bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Crystal Structure, Density Functional Theory (DFT) Calculations and Molecular Orbital Calculations of 4-Bromoanilinium Perchlorate Single Crystal
Authors: Waqas Alam Mir , Farhan Mohd , Souayeh Basma , Aamir Muhammad , Khan Muhammad Shuaib
Published: September 2021

The non-covalent interactions have an extensive impact on the physical, chemical and biological activity of materials. A new anilinium derivative, 4-bromoanilinium perchlorate (4BAP), has been synthesized, and its structure was determined by single-crystal X-ray diffraction analysis. The quantum chemical calculation tools are implemented to explore the electronic and structural properties of 4BAP. The lattice parameters of the crystal structure are a = 5.0752 (8), b = 7.0540 (11), c = 13.5360 (2) Å, α = 91.073 (5)°, β = 90.991 (5)° and γ = 105.052 (5)°, with 2 molecules per unit cell (Z = 2). In the crystal structure of 4BAP, N-H⋯O hydrogen bond interactions dominate. Along the b-axis, the molecules strongly interact through N1-H3⋯O4 hydrogen bonds, and the hydrogen bonding links the molecules into extended chains running along the b-axis. The more delocalized electrons around the aromatic ring may influence the nonlinear activity of the materials. NBO results suggested more electron delocalization around the aromatic ring, which suggests that the title molecule could be used for nonlinear optical applications. The feasible reactivity tendency was determined from the frontier molecular orbital (FMO) analysis. The H...H interactions account for 9.8% of the surface area, and the crystal structure can accommodate a higher fraction of hydrogen atoms. The calculated values of dipole moment, polarizability and first-order hyperpolarizability are 13.5028 D, 20.504 × 10−24 esu and 2.1218 × 10−30 esu, respectively.
Performance of Carbide Alloy Compounds in Carbon Doped MoNbTaW
Authors: Zhang Congyan , Bhandari Uttam , Lei Jialin , Zeng Congyuan , Guo Shengmin , Choi Hyunjoo , Nam Seungjin , Yan Jinyuan , Yang Shizhong , Gao Feng
Published: September 2021

In this work, the performance of the carbon doped compositionally complex alloy (CCA) MoNbTaW was studied under ambient and high pressure and high temperature conditions. TaC and NbC carbides were formed when a large concentration of carbon was introduced while synthesizing the MoNbTaW alloy. Both FCC carbides and BCC CCA phases were detected in the sample compound at room temperature, in which the BCC phase was believed to have only refractory elements MoNbTaW while FCC carbide came from TaC and NbC. Carbides in the carbon doped MoNbTaW alloy were very stable since no phase transition was obtained even under 3.1 GPa and 870 °C by employing the resistor-heating diamond anvil cell (DAC) synchrotron X-ray diffraction technique. Via in situ examination, this study confirms the stability of carbides and MoNbTaW in the carbon doped CCA even under high pressure and high temperature.
Synthesis, Crystal Structure, Inhibitory Activity and Molecular Docking of Coumarins/Sulfonamides Containing Triazolyl Pyridine Moiety as Potent Selective Carbonic Anhydrase IX and XII Inhibitors
Authors: Aimene Yassine , Eychenne Romain , Rodriguez Frédéric , Mallet-Ladeira Sonia , Saffon-Merceron Nathalie , Winum Jean-Yves , Nocentini Alessio , Supuran Claudiu T. , Benoist Eric , Seridi Achour
Published: September 2021

In this work, two classes of Carbonic Anhydrase (CA) inhibitors, sulfonamide and coumarin derivatives linked to pyta moiety (2a-b) and their corresponding rhenium complexes (3a-b), were designed. These compounds were synthesized and fully characterized by classical analytical methods and X-ray diffraction. All the synthesized compounds were evaluated for their inhibitory activity against the hCA isoforms I, II, IX and XII. They exhibited high inhibitory activities in the range of nanomolar for both hCA IX and hCA XII isoforms. The sulfonamide compound 2a showed the strongest inhibition against the tumour-associated hCA IX isoform with a Ki of 11.7 nM. The tumour-associated isoforms hCA IX and hCA XII were selectively inhibited by all the coumarin derivatives, with inhibition constants ranging from 12.7 nM (2b) to 44.5 nM (3b), while the hCA I and II isoforms were slightly inhibited (in the micromolar range), as expected. In terms of selectivity, compared to previously published rhenium complex-based CA inhibitors, complex 3b showed one of the highest selectivities against hCA IX and hCA XII compared to the off-target isoforms hCA I and hCA II, making it a potential anti-cancer drug candidate. Molecular docking calculations were performed to investigate the inhibition profiles of the investigated compounds at the tumour-associated hCA IX active site and to rationalize our results.
Study of Microstructural and Mechanical Properties of Al/SiC/TiO2 Hybrid Nanocomposites Developed by Microwave Sintering
Authors: Mattli Manohar Reddy , Matli Penchal Reddy , Khan Adnan , Abdelatty Rokaya Hamdy , Yusuf Moinuddin , Ashraf Abdulla Al , Kotalo Rama Gopal , Shakoor Rana Abdul
Published: September 2021

