:2. The dye was characterized by spectroscopic analysis of visible ultraviolet (UV-Vis) and infrared (IR), in addition to his studio in steering sensitivity as an acid-base indicator. This dye is useful as an acid-base indicator in strong acid-strong base volumes and did not require large amounts of it as it has high sensitivity. The results indicate that curcumin as an acid-base indicator allows the development of new standards in different chemistry fields that require this type of analysis.


Author(s):  
Mohammed Jasim QASIM ◽  
◽  
Israa Qusay FALIH

Diabetes mellitus (DM) is a clinical disease correlated with a deficiency of insulin secretion or action. It is one of the leading causes of morbidity and mortality worldwide. The global burden of diabetes is rising due to increasing obesity and population aging. Urinary tract infections (UTI) are common microbial infections known to affect the different parts of the urinary tract accounting for major antibacterial drug consumption. About 150 million UTI cases were diagnosed every year. Urinary tract infections are the most important and most common site of infections in a diabetic patient. Diabetic patients have been found to have a 5-fold frequency of acute pyelonephritis at autopsy than non-diabetics. Most of the urinary tract infections in patients with diabetes are relatively asymptomatic. The presence of this syndrome predisposes to much more severe infections, particularly in patients with acute ketoacidosis, poor diabetic control, diabetic complications such as neuropathy, vasculopathy, and nephropathy. The Gram-negative aerobic bacilli are the large group of bacterial pathogens that cause UTI with few species of Gram-positive bacteria. However, some fungi, parasites, and viruses have also been reported to invade the urinary tract. Urinary tract infection affects women more than men due to several factors such as proximity of the genital tract to the urethra, anatomy of the female urethra, sexual activity, menopause, and pregnancy. Other possible risk factors of UTI include allergy, obesity, diabetes, past history of UTI, contraceptive use, catheter use, and family history.


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