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Raman spectra are often masked by strong fluorescence, which severely hinders the applications of Raman spectroscopy. Herein, for the first time, we report ionic-wind-enhanced Raman spectroscopy (IWERS) incorporated with photobleaching (PB) as a noninvasive approach to detect fluorescent and vulnerable samples without a substrate. In this study, ionic wind (IW) generated by needle-net electrodes transfers charges to the sample surface in air on the scale of millimeters rather than nanometers in surface-enhanced Raman spectroscopy. Density functional theory calculations reveal that the ionic particles in IW increase the susceptibility of the sample molecules, thus enhancing the Raman signals. Meanwhile, the incorporation of IW with PB yields a synergistic effect to quench fluorescence. Therefore, this approach can improve the signal-to-noise ratio of Raman peaks up to three times higher than that with only PB. At the same time, IWERS can avoid sample pollution and destruction without substrates as well as high laser power. For archeological samples and a red rock as an analogue to Mars geological samples, IWERS successfully identified weak but key Raman peaks, which were masked by strong florescence. It suggests that IWERS is a promising tool for characterizations in the fields of archeology, planetary science, biomedicine, and soft matter.

To investigate the clinical outcome and factors affecting the prognosis of endovascular mechanical thrombectomy of acute vertebrobasilar artery occlusion.Eighty-three patients with acute vertebrobasilar artery occlusion were treated with endovascular mechanical thrombectomy, and the recanalization rate, clinical outcomes at three months, modified DWI-PC-ASPECTS, and MRA-BATMAN scores were analyzed.Following acute mechanical thrombectomy, the TICI 2B-3 score was achieved in all patients (100%). At three-month evaluation, 56 (67.5%) patients had good prognosis with the mRS score of 0-2, including 13 (23.2%) patients who had arterial occlusion caused by emboli and 43 (76.8%) who had atherosclerotic stenosis. In analyzing factors affecting the prognosis, a significant difference (P 0.05) existed between patients with good (mRS 0-2) and poor (mRS 3-6) prognosis in the NIHSS (17.3 vs. 31.2, P = 0.000001), modified DWI-PC-ASPECTS (10.4 vs. 7.8, P = 0.021), and MRA-BATMAN (6.3 vs. 4.6, P = 0.003) scores. Univariate Logistic regression analysis demonstrated NIHS score ≥ 21, modified DWI-PC-ASPECTS score ≤ 8.5, and MRA-BATMAN score ≤ 6.5 to be the risk factors for poor prognosis. Multivariate Logistic regression analysis revealed NIHSS score ≥ 21 as an independent risk factor for poor prognosis.Endovascular mechanical thrombectomy is safe and effective in recanalizing occluded vertebrobasilar artery occlusion, and NIHS score ≥ 21, modified DWI-PC-ASPECTS score ≤ 8.5, and MRA-BATMAN score ≤ 6.5 are the risk factors for poor prognosis.

BACKGROUND: The analysis of seismic stability of structure is important in the field of engineering. OBJECTIVE: This study aims to verify the reliability of numerical simulation in seismic stability of reinforced concrete (RC) frame structure. METHODS: Based on the numerical simulation, the material constitutive model of RC frame structure was introduced and then a finite element model was established through ABAQUS to analyze its seismic stability. RESULTS: The simulation results of ABAQUS were similar to the test values, the tangent slope of the skeleton curve of the structure decreased gradually, the interstorey displacement of storey 1 was the largest, the maximum error of the interstorey displacement angle was 0.005, and the ductility coefficient was 4. CONCLUSIONS: The experimental results verify the reliability of the numerical simulation method and provide some theoretical support for its better application in the study of seismic stability.

