bluuebunny/crossref_metadata_2025 huggingface dataset:
Spalling Resistance of Fiber-Reinforced Ultra-High-Strength Concrete Subjected to the ISO-834 Standard Fire Curve: Effects of Thermal Strain and Water Vapor Pressure
Authors: Lee Taegyu , Kim Gyuyong , Choe Gyeongcheol , Hwang Euichul , Lee Jaesung , Ryu Dongwoo , Nam Jeongsoo
Published: August 2020

The prevention and mitigation of spalling in high-strength concrete (HSC) rely on mixing polypropylene (PP) as an additive reinforcement. The dense internal structures of ultra-high-strength concrete (UHSC) result in risks associated with a high thermal stress and high water vapor pressure. Herein, the effects of pore formation and thermal strain on spalling are examined by subjecting fiber-laden UHSC to conditions similar to those under which the ISO-834 standard fire curve was obtained. Evaluation of the initial melting properties of the fibers based on thermogravimetric analysis (TGA) and differential thermal analysis (DTA) demon strated that although nylon fibers exhibit a higher melting point than polypropylene and polyethylene fibers, weight loss occurs below 200 °C. Nylon fibers were effective at reducing spalling in UHSC compared to polypropylene and polyethylene fibers as they rapidly melt, leading to pore formation. We anticipate that these results will serve as references for future studies on the prevention of spalling in fiber-reinforced UHSC.
The Effect of Heat Treatment on the Microstructure and Mechanical Properties of the Novel Low-Cost Ti-3Al-5Mo-4Cr-2Zr-1Fe Alloy
Authors: Sun Meng , Li Dong , Guo Yanhua , Wang Ying , Dong Yuecheng , Dan Zhenhua , Chang Hui
Published: August 2020

In order to reduce the cost of titanium alloys, a novel low-cost Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) titanium alloy was developed. The influence of heat treatment on the microstructure characteristics and mechanical properties of the new alloy was investigated. The results showed that the microstructure of Ti-35421 alloy consists of a lamina primary α phase and a β phase after the solution treatment at the α + β region. After aging treatment, the secondary α phase precipitates in the β matrix. The precipitation of the secondary α phase is closely related to heat treatment parameters—the volume fraction and size of the secondary α phase increase when increasing the solution temperature or aging time. At the same solution temperature and aging time, the secondary α phase became coarser, and the fraction decreased with increasing aging temperature. When Ti-35421 alloy was solution-treated at the α + β region for 1 h with aging surpassing 8 h, the tensile strength, yield strength, elongation and reduction of the area were achieved in a range of 1172.7–1459.0 MPa, 1135.1–1355.5 MPa, 5.2–11.8%, and 7.5–32.5%, respectively. The novel low-cost Ti-35421 alloy maintains mechanical properties and reduces the cost of materials compared with Ti-3Al-5Mo-5V-4Cr-2Zr (Ti-B19) alloy.
Wettability of Asphalt Concrete with Natural and Recycled Aggregates from Sanitary Ceramics
Authors: Andrzejuk Wojciech , Szewczak Andrzej , Fic Stanisław , Łagód Grzegorz
Published: August 2020

In line with the current trend of seeking alternative methods for modification of the existing building composites, such as mineral–asphalt mixtures (MAMs), the materials from concrete and ceramics recycling are being used in increasingly wider applications. When added to MAMs as an aggregate, ceramic building material, which has different properties than the raw material (clay), may significantly influence the aggregate properties, including the wettability, porosity, asphalt adhesion, and consequently the mixture durability. The material’s microstructure was found using SEM. The wetting properties of mineral–asphalt mixtures were determined by measuring the contact angles (CA) of their surfaces, using water as the measuring liquid. The total surface free energy (SFE) values were determined using the Neumann method. When analyzing the research results, it can be noticed that the chemical composition of the ceramic aggregate has a significant influence on the adhesion of asphalt to its surface due to the chemical affinity. Waste ceramic aggregate, despite its acidic pH value being connected with its elevated silica content, exhibits good adhesive properties.
Viscous Flow of Supercooled Liquid in a Zr-Based Bulk Metallic Glass Synthesized by Additive Manufacturing
Authors: Kosiba Konrad , Deng Liang , Scudino Sergio
Published: August 2020

The constraint in sample size imposed by the critical cooling rate necessary for glass formation using conventional casting techniques is possibly the most critical limitation for the extensive use of bulk metallic glasses (BMGs) in structural applications. This drawback has been recently overcome by processing glass-forming systems via additive manufacturing, finally enabling the synthesis of BMGs with no size limitation. Although processing by additive manufacturing allows fabricating BMG objects with virtually no shape limitation, thermoplastic forming of additively manufactured BMGs may be necessary for materials optimization. Thermoplastic forming of BMGs is carried out above the glass transition temperature, where these materials behave as highly viscous liquids; the analysis of the viscosity is thus of primary importance. In this work, the temperature dependence of viscosity of the Zr52.5Cu17.9Ni14.6Al10Ti5 metallic glass fabricated by casting and laser powder bed fusion (LPBF) is investigated. We observed minor differences in the viscous flow of the specimens fabricated by the different techniques that can be ascribed to the higher porosity of the LPBF metallic glass. Nevertheless, the present results reveal a similar overall variation of viscosity in the cast and LPBF materials, which offers the opportunity to shape additively manufactured BMGs using already developed thermoplastic forming techniques.
Validation of a Homogeneous Incremental Centrifugal Liquid Sedimentation Method for Size Analysis of Silica (Nano)particles
Authors: Antúnez Domínguez Jesús Manuel , Ramaye Yannic , Dabrio Marta , Kestens Vikram
Published: August 2020

