Evaluation of Shear Horizontal Surface Acoustic Wave Biosensors Using “Layer Parameter” Obtained from Sensor Responses during Immunoreaction

Shear horizontal surface acoustic wave (SH-SAW) biosensors measure the reaction of capture antibodies immobilized on the sensing surface to capture test molecules (antigens) by using the change in SH-SAW propagation characteristics. SH-SAW displacement exists not only on the SH-SAW propagating surface, but also partially penetrates the specimen liquid to a certain depth, which is determined by the liquid properties of the specimen and the operating frequency of the SH-SAW. This phenomenon is called viscosity penetration. In previous studies, the effect of viscosity penetration was not considered in the measurement of SH-SAW biosensors, and the mass or viscosity change caused by the specific binding of capture antibodies to the target antigen was mainly used for the measurement. However, by considering the effect of viscosity penetration, it was found that the antigen–antibody reaction could be measured and the detection characteristics of the biosensor could be improved. Therefore, this study aims to evaluate the detection properties of SH-SAW biosensors in the surface height direction by investigating the relationship between molecular dimensions and SH-SAW propagation characteristics, which are pseudo-changed by varying the diameter of gold nanoparticles. For the evaluation, we introduced a layer parameter defined by the ratio of the SH-SAW amplitude change to the SH-SAW velocity change caused by the antigen–antibody reaction. We found a correlation between the layer parameter and pseudo-varied molecular dimensions. The results suggest that SH-SAW does not only measure the mass and viscosity but can also measure the size of the molecule to be detected. This shows that SH-SAW biosensors can be used for advanced functionality.

Tingkat Bahaya Longsorlahan di Sub DAS Ngrancah Kabupaten Kulonprogo

Indonesia merupakan negara yang memiliki intensitas kebencanaan yang tergolong tinggi, termasuk bencana alam seperti longsorlahan. Dalam catatan BNPB diketahui bahwa selama tahun 2020 tercatat 573 kejadian longsorlahan. Pada wilayah Provinsi Daerah Istimewa Yogyakarta khususnya wilayah Sub DAS Ngrancah yang terletak di Kabupaten Kulon Progo juga terjadi beberapa kejadian longsorlahan. Oleh karena itu untuk meminimalisir kejadian maupun kerugian akibat longsorlahan perlu dilakukan penelitian yang membahas tentang tingkat bahaya longsorlahan. Penelitian ini memiliki tujuan yaitu menganalisis tingkat bahaya longsorlahan dan persebaran tingkat bahaya longsorlahan berdasarkan zonasi Sub DAS Ngrancah. Data yang digunakan adalah data skunder yang diperoleh dari beberapa instansi pemerintahan sedangkan metode untuk analisis menggunakan tumpeng tindih antar layer parameter dan skoring pada setiap parameter yang digunakan. Hasil penelitian menunjukkan bahwa terdapat tiga tingkat bahaya yang tersebar di wilayah Sub DAS Ngrancah yaitu sedang (74 satuan lahan), cukup tinggi (380 satuan lahan) dan tinggi (155 satuan lahan). Sedangkan persebaran tingkat bahaya longsorlahan cukup tinggi dan tinggi sebagian besar tersebar di wilayah zona hulu (upper stream) dan zona tengah (middle stream). Diharapkan hasil penelitian ini dijadikan sebagai salah satu referensi semua stakeholders dalam pengelolaan wilayah Sub DAS Ngrancah sesuai dengan kemampuan lahan itu sendiri.

Methodology for developing a combined technological process based on modifying the properties and changing the surface layer parameter

The article reveals information links between acoustic properties and parameters of the metal microstructure. A large number of regulatory documents and a lack of scientific concept lead to the system errors when estimating condition of both longterm operating metal and the product in the whole. The article considers methodology for developing a combined technological process based on modification of properties and change of the coatings' surface layer parameters, with an estimation of their efficiency in terms of productivity based on the criterial use of productivity principles. The analysis of technological activities for the productivity coefficient and the criterial estimates confirmed their efficiency.

RESPIRE: A Spectral Kurtosis-based Method to Extract Respiration Rate from Wearable PPG Signals

In this paper, we present the design of a wearable photoplethysmography (PPG) system, R-band for acquiring the PPG signals. PPG signals are influenced by the respiration or breathing process and hence can be used for estimation of respiration rate. R-Band detects the PPG signal that is routed to a Bluetooth low energy device such as a nearbyplaced smartphone via microprocessor. Further, we developed an algorithm based on Extreme Learning Machine (ELM) regression for the estimation of respiration rate. We proposed spectral kurtosis features that are fused with the state-ofthe-art respiratory-induced amplitude, intensity and frequency variations-based features for the estimation of respiration rate (in units of breaths per minute). In contrast to the neural network (NN), ELM does not require tuning of hidden layer parameter and thus drastically reduces the computational cost as compared to NN trained by the standard backpropagation algorithm. We evaluated the proposed algorithm on Capnobase data available in the public domain.

X-ray investigation of strained epitaxial layer systems by reflections in skew geometry

Four different SiGe/Si layer structures, pseudomorphically grown and (partially) relaxed, are used as examples to demonstrate that reflections in symmetric skew geometry can successfully be used to realize a complex analysis of these systems. Taking the intensity exactly along the truncation rod of a reciprocal lattice point, it is possible to simulate this diffraction curve and determine the layer parameter in the projection according to the netplane tilt relative to the surface. The main precondition for this technique and for performing reciprocal space mapping with sufficiently high resolution is a low angular divergence of the incident and detected beams perpendicular to the diffraction plane, which can also be achieved by suitable optical elements on laboratory-based diffractometers.