cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.6943769
title: MEASURING THE CONDUCTIVITY OF VERY DILUTE ELECTROLYTE SOLUTIONS, DROP BY DROP

description: Undergraduate experiments on ionic conductivity are common practice in general chemistry and advanced physical chemistry laboratories. Often, the conductivities are measured for solutions prepared for various salts, in a range of concentrations, and the relationship between solution conductivity and concentration is interpreted in terms of the Kohlrausch law. Contaminations can dominate the conductivity of the solutions such that students might obtain unsatisfactory results for analysis. Here, the experience of using a simple experimental procedure to obtain the concentration dependence of ionic conductivities for very dilute (sub-millimolar) electrolyte solutions in undergraduate laboratories is described. The experiment consists of measuring the conductivity of solutions of increasing concentration prepared by dropping the electrolyte solution into an initial vessel of deionized water. The range of concentrations achieved is one in which the conductivities vary linearly with the concentrations, such that the molar conductivities can be obtained directly without the use of the Kohlrausch equation. The simplicity of the experimental procedure leads the students to obtain good quality results using minimal amounts of materials. Examples are presented for the conductivities of strong electrolytes, and for the weak acetic acid electrolyte, for which the conductivity is dependent on the degree of dissociation also for dilute solutions.
DOI: 10.6084/m9.figshare.6943766.v1
title: Artificial feeding systems for calves in tropical conditions

description: ABSTRACT The objective of this study was to evaluate the bioeconomic performance of calves in the first 60 days of life submitted to three feeding systems. Twenty-four calves (Dutch x Guzerá) were used, 12 males and 12 females, with initial weight of 32.25±4.8kg for females and 36.92±6.8kg for males. The animals were distributed in a completely randomized design, in a factorial scheme (3 x 2). The calves received water at will and six liters of milk replacer a day for 60 days in three different strategies, called the suckling system (SA-30: 3 liters of milk replacer, twice a day until 30 days of age; SA-45: 3 liters of milk replacer, twice a day until 45 days of age; SA-49: 3 liters of milk replacer, twice daily up to 49 days old). The lactation systems studied did not present statistical difference (P&gt;0.05) for the consumption and digestibility of nutrients, except for organic matter (OM) and ethereal extract (EE). There was an interaction (P&lt;0.05) between the suckling system and sexual class for the OM and EE intakes, as well as for the average daily gain, in which HS 49 males presented higher averages in relation to SA 30. The bioeconomic performance of male calves from the lactation system 49 was superior and presented the best cost-benefit ratio among the systems studied.
DOI: 10.6084/m9.figshare.6943769.v1
title: MEASURING THE CONDUCTIVITY OF VERY DILUTE ELECTROLYTE SOLUTIONS, DROP BY DROP

description: Undergraduate experiments on ionic conductivity are common practice in general chemistry and advanced physical chemistry laboratories. Often, the conductivities are measured for solutions prepared for various salts, in a range of concentrations, and the relationship between solution conductivity and concentration is interpreted in terms of the Kohlrausch law. Contaminations can dominate the conductivity of the solutions such that students might obtain unsatisfactory results for analysis. Here, the experience of using a simple experimental procedure to obtain the concentration dependence of ionic conductivities for very dilute (sub-millimolar) electrolyte solutions in undergraduate laboratories is described. The experiment consists of measuring the conductivity of solutions of increasing concentration prepared by dropping the electrolyte solution into an initial vessel of deionized water. The range of concentrations achieved is one in which the conductivities vary linearly with the concentrations, such that the molar conductivities can be obtained directly without the use of the Kohlrausch equation. The simplicity of the experimental procedure leads the students to obtain good quality results using minimal amounts of materials. Examples are presented for the conductivities of strong electrolytes, and for the weak acetic acid electrolyte, for which the conductivity is dependent on the degree of dissociation also for dilute solutions.
DOI: 10.6084/m9.figshare.6943763
title: Growth and nutrient contents in lowland rice due to phosphorus and potassium fertilization