Urea oxidation reaction (UOR) has been proposed to replace the formidable oxygen evolution reaction (OER) to reduce the energy consumption for producing hydrogen from electrolysis of water owing to its much lower thermodynamic oxidation potential compared to that of the OER. Therefore, exploring a highly efficient and stable hydrogen evolution and urea electrooxidation bifunctional catalyst is the key to achieve economical and efficient hydrogen production. In this paper, we report a heterostructured sulfide/phosphide catalyst (Ni3S2-Ni3P/NF) synthesized via one-step thermal treatment of Ni(OH)2/NF, which allows the simultaneous occurrence of phosphorization and sulfuration. The obtained Ni3S2-Ni3P/NF catalyst shows a sheet structure with an average sheet thickness of ∼100 nm, and this sheet is composed of interconnected Ni3S2 and Ni3P nanoparticles (∼20 nm), between which there are a large number of accessible interfaces of Ni3S2-Ni3P. Thus, the Ni3S2-Ni3P/NF exhibits superior performance for both UOR and hydrogen evolution reaction (HER). For the overall urea-water electrolysis, to achieve current densities of 10 and 100 mA cm-2, cell voltage of only 1.43 and 1.65 V is required using this catalyst as both the anode and the cathode. Moreover, this catalyst also maintains fairly excellent stability after a long-term testing, indicating its potential for efficient and energy-saving hydrogen production. The theoretical calculation results show that the Ni atoms at the interface are the most efficient catalytically active site for the HER, and the free energy of hydrogen adsorption is closest to thermal neutrality, which is only 0.16 eV. A self-driven electron transfer at the interface, making the Ni3S2 sides become electron donating while Ni3P sides become electron withdrawing, may be the reason for the enhancement of the UOR activity. Therefore, this work shows an easy treatment for enhancing the catalytic activity of Ni-based materials to achieve high-efficiency urea-water electrolysis.

Plate type fuel element is widely used in integral and test reactor cores with the advantages of higher power density, deeper fuel burnup and more compact structure. In the semi-closed narrow gap rectangular channel, physics-structure coupling effect under low pressure condition will lead to very complex coolant flow and heat transfer phenomena. Knowledges of the bubble movement and deformation regime are important for studying the mechanism of gas-liquid two-phase flow. In this work, a visual experimental investigation was carried out for the bubble rising characteristics and bubble three-dimensional (3D) reconstruction in a rectangular channel. The process of the bubbles motion was observed by two vertically placed high-speed cameras. By controlling the power of the oxygen pump and the aperture of the air outlet respectively, the rate of bubble formation can be controlled, which eliminated the effects of bubble-to-bubble interactions by increasing the distance between the bubbles. Based on the extracted parameters obtained by digital image processing and assumption that each cross section along the height of bubble to be an ellipse, a new method for reconstructing bubble shape was proposed, using 3D modeling method which can more closely simulates objects to connect bubble elliptic cross sections smoothly under the condition that the cross sections of bubble were not changed as much as possible. Then the bubble shape and trajectory were reconstructed. The results showed that the 3D trajectory of bubble was oscillating and the reconstructed bubble shape not only conformed to the projected contour but also satisfied the effect of surface tension which lead to smooth shape of the bubbles in any time.

An accurate measurement for the modality and motion parameters of bubbles is of great significance. In the existing bubble measurement methods, there are some problems that are desirable to be solved, such as system complexity, poor real-time performance, and the deviation due to two-dimensional measurement. To overcome these challenges, we developed a novel three-dimensional analysis method based on light field imaging diagnosis and deep learning algorithm. Different from traditional two-dimensional reconstruction, the bubble depth can be computed from light field images directly through digital refocusing technology. After calibrating, the conversion between the camera coordinate system and the real-world coordinate system is achieved through the sharpness evaluation algorithm. According to the corresponding relationship, the refocused image could be calibrated to the actual position in real world. Combined with the Multi-input Residual Convolution Neural Network, (MRCNN), the bubble depth could be computed fully automated from given images at high accuracy. Based on the above works, the three-dimensional reconstruction model for bubble flow can be established by coupling the depth and the parameters extracted through bounding boxes. The proposed method solves the problem that conventional imaging can only perform the two-dimensional measurement, which contributes to the error during the measurement process. Results show a promising performance on the three-dimensional reconstruction of bubble flow, validating the feasibility of the three-dimensional measurement method for bubbles in gas-liquid two-phase flow based on light field imaging diagnosis and deep learning algorithm.

As the final heat sink of the nuclear power plant, the cool source is responsible for the safety function of the waste heat export of the reactor. The explosive invasion of marine organisms and other wastes have a great impact on the cold source system of nuclear power plants, which will lead to transient events, load reduction and shutdown of nuclear power unit, and even affect the availability of the cold source system in severe cases. which are huge threats and challenges for the safe and stable operation of unit. thereby reducing the power generation efficiency, safety, economy, and sustainable development of nuclear power plants. Clogging of the CFI drum net is one of the important factors causing cold source system accidents. this paper puts forward the solution idea of maintaining the water level of the forebay through the variable frequency pump, so as to ensure that the CRF pump keeps running state under the condition of cold source blockage, so as to maintain the function of the cold source system. and based on the full range simulator of nuclear power units, consider CFI drum network differential pressure high alarm failure combined with a monitoring device for the blockage degree of the drum net, the scheme is simulated and verified, and the load that the nuclear power unit can operate safely under different blocking degrees of drum network is given. the research results of this paper provide a solution for alleviating the cold source problem, and the solution can also provide a reference for the safety improvement of the cold source of actual unit and the design of new reactor.