Silica nanoparticles display many unique physicochemical properties that make them desirable for use in a wide variety of consumer products and composite materials. Accurately measuring the size of these nanoparticles is important for achieving the desired nanoscale functionality of the final product and for regulatory compliances. This study covers the validation of a centrifugal liquid sedimentation method for accurate measurement of the Stokes diameter of silica particles with a near-spherical shape and dimensions in the nanometer and sub-nanometer scale range. The validated method provided unbiased results in the range of 50 nm to 200 nm, with a lower limit of detection of ≤20 nm. The relative standard uncertainties for precision, quantified in terms of repeatability and day-to-day variation, ranged from 0.2% to 1.0% and from <0.1% to 0.5%, respectively. The standard uncertainty for trueness was assessed at 4.6%. Within its working range, the method was found robust with respect to the type of cuvette, light factor, operator, and for defining the meniscus of the sample suspension. Finally, a relative expanded measurement uncertainty of 10% confirmed the satisfactory performance of the method.
Comparing Multi-Walled Carbon Nanotubes and Halloysite Nanotubes as Reinforcements in EVA Nanocomposites
Authors: Zubkiewicz Agata , Szymczyk Anna , Franciszczak Piotr , Kochmanska Agnieszka , Janowska Izabela , Paszkiewicz Sandra
Published: August 2020

The influence of carbon multi-walled nanotubes (MWCNTs) and halloysite nanotubes (HNTs) on the physical, thermal, mechanical, and electrical properties of EVA (ethylene vinyl acetate) copolymer was investigated. EVA-based nanocomposites containing MWCNTs or HNTs, as well as hybrid nanocomposites containing both nanofillers were prepared by melt blending. Scanning electron microcopy (SEM) images revealed the presence of good dispersion of both kinds of nanotubes throughout the EVA matrix. The incorporation of nanotubes into the EVA copolymer matrix did not significantly affect the crystallization behavior of the polymer. The tensile strength of EVA-based nanocomposites increased along with the increasing CNTs (carbon nanotubes) content (increased up to approximately 40% at the loading of 8 wt.%). In turn, HNTs increased to a great extent the strain at break. Mechanical cyclic tensile tests demonstrated that nanocomposites with hybrid reinforcement exhibit interesting strengthening behavior. The synergistic effect of hybrid nanofillers on the modulus at 100% and 200% elongation was visible. Moreover, along with the increase of MWCNTs content in EVA/CNTs nanocomposites, an enhancement in electrical conductivity was observed.
Chemically Grafting Carbon Nanotubes onto Carbon Fibers for Enhancing Interfacial Properties of Fiber Metal Laminate
Authors: Ji Fan , Liu Cheng , Hu Yubing , Xu Shengnan , He Yiyan , Zhou Jin , Zhang Yanan
Published: August 2020

This paper primarily investigates the effects of chemically grafted modified carbon fibers on the bonding properties of fiber metal laminates (FMLs). Relative elemental content on the carbon fibers’ surface was performed via X-ray photoelectron spectroscopy (XPS). Scanning electron microscopy (SEM) was utilized to observe the material microstructure. The effect of chemically grafted carbon fibers on the bond strengths of FMLs was experimentally investigated through lap joint testing. The carbon nanotubes (CNTs) grafting concentration and curing conditions of the samples were also investigated. The test results demonstrate that grafting concentrations of 0.1, 0.2, and 0.3 mg/mL CNT solution increased the bond strength of the cured samples under vacuum conditions by 63.51%, 87.16%, and 71.56%, respectively. In addition, the bond strengths of vacuum-cured samples were also increased.
Significance of acPWV for Survival of Hemodialysis Patients
Authors: Petrovic Marko , Baralic Marko , Brkovic Voin , Arsenovic Aleksandra , Stojanov Vesna , Lalic Natasa , Stanisavljevic Dejana , Jankovic Aleksandar , Radivojevic Nenad , Pejanovic Svetlana , Maric Ivko , Lezaic Visnja
Published: August 2020

Background and Objectives: Abnormal arterial stiffness (AS) is a major complication in end-stage kidney disease (ESKD) patients treated by dialysis. Our study aimed to determine the significance of AS for survival of prevalent dialysis patients, as well as its association with cardiovascular parameters or vascular calcification promoters/inhibitors or both and AS. Materials and Methods: The study involved 80 adult hemodialysis patients. Besides standard laboratory analyses, we also determined promoters and inhibitors of vascular calcification (bone biomarkers): serum levels of fibroblast growth factor 23 (FGF23), soluble Klotho, intact parathormone (iPTH), 1,25-dihydroxyvitamin D3, osteoprotegerin, sclerostin, AS measured as ankle carotid pulse wave velocity (acPWV), Ankle Brachial Index (ABI), and vascular calcification (VC) score. Patients were monitored for up to 28 months. According to the median acPWV value, we divided patients into a group with acPWV ≤ 8.8 m/s, and a group with acPWV > 8.8 m/s, and the two groups were compared. Results: Values for bone biomarkers were similar in both groups. Mean arterial blood pressure (MAP), central systolic and diastolic brachial blood pressure, heart rate, and pulse pressure were higher in the group with acPWV > 8.8 m/s than in the group with acPWV ≤ 8.8 m/s. The mortality was higher for patients with acPWV > 8.8 m/s at any given time over 28 months of follow-up. In multivariable analysis, predictors of higher acPWV were age >60.5, higher pulse rate, and higher central systolic or brachial diastolic blood pressure. Conclusions: According to our results, we advise the measurement of acPWV preferentially in younger dialysis patients for prognosis, as well as intervention planning before the development of irreversible changes in blood vessels. In addition, measuring central systolic blood pressure seems to be useful for monitoring AS in prevalent hemodialysis patients.
The Beginning of Western Greek Amphorae Production in Western Sicily: Archaeometric and Archaeological Studies on 6th–5th Centuries BCE Amphorae Manufactured in Himera
Authors: Montana Giuseppe , Randazzo Luciana , Bechtold Babette
Published: August 2020

