Efficient detectors for MIMO‐OFDM systems under spatial correlation antenna arrays

David William Marques Guerra,Rafael Masashi Fukuda,Ricardo Tadashi Kobayashi,Taufik Abrão 한국전자통신연구원 2018 ETRI Journal Vol.40 No.5

This work analyzes the performance of implementable detectors for the multiple‐input multiple‐output (MIMO) orthogonal frequency division multiplexing (OFDM) technique under specific and realistic operation system conditions, including antenna correlation and array configuration. A time‐domain channel model was used to evaluate the system performance under realistic communication channel and system scenarios, including different channel correlation, modulation order, and antenna array configurations. Several MIMO‐OFDM detectors were analyzed for the purpose of achieving high performance combined with high capacity systems and manageable computational complexity. Numerical Monte Carlo simulations demonstrate the channel selectivity effect, while the impact of the number of antennas, adoption of linear against heuristic‐based detection schemes, and the spatial correlation effect under linear and planar antenna arrays are analyzed in the MIMO‐OFDM context.

Optimization of the operating parameters using RSM for the Fenton oxidation process and adsorption on vegetal carbon of MO solutions

Adriana Saldana-Robles,Juan M. Peralta-Hernandez,Ricardo Guerra-Sanchez,Manuel I. Maldonado-Rubio 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.3

This study focused on the application of RSM on the Fenton process and the adsorption of vegetal carbon(VC) to obtain the optimal conditions for the minimization of the colored synthetic wastewater. Methylorange (MO) with an azo dye was used as the model organic compound. Fenton processes wereinvestigated to establish the optimal conditions. The Fe2+/H2O2 ratio was studied to establish the majorMO degradation when 100 and 200 mg/L of MO were treated. For the adsorption process, to determinethe optimal conditions, the principal variables studied were the vegetal carbon mass dosage, degradationtime and dye concentration.

Electrochemical oxidation of methyl orange azo dye at pilot flow plant using BDD technology

Cecilia Ramırez,Juan M. Peralta-Hernandez,Adriana Saldana,Berenice Hernandez,Roberto Acero,Ricardo Guerra,Sergi Garcia-Segura,Enric Brillas 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

Solutions of methyl orange azo dye were degraded by electrochemical oxidation using a 3 L flow plant with a boron-doped diamond (BDD)/stainless steel cell operating at constant current density, ambient temperature and liquid flow rate of 12 L min-1. A 23 factorial design considering the applied current density, azo dye concentration and electrolysis time as variable independents was used to analyze the process by response surface methodology. LC–MS analysis revealed the formation of seven oxidation products from the cleavage of the –N55N– group of the dye, followed by deamination, formation of a nitro group and/or desulfonation of the resulting aromatics.

Effects of dietary L-glutamine and glutamic acid combination, and whey powder on the performance and nutrient digestion in weaned piglets fed grain-based diets

Almeida Jonathan Mádson dos Santos,Pascoal Leonardo Augusto Fonseca,de Almeida Jorge Luiz Santos,Guerra Ricardo Romão,da Silva José Humberto Vilar,da Silva David Rwbystanne Pereira,Silva Neto Manoel R 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.12

Objective: The present study aimed to evaluate the influence of including L-glutamine along with glutamic acid as a supplement in weaned piglets’ diets with and without whey powder. Methods: Two assays were carried out. A total of 40 piglets ([Landrace×Large White]× Pietrain) weaned at 24 days of age with an initial body weight of 6.6±0.6 kg were used in the first assay, and the following parameters were evaluated: growth performance, the incidence of diarrhea, morphometry, intestinal integrity, and hepatic glycogen index. The animals were then blocked into four groups according to different diets: diet all-grain feeding (G); diet all-grain feeding with whey powder (GW); and with vs without 1% supplementation of the commercial product containing L-glutamine and glutamic acid (A or NA). Whey powder was added according to the stage of life, corresponding to 17%, 10%, and 5%, respectively, in order to meet the need for lactose. The animals were evaluated at 24 to 42 days and at 24 to 55 days of age. The nutrient digestibility for the second assay was carried out by using 24 animals with an average weight of 11.49±1.6 kg, and the same diets were tested. Results: The supplementation of L-glutamine + glutamic acid or the addition of whey powder in diets for weaned piglets provided (p<0.05) greater feed intake, greater weight gain and improved feed conversion in the initial period (24 to 42 days age). However, in the whole period (24 to 55 days age) only amino acid supplementation affected (p<0.05) growth performance. There was a positive interaction (p<0.05) between the type of diet and L-glutamine + glutamic acid supplementation on villus height, crypt depth and the villus:crypt ratio in the duodenum. In addition, L-glutamine + glutamic acid supplementation reduced (p<0.05) the crypt depth and improved the villus:crypt ratio in the jejunum. The inclusion of whey powder affected (p<0.05) positively the digestibility coefficients analyzed except mineral matter digestibility coeficients. The supplementation of 1% the commercial product composed of L-glutamine and glutamic acid improved (p<0.05) only the digestibility coefficient of crude protein. Conclusion: These results indicate that supplementation of 1% commercial product containing L-glutamine + glutamic acid in diets for piglets from 24 to 55 days of age, dispenses with the use of whey powder when evaluating growth performance. Amino acid supplementation alone or associated with whey powder affects (p<0.05) positively the indicators of the intestinal integrity. Objective: The present study aimed to evaluate the influence of including L-glutamine along with glutamic acid as a supplement in weaned piglets’ diets with and without whey powder.Methods: Two assays were carried out. A total of 40 piglets ([Landrace×Large White]× Pietrain) weaned at 24 days of age with an initial body weight of 6.6±0.6 kg were used in the first assay, and the following parameters were evaluated: growth performance, the incidence of diarrhea, morphometry, intestinal integrity, and hepatic glycogen index. The animals were then blocked into four groups according to different diets: diet all-grain feeding (G); diet all-grain feeding with whey powder (GW); and with vs without 1% supplementation of the commercial product containing L-glutamine and glutamic acid (A or NA). Whey powder was added according to the stage of life, corresponding to 17%, 10%, and 5%, respectively, in order to meet the need for lactose. The animals were evaluated at 24 to 42 days and at 24 to 55 days of age. The nutrient digestibility for the second assay was carried out by using 24 animals with an average weight of 11.49±1.6 kg, and the same diets were tested.Results: The supplementation of L-glutamine + glutamic acid or the addition of whey powder in diets for weaned piglets provided (p<0.05) greater feed intake, greater weight gain and improved feed conversion in the initial period (24 to 42 days age). However, in the whole period (24 to 55 days age) only amino acid supplementation affected (p<0.05) growth performance. There was a positive interaction (p<0.05) between the type of diet and L-glutamine + glutamic acid supplementation on villus height, crypt depth and the villus:crypt ratio in the duodenum. In addition, L-glutamine + glutamic acid supplementation reduced (p<0.05) the crypt depth and improved the villus:crypt ratio in the jejunum. The inclusion of whey powder affected (p<0.05) positively the digestibility coefficients analyzed except mineral matter digestibility coeficients. The supplementation of 1% the commercial product composed of L-glutamine and glutamic acid improved (p<0.05) only the digestibility coefficient of crude protein.Conclusion: These results indicate that supplementation of 1% commercial product containing L-glutamine + glutamic acid in diets for piglets from 24 to 55 days of age, dispenses with the use of whey powder when evaluating growth performance. Amino acid supplementation alone or associated with whey powder affects (p<0.05) positively the indicators of the intestinal integrity.