Aluminum hybrid metal matrix nanocomposites (Al/SiC/TiO2) were synthesized through a microwave-assisted powder metallurgy process, and their evolved microstructure and mechanical properties were investigated. The Al/SiC/TiO2 hybrid nanocomposites were prepared by reinforcing aluminum (Al) matrix with a fixed amount of silicon carbide (SiC) nanoparticles (5 wt.%) and varying concentrations of titanium dioxide (TiO2) nanoparticles (3, 6, and 9 wt.%). The morphology results revealeda uniform distribution of SiC and TiO2 reinforcements in the aluminum matrix. An increase in the hardness and compressive strength of the Al/SiC/TiO2 hybrid nanocomposites was noticed with the increasein TiO2 nanoparticles. The Al/SiC/TiO2 hybrid nanocomposites that had an optimum amount of TiO2 nanoparticles (9 wt.%) showcased the best mechanical properties, with maximum increments of approximately 124%, 90%, and 23% of microhardness (83 ± 3 HV), respectively, yield strength (139 ± 8 MPa), and ultimate compression strength (375 ± 6 MPa) as compared to that of pure Al matrix. The Al/SiC/TiO2 hybrid nanocomposites exhibited the shear mode of fracture during their deformation process.
Analysis of Microstructure and Mechanical Properties of Bi-Modal Nanoparticle-Reinforced Cu-Matrix
Authors: Hamid Fadel S. , A. Elkady Omayma , Essa A. R. S. , El-Nikhaily A. , Elsayed Ayman , Eessaa Ashraf K.
Published: September 2021

Bi-modal particles are used as reinforcements for Cu-matrix. Nano TiC and/or Al2O3 were mechanically mixed with Cu particles for 24 h. The Cu-TiC/Al2O3 composites were successfully produced using spark plasma sintering (SPS). To investigate the effect of TiC and Al2O3 nanoparticles on the microstructure and mechanical properties of Cu-TiC/Al2O3 nanocomposites, they were added, whether individually or combined, to the copper (Cu) matrix at 3, 6, and 9 wt.%. The results showed that titanium carbide was homogeneously distributed in the copper matrix, whereas alumina nanoparticles showed some agglomeration at Cu grain boundaries. The crystallite size exhibited a clear reduction as a reaction to the increase of the reinforcement ratio. Furthermore, increasing the TiC and Al2O3 nanoparticle content in the Cu-TiC/Al2O3 composites reduced the relative density from 95% for Cu-1.5 wt.% TiC and 1.5 wt.% Al2O3 to 89% for Cu-4.5 wt.% TiC and 4.5 wt.% Al2O3. Cu-9 wt.% TiC achieved a maximum compressive strength of 851.99 N/mm2. Hardness values increased with increasing ceramic content.
Prognostic Role of Minimal Disseminated Disease and NOTCH1/FBXW7 Mutational Status in Children with Lymphoblastic Lymphoma: The AIEOP Experience
Authors: Lovisa Federica , Gallingani Ilaria , Varotto Elena , Pasin Cristiano , Carraro Elisa , Michielotto Barbara , Garbin Anna , Damanti Carlotta Caterina , Pizzi Marco , d’Amore Emanuele S. G. , Piglione Matilde , Muggeo Paola , Buffardi Salvatore , Vinti Luciana , Folsi Veronica Maria , Onofrillo Daniela , Biffi Alessandra , Buldini Barbara , Pillon Marta , Mussolin Lara
Published: September 2021

NOTCH1/FBXW7 (N/F) mutational status at diagnosis is employed for T-cell lymphoblastic lymphoma (T-LBL) patients’ stratification in the international protocol LBL 2018. Our aim was to validate the prognostic role of Minimal Disseminated Disease (MDD) alone and in combination with N/F mutational status in a large retrospective series of LBL pediatric patients. MDD was analyzed in 132 bone marrow and/or peripheral blood samples by flow cytometry. Mutations in N/F genes were analyzed on 58 T-LBL tumor biopsies. Using the previously established cut-off of 3%, the four-year progression-free survival (PFS) was 57% for stage I–III patients with MDD ≥ 3% versus 80% for patients with MDD inferior to cut-off (p = 0.068). We found a significant worsening in the four-year PFS for nonmutated (51 ± 12%) compared to mutated patients (100%, p = 0.0013). Combining MDD and N/F mutational status in a subgroup of available cases, we found a statistically significant difference in the four-year PFS for different risk groups (p = 0.0012). Overall, our results demonstrate that N/F mutational status has a more relevant prognostic value than MDD at diagnosis. However, the combination of N/F mutations with MDD analysis could identify patients with very aggressive disease, which might benefit from a more intensive treatment.
A Combined TLR7/TLR9/GATA3 Score Can Predict Prognosis in Biliary Tract Cancer
Authors: Branchi Vittorio , Esser Laura , Boden Corinna , Jafari Azin , Henn Jonas , Lingohr Philipp , Gonzalez-Carmona Maria A. , Schmitz Marc , Weismüller Tobias J. , Strassburg Christian P. , Manekeller Steffen , Kristiansen Glen , Kalff Jörg C. , Matthaei Hanno , Toma Marieta I.
Published: September 2021

