bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon Nanotube (CNT) Encapsulated Magnesium-Based Nanocomposites to Improve Mechanical, Degradation and Antibacterial Performances for Biomedical Device Applications
Authors: Zhao Jinguo , Haowei Ma , Saberi Abbas , Heydari Zahra , Baltatu Madalina Simona
Published: October 2022

Nowadays, magnesium (Mg) composites are gaining much attention in biomedical device applications due to their biocompatibility and biodegradability properties. This research is to study the microstructure, mechanical, corrosive and antibacterial properties of Mg−2.5Zn−0.5Zr/xCNT (x = 0, 0.3, 0.6, 0.9) composites made with mechanical alloying and semi-powder metallurgy (SPM) processes, accompanied by SPS. Based on the microstructural characteristics, CNTs were almost uniformly distributed in the Mg matrix. The results displayed that the hardness and ultimate compressive strength (UCS) of the composites were meaningfully increased compared to a Mg matrix. Moreover, the degradation rate of Mg composites was almost halved in the presence of small amounts of CNTs in the Kokubo simulated body fluid (SBF). Due to the slowed degradation process, the Mg−2.5Zn−0.5Zr/0.6CNT biocomposites exhibited excellent cellular compatibility. Evaluation of antibacterial activity displayed that adding CNTs to the Mg matrix could significantly prevent the growing of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In general, the research results showed that CNTs are an efficient reinforcement for Mg−2.5Zn−0.5Zr/CNTs biocomposites, which leads to improved mechanical, degradation and antibacterial performances.
Investigation of Hybrid Films Based on Fluorinated Silica Materials Prepared by Sol–Gel Processing
Authors: Purcar Violeta , Rădiţoiu Valentin , Raduly Florentina Monica , Rădiţoiu Alina , Căprărescu Simona , Frone Adriana Nicoleta , Nicolae Cristian-Andi , Anastasescu Mihai
Published: October 2022

In this research, fluorinated silica materials were prepared through sol–gel processing with tetraethylorthosilicate (TEOS), triethoxymethylsilane (MTES), and trimethoxyhexadecylsilane (HDTMES), using a fluorinated solution (FS) under acidic medium. The fluorinated solution (FS) was obtained by diluting the perfluorooctanoic acid (PFOA) in 2-propanol. These fluorinated sol–gel silica materials were placed on the glass surfaces in order to achieve the antireflective and hydrophobic fluorinated hybrid films. The structure and surface properties of the final samples were investigated by Fourier transform infrared spectroscopy (FTIR), ultraviolet/visible spectroscopy, thermogravimetric analysis (TGA), atomic force microscopy (AFM), and contact angle (CA) determinations. FTIR spectra demonstrated the presence of a silica network modified with alkyl and fluoroalkyl groups. Thermal analysis showed that the fluorinated sol–gel silica materials prepared with HDTMES have a good thermostability in comparison with other samples. Ultraviolet/visible spectra indicated that the fluorinated hybrid films present a reflectance of ~9.5%, measured at 550 nm. The water contact angle analysis found that the wettability of fluorinated hybrid films was changed from hydrophilic (64°) to hydrophobic (~104°). These hybrid films based on fluorinated sol–gel silica materials can be useful in various electronics and optics fields.
Microstructure and Properties of Microwave-Sintered Nd2Fe14Bp/2024 Aluminum-Alloy–Co Composites
Authors: Qin Tao , Li Guirong , Wang Hongming , Su Wenxue , Dong Chao , Yu Jincheng
Published: October 2022

This study aimed at the preparation of a 2024 aluminum alloy (2024Al) matrix composite with high strength, high toughness and high magnetic properties that can be used in practical applications. Therefore, Nd2Fe14Bp/2024Al–Co composites with different Co contents (wt.%) were prepared by ball milling, cold isostatic pressing and microwave sintering. The effects of the Co content on the microstructure, mechanical properties and magnetic properties of the prepared composites were studied. Under the conditions of the sintering temperature of 490 °C, heating rate of 20 min/°C and soaking time of 30 min, it was found that with the increase in Co content (0→2.5%→5%→7.5%→10%), the grain size first decreased and then increased, and reached the optimal value of about 3–5 μm when the Co content was 7.5%, with the microstructure being relatively uniform. At the same time, the compactness of the composite arrived at a maximum of 95.4%. The main particle phases in the composite were Nd2Fe14B, Nd2 (Fe, Co)14B and Co particles. In the nanoindentation test, the interface strength of the 7.5% Co sample was significantly higher than that of the Co-free sample. In addition, the microhardness, yield strength and compressive strength of the 7.5% Co sample were 152 HV, 210 MPa and 269 MPa, respectively, which increased by 67%, 78% and 75%, respectively, compared with the Co-free sample. With the increase in Co content, the remanence (Br), coercivity (Hcj) and maximum magnetic energy product ((BH) max) of the composites first increased and then decreased. When the Co content was 7.5%, the three performance indicators reached their optimum values, which were Br: 0.20 (T), Hcj: 4.6 (kOe) and (BH)max: 28.36 (kJ/m3). The expected goal of the lightweight magnetic materials was achieved, and the action mechanism of Co addition in the composites was also analyzed in detail.
Long-Term Toxicities of Immune Checkpoint Inhibitor (ICI) in Melanoma Patients
Authors: Tong Justin , Kartolo Adi , Yeung Cynthia , Hopman Wilma , Baetz Tara
Published: October 2022

