bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Acoustic Comfort and Sound Energy Transmission in a Yacht
Authors: Kanka Simon , Fredianelli Luca , Artuso Francesco , Fidecaro Francesco , Licitra Gaetano
Published: January 2023

After being neglected for a long time, in the last years, ships have been recognized and studied as sound emitters. The sound energy they generate impacts the outside, but it can also affect the indoor quality of life if the environments are not properly designed. In fact, acoustic comfort plays a pivotal role, particularly in recreational crafts. In the present work, room acoustics and acoustic camera measurements were performed, inside a 50 m length overall yacht, chosen as a case study in order to evaluate the acoustic comfort. The Italian classification procedure UNI 11367:2010 for buildings was applied, and results have been compared to other international comfort classes. However, all of these are based on prescription for standard buildings, and the present work highlights that they do not account for the effective ship’s acoustic issues: sound energy transfer from impacts over ceilings and sound energy leakage. While attention of shipbuilders in acoustic comfort is shown in the measured good reverberation times, the acoustic camera revealed sound energy leakages corresponding to hidden escape ways that have been poorly insulated. This compromises the standardized sound difference between contiguous compartments and also the thermal insulation, as leakage involves air passages. The present work attempts to evolve the classification procedure by also including, for the first time, the reverberation time, but future studies focused on finding correct standardized impact level noise for ship cases are needed. In fact, their values were very high and not comparable with those measured in actual buildings and for which reference values have been designed.
Proposal of a Simplified Tool for Early Acoustics Design Stage of Classrooms in Compliance with Speech Intelligibility Thresholds
Authors: Croce Paolo , Leccese Francesco , Salvadori Giacomo , Berardi Umberto
Published: January 2023

The speech intelligibility properties of classrooms greatly influence the learning process of students. Proper acoustics can promote the inclusion of foreign students and children with learning or hearing impairments. While awareness of the topic is increasing, there is still no parameter that can describe all aspects of speech transmission inside a room. This complicates the design of classrooms and requires designers to have extensive knowledge of theory and experience. In the scientific and technical literature, there is a lack of predictive tools, easy to use by designers, which can guide the choices in the early design stages in order to move towards technical solutions able to ensure adequate levels of speech intelligibility. For this reason, in this paper, the most relevant speech intelligibility parameters found in the literature were collected and discussed. Among these, the Clarity index and Speech Transmission Index were singled out as the most effective ones, whose prediction can be made with relatively simple methods. They were then analyzed through their prediction formulas, and a tool was proposed to allow an easy estimation of the minimum total equivalent sound absorption area needed in a classroom. This tool greatly simplifies the early acoustics design stage, allowing the intelligibility of speech within a classroom to be increased without requiring much theoretical effort on the part of the designers.
Doubly Fed Induction Machine-Based DC Voltage Generator with Reduced Oscillations of Torque and Output Voltage
Authors: Iwański Grzegorz , Piwek Mateusz , Dauksha Gennadiy
Published: January 2023

The doubly fed induction machine (DFIM)-based DC voltage generator is equipped with a stator-connected diode rectifier. The six-pulse diode rectifier as a nonlinear circuit introduces harmonics in the stator and rotor current and distorts the machine stator voltage, as well as the stator flux. This causes electromagnetic torque oscillations and instantaneous power components oscillations. The torque oscillations adversely impact the mechanical parts of the drive-train and oscillations of the p component of instantaneous power influence DC-bus voltage oscillations. The oscillations can be somewhat cancelled by control methods. However, cancellation of electromagnetic torque is not strictly coupled with cancellation of oscillations of the p component of instantaneous power. The paper presents an analysis of influence of the control methods aimed at a reduction of torque oscillations on the output voltage oscillations level in the stand-alone DFIM-based DC voltage generator. Field-oriented control FOC with current controllers and space vector modulation-based direct torque control DTC-SVM with flux module regulation have been compared with control in which electromagnetic torque is one of the commanded variables, whereas the second variable is the dot product of stator flux and rotor current space vectors. The contributions of this paper are the introduction of a new variable in the second control path in the DTC-SVM method instead of flux vector length and the proof that it can reduce torque and DC-bus voltage oscillations in the DFIG-DC system. Additionally, this paper reveals that for proper stator-to-rotor-turns ratio of a doubly fed machine necessary for reduction of the rotor converter power, lower DC-bus voltage can be obtained than is required for full realization rotor side voltage requested by rotor current controllers. This is the reason why, regardless of the control method, torque oscillations cannot be always fully cancelled, and a comparative study of the methods at these conditions has been conducted in simulation and in laboratory tests.
Local Authority Investments in the Field of Energy Transition and Their Determinants (on the Example of South-Eastern Poland)
Authors: Kata Ryszard , Pitera Rafał
Published: January 2023