Biliary tract cancer (BTC) refers to a heterogenous group of epithelial malignancies arising along the biliary tree. The highly aggressive nature combined with its silent presentation contribute to the dismal prognosis of this tumor. Tumor-infiltrating immune cells (TIICs) are frequently present in BTC and there is growing evidence regarding their role as therapeutic targets. In this study, we analyzed the immune cell infiltration in BTC and developed a promising immune signature score to predict prognosis in BTC. Immunohistochemistry (IHC) was carried out on tissue microarray sections from 45 patients with resectable cholangiocarcinoma for the detection of 6-sulfoLacNAc+ monocytes (slanMo), BDCA-2+ plasmacytoid dendritic cells (pDC), CD8+ or CD4+T-lymphocytes, CD103+ cells, GATA3+ cells, Toll-like receptor (TLR) 3, 7 and 9-expressing cells as well as programmed cell death protein 1 and programmed cell death ligand 1 positive cells. Data from the IHC staining were analyzed and correlated with clinicopathological and survival data. High expression of TLR7, TLR9, and GATA3 was associated with improved overall survival (OS, Log-rank p < 0.05). In addition, TLR9 was associated with better disease-free survival (Log-rank p < 0.05). In the multivariate Cox proportional-hazards model for OS, the TLR/TLR9/GATA3 score was found to be an independent prognostic factor for OS (“Score 2” vs. “Score 0”: HR 11.17 95% CI 2.27–54.95, p < 0.01).
Why Has Metabolomics So Far Not Managed to Efficiently Contribute to the Improvement of Assisted Reproduction Outcomes? The Answer through a Review of the Best Available Current Evidence
Authors: Siristatidis Charalampos , Dafopoulos Konstantinos , Papapanou Michail , Stavros Sofoklis , Pouliakis Abraham , Eleftheriades Anna , Sidiropoulou Tatiana , Vlahos Nikolaos
Published: September 2021

Metabolomics emerged to give clinicians the necessary information on the competence, in terms of physiology and function, of gametes, embryos, and the endometrium towards a targeted infertility treatment, namely, assisted reproduction techniques (ART). Our minireview aims to investigate the current status of the use of metabolomics in assisted reproduction, the potential flaws in its use, and to propose specific solutions towards the improvement of ART outcomes through the use of the intervention. We used published reports assessing the role of metabolomic investigation of the endometrium, oocytes, and embryos in improving clinical outcomes in women undergoing ART. We initially found that there is no evidence to support that fertility outcomes can be improved through metabolomics profiling. In contrast, it may be helpful for understanding and appraising the nutritional environment of oocytes and embryos. The causes include the different infertility populations, the difference between animals and humans, technical limitations, and the great heterogeneity in the variables employed. Suggested steps include the standardization of variables of the method itself, the universal creation of a panel where all biomarkers are stored concerning specific infertile populations with different phenotypes or etiologies, specific bioinformatics contribution, significant computing power for data processing, and importantly, properly conducted trials.
Validation and Optimization of Proximal Femurs Microstructure Analysis Using High Field and Ultra-High Field MRI
Authors: Soldati Enrico , Vicente Jerome , Guenoun Daphne , Bendahan David , Pithioux Martine
Published: September 2021

Trabecular bone could be assessed non-invasively using MRI. However, MRI does not yet provide resolutions lower than trabecular thickness and a comparative analysis between different MRI sequences at different field strengths and X-ray microtomography (μCT) is still missing. In this study, we compared bone microstructure parameters and bone mineral density (BMD) computed using various MRI approaches, i.e., turbo spin echo (TSE) and gradient recalled echo (GRE) images used at different magnetic fields, i.e., 7T and 3T. The corresponding parameters computed from μCT images and BMD derived from dual-energy X-ray absorptiometry (DXA) were used as the ground truth. The correlation between morphological parameters, BMD and fracture load assessed by mechanical compression tests was evaluated. Histomorphometric parameters showed a good agreement between 7T TSE and μCT, with 8% error for trabecular thickness with no significative statistical difference and a good intraclass correlation coefficient (ICC > 0.5) for all the extrapolated parameters. No correlation was found between DXA-BMD and all morphological parameters, except for trabecular interconnectivity (R2 > 0.69). Good correlation (p-value < 0.05) was found between failure load and trabecular interconnectivity (R2 > 0.79). These results suggest that MRI could be of interest for bone microstructure assessment. Moreover, the combination of morphological parameters and BMD could provide a more comprehensive view of bone quality.
Patients with Systemic Sclerosis with and without Overlap Syndrome Show Similar Microvascular Abnormalities
Authors: Nagy Gabriella , Czirják László , Kumánovics Gábor
Published: September 2021

Introduction: Nailfold video capillaroscopy (NVC) is a useful tool for measuring capillary density (CD) and capillary morphology parameters and is mainly used in systemic sclerosis (SSc). Objective: We aimed to assess the prevalence of an SSc pattern and CD in different connective tissue diseases (CTDs). Methods: NVC was performed on 268 patients with CTDs. Control groups consisted of 104 healthy volunteers (HVs) and 36 primary Raynaud’s patients (PRPs). Results: Decreased CD was more prevalent in SSc, systemic lupus erythematosus (SLE), inflammatory myopathies (IIM), and overlap CTD patients compared with both controls. Average CD, the prevalence of decreased CD, and the prevalence of an SSc pattern did not differ significantly between SSc patients with (n = 39) and without (n = 50) overlap syndrome. An SSc pattern was significantly more prevalent in SLE (23%), SSc (82%), IIM (35%), and rheumatoid arthritis (17%) compared with both control groups. The prevalence of an elevated microangiopathy evaluation score (MES) was significantly higher in SLE, SSc, and IIM than in the HVs. Conclusion: The presence of another CTD in SSc did not influence CD or morphology. An SSc pattern may also be present in CTDs other than SSc. The MES is a useful instrument to distinguish between patients with CTDs and controls.
Non-Lead Protective Aprons for the Protection of Interventional Radiology Physicians from Radiation Exposure in Clinical Settings: An Initial Study
Authors: Kato Mamoru , Chida Koichi , Munehisa Masato , Sato Tadaya , Inaba Yohei , Suzuki Masatoshi , Zuguchi Masayuki
Published: September 2021

