F2 Films Research Articles

The influence of implantation of Mg+ ions and subsequent annealing on the composition, electronic structures, emission and optical properties of CdF2

Relevance. In the case of bombardment with Mg metal ions, the changes are accompanied by the introduction of metal atoms and the formation of various types of compounds. Thus, CdF2 is intensively decomposed into components in the near-surface layer in the process of ion implantation. A small part of these components can be sprayed from the surface. Due to the high chemical activity, almost all of the liberated fluorine atoms again enter into a chemical bond with both the atoms of the alloying element and the atoms of cadmium. Consequently, three-component compounds are formed in the near-surface layer. Therefore, it is necessary to define the electronic states, band energy, and optical parameters of CdF2 and Cd0.6Mg0.4F2 films. Purpose. The composition, structure, and properties of CdF2 implanted with Mg+ ions in combination with thermal and laser annealing for the first time were the research aims. Methodology. The experimental studies were carried out at a vacuum of at least 10-7 Pa using the methods of Auger electron spectroscopy (AES) and ultraviolet photoelectron spectroscopy (UVES). The depth distribution profiles of atoms were determined by the AES method in combination with layer-by-layer etching of the surface with Ar+ ions with E0=2-3 keV. Results. CdF2 is intensively decomposed into components in the near-surface layer in the process of ion implantation. Consequently, three-component compounds are formed in the near-surface layer. Band-energy parameters and densities of the state of electrons in the valence band of this film are determined. Conclusions. The effect of the implantation of Mg+ ions on the composition and electronic structure of single-crystal CdF2/Si(III) films was studied for the first time. The densities of electronic states, band-energy and optical parameters of CdF2 and Cd0.6Mg0.4F2 films have been determined

Polyfunctional phytic acid-based reactive diluent for UV-curable coating with improved flame-retardant performance and toughness

The shortcomings of oligomer resin, including its high viscosity, easy brittleness and lack of flame-retardant performance, obviously limit the application fields of the related coatings. Herein, a UV-curable polyfunctional biomass-based diluent (PAGMA) is conveniently and effectively synthesized by grafting glycidyl methacrylate onto phytic acid. The structural characterization of PAGMA is identified by FT-IR and 1H NMR tests. Moreover, PAGMA diluent is mixed with UV-curable epoxidized soybean oil-based acrylic resin (ESO-based resin), and the influences of PAGMA on the viscosity of ESO-based resin, the mechanical property and the flame-retardant efficiency of the related films are systemically researched. All results demonstrate that the viscosity of composite resin (R2 resin) with 20 wt% PAGMA reduces by 39.2% compared with that of ESO-based resin. And the toughness of the cured film (F2 film) prepared by R2 resin achieves about 1.18 MJ·m-3, which is 2.26 times as large as the cured film prepared without PAGMA (F0 film). Furthermore, the limiting oxygen index value of F2 film improves by 31.2% compared with that of F0 film, and the F2 film can self-extinguish after being ignited. Thus, the prepared polyfunctional biomass diluent can be applied to UV-curable coatings to decline the coating viscosity and enhance the comprehensive properties of coating films, which assists in broadening the application fields of UV-curable materials, especially in fire prevention.

Biocomposites Based on Plasticized Wheat Flours: Effect of Bran Content on Thermomechanical Behavior.

In the present work, the effect of different bran content on the overall thermomechanical behavior of plasticized wheat flours (thermoplastic wheat flour; TPWF) was investigated. Refined flour (F0) with negligible bran fiber content, F1 flour (whole grain flour, 20% wt. bran), F3 (50% wt. bran) and F2 (F1:F3, 50:50) film samples were realized by extrusion process. The effect of TPWF blending with two different biopolymers (polycaprolactone and poly butyrate adipate terephthalate), combined with the presence of citric acid as compatibilizer was also considered. Results from FESEM analysis and tensile characterization demonstrated that PCL was able to reach improved compatibility with the plasticized flour fraction at intermediate bran content (F2 based formulation) when 25% wt. of biopolymeric phase was added. Additionally, it was proved that improvements can be achieved in both thermal and mechanical performance when higher shear rate (120 rpm) and low temperature profiles (Tset2 = 130–135–140 °C) are selected. Disintegrability of the TPWF basic formulations in compositing conditions within 21 days was also confirmed; at the same time, an absence of any phytotoxic event of compost itself was registered. The obtained results confirmed the suitability of these materials, realized by adding different bran contents, to mechanically compete with bioplastics obtained by using purified starches.