About 560 western Greek amphorae (6th–5th centuries BCE) re-used in enchytrismos burials were unearthed in the necropolis of the Dorian-Chalcidian colony of Himera in northwestern Sicily. Among the most striking issues is the determination of their geographical provenance. For this purpose, ceramic samples chipped from freshly broken surfaces of all the amphorae were first subdivided into macrofabrics by the use of a hand lens. Thereon, the samples were studied in accordance with standardized methods by the use of reflected light microscopy. Due to the special focus of our project on the characterization of Sicilian productions, a selection of amphorae which showed visible, macroscopic affinities with the majority of the macrofabrics previously attributed to the region of Himera was submitted for thin-section petrography at the polarizing microscope and chemical analyses (ICP-MS and ICP/OES). This new data set was compared with reference samples investigated by previous research, referring to ceramic raw clays of the colony’s territory and local tablewares of the Iato K480-type. Our study confirms the local manufacture of the entire selection of transport vessels. The identification of a production of western Greek wine (?) amphorae in Himera dating mainly from the third quarter of the 6th to the first quarter of the 5th century BCE breaks new grounds in view of a better interpretation of the colony’s economic development during the later archaic period. Furthermore, it underlines Himera’s prominent position within the wider frame of regional economic interaction.
Compensatory Neuroprotective Response of Thioredoxin Reductase against Oxidative-Nitrosative Stress Induced by Experimental Autoimmune Encephalomyelitis in Rats: Modulation by Theta Burst Stimulation
Authors: Stevanovic Ivana , Ninkovic Milica , Mancic Bojana , Milivojevic Marija , Stojanovic Ivana , Ilic Tihomir , Vujovic Maja , Djukic Mirjana
Published: August 2020

Cortical theta burst stimulation (TBS) structured as intermittent (iTBS) and continuous (cTBS) could prevent the progression of the experimental autoimmune encephalomyelitis (EAE). The interplay of brain antioxidant defense systems against free radicals (FRs) overproduction induced by EAE, as well as during iTBS or cTBS, have not been entirely investigated. This study aimed to examine whether oxidative-nitrogen stress (ONS) is one of the underlying pathophysiological mechanisms of EAE, which may be changed in terms of health improvement by iTBS or cTBS. Dark Agouti strain female rats were tested for the effects of EAE and TBS. The rats were randomly divided into the control group, rats specifically immunized for EAE and nonspecifically immuno-stimulated with Complete Freund’s adjuvant. TBS or sham TBS was applied to EAE rats from 14th–24th post-immunization day. Superoxide dismutase activity, levels of superoxide anion (O2•–), lipid peroxidation, glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH), and thioredoxin reductase (TrxR) activity were analyzed in rat spinal cords homogenates. The severity of EAE clinical coincided with the climax of ONS. The most critical result refers to TrxR, which immensely responded against the applied stressors of the central nervous system (CNS), including immunization and TBS. We found that the compensatory neuroprotective role of TrxR upregulation is a positive feedback mechanism that reduces the harmfulness of ONS. iTBS and cTBS both modulate the biochemical environment against ONS at a distance from the area of stimulation, alleviating symptoms of EAE. The results of our study increase the understanding of FRs’ interplay and the role of Trx/TrxR in ONS-associated neuroinflammatory diseases, such as EAE. Also, our results might help the development of new ideas for designing more effective medical treatment, combining neuropsychological with noninvasive neurostimulation–neuromodulation techniques to patients living with MS.
Fatty Acid Synthase: An Emerging Target in Cancer
Authors: Fhu Chee Wai , Ali Azhar
Published: August 2020

In recent years, lipid metabolism has garnered significant attention as it provides the necessary building blocks required to sustain tumor growth and serves as an alternative fuel source for ATP generation. Fatty acid synthase (FASN) functions as a central regulator of lipid metabolism and plays a critical role in the growth and survival of tumors with lipogenic phenotypes. Accumulating evidence has shown that it is capable of rewiring tumor cells for greater energy flexibility to attain their high energy requirements. This multi-enzyme protein is capable of modulating the function of subcellular organelles for optimal function under different conditions. Apart from lipid metabolism, FASN has functional roles in other cellular processes such as glycolysis and amino acid metabolism. These pivotal roles of FASN in lipid metabolism make it an attractive target in the clinic with several new inhibitors currently being tested in early clinical trials. This article aims to present the current evidence on the emergence of FASN as a target in human malignancies.
Investigation on the Interaction between Cellulosic Paper and Organic Acids Based on Molecular Dynamics
Authors: Zhu Mengzhao , Gu Chao , Zhu Wenbing
Published: August 2020