Radiation protection/evaluation during interventional radiology (IVR) poses a very important problem. Although IVR physicians should wear protective aprons, the IVR physician may not tolerate wearing one for long procedures because protective aprons are generally heavy. In fact, orthopedic problems are increasingly reported in IVR physicians due to the strain of wearing heavy protective aprons during IVR. In recent years, non-Pb protective aprons (lighter weight, composite materials) have been developed. Although non-Pb protective aprons are more expensive than Pb protective aprons, the former aprons weigh less. However, whether the protective performance of non-Pb aprons is sufficient in the IVR clinical setting is unclear. This study compared the ability of non-Pb and Pb protective aprons (0.25- and 0.35-mm Pb-equivalents) to protect physicians from scatter radiation in a clinical setting (IVR, cardiac catheterizations, including percutaneous coronary intervention) using an electric personal dosimeter (EPD). For radiation measurements, physicians wore EPDs: One inside a personal protective apron at the chest, and one outside a personal protective apron at the chest. Physician comfort levels in each apron during procedures were also evaluated. As a result, performance (both the shielding effect (98.5%) and comfort (good)) of the non-Pb 0.35-mm-Pb-equivalent protective apron was good in the clinical setting. The radiation-shielding effects of the non-Pb 0.35-mm and Pb 0.35-mm-Pb-equivalent protective aprons were very similar. Therefore, non-Pb 0.35-mm Pb-equivalent protective aprons may be more suitable for providing radiation protection for IVR physicians because the shielding effect and comfort are both good in the clinical IVR setting. As non-Pb protective aprons are nontoxic and weigh less than Pb protective aprons, non-Pb protective aprons will be the preferred type for radiation protection of IVR staff, especially physicians.
A New Anatomical Classification for Tibialis Posterior Tendon Insertion and Its Clinical Implications: A Cadaveric Study
Authors: Park Jeong-Hyun , Kim Digud , Kwon Hyung-Wook , Lee Mijeong , Choi Yu-Jin , Park Kwang-Rak , Youn Kwan Hyun , Cho Jaeho
Published: September 2021

The variations in the tibialis posterior tendon (TPT) could not be defined by previous classification; thus, this study used a larger-scale cadaver with the aim to classify the types of TPT insertion based on the combination of the number and location of TPT insertions. A total of 118 feet from adult formalin-fixed cadavers were dissected (68 males, 50 females). The morphological characteristics and measurements of TPT insertion were evaluated. Four types of TPT insertions were classified, wherein the most common type was type 4 (quadruple insertions, 78 feet, 66.1%), which was divided into four new subtypes that were not defined in the previous classification. The second most common type was type 3 (triple insertions, 25 feet, 21.2%) with three subtypes, including the new subtype. Type 2 was found in 13 feet (11%), and the rarest type was type 1 (2 feet, 1.7%), wherein the main tendon was only attached to the navicular bone and the medial cuneiform bone. We suggest high morphological variability of the TPT in relation to the insertion location, along with the possibility of significant differences according to race and gender. Moreover, this classification will help clinicians understand adult flatfoot deformity-related posterior tibial tendon dysfunction (PTTD).
The Clinical Importance of IL-6, IL-8, and TNF-α in Patients with Ovarian Carcinoma and Benign Cystic Lesions
Authors: Pawlik Weronika , Pawlik Jakub , Kozłowski Mateusz , Łuczkowska Karolina , Kwiatkowski Sebastian , Kwiatkowska Ewa , Machaliński Bogusław , Cymbaluk-Płoska Aneta
Published: September 2021

The exact pathogenesis and influence of various cytokines in patients with ovarian lesions remains unclear. Hence, this study aimed to investigate whether IL-6, IL-8, and TNF-α could be considered as new useful markers for diagnosis of ovarian cancer. 63 women diagnosed with ovarian cancer (OC) and 53 patients with benign ovarian cystic (BOC) lesions were included in this study. Serum levels of IL-6, IL-8, and TNF-α were measured using ELISA. Statistical comparisons were made using the Mann–Whitney U test and all correlations were evaluated by Spearman’s ranks. The serum IL-8 and TNF-α concentration measured in the OC Group was significantly higher than in the BOC Group (p < 0.05). The cutoff level of IL-8 and TNF-α in the serum was set at 4.09 ng/mL and 2.63 ng/mL, respectively, with the sensitivity and specificity of 70% and 96% for IL-8 and 85.7% and 79.3% for TNF-α (p < 0.0001). These results suggest that IL-8 and TNF-α are useful biomarkers for predicting the malignant character of lesions of the ovary. The present study highlighted the importance of measuring the cytokines such as IL-8 and TNF-α in patients with ovarian lesions in predicting the clinical outcome.
Clinical Characteristics, Treatment Modalities, and Potential Contributing and Prognostic Factors in Patients with Bone Metastases from Gynecological Cancers: A Systematic Review
Authors: Salamanna Francesca , Perrone Anna Myriam , Contartese Deyanira , Borsari Veronica , Gasbarrini Alessandro , Terzi Silvia , De Iaco Pierandrea , Fini Milena
Published: September 2021