Fast Dissolving Sublingual Strips: A Novel Approach for the Delivery of Isosorbide Dinitrate

Background: Isosorbide dinitrate (ISDN) is used for treating the angina attacks. In addition, oral ISDN is available in immediate and sustained release formulations and the bioavailability of ISDN is about 20-25% when taken orally. Further, the ISDN films are developed for sublingual drug delivery by improving drug bioavailability. The present study aimed to design and evaluate the physicochemical properties of the film formulation for sublingual delivery of ISDN. Methods: In the present study, sublingual films were prepared by the solvent casting technique using the hydroxypropyl methylcellulose (HPMC) polymers (i.e., 100, 150 and 200 mg) with a different drug to polymer ratios (i.e., 1:5, 1:7.5 and 1:10). Then, ISDN was evaluated for the film appearance, drug content, surface pH, mucoadhesion force, differential scanning calorimetry (DSC), in vitro drug release, and ex vivo permeability. Results: Based on the results, F3 formulation (1:10 ISDN to HPMC ratio) showed acceptable thickness (0.93 mm), weight (11.14 mg), surface pH (7.82), moisture absorption capacity (6.08%), elasticity (>200), mucoadhesion force (18.05 N/cm2), and drug content (6.22%). Furthermore, the results demonstrated that HPMC polymer improved the characteristics of the films, modified the bioadhesiveness, and finally, enhanced elasticity. However, DSC thermogram failed to show any crystalline drug substance in the films except for F1 (immediate release) and the endothermic peak of ISDN was absent in F2 and F3 films. Therefore, the drug which was entrapped into the film was in an amorphous or disturbed-crystalline phase of the molecular dispersion or dissolved in the melted polymer in the polymeric matrix. Moreover, the drug release from the films was faster compared to the tablet® (P<0.05). Conclusion: In general, the formulation of F1 was observed to be an appropriate candidate for developing the sublingual film for the remedial use.

Elaboration and characterization of pectin-gellan films added with concentrated supernatant of Streptococcus infantarius fermentations, and EDTA: effects on the growth of Escherichia coli, Staphylococcus aureus and Listeria monocytogenes in a Mexican cheese medium, and physical-mechanical properties

Abstract Films were prepared with 0.2% (w/v) gellan gum, 1% (w/v) citric pectin, 0.5% (w/v) glycerol, 5 mM CaCl2, 0.05 M Ethylenediaminetetraacetic acid (EDTA), and different concentrations of an antimicrobial activity-concentrated supernatant (AMC) obtained from fermentations of Streptococcus infantarius, which produces bacteriocin-like inhibitory substances (i.e., treatments F1, F2 and F3 with 75, 90 and 120 arbitrary units (AU)/mL, respectively). The treatments were based on a minimum-inhibitory-concentration (i.e., AMC, 90 AU/mL, plus EDTA, 0.05 M) for Escherichia coli, Staphylococcus aureus and Listeria monocytogenes growing in brain-heart-infusion medium at 35 °C. The films hindered the bacterium growth in selective media: E. coli -MacConkey, S. aureus-Baird Parker and L. monocytogenes -Oxford, during 30 days at 25 °C. Moreover, the F2 films entirely inhibited the growth of the tested bacteria in a Mexican cheese medium, in 7-day cultures at 35 °C; contrariwise, controls with no film exhibited bacterial growths in the range 107 -109 CFU/g. The physical-mechanical properties of the films were changed by the addition of EDTA-AMC, being (F2 film)/(control-film with no AMC nor EDTA): Young’s modulus (MPa), 1,394/707; Elongation at break (%), 1.9/9.3; Stress at break (MPa), 5.7/12.6; Water Vapour Permeability (10-11 g m Pa-1 s-1 m -2), 3/20, and Oxygen Permeability (10-12 g m Pa-1 s -1 m-2), 1.9/1.2.

