Rich Component Research Articles

The Human Milk Oligosaccharide 2'-Fucosyllactose Shows an Immune-Enhancing Effect in a Cyclophosphamide-Induced Mouse Model.

The 2'-fucosyllactose (2'-FL) is the richest components in a human milk oligosaccharide. Several studies have reported that 2'-FL has beneficial effects in infants. However, there are few studies on its immune-enhancing effects. This research aimed to examine the immune-enhancing effect of 2'-FL on immunosuppression by cyclophosphamide (CCP) in ICR mice. Mice were orally administered distilled water or 0.5 mg/kg B.W. 2'-FL for 14 days. An immunocompromised mouse model was induced using CCP 80 mg/kg B.W. at 12-14 days. Using the CCP had effects on reducing their body weight, organ weight, spleen index, natural killer (NK) cell activity, and cytokines concentration and expression. This study also used concanavalin A-mediated T-cell proliferation to verify the immune-enhancing effects in the sample. Body weight, spleen index, organ weight, and cytokine levels were measured to estimate the immune-enhancing effects. The body weight at 14 days tended to increase, and the spleen weight and index significantly increased in the 2'-FL group compared to the CCP group. The NK cell activity increased in the 2'-FL group compared to the CCP group, but there was no significant difference. The concentration of interleukin (IL)-2 tended to recover in the 2'-FL group compared to the CCP group. The 2'-FL group showed a significant increase of IL-10 and IFN-gamma concentration compared to the CCP group. In addition, there was a trend of increased IL-10 mRNA expression compared to the CCP group. These results revealed that 2'-FL improved CCP-induced immunosuppression, suggesting that 2'-FL may have the potential to enhance the immune system.

Application of the Extracts of Punica granatum in Oral Cancer: Scoping Review.

The Punica granatum L. is an ancient fruit plant native to south-western Asia. It belongs to the Litraceae family and of its genus we have only one other Punica protopunic species. The fruit is rich in polyphenols, whose extract is consumed as a food and is considered safe. In medicine, it is used for its antioxidant properties; it has a rich component of tannic polyphenols among which the most bioactive are: punicalagin (flavonoids) and anthocyanins (delphinidin, cyanidin, pelargonidin), which are found mainly in the skins and in the pericarp; however, all the parts of the Punica granatum are used for therapeutic purposes as anti-inflammatories and analgesics and in diabetes and cardio-vascular disease. Punica granatum extracts also show interesting anticancer activities in influencing tumorgenesis and angiogenesis and cell transformation and proliferation. The purpose of this scoping review is to summarize all the scientific evidence on the possible applications of Punica granatum extracts in the treatment and prevention of oral cavity tumors to investigate the anticancer properties of the active ingredients extracted from Punica granatum. Methods: The scoping review was carried out following the PRISMA-ScR checklist; the search was performed on three databases (Scopus, Science direct and PubMed) and one registry (Cochrane library). Results: The search produced a number of bibliographic sources equal to 11,403; with the removal of duplicates, 670 potentially admissible articles were obtained, from 24 of which only 7 in vitro studies on OSCC cell lines were included. Conclusions: From the preliminary data on the cellular lines of OSCC, it emerges that for oral cancer there are conditions for which the extracts of Punic granatum are effective at least from a prevention perspective.

Effects of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Infection on the Surface Glycoprofiling of Porcine Pulmonary Microvascular Endothelial Cells.