This article deals with the development of renewable energy sources and their role in the transformation of energy. The main purpose of this article is to analyze the role of local governments in Poland in accelerating energy transformation at the local level through the implementation of municipal investments. The potential activities of the municipalities in the area of local eco-energy were presented, with particular emphasis on their own investment projects. The involvement of municipalities in the implementation of their own projects in the area of energy transformation was assessed, and the sources of financing for such projects were determined. A diagnosis of barriers and limitations to the increase in the participation of communes in this area was also made. This research was carried out in the Podkarpackie and Lublin regions in southern Poland. The research results indicate that local government authorities are willing to accept contributing to eco-energy projects, but only when nonrepayable funds are involved in the financial assembly. In such a situation, they are also willing to seek loans as a source of bridge financing or financing the unit’s own contribution. Financial constraints are of key importance for municipal investments in the area of energy transformation. Among the internal factors that hinder the investments of communes in the area of energy transformation, financial constraints (budget) were definitely dominant. These limitations far exceeded the costs associated with energy planning, as well as the spatial and location barriers felt by local government officials.
Direct Study of CO2 Capture Efficiency during Microalgae Arthrospira platensis Cultivation at High CO2 Concentrations
Authors: Chunzhuk Elizaveta A. , Grigorenko Anatoly V. , Chernova Nadezhda I. , Kiseleva Sofya V. , Ryndin Kirill G. , Popel Oleg S. , Malaniy Sergey Ya , Slavkina Olga V. , de Farias Neves Fabio , Leng Lijian , Kumar Vinod , Vlaskin Mikhail S.
Published: January 2023

Direct study of CO2 capture efficiency during microalgae Arthrospira platensis cultivation at high CO2 concentrations was carried out. Microalgae were grown in a 90 L photobioreactor on Zarrouk’s medium prepared with distilled water. Three 15-day experiments were carried out with different initial CO2 concentrations: 1, 5, and 9 vol.%. During the experiments, both the change in the optical density of the microalgae suspension and the direct change in the CO2 concentration in the chamber were measured. The maximum decrease in CO2 concentration due to the growth of microalgae was 0.10 vol.% (CO2)/day in the experiment with an initial CO2 concentration of 5 vol.%. Growth rate of biomass density was 79.4, 76.3, and 48.4 (mg/L)/day at 1, 5, and 9 vol.% CO2 concentrations, respectively. During the experiment with initial CO2 concentrations of 1 and 5 vol.%., pH of the culture medium was increased, but pH was decreased from 9.2 to 8.8 at 9 vol.%. In general, good viability (high quality of biomass and high rate of its growth) of Arthrospira platensis was established at 1 and 5 vol. (CO2)%, while massive death of Arthrospira platensis cells was observed in the experiment with 9 vol. (CO2)%. Biochemical analysis of the resulting biomass revealed a decrease in the content of lipids and proteins with an increase in CO2 concentration.
Jatropha’s Rapid Developments and Future Opportunities as a Renewable Source of Biofuel—A Review
Authors: Abdudeen Asarudheen , Selim Mohamed Y. E. , Sekar Manigandan , Elgendi Mahmoud
Published: January 2023

Biofuel is an attractive alternative to fossil fuels since it is renewable and biodegradable—it is mainly made from edible and non-edible sources. Globally, the usage of renewable biofuels is expected to rise quickly. The rising production and use of biofuel has prompted an examination of its environmental impact. Biodiesel is a fatty acid methyl ester generated from sustainable lipid feedstock that substitutes petroleum-based diesel fuel. Non-food oils, such as Jatropha, waste cooking oil, and by-products of vegetable oil from refineries provide inexpensive feedstock for biodiesel manufacturing. Due to its increased oil yield, adequate fatty acid content, tolerance to various agro-climatic conditions, and short gestation period, Jatropha may be one of the most promoted oilseed crops worldwide. Furthermore, Jatropha can provide several economic and agronomic advantages because it is a biodegradable, renewable plant. This study examines whether Jatropha can be considered as the most preferable biofuel in the future. The study begins with an overview of current fuels, including their classifications, dynamic changes in consumption, advantages, and cross-examining the limitations to identify the significance of bringing an alternate fuel. Then we elaborate on the outlook of the Jatropha crop, followed by evaluating its availability, opportunity, and advantages over other biofuels. Subsequently, the extraction methods, including the transesterification process and integration methods for improving the efficiency of Jatropha fuel, are also reviewed in the paper. We also assess the current stage of Jatropha cultivation in different countries with its challenges. The review concludes with future perspectives and directions for research.
Approach for a Global Route-Based Energy Management System for Electric Vehicles with a Hybrid Energy Storage System
Authors: Nguyen Tuyen , Rauch Yannick , Kriesten Reiner , Chrenko Daniela
Published: January 2023