description: ABSTRACT In order to reach an optimum and sustainable production, growers must know the fertilizing potassium (K) and phosphorous (P) application rates. The present study aimed to determine the rice development in response to combined rates of P and K, on Plinthaquults (380-400 g kg-1 of clay), under high and low fertility conditions, in the tropical lowland plain of the Araguaia river, Brazil. Three field experiments were performed, each one consisting of a completely randomized factorial block design, with three replications. Treatments included a combination of six K2O rates (0 kg ha-1, 30 kg ha-1, 60 kg ha-1, 90 kg ha-1, 120 kg ha-1 and 150 kg ha-1) with six P2O5 rates (0 kg ha-1, 30 kg ha-1, 60 kg ha-1, 90 kg ha-1, 120 kg ha-1 and 150 kg ha-1). No interaction effect between P and K rates was observed for the evaluated variables in any fertility level/year. Phosphorous application under low fertility conditions, as well as K under high fertility conditions, affect overall crop nutrition, tillering capacity, yield components and grain yield of lowland rice, though no effects were observed due to the P application in high fertility soils and K in low fertility soils. Under high fertility conditions, the grain yield increment rate due to the K application was 4.04 kg ha-1, whereas in the low fertility areas, such as recently cleared fields, a maximum yield of 7,161 kg ha-1 was achieved by applying 140 kg ha-1 of P.
DOI: 10.6084/m9.figshare.6943763.v1
title: Growth and nutrient contents in lowland rice due to phosphorus and potassium fertilization

description: ABSTRACT In order to reach an optimum and sustainable production, growers must know the fertilizing potassium (K) and phosphorous (P) application rates. The present study aimed to determine the rice development in response to combined rates of P and K, on Plinthaquults (380-400 g kg-1 of clay), under high and low fertility conditions, in the tropical lowland plain of the Araguaia river, Brazil. Three field experiments were performed, each one consisting of a completely randomized factorial block design, with three replications. Treatments included a combination of six K2O rates (0 kg ha-1, 30 kg ha-1, 60 kg ha-1, 90 kg ha-1, 120 kg ha-1 and 150 kg ha-1) with six P2O5 rates (0 kg ha-1, 30 kg ha-1, 60 kg ha-1, 90 kg ha-1, 120 kg ha-1 and 150 kg ha-1). No interaction effect between P and K rates was observed for the evaluated variables in any fertility level/year. Phosphorous application under low fertility conditions, as well as K under high fertility conditions, affect overall crop nutrition, tillering capacity, yield components and grain yield of lowland rice, though no effects were observed due to the P application in high fertility soils and K in low fertility soils. Under high fertility conditions, the grain yield increment rate due to the K application was 4.04 kg ha-1, whereas in the low fertility areas, such as recently cleared fields, a maximum yield of 7,161 kg ha-1 was achieved by applying 140 kg ha-1 of P.
DOI: 10.6084/m9.figshare.6943754
title: CORK MEMBRANE FOR EFFICIENT OIL AND WATER SEPARATION

description: Cork is a renewable, biocompatible, environmentally friendly and abundant biological material with microscale cellular structure. Fabrication of filtration membranes for the separation of oil and water by utilizing such natural materials to replace nonnatural membranes is a green method. A cork membrane with a water contact angle greater than 150° and an oil contact angle close to 0° was fabricated by chemically modifying cork membranes with 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane. The special wettability was achieved owing to the cellular structure and the surface composition of the cork membrane. Just like nonnatural filtration membranes, natural cork membranes exhibited excellent permeability for oils. After at least 40 cycles of oil-removal processes, the separation efficiency of the membrane was still above 99.1%. Under harsh conditions such as strong acid/alkali, high humidity, and high temperature environments, the wettability and separation efficiency exhibited excellent stability and durability. This method offers an opportunity to the practical applications of the superhydrophobic cork membrane.
DOI: 10.6084/m9.figshare.6943757
title: Stabilityof the caranhain differentstorage periods

