Sufficient Efficiency Research Articles

All-Polymer Indoor Photovoltaic Modules

Indoor photovoltaic (IPV) with power output over 100 μW is promising to power the numerous sensor nodes in Internet of Things (IoT) ecosystem. All polymer photovoltaic has the advantages of excellent thermal stability and superior mechanical property. In this work, we fabricate the first all-polymer indoor photovoltaic module with the active area of 10 cm2. The module uses polymer doner CD1 and new polymer acceptor PBN21 with medium optical bandgap of 1.9 eV as the active layer. It is processed with ecofriendly solvent tetrahydrofuran and the morphology can be improved by blade coating at 55 oC. Under light emitting diode illumination at 1000 lux, the module exhibits a power conversion efficiency of 12.04% and a power output of 367.2 μW. The sufficient power output, high efficiency, excellent stability and eco-friendly processing indicate that allpolymer indoor photovoltaic is a promising approach to achieve the self-powered of sensor nodes in IoT ecosystem.

Selective Bacterial Targeting and Infection-Triggered Release of Antibiotic Colistin Conjugates.

In order to render potent, but toxic antibiotics more selective, we have explored a novel conjugation strategy that includes drug accumulation followed by infection‐triggered release of the drug. Bacterial targeting was achieved using a modified fragment of the human antimicrobial peptide ubiquicidin, as demonstrated by fluorophore‐tagged variants. To limit the release of the effector colistin only to infection‐related situations, we introduced a linker that was cleaved by neutrophil elastase (NE), an enzyme secreted by neutrophil granulocytes at infection sites. The linker carried an optimized sequence of amino acids that was required to assure sufficient cleavage efficiency. The antibacterial activity of five regioisomeric conjugates prepared by total synthesis was masked, but was released upon exposure to recombinant NE when the linker was attached to amino acids at the 1‐ or the 3‐position of colistin. A proof‐of‐concept was achieved in co‐cultures of primary human neutrophils and Escherichia coli that induced the secretion of NE, the release of free colistin, and an antibacterial efficacy that was equal to that of free colistin.

Effect of heat treatment with biopreparation on the quality of tomato fruit during storage

Tomato fruits are characterized by a high content of biologically active substances, which makes them an irreplaceable component of nutrition. However, tomatoes are perishable products and require additional measures to extend storage. One of the most problematic areas is the limited use of synthetic chemicals for processing fruit prior to storage. An alternative to them are natural exogenous preparations with antioxidant and disinfectant effects, which are environmentally friendly. However, the treatment of fruits with natural substances does not have sufficient efficiency in comparison with synthetic ones, which requires a combination with other post-harvest measures to increase cold stress. The object of research is the process of storing tomato fruits using heat treatment with a biological product. Numerous studies indicate the feasibility of using the processing of fruits with biological products to extend their storage duration. Standardized preparations based on bee products are of great interest. The research carried out in this work is aimed at extending the shelf life of tomato fruits while maintaining their quality by heat treatment of tomatoes with a solution of a biological product (tincture of the biomass of the larvae of the greater wax moth) before storage. In the course of the study, it was found that such treatment prolongs the shelf life of blank tomatoes up to 50 days, which is 40 % longer compared to the control. It has been proven that fruits treated with a biological product demonstrate a low level of metabolic processes. This is due to the fact that the proposed treatment slows down the rate of accumulation and degradation of sugars and organic acids. In particular, in fruits treated with a biological product, the sugar content is 8.8–10.6 % higher than in the control. The rate of decrease in the level of titratable acidity in the variants treated with the biological product is 15–19 % slower than in the control. The above results indicate the effectiveness of the use of a biological product for storing tomato fruits in comparison with similar measures.