ICI therapy has greatly improved patient outcomes in melanoma, but at the cost of immune-related adverse events (irAEs). Data on the chronicity of irAEs, especially in real-world settings, are currently limited. We performed a retrospective chart review of 161 adult patients with melanoma treated with at least one cycle of ICI regimen in the adjuvant or metastatic setting: 129 patients received PD-1 inhibitor monotherapy and 32 received dual immunotherapy. Patients were grouped by duration of irAE: permanent (no complete resolution), long-term (resolution over a period ≥ 6 months), transient (resolution over a period < 6 months), or no irAEs. A total of 283 irAEs were reported in the whole patient population. Sixty-six (41.0%) patients developed permanent irAEs, fifteen (9.3%) experienced long-term irAEs as their longest-lasting toxicity, thirty-four (21.1%) developed transient irAEs only, and forty-six (28.6%) experienced no irAEs. Permanent irAEs occurred in 21 (65.6%) patients treated with dual immunotherapy and in 45 (34.9%) patients treated with monotherapy. The majority of permanent irAEs were endocrine-related (36.0%) or skin-related (32.4%). Grade 3–4 permanent irAEs occurred in 20 (12.4%) patients and included toxicities such as adrenal insufficiency, myocarditis, and myelitis. Fifty-three (32.9%) patients were still requiring treatment for long-term or permanent irAEs 6 months or more following the completion of ICI therapy, including twenty-four patients on thyroid hormone replacement and twenty-two on oral steroids. ICI treatment was temporarily interrupted for 64 (22.6%) irAEs and permanently discontinued due to irAEs in 38 patients (13.6% of irAEs, 23.6% of patients); additionally, 4 (2.5%) patients died of irAEs. Our findings show that ICI treatment in melanoma is associated with a wide range of toxicities that can be permanent and may have long-lasting impacts on patients, which should therefore be discussed when obtaining consent for treatment.
Dispersal and Space Use of Captive-Reared and Wild-Rehabilitated Harpy Eagles Released in Central American Landscapes: Implications for Reintroduction and Reinforcement Management
Authors: Naveda-Rodríguez Adrián , Campbell-Thompson Edwin , Watson Richard T. , McCabe Jennifer , Vargas Félix Hernán
Published: October 2022

Understanding the spatial context of animal movements is fundamental for the establishment and management of protected areas. We tracked, by telemetry devices, 31 captive-reared and 5 wild-rehabilitated Harpia harpyja and estimated the dispersal and space use after release in Mesoamerica. We evaluated the effectiveness of protected areas in the protection of home ranges and examined how individual traits, release methods and landscape features influenced the dispersal and home range using mixed-effects models. The mean post-release dispersal was 29.4 km (95% CI: 22.5–38.5), and the annual home ranges averaged 1039.5 km2 (95% CI: 627–1941). The home ranges were influenced by the release method, patch richness, patch and edge density and contagion. The currently protected areas in Mesoamerica may not be effective conservation units for this species. The Harpy Eagle average home range greatly exceeded the average size of 1115 terrestrial protected areas (52.7 ± 6.1 km2) in Mesoamerica. Due to their wide use of space, including transboundary space, Harpy Eagle conservation efforts may fail if they are not carefully coordinated between the countries involved. Future restoration efforts of umbrella forest-dwelling raptors should select release sites with highly aggregated and poorly interspersed forests. The release sites should have a buffer of approximately 30 km and should be located completely within protected areas.
Blood Parasites of Vangas and Other Corvoidea on Madagascar
Authors: Magaña Vázquez Regina , Woog Friederike , Dinkel Anke , Mackenstedt Ute , Musa Sandrine
Published: October 2022

Madagascar hosts a great diversity of bird species. This study focuses on the description of the diversity and prevalence of blood parasites (Haemosporida, trypanosomes and filarioid nematodes) in 131 blood samples of 14 species of Corvoidea, namely vangas (Vangidae), Coracina cinerea (Campephagidae), Dicrurus forficatus (Dicruridae) and Terpsiphone mutata (Monarchidae) found in primary rainforests on Madagascar. Blood parasites were detected using both molecular and microscopic methods. Multiplex PCR was used to detect mixed haemosporidian infections and nested PCR was used to describe a 479 bp fragment of the haemosporidian cytochrome b (cytb) gene. Furthermore, a 770 bp SSU rRNA fragment of trypanosomes, and, for microfilariae, a 690 bp fragment of 28S rRNA, as well as a 770 bp fragment of 28S rRNA, were amplified for identification using nested PCRs. Phylogenetic analyses were carried out for all sequences obtained from all blood parasite taxa. Over half of the samples (54.2%; n = 71) were infected with Haemosporida, whereas only 21.4% (n = 28) were infected with Trypanosoma and 5.3% (n = 7) contained filarioid nematode DNA. Fourteen of 56 blood smears contained some of the above-mentioned parasite taxa. The results corroborate the great diversity of blood parasites in the different bird species studied, especially in vangas. Vangas had the greatest diversity of parasites found, as well as the highest number of multiple infections, which may be due to their morphological diversity and resulting habitat use. Fifteen haemosporidian lineages, seven Trypanosoma and five filarioid nematode isolates were newly discovered in the avian species studied, particularly in the vangas. Members of the other Corvoidea families on Madagascar showed a lower susceptibility for avian haemosporidian parasites than vangas, which could be attributed to possible resistance against those parasites. The study confirmed the host specificity of some Haemosporida and microfilariae; however, it demonstrated that this was not the case for Trypanosoma.
Clear Cell Acanthoma with Malignant Cytologic Features: A Case Report and Review of the Literature
Authors: Melson Gabriella , Saliba Elie , Patel Shreya , Eisen Richard , Brem Candice E.
Published: October 2022