The detection effect of the transient electromagnetic method is ambiguous in engineering applications due to the existence of interference sources, so explaining the influence of these fixed interference sources on is crucial. In this paper, the response characterisation of transient electromagnetic signals of fixed interference sources are thoroughly investigated. First, the secondary field generated by these interference sources is analyzed, and a typical fixed interference source is calculated. Then, a sensitivity analysis of the transient electromagnetic response curve is carried out. Finally, the mathematical superposition method for multiple field sources is proposed and verified. The results illustrate that the transient electromagnetic response curve of uniform full-space surrounding rock with a single fixed interference source has an apparent lifting phenomenon in the middle stage and presents an approximate horizontal change rule at the late stage. The transient electromagnetic response curves of multiple field sources separately illustrate the response characterisation of different field sources at different time stages. These research results can provide a valuable reference for the on-site interpretation of detection signals.

Recent work showed neural-network based approaches to reconstructing images from compressively sensed measurements offer significant improvements in accuracy and signal compression. Such methods can dramatically boost the capability of computational imaging hardware. However, to date, there have been two major drawbacks: (1) the high-precision real-valued sensing patterns proposed in the majority of existing works can prove problematic when used with computational imaging hardware such as a digital micromirror sampling device and (2) the network structures for image reconstruction involve intensive computation, which is also not suitable for hardware deployment. To address these problems, we propose a novel hardware-friendly solution based on mixed-weights neural networks for computational imaging. In particular, learned binary-weight sensing patterns are tailored to the sampling device. Moreover, we proposed a recursive network structure for low-resolution image sampling and high-resolution reconstruction scheme. It reduces both the required number of measurements and reconstruction computation by operating convolution on small intermediate feature maps. The recursive structure further reduced the model size, making the network more computationally efficient when deployed with the hardware. Our method has been validated on benchmark datasets and achieved state of the art reconstruction accuracy. We tested our proposed network in conjunction with a proof-of-concept hardware setup.

Multiple-ring naphthalenediammonium is employed for the first time to overcome the intrinsic instability of β-CsPbI3 perovskite via anchoring the ammonium groups occupying A-site vacancies. It improves charge transport and moisture stability giving out a champion power conversion efficiency of 16.69% for an excellent inorganic perovskite solar cell.

Poly(lactic acid) (PLA) has attracted much attention as a substitute for petroleum-based plastics, but its low heat resistance limits its application range in packaging fields and disposable products. This paper summarizes the structural factors affecting the heat resistance of PLA and systematically summarizes methods to improve its heat resistance. PLA is a semi-crystalline polymer, and crystallinity, crystal size, and other factors are important factors affecting heat resistance. This paper systematically analyzes the means to control the crystallization behavior of PLA, and summarizes the effects of nucleating agents, cross-linking, grafting, and annealing processes on the crystallization behavior and heat resistance of PLA. The effects of PLA molecular chain cross-linking and grafting on the motility of PLA molecular chains and the heat resistance of PLA materials are further discussed from the perspective of PLA molecular chain segment movement. The research work on combining PLA with reinforcements such as high heat-resistant polymer materials, fiber, and nanoparticles to improve the mechanical properties and heat resistance of PLA by introducing rigid groups or structures is described in detail. Improving the heat resistance of PLA material is an important strategy to promote the application of biodegradable materials, and has broad research value and application prospects.