Reduction of water chromaticity by materials with capillary properties

The presence of a significant amount of plant and animal organic residues in the environment leads to intensive pollution of natural waters and significant deterioration of water chromaticity. Ukrainian regulatory documents on the quality of drinking water establish a level of 20 degrees for water chromaticity. Hence, in most cases, natural water must be additionally treated before consumption. The coagulation, flocculation, filtration and flotation are today the most widespread methods for normalizing the water chromaticity level. All these processes are quite complex and expensive, require the use of additional reagents and lead to secondary water pollution. The use of materials with capillary properties is a promising method since it simultaneously ensures the liquid phase transport without excess pressure and water cleaning from various pollutants. This method, used to reduce water chromaticity, found that sufficient efficiency could be provided only for the initial water chromaticity level within 20 - 80° CCS and at pH level within 2.0 - 4.0. Under other conditions, all studied tissue samples as a material for capillary filter, such as cotton, linen, polyester and gabardine, did not provide the value of water chromaticity required for drinking water. Even worse results were obtained for water with initial chromaticity more than 80 degrees. Considering that the described method can provide the maximum efficiency only in a highly acidic medium, it is assumed that the surface charge of the capillary filter fibers and humic acid particles could be the critical factor in the reduction of water chromaticity. In a wide pH range, the surface of the humic particles is charged mainly negatively. The surface of cellulose fibers is also negatively charged in the pH range of 2.0 - 11.0. Therefore, the results of experiments can be explained from this point of view. There are no research data in these fields at all. One of the possible ways to improve the efficiency of water chromaticity reduction by the proposed method is to select fabrics with appropriate physicochemical surface properties. Also, capillary filtration process can be treated with special reagents for giving the fiber surface the required charge. Water treatment by series of several connected capillary filters can be a promising way. In general, given the simplicity of the filter design, low total cost of the water treatment process, and zero energy losses, the studied method is quite promising for industrial implementation and needs more detailed research.

Frequency-Dependent Sonochemical Processing of Silicon Surfaces in Tetrahydrofuran Studied by Surface Photovoltage Transients.

The field of chemical and physical transformations induced by ultrasonic waves has shown steady progress during the past decades. There is a solid core of established results and some topics that are not thoroughly developed. The effect of varying ultrasonic frequency is among the most beneficial issues that require advances. In this work, the effect of sonication of Si wafers in tetrahydrofuran on the photovoltage performance was studied, with the specific goal of studying the influence of the varying frequency. The applied ultrasonic transducer design approach enables the construction of the transducer operating at about 400 kHz with a sufficient sonochemical efficiency. The measurements of the surface photovoltage (SPV) transients were performed on p-type Cz-Si(111) wafers. Sonication was done in tetrahydrofuran, methanol, and in their 3:1 mixture. When using tetrahydrofuran, the enhanced SPV signal (up to ≈80%) was observed due to increasing sonication frequency to 400 kHz. In turn, the signal was decreased down to ≈75% of the initial value when the frequency is lowered to 28 kHz. The addition of methanol suppressed this significant difference. It was implied that different decay processes with hydrogen decomposed from tetrahydrofuran could be attempted to explain the mechanism behind the observed frequency-dependent behavior.

Sensitivity of subglacial drainage to water supply distribution at the Kongsfjord basin, Svalbard

Abstract. By regulating the amount, the timing, and the location of meltwater supply to the glacier bed, supraglacial hydrology potentially exerts a major control on the evolution of the subglacial drainage system, which in turn modulates ice velocity. Yet the configuration of the supraglacial hydrological system has received only little attention in numerical models of subglacial hydrology so far. Here we apply the two-dimensional subglacial hydrology model GlaDS (Glacier Drainage System model) to a Svalbard glacier basin with the aim of investigating how the spatial distribution of meltwater recharge affects the characteristics of the basal drainage system. We design four experiments with various degrees of complexity in the way that meltwater is delivered to the subglacial drainage model. Our results show significant differences between experiments in the early summer transition from distributed to channelized drainage, with discrete recharge at moulins favouring channelization at higher elevations and driving overall lower water pressures. Otherwise, we find that water input configuration only poorly influences subglacial hydrology, which instead is controlled primarily by subglacial topography. All experiments fail to develop channels of sufficient efficiency to substantially reduce summertime water pressures, which we attribute to small surface gradients and short melt seasons. The findings of our study are potentially applicable to most Svalbard tidewater glaciers with similar topography and low meltwater recharge. The absence of efficient channelization implies that the dynamics of tidewater glaciers in the Svalbard archipelago may be sensitive to future long-term trends in meltwater supply.

Evaluation of the designed multi-epitope protein of Brucella melitensis in guinea pigs.