Previously, our study has demonstrated that porcine pulmonary microvascular endothelial cells (PPMVECs) were susceptible to highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) and produced a significant non-specific immune response to it. The significance of microvascular endothelial glycocalyx is increasingly attracting attention, and its rich carbohydrate components are not only important signaling molecules, but also remarkably influence the signaling of most proteins. Comprehending changes in the carbohydrate chains contributes to understanding cell functions. This study aimed to reveal the effects of HP-PRRSV infection on the surface carbohydrate chains of PPMVECs. PPMVECs were isolated and cultured in vitro and infected with HP-PRRSV HN and JXA1 strains. Scanning electron microscopy analysis indicated that at 48 h post-infection, some broken holes were in their cell membranes, and that the surface fibrous glycocalyx was obviously reduced or even disappeared. Lectin microarray analysis indicated that the fluorescence intensities of 8 and 7 lectin sites were significantly changed by the HP-PRRSV HN and JXA1 strains, respectively, among which there were 6 common lectin sites. The up-regulation of common lectins (RCA-I, LEL, and STL) and the down-regulation of common lectins (LCA, DSA, and PHA-E) were confirmed by lectin fluorescence staining and lectin flow cytometry, respectively. Together, the results show that the HP-PRRSV infection can induce the glycocalyx disruption of PPMVECs and their surface glycoprofiling changes, and that the poly-N-acetyllactosamine and complex N-glycan are the main up-regulated and down-regulated carbohydrate chains, respectively. Our findings may provide insights into revealing the pathogenesis of HP-PRRSV from the perspective of glycobiology.

Odontogenic Chronic Rhinosinusitis: Structured Histopathology Evidence in Different Patho-Physiological Mechanisms.

An increased odontogenic chronic rhinosinusitis (oCRS) occurrence rate has quite recently been reported, likely due to an intensification of conservative dental surgery and implantology. The main aim of the study was to report for the first time the structured histopathological characteristics of the surgical specimens of oCRS. Possible associations between histopathological features and oCRS patho-physiological mechanisms were also evaluated. Structured histopathology features were investigated in the sinonasal mucosa tissue of 42 consecutive oCRS patients.Mean tissue eosinophil counts were significantly different between oCRS with radicular cysts, dental implants, or other dental diseases (p =0.0118): mean tissue eosinophil count was higher in oCRS with dental implants. Sub-epithelial edema score and squamous metaplasia presence were significantly different when comparing the above-mentioned sub-cohorts of oCRS (p =0.0099 and p =0.0258). In particular, squamous metaplasia was more present in oCRS cases with radicular cysts than in those with a dental implant (p =0.0423). Fibrosis presence was significantly different comparing the three sub-cohorts of oCRS (p =0.0408), too. This preliminary evidence supports the hypothesis that: (i) structural histopathology can become a useful tool for clinic-pathological practice in diagnostic, therapeutic, and prognostic terms in CRS; (ii) that oCRS, as CRS in general, is a histo-pathologically heterogeneous disease; (iii) oCRS resulting from dental implants disorders can frequently be characterized as a CRS with a rich tissue eosinophilic component.

INVESTIGATION OF THE EFFECT OF APPLE POMACE ON THE TEXTURAL CHARACTERISTICS, FIBRE CONTENT, AND MOISTURE CONTENT OF SPONGE CAKES

Apple pomace, a by-product from apple processing industries, is a popular raw material, which has characteristics of a rich nutritional component, so its utilisation is of great interest. The purpose of this research was to study the effect of apple pomace on the textural characteristics and moisture and fibre contents of sponge cakes. Besides, the relationship between the properties under examination has been investigated. Rheology encompasses many characteristics of the product and plays a pivotal role in consumer acceptance. Rheology, in particular, considers the flow and deformation of bakery products. Sponge cakes were produced with wheat flour partially (by 15%, 25%, and 50%) replaced with apple pomace powder. The addition of 15% and 25% of apple pomace to sponge cakes leads to significant differences in the textural indicators, and with the addition of 50% of apple pomace, there is a maximum improvement in all textural characteristics. With an increase in the amount of apple pomace added, there is an increase in the content of fibre and moisture in the sponge cakes. Apple pomace is used as a valuable source of food fibre in the cake technology. The correlation analysis has found that fibre and moisture changes exhibit a strong correlation with rupture deformation and stickiness. Very strong and statistically significant dependence with a negative value has only been found between the moisture content and stickiness (r = ‑0.965, p<0.05). This statistically significant dependence shows that as the fibre content in sponge cakes increases, the stickiness values decrease due to the negative value of the Pearson coefficient (r = -0.965, p<0.05). From the correlation coefficients, it has been shown that the rupture force and deformation exhibit the same very strong and statistically significant correlation with the textural characteristics – rupture energy, hardness, gumminess, and compressive strength (r = 0.993, r = 0.984, r = 0.996, and r = 0.999, p<0.05). The Pearson correlation coefficients of rupture energy are positive and statistically significant in relation to hardness, gumminess, and compressive strength (r = 0.957, r = 0.983, and r = 0.992, p<0.05). These strong and statistically significant dependences are found between Pearson’s hardness coefficient on the one hand and gumminess and compressive strength on the other (r = 0.992 and r = 0.984, p<0.05).

