bluuebunny/crossref_metadata_2025 huggingface dataset:
Start-Up of a Solid Oxide Fuel Cell System with a View to Materials Science-Related Aspects, Control and Thermo-Mechanical Stresses
Authors: Eichhorn Colombo Konrad W. , Kharton Vladislav V.
Published: June 2021

The start-up of a solid oxide fuel cell (SOFC) is investigated by means of numerical simulation with a view to material and operational constraints on a component and system level, as well as thermo-mechanical stresses. The applied multi-physics modeling approach couples thermal-, electrochemical, chemical-, and thermo-mechanical phenomena. In addition to constraints, emphasis is given to degrees of freedom with respect to manipulated and controlled variables of the system. Proper ramping during the start-up procedure keeps critical parameter values within a safe regime. Of particular interest are gradient in terms of temperature and chemical concentrations. Nevertheless, simulations show that thermo-mechanical stresses are relatively high during the initial start-up phase, the system is, thus, more susceptible to failure. The combination of multi-physics modeling in conjunction with practical control aspects for start-up of an SOFC, which is presented in this paper, is important for applications.
Study on the Reliability of Sn–Bi Composite Solder Pastes with Thermosetting Epoxy under Thermal Cycling and Humidity Treatment
Authors: Liu Lu , Xue Songbai , Ni Ruiyang , Zhang Peng , Wu Jie
Published: June 2021

In this study, a Sn–Bi composite solder paste with thermosetting epoxy (TSEP Sn–Bi) was prepared by mixing Sn–Bi solder powder, flux, and epoxy system. The melting characteristics of the Sn–Bi solder alloy and the curing reaction of the epoxy system were measured by differential scanning calorimeter (DSC). A reflow profile was optimized based on the Sn–Bi reflow profile, and the Organic Solderability Preservative (OSP) Cu pad mounted 0603 chip resistor was chosen to reflow soldering and to prepare samples of the corresponding joint. The high temperature and humidity reliability of the solder joints at 85 °C/85% RH (Relative Humidity) for 1000 h and the thermal cycle reliability of the solder joints from −40 °C to 125 °C for 1000 cycles were investigated. Compared to the Sn–Bi solder joint, the TSEP Sn–Bi solder joints had increased reliability. The microstructure observation shows that the epoxy resin curing process did not affect the transformation of the microstructure. The shear force of the TSEP Sn–Bi solder joints after 1000 cycles of thermal cycling test was 1.23–1.35 times higher than the Sn–Bi solder joint and after 1000 h of temperature and humidity tests was 1.14–1.27 times higher than the Sn–Bi solder joint. The fracture analysis indicated that the cured cover layer could still have a mechanical reinforcement to the TSEP Sn–Bi solder joints after these reliability tests.
Local Chemotherapy as an Adjuvant Treatment in Unresectable Squamous Cell Carcinoma: What Do We Know So Far?
Authors: Bennardo Luigi , Bennardo Francesco , Giudice Amerigo , Passante Maria , Dastoli Stefano , Morrone Pietro , Provenzano Eugenio , Patruno Cataldo , Nisticò Steven Paul
Published: June 2021

Background: Squamous cell carcinoma (SCC) is one of the most common cancers involving skin and oral mucosa. Although this condition’s gold-standard treatment is the surgical removal of the lesions, the physician must propose alternative treatments in some cases due to the patient’s ineligibility for surgery. Among the available alternative therapies, local chemotherapy may represent an initial treatment in combination with radiotherapy or systemic chemotherapy due to the low frequency of side-effects and the lack of necessity for expensive devices. Methods: In this paper, we review all available literature in various databases (PubMed, Scopus-Embase, Web of Science), proposing local chemotherapy as a treatment for cutaneous and oral SCC. Exclusion criteria included ocular lesions (where topical treatments are common), non-English language, and non-human studies. Results: We included 14 studies in this review. The majority were case reports and case series describing the treatment of non-resectable localized SCC with either imiquimod or 5-fluorouracil. We also analyzed small studies proposing combination treatments. Almost all studies reported an excellent clinical outcome, with a low risk of relapses in time. Conclusions: Resection of the lesion remains the gold-standard treatment for SCC. When this approach is not feasible, local chemotherapy may represent a treatment alternative, and it may also be associated with radiotherapy or systemic chemotherapy.
Coverage Increases of Porites astreoides in Grenada Determined by Shifts in Size-Frequency Distribution
Authors: Eagleson Ryan G. , Lumsden John S. , Álvarez-Filip Lorenzo , Herbinger Christophe M. , Horricks Ryan A.
Published: June 2021