description: ABSTRACT The objective of this study was to verify the influence of storage time on the microbiological, physical-chemical, and sensorial quality of the fish (Piaractusmesopotamicus). The fish were stored on ice for 0, 7, 14, 21, and 28 days and submitted to counts of mesophilic, psychrotrophic, coliform microorganisms at 35ºC and 45ºC, Salmonella sp. and coagulase positive staphylococci. Analyzes of temperature, pH, acidity, volatile bases, proteins, lipids, ashes, humidity, cooking test, as well as sensorial analysis were performed. Counts of mesophiles, psychrotrophic, coliforms at 35°C and 45°C increased with storage time. The presence of Salmonella sp. was not observed, whereas the coagulase positive Staphylococcus count was &lt;10 (est) CFU/g in all storage periods. It was also observed that the storage time had influence on all physical-chemical variables, except for temperature. In the sensorial analysis, a linear increase of the quality index (IQ) was verified throughout the storage and the rejection occurred at 14 days.
DOI: 10.6084/m9.figshare.6943757.v1
title: Stabilityof the caranhain differentstorage periods

description: ABSTRACT The objective of this study was to verify the influence of storage time on the microbiological, physical-chemical, and sensorial quality of the fish (Piaractusmesopotamicus). The fish were stored on ice for 0, 7, 14, 21, and 28 days and submitted to counts of mesophilic, psychrotrophic, coliform microorganisms at 35ºC and 45ºC, Salmonella sp. and coagulase positive staphylococci. Analyzes of temperature, pH, acidity, volatile bases, proteins, lipids, ashes, humidity, cooking test, as well as sensorial analysis were performed. Counts of mesophiles, psychrotrophic, coliforms at 35°C and 45°C increased with storage time. The presence of Salmonella sp. was not observed, whereas the coagulase positive Staphylococcus count was &lt;10 (est) CFU/g in all storage periods. It was also observed that the storage time had influence on all physical-chemical variables, except for temperature. In the sensorial analysis, a linear increase of the quality index (IQ) was verified throughout the storage and the rejection occurred at 14 days.
DOI: 10.6084/m9.figshare.6943754.v1
title: CORK MEMBRANE FOR EFFICIENT OIL AND WATER SEPARATION

description: Cork is a renewable, biocompatible, environmentally friendly and abundant biological material with microscale cellular structure. Fabrication of filtration membranes for the separation of oil and water by utilizing such natural materials to replace nonnatural membranes is a green method. A cork membrane with a water contact angle greater than 150° and an oil contact angle close to 0° was fabricated by chemically modifying cork membranes with 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane. The special wettability was achieved owing to the cellular structure and the surface composition of the cork membrane. Just like nonnatural filtration membranes, natural cork membranes exhibited excellent permeability for oils. After at least 40 cycles of oil-removal processes, the separation efficiency of the membrane was still above 99.1%. Under harsh conditions such as strong acid/alkali, high humidity, and high temperature environments, the wettability and separation efficiency exhibited excellent stability and durability. This method offers an opportunity to the practical applications of the superhydrophobic cork membrane.
DOI: 10.6084/m9.figshare.6943745
title: Predictive ability of accruals before and after IFRS in the Brazilian stock market

description: ABSTRACT This study aimed to analyze and assess the predictive ability of discretionary accruals (DAs) and non-discretionary accruals (NDAs) for forecasting future cash flows before and after the convergence with International Financial Reporting Standards (IFRS) in Brazil. The study is warranted due to the scarcity of research in Brazil on the subject and is relevant because it aims to shed light on whether the changes occurring due to convergence with IFRS in Brazil have improved accounting quality. The accounting choices of managers and accountants in the Brazilian stock market, enabled by IFRS, contribute to an apparent improvement in accounting quality in terms of reliability, the faithful representation of entities’ equity and financial positions, and in particular, the predictive ability for forecasting future cash flows. The population was composed of publicly traded companies listed on the Bovespa and São Paulo Stock, Commodities, and Futures Exchange (BM&FBovespa) in 2004 to 2007 and 2010 to 2015. The non-probability convenience sample is composed of 715 enterprises, once companies from the “finance and insurance” and “funds” sectors and even those considered as “holding” were excluded. The data were pooled by year, as they contain different companies over the time series (unbalanced panel data). The DAs and NDAs produced prior to full convergence with IFRS are negative and statistically significant for predicting future cash flows in the Brazilian stock market, which indicated opportunistic/contractual earnings management. One of the possible explanations for this would be the influence of government tax authorities on Brazilian accounting norms, which could induce managers to manipulate accounting results with the aim of reducing earnings in order to pay fewer taxes, for example. The DAs and NDAs produced after IFRS are positive and statistically significant for predicting future cash flows in the Brazilian stock market, signaling the motivation of discretionary accounting choices under the informational aspect. Current DAs and NDAs add informational power compared to current aggregate accruals. It has also been observed that the current DAs and NDAs originating after IFRS in Brazil, compared to current aggregate accruals, have an informational gain in relation to those produced before.
DOI: 10.6084/m9.figshare.6943748
title: Use of management reports and performance of sales managers in an insurance company

