Unsmooth Surface Research Articles

Piezoelectric Biosensor based on ultrasensitive MEMS system

The lack of ultrasensitive biosensors is the major challenge in the control of pandemics at the very initial stage, so it is necessary to develop new biosensors for the prompt treatment, and the piezoelectric biosensor based on ultrasensitive MEMS system offers a good opportunity. This paper presents a novel approach using polyvinylidene fluoride (PVDF) unsmooth nanofibers to transfer electronic current. The unique unsmooth surface of these nanofibers provides a high surface energy (geometrical potential), making them highly sensitive to microorganisms (e.g., viruses) absorbed on their surface. The absorption of viruses has an obvious effect on the nanofiber’s displacement and electrical resistivity. This paper presents a mathematical model that demonstrates the system's ultra-sensitivity. This rigorous mathematical analysis shows that even when the pull-in voltage in the PVDF nanofiber changes by just 0.0589 %, a dramatic shift from normal periodic motion to pull-in motion is predicted. This paper provides a new and reliable theoretical way to detect pandemics at the very beginning stage.

Characterization of a bioplastic spoon based on kepok banana (Musa acuminata balbisiana C.) starch with the addition of areca nut shells (Areca catechu L.) and glycerol

Bioplastic spoon is one of the complementary packaging for food products, especially instant food, its massive use makes plastic spoon waste contribute to reduce the plastic waste that is dumped into the environment. This study aims to produce and characterize bioplastic spoons made from kepok banana peel starch with areca nut shells as fillers and glycerol as plasticizer which is environmentally friendly. This study consisted of four stages, such as the stage of making Kepok Banana Peel starch, the stage of extracting cellulose rind of Areca Nut, the stage of making bioplastic spoons and the stage of testing parameters. Various concentration of the cellulose (0%; 5%; 15%; and 20% w/w) and glycerol (0 mL; 2 mL; 3 mL and 5 mL) was added to the mixture that contain 8 g of kepok banana peel starch and 150 mL of aquadest. Then, the mixture was moulded to spoon mold that made from flexi glass material and dried in an oven at a temperature of 60 0C for 5 hours and stored in the desiccator. The results showed that the properties of the bioplastic spoon such as tensile strength were decreased while more concentration of the areca nut shells and Glycerol was added. For the elongation of the bioplastic spoon, the addition of areca nut shells and glycerol can increased the elongation of bioplastic spoon. The SEM results show that the bioplastic spoon have a rough or unsmooth surface due to undissolved starch and cellulose fibers. Meanwhile for the biodegradation of the bioplastic spoon, the addition of areca nut shells and glycerol can increased the biodegradation of bioplastic spoon. In conclusion, these results indicate that the addition of areca nut shells and glycerol affects the properties of bioplastic spoon.

Multisolid waste collaborative production of aeolian sand-red mud-fly ash cemented paste backfill

This study proposed the novel idea of anaolian sand-red mud-fly ash cemented paste backfill (ARFCPB) to realize low-carbon backfill mining. This idea realizes large-scale disposal and resource utilization of red mud (RM) and fly ash (FA) solid wastes. The influence of the FA/RM mass ratio and mass concentration on the mechanism of action of ARFCPB was explored through comprehensive rheological performance, mechanical property, microscopic, and leaching toxicity tests. The results showed that the fresh ARFCPB slurry could be described by the Herschel–Bulkley model (R2 ≥ 0.964). As the FA/RM mass ratio increased, the ARFCPB slurry yield stress decreased, the thixotropy decreased, and the slump increased. This is because RM has a large specific surface area and an unsmooth surface, resulting in greater water absorption by RM than by FA. In addition, the uniaxial compressive strength (UCS) of ARFCPB can meet the needs of backfill mining with higher strength requirements. UCS first increases and then decreases with increasing FA/RM mass ratio, which is optimal when the mass ratio of FA to RM is 4. When the FA/RM mass ratio was 4, the UCSs of specimens A4 and B4 with mass concentrations of 78% and 80%, respectively, were 5.6 MPa and 6.4 MPa after 28 days of curing. The leaching results of heavy metal ions in group B4 meet the Class III groundwater standards and can be used for centralized drinking water sources and industrial and agricultural water. Considering the fluidity characteristics, mechanical properties, and leaching results, B4 was identified as the optimal formulation. Finally, the microstructure of the ARFCPB was studied using ultrasonic pulse velocity (UPV) and SEM. The results can contribute to clean production in the aluminum production industry, coal-fired power plants, and coal mines.

