Evaluation of mandibular growth in a prepubertal Class I and Class II population: a longitudinal analysis.

Objective: This study aims to identify the presence, timing, and magnitude of a prepubertal mandibular growth spurt in a Class I and Class II population.

Methods: From the Burlington and Iowa Growth study of the AAOF Craniofacial Growth Legacy Collection, 83 Class I subjects (37 females and 46 males) and 32 Class II subjects (18 males and 14 females) were identified, as having at least seven consecutive annual lateral cephalograms taken from 5 to 11 years of age. Only subjects with a normodivergent facial pattern were considered.

Organofunctionalized Amazon smectite for dye removal from aqueous medium--kinetic and thermodynamic adsorption investigations.

The objective of this study is to examine the adsorption behavior of Sumifix Brilliant Orange 3R textile dye from aqueous solution on smectite sample, an abundant Amazon clay. The original smectite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine was anchored onto smectite surface by heterogeneous route.

Adsorption of methylene blue on raw and MTZ/imogolite hybrid surfaces: effect of concentration and calorimetric investigation.

The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline (MTZ). The compound 2-mercaptothiazoline was anchored onto imogolite surface by heterogeneous route. Due to the increment of basic centers attached to the pendant chains the dye adsorption capability of the final chelating material, was found to be higher than is precursor.

Amazon kaolinite functionalized with diethylenetriamine moieties for U(VI) removal: thermodynamic of cation-basic interactions.

The compound N-[3-(trimethoxysilyl)propyl]diethylenetriamine (MPDET) was anchored onto Amazon kaolinite surface (KLT) by heterogeneous route. The modified and natural kaolinite clay samples were characterized by transmission electron microscopy (TEM), scanning electron microscopic (SEM), N(2) adsorption, powder X-ray diffraction, thermal analysis, ion exchange capacities, and nuclear magnetic nuclei of (29)Si and (13)C. The well-defined peaks obtained in the (13)C NMR spectrum in the 5.

Adsorption of arsenic ions on Brazilian sepiolite: effect of contact time, pH, concentration, and calorimetric investigation.

The original sepiolite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine (AMP) was anchored onto Amazon sepiolite surface by heterogeneous route. The natural (SPT) and modified (SPT(AMP)) sepiolite samples were characterized by elemental analysis, SEM, N(2) adsorption, and nuclear magnetic nuclei of (29)Si and (13)C.

Modification of hectorite by organofunctionalization for use in removing U(VI) from aqueous media: thermodynamic approach.

A Hectorite sample (H) has been chemically modified with N-propyldiethylenetrimethoxysilane and bis[3-(triethoxysilyl)propyl]tetrasulfide. The resulting materials (H(3TPT) and H(NPTM)) have been characterized through elemental analysis, X-ray diffractometry, carbon nuclear magnetic resonance in the solid state, textural analysis, and thermogravimetric analysis. The adsorption experiments were performed under batch process with pH, ionic strength, contact time, and uranyl concentration as variables.

Application of natural and modified hectorite clays as adsorbents to removal of Cr(VI) from aqueous solution--thermodynamic and equilibrium study.

A hectorite (H) clay sample has been modified with 2-mercaptobenzimidazole (MBI) using homogeneous and heterogeneous routes. Both modification methodologies resulted in similar products, named H(HOM) and H(HET), respectively. These materials were characterized by CO(2) gas adsorption, elemental analysis, nuclear magnetic nuclei of carbon-13 and silicon-29.

Immobilization of 5-amino-1,3,4-thiadiazole-thiol onto kanemite for thorium(IV) removal: thermodynamics and equilibrium study.

The compound 5-amino-1,3,4-thiadiazole-thiol (ATT) was anchored onto an Amazon kanemite surface (K) by homogeneous and heterogeneous routes. Both kanemite modification methodologies resulted in similar products, named K(CTT) and K(ATT), respectively. The modified and natural kanemite samples were characterized by textural analysis, FT-Raman, and nuclear magnetic nuclei of (29)Si and (13)C.

Layer silicates modified with 1,4-bis(3-aminopropyl)piperazine for the removal of Th(IV), U(VI) and Eu(III) from aqueous media.

Natural montmorillonite (M) and synthetic kanemite (K) have been functionalized with 1,4-bis(3-aminopropyl)piperazine reacted with methylacrylate to yield new inorganic-organic chelating materials. The original and modified materials were characterized by X-ray diffractometry, textural analysis, SEM and nuclear magnetic nuclei of carbon-13 and silicon-29. The chemically modified clay samples (M-APPMA and K-APPMA) showed modification of its physical-chemical properties including: specific area 45.

Designed pendant chain covalently bonded to analogue of heulandite for removal of divalent toxic metals from aqueous solution: thermodynamic and equilibrium study.

An analogue of heulandite was synthesized by using inorganic salts as a source for silicon and aluminum in the hydrothermal synthesis of the material. The resulting solid was modified by organofunctionalization with 1,4-bis(3-aminopropyl)piperazine and subsequent reaction with methylacrylate in a heterogeneous route. The original (HEU) and modified silicate (HEU(APPMA)) samples were characterized by textural analysis, SEM, and nuclear magnetic nuclei of (29)Si and (13)C.

Adsorption of thorium cation on modified clays MTTZ derivative.

Diquite (D) and bentonite (B) mineral samples from the Amazon region, Brazil, were modified by MTTZ derivative (5-mercapto-1-methyltetrazole) using heterogeneous route. These materials were characterized by textural and elemental analysis, transmission electron microscopy (TEM), power X-ray diffraction and (13)C NMR spectroscopy. The chemically modified clay (D(MTTZ) and B(MTTZ)) samples showed modification of its physical-chemical properties including: specific area 41.

Kinetic and thermodynamic uranyl (II) adsorption process into modified Na-Magadiite and Na-Kanemite.

The compound 2-mercaptopyrimidine (MPY) was attached onto synthetic Na-Magadiite (M) and Na-Kanemite (K) samples by homogeneous route. The final matrices named M(MPY) and K(MPY) have been characterized through X-ray powder diffraction and scanning electron microscopy (SEM). The resulted materials were submitted to process of adsorption with uranyl solution at pH 2.

Adsorption of arsenic(V) into modified lamellar Kenyaite.

The synthetic Kenyaite sample was used for organofunctionalization process with N-propyldiethylenetrimethoxysilane and bis[3-(triethoxysilyl)propyl]tetrasulfide. The resulted materials were submitted to process of adsorption with arsenic solution at pH 2.0 and 298+/-1K.

Kinetics and modified clay thermodynamic from the Brazilian amazon region for lead removal.

Modified Brazilian smectite-bearing clay samples displayed ability for lead adsorption. The structure modification of smectite were obtained through pillaring process and functionalization with [3-(2-aminoethylamino)propyl]trimethoxysilane. The chemical modification process increases the basal spacing of the natural smectite from 1.

Adsorptive, thermodynamic and kinetic performances of Al/Ti and Al/Zr-pillared clays from the Brazilian Amazon region for zinc cation removal.

Smectite clay samples from the Amazon region, Brazil, were pillarized by intercalating the species obtained from the chemical reactions: (i) AlCl3.6H2O/NaOH, (ii) titanium ethoxide in hydrochloric acid and (iii) direct use of ZrOCl2.8H2O solution.