Dimension Icon Research Articles

Surface roughness and optical characteristics evaluations after chairside adjustment of different zirconia types.

Limited evidence is available for the effect of chairside adjustment using rotary cutting instruments on the surface roughness and optical properties of different zirconia types. To evaluate the effect of simulated adjustments on surface roughness and optical properties of different zirconia types. Three Partially Stabilized Zirconia (PSZ) types based on mole percent yttria (Y) concentration from the same manufacturer (Katana; Kuraray) were used: 3Y-PSZ, 4Y-PSZ, and 5Y-PSZ. Thirty disk-shaped specimens (Ø14 × 1.2 mm) from different zirconia types (N = 90) were prepared. Specimens were either left without adjustment (NA), adjusted with Dialite ZR finishing and polishing system (Brasseler) (APol), or adjusted with course diamond instruments only (ADia). The specimens were distributed into 9 groups (n = 10): Group 3Y-PSZ/NA, Group 3Y-PSZ/APol, Group 3Y-PSZ/ADia, Group 4Y-PSZ/NA, Group 4Y-PSZ/APol, Group 4Y-PSZ/ADia, Group 5Y-PSZ/NA, Group 5Y-PSZ/APol, and Group 5Y-PSZ/ADia. The surface roughness of specimen was analyzed using an Atomic Force Microscope (AFM) (Bruker's Dimension Icon, Bruker) and Root Means Square (RMS) were recorded (nm). Surface Gloss (SG), Translucency Parameter (TP), and Contrast Ratio (CR) values of all groups were recorded using an integrating sphere spectrophotometer. Statistical analysis was performed using analysis of variance (ANOVA) and Tukey's multiple comparison tests for pairwise comparisons at p < 0.05 and 95% confidence interval. APol had no effect on the surface roughness (p = 0.88) while ADia had a significant negative effect (p < 0.05) despite the type of zirconia. Out of the three testes optical properties, only SG was negatively affected by ADia for all types of zirconia (p < 0.05). The two adjustment types did not affect the TP of all the tested zirconia (p = 0.91). The CR was not affected by the tested adjustments for all zirconia types (p = 0.726). Proper zirconia adjustment following a sequence of burs and polishers can maintain acceptable roughness and optical properties. Adjustment of zirconia with rough diamond can lead to deleterious effects and should be avoided. Chairside adjustment of zirconia could lead to rougher surface and unpredictable changes of surface gloss. Therefore, zirconia adjustment should be minimized to the greatest extent possible and a proper protocol should be followed if had to be done.

Bidirectional Light-Driven Ion Transport through Porphyrin Metal–Organic Framework-Based van der Waals Heterostructures via pH-Induced Band Alignment Inversion

Bidirectional Light-Driven Ion Transport through Porphyrin Metal–Organic Framework-Based van der Waals Heterostructures via pH-Induced Band Alignment Inversion

Water-in-Water Emulsions, Ultralow Interfacial Tension, and Biolubrication

Water-in-Water Emulsions, Ultralow Interfacial Tension, and Biolubrication

The Enhancement of Selectivity and Activity for Two-Electron Oxygen Reduction Reaction by Tuned Oxygen Defects on Amorphous Hydroxide Catalysts

Amorphous catalysts, thanks to their unique coordinately unsaturated properties and abundant of defect sites, incline to possess higher activity and selectivity than their crystalline counterparts....

X-ray Tomography, AFM and Nanoindentation Measurements for Recyclability Analysis of 316L Powders in 3D Printing Process

Recyclability of the leftover metallic powder within the Additive manufacturing (3D printing) process has been less systematically investigated by the research groups although it is a usual practice in most academic and industrial laboratories to reuse the leftover powders for subsequent printing cycles. A better understanding of these mechanisms will assist in optimizing the number of times the recycled powder can be reused in the process to reduce the powder waste. We have recently focused on characterization of recycled powders left in the powder bed after the powder bed fusion process and evaluated the extent of porosity in the powder particles. X-ray computing tomography technique (XCT) has been used to analyze the concentration of porosity, inclusions and dendrites induced inside the recycled powder particles and compared that to the fresh counterparts. The XCT resolution of 2 µm was set to separately scan the powder badges for 3 hours. A roughly 10% more porosity has been calculated in reused powder particles (in at least 10 times reused power). Atomic Force Microscopy (AFM) was used to measure the roughness of the surface of powder particles which shows average roughness of 4.29 nm and 5.49 nm for the virgin and recycled powders, respectively. Nanoindentation measurement were also applied on a number of locations of the particles to compare the hardness of the virgin and recycled powders. For example, the recycled powder shows smaller a hardness of 207 GPa and an effective modulus of 9.60 GPa (average values) compared to 237 GPa and 9.87 GPa (average values) for it’s virgin counterpart which can be correlated to porosities created beneath the surface. Nanoindentation was also applied on (micro and nano) polished surface of the particles under a force of 250 µN for up to 10 seconds. The stainless Steel 316L powder has been the material under study with the powder particles of average size 50 µm which were analyzed using Xradia XCT, Bruker Dimension ICON AFM and Bruker HYSITRON TI Nanoindentation systems. Further investigation is ongoing to correlate the mechanical properties of the manufactured parts to the microstructure and chemical compositions of the virgin and recycled powders.