Despite coral community collapse, the mustard hill coral (Porites astreoides) is a species currently experiencing success throughout the Caribbean. The inshore reefs of Grenada were selected to study the influence of benthic factors on the abundance, size, and coverage of P. astreoides colonies. Surveys of reef communities along established 30 m transects were conducted at eight sites in 2014 and 2017 using a 0.5 m² quadrat. Coral Point Count was used to annotate the images, estimating the coverage of scleractinian corals, sponges, algae, and benthic substrates. Coverage, size, and abundance of P. astreoides colonies were quantified using the area measurement tool in ImageJ standardized against the quadrats. There were significant differences in benthic community assemblages between islands, selected sites, and between years. From 2014 to 2017 there was a significant decrease in the mean abundance of P. astreoides colonies and significant increases in mean colony size and coverage. The presence of P. astreoides colonies was significantly correlated with: rubble (−), sand (−); pavement (+); macroalgae (−); coralline algae (+); sponges (varying response); gorgonians (−); massive corals (+); and branching corals (−). P. astreoides follows similar recruitment patterns as other scleractinian corals. Observed changes in P. astreoides populations appear to indicate a recovery event following a disturbance, potentially tropical storm Chantal in 2013.
Of Necks, Trunks and Tails: Axial Skeletal Diversity among Vertebrates
Authors: Mallo Moisés
Published: June 2021

The axial skeleton of all vertebrates is composed of individual units known as vertebrae. Each vertebra has individual anatomical attributes, yet they can be classified in five different groups, namely cervical, thoracic, lumbar, sacral and caudal, according to shared characteristics and their association with specific body areas. Variations in vertebral number, size, morphological features and their distribution amongst the different regions of the vertebral column are a major source of the anatomical diversity observed among vertebrates. In this review I will discuss the impact of those variations on the anatomy of different vertebrate species and provide insights into the genetic origin of some remarkable morphological traits that often serve to classify phylogenetic branches or individual species, like the long trunks of snakes or the long necks of giraffes.
Performance of Integrated Near-Infrared Spectroscopy and Intravascular Ultrasound (NIRS-IVUS) System against Quantitative Flow Ratio (QFR)
Authors: Dobrolińska Magdalena M. , Gąsior Paweł M. , Pociask Elżbieta , Smolka Grzegorz , Ochala Andrzej , Wojakowski Wojciech , Roleder Tomasz
Published: June 2021

Quantitative flow ratio (QFR) is a new opportunity to analyze functional stenosis during invasive coronary angiography. Together with a well-known intravascular ultrasound (IVUS) and a new player in the field, near-infrared spectroscopy (NIRS), it is gaining a lot of interest. The aim of the study was to compare QFR results with integrated IVUS-NIRS results acquired simultaneously in the same coronary lesion. We retrospectively enrolled 66 patients in whom 66 coronary lesions were assessed by NIRS-IVUS and QFR. Lesions were divided into two groups based on QFR results as QFR-positive group (QFR ≤ 0.8) or QFR-negative group (QFR > 0.8). Based on ROC curve analysis, the best cut-off values of minimal lumen area (MLA), minimal lumen diameter (MLD) and percent diameter stenosis for predicting QFR ≤ 80 were 2.4 (AUC 0.733, 95%CI 0.61, 0.834), 1.6 (AUC 0.768, 95%CI 0.634, 0.872) and 59.5 (AUC 0.918, 95%CI 0.824, 0.971), respectively. In QFR-positive lesions, the maxLCBI4mm was significantly higher than in QFR-negative lesions (450.12 ± 251.0 vs. 329.47 ± 191.14, p = 0.046). The major finding of the present study is that values of IVUS-MLA, IVUS-MLD and percent diameter stenosis show a good efficiency in predicting QFR ≤ 0.80. Moreover, QFR-positive lesions are characterized by higher maxLCBI4mm as compared to the QFR-negative group.
HHV8-Positive Castleman Disease and In Situ Mantle Cell Neoplasia within Dermatopathic Lymphadenitis, in Longstanding Psoriasis
Authors: Zanelli Magda , Stingeni Luca , Zizzo Maurizio , Martino Giovanni , Sanguedolce Francesca , Marra Andrea , Crescenzi Barbara , Pileri Stefano A. , Ascani Stefano
Published: June 2021

A 73-year-old man presented with multiple lymphadenopathy. He had a 20-year history of palmoplantar psoriasis evolved to a diffuse erythrodermic picture in the last two years. Topic and systemic medications including prednisolone, acitretin, anti-IL17 (ixekizumab), TNF inhibitor (adalimumab), anti-IL23 (guselkumab), methotrexate, cyclosporine, and phosphodiesterase 4 inhibitor (apremilast) were ineffective. Repeated skin biopsies excluded mycosis fungoides, confirming psoriasis; molecular analysis of T-cell receptor genes ruled out clonality. The axillary lymph node histology documented a dermatopathic lymphadenitis, often associated with chronic cutaneous inflammatory diseases. At an accurate morphological evaluation, features of HHV8-positive multicentric Castleman disease were observed. Moreover, in a few follicles, in situ mantle cell neoplasia was identified. The translocation t(11;14)(q13;q32), characteristic of mantle cell lymphoma, and the monoclonal IGH gene rearrangement were present. HHV8 DNA was identified on plasma sample. Multicentric Castleman disease in psoriatic patients is a rare event and it might be favored by the immunomodulatory treatment in longstanding psoriasis. Multicentric Castleman disease patients are predisposed to developing simultaneous or subsequent lymphoma. In situ mantle cell neoplasia often behaves indolently, although it may progress to overt mantle cell lymphoma. Rituximab achieved a good control of psoriasis. Unfortunately, the patient developed Staphylococcus aureus sepsis for which he is currently on antibiotic therapy.
The Effect of HbA1c Variability as a Risk Measure for Microangiopathy in Type 1 Diabetes Mellitus
Authors: Romero-Aroca Pedro , Navarro-Gil Raul , Feliu Albert , Valls Aida , Moreno Antonio , Baget-Bernaldiz Marc
Published: June 2021

