Mixed System Research Articles

Effect of cultures of synthetic starters on the flavour and ethyl carbamate content of rice wine

SummaryEthyl carbamate (EC) concentration is an important indicator of the safety of rice wine. In this study, the effects of replacing traditional starters with synthetic starters on the quality of rice wine were studied to provide a basis for the application of laboratory strains to explore the metabolic basis of EC formation in rice wine fermentation systems. The effects of synthetic starters on the physicochemical indices, free amino acids, flavour compounds, urea and EC of rice wine were studied. The results showed that the microorganism species and inoculation fermentation method strongly influenced the physicochemical and flavour properties of the rice wine, among which continuous co‐fermentation improved the mellowness and flavour of the rice wine. The concentrations of urea and EC in rice wine fermented with synthetic starters decreased significantly compared with those in the control group, in which the urea content decreased by up to 97.4% and the EC content decreased by up to 90.9%. In addition, the flavour compound data showed that the differences in the aromas of rice wine fermented with different starters were mainly due to the differences in the contents of alcohols and esters. These findings suggest that EC can be regulated by changes in starters and provide guidance for the optimal configuration of mixed fermentation systems.

The mixed system of complementing the armed forces – a requirement for the Republic of Moldova

Military service is a complex social and legal phenomenon that is at the basis of the completion and functioning of the armed forces. Depending on the completion system, the armed forces may be composed of conscripts, volunteers and/or professional military personnel. Contractbased military service significantly contributes to strengthening the armed forces’ operationalcapabilities. Conscript military service is the main form for the military training of citizens who are later included in the reserve to ensure the mobilization of the army. The mixed system of complementing the armed forces organized in the Republic of Moldova responds to the interests of the military construction in the new security conditions after the start of the war in Ukraine.

Thermal and Hydrodynamic Measurements of a Novel Chaotic Micromixer to Enhance Mixing Performance

In this study, three-dimensional simulations were conducted on a new passive micromixer to assess the thermal and hydrodynamic behaviors of Newtonian and non-Newtonian fluids subjected to low generalized Reynolds numbers (0.1 to 50) and shear-thinning properties. To acquire a more profound comprehension of the qualitative and quantitative fluctuations in fluid fraction using the CFD Fluent Code, the mass mixing index, rheological behavior, performance index, mixing energy cost, mass fraction distributions, temperature contours, and pressure drop were compared to illustrate the importance of the mixer geometry in the context of two miscible fluids with varying inlet temperatures. The selected geometry is characterized by a robust chaotic flow that substantially enhances thermal and hydrodynamic performance across all Reynolds numbers. A mass mixing exceeding 72.5% is obtained when Re = 5, reaching 93.5% when Re = 50. Furthermore, the evolution of thermal mixing for all behavior indexes reaches a step of 98% with minimal pressure losses. This work enabled the demonstration of a chaotic geometry in a highly efficient mixing system, leading to enhanced thermal performance for both Newtonian and non-Newtonian fluids. The results of the hydrodynamic and thermal characterization of the mixing of shear-thinning fluids within the micromixers under investigation are conclusive.

A novel mixed reality remote collaboration system with adaptive generation of instructions

Mixed Reality (MR) remote collaboration supports a shared workspace and various non-verbal communication cues that enable remote experts to express ideas in an immersive Virtual Reality (VR) space to guide local workers in industrial physical tasks by creating Augmented Reality (AR) instructions, such as remote assembly/disassembly guidance, emergency maintenance, and training. However, due to the information non-symmetrical caused by geographical distribution, it can be challenging and high-workload for remote experts to create clear and detailed AR instructions for local workers to match spatial relationships with the local workspace, while comprehensively considering the situation information (e.g., task-related objects and partner’s environment) in complex industrial physical tasks. Advances in ambient intelligence bring ideas for building a new remote collaboration framework that supports the adaptive generation of instructions. In the study, we developed a novel MR remote collaboration prototype system, which can automatically and adaptively generate clear, detailed, and standardized AR instructions based on remote experts’ simple and intuitive interactions and local contextual information to assist remote experts in guiding local workers to complete industrial physical tasks, especially industrial assembly tasks. The effect of two interfaces on industrial assembly tasks involving relatively complex process information and environments was explored in a user study: one was a baseline solution that uses a typical MR remote collaboration interface to support remote experts to create instructions (RECI) using popular non-verbal communication cues in the shared local 3D stereoscopic scene, and the other was our novel interface that additionally supported the adaptive generation of instructions via context awareness (AGICA) on top of the typical interface. The result of the user study showed that AGICA significantly improves collaboration performance, reduces errors and workload, and enhances usability and user experience compared to RECI. This demonstrates that supporting the adaptive generation of instructions is a feasible way to enhance MR remote collaboration in industrial assembly tasks with relatively complex process information and environments. Our research findings have a certain guiding significance for the design of MR remote collaboration systems in such tasks.

