bluuebunny/crossref_metadata_2025 huggingface dataset:
Laparoscopic Management of Initially Unrecognized Splenic Hydatid Cysts: A Case Report and Review of the Literature
Authors: Milosavljevic Vladimir , Veselinovic Milan , Tadic Boris , Galun Danijel , Ceranic Miljan , Eric Dragan , Bjelovic Milos
Published: December 2019

We present a case report that demonstrates diagnostic and intraoperative challenges in the laparoscopic management of initially unrecognized splenic hydatid disease. A male patient, aged 44, was admitted to our department with a big unilocular splenic cyst, radiologically (ultrasonography, computed tomography) characterized as a simple cyst. Serological tests for anti-Echonococcus antibody were negative, and chests X-ray findings were unremarkable, so laparoscopic cyst fenestration with omentoplasty was planned. The intraoperative finding did not correspond to a simple splenic cyst. Hydatid daughter cysts were recognized after the careful opening of the cyst wall. The operation was completed without shifting to open procedures. Laparoscopic partial pericystectomy with omentoplasty is a safe and effective surgical procedure for the management of splenic hydatid disease.
Synthesis of Imidazolium based PILs and Investigation of Their Blend Membranes for Gas Separation
Authors: Chouliaras Thanasis , Vollas Aristofanis , Ioannides Theophilos , Deimede Valadoula , Kallitsis Joannis
Published: December 2019

Polymeric (ionic liquid) (PIL) copolymers bearing cationic imidazolium pendants and polar acrylic acid groups (P(VBCImY-co-AAx)), which both favor the interaction with CO2 molecules, have been synthesized and blended with film forming, high glass transition temperature aromatic polyether-based pyridinium PILs (PILPyr). The blend membranes based on the above combination have been prepared and characterized in respect to their thermal and morphological behavior as well as to their gas separation properties. The used copolymers and blends showed a wide range of glass transition temperatures from 32 to 286 °C, while blends exhibited two phase morphology despite the presence of polar groups in the blend components that could participate in specific interactions. Finally, the membranes were studied in terms of their gas separation behavior. It revealed that blend composition, counter anion type and acrylic acid molar percentage affect the gas separation properties. In particular, PILPyr-TFSI/P(VBCImTFSI-co-AA20) blend with 80/20 composition shows CO2 permeability of 7.00 Barrer and quite high selectivity of 103 for the CO2/CH4 gas pair. Even higher CO2/CH4. selectivity of 154 was achieved for PILPyr-BF4/P(VBCImBF4-co-AA10) blend with composition 70/30.
The Bacterial Amyloid-Like Hfq Promotes In Vitro DNA Alignment
Authors: Wien Frank , Martinez Denis , Le Brun Etienne , Jones Nykola C. , Vrønning Hoffmann Søren , Waeytens Jehan , Berbon Melanie , Habenstein Birgit , Arluison Véronique
Published: December 2019

The Hfq protein is reported to be involved in environmental adaptation and virulence of several bacteria. In Gram-negative bacteria, Hfq mediates the interaction between regulatory noncoding RNAs and their target mRNAs. Besides these RNA-related functions, Hfq is also associated with DNA and is a part of the bacterial chromatin. Its precise role in DNA structuration is, however, unclear and whether Hfq plays a direct role in DNA-related processes such as replication or recombination is controversial. In previous works, we showed that Escherichia coli Hfq, or more precisely its amyloid-like C-terminal region (CTR), induces DNA compaction into a condensed form. In this paper, we evidence a new property for Hfq; precisely we show that its CTR influences double helix structure and base tilting, resulting in a strong local alignment of nucleoprotein Hfq:DNA fibers. The significance of this alignment is discussed in terms of chromatin structuration and possible functional consequences on evolutionary processes and adaptation to environment.
Modifications of the Aerobic Respiratory Chain of Paracoccus Denitrificans in Response to Superoxide Oxidative Stress
Authors: Sedláček Vojtěch , Kučera Igor
Published: December 2019

Paracoccus denitrificans is a strictly respiring bacterium with a core respiratory chain similar to that of mammalian mitochondria. As such, it continuously produces and has to cope with superoxide and other reactive oxygen species. In this work, the effects of artificially imposed superoxide stress on electron transport were examined. Exposure of aerobically growing cells to paraquat resulted in decreased activities of NADH dehydrogenase, succinate dehydrogenase, and N,N,N’,N’-tetramethyl-p-phenylenediamine (TMPD) oxidase. Concomitantly, the total NAD(H) pool size in cells was approximately halved, but the NADH/NAD+ ratio increased twofold, thus partly compensating for inactivation losses of the dehydrogenase. The inactivation of respiratory dehydrogenases, but not of TMPD oxidase, also took place upon treatment of the membrane fraction with xanthine/xanthine oxidase. The decrease in dehydrogenase activities could be fully rescued by anaerobic incubation of membranes in a mixture containing 2-mercaptoethanol, sulfide and ferrous iron, which suggests iron–sulfur clusters as targets for superoxide. By using cyanide titration, a stress-sensitive contribution to the total TMPD oxidase activity was identified and attributed to the cbb3-type terminal oxidase. This response (measured by both enzymatic activity and mRNA level) was abolished in a mutant defective for the FnrP transcription factor. Therefore, our results provide evidence of oxidative stress perception by FnrP.
The Simplified Human Intestinal Microbiota (SIHUMIx) Shows High Structural and Functional Resistance against Changing Transit Times in In Vitro Bioreactors
Authors: Schäpe Stephanie Serena , Krause Jannike Lea , Engelmann Beatrice , Fritz-Wallace Katarina , Schattenberg Florian , Liu Zishu , Müller Susann , Jehmlich Nico , Rolle-Kampczyk Ulrike , Herberth Gunda , von Bergen Martin
Published: December 2019