Оценка механических характеристик кристаллов соляных пород на основе математической модели процесса наноиндентирования на зондовом силовом микроскопе Dimension Icon

Зондовый силовой микроскоп (ЗСМ) Dimension Icon применяется как для оценки рельефа поверхности исследуемого образца, так и для получения силового отклика образца при взаимодействии кантилевера (индентора специальной формы, расположенного на конце упругой консоли) с поверхностью образца. При этом, в отличие от других приборов, например NanoTest-600, где в результате индентирования исследователь получает величину твердости и эффективного модуля упругости с помощью программного обеспечения, «зашитого» в данный прибор, ЗСМ позволяет получить только кривую отклонения индентора в зависимости от перемещения основания кантилевера. Зная коэффициент жесткости на изгиб упругой консоли, исследователь может самостоятельно определить кривую «усилие-перемещение» индентора на этапе нагрузки и разгрузки. Далее возникает задача интерпретации полученной кривой: каким образом можно оценить механические характеристики материала на ее основе? Ответ на этот вопрос зависит, в частности, от характера механического поведения материала. Для диапазона глубин индентирования, превышающих головную сферическую часть зонда кантилевера, при предположении упруго-идеально-пластической модели материала рассмотрена двумерная осесимметричная задача индентирования образца на этапе нагрузки и разгрузки. Численное моделирование осуществлено в пакете ANSYS в рамках контактной задачи в предположении абсолютно жесткого наконечника кантилевера. Путем обработки результатов вычислительного эксперимента предложена методика оценки предела текучести и модуля упругости поверхностных слоев образца. На основе данных ранее проведенных экспериментов получены конкретные значения механических характеристик для кристаллов соляных пород.

EVALUATION OF THE PROPERTIES OF DIAMOND-LIKE CARBON COATINGS LUBRICATED WITH IONIC LIQUIDS

The purpose of the study was to evaluate the properties of DLC coatings with ionic liquids used as lubricants. The type a-C: H DLC coatings were deposited onto the 100Cr6 steel substrate by PVD. The surface topography of the DLC coatings was studied with a Bruker's Dimension Icon® Atomic Force Microscope (AFM), and surface morphology testing, cross section and chemical composition analyses were performed using the Jeol JSM-7100F scanning electron microscope, equipped with an EDS microanalyzer. Surface geometry measurements prior to and after tribological tests were performed on a Taylor Hobson's Talysurf CCI contactless optical profilometer. The tribological tests were carried out on an Anton Paar TRB tribotester under technically dry and lubricated friction with an ionic liquid, 1-Butyl-3-methylimidazolium tetrafluoroborate. The results show that DLC coatings and ionic liquids can significantly reduce resistance to motion.

Atomic force microscopy and scanning electron microscopy analysis of daily disposable limbal ring contact lenses

