bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of Urine Flow with Multiple Sizes of Double-J Stents
Authors: Kim Hyoung-Ho , Kim Kyung-wuk , Choi Young Ho , Lee Seung Bae , Baba Yasutaka
Published: June 2020

This study investigated which sizes of double-J stents are more effective in achieving an acceptable urine flow through stenotic and stented ureters. Sixty four computational fluid dynamics models of the combinations of two different gauge ureters (4.57 mm and 5.39 mm in diameter) with four different levels of ureteral and four different sizes of double-J stents were developed for the numerical analysis of urine flow in the ureter. Luminal, extraluminal, and total flow rates along the ureter were measured, and the flow patterns around the ports and side holes were investigated. For the 4.57-mm ureter, the total flow rate for each gauge of stent was 23–63 mL/h (5 Fr), 20–47 mL/h (6 Fr), 17–35 mL/h (7 Fr), and 16–26 mL/h (8 Fr) and for the 5.39-mm ureter, the total flow rate for each gauge of stent was 43–147 mL/h (5 Fr), 36–116 mL/h (6 Fr), 29–92 mL/h (7 Fr), and 26–71 mL/h (8 Fr). With a 74% stenosis, all stents allowed a low flow rate, and the differences in flow rates between the stents were small. At the other levels of stenosis, 5 Fr stents allowed greater flow rates than the 8 Fr stents. The luminal flow rate increased just before the area of stenosis and decreased after the stenosis because of the increase and decrease in the luminal flow through the side holes before and after the stenosis. Therefore, a larger double-J stent is not favorable in achieving an acceptable urine flow through the stenotic and stented ureters. The results in this study could not be necessarily correlated with clinical situation because peristalsis, viscosity of the urine and real format of the ureter were not considered in our model. In vivo experiments are necessary for confirmation of our findings. Double J stents are commonly used in the ureteral stenosis or occlusion, especially due to ureter stones which obstruct the flow of urine. Clinicians choose the size of double J stent on the basis of their clinical experience. Here, we tried to know which sizes of double J stents are better for sufficient urine flow. According to various documents that try to determine the optimal shape of double J stents to increase the urine flow through the ureter, mostly bigger stent is recommended to occur maximum urine flow. However, in case of ureter with stenosis or occlusion, the right size of the double J stent may vary depending on the degree of stenosis in the ureter. To find appropriate stent size for the ureter with stenosis, computational fluid dynamics was conducted. This study shows that smaller diameter stents are more appropriate than larger diameter stents depending on the situation.
Swing Analysis and Control Research of the Space Tethered Combination in the Maneuver Process
Authors: Wang Ban , Guo Jifeng , Yan Yuchen , Zhou Chuanping
Published: June 2020

Swing usually occurs in the maneuver process of a tethered combination, which is constituted of a platform, a tether and a target (i.e., space debris) for capture. Therefore, a dynamical model of the space tethered combination was established, based on the maneuver of the mission platform in a short time. The conditions for the three swing formations of the tethered combination were obtained according to the analysis of the dynamical model. In order to solve the swing problem, anti-swing control strategies, based on linear feedback control, approximate linearization control and variable structure control, were proposed, respectively. Furthermore, simulation results verified the correctness and effectiveness of the above strategies. To test the validity of the control strategies, a ground experiment setup was built according to the similarity of dynamics. The experimental results show that linear feedback control and approximate linearization control can suppress the in-plane and out-of-plane swing of the combination rapidly.
Detection of Parking Slots Based on Mask R-CNN
Authors: Jiang Shaokang , Jiang Haobin , Ma Shidian , Jiang Zhongxu
Published: June 2020

Obtaining information on parking slots is a prerequisite for the development of automatic parking systems, which is an essential part of the automatic driving processes. In this paper, we proposed a parking-slot-marking detection approach based on deep learning. The detection process involves the generation of mask of the marking-points by using the Mask R-CNN algorithm, extracting parking guidelines and parallel lines on the mask using the line segment detection (LSD) to determine the candidate parking slots. The experimental results show that the proposed method works well under the condition of complex illumination and around-view images from different sources, with a precision of 94.5% and a recall of 92.7%. The results also indicate that it can be applied to diverse slot types, including vertical, parallel and slanted slots, which is superior to previous methods.
Non-Destructive Techniques for Building Evaluation in Urban Areas: The Case Study of the Redesigning Project of Eleftheria Square (Nicosia, Cyprus)
Authors: Cozzolino Marilena , Gentile Vincenzo , Mauriello Paolo , Peditrou Agni
Published: June 2020

This paper deals with the application of non-destructive geophysical techniques of investigation in the urban environment of the city of Nicosia (Cyprus). The main aim of the research was, in the frame of the Eleftheria Square redesign project, to image subsurface properties in order to reduce the impact of hazards on the old buildings (therefore preserving the cultural heritage of the place), and on the new infrastructure under construction. Since 2008, electrical resistivity tomography (ERT), ground penetrating radar (GPR) and induced electromagnetic method (EMI) were employed during the different phases of the project to provide an understanding of geological stratigraphy, the detection of buried objects (archaeological structures and underground utilities) and the solution of unexpected events (such as water infiltration in the course of works). The geophysical results proved the efficiency of the adopted methods, adding scientific value to the knowledge of the studied area. The new gathered information helped the public administration technicians to plan direct and targeted interventions and to modify the original design of the project according to the discovery of archaeological findings.
On the Influence of Suspension Geometry on Steering Feedback
Authors: Bonera Emanuele , Gadola Marco , Chindamo Daniel , Morbioli Stefano , Magri Paolo
Published: June 2020

