bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Evaluation of Massively Parallel Systems Using SPEC OMP Suite
Authors: Mustafa Dheya
Published: May 2022

Performance analysis plays an essential role in achieving a scalable performance of applications on massively parallel supercomputers equipped with thousands of processors. This paper is an empirical investigation to study, in depth, the performance of two of the most common High-Performance Computing architectures in the world. IBM has developed three generations of Blue Gene supercomputers—Blue Gene/L, P, and Q—that use, at a large scale, low-power processors to achieve high performance. Better CPU core efficiency has been empowered by a higher level of integration to gain more parallelism per processing element. On the other hand, the Intel Xeon Phi coprocessor armed with 61 on-chip x86 cores, provides high theoretical peak performance, as well as software development flexibility with existing high-level programming tools. We present an extensive evaluation study of the performance peaks and scalability of these two modern architectures using SPEC OMP benchmarks.
A Proposed Safari Park in a Subtropical Forest in Northeastern Bangladesh Will Be Detrimental to Native Biodiversity
Authors: Khan Mohammad Ali Reza , Haque Enam Ul , Khan M. Monirul H. , Ahmed Inam , Chakma Suprio , Naher Habibon , Chowdhury Mohammad Abdul Wahed , Mukul Sharif Ahmed , Chowdhury Sayam U. , Rahman Shahriar Caesar , Kabir M. Tarik , Rahman Hasan Arif , Akash Muntasir , Mukutmoni Mandira , Ghose Animesh , Al-Razi Hassan , Muzaffar Sabir Bin
Published: May 2022

Biodiversity in tropical and subtropical forests are at high risk of decline due to rapid anthropogenic development. Planned activities that potentially benefit communities near forests are often undertaken at the expense of forest biodiversity. Recently, the Government of Bangladesh released plans to develop a safari park in Lathitila forest in northeastern Bangladesh. This mixed evergreen, stream-fed, trans-border forest harbors 26 globally threatened species. The proposed plan aims to bring several exotic game animals such as the lion (Panthera leo), spotted hyaena (Crocuta crocuta) and cheetah (Acionyx jubatus) to be maintained in captivity. Additionally, exotic bird aviaries, gardens, a dolphinarium, a marine aquarium exhibit, and a carp pond have been proposed for construction. Here, we (i) summarize some of the key attributes of safari parks and the misconceptions associated with them; (ii) highlight some of the planned development activities of the proposed safari park; (ii) list the threatened species found in the area, and (iii) explain why establishing a park in the area would be detrimental the region’s biodiversity. We urge the government to abandon the plans to develop a safari park and suggest that the area be brought under formal protection for the benefit of biodiversity conservation.
Permanent Make-Up (PMU) Inks Decolorization Using Plant Origin Materials
Authors: Andreou Eleni , Triantafyllou Agapi K. , Mountsaki Soultana , Rallis Efstathios , Lamari Fotini N. , Hatziantoniou Sophia , Kefala Vasiliki
Published: May 2022

Permanent make-up (PMU) has become a very popular application over the last few years. The ingredients of PMU inks, used over the face area, are organic and inorganic substances very close to the chemical composition of tattoo inks. As the application rates increase, the demand for PMU removal rises. The aim of this study is to assess the decolorization of PMU inks using preparations originating from different plant sources. The leaves of Pelargonium zonale (PE) were extracted with water for 48 h. The Total Phenolic Content (TPC) of the extract was determined using the Folin–Ciocalteu technique reaching 201.34 ± 4.57 μg Gallic Acid Equivalents (GAE)/mL of extract. The antioxidant activity of the extract was 20.87 ± 0.36 μg of Trolox equivalents (TE)/mL and 3.56 ± 0.43 mg FeSO4×7H2O mL of extract when assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric reducing antioxidant power (FRAP) assay respectively. The decolorization potential of PE leaf extract on five commercially available PMU inks of different hues was assessed by UV-Vis spectrophotometry in comparison to polyphenol oxidases enzyme (PPO). The results demonstrated higher absorption reduction that indicates decolorization potential for the inks that have mainly ferrous oxides as colorants.
Evolution of Nanodomains and Formation of Self-Organized Structures during Local Switching in X-Cut LNOI
Authors: Slautin Boris , Turygin Anton , Pashnina Elena , Slautina Alla , Chezganov Dmitry , Shur Vladimir
Published: May 2022

The features of nanodomain growth during local switching in X-cut lithium niobate on insulator (LNOI) were comprehensively studied using the biased tip of a scanning probe microscope. The obtained results were discussed in terms of the kinetic approach. The revealed differences in domain growth in bulk LN and LNOI were attributed to the higher bulk conductivity of LNOI. The obtained influence of humidity on the shape and growth of isolated domains was attributed to the water meniscus. Analysis of the transition between the “forward growth” and “sideways growth” stages was performed by switching to the stripe electrode. A sand-glass-shaped domain was formed due to growth in the opposite direction after the domain touched the electrode. Stable periodical domain structures down to 300 nm were created and characterized in LNOI. Highly ordered comb-like domains of various alternating lengths, including four- and eight-fold increase periods, were produced by performing biased tip scanning along the Y axis. The obtained knowledge is important for the future development of nanodomain engineering methods in monocrystalline ferroelectric thin films on insulators.
Synthesis of Needle-like Nanostructure Composite Electrode of Co3O4/rGO/NF for High-Performance Symmetric Supercapacitor
Authors: Wang Xiaoyan , Lu Shixiang , Xu Wenguo
Published: May 2022