Background: To measure the relationship between variability in HbA1c and microalbuminuria (MA) and diabetic retinopathy (DR) in the long term. Methods: A prospective case-series study, was conducted on 366 Type 1 Diabetes Mellitus patients with normoalbuminuria and without diabetic retinopathy at inclusion. The cohort was followed for a period of 12 years. The Cox survival analysis was used for the multivariate statistical study. The effect of variability in microangiopathy (retinopathy and nephropathy) was evaluated by calculating the standard deviation of HbA1c (SD-HbA1c), the coefficient of variation of HbA1c (CV-HbA1c), average real variability (ARV-HbA1c) and variability irrespective of the mean (VIM-HbA1c) adjusted for the other known variables. Results: A total of 106 patients developed diabetic retinopathy (29%) and 73 microalbuminuria (19.9%). Overt diabetic nephropathy, by our definition, affected only five patients (1.36%). Statistical results show that the current age, mean HbA1c, SD-HbA1c and ARV-HbA1c are significant in the development of diabetic retinopathy. Microalbuminuria was significant for current age, mean HbA1c, CV-HbA1c and ARV-HbA1c. Conclusions: By measuring the variability in HbA1c, we can use SD-HbA1c and ARV-HbA1c as possible targets for judging which patients are at risk of developing DR and MA, and CV-HbA1c as the target for severe DR.
Microperimetry-Assessed Functional Alterations and OCT-Changes in Patients after Retinal Detachment Surgery Using Pars Plana Vitrectomy and SF6 Tamponade
Authors: Díaz-Barreda María D. , Bartolomé-Sesé Isabel , Boned-Murillo Ana , Ferreras Antonio , Orduna-Hospital Elvira , Ascaso Francisco J. , Pinilla Isabel
Published: June 2021

Background: We study the retinal function measured by macular integrity assessment microperimetry (MAIA) and structural changes assessed by scanning swept source optical coherence tomography (SS-OCT) between healthy individuals and patients undergoing pars plana vitrectomy (PPV) after rhegmatogenous retinal detachment (RRD). Methods: Cross-sectional study. Early Treatment Diabetic Retinopathy Study (ETDRS) grids were measured by SS-OCT and compared with the MAIA parameters. Results: Thirty-eight eyes with RRD (19 macula-on and 19 macula-off) were compared with 113 healthy eyes. The retinal sensitivity and average total threshold were reduced in all sectors in the RRD group; macular integrity index was increased. Macular thicknesses in total retina and ganglion cell layer (GCL)++ protocols were higher in the RRD group in nasal outer (NO) and central (C) sectors and only in C sector for GCL+ protocol. Thicknesses were lower in total retina, GCL++ protocols in the temporal outer (TO) sector and in the GCL+ protocol in NO sector. Best-corrected visual acuity (BCVA) correlated moderately with retinal sensitivity in all sectors and in just several sectors with time between the date of surgery and the test. The central nasal (CN) sector thickness and the average total threshold were higher in the macula-on subgroup. Conclusions: RRD and subsequent surgery results in functional and structural changes, especially in individuals with macular detachment.
Post-Mortem Detection of SARS-CoV-2 RNA in Long-Buried Lung Samples
Authors: Musso Nicolò , Falzone Luca , Stracquadanio Stefano , Bongiorno Dafne , Salerno Monica , Esposito Massimiliano , Sessa Francesco , Libra Massimo , Stefani Stefania , Pomara Cristoforo
Published: June 2021

The Coronavirus Disease 19 (COVID-19) pandemic has caused an unexpected death toll worldwide. Even though several guidelines for the management of infectious corpses have been proposed, the limited number of post-mortem analyses during the pandemic has led to inaccuracies in the counting of COVID-19 deaths and contributed to a lack of important information about the pathophysiology of the SARS-CoV-2 infection. Due to the impossibility of carrying out autopsies on all corpses, the scientific community has raised the question of whether confirmatory analyses could be performed on exhumed bodies after a long period of burial to assess the presence of SARS-CoV-2 RNA. Post-mortem lung samples were collected from 16 patients who died from COVID-19 infection and were buried for a long period of time. A custom RNA extraction protocol was developed to enhance extraction of viral RNA from degraded samples and highly sensitive molecular methods, including RT-qPCR and droplet digital PCR (ddPCR), were used to detect the presence of SARS-CoV-2 RNA. The custom extraction protocol developed allowed us to extract total RNA effectively from all lung samples collected. SARS-CoV-2 viral RNA was effectively detected in all samples by both RT-qPCR and ddPCR, regardless of the length of burial. ddPCR results confirmed the persistence of the virus in this anatomical niche and revealed high viral loads in some lung samples, suggesting active infection at the time of death. To the best of our knowledge, this is the first study to demonstrate the persistence of SARS-CoV-2 viral RNA in the lung even after a long post-mortem interval (up to 78 days). The extraction protocol herein described, and the highly sensitive molecular analyses performed, could represent the standard procedures for SARS-CoV-2 detection in degraded lung specimens. Finally, the innovative results obtained encourage post-mortem confirmatory analyses even after a long post-mortem interval.
Influence of Anatomical Parameters on the Dimensions of the Subantral Space and Sinus Mucosa Thickening after Sinus Floor Elevation. A Retrospective Cone Beam Computed Tomography Study
Authors: Omori Yuki , Nakajima Yasushi , Imai Hideki , Yonezawa Daichi , Ferri Mauro , Apaza Alccayhuaman Karol Alí , Botticelli Daniele
Published: June 2021