The usage of batteries and supercapacitors in the field of electric vehicles is becoming increasingly prominent in both research and development. Due to the complementary advantages of the two systems, high energy density, and high power density, a combined battery/supercapacitor system offers potential. To effectively utilise the potential of such a hybrid energy storage system (HESS), one requires an intelligent energy management system (EMS). The EMS is responsible for controlling the electrical power between the battery and the supercapacitor in such a way that the required power can be optimally distributed at all times (currently and in the future). For this purpose, the energy management system utilises information on the driving route and, based on this information, shall calculate a global strategy for the continuous power distribution. The controlled power distribution should take place in real time and be robust against discrepancies so that unpredictable or unreliably predictable events do not significantly influence the functionality. For the implementation of the concept, a rule-based power distribution is implemented in combination with a predictive energy management. Here, the energy management is combined with a rule-based strategy calculation based on data on the route to be driven with a global optimization for the calculation of a route-specific strategy. Depending on the selected objective, the increase in energy efficiency, or lifetime, the operation of the power control is optimised. Due to the functional separation, the continuous power control can operate in real time, while more computational time can be spent on the calculations of the power management strategy, which accordingly does not need to be executed in real time. The results show that by using the presented EMS, especially in combination with a route-specific parameterisation, a significant effect on the energy efficiency and/or battery lifetime can be achieved. The average battery energy consumption can be reduced by up to 9.14% on urban routes. Regarding battery lifetime, the average battery usage can be reduced up to 13.35% and the battery energy losses even up to 62.72%.
Divergent Effects of Fertilizer Regimes on Taxonomic and Functional Compositions of Rhizosphere Bacteria and Fungi in Phoebe bournei Young Plantations Are Associated with Root Exudates
Authors: Luo Zhong , Yang Xisha , Li Jing , Wen Shizhi , Yang Lili , Ji Li , He Gongxiu
Published: January 2023

Fertilization is widely acknowledged as being an essential practice to improve forest productivity in forest ecosystems. However, too little consideration has been given to the taxonomic and functional compositions of rhizosphere soil microbes and their interactions with root exudates under different fertilizer regimes in forest plantations. Here, we investigated the effects of four typical fertilizer regimes (CK, no fertilizer; CF, compound fertilizer; OF, organic fertilizer; CMF, compound microbial fertilizer) on soil microbial communities and their potential functional groups in Phoebe bournei young plantations, as well as their associations with soil physicochemical properties and root exudates. These results showed that fertilizer regimes strikingly affected the rhizosphere soil microbial community compositions and alpha diversity indices. The pathotroph was the dominant fungal guild. With the applications of three fertilizations, the relative abundances of the plant pathogen and arbuscular mycorrhiza increased. The alpha diversity of soil bacteria was highest under the OF regime, and soil fungal diversity was more powerfully affected by the amendment of CMF. Additionally, while the fungal community was simultaneously influenced by soil physiochemical factors and root exudates, the bacterial community in the rhizosphere was mostly impacted by root exudates. More importantly, the application of OF and CF induced dramatic growths of Fusarium, while CMF treatment including Bacillus suppressed the development of Fusarium via adjusting bacterial species. Overall, our findings exhibit the divergent responses of rhizosphere bacteria and fungi to fertilizer regimes in P. bournei young plantations. The application of organic fertilizer provides benefits for rhizosphere bacteria, and microbial fertilizer can help alleviate inhibition through changing pathogens.
Overwintering Migration of the Double-Spined Spruce Bark Beetle Ips duplicatus (Sahlberg, 1836) (Coleoptera; Curculionidae)
Authors: Davídková Markéta , Kleinová Lenka , Doležal Petr
Published: January 2023

The double-spined bark beetle, Ips duplicatus, is an example of a species whose economic importance has increased in many European countries over the past decade. Many aspects of its life cycle remain unknown, complicating its management. I. duplicatus adults overwinter in forest litter, which makes the removal of infested trees during winter ineffective. Therefore, this study focuses on the mechanisms and timing of I. duplicatus overwintering migration into the forest litter. Only 2.2% of adult I. duplicatus overwintered under the bark of spruce logs stored outdoors from August 2016 to March 2017. In all, 94.4% of the beetles emerged and burrowed in forest litter. Migration began in late August, peaked in mid-September, and lasted until mid-October. At that time, forest litter collected at the base of an infested tree contained an average of 154.7 ± 23.9 I. duplicatus. Catches of migrating adults on glue stripes proved that the beetles walked down the trunk on days when the average daily temperature reached 10–15 °C. Based on the results, we suggest that trees infested with I. duplicatus that have completed their development into adults should be removed no later than September. Sanitation cutting in the following months is not effective against this pest.
Supply Chain Actors’ Perspectives Concerning the Cultivation of Specialty Wood-Decay Mushrooms in Finland
Authors: Miina Jari , Muttilainen Hanna , Vornanen Juha , Vanhanen Henri
Published: January 2023