BackgroundMechanical thrombectomy is the standard treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO) in the anterior circulation. This trial aimed to indicate whether Skyflow, a new thrombectomy device, could achieve the same safety and efficacy as Solitaire FR in the treatment of AIS.MethodsThis study was a prospective, multicenter, randomized, single blind, parallel, positive controlled, non-inferiority clinical trial. Patients with intracranial anterior circulation LVO within 8 hours from onset were included to receive thrombectomy treatment with either the Skyflow or Solitaire FR stent retriever. The primary endpoint was the rate of successful reperfusion (modified Treatment In Cerebral Infarction (mTICI) ≥2b) after the operation. The safety endpoints were the rate of symptomatic intracranial hemorrhage (sICH) and subarachnoid hemorrhage (SAH) at 24 hours after operation.ResultsA total of 95 and 97 patients were involved in the Skyflow group and Solitaire FR group, respectively. A successful reperfusion (mTICI ≥2b) was finally achieved in 84 (88.4%) patients in the Skyflow group and 80 (82.5%) patients in the Solitaire FR group. Skyflow was non-inferior to Solitaire FR in regard to the primary outcome, with the criterion of a non-inferiority margin of 12.5% (p=0.0002) after being adjusted for the combined center effect and the National Institutes of Health Stroke Scale (NIHSS) score. The rate of periprocedural sICH and SAH did not differ significantly between the two groups.ConclusionEndovascular thrombectomy with the Skyflow stent retriever was non-inferior to Solitaire FR with regard to successful reperfusion in AIS due to LVO (with a pre-specified non-inferiority margin of 12.5%).

Poly (lactic acid) (PLA) with branched structure has abundant terminal groups, high melt strength, good rheological properties, and excellent processability; it is a new research and application direction of PLA materials. This study mainly summarizes the molecular structure design, preparation methods, basic properties of branched PLA, and its application in modified PLA materials. The structure and properties of branched PLA prepared by ring-opening polymerization of monomer, functional group polycondensation, and chain extender in the processing process were introduced. The research progress of in situ formation of branched PLA by initiators, multifunctional monomers/additives through dynamic vulcanization, and irradiation induction was described. The effect of branched PLA on the structure and properties of linear PLA materials was analyzed. The role of branched PLA in improving the crystallization behavior, phase morphology, foaming properties, and mechanical properties of linear PLA materials was discussed. At the same time, its research progress in biomedicine and tissue engineering was analyzed. Branched PLA has excellent compatibility with PLA, which has important research value in regulating the structure and properties of PLA materials.

Urea oxidation reaction (UOR) has been proposed to replace the formidable oxygen evolution reaction (OER) to reduce the energy consumption for producing hydrogen from electrolysis of water owing to its much lower thermodynamic oxidation potential compared to that of the OER. Therefore, exploring a highly efficient and stable hydrogen evolution and urea electrooxidation bifunctional catalyst is the key to achieve economical and efficient hydrogen production. In this paper, we report a heterostructured sulfide/phosphide catalyst (Ni

Methane (CH4) is a major greenhouse gas emitted by the industry, agriculture and natural processes such as degradation of organic matter in anaerobic waters and soils. Addition of biochars to soils has been investigated to control greenhouse gas emission, but actually there are still current conflicting views: do biochars promote or suppress greenhouse gas emissions? In particular, the role of acetate, a product of organic matter degradation and substrate of methanogenesis, is poorly known. Here, we studied the effect of acetate concentrations on CH4 production by soils amended with biochar. Results show that biochar decreased CH4 release at low acetate concentration, below 0.2 mM. Gompertz modeling reveals that CH4 production rate can be reduced by up to 26.2% by biochar application. In apparent conflict, results show also that biochar stimulated methanogenesis at higher acetate concentrations, above 2 mM. Moreover, the application of CH3F, an inhibitor of acetoclastic methanogenesis, demonstrated that biochar mildly strengthened acetoclastic methanogenesis, thus confirming that biochar favors methane production. 13C isotope analysis demonstrated that CH4 is derived from direct acetate cleavage when the methanogenic substrate, e.g., acetate, was relatively abundant. Data from 16S rRNA sequencing suggest that CH4 is produced by the metabolism of Methanosarcinaceae. This work provides extra perspective that promotion or suppression of CH4 release by biochar may depend on acetate concentration in terrestrial methanogenic environments.

The precise control and in-depth understanding of the anisotropic crystal screw dislocation growth could yield further optimization of nanomaterial design and broader applications, yet the studies of rational control and kinetics for more complex nanostructures are still insufficient. In this work, by programming synthesis conditions, we achieve a controllable three-dimensional (3D) screw dislocation growth of hierarchical nanostructures, including nanowires, nanoplates, and previously unreported hierarchical hollow nanobelts, via a facile chemical vapor deposition approach. Notably, the screw dislocation growth in nanobelts is confirmed by the clear observations of the stepwise spiral terraces with initial hexagonal to octagonal shapes and the hollow cores in the growth spiral centers, as well as the fundamental Burton-Cabrera-Frank crystal growth theoretical calculations. The formation of the nanowires and nanoplates can be well interpreted by the previously reported screw dislocation growth model, while a new 3D screw dislocation growth model with considering of transition in growth velocities and directions is proposed to interpret the formation of the nanobelts and other potential complex nanostructures. This study not only enriches our understanding of the screw dislocation growth kinetics but also guides us to achieve the precise morphological design and control in nanosynthesis.