Iridescent structural colors printing on cellulose fabrics with robust structural coloration

Structural coloration originating from colloidal particle assembly has drawn tremendous interest because of the brilliant dye-free colors in line with green and low-carbon development of the world. However, challenges like preparing structural colors with high saturation, durability, and time-efficiency in an unsmooth flexible surface such as fabrics are still remain. Here, a facile photopolymerization process is developed to construct high saturation and durable structural colors on cotton fabrics. The structural colors derive from the fast assembly of external magnetic field triggered Fe3O4@C particles. It is easy to regulate structural colors by adjusting magnetic particle sizes. In addition, by designing photo masks on transparent polyester films, the magnetic field induced assembly and photo polymerization strategy can conveniently print structural colored patterns on cotton fabric. This strategy may open a new gate in the textile printing field, as well as bring a new method by using fabrics to improve the mechanical properties of structural colors.

Research on the directional characteristics of wind noise emitted by bionic rods

In this paper, the directional characteristics of wind noise emitted by different bionic rods were studied based on a hybrid computational aeroacoustics method. The noise reduction mechanism of surface grooves, pits, and bumps was analyzed, respectively. The basic principle of noise reduction is to reduce the influence of the vortex shedding on the rod by changing the shape of the rod or passive control technology to reduce the dipole sound source. The unsmooth transverse surface will increase the loss of flow on the leading edge of the rod and reduce the vertical effect of vortex shedding on the rod. The convex leading edge of the rod can help to transfer the vertical noise from low frequency to high frequency and reduce the vertical effect of wake vortex shedding to reduce the peak sound pressure level. The cost of those was the increase in the aerodynamic drag and the increase in noise in the flow direction (the increase in the amplitude of drag fluctuation). In particular, the longitudinal v-groove structure on the surface of the elliptical rod can reduce the circumferential aerodynamic noise while keeping the aerodynamic drag coefficient unchanged.

Blue laser welding of laminated electrical steels: Dynamic process, weld bead characteristics, mechanical and magnetic properties

Laminated electrical steels are the key material structure of the stator and rotator of a motor, where high-quality welding is crucial for improving the performance of the electric machine. However, it is challenging to achieve a desired balance among the magnetic properties, mechanical properties, and welding efficiency for the laminated electrical steels at present. This work first adopted a 450 nm flat-top blue laser with a maximum power of 2000 W, which has a higher primary absorption rate to Fe compared to that of the conventionally used 980-1080 nm infrared laser, to join the laminated electrical steels. The dynamic process, weld bead characteristics, mechanical properties, and magnetic properties of the blue laser welding of laminated electric steels were investigated. The results show that a flat-top and large-spot blue laser can make the molten pool have a self-stabilizing ability to keep the continuity when encountering the gap and unsmooth surface. Moreover, a further improved self-stabilizing ability is observed for a small welding speed. The largest depth and width of the blue laser weld bead in this work are 2.30 and 0.57 mm, respectively, with a shear strength of up to 1700 N, which are achieved at the laser power of 1500 W and welding speed of 10 mm/s. In addition, the work also validated that the blue laser could significantly reduce the splashing in welding of electrical steel laminations and improve the welding efficiency, which provides a promising solution for high-performance electrical machine manufacturing.

Automatic Diagnosis of Elbow Arthritis Based on Edge Algorithm

Osteoarthritis is an age-related degenerative joint disease; it is mainly because the cartilage tissue between bones is worn and thinned, which leads to the damage of the periosteum and bone including the surrounding ligaments. Clinically, its manifestations are mainly joint pain, swelling, stiffness, and even partial loss of function, which seriously affects the quality of life of patients. The main clinical manifestations are elbow joint pain and limited movement. Elbow articular cartilage degenerates and falls off, and the more serious manifestation is subchondral hyperosteogeny and sclerosis, which leads to unsmooth articular surface and narrow joint space. Finally, elbow joint pain is severe with different degrees of mobility disorder, elbow joint extension and flexion range is getting smaller and smaller, and elbow joint pain is getting more and more serious. In this paper, the segmentation of left and right elbow images is completed based on gray projection through the analysis of image gray distribution. After obtaining the region of interest of elbow joint, the extraction algorithm of elbow joint hard bone edge is studied. Firstly, the extraction of elbow joint hard bone contour edge is completed based on active shape model algorithm combined with image characteristics. Finally, according to the extraction results of hard bone contour edge, this paper realizes the automatic diagnosis of multiple elbow arthritis indexes and compares with the results given by the image set, which proves that the whole algorithm has good adaptability and accuracy.