Clear cell acanthoma (CCA) is classically considered a benign epidermal tumor, although rare case reports have described CCA with malignant features. Here, we present a case of a patient with a biopsy proven CCA that regrew post-biopsy and was subsequently completely excised. Histologic examination of the tumor in the excision specimen revealed malignant cytologic features that were not present in the initial biopsy. A review of the literature identified five additional cases of CCA with similar malignant cytologic features. On analysis, common histopathologic characteristics included cellular pleomorphism, increased nuclear-to-cytoplasmic ratio, prominent nucleoli, and atypical mitotic figures. We support the designation of atypical clear cell acanthoma for these entities with features of both CCA and significant cytologic atypia. As none of these cases exhibited clinically aggressive behavior, further study is warranted.
Dual-Energy CT for Accurate Discrimination of Intraperitoneal Hematoma and Intestinal Structures
Authors: Winkelmann Moritz T. , Hagen Florian , Artzner Kerstin , Bongers Malte N. , Artzner Christoph
Published: October 2022

The purpose of this study was to evaluate the potential of dual-energy CT (DECT) with virtual unenhanced imaging (VNC) and iodine maps (IM) to differentiate between intraperitoneal hematomas (IH) and bowel structures (BS) compared to linearly blended DECT (DE-LB) images (equivalent to single-energy CT). This retrospective study included the DECT of 30 patients (mean age: 64.5 ± 15.1 years, 19 men) with intraperitoneal hematomas and 30 negative controls. VNC, IM, and DE-LB were calculated. Imaging follow-up and surgical reports were used as references. Three readers assessed diagnostic performance and confidence in distinguishing IH and BS for DE-LB, VNC, and IM. Diagnostic confidence was assessed on a five-point Likert scale. The mean values of VNC, IM, and DE-LB were compared with nonparametric tests. Diagnostic accuracy was assessed by calculating receiver operating characteristics (ROC). The results are reported as medians with interquartile ranges. Subjective image analysis showed higher diagnostic performance (sensitivity: 96.7–100% vs. 88.2–96.7%; specificity: 100% vs. 96.7–100%; p < 0.0001; ICC: 0.96–0.99) and confidence (Likert: 5; IRQ [5–5] vs. 4, IRQ [3–4; 4–5]; p < 0.0001; ICC: 0.80–0.96) for DECT compared to DE-LB. On objective image analysis, IM values for DECT showed significant differences between IH (3.9 HU; IQR [1.6, 8.0]) and BS (39.5 HU; IQR [29.2, 43.3]; p ≤ 0.0001). VNC analysis revealed a significantly higher attenuation of hematomas (50.5 HU; IQR [44.4, 59.4]) than BS (26.6 HU; IQR [22.8, 32.4]; p ≤ 0.0001). DE-LB revealed no significant differences between hematomas (60.5 HU, IQR [52.7, 63.9]) and BS (63.9 HU, IQR [58.0, 68.8]; p > 0.05). ROC analysis revealed the highest AUC values and sensitivity for IM (AUC = 100%; threshold by Youden-Index ≤ 19 HU) and VNC (0.93; ≥34.1 HU) compared to DE-LB (0.64; ≤63.8; p < 0.001). DECT is suitable for accurate discrimination between IH and BS by calculating iodine maps and VNC images.
TMP19: A Novel Ternary Motif Pattern-Based ADHD Detection Model Using EEG Signals
Authors: Barua Prabal Datta , Dogan Sengul , Baygin Mehmet , Tuncer Turker , Palmer Elizabeth Emma , Ciaccio Edward J. , Acharya U. Rajendra
Published: October 2022

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition worldwide. In this research, we used an ADHD electroencephalography (EEG) dataset containing more than 4000 EEG signals. Moreover, these EEGs are noisy signals. A new hand-modeled EEG classification model has been proposed to separate healthy versus ADHD individuals using the EEG signals. In this model, a new ternary motif pattern (TMP) has been incorporated. We have mimicked deep learning networks to create this hand-modeled classification method. The Tunable Q Wavelet Transform (TQWT) has been utilized to generate wavelet subbands. We applied the proposed TMP and statistics to construct informative features from both raw EEG signals and wavelet bands by generating TQWT. Herein, features have been generated by 18 subbands and the original EEG signal. Thus, this model is named TMP19. The most informative features have been chosen by deploying neighborhood component analysis (NCA), and the selected features have been classified using the k-nearest neighbor (kNN) classifier. The used ADHD EEG dataset has 14 channels. Thus, these three phases—(i) feature extraction with TQWT, TMP, and statistics; (ii) feature selection by deploying NCA; and (iii) classification with kNN—have been applied to each channel. Iterative hard majority voting (IHMV) has been applied to obtain a higher and more general classification response. Our model attained 95.57% and 77.93% classification accuracies by deploying 10-fold and leave one subject out (LOSO) cross-validations, respectively.
Reference Intervals for Coagulation Parameters in Developmental Hemostasis from Infancy to Adolescence
Authors: Di Felice Giovina , Vidali Matteo , Parisi Gelsomina , Pezzi Simona , Di Pede Alessandra , Deidda Giulia , D’Agostini Matteo , Carletti Michaela , Ceccarelli Stefano , Porzio Ottavia
Published: October 2022

