Wet Method Research Articles

SLAKES Smartphone Application to Identify the Difference in Soil Aggregate Stability Under Cover Crop Management for Soils with Fragipan Horizon

ABSTRACT Fragipan subsoil horizons have poor soil aggregate stability that slakes in rise with the water table. The intensity of slaking can be used as a proxy to identify the presence of fragipan horizon in a soil profile. Fairly new, ‘Slakes,’ a smartphone application provides an aggregate stability index (ASI) based on fitting a Gompretz function over changes in area of disintegrating soil peds immersed in water for over 10 min through the analysis of images taken by a smartphone camera. Objectives of this study were twofold: first, to identify changes in ASI values with the adoption of cover crops, and second, to apply Slakes value to identify the fragipan horizon. We compared ASI values for with (CC) and without (NCC) a cover crop mix at two on-farm fields with fragipan subsoil horizons in southern Illinois. The conventional wet aggregate stability method did not show any differences (p = .10) between CC and NCC for the surface Ap horizon at both sites. However, the ASI score of CC was higher than NCC for the site with 10 years under CC, but the opposite trend was observed for the other site. In general, the Ap horizon had the highest ASI score with an average value of 0.48 and it significantly declined for the Bt horizon (0.29). This study showed that the Slake-ASI score has value to identify changes in management practices on surface soils. However, applying Slakes to identify the fragipan horizon would require a shorter time length (<10 min) and large-scale calibration.

Dry Fractionation for Sustainable Production of Functional, Nutritional and Palatable Grain Legume Protein Ingredients

Abstract Grain legumes such as pea, faba bean, lupin and soybean are an important protein source for the production of plant-based foods and thus facilitate the protein transition. For many food applications, the proteins are first isolated using conventional wet methods that are resource intensive. Dry fractionation processes are therefore developed to facilitate a more sustainable protein transition. This review discusses the status of dry fractionation of grain legumes to produce protein-rich ingredients for food production and how the use of these dry-enriched ingredients could be further enhanced. Dry fractionation includes dry milling and dry separation technologies which are first briefly described. There are different strategies to further improve the separation, which include pre-treatments and improving powder bulk behaviour. Pre- and post-treatments not only improve the functional properties of dry-enriched protein ingredients but also enhance the nutritional value of the ingredients and minimize off-flavours. Opportunities still exist to further optimise dry fractionation techniques and pre-treatments to increase the purity and yield. Finally, the use of dry-enriched fractions should be accelerated by development of 1) functionality-driven ingredient formulation strategies and 2) new physical post-modifications and food fermentation strategies to enhance functionality, nutritional value and taste of the ingredients to prepare attractive food products.

Molecular Clip Strategy of Modified Sulfur Cathodes for High-Performance Potassium Sulfur Batteries.

Potassium-sulfur (K-S) batteries are severely limited by the sluggish reaction kinetics of the cyclooctasulfur (cyclo-S8) electrode with low conductivity, which urgently requires a novel cathode to facilitate activity to improve sulfur utilization. In this study, using the wet chemistry method, the molecular clip of Li+ is created to replace cyclo-S8 molecular with the highly active chain-like S6 2- molecular. The molecular clip strategy effectively lowers the reaction barrier in potassium-sulfur systems, and the stretching of S─S bonds weakens the binding between sulfur atoms, facilitating the transformation of potassium polysulfides (KPSs). The as-prepared cathode exhibits a reversible capacity of 894.8mAhg-1 at a current rate of 0.5C. It maintains a long cycle life of 1000 cycles with a stable coulombic efficiency in the potassium-sulfur cells without cathode catalysts. Operando XRD and Raman spectra combined with density functional theory (DFT) calculations, revealing the high efficiency of enhanced conversion of potassium polysulfide for high-performance K-S batteries.