In this work, a hierarchical electrode structure of cobaltosic oxide (Co3O4) growing on a reduced graphene oxide (rGO)-covered nickel foam (NF) substrate (named Co3O4/rGO/NF) is fabricated by a facile hydrothermal and subsequent annealing process. Thousands of nanoneedle units uniformly arranged on the surface of the rGO sheet stimulate the evident increase in the specific surface area and thus produce more active sites. Because of the special hierarchical structure, the Co3O4/rGO/NF electrode shows a high specific capacitance of 1400 F g−1 at 1 A g−1 and retains 58% capacitance even when the current density increases to 30 A g−1. In addition, a symmetric supercapacitor based on the Co3O4/rGO/NF electrode is assembled, exhibiting high specific capacitance of 311 F g−1 at 1 A g−1, as well as remarkable power density and energy density (40.67 Wh kg−1 at 12 kW kg−1). The device also demonstrates a great cycling performance after 10,000 cycles under the current density of 10 A g−1, acquiring 89.69% capacitance retention of the initial state. The accessible synthetic method and superior electrochemical performance of the Co3O4/rGO/NF composite electrode implicate its extensive application prospects in terms of new energy storage.
Simulation of Amorphous Silicon Carbide Photonic Crystal Absorption Layer for Solar Cells
Authors: Zhou Lin , Xu Yuwei , Tan Shuyu , Liu Meijie , Wan Yong
Published: May 2022

In this work, the amorphous silicon carbide (a-SiC) with low cost and high extinction coefficient was used as the light absorption layer of solar cells, and the photonic crystal (PC) structure and defect structure were introduced. By optimizing the scatterer shape, structural parameters and defect types of photonic crystal, the absorption efficiency of the light absorption layer was further improved. The results show that the photonic crystal absorption layer with vacancy line defect is better than the perfect photonic crystal absorption layer. Meanwhile, the absorption efficiency of the photonic crystal absorption layer significantly improves in the case that the scatterer is an elliptical cylindrical air hole scatterer. When the incident light is in the wavelength range of 0.30~0.80 μm and the absorption layer height is 0.60 μm, the absorption efficiency of the absorption layer can reach 95.60%. Compared with the absorption layer without photonic crystal structure, the absorption layer is increased by 43.24%. At the same time, the absorption layer has little dependence on the incidence angle of sunlight. When the incidence angle is 65°, the absorption efficiency is still higher than 80%.
Cobalt, Ferrum Co-Doped Ni3Se4 Nano-Flake Array: An Efficient Electrocatalyst for the Alkaline Hydrogen Evolution and Overall Water Splitting
Authors: Zhou Chuancang , Wu Hongyu , Zhang Feipeng , Miao Yigao
Published: May 2022

Herein, Co, Fe co-doped Ni3Se4 nano-flake array (Ni0.62Co0.35Fe0.03)3Se4) was prepared on conductive carbon cloth by a two-step hydrothermal method. XRD and EDX analysis show that the nanosheets are monoclinic Ni3Se4, and Co, and Fe were doped into the lattice of Ni3Se4. Electrochemical tests showed that Co, Fe co-doping can effectively improve the hydrogen evolution activity of Ni3Se4 in acidic and alkaline environment. When the current density of (Ni0.62Co0.35Fe0.03)3Se4/CC is 10 mA/cm2 in 1 M KOH solution, the overpotentials of hydrogen evolution and oxygen evolution are 87 mV and 53.9 mV, respectively, and the Tafel slopes are 122.6 and 262 mV/dec. The electrochemical active area test (ECSA) and the polarization curve test further show that (Ni0.62Co0.35Fe0.03)3Se4/CC has a larger electrochemical active area (34.8 mF/cm2), lower electrolytic potential (0.9 V at 10 mA/cm2) and better stability. Therefore, the novel bifunctional catalyst synthesized by a simple method is a promising candidate for large-scale industrial water electrolysis.
COVID-19 Impact on Diagnosis and Staging of Colorectal Cancer: A Single Tertiary Canadian Oncology Center Experience
Authors: Castonguay Mathias , El Sayed Rola , Richard Corentin , Vachon Marie-France , Nassabein Rami , Charpentier Danielle , Tehfé Mustapha
Published: May 2022