Feedback through the steering wheel is known as the most important source of information to the driver. The so-called steering feeling, composed of self-aligning actions coming from tyres and suspension geometry all the way through mechanical linkages to the driver’s hands, provides vital communication for intuitive driving, and it is therefore utterly important for safety and for a pleasant driving experience as well. Subtle forces and vibrations, due to the interaction between the tyre contact patch and the road surface texture, also play a role, provided they are not heavily filtered or cancelled by the power steering system. Human perception is guided by experience in order to establish correlations between steering feedback and vehicle motion in terms of straight-line stability, cornering speed, tyre adhesion and available friction, vehicle balance, and so on. A front-wheel drive car is potentially a critical vehicle from this point of view, especially when the powertrain can deliver large torque figures, and even more so if a limited-slip differential (LSD) or a similar active device is present in order to improve traction capabilities. Any difference between the two wheels in terms of tractive force can result into the so-called torque steer issue, that is to say, a “pulling” sensation on the steering wheel or a shifting of the vehicle from the desired trajectory. This paper analyses the torque steer phenomenon on an all-wheel-drive, full electric sportscar where a significant portion of the torque is transferred to the front axle. The effects of suspension kinematics and the load variation at tyre contact patch level are taken into account. For evaluating the impact of steering feedback, the VI-grade® simulation software is adopted and a test campaign on the professional driving simulator available at the University of Brescia has been carried out in order to understand the impact of steering feedback on driver perception and performance.
Biological Effect of Single or Combined Pharmacological Therapy Using Alendronate and Simvastatin on Implant Osseointegration: An In Vivo Study in Healthy and Osteoporotic Rat Models
Authors: Basudan Amani M. , Shaheen Marwa Y. , Niazy Abdurahman A. , van den Beucken Jeroen J.J.P. , Jansen John A. , Alghamdi Hamdan S.
Published: June 2020

To evaluate peri-implant bone formation following single or combined systemic administration of alendronate and simvastatin in healthy and osteoporotic rats, eighty female Wistar rats were ovariectomized (n = 40) or sham-operated (n = 40). At six weeks, implants were placed in femoral condyles. Then, ovariectomized (OVX) and sham-operated (SHAM) animals received daily subcutaneous alendronate (50 µg/kg), simvastatin (5 mg/kg), or both, for three weeks. Control animals received subcutaneous saline. Thereafter, specimens were retrieved for biomechanical testing, histological evaluation, and bone area (BA%) and bone-to-implant contact (BIC%). In healthy and osteoporotic rats, similar (p > 0.05) push-out values were observed for all groups. For BA% analysis, control rats showed similar results for OVX (9.2% ± 2.4%) and SHAM (11.1% ± 3.5%) animals. In contrast, single or combined drug therapy significantly increased BA% compared to controls in both healthy and osteoporotic conditions (p < 0.05). In osteoporotic conditions, alendronate alone showed a superior effect on BA% compared to simvastatin alone, or their combination. Systemic alendronate, simvastatin, or both showed a similar BIC% compared to controls (p > 0.05). The present study demonstrates that single or combined systemic alendronate and simvastatin increases bone formation around implants (i.e., distance osteogenesis) in healthy and osteoporotic bone conditions. However, these drugs showed no beneficial effect on direct bone-to-implant contact or implant fixation.
Mechanical and Fiber-Bridging Behavior of Slag-Based Composite with High Tensile Ductility
Authors: Choi Jeong-Il , Kim Hyeong-Ki , Lee Bang Yeon
Published: June 2020

This paper presents an experimental and analytical investigation of the fundamental mechanism of the highly ductile behavior of strain-hardening slag-based composite reinforced by polyethylene fibers. Composite properties, including compressive strength and tensile behavior of the composite, were identified. Micromechanical characteristics, including matrix fracture toughness and interfacial properties between matrix and fiber, were investigated and the fiber-bridging behavior of the composite was simulated. The tensile behavior of the composite was evaluated by micromechanical analysis. Test results showed that the composite had extremely high tensile ductility of up to 7.5% and high tensile strength of 8.5 MPa, along with a moderate compressive strength of 36.8 MPa. Saturated cracking patterns with controlled crack width of 59.8 μm were also observed in the composite. Considering the variation of matrix properties and fiber distribution, the theoretical fiber-bridging curve simulated the tensile behavior of the composite well, and the micromechanical analysis results supported the tensile behavior of the composite.
Effect of Whole-Body Vibration on the Functional Responses of the Patients with Knee Osteoarthritis by the Electromyographic Profile of the Vastus Lateralis Muscles during the Five-Repetition Chair Stand Test: A Randomized Crossover Trial
Authors: Moreira-Marconi Eloá , Teixeira-Silva Ygor , Meirelles Alexandre Gonçalves de , Moura-Fernandes Marcia Cristina , Lopes-Souza Patrícia , Reis-Silva Aline , Marchon Renata Marques , Guedes-Aguiar Eliane de Oliveira , Paineiras-Domingos Laisa Liane , de Sá-Caputo Danúbia da Cunha , Melo-Oliveira Maria Eduarda de Souza , Oliveira Bruno Bessa Monteiro de , Gama Marco Antônio de Souza , Alvim-Oliveira Roges , Batouli-Santos Daniel , Lacerda Ana Cristina Rodrigues , Mendonça Vanessa Amaral , Xavier Vinicius Layter , Oliveira Liszt Palmeira de , Mozella Alan de Paula , Sañudo Borja , Seixas Adérito , Taiar Redha , Cochrane Darryl , Bernardo-Filho Mario
Published: June 2020

