Susilo Indrawati^*, Lila Yuwana, Suyatno, Mochamad Zainuri, Darminto^*

Journal of Renewable Materials, Vol.12, No.5, pp. 909-921, 2024, DOI:10.32604/jrm.2024.048452

Abstract Recently, abaca fibers have become the focus of specialized research due to their intriguing characteristics, with their outstanding mechanical properties being a particularly notable. In the conducted study, the abaca fibers underwent a preliminary treatment process involving an alkaline solution, which was composed of 0.5% sodium hydroxide (NaOH) and 50% acetic acid (CHCOOH). This process entailed immersing each fiber in the solution for a period of one hour. This treatment led to a 52.36% reduction in lignin content compared to the levels before treatment, resulting in a dramatic decrease in the full width at half… More > Graphic Abstract

Ivan Sboev^1,*, Tatyana Lyubimova^2,3, Konstantin Rybkin³, Michael Kuchinskiy^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1425-1439, 2024, DOI:10.32604/fdmp.2024.051341

Abstract The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis, extraction and separation. One of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the chamber. Cavitation has a strong impact on the surface degradation mechanisms. In this work, a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL Multiphysics. The numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions More > Graphic Abstract

Teng Teng^1,2, Yuhe Cai³, Linchao Wang^3,*, Yanzhao Zhu²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1181-1202, 2024, DOI:10.32604/fdmp.2023.044532

Abstract Liquid nitrogen has shown excellent performances as a good fracturing medium in the extraction of unconventional natural gas, and its application in coalbed methane extraction is currently a research hotspot. This study focuses on the acoustic emission properties of coal specimens treated utilizing liquid nitrogen with varying initial temperatures in a three-point bending environment. Through examination of the load-displacement curves of the considered coal samples, their mechanical properties are also revealed for different initial temperatures and cycling frequencies. The findings demonstrate a gradual decline in the maximum load capacity of coal rock as the temperature… More >

Ruijin Huo^1,2,3, Qingxiang Pei^1,2,3, Xiaohui Yuan^1,*, Yanming Xu³

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2053-2077, 2024, DOI:10.32604/cmes.2024.049185

Abstract In this paper, a generalized th-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems. The Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field, and the th-order discretization formulation of the boundary integral equation is derived. In addition, the computation of loop subdivision surfaces and the subdivision rules are introduced. In order to confirm the effectiveness of the algorithm, the computed results are contrasted and analyzed with the results under Monte More >

RAJEEV KUMAR

Journal of Polymer Materials, Vol.37, No.3-4, pp. 131-142, 2020, DOI:10.32381/JPM.2020.37.3-4.2

Abstract The optical, electrical and acoustical properties of a polymer solution based on polyvinyl pyrrolidone (PVP) doped with different concentration of cupric sulphate (CuSO₄ ) were studied.UVVIS spectroscopy results reflected that absorption increases in asymmetric manner and the absorption peak showed red shift with increasing Cu ions concentration. The optical band gap (direct and indirect) was found to decrease with increase in Cu ions concentration in the polymer due to increase in the density of localized states in the band-gap.The value of Urbach energy is also evaluated from the transmission spectra and the activation energies are also More >

K. KRISHNAMOORTHY^a,*, N. PRABHU^b

Journal of Polymer Materials, Vol.40, No.3-4, pp. 215-226, 2023, DOI:10.32381/JPM.2023.40.3-4.7

Abstract The acoustic emission monitoring with artificial neural networks predicts the ultimate strength of glass/epoxy composite laminates using Acoustic Emission Data. The ultimate loads of all the specimens were used to characterise the emission of hits during failure modes. The six layered glass fiber laminates were prepared (in woven mat form) with epoxy as the binding medium by hand lay-up technique. At room temperature, with a pressure of 30 kg/cm², the laminates were cured. The laminates of standard dimensions as per ASTM D3039 for the tensile test were cut from the lamina. The Acoustic Emission (AE) test More >

Channarong Wantha^a, Kriengkrai Assawamartbunlue^a,*

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-8, 2011, DOI:10.5098/hmt.v2.4.3006

Abstract This paper presents a study of the impact of the resonance tube on performance of a thermoacoustic stack. The resonance tube is a key component of a standing-wave thermoacoustic refrigerator. The appropriated resonance tube’s length leads to an increase of performance of the stack in terms of the temperature difference. The results also indicate that the optimal operating frequency differs from the design based on the equation of a half-wavelength. The resonance tube length is elongated to compensate for some effects that occur in the resonance tube, especially when the stack is placed in the More >

Syeda Humaira Tasnim^a,*, Shohel Mahmud^b, Roydon Andrew Fraser^a

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-10, 2011, DOI:10.5098/hmt.v2.1.3006

Abstract In this paper, we experimentally measure the temperature fields at different locations on the stack plate and in the surrounding working fluid in a standing wave thermoacoustic device. The temperature measurements at the stack extremities and at the neighboring gas show axial heat transfer at the stack extremities, as opposed to the hypothesis of a perfectly isolated stack used in the linear thermoacoustic theory. Four different mechanisms of heat transfer are identified at the stack extremities in the present study. This information is necessary for the optimization of the performances of practical thermoacoustic engines. For More >

Jizhao Liu^1,2, Jiang Hui^1,2,*, Zhaofa Wang^1,2

Sound & Vibration, Vol.58, pp. 151-169, 2024, DOI:10.32604/sv.2024.045193

Abstract User authentication on smart devices is crucial to protecting user privacy and device security. Due to the development of emerging attacks, existing physiological feature-based authentication methods, such as fingerprint, iris, and face recognition are vulnerable to forgery and attacks. In this paper, GestureID, a system that utilizes acoustic sensing technology to distinguish hand features among users, is proposed. It involves using a speaker to send acoustic signals and a microphone to receive the echoes affected by the reflection of the hand movements of the users. To ensure system accuracy and effectively distinguish users’ gestures, a… More >

Xiaodan Wang^1,*, Zheng Xie², Guiping Du³

International Journal of Mental Health Promotion, Vol.26, No.2, pp. 149-160, 2024, DOI:10.32604/ijmhp.2023.030755

Abstract Research purpose: This study implemented somatosensory music therapy on patients with depressive disorders, and explored the effects of somatosensory music therapy on the degree of depression, positive and negative emotions, intuitive stress and autonomic nervous function of patients. Research method: We collected 66 patients diagnosed with depression from the Department of Psychological Medicine of Henan Provincial People’s Hospital, and divided them into a control group and an intervention group according to the random number table, with 33 people in each group. The control group received routine psychiatric treatment and nursing. On the basis of the control… More >