Organic acid is an important factor that accelerates the aging of cellulosic insulation materials. In this study, the interactions between cellulose and five acids, representative of what may be found in an aging transformer, were studied using molecular dynamics. The adsorption process of the five acids onto the surface of crystalline cellulose shows that the three low molecular acids are more readily adsorbed onto cellulose than the two high molecular acids. The deformation and adsorption energies of the acids all increase with an increase in molecular weight when they are stably interacting with cellulose. However, the differences between adsorption energies and deformation energies are positive for the three low molecular acids, whereas they are negative for the two high molecular acids. This indicates that the attachments onto cellulose of low molecular acids are considerably more stabilized than those of the high molecular acids. This is consistent with the experimental results. Furthermore, based on the calculated solubility parameters of acids, the experimental result that the three low molecular acids are to a large degree absorbed onto the cellulose, whereas the two high molecular acids remain in the oil, was theoretically elucidated using the theory of similarity and intermiscibility.
Scaffold Modifications in Erythromycin Macrolide Antibiotics. A Chemical Minireview
Authors: Undheim Kjell
Published: August 2020

Clarithromycin and congeners are important antibacterial members of the erythromycin A 14-membered macrocyclic lactone family. The macrolide scaffold consists of a multifunctional core that carries both chemically reactive and non-reactive substituents and sites. Two main approaches are used in the preparation of the macrolides. In semisynthesis, the naturally occurring macrocycle serves as a substrate for structural modifications of peripheral substituents. This review is focused on substituents in non-activated positions. In the total synthesis approach, the macrolide antibiotics are constructed by a convergent assembly of building blocks from presynthesized substrates or substrates prepared by biogenetic engineering. The assembled block structures are linear chains that are cyclized by macrolactonization or by metal-promoted cross-coupling reactions to afford the 14-membered macrolactone. Pendant glycoside residues are introduced by stereoselective glycosylation with a donor complex. When available, a short summary of antibacterial MIC data is included in the presentations of the structural modifications discussed.
Nanotreatment and Nanodiagnosis of Prostate Cancer: Recent Updates
Authors: Barani Mahmood , Sabir Fakhara , Rahdar Abbas , Arshad Rabia , Kyzas George Z.
Published: August 2020

The fabrication and development of nanomaterials for the treatment of prostate cancer have gained significant appraisal in recent years. Advancements in synthesis of organic and inorganic nanomaterials with charge, particle size, specified geometry, ligand attachment etc have resulted in greater biocompatibility and active targeting at cancer site. Despite all of the advances made over the years in discovering drugs, methods, and new biomarkers for cancer of the prostate (PCa), PCa remains one of the most troubling cancers among people. Early on, effective diagnosis is an essential part of treating prostate cancer. Prostate-specific antigen (PSA) or serum prostate-specific antigen is the best serum marker widely accessible for diagnosis of PCa. Numerous efforts have been made over the past decade to design new biosensor-based strategies for biomolecules detection and PSA miniaturization biomarkers. The growing nanotechnology is expected to have a significant effect in the immediate future on scientific research and healthcare. Nanotechnology is thus predicted to find a way to solve one of the most and long-standing problem, “early cancer detection”. For early diagnosis of PCa biomarkers, different nanoparticles with different approaches have been used. In this review, we provide a brief description of the latest achievements and advances in the use of nanoparticles for PCa biomarker diagnosis.
Rheology by Design: A Regulatory Tutorial for Analytical Method Validation
Authors: Simões Ana , Miranda Margarida , Cardoso Catarina , Veiga Francisco , Vitorino Carla
Published: August 2020

The increasing demand for product and process understanding as an active pursuit in the quality guideline Q8 and, more recently, on the draft guideline on quality and equivalence of topical products, has unveiled the tremendous potential of rheology methods as a tool for microstructure characterization of topical semisolid dosage forms. Accordingly, procedure standardization is a dire need. This work aimed at developing and validating a methodology tutorial for rheology analysis. A 1% hydrocortisone cream was used as model cream formulation. Through a risk assessment analysis, the impact of selected critical method variables (geometry, temperature and application mode) was estimated in a broad range of rheological critical analytical attributes—zero-shear viscosity, upper-shear thinning viscosity, lower-shear thinning viscosity, infinite-shear viscosity, rotational yield point, thixotropic relative area, linear viscoelastic region, oscillatory yield point, storage modulus, loss modulus, and loss tangent. The proposed validation of the approach included the rheometer qualification, followed by the validation of numerous operational critical parameters regarding a rheology profile acquisition. The thixotropic relative area, oscillatory yield point, flow point and viscosity related endpoints proved to be highly sensitive and discriminatory parameters. This rationale provided a standard framework for the development of a reliable and robust rheology profile acquisition.
Investigating the Mechanisms of AquaporinZ Reconstitution through Polymeric Vesicle Composition for a Biomimetic Membrane
Authors: Zhou Danhua , Zhou Hu , Zhou Shufeng , Tong Yen Wah
Published: August 2020

Aquaporin-Z (AqpZ) are water channel proteins with excellent water permeability and solute rejection properties. AqpZ can be reconstituted into vesicles utilizing cell-like bilayer membranes assembled from amphiphilic block copolymers, for the preparation of high-performance biomimetic membranes. However, only a few copolymers have been found suitable to act as the membrane matrix for protein reconstitution. Hence, this work analyzes the mechanism of protein reconstitution based on a composition-reconstitution relationship. The vesicle formation and AqpZ reconstitution processes in various amphiphilic block copolymers were investigated in terms of size, morphology, stability, polymeric bilayer membrane rigidity, and thermal behavior. Overall, this study contributes to the understanding of the composition-reconstitution relationship of biomimetic membranes based on AqpZ-reconstituted polymeric vesicles.
Production of Porous Films Based on Biodegradable Polyesters by the Casting Solution Technique Using a Co-Soluble Porogen (Camphor)
Authors: Boyandin Anatoly Nikolayevich , Dvoinina Ljublyana Mikhailovna , Sukovatyi Aleksey Grigorievich , Sukhanova Anna Alekseevna
Published: August 2020