The purpose of this study is to review the clinical characteristics, treatment modalities, and potential contributing and prognostic factors of bone metastases from gynecological cancers (GCs). A systematic literature search on PubMed, Scopus, Web of Science Core Collection and Cochrane Central Register of Controlled Trials databases was conducted. Thirty-one studies, all retrospective, were included in this review, for a total of 2880 patients with GC bone metastases. Primary tumors leading to bone metastases included endometrial cancer (EC), cervical cancer (CC), ovarian cancer (OC), uterine sarcoma (US) and vulvar cancer (VuC), mainly with an International Federation of Gynecology and Obstetrics (FIGO) Stage of III and IV. The main bone metastatic lesion site was the vertebral column, followed by the pelvic bone and lower extremity bones. The median survival rate after bone metastases diagnosis ranged from 3.0 to 45 months. The most frequent treatments were palliative and included radiotherapy and chemotherapy, followed by surgery. The findings of this review give a first dataset for a greater understanding of GC bone metastases that could help clinicians move toward a more “personalized” and thus more effective patient management.
Slow-Time Code Design for Space-Time Adaptive Processing in Airborne Radar
Authors: Li Shiyi , Wang Na , Zhang Jindong , Xue Chenyan , Zhu Daiyin
Published: September 2021

Space-time adaptive processing (STAP) techniques have been motivated as a key enabling technology for advanced airborne radar applications. In this paper, a slow-time code design is considered for the STAP technique in airborne radar, and the principle for improving signal-to-clutter and noise ratio (SCNR) based on slow-time coding is given. We present two algorithms for the optimization of transmitted codes under the energy constraint on a predefined area of spatial-frequency and Doppler-frequency plane. The proposed algorithms are constructed based on convex optimization (CVX) and alternating direction (AD), respectively. Several criteria regarding parameter selection are also given for the optimization process. Numerical examples show the feasibility and effectiveness of the proposed methods.
Quantitative Comparison between the Smartphone Based Experiments for the Gravity Acceleration Measurement at Home
Authors: Anni Marco
Published: September 2021

Smartphones are currently proposed as potential portable laboratories to perform a wide variety of physical experiments for teaching purpose. However, the frequent lack of clarity about the ease of replication of the experiments and on their accuracy often limits their effective use. In this work we deeply compare several smartphone-based experiments to determine the gravity acceleration g by only using cheap materials easily available at home. The experiment and the data analysis complexity are progressively increased, starting from fast and easy to replicate methods. The advantages and possible limits of all the methods are deeply discussed in order to allow an evaluation of the most suitable method for any particular teaching scenario.
U.S. Parents’ Reports of Assisting Their Children with Distance Learning during COVID-19
Authors: Sonnenschein Susan , Grossman Elyse R , Grossman Julie A
Published: September 2021

COVID-19 has caused increased stress among U.S. adults, with many reporting concerns assisting their children with distance learning due to school closures. This study surveyed U.S. parents–most of whom were middle-aged, White, affluent, and female–to learn what types of distance learning activities parents engaged in with their children during COVID-19; whether these types of activities varied by the child’s age; and whether there was an association between engaging in these activities and stress. Most parents engaged in Monitoring, Teaching or Technology support activities with their children. Although these activities varied by child’s age, parents who reported engaging in any distance learning activity reported increased stress.
Adaptive Transfer Learning Based on a Two-Stream Densely Connected Residual Shrinkage Network for Transformer Fault Diagnosis over Vibration Signals
Authors: Liu Xiaoyan , He Yigang , Wang Lei
Published: September 2021

Vibration signal analysis is an efficient online transformer fault diagnosis method for improving the stability and safety of power systems. Operation in harsh interference environments and the lack of fault samples are the most challenging aspects of transformer fault diagnosis. High-precision performance is difficult to achieve when using conventional fault diagnosis methods. Thus, this study proposes a transformer fault diagnosis method based on the adaptive transfer learning of a two-stream densely connected residual shrinkage network over vibration signals. First, novel time-frequency analysis methods (i.e., Synchrosqueezed Wavelet Transform and Synchrosqueezed Generalized S-transform) are proposed to convert vibration signals into different images, effectively expanding the samples and extracting effective features of signals. Second, a Two-stream Densely Connected Residual Shrinkage (TSDen2NetRS) network is presented to achieve a high accuracy fault diagnosis under different working conditions. Furthermore, the Residual Shrinkage layer (RS layer) is applied as a nonlinear transformation layer to the deep learning framework to remove unimportant features and enhance anti-interference performance. Lastly, an adaptive transfer learning algorithm that can automatically select the source data set by using the domain measurement method is proposed. This algorithm accelerates the training of the deep learning network and improves accuracy when the number of samples is small. Vibration experiments of transformers are conducted under different operating conditions, and their results show the effectiveness and robustness of the proposed method.
Ultra-Compact mm-Wave Monolithic IC Doherty Power Amplifier for Mobile Handsets
Authors: Sajedin Maryam , Elfergani Issa , Rodriguez Jonathan , Abd-Alhameed Raed , Fernandez-Barciela Monica , Violas Manuel
Published: September 2021