Many functions in host–microbiota interactions are potentially influenced by intestinal transit times, but little is known about the effects of altered transition times on the composition and functionality of gut microbiota. To analyze these effects, we cultivated the model community SIHUMIx in bioreactors in order to determine the effects of varying transit times (TT) on the community structure and function. After five days of continuous cultivation, we investigated the influence of different medium TT of 12 h, 24 h, and 48 h. For profiling the microbial community, we applied flow cytometric fingerprinting and revealed changes in the community structure of SIHUMIx during the change of TT, which were not associated with changes in species abundances. For pinpointing metabolic alterations, we applied metaproteomics and metabolomics and found, along with shortening the TT, a slight decrease in glycan biosynthesis, carbohydrate, and amino acid metabolism and, furthermore, a reduction in butyrate, methyl butyrate, isobutyrate, valerate, and isovalerate concentrations. Specifically, B. thetaiotaomicron was identified to be affected in terms of butyrate metabolism. However, communities could recover to the original state afterward. This study shows that SIHUMIx showed high structural stability when TT changed—even four-fold. Resistance values remained high, which suggests that TTs did not interfere with the structure of the community to a certain degree.
Characterization and Phylodynamics of Reassortant H12Nx Viruses in Northern Eurasia
Authors: Sharshov Kirill , Mine Junki , Sobolev Ivan , Kurskaya Olga , Dubovitskiy Nikita , Kabilov Marsel , Alikina Tatiana , Nakayama Momoko , Tsunekuni Ryota , Derko Anastasiya , Prokopyeva Elena , Alekseev Alexander , Shchelkanov Michael , Druzyaka Alexey , Gadzhiev Alimurad , Uchida Yuko , Shestopalov Alexander , Saito Takehiko
Published: December 2019

Wild waterfowl birds are known to be the main reservoir for a variety of avian influenza viruses of different subtypes. Some subtypes, such as H2Nx, H8Nx, H12Nx, and H14Nx, occur relatively rarely in nature. During 10-year long-term surveillance, we isolated five rare H12N5 and one H12N2 viruses in three different distinct geographic regions of Northern Eurasia and studied their characteristics. H12N2 from the Far East region was a double reassortant containing hemagglutinin (HA), non-structural (NS) and nucleoprotein (NP) segments of the American lineage and others from the classical Eurasian avian-like lineage. H12N5 viruses contain Eurasian lineage segments. We suggest a phylogeographical scheme for reassortment events associated with geographical groups of aquatic birds and their migration flyways. The H12N2 virus is of particular interest as this subtype has been found in common teal in the Russian Far East region, and it has a strong relation to North American avian influenza virus lineages, clearly showing that viral exchange of segments between the two continents does occur. Our results emphasize the importance of Avian Influenza Virus (AIV) surveillance in Northern Eurasia for the annual screening of virus characteristics, including the genetic constellation of rare virus subtypes, to understand the evolutionary ecology of AIV.
Profiling the Oral Microbiome and Plasma Biochemistry of Obese Hyperglycemic Subjects in Qatar
Authors: Sohail Muhammad U. , Elrayess Mohamed A. , Al Thani Asma A. , Al-Asmakh Maha , Yassine Hadi M.
Published: December 2019

The present study is designed to compare demographic characteristics, plasma biochemistry, and the oral microbiome in obese (N = 37) and lean control (N = 36) subjects enrolled at Qatar Biobank, Qatar. Plasma hormones, enzymes, and lipid profiles were analyzed at Hamad Medical Cooperation Diagnostic Laboratory. Saliva microbiome characterization was carried out by 16S rRNA amplicon sequencing using Illumina MiSeq platform. Obese subjects had higher testosterone and sex hormone-binding globulin (SHBG) concentrations compared to the control group. A negative association between BMI and testosterone (p < 0.001, r = −0.64) and SHBG (p < 0.001, r = −0.34) was observed. Irrespective of the study groups, the oral microbiome was predominantly occupied by Streptococcus, Prevotella, and Veillonella species. A generalized linear model revealed that the Firmicutes/Bacteroidetes ratio (2.25 ± 1.83 vs. 1.76 ± 0.58; corrected p-value = 0.04) was higher, and phylum Fusobacteria concentration (4.5 ± 3.0 vs. 6.2 ± 4.3; corrected p-value = 0.05) was low in the obese group compared with the control group. However, no differences in microbiome diversity were observed between the two groups as evaluated by alpha (Kruskal–Wallis p ≥ 0.78) and beta (PERMANOVA p = 0.37) diversity indexes. Certain bacterial phyla (Acidobacteria, Bacteroidetes, Fusobacteria, Proteobacteria, Spirochaetes, and Firmicutes/Bacteroidetes) were positively associated (p = 0.05, r ≤ +0.5) with estradiol, fast food consumption, creatinine, breastfed during infancy, triglycerides, and thyroid-stimulating hormone concentrations. In conclusion, no differences in oral microbiome diversity were observed between the studied groups. However, the Firmicutes/Bacteroidetes ratio, a recognized obesogenic microbiome trait, was higher in the obese subjects. Further studies are warranted to confirm these findings in a larger cohort.
Understanding Long Noncoding RNA and Chromatin Interactions: What We Know So Far
Authors: Mishra Kankadeb , Kanduri Chandrasekhar
Published: December 2019