Background: Public health measures have imposed drastic reductions in cancer screening programs at the beginning of the COVID-19 pandemic, with an unknown impact on the diagnosis and staging of colorectal cancer (CRC). Methods: Newly diagnosed CRC cases at the Centre Hospitalier de l’Université de Montréal (CHUM) were divided into two groups according to the timeline: pre-pandemic (1 January 2018–12 March 2020), and pandemic (13 March 2020–30 June 2021) periods. Colonoscopy, surgery, and staging at diagnosis during the pandemic period were compared to the pre-pandemic period. Results: 254 CRC diagnoses were made during the pre-pandemic period in comparison to 125 during the pandemic period. Mean diagnosis rates were lower in the pandemic period (7.8 vs. 9.8 diagnoses/month, p = 0.048). Colonoscopy deadlines were less respected in the pandemic period (51.7% vs. 38.3%, p = 0.049). The rate of elective surgery did not differ (2.9 vs. 3.5 surgeries/month, p = 0.39) and mean delays were similar (58.6 vs. 60.4 days, p = 0.77). Stages at diagnosis did not differ (p = 0.17). Most of the delayed colonoscopies led to a stage 0 or I CRC (p = 0.2). Conclusion: In our center, the COVID-19 pandemic resulted in a decreased rate of CRC diagnosis and increased endoscopic delays without affecting the rate of advanced stage disease. Delays to surgery were quite similar once the CRC diagnosis was established.
Serosurvey of Selected Zoonotic Pathogens in Polar Bears (Ursus maritimus Phipps, 1774) in the Russian Arctic
Authors: Alekseev Alexander Yu. , Boltunov Andrei N. , Derko Anastasiya A. , Sharshov Kirill A. , Adamenko Lyubov S. , Shestopalov Alexander M.
Published: May 2022

Antibodies to several pathogens were detected in the serum samples of nine polar bears (Ursus maritimus, Phipps, 1774) from areas of the Russian Arctic. Plasma was studied for antibodies to sixteen infectious and parasitic diseases using indirect Protein-A ELISA. It is known that when using ELISA, the interaction of antibodies with a heterologous antigen is possible due to immunological crossings between antigens. We investigated the plasma for the presence of antibodies to the major pathogens and for the presence of antibodies to pathogens, for which the cross-immunological reactions to these pathogens are described. For example, antibodies to the pathogens of opisthorchiasis, clonorchiasis, and ascariasis were found simultaneously in four polar bears. Antibodies to both anisakidosis and trichinellosis pathogens were found in six animals. The data obtained may also indicate a joint invasion by these pathogens. Unfortunately, due to the small number of animals sampled, it is impossible to carry out statistical processing of the data.
Over, Under, Sideways and Down: Patterns of Marine Species Richness in Nearshore Habitats off Santa Catalina Island, California
Authors: Ginsburg David W. , Huang Andrew H.
Published: May 2022

Santa Catalina Island, located off the southern California coast, is home to the Blue Cavern Onshore State Marine Conservation Area (SMCA), which is recognized as a marine protected area. Here, we provide an updated species inventory of nearshore macroalgae, seagrasses, bony and cartilaginous fishes and invertebrates documented inside the Blue Cavern Onshore SMCA. Species richness data were compiled using scuba-based visual surveys conducted in the field, references from the primary and gray literature, museum records, unpublished species lists and online resources. The current checklist consists of 1091 marine species from 18 different taxonomic groups, which represents an ~43% increase in species diversity compared to the value reported previously. These data are indicative of the high biodiversity known from the Southern California Bight (SCB) region. The total number of intertidal and subtidal taxa reported represent approximately 85% and 45% of the documented macroalgae and plants, 41% and 24% invertebrates, and 62% and 20% of fishes from Catalina Island and the SCB, respectively. Among the marine taxa documented, 39 species either have undergone a geographic range shift or were introduced as the result of human activities, while another 4 species are listed as threatened, endangered or critically endangered. Research findings presented here offer an important baseline of species richness in the California Channel Islands and will help improve the efforts by resource managers and policy makers to conserve and manage similar habitats in the coastal waters off southern California.
Scar Endometriosis: A Rare Cause of Abdominal Pain
Authors: Nepali Rohit , Upadhyaya Kafle Santosh , Pradhan Tarun , Dhamala Jiba Nath
Published: May 2022

Scar endometriosis or incisional endometriosis is the presence of endometrial tissues with glands in the previous incision or scar. Its overall estimated incidence after post-cesarean and post-hysterectomy is 0.03–0.4% and 1.08–2%, respectively. The patient presents with non-specific symptoms such as cyclical abdominal pain at the site of a previous surgical incision and scar and an abdominal lump with a cyclical increment in size, which is tender. The diagnosis is made only after the surgical excision with confirmation by histopathological analysis. We present the case of a 31-year-old female complaining of cyclical abdominal pain and a lump on the right side of a Pfannenstiel incision for five months. She had undergone two Lower Segment Caesarean Sections (LSCSs); the last surgery was eight months prior. Surgical excision was planned with the corresponding clinical features and radiological data. After the surgical excision, the sample was sent for histopathological examination, and scar endometriosis was diagnosed.
Improved Self-Management in People with Type 1 Diabetes: A Qualitative Study of Sense of Coherence in Daily Life One Year after the First COVID-19 Lockdown in Denmark
Authors: Mikkelsen Kristine Zoëga , Rosholm Anna-Sofie Holtze , Lee Kim , Grabowski Dan
Published: May 2022