Background: Various anatomical parameters might influence the surgical approach for maxillary sinus floor elevation. The objective of the present study was to retrospectively evaluate the influence of anatomical parameters on the dimensions of the subantral space and of the sinus mucosa thickening after sinus floor elevation. Material and Methods: Seventy-eight maxillary sinuses in sixty-five patients were evaluated on cone beam computed tomographies taken before surgery and after one week (t1w) and nine months (t9m). Several parameters such as the distance XF between an axis parallel to the base of the nose (X-axes) and the sinus floor (F) were correlated with the height gain (IF) at t1w and t9m and the post-surgical edema. Results: A weak significant positive correlation was observed between height gain vs. sinus height of interest (XF), the balcony, and the sinus floor angle. The post-surgical edema was influenced by the initial mucosa thickness and the xenograft used. Conclusions: Various parameters might affect height gain and sinus mucosa thickening after sinus floor elevation. The height of interest, the balcony, and the sinus floor angle showed significant correlations with height gain. The initial thickness of the mucosa and the biomaterial used influenced the post-surgical edema.
Accuracy-Risk Trade-Off Due to Social Learning in Crowd-Sourced Financial Predictions
Authors: Adjodah Dhaval , Leng Yan , Chong Shi Kai , Krafft P. M. , Moro Esteban , Pentland Alex
Published: June 2021

A critical question relevant to the increasing importance of crowd-sourced-based finance is how to optimize collective information processing and decision-making. Here, we investigate an often under-studied aspect of the performance of online traders: beyond focusing on just accuracy, what gives rise to the trade-off between risk and accuracy at the collective level? Answers to this question will lead to designing and deploying more effective crowd-sourced financial platforms and to minimizing issues stemming from risk such as implied volatility. To investigate this trade-off, we conducted a large online Wisdom of the Crowd study where 2037 participants predicted the prices of real financial assets (S&P 500, WTI Oil and Gold prices). Using the data collected, we modeled the belief update process of participants using models inspired by Bayesian models of cognition. We show that subsets of predictions chosen based on their belief update strategies lie on a Pareto frontier between accuracy and risk, mediated by social learning. We also observe that social learning led to superior accuracy during one of our rounds that occurred during the high market uncertainty of the Brexit vote.
Improving Heterogeneous Network Knowledge Transfer Based on the Principle of Generative Adversarial
Authors: Lei Feifei , Cheng Jieren , Yang Yue , Tang Xiangyan , Sheng Victor S. , Huang Chunzao
Published: June 2021

Deep learning requires a large amount of datasets to train deep neural network models for specific tasks, and thus training of a new model is a very costly task. Research on transfer networks used to reduce training costs will be the next turning point in deep learning research. The use of source task models to help reduce the training costs of the target task models, especially heterogeneous systems, is a problem we are studying. In order to quickly obtain an excellent target task model driven by the source task model, we propose a novel transfer learning approach. The model linearly transforms the feature mapping of the target domain and increases the weight value for feature matching to realize the knowledge transfer between heterogeneous networks and add a domain discriminator based on the principle of generative adversarial to speed up feature mapping and learning. Most importantly, this paper proposes a new objective function optimization scheme to complete the model training. It successfully combines the generative adversarial network with the weight feature matching method to ensure that the target model learns the most beneficial features from the source domain for its task. Compared with the previous transfer algorithm, our training results are excellent under the same benchmark for image recognition tasks.
Viewing Direction Based LSB Data Hiding in 360° Videos
Authors: Tran Dang Ninh , Zepernick Hans-Jürgen , Chu Thi My Chinh
Published: June 2021

In this paper, we propose a viewing direction based least significant bit (LSB) data hiding method for 360° videos. The distributions of viewing direction frequency for latitude and longitude are used to control the amount of secret data to be hidden at the latitude, longitude, or both latitude and longitude of 360° videos. Normalized Gaussian mixture models mimicking the viewing behavior of humans are formulated to define data hiding weight functions for latitude, longitude, and both latitude and longitude. On this basis, analytical expressions for the capacity offered by the proposed method to hide secret data in 360° cover videos are derived. Numerical results for the capacity using different numbers of bit planes and popular 360° video resolutions for data hiding are provided. The fidelity of the proposed method is assessed in terms of the peak signal-to-noise ratio (PSNR), weighted-to-spherically uniform PSNR (WS-PSNR), and non-content-based perceptual PSNR (NCP-PSNR). The experimental results illustrate that NCP-PSNR returns the highest fidelity because it gives lower weights to the impact of LSB data hiding on fidelity outside the front regions near the equator. The visual quality of the proposed method as perceived by humans is assessed using the structural similarity (SSIM) index and the non-content-based perceptual SSIM (NCP-SSIM) index. The experimental results show that both SSIM-based metrics are able to account for the spatial perceptual information of different scenes while the PSNR-based fidelity metrics cannot exploit this information. Furthermore, NCP-SSIM reflects much better the impact of the proposed method on visual quality with respect to viewing directions compared to SSIM.
Noise2Noise Improved by Trainable Wavelet Coefficients for PET Denoising
Authors: Kang Seung-Kwan , Yie Si-Young , Lee Jae-Sung
Published: June 2021