With the evolution of technologies that deal with global detection of RNAs to probing of lncRNA-chromatin interactions and lncRNA-chromatin structure regulation, we have been updated with a comprehensive repertoire of chromatin interacting lncRNAs, their genome-wide chromatin binding regions and mode of action. Evidence from these new technologies emphasize that chromatin targeting of lncRNAs is a prominent mechanism and that these chromatin targeted lncRNAs exert their functionality by fine tuning chromatin architecture resulting in an altered transcriptional readout. Currently, there are no unifying principles that define chromatin association of lncRNAs, however, evidence from a few chromatin-associated lncRNAs show presence of a short common sequence for chromatin targeting. In this article, we review how technological advancements contributed in characterizing chromatin associated lncRNAs, and discuss the potential mechanisms by which chromatin associated lncRNAs execute their functions.
Dietary Factors in the Control of Gut Homeostasis, Intestinal Stem Cells, and Colorectal Cancer
Authors: Francescangeli Federica , De Angelis Maria Laura , Zeuner Ann
Published: December 2019

Colorectal cancer (CRC) is the third commonly diagnosed cancer and the second leading cause of cancer-related deaths worldwide. Global CRC burden is expected to increase by 60% in the next decade, with low-income countries experiencing an escalation of CRC incidence and mortality in parallel to the adoption of western lifestyles. CRC incidence is also sharply increasing in individuals younger than 50 years, often presenting at advanced stages and with aggressive features. Both genetic and environmental factors have been recognized as major contributors for the development of CRC, the latter including diet-related conditions such as chronic inflammation and obesity. In particular, a diet rich in fat and sugars (Western-style diet, WSD) has been shown to induce multiple pathophysiological changes in the intestine linked to an increased risk of CRC. In this scenario, dietary factors have been recently shown to play novel unexpected roles in the regulation of intestinal stem cells (ISCs) and of the gut microbiota, which represent the two main biological systems responsible for intestinal homeostasis. Furthermore, diet is increasingly recognized to play a key role in the neoplastic transformation of ISCs and in the metabolic regulation of colorectal cancer stem cells. This review illustrates novel discoveries on the role of dietary components in regulating intestinal homeostasis and colorectal tumorigenesis. Particular focus is dedicated to new areas of research with potential clinical relevance including the effect of food components on ISCs and cancer stem cells (CSCs), the existence of CRC-specific microbial signatures and the alterations of intestinal homeostasis potentially involved in early-onset CRC. New insights on the role of dietary factors in intestinal regulation will provide new tools not only for the prevention and early diagnosis of CRC but also for improving the effectiveness of current CRC therapies.
Additive Manufacturing of Personalized Pharmaceutical Dosage Forms via Stereolithography
Authors: Healy Andrew V. , Fuenmayor Evert , Doran Patrick , Geever Luke M. , Higginbotham Clement L. , Lyons John G.
Published: December 2019

The introduction of three-dimensional printing (3DP) has created exciting possibilities for the fabrication of dosage forms, paving the way for personalized medicine. In this study, oral dosage forms of two drug concentrations, namely 2.50% and 5.00%, were fabricated via stereolithography (SLA) using a novel photopolymerizable resin formulation based on a monomer mixture that, to date, has not been reported in the literature, with paracetamol and aspirin selected as model drugs. In order to produce the dosage forms, the ratio of poly(ethylene glycol) diacrylate (PEGDA) to poly(caprolactone) triol was varied with diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (Irgacure TPO) utilized as the photoinitiator. The fabrication of 28 dosages in one print process was possible and the printed dosage forms were characterized for their drug release properties. It was established that both drugs displayed a sustained release over a 24-h period. The physical properties were also investigated, illustrating that SLA affords accurate printing of dosages with some statistically significant differences observed from the targeted dimensional range, indicating an area for future process improvement. The work presented in this paper demonstrates that SLA has the ability to produce small, individualized batches which may be tailored to meet patients’ specific needs or provide for the localized production of pharmaceutical dosage forms.
Self-Micellizing Technology Improves the Properties of Ezetimibe and Increases Its Effect on Hyperlipidemic Rats
Authors: Torrado-Salmerón Carlos , Guarnizo-Herrero Víctor , Cerezo-Garreta Javier , Torrado Durán Guillermo , Torrado-Santiago Santiago
Published: December 2019