During the first lockdown of the COVID-19 pandemic, people with type 1 diabetes (T1D) were worried, stressed, and experienced changes in their self-management practices. Studies found that many had difficulties managing their disease, while others showed improvements. Since the first lockdown, the virus and subsequent lockdowns have become a more regular part of everyday life. The present study investigated how the COVID-19 pandemic, one year after its outbreak, has affected self-management in people with T1D. The dataset consisted of seven semi-structured interviews with adults with T1D, which were interpreted using Antonovsky’s theory of Sense of Coherence (SOC). We found that the pandemic and the ensuing lockdowns had contributed to better self-management in people with T1D, as they had developed a strong SOC. Knowledge from healthcare professionals and their own experiences with the COVID-19 pandemic had caused them to experience stronger comprehensibility, which had been crucial to experiencing strong manageability, enabling them to make active choices to maintain good glycemic control. Furthermore, better opportunities and more motivation had allowed them to experience stronger meaningfulness regarding immersing themselves in their treatment. Our findings show that, during health crises, having a strong SOC is important for disease management among people with T1D.
On The Biophysical Complexity of Brain Dynamics: An Outlook
Authors: Shettigar Nandan , Yang Chun-Lin , Tu Kuang-Chung , Suh C. Steve
Published: May 2022

The human brain is a complex network whose ensemble time evolution is directed by the cumulative interactions of its cellular components, such as neurons and glia cells. Coupled through chemical neurotransmission and receptor activation, these individuals interact with one another to varying degrees by triggering a variety of cellular activity from internal biological reconfigurations to external interactions with other network agents. Consequently, such local dynamic connections mediating the magnitude and direction of influence cells have on one another are highly nonlinear and facilitate, respectively, nonlinear and potentially chaotic multicellular higher-order collaborations. Thus, as a statistical physical system, the nonlinear culmination of local interactions produces complex global emergent network behaviors, enabling the highly dynamical, adaptive, and efficient response of a macroscopic brain network. Microstate reconfigurations are typically facilitated through synaptic and structural plasticity mechanisms that alter the degree of coupling (magnitude of influence) neurons have upon each other, dictating the type of coordinated macrostate emergence in populations of neural cells. These can emerge in the form of local regions of synchronized clusters about a center frequency composed of individual neural cell collaborations as a fundamental form of collective organization. A single mode of synchronization is insufficient for the computational needs of the brain. Thus, as neural components influence one another (cellular components, multiple clusters of synchronous populations, brain nuclei, and even brain regions), different patterns of neural behavior interact with one another to produce an emergent spatiotemporal spectral bandwidth of neural activity corresponding to the dynamical state of the brain network. Furthermore, hierarchical and self-similar structures support these network properties to operate effectively and efficiently. Neuroscience has come a long way since its inception; however, a comprehensive and intuitive understanding of how the brain works is still amiss. It is becoming evident that any singular perspective upon the grandiose biophysical complexity within the brain is inadequate. It is the purpose of this paper to provide an outlook through a multitude of perspectives, including the fundamental biological mechanisms and how these operate within the physical constraints of nature. Upon assessing the state of prior research efforts, in this paper, we identify the path future research effort should pursue to inspire progress in neuroscience.
Migration Potential of Students and Development of Human Capital
Authors: Shutaleva Anna , Martyushev Nikita , Starostin Alexey , Salgiriev Ali , Vlasova Olga , Grinek Anna , Nikonova Zhanna , Savchenko Irina
Published: May 2022

Studying student migration trends is a significant task in studying human capital development as one of the leading factors in sustainable socio-economic development. The migration potential of students impacts the opportunities and prospects for sustainable development. The study of factors influencing the migration behavior of students acquires special significance in this article. The interpersonal competencies of the population impact its migration potential. Migration processes impact the differentiation of regions in terms of human capital. This article is based on theoretical and practical research on human capital, its formation, development, and migration as a factor in human capital development. The practical part of the study presents an analysis of data obtained from a sociological study of the factors that determine internal and international migration. An anonymous sociological survey of students in Ekaterinburg, Kursk, and Tomsk (Russia) was conducted in several stages. The first stage was implemented in October and December 2020 (N = 958). The second stage was implemented in October and November 2021 (N = 960). This study allows for tracing how the COVID-19 pandemic affects the migration potential of students and their desire for a satisfactory career path.
Numerical Solutions of a Differential System Considering a Pure Hybrid Fuzzy Neutral Delay Theory
Authors: Dhandapani Prasantha Bharathi , Thippan Jayakumar , Martin-Barreiro Carlos , Leiva Víctor , Chesneau Christophe
Published: May 2022

In this paper, we propose and derive a new system called pure hybrid fuzzy neutral delay differential equations. We apply the classical fourth-order Runge–Kutta method (RK-4) to solve the proposed system of ordinary differential equations. First, we define the RK-4 method for hybrid fuzzy neutral delay differential equations and then establish the efficiency of this method by utilizing it to solve a particular type of fuzzy neutral delay differential equation. We provide a numerical example to verify the theoretical results. In addition, we compare the RK-4 and Euler solutions with the exact solutions. An error analysis is conducted to assess how much deviation from exactness is found in the two numerical methods. We arrive at the same conclusion for our hybrid fuzzy neutral delay differential system since the RK-4 method outperforms the classical Euler method.
TCP-LoRaD: A Loss Recovery and Differentiation Algorithm for Improving TCP Performance over MANETs in Noisy Channels
Authors: Sarkar Nurul I. , Ho Ping-Huan , Gul Sonia , Zabir Salahuddin Muhammad Salim
Published: May 2022