Integrating the essence of metal organic framework-derived ZnCoTe–N–C/MoS2 cathode and ZnCo-NPS-N-CNT as anode for high-energy density hybrid supercapacitors

Transition bimetallic compounds are exploited as high-capacity electrode materials for supercapacitors due to their abundant electroactive sites and electrical conductivity. However, it remains grand challenge to construct supercapacitor devices that deliver high energy density. Here, we report an attractive one-stone-two-birds strategy to develop metal organic frameworks (MOFs) derived cathodes and anodes consisting of zinc cobalt telluride integrated nitrogen doped carbon (ZnCoTe–N–C) and zinc cobalt nanoparticles encased nitrogen doped carbon nanotubes (ZnCo-NPs-N-CNTs), respectively. Particularly, ZnCoTe–N–C cathode exhibited high specific capacity of 192.77 mA h g−1, which was further improved by the presence of hierarchical molybdenum disulfides (MoS2) nanosheets. Increased electrochemical active sites provided by MoS2 nanosheets energizes both the capacity and stability of the electrode. Consequently, the ZnCoTe–N–C/MoS2 electrodes showed a higher specific capacity of 342.55 mA h g−1 as well as excellent long-term stability. Besides, the ZnCo-NPs-N-CNTs demonstrated an initial capacity of 207.22 mA h g−1 and retained a high specific capacity even after 50 A g−1. The excellent electrochemical activity of the electrodes is attributed to the incorporation of redox rich bimetallic components and nitrogen rich carbon directly grown on the current collector, which reduces the dead volume and avoids volume expansion during charge discharge process. Finally, a hybrid asymmetric supercapacitor (HASCs) assembled using ZnCoTe–N–C/MoS2 and ZnCo-NPs-N-CNTs delivered a high specific energy density and power density maintaining 93.6% of its capacitance after 20,000 cycles. This study expands a way to construct a hybrid supercapacitor with well-designed structure and superior performance for clean energy storage technologies utilizing minimum resources.

Interconnected pyrolysis and gasification of typical biomass in a novel dual fluidized bed

A novel 50 kg/h dual fluidized bed (DFB) was designed and constructed, and pilot study of interconnected pyrolysis and gasification/activation were conducted. Four typical biomass materials were investigated and compared in DFB system. Pyrolyzer temperature and riser temperature were 480–550 °C and 800–850 °C, respectively. Dolomite were used as bed material, and superheated steam was adopted as the fluidizing gas in pyrolyzer and transport gas in loop seals. Biochars were comprehensively characterized and analyzed, and were potential matrix for carbon-based materials. Biochar from wood sawdust was the best carbon-based material matrix compared to other biochars with the highest adsorption capacities of iodine (397.08 mg/g) and methylene blue (600.15 mg/g). Phenols and benzenes (total content of 63.26–97.36%) were the richest components in all bio-oils. Non-condensable pyrolysis gas from corn cob had the highest heating value (10.14 MJ/Nm3) and largest H2 content (23.91 vol%). The total energy yield was 63.54–84.95%, while energy efficiency was 63.79–82.47%. The carbon fixation ratio was in the range of 38.61–53.27% and the highest carbon fixation ratio was 53.27% from peanut shells. The advantages and feasibility of interconnected pyrolysis and gasification/activation technologies by DFB for biomass utilization and carbon capture were assessed in this pilot study. DFB is a promising technology to achieve carbon negative economy, and deserves more research in the future.