The aim of this work was to develop ezetimibe self-micellizing solid dispersions using Kolliphor® RH40 (MS-K) as a surfactant incorporating ezetimibe (EZ) into the croscarmellose hydrophilic carrier. Different ezetimibe:Kolliphor® ratios were studied to select micellar systems that improve the dissolution properties of ezetimibe. The different formulations were characterized by means of solid state analysis by SEM, powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and dissolution studies. These physicochemical studies showed a decrease from the crystalline structure of ezetimibe (EZ) to its amorphous state in the micellar systems (MS-K). A rapid dissolution profile was observed in these micellar systems compared to the drug raw material and physical mixture. Efficacy studies were conducted using a high-fat diet that induced hyperlipidemic rats. The micellar system selected (MS-K 1:0.75) revealed a significant improvement in serum levels of total cholesterol (TC), low-density lipoproteins (LDL), and triglycerides (TG) compared to ezetimibe raw material. The histopathological examination of liver tissue also showed that this micellar system exhibited more beneficial effects on liver steatosis compared to ezetimibe raw material (EZ-RM) and the high-fat diet group (HFD). This study suggests that EZ micellar systems using Kolliphor® RH40 could enhance the antihyperlipidemic effect of ezetimibe and reduce liver steatosis.
Composite Cryogel with Polyelectrolyte Complexes for Growth Factor Delivery
Authors: Sultankulov Bolat , Berillo Dmitriy , Kauanova Sholpan , Mikhalovsky Sergey , Mikhalovska Lyuba , Saparov Arman
Published: December 2019

Macroporous scaffolds composed of chitosan (CHI), hydroxyapatite (HA), heparin (Hep), and polyvinyl alcohol (PVA) were prepared with a glutaraldehyde (GA) cross-linker by cryogelation. Addition of PVA to the reaction mixture slowed down the formation of a polyelectrolyte complex (PEC) between CHI and Hep, which allowed more thorough mixing, and resulted in the development of the homogeneous matrix structure. Freezing of the CHI-HA-GA and PVA-Hep-GA mixture led to the formation of a non-stoichiometric PEC between oppositely charged groups of CHI and Hep, which caused further efficient immobilization of bone morphogenic protein 2 (BMP-2) possible due to electrostatic interactions. It was shown that the obtained cryogel matrix released BMP-2 and supported the differentiation of rat bone marrow mesenchymal stem cells (rat BMSCs) into the osteogenic lineage. Rat BMSCs attached to cryogel loaded with BMP-2 and expressed osteocalcin in vitro. Obtained composite cryogel with PEC may have high potential for bone regeneration and tissue engineering applications.
An Integrated Health-System Specialty Pharmacy Model for Coordinating Transitions of Care: Specialty Medication Challenges and Specialty Pharmacist Opportunities
Authors: Zuckerman Autumn D. , Carver Alicia , Cooper Katrina , Markley Brandon , Mitchell Amy , Reynolds Victoria W. , Saknini Marci , Wyatt Houston , Kelley Tara
Published: December 2019

Adherence and persistence to specialty medications are necessary to achieve successful outcomes of costly therapies. The increasing use of specialty medications has exposed several unique barriers to certain specialty treatments’ continuation. Integrated specialty pharmacy teams facilitate transitions in sites of care, between different provider types, among prescribed specialty medications, and during financial coverage changes. We review obstacles encountered within these types of transitions and the role of the specialty pharmacist in overcoming these obstacles. Case examples for each type of specialty transition provide insight into the unique complexities faced by patients, and shed light on pharmacists’ vital role in patient care. This insightful and real-world experience is needed to facilitate best practices in specialty care, particularly in the growing number of health-system specialty pharmacies.
Building a Patient-Centered Weight Management Program: A Mixed Methods Project to Obtain Patients’ Information Needs and Ideas for Program Structure
Authors: Arnold Austin , Holmes Erin , Rosenthal Meagen
Published: December 2019

Achieving and maintaining weight loss for large segments of the population remains elusive, despite evidence demonstrating the value of many weight management programs. This study aimed to gather patients’ perceptions on weight management education needs, and ideas for the structure of a weight management program to be delivered in community pharmacies. This was an exploratory mixed methods study combining qualitative focus group interviews with a cross-sectional survey. Three focus group interviews were conducted, along with a brief survey based on focus groups findings and sent to all eligible participants. The survey allowed for individual responses on the program components and narrowing down of focus group findings. Nearly half of the respondents (45.9%) wanted further education on limiting carbohydrate and sugar intake. Participants were most interested in identifying different exercises appropriate for those with physical limitations (48.6%). Most participants preferred 1 h meetings (70.3%) that contain a mix of one-on-one and group meeting formats (67.6%). The results of the study suggest a three-month weight management program, with a combination of group and individual in-person meetings occurring twice per month, would be of most interest to patients.
Particle-in-Cell Simulation of Quasi-Neutral Plasma Trapping by RF Multipole Electric Fields
Authors: Hicks Nathaniel K. , Bowman Amanda , Godden Katarina
Published: December 2019

Radio-frequency (RF) charged particle traps, such as the Paul trap or higher order RF multipole traps, may be used to trap quasi-neutral plasma. The presence of positive and negative plasma species mitigates the ejection of particles that occurs due to space charge repulsion. For symmetric species, such as a pair plasma, the trapped particle distribution is essentially equal for both species. For plasma with species of disparate charge-to-mass ratio, the RF parameters are chosen to directly trap the lighter species, leading to loss of the heavier species until sufficient net space charge develops to prevent further loss. Two-dimensional (2D) electrostatic particle-in-cell simulations are performed of cases with mass ratio m+/m− = 10, and also with ion–electron plasma. Multipole cases including order N = 2 (quadrupole) and higher order N = 8 (hexadecapole) are considered. The light ion-heavy ion N = 8 case exhibits particles losses less than 5% over 2500 RF periods, but the N = 8 ion–electron case exhibits a higher loss rate, likely due to non-adiabaticity of electron trajectories at the boundary, but still with low total electron loss current on the order of 10 μA. The N = 2 ion-electron case is adiabatic and stable, but is subject to a smaller trapping volume and greater initial perturbation of the bulk plasma by the trapping field.
Durable Antimicrobial Behaviour from Silver-Graphene Coated Medical Textile Composites
Authors: Noor Nuruzzaman , Mutalik Suhas , Younas Muhammad Waseem , Chan Cheuk Ying , Thakur Suman , Wang Faming , Yao Mian Zhi , Mou Qianqian , Leung Polly Hang-mei
Published: December 2019