The objective of this paper was to understand the perspectives of multiple stakeholders on the adoption of specialty wood-decay mushroom cultivation on stumps in connection with timber harvesting in Finland. The perspectives of supply chain actors, i.e., forest owners, forest harvesting entrepreneurs, forest professionals, and natural product entrepreneurs, were assessed using web-based questionnaires. Forest professionals (34%) were most interested in specialty mushroom cultivation in co-operation with companies selling cultures or buying mushrooms, whereas about one-fourth of the forest owners (23%) indicated that interest. Forest owners were willing to do the cultivation by themselves and to lease their forests for mushroom cultivation. Compared to household users, forest owners who had commercialised the non-timber forest products (NTFPs) of their forests or were willing to sell licences for NTFP picking and gathering permits were more interested in mushroom cultivation. Additionally, background information on forest owners, such as part-time forestry entrepreneurship, younger age, male gender, and higher education, significantly increased the odds of indicating interest in participating in the supply chain. One-fourth of the harvesting entrepreneurs (25%) indicated an interest in marketing and providing specialty mushroom cultivation services to forest owners in timber harvesting. Specialty mushrooms were already used by 26% of natural product entrepreneurs, and 40% indicated that specialty mushrooms could be used in the future. The shortage of information on, for example, cultivation success, yield, and costs, as well as profitability analyses, was acknowledged by all supply chain actors as the most serious barrier inhibiting their partnership in the production and utilisation of specialty mushrooms.
Evaluation of Laminaria Digitata Hydrolysate for the Production of Bioethanol and Butanol by Fermentation
Authors: Moenaert Antoine , López-Contreras Ana M. , Budde Miriam , Allahgholi Leila , Hou Xiaoru , Bjerre Anne-Belinda , Örlygsson Johann , Karlsson Eva Nordberg , Friðjónsson Ólafur H. , Hreggviðsson Guðmundur Óli
Published: January 2023

Seaweeds (macroalgae) are gaining attention as potential sustainable feedstock for the production of fuels and chemicals. This comparative study focuses on the characterization of the microbial production of alcohols from fermentable carbohydrates in the hydrolysate of the macroalgae Laminaria digitata as raw material. The potential of a hydrolysate as a carbon source for the production of selected alcohols was tested, using three physiologically different fermentative microbes, in two main types of processes. For the production of ethanol, Saccharomyces cerevisiae was used as a benchmark microorganism and compared with the strictly anaerobic thermophile Thermoanaerobacterium strain AK17. For mixed production of acetone/isopropanol, butanol, and ethanol (A/IBE), three strictly anaerobic Clostridium strains were compared. All strains grew well on the hydrolysate, and toxicity constraints were not observed, but fermentation performance and product profiles were shown to be both condition- and strain-specific. S. cerevisiae utilized only glucose for ethanol formation, while strain AK17 utilized glucose, mannitol, and parts of the glucan oligosaccharides. The clostridia strains tested showed different nutrient requirements, and were able to utilize glucan, mannitol, and organic acids in the hydrolysate. The novelty of this study embodies the application of different inoculates for fermenting a common brown seaweed found in the northern Atlantic Ocean. It provides important information on the fermentation properties of different microorganisms and pinpoints the value of carbon source utilization when selecting microbes for efficient bioconversion into biofuel and chemical products of interest.
CFD Comparison of the Influence of Casting of Samples on the Fiber Orientation Distribution
Authors: Goidyk Oksana , Heinštein Mark , Herrmann Heiko
Published: January 2023

The main goal of this research is to show that even a small deviation from the prescribed casting method EN 14651 causes a difference in fiber orientation distribution in sample beams. A further goal is to investigate the difference in the fiber orientation between bottom and side layers, which would carry the tensile load in the in-situ situation (bottom layer) compared to testing according to EN 14651 (side layer). Nowadays, the development of the proper numerical simulations that aim to visualize the casting process of the fresh concrete flow is a promising challenge in the construction industry. To be able to predict the orientation and spatial distribution of the short fibers using numerical tools may significantly simplify the investigations of the fibered composite materials. This paper compares simulations of different casting methods of the fiber concrete mixture with various flowabilities. The casting of the testing specimen was simulated in different ways: the filling of the formwork according to EN 14651, from the center only and from one edge of the formwork using computational fluid dynamics. The influence of different casting methods in combination with four specific sets of the rheological parameters on the final fiber orientation distribution is discussed. The presented outcomes of the simulations demonstrate that even a minor change in the casting procedure can significantly alter the final characteristics of the material.
Environmental Characteristics Associated with the Presence of the Pelagic Stingray (Pteroplatytrygon violacea) in the Pacific High Sea
Authors: Wang Jiaqi , Gao Chunxia , Wu Feng , Dai Libin , Ma Qiuyun , Tian Siquan
Published: January 2023

The pelagic stingray (Pteroplatytrygon violacea), perhaps the only stingray to inhabit open ocean waters, is highly interactive with longline and purse seine fisheries. The threat to P. violacea posed by high bycatch mortality has received widespread attention. To date, the environmental preference of P. violacea, which is important in designing conservation and management measures, has not been well studied. Based on data collected during a 2016–2019 survey in the Pacific Ocean by national observers of tuna longline fisheries, the relationship between the presence of P. violacea and spatiotemporal and environmental variables was first analyzed using the Generalized Additive Model. The results showed that geographic location (latitude and longitude) was the most influential variable. Monthly, P. violacea is frequently present in the Pacific high sea from December to May. The El Niño–Southern Oscillation had a significant impact on the presence of P. violacea in the Pacific high sea, with both the cold (Ocean Nino Index <−0.5) and warm (Ocean Nino Index >1) phases leading to a decrease in its presence. Regarding the environmental factors, we found that high presence was associated with low salinity (33.0~34.5 psu), a relatively high concentration of chlorophyll (0.2–0.35 mg/m3), and warm water (>20 °C). P. violacea was most likely observed in the waters offshore, closer to seamounts, and with water depths between 4000 and 5000 m. Four areas, including those east of the Solomon Islands and east of Kiribati, areas west of the Galapagos Islands, and areas near the coastal upwelling of northern Peru, related to upwelling systems or seamounts, were identified as the potential key habitats of P. violacea. Predicted distribution maps showed a significant seasonal variation in the presence of P. violacea. Moreover, the yearly change in the presence of P. violacea in the Pacific high sea indicated a possible decreasing trend in recent years. The information first provided here is essential for developing conservation and management measures for P. violacea to prevent the unavoidable ecological consequences of bycatch or other anthropogenic factors.
Research on Location Selection of Personnel Door and Anemometer Based on FLUENT
Authors: Qin Tao , Zhang Teng , Duan Yanwei , Liu Yongli
Published: January 2023