Knee osteoarthritis (KOA) can cause functional disability. Neuromuscular function is relevant in the development and progression of KOA. It can be evaluated by the analysis of the surface electromyography (sEMG), which has an important role in the understanding of KOA. Whole-body vibration (WBV) is an intervention suggested to treat KOA. The objective of this work was to verify the effectiveness of WBV on the functionality of lower limbs by the electromyographic profile of the vastus lateralis (VL) muscles during the five-repetition chair stand test (5CST) in patients with KOA. This was a two-period crossover trial study (8-week washout). Nineteen patients with KOA were allocated to the group submitted to WBV (WBVG), with peak-to-peak displacement of 2.5 to 7.5 mm, frequency from 5 to 14 Hz, and acceleration peak from 0.12 to 2.95 g, or to the control group (0 Hz) (2 days per week for 5 weeks). The 5CST and the sEMG of the VL during 5CST were evaluated before and after the interventions. Results: Significant differences in 5CST were evident only in WBVG (p = 0.018), showing a decrease of the execution time. The sEMG profile showed no significative difference. Therefore, only 10 sessions of WBV with comfortable posture can bring about improvement in functionality of KOA patients without alteration of the muscle excitation.
A Novel Fault Diagnosis Algorithm for Rolling Bearings Based on One-Dimensional Convolutional Neural Network and INPSO-SVM
Authors: Shao Yang , Yuan Xianfeng , Zhang Chengjin , Song Yong , Xu Qingyang
Published: June 2020

Deep learning based intelligent fault diagnosis methods have become a research hotspot in the fields of fault diagnosis and the health management of rolling bearings in recent years. To effectively identify incipient faults in rotating machinery, this paper proposes a novel hybrid intelligent fault diagnosis framework based on a convolutional neural network and support vector machine (SVM). First, an improved one-dimensional convolutional neural network (1DCNN) was adopted to extract fault features, and the state information and intrinsic properties of the raw vibration signals were mined. Second, the extracted features were used to train the SVM, which was applied to classify the fault category. The proposed hybrid framework combined the excellent classification performance of the SVM for small samples and the strong feature-learning ability of CNN network. In order to tune the parameters of the SVM, an improved novel particle swarm optimization algorithm (INPSO) which combined the Tent map and Lévy flight strategy was proposed. Numerical experimental results indicated that the proposed PSO variant had a better performance in searching accuracy and convergence speed. At last, multiple groups of rolling bearing fault diagnosis experiments were carried out and experimental results showed that, with the proposed 1DCNN-INPSO-SVM model, the hybrid framework was capable of diagnosing with high precision for rolling bearings and superior to some traditional fault diagnosis methods.
Fragile Traces, Treacherous Sands: Ronen Sharabani and Micha Ullman’s Intergenerational Encounter
Authors: Aldouby Hava
Published: June 2020

This paper addresses an intriguing intergenerational encounter between Micha Ullman (b. Tel Aviv 1939), one of Israel’s most prominent senior artists, and Ronen Sharabani (b. Tel Aviv 1974), a young media artist. The two artists’ otherwise divergent practices converge in their use of sand and red earth as their primary media. The paper brings Mieke Bal’s concept of migratory aesthetics and Jill Bennett’s phenomenological approach to trauma-related art to bear on Ullman’s fragile earth installations and perforated sand tables, and on Sharabani’s projections of Virtual Reality onto sand. Also addressed is Sharabani’s series Vitual Territories (2019), in which digitally manipulated views from Google Earth probe geographical sites that resonate with migratory histories. The paper traces two main trajectories upon which the oeuvres of Ullman and Sharabani interface. The first category, “treacherous sands”, relates to installations involving sand tables and other containers of soil. In turn, the category of “fragile traces” addresses installations that feature various architectural ground plans modeled in sand. In these installations, sand is the quintessential terra infirma. At the same time, however, the paper proposes that through the haptic appeal of the medium of sand, these installations counter the pervasive anxiety of shifting ground with an augmented sense of bodily presence.
The Dynamic Response of the Vibrating Compactor Roller, Depending on the Viscoelastic Properties of the Soil
Authors: Dobrescu Cornelia
Published: June 2020