description: ABSTRACT This article aims to investigate the relationship between perceptions of the enabling dimension and the technical validity of the management reports of an insurance company and the performance of its sales managers, mediated by the use of these reports. Companies invest resources in providing management reports for business managers to take decisions, so understanding what influences the use of these reports and whether this use is associated with performance constitutes a relevant subject for both academia and professional practice. The results may be useful for organizations that are taking decisions to invest in management reports, showing that technical validity is what best influences the use of these reports, at least in the short term, which is also a contribution to the theory. Secondary data were combined with a survey of 231 respondents from an insurance company and analyzed using the structural equation modeling (SEM) technique via partial least squares (PLS). The article contributes to the literature and management accounting practice by demonstrating that, unlike in previous studies, the enabling dimension does not positively influence the use of management reports. On the other hand, the study shows that technical validity, which is a more tangible dimension of the quality of management reports, is positively associated with their use and that this use influences the performance of the sales managers. Keywords: use of management reports, sales performance, sales managers, insurers, enabling.
DOI: 10.6084/m9.figshare.6943745.v1
title: Predictive ability of accruals before and after IFRS in the Brazilian stock market

description: ABSTRACT This study aimed to analyze and assess the predictive ability of discretionary accruals (DAs) and non-discretionary accruals (NDAs) for forecasting future cash flows before and after the convergence with International Financial Reporting Standards (IFRS) in Brazil. The study is warranted due to the scarcity of research in Brazil on the subject and is relevant because it aims to shed light on whether the changes occurring due to convergence with IFRS in Brazil have improved accounting quality. The accounting choices of managers and accountants in the Brazilian stock market, enabled by IFRS, contribute to an apparent improvement in accounting quality in terms of reliability, the faithful representation of entities’ equity and financial positions, and in particular, the predictive ability for forecasting future cash flows. The population was composed of publicly traded companies listed on the Bovespa and São Paulo Stock, Commodities, and Futures Exchange (BM&FBovespa) in 2004 to 2007 and 2010 to 2015. The non-probability convenience sample is composed of 715 enterprises, once companies from the “finance and insurance” and “funds” sectors and even those considered as “holding” were excluded. The data were pooled by year, as they contain different companies over the time series (unbalanced panel data). The DAs and NDAs produced prior to full convergence with IFRS are negative and statistically significant for predicting future cash flows in the Brazilian stock market, which indicated opportunistic/contractual earnings management. One of the possible explanations for this would be the influence of government tax authorities on Brazilian accounting norms, which could induce managers to manipulate accounting results with the aim of reducing earnings in order to pay fewer taxes, for example. The DAs and NDAs produced after IFRS are positive and statistically significant for predicting future cash flows in the Brazilian stock market, signaling the motivation of discretionary accounting choices under the informational aspect. Current DAs and NDAs add informational power compared to current aggregate accruals. It has also been observed that the current DAs and NDAs originating after IFRS in Brazil, compared to current aggregate accruals, have an informational gain in relation to those produced before.
DOI: 10.6084/m9.figshare.6943748.v1
title: Use of management reports and performance of sales managers in an insurance company