Sonographic Diagnosis of Medial Meniscocapsular Separation of the Knee

Medial meniscocapsular separation (MCS) is an uncommon knee injury. No dedicated sonographic study on medial MCS has been reported thus far. This article retrospectively analyzes the sonogram of two patients with medial MCS confirmed by either magnetic resonance imaging (MRI) or surgery. Both patients are in their 30s with sports-related medial knee injuries. Sonograms of their medial knees displayed similar features of fluid collection between the medial meniscus and the deep portion of the medial collateral ligament (MCL), and an unsmooth outer surface of the meniscus. Meniscal tear and MCL injury were also found in both of these patients. Sonographic diagnostic criteria for the medial MCS are proposed based on the two patient cases. The differentiation of medial MCS from other cystic lesions in the medial parameniscal area is also discussed.

Two-scale mathematical model for tsunami wave

Scale or dimension is critical for all physical laws, and different scales might result in distinct and sometimes contradicting laws for the same phenomenon. In this study, the idea of the two-scale fractal is utilized to model the time-fractional tsunami wave traveling on an unsmooth surface. Mass and momentum conservation equations are established in a fractal space. To covert the considered fractional model into a differential equation, the fractional complex transform is used, then He’s variational iteration method is adopted to solve the resultant equation. The fractal model helps in studying the dynamic behavior of tsunami wave and their prevention through boundary control. The present study sheds new light on two-scale fluid mechanics.

FRACTAL OSCILLATION AND ITS FREQUENCY-AMPLITUDE PROPERTY

When an oscillator vibrates in a porous medium or along an unsmooth surface, a fractal model can be adopted using the two-scale fractal derivative. This paper elucidates a simple but effective method for fast and exclusive insight into the asymptotically periodic property at the initial stage and the extremely low frequency property when time tends to infinity. Some examples are illustrated to show the one-step solution process and the accurate results.

Physical-chemical Characterization of Nano-Zinc Oxide/Activated Carbon Composite for Phenol Removal from Aqueous Solution

Oil palm shell was used as a precursor for preparation of activated carbon using different chemical activations (potassium hydroxide (KOH), zinc chloride (ZNCl2), and phosphoric acid (H3PO4)). Each activated carbons (AC) was mixed with nano-zinc oxide to form a composite. From the gas sorption analyzer, it is showed that nitrogen adsorption isotherms show Type II for ZnO/AC-KOH and ZnO/AC-ZnCl2 corresponding to the micro- and mesoporous structures, respectively. However, the nitrogen adsorption isotherm of ZnO/AC-H3PO4 exhibits the Type I with predominantly microporous structures. The SEM micrographs produced unsmooth surface and different pore sizes. The XRD patterns at 2θ of 25.06° and 26.75° were come from amorphous activated carbon. The peak intensity of ZnO was weak due to low concentration of zinc precursor. However, the ZnO of ZnO/AC-ZnCl2 showed strongly peak intensity. The effectiveness of the composites was examined for phenol removal determined by UV-Vis Spectrophotometer method. The equilibrium adsorption follows the Langmuir and Freundlich models according to the best correlation coefficient (R2). The kinetic model was only obtained for the pseudo-second-order with the best linearity of the correlation coefficient (R2). The results of this study showed that the oil palm shell has a great potential for ZnO/AC with excellent adsorptive property. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Fractal diffusion of silver ions in hollow cylinders with unsmooth inner surface

This article studies the ion release from an unsmooth inner surface of a hollow fiber. A fractal diffusion model is established using the fractal derivative, and the effect of the fractal dimension on the ion release is elucidated. The present theory provides a theoretical basis for the optimization of a hollow fiber contained silver ions for practical applications.