Background: The objective of this study was to establish the age and sex-dependent reference intervals for coagulation assays evaluated in healthy children, ranging from 0 days to 16 years old. Methods: PT, aPTT, Fibrinogen (functional), Antithrombin activity, Protein C anticoagulant activity, Protein S free antigen, Thrombin time, D-Dimer, Von Willebrand Factor antigen, Lupus anticoagulant (screening), extrinsic and intrinsic pathway factors, and activated Protein C resistance were evaluated using STA-R Max2. Results: A total of 1280 subjects (671 males and 609 females) were divided into five groups, according to their age: 0–15 days (n = 280, 174 M and 106 F), 15–30 days (n = 208, 101 M and 107 F), 1–6 months (n = 369, 178 M and 191 F), 6–12 months (n = 214, 110 M and 104 F), and 1–16 years (n = 209, 108 M and 101 F). The 95% reference intervals and the 90% CI were established using the Harrell–Davis bootstrap method and the bootstrap percentile method, respectively. Conclusions: The present study supports the concept that adult and pediatric subjects should be evaluated using different reference intervals, at least for some coagulation tests, to avoid misdiagnosis, which can potentially lead to serious consequences for patients and their families, and ultimately the healthcare system.
Ultrasound-Guided Radiofrequency Ablation for Primary Hyperparathyroidism Induced by Multiple Endocrine Neoplasia 1—A Case Report
Authors: Han Zhenping , Li Tingting , Wang Siyi , Gao Li , Hu Ying , Zhao Yu , Yan Jieping
Published: October 2022

Multiple endocrine neoplasia type 1 (MEN1) is a syndrome characterized by the occurrence of two or more endocrine gland tumors. Here, we show a case of a 52-year-old man diagnosed with MEN1 through gastrinoma, parathyroid adenoma and gene detection. The MEN1 patient’s case was complicated with relapsed primary hyperparathyroidism (PHPT), and they received ultrasound-guided radiofrequency ablation (RFA). The patient had a remarkable recovery after RFA treatment for the relapsed PHPT. It might be an alternative treatment for MEN1 patients with poor conditions such as high surgical risk, unwillingness to choose parathyroid surgery or those unable to tolerate surgery. Individualized therapy significantly benefits the prognosis of MEN1 patients.
Human Papillomavirus Infection and Oropharyngeal and Gastrointestinal Cancers: A Causal Relationship?
Authors: Deniz Zeynep , Uraz Suleyman , Holem Ryan , Ozaras Resat , Tahan Veysel
Published: October 2022

The human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. The risk of being infected at least once in a lifetime among both men and women is estimated to be 50%. Although the majority of HPV infections are asymptomatic and improve within 2 years, approximately 10% of individuals develop a persistent infection and have an increased risk of developing carcinomas. The association of HPV and genital cancer is well established. However, there is evidence that HPV may also be associated with other cancers, including those of the gastrointestinal system. The aim of this review is to organize the current evidence of associations between HPV infections and oropharyngeal and gastrointestinal cancers, including the following: oropharyngeal, esophageal, gastric, colorectal, and anal cancers. A comprehensive review of the most up-to-date medical literature concluded that an HPV infection might have a role in the oncogenesis of gastrointestinal tract cancers. HPV may have a causal relationship with oropharyngeal and esophageal squamous cell cancers. However, the association between HPV and gastric and colorectal cancers is weaker. The development of cancer in the oropharyngeal and gastrointestinal tract is usually multifactorial, with HPV having a role in at least a subset of these cancers. HPV infections pose a big challenge due to their burden of infection and their oncogenic potential.
System Identification of Heterogeneous Multirotor Unmanned Aerial Vehicle
Authors: Hoshu Ayaz Ahmed , Wang Liuping , Ansari Shahzeb , Sattar Abdul , Bilal Manzoor Hyder Alias
Published: October 2022

An energy efficient heterogeneous multirotor unmanned aerial system (UAS) is presented in this paper, wherein, the aerodynamical characteristics of both helicopter and quadrotor are obtained in a single multirotor design. It features the energy efficiency and endurance of a helicopter, while keeping the mechanical simplicity, control and maneuverability of a quadrotor; employing a single large central rotor to get majority of the lift and four small arm canted rotors for control. Developing the stable and robust control strategy requires the accurate model of system. Due to the added mechanical complexities of the new design including the existence of couplings and gyroscopics, the modelling through the dynamic equations of the multirotor would not be possible in providing accurate results. Therefore, precise system modelling is required for the development of stable and robust control strategy. This paper proposes a novel system identification method with the objective to experimentally estimation of the precise dynamic model of the heterogeneous multirotor. The approach comprises of the utilization of input excitation signals, frequency sampling filter and derivation of transfer functions through complex curve fitting method. To validate the accuracy of the obtained transfer functions, the experimentally auto-tuned PID controllers are implemented over the transfer functions. Custom designed fight controller is used to experimentally implement the proposed idea. Presented results demonstrate the efficacy of the proposed approach for heterogeneous multirotor UAS.
RISE: Rolling-Inspired Scheduling for Emergency Tasks by Heterogeneous UAVs
Authors: Fei Bowen , Liu Daqian , Bao Weidong , Zhu Xiaomin , Zou Mingyin
Published: October 2022