Convolutional neural networks (CNN) have been shown to provide a good solution for classification problems that utilize data obtained from vibrational spectroscopy. Moreover, CNNs are capable of identifying substances from noisy spectra without the need for additional preprocessing. However, their application in practical spectroscopy is restricted due to two reasons. First the effectiveness of classification using CNNs diminishes rapidly when only a small number of spectra per substance are available for training (which is a typical situation in real applications). Secondly, to accommodate new, previously unseen, substance classes the network must be retrained which is computationally intensive. Here we address these issues by reformulating a multi-class classification problem with a large number of classes to a binary classification problem for which the available data is sufficient for representation learning. Hence, we define the learning task as identifying pairs of inputs as belonging to the same class or different classes. We achieve this using a Siamese convolutional neural network. A novel sampling strategy is proposed to address the imbalance problem in training the Siamese network. The trained network can classify samples of previously unseen substance classes using just a single reference sample (termed as one-shot learning in the machine learning community). Our results on three independent Raman datasets demonstrate much better accuracy than other practical systems to date, while allowing effortless updates of the system's database with new substance classes.

Efficient valorization of cellulose is a sustainable route yet a challenging topic to solve the crisis of fossil resources. Although heterogeneous catalysts such as metal oxides have various advantages, the low surface contact area between metal oxides and cellulose is unfavourable for the hydrolysis of cellulose and thus restricts the application of metal oxides in direct conversion of cellulose to 5-hydroxymethylfurfural (HMF). This work presented the utilization of in-situ carbonic acid from CO2 as a green acid to enhance the conversion of cellulose to HMF in the presence of ZrO2 and TiO2. Combination of in-situ carbonic acid, ZrO2 and TiO2 exhibited a distinctive catalysis on the hydrolysis of cellulose and monosaccharide, isomerization of glucose and monosaccharide conversion in tetrahydrofuran (THF)/H2O/NaCl system. Especially, in-situ carbonic acid played a significant role in cellulose degradation and accelerated transforming insoluble polysaccharide into soluble oligosaccharide or monosaccharide, and thus promoted the cellulose conversion catalyzed by metal oxides. A high yield of HMF from cellulose (48.4%) was achieved by physically mixing commercial TiO2, ZrO2, and CO2. Due to the significant effects on cellulose degradation and HMF selectivity improvement, in-situ carbonic acid offers a green, low-cost and environmentally friendly co-catalyst for highly effective converting cellulose into HMF.

Grouted connections are critical parts of the integrity of offshore wind turbine structures since they transfer the upper loads to the lower foundations. In this paper, grouted connection specimens were experimentally studied to investigate the interaction between bending moment and axial load. They were subjected to a horizontal loading with various axial load ratios. The mechanical behavior of these specimens such as bearing capacity, ductility and failure mode was investigated. Furthermore, strain distributions on steel tubes of grouted connection were evaluated to learn the load transferring mechanism. Experimental results showed that grouted connection specimens had good ductility and sufficient bearing capacity. With the increasing of the axial compression level, the lateral bearing capacity and ductility of grouted connection decreased.

Objective To explore the possibility of laparoscopic pancreaticoduodenectomy (LPD) with transanal specimen extraction for periampullary tumors. Background Natural orifice specimen extraction (NOSE) has been widely performed in colorectal surgery. But so far there is no report regarding NOSE in LPD. Methods Data of 3 patients who underwent LPD with transanal specimen extraction by the same surgeon between July 2018 to March 2019 due to periampullary tumors were evaluated retrospectively. Results All patients underwent LPD with no conversion to open surgery. Specimens were all extracted transanally. No complications occurred except for delayed gastric emptying in one patient. The patients' anorectal function was intact and no opioids were required postoperatively. After a follow-up of 17-25 months, all patients were alive with no tumor recurrence. Conclusion Treatment of periampullary tumors by LPD with transanal specimen extraction is feasible and safe.