The structural design of ventilation structures and the arrangement of anemometers in the main ventilation roadway of an underground mine play an important role in the accurate measurement of air speed. It is one of the important tasks of mine ventilation management and intelligent-ventilation-system construction to determine the position of anemometers. In this paper, the CFD numerical simulation method is used to determine the position of the personnel door in the automatic air door by FLUENT software simulating and analyzing the air-speed cloud diagram and air-pressure cloud diagram in the two-dimensional roadway model. Under the same air speed, comparing the air-speed distribution of different cross-sections in the three-dimensional roadway model when the wide door and the personnel door are opened, the anemometer is set at the 25 m cross-section behind the air door, and the air-speed distribution of the cross-section at different air speeds is simulated. The average air-speed line and the specific installation position of the anemometer on the line are obtained by Origin software. The result shows that the position of the personnel door is 400 mm from the middle line of the roadway, and the measurement error of the anemometer is small on the left side of the roadway (0.41, 2.45) and the right side of the roadway (4.59, 2.43) at 25 m behind the air door, which provides a theoretical basis for the measurement of air speed in a coal mine ventilation roadway.
Sheep’s Butter and Correspondent Buttermilk Produced with Sweet Cream and Cream Fermented by Aromatic Starter, Kefir and Probiotic Culture
Authors: Silva Tânia , Pires Arona , Gomes David , Viegas Jorge , Pereira-Dias Susana , Pintado Manuela E. , Henriques Marta , Pereira Carlos Dias
Published: January 2023

Small ruminant dairy products are common in some Mediterranean countries, in the Middle East and Africa, and can play a particular role in the development of rural areas. Butter has been the object of few research studies aimed at evaluating its potential as a vehicle for probiotic microorganisms. Moreover, the recovery of fermented buttermilk with functional properties can be considered an excellent opportunity to value this dairy byproduct. Therefore, the purpose of the present work was to develop different sheep butters and respective buttermilks after cream fermentation by: (1) a mesophilic aromatic starter (A); (2) a kefir culture (K); and (3) a mixture of probiotic bacteria (P). The butters and buttermilk produced with fermented cream were compared with non-fermented sweet cream (S) butter or buttermilk, respectively, regarding their physicochemical, microbiological and sensory characteristics. The adjusted production (%, w/v) obtained for butter were: S (44.48%), A (36.82%), K (41.23%) and P (43.36%). S, A and K butters had higher solids, fat and ashes contents than P butter. The probiotic butter had a total fat of ca. 75% (w/w), below the legal limits, while all others had fat levels above 81.5%. In all samples, the pH decreased and the acidity increased over 90 days of refrigerated storage. These variations were more evident in the P butter, which agrees with the highest lactic acid bacteria counts found in this sample. Differences in color between samples and due to storage time were also observed. In general, the butter samples tended to become darker and yellower after the 60th day of storage. Texture analysis showed comparable results between samples and greater hardness was observed for the P butter, most probably due to its higher relative saturated fatty acids content (66.46% compared to 62–64% in S, A and K butters). Regarding rheological properties, all butters showed pseudoplastic behavior, but butter P had the lowest consistency index (249 kPa.sn−1). The probiotic butter and the corresponding buttermilk had viable cell counts greater than 7 Log CFU/g, indicating their suitability as probiotic carriers. All products were well accepted by consumers and small, but non-significant, differences (p > 0.05) were observed in relation to the sensory parameters evaluated. In general, it can be concluded that the use of adequate starter cultures can allow the production of innovative and potentially healthier products, alongside the valorization of dairy byproducts, improving the income of small-scale producers.
Screening of Different Essential Oils Based on Their Physicochemical and Microbiological Properties to Preserve Red Fruits and Improve Their Shelf Life
Authors: Najmi Ziba , Scalia Alessandro Calogero , De Giglio Elvira , Cometa Stefania , Cochis Andrea , Colasanto Antonio , Locatelli Monica , Coisson Jean Daniel , Iriti Marcello , Vallone Lisa , Rimondini Lia
Published: January 2023