Silver nanoparticle (AgNP) and AgNP/reduced graphene oxide (rGO) nanocomposite impregnated medical grade polyviscose textile pads were formed using a facile, surface-mediated wet chemical solution-dipping process, without further annealing. Surfaces were sequentially treated in situ with a sodium borohydride (NaBH4) reducing agent, prior to formation, deposition, and fixation of Ag nanostructures and/or rGO nanosheets throughout porous non-woven (i.e., randomly interwoven) fibrous scaffolds. There was no need for stabilising agent use. The surface morphology of the treated fabrics and the reaction mechanism were characterised by Fourier transform infrared (FTIR) spectra, ultraviolet-visible (UV–Vis) absorption spectra, X-ray diffraction (XRD), Raman spectroscopy, dynamic light scattering (DLS) energy-dispersive X-ray analysis (EDS), and scanning electron microscopic (SEM). XRD and EDS confirmed the presence of pure-phase metallic silver. Variation of reducing agent concentration allowed control over characteristic plasmon absorption of AgNP while SEM imaging, EDS, and DLS confirmed the presence of and dispersion of Ag particles, with smaller agglomerates existing with concurrent rGO use, which also coincided with enhanced AgNP loading. The composites demonstrated potent antimicrobial activity against the clinically relevant gram-negative Escherichia coli (a key causative bacterial agent of healthcare-associated infections; HAIs). The best antibacterial rate achieved for treated substrates was 100% with only a slight decrease (to 90.1%) after 12 equivalent laundering cycles of standard washing. Investigation of silver ion release behaviours through inductively coupled plasmon optical emission spectroscopy (ICP-OES) and laundering durability tests showed that AgNP adhesion was aided by the presence of the rGO host matrix allowing for robust immobilisation of silver nanostructures with relatively high stability, which offered a rapid, convenient, scalable route to conformal NP–decorated and nanocomposite soft matter coatings.
Improved Thermal Insulating Properties of Renewable Polyol Based Polyurethane Foams Reinforced with Chicken Feathers
Authors: Aranberri Ibon , Montes Sarah , Wesołowska Ewa , Rekondo Alaitz , Wrześniewska-Tosik Krystyna , Grande Hans-Jürgen
Published: December 2019

In the present work, sustainable rigid polyurethane foams (RPUF) reinforced with chicken feathers (CF) were prepared and characterized. The bio-based polyol used to formulate the foams was obtained from castor oil. This investigation reports the influence of the chicken feathers fibers as reinforcement of RPUF, on water absorption, thermal, mechanical and morphological properties (field-emission scanning electron microscope—FESEM) and thermal conductivity on water-blown biofoams. It was found that the biofoams improved thermal insulating properties when CF was added. The addition of CF to foams provided lower heat flux density to the biofoams obtaining bio-based materials with better insulation properties. The results obtained in this study proved that the incorporation of CF to RPUF modified the cell structure of the foams affecting their physical and mechanical properties, as well as functional properties such as the heat transmission factor. These biofoams containing up to 45% of bio-based materials have shown the potential to replace fully petroleum-based foams in thermal insulation applications.
Experimental Study on Spray Breakup in Turbulent Atomization Using a Spiral Nozzle
Authors: Krištof Ondřej , Bulejko Pavel , Svěrák Tomáš
Published: December 2019

Spiral nozzles are widely used in wet scrubbers to form an appropriate spray pattern to capture the polluting gas/particulate matterwith the highest possible efficiency. Despite this fact, and a fact that it is a nozzle with a very atypical spray pattern (a full cone consisting of three concentric hollow cones), very limited amount of studies have been done so far on characterization of this type of nozzle. This work reports preliminary results on the spray characteristics of a spiral nozzle used for gas absorption processes. First, we experimentally measured the pressure impact footprint of the spray generated. Then effective spray angles were evaluated from the photographs of the spray and using the pressure impact footprint records via Archimedean spiral equation. Using the classical photography, areas of primary and secondary atomization were determined together with the droplet size distribution, which were further approximated using selected distribution functions. Radial and tangential spray velocity of droplets were assessed using the laser Doppler anemometry. The results show atypical behavior compared to different types of nozzles. In the investigated measurement range, the droplet-size distribution showed higher droplet diameters (about 1 mm) compared to, for example, air assisted atomizers. It was similar for the radial velocity, which was conversely lower (max velocity of about 8 m/s) compared to, for example, effervescent atomizers, which can produce droplets with a velocity of tens to hundreds m/s. On the contrary, spray angle ranged from 58° and 111° for the inner small and large cone, respectively, to 152° for the upper cone, and in the measured range was independent of the inlet pressure of liquid at the nozzle orifice.
Evolutionary Observer Ensemble for Leak Diagnosis in Water Pipelines
Authors: Navarro A. , Delgado-Aguiñaga J. A. , Sánchez-Torres J. D. , Begovich O. , Besançon G.
Published: December 2019