Objective(s):One of the causes of human and animal zoonotic infections is Brucella melitensis, which is transmitted to humans through dairy products. It seems for prevention of human infection we might protect the livestock by an efficient protein as a vaccine candidate. For this purpose, the use of immunogenic proteins of bacteria is able to create immunity the same as the traditional vaccines.Materials and Methods:In this study, by finding the immunogenic antigens of this bacterium by 2-dimensional gel electrophoresis and MALDI-TOF methods and also the proteins reported in other studies, we found the epitopes of the bacterial antigenic determinants in silico. Nineteen peptides of T and B epitopes were selected. They were ligated with linkers and after gene synthesis, the designed polypeptide was expressed in Escherichia coli BL21. The purified recombinant MEL protein mixed with chitin was injected subcutaneously into three 300 g male guinea pigs three times. Also, PBS control and Rev.1 commercial vaccine groups were considered. Results:The results show that MEL polypeptide is equal to the Rev.1 vaccine in stimulating secretion of IFNγ and IL2 and specific IgG. High levels of IL-2 emphasize the activation of the cellular immunity, and in particular comparison of PI in guinea pig’s spleen cells treated with recombinant MEL protein on days 0 and 5 show that it has significant proliferation compared with PBS unstimulated cells.Conclusion:This recombinant protein could be a subunit protein with sufficient efficiency in stimulating the humoral and cellular-mediated immune system against B. melitansis.

Integrating Predictive Maintenance in Adaptive Process Scheduling for a Safe and Efficient Industrial Process

Predictive maintenance (PM) algorithms are widely applied for detecting operational anomalies on industrial processes to schedule for a maintenance intervention before a possible breakdown; however, much less focus has been devoted to the use of such prognostics in process scheduling. The existing solutions mostly integrate preventive approaches to protect the machines, usually causing downtimes. The premise of this study is to develop a process scheduling mechanism that selects an acceptable operating condition for an industrial process to adapt to the predicted anomalies. As PM is largely a data-driven approach (hence, it relies on the setup), we first compare different PM approaches and identify a one-class support vector machine (OCSVM) as the best performing option for the anomaly detection on our setup. Then, we propose a novel pipeline to integrate maintenance predictions into a real-time, adaptive process scheduling mechanism. According to the abnormal readings, it schedules for the most suitable operation, i.e., optimizing for machine health and process efficiency, toward preventing breakdowns while maintaining its availability and operational state, thereby reducing downtimes. To demonstrate the pipeline on the action, we implement our approach on a small-scale conveyor belt, utilizing our Internet of Things (IoT) framework. The results show that our PM-based adaptive process control retains an efficient process under abnormal conditions with less or no downtime. We also conclude that a PM approach does not provide sufficient efficiency without its integration into an autonomous planning process.

A Component-Sizing Methodology for a Hybrid Electric Vehicle Using an Optimization Algorithm

Many leading companies in the automotive industry have been putting tremendous effort into developing new powertrains and technologies to make their products more energy efficient. Evaluating the fuel economy benefit of a new technology in specific powertrain systems is straightforward; and, in an early concept phase, obtaining a projection of energy efficiency benefits from new technologies is extremely useful. However, when carmakers consider new technology or powertrain configurations, they must deal with a trade-off problem involving factors such as energy efficiency and performance, because of the complexities of sizing a vehicle’s powertrain components, which directly affect its energy efficiency and dynamic performance. As powertrains of modern vehicles become more complicated, even more effort is required to design the size of each component. This study presents a component-sizing process based on the forward-looking vehicle simulator “Autonomie” and the optimization algorithm “POUNDERS”; the supervisory control strategy based on Pontryagin’s Minimum Principle (PMP) assures sufficient computational system efficiency. We tested the process by applying it to a single power-split hybrid electric vehicle to determine optimal values of gear ratios and each component size, where we defined the optimization problem as minimizing energy consumption when the vehicle’s dynamic performance is given as a performance constraint. The suggested sizing process will be helpful in determining optimal component sizes for vehicle powertrain to maximize fuel efficiency while dynamic performance is satisfied. Indeed, this process does not require the engineer’s intuition or rules based on heuristics required in the rule-based process.

Gaussian process regression for direct laser absorption spectroscopy in complex combustion environments

Tunable diode laser absorption spectroscopy (TDLAS) has been proved to be a powerful diagnostic tool in combustion research. However, current methods for post-processing a large number of blended spectral lines are often inadequate both in terms of processing speed and accuracy. The present study verifies the application of Gaussian process regression (GPR) on processing direct absorption spectroscopy data in combustion environments to infer gas properties directly from the absorbance spectra. Parallelly-composed generic single-output GPR models and multi-output GPR models based on linear model of coregionalization (LMC) are trained using simulated spectral data at set test matrix to determine multiple unknown thermodynamic properties simultaneously from the absorbance spectra. The results indicate that compared to typical data processing methods by line profile fitting, the GPR models are proved to be feasible for accurate inference of multiple gas properties over a wide spectral range with a manifold of blended lines. While further validation and optimization work can be done, parallelly composed single-output GPR model demonstrates sufficient accuracy and efficiency for the demand of temperature and concentration inference.