The present paper addresses the problem of the dynamic response of a vibrating equipment for soil compaction. In essence, dynamic response vibrations are analysed by applying an inertial-type perturbing force. This is generated by rotating an eccentric mass with variable angular velocity, in order to reach the regime necessary to ensure the degree of compaction. The original character of the research is that during the compaction process, the soil layers with certain compositions of clay, sand, water and stabilizing substances change their rigidity and/or amortization. In this case, two situations were analysed, both experimentally and with numerical modelling, with special results and practical engineering conclusions, favourable to the evaluation of the interaction between vibrator roller–compacted ground. We mention that the families of amplitude–pulse and transmitted force–pulse response curves are presented, from which the dynamic effect in the compaction process results after each passage on the same layer of soil, until the necessary compaction state is reached.
Evaluation of Hurricane Harvey (2017) Rainfall in Deterministic and Probabilistic HWRF Forecasts
Authors: Ko Mu-Chieh , Marks Frank D. , Alaka Ghassan J. , Gopalakrishnan Sundararaman G.
Published: June 2020

Rainfall forecast performance was evaluated for the first time for the Hurricane Weather Research and Forecasting (HWRF) model. This study focused on HWRF performance in predicting rainfall from Hurricane Harvey in 2017. In particular, two configurations of the 2017 version of HWRF were investigated: a deterministic version of the Basin-scale HWRF (HB17) and an ensemble version of the operational HWRF (H17E). This study found that HB17 generated reasonable rainfall patterns and rain-rate distributions for Hurricane Harvey, in part due to accurate track forecasts. However, the estimated rain rates near the storm center (within 50 km) were slightly overestimated. In the rainband region (150 to 300 km), HB17 reproduced heavy rain rates and underestimated light rain rates. The accumulated rainfall pattern successfully captured Harvey’s intense outer rainband with adequate spatial displacement. In addition, the performance of H17E on probabilistic rainfall has shown that the ensemble forecasts can potentially increase the accuracy of the predicted locations for extreme rainfall. Moreover, the study also indicated the importance of high-resolution dynamical models for rainfall predictions. Although statistical models can generate the overall rainfall patterns along a track, extreme rainfall events produced from outer rainbands can only be forecasted by numerical models, such as HWRF. Accordingly, the HWRF models have the capability of simulating reasonable quantitative precipitation forecasts and providing essential rainfall guidance in order to further reduce loss of life and cost to the economy.
Objective Identification and Multi-Scale Controlling Factors of Extreme Heat-Wave Events in Southern China
Authors: Chen Wenjiang , Fu Joshua-Xiouhua , Li Guoping
Published: June 2020

Southern China (SC) is often subjected to the impacts of extreme heat-wave (EHW) events with hot days covering large areas and lasting extended periods in the boreal summer. The present study explores new objective identification methods of the EHW events and reveals the controlling factors of different spatial-temporal variations in shaping the EHW events over SC from 2000 to 2017 with in-situ observations and latest reanalysis. A compound index of the EHW (with impact area, duration, and magnitude) was defined to quantify the overall intensity of the EHW events in SC. It was found that synoptic variability and 10–30-day intra-seasonal variability (ISV) induce the onsets of the EHW events, while 30–90-day ISV shapes the durations. An innovative daily compound index was introduced to track the outbreak of the EHW events. The occurrences of the EHW in SC are coincident with the arrivals of intra-seasonal signals (e.g., the anomalies of outgoing long-wave radiation (OLR) and 500 hPa geopotential height) propagating from the east and south. About 12 days before the onset of the EHW in SC, the 10–30-day positive anomalies of 500 hPa geopotential height and OLR appear near the equatorial western Pacific, which then propagate northwestward to initiate the EHW in SC. At the same time, the 30–90-day suppressed phase propagates northeastward from the Indian Ocean to the SC to sustain the EHW events. On the interannual time scale, it was found that the EHW events in SC occurred in those years with robust warming of the western North Pacific in early summer (May and June) and warming of the equatorial eastern Pacific in the preceding winter (December, January, and February). An interannual sea surface temperature anomalous (SSTA) index, which adds together the SSTA over the above two regions, serves as a very useful seasonal predictor for the EHW occurrences in SC at least one-month ahead.
Exploring the Role of Non-Coding RNAs in the Pathophysiology of Systemic Lupus Erythematosus
Authors: Taheri Mohammad , Eghtedarian Reyhane , Dinger Marcel E. , Ghafouri-Fard Soudeh
Published: June 2020

Systemic lupus erythematosus (SLE) is a chronic immune-related disorder designated by a lack of tolerance to self-antigens and the over-secretion of autoantibodies against several cellular compartments. Although the exact pathophysiology of SLE has not been clarified yet, this disorder has a strong genetic component based on the results of familial aggregation and twin studies. Variation in the expression of non-coding RNAs has been shown to influence both susceptibility to SLE and the clinical course of this disorder. Several long non-coding RNAs (lncRNAs) such as GAS5, MALAT1 and NEAT1 are dysregulated in SLE patients. Moreover, genetic variants within lncRNAs such as SLEAR and linc00513 have been associated with risk of this disorder. The dysregulation of a number of lncRNAs in the peripheral blood of SLE patients has potentiated them as biomarkers for diagnosis, disease activity and therapeutic response. MicroRNAs (miRNAs) have also been shown to affect apoptosis and the function of immune cells. Taken together, there is a compelling rationale for the better understanding of the involvement of these two classes of non-coding RNAs in the pathogenesis of SLE. Clarification of the function of these transcripts has the potential to elucidate the molecular pathophysiology of SLE and provide new opportunities for the development of targeted therapies for this disorder.
Comparative Genomics Reveals a Significant Sequence Variability of Myticin Genes in Mytilus galloprovincialis
Authors: Rey-Campos Magalí , Novoa Beatriz , Pallavicini Alberto , Gerdol Marco , Figueras Antonio
Published: June 2020