Experimental Study on the Factors Affecting Pedestrian Exit Selection on the Basis of the Mixed Reality Evacuation LVC Simulation System

Evacuation rules for pedestrians in emergencies are of great significance for the design of building exits, exit management, and evacuation facilities. Based on the mixed reality evacuation LVC simulation system we developed, in this paper, three kinds of pedestrian exit selection experiments were carried out, in which the influence of distance and exit selection on pedestrian exit selection was studied. In line with common sense, during the single-factor control tests, the participants preferred the exit with fewer people and at a closer distance. The two-factor combined effect of the above two factors was also studied. It can be found that the participants preferred to choose the least crowded exit with a closer distance for evacuation. Among these two factors, the participants would give priority to the number of people at the exit. In addition, participants show different trajectories for the difference in the number of people at the two exits. Their walking trajectory was close to an arc line in the case of an equal number of people at two exits. The results of this paper provide a theoretical basis for research on designing evacuation facilities and guiding evacuees, and allows us to explore a new approach for mixed reality evacuation research by conducting virtual crowd experiments in a real environment.

The intruder motion in a cubic granular container

The Brazil nut effect is a key issue impeding the uniform distribution of particles in a mixed granular system. Extensive research was conducted on this segregation phenomenon in the 1990s and 2000s to identify the mechanisms and influencing factors involved. However, due to limitations in experimental techniques, the scope and effectiveness of research have been restricted. In this study, the Hall-effect magnetic sensing technique was utilized to track the motion of a single magnetic sphere (referred to as the intruder) within a cubic granular bed. This tracking method allowed for the measurement of the intruder's equilibrium positions as well as its trajectories. In a vibration-fluidized cubic granular container, an interesting phenomenon was observed: the intruder displayed a unique periodic helical oscillatory motion near the corner of the cubic container, with the oscillation amplitude gradually attenuating until stabilizing at its equilibrium position. A discrete element method simulation was carried out, revealing that the granular convection flow ascends from the center and descends near the container walls, with a faster flow rate at the four corners. An equation of motion was established accordingly for an intruder in such a convective granular flow, providing a comprehensive explanation for the observed intruder behavior. As a result of this comprehensive approach, we have uncovered the unique phenomenon of different mechanisms collectively driving the periodic spiral oscillation of the intruder before it eventually rested in its equilibrium position, a phenomenon whose mechanism has not previously been investigated in the literature.

A microfluidic and Langmuir approach to unveil the interplay between hydroxypropyl methylcellulose and zein nanoparticles on the stability of Pickering emulsions

Utilizing microfluidic technology and Langmuir trough, the study investigated how hydroxypropyl methylcellulose (HPMC) interact with zein nanoparticles (ZNPs) at interfaces and their collective impact on emulsion stability. Herein, microchips were designed with varying adsorption channel lengths to study the effect of adsorption kinetics on the coalescence stability, while Langmuir assessments provided insights into particle adsorption kinetic and film properties of emulsion stabilization mechanisms. Results suggested that HPMC's incorporation expedited ZNPs' rearrangement rates at the interface, especially at low concentrations, resulting in a synergistic reduction in interfacial tension. However, at high HPMC concentration, a competitive adsorption scenario emerged between ZNPs and HPMC, leading to increased interfacial tension and instability. Microfluidic analyses of droplet coalescence, alongside Langmuir-derived interfacial rheology data, revealed that while a small amount of HPMC significantly bolstered emulsion stability by enhancing viscoelastic properties of interfacial film, an excess of HPMC inversely affected these parameters, diminishing film elasticity and thus, the emulsion's coalescence resistance. The adsorption kinetic and the interaction on interface of HPMC and zein particles were analyzed via microfluidic and LB technology in this study, which will not only expand our current strategies for interface engineering of emulsions, but also deepens our understanding of the interplay between mixed particle system adsorption properties, interfacial rheology, and Pickering composite emulsion stability.