Cellulose Orodispersible Films of Donepezil: Film Characterization and Drug Release

Three versatile formulations (F1, F2, and F3) of orodispersible films (ODFs) containing donepezil hydrochloride were prepared from cellulose derivatives by solvent casting technique for the treatment of Alzheimer’s disease. The interaction between polymer and drug was investigated by spectral methods including UV, FTIR and 1H NMR and by microscopy techniques including AFM, SEM, and optical examination. Fourier transform infrared spectroscopy (FTIR) confirmed the compatibility of drug and polymer in ODF formulations. Hydrogen bonding interaction was studied by 1H NMR spectroscopy. Atomic force microscopy (AFM) of F3 films showed an average roughness of 75.34 nm and irregular particle size. According to scanning electron microscopy (SEM) data, the average particle size in F1, F2, and F3 films was 30, 37 and 50 μm, respectively. ODFs containing CMC-sodium in combination with HPMC (F3) showed faster disintegration of drug (93.01%) in comparison to F1, F2, and marketed formulation. ODF films of F3 formulation showed high surface roughness and greater pore size, which favored better and faster drug release properties.

Transformation of Chicken Feather Keratin and Pomelo Peel Pectin into Biodegradable Composite Film

The study was planned to utilize chicken feather protein (CFP) and pomelo peel pectin (PPP) to develop the composite film. The five films were prepared with varying proportion of CFP and PPP in ratio of 0:100 (F1), 25:75 (F2), 50:50 (F3), 75:25 (F4) and 100:0 (F5). All films were tested for their mechanical and barrier properties. However, among all the composite films, F2 film was more adequate by considering its overall properties. The WVP, moisture absorption, water solubility, breakage strength and elongation of F2 film were reported as 14.27 × 10−9 g/Pa h m, 13.83, 100%, 285.885 g and 13.17% respectively and it was ahead of the other films. The selected film F2 was used for wrapping of the fried fish fillet and was stored for 5 days in a closed container and compared with unwrapped fried fish fillet. Wrapping of fried fish fillets resulted in less weight loss, lowered hardness value and reduction in surface microbial count.

DEVELOPMENT AND EVALUATION OF ORODISPERSIBLE FILMS OF LAMOTRIGINE: HYDROXYPROPYL Β CYCLODEXTRIN INCLUSION COMPLEX.

Orodispersible film is the type of drug delivery systems which when placed in the oral cavity disintegrates or dissolves within few seconds without water intake. This type of technology offer a convenient alternative way of dosing medication, not to special population groups, but also to the general population. The present investigation highlights on the formulation and evaluation of orodispersible films of poorly soluble antiepileptic drug lamotrigine. Dissolution characteristics of the drug was improved by forming inclusion complexes with hydroxypropyl β‐cyclodextrin (HPβCD) employing co-evaporation technique and the complexes were characterized by differential scanning calorimetry (DSC) and fourier transformation infrared spectroscopy (FTIR). Orodispersible films of LMN-HPβCD (1:1) were prepared by the solvent-casting method; using water soluble film forming polymers such as hydroxyl propyl methyl cellulose (HPMC15), polyvinyl alcohol (PVA) and Sodium carboxy methyl cellulose (SCMC).Propylene glycol and glycerin were used as plasticizers. The prepared films were evaluated for their physicochemical characteristics such as appearance, thickness, folding endurance, drug content uniformity, surface pH, disintegration time and mechanical properties, in vitro drug release and stability studies were performed for the optimized formula according to the ICH guideline under 40°C/75% RH for three months. Amongst all formulations F2 films prepared with1% w/v PVA plasticized with 3% glycerin was considered as the optimized formulation, it has the highest drug release, satisfactory in vitro disintegration time, tensile strength, % elongation, folding endurance and stable formula. Overall results suggest that PVA is an excellent film former for antiepileptic drug lamotrigine. Therefore, orodispersible films is considered to be potentially suitable for the immediate release whenever required of lamotrigine to improve patient compliance.