Metal Powder Production by Atomization of Free-Falling Melt Streams Using Pulsed Gaseous Shock and Detonation Waves

A new method of producing metal powders for additive manufacturing by the atomization of free-falling melt streams using pulsed cross-flow gaseous shock or detonation waves is proposed. The method allows the control of shock/detonation wave intensity (from Mach number 4 to about 7), as well as the composition and temperature of the detonation products by choosing proper fuels and oxidizers. The method is implemented in laboratory and industrial setups and preliminarily tested for melts of three materials, namely zinc, aluminum alloy AlMg5, and stainless steel AISI 304, possessing significantly different properties in terms of density, surface tension, and viscosity. Pulsed shock and detonation waves used for the atomization of free-falling melt streams are generated by the pulsed detonation gun (PDG) operating on the stoichiometric mixture of liquid hydrocarbon fuel and gaseous oxygen. The analysis of solidified particles and particle size distribution in the powder is studied by sifting on sieves, optical microscopy, laser diffraction wet dispersion method (WDM), and atomic force microscopy (AFM). The operation process is visualized by a video camera. The minimal size of the powders obtained by the method is shown to be as low as 0.1 to 1 μm, while the maximum size of particles exceeds 400–800 μm. The latter is explained by the deficit of energy in the shock-induced cross-flow for the complete atomization of the melt stream, in particular dense and thick (8 mm) streams of the stainless-steel melt. The mass share of particles with a fraction of 0–10 μm can be at least 20%. The shape of the particles of the finest fractions (0–30 and 30–70 μm) is close to spherical (zinc, aluminum) or perfectly spherical (stainless steel). The shape of particles of coarser fractions (70–140 μm and larger) is more irregular. Zinc and aluminum powders contain agglomerates in the form of particles with fine satellites. The content of agglomerates in stainless-steel powders is very low. In general, the preliminary experiments show that the proposed method for the production of finely dispersed metal powders demonstrates potential in terms of powder characteristics.

Fabrication and characterization of silver nanowire-coated porous alginate wet-laid webs for wound dressing applications

Fabrication and characterization of silver nanowire-coated porous alginate wet-laid webs for wound dressing applications

Wet-spun Ni, N-Codoped Macroporous Carbon Fibers for Efficient CO2 Electroreduction and Zn-CO2 Batteries

Developing efficient and cost-effective electrocatalysts for the electrocatalytic CO2 reduction reaction (eCO2RR) is highly desirable for carbon neutrality and clean energy. Herein, a self-sacrificing template-assisted wet spinning method is developed...

Lithiation-driven cascade dissolution coprecipitation of sulfide superionic conductors

We present a Li2S-free and cost-effective wet chemistry method for the preparation of sulfide solid electrolytes (SSEs), which addresses a major challenge in the commercialization of all-solid-state batteries (ASSBs). Our method universally synthesizes various electrolytes, including LixMS4 (M = P, Sb, or Si) and Li6PS5X (X = Cl, Br, or I). It particularly produces Li6PS5Cl of high quality (5.7 mS cm−1 of ionic conductivity at 25°C) at a material cost of one-tenth of previously reported methods. The synthesis process, featuring a cascade-dissolution-coprecipitation mechanism, is investigated using analytical techniques for soluble intermediates and sediment products. The Li6PS5Cl-based pellet ASSBs with a LiNi0.8Mn0.1Co0.1O2 cathode and a Li-In anode provide high initial capacity (190 mAh g−1 at a 0.1C rate, 55°C) and hold a capacity retention of > 80% after 1,000 cycles at a 2.0C rate. Additionally, a 0.7 Ah pouch cell with a silver/carbon anode exhibits a remarkable energy density (352.8 Wh kg−1 at 45°C). This solvent-based and Li2S-free synthetic process proposes a cost-effective pathway toward sustainable mass production for synthesizing SSEs.

An environmentally friendly, rainfall-resistant suspension prepared based on halloysite nanotubes for the delivery of hydrophobic pesticides

The application of nanomaterials in pesticide system shows many advantages such as enhanced dispersion stability, high foliar affinity, improved insecticidal effect, and reduced environmental risks. In the study, a simple wet grinding method was used to decrease the particles size of the pesticides chlorobenzuron and indoxacarb (CI) in presence of halloysite nanotubes (HNTs). The irregularly shaped suspension pesticide system (CI@HNTs) in size of ∼ 2 μ m is obtained via HNTs and xanthan gum (XG) encapsulation of the hydrophobic pesticides. Attributed to the small size and interfacial interactions of HNTs, CI@HNTs have excellent stability, dispersion and slow release behavior. CI@HNTs exhibit enhanced foliar wettability, spreading and topological effect on plant leaves compare to commercial suspension concentrate (SC) product and CI (without HNTs), which results in high resistance to rainfall washout. In the crop model treated by fall armyworm, the mortality rate is 53.3 % in CI group, while the mortality is 75.0 % in CI@HNTs-8 which is 1.41 times that of CI. In addition, the safety of CI@HNTs is systematically evaluated, and the results show that the toxicity of CI@HNTs to the wheat and the aquatic organism zebrafish is lower than that of the SC. This study develops an economical, efficient and environmentally friendly pesticide system based on natural clay nanotubes, which shows promising applications in sustainable agricultural production.