Porous films have been prepared from degradable polymers—poly-3-hydroxybutyrate (PHB), poly-ε-caprolactone (PCL) and a blend of these polymers (1:3)—by adding porogen (camphor) to the polymer solution at 10%, 30% or 50% of the total mass of the polymer and porogen, and leaching it out afterwards. After the rinse, camphor content in films decreased to about 0.025%. The structure, physical/mechanical and biological properties of the films were investigated as dependent on their composition and porosity, which varied depending on the amount of camphor added. The surface of PHB films was porous, the PCL films were relatively smooth, and the PHB/PCL films had an intermediate structure. The addition of camphor increased the thickness (from 35 to 45 µm, from 40 to 80 µm and from 20 to 65 µm for PHB, PCL and PHB/PCL, respectively) and porosity (from 4.2(±3.6)% to 50.0(±12.8)%, from 6.4(±5.5)% to 54.5(±6.0)% and from 4.9(±4.8)% to 51.5(±5.8)%, respectively) of the films. The introduction (and removal) of 10% camphor into the PHB and PHB/PCL films led to an approximately twofold increase in the polar component of the free surface energy (from 5.4 ± 0.38 to 11.8 ± 1.33 and from 2.7 ± 0.13 to 5.2 ± 0.09 mN/m, respectively) but in other cases, on the contrary, a decrease in this indicator was registered. The increase of camphor addition from 0% to 50% gradually impaired mechanical properties of the films: so, Young’s modulus decreased from 3.6 to 1.8 GPa, from 0.30 to 0.12 GPa and from 0.50 to 0.20 GPa for PHB, PCL and PHB/PCL, respectively. At the same time, the water vapor transmission rate considerably increased from 197.37 ± 23.62 to 934.03 ± 114.34 g/m2/d for PHB films; from 1027.99 ± 154.10 to 7014.62 ± 280.81 g/m2/d for PCL films; and from 715.47 ± 50.08 to 4239.09 ± 275.54 g/m2/d for PHB/PCL films. Results of biocompatibility testing in the culture of NIH 3T3 mouse fibroblast cells showed that for the most of experimental samples cell adhesion and proliferation were comparable or superior to the corresponding parameters on the initial nonporous films. The best results were obtained for PHB films where at Day 3 of the experiment the registered cell density for experimental samples arrived at 2.66(±0.26) × 105 cells/cm2 versus 1.29(±0.33) × 105 cells/cm2 in the control. So, the proposed method can be used to construct highly porous cell scaffolds for cellular engineering.
3D Interconnected Boron Nitride Networks in Epoxy Composites via Coalescence Behavior of SAC305 Solder Alloy as a Bridging Material for Enhanced Thermal Conductivity
Authors: Kim Youjin , Kim Jooheon
Published: August 2020

In this study, hybrid fillers of spherically shaped aggregated boron nitride (a-BN) attached with SAC305, were fabricated via simple stirring and the vacuum filtration method. a-BN was used as the primary conductive filler incorporated with epoxy resin, and these fillers were interconnected each other via the coalescence behavior of SAC305 during the thermal curing process. Based on controlled a-BN content (1 g) on 3 g of epoxy, the thermal conductivity of the composite filled with hybrid filler (a-BN:SAC305 = 1:0.5) reached 0.95 W/mK (33 wt%) due to the construction of the 3D filler network, whereas that of composite filled with raw a-BN was only 0.60 W/mK (25 wt%). The thermal conductivity of unfilled epoxy was 0.19 W/mK.
Towards Sustainable Management of Mineral Fertilizers in China: An Integrative Analysis and Review
Authors: Yu Xiaomin , Li Haigang , Doluschitz Reiner
Published: August 2020

China has not only successfully fed 20% of the world’s population using only 9% of the world’s arable land; it has also become the world’s largest producer of various agricultural products. The widespread application of mineral fertilizers played a critical role in accomplishing this achievement. In this study, we conducted an integrative analysis of China’s mineral fertilizers over the last six decades from multiple perspectives—domestic production, consumption and international trade at national and international levels, and the agricultural use of fertilizers at a regional level. In addition, we quantitatively estimated fertilizer nutrient surpluses for 30 provinces in mainland China for the time period spanning from 1987 to 2018 and integrated the results as a reference to the evaluation of the implementation of the Zero Growth Action Plan regulating fertilizer use by 2020. We concluded that by 2019, 83% and 93% of the provinces had already achieved zero growth in fertilizer use and fertilizer nutrient surpluses, respectively. This shows promising potential for China in finalising the Zero Growth Action Plan of Fertilizers nationwide by 2020.
Evaluation of the 50% Infectious Dose of Human Norovirus Cin-2 in Gnotobiotic Pigs: A Comparison of Classical and Contemporary Methods for Endpoint Estimation
Authors: Ramesh Ashwin K. , Parreño Viviana , Schmidt Philip J. , Lei Shaohua , Zhong Weiming , Jiang Xi , Emelko Monica B. , Yuan Lijuan
Published: August 2020