The significant statistical noise and limited spatial resolution of positron emission tomography (PET) data in sinogram space results in the degradation of the quality and accuracy of reconstructed images. Although high-dose radiotracers and long acquisition times improve the PET image quality, the patients’ radiation exposure increases and the patient is more likely to move during the PET scan. Recently, various data-driven techniques based on supervised deep neural network learning have made remarkable progress in reducing noise in images. However, these conventional techniques require clean target images that are of limited availability for PET denoising. Therefore, in this study, we utilized the Noise2Noise framework, which requires only noisy image pairs for network training, to reduce the noise in the PET images. A trainable wavelet transform was proposed to improve the performance of the network. The proposed network was fed wavelet-decomposed images consisting of low- and high-pass components. The inverse wavelet transforms of the network output produced denoised images. The proposed Noise2Noise filter with wavelet transforms outperforms the original Noise2Noise method in the suppression of artefacts and preservation of abnormal uptakes. The quantitative analysis of the simulated PET uptake confirms the improved performance of the proposed method compared with the original Noise2Noise technique. In the clinical data, 10 s images filtered with Noise2Noise are virtually equivalent to 300 s images filtered with a 6 mm Gaussian filter. The incorporation of wavelet transforms in Noise2Noise network training results in the improvement of the image contrast. In conclusion, the performance of Noise2Noise filtering for PET images was improved by incorporating the trainable wavelet transform in the self-supervised deep learning framework.
On the Improvement of the Isolation Forest Algorithm for Outlier Detection with Streaming Data
Authors: Heigl Michael , Anand Kumar Ashutosh , Urmann Andreas , Fiala Dalibor , Schramm Martin , Hable Robert
Published: June 2021

In recent years, detecting anomalies in real-world computer networks has become a more and more challenging task due to the steady increase of high-volume, high-speed and high-dimensional streaming data, for which ground truth information is not available. Efficient detection schemes applied on networked embedded devices need to be fast and memory-constrained, and must be capable of dealing with concept drifts when they occur. Different approaches for unsupervised online outlier detection have been designed to deal with these circumstances in order to reliably detect malicious activity. In this paper, we introduce a novel framework called PCB-iForest, which generalized, is able to incorporate any ensemble-based online OD method to function on streaming data. Carefully engineered requirements are compared to the most popular state-of-the-art online methods with an in-depth focus on variants based on the widely accepted isolation forest algorithm, thereby highlighting the lack of a flexible and efficient solution which is satisfied by PCB-iForest. Therefore, we integrate two variants into PCB-iForest—an isolation forest improvement called extended isolation forest and a classic isolation forest variant equipped with the functionality to score features according to their contributions to a sample’s anomalousness. Extensive experiments were performed on 23 different multi-disciplinary and security-related real-world datasets in order to comprehensively evaluate the performance of our implementation compared with off-the-shelf methods. The discussion of results, including AUC, F1 score and averaged execution time metric, shows that PCB-iForest clearly outperformed the state-of-the-art competitors in 61% of cases and even achieved more promising results in terms of the tradeoff between classification and computational costs.
The Impact of Energy Storage along with the Allocation of RES on the Reduction of Energy Costs Using MILP
Authors: Andrychowicz Mateusz
Published: June 2021

The paper shows a method of optimizing local initiatives in the energy sector, such as energy cooperatives and energy clusters. The aim of optimization is to determine the structure of generation sources and energy storage in order to minimize energy costs. The analysis is carried out for the time horizon of one year, with an hourly increment, taking into account various RES (wind turbines (WT), photovoltaic installations (PV), and biogas power plant (BG)) and loads (residential, commercial, and industrial). Generation sources and loads are characterized by generation/demand profiles in order to take into account their variability. The optimization was carried out taking into account the technical aspects of the operation of distribution systems, such as power flows and losses, voltage levels in nodes, and power exchange with the transmission system, and economic aspects, such as capital and fixed and variable operating costs. The method was calculated by sixteen simulation scenarios using Mixed-Integer Linear Programming (MILP).
Effect of Molybdenum Disulfide on the Performance of Polyaniline Based Counter Electrode for Dye-Sensitized Solar Cell Applications
Authors: Ghafoor Usman , Aqeel Anas Bin , Zaman Uzair Khaleeq uz , Zahid Taiba , Noman Muhammad , Ahmad Muhammad Shakeel
Published: June 2021