Application of downshifting and antireflection stacked layers synthesized using a wet chemistry method with broad UV excitation for silicon heterojunction solar cells

Downshifting and antireflection materials enhance the short-circuit current density of the solar cell module while reducing ultraviolet degradation in SHJs.

Formulation and Evaluation of Fast Disintegrating Tablets Containing Broccoli Extract (Brassica oleracea) Using Crospovidone and Ac-Di Sol as Superdisintegrants

Broccoli (Brassica oleracea) is known to contain flavonoid and glucosinolate compounds that act as acetylcholine enzyme inhibitors to improve memory in humans. To be practical and easy to use, broccoli is made in tablet dosage form. This study aims to determine the effect of the super disintegrants concentration of crospovidone and Ac-Di Sol on the physical quality of the Fast-Disintegrating Tablet (FDT) of broccoli extract. A total of 3 formulas were made using the wet granulation method and different concentrations of crospovidone and Ac-Di Sol, namely formula 1 (crospovidone 5% : Ac-Di-Sol 2%), formula 2 (crospovidone 4.5% : Ac-Di-Sol 2.5%), and formula 3 (crospovidone 4% : Ac-Di-Sol 3%). Tablet quality testing included hardness, friability, disintegration time, wetting time, and determination of total flavonoid content of tablet. The results of tablets have a brownish white colour with black spots, are round with a flat surface, have a distinctive odour, and have a slightly bittersweet taste. ANOVA statistical analysis of tablet hardness (p &gt; 0.05) showed that there was no significant effect of crospovidone and Ac-Di-Sol concentrations on tablet hardness. While other test results showed a significant effect of crospovidone and Ac-Di-Sol concentrations on tablet friability (p &lt; 0.05), disintegration time (p &lt; 0.05), and wetting time (p &lt; 0.05). Formula 1 (crospovidone 5% and Ac-Di-Sol 2%) is the best formula based on the physical quality of tablets, with an average tablet hardness value of 2.23 kp, friability of 0.95%, disintegration time of 1 minute 37 seconds, wetting time of 1 minute 15 seconds, and total flavonoid content of 2.62 mg QE/g (101.83%).

Synthesis of Fe90Nb10 via wet mechanical milling method and its structural, magnetic and thermal characterization

Synthesis of Fe90Nb10 via wet mechanical milling method and its structural, magnetic and thermal characterization

Study on Differential Pulse Anodic Stripping Voltammetry Method for Simultaneous Determination of Trace amount of Zn, Cd, Pb, Cu in some Cough Syrups in Vietnam

The optimal measurement parameters of differential pulse anodic stripping voltammetry method (DP-ASV) to simultaneously determine the trace amount of the four elements Zn, Cd, Pb, Cu have been studied, including the sweep rate, pulse amplitude, drop size of mercury, initial purge, equilibration time. The analytical procedure was applied to determine Zn, Cd, Pb, Cu in 12 cough syrup samples in Viet Nam, including 6 functional food samples and 6 medicinal samples. The quantitative echnique used was standard addition and the applicability of quantitative elements in self - made samples was studied. Cough syrup analysis samples were digested using the wet ashing method in microwave oven. Research results show that there are no regular differences in elements content between medicinal cough syrup samples and functional food samples, except for functional food samples TP08 which has Pb content and the syrup medicine sample TH03 which has Cu content many times higher than other types. However, the content of the studied elements is within the allowable limits according to curent regulations (QCVN 8-2:2011/BYT; 46/2007/QĐ-BYT, WHO). The method has low detection limits and limit of quantification with ppb level, the relative standard deviations (% RSD) of repeated measurements are less than 3%, and recovery reflects the accuracy of the analytical method for elements ranging from 61.0 % to 87.5 %, which meets AOAC requirements for trace.

