Protruding Structure Research Articles

Dynamic photocatalytic membrane coated with ZnIn2S4 for enhanced photocatalytic performance and antifouling property

The dynamic photocatalytic membrane coated with ZnIn2S4 was fabricated to solve the problems of suspended photocatalyst separation and membrane fouling that occur in applying photocatalytic technology and membrane separation technology, respectively. The structural characteristics, photocatalytic performance, and antifouling property of dynamic photocatalytic membranes with different loadings of ZnIn2S4 were systematically investigated. As the loading of photocatalysts increases, a uniform and dense photocatalytic layer formed on the membrane surface, and the surface morphology changed from a protruding structure to an undulating mountain-like structure. The roughness and absorption performance for UV–Vis of dynamic photocatalytic membranes increased because of the formation of a photocatalytic layer while the chemical property and water flux did not change. The removal efficiencies of fluvastatin and total organic carbon by dynamic photocatalytic membranes were significantly increased compared with that of the pristine polyvinylidene fluoride (PVDF) membrane, indicating that the dynamic photocatalytic membranes possessed excellent photocatalytic performance and high stability. Meanwhile, the dynamic photocatalytic membranes exhibited a greater antifouling property than the pristine PVDF membrane because of the formation of the photocatalytic layer on the membrane surface. Therefore, the fabrication of dynamic photocatalytic membrane is an effective method to promote the advantageous combination of photocatalytic technology and membrane separation technology.

Morphology, phylogeny and taxonomy of the genus Sectonema (Nematoda, Aporcelaimidae)

AbstractThis contribution provides new insights in the phylogeny and taxonomy of the nematode genus Sectonema with an integrative approach. A brief historical outline of the matter is presented. Then, the morphological pattern of the genus is revised and illustrated, the nature of its stomatal protruding structure, either a reduced odontostyle or a mural tooth, being its most relevant diagnostic feature. The existence of cilia‐ or seta‐like structures in the perioral area and/or at the anterior part of cheilostom of some species is evidenced by SEM observations for the first time. Available molecular data (D2–D3 LSU‐rRNA gene) are analysed, including two new sequences of S. septentrionale from Spain. The monophyly of the genus is confirmed, and two species groups with geographical projection are tentatively identified. A close relationship with Metaporcelaimus is also demonstrated as both taxa constitute a highly supported clade. A likely polyphyly of the family Aporcelaimidae is once more demonstrated. Finally, an updated taxonomy of the genus is proposed, including revised diagnosis, list of species, identification key and a compendium of their main morphometrics.

Capacitive Pressure Sensor with Wide-Range, Bendable, and High Sensitivity Based on the Bionic Komochi Konbu Structure and Cu/Ni Nanofiber Network.

High-performance flexible pressure sensors have an essential application in many fields such as human detection and human-computer interaction. Herein, on the basis of the dielectric layer of a bionic komochi konbu structure, we propose a low-cost and novel capacitive sensor that achieves high sensitivity and stability over a broad range of tactile pressures. Further, the flexible and durable electrode layer of the transparent junctionless copper/nickel-nanonetwork was prepared based on electrospinning and electroless deposition techniques, which ensured high bending stability and high cycle stability of our sensor. More importantly, because of the sizeable protruding structure and internal micropores in the elastomer structure we designed, the inward curling of the protruding structure and the effectual closing of the micropores increase the effective dielectric constant under the action of the compressive force, improving the sensitivity of the sensor. Measured response and relaxation time (162 ms) are 250 times faster than those of a conventional flatpolydimethylsiloxanecapacitive sensor. In addition, the fabricated capacitive pressure sensor demonstrates the ability to be used on wearable applications, not only to quickly recognize the tapping and bending of a finger but also to show that the pressure of the finger can be sensed when the finger grabs the object. The sensors we have developed have shown great promise in practical applications, such as human rehabilitation and exercise monitoring, as well as human-computer interaction control.

Sensitivity analysis of geometrical parameters to study haemodynamics and thrombus formation in the left atrial appendage.

The left atrial appendage (LAA) is a complex and heterogeneous protruding structure of the left atrium (LA). In atrial fibrillation patients, it is the location where 90% of the thrombi are formed. However, the role of the LAA in thrombus formation is not fully known yet. The main goal of this work is to perform a sensitivity analysis to identify the most relevant LA and LAA morphological parameters in atrial blood flow dynamics. Simulations were run on synthetic ellipsoidal left atria models where different parameters were individually studied: pulmonary veins and mitral valve dimensions; LAA shape; and LA volume. Our computational analysis confirmed the relation between large LAA ostia, low blood flow velocities and thrombus formation. Additionally, we found that pulmonary vein configuration exerted a critical influence on LAA blood flow patterns. These findings contribute to a better understanding of the LAA and to support clinical decisions for atrial fibrillation patients.