A novel design for dielectric elastomer pressure sensors based on a capacitive measurement principle is introduced. Compared with easily compressible and highly sensitive dielectric elastomer sensors containing internal voids, the new sensors are compact and suitable for an elevated pressure range up to about 2 MPa. In these sensors, a dielectric elastomer film with several dielectric and electrode layers is covered on both surfaces by plates, which exhibit a pattern of openings. When the sensor film is compressed, the elastomer material can expand into these openings, which reduces the film thickness and increases the capacitance. The dielectric elastomer film consists of a soft silicone with carbon black particles in the electrode layers. With this design, the sensitivity of the pressure sensors in terms of the capacitance increase is enhanced in comparison with reference sensors without openings in the plates and the disturbing hysteresis of the capacitance vs. pressure curves is reduced. With FEM Multiphysics simulations, the capacitance enhancement upon pressure increase and the sensor deformation were calculated and compared with experimental data. In a systematic study, different parameters of the sensor design were varied, in order to evaluate their influence on the sensor performance. The results of this study are presented in the paper.

Background Despite increasing acceptance in colorectal surgery, natural orifice specimen extraction (NOSE) surgery for the treatment of gastric cancer is still in its infancy, especially via the transrectal approach, which was barely reported. So little is known about its complications. Here we report the first case of proctotomy leak after transrectal NOSE gastrectomy, and our experience in preventive interventions. Case presentation A 62-year-old male patient complaining of upper abdominal pain who underwent open distal gastrectomy for gastric cancer one year ago was diagnosed with recurrent gastric cancer by gastroscopic biopsy. We performed laparoscopic total gastrectomy with transrectal specimen extraction on the patient. The operation was completed in a total laparoscopic approach and the specimen was extracted through a 3 cm longitudinal incision in the anterior wall of the upper rectum, then interrupted sutures were used for full-thickness closure of the rectal incision. The operative time was 470 min and intra-operative blood loss was 100 mL. The postoperative pathological examination showed pT1bN0M0 gastric adenocarcinoma. The patient developed proctotomy leak on the 10th postoperative day. We analyzed the causes of this rare complication and put forward a series of technical improvements. After failure of conservative treatment, a diverting ileostomy was created and the patient eventually recovered. We successfully prevented proctotomy leak in the subsequent 20 transrectal NOSE gastrectomies using improved techniques. Conclusions Proctotomy leak after transrectal specimen extraction should be considered among the complications of NOSE surgery and can be prevented by technical precautions.

Hyphenated techniques, providing comprehensive information in various aspects such as constituent, structure, functional group, and morphology, play an important role in scientific research. Nowadays, coupling characterization of the same position in microscale is in great need in the field of nanomaterial research and exploration. In this article, a new hyphenated technique was developed to facilitate the coupling characterization of atomic force microscope (AFM) and scanning electron microscope (SEM) by designing a universal positioning system. The system consisted of a specimen holder with coordinate grids and a software for converting the coordinate values of the same point to fit SEM, specimen holder, and AFM system. In working condition, the coordinates of the labeled points and target position were firstly extracted from the SEM operation software, then converted into the numerical values adapted to the specimen holder itself, and finally transformed into the coordinates matching the AFM system. The experimental result showed that a retrieving rate of 96% was achieved for a spherical target with a diameter of 1 μm in a 30 μ m × 30 μ m square. The hyphenated technique is a universal, accurate, efficient, and financially feasible method in microanalysis field and has great application potential.

Multiple-ring naphthalenediammonium is employed for the first time to overcome the intrinsic instability of β-CsPbI

Different capacitive and resistive elastomer sensors for the measurement of the filling level of water in a vertical plastic tube are introduced in the paper. The filling level sensors consist of elastomer membranes carrying electrically conductive layers with special geometrical designs. Three different basic sensor principles in various versions were investigated. First, capacitive strain sensors with different electrode designs detect the pressure of the water column above the elastomer membrane by measuring the change of electrical capacitance due to the stretch deformation. The shape of the electrode layers on these sensors affects their measuring sensitivity. Second, resistive strain sensors are also stretched by the water pressure acting on the membrane, but here the stretch changes the electrical resistance of the sensor. The resistor on the membrane is a silicone layer with conductive particles, which consist of carbon black or alternatively of silver-coated copper flakes. Depending on the kind and the concentration of the particles, the resistance of the sensor and its variation upon stretch can be tuned. Third, capacitive proximity sensors detect the height of the water level by measuring the capacitance between two neighbored electrode layers on the membrane. In this configuration, the sensor is a long elastomer film along the length of the plastic tube. The advantages and disadvantages of the different sensor principles are discussed. This discussion includes the sensor characteristics in terms of the change of capacitance or resistance vs. water level in the tube and also the creep behavior of the different filling level sensor types at constant water filling level.