Formulation and optimization of duloxetine hydrochloride buccal films: in vitro and in vivo evaluation

Duloxetine hydrochloride (DH) is a serotonin–norepinephrine reuptake inhibitor (SSNRI) indicated for the treatment of depression. Duloxetine suffers from reduced oral bioavailability (≈50%) due to hepatic metabolism. This study aims to develop DH buccoadhesive films to improve its bioavailability. DH buccoadhesive films were prepared adopting the solvent casting method using hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA). The prepared films were evaluated for weight uniformity, drug content, surface pH, swelling index, mucoadhesion strength and drug release percentages. Accelerated stability and bioavailability studies in healthy human volunteers were also performed for the selected films. Results of the evaluation tests showed that the optimum physicochemical characters were obtained by the films prepared with 2% HPMC using 10% propylene glycol (F2 films). Accelerated stability studies revealed that DH showed proved stability throughout the experiment time. DH bioavailability from F2 films was determined and compared with that of the marketed oral capsules (Cymbalta® 30 mg). The pharmacokinetic results showed that Cmax for F2 was higher than the market product. In addition, ANOVA analysis showed that a Tmax of F2 film was significantly lower, while, the AUC0–72 of F2 was significantly higher than that of Cymbalta capsules. The percentage relative bioavailability of DH from F2 was found to be 296.39%. Therefore, the prepared buccal films offer an alternative route for the administration of DH with the possibility of improving its bioavailability.

Turmeric dye extraction residue for use in bioactive film production: Optimization of turmeric film plasticized with glycerol

Four turmeric flour fractions (F1, F2, F3, and F4) were produced from the turmeric dye extraction residue by wet milling and sieving for film production. F2, which presented the lowest lignocellulosic and the highest starch content, provided the best material for film production. The main objectives of the present study were (i) to evaluate the effect of heating temperature (T) and pH on the mechanical and functional properties of F2 film plasticized with glycerol, and (ii) to optimize the process conditions (T, pH) by response surface method and multi-response analyses. Higher T (>90 °C) and alkaline pH produced a denser and mechanically stronger polymer matrix and more soluble film. In contrast, less soluble films were produced at intermediate T and pH. The effect of T and pH on the mechanical properties and solubility of turmeric films is associated with starch gelatinization and protein solubilization and denaturation. High T produced loss of the curcuminoids and antioxidant activity of turmeric films. The optimal conditions were T of 85.1 °C and pH of 8.1. These conditions yielded films with high mechanical strength (9 MPa), low solubility (37%), and low water vapor permeability (0.352 g mm h−1 m−2 kPa−1).

Effect of storage time on physicochemical and textural properties of sausages covered with oxidized banana starch film with and without betalains

In this study, two types of oxidized banana starch films (betalains and no betalains) were prepared and used as covering for sausages, then were refrigerated for 20 days at 4°C and 5% relative humidity (RH). The sausages covered were analyzed (covered with films without betalains = F1 and covered with films with betalains = F2) and they were compared with a control (without covering). The sausages were evaluated every 5 days by physicochemical analysis of color, size, weight loss, pH and quantification of betalains in the films. Textural analysis was performed on the sausages. The results indicated that films did not significantly alter the color or moisture loss during storage (P > 0.05), while the F2 films maintained the amount of thiobarbituric acid reactive substances in the sausages during storage (P < 0.05). Sausages covered with both types of film maintained their texture characteristics for longer compared to the control.

The Use of Duo-Functional PVC Film for Conservation of Minimally Processed Apples

Several conservation strategies regarding minimally processed vegetables (MPV) are applied keep organoleptic features and quality, in particular the use of active packaging to slow down enzymatic browning reactions and microbial growth. Based on such context, polyvinyl chloride (PVC) films with antimicrobial and antibrowning properties—due to the addition of a mix of additives (MA) that comprise pure (KM) and encapsulated (EKM) potassium metabisulfite—are the core of the current study to find out their influence on the quality parameters applied to minimally processed apples. The sol–gel method was used in the encapsulation process and the PVC films were prepared by applying 0.1 (w/w; F01), 1.0 (w/w; F1), and 2.0 (w/w; F2) of MA (KM and EKM), as well as the use of control film, for industrial extrusion processing. The EKM was chemically and morphologically characterized and the mechanical properties of the films were set. Minimally processed apples were prepared and packed in films for 20 days. The prepared packages were stored at different temperatures and evaluated for color variations as well as for chemical and microbiological quality. The encapsulation process increased the additive's thermal resistance. It also preserved the main characteristics of the additives that were incorporated into the process. It did not interfere in the machinability conditions of the films. The outcomes showed satisfactory effects regarding the maintenance of color and microbiological qualities. The F2 film could show toxicological safety for the minimally processed apples for 10 days at 8 °C. Therefore, duofunctional films are a good alternative for minimally processed apples storage.