Dye-sensitized solar cells are gaining interest in the aerospace industry, extending their applications from solar-powered drones to origami-style space-based solar power stations due to their flexibility, light weightiness, and transparency. The major issue with its widespread commercial use is the employment of expensive Pt-based counter electrodes. In this study, an attempt has been made to replace the Pt with Polyaniline (PANI)/Molybdenum sulfide (MoS2) nanocomposite. The nanocomposites i.e., PANI-0.5wt% MoS2, PANI-2wt%MoS2, PANI-5wt%MoS2, and PANI-7wt%MoS2and PANI-9wt%MoS2, have been synthesized and compared with standard Pt-based CE. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction methods have been utilized to study both surface morphology and structural composition. Fourier transform infrared has also been used to identify redox-active functionalities. Electron impedance spectroscopy and cyclic voltammetry have been employed to study electron transfer and catalytic activity. Finally, I-V testing has been conducted using a sun simulator. A maximum efficiency of 8.12% has been observed with 7wt% MoS2 in the PANI matrix at 6 µm thickness, which is 2.65% higher compared to standard Pt-based CE (7.91%). This is due to high electronic conduction with the addition of MoS2, improved catalytic activity, and the high surface area of the PANI nano-rods.
Emission Mitigation and Energy Security Trade-Off: Role of Natural Gas in the Indian Power Sector
Authors: Das Nandini , Dasgupta Shyamasree , Roy Joyashree , Langhelle Oluf , Assadi Mohsen
Published: June 2021

India’s Nationally Determined Contributions (NDC) aim to increase the share of non-fossil fuel, especially renewables, in power generation. But at the same time, it mentions that coal is likely to dominate the power generation in the short and medium term to meet the increase in demand and support the intermittency of renewable energy-based power generation. Thus, additional efforts to transform the thermal power generation to a more efficient and less emitting one in the near term by increasing the use of natural gas (a fossil fuel with a lower emission factor than coal) may be planned towards achieving India’s additional mitigation commitments. The paper presents the implications of a proposed increase in the share of natural gas in thermal power generation of India by looking into the trade-off between emission mitigation and energy security. Along with a Reference Scenario, three alternative emission scenarios are proposed to understand the likely impacts of increased penetration of natural gas in power generation on India’s projected emission profile up to 2050. Results suggest that higher mitigation potential can be achieved through fuel-switch in thermal generation and technological up-gradation to enhance energy use efficiency. The energy security due to the increased share of natural gas imports can be dealt with by diversifying import sources. Shifts can achieve this in the emphasis on long-term contracts.
Evaluation of Model Calibration Method for Simulation Performance of a Public Hospital in Brazil
Authors: da Silva Pedro Paulo Fernandes , Neto Alberto Hernandez , Sauer Ildo Luis
Published: June 2021

This work presents an extensive study on methodologies to calibrate electric energy consumption in buildings. A comparison between several calibration methodologies shows different approaches addressing the same issue, suggesting a lack of a unique methodology that is reproducible for every building. Additionally, no methodology fits the Brazilian public context, such as the predominance of Unitary Air Conditioning Systems (UACS) and buildings which have operated for more than 30 years. A new calibration methodology for performance simulation is proposed to deal with such features. The methodology is separated into two evidence-based steps according to the size of the Heating, Ventilation and Air Conditioning (HVAC) systems used to control buildings’ indoor environments: the first step is dedicated to calibrating medium- and large-sized HVAC systems, and the second step is dedicated to calibrating small-sized HVAC systems. University Hospital of University of São Paulo (UH-USP) is used as a test bed to implement the proposed methodology. Accuracy indicators show the efficiency of the methodology in terms of calibrating a simulation of the whole UH-USP building and Chilled Water Plant on a monthly basis in terms of accuracy and the time needed to perform the calibration. However, regarding simulation of UACS, the application of the methodology was inconclusive. This study leaves open the question of the trade-off between increasing model outcome accuracy and the strictness of accuracy indicators applied to UACS and poorly automated large-sized air conditioners.
Numerical Modeling of Sublimation of Ammonium Carbamate Applied to Supply System of NOx Reductant
Authors: Woo Sang-Hee , Noh Jung-Hun , Raza Hassan , Kim Hongsuk
Published: June 2021

Recently, ammonium carbamate (AC) has attracted attention as a substitute for urea, which is a commonly used reductant for NOx emitted from combustion engines. The AC exists as a solid at room temperature, and it is decomposed to NH3 and CO2 gases by heating. Therefore, adequate heat transfer is an essential issue in the design of AC pyrolysis reactor. In this study, a numerical model that describes the sublimation of AC was developed. For modeling, this study considered the three different calculation zones: solid-phase zone, gas-phase zone, and sublimation zone. Additionally, during the sublimation process, collapse of upper solid AC into the hollow space below by the effect of gravity is considered. As a result, it is presented that the modeling shows reasonable information about the AC sublimation in a reactor, such as temperatures in a reactor, pressure of reactor, and flow rate of sublimated gas. However, it is also found that accurate prediction of spatial temperature distribution is challenging because it is related to the accurate prediction of the internal shape of AC and its collapse in a reactor.
Numerical Simulation of Elbow Erosion in Shale Gas Fields under Gas-Solid Two-Phase Flow
Authors: Hong Bingyuan , Li Xiaoping , Li Yanbo , Li Yu , Yu Yafeng , Wang Yumo , Gong Jing , Ai Dihui
Published: June 2021