Myticins are cysteine-rich antimicrobial peptides highly expressed in hemocytes of Mytilus galloprovincialis. Along with other antimicrobial peptides (AMPs), myticins are potent effectors in the mussel immune response to pathogenic infections. As intertidal filter-feeders, mussels are constantly exposed to mutable environmental conditions, as well as to the presence of many pathogens, and myticins may be key players in the great ability of these organisms to withstand these conditions. These AMPs are known to be characterized by a remarkable sequence diversity, which was further explored in this work, thanks to the analysis of the recently released genome sequencing data from 16 specimens. Altogether, we collected 120 different sequence variants, evidencing the important impact of presence/absence variation and positive selection in shaping the repertoire of myticin genes of each individual. From a functional point of view, both the isoelectric point (pI) and the predicted charge of the mature peptide show unusually low values compared with other cysteine-rich AMPs, reinforcing previous observations that myticins may have accessory functions not directly linked with microbe killing. Finally, we report the presence of highly conserved regulatory elements in the promoter region of myticin genes, which might explain their strong hemocyte-specific expression.
Brain NMDA Receptors in Schizophrenia and Depression
Authors: Adell Albert
Published: June 2020

N-methyl-D-aspartate (NMDA) receptor antagonists such as phencyclidine (PCP), dizocilpine (MK-801) and ketamine have long been considered a model of schizophrenia, both in animals and humans. However, ketamine has been recently approved for treatment-resistant depression, although with severe restrictions. Interestingly, the dosage in both conditions is similar, and positive symptoms of schizophrenia appear before antidepressant effects emerge. Here, we describe the temporal mechanisms implicated in schizophrenia-like and antidepressant-like effects of NMDA blockade in rats, and postulate that such effects may indicate that NMDA receptor antagonists induce similar mechanistic effects, and only the basal pre-drug state of the organism delimitates the overall outcome. Hence, blockade of NMDA receptors in depressive-like status can lead to amelioration or remission of symptoms, whereas healthy individuals develop psychotic symptoms and schizophrenia patients show an exacerbation of these symptoms after the administration of NMDA receptor antagonists.
Exercise-Based Cardiac Rehabilitation Modulates Prefrontal Cortex Oxygenation during Submaximal Exercise Testing in Cardiovascular Disease Patients
Authors: Moriarty Terence , Bourbeau Kelsey , Mermier Christine , Kravitz Len , Gibson Ann , Beltz Nicholas , Negrete Omar , Zuhl Micah
Published: June 2020

The purpose of this study was to investigate if prefrontal cortex (PFC) oxygenation during incremental exercise is altered among cardiovascular disease (CVD) patients who completed 6 weeks of exercise-based cardiac rehabilitation (CR). Nineteen (male = 14, female = 5; 65.5 ± 11.5 years) participants from an outpatient CR program were enrolled in the study. Each participant completed a submaximal graded treadmill evaluation at intake and again upon completion of 18 individualized CR sessions. Functional near-infrared spectroscopy (fNIRS) imaging was used to measure left- and right- PFC (LPFC and RPFC) oxygenation parameters during the submaximal exercise evaluations. Patients showed improvements in cardiorespiratory capacity (pre 5.5 ± 2.5 vs. post 6.9 ± 2.8 metabolic equivalents (METs)). A significant decrease in LPFC and RPFC oxygenation was observed during the post-CR exercise test compared to pre-CR. CVD patients enrolled in 6 weeks of CR showed significant improvements in functional capacity along with decreased cortical oxygenation during submaximal exercise. Exercise training may cause distribution of cortical resources to motor regions that support sustained exercise.
Activity in the Photodegradation of 4-Nitrophenol of a Zn,Al Hydrotalcite-Like Solid and the Derived Alumina-Supported ZnO
Authors: Trujillano Raquel , Nájera César , Rives Vicente
Published: June 2020

A Zn,Al layered double hydroxide (LDH), with the hydrotalcite structure and the mixed oxide obtained upon its calcination at 650 °C, was tested in the adsorption and photocatalytic degradation of 4-Nitrophenol in aqueous solution. The Zn,Al LDH was fast and easily obtained by the coprecipitation method. Hydrothermal treatment under microwave irradiation was applied to compare the effect of the ageing treatment on the photocatalytic behavior. The efficiency of the synthetized solids was compared to that of a commercial ZnO. The ageing treatment did not improve the performance of the original samples in the degradation of 4-nitrophenol. The activity of the synthetized solids tested exceeded that observed for the reaction with commercial ZnO. The photocatalytic performance of the original non-calcined hydrotalcite is similar to that of commercial ZnO. The calcined hydrotalcite showed a better performance in the adsorption-degradation of the contaminant than ZnO, and its reusability would be possible as it recovered the hydrotalcite-like structure during the reaction.
Utilization of Waste Grooved Razor Shell (GRS) as a Catalyst in Biodiesel Production from Refined and Waste Cooking Oils
Authors: Aitlaalim Abdellah , Ouanji Fatiha , Benzaouak Abdellah , El Mahi Mohammed , Lotfi El Mostapha , Kacimi Mohamed , Liotta Leonarda Francesca
Published: June 2020