Positive and negative likelihood ratios of two anthropometric indices (Waist/Height Index and Waist/Hip Index) in the diagnosis of pathological nutritional situations overweight and obesity

Background and objective. Koch et al., reported that the Waist/Hip Index more accurately predicts cardiovascular risk factors and mortality. Huaman et al., reported that the Waist/Height Index can be used as a diagnostic test for metabolic syndrome, since it has a high significant value. To determine whether two anthropometric indices have sufficient prognostic efficiency or moderate prognostic efficiency by combining sensitivity and specificity using positive and negative likelihood ratios in a single expression. Material and methods. Quantitative epistemological approach. Descriptive observational epidemiological study without directionality and with prospective temporality. Three husband adult patients of both genders who attended the Integral Hospital "Jose Maria Morelos" were studied. As a reference test or Gold Standard was used the Lorentz Equation as a reference test. Results. The results for the positive likelihood ratios corresponded to 13.41 and 1.72 for the anthropometric indices Waist/Height Index and Waist/Hip Index, respectively. The results for the negative likelihood ratios corresponded, respectively, to 0.07 and 0.48 for the anthropometric indices Waist/Height Index and Waist/Hip Index. Conclusions. The best anthropometric index for the diagnosis of overweight and obesity pathological nutritional situations corresponds to the Waist/Height Index, since the results of the positive and negative likelihood ratios report sufficient prognostic efficiencies. On the other hand, the results of the positive and negative likelihood ratios report, respectively, negligible prognostic efficiency and poor prognostic efficiency for the Waist/Hip Index.

Possibility of intracavity terahertz difference frequency generation in a two-frequency GaAsP/AlGaAs/GaAs quantum well laser.

We consider the GaAsP/AlGaAs/GaAs laser design with two different quantum wells for simultaneous generation of ${{\rm{TE}}_0}$ and ${{\rm{TM}}_0}$ modes having different frequencies in near-IR range. We theoretically investigate the possibility of effective difference frequency generation in the 7.5-8 and 10.5-11 THz regions in the laser design proposed. Resonant increase of second-order susceptibility in AlGaAs in these ranges provides sufficient generation efficiency. We demonstrate an output power-conversion factor for the difference frequencies in the 7.5-8 THz range to be up to ${{4 {-} 8}}\;{{\rm{MW}}^{- 1}}$ at room temperature in such a laser.

Seismic Behavior of Innovative Precast Superimposed Concrete Shear Walls with Spiral Hoop and Bolted Steel Connections

Owing to the desirable bond strength and excellent workability, spiral hoop and bolted steel connectors are introduced to enhance the connecting performance of superimposed reinforced concrete shear wall (SRCSW) system. In order to investigate the seismic performance of SRCSWs, applying such connecting methods under flexure-shear interaction and flexural dominated status, two groups of precast (PC) specimens were constructed: one-story and two-story specimens. Seismic behavior in terms of crack patterns, load-displacement response, ductility, stiffness degradation, strain response, and deformation results of SRCSWs is evaluated by the quasistatic cyclic test. It is shown that the wall specimens with the proposed connectors exhibited similar failure mode to that of the cast-in-place (CIP) walls and possessed adequate seismic performance such as lateral resistance, ultimate drift ratio, and lateral stiffness besides the ease of erection. The strain responses and deformation results of the PC specimens under reversed cyclic loading were presented to evaluate the effectiveness of the introduced connections. The test results indicated that the PC walls adopting bolted steel connectors behaved better in force transmission and exhibited greater integrity characteristic compared with the specimens having spiral hoop connectors. Lastly, simplified finite element models considering the nonlinear slip behavior within the connection joint of SRCSWs were established and verified, which could provide sufficient accuracy and efficiency to predict the seismic response of the proposed wall system.

Decoding space syntax on the translation of site cluster permeability into building courtyard

An urban environment leads to tropical building adaptation by providing sufficient thermal comfort and energy efficiency. For generating the physiological cooling, interconnected attribute of site cluster permeability is translated into lower context such as building scale to provide optimal wind speed to restore thermal comfort. It will be expected to find the critical factor which most influences the performance. Meanwhile, the encoding of the space connectivity to accelerate air movement has been evaluated by previous studies. In this paper, the counter reading of visibility relationships analysis on computational fluid dynamics is conducted and decoded by DepthmapX simulation. The site clusters type of grid, cul-de-sac, and the open area plan of a loop represent housing estates in some tropical regions as the cases. The results highlighted that 50% or more translated air movement from the site to the building scale environment is determined by the dominated warmest connectivity of open space. The potency of energy efficiency is indicated by the capability of accommodating both social connectivity and environmental performance. Furthermore, the code of irregular building patterns by increasing air movement has low spatial and social connectivity because of space depthless. Providing open space for site planning encourages both environmental and social qualities.