Human noroviruses (HuNoVs) are the leading causative agents of epidemic and sporadic acute gastroenteritis that affect people of all ages worldwide. However, very few dose–response studies have been carried out to determine the median infectious dose of HuNoVs. In this study, we evaluated the median infectious dose (ID50) and diarrhea dose (DD50) of the GII.4/2003 variant of HuNoV (Cin-2) in the gnotobiotic pig model of HuNoV infection and disease. Using various mathematical approaches (Reed–Muench, Dragstedt–Behrens, Spearman–Karber, logistic regression, and exponential and approximate beta-Poisson dose–response models), we estimated the ID50 and DD50 to be between 2400–3400 RNA copies, and 21,000–38,000 RNA copies, respectively. Contemporary dose–response models offer greater flexibility and accuracy in estimating ID50. In contrast to classical methods of endpoint estimation, dose–response modelling allows seamless analyses of data that may include inconsistent dilution factors between doses or numbers of subjects per dose group, or small numbers of subjects. Although this investigation is consistent with state-of-the-art ID50 determinations and offers an advancement in clinical data analysis, it is important to underscore that such analyses remain confounded by pathogen aggregation. Regardless, challenging virus strain ID50 determination is crucial for identifying the true infectiousness of HuNoVs and for the accurate evaluation of protective efficacies in pre-clinical studies of therapeutics, vaccines and other prophylactics using this reliable animal model.
Microplastic and Fibre Contamination in a Remote Mountain Lake in Switzerland
Authors: Negrete Velasco Angel de Jesús , Rard Lionel , Blois Wilfried , Lebrun David , Lebrun Franck , Pothe Franck , Stoll Serge
Published: August 2020

The contamination of aquatic environments by microplastics has been largely documented in the last years, especially in oceans, rivers, and lakes, but their occurrence in remote mountain lakes has been scarcely considered. This work aims to investigate the presence and abundance of microplastics and fibres in a remote, alpine, and uninhabited lake in Switzerland (Sassolo). In this study, the water column as well as the sediments were analysed. The isolation of microplastics and fibres from the samples of the sediment was achieved with a digestion process using H2O2 and a density separation technique with NaI. Classification of microparticles (from 5 mm to 125 μm) was first developed with an optical microscope. Infrared spectroscopy was then used to identify and characterize the chemical nature of the microplastics and fibres. On average, 2.6 microplastics and 4.4 fibres per litre were identified in the water column. On the other hand, the results of the sediment samples revealed significant fibre concentrations compared to plastic microparticles (514 fibres and 33 microplastics per kilogram). The most abundant types of microplastic identified in the samples were composed of polyethylene (PE) and polypropylene (PP). Microplastic and fibre sources were not determined, but it is likely that the number of human activities in this area as well as aerial deposition are contributing to contaminate this remote environment with microplastics and fibres.
Effects of Nonhomogeneous Soil Characteristics on the Hydrologic Response: A Case Study
Authors: Hwang JiHyeong , Lee HyungKeun , Lee Khil
Published: August 2020

This study examined how different nonhomogeneous soil characteristics affected hydrologic responses in rainfall-runoff models. The cell-based FLO-2D and lumped Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) were setup. Then, water loss parameters of both the Green-Ampt infiltration approach and curve number method were prescribed and applied in three different ways: (i) a separate value for each cell (mosaic; (ii) a representative as a most frequent occurring value for a large area (predominant); (iii) and a representative as an arithmetic mean value for a watershed (arithmetic mean). The spatial variability of nonhomogeneous catchment parameters was disregarded in lumped models, while each cell had distinct surface parameters in the distributed models. This study shows that the hydrologic response was meaningfully different in different representations. For the study site, the mosaic method was recommended for distributed models, and arithmetic mean was recommended for lumped models.
Application of the Segregation Potential Model to Freezing Soil in a Closed System
Authors: Zhang Xiyan , Sheng Yu , Huang Long , Huang Xubin , He Binbin
Published: August 2020

Previous studies have shown that an accurate prediction of frost heaves largely depends on the pore water pressure and hydraulic conductivity of frozen fringes, which are difficult to determine. The segregation potential model can avoid this problem; however, the conventional segregation potential is considered to be approximately unchanged at a steady state and only valid in an open system without dehydration in the unfrozen zone. Based on Darcy’s law and the conventional segregation potential, the segregation potential was expressed as a function of the pore water pressure at the base of the ice lens, the pore water pressure at the freezing front, the freezing temperature, the segregation freezing temperature and the hydraulic conductivity of the frozen fringe. This expression indicates that the segregation potential under quasi-steady-state conditions is not a constant in a closed system, since the pore water pressure at the freezing front varies with the freezing time owing to the dehydration of the unfrozen zone, and that when the pore water pressure at the freezing front is equal to that at the base of the ice lens, the water migration and frost heave will be terminated. To analyze the possibility of applying the segregation potential model in a closed system, a series of one-sided frost heave tests under external pressure in a closed system were carried out in a laboratory, and the existing frost heaving test data from the literature were also analyzed. The results indicate that the calculated frost heave was close to the tested data, which shows the applicability of the model in a closed system. In addition, the results show the rationality of calculating the segregation potential from the frost heaving test by comparing the potential with that calculated from the numerical simulation results. This study attempted to extend the segregation potential model to freezing soil in a closed system and is significant to the study of frost heaves.
Специализированные смеси масел для лечения и профилактики заболеваний нарушения липидного обмена
Authors: Григорьева Валентина Николаевна , Гапонова Лилия Валентиновна , Полежаева Татьяна Андреевна , Матвеева Галина Алексеевна
Published: August 2020