Strawberries and raspberries are susceptible to physiological and biological damage. Due to the consumer concern about using pesticides to control fruit rot, recent attention has been drawn to essential oils. Microbiological activity evaluations of different concentrations of tested EOs (cinnamon, clove, bergamot, rosemary and lemon; 10% DMSO-PBS solution was used as a diluent) against fruit rot fungal strains and a fruit-born human pathogen (Escherichia coli) indicated that the highest inhibition halos was found for pure cinnamon and clove oils; according to GC-MS analysis, these activities were due to the high level of the bioactive compounds cinnamaldehyde (54.5%) in cinnamon oil and eugenol (83%) in clove oil. Moreover, thermogravimetric evaluation showed they were thermally stable, with temperature peak of 232.0 °C for cinnamon and 200.6/234.9 °C for clove oils. Antibacterial activity evaluations of all tested EOs at concentrations from 5–50% (v/v) revealed a concentration of 10% (v/v) to be the minimum inhibitory concentration and minimum bactericidal concentration. The physicochemical analysis of fruits in an in vivo assay indicated that used filter papers doped with 10% (v/v) of cinnamon oil (stuck into the lids of plastic containers) were able to increase the total polyphenols and antioxidant activity in strawberries after four days, with it being easier to preserve strawberries than raspberries.
Variation and Correlation Analysis of Flavour and Bacterial Diversity of Low-Salt Hotpot Sauce during Storage
Authors: Xia Yanan , Eerdun Bayaer , Wang Junlin , Li Yankai , Shuang Quan , Chen Yongfu
Published: January 2023

Culinary circles have experienced a recent trend towards low-salt hotpot sauces. Here, changes in the physicochemical quality, flavour, and bacterial diversity of hotpot sauces with different salt concentrations were studied during storage. The results indicated that the peroxide and acid values of hotpot sauce increased gradually and that the quality began to deteriorate with storage. A storage temperature of 4 °C and salt concentration above 4.4% significantly reduced spoilage. The salt concentration had no significant effect on the flavour but extended storage resulted in significant differences in flavour reflected in the changes of sweet, sour, bitter, umami, aftertaste-A, abundance, organic sulphide, and alkanes. Significant differences were found in the bacterial composition between samples stored at different temperatures. Norank-f-o-Chloroplast was the main bacterium in the samples stored at low temperatures, which was beneficial for preservation. Bacillus was detected in 4.1% NaCl samples stored at 25 °C, directly promoting sauce spoilage and an unpleasant flavour. This bacterium signalled the spoilage of low-salt hotpot sauce stored at room temperature.
Structural, Physicochemical and Digestive Property Changes of Potato Starch after Continuous and Repeated Dry Heat Modification and Its Comparative Study
Authors: Guo Shuangfeng , Wu Hao , Liu Xinyue , Zhao Wenqing , Zheng Jiayu , Li Wenhao
Published: January 2023

To investigate the effects of repeated dry heat treatment (RDH) and continuous dry heat treatment (CDH) on the structure and physicochemical and digestive properties of potato starch, potato starch was treated continuously and repeatedly at 130 °C for 3–18 h. The results showed that the crystalline form of starch was consistent with the original type B. Still, its physicochemical properties, such as swelling power, transparency, peak viscosity (PV), final viscosity (FV), breakdown (BD) and thermal properties (To, Tp, Tc, ΔT), tended to decrease. At the same time, solubility and RS increased after dry heat treatment. Moreover, RDH-treated starches were higher than CDH-treated ones in terms of molecular weight, crystallinity, swelling power, transparency and final viscosity for the same treatment time. Still, there was no significant difference between the thermal properties of the two. Meanwhile, the resistant starch (RS) content showed a downward trend after the peak value of 9 h of CDH treatment and five cycles of RDH treatment with increasing treatment time and the number of cycles, indicating a decrease in the overall digestibility of the starch. Overall, RDH had a more significant effect on potato starch’s structure and physicochemical properties than CDH.
Bifidobacterium animalis A12, a Probiotic Strain That Promotes Glucose and Lipid Metabolism, Improved the Texture and Aroma of the Fermented Sausage
Authors: Zhang Yan , Hou Yubing , Zhang Shunliang , Jing Nanqing , Zhang Hongxing , Xie Yuanhong , Liu Hui , Yan Jianguo , Ren Jianhua , Jin Junhua
Published: January 2023

Bifidobacterium animalis A12 was used for the development of fermented sausage. The growth activity, tolerance, and enzyme activity of B. animalis A12 and its contribution to the texture and flavour of fermented sausages were evaluated. Additionally, the sensory texture, flavour components, and amino acid nutrients during the fermentation process were assessed. B. animalis had high tolerance to NaCl and nitrite, and B. animalis A12 had protease and lipase activities. The pH value of sausage fermented with B. animalis A12 was lower than that of sausage fermented without any fermentation strain. Hexanal, heptanal, decanal, cis-2-decanal, and 4-methoxy-benzaldehyde are the unique aldehydes flavour components of fermented sausages in the A12 group. The highest content of volatile flavour substances and amino acids, and the color and texture characteristics of fermented sausage in the experimental group at 18 h were better than those at other times. These results suggest that B. animalis A12 has the potential to be used as a starter culture for im-proving flavour and texture in fermented sausage.
Red Meat Derived Glycan, N-acetylneuraminic Acid (Neu5Ac) Is a Major Sialic Acid in Different Skeletal Muscles and Organs of Nine Animal Species—A Guideline for Human Consumers
Authors: Jahan Marefa , Thomson Peter C. , Wynn Peter C. , Wang Bing
Published: January 2023

