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Copyright of Agroindustrial Science is the property of Agroindustrial Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Reverse osmosis (RO) is a method for purifying water. Ir separates water from incrustations, through semi-permeable membranes; absorption of scales can cause damage to the membranes, affecting the process. Injecting antifouling removes and inhibits its overproduction. The objective of this scientific article is to learn about antiscalants, using as a method the bibliographic review of previous works that have operated with these, through the analysis of their processes and conclusions, to study how they vary from each other and which one implies better results. Objective: To analyze the most common antifoulings today through a bibliographic review, where compounds that have metaphosphates and polymers as a chemical base are studied. Materials and Methods: The review of 3 original publications that posed as the main topic the use of different antiscalants and their action on the membranes of reverse osmosis equipment was carried out. The reviewed articles were published in the 2018-2021 period, taking into consideration the quality and nature of the publications. Results and Discussion: According to the comparative analysis of the chosen antiscalants, the effect they have with respect to the membranes of reverse osmosis equipment was monitored. To analyze the results, aspects of function, dosage, injection point and conclusions obtained from each one were considered. Conclusions: Compared to phosphinocarboxylic acid and the modified base, sodium hexametaphosphate has shown better results in the industry with respect to reverse osmosis membranes in water purification processes. [ABSTRACT FROM AUTHOR]

Copyright of Revista Facultad de Ciencias Basicas is the property of Revista Facultad de Ciencias Basicas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main objective of this paper was to carry out the evaluation of the liquefaction process on Water Hyacinth biomass. To achieve this, a factorial experimental design with a cubic model was developed, for determining the effect of the variables temperature, time and liquid/solid ratio (L/S) on the response variable Energy Yield (EY). Best results were obtained at 300°C, 60 min and L/S = 10 (exp. 15) with RE of 6.34 MJ/kg biomass, at 300°C, 30 min and L/S = 10 (exp. 5) with EY of 6.31 MJ/kg biomass and at 270°C, 60 min and L/S = 20 (exp. 9) with 6.29 MJ/kg biomass, selecting the conditions of exp. 5 as the most appropriate given the lower L/S ratio and the shorter reaction time. The advantage of catalyst presence in the reaction was evident when comparing the results of the EY in exp. 26 with catalyst (5.9 MJ/kg biomass) and experiment without catalyst (3.3 MJ / kg biomass) under the same conditions. It was also possible to determine that the biooils were composed mainly of aromatic compounds, fatty acids, aliphatic hydrocarbons, ketones, aldehydes and alcohols, and carboxylic acids under more drastic conditions. [ABSTRACT FROM AUTHOR]

Copyright of Zephyrus is the property of Ediciones Universidad de Salamanca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

By a free radical polymerization reaction poly(acrylamide-co-itaconic acid), poly(AAm-co-AI); and poly(acrylamide-co-maleic acid), poly(AAm-co-AM); copolymers hydrogels were synthesized; with the purpose of studying the effect of the chemical structure of these di-carboxylic acids on the absorbing capacity of Ni2+ and Mg2+ ions. The swell ability and swelling kinetics of the hydrogels were calculated with the swelling index (Hp) and the metal ion absorption capacity was measured by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Studies indicated that both hydrogels have higher affinity for the Ni2+ ions. Also, when comparing the effectiveness of the acid monomers used, for the removal of the cations, it was obtained that the poly(AAm-co-AI) hydrogel is more effective, and is able to remove twice the Mg2+ ions compared to the poly(AAm-co-AM) hydrogel. The results are explained in terms of the structural difference of the acid monomers used and the electron configuration of the ions evaluated, which is related to the polymerion interactions that occur during the ion absorption process. [ABSTRACT FROM AUTHOR]

Characterization of a cellulose-based copolymer synthesized in ICIDCA laboratories by etherification, in two steps, with carboxyl and benzyl groups was realized. Incorporating benzyl and carboxyl groups in the cellulose was evident by 1H NMR. Degrees of substitution calculated from nuclear magnetic resonance were 0.44 to 0.1 carboxyl groups and to the benzyls, for a balance 4/1 between hydrophilic and hydrophobic groups. After derivatization the sample is decomposed at much lower temperature than the original material, indicating that the thermal stability is lower than of the native cellulose and the images from scanning electron microscopy show changes in the initial morphology of the material. [ABSTRACT FROM AUTHOR]