Mobile Ad hoc Networks (MANETs) are becoming popular technologies because they offer flexibility in setting up anytime and anywhere, and provide communication support on the go. This communication requires the use of Transmission Control Protocol (TCP) which is not originally designed for use in MANET environments; therefore, it raises serious performance issues. To overcome the deficiency of the original TCP, several modifications have been proposed and reported in the networking literature. TCP-WELCOME (Wireless Environment, Link losses, and Congestion packet loss ModEls) is one of the better TCP variants suitable for MANETs. However, it has been found that this protocol has problems with packet losses because of network congestion as it adopts the original congestion control mechanism of TCP New Reno. We also found that TCP-WELCOME does not perform well in noisy channel conditions in wireless environments. In this paper, we propose a novel loss recovery and differentiation algorithm (called TCP-LoRaD) to overcome the above-mentioned TCP problems. We validate the performance of TCP-LoRaD through an extensive simulation setup using Riverbed Modeler (formerly OPNET). Results obtained show that the proposed TCP-LoRaD offers up to 20% higher throughput and about 15% lower end-to-end delays than the TCP-WELCOME in a noisy channel under medium to high traffic loads.
Augmenting Ear Accessories for Facial Gesture Input Using Infrared Distance Sensor Array
Authors: Futami Kyosuke , Oyama Kohei , Murao Kazuya
Published: May 2022

Simple hands-free input methods using ear accessories have been proposed to broaden the range of scenarios in which information devices can be operated without hands. Although many previous studies use canal-type earphones, few studies focused on the following two points: (1) A method applicable to ear accessories other than canal-type earphones. (2) A method enabling various ear accessories with different styles to have the same hands-free input function. To realize these two points, this study proposes a method to recognize the user’s facial gesture using an infrared distance sensor attached to the ear accessory. The proposed method detects skin movement around the ear and face, which differs for each facial expression gesture. We created a prototype system for three ear accessories for the root of the ear, earlobe, and tragus. The evaluation results for nine gestures and 10 subjects showed that the F-value of each device was 0.95 or more, and the F-value of the pattern combining multiple devices was 0.99 or more, which showed the feasibility of the proposed method. Although many ear accessories could not interact with information devices, our findings enable various ear accessories with different styles to have eye-free and hands-free input ability based on facial gestures.
Methodology for Power-Performance Trade-Off Management in Real-Time Embedded Applications
Authors: Popović Ivan , Janković Strahinja
Published: May 2022

An increasing number of battery-powered devices that are used outdoors or in mobile systems put emphasis on the power and energy efficiency as a form of trade-off between application performance and system power consumption. However, lack of objective metrics for the evaluation of application performance degradation poses difficulties for managing such trade-offs in real-time applications. The proposed methodology introduces metrics for modeling of application performance and the technique for its control, enabling more efficient power–performance trade-off management. The methodology allows for selective system performance degradation and fine-grained control of system behavior in the power–performance domain by extending the set of operating point parameters controllable through real-time application. The utilization and the effectiveness of the proposed methodology is evaluated in a simulated environment for different scenarios of the application execution, including system operation above the utilization bounds.
Adaptive NN Control of Electro-Hydraulic System with Full State Constraints
Authors: Jiang Chenyang , Sui Shuai , Tong Shaocheng
Published: May 2022

This paper presents an adaptive neural network (NN) control approach for an electro-hydraulic system. The friction and internal leakage are nonlinear uncertainties, and the states in the considered electro-hydraulic system are fully constrained. In the control design, the NNs are utilized to approximate the nonlinear uncertainties. Then, by constructing barrier Lyapunov functions and based on the adaptive backstepping control design technique, a novel adaptive NN control scheme is formulated. It has been proven that the developed adaptive NN control scheme can sustain the controlled electro-hydraulic system to be stable and make the system output track the desired reference signal. Furthermore, the system states do not surpass the given bounds. The computer simulation results verify the effectiveness of the proposed controller.
Design of the Buck Converter without Inductor Current Sensor
Authors: Chou Hsiao-Hsing , Luo Wen-Hao , Wang San-Fu
Published: May 2022

This paper proposes a novel control scheme for the buck converter without an inductor current sensor. The architecture of the proposed buck converter is simple and suitable for integration and mass production. It employs an output-voltage-measurement method to determine the switch ON time; therefore, the current sensor is not required. The design specification targets the application with a standard battery power source to generate the low voltages for low-power MCU or ASIC. The load current range aims for several hundred milliamps. The proposed control scheme is analyzed and simulated by SIMPLIS. The control scheme, theoretical analysis, circuit realization, contributions, advantages, and simulation results are presented in this paper. Furthermore, the circuit can be fabricated by a 0.35 μm CMOS process.
A Novel Artificial Intelligence Maximum Power Point Tracking Technique for Integrated PV-WT-FC Frameworks
Authors: Khan Mohammad Junaid , Kumar Divesh , Narayan Yogendra , Malik Hasmat , García Márquez Fausto Pedro , Gómez Muñoz Carlos Quiterio
Published: May 2022