Biodiesel is a potential alternative for fossil fuel. However, its large-scale application is held up by the disadvantage of a homogenous process, the scarce availability of raw materials and the production cost, which is higher than for fossil diesel. In this work, biodiesel production was carried out using both refined and used cooking oils. The process was investigated in a batch reactor, in the presence of CaO as a heterogeneous catalyst prepared by the calcination of the natural Waste Grooved Razor Shell (GRS). Characterizations by X-Ray Diffraction (XRD) and Thermal Gravimetric (TG)/Differential Thermal Analysis (DTA) showed that the as-received GRS consists of aragonite, (i.e., CaCO3) as the main component and of water and organic matter in a lower amount. After calcination at 900 °C, CaO was formed as the only crystalline phase. The effects of several experimental parameters in the transesterification reactions were studied, and their impact on the produced biodiesel properties was investigated. The studied variables were the methanol/oil molar ratio, the catalyst weight percentage (with respect to the oil mass), the calcination temperature of the parent GRS and the recycling and regeneration of the catalyst. The physico-chemical and fuel properties, i.e., viscosity, density and acid value of used oils and of the produced biodiesel, were determined by conventional methods (American Society for Testing and Materials (ASTM) methods) and compared with the European standards of biodiesel. The optimal identified conditions were the following: the use of a 15:1 methanol/oil molar ratio and 5 wt% of CaO with respect to the oil mass. After 3 h of reaction at 65 °C, the biodiesel yield was equal to 94% and 99% starting from waste and refined oils, respectively.
Equilibrium Moisture and Drying Kinetics Modelling of Macroalgae Species Ulva ohnoi and Oedogonium intermedium
Authors: Walker Craig , Cole Andrew , Antunes Elsa , Sheehan Madoc
Published: June 2020

Algae-based products have applications in the food and pharmaceutical industries, bioremediation of waste streams and biofuel production. Drying has been recognised to constitute the largest energy cost in algae processing, yet there is limited data or modelling characterising the drying kinetics of macroalgae. This research modelled the equilibrium moisture content of two macroalgae species, Ulva ohnoi, a saltwater alga and Oedogonium intermedium, a freshwater alga. The Guggenheim–Anderson–de Boer model was found to best represent experimental equilibrium moisture contents. Drying rate curves obtained under both convective and radiative conditions were fitted to an analytical solution of Fick’s second law, including the modelled equilibrium moisture values. Effective diffusivity values for the two species are presented.
Anti-Graffiti Coatings on Stones for Historical Buildings in Turin (NW Italy)
Authors: Ricci Chiara , Gambino Francesca , Nervo Marco , Piccirillo Anna , Scarcella Arianna , De Stefanis Alessandra , Pozo-Antonio Jose Santiago
Published: June 2020

The application of anti-graffiti products to stones belonging to architectural heritage is a common procedure that is currently complementary to traditional graffiti removal treatments, such as chemical and mechanical cleaning. In this study, two anti-graffiti coatings (a sacrificial product and a permanent one) were tested on four stones (with a different texture, mineralogy, and surface finish) commonly found in the historical city center of Turin (Italy). In order to evaluate the effectiveness of the anti-graffiti products, the removal of two graffiti paints with different compositions was tested. The results of the cleaning procedures performed on the surfaces coated with anti-graffiti products were evaluated, considering both the graffiti remains and the alterations induced on the surface. Chemical cleaning based on the use of a low-toxic ternary solvent mixture was applied on the unprotected stones for a comparison with the results obtained on the surfaces coated with anti-graffiti products. The samples were observed under stereomicroscopy and ultraviolet fluorescence photography and all of the treated surfaces were evaluated by roughness measurements, the contact sponge method, static contact angle measurements, and scanning electron microscopy. The composition of the anti-graffiti product, the graffiti paint to be cleaned, and the remover recommended by the manufacturer proved to be key factors for the cleaning effectiveness achieved on coated surfaces. Moreover, to a lesser extent, the mineralogy, texture, and surface finish of the stone also influenced the results of the cleaning procedures. The sacrificial anti-graffiti product enhanced the cleaning effectiveness on all stones if compared to uncoated surfaces; however, the permanence of coating remains on the surface after cleaning proved to be critical. Regarding the use of the permanent anti-graffiti products, intense disparate results were achieved, depending on the graffiti paint composition.
Modulus, Strength and Cytotoxicity of PMMA-Silica Nanocomposites
Authors: Balos Sebastian , Puskar Tatjana , Potran Michal , Milekic Bojana , Djurovic Koprivica Daniela , Laban Terzija Jovana , Gusic Ivana
Published: June 2020