Research on the Control System for the Use of Biogas Slurry as Fertilizer

Due to its rich nutritional composition, biogas slurry can serve as a special liquid fertilizer. However, the application of slurry in agricultural fields currently faces challenges such as reliance on skilled famers’ experience, low precision, and difficulty in accurately controlling the irrigation dosage. To address these issues, an agricultural biogas slurry mixing agricultural machinery and its system has been designed and developed with the aim of enhancing the precision and safety of slurry application. The structure of the device has been designed, filter components have been selected, and improvements have been made to the structure of traditional connectors. Taking into account factors such as soil and humidity, an algorithm based on biogas slurry conductivity for slurry mixing decisions and the feedback control mechanism has been designed. After assembling the prototype, experiments were conducted, and the results showed that after processing by the system, compared to the calculated theoretical optimum, the concentration error of each component in the mixed fertilizer was controlled within 10%, and the conductivity fluctuation range was within 5%. This indicates that the overall ratio accuracy and stability of the biogas slurry mixing system are high. The biogas slurry mixing agricultural machinery and its system provide a novel intelligent equipment solution for the precise application of slurry, effectively enhancing the accuracy and safety of slurry application, reducing the use of chemical fertilizers during agricultural irrigation, and minimizing pollution to the environment and soil.

Multidimensional performance of agroecology in mixed and agropastoral farming systems of Ethiopia: empirical evidence based on the tool for agroecological performance evaluation (TAPE)

ABSTRACT This study presents the results of agroecological performance evaluation in Ethiopia. The study utilized the TAPE methodology on a relatively large number of farms (619). The results showed that transition to agroecology had a positive effect on tenure security, agricultural output, gross revenue, and diversity of Income-Generating Activities. More advanced agroecological farms were found to have better soil health and agrobiodiversity, and reduced use of chemical pesticides. They were also associated with better dietary diversity; more empowered youth and women; and created on-farm employment opportunities. These results call for support and public investments on agroecological transition in the country.

Investigation on UV/flame retardant protection of outdoor‐applied cotton fabrics by tannic acid/phytic acid system

AbstractThe ultraviolet/flame retardant protection cotton fabric is successfully prepared using a spray baking process with tannic acid (TA) and phytic acid (PA) as key ingredients to address the issues of cotton fabric such as high flammability and lack of ultraviolet (UV) resistance. With respect to the treated fabric by 4 wt% PA solution and 3 wt% TA solution, it presented 29.5% limited oxygen index (LOI) value, 8.0 cm damaged length and 26.4 ultraviolet protection factor (UPF), while they were 28.3%, 7.5 cm and 30.6 for treated fabric by 3 wt% PA solution and 4 wt% TA solution, which indicated that in the mixed system, although TA primarily acted as an anti‐UV agent, it also exhibited flame retardant properties, and PA primarily functioned as a flame retardant and could provide a certain degree of UV protection. The prepared cotton fabric through this facile method presented excellent UV/flame retardant protection capabilities, and improved the functional efficiency of TA and PA materials. Moreover, as‐prepared fabric showed great application potential, especially in outdoor‐applied fields such as sportswear, sunshade tents, sunshade hats, and so on.

Designing and evaluation of a mixed reality system for crime scene investigation training: a hybrid approach

Police investigation in real-life crime scenes is an essential aspect of forensic science education. However, the practicality of bringing young investigators to actual crime scenes is often hindered by the costs and challenges involved. In order to overcome these obstacles, new technologies such as mixed reality (MR) are being explored as potential solutions. MR technology offers an interactive and cost-effective way to simulate real-life crime scenes, providing a valuable training experience for young investigators. This paper presents a novel design of a MR system using Microsoft HoloLens 2.0, which is tailored to work in a spatial 3D scanned and reconstructed crime scene using FARO point cloud 3D scanner X130 blended with photogrammetry techniques. The system was developed through the lens of Experiential Learning Theory and designed using a participatory approach, providing a cost-effective solution to help trained Kuwaiti police officers enhance their investigative skills. In order to evaluate the system’s user experience and user interaction, the Questionnaire of User Interaction Satisfaction and User Experience Questionnaire were utilised. Forty-four young police officers evaluated the system. Police students showed positive levels of satisfaction with user interaction and overall user experience with minimal negative feedback. Female students showed higher satisfaction with the overall impression compared to male students. Based on the positive feedback regarding the system expansion, the system will be taken into the commercialisation stage in the future to be provided as an essential tool for crime scene education and investigation practices.

