Magnitude Modulation for VSAT’s Low Back-Off Transmission

Marco Gomes,Francisco Cercas,Vitor Silva,Martin Tomlinson 한국통신학회 2010 Journal of communications and networks Vol.12 No.6

This paper addresses the problem of controlling the envelope’s power peak of single carrier modulated signals, band limited by root-raised cosine (RRC) pulse shaping filters, in order to reduce power amplifier back-off for very small aperture terminals ground stations. Magnitude modulation (MM) is presented as a very efficient solution to the peak-to-average power ratio problem. This paper gives a detailed description of the MM concept and its recent evolutions. It starts by extending the look-up-table (LUT)based approach of the MM concept to M-ary constellations with M ≤ 16. The constellation and RRC symmetries are explored,allowing considerable reduction on LUT computation complexity and storage requirements. An effective multistage polyphase (MPMM) approach for the MM concept is then proposed. As opposed to traditional LUT-MM solutions, MM coefficients are computed in real-time by a low complexity multirate filter system. The back-off from high-power amplifier saturation is almost eliminated (reduction is greater than 95%) with just a 2-stage MPMMsystem even for very demanding roll-off cases (e.g., α = 0.1). Also, the MPMM is independent of modulation in use, allowing its easy application to constellations withM>16.

Magnitude Modulation for VSAT's Low Back-Off Transmission

Gomes, Marco,Cercas, Francisco,Silva, Vitor,Tomlinson, Martin The Korea Institute of Information and Commucation 2010 Journal of communications and networks Vol.12 No.6

This paper addresses the problem of controlling the envelope's power peak of single carrier modulated signals, band limited by root-raised cosine (RRC) pulse shaping filters, in order to reduce power amplifier back-off for very small aperture terminals ground stations. Magnitude modulation (MM) is presented as a very efficient solution to the peak-to-average power ratio problem. This paper gives a detailed description of the MM concept and its recent evolutions. It starts by extending the look-up-table (LUT) based approach of the MM concept to M-ary constellations with M ${\leq}$ 16. The constellation and RRC symmetries are explored, allowing considerable reduction on LUT computation complexity and storage requirements. An effective multistage polyphase (MPMM) approach for the MM concept is then proposed. As opposed to traditional LUT-MM solutions, MM coefficients are computed in real-time by a low complexity multirate filter system. The back-off from high-power amplifier saturation is almost eliminated (reduction is greater than 95%) with just a 2-stage MPMM system even for very demanding roll-off cases (e.g., ${\alpha}$ = 0,1). Also, the MPMM is independent of modulation in use, allowing its easy application to constellations with M > 16.

Pectin and SDS as auxiliary flocculants for complementary treatment of textile wastewater by electrocoagulation

Mauro Cosme de Carvalho Góes,Marcos Paulo Ribeiro Garcez,Andréa Roberta Ferreira Siqueira,Thiago Palhares Farias,Claudemir Gomes de Santana,Jonas de Jesus Gomes da Costa Neto,Cicero Wellington Brito B 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.8

Textile wastewaters currently remain as one of the major sources of environmental pollution. In addition to the presence of several recalcitrant species, the volume of the effluent to be treated is usually quite high, due to the excessive consumption of water in this kind of processing. To avoid all the negative impacts associated with the discharge of these untreated effluents, effective remediation techniques should be applied. Although there are currently several methods available, due to complexity and volume of the wastewater, combined technologies can provide better efficiency, lower cost and less time consumption. In this work, electrocoagulation (EC) combined with the conventional flocculation process was studied for the removal of methylene blue dye (MB) in aqueous medium. Under specific EC conditions (4 pairs of electrodes, 2.5 cm spacing, electrolysis time of 203min, pHinitial 4, 32 V, 1.5 A) it was possible to remove 63% of the dye. Combining EC with conventional flocculation, a notable reduction in electrolysisrequired time (203 to 60 min), dye (99.8%), color (100%) and turbidity (99.2%) was observed.

Regarding Camurati-Engelmann Disease

Melissa Machado Viana,Sabrina Versuti Nunes,Davi Coutinho F. Fernandes Gomes,Marco Antônio Percope de Andrade,Marcos José Burle de Aguiar 대한정형외과학회 2018 Clinics in Orthopedic Surgery Vol.10 No.1

Effect of intracanal medications on the interfacial properties of reparative cements

Andrea Cardoso Pereira,Mariana Valerio Pallone,Marina Angélica Marciano,Karine Laura Cortellazzi,Marcos Frozoni,Brenda P. F. A. Gomes,José Flávio Affonso de Almeida,Adriana de Jesus Soares 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.2