Key advantages of Poly(methyl methacrylate)—PMMA for denture application are related to aesthetics and biocompatibility, while its main deficiency is related to mechanical properties. To address this issue, SiO2 nanoparticle reinforcement was proposed, containing 0 to 5% nanosilica, to form nanocomposite materials. Flexural strengths and elastic moduli were determined and correlated to nominal nanoparticle content and zeta potential of the liquid phase nanoparticle solutions. Another issue is the biocompatibility, which was determined in terms of cytotoxicity, using L929 and MRC5 cell lines. The addition of nanoparticle was proved to be beneficial for increasing flexural strength and modulus, causing a significant increase in both strength and moduli. On the other hand, the formation of agglomerates was noted, particularly at higher nanoparticle loadings, affecting mechanical properties. The addition of nanosilica had an adverse effect on the cytotoxicity, increasing it above the level present in unmodified specimens. Cytotoxic potential was on the acceptable level for specimens with up to 2% nanosilica. Consequently, nanosilica proved to be an effective and biocompatible means of increasing the resistance of dental materials.
Finite Element Simulation of Multilayer Electron Beam Melting for the Improvement of Build Quality
Authors: Galati Manuela , Di Mauro Oscar , Iuliano Luca
Published: June 2020

Macroscale modeling plays an essential role in simulating additive manufacturing (AM) processes. However, models at such scales often pay computational time in output accuracy. Therefore, they cannot forecast local quality issues like lack of fusion or surface roughness. For these reasons, this kind of model is never used for process optimization, as it is supposed to work with optimized parameters. In this work, a more accurate but still simple three-dimensional (3D) model is developed to estimate potential faulty process conditions that may cause quality issues or even process failure during the electron beam melting (EBM) process. The model is multilayer, and modeling strategies are developed to have fast and accurate responses. A material state variable allows for the molten material to be represented. That information is used to analyze process quality issues in terms of a lack of fusion and lateral surface roughness. A quiet element approach is implemented to limit the number of elements during the calculation, as well as to simulate the material addition layer by layer. The new material is activated according to a predefined temperature that considers the heat-affected zone. Heat transfer analysis accuracy is comparatively demonstrated with a more accurate literature model. Then, a multilayer simulation validates the model capability in predicting the roughness of a manufactured Ti6Al4V sample. The model capability in predicting a lack of fusion is verified under a critical process condition.
Multifocal Amelanotic Melanoma of the Hard Palate: A Challenging Case
Authors: Limongelli Luisa , Cascardi Eliano , Capodiferro Saverio , Favia Gianfranco , Corsalini Massimo , Tempesta Angela , Maiorano Eugenio
Published: June 2020

Among all melanomas, the mucosal type is very rare and may occur in the sino-nasal mucosa, vagina, anus and the oral cavity. At variance with melanomas of the skin, no risk factors, such as familiarity, UV-exposure and skin phenotype, have been clearly identified for such neoplasms. Frequently, the diagnosis is delayed and achieved at advanced stages or when metastases have already occurred. The authors report on a case of mucosal melanoma of the oral cavity presenting as a mass of the hard palate in a 50-year old male, and the corresponding diagnostic-therapeutic pathway.
Sport and Its Relationship with Oncology in Future Primary Education Teachers
Authors: Melero García Lucía , Hernández Fernández Antonio , Pérez Navío Eufrasio
Published: June 2020

This essay is aimed at analyzing the existing relationships between oncological problems and sport in future primary education teachers. This relationship was validated and confirmed by realizing a factorial analysis using an ad hoc-created Likert scale. To come up to certain conclusions, a non-experimental, descriptive, explanatory and correlational investigation process was carried out. The instrument used to collect the data have been made through Likert scale, which was validated in contents and with an excellent Cronbach’s alpha (0.952). The validity of construct was made with factorial analysis exploratory (KMO (0.722), Bartlett (0.000), determinant (3.266E−23)). Three different samples have been taken from 900 students (years 2017–2018–2019), being 896 subjects for research. Those persons were students from the fourth year of primary education degree at University of Jaen. The Kruskal–Wallis test allows us to keep the null hypothesis and make the P of Pearson. As a conclusion, we emphasize that there is a relationship between oncological problems and sport and future primary teachers should be informed about this relationship, as well as the importance of cancer and bones tumors and their relationship with sport, the media used to train in oncological problems may be less important.
Comparative Performance Evaluation of Modern Heterogeneous High-Performance Computing Systems CPUs
Authors: Sorokin Aleksei , Malkovsky Sergey , Tsoy Georgiy , Zatsarinnyy Alexander , Volovich Konstantin
Published: June 2020

The study presents a comparison of computing systems based on IBM POWER8, IBM POWER9, and Intel Xeon Platinum 8160 processors running parallel applications. Memory subsystem bandwidth was studied, parallel programming technologies were compared, and the operating modes and capabilities of simultaneous multithreading technology were analyzed. Performance analysis for the studied computing systems running parallel applications based on the OpenMP and MPI technologies was carried out by using the NAS Parallel Benchmarks. An assessment of the results obtained during experimental calculations led to the conclusion that IBM POWER8 and Intel Xeon Platinum 8160 systems have almost the same maximum memory bandwidth, but require a different number of threads for efficient utilization. The IBM POWER9 system has the highest maximum bandwidth, which can be attributed to the large number of memory channels per socket. Based on the results of numerical experiments, recommendations are given on how the hardware of a similar grade can be utilized to solve various scientific problems, including recommendations on optimal processor architecture choice for leveraging the operation of high-performance hybrid computing platforms.
Study of NVIS Channel for USN Protocol Definition in Antarctica
Authors: Maso Josep M. , Porte Joaquim , Pijoan Joan L. , Badia David
Published: June 2020