Flexible multichannel vagus nerve electrode for stimulation and recording for heart failure treatment

Vagus nerve stimulation is an emerging bioelectronic medicine to modulate cardiac function, as the nerve provides parasympathetic innervation to the heart. In this study, we developed a polyimide based 2D cuff electrode to wrap around on the vagus nerve. Thanks to the tiny size and bendable protruding structure of the contact tips of the device, the electrode sites are able to flexibly bend to touch the nerve, selectively record and stimulate the vagus nerve. Gold, platinum and platinum black materials were chosen to compose the electrodes for nerve stimulation and recording, respectively. Since the platinum black has ~30 times larger charge delivery capacity (CDC) than gold, Pt black electrode is used for nerve stimulation. The electrochemical impedance spectroscopy and cyclic voltammetry measurement of the three materials were conducted in vitro, revealing the results of 405 kΩ, 41 kΩ, 10.5 kΩ, @1 kHz and 0.81 mC/cm2, 4.26 mC/cm2, 25.5 mC/cm2, respectively (n = 3). The cuff electrodes were implanted into the right-sided vagus nerve of rats for in vivo experiment. Biphasic current configuration was implemented for nerve stimulation with frequency of 10 Hz, pulse during of 300 μs and various currents stimulus. The result shows the heart beat frequency drops up to 36% during the stimulation and was able to return the regular frequency as stimulation was removed. Subsequently, the vagus nerve signals were recorded with the four channel cuff electrodes. The magnitude of the compound nerve action potentials (CNAPs) is ~10 μV and the signal to noise ratio (SNR) is ~20.

Settlement of the classification of Svistella Gorochov and Paratrigonidium Brunner von Wattenwyl using morphology and molecular techniques, with the description of a new species from Yunnan, China (Orthoptera: Trigonidiidae: Trigonidiinae).

It is difficult to distinguish the genera Svistella and Paratrigonidium on the basis of morphology. Gorochov postulated that Svistella spp. possess the following identification characters: posterior lateral lobes of epiphallus long and narrow at apex, guide rod elongate, attachment plate of the spermatophore consisting of three sclerites (a narrow middle sclerite bearing no protruding structure, and a pair of lateral ones extending to the sides). These features have not been extensively evaluated. In this study, the COI gene was sequenced and was used as a DNA marker to distinguish two genera. The results showed that each genus formed a monophyly, respectively. One new species, Svistella fuscoterminata sp. nov., was found in Yunnan, China. Although its genitalia were similar to that of Paratrigonidium spp., the molecular result supported the new species belonging to Svistella. The specimens are deposited in East China Normal University, Biology of History Museum (ECNU) and Shanghai Entomological Museum (SEM).

A DFT investigation on group 8B transition metal-doped silicon carbide nanotubes for hydrogen storage application

The binding of group 8B transition metal (TMs) on silicon carbide nanotubes (SiCNT) hydrogenated edges and the adsorption of hydrogen molecule on the pristine and TM-doped SiCNTs were investigated using the density functional theory method. The B3LYP/LanL2DZ method was employed in all calculations for the considered structural, adsorption, and electronic properties. The Os atom doping on the SiCNT is found to be the strongest binding. The hydrogen molecule displays a weak interaction with pristine SiCNT, whereas it has a strong interaction with TM-doped SiCNTs in which the Os-doped SiCNT shows the strongest interaction with the hydrogen molecule. The improvement in the adsorption abilities of hydrogen molecule onto TM-doped SiCNTs is due to the protruding structure and the induced charge transfer between TM-doped SiCNT and hydrogen molecule. These observations point out that TM-doped SiCNTs are highly sensitive toward hydrogen molecule. Moreover, the adsorptions of 2–5 hydrogen molecules on TM-doped SiCNT were also investigated. The maximum storage number of hydrogen molecules adsorbed on the first layer of TM-doped SiCNTs is 3 hydrogen molecules. Therefore, TM-doped SiCNTs are suitable to be sensing and storage materials for hydrogen gas.