This work deals with the Leak Detection and Isolation (LDI) problem in water pipelines based on some heuristic method and assuming only flow rate and pressure head measurements at both ends of the duct. By considering the single leak case at an interior node of the pipeline, it has been shown that observability is indeed satisfied in this case, which allows designing an observer for the unmeasurable state variables, i.e., the pressure head at leak position. Relying on the fact that the origin of the observation error is exponentially stable if all parameters (including the leak coefficients) are known and uniformly ultimately bounded otherwise, the authors propose a bank of observers as follows: taking into account that the physical pipeline parameters are well-known, and there is only uncertainty about leak coefficients (position and magnitude), a pair of such coefficients is taken from a search space and is assigned to an observer. Then, a Genetic Algorithm (GA) is exploited to minimize the integration of the square observation error. The minimum integral observation error will be reached in the observer where the estimated leak parameters match the real ones. Finally, some results are presented by using real-noisy databases coming from a test bed plant built at Cinvestav-Guadalajara, aiming to show the potentiality of this method.
Activation Energy and Second Order Slip in Bioconvection of Oldroyd-B Nanofluid over a Stretching Cylinder: A Proposed Mathematical Model
Authors: Tlili Iskander , Waqas H. , Almaneea Abulmajeed , Khan Sami Ullah , Imran M.
Published: December 2019

The thermal performances based on the interaction of nanoparticles are the topic of great interest in recent years. In the current continuation, we have utilized the activation energy and thermal radiation consequences in the bioconvection flow of magnetized Oldroyd-B nanoparticles over a stretching cylinder. As a novelty, the second order slip features (Wu’s slip) and convective Nield boundary assumptions are also introduced for the flow situation. The heat performances of nanofluids are captured with an evaluation of the famous Buongiorno’s model which enables us to determine the attractive features of Brownian motion and thermophoretic diffusion. The suggested thermal system is based on the flow velocity, nanoparticles temperature, nanoparticles volume fraction and motile microorganisms. The governing flow equations for the flow problem are constituted with relevant references for which numerically solution is developed via shooting algorithm. A detailed graphically analysis for the assisted flow problem is performed in view of the involved parameters. Although some studies are available in the literature which deals with the flow of various fluids over-stretching cylinder, the phenomenon of bioconvection and other interesting features are not reported yet. Therefore, present scientific computations are performed to fill this gap and the reported results can be more useful for the enhancement of thermal extrusion processes, solar energy systems, and biofuels.
Numerical Simulation on Hydraulic Characteristics of Nozzle in Waterjet Propulsion System
Authors: Wang Chuan , He Xiaoke , Cheng Li , Luo Can , Xu Jing , Chen Kun , Jiao Weixuan
Published: December 2019

As an important over-current component of the waterjet propulsion system, the main function of a nozzle is to transform the mechanical energy of the propulsion pump into the kinetic energy of the water and eject the water flow to obtain thrust. In this study, the nozzle with different geometry and parameters was simulated based on computational fluid dynamics simulation and experiment. Numerical results show a good agreement with experimental results. The results show that the nozzle with a circular shape outlet shrinks evenly. Under the designed flow rate condition, the velocity uniformity of the circular nozzle is 0.26% and 0.34% higher than that of the elliptical nozzle and the rounded rectangle nozzle, respectively. The pump efficiency of the circular nozzle is 0.31% and 0.14% higher than that of the others. The pressure recovery and hydraulic loss of the circular nozzle are superior. The hydraulic characteristics of the propulsion pump and waterjet propulsion system are optimal when the nozzle area is 30% times the outlet area of the inlet duct. Thus, the shaft power, head, thrust, and system efficiency of the propulsion pump and waterjet propulsion system are maximized. The system efficiency curve decreases rapidly when the outlet area exceeds 30% times the outlet area of the inlet duct. The transition curve forms greatly affect thrust and system efficiency. The transition of the linear contraction shows improved uniformity, and the hydraulic loss is reduced. Furthermore, the hydraulic performance of the nozzle with a linear contraction transition is better than that of others.
A Risk Aversion Dispatching Optimal Model for a Micro Energy Grid Integrating Intermittent Renewable Energy and Considering Carbon Emissions and Demand Response
Authors: Fu Xiaoxu , Fan Wei , Lin Hongyu , Li Nan , Li Peng , Ju Liwei , Zhou Feng’ao
Published: December 2019

This paper focuses on an optimal schedule for a micro energy grid considering the maximum total carbon emission allowance (MTEA). Firstly, the paper builds an energy devices operation model and demand response (DR) model. Secondly, to maximize the economical operation revenue, the basic scheduling model for the micro energy grid is constructed. Thirdly, the conditional value at risk method and robust stochastic theory are introduced to describe the uncertainty of wind power, photovoltaic power, and load, and a risk aversion model is proposed. Finally, this paper selects the Xinxiang active distribution network demonstration project in Jining, China as an example. The results show that: (1) a micro energy grid can make the most use of the complementary characters of different energy sources to meet different energy demands for electricity, heat, cold, and gas; (2) the risk aversion scheduling model can represent the influence of uncertainty variables in objective functions and constraints, and provide a basis for decision makers who have different attitudes; and (3) DR can smooth the energy load curves. MTEA can enhance the competitiveness of the clean energy market, thus promoting the grid-connected generation of clean energy. Therefore, the risk aversion model can maximize the economic benefits and provide a basis for decision makers while rationally controlling risks.
Optimization of the Technology Transfer Process Using Gantt Charts and Critical Path Analysis Flow Diagrams: Case Study of the Korean Automobile Industry
Authors: Lee Sangkon , Shvetsova Olga A.
Published: December 2019