Every year, the number of ubiquitous sensor networks (USN) is increasing and the need for remote USN communications is emerging in some scenarios. As an alternative to satellite communications, more interests are focused on high frequencies (HF) communications as a low-cost option to reach links of more than 250 km without a line of sight. The HF standards are designed for generic communication channels being not robust for near vertical incidence skywave (NVIS) USN. In this article, we propose a new protocol for USN in remote places based on NVIS communications. For that purpose, we study the main characteristics of the NVIS channel with the presence of groundwaves, particularly in Antarctica. We analyze the availability of the channel, the height of the layers, the delay spread, and the Doppler spread. On the basis of the results obtained, we propose two protocols based on an OFDM (orthogonal frequency division multiplexing) modulation depending on the presence of the groundwave at the receiver. Finally, we make a simulation of the two OFDM configurations and we compare it with real tested standard modulations. The results show a better performance of the new protocol compared to the current HF standards.
Boosted Trees Algorithm as Reliable Spectrum Sensing Scheme in the Presence of Malicious Users
Authors: Gul Noor , Khan Muhammad Sajjad , Kim Su Min , Kim Junsu , Elahi Atif , Khalil Zafar
Published: June 2020

Cooperative spectrum sensing (CSS) has the ability to accurately identify the activities of the primary users (PUs). As the secondary users’ (SUs) sensing performance is disturbed in the fading and shadowing environment, therefore the CSS is a suitable choice to achieve better sensing results compared to individual sensing. One of the problems in the CSS occurs due to the participation of malicious users (MUs) that report false sensing data to the fusion center (FC) to misguide the FC’s decision about the PUs’ activity. Out of the different categories of MUs, Always Yes (AY), Always No (AN), Always Opposite (AO) and Random Opposite (RO) are of high interest these days in the literature. Recently, high sensing performance for the CSS can be achieved using machine learning techniques. In this paper, boosted trees algorithm (BTA) has been proposed for obtaining reliable identification of the PU channel, where the SUs can access the PU channel opportunistically with minimum disturbances to the licensee. The proposed BTA mitigates the spectrum sensing data falsification (SSDF) effects of the AY, AN, AO and RO categories of the MUs. BTA is an ensemble method for solving spectrum sensing problems using different classifiers. It boosts the performance of some weak classifiers in the combination by giving higher weights to the weak classifiers’ sensing decisions. Simulation results verify the performance improvement by the proposed algorithm compared to the existing techniques such as genetic algorithm soft decision fusion (GASDF), particle swarm optimization soft decision fusion (PSOSDF), maximum gain combination soft decision fusion (MGCSDF) and count hard decision fusion (CHDF). The experimental setup is conducted at different levels of the signal-to-noise ratios (SNRs), total number of cooperative users and sensing samples that show minimum error probability results for the proposed scheme.
Performance Improvement of Matrix Converter Direct Torque Control System
Authors: Zou Bowei , Guo Yougui , Xiao Xi , Yang Bowen , Wang Xiao , Shi Mingzhang , Tu Yulin
Published: June 2020

In asynchronous motor direct torque control systems, the power supply using the matrix converter can achieve the effect of direct torque control and also has the advantages of the matrix converter. Nonetheless, direct torque control still has drawbacks in terms of pulsation. In this paper, the characteristics of direct torque control method and its existing problems are analyzed in depth. In view of the shortcomings of torque ripple, an improved scheme of torque tracking control is proposed based on conventional control methods. On the basis of theoretical simulation, DSP and FPGA algorithms are designed respectively in C language and VHDL to implement the proposed control strategy. Finally, a highly integrated experimental platform of matrix converter has been developed to verify the proposed control strategy. The simulation and experimental results verify the correctness and effectiveness of the improved scheme.
Building Resilient Urban Communities: The Case Study of Setubal Municipality, Portugal
Authors: Santos Angela , Sousa Nuno , Kremers Horst , Bucho José Luís
Published: June 2020

The Sendai Framework for Disaster Risk Reduction provides several guidelines that countries should follow. Still, some scientific papers discussed the limitations, difficulties, and strategies in the implementation of these guidelines. Therefore, the objective of this review is to understand what Setubal has done to cope with disasters, and the practical strategies to mitigate them. To achieve this, several methodological guidelines and Portuguese legal documents were analyzed. The results focus on the top four natural disasters that impacted the study area (landslides, earthquakes, tsunamis, and floods), and the current pandemic of COVID-19. The practical strategies implemented on the territory involve the installation of equipment such as emergency signs and electronic panels that allow the dissemination of information to the communities in real-time. Also, the collaboration with national and international scientists provided new insight to cope with disasters, by bridging the gap between law enforcement agencies, science, first responders, and the practical needs that local stakeholders must solve on the territory. Moreover, Setubal has implemented a variety of practical and innovative measures, and therefore, could be used as a model not only to other Portuguese municipalities but also to other countries.