Structure analyses of the explosive extratropical cyclone: A case study over the Northwestern Pacific in March 2007

The synoptic situation and mesoscale structure of an explosive extratropical cyclone over the Northwestern Pacific in March 2007 are investigated through weather station observations and data reanalysis. The cyclone is located beneath the poleward side of the exit of a 200 hPa jet, which is a strong divergent region aloft. At mid-level, the cyclone lies on the downstream side of a well-developed trough, where a strong ascending motion frequently occurs. Cross-section analyses with weather station data show that the cyclone has a warm and moist core. A ‘nose’ of the cold front, which is characterized by a low-level protruding structure in the equivalent potential temperature field, forms when the cyclone moves offshore. This ‘nose’ structure is hypothesized to have been caused by the heating effect of the Kuroshio Current. Two low-level jet streams are also identified on the western and eastern sides of the cold front. The western jet conveys cold and dry air at 800–900 hPa. The wind in the northern part is northeasterly, and the wind in the southern part is northwesterly. By contrast, the eastern jet carries warm and moist air into the cyclone system, ascending northward from 900 hPa to 600–700 hPa. The southern part is dominated by the southerly wind, and the wind in the northern part is southwesterly. The eastern and western jets significantly increase the air temperature and moisture contrast in the vicinity of the cold front. This increase could play an important role in improving the rapid cyclogenesis process.

Fabrication and evaluation of a protruding Si-based printhead for electrohydrodynamic jet printing

A printhead that is compatible with Si-based processes and able to generate homogeneous micro- and nano-scale droplets plays an important role in electrohydrodynamic jet printing (E-jet printing) for the large-scale manufacturing. This paper proposes the design, fabrication and evaluation of a novel protruding Si-based printhead for E-jet printing. The protruding nozzle can concentrate the electrical field and restrain the lateral wetting so as to improve the jetting stability. However, it is a challenge to have both the protruding structure and a stable solution/voltage supply. Accordingly, a set of micro-manufacturing processes, as well as methods of adopting hydrophobic and insulation treatments, are also presented to stabilize the solution/voltage supply. The diameter and height of the protruding nozzle are 50 µm and 60 µm, respectively. Printing tests are performed using both quantum dots solution (CdSe/CdS/ZnS) and a mixed solution of glycerol, ethylene glycol and water. Feasibility of the protruding nozzle is proved by experiments that a stable meniscus with Taylor cone could form on the nozzle orifice, and fine dots (⩽30 µm) could be printed successfully and continuously. The protruding design and micro-fabrication processes of the protruding Si-based printhead pave the way for the multi-nozzle E-jet printing with high efficiency and resolution.

The influence of protruding filamentous bacteria on floc stability and solid-liquid separation in the activated sludge process

Filamentous bacteria can impact on the physical properties of flocs in the activated sludge process assisting solid-liquid separation or inducing problems when bacteria are overabundant. While filamentous bacteria within the flocs are understood to increase floc tensile strength, the relationship between protruding external filaments, dewatering characteristics and floc stability is unclear. Here, a quantitative methodology was applied to determine the abundance of filamentous bacteria in activated sludge samples from four wastewater treatment plants. An automated image analysis procedure was applied to identify filaments and flocs and calculate the length of the protruding filamentous bacteria (PFB) relative to the floc size. The correlation between PFB and floc behavior was then assessed. Increased filament abundance was found to increase interphase drag on the settling flocs, as quantified by the hindered settling function. Additionally, increased filament abundance was correlated with a lower gel point concentration leading to poorer sludge compactability. The floc strength factor, defined as the relative change in floc size upon shearing, correlated positively with filament abundance. This influence of external protruding filamentous bacteria on floc stability is consistent with the filamentous backbone theory, where filamentous bacteria within flocs increase floc resistance to shear-induced breakup. A qualitative correlation was also observed between protruding and internal filamentous structure. This study confirms that filamentous bacteria are necessary to enhance floc stability but if excessively abundant will adversely affect solid-liquid separation. The tools developed here will allow quantitative analysis of filament abundance, which is an improvement on current qualitative methods and the improved method could be used to assist and optimize the operation of waste water treatment plants.

Optical and structural approaches for improved luminance distribution and enhanced efficiency of organic light emitting diodes

We combined cavity based optical method and polymer based structural approach to achieve efficiency enhancement and widened luminance distribution of organic light emitting diodes. Cavity method was implemented by adjusting the thickness of the hole transport layer and using a ITO-Metal-ITO transparent electrode. Utilizing the lateral phase separation of immiscible polystyrene/ polyethylene glycol binary system, we have fabricated an aperiodic protruding structure. The application of the two methods yielded two fold efficiency enhancement and widened luminance distribution. To be specific the external quantum efficiency increased from 8.9% to 17.9%.