Polysulfone Hollow Fiber Membrane Mixed with Peat Clay Particles: Fabrication and Properties

In this work, the effect of peat clay particles (PCP) was investigated as pore former of polysulfone (PSf) hollow fiber membrane properties. Preparation of polysulfone membrane dope solution conducted by phase inversion technique using wet spinning method. A homogeneous dope solution is added with peat clay from four composition variations of 0-6 wt%. Followed by mixed dope until homogeneous for an hour at room temperature (~29 °C). The preparation of peat clay before used is by having it calcinated at 600 °C for 1 hour, then sifted to a size of 120 mesh. The hollow fiber membrane is casted using the wet spinning method with the dope solution flow rate set at 4 mL/min and the bore fluid flow rate at 4 mL/min. The hollow fiber membrane that has been formed is analyzed by FTIR, contact angle, water absorption, and porosity. The characteristics of the membrane show that the functional group in the addition of peat clay in the absorption of Si-OH and Si-O-Si. The specific spectrum of PSf-PEG/PC is indicated by peak wavenumbers 872 – 874 cm-1. Polysulfone hollow fiber membrane mixed with peat clay shows the contact angle on the membrane surface shows hydrophobic characteristics without addiction of peat clay particles and become slightly hydrophilic with peat clay addiction of 71.28°. In addition, water absorption in each sample increases with the addition of peat clay from 0 to 4 wt%. The ability of water absorption increased to 32.51%, and membrane porosity increased from 23.66% to 38.87%. It is concluded that polysulfone hollow fiber membranes are enhanced by adding peat clay as a pore builder and hydrophilic additives and become less fouling in future application for water/wastewater treatment.Keywords: Peat clay, hollow fiber membrane, polysulfone, wet spinning, montmorillonite

Corrosion Performance of Steel Bar Embedded in Seawater Mixed Mortar with Batching Plant Waste

Reinforcing steel deterioration is complicated by corrosion. Reinforcing steel corrosion can weaken a structure. Corrosion cannot be eliminated; however, it can be reduced to increase building service life. The objective of the research it to demonstrate the effect of coating method as corrosion prevention and the cover depth to the corrosion performance of steel bar embedded in seawater mixed mortar. This study examines the corrosion rate of steel reinforcement in a 15 x 15 x 15 cm mortar cube made by using seawater as mixing water and containing Portland Pozzolan Cement (PPC) as a binder material. This study also experiences numerous corrosion mitigation methods using wet, dry, and dry-wet cycle exposure methods. The reinforcement and mortar surface were protected with anti-corrosive paint. Additionally, specimens without protective measures were also fabricated for comparison. Two reinforcing steels were attached in the two different cover depths, 3 cm and 5 cm. This study used sand and batching plant byproducts as fine aggregate. Study found a hierarchy of corrosion-causing exposures. The dry-wet cycle was the most corrosive, followed by wet and dry. Steel coating prevents corrosion better than surface coating. However, both methods outperformed the uncoated method in corrosion resistance. The mortar cover was 5 cm thick, compared to 3 cm expected. A combination of mortar with fine sand aggregate outperformed dry mortar made from batching plant leftovers. The investigation of corrosion potential through the utilization of the half-cell potential technique reveals that the outcomes obtained from test specimens using the steel coating prevention approach exhibit a higher degree of positivity in comparison to the prevention method including surface coating. The unprotected approach exhibits outcomes that lean towards being more unfavorable compared to the steel coating prevention method and the surface coating prevention method. The findings indicate that the performance of reinforcing steel embedded within a 3 cm mortar cover depth is often worse when compared to reinforcing steel situated inside a 5 cm mortar cover depth.

Upcycling of Eggshell Waste into Calcium Phosphates for Use in Sustainable Biomedical Engineering Applications

Eggshells are an inorganic waste, and their accumulation rate is increasing globally, complicating waste management. However, the European Union defines eggshells as low-risk material that can be recycled and reused safely in other applications. Their chemical composition renders them an attractive precursor of calcium phosphate materials (CaPs). Because of their remarkable biocompatibility and capacity for natural degradation, CaPs are frequently employed in biomedical engineering applications. In this research, the wet precipitation method was employed for fabricating CaP powder. Initially, the eggshells were processed into CaCO3 powder and then reacted with HCl to obtain CaCl2 (aq). This reacted with Na2HPO4 to obtain a precipitate that was filtered and dried. The precipitate in powder form underwent X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis to evaluate its microstructure, and elemental and phase composition. The results indicated that the recovered powder was brushite.