The development of each country depends on electricity. In this regard, conventional energy sources, e.g., diesel, petrol, etc., are decaying. Consequently, the investigations of renewable energy sources (RES) are increasing as alternate energy sources for the fulfillment of energy requirements. The output characteristics of RES are becoming non-linear. Therefore, the maximum power point tracking (MPPT) techniques are critical for extracting the maximum power point (MPP) from RES, e.g., photovoltaic (PV) and wind turbines (WT). RES such as the Fuel Cell (FC) has been hailed as one of the major capable RES for automobile applications since they continually create electricity for the dc-link (even if one or both RES are not supplied by solar and wind, the FC will continue to supply to the load). Adaptive Neuro-Fuzzy Inference System (AN-FIS) MPPT for PV, WT, FC, and Hybrid RES is employed in this research article to solve this problem. The high step-ups (boost converters) are connected with PV and FC modules, and the buck converter is connected with the WT framework, to extract the maximum amount of power using MPPT algorithms. The performance of proposed frameworks based on MPPT algorithms is assessed in variable operating conditions such as Solar-Radiation (SR), Wind-Speed (WS), and Hydrogen-Fuel-Rate (HFR). A novel AN-FIS MPPT framework has enhanced the power of Hybrid RES at DC-link, and also reduced the simulation time to reach the MPP when compared to the perturb and observe (P-&-O), Fuzzy-Logic Controller (F-LC), and artificial neural network (AN-N) MPPTs.
Multi-Criteria Optimal Design for FUEL Cell Hybrid Power Sources
Authors: Ceschia Adriano , Azib Toufik , Bethoux Olivier , Alves Francisco
Published: May 2022

This paper presents the development of a global and integrated sizing approach under different performance indexes applied to fuel cell/battery hybrid power systems. The strong coupling between the hardware sizing process and the system supervision (energy management strategy EMS) makes it hard for the design to consider all the possibilities, and today’s methodologies are mostly experience-based approaches that are impervious to technological disruption. With a smart design approach, new technologies are easier to consider, and this approach facilitates the use of new technologies for transport applications with a decision help tool. An automotive application with a hybrid fuel cell (PEMFC)/battery (Li-Ion) is considered to develop this approach. The proposed approach is based on imbricated optimization loops and considers multiple criteria such as the fuel consumption, reliability, and volume of the architecture, in keeping with industry expectations to allow a good trade-off between different performance indexes and explore their design options. This constitutes a low computational time and a very effective support tool that allows limited overconsumption and lifetime reduction for designed architecture in extreme and non-optimal use. We obtain, thanks to this work, a pre-design tool that helps to realize the first conception choice.
Artificial Neural Network-Based Caprock Structural Reliability Analysis for CO2 Injection Site—An Example from Northern North Sea
Authors: Ahmadi Goltapeh Sajjad , Rahman Md Jamilur , Mondol Nazmul Haque , Hellevang Helge
Published: May 2022

In CO2 sequestration projects, assessing caprock structural stability is crucial to assure the success and reliability of the CO2 injection. However, since caprock experimental data are sparse, we applied a Monte Carlo (MC) algorithm to generate stochastic data from the given mean and standard deviation values. The generated data sets were introduced to a neural network (NN), including four hidden layers for classification purposes. The model was then used to evaluate organic-rich Draupne caprock shale failure in the Alpha structure, northern North Sea. The train and test were carried out with 75% and 25% of the input data, respectively. Following that, validation is accomplished with unseen data, yielding promising classification scores. The results show that introducing larger input data sizes to the established NN provides better convergence conditions and higher classification scores. Although the NN can predicts the failure states with a classification score of 97%, the structural reliability was significantly low compare to the failure results estimated using other method. Moreover, this indicated that during evaluating the field-scale caprock failure, more experimental data is needed for a reliable result. However, this study depicts the advantage of machine learning algorithms in geological CO2 storage projects compared with similar finite elements methods in the aspect of short fitting time, high accuracy, and flexibility in processing different input data sizes with different scales.
Thermo-Economic Performance Evaluation of a Conical Solar Concentrating System Using Coil-Based Absorber
Authors: Alsalame Haedr Abdalha Mahmood , Hussain Muhammad Imtiaz , Amjad Waseem , Ali Asma , Lee Gwi Hyun
Published: May 2022

Pollution and the increase in greenhouse gas (GHG) emissions have long been linked to the world’s increasing need for fossil fuels to generate energy. Every day, the energy consumption is increasing; therefore, it is important to improve technologies that use renewable energy sources. With the abundant availability of sustainable energy, solar power is becoming a necessity. However, solar energy has a low energy density and therefore requires a large installation area, which requires heat collection and heat storage technology. Much research is now being done on the conical solar systems to improve efficiency including calculating an optimal cone angle, finding the best flow ratio and the best absorber design, etc. Therefore, in this study, thermal performance of a conical solar collector (CSC) was assessed with a new design of concentric tube absorber (addition of a coil) and compared to the existing circular tube absorber. It was found that 6 L/min flow rate of heating medium (distilled water and CuO nanofluid) gave lower payback period and higher solar fraction of the system in both cases of absorber tube, i.e., without coil and with coil. However, comparatively, thermal efficiency of CSC with coil-based absorber was almost 10–12% higher than conventional system (without coil) regardless of type of heating medium used.
Renewable Electricity Generation in Small Island Developing States: The Effect of Importing Ammonia
Authors: Sagel Victor N. , Rouwenhorst Kevin H. R. , Faria Jimmy A.
Published: May 2022