Nondrug reinforcers contingent on alternative behavior or abstinence increase resistance to extinction and reinstatement of ethanol-maintained behavior.

The effects of delivering nondrug alternative reinforcement on resistance to extinction and reinstatement of rats' ethanol-maintained lever pressing were evaluated in two experiments. In both, rats self-administered ethanol by lever pressing in a two-component multiple schedule during baseline. In the Rich component, alternative food reinforcement was made available for performing an alternative response (Experiment 1) or according to a differential-reinforcement-of-other-behavior schedule for lever pressing (Experiment 2). In the Lean component, only ethanol was available. Moreover, the frequency of alternative reinforcement was manipulated across conditions in Experiment 1. Following baseline, lever pressing was extinguished in both components by suspending ethanol reinforcement, and alternative food reinforcers were discontinued. Finally, to test for reinstatement, ethanol reinforcers were delivered independently of lever pressing in both components. In both experiments, proportion-of-baseline response rates were higher during extinction and reinstatement testing in the Rich component than in the Lean component (although differentiation was not observed at the lowest frequency of alternative reinforcement in Experiment 1). Thus, alternative nondrug reinforcers increased resistance to extinction and reinstatement of rats' ethanol-maintained lever pressing, even when those reinforcers were delivered contingently on an alternative response or on abstinence from lever pressing.

Frequency-modulated continuous waves controlled by space-time-coding metasurface with nonlinearly periodic phases

The rapid development of space-time-coding metasurfaces (STCMs) offers a new avenue to manipulate spatial electromagnetic beams, waveforms, and frequency spectra simultaneously with high efficiency. To date, most studies are primarily focused on harmonic generations and independent controls of finite-order harmonics and their spatial waves, but the manipulations of continuously temporal waveforms that include much rich frequency spectral components are still limited in both theory and experiment based on STCM. Here, we propose a theoretical framework and method to generate frequency-modulated continuous waves (FMCWs) and control their spatial propagation behaviors simultaneously via a novel STCM with nonlinearly periodic phases. Since the carrier frequency of FMCW changes with time rapidly, we can produce customized time-varying reflection phases at will by the required FMCW under the illumination of a monochromatic wave. More importantly, the propagation directions of the time-varying beams can be controlled by encoding the metasurface with different initial phase gradients. A programmable STCM prototype with a full-phase range is designed and fabricated to realize reprogrammable FMCW functions, and experimental results show good agreement with the theoretical analyses.

A mesoscale analysis of relations between fish species richness and environmental and anthropogenic pressures in the Mediterranean Sea

Although there is a great knowledge about individual anthropogenic threats to different fish species in the Mediterranean Sea, little is known about how these threats accumulate and interact to affect fish species richness in conjunction with environmental dynamics. This study assesses the role of these threats in the fish richness component and identifies the main areas where the interaction between fish species richness and threats is highest. Our results show that fish richness seems to be higher in saltier and colder areas where the chlorophyll-a and phosphate concentrations are lower. Among the anthropogenic threats analyzed, the costal impact and the fishing effort seems to be the more relevant ones. Overall areas with high fish richness are mainly located along the western and northern shores, with lower values in the south-eastern regions. Areas of potential high cumulative threats are widespread in both the western and eastern basins, with fewer areas located in the south-eastern region. By describing the spatial patterns of the fish richness and which drivers explain these patterns we can also identify which anthropogenic activities can be managed more effectively to maintain and restore marine fish biodiversity in the basin.

The Akebia Genus as a Novel Forest Crop: A Review of Its Genetic Resources, Nutritional Components, Biosynthesis, and Biological Studies.