Research on the design and application of efficient catalysts based on interfacial chemistry: Molecular catalysts in gas-liquid mixed systems

Major challenges existing in the photocatalytic gas-liquid mixing system model include the mass transfer limit at the gas-liquid interface and the depth of light penetration. For this purpose, amphiphilic molecular catalysts were prepared by monovacancy phosphomolybdate modified by propyltrimethoxysilane. It is also used as a photocatalyst in the model reaction (molecular oxygen oxidation of aromatic alcohol). The amphiphilic molecular catalyst in the reaction is similar to surfactant behavior, not only can adsorb in the gas-liquid interface, ensure the direct contact between oxygen, catalyst and reactants, improve the efficiency of mass transfer, and also reduce the surface tension of aromatic alcohol, gas-liquid-solid three-phase system into foam system. The formed foam system amplifies the interface area of the reaction, enhances the light penetration depth and significantly promotes the reaction rate. The insights gained from our study provide a new perspective on the design of photocatalysis in a gas-liquid hybrid system.

Non‐Hermitian Control of Multimode Duan‐PPT Criteria and Steering in Energy‐Level Cascaded Four‐Wave Mixing Processes

AbstractThe non‐Hermitian singularity control of multimode entanglement in the energy‐level cascaded four‐wave mixing system within a single atomic vapor is of great significance and importance. In this study, a non‐Hermiticity system by means of quasi‐quantization of energy‐band based on non‐Hermiticity systems is constructed. By employing atomic coherence in the non‐Hermiticity system, high‐dimensional quantized photon correlations underdressed field‐induced parity‐time (PT) symmetry and symmetry breaking through the quantization of energy levels are studied. Such a phenomenon happens at microscopic (nanoscale) when the eigenvalues of dressed energy‐level and multimode entanglement are considered for both real and imaginary parts symmetry breaking. Double dressing effect is observed with more coherent channels and larger information capacity than single dressing in the energy‐level cascaded four‐wave mixing system. The study found that the splitting of the real part is larger than an imaginary part in a second‐order system, and the imaginary part splitting is also greater than the real part splitting in a third‐order system. The real part (in phase) is constructive dressing quantization, and the imaginary (out of phase) is destructive dressing quantization. Exceptional points (EP points) can be used to enhance sensitivity detection of entanglement quantum state.

Research on quantum correlations and Uhlmann phase in two-fermion mixed state system

Geometric phase, characterized by its unique properties has been an interesting subject since the discovery of Berry phase. A state inevitably becomes a mixed state in the environment. Uhlmann phase can be applied to mixed states and may be the generalization of Berry phase. In this paper, we use a pair of interacting spin-1/2 fermions, where one particle is influenced by an external magnetic field, while the other remains unaffected, to investigate quantum correlations and Uhlmann phase, we define g, p as the ratio of the particle coupling intensity to the magnetic field, and q as the depolarization parameter. Through calculation, we get the specific parameter range q of steering and Bell nonlocality under the depolarized noise channel, q∈0,1−4+g24+2g2 (steering) and q∈0,1−4+g24+3g2 (Bell nonlocality). Moreover, by using Uhlmann phase, we obtain a simple discrimination criterion of the steerability (Bell nonlocality) of the mixed system.

Food production and biodiversity are not incompatible in temperate heterogeneous agricultural landscapes

We need landscape-scale approaches to design and manage agro-ecosystems that can sustain both agricultural production and biodiversity conservation. In this study, yield figures provided by 299 farmers served to quantify the energy-equivalents of food production across different crops in 49 1-km2 landscapes. Our results show that the relationship between bird diversity and food energy production depends on the proportion of farmland within the landscape, with a negative correlation observed in agriculture dominated landscapes (≥ 64–74% farmland). In contrast, neither typical farmland birds nor butterflies showed any significant relationship with total food energy production. We conclude that in European temperate regions consisting of small-scale, mixed farming systems (arable and livestock production), productivity and biodiversity conservation may not be purely antagonistic, particularly when (semi-)natural habitats make up a large fraction of the landscape (≥ 20%).

Mesophase pitch-derived porous carbon constructed by template/activation synchronous pore-forming technology for electrochemical energy storage

Porous carbon materials with high specific surface area and wide pore size distribution play a crucial role in the energy storage process. In this paper, a mixed sol-gel system of carbon source, chemical activator and salt template agent was constructed using raw pitch, o-xylene soluble substance and their mesophase as carbon source, NaCl as template agent and KOH as activator. After one step process of high temperature treatment, porous carbon materials with high specific surface area (SBET 1969 m2/g) and wide nanopore distribution (0.4–6 nm) were obtained. The electrochemical properties of the prepared mesophase porous carbon materials were tested. At a charge-discharge rate of 80 mA/g, a specific capacitance of 102.5 F/g can be achieved for porous carbon materials obtained from the o-xylene soluble mesophase, indicating the feasibility of preparing porous carbon electrode materials by o-xylene soluble mesophase. The development of template/activation synchronous pore-forming technology can integrate the advantages of the two kinds of pore-forming technologies, reduce the demand for pore size control in porous carbon materials, and promote the one-step realization of porous carbon materials with high specific surface area, wide pore size distribution and controllable pore size.