Size Fractionation of Graphene Oxide Sheets by pH-Assisted Selective Sedimentation

Graphene oxide (GO) sheets prepared by Hummers' method have been separated into two portions with large (f1) or small (f2) lateral dimensions from their aqueous dispersion. This method is based on the selective precipitation of GO sheets with lateral dimensions mostly (>90%) larger than 40 μm(2) at a pH value of 4.0 because of their larger hydrophobic planes and fewer hydrophilic oxygenated groups. The hydrazine reduced Langmuir-Blodgett (LB) films of f1 showed much higher conductivities than those of f2. Furthermore, the thin film of f1 prepared by filtration exhibited a smaller d-space and much higher tensile strength and modulus than those of f2 films. The one-step size fractionation method reported here is simple, cheap, efficient, and environmentally friendly, which can be used for the size fractionation of GO sheets in large scale.

Temperature-induced sign change of the exchange bias in Fe0.82Zn0.18F2/Co bilayers

A single crystal, (110)-oriented dilute antiferromagnet (AF) Fe0.82Zn0.18F2 film was grown via molecular beam epitaxy on a (110)-MgF2 substrate by codepositing FeF2 and ZnF2, followed by 1.0 nm pure FeF2 and 18 nm Co layers. The exchange bias (HE) and coercivity (HC) of the Co film strongly depend on the cooling field (HCF) and temperature. For 0⩽HCF&amp;lt;2 kOe, HE&amp;lt;0 in the whole temperature range before reaching zero at the blocking temperature (TB). For HCF⩾15 kOe, HE&amp;gt;0 for T&amp;lt;TB. In both cases, HC peaks when T∼TB. For 2 kOe⩽ HCF&amp;lt;15 kOe, HE&amp;lt;0 at low temperatures, and then suddenly becomes positive at a characteristic switching temperature TS(&amp;lt;TB). TS decreases as HCF is increased and HC peaks at both T∼TS and T∼TB. These results indicate that for intermediate HCF unstable domains are created in the AF during the cooling procedure. The domains suddenly disappear as enough thermal energy is available to switch them when perturbed by the rotation of the ferromagnetic magnetization.

Effect of Molar Ratio of (CaxBay)F2 Films on Electrical Characteristics of Metal/Fluoride/InP Structures

(Cax Bay )F2 (x:y=7:3, 1:1 and 3:7)/n-type InP (100) metal-insulator-semiconductor (MIS) structures were investigated by means of capacitance-voltage ( C-V) measurements and X-ray photoelectron spectroscopy (XPS) to study the effect of the molar ratio (x:y) of the fluoride films on the quality of the interface between the fluoride and InP. The fluoride films were deposited on the InP substrates by co-evaporating CaF2 and BaF2 powders in a vacuum of about 1-2×10-6 Torr. The best C-V characteristics were obtained for the lattice-matched (CaBa)F2 (Ca:Ba=1:1 in molar ratio)/InP and the next-best, for the (CaBa)F2 (Ca:Ba=7:3)/InP MIS structures. On the other hand, poor C-V characteristics were obtained for the (CaBa)F2 (Ca:Ba=3:7)/InP and the SrF2/InP structures, though their lattice matchings were better than that of the (CaBa)F2 (Ca:Ba=7:3)/InP structure. It is therefore concluded that the lattice matching between the fluoride film and the InP substrate is probably the most important factor for obtaining a good-quality interface; however, the presence of a fair amount of the “stable” Ca-P bonds is also effective to obtain a stable interface between fluoride and InP. The XPS data indicated that fluoride films with distinct and uniform chemical compositions were formed from the top surface to the interface with the InP substrate even by the conventional vacuum evaporation technique. The peak binding energy of the XPS signal from the Ba 3d core level shifts to the lower energy side, while that from the Ca 2p core level shifts to the higher energy side with increase in the ratio of Ba to Ca. These shifts are nearly linear with the change of the mixed molar ratio. These findings can be explained by a difference in ionic radii between Ba and Ca in the fluorite structure and indicate that the molar ratios in the fluoride films are the same as the mixed molar ratios of the source powders. Native oxides of InP such as In2O3, InPO3 and InPO4 were found to be removed or reduced by the fluoride films during or after deposition of these films. A small amount of oxygen was included in the fluoride film, indicating that the fluoride film reduced the native oxide of InP and became oxidized itself.