The multiple unmanned aerial vehicles (UAVs) system is highly sought after in the fields of emergency rescue and intelligent transportation because of its strong perception and extensive coverage. Formulating a reasonable task scheduling scheme is essential to raising the task execution efficiency of the system. However, the dynamics of task arrival and the heterogeneity of UAV performance make it more difficult for multiple UAVs to complete the tasks. To address these issues, this paper focuses on the multi-UAV scheduling problem and proposes a method of rolling-inspired scheduling for emergency tasks by heterogeneous UAVs (RISE). In order to ensure that emergency tasks can be allocated to UAVs in a real-time manner, a task grouping strategy based on a density peaks (DP) clustering algorithm is designed, which can quickly select UAVs with matching performance for the tasks arriving at the system. Furthermore, an optimization model with multiple constraints is constructed, which takes the task profit and UAV flight cost as the objective function. Next, we devise a rolling-based optimization mechanism to ensure that the tasks with shorter deadlines are executed first while maximizing the objective function, so as to obtain the optimal task execution order for each UAV. We conduct several groups of simulation experiments, and extensive experimental results illustrate that the number of tasks successfully scheduled and the utilization rate of UAVs by RISE are superior to other comparison methods, and it also has the fastest running time. It further proves that RISE has the capability to improve the completion rate of emergency tasks and reduce the flight cost of multiple UAVs.
A High-Resolution Lead-Lag Analysis of US GDP, Employment, and Unemployment 1977–2021: Okun’s Law and the Puzzle of Jobless Recovery
Authors: Seip Knut , Zhang Dan
Published: October 2022

Okun’s law is formulated as the ratio between GDP and unemployment (UE): β = f(GDP/UE). It is used to investigate the relations between output and labor input across regions or across business cycles. Based on results by James D. Hamilton we replaced the United States UE with employment (EM) for the years 1977 to 2021 and examined how employment changed relative to output during recessions and recoveries. We found that (i) EM was leading GDP before and lagging GDP after all recessions, except the 2020 recession. (ii) The βE(9) = GDP/EM for rolling ordinary linear regression over 9 months decreases just after a recession and then recovers over 2- to 4-year periods. (iii) The two series showing that EM → GDP and βE(9) < 0.5 coincided in the 34 months that partly preceded and partly followed five of six NBER recession dates, providing a probability of ≈0.0002 to coincide with the recessions by chance. Thus, the two series may be used to support forecasts of coming recessions. Since EM precedes GDP and labor productivity declines before recessions, a policy recommendation for avoiding “jobless recovery” is that employment should not increase more rapidly than the real economy.
Importance of Feedstock in a Small-Scale Agricultural Biogas Plant
Authors: Czubaszek Robert , Wysocka-Czubaszek Agnieszka , Banaszuk Piotr
Published: October 2022

Although no legal sustainability criteria have been formulated for electricity and heat production from biogas, the sustainability and profitability of large-scale biogas plants which use mainly energy crops is now questioned. Small (farm-size) biogas plants characterized by CHP electrical output in the range between 15 kWel and 99 kWel, operating on agricultural wastes and by-products, seem more suitable; however, the variety of feedstock may be crucial in the proper design and operation of such family biogas plants. This paper aims to present the problems that occurred in small agricultural biogas plants fed with sheep manure (SM), horse manure (HM), and grass-clover silage (GCS). This paper also focuses on analyzing the energy balance and carbon dioxide (CO2) emissions related to four technological solutions (Scenarios 1–4) based on various feedstocks, grinding and feeding systems, and wet/dry fermentation. The biogas plant was originally based on dry fermentation with an organic loading rate ~10.4 kgVS·m−3·d−1, a hydraulic retention time of 16 days, and temperature of 45 °C in the fermentation chamber. The material was shredded and mixed in a mixing device, then the mixture of manures and silage was introduced to the horizontal fermentation chamber through a system of screw feeders. The biogas and the digestate were collected in a reinforced concrete tank. The biogas was sent to the CHP unit of an installed electrical power of 37 kWel, used to produce electricity and recover the heat generated in this process. Scenario 1 is based on the design assumptions used for the biogas plant construction and start-up phase. Scenario 2 includes a new feeding and grinding system, in Scenario 3 the feedstock is limited to SM and HM and wet fermentation is introduced. In Scenario 4, a dry fermentation of SM, HM, and maize silage (MS) is assumed. Avoided CO2 emissions through electricity and heat production from biogas were the highest in the case of Scenarios 1 and 4 (262,764 kg CO2·y−1 and 240,992 kg CO2·y−1) due to high biogas production, and were the lowest in Scenario 3 (7,481,977 kg CO2·y−1) because of the low specific methane yield (SMY) of SM and HM. Nevertheless, in all scenarios, except Scenario 3, CO2 emissions from feedstock preparation and biogas plant operation are much lower than that which can be avoided by replacing the fossil fuel energy for the electricity and heat produced from biogas. Our observations show that a small agricultural biogas plant can be an effective energy source, and can contribute to reducing CO2 emissions only if the appropriate technological assumptions are adopted, and the entire installation is designed correctly.
A Multi-Layer Data-Driven Security Constrained Unit Commitment Approach with Feasibility Compliance
Authors: Feliachi Ali , Iqbal Talha , Choudhry Muhammad , Ul Banna Hasan
Published: October 2022