Application value of multi-detector computed tomography evaluating the clinical staging of adenocarcinoma of the esophagogastric junction after neoadjuvant chemotherapy

Application value of multi-detector computed tomography evaluating the clinical staging of adenocarcinoma of the esophagogastric junction after neoadjuvant chemotherapy

FORMULATION OF MULBERRY LEAF (MORUS ALBA L.) EXTRACT HYDROGEL BEADS USING CROSS-LINKED PECTIN

Objective: Nutraceutical products have now gained considerable interest to be consumed regularly. Since the active substances in nutraceuticalproducts are provided by nature, they are safe to consume. The development of a dosage form and the appearance of a modern nutraceutical productcan improve product quality. Therefore, this research aimed to formulate a nutraceutical product, mulberry leaf extract, into hydrogel beads that swellin water and that can be administered orally.Methods: Deoxynojirimycin, the active substance in mulberry leaf extract hydrogel beads, has the efficacy of an anti-diabetic agent. In this research,there were four formulations: The variations 1:2 and 1:3 of the extract-to-polymer ratio and the variations 2.5% and 5% of the cross-linkerconcentration.Results: The results showed that hydrogel beads had a spherical form with an unsmooth surface and a brown color, and they were able to swell inwater. The best formula was Formula 1, with a 1:2 extract-to-polymer ratio and a 2.5% cross-linker concentration. Formula 1 produced an averagediameter of 3.6 mm, a swelling ability of 210.68%, and immediate swelling in water for 30 seconds.Conclusions: Mulberry leaf extract hydrogel beads could be used as an interesting nutraceutical product.

Two-dimensional spin coating with a vertical centrifugal force and the effect of artificial gravity on surface leveling

This study focuses on an innovative method for spin coating called the two-dimensional (2D) spin coating method. Using a centrifugal force applied by a rotary machine perpendicular to the wafer surface body, a vertical centrifuge force (VCF) was generated. The VCF allowed controllable artificial gravity acceleration to be generated and caused the coating to face this elevated gravity acceleration to adjust and normalize the high and low surface tension stresses. Previous surface leveling mathematics were analyzed and modified. The modified calculations indicate that the effect of additional gravity exerted on the liquid’s surface can reduce the amplitude of surface leveling. To experimentally investigate this phenomenon, a 2D spin coater was designed and manufactured. Higher artificial gravity overcame some common coating defects, such as cloudiness, edge beading, inner layer bubbling, and unsmooth surface leveling. Photoresist (AZP4620) was used as the coating material. The surface roughness was analyzed by atomic force microscopy (AFM) and the layer properties were also imaged by scanning electron microscopy (SEM). The AFM results (average and root-mean-square roughness) indicated a decrease in surface leveling amplitude by increasing the VCF. SEM images showed condensed layers without any porosity or rupture. The experimental results agreed with the simulations and calculated values.

Structured Hysteroscopic Evaluation of Endometrium in Women With Postmenopausal Bleeding.

To evaluate visual pattern parameters obtained with hysteroscopy for the prediction of endometrial cancer, to evaluate observer variation of these parameters, and to present a scoring system of the parameters for the prediction of malignancy compared with subjective evaluation. A prospective controlled study (Canadian Task Force classification II-1). A university clinic. One hundred forty-nine consecutive women with postmenopausal bleeding and an endometrium thickness ≥ 5 mm. Sixty-one (41%) had endometrial cancer. Forty-six of 149 women were referred based on suspected malignancy. Endometrial pattern characteristics for endometrial cancer were evaluated in hysteroscopic video clips. The reference standard was pathologic evaluation of resectoscopic samples or hysterectomy. Using multivariate logistic regression, image parameters were correlated with the presence of endometrial cancer. A scoring system of visual parameters for the prediction of malignancy was compared with subjective evaluation of malignancy. A score for lesion surface, necrosis, and vessels had an area under the curve (AUC) of 0.89, 0.89, and 0.87, respectively. A hysteroscopic cancer (HYCA) scoring system based on unsmooth lesion surface, papillary projections, surface necrosis, "candy floss" necrosis, white hyperintense spots, irregular branching vessels, and irregular distribution of irregular vessels was able to predict cancer (AUC = 0.964) with higher accuracy than subjective evaluation (AUC = 0.859, p < .01). At a score value ≥ 3, sensitivity was 89% and specificity was 92% with moderate agreement between observers (kappa = 0.56 [0.42-0.71]). A systematic pattern evaluation of optimal parameters by a HYCA scoring system based on systematically defined terms may increase accuracy in the diagnosis of endometrial cancer and should be further elaborated and external validity tested in unselected women with postmenopausal bleeding.