Erosion is one of the most common forms of material failure and equipment damage in gas transmission pipelines. Shale gas fields use hydraulic fracturing whereby solid particles are often carried in the gas flow, and the pipeline is in a high-pressure state, which is more likely to cause erosion. The prediction of particle erosion regulation in gas-solid two-phase flow is an effective means to ensure the safe operation of shale gas fields. In this paper, an integrated CFD-DPM model is established to investigate the erosion of 90° elbow in a shale gas field under gas-solid two-phase flow, employing the realizable k-ε turbulence model, discrete phase model, and erosion rate prediction model. The reliability of the proposed numerical models is verified by comparing the predicted data with the experimental data. Moreover, the effects of six important factors on maximum erosion rate are analyzed, including gas velocity, mass flow rate of sand particles, particle diameter, shape coefficient of sand particles, pipeline diameter, elbow radius of curvature. Specifically, the results indicate that the gas velocity, mass flow rate and shape coefficient of sand particles are positively correlated with the maximum erosion rate, while the pipe diameter and the elbow radius of curvature are negatively correlated with the maximum erosion rate. A new correlation was developed, which included four dimensionless groups, namely Reynolds number, diameter ratio, density ratio and particle number. The correlation can be used to predict maximum corrosion rate of elbows. This work can provide data reference and theoretical basis for mitigating the erosion rate of pipelines and managing the integrity of gas pipelines.
The Impact of Atmospheric Precipitation on Wastewater Volume Flowing into the Wastewater Treatment Plant in Nowy Targ (Poland) in Terms of Treatment Costs
Authors: Bugajski Piotr , Nowobilska-Majewska Elwira , Majewski Michał
Published: June 2021

This study determined the influence of precipitation occurring in the sewerage catchment basin in Nowy Targ (Poland) on the amount of wastewater inflow to the wastewater treatment plant, and determined the costs resulting from the treatment of accidental (rain) water entering the analyzed sewerage system. The research was conducted from 2016 to 2019, for which daily precipitation and average daily wastewater inflows in the so-called dry, normal, and very wet periods were analyzed. The research period was divided into six characteristic intervals in terms of precipitation. It was found that, on days with different precipitation intensity, the amount of accidental water as a proportion of the total amount of wastewater flowing into the plant ranges from 9.6% to 34.1%. The annual costs incurred by the operator resulting from the environmental fee are 1625.8 EUR/year. Alternatively, the costs resulting from financial expenditures for wastewater treatment processes amount to 337,651 EUR/year. The results of the research provide important information for sewage network operators to take effective actions to eliminate illegal connections of roof gutters and/or yard inlets to the sanitary collectors, and to replace the combined sewage system in Nowy Targ with a distributed sewerage system. This would reduce the costs of wastewater treatment and the irregularity of wastewater inflow.
The COVID-19 Pandemic in Brazil: Some Aspects and Tools
Authors: Marinho Pedro Rafael D. , Cordeiro Gauss M. , Coelho Hemilio Fernandes C. , Cabral Poliana C.
Published: June 2021

The article presents some aspects related to the COVID-19 pandemic in Brazil including public health, challenges facing healthcare workers and adverse impacts on the country’s economy. Its main contribution is the availability of two web applications for online monitoring of the evolution of the pandemic in Brazil and South America. The applications provide the possibility to download data in different formats, view interactive maps and graphs of the cumulative confirmed cases, deaths and lethality rates, in addition to presenting plots of moving averages for states and municipalities. The predictions about new cases and new deaths caused by COVID-19, in states and regions of Brazil, are also reported using GAMLSS models. The forecasts can be easily used by public managers for effective decision-making.
Revealing Changes in the Stem Form and Volume Allocation in Diverse Boreal Forests Using Two-Date Terrestrial Laser Scanning
Authors: Luoma Ville , Yrttimaa Tuomas , Kankare Ville , Saarinen Ninni , Pyörälä Jiri , Kukko Antero , Kaartinen Harri , Hyyppä Juha , Holopainen Markus , Vastaranta Mikko
Published: June 2021

Tree growth is a multidimensional process that is affected by several factors. There is a continuous demand for improved information on tree growth and the ecological traits controlling it. This study aims at providing new approaches to improve ecological understanding of tree growth by the means of terrestrial laser scanning (TLS). Changes in tree stem form and stem volume allocation were investigated during a five-year monitoring period. In total, a selection of attributes from 736 trees from 37 sample plots representing different forest structures were extracted from taper curves derived from two-date TLS point clouds. The results of this study showed the capability of point cloud-based methods in detecting changes in the stem form and volume allocation. In addition, the results showed a significant difference between different forest structures in how relative stem volume and logwood volume increased during the monitoring period. Along with contributing to providing more accurate information for monitoring purposes in general, the findings of this study showed the ability and many possibilities of point cloud-based method to characterize changes in living organisms in particular, which further promote the feasibility of using point clouds as an observation method also in ecological studies.
Heterocyclic Aromatic Amines in Meat: Formation, Isolation, Risk Assessment, and Inhibitory Effect of Plant Extracts
Authors: Nadeem Hafiz Rehan , Akhtar Saeed , Ismail Tariq , Sestili Piero , Lorenzo Jose Manuel , Ranjha Muhammad Modassar Ali Nawaz , Jooste Leonie , Hano Christophe , Aadil Rana Muhammad
Published: June 2021