Security constrained unit commitment is an essential part of the day-ahead energy markets. The presence of discrete and continuous variables makes it a complex, mixed-integer, and time-hungry optimization problem. Grid operators solve unit commitment problems multiple times daily with only minor changes in the operating conditions. Solving a large-scale unit commitment problem requires considerable computational effort and a reasonable time. However, the solution time can be improved by exploiting the fact that the operating conditions do not change significantly in the day-ahead market clearing. Therefore, in this paper, a novel multi-layer data-driven approach is proposed, which significantly improves the solution time (90% time-reduction on average for the three studied systems). The proposed approach not only provides a near-optimal solution (<1% optimality gap) but also ensures that it is feasible for the stable operation of the system (0% infeasible predicted solutions). The efficacy of the developed algorithm is demonstrated through numerical simulations on three test systems, namely a 4-bus system and the IEEE 39-bus and 118-bus systems, and promising results are obtained.
Cloud-Based Platform for Photovoltaic Assets Diagnosis and Maintenance
Authors: Livera Andreas , Tziolis Georgios , Franquelo Jose G. , Bernal Ruben Gonzalez , Georghiou George E.
Published: October 2022

A cloud-based platform for reducing photovoltaic (PV) operation and maintenance (O&M) costs and improving lifetime performance is proposed in this paper. The platform incorporates a decision support system (DSS) engine and data-driven functionalities for data cleansing, PV system modeling, early fault diagnosis and provision of O&M recommendations. It can ensure optimum performance by monitoring in real time the operating state of PV assets, detecting faults at early stages and suggesting field mitigation actions based on energy loss analysis and incidents criticality evaluation. The developed platform was benchmarked using historical data from a test PV power plant installed in the Mediterranean region. The obtained results showed the effectiveness of the incorporated functionalities for data cleansing and system modeling as well as the platform’s capability for automated PV asset diagnosis and maintenance by providing recommendations for resolving the detected underperformance issues. Based on the DSS recommendations, approximately 7% of lost energy production could be recovered by performing field mitigation activities (e.g., corrective actions).
Reliability Enhancement of Photovoltaic Systems under Partial Shading through a Two-Step Module Placement Approach
Authors: Aljafari Belqasem , Satpathy Priya Ranjan , Madeti Siva Rama Krishna , Vishnuram Pradeep , Thanikanti Sudhakar Babu
Published: October 2022

Partial shading has a negative impact on photovoltaic systems by forcing the connected modules to generate lower power, creating severe unexpected power losses. To resolve this issue, numerous solutions have been proposed, among which configuration modification has recently attracted a greater audience. The preliminary approach to module reconfiguration was based on the alteration of electrical connections through switches, which introduces lag due to the large number of switches and sensors, complex algorithms, and impractical application. Hence, static techniques are considered to be a cost-effective, low-complexity and easy-to-adopt solution for efficiently reducing the losses due to shading. Hence, this paper proposes a two-step module replacement approach that is validated under multiple partial shading conditions, and the performance is compared with various conventional and hybrid configurations and a static electrical reconfiguration technique using mathematical analysis, comparative parameters and power curves analysis. The validation was performed using the MATLAB platform for two system sizes—6 × 6 and 18 × 3—proving its applicability for arbitrary system sizes. On the basis of the depth investigation, an average power increase of 17.49%, 14.47%, and 14.12% for the two-step approach compared to the conventional, hybrid and electrical reconfiguration was observed in the partial shading cases considered.
Classifying Regional and Industrial Characteristics of GHG Emissions in South Korea
Authors: Kang Hyungsu , Zoh Hyunmin Daniel
Published: October 2022

South Korea officially committed to reducing 40% of its total carbon emissions by 2030, but the country has a carbon-dependent economic structure based on the manufacturing industry. Additionally, the industrial structure of each region in South Korea is heterogeneous. In this regard, policymakers should analyze the carbon emission condition at a regional level because abatement aspects are heterogeneous by urban spatial production. However, although various studies have developed a methodology to evaluate the GHG emission condition, these studies failed to consider the fundamental aspect of regional heterogeneity. In this regard, this study suggests a quantitative method to assess the potential of the carbon neutrality of regions and industries by using both shift-share analysis and the Log Mean Divisia Index method. Shift share analysis is used to quantify the relation between the industry and regional characteristics, and the Log Mean Divisia Index method can decompose each effect for economic growth and technological progress. By combining these two methods, this study suggests four classifications to evaluate regional and industrial characteristics of GHG emissions and analyze each region’s emission status in terms of the mining and manufacturing industry in South Korea.
Effect of Temperature on Energy Consumption and Polarization in Reverse Osmosis Desalination Using a Spray-Cooled Photovoltaic System
Authors: Armendáriz-Ontiveros María Magdalena , Dévora-Isiordia Germán Eduardo , Rodríguez-López Jorge , Sánchez-Duarte Reyna Guadalupe , Álvarez-Sánchez Jesús , Villegas-Peralta Yedidia , Martínez-Macias María del Rosario
Published: October 2022

Reverse osmosis (RO) desalination is considered a viable alternative to reduce water scarcity; however, its energy consumption is high. Photovoltaic (PV) energy in desalination processes has gained popularity in recent years. The temperature is identified as a variable that directly affects the behavior of different parameters of the RO process and energy production in PV panels. The objective of this study was to evaluate the effect of temperature on energy consumption and polarization factor in desalination processes at 20, 23, 26 and 30 °C. Tests were conducted on a RO desalination plant driven by a fixed 24-module PV system that received spray cooling in the winter, spring and summer seasons. The specific energy consumption was lower with increasing process feed temperature, being 4.4, 4.3, 3.9 and 3.5 kWh m−3 for temperatures of 20, 23, 26 and 30 °C, respectively. The water temperature affected the polarization factor, being lower as the temperature increased. The values obtained were within the limits established as optimal to prevent the formation of scaling on the membrane surface. The spray cooling system was able to decrease the temperature of the solar cells by about 6.2, 13.3 and 11.5 °C for the winter, spring and summer seasons, respectively. The increase in energy production efficiency was 7.96–14.25%, demonstrating that solar cell temperature control is a viable alternative to improve power generation in solar panel systems.
Automatic Monitoring System for Online Module-Level Fault Detection in Grid-Tied Photovoltaic Plants
Authors: Aljafari Belqasem , Madeti Siva Rama Krishna , Satpathy Priya Ranjan , Thanikanti Sudhakar Babu , Ayodele Bamidele Victor
Published: October 2022