The development of transfer technologies for advanced 2D circuits integration

AbstractIn the light of the scaling limitations of conventional CMOS technology, two‐dimensional (2D) materials offer a transformative avenue for advancing Moore's law in the post‐Moore era. The technology for transferring 2D materials serves as a crucial link between their synthesis and device integration. This review provides a comprehensive assessment of advancements in the transfer technologies and integration of 2D materials, which are essential for next‐generation electronics. Firstly, state‐of‐the‐art methodologies for high‐quality, wafer‐scale transfer of 2D materials, including both wet and dry transfer methods are thoroughly reviewed. And the requirements for massive transfer of 2D materials compatible with silicon line while preserving their intrinsic properties are disscussed. Next, we focus on 2D integration techniques, paying special attention to the construction of van der Waals contacts at the 2D material/dielectric interface and 2D material/metal electrode interface. Finally, the potential for layer‐by‐layer or tier‐by‐tier transfer 2D devices for monolithic 3D integration was also discussed. This review concludes by highlighting the significant challenges that remain in leveraging the potential of 2D materials at the circuit and system levels, proposing forward‐looking development in transfer strategies.

Investigation of Avocado Pear (&amp;lt;i&amp;gt;Persea americana&amp;lt;/i&amp;gt;) Seed Starch as Binder and Disintegrant in the Formulation of Paracetamol Tablet

&amp;lt;i&amp;gt;Background&amp;lt;/i&amp;gt;: Avocado pear seeds are usually discarded as agricultural waste, the need arises therefore, to investigate their potentials as pharmaceutical excipients. Objective: The objective of this research was to extract, characterize, formulate and do in-vitro evaluation of the formulated paracetamol tablets. &amp;lt;i&amp;gt;Methods&amp;lt;/i&amp;gt;: Ripe avocado (&amp;lt;i&amp;gt;Persea americana&amp;lt;/i&amp;gt;) fruits were harvested in the month of April from a farm at Okada town. The seeds were authenticated by a taxonomist at the Department of Plant Biology, University of Benin, with Harbarium number UB/PB/24 0201. The seeds were prepared, dried and milled to fine powder and extracted using a standard procedure by Silva &amp;lt;i&amp;gt;et al&amp;lt;/i&amp;gt;., 2013. The powder was subjected to phytochemical analysis and characterized for its micromeritic properties, and high-resolution analyses using differential scanning calorimetry, fourier transform infrared spectroscopy, scanning electron microscopy and x-ray diffractometry. Batches of paracetamol granules were prepared with avocado starch powder as disintegrant (2.5 - 15%w/w) and starch mucilage as binder (5.0 – 15 %w/v) using the wet granulation method. Granule flow properties were investigated before compression into tablets. Tablets were evaluated for physicochemical properties and drug-excipient interaction was investigated using DSC and FTIR. &amp;lt;i&amp;gt;Results&amp;lt;/i&amp;gt;: Phytochemistry shows presence of saponins, flavonoids, tannins, alkaloids and glycosides. The starch was light-brown, odorless, tasteless and smooth in texture. Slightly soluble in water at room temperature, melting point range 102 - 114°C, moisture content 22.7 ± 2.40%; hydration capacity 2.76 ± 1.20 (g/g), swelling and moisture sorption capacities of 46.43 ± 1.50% and 115.34 ± 1.55%, respectively. Thermogram exhibited a single sharp peak of the extracted starch, FTIR shows no interactions, SEM and XRD results confirmed semi-crystalline powder with fluffy discrete particles. Granules exhibited fair to good flow properties; the tablets were uniform in weight, mean hardness values ≥ 58.84 N, friability 0.14 -1.56 %, disintegration times 0.50 – 11.12 mins and variable drug release 72.78 - 90.67% in 1.0 h. sss&amp;lt;i&amp;gt;Conclusion&amp;lt;/i&amp;gt;: Tablets formulated with the extracted starch as disintegrant gave superior tablet properties, hence a viable local substitute that can be employed at higher concentrations as super-disintegrant and good mucilage binder at higher %w/v concentrations for oral solid dosage formulations.