Heterocyclic aromatic amines (HAAs) are potent carcinogenic compounds induced by the Maillard reaction in well-done cooked meats. Free amino acids, protein, creatinine, reducing sugars and nucleosides are major precursors involved in the production of polar and non-polar HAAs. The variety and yield of HAAs are linked with various factors such as meat type, heating time and temperature, cooking method and equipment, fresh meat storage time, raw material and additives, precursor’s presence, water activity, and pH level. For the isolation and identification of HAAs, advanced chromatography and spectroscopy techniques have been employed. These potent mutagens are the etiology of several types of human cancers at the ng/g level and are 100- to 2000-fold stronger than that of aflatoxins and benzopyrene, respectively. This review summarizes previous studies on the formation and types of potent mutagenic and/or carcinogenic HAAs in cooked meats. Furthermore, occurrence, risk assessment, and factors affecting HAA formation are discussed in detail. Additionally, sample extraction procedure and quantification techniques to determine these compounds are analyzed and described. Finally, an overview is presented on the promising strategy to mitigate the risk of HAAs by natural compounds and the effect of plant extracts containing antioxidants to reduce or inhibit the formation of these carcinogenic substances in cooked meats.
The Wisdom of the Data: Getting the Most Out of Univariate Time Series Forecasting
Authors: Petropoulos Fotios , Spiliotis Evangelos
Published: June 2021

Forecasting is a challenging task that typically requires making assumptions about the observed data but also the future conditions. Inevitably, any forecasting process will result in some degree of inaccuracy. The forecasting performance will further deteriorate as the uncertainty increases. In this article, we focus on univariate time series forecasting and we review five approaches that one can use to enhance the performance of standard extrapolation methods. Much has been written about the “wisdom of the crowds” and how collective opinions will outperform individual ones. We present the concept of the “wisdom of the data” and how data manipulation can result in information extraction which, in turn, translates to improved forecast accuracy by aggregating (combining) forecasts computed on different perspectives of the same data. We describe and discuss approaches that are based on the manipulation of local curvatures (theta method), temporal aggregation, bootstrapping, sub-seasonal and incomplete time series. We compare these approaches with regards to how they extract information from the data, their computational cost, and their performance.
Modern Forms of Populism and Social Policies: Personal Values, Populist Attitudes, and Ingroup Definitions in Support of Left-Wing and Right-Wing Welfare Policies in Italy
Authors: Miglietta Anna , Loera Barbara
Published: June 2021

We analyzed the relationship between modern forms of populism and citizen support for exclusive welfare policies and proposals, and we focused on support for left-wing- and right-wing-oriented welfare policies enacted or proposed during the Lega Nord (LN)–Five Star Movement (FSM) government in Italy (2018–2019). In light of the theoretical perspective of political ideology as motivated by social cognition, we examined citizens’ support for the two policies considering adherence to populist attitudes, agreement on the criteria useful to define ingroup membership, and personal values. We also took into account the role of cognitive sophistication in populism avoidance. A total of 785 Italian adults (F = 56.6; mean age = 35.8) completed an online survey in the summer of 2019 based on the following: support for populist policies and proposals, political ideologies and positioning, personal values, and ingroup boundaries. We used correlation and regression analyses. The results highlight the relationships between populism and political conservatism. Populism was related to the vertical and horizontal borders defining the “people”; cognitive sophistication was not a relevant driver. We identified some facilitating factors that could promote adherence to and support for public policies inspired by the values of the right or of the left, without a true ideological connotation.
Complex Modes of Inheritance in Hereditary Red Blood Cell Disorders: A Case Series Study of 155 Patients
Authors: Andolfo Immacolata , Martone Stefania , Rosato Barbara Eleni , Marra Roberta , Gambale Antonella , Forni Gian Luca , Pinto Valeria , Göransson Magnus , Papadopoulou Vasiliki , Gavillet Mathilde , Elalfy Mohsen , Panarelli Antonella , Tomaiuolo Giovanna , Iolascon Achille , Russo Roberta
Published: June 2021

Hereditary erythrocytes disorders include a large group of conditions with heterogeneous molecular bases and phenotypes. We analyzed here a case series of 155 consecutive patients with clinical suspicion of hereditary erythrocyte defects referred to the Medical Genetics Unit from 2018 to 2020. All of the cases followed a diagnostic workflow based on a targeted next-generation sequencing panel of 86 genes causative of hereditary red blood cell defects. We obtained an overall diagnostic yield of 84% of the tested patients. Monogenic inheritance was seen for 69% (107/155), and multi-locus inheritance for 15% (23/155). PIEZO1 and SPTA1 were the most mutated loci. Accordingly, 16/23 patients with multi-locus inheritance showed dual molecular diagnosis of dehydrated hereditary stomatocytosis/xerocytosis and hereditary spherocytosis. These dual inheritance cases were fully characterized and were clinically indistinguishable from patients with hereditary spherocytosis. Additionally, their ektacytometry curves highlighted alterations of dual inheritance patients compared to both dehydrated hereditary stomatocytosis and hereditary spherocytosis. Our findings expand the genotypic spectrum of red blood cell disorders and indicate that multi-locus inheritance should be considered for analysis and counseling of these patients. Of note, the genetic testing was crucial for diagnosis of patients with a complex mode of inheritance.