Hydrogen adsorption on graphene sheets doped with group 8B transition metal: A DFT investigation

The binding of group 8B transition metals (TMs) on graphene sheet (GS) with hydrogen–terminated edges and the adsorption of hydrogen molecules on the pristine and TM–doped GSs were investigated using the density functional theory. The calculation showed that all TM atoms had strong binding with GS, in which the Os atom displayed the strongest interaction with GS. The hydrogen molecule displayed a weak interaction with pristine GS, whereas it had a strong interaction with TM–doped GSs, in which the Os–doped GS showed the strongest interaction with the hydrogen molecule. Moreover, the adsorptions of 2–5 hydrogen molecules adsorbed on Os–doped GS were also investigated, which three hydrogen molecules were adsorbed on the first adsorption layer of Os–doped GS. The increase in the adsorption abilities of hydrogen molecules onto the TM–doped GSs was due to the protruding structure and the TM induced charge transfer between TM–doped GSs and the hydrogen molecules. These observations showed that TM–doped GSs were highly sensitive toward hydrogen molecules. Therefore, the present results may be useful for the design of doping of TM on GS candidates, such as adsorbent and storage.

Polymeric C-shaped cuff electrode for recording of peripheral nerve signal

We reported a polyimide-based C-shaped neural interface electrode to record peripheral nerve signal from the rat sciatic nerve. The neural interface electrode consisted of four recording probes protruded from the C-shaped frame, and two reference electrode sites on the C-shaped frame. Thanks to the unique bendable protruding structure of the recording probes, electrode sites were able to adapt to and maintain close contact to the nerve without restricting nerve movement. Gold, gold–carbon nanotube (CNT) composite, and platinum were chosen as the electrode materials. The electrodes were characterized by electrochemical impedance spectroscopy (EIS) analysis in phosphate buffer solution (PBS) (pH 7.4). The results showed that the gold-CNT electrode (area of 8500μm2) had an average impedance of 11.1kΩ, approximately 15-fold and 3-fold lower than gold and platinum, respectively. An in vivo nerve signal recording test was also performed using the three electrodes. The magnitude of the compound nerve action potentials (CNAPs), the latency of the onset and the duration of the CNAPs were measured and analyzed under various stimulus currents. The results of the CNAPs magnitude and the signal-to-noise ratio (SNR) indicated a proportional relationship to the stimulus current beyond the threshold current of 0.3mA. Our electrode has the capability to measure nerve signals less than 5μV.

Microstructure and Mechanism of Concrete Using Inorganic Silicate Admixture

The study evaluates the properties of concrete mixed with inorganic silicate admixture. The admixture was used in proportions of 3%, 5%, and 7% of the weight of the cement. We performed tests on compressive strength and elastic modulus to evaluate the mechanical properties of concrete. Results show that the addition of the inorganic silicate admixture has a positive influence on the mechanical properties of concrete, with the best results obtained with 3% admixture. MIP porosity measurements determined that the addition of inorganic silicate admixture increased the density of the porous structure. SEM microscopic analysis revealed many needle-like protrusions into the porous structure of concrete. XRF chemical composition analysis indicated that these structures comprised mainly Na2O and SiO2. Can with cement hydration products Ca(OH)2 bring in Chemical reaction. Inferred pore structure Within be C-S-H gel of needle-like protruding structure. it can improve the main cause of mechanical properties of concrete.

Preparation and Electrochemical Properties of Poly(p-Chloroaniline)

Polymerization of p-chloroaniline (CA) was achieved electrochemically in aqueous solution containing H2SO4 as supporting electrolyte. The films were obtained by applying sequential linear potential scan rate 20mV/s between -0.5 to 1.5V versus Ag/AgCl electrode. The polymer was characterized by UV-visible and FT-IR spectroscopy. We observed the morphologies of PCA films through the scanning electronic microscope (SEM), showing island protruding structure. The Tafel curves showed that PCA can be used as anti-corrosion material.