Green synthesis of gold nanoparticles: pros and cons of natural compounds

Abstract Gold nanoparticles (AuNPs) have attracted scientific interest for their unique properties and diverse applications, across biomedical fields, including sensing, diagnostics, and therapeutic interventions. However, standard wet chemistry synthetic methods for particles synthesis bare limitations, particularly in separating AuNPs from the reaction mixture. Therefore, there is a growing demand for environmentally friendly synthesis routes that minimize waste and utilize non-toxic solvents. Despite advances in this field, many current studies lack standardized protocols, and the underlying mechanisms of the reducing reaction remain unclear. Through comprehensive spectroscopic and morphological analyses, we investigated the redox reactions involved in AuNP formation with various natural extracts, aiming to establish an optimized protocol for producing small, spherical, and monodisperse AuNPs. Our findings demonstrate that cocoa powder extract effectively yields reproducible, spherical AuNPs with a diameter of 11 nm. Comparative analysis with single cocoa powder molecular components identified catechins, a class of flavonoids, as the primary reducing agent in green AuNP synthesis. Catechins also form a protective layer around the AuNPs. However, the simultaneous, unavoidable presence of this layer implemented with fatty acids and proteins, although fundamental for colloidal stability, limits further functionalization of the AuNPs, highlighting a trade-off between stability and functional versatility.

Nanocomposites Based on Iron Oxide and Carbonaceous Nanoparticles: From Synthesis to Their Biomedical Applications.

Nanocomposites based on Fe3O4 and carbonaceous nanoparticles (CNPs), including carbon nanotubes (CNTs) and graphene derivatives (graphene oxide (GO) and reduced graphene oxide (RGO)), such as Fe3O4@GO, Fe3O4@RGO, and Fe3O4@CNT, have demonstrated considerable potential in a number of health applications, including tissue regeneration and innovative cancer treatments such as hyperthermia (HT). This is due to their ability to transport drugs and generate localized heat under the influence of an alternating magnetic field on Fe3O4. Despite the promising potential of CNTs and graphene derivatives as drug delivery systems, their use in biological applications is hindered by challenges related to dispersion in physiological media and particle agglomeration. Hence, a solid foundation has been established for the integration of various synthesis techniques for these nanocomposites, with the wet co-precipitation method being the most prevalent. Moreover, the dimensions and morphology of the composite nanoparticles are directly correlated with the value of magnetic saturation, thus influencing the efficiency of the composite in drug delivery and other significant biomedical applications. The current demand for this type of material is related to the loading of a larger quantity of drugs within the hybrid structure of the carrier, with the objective of releasing this amount into the tumor cells. A second demand refers to the biocompatibility of the drug carrier and its capacity to permeate cell membranes, as well as the processes occurring within the drug carriers. The main objective of this paper is to review the synthesis methods used to prepare hybrids based on Fe3O4 and CNPs, such as GO, RGO, and CNTs, and to examinate their role in the formation of hybrid nanoparticles and the correlation between their morphology, the dimensions, and optical/magnetic properties.

Comparing Polymerization Shrinkage Measurement Methods for Universal Shade Flowable Resin-Based Composites.

Universal shade flowable composites have been introduced to mimic tooth structure with reduced color mismatch and reduced chair time and cost. However, the polymerization shrinkage of resin material may lead to sensitivity and restoration failure. The purpose of this study was to compare the polymerization shrinkage of recently introduced universal shade flowable resin-based composites using both wet and dry density methods. Using two measurement methods, ISO 17304 (wet method) and a gas displacement pycnometry system (dry method), the density of the unpolymerized and the polymerized RBCs were measured, and the polymerization shrinkage was calculated from the density difference. Scanning electron microscopy was used to visualize filler particles. The polymerization shrinkage showed significant differences between many materials. In particular, Bulk Base HARD II Medium Flow showed significantly lower polymerization shrinkage than all the other materials. Shrinkages measured by different methods were significantly different in all cases. The wet method measured a smaller shrinkage than the dry method in most cases, but the shrinkage measured for Gracefil LoFlow was larger with the wet method. Shrinkage between universal shade flowable resin-based composites significantly varied based on both material and measurement method. The polymerization shrinkage of resin-based composites is an important factor in biomimetic clinical dentistry, and work must be conducted to measure it accurately and with more standardization.