BackgroundLimbal ring (also known as ‘circle’) contact lenses are becoming increasingly popular, especially in Asian markets because of their eye‐enhancing effects. The pigment particles that give the eye‐enhancing effects of these lenses can be found on the front or back surface of the contact lens or ‘enclosed’ within the lens matrix. The purpose of this research was to evaluate the pigment location and surface roughness of seven types of ‘circle’ contact lenses.MethodsScanning electron microscopic (SEM) analysis was performed using a variable pressure Hitachi S3400N instrument to discern the placement of lens pigments. Atomic force microscopy (Dimension Icon AFM from Bruker Nano) was used to determine the surface roughness of the pigmented regions of the contact lenses. Atomic force microscopic analysis was performed in fluid phase under contact mode using a Sharp Nitride Lever probe (SNL‐10) with a spring constant of 0.06 N/m. Root mean square (RMS) roughness values were analysed using a generalised linear mixed model with a log‐normal distribution. Least square means and their corresponding 95% confidence intervals were estimated for each brand, location and pigment combination.ResultsSEM cross‐sectional images at 500× and 2,000× magnification showed pigment on the surface of six of the seven lens types tested. The mean depth of pigment for 1‐DAY ACUVUE DEFINE (1DAD) lenses was 8.1 μm below the surface of the lens, while the remaining lens types tested had pigment particles on the front or back surface. Results of the atomic force microscopic analysis indicated that 1DAD lenses had significantly lower root mean square roughness values in the pigmented area of the lens than the other lens types tested.ConclusionsSEM and AFM analysis revealed pigment on the surface of the lens for all types tested with the exception of 1DAD. Further research is required to determine if the difference in pigment location influences on‐eye performance.

PENDIDIKAN KARAKTER BAGI ANAK USIA SEKOLAH DASAR MELALUI SEMIOTIK GERAK TARI BESKALAN

&lt;p&gt;The purpose of this research detailed as follows: describe the optimization of the formation of character values in school age children through dance Beskalan semiotic in Malang derby dance studio, dance semiotic determine the influence that proxy Beskalan into Dimension Icon, Index and Dimensions symbol of the establishment character values in school age children Dancing in Malang, knowing the dimensions of the most influential on the formation of character values in school age children in the dance studio in the city of Malang. Test the hypothesis that the function t test is used to determine the effect of partially between the independent variable (x) with variable (y). To determine the effect of simultaneously between the dependent variable with the independent variable F. Both trials used the t test and F test used 5% significance level. Researchers used a serial computer with SPSS 18 for windows to perform hypothesis testing. Keywords: character, semiotik, dance, beskalan, value.&lt;/p&gt;&lt;p&gt;Tujuan dari penelitian ini dirinci sebagai berikut: menggambarkan optimalisasi pembentukan nilai-nilai karakter pada anak-anak usia sekolah melalui semiotik tari Beskalan di studio tari derby Malang, menari semiotik menentukan pengaruh bahwa proxy Beskalan ke Dimensi Icon, Index dan Dimensi simbol nilai karakter berdirinya pada anak-anak usia sekolah Dancing di Malang, mengetahui dimensi yang paling berpengaruh pada pembentukan nilai-nilai karakter pada anak-anak usia sekolah di studio tari di kota Malang. Ujilah hipotesis bahwa uji fungsi t digunakan untuk mengetahui pengaruh secara parsial antara variabel independen (x) dengan variabel (y). Untuk mengetahui pengaruh secara simultan antara variabel dependen dengan variabel independen F. Kedua uji coba menggunakan uji t dan uji F digunakan tingkat signifikansi 5%. Peneliti menggunakan komputer serial dengan SPSS 18 for windows untuk melakukan pengujian hipotesis.&lt;/p&gt;

Elevated YAP and Its Downstream Targets CCN1 and CCN2 in Basal Cell Carcinoma: Impact on Keratinocyte Proliferation and Stromal Cell Activation

Elevated YAP and Its Downstream Targets CCN1 and CCN2 in Basal Cell Carcinoma: Impact on Keratinocyte Proliferation and Stromal Cell Activation

Focus on semiconductors and software

Focus on semiconductors and software

Nano-range mechanical characteristics of carnallite, spathic salt and sylvite

The authors discuss experimental nano-indentation results obtained on carnallite, spathic salt and sylvite grains on Dimension ICON scanning probe microscope, as well as comparative assessments of elasticity modulus and hardness of the minerals.

Comparative characterization of surface roughness of sylvite, spathic salt and carnallite gains in nanorange

The article considers statistical properties of surfaces of sylvite, spathic salt and carnallite grains in nanorange. The authors describe processed experimental data obtained on scanning microprobe Dimension ICON in nanorange for grains of the Upper Kama potassium and potash-magnesium rock salts. Fractal dimension determined by minimum cover method is used as a characteristic of the grain surface roughness. The authors find differences in statistic properties of one-dimension divergent cuts of the grain surfaces.

Focus on materials

Focus on materials

Nano- and micro-range mechanical characteristics of sylvite grain

The paper discusses the indentation testing of sylvite grain using scanning probing microscope Dimension ICON and facility NanotTest-600. The authors present the approximated processing procedure for experimental curves and compare the obtained values of hardness and elastic modulus at different scale levels.