Introduction. For this research work, the acid whey produced by Oaxaca cheese industry in a UASB reactor was used. The reactor was subjected to three constant charges and three punctual charges of the whey. The reactor had a nominal capacity of 2.9 L with 1.9 days of hydraulic retention with an upward flow and a sludge blanket of 40% of the reactor's volume. Objective. Evaluate the behavior of the UASB reactor with three different charges of whey. Materials and methods. Three different constant charges of whey were used (5200, 7800 and 10500 mg CDO/L each one) during 22 days, and punctual charges of 32000, 47000 and 65000 mg DQO/L per day of whey, for each one, during 24 hours. Both the influent and the effluent were determined: total of sugars, volatile fatty acids (VFA's) protein, pH, methane and CDO. Results. The findings demonstrated that in the constant charges used the removal efficiency of CDO was 26 %, and for the punctual charges was 57 %. The sugar degradation efficiency was 95% for the constant and the punctual charges. For the protein, the removal efficiencies in the constant charges were above 27 % and for the punctual charges the efficiency was 46 %. Conclusion. The values of volatile fatty acids and methane were all within the limits for a good functioning of the reactor. Nevertheless, the pH had acid values below the ones recommended. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Superficies y Vacío is the property of Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Avances en Ciencias e Ingeniería is the property of Avances en Ciencias e Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tecnura is the property of Tecnura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Superficies y Vacío is the property of Sociedad Mexicana de Ciencia y Tecnologia de Superficies y Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: to verify the effect of three storage conditions on human milk acidity and to determine the quantity of lipids, total solids, ash, calcium, and total proteins. Methods: the sample comprised healthy milk donors to the Human Milk Bank of the University Hospital of Maringá (n37), State of Paraná, Brazil. The quantities of lipids, protein, total solids, ash and calcium were measured, as well as acidity. The study protocol included three storage conditions: time zero, after 4h storage at room temperature and after 24h under refrigeration. Results: the average concentrations of nutrients found in this study were comparable to those described in milk from lactating mothers of developed countries or other Brazilian regions, which is suitable forfeeding newborns. As for acidity, variations were observed between individuals for the storage condi- tions involving 4h and 24h, which did not occur for the condition of Oh. A weak correlation between the variables of acidity and protein content was observed, as well as for acidity and calcium. Conclusions: the acidity does not have a sign iji- cant influence on the concentration of the nutrients, at least under the storage conditions studied here. The best way to preserve human milk is to freeze it imme- diately after collection. [ABSTRACT FROM AUTHOR]

The students of the career in Agronomical Engineering of the Faculty of Agricultural Sciences of the University of Ciego de Avila, face difficulties to manage the concepts of the unit Carboxilic Acids. These are more evident when they have to compare their structure and properties with the ones of the other organic functions such as aldehydes and cetones as well as alcohols and phenols. One of the reasons of these difficulties can be found in the dynamics of the Educational Learning Process. The student doesn't face the solution of the problems that allow them to find out structural similarities and differences between these substances and following this the justification of the physical and chemical properties. In order to solve this problem, a dynamic of the Educational Learning Process based on a model for the systematization of the contents is proposed. The possibility of the implementation and contribution to the solution of the problem was certified by the criteria of the experts. [ABSTRACT FROM AUTHOR]

The direct conversion of solid-supported carboxylic acid allyl esters to carboxamides through the use of phenylsilane and catalytic Pd(PPh3)4 under mild reaction conditions is reported. The use of this methodology for the generation of a 48 compound solidphase array is described herein. [ABSTRACT FROM AUTHOR]

During spring of 2000, formic acid (85 %) and fluvalinate (3%) effectiveness against Varroa destructor Anderson y Trueman, was compared in Apis mellifera L. colonies located at Chillán Campus of University of Concepción (36°36' S - 72°0,6'O). Three groups of 10 beehives were formed. Group 1 was treated with formic acid to 85 %, applied in Universal Evaporator MHT®. Group 2 was used as control, without receiving any treatment. Group 3 was treated with fluvalinate 3% (rever concentración) impregnated splints. At the end of treatment, all colonies received a test treatment with Bayvarol® (Flumetrina). The biggest effectiveness was in fluvalinate treated group, with an average of 98.05 ± 2.13 %. In formic acid treated group an average effectiveness of 88.26 ± 9.12% was obtained, while in the control group the natural mortality was 41.11 ± 11.52 %. [ABSTRACT FROM AUTHOR]

Production of specific antibodies against compounds of low molecular weight (antibodies antihaptens) require the design of an immunization scheme employing as immunogen.a convenient synthetized hapten-carrier protein conjugate. A large number of organic compounds has been used as haptens, for example carboxylic acids as vanilmandelic acid (VMA), homovanillinic acid (HVA), palmitic acid, stearic acid and oleic acid, amines as norepinephrine, epinephrine, and metanphetamine, opium alkaloids as thebaine, codeine, morphine and cocaine, vitamins such as vitamin A, vitamin D3, vitamin B12, and biotine (vitamin H). Methods of preparation and characterization of hapten-carrier protein conjugates, and the evaluation of their immunogenic properties are described in this paper. [ABSTRACT FROM AUTHOR]