Sialic acids (Sias) are acidic monosaccharides and red meat is a notable dietary source of Sia for humans. Among the Sias, N-acetylneuraminic acid (Neu5Ac) and 2-keto-3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) play multiple roles in immunity and brain cognition. On the other hand, N-glycolylneuraminic acid (Neu5Gc) is a non-human Sia capable of potentiating cancer and inflammation in the human body. However, their expression within the animal kingdom remains unknown. We determined Neu5Ac and KDN in skeletal muscle and organs across a range (n = 9) of species using UHPLC and found that (1) caprine skeletal muscle expressed the highest Neu5Ac (661.82 ± 187.96 µg/g protein) following by sheep, pig, dog, deer, cat, horse, kangaroo and cattle; (2) Among organs, kidney contained the most Neu5Ac (1992–3050 µg/g protein) across species; (3) ~75–98% of total Neu5Ac was conjugated, except for in dog and cat muscle (54–58%); (4) <1% of total Sia was KDN, in which ~60–100% was unconjugated, with the exception of sheep liver and goat muscle (~12–25%); (5) Neu5Ac was the major Sia in almost all tested organs. This study guides consumers to the safest red meat relating to Neu5Ac and Neu5Gc content, though the dog and cat meat are not conventional red meat globally.
Fine Cocoa Fermentation with Selected Lactic Acid Bacteria: Fermentation Performance and Impact on Chocolate Composition and Sensory Properties
Authors: Korcari Dea , Fanton Alberto , Ricci Giovanni , Rabitti Noemi Sofia , Laureati Monica , Hogenboom Johannes , Pellegrino Luisa , Emide Davide , Barbiroli Alberto , Fortina Maria Grazia
Published: January 2023

Cocoa fermentation is a central step in chocolate manufacturing. In this research, we performed controlled fermentations of a fine cocoa variety to evaluate the impact of adjunct cultures of selected lactic acid bacteria (LAB) on fermentation parameters, chemical composition, and sensory profile of fine cocoa and chocolate. Improved fermentation processes were carried out at the Centre for the Integral Transformation of Cacao (CETICO) in Dominican Republic. Two strains of LAB, previously isolated from cocoa, and belonging to Lactiplantibacillus fabifermentans and Furfurilactibacillus rossiae species, were employed. Fermentation parameters, protein, peptide and free amino acid profiles of the fermented cocoa and volatile molecules were determined. Sensory analysis of the derived chocolate was also carried out. The obtained results indicated that the addition of the adjunct cultures influences the proteolytic processes and the free amino acid profile. Finally, the adjunct cultures increased the complexity of the flavour profile of the chocolate as they received a higher score for descriptors commonly used for fine chocolate, such as honey and red fruits. The results obtained showed that the selected strains can be an added value to the development of specific flavours that are desirable at industrial level.
Comparative Assessment of Functional Components and Antioxidant Activities between Hippophae rhamnoides ssp. sinensis and H. tibetana Berries in Qinghai–Tibet Plateau
Authors: Su Tingting , Wei Juan , Zhao Jinmei , Jiang Yumei , Bi Yang , George Galitsyn
Published: January 2023

The Qinghai–Tibet Plateau is the main production area of Hippophae rhamnoides ssp. sinensis (Rha) and H. tibetana (Tib), but studies on the types and contents of soluble sugars, organic acids, free phenolics, bound phenolics, vitamin C (VC), tocopherol (VE) and carotenoids of the two sea buckthorn berries from this region have not been reported. In this paper, we found that the soluble sugars in Rha and Tib were mainly glucose and fructose; Rha exhibited a higher content of total sugar and fructose compared to Tib. The organic acids were mainly quinic acid and malic acid; Rha exhibited a higher content of total acids and quinic acid, but lower tartaric acid and citric acid compared to Tib. Rha also possessed a higher total (free and bound) phenolic as well as total (free and bound) flavonoid content than those in Tib; twelve phenolic compounds were analyzed, among which flavonols were dominant. Catechin, isorhamnetin and quercetin were the main phenolic substances. VC and VE (γ-tocopherol (γ-VE) and δ-tocopherol (δ-VE)) were higher in Rha than Tib. The total carotenoid, lutein, β-carotene and lycopene content of Tib was remarkably higher than that in Rha. Moreover, both Rha and Tib showed good in vitro and cellular antioxidant activities, and Rha had a stronger antioxidant activity. Taken together, Rha had a higher antioxidant activity, which may be due to its higher content of phenolics, flavonoids, VC and VE.
Shelf Life Extension and Nutritional Quality Preservation of Sour Cherries through High Pressure Processing
Authors: Tenuta Maria Concetta , Artoni Elisa , Fava Patrizia , Bignami Cristina , Licciardello Fabio
Published: January 2023