Разработка масел для специализированного питания больных с нарушениями липидного обмена (ожирение, метаболический синдром, онкологические заболевания и так далее) является чрезвычайно важной для диетического лечения данных патологий. Основные аспекты разработки специализированных продуктов питания: выбор качественного сырья с адекватным нутриентным составом и соответствующего требованиям действующих регламентов и нормативов для него, составление сбалансированных рецептур отвечающих медико-биологическим требованиям, разработка технологий позволяющая сохранить все полезные свойства исходного сырья. При разработке специализированных смесей растительных масел особое внимание уделялось подбору сырья, составлению рецептур смесей, сбалансированных по жирнокислотному и витаминному составам и обладающих оптимальными физико-химическими и органолептическими показателями с учётом взаимного влияния компонентов, позволяющего получить смеси, устойчивые к окислению; составление технологической схемы производства смесей масел с отработкой технологических параметров, обеспечивающих максимальную сохранность биологически ценных веществ исходного сырья, предотвращение образования физиологически неблагоприятных веществ.
Факторы, влияющие на электрический заряд дрожжевых клеток Saccharomyces cerevisiae
Authors: Меледина Татьяна Викторовна , Маньшин Дмитрий Викторович , Головинская Оксана Владимировна , Харба Разан , Иванова Вера Анатольевна , Морозов Артём Александрович
Published: August 2020

Проблема коллоидной нестабильности пива отчасти может быть решена за счет адсорбционной способности дрожжевых клеток. Предполагается, что увеличение количества извлекаемых в результате сорбции коллоидов, может быть достигнуто путем увеличения отрицательного заряда клеток. Электрический заряд клеточной поверхности дрожжей обусловлен молекулярным составом клеточной стенки, в основном функциональными группами внешнего слоя маннопротеинов – фосфатными, карбоксильными и аминогруппами. В рассматриваемых работах с использованием метода рентгеновской фотоэлектронной спектроскопии было показано, что заряд клеточной поверхности, охарактеризованный дзета-потенциалом или электрофоретической подвижностью, определяется концентрациями поверхностного фосфора и азота, а также их отношением. Как правило, для штаммов низового брожения свойственны более высокие концентрации поверхностного фосфора и более низкие значения отношения N/P, обратное справедливо для верховых штаммов. С другой стороны, физико-химические факторы внешней среды также влияют на электрический заряд клеток. В ходе аналитического обзора было выявлено влияние таких факторов как рН, времени процесса ферментации, аэрации сусла и внесения свободного фосфора в культуральную среду. Так с уменьшением рН электрический заряд или характеризующий его дзета-потенциал становится более положительным. Поскольку в ходе ферментации наблюдается снижение рН, электрический заряд также становится более положительным с протеканием процесса брожения. Аэрация, внесение свободного фосфора и увеличение первоначальной плотности сусла, наоборот, увеличивают отрицательный заряд клеток. Наконец увеличение числа циклов повторного брожения приводит к изменению электрического заряда в направлении положительных значений. Согласно представленным данным, может быть сделан вывод о том, что путем варьирования и подбора упомянутых факторов возможно достичь увеличения отрицательного заряда клеточной поверхности дрожжей. Однако для подтверждения предположения об увеличении извлекаемых путем адсорбции коллоидов за счет увеличения отрицательного заряда клеток требуются дальнейшие экспериментальные исследования данного вопроса.
Кексы с полбяной мукой для питания детей младшего школьного возраста
Authors: Магомедов Газибег Омарович , Лобосова Лариса Анатольевна , Малютина Татьяна Николаевна , Рожков Сергей Анатольевич
Published: August 2020

Цель исследования – разработка рецептурного состава кекса с нетрадиционным сырьем. Работа выполнена в Воронежском государственном университете инженерных технологий на кафедре технологии хлебопекарного, кондитерского, макаронного и зерноперерабатывающего производств. Перспективными сырьевыми источниками являются растительные ресурсы, в частности полбяная мука. Обоснован выбор рецептурных компонентов, показана их пищевая и энергетическая ценность. Определяли органолептически (по ГОСТ 5897-90) внешний вид, вкус, цвет, запах, форму, поверхность, вид в изломе изделий, массовую долю сухих веществ (СВ) в сырье, полуфабрикатах и изделиях высушиванием при температуре 130 ºС в сушильном шкафу в течение 40 мин (ГОСТ 5900-2014); щелочность согласно ГОСТ 5898-87, плотность по ГОСТ 15810-2014. Расчет пищевой и энергетической ценности проводили расчетным путем. Проведена замена яблочного пюре на смесь яблочно-грушево-сливово-абрикосово-персикового пюре (соотношение 25:25:20:15:15) в пересчете на сухие вещества. Мука пшеничная первого сорта заменена на полбяную в соотношениях 80:20; 70:30; 60:40; 50:50. Рациональной выбрана дозировка 70:30. По органолептическим показателям разработанные изделия отличает приятный золотистый цвет мякиша, вкус, свойственный фруктовой добавке. Расширен ассортимент мучных кондитерских изделий для питания детей младшего школьного возраста.
Cовершенствование технологии кисломолочного напитка «Быырпах»
Authors: Занданова Туяна Нимбуевна , Ахременко Яна Александровна
Published: August 2020