Improvement of the interface properties of Ca0.43Se0.57F2 on GaAs(100) by rapid thermal annealing

The interface properties of Ca0.43Sr0.57F2 films grown by a thermal evaporation technique on GaAs(100) substrates were investigated. It was found that in situ rapid thermal annealing, typically at 590 degrees C for 10 s, was useful for improving the interface properties of fluoride/GaAs MIS structures. Analysis by double crystal X-ray diffraction and photoluminescence spectroscopy indicates good interface of the Ca0.43Sr0.57F2/GaAs heterostructure.

Effects of Surface Orientation and Molar Ratio of (SrxCay)F2 Films on Electrical Characteristics of Metal/Fluoride/GaAs Structures

The (Srx Cay )F2 (x:y=3:7, 1:1 and 7:3)/GaAs (100), (111)A and (111)B metal-insulator-semiconductor (MIS) structures were investigated by the capacitance-voltage (C-V) measurements and the X-ray photoelectron spectroscopy (XPS) to study the effects of the surface orientation of GaAs and the mol ratio (x:y) of the fluoride films on the quality of the interface between these fluoride films and GaAs. The fluoride films were deposited on the GaAs substrates by co-evaporating SrF2 and CaF2 powders in a vacuum of 1–2×10-6 Torr. The C-V measurements indicated that the best result was obtained for the (SrCa)F2(Sr:Ca=1:1 in molar ratio)/GaAs (100) surface and the next, for the (Sr0.3Ca0.7)F2/GaAs (111)B surface. Very poor C-V characteristics were obtained for the GaAs (111)A surface for all the molar ratios of Sr and Ca studied here. It is concluded that the lattice matching between the fluoride film and GaAs plays an important role in the formation of a good-quality interface for the GaAs (100)-oriented surface, while the presence of a large amount of stable Ca–As bonds is more effective for GaAs (111)-oriented surfaces. The XPS data indicated that the native oxide of GaAs, which is mainly composed of As2O3 and Ga2O3, was removed upon evaporation of the fluoride films. Sr is considered to reduce the native oxide and was oxidized itself. Sharp peaks of the XPS data were observed and the binding energies of these peaks varied nearly linearly with the molar ratio of Sr and Ca. These indicate that stoichiometric (Srx Cay )F2 films were formed even by the conventional vacuum-evaporation technique. Elemental Sr and/or Ca was observed to exist at the interface with GaAs.

Photoemission study of Ca1-xSrxF2 films grown by MBE on GaAs(100)

The MBE growth and interface formation of thin Ca0.43Sr0.57F2 films deposited on GaAs(100) has been studied using synchrotron radiation photoemission spectroscopy. Surface sensitive core level spectra and RHEED suggest an extended fluorine-deficient interface for growth at 325°C. Annealing experiments confirm the loss of fluorine at temperatures equal to or greater than 325°C. As 3d spectra did not provide evidence for Ca-As bonds. The fluoride interface formed under these conditions apears to be atomically abrupt but contains a considerable amount of fluorine vacancies. Despite the reduction in interfacial strain by using a lattice matched mixed fluoride of composition Ca0.43Sr0.57F2, RHEED images indicate growth of epitaxial islands.

Characterization of epitaxial group II fluoride films on (100)‐oriented GaAs substrates by ion backscattering and channeling

AbstractLattice matched (Ca, Sr)F2 and related fluoride films grown on (100)GaAs substrates were investigated by Rutherford backscattering/Channeling. This technique allows the characterization of the 30–250 nm thick heteroepitaxial layers with respect to chemical composition, film thickness, interface roughness and crystalline perfection. The first flash evaporated GaAs/fluoride/GaAs structure are briefly reported.

Characterization of epitaxial (Ca,Ba)F2 films on Si(111) substrates

We have investigated epitaxial BaF2/CaF2 bilayers on Si(111) with ion channeling, grazing-incidence x-ray diffraction, and transmission electron microscopy. The BaF2 layer, which was grown on a thin intermediate CaF2 layer, showed a channeling minimum yield of 8% and a residual strain of 0.2%. Regions of BaF2 with a mosaic spread in orientation were observed but otherwise the epitaxial quality of the fluoride bilayer was found to be very good.