This research is focused on the technology transfer process in the automobile industry using project management tools. The aim of this research is the development of a technology-transfer model using Gantt charts and Critical Path Analysis flow diagrams to achieve a sustainable planning process in the global environment. To achieve this goal, the authors use Gantt charts and Critical Path Analysis flow diagrams. The hypothesis and three research questions are presented, which suggest a relationship between project management tools and the sustainable planning process of technology transfer. During the research, we use the case study of the Korean automobile industry as an excellent example of the technology-transfer process in global markets. A single project of technology transfer is discussed: the technology knowledge transfer from Korean headquarters to a Russian manufacturing subsidiary (Hyundai Motor Corporation). Quantitative data were collected through the open resources of the corporation; the qualitative data were analyzed through a case study and model parameter evaluation. The significant result that the combination of Gantt Charts and Critical Path Analysis flow diagrams methods improves the planning process for technology-transfer projects was found in this survey. It is noticed that (a) it is useful to apply project-management tools for technology transferring models; (b) Gantt Charts and Critical Path Analysis flow diagrams have a sustainable impact on technology transfer projects; and (c) critical paths and operational reserves in network diagrams help to optimize the planning process for technology transfer.
Design and Implementation of the Off-Line Robust Model Predictive Control for Solid Oxide Fuel Cells
Authors: Chatrattanawet Narissara , Kheawhom Soorathep , Chen Yong-Song , Arpornwichanop Amornchai
Published: December 2019

An off-line robust linear model predictive control (MPC) using an ellipsoidal invariant set is synthesized based on an uncertain polytopic approach and then implemented to control the temperature and fuel in a direct internal reforming solid oxide fuel cell (SOFC). The state feedback control is derived by minimizing an upper bound on the worst-case performance cost. The simulation results indicate that the synthesized robust MPC algorithm can control and guarantee the stability of the SOFC; although there are uncertainties in some model parameters, it can keep both the temperature and fuel at their setpoints.
Use of A Neural Network-Based Ocean Body Radiative Transfer Model for Aerosol Retrievals from Multi-Angle Polarimetric Measurements
Authors: Fan Cheng , Fu Guangliang , Di Noia Antonio , Smit Martijn , H.H. Rietjens Jeroen , A. Ferrare Richard , Burton Sharon , Li Zhengqiang , P. Hasekamp Otto
Published: December 2019

For aerosol retrieval from multi-angle polarimetric (MAP) measurements over the ocean it is important to accurately account for the contribution of the ocean-body to the top-of-atmosphere signal, especially for wavelengths <500 nm. Performing online radiative transfer calculations in the coupled atmosphere ocean system is too time consuming for operational retrieval algorithms. Therefore, mostly lookup-tables of the ocean body reflection matrix are used to represent the lower boundary in an atmospheric radiative transfer model. For hyperspectral measurements such as those from Spectro-Polarimeter for Planetary Exploration (SPEXone) on the NASA Plankton, Aerosol, Cloud and ocean Ecosystem (PACE) mission, also the use of look-up tables is unfeasible because they will become too big. In this paper, we propose a new method for aerosol retrieval over ocean from MAP measurements using a neural network (NN) to model the ocean body reflection matrix. We apply the NN approach to synthetic SPEXone measurements and also to real data collected by SPEX airborne during the Aerosol Characterization from Polarimeter and Lidar (ACEPOL) campaign. We conclude that the NN approach is well capable for aerosol retrievals over ocean, introducing no significant error on the retrieved aerosol properties
The Influence of Vegetation Characteristics on Individual Tree Segmentation Methods with Airborne LiDAR Data
Authors: Yang Qiuli , Su Yanjun , Jin Shichao , Kelly Maggi , Hu Tianyu , Ma Qin , Li Yumei , Song Shilin , Zhang Jing , Xu Guangcai , Wei Jianxin , Guo Qinghua
Published: December 2019

This study investigated the effects of forest type, leaf area index (LAI), canopy cover (CC), tree density (TD), and the coefficient of variation of tree height (CVTH) on the accuracy of different individual tree segmentation methods (i.e., canopy height model, pit-free canopy height model (PFCHM), point cloud, and layer stacking seed point) with LiDAR data. A total of 120 sites in the Sierra Nevada Forest (California) and Shavers Creek Watershed (Pennsylvania) of the United States, covering various vegetation types and characteristics, were used to analyze the performance of the four selected individual tree segmentation algorithms. The results showed that the PFCHM performed best in all forest types, especially in conifer forests. The main forest characteristics influencing segmentation methods were LAI and CC, LAI and TD, and CVTH in conifer, broadleaf, and mixed forests, respectively. Most of the vegetation characteristics (i.e., LAI, CC, and TD) negatively correlated with all segmentation methods, while the effect of CVTH varied with forest type. These results can help guide the selection of individual tree segmentation method given the influence of vegetation characteristics.
A Generic Model of the Pseudo-Random Generator Based on Permutations Suitable for Security Solutions in Computationally-Constrained Environments
Authors: Unkašević Tomislav , Banjac Zoran , Milosavljević Milan
Published: December 2019