This work develops a novel dynamic load modulation Power Amplifier (PA) circuity that can provide an optimum compromise between linearity and efficiency while covering multiple cellular frequency bands. Exploiting monolithic microwave integrated circuits (MMIC) technology, a fully integrated 1W Doherty PA architecture is proposed based on 0.1 μm AlGaAs/InGaAs Depletion-Mode (D-Mode) technology provided by the WIN Semiconductors foundry. The proposed wideband DPA incorporates the harmonic tuning Class-J mode of operation, which aims to engineer the voltage waveform via second harmonic capacitive load termination. Moreover, the applied post-matching technique not only reduces the impedance transformation ratio of the conventional DPA, but also restores its proper load modulation. The simulation results indicate that the monolithic drive load modulation PA at 4 V operation voltage delivers 44% PAE at the maximum output power of 30 dBm at the 1 dB compression point, and 34% power-added efficiency (PAE) at 6 dB power back-off (PBO). A power gain flatness of around 14 ± 0.5 dB was achieved over the frequency band of 23 GHz to 27 GHz. The compact MMIC load modulation technique developed for the 5G mobile handset occupies the die area of 3.2 mm2.
FPGA Implementation of the Range-Doppler Algorithm for Real-Time Synthetic Aperture Radar Imaging
Authors: Choi Yeongung , Jeong Dongmin , Lee Myeongjin , Lee Wookyung , Jung Yunho
Published: September 2021

In this paper, we propose a range-Doppler algorithm (RDA)-based synthetic aperture radar (SAR) processor for real-time SAR imaging and present FPGA-based implementation results. The processing steps for the RDA include range compression, range cell migration correction (RCMC), and azimuth compression. A matched filtering unit (MFU) and an RCMC processing unit (RPU) are required for real-time processing. Therefore, the proposed RDA-based SAR processor contains an MFU that uses the mixed-radix multi-path delay commutator (MRMDC) FFT and an RPU. The MFU reduces the memory requirements by applying a decimation-in-frequency (DIF) FFT and decimation-in-time (DIT) IFFT. The RPU provides a variable tap size and variable interpolation kernel. In addition, the MFU and RPU are designed to enable parallel processing of four 32-bit which are transferred via a 128-bit AXI bus. The proposed RDA-based SAR processor was designed using Verilog-HDL and implemented in a Xilinx UltraScale+ MPSoC FPGA device. After comparing the execution time taken by the proposed SAR processor with that taken by an ARM cortex-A53 microprocessor, we observed a 85-fold speedup for a 2048 × 2048 pixel image. A performance evaluation based on related studies indicated that the proposed processor achieved an execution time that was approximately 6.5 times less than those of previous FPGA implementations of RDA processors.
Agent in a Box: A Framework for Autonomous Mobile Robots with Beliefs, Desires, and Intentions
Authors: Gavigan Patrick , Esfandiari Babak
Published: September 2021

This paper provides the Agent in a Box for developing autonomous mobile robots using Belief-Desire-Intention (BDI) agents. This framework provides the means of connecting the agent reasoning system to the environment, using the Robot Operating System (ROS), in a way that is flexible to a variety of application domains which use different sensors and actuators. It also provides the needed customisation to the agent’s reasoner for ensuring that the agent’s behaviours are properly prioritised. Behaviours which are common to all mobile robots, such as for navigation and resource management, are provided. This allows developers for specific application domains to focus on domain-specific code. Agents implemented using this approach are rational, mission capable, safety conscious, fuel autonomous, and understandable. This method was used for demonstrating the capability of BDI agents to control robots for a variety of application domains. These included simple grid environments, a simulated autonomous car, and a prototype mail delivery robot. From these case studies, the approach was demonstrated as capable of controlling the robots in the application domains. It also reduced the development burden needed for applying the approach to a specific robot.
Realization of Low-Voltage and High-Current Rectifier Module Control System Based on Nonlinear Feed-Forward PID Control
Authors: Liu Jinfeng , He Jiawei , Iu Herbert Ho-Ching
Published: September 2021

The low-voltage and high-current permanent magnet synchronous generator (PMSG), which has characteristics of high power density, small size, and excellent energy saving, is representative of the generators. As a key module of the integrated DC output system of PMSG, the low-voltage and high-current rectifier module is also a nonlinear time-varying system that is readily influenced by parametric changes and external disturbances. Aiming at the shortcomings of traditional control strategies, this paper proposes a novel low-voltage and high-power rectifier module control strategy based on nonlinear feed-forward PID control. The controller has a wide range of environmental applications because of its greater robustness. At the same time, the introduction of feed-forward control shortens regulation time of the system. Therefore, the combination of the two control methods can improve the dynamic performance of the system without influencing the steady-state performance. The simulation model of an integrated rectifier system based on SVPWM control was constructed by Simulink, which can achieve a rated output of 5 V/300 A. At the same time, the simulation model of the controller is constructed and applied to the rectifier output system of a 5 V/300 A synchronous generator to complete the nonlinear feed-forward PID control. Through the comparison between simulation and experiment, it has been proven that the control method can effectively resist the load disturbances and improve the response speed of the system.
Development of a Real-Time Magnetic Field Measurement System for Synchrotron Control
Authors: Vella Wallbank Joseph , Amodeo Maria , Beaumont Anthony , Buzio Marco , Di Capua Vincenzo , Grech Christian , Sammut Nicholas , Giloteaux David
Published: September 2021