Objectives: The purpose of the present study was to evaluate the effect of calcium hydroxide with 2% chlorhexidine gel (HCX) or distilled water (HCA) compared to triple antibiotic paste (TAP) on push-out bond strength and the cement/dentin interface in canals sealed with White MTA Angelus (WMTA) or Biodentine (BD). Materials and Methods: A total of 70 extracted human lower premolars were endodontically prepared and randomly divided into 4 groups according to the intracanal medication, as follows: group 1, HCX; group 2, TAP; group 3, HCA; and group 4, control (without intracanal medication). After 7 days, the medications were removed and the cervical third of the specimens was sectioned into five 1-mm sections. The sections were then sealed with WMTA or BD as a reparative material. After 7 days in 100% humidity, a push-out bond strength test was performed. Elemental analysis was performed at the interface, using energy-dispersive spectroscopy. The data were statistically analyzed using analysis of variance and the Tukey test (p < 0.05). Results: BD presented a higher bond strength than WMTA (p < 0.05). BD or WMTA in canals treated with calcium hydroxide intracanal medications had the highest bond strength values, with a statistically significant difference compared to TAP in the WMTA group (p < 0.05). There were small amounts of phosphorus in samples exposed to triple antibiotic paste, regardless of the coronal sealing. Conclusions: The use of intracanal medications did not affect the bond strength of WMTA and BD, except when TAP was used with WMTA.

Lens culinaris: A New Biocatalyst for Reducing Carbonyl and Nitro Groups

Daniele Alves Ferreira,Robério Costa da Silva,João Carlos da Costa Assunção,Marcos Carlos de Mattos,Telma Leda Gomes de Lemos,Francisco José Queiroz Monte 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.2

A series of aliphatic and aromatic aldehydes and ketones, as well as some nitrocompounds were reduced using whole plant cells from Lens culinaris seeds. In addition, we also investigated the possibility of enzymatic ester hydrolysis to explore the potential of these seeds. The reduced ketones products were obtained in yields of 8 ~82% and enantiomeric excess of 39 ~ 75%. Aldehydes were more reactive than ketones with high chemical yield (95→99%), whereas the aromatic nitrocompounds showed low (2%) to high (> 99%) conversion depending upon the nature and position of the aromatic ring substituents. Ester hydrolysis by the Lens culinaris was quite effective with the ester p-nitrophenyl acetate (> 99% conversion).

Effect of intracanal medications on the interfacial properties of reparative cements

Pereira, Andrea Cardoso,Pallone, Mariana Valerio,Marciano, Marina Angelica,Cortellazzi, Karine Laura,Frozoni, Marcos,Gomes, Brenda P.F.A.,de Almeida, Jose Flavio Affonso,de Jesus Soares, Adriana The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.2

Objectives: The purpose of the present study was to evaluate the effect of calcium hydroxide with 2% chlorhexidine gel (HCX) or distilled water (HCA) compared to triple antibiotic paste (TAP) on push-out bond strength and the cement/dentin interface in canals sealed with White MTA Angelus (WMTA) or Biodentine (BD). Materials and Methods: A total of 70 extracted human lower premolars were endodontically prepared and randomly divided into 4 groups according to the intracanal medication, as follows: group 1, HCX; group 2, TAP; group 3, HCA; and group 4, control (without intracanal medication). After 7 days, the medications were removed and the cervical third of the specimens was sectioned into five 1-mm sections. The sections were then sealed with WMTA or BD as a reparative material. After 7 days in 100% humidity, a push-out bond strength test was performed. Elemental analysis was performed at the interface, using energy-dispersive spectroscopy. The data were statistically analyzed using analysis of variance and the Tukey test (p < 0.05). Results: BD presented a higher bond strength than WMTA (p < 0.05). BD or WMTA in canals treated with calcium hydroxide intracanal medications had the highest bond strength values, with a statistically significant difference compared to TAP in the WMTA group (p < 0.05). There were small amounts of phosphorus in samples exposed to triple antibiotic paste, regardless of the coronal sealing. Conclusions: The use of intracanal medications did not affect the bond strength of WMTA and BD, except when TAP was used with WMTA.

Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography

Eduarda Helena Leandro do Nascimento,Maria Luiza dos Anjos Pontual,Andréa dos Anjos Pontual,Danyel Elias da Cruz Perez,José Natal Figueiroa,Marco Antônio Gomes Frazão,Flávia Maria de Moraes Ramos-Pere 대한영상치의학회 2016 Imaging Science in Dentistry Vol.46 No.2

Purpose: Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. Results: An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). Conclusion: In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles. Materials and Methods CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. Anatomic Variation; Cone-Beam Computed Tomography; Mandible Results An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). Conclusion In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases ... Purpose: Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. Results: An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). Conclusion: In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles. Materials and Methods CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. Results An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). Conclusion In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles.

Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography

Nascimento, Eduarda Helena Leandro do,Pontual, Maria Luiza dos Anjos,Pontual, Andrea dos Anjos,Perez, Danyel Elias da Cruz,Figueiroa, Jose Natal,Frazao, Marco Antonio Gomes,Ramos-Perez, Flavia Maria d Korean Academy of Oral and Maxillofacial Radiology 2016 Imaging Science in Dentistry Vol.46 No.2

Purpose: Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. Results: An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, $1.1{\pm}0.8mm$). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). Conclusion: In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles.