Combinations Of Surface Treatments Research Articles

Effect of Surface Treatments with Plasma and Chemical Bond on Shear Bond Strength of Acrylic Denture Teeth to Flexible and Heat-Cured Denture Base Material: An In Vitro Study

Introduction: We aimed to evaluate the shear bond strength of acrylic denture teeth to flexible and heat-cured denture base material after surface treatments with argon plasma, chemical bonding agent (PALFIQUE universal), and combination. Methods: A total of 80 incisor acrylic denture teeth were treated with a argonplasma, chemical bond (PALFIQUE universal bond), and a combination with 10 samples for each group. The neck (gingival portion) of teeth was cut at a 45° angle, and the teeth were attached to heat-cured acrylic resin and flexible denture base material. All the specimens were stored in artificial saliva for 7 days in an incubator (37 °C). A shear bond strength test was conducted using an Instron universal testing machine. Data were analyzed by the analysis of variance (ANOVA) and the Tukey’s honest significant difference post hoc test using R 4.2.3. Results: A statistically significant difference was found among study groups regarding the type of base, surface treatment with bond, plasma, and combination of bond and plasma (P < 0.00). The Tukey’s test showed that in a heat-cured base, the difference between the control and surface treatment with bond was not significant (P > 0.05). Also, in the flexible base group, the difference between the control and surface treatment with plasma was not significant (P = 0.162). Conclusion: In heat-cured denture-base group, the shear bond strength increased significantly with the combination of surface treatment with argon plasma and a chemical bonding agent (PALFIQUE universal). In the flexible denture-base group, the shear bond strength increased significantly with use of a surface treatment with a chemical bonding agent (PALFIQUE universal).

Metal-composite hybrid joint adhesion and testing optimization for electric vehicle applications

ABSTRACT Lightweight is a critical feature in automotive applications, especially in electric vehicle applications due to the heavyweight of batteries, thus contributing to improve vehicle efficiency. Multi-material solutions were studied in this paper as a strategy for lightweighting, focusing on the improvement of metal-composite joints obtained by overmolding through the comparison of different laser treated textures and processing parameters. In addition, testing methods to assess the adhesion of these joints were analysed. Firstly, steel surface treatment was carried out by pulsed laser radiation producing different patterns. Secondly, over injection of the composite material based on polyamide 6.6 with 40% recycled carbon fiber was carried out with different processing parameters. The mechanical performance of the joints was assessed through shear-strength analysis, and the morphological analysis was carried out. As outcome, the optimal combination of surface treatment and processing parameters was selected. Finally, a finite element analysis was carried out to evaluate comparatively the suitability of a testing method proposed as an alternative to the standard single lap shear tests, with a configuration that facilitates the specimens manufacturing and test execution. As a result, the adequacy of the method for the assessment of the shear strength of this type of joints was demonstrated.

Technical assessment of shear bond strength at ceramo-alloy interface after various surface treatment combinations and application of metal bonding agent.

Bonding between metal and ceramic is one of the most important aspects of a successful prosthesis. Various methods have been recommended for preparing the metal surface to enhance the bond between metal and ceramic including the use of a metal bonding agent. This study aims to evaluate and compare the shear bond strength of the metal-ceramic (M-C) interface after combinations of various surface treatments including the application of a metal bonding agent. 40 Ni-Cr alloy specimens were made and divided into 4 groups of 10 each based on the combination of surface treatments. Sandblasting, surface grinding, and Oxidation heat treatment (OHT) were performed on specimens from Group 1 (Control). In addition, Group 2 specimens received ultrasonic cleaning, Group 3 steam cleaning, and Group 4 metal bonding agent application. Following surface treatments on all specimens, porcelain build-up was performed, and shear bond strength was tested in a Digital Universal testing machine. The statistical tests used were independent t-test and ANOVA. Results revealed that Group 4 specimens had the highest mean value of shear bond strength of 39.087 MPa while Group 3 specimens showed the least mean shear bond strength of 18.154 MPa with highly statistically significant results (p< 0.001). The surface treatments and application of bonding agent to metal prior to porcelain application resulted in increased shear bond strength of the metal-ceramic interface.

Effect of Dentin and Zirconia Surface Treatments with Laser Irradiation Versus Sandblasting on the Bonding Ability of Zirconia.

Objective: This study aimed to investigate the effects of laser irradiation applied to zirconia and tooth surfaces on shear bond strength (SBS) compared with acid etching and sandblasting. Background: The effect of laser irradiation on the bond strength between zirconia and adhesives is a controversial issue for dentin surface treatments. In addition, the effects of different combinations of surface treatments to increase adhesion on both the zirconia and dentin surfaces remain unclear. Materials and methods: A total of 90 tooth samples were assigned into groups according to various pretreatments: control group was left untreated, acid etching, and Erbium, Chromium:Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser irradiation group (15 Hz, 2 W). In addition, the zirconia specimens were separated into three groups (n = 10) according to the different surface treatments performed: sandblasting (120 μm Al2O3), Er,Cr:YSGG laser (15 Hz, 2 W), and as untreated surface. The zirconia samples were cemented to the dentin surface using dual-cure resin cement and subjected to an SBS test at a speed of 0.5 mm/min under a universal testing machine until fractures occurred in the bonding surface. Results: The highest SBS values were observed in Group tooth acid (TA)-zirconia Er,Cr:YSGG laser (ZL), followed by Group tooth Er,Cr:YSGG laser (TL)-zirconia sandblasting (ZS) and Group TA-zirconia control (ZC). The lowest SBS values were found in Group TA-ZS. Significant intergroup difference was noted between Group TA-ZL, Group tooth control (TC)-ZC, Group TL-ZS, and Group TC-ZC. However, no significant difference was noted between Group TA-ZL, Group TL-ZS, and Group TA-ZC. Conclusions: Acid etching and laser treatments applied to the dentin and zirconia surfaces were found to be effective techniques for improving the zirconia-dentin bond, respectively. Clinical Trial Registration number: 33216249-604.01.02-E.24308.

Surface roughness and characteristics of CAD/CAM zirconia and glass ceramics after combined treatment procedures

BackgroundThe roughening of the inner surface of a fixed ceramic restoration is an important factor for the bonding process. The aim of this study is to investigate the effect of combined surface treatments (acid etching, air-abrasion and Er: YAG Laser) on surface roughness of CAD/CAM fabricated zirconia (ZrO2) and lithium-disilicate glass ceramics (LDS).MethodsSixty ZrO2 (Ceramill Zi) and LDS (IPS e.max CAD) specimens, (5 mm in width, 5 mm in length and 1.5 mm in height) were fabricated using CAD/CAM and sintered according to the manufacturer’s instructions. All specimens subjected to three surface treatment combinations; etching with 4% hydrofluoric acide (HF), airborne-particle abrasion with 110-μm alumina (Al2O3) (AP) and Er:YAG laser (Er:YAG) (Group A—HF + AP; Group B—Er:YAG + AP, and Group C—Er:YAG + HF). Perthometer was used to measure the surface roughness of the specimens before and after the tretments.ResultsGroup A presented the highest Ra (LDS 0.81 ± 0.27 and ZrO2 0.67 ± 0.21 after treatment) and Group C the lowest (LDS 0.45 ± 0.13 and ZrO2 0.26 ± 0.07, after treatment). Compared with before treatment, the Ra were significantly different only in Group A both ZrO2 and LDS after treatment (p < 0.05). Qualitative SEM images suggested the surface topography of the ZrO2 was smoother than the LDS. Less surface changes were observed in the Er:YAG combined procedures than HF + AP.ConclusionsHF + AP was significantly succesful in modifying the ceramic surface. Er:YAG did not sufficiently promote the surface topography, even if combined with any other treatments. Overall, surface tretments on ZrO2 not easier than LDS.

Evaluation of Zirconia Surface Roughness after Different Surface Treatment with Sandblasting, Hydrofluoric Acid Etching, and Combination Treatment

Zirconia is one of the materials used in prosthetic restoration because of its better physical, mechanical, chemical, and biological properties. The surface treatment for zirconia can be mechanical, with grinding, sandblasting, and laser or chemically, with silane and etching. The combination of chemical and mechanical surface treatment can increase the surface roughness so that the bonding with the resin cement also increases. The study aims to examine the zirconia surface roughness after different surface treatments. This study used 25 zirconia samples in 10x10x2 mm square-shaped, divided into five groups. Group 1 treats sandblasting as a control. Group 2 sandblasting then etching with 9.5% hydrofluoric acid at 25°C for 60 minutes. Group 3 sandblasting then etching with 9.5% hydrofluoric acid at 100°C for 1 minute. Group 4 etching with 9.5% hydrofluoric acid at 25°C for 60 minutes. Group 5 etching with 9.5% hydrofluoric acid at 1000C for 1 minute. The samples were cleaned with an ultrasonic cleaner and tested using a profilometer. The data test by using the ANOVA test and T-test. The highest surface roughness was the combination of sandblasting with 9.5% hydrofluoric acid etching at 25°C for 60 minutes. The lowest was 9.5% hydrofluoric acid etching at 100°C for 1 minute. ANOVA statistical analysis with a p-value &lt;0.05 ((8.4051 x 10-12) indicates that the test was significant. The result of this study was the combination of surface treatments resulted in higher surface roughness. Duration of the etching time affected the increase of zirconia surface roughness.

Effect of surface treatment on photo-electric properties of CZT thick film for radiation detector

The rough surface of CZT film is detrimental to both the surface leakage current and photoelectric response sensitivity. Here, the effect of different surface treatment techniques, such as manual mechanical polishing, chemical etching and passivation, on surface quality and photoelectric properties of the CZT thick film was investigated. The results demonstrated that a combination of surface treatments including mechanical polishing, chemical etching, and passivation can effectively improve the surface quality of CZT polycrystalline thick film, thus reducing the surface leakage current. The dark current of MPEP treated by mechanical polishing, chemical etching and passivation in turn is one order of magnitude smaller than that of as-grown CZT film. The resistivity of MPEP is 1.20 × 1010 Ω cm, which is 8.1 times that of as-grown film. The combination of surface treatment process greatly reduced surface leakage current, improved the resistivity and X-ray photoconductivity response performance of CZT coplanar detector. Our findings provide a guide for surface treatment to further improve both the photoelectric properties of photodevice based on the CZT thick film.

A Shift to Synergistic Surface Treatment Using Laser to Enhance the Bonding of Zirconia to Veneering Ceramic: An In Vitro Study

The aim of this study was to evaluate the effect of combination of surface treatment using laser along with other modalities of surface treatment on shear bond strength of zirconia to veneering ceramic. Milled and sintered zirconia cylinders (n = 150) were used in the study which were divided into six groups that were subjected to various surface treatments. Samples in group I were subjected to sandblasting. In group II Laser (Er: YAG) surface treatment was performed. Samples in group III were subjected to sandblasting followed by laser ablation. In group IV laser ablation was carried out followed by liner application, and samples in group V were subjected to laser ablation followed by argon plasma treatment. Instron machine was used to test the shear bond strength (SBS). One-way ANOVA and Bonferroni test were used for statistical analysis. Samples in group III showed highest values for SBS followed by groups I, IV, and V with less SBS value for group II. Thus, the results conclude the use of combination of surface treatment using laser to be an effective modality to enhance the shear bond strength of zirconia. Synergistic surface treatment using laser increases the bond strength of zirconia prosthesis to veneering ceramic improving its clinical longevity.

Two-step surface functionalization/alignment strategy to improve CO2/N2 separation from mixed matrix membranes based on PEBAX and graphene oxide

In this study, a simple method to prepare mixed matrix membranes (MMM) based on Pebax with functionalized/oriented graphene oxide (GO) nanosheets is presented to improve CO2/N2 separation. First, the GO nanosheets were surface modified with different amounts of m-phenylenediamine (mPD) to maximize the CO2 adsorption affinity and minimize GO agglomeration within the matrix. Then, an external electric field was applied to organize/orient the GO nanosheets (modified and unmodified) during membrane preparation. The separation performance results showed that the CO2 permeability of unmodified and amine-functionalized GO-filled MMM respectively increased by 1.7 and 2.1 times compared to the neat matrix. This improvement is attributed to the high affinity of amino groups for CO2 uptake. Furthermore, applying a vertical electric field increased the CO2 permeability compared to a random GO orientation state by 1.3 and 2.8 times for the unmodified and modified GO-filled MMM, respectively. This significant improvement is related to a lower tortuosity in the membrane, improving the passage of gas molecules. Overall, the combination of surface treatment (amino group) and orientation (electric field) on GO nanosheets leads to better CO2 permselectivity for the membranes studied.

The Influence of Combined Surface Treatmentsusing Plasma of Argon, Er:Yag Laser and Sandblasting on the Shear Bond Strength of Zirconia Core to the Veneering Ceramic – In Vitro Study

Background: Success of zirconia-based prosthesis is greatly affected by ceramic chipping and delamination due to poor bonding between zirconia framework and veneering ceramic. This study uses combination of surface treatment with Non-thermal Argon Plasma to evaluate its effect on Shear Bond Strength (SBS). Objective: The study aimed to evaluate the effect of different surface treatment using sandblasting, argon plasma, Er:YAG laser and its combination on SBS of zirconia to veneering ceramic. Material and Method: 150 milled and sintered zirconia blocks (10mm x 18mm) were subjected to various surface treatments and were randomly divided into five groups according to the surface treatment methods namely. Group 1: Argon plasma(220 V,100W and constant gas pressure 1 kg/cm2 and gas flow 8.5L/min) + Liner (E max ceram zirliner), Group 2: Atmospheric pressure argon plasma, Group 3: Sandblasting, Group 4: Sandblasting + Laser ablation ( Er:YAG ; 300mJ/pulse energy, frequency-10Hz ) + Argon plasma and Group 5: Sandblasting + Argon plasma. Specimens were subjected to shear bond strength test by a universal testing machine with a crosshead speed of 1 mm/min. The data were analysed with one-way ANOVA and Bonferoni test for multiple comparisons tests (α=0.05). Result: Highest shear bond strength value was obtained for Group 4 followed by Group 5, Group 3, Group 2 with least value obtained for Group 1. Conclusion: This study shows that sandblasting + Er:YAG + Argon plasma showed higher shear bond strength when compared to other groups.

Effects of Different Tooth Conditioners on the Bonding of Universal Self-etching Adhesive to Enamel.

To investigate the effects of several etching products prior to the application of a one-step self-etch adhesive (1-SEA) or two-step self-etch adhesive (2-SEA) on enamel by microshear bond strength (µSBS) testing and observation of the adhesive-enamel interface. Ground human enamel surfaces were randomly assigned to one of eight groups according to the combination of surface treatments (either no conditioner [NC], ME [Multi Etchant], EC [Enamel Conditioner], or KE [K-etchant Gel]) and adhesive (ADU [Adhese Universal] or SE2 [Clearfil SE Bond 2]). All groups were further divided into two subgroups: 0 or 10,000 thermal cycles (TC). Then, the µSBS test was performed. The adhesive-enamel interface after acid-base challenge and the surface structure after conditioner application were also observed. With 10,000 TCs, there was no statistically significant difference between ME-ADU and NC-ADU. On the other hand, the µSBS of EC-ADU or KE-ADU was significantly higher than that of NC-ADU, while that of ME-SE2 was significantly lower than NC-SE2. There was no significant difference between EC-SE2, NC-SE2, and KE-SE2. Formation of an acid-base resistance zone (ABRZ) was confirmed in all groups. However, funnel-shaped erosion, which indicates interfacial defects, was observed in the NC-ADU, ME-ADU, and ME-SE2 groups. For enamel bonding, application of EC or KE prior to ADU increased the bond strength and created a stable adhesive-enamel interface. On the other hand, SE2 also had stable shear bond strength and interface without the use of conditioners. However, ME decreased the bonding performance of SE2.

Friction Stir Welding of AA2099-T83 and AA2060-T8E30 Aluminium Alloys with New Cr-Free Surface Treatments and Sealant Application

The feasibility for friction stir welding (FSW) surface-treated AA2099-T83 aluminium extrusions with AA2060-T8E30 aluminium sheets in the overlap configuration and using a sealant at the interface was investigated in this work. New Cr-free surface treatments such as thin film sulphuric acid anodising (TFSAA) and sol–gel were applied to the parent materials, and a sealant was applied before applying the FSW process. FSW welds were produced using several combinations of surface treatments and sealant application with no significant influence on FSW process stability and performance. The metallographic examination of the welds showed that a good protection of the crevice was achieved with some sealant accumulation at the edges of the overlapping region. The microstructural analysis showed no sealant remnants but the presence of some oxide remnants in the stir zone (SZ) of the welds, especially in the TFSAA treated parent material cases. However, these remnants did not show any significant effect in the static pull-out strength of the joints and failures at the most stressed zone of the AA2099-T83 extrusions outside the FSW weld region were consistently obtained.

Repair bond strength of aged resin composite using different surface treatments and bonding protocols

Background: Repair of direct composites are less invasive than replacement, diminishing the risk of iatrogenic exposure of the pulp and the risk of detrimental to adjacent teeth, all in all, reducing the procession of the “restoration death spiral”. Aim: This study aimed to evaluate the repair bond strength of aged resin composites using different surface treatments and bonding protocols. Materials and Methods: A total of 45 discs (n=45) were fabricated of Nanohybrid composite measuring about 2.5 mm in height and 3.5 mm in diameter and were mounted in acrylic resin and subjected to 10,000 thermal cycles between 5-55 ? C with 30 seconds of dwell time in a thermocycler in order to simulate artificial ageing. All these samples were assigned into three groups (n=15) based on the surface treatment protocol. According to the bonding protocol, the samples in each group are further divided into three subgroups (n=5). After surface treatments of the aged composites, the application of bonding agent followed by new composite material was performed. All the samples were stored in distilled water at 37 ? C for 24 hours. The shear bond strength of the samples was measured using a universal testing machine at a crosshead speed of 1mm/min. Results: Among the groups, the mean bond strength in medium grain diamond bur and 37% phosphoric acid etchant with the universal bonding agent subgroup was higher 852.56±27.71 than the remaining groups. The lowest mean bond strength of 200.9±10.62 was observed in 37% Etchant with direct composite subgroup. Conclusion: Different combinations of surface treatments and bonding protocols affect shear bond strength differently. The highest shear bond strength values were achieved for the group where surface treatment was done with the combination of blue diamond bur and 37% phosphoric acid along with a universal bonding agent.

How to Control Powder Alignment to Maximize Functionality and Performance of Color Cosmetics and Sunscreen

Control of powder alignment is essential for maximizing the functionality of color cosmetics and sunscreens. Various surface treatments were applied to nanosized titanium dioxide to modify their surface characteristics. Such modifications can be used to control the behavior of dispersions in cosmetics, enabling them to align uniformly. The powders were mixed with solvents and applied to a cellulose triacetate film. The features of powder alignment on the film were evaluated using several approaches. When the type of surface treatment changed by varying the weight ratio, there was no significant correlation between its alignment and treatment. However, when we focused on the pseudo-HLB each treated pigment, their alignments were correlated. It was confirmed that the powders subjected to the appropriate surface treatment combinations from the pseudo-HLB standpoint made it possible to align uniformly and create a smooth coating film. As a result, it has a high UV-shielding ability. The surface-treated powders in this study were found to change the UV shielding ability and surface roughness of the layer formed when they were formed by spreading the sample powder dispersion and drying of the film. It was suggested that the pseudoHLB, which is calculated based on the chemical structure after the surface treatment process, is useful for choosing the optimum surface treatment to create a uniformly aligned pigment layer.

The Effect of Different Combinations of Surface Treatments and Bonding Agents on the Shear Bond Strength Between Titanium Alloy and Lithium Disilicate Glass-Ceramic

In order to obtain a more-natural esthetic prothesis, the use of hybrid abutments is becoming widespread in implant dentistry. The aim of this in vitro study was to assess the effects of different surface treatments, as well as the effects of different combinations of surface treatments and cementation protocols, on the shear bond strength between titanium alloy disks and lithium disilicate glass-ceramics. Forty titanium-alloy disks (4 × 6.6 mm) were fabricated using computer-aided designed/computer-assisted manufacturing, and an identical number of lithium disilicate glass-ceramic disks of similar sizes were fabricated by a heat-pressing technique to be attached to the titanium disks. The specimens from each material group were divided into two groups (n = 20 each) according to the surface treatment type: alumina airborne-particle abrasion or etching with hydrofluoric acid. Each group was then divided into two subgroups (n = 10) depending on the resin-cement type: Multilink Hybrid Abutment Cement (Ivoclar Vivadent) or PANAVIA SA Cement Plus (Kuraray). After thermocycling (5,000 cycles), a shear bond strength (SBS) test was conducted using a universal testing machine. Statistical analysis was performed by analysis of one-way analysis of variance and unpaired tests (P < .05). Statistically, the highest SBS values were obtained using airborne-particle abrasion. The surface treatment of titanium alloys by sandblasting led to a higher SBS compared to etching with hydrofluoric acid. The cement type also had a significant influence on SBS results.

Effect of surface treatments and universal adhesive application on the microshear bond strength of CAD/CAM materials.

PURPOSEThe aim of this study was to evaluate the microshear bond strength (µSBS) of four computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three different surface treatment protocols.MATERIALS AND METHODSFour different CAD/CAM blocks were used in this study: (1) flexible hybrid ceramic (FHC), (2) resin nanoceramic (RNC), (c) polymer infiltrated ceramic network (PICN) and (4) feldspar ceramic (FC). All groups were further divided into four subgroups according to surface treatment: control, hydrofluoric acid etching (HF), air-borne particle abrasion with aluminum oxide (AlO), and tribochemical silica coating (TSC). After surface treatments, silane was applied to half of the specimens. Then, a silane-containing universal adhesive was applied, and specimens were repaired with a composite, Next, μSBS test was performed. Additional specimens were examined with a contact profilometer and scanning electron microscopy. The data were analyzed with ANOVA and Tukey tests.RESULTSThe findings revealed that silane application yielded higher µSBS values (P<.05). All surface treatments were showed a significant increase in µSBS values compared to the control (P<.05). For FHC and RNC, the most influential treatments were AlO and TSC (P<.05).CONCLUSIONSurface treatment is mandatory when the silane is not preferred, but the best bond strength values were obtained with the combination of surface treatment and silane application. HF provides improved bond strength when the ceramic content of material increases, whereas AlO and TSC gives improved bond strength when the composite content of material increases.

The Improvement of Wear Characteristics on 316L Stainless Steel by Dual Surface Treatment Method

Stainless steel is used widespread in various industries, but it has poor wear resistance. Therefore, this study aims to investigate the wear resistance of enhanced surface of 316L stainless steel by applying the combination of surface treatments that consist of shot blasting followed by paste boronizing. Glass beads with diameter 250 microns and the blasting pressure of 6 bar has been used as the shot material in conducting shot blasting process. Paste boronizing process was conducted at temperature 950°C for 8 hours soaking. Data were collected and analyzed which concentrating on the samples’ microstructure, microhardness and wear evaluation. Shot blasting improves the case depth of boride layers formed after performing paste boronizing by boosting the boron diffusion owing to the grain refinement created by shot blasting. The ultimate combination of shot blasting and paste boronizing parameters enhance the case depth of the smooth and compact boride layers with high boron content. The hardness performance increase 624% compared to untreated 316L stainless steel which also highly improve the wear resistance of the material. In this investigation, these dual processes of surface treatment which are shot blasting and paste boronizing can be applied in fabricating the improved 316L stainless steel for industrial usages.

Effect of different surface treatments on the repair bond strength of resin composites with titanium

The purpose of this study was to evaluate the effect of different surface treatment combinations on the bonding of composite resins to NiCr and titanium alloys after thermal cycling. Square-shaped specimens (10 mm x 10 mm x 2 mm) were made from NiCr and titanium alloys. The specimens were divided into 6 pretreatment groups (n = 11): (1) machined titanium (control, no treatment); (2) CoJet sand application; (3) grinding with a diamond bur; (4) metal primer application; (5) CoJet sand + metal primer application; and (6) grinding with a diamond bur + metal primer application. The surface roughness of the mechanically treated specimens (control, grinding, CoJet sand) was evaluated. The surface morphology of both metals and elemental composition were examined with SEM and EDS. The composite resin was applied to the specimens. Shear bond strength (SBS) was tested after thermal cycling (5000 cycles, 5 °C to 55 °C). Failure modes were determined. The data were analyzed using the Shapiro-Wilk test, two-way ANOVA and post hoc Fisher’s LSD test (p = .05). For titanium specimens, the grinding + metal primer exhibited higher values than the other groups, and all groups showed higher SBS values than the control group. Combined use of CoJet sand, grinding with a diamond bur, and metal primer application would be useful for enhancing the bond strength of composite resin to titanium. The grinding of the NiCr surface with a diamond bur is the only method that could improve the bond strength of a composite resin compared to the other methods.

Design of Two Layer Depth-encoding Detector Module with SiPM for PET

A depth-encoding detector module with silicon photomultipliers(SiPMs) using two layers of scintillation crystal array was designed, and the position measurement capability was verified using DETECT2000. The depth of interaction of the crystal pixels with the gamma rays was tracked through the image acquired with the combination of surface treatment of the crystal pixels and reflectors. The bottom layer was treated as a reflector except for the optically coupled surfaces, and the crystals of top layer were optically coupled each other except for the outer surfaces so that the light sharing was made easier than the bottom layer. Flood images were obtained through the combination of specular reflectors and random reflectors, grounded and polished surfaces of crystal pixels, and the positions at which layer images were generated were measured and analyzed. The images were reconstructed using the Anger algorithm, whose the SiPM signals were reduced as the 16-channels to 4-channels. In the combination of the grounded surface and all reflectors, the depth positions were discriminated into two layers, whereas it was impossible to separate the two layers in the all polished surface combinations. Therefore, using the combination of grounded surface crystal pixels and reflectors could improve the spatial resolution at the outside of the field of view by measuring the depth position in preclinical positron emission tomography.

Effects of applying a combination of surface treatments on the mechanical behavior of basalt fiber metal laminates

The surface treatment of metals has a great role on the adhesion of the metals to the polymers. There are various surface treatment methods for adhesive joint applications. However, the effect of the combination of surface treatment methods on the mechanical behavior of adhesive joints has not been extensively studied. In this study, the effects of applying a combination of surface treatments on the flexural and Charpy impact behavior of fiber metal laminates (FMLs) were investigated. The surface treatments included forest product laboratory etching (FPL), sulfuric acid anodizing (SAA), sandblasting, sandblasting + FPL and sandblasting + SAA. The FMLs were made from Al2024-T3, basalt fibers and epoxy. Scanning electron microscopy (SEM) was used to study the surface morphology of the Al2024-T3 laminates and fracture surface of the samples. Furthermore, the surface roughness of the Al2024-T3 sheets after different surface treatments were evaluated using profilometry. Results showed that the adhesion of Al2024-T3 to polymeric layers was significantly affected by various surface treatments. Results of bending tests indicated that the highest bending strength and strain to failure values were respectively achieved for the SAA and sandblast treated samples. On the other hand, although there was a slight improvement in the bending strength, the application of SAA or FPL etching after sandblasting caused a negative effect on the strain to failure value of the samples. However, impact test findings showed that the combination of FPL or SAA treatments after sandblasting rendered positive effects on the low-velocity impact behavior of the FMLs.