Recently, we demonstrated for Curaçao that renewable electricity generation from wind combined with energy storage in the form of ammonia is competitive with imported fossil fuels, such as LNG, oil, and coal. In the current work, we have expanded the model by considering imported green ammonia as an alternative to local electricity generation and storage. Local production of ammonia as an energy storage medium was compared with imported ammonia to make up the electricity produced from onshore wind, for Curaçao and Fiji’s largest island Viti Levu. Curaçao and Viti Levu have been selected as two interesting extremes with favorable and non-favorable wind conditions, respectively. Assuming a market price of 500 USD/t NH3, it is found that importing ammonia is the most feasible solution for both islands, with a levelized cost of electricity (LCOE) of 0.11 USD/kWh for Curaçao and 0.37 USD/kWh for Viti Levu. This compares to 0.12 USD/kWh for Curaçao; however, for Viti Levu, this value increases to 1.10 USD/kWh for a completely islanded system based on onshore wind and imported ammonia. These islands represent two extreme cases in terms of wind load factor and load consistency, as Curaçao has a high and consistent wind load factor when compared to Viti Levu. Thus, the conclusions obtained for these locations are expected to be applicable for other small island developing states.
Tell Me More: Automating Emojis Classification for Better Accessibility and Emotional Context Recognition
Authors: Atif Muhammad , Franzoni Valentina
Published: May 2022

Users of web or chat social networks typically use emojis (e.g., smilies, memes, hearts) to convey in their textual interactions the emotions underlying the context of the communication, aiming for better interpretability, especially for short polysemous phrases. Semantic-based context recognition tools, employed in any chat or social network, can directly comprehend text-based emoticons (i.e., emojis created from a combination of symbols and characters) and translate them into audio information (e.g., text-to-speech readers for individuals with vision impairment). On the other hand, for a comprehensive understanding of the semantic context, image-based emojis require image-recognition algorithms. This study aims to explore and compare different classification methods for pictograms, applied to emojis collected from Internet sources. Each emoji is labeled according to the basic Ekman model of six emotional states. The first step involves extraction of emoji features through convolutional neural networks, which are then used to train conventional supervised machine learning classifiers for purposes of comparison. The second experimental step broadens the comparison to deep learning networks. The results reveal that both the conventional and deep learning classification approaches accomplish the goal effectively, with deep transfer learning exhibiting a highly satisfactory performance, as expected.
Somatic Condition and Reproductive Potential as a Tandem in European Sardine: An Analysis with an Environmental Perspective in the Northern Adriatic (Gulf of Trieste)
Authors: Caballero-Huertas Marta , Frigola-Tepe Xènia , Viñas Jordi , Muñoz Marta
Published: May 2022

The European sardine’s condition is reflected in its reproductive potential, and therefore, in its status as a fishery resource. These values depend on the stock’s distribution and resource availability, which is highly determined by environmental characteristics. Sardines from the productive Gulf of Trieste (in the North Adriatic), located in the northernmost section of the most septentrional Mediterranean sub-basin in which sardine exploitation has traditionally been intensive, were analysed. The reproductive cycle and gonadosomatic index (GSI) were studied. Tissue and mesenteric fat values, as well as vacuity (% V), relative condition (Kn), and hepatosomatic (HSI) indices were evaluated due to their potential relationships with reproductive performance. The results suggested opposite patterns between fat reserves and GSI, while Kn showed a relationship neither with GSI, nor with reproductive stage, which led us to conclude that it is more advisable to apply direct lipid indices to project their contribution to reproductive potential. Moreover, the females’ condition was generally better than that of the males, added to an advanced gonadal development during spring and summer, albeit males and females reached the spawning season together. Moreover, females’ GSIs were significantly higher during active spawning. Furthermore, correlation analyses showed that SST was related with the parameters evaluated, as well as the available portion of productivity for the fish (OPFish), which may explain the sardines’ better condition and GSIs than their chlorophyll concentration.
Advances in the Prediction of the Statistical Properties of Wall-Pressure Fluctuations under Turbulent Boundary Layers
Authors: Grasso Gabriele , Roger Michel , Moreau Stéphane
Published: May 2022

Analytical or empirical models of the wall-pressure power spectral density under a turbulent boundary layer are often validated on test cases in an incompressible flow regime. In this work, an analytical model based on the compressible Poisson equation for the unsteady pressure in a turbulent boundary layer is developed. The Large Eddy Simulation of the flow over a controlled-diffusion airfoil at Mach 0.5 is used to validate the assumptions made on the statistical properties of the boundary layer turbulence and to validate the prediction of the statistics of the wall-pressure fluctuations. The predicted wall-pressure spectrum also compares favorably with experimental data.
Quality Characteristics of Substitute Meat Patties Developed Using Aruncus dioicus var. kamtschaticus Hara
Authors: Shin Kyung-Ok , Hwang Hyo-Jeong , Han Kyoung-Sik , Lee Yoo-Jin
Published: May 2022