In this paper, a novel fault detection and diagnosis technique for a grid-tied photovoltaic (GTPV) with the ability of module-level fault location and differentiation is proposed. The proposed system measures the voltage, current, and temperature of the PV modules using low-cost sensors and critically compares them with the mathematical evaluated data to locate the type and location of the fault in the system. Additionally, a power line communication (PLC)-based low-cost PV monitoring system for tracking the operation of individual modules along with a fault detection algorithm is proposed to detect and locate the fault in the system. An intuitive online web application is also created to make it simple for users to view monitored data online. The suggested method is shown to have reduced computing needs; thus, the transmission of data and fault diagnosis is performed using the same microcontroller without the need for extra hardware or simulation software. The usefulness of the proposed method in identifying different fault occurrences in GTPV systems has been shown via experimental findings.
Application of Immobilized Yeasts for Improved Production of Sparkling Wines
Authors: Fernández-Fernández Encarnación , Rodríguez-Nogales José Manuel , Vila-Crespo Josefina , Falqué-López Elena
Published: October 2022

Verdejo sparkling wines from two consecutive vintages were elaborated following the “champenoise” method. The second fermentation was developed with the same free or immobilized Saccharomyces cerevisiae bayanus yeast strain, carrying out four batch replicates each year. The sparkling wines were analyzed after 9 months of aging, showing no significant differences among the two typologies in the enological parameters (pH, total acidity, volatile acidity, reducing sugars, and alcoholic strength), the effervescence, or the spectrophotometric measurements. The free amino nitrogen content was significantly higher in the sparkling wines obtained from immobilized yeasts, nevertheless, the levels of neutral polysaccharides and total proteins were lower. No significant differences in the volatile composition were found, except for only two volatile compounds (isobutyric acid and benzyl alcohol); however, these two substances were present at levels below their respective olfactory thresholds. The sensory analysis by consumers showed identical preferences for both types of sparkling wines, except for the color acceptability. The descriptive analysis by a tasting panel revealed that sensorial differences between both sparkling wines were only found for the smell of dough. Therefore, the use of immobilized yeasts for the second fermentation of sparkling wines can reduce and simplify some enological practices such as the procedure of riddling and disgorging, with no impact on the so-mentioned quality parameters.
A Molecular Dynamic Model of Tryptophan Overproduction in Escherichia coli
Authors: Castro-López Diego Andrés , González de la Vara Luis E. , Santillán Moises , Martínez-Antonio Agustino
Published: October 2022

Several deterministic models simulate the main molecular biology interactions among the numerous mechanisms controlling the dynamics of the tryptophan operon in native strains. However, no models exist to investigate bacterial tryptophan production from a biotechnological point of view. Here, we modified tryptophan models for native production to propose a biotechnological working model that incorporates the activity of tryptophan secretion systems and genetic modifications made in two reported E. coli strains. The resultant deterministic model could emulate the production of tryptophan in the same order of magnitude as those quantified experimentally by the genetically engineered E. coli strains GPT1001 and GPT1002 in shake flasks. We hope this work may contribute to the rational development of biological models that define and include the main parameters and molecular components for designing and engineering efficient biotechnological chassis to produce valuable chemicals.
Effect of Different Inducer Sources on Cellulase Enzyme Production by White-Rot Basidiomycetes Pleurotus ostreatus and Phanerochaete chrysosporium under Submerged Fermentation
Authors: Datsomor Osmond , Yan Qi , Opoku-Mensah Louis , Zhao Guoqi , Miao Lin
Published: October 2022

Cellulase enzymes attract a lot of research due to their industrial application. Diverse cellulase-producing organisms and substances that induce cellulase are highly sought after. This study aimed to evaluate the effect of different inducer sources on cellulase production by white rot fungi P. ostreatus CGMCC 3.7292 and P. chrysosporium CGMCC 3.7212 under submerged fermentation employing a completely randomized experimental design. The different inducer sources tested were nitrogen (yeast, potassium nitrate, sodium nitrate, ammonium sulphate, aqueous ammonia and urea), carbon (malt extract, glucose, fructose, carboxymethylcellulose, starch and xylose) and agro-biomass (stevia straw, wheat straw, oat straw, alfalfa straw, corn cobs and corn stover). These inducer sources strongly impacted enzyme activities by P. ostreatus CGMCC 3.7292 and P. chrysosporium CGMCC 3.7212. The suitable nitrogen and carbon inducer sources for cellulase activity by P. ostreatus and P. chrysosporium were yeast (1.354 U/mL and 1.154 U/mL) and carboxymethylcellulose (0.976 U/mL and 0.776 U/mL) while the suitable agro-biomass were wheat straw (6.880 U/mL) and corn stover (6.525 U/mL), respectively. The least inducer sources in terms of nitrogen, carbon and agro-biomass for cellulase activity by P. ostreatus and P. chrysosporium were urea (0.213 U/mL and 0.081 U/mL), glucose (0.042 U/mL and 0.035), xylose (0.042 U/mL and 0.035 U/mL) and stevia straw (1.555 U/mL and 0.960 U/mL). In submerged fermentation, the cellulase enzyme activity of P. ostreatus in response to various inducer sources was relatively higher than P. chrysosporium.
Low-Temperature Pretreatment of Biomass for Enhancing Biogas Production: A Review
Authors: Wang Ming , Wang Jianlin , Li Yunting , Li Qichen , Li Pengfei , Luo Lina , Zhen Feng , Zheng Guoxiang , Sun Yong
Published: October 2022