The present study assessed the effectiveness of high pressure processing (HPP) for the quality maintenance of pitted sour cherries, with special regard to microbial stabilization and the maintenance of color and of chemical–nutritional properties. The HPP treatment (600 MPa for 3 min at 4 °C) was effective at minimizing the initial microbial load, which remained at negligible levels throughout 5 months of refrigerated storage. The color and total phytochemical content of sour cherries were not influenced by the HPP treatment and were maintained at levels comparable with the fresh product for 3 months of refrigerated storage. For longer storage periods, the typical red color decreased, in agreement with the content of total anthocyanins, which showed a significant decrease (up to 65% after 5 months). The antioxidant activity, measured by the ABTS and DPPH assays, was not affected by the HPP treatment, but slightly reduced during refrigerated storage. The study suggests that HPP may be exploited to extend the shelf life, while maintaining the fresh-like features of sour cherries, thus offering an alternative option to current preservation techniques (based on freezing or heating) commonly applied to this product.
The ngEHT Analysis Challenges
Authors: Roelofs Freek , Blackburn Lindy , Lindahl Greg , Doeleman Sheperd S. , Johnson Michael D. , Arras Philipp , Chatterjee Koushik , Emami Razieh , Fromm Christian , Fuentes Antonio , Knollmüller Jakob , Kosogorov Nikita , Müller Hendrik , Patel Nimesh , Raymond Alexander , Tiede Paul , Traianou Efthalia , Vega Justin
Published: January 2023

The next-generation Event Horizon Telescope (ngEHT) will be a significant enhancement of the Event Horizon Telescope (EHT) array, with ∼10 new antennas and instrumental upgrades of existing antennas. The increased uv-coverage, sensitivity, and frequency coverage allow a wide range of new science opportunities to be explored. The ngEHT Analysis Challenges have been launched to inform the development of the ngEHT array design, science objectives, and analysis pathways. For each challenge, synthetic EHT and ngEHT datasets are generated from theoretical source models and released to the challenge participants, who analyze the datasets using image reconstruction and other methods. The submitted analysis results are evaluated with quantitative metrics. In this work, we report on the first two ngEHT Analysis Challenges. These have focused on static and dynamical models of M87* and Sgr A* and shown that high-quality movies of the extended jet structure of M87* and near-horizon hourly timescale variability of Sgr A* can be reconstructed by the reference ngEHT array in realistic observing conditions using current analysis algorithms. We identify areas where there is still room for improvement of these algorithms and analysis strategies. Other science cases and arrays will be explored in future challenges.
Thermosensitive Shape-Memory Poly(stearyl acrylate-co-methoxy poly(ethylene glycol) acrylate) Hydrogels
Authors: Tokuyama Hideaki , Iriki Ryo , Kubota Makino
Published: January 2023

Stimuli-sensitive hydrogels are highly desirable candidates for application in intelligent biomaterials. Thus, a novel thermosensitive hydrogel with shape-memory function was developed. Hydrophobic stearyl acrylate (SA), hydrophilic methoxy poly(ethylene glycol) acrylate (MPGA), and a crosslinking monomer were copolymerized to prepare poly(SA-co-MPGA) gels with various mole fractions of SA (xSA) in ethanol. Subsequently, the prepared gels were washed, dried, and re-swelled in water at 50 °C. Differential scanning calorimetric (DSC) and compression tests at different temperatures revealed that poly(SA-co-MPGA) hydrogels with xSA > 0.5 induce a crystalline-to-amorphous transition, which is a hard-to-soft transition at ~40 °C that is based on the formation/non-formation of a crystalline structure containing stearyl side chains. The hydrogels stored in water maintained an almost constant volume, independent of the temperature. The poly(SA-co-MPGA) hydrogel was soft, flexible, and deformed at 50 °C. However, the hydrogel stiffened when cooled to room temperature, and the deformation was reversible. The shape-memory function of poly(SA-co-MPGA) hydrogels is proposed for potential use in biomaterials; this is partially attributed to the use of MPGA, which consists of relatively biocompatible poly(ethylene glycol).
Tuning of Optical Stopband Wavelength and Effective Bandwidth of Gel-Immobilized Colloidal Photonic Crystal Films
Authors: Amano Ami , Kanai Toshimitsu
Published: January 2023

We show that both the optical stopband wavelength and effective bandwidth of films of gel-immobilized loosely packed colloidal photonic crystals can be controlled over a wide range. When the gelation reagent of the charge-stabilized colloidal crystals was photopolymerized under ultraviolet light using different upper- and bottom-light intensities, it resulted in a gel-immobilized colloidal crystal film with a broadened Bragg reflection peak. Moreover, the width of the Bragg peak increased from 30 to 190 nm as the difference between the light intensities increased. Films with wider Bragg peaks exhibited a brighter reflection color because of the superposition of the shifted Bragg reflections. Furthermore, the Bragg wavelength could be varied over a wide range (500–650 nm) while maintaining the same broadened effective bandwidth by varying the swelling solvent concentration. These findings will expand the applicability of colloidal crystals for use in photonic devices and color pigments.