description: ABSTRACT This article aims to investigate the relationship between perceptions of the enabling dimension and the technical validity of the management reports of an insurance company and the performance of its sales managers, mediated by the use of these reports. Companies invest resources in providing management reports for business managers to take decisions, so understanding what influences the use of these reports and whether this use is associated with performance constitutes a relevant subject for both academia and professional practice. The results may be useful for organizations that are taking decisions to invest in management reports, showing that technical validity is what best influences the use of these reports, at least in the short term, which is also a contribution to the theory. Secondary data were combined with a survey of 231 respondents from an insurance company and analyzed using the structural equation modeling (SEM) technique via partial least squares (PLS). The article contributes to the literature and management accounting practice by demonstrating that, unlike in previous studies, the enabling dimension does not positively influence the use of management reports. On the other hand, the study shows that technical validity, which is a more tangible dimension of the quality of management reports, is positively associated with their use and that this use influences the performance of the sales managers. Keywords: use of management reports, sales performance, sales managers, insurers, enabling.
DOI: 10.6084/m9.figshare.6943739
title: Chitosan and gum arabic nanoparticles for heavy metal adsorption

description: Abstract Chitosan (CT) is a polysaccharide with the ability to adsorb metals on its surface. In this work, CT-based nanoparticles (NPs) are produced by complex formation with gum arabic (GA) to increase their adsorbent potential for removal of heavy metals in aqueous medium. Adsorption efficiency is evaluated as a function of NP composition and polysaccharide concentration. NPs are sized from 250 to 375 nm at a zeta potential up to -25 mV, suggesting stability to adsorb metals. In particular, CTGA56 and CTGA80 NPs adsorbed a substantially higher amount of copper ions than pure CT. Adsorption kinetics studies showed that the reaction process followed a pseudo second-order model and the adsorption isotherm results fit a Langmuir model, highlighting the monolayer adsorption process with prominent adsorption capacity. These findings indicate the adsorbent potential of CTGA NPs and suggest that these particles can be used for removal of metal ions from contaminated water sources.
DOI: 10.6084/m9.figshare.6943739.v1
title: Chitosan and gum arabic nanoparticles for heavy metal adsorption

description: Abstract Chitosan (CT) is a polysaccharide with the ability to adsorb metals on its surface. In this work, CT-based nanoparticles (NPs) are produced by complex formation with gum arabic (GA) to increase their adsorbent potential for removal of heavy metals in aqueous medium. Adsorption efficiency is evaluated as a function of NP composition and polysaccharide concentration. NPs are sized from 250 to 375 nm at a zeta potential up to -25 mV, suggesting stability to adsorb metals. In particular, CTGA56 and CTGA80 NPs adsorbed a substantially higher amount of copper ions than pure CT. Adsorption kinetics studies showed that the reaction process followed a pseudo second-order model and the adsorption isotherm results fit a Langmuir model, highlighting the monolayer adsorption process with prominent adsorption capacity. These findings indicate the adsorbent potential of CTGA NPs and suggest that these particles can be used for removal of metal ions from contaminated water sources.
DOI: 10.6084/m9.figshare.6943733
title: UATR and NIRA evaluation in the quantification of ATBC in NC blends

description: Abstract The paint industry requires rapid and accurate methodologies of raw materials qualitiy controls. For example, the evaluation of the suitable ratio of binary mixtures of polymer/plasticizer such as nitrocellulose (NC)/acetyl tributyl citrate (ATBC) must be done, since this ratio is directly related to the performance of the final product. However, there is a small number of quantitative methodologies of such control in the literature. In this context, in this paper, the applicability of Infrared Fourier Transform Spectroscopy (FT-IR) techniques by using universal total attenuated reflection (UATR), in the middle infrared (MIR), and the reflectance analysis in the near infrared region (NIRA) is evaluated for the quantification of plasticizer ATBC in mixtures with NC. MIR and NIR methodologies presented good results such as: practicality of not requiring refined sample preparation, analysis time about 30 min and good accuracy, suitable data for using in the quality control laboratories of paint industry.