Symmetric cryptography methods have an important role in security solutions design in data protection. In that context, symmetric cryptography algorithms and pseudo-random generators connected with them have strong influence on designed security solutions. In the computationally constrained environment, security efficiency is also important. In this paper we proposed the design of a new efficient pseudo-random generator parameterized by two pseudo-random sequences. By the probabilistic, information-theoretic and number theory methods we analyze characteristics of the generator. Analysis produced several results. We derived sufficient conditions, regarding parameterizing sequences, so that the output sequence has uniform distribution. Sufficient conditions under which there is no correlation between parameterizing sequences and output sequence are also derived. Moreover, it is shown that mutual information between the output sequence and parameterizing sequences tends to zero when the generated output sequence length tends to infinity. Regarding periodicity, it is shown that, with appropriately selected parameterizing sequences, the period of the generated sequence is significantly longer than the periods of the parameterizing sequences. All this characteristics are desirable regarding security applications. The efficiency of the proposed construction can be achieved by selection parameterizing sequences from the set of efficient pseudo-random number generators, for example, multiple linear feedback shift registers.
Velocity Control of Traveling-Wave Ultrasonic Motors Based on Stator Vibration Amplitude
Authors: Fang Zhiwei , Yang Tianyue , Zhu Yuanfei , Li Shiyang , Yang Ming
Published: December 2019

Nonlinearity and resonance frequency shift make it difficult to control the operation of the traveling-wave ultrasonic motors (TWUSMs) in a wide velocity and load range. In this paper, a velocity control scheme based on the stator vibration amplitude and the parallel resonance frequency (VCBVF) of TWUSMs is proposed. Then, the stator vibration amplitude (SVA) and parallel resonance frequency ( f p ) are detected by a transformer ratio-arm bridge. Based on the linear relationship between the velocity and the SVA of TWUSMs, the proposed scheme achieves the control of the mechanical loop and the electrical loop. The linear relationship between the velocity and the SVA makes the mechanical loop achieve the target velocity efficiently, according to the SVA, and the electrical loop could provide the target SVA quickly. Experimental results show that the response time of velocity is 3–4 ms under different load torques and the overshoot is less than 22%. In addition, the proposed scheme improves the efficiency of TWUSMs due to f p tracking. Due to directing the SVA control, the proposed scheme can heighten the velocity response and the load adaptability of TWUSMs, and promote the application of TWUSMs under various conditions.
Phase Difference Measurement of Under-Sampled Sinusoidal Signals for InSAR System Phase Error Calibration
Authors: Yuan Zhihui , Gu Yice , Xing Xuemin , Chen Lifu
Published: December 2019

Phase difference measurement of sinusoidal signals can be used for phase error calibration of the spaceborne single-pass interferometric synthetic aperture radar (InSAR) system. However, there are currently very few papers devoted to the discussion of phase difference measurement of high-frequency internal calibration signals of the InSAR system, especially the discussion of sampling frequency selection and the corresponding measuring method when the high-frequency signals are sampled under the under-sampling condition. To solve this problem, a phase difference measurement method for high-frequency sinusoidal signals is proposed, and the corresponding sampling frequency selection criteria under the under-sampling condition is determined. First, according to the selection criteria, the appropriate under-sampling frequency was chosen to sample the two sinusoidal signals with the same frequency. Then, the sampled signals were filtered by limited recursive average filtering (LRAF) and coherently accumulated in the cycle of the baseband signal. Third, the filtered and accumulated signals were used to calculate the phase difference of the two sinusoidal signals using the discrete Fourier transform (DFT), digital correlation (DC), and Hilbert transform (HT)-based methods. Lastly, the measurement accuracy of the three methods were compared respectively by different simulation experiments. Theoretical analysis and experiments verified the effectiveness of the proposed method for the phase error calibration of the InSAR system.
Vision-Based Attentiveness Determination Using Scalable HMM Based on Relevance Theory
Authors: Tiawongsombat Prasertsak , Jeong Mun-Ho , Pirayawaraporn Alongkorn , Lee Joong-Jae , Yun Joo-Seop
Published: December 2019

Attention capability is an essential component of human–robot interaction. Several robot attention models have been proposed which aim to enable a robot to identify the attentiveness of the humans with which it communicates and gives them its attention accordingly. However, previous proposed models are often susceptible to noisy observations and result in the robot’s frequent and undesired shifts in attention. Furthermore, most approaches have difficulty adapting to change in the number of participants. To address these limitations, a novel attentiveness determination algorithm is proposed for determining the most attentive person, as well as prioritizing people based on attentiveness. The proposed algorithm, which is based on relevance theory, is named the Scalable Hidden Markov Model (Scalable HMM). The Scalable HMM allows effective computation and contributes an adaptation approach for human attentiveness; unlike conventional HMMs, Scalable HMM has a scalable number of states and observations and online adaptability for state transition probabilities, in terms of changes in the current number of states, i.e., the number of participants in a robot’s view. The proposed approach was successfully tested on image sequences (7567 frames) of individuals exhibiting a variety of actions (speaking, walking, turning head, and entering or leaving a robot’s view). From these experimental results, Scalable HMM showed a detection rate of 76% in determining the most attentive person and over 75% in prioritizing people’s attention with variation in the number of participants. Compared to recent attention approaches, Scalable HMM’s performance in people attention prioritization presents an approximately 20% improvement.