The genus Akebia belongs to the Lardizabalaceae family and comprises five species that are primarily distributed in East Asia. Plants of the Akebia genus comprise deciduous and semi-evergreen perennial twining vines that have been used in Chinese herbal medicine for at least 2000 years. The plants of this genus have the potential to form a novel forest crop with high nutritional and economic value because their fruit has a delicious sweet taste and rich nutrient components. In this study, we organized, analyzed, and evaluated the available published scientific literature on the botanical, ecological, and phytochemical characteristics of Akebia plants. Based on these studies, we briefly introduced botanical and ecological characteristics and focused on reviewing the development and utilization of wild genetic resources in the genus Akebia. We further explored the genus' rich nutritional components, such as triterpenes, flavonoids, polyphenols, polysaccharides, and fatty acids, and their potential use in food and health improvement applications. In addition, several papers describing advances in biotechnological research focusing on micropropagation, nutrient biosynthesis, and fruit ripeness were also included. This review provides comprehensive knowledge of the Akebia genus as a new forest crop for food and fruit utilization, and we also discuss future breeding and research prospects.

Multiple ionic conduction highways and good interfacial stability of ionic liquid-encapsulated cross-linked polymer electrolytes for lithium metal batteries

PEO-based electrolytes are promising for solid-state lithium metal batteries, but their low ionic conductivity and unstable interfacial compatibility with electrodes are the bottlenecks restricting their further applications. Herein, a unique ionic liquid (Pyr14TFSI)-encapsulated cross-linked polymer electrolyte with abundant ether–oxygen repeat units (C-SPE-IL) is proposed and prepared through an in-situ thermal polymerization process. The Pyr14+ cations of ionic liquid present a stronger affinity towards ether–oxygen groups by means of tight coordinated interactions, which promotes ionic liquid encapsulated uniformly in the polymer matrix to release more mobile Li ions into ionic liquid and create multiple ionic conduction highways in both ionic liquid and polymer matrix. The C-SPE-IL shows a much higher ionic conductivity of 3.98 × 10−4 S/cm at 30 °C. Moreover, tight interfaces with LiF– and Li3N– rich components between C-SPE-IL and Li anode are constructed to ensure effective suppression of lithium dendrites during cycling. The LiFePO4/Li batteries using C-SPE-IL present stable cycling performances at both 35 °C and 60 °C. This work provides a facile and accessible approach to design novel SPE with both ionic conduction highways and good interfacial stability for high-performance solid-state lithium metal batteries.

A Comprehensive Review on Efficacy of Leukocyte and Platelet-rich Fibrin (L-PRF) Administration in Reconstruction of Oral and Maxillofacial Structures

Several studies have shown that growth factors are effective in soothing inflammatory processes involved in the initial hemostasis phase of wound healing. Leukocyte and platelet-rich fibrin (L-PRF) is the second generation of concentrated platelets that have been shown to stimulate the proliferation of osteoblasts, gingival fibroblasts, and periodontal ligament cells. Rich platelet components have an immune function and antibacterial properties, which play a critical role in the wound healing process. The present study aimed to review the reported documents on L-PRF administration in regeneration and wound healing of oral and maxillofacial surgeries. The research was performed using well-known medical databases to find controlled clinical trials that used L-PRF as a cotreatment strategy during oral and maxillofacial surgeries. Eligible articles published between 2000 and 2022 in PubMed, Web of Science, Science Direct, and Scopus databases were selected for this review. According to the results of this study, L-PRF has significant effectiveness as a maxillofacial regenerative therapy by improving para-clinical parameters after surgery. However, more clinical practice and additional research are essential for the development of this complementary treatment method

More Constructions of Light MDS Transforms Based on Known MDS Circulant Matrices

Maximum distance separable (MDS) codes have the maximum branch number in cryptography, and they are generally used in diffusion layers of symmetric ciphers. The diffusion layer of the Advanced Encryption Standard (AES) uses the circulant MDS matrix with the row element of {2;3;1;1} in F28. It is the simplest MDS matrix in F2n4, recorded as A=Circ(2;3;1;1). In this paper, we study the more extensive MDS constructions of A in F2n4. By transforming the element multiplication operation in the finite field into the bit-level operation, we propose a multivariable operation definition based on simple operations, such as cyclic shift, shift, and XOR. We apply this multivariable operation to more lightweight MDS constructions of A and discuss the classification of the MDS clusters. We also give an example of the MDS cluster of A. Without changing the structure, elements, and the implementation cost of the known MDS matrix, the number of existing MDS transformations is expanded to n2/2 times that of its original. The constructions in this paper provide rich component materials for the design of lightweight cryptographic algorithms.