Investigation of Biosurfactant-Producing Indigenous Microorganisms that Enhance Residue Oil Recovery in an Oil Reservoir After Polymer Flooding

Three biosurfactant-producing indigenous microorganisms (XDS1, XDS2, XDS3) were isolated from a petroleum reservoir in the Daqing Oilfield (China) after polymer flooding. Their metabolic, biochemical, and oil-degradation characteristics, as well as their oil displacement in the core were studied. These indigenous microorganisms were identified as short rod bacillus bacteria with white color, round shape, a protruding structure, and a rough surface. Strains have peritrichous flagella, are able to produce endospores, are sporangia, and are clearly swollen and terminal. Bacterial cultures show that the oil-spreading values of the fermentation fluid containing all three strains are more than 4.5 cm (diameter) with an approximate 25 mN/m surface tension. The hydrocarbon degradation rates of each of the three strains exceeded 50%, with the highest achieving 84%. Several oil recovery agents were produced following degradation. At the same time, the heavy components of crude oil were degraded into light components, and their flow characteristics were also improved. The surface tension and viscosity of the crude oil decreased after being treated by the three strains of microorganisms. The core-flooding tests showed that the incremental oil recoveries were 4.89-6.96%. Thus, XDS123 treatment may represent a viable method for microbial-enhanced oil recovery.

High-Aspect-Ratio Structure Fabrication on (110)-Oriented Silicon Surfaces Using Tribo-Nanolithography

This study investigated methods of fabricating high-aspect-ratio structures on a silicon surface using a combination of tribo-nanolithography and wet chemical etching. Tribo-nanolithography forms an amorphous phase on a single-crystal silicon surface that has an etch resistance against potassium hydroxide so that a protruding structure can be fabricated by wet chemical etching. To fabricate high-aspect-ratio structures, (110)-oriented silicon was used, and the effect of machining parameters on the structure shape was investigated. The results showed that a structure with vertical side walls could be fabricated by machining along the (112) direction. The etch resistance against potassium hydroxide depended on the normal load and number of repetitions, and the width and the maximum height were functions of these conditions. The aspect ratio of the structure increased with the etch time as long as the amorphous phase was maintained. A sub-micrometer-scale high-aspect-ratio structure was fabricated based on these results, demonstrating the possibility of using this simple and effective method.

Active compensation for portal machines

The cutting performance of a machine tool is mainly determined by its static and dynamic behavior. During a cutting process high static and dynamic forces may occur, which result in instabilities of the cutting process. Especially, long protruding structure components, such as z-slider of a portal machine, represent a distinct weak spot concerning their structural behavior. The structure integrated compensation modules represent a new approach to compensate static and dynamic deformations of slider structures and help to achieve a considerable improvement of their compliancy behavior.

A mechanism aiding simultaneously reciprocal mating in snails

The majority of hermaphroditic animals mate on a given occasion as either male or female, but terrestrial snails and slugs generally mate reciprocally with each partner participating in both sexual roles. This manner of mating requires that the genitalia be exactly opposed prior to copulation attempts, a task made difficult in snails and slugs by the absence of hearing and very limited vision. In the brown garden snail, Cornu aspersum (Müller, 1774), we found that a small protruding structure associated with the genital atrium plays an important role in positioning the snails prior to copulation. Lesions of the penial lobe reduced mating success rates, delayed mating, increased the number of attempted intromissions, and increased the number of unilateral intromissions. The sensory capacity of the penial lobe is demonstrated by histological and electrophysiological evidence, and behavioral data suggest that the lobe is also a stimulus for the partner snail. A literature review suggests that structures functionally equivalent to the penial lobe may be present in many gastropod molluscs that mate simultaneously and reciprocally, but in none that mate in other ways.

Effect of Machine Parameters on Threshing Quality for Seed Crop of Chickpea

Chickpea is an important pulse crop of Indian sub continent, but with low productivity. Non-availability of quality seeds is one of the major reasons for low productivitiy. Being dicotyledonous and the germ tip being located at the protruding structure, the seeds are prone to mechanical injuries during threshing. A study was conducted to investigate the effect of machine parameters on threshing quality for chickpea seed crop. The type of threshing element, cylinder speed and feed rate had significant effect on threshed seed quality as well as the performance of the thresher. Teflon coated iron beater threshing element at 8.94m/s cylinder speed at feed rate 200 kg/h was optimum for minimal visible and invisible injury of seeds. The threshing efficiency, thrower loss and cleaning efficiency was 98.96%, 0.95% and 91.93 %, respectively, and within acceptable limits. A radiographic index was developed to provide combined information of mechanical abused seed value.