We developed a vegetable alternative to meat patties using Aruncus dioicus var. kamtschaticus Hara (A. dioicus) and used it to generate basic data for the alternative meat market by comparing nutritional and microbiological components with commercially available vegetable and meat patties. Nutrient analysis, microbiological analysis, chromaticity, and texture analysis were performed on substitute meat patties (SMPs) with A. dioicus and commercially available vegetable and animal patties. Among sugars, the contents of fructose and maltose were respectively high in commercial meat patties (CMPs) and SMPs. SMPs were low in saturated and trans-fat, and high in ω-3 fatty acids. The contents (in descending order) of leucine > phenylalanine > threonine > isoleucine were high in SMPs and commercial vegetable patties (CVPs). Qualitative and quantitative findings of Escherichia coli (E. coli) and Staphylococcus aureus were all negative. Our SMPs had high lightness (L*), low redness (a*), and low yellowness (b*). The hardness, chewiness, and resilience of our SMPs were lower than those of other vegetable and animal patties. Considering our results, the method of manufacturing SMPs developed in the present study allows meat to be flavored without significant nutritional differences compared with commercially available CMPs. Our findings provide a base for studies on future meat alternatives.
In Vitro Study of Probiotic, Antioxidant and Anti-Inflammatory Activities among Indigenous Saccharomyces cerevisiae Strains
Authors: Siesto Gabriella , Pietrafesa Rocchina , Infantino Vittoria , Thanh Channmuny , Pappalardo Ilaria , Romano Patrizia , Capece Angela
Published: May 2022

Nowadays, the interest toward products containing probiotics is growing due to their potential health benefits to the host and the research is focusing on search of new probiotic microorganisms. The present work was focused on the characterization of indigenous Saccharomyces cerevisiae strains, isolated from different food matrixes, with the goal to select strains with probiotic or health-beneficial potential. A preliminary screening performed on fifty S. cerevisiae indigenous strains, in comparison to a commercial probiotic strain, allowed to individuate the most suitable ones for potential probiotic aptitude. Fourteen selected strains were tested for survival ability in the gastrointestinal tract and finally, the strains characterized for the most important probiotic features were analyzed for health-beneficial traits, such as the content of glucan, antioxidant and potential anti-inflammatory activities. Three strains, 4LBI-3, LL-1, TA4-10, showing better attributes compared to the commercial probiotic S.cerevisiae var. boulardii strain, were characterized by interesting health-beneficial traits, such as high content of glucan, high antioxidant and potential anti-inflammatory activities. Our results suggest that some of the tested S. cerevisiae strains have potential as probiotics and candidate for different applications, such as dietary supplements, and starter for the production of functional foods or as probiotic to be used therapeutically.
Dynamics of Physicochemical Properties, Functional Compounds and Antioxidant Capacity during Spontaneous Fermentation of Lycium ruthenicum Murr. (Qinghai–Tibet Plateau) Natural Vinegar
Authors: Gao Qingchao , Song Yangbo , Liang Ying , Li Yahui , Chang Yingjiu , Ma Rong , Cao Xiaohai , Wang Shulin
Published: May 2022

Functional fermented fruit drinks are known worldwide for their health-promoting potential. Black wolfberry (BW) has high nutritional value, and its relative product development can be enriched through fermentation technology, so that its market might be broadened. Total acid, sugars, proteins, enzymes, anthocyanins, flavonoids, polyphenols, organic acids and DPPH free radical scavenging ability (DPPH) were tracked and determined by colorimetric method and HPLC during spontaneous fermentation of BW vinegar. The antioxidant capacity in vitro of BW vinegar was evaluated based on the dynamics of antioxidant contents and DPPH. The results showed that total acid continuously increased during fermentation, yet total sugar and reducing sugar shared a similar decreasing trend. The composition of samples differed in terms of total anthocyanins, total flavonoid, total polyphenol, total protein, superoxide dismutase (SOD), amylase, organic acids and DPPH through spontaneous fermentation. Functional compounds including total polyphenol, total flavonoid and three organic acids (γ-aminobutyric acid, lactic acid and gallic acid) played the main roles in antioxidation. Unexpectedly, SOD and ascorbic acid as antioxidants did not correlate with DPPH, but they were rich in the final products at 754.35 U/mL and 3.39 mg/mL, respectively. Generally, the quality of BW vinegar has been improved based on analyzing dynamics on functional compounds, organic acids and antioxidant capacity, which proves that BW vinegar obtained by spontaneous fermentation should be a potential source of fermented food with antioxidant effects for consumers.
Gamma-Ray Bursts Afterglow Physics and the VHE Domain
Authors: Miceli Davide , Nava Lara
Published: May 2022

Afterglow radiation in gamma-ray bursts (GRB), extending from the radio band to GeV energies, is produced as a result of the interaction between the relativistic jet and the ambient medium. Although in general the origin of the emission is robustly identified as synchrotron radiation from the shock-accelerated electrons, many aspects remain poorly constrained, such as the role of inverse Compton emission, the particle acceleration mechanism, the properties of the environment and of the GRB jet itself. The extension of the afterglow emission into the TeV band has been discussed and theorized for years, but has eluded for a long time the observations. Recently, the Cherenkov telescopes, MAGIC and H.E.S.S., have unequivocally proven that afterglow radiation is also produced above 100 GeV, up to at least a few TeV. The accessibility of the TeV spectral window will largely improve with the upcoming facility CTA (the Cherenkov Telescope Array). In this review article, we first revise the current model for afterglow emission in GRBs, its limitations and open issues. Then, we describe the recent detections of very high energy emission from GRBs and the origin of this radiation. Implications on the understanding of afterglow radiation and constraints on the physics of the involved processes will be deeply investigated, demonstrating how future observations, especially by the CTA Observatory, are expected to give a key contribution in improving our comprehension of such elusive sources.