Wireless accessing of salivary biomarkers based wearable electrochemical sensors: A mini-review

The seemingly inevitable advancement in non-invasive monitoring of biomarkers in saliva has spurred wearable electronics and miniature electrochemical sensors to help us lead a comfortable, healthier life. Saliva is a readily available biofluid with rich components such as electrolytes, metabolites, and protein biomarkers. However, fabricating a flexible tiny wearable platform tethered to the body for quantifying biomarkers and retrieving the data from a smartphone via a wireless module. Miniaturized circuits (include a flexible printed circuitry board) with electrochemical sensor modules securely attached to a dental ornament device for intra-oral monitoring of multiple significant disease biomarkers and gain access to them from a customized app of a portable wireless monitor (e.g. Mobile phone, iPad, laptop) by connecting via a microcontroller and Bluetooth enabled settings. This mini-review will focus on the wireless wearable electrochemical sensing motifs developed for saliva biomarkers, challenges, and a quick future outlook.

Identification of Nutmeg With Different Mildew Degree Based on HPLC Fingerprint, GC-MS, and E-Nose.

Nutmeg (Myristicae Semen), the so-called Rou-Dou-Kou in Chinese, is one kind of Chinese herbal medicines (CHMs) as well as a globally popular spice. Hence, its stable quality and safe application attract more attention. However, it is highly prone to mildew during storage due to its rich volatile components and fatty oil. Therefore, in this study, an electronic nose (E-nose) was introduced to attempt to reliably and rapidly identify nutmeg samples with different degrees of mildew. Meanwhile, the chemical composition and volatile oil were analyzed using HPLC fingerprint and GC-MS, respectively, which could support and validate the result of E-nose. The results showed that the cluster results of HPLC fingerprint and GC-MS were generally consistent with E-nose, and they all clustered into two categories. Additionally, a discriminant model was established, which divided the samples into three categories: mildew-free, mildew-slight, and mildew, and a high DPR was obtained, which indicates that the E-nose could be a novel and promising approach for the establishment of a quality evaluation system to identify CHMs with different degrees of mildew rapidly, especially to identify early mildew.

In Vitro Antibacterial Effect of Essential Oil and Two Extracts of Myrtus Communis Leaves

Our study aims at evaluating the efficacy of extracts and essential oil of Myrtus communis leaves from the Syrian coast against several bacterial strains. The leaves were collected and dried, extracted for essential oil and ethanolic and hexan extracts were prepared. The yield of essential oil was measured and the chemical composition of the essential oil was determined using Gas Chromatography. The yield of essential oil was 1.3 ml/100 g, and the richest component was alpha-pinene. Our results showed that the ethanolic and hexan extracts of Myrtus communis had higher antibacterial activity against Gram positive bacteria (Staphylococcus aureus and Streptococcus pyogenes) than Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The ethanolic extract showed the greatest inhibitory effect against Staphylococcus aureus. These results demonstrate that Myrtus communis leaves extract has high antibacterial activity, making it a source of compounds to be used for the treatment of Gram-positive bacterial infections.

Chinese Baijiu: The Perfect Works of Microorganisms.