The precise knowledge of the magnetic field produced by dipole magnets is critical to the operation of a synchrotron. Real-time measurement systems may be required, especially in the case of iron-dominated electromagnets with strong non-linear effects, to acquire the magnetic field and feed it back to various users. This work concerns the design and implementation of a new measurement system of this kind currently being deployed throughout the European Organization for Nuclear Research (CERN) accelerator complex. We first discuss the measurement principle, the general system architecture and the technology employed, focusing in particular on the most critical and specialized components developed, that is, the field marker trigger generator and the magnetic flux integrator. We then present the results of a detailed metrological characterization of the integrator, including the aspects of drift estimation and correction, as well as the absolute gain calibration and frequency response. We finally discuss the latency of the whole acquisition chain and present an outline of future work to improve the capabilities of the system.
A Flexible Input Mapping System for Next-Generation Virtual Reality Controllers
Authors: Lee Eun-Seok , Shin Byeong-Seok
Published: September 2021

This paper proposes an input mapping system that can transform various input signals from next-generation virtual reality devices to suit existing virtual reality content. Existing interactions of virtual reality content are developed based on input values for standardized commercial haptic controllers. This prevents the challenge of new ideas in content. However, controllers that are not compatible with existing virtual reality content have to take significant risks until commercialization. The proposed system allows content developers to map streams of new input devices to standard input events for use in existing content. This allows the reuse of code from existing content, even with new devices, effectively reducing development tasks. Further, it is possible to define a new input method from the perspective of content instead of the sensing results of the input device, allowing for content-specific standardization in content-oriented industries such as games and virtual reality.
A Survey on QoE-Oriented VR Video Streaming: Some Research Issues and Challenges
Authors: Ruan Jinjia , Xie Dongliang
Published: September 2021

With the advent of the information age, VR video streaming services have emerged in large numbers in scenarios such as immersive entertainment, smart education, and the Internet of Vehicles. People are also demanding an increasing number of virtual-reality (VR) services, and service providers must ensure a good user experience. Therefore, the quality of the VR user’s experience is receiving increasing attention from academia and industry. The review in this paper focuses on a comprehensive summary of the current state of quality-of-experience (QoE) technologies applied to VR video streaming. First, we review the main influencing factors of QoE and VR video streaming. Second, the user QoE for VR evaluation is discussed. Third, the modeling of QoE for VR video streaming, the QoE-oriented VR optimization problem, and enabling techniques of machine learning for VR video streaming improvement are summarized. Lastly, we present current challenges and possible future research directions.
Exploiting the Outcome of Outlier Detection for Novel Attack Pattern Recognition on Streaming Data
Authors: Heigl Michael , Weigelt Enrico , Urmann Andreas , Fiala Dalibor , Schramm Martin
Published: September 2021

Future-oriented networking infrastructures are characterized by highly dynamic Streaming Data (SD) whose volume, speed and number of dimensions increased significantly over the past couple of years, energized by trends such as Software-Defined Networking or Artificial Intelligence. As an essential core component of network security, Intrusion Detection Systems (IDS) help to uncover malicious activity. In particular, consecutively applied alert correlation methods can aid in mining attack patterns based on the alerts generated by IDS. However, most of the existing methods lack the functionality to deal with SD data affected by the phenomenon called concept drift and are mainly designed to operate on the output from signature-based IDS. Although unsupervised Outlier Detection (OD) methods have the ability to detect yet unknown attacks, most of the alert correlation methods cannot handle the outcome of such anomaly-based IDS. In this paper, we introduce a novel framework called Streaming Outlier Analysis and Attack Pattern Recognition, denoted as SOAAPR, which is able to process the output of various online unsupervised OD methods in a streaming fashion to extract information about novel attack patterns. Three different privacy-preserving, fingerprint-like signatures are computed from the clustered set of correlated alerts by SOAAPR, which characterizes and represents the potential attack scenarios with respect to their communication relations, their manifestation in the data’s features and their temporal behavior. Beyond the recognition of known attacks, comparing derived signatures, they can be leveraged to find similarities between yet unknown and novel attack patterns. The evaluation, which is split into two parts, takes advantage of attack scenarios from the widely-used and popular CICIDS2017 and CSE-CIC-IDS2018 datasets. Firstly, the streaming alert correlation capability is evaluated on CICIDS2017 and compared to a state-of-the-art offline algorithm, called Graph-based Alert Correlation (GAC), which has the potential to deal with the outcome of anomaly-based IDS. Secondly, the three types of signatures are computed from attack scenarios in the datasets and compared to each other. The discussion of results, on the one hand, shows that SOAAPR can compete with GAC in terms of alert correlation capability leveraging four different metrics and outperforms it significantly in terms of processing time by an average factor of 70 in 11 attack scenarios. On the other hand, in most cases, all three types of signatures seem to reliably characterize attack scenarios such that similar ones are grouped together, with up to 99.05% similarity between the FTP and SSH Patator attack.
Calculation Methodologies of Complex Permeability for Various Magnetic Materials
Authors: Lee Eun S. , Choi Byeong Guk
Published: September 2021