Low-temperature pretreatment (LTPT, Temp. < 100 °C or 140 °C) has the advantages of low input, simplicity, and energy saving, which makes engineering easy to use for improving biogas production. However, compared with high-temperature pretreatment (>150 °C) that can destroy recalcitrant polymerized matter in biomass, the action mechanism of heat treatment of biomass is unclear. Improving LTPT on biogas yield is often influenced by feedstock type, treatment temperature, exposure time, and fermentation conditions. Such as, even when belonging to the same algal biomass, the response to LTPT varies between species. Therefore, forming a unified method for LTPT to be applied in practice is difficult. This review focuses on the LTPT used in different biomass materials to improve anaerobic digestion performance, including food waste, sludge, animal manure, algae, straw, etc. It also discusses the challenge and cost issues faced during LTPT application according to the energy balance and proposes some proposals for economically promoting the implementation of LTPT.
Effect of the Pore Geometry on the Driving Pressure across a Bubble Penetrating a Single Pore
Authors: Ansari Shadi , Nobes David S.
Published: October 2022

The passage of a bubble and the required energy for its motion through a confining pore can potentially be affected by the surface roughness and geometry of the pore. The motion of an isolated bubble passing through four different pore geometries (three circular pores, a smooth pore and 2 with different roughness, and a sharp triangular pore) is investigated. The shape of the deformed bubble passing these geometries was evaluated to determine the pressure drop across the bubble and hence the driving force to cause motion. The results of investigating the motion of the bubbles and the change in the pressure and velocity of the bubbles showed that the pore shape and surface roughness have a significant effect on the passage of the isolated phase. The motion of the bubble entering the entrance of the circular pores was similar for all circular cases. On exiting, however, a clear difference between the cases due to the presence of the peaks of the roughness was observed. These results indicate that, in addition to the critical pressure at the entrance of the pore, extra resistance will be introduced due to bubble phase pinning at the exit caused by roughness of the pore.
Germination of White and Red Quinoa Seeds: Improvement of Nutritional and Functional Quality of Flours
Authors: Guardianelli Luciano Martín , Salinas María Victoria , Brites Carla , Puppo María Cecilia
Published: October 2022

Quinoa is an Andean grain, classified as pseudocereal and the exploitation of its nutritional profile is of great interest for the cereal-based industry. The germination of quinoa seeds (white and red royal) was tested at 20 °C for different times (0, 18, 24 and 48 h) to select the best conditions for improving the nutritional quality of their flours. Changes in proximal composition, total phenolic compounds, antioxidant activity, mineral content, unsaturated fatty acids and essential amino acids profiles of germinated quinoa seeds were determined. In addition, changes in structure and thermal properties of the starch and proteins as consequence of germination process were analyzed. In white quinoa, germination produced an increase in the content of lipids and total dietary fiber, at 48 h, the levels of linoleic and α-linolenic acids and antioxidant activity increase, while in red quinoa, the component that was mostly increased was total dietary fiber and, at 24 h, increased the levels of oleic and α-linolenic acids, essential amino acids (Lys, His and Met) and phenolic compounds; in addition, a decrease in the amount of sodium was detected. On the basis of the best nutritional composition, 48 h and 24 h of germination were selected for white and red quinoa seeds, respectively. Two protein bands were mostly observed at 66 kDa and 58 kDa, being in higher proportion in the sprouts. Changes in macrocomponents conformation and thermal properties were observed after germination. Germination was more positive in nutritional improvement of white quinoa, while the macromolecules (proteins and starch) of red quinoa presented greater structural changes. Therefore, germination of both quinoa seeds (48 h-white quinoa and 24 h-red quinoa) improves the nutritional value of flours producing the structural changes of proteins and starch necessary for obtaining high quality breads.
Novel Insight into the Formation of Odour—Active Compounds in Sea Buckthorn Wine and Distilled Liquor Based on GC–MS and E–Nose Analysis
Authors: Xia Yanan , Zha Musu , Liu Hao , Shuang Quan , Chen Yongfu , Yang Xujin
Published: October 2022

Sea buckthorn wine (SW) and distilled liquor (DL) are fruit wines with beneficial health effects. However, their unpleasant flavour limits their development and widespread acceptance. Therefore, it is necessary to analyse their flavour composition and changes. In this study, differential metabolites of sea buckthorn DL during processing were analysed, and the relationships between E–nose sensor values and key volatile organic compounds (VOCs) were established. The results show that 133 VOCs were identified, with 22 aroma–contributing components. Fermentation significantly increased the content of VOCs, especially esters. A total of seven and 51 VOCs were significantly upregulated after fermentation and distillation, respectively. Meanwhile, seven sensors were positively correlated with the increased level of alcohols and esters, and reflected the increasing trends of 10 key VOCs.