Preparation of popcorn-shaped CdS nanoparticles by hydrothermal method and their potent photocatalytic degradation efficiency

In this study, popcorn-shaped with unsmooth surface cadmium sulfide (CdS) nanoparticles were prepared successfully by a facile and convenient one-pot strategy, using PVP-K30 as surfactant. Structure and component of CdS samples were characterized by XRD and EDX respectively, morphology was studied by SEM and FESEM. The synthetic mechanism of the unsmooth CdS nanospheres was assumed through the above characterization also. From the results, the popcorn-shaped CdS nanoparticles could photocatalytically degrade methyl orange efficiently under visible light irradiation, which is much better than CdS nanoparticles prepared without PVP. These results suggest that the as-prepared CdS nanoparticles might be used as a potential photocatalyst to treat the organic pollutants efficiently under visible light irradiation.

Significant improvement of ZnS film electrical and optical performance by indium incorporation

This paper reports a new material, indium-doped ZnS (ZnS:In) film, which is fabricated for the first time to improve its electrical and optical performance. By electron beam evaporation technology and the optimized annealing treatment, high quality ZnS:In film is prepared. XRD indicates that the incorporation of 6 at.% indium atoms into ZnS film causes little lattice deformation. The AFM results imply that large sized particles are compactly dispersed in the ZnS:In layer and results in an unsmooth surface. Electrical and optical property tests show that the resistivity of ZnS film is greatly decreased to 4.46 × 10−2 Ω·cm and the optical transmittance is improved to 85% in the visible region. Comparing with the results in other literatures, significant progress in electrical/optical performance has been made in this paper.

Centrifuge modeling of interaction between reverse faulting and tunnel

In this study, a series of centrifuge tests, modeling reverse fault rupture with 60° dip angle, were conducted in a dry sandy soil with a tunnel embedded in the soil layer. The test results showed that the tunnel and soil responses depended on the tunnel position, soil relative density and tunnel rigidity. Tunnels appeared be able to deviate the fault rupture path, while this deviation may be associated with significant rotation and displacement of the tunnel. However, a deeper tunnel was able to diffuse the shear deformation to a wider zone with an unsmooth surface displacement which may cause severe damage to the surface structures. Finally, the tunnel rotation, the location of the fault outcropping, the vertical displacement of the ground surface, the effect of tunnel rigidity on fault rupture path and surface displacement and the effect of soil relative density on fault–tunnel interaction were reported and discussed in this study.

Double-balloon enteroscopy for mesenchymal tumors of small bowel: Nine years’ experience

To assess the value of double-balloon enteroscopy (DBE) for the diagnosis of gastrointestinal mesenchymal tumors (GIMTs) in the small bowel and clarify their clinical and endoscopic characteristics. A retrospective review in a total of 783 patients who underwent a DBE procedure from January 2003 to December 2011 was conducted. Data from patients with pathologically confirmed GIMTs were analyzed at a single tertiary center with nine years' experience. The primary outcomes assessed included characteristics of patients with GIMTs, indications for DBE, overall diagnostic yield of GIMTs, endoscopic morphology, positive biopsy, comparison of diagnosis with capsule endoscopy, and subsequent interventional management. GIMTs were identified and analyzed in 77 patients. The mean age was 47.74 ± 14.14 years (range: 20-77 years), with 63.6% being males. The majority of individuals presented with gastrointestinal bleeding, accounting for 81.8%, followed by abdominal pain, accounting for 10.4%. Small bowel pathologies were found in 71 patients, the detection rate was 92.2%. The diagnostic yield of DBE for GIMTs was 88.3%. DBE was superior to capsule endoscopy in the diagnosis of GIMTs (P = 0.006; McNemar's χ(2) test). Gastrointestinal stromal tumor was the most frequent and leiomyoma was the second frequent GIMT. Single and focal lesions were typical of GIMTs, and masses with smooth or unsmooth surface were the most common in the small bowel. GIMTs were removed from all the patients surgically except one patient treated with endoscopic resection. DBE is a safe and valuable procedure for patients with suspected GIMTs, and it provides an accurate position for subsequent surgical intervention.