In order to design power converters and wireless power systems using high-frequency magnetic materials, the magnetic characteristics for the inductors and transformers should be specified in detail w.r.t. the operating frequency. For investigating the complex permeability of the magnetic materials by simply test prototypes, the inductor model-based calculation methodologies for the complex permeability are suggested to find the core loss characteristics in this paper. Based on the measured results of the test voltage Ve, current Ie, and phase difference θe, which can be obtained simply by an oscilloscope and a function generator, the real and imaginary permeability can be calculated w.r.t. operating frequency by the suggested calculation methodologies. Such information for the real and imaginary permeability is important to determine the size of the magnetic components and to analyze the core loss. To identify the superiority of the high-frequency magnetic materials, three prototypes for a ferrite core, amorphous core, and nanocrystalline core have been built and verified by experiment. As a result, the ferrite core is superior to the other cores for core loss, and the nanocrystalline core is recommended for compact transformer applications. The proposed calculation for the complex (i.e., real and imaginary) permeability, which has not been revealed in the datasheets, provides a way to easily determine the parameters useful for industrial electronics engineers.
Proxy-Based Adaptive Transmission of MP-QUIC in Internet-of-Things Environment
Authors: Firmansyah Muhammad Hafidh , Jung Joong-Hwa , Koh Seok-Joo
Published: September 2021

With the growth of Internet of Things (IoT) services and applications, the efficient transmission of IoT data has been crucially required. The IETF has recently developed the QUIC protocol for UDP-based multiplexed and secure transport. The Multipath QUIC (MP-QUIC) is also being discussed as an extension of QUIC in the multipath network environment. In this paper, we propose a proxy-based adaptive MP-QUIC transmission for throughput enhancement in the IoT environment. In the proposed scheme, a proxy device is employed between IoT clients and IoT server to aggregate the traffics of many clients in the access network. The proxy will transport a large among of traffics to the server, adaptively to the network conditions, by using multiple paths in the backbone network. For this purpose, the proxy device employs a path manager to monitor the current network conditions and a connection manager to manage the MP-QUIC connections with the IoT server over the backbone network with multiple paths. For effective MP-QUIC transmission, the proxy will transmit the prioritized packets to the server using the best path with the lowest round-trip time (RTT), whereas the non-prioritized packets are delivered over the other paths for traffic load balancing in the network. From the testbed experimentations with the MP-QUIC implementation and ns-3 simulation modules, we see that the proposed scheme can outperform the normal QUIC (using a single path) and the existing MP-QUIC scheme (using the round-robin policy) in terms of response delay and total transmission delay. Such performance gaps tend to increase as the link delays and packet loss rates get larger in the network.
Noise Reduction Design with Trapezoidal Back-EMF and Asymmetric Air-Gap for Single-Phase BLDC Refrigerator Cooling Fan Motor
Authors: Lee Jin-Hwan , Jung Sang-Yong
Published: September 2021

In this study, a novel method for reducing the noise generated by single-phase claw-pole motors employed as refrigerator fan blowers is proposed. A single-phase claw-pole motor has the advantages of low manufacturing cost, easy manufacturing, and a high number of turns. However, in such motors, current delays occur owing to a high inductance; therefore, it is necessary to merge the back-electromotive force and current phases into the same phase using the phase advance method. Additionally, a single-phase motor exhibits dead torque and zero torque at an electrical angle of 180° owing to its electrical characteristics, and the dead torque deteriorates the average torque and torque ripple characteristics of the motor. In this study, a novel method is proposed to make the air gap asymmetrical by tilting the claw to reduce the noise generated by single-phase claw-pole motors. An asymmetric air gap allows the cogging torque to eliminate the dead torque caused by alignment torques, causing the torque ripple to decrease. To validate the effectiveness of the proposed method, the proposed model is compared with a base model via three-dimensional finite element analysis. Furthermore, the two models are manufactured and a noise test is conducted in an anechoic chamber to compare the noise difference between the two models.
An In-Depth Life Cycle Assessment (LCA) of Lithium-Ion Battery for Climate Impact Mitigation Strategies
Authors: Sadhukhan Jhuma , Christensen Mark
Published: September 2021

Battery energy storage systems (BESS) are an essential component of renewable electricity infrastructure to resolve the intermittency in the availability of renewable resources. To keep the global temperature rise below 1.5 °C, renewable electricity and electrification of the majority of the sectors are a key proposition of the national and international policies and strategies. Thus, the role of BESS in achieving the climate impact mitigation target is significant. There is an unmet need for a detailed life cycle assessment (LCA) of BESS with lithium-ion batteries being the most promising one. This study conducts a rigorous and comprehensive LCA of lithium-ion batteries to demonstrate the life cycle environmental impact hotspots and ways to improve the hotspots for the sustainable development of BESS and thus, renewable electricity infrastructure. The whole system LCA of lithium-ion batteries shows a global warming potential (GWP) of 1.7, 6.7 and 8.1 kg CO2 eq kg−1 in change-oriented (consequential) and present with and without recycling credit consideration, scenarios. The GWP hotspot is the lithium-ion cathode, which is due to lithium hexafluorophosphate that is ultimately due to the resource-intensive production system of phosphorous, white, liquid. To compete against the fossil economy, the GWP of BESS must be curbed by 13 folds. To be comparable with renewable energy systems, hydroelectric, wind, biomass, geothermal and solar (4–76 g CO2 eq kWh−1), 300 folds reduction in the GWP of BESS will be necessary. The areas of improvement to lower the GWP of BESS are as follows: reducing scopes 2–3 emissions from fossil resource use in the material production processes by phosphorous recycling, increasing energy density, increasing lifespan by effective services, increasing recyclability and number of lives, waste resource acquisition for the battery components and deploying multi-faceted integrated roles of BESS. Achieving the above can be translated into an overall avoided GWP of up to 82% by 2040.