В настоящее время на отечественном рынке стремительно развивается ассортимент молочных продуктов с пробиотическими свойствами. В сложившейся конкурентной среде при разработке новых технологий кисломолочных продуктов необходимо помимо благоприятного воздействия на микрофлору человека учитывать потребительскую привлекательность органолептических показателей. В работе представлены исследования по совершенствованию технологии популярного в Якутии напитка Быырпах. Это кисломолочный напиток, производимый из нормализованного до массовой доли жира 1% пастеризованного охлажденного молока, заквашенного лактобактериями и дрожжами до кислотности 70-90 oТ. Напиток серийно производится молокоперерабатывающими предприятиями в Якутии по ТУ9220-001-067027-02. Молоко заквашивают пересадочным способом комбинированной закваской на чистых культурах термофильного стрептококка, болгарской палочки и дрожжей, сбраживающих лактозу. Для активизации спиртового брожения добавляют сахар. В связи с этим для повышения биологической ценности и снижения санитарно-гигиенических рисков производства напитка в работе предлагается использование бактериального концентрата микробного консорциума. Бактериальный концентрат содержит микробный консорциум, сформированный длительным совместным культивированием микрофлоры кефирной грибковой закваски и термофильных лактобактерий Lactobacillus acidophilus, Lactobacillus bulgaricus. Полученный микробный консорциум по своему составу близок естественной популяции микроорганизмов курунги и кумыса. Доказана ее высокая антибиотическая и адгезивная активность. В результате исследований по выбору оптимальной дозы вносимого бактериального концентрата установлено, что 0,01% позволяет в течение 10 часов культивирования получить продукт с титруемой кислотностью 90 oТ. Так же установлено, что для активизации дрожжевой микрофлоры в технологии нужно предусмотреть созревание кисломолочного продукта при 16 oС в течение 8 часов. Готовый продукт обладает антибиотической активностью по отношению к патогенной и гнилостной микрофлоре. Изучение органолептических показателей свидетельствует, что применения бактериального концентрата микробного консорциума позволяет получить продукт, соответствующий по своим показателям прохладительному напитку Быырпах.
Uma tecnologia de saneamento ecológico para a recuperação de fósforo e reflexões sobre a prática de design tecnológico: incorporando valores socioambientais
Authors: Tonzar Chaves Vitor , Contrera Ronan Cleber
Published: August 2020

Tradicionalmente, o design das tecnologias sanitárias é pensado para a remoção de nutrientes. Para que sejam criadas soluções sanitárias capazes de aproveitar os recursos presentes no esgoto, é necessário que os engenheiros adequem sua forma de projetar. Neste trabalho é apresentada uma reflexão com o intuito de dialogar com a comunidade técnico-científica da área sobre a necessidade dessa inflexão na maneira de agir/pensar. Além disso, é apresentada uma tecnologia baseada nesses princípios que é capaz de promover a reciclagem do fósforo presente no esgoto. A tecnologia é composta por 4 reatores: fossa digestora, decantador, alagado construído vertical e alagado construído parcialmente preenchido com lodo de ETA. O sistema apresentou eficiência de remoção de 94,4% ± 3,2% para DQO e de 91,2% ± 7,8% para sólidos suspensos. A eficiência de remoção do fósforo reativo solúvel (Psolúvel) foi de 95% e diminuiu até atingir a saturação do adsorvente. Os autores concluem que a aplicação do lodo férrico é interessante para promover uma tecnologia de baixo custo e baixa demanda operacional para recuperação de fósforo. O tempo de vida do adsorvente foi estimado entre 1,6 e 9,7 anos. Palavras-chave: Sustentabilidade. Recuperação de Fósforo. Saneamento Ecológico. Lodo ETA. Alagados Construídos.
Incorporation of sarcolemmal calcium transporters into the Shorten et al. (2007) model of skeletal muscle: equations, coding, and stability
Authors: Noble Denis , Tasaki Kazuyo , Noble Penelope J. , Shorten Paul R. , Garny Alan , Afshar Nima
Published: August 2020

We describe a major development of the Shorten et al. (Shorten et al., 2007) model of skeletal
muscle electrophysiology, biochemistry, and mechanics. The model was developed by incorporating
equations for sarcolemmal transport of calcium ions, including L-type calcium channel,
sodium-calcium exchange, calcium pump, and background calcium channel. The extended model
also includes an addition to the equations for extracellular potassium ion movements to enable
the exchange of potassium ions between bulk (plasma) concentration and the interstitial and
tubular compartments to be modeled. In further research in an accompanying paper (Tasaki et
al, 2019), we succeeded in reproducing muscle cramp, as well as its prevention and reversal, by
investigating muscle contraction and cramp using this extended model in comparison with the
original model.
Nanomaterials in Soil Environment: A Review
Authors: BHATTACHARYA SATYA SUNDAR , Das Subhasish
Published: August 2020

Nanomaterials (NMs) have become an integral part of our daily life and their extensive uproduction will only increase with the coming time. These NMs exhibit significant contrast in regard to dimension, reaction, and structure. The most important aspect of the NMs is that these can be easily manipulated and engineered to custom-suit different functions/industries. Owing totheir dynamic nature, these NMs behave differently when introduced in any medium. In soil, the behavior of NMs is significantly controlled by the interactions of nanomaterials with soil phases. Although, NMs are deemed beneficial for human-use yet these also carry lethal effects. Moreover, there is dearth of adequate research with respect to the interactions amongnanomaterials and soil physicochemical properties; their accumulation-dissolution dynamics in soil-plant systems; and their long term influence on soil health. Several NMs induce physiological stress when introduced inside the body. Thus, various researchers have devised green pathways for producing NMs, although their wide applicability is still questionable. Although the domain of nanotechnology is greatly explored yet there remain several grey areaswhich need to be addressed for sustainable utilization of these unique materials in the benefit of humankind.