Portugaliae
Electrochimica Acta

Bd was produced by transesterification of refined NSO with MeOH and CaO catalyst using batch mode. Physicochemical properties of NSO and Bd as an alternative diesel fuel were characterized using ASTM fuel test standards. The FA composition and functional groups of Bd were investigated using GC-MS and FT-IR, respectively. The effect of basic parameters such as reaction catalyst Ct, MeOH/oil molar ratio, reaction T and time, and SS were determined using batch mode. These process parameters were optimized using RSM and ANOVA. The importance of various process parameters and their combined effects on transesterification performance was determined through CCD. Statistical analyzes of the data led to the development of a second-order quadratic polynomial regression model that established the relationship between Bd yield and process variables. The model was able to adequately predict Bd yield with R2 value of 0.9942. The obtained results were in good agreement with published data for Bd from other vegetable oils, as well as with various international standards for this product. An optimal yield of 94% was achieved under optimal conditions of catalyst Ct (4 wt%), MeOH/oil molar ratio of 8:1, T of 55 °C, time of 60 min and SS of 400 rpm. The results show that Bd produced using alcohol in the transesterification process improved CP and CFPP properties. Keywords: ANOVA; Bd; NSO; oil transesterification; optimization; RSM.

Poultry meat is a high-protein source that is consumed all over the world. This source is tainted not only by viruses but also by environmental contaminants, including HM. This study aimed to detect HM in the tissues (liver, gizzard, muscles, heart and kidney) of BC and DC in Quetta city, Balochistan, Pakistan for the first time, using AAF. Samples were collected from different regions of the district, and prepared for analysis. The measured Ct (mg/L) of detected HM like Pb (0.30-0.83), Co (0.18-0.35), Mn (0.10-0.21), Fe (0.32-12.70) and Cu (3.79-4.51) varied across different organs in analyzed BC and DC samples. Cu, Mn, Co and Fe content was within the range of acceptable values established by WHO and ANZFA. However, Ct of Pb for BC and DC exceeded WHO’s (0.2 mg/L) and EU’s (0.1 mg/L) permissible limits. Therefore, more in depth research studies on poultry feed should be carried out, for its improvement and safety. Keywords: AAS; BC; DC; HM.

NH has the ability to control corrosion of various metals and alloys such as Al, CS, Cu, Cu Sn, MS, Sn and SS. It behaves as a CI in acidic, basic or neutral media. In the several studies herein reviewed, various techniques like WL, and electrochemical methods such as PDP and EIS, have been used to evaluate NH corrosion IE (%). Protective films have been analyzed by FT-IR, UV-vis spectroscopy, GC-MS, SEM and EDX methods. NH adsorption onto the metals and alloys surface has obeyed Langmuir’s isotherm. PDP studies have revealed that NH may function as an anodic, cathodic or mixed type of CI, depending on the metal nature and on the corrosive environment. Keywords: CI; EDX; EIS; FT-IR; GC-MS; NH; PDP; SEM; WL.

Modern predictive modeling techniques, such as regression, NN and decision trees can be used to build better and more useful models. JMP 17.2.0 was used in this study to develop a fitting model for microbial growth observed data from chicken manure and banana peels labelled as Sample A, and a single chicken manure substrate, identified as Sample B. Statistical metrics, including COD (R2), RASE, MAD, negative log-likelihood and SSE were used to determine best predictions for Ct (X) from biomass of 22 and 24 samples (A and B) on SC (S) and SGR of microorganisms (μ). Along with estimated Monod parameters, TanH function SAS codes for 3 declared hidden layers, also demonstrated by surface plots, portrayed Sample B predicted model as the best one, even though the 2 samples datasets R2 values for training (A: 0.9887916 and B: 1.0000) and validation (A: 0.9787637 and B: 0.9999999) pointed to a good fit. According to findings, optimal conditions for datasets were: A- biomass = 899868717 mg/L and SC = 4.62 x 109 mg/L, correspondent to high µ (0.010201 h-1); and B- biomass = 15351147 mg/L and SC = 9.2322 x 109 mg/L, consistent with µ of 0.007316 h-1. RMSE, which is the standard method of choice for evaluating the accuracy of predictive models, including those based on NN, should be activated in future studies. This research is both timely and relevant in the pursuit of sustainable waste management and renewable energy generation. Keywords: ANN; JMP; Monod; SAS code; SGR; SC; TanH function.

The present study conducted investigations on Bd generated from palm WCO. In TE reaction, alkaline bases for catalysts are often employed. However, since WCO contains high Ct of free fatty acids, its direct use is not feasible, due to layer separation and saponification issues. A two-step process of esterification and TE was herein carried out. GC made from biomass was used. With lower Ct of WCO, maximum Bd yield was achieved using 5 wt.% from GC, CH₃OH:oil ratio of 12:1, reaction time of 70 min, T of 150 ºC and stirring speed of 600 rpm. TE’s second stage employed NaOH, T of 70 ºC and Ct of 1.0 wt.%, for 70 min. Final yield was 95.65 wt.%. Most important variables determining economic feasibility were plant capacity and pricing of feedstock oil and Bd. Keywords: Bd; catalyst; esterification; GC; TE; WCO.