Evidence of autotrophic direct electron transfer denitrification (DETD) by Thiobacillus species enriched on biocathodes during deep polishing of effluent from a municipal wastewater treatment plant

Cathodes can play a pivotal role as electron donors for denitrification in wastewater treatment plants, facilitating the removal of nitrogen-containing compounds such as nitrate. Denitrifying bacteria can either accept electrons directly from the electrode or indirectly via electron shuttling intermediaries generated at the cathode. In this study, comparative analyses were conducted between two denitrifying electrochemical reactors with biocathodes poised at different potentials, one that generated H2 through water electrolysis and one that did not (−500 mV and −800 mV vs. SHE). Nitrogen removal efficiencies were much higher in the −500 mV (vs. SHE) system, >93 % compared to only 20 %. Notably, a biofilm formed exclusively on the −500 mV (vs. SHE) cathode, predominantly composed of Thiobacillus species, with the majority most similar to Thiobacillus strain 65-29. Metatranscriptomics showed that genes from Thiobacillus strain 65-29 encoding outer surface c-type cytochrome and porin proteins that could facilitate direct electron uptake, were markedly up-regulated in the −500 mV (vs. SHE) reactor. Reduced sulfur species generated by the cathode and sulfate reducing bacteria might have also provided a source of electrons for nitrate reduction. In fact, Thiobacillus in the −500 mV (vs. SHE) system exhibited elevated expression of genes involved in thiosulfate (soxABXYZ), sulfite (soeABC), and sulfide (fccAB) oxidation. These findings offer valuable insights into the mechanisms of autotrophic denitrification by Thiobacillus in mixed culture systems and provide practical guidance for engineering applications.

Distributed State Estimation for Mixed Delays System Over Sensor Networks With Multichannel Random Attacks and Markov Switching Topology.

This article deals with the distributed state estimation for mixed delays system under unknown attacks. A new multichannel random attack model is established for the first time, where network attacks are considered to exist in three channels: the target-to-sensor channel, the senor-to-sensor channel, and the sensor-to-estimator channel. In the above model, transmitted packets are allowed to be attacked multiple times simultaneously, and when they are successfully attacked, the transmitted information is modified. Besides, the topology of the sensor network is considered to change dynamically according to the Markov chain. Based on the newly established distributed estimation model, the estimation error system is proven to be asymptotically mean-square stable under a given H∞ antidisturbance index by using a Lyapunov theory and a stochastic analysis technique; then, the estimator parameter matrices are solved utilizing a linearization method. Finally, several simulation examples are listed to testify the effectiveness of the designed algorithm.

Super paramagnetism phenomenon for a mixed spin ferrimagnetic binary system

Super paramagnetism phenomenon for a mixed spin ferrimagnetic binary system

Sero-epidemiological study of brucellosis in cattle under pastoral/agro-pastoral and mixed crop-livestock systems in South Omo, southern Ethiopia

BackgroundIn the pastoral/agro-pastoral communities in Ethiopia, like in South Omo, brucellosis constitutes a serious health threat for livestock and the public. The public health risk is especially high in these communities, as their way of life is highly linked with their herds. ObjectiveThe study was conducted to estimate the seroprevalence and identify potential risk factors of cattle brucellosis in South Omo zone in southern Ethiopia. MethodsA total of 614 traditionally managed local zebu female cattle, above six months old, were bled and data on hypothesized risk factors were collected using a semi-structured questionnaire. The preliminary screening of the sera for Brucella antibodies was done using Rose Bengal Plate Test (RBPT) and positive sera were further subjected to complement fixation test (CFT). ResultsThe overall animal level seroprevalence of brucellosis was 2.8 % (95 % CI: 1.72–4.41) while herd level prevalence was 11.3 % (95 % CI: 6.5–19.0). Among the risk factors considered, seroprevalence was associated with herd size, new animal introduction, district, history of occurrence of abortion, and retained fetal membranes (RFM), at both individual- and herd-level (p < 0.05). Higher seroprevalence of brucellosis was observed in cows than heifers and in animals older than 4 years (p < 0.05). Brucella seroprevalence was higher in herds in lowland areas than those in mid-altitude and highlands (p < 0.05). ConclusionThe individual and herd level prevalence observed in our study indicates endemicity of brucellosis and the potential public health threat it poses in pastoral and agro-pastoral areas of southern Ethiopia. The results of the study also suggest that the disease might be responsible for significant losses in cattle productivity due to impaired reproductive performance.