István Bíró

57197441259

Publications - 5

Research progress in small-molecule donor-polymer acceptor organic photovoltaic cells

Publication Name: Organic Electronics

Publication Date: 2025-11-01

Volume: 146

Issue: Unknown

Page Range: Unknown

Description:

Organic solar cells (OSCs), characterized by their lightweight, flexibility, solution-processability for large-area fabrication, and low cost, exhibit significant complementary advantages to silicon-based photovoltaics, positioning them as a cutting-edge research frontier in clean energy. Among emerging architectures, small-molecule donor/polymer acceptor (SDPA)-based OSCs have attracted considerable attention due to their unique active layer stability, particularly their ability to maintain optimized phase-separated morphology under high-temperature conditions (>85 °C), offering potential to overcome the stability bottleneck in organic photovoltaic industrialization. However, the current record power conversion efficiency (PCE) of SDPA-OSCs remains at 12.1 %, significantly lagging behind mainstream bulk heterojunction systems (PCE >20 %). To advance the efficiency of SDPA-OSCs, extensive efforts have been devoted to optimizing materials, device engineering, and processing techniques. This review systematically summarizes recent progress in SDPA-OSCs from the perspectives of device architecture and active layer processing. Key focus areas include the impact of device structure engineering (conventional vs. inverted configurations) and active layer fabrication strategies (bulk heterojunction solution-coating and layer-by-layer deposition techniques) on charge carrier transport and device performance. By establishing robust “material structure–morphology–device performance” correlations, this work provides critical insights and technical references for developing high-efficiency SDPA-OSCs. Furthermore, future research directions and challenges in material innovation, morphology control, and scalable manufacturing are discussed to guide the advancement of SDPA-based organic photovoltaics.

Open Access: Yes

DOI: 10.1016/j.orgel.2025.107325

Biomechanical Characteristics of adolescent Cervical Forward Flexion analyses Based on the Finite Element Method

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 479-485

Description:

Adolescents' poor sitting posture is hazardous, and long-term poor sitting posture can lead to elevated incidence of neck pain. This study investigated the biomechanical attributes of the adolescent neck to mitigate the hazards of poor sitting posture and to provide recommendations for adolescent neck health; The C1-T3 images of the cervical region were acquired from the same subject in normal posture as well as in cervical forward flexion posture with a gap between scans of 0.50mm, and the CT images were transformed into DOCM format in Mimics for subsequent 3D modelling. A finite element (FE) model of the C1-T3 normal posture as well as the cervical forward flexion posture was established. In order to investigate the differences between the two models' cervical vertebrae and intervertebral disc stress, the stress and intervertebral disc strain of the two models were compared. A standard cervical spine model and a FE model for cervical forward flexion were created and validated. The range of motion, vertebral body, and intervertebral disc stresses were examined for both models. Comparison with previous literature confirmed the accuracy of the forward flexion model, showing consistent results with the normal cervical spine model. In the forward flexion direction, the model demonstrated increased stresses in the vertebral body, particularly in the anterior side, surpassing those in the normal model. The maximum stress in the vertebral body reached 5.99 MPa, and in the intervertebral disc, it was 1.02 MPa. Overall, stresses in the anterior cervical flexion model exceeded those in the normal model. Poor neck posture leads to more pronounced stress concentration phenomena in the vertebral body, increasing peak pressure in the vertebral body, in addition increasing com-pression on the intervertebral discs, leading to an increased risk of neck pain risk as well as cervical dysplasia, and therefore excessive forward flexion of the cervical spine in adolescents should be avoided.

Open Access: Yes

DOI: 10.3233/ATDE240583

Real-Time IoT Solution to Monitor and Control dMVHR Units in Real-Life Environment

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2024-01-01

Volume: 21

Issue: 6

Page Range: 303-322

Description:

This paper presents an up-and-running control system, using IoT hardware, for multiple decentralized mechanical ventilation with heat recovery (dMVHR) units to enhance the overall performance of heat exchangers and the air quality of a real-life environment. The implemented control and monitoring system is able to measure the thermal efficiency of the complete ventilation system under real working conditions. Fan speed is automated based on the measured CO2eq levels in the bedrooms of the building, however, manual control is also possible. Temperature, relative humidity and CO2eq levels can be monitored live on the user’s smart device, while data can be exported through Google cloud system. Data values can be stored and accessed any time by legit users. The thermal efficiency of the individual units and the whole ventilation system was investigated and experimentally verified under real-life conditions, using the implemented centralized control and monitoring system.

Open Access: Yes

DOI: 10.12700/APH.21.6.2024.6.16

Effects of Different Longitudinal Bending Stiffness Shoes on Distal Joint Kinematics and Muscular Mechanics in Adolescent amateur Runners

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 472-478

Description:

Research has indicated that modifying shoes' longitudinal bending stiffness (LBS) could potentially influence running biomechanics and performance among amateur runners. Nevertheless, scant attention has been given to adolescent runners in previous studies, leaving the impact of various LBS shoes on distal joint kinematics and muscular mechanics unclear. Given the distinctive musculoskeletal attributes of adolescents, delving into this matter holds significant importance. Thirteen adolescent amateur runners with rear foot strikes were recruited for the study. Each participant performed running tasks along a 10-meter runway at a speed of 3.3±5% m/s while wearing two types of LBS shoes, randomized for each trial. The specific LBS values of the shoes were 2.7 Nm/rad (low) and 8.6 Nm/rad (high). Lower limb joint biomechanical data were collected using a Vicon motion analysis system and AMTI force platform. Lower limb joint kinematics and muscular mechanics were analyzed using Opensim software. Paired t-tests were employed to identify differences in distal joint kinematics and muscular mechanics during stance phases. We found that there was a significant increase in contact time, while the range of motion (ROM) of the metatarsophalangeal (MTP) joint in the sagittal plane significantly decreased in the high LBS shoe condition. Additionally, the impulse of flexor digitorum brevis and flexor hallucis longus significantly increased under the high LBS shoe condition. The results show that high LBS shoes impose a greater load on the distal muscles, potentially elevating the risk of running-related injuries. The low LBS shoes are more suitable for adolescent runners.

Open Access: Yes

DOI: 10.3233/ATDE240582

Experimental Study on Ground Reaction Force Parameters with Regard to Novice and Recreational Runners

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 530-537

Description:

The connection between running experience and running-related injuries is still unclear, and the underlying mechanisms are yet to be fully investigated. Therefore, this study aimed to investigate differences in ground reaction forces (GRFs) between novice runners and recreational runners. 15 novice and 15 recreational runners participated in this study. An independent samples T-test was applied using SPSS 25.0 and SPM1D via Matlab. The results showed that recreational runners exhibited a significantly larger peak vertical impact force and peak medial force than the novice group, while the peak propulsive force was smaller than the novice group. The SPM1D results also showed that recreational runners and novice runners exhibited significant differences in medial-lateral force, anterior-posterior force and vertical force. The differences between the groups may reveal differences in running kinetics, which could be related to superior running performance or ability. Valuable insights may be gained from this study to guide future research on injury risks and performance benefits from running.

Open Access: Yes

DOI: 10.3233/ATDE240590