Chinese Baijiu is one of the famous distilled liquor series with unique flavors in the world. Under the open environment, Chinese Baijiu was produced by two solid-state fermentation processes: jiuqu making and baijiu making. Chinese Baijiu can be divided into different types according to the production area, production process, starter type, and product flavor. Chinese Baijiu contains rich flavor components, such as esters and organic acids. The formation of these flavor substances is inseparable from the metabolism and interaction of different microorganisms, and thus, microorganisms play a leading role in the fermentation process of Chinese Baijiu. Bacteria, yeasts, and molds are the microorganisms involved in the brewing process of Chinese Baijiu, and they originate from various sources, such as the production environment, production workers, and jiuqu. This article reviews the typical flavor substances of different types of Chinese Baijiu, the types of microorganisms involved in the brewing process, and their functions. Methods that use microbial technology to enhance the flavor of baijiu, and for detecting flavor substances in baijiu were also introduced. This review systematically summarizes the role and application of Chinese Baijiu flavor components and microorganisms in baijiu brewing and provides data support for understanding Chinese Baijiu and further improving its quality.

Effect of equivalence ratio and temperature on soot formation in partially premixed counterflow flames

Soot formation is quantified in detail (volume fraction, particle size, number concentration, and light emissivity dispersion exponent) in a series of partially premixed counterflow flames of ethylene at equivalence ratios, Φ, equal to 6.5, 5.0, and 4.0, and with maximum temperature spanning approximately 200 K. The focus is to investigate the effect of peak temperature and equivalence ratio on soot formation while maintaining constant global strain and stoichiometric mixture fraction. Oxygen is progressively displaced from the oxidizer to the fuel stream of a diffusion flame to stabilize partially premixed flames of decreasing Φ, showing a double-flame structure consisting of a rich premixed flame component stabilized on the fuel side of the stagnation plane and a diffusion flame component stabilized on the oxidizer side. Soot is detected in the region sandwiched between the two flame components, is formed in both of them, and is convected away radially at the Particle Stagnation Plane (PSP). At fixed Φ, raising the peak temperature invariably raises the soot volume fraction throughout the probed region. Vice versa, at fixed peak temperature, lowering the equivalence ratio causes the premixed flame component to shift away from the diffusion flame component, with the consequent broadening of the soot forming region and an increase in both soot volume fraction as well as soot particle sizes through an enhancement of surface growth. Detailed probing of the region in the vicinity of the PSP offers evidence of soot oxidation from molecular oxygen. Furthermore, when the maximum temperature is sufficiently low, the net soot production rate turns negative because surface oxidation overwhelms surface growth. Comparing the soot number production rate inferred from experiments to the dimerization rate of benzene (C6H6), naphthalene (C10H8), and pyrene (C16H10) reveals that only the smallest aromatics are present in flames at sufficiently large concentrations to account for soot nucleation. This observation applies to both the diffusion flame and the premixed flame components and confirms previous findings in strictly diffusion flames.

Dynamic Response Analysis of Dual-Rotor System with Rubbing Fault by Dimension Reduction Incremental Harmonic Balance Method

The dimension reduction incremental harmonic balance (DRIHB) method is developed to study the dynamic behavior of dual-rotor system with multi-frequency excitations and nonlinear rubbing faults. On the basis of consideration of an aero-engine, a dynamic model of rotor system is built and the piecewise-nonlinear model of rubbing force is used to investigate the nonlinear behavior of system. Considering the features of multi-frequency excitation, high dimension and strong nonlinearity of dual-rotor system, the dimension reduction approach combined with the incremental harmonic balance (IHB) method is derived for theoretically studying the dynamic response of system with nonlinear rubbing fault. The accuracy and efficiency of the method are proved through comparison with the numerical simulation result solved by the Newmark-[Formula: see text] method and the IHB method. Then, the influences of rubbing stiffness, contact gap, rotational speed and speed ratio on dynamic response are studied and discussed. It is shown that the dual-rotor system with nonlinear rubbing fault will cause the system to generate rich combination frequency components in addition to excitation frequency. All the works indicate that the DRIHB method is an effective tool for studying the nonlinear behavior of dual-rotor systems with multi-frequency excitation, high dimensions and strong nonlinearities.