Biomass Sea-Based Supply Chains and the Secondary Ports in the Era of Decarbonization

One of the tools to attain the goal of climate-neutrality by 2050 by the European Union is increasing the share of renewable energy sources (RESs) in the energy mix of member states. A major part of the future bioenergy mix is to be played by biomass. As many hazards have been pointed out when using forest biomass, particular attention is paid to the potential of agro biomass. However, as agro biomass is sourced mostly locally, the supply may not be sufficient to meet the growing demand. Therefore, international trade (including overseas) might become increasingly important to meet the EU renewable energy targets. In this context, it is seaports that may play a major part in developing biomass supply chains. The main purpose of the article is to fill the research gap by identifying the pros and cons for the development of biomass sea-based supply chains through secondary ports and specifying their relevance from the perspective of major stakeholders in the context of decarbonization processes. The supplementary purpose of the study was the verification of the environmental sustainability of biomass sea-based supply chains through secondary ports versus land transport (carbon footprint). This study applied the single case study method (the case of the secondary port in Szczecin). The case study strategy involved qualitative and quantitative research techniques. Our research study showed that (1) overseas agro biomass (wastes and residues) may become a significant tool in the process of decarbonization of economies that are heavily reliant on coal as a transition fuel and as a stable RES in the structure of the future energy mix; and (2) biomass sea-based supply chains may be an attractive alternative for secondary ports affected by negative outcomes of decarbonization. However, a dedicated biomass terminal would make the secondary ports more attractive for this type of cargo. A biomass terminal may provide sufficient port service efficiency and enable harmonization of deliveries. Additionally, the carbon footprint analysis performed in this study has shown that biomass sea-based supply chains generate lower CO2 emissions than alternative land deliveries.

Enhanced combustion behavior and NOx reduction performance in a CFB combustor by combining flue gas recirculation with air-staging: Effect of injection position

In circulating fluidized bed (CFB) boilers, the flue gas recirculation (FGR) is an important technical means to promote de-NOx combustion. However, the conventional injection position of recycled gas seriously hinders the combustion efficiency and the flexibility of load regulation. To solve this, thermal-state experiments are conducted on a lab-scale CFB combustor to explore the feasibility of adopting novel FGR and air staging technology to achieve low NOx emission and sufficient combustion efficiency. The effects of FGR/supplementary burnout air (SBA) injection positions and operating parameters on temperature profile, combustion efficiency and original NOx emission in the furnace are discussed in detail. The synergistic effect of FGR and SBA on combustion characteristics and NOx reduction is also analyzed. Eventually, a systematic approach to enhance NOx control and combustion efficiency in fluidized bed is proposed. The key results indicate that the NOx reduction rate reaches 46.15% by adopting middle FGR and top SBA, which exceeds the reduction performance of utility boilers with conventional FGR. Also, the furnace outlet temperature and combustion efficiency can be ensured to be over 860 °C and 98.4% respectively, thus to provide new technical basis for enhancing de-NOx combustion in CFB boiler at low load, as well as the prospective guidance for FGR retrofitting of various fluidized bed combustors.

Investigation of zinc binding properties onto natural and synthetic zeolites: Implications for soil remediation

Abstract Although the potential of natural zeolites for water and soil remediation has been widely studied, the use of synthetic zeolites, especially from by-product/waste materials, is still rather scarce. Therefore, we present a complex study investigating the adsorption mechanisms of Zn(II) on natural (ZC), synthetic (13X), and perlite by-product (ZP) zeolites under different conditions including laboratory solutions, extracted soil solutions and real metal-rich soils. Adsorption mechanisms in laboratory solutions were studied by a combination of adsorption modeling, including a non-electrostatic modeling with two surface sites corresponding to cation exchange and surface complexation (NEM-CE/SC); desorption experiments and comprehensive solid-state analyses. Based on the obtained results, the adsorbed amount and strength of binding decreased in the order of synthetic > perlite by-product > natural zeolite. In the case of natural zeolite, the prevailing effect of CE is expected. Contrarily, the influence of both CE and SC is expected for synthetic zeolites. The experiments in soil solutions showed sufficient sorption efficiency and chemical stability of all materials with a slight pH increase after the application of both synthetic zeolites. Soil incubation experiments showed reversible binding of Zn on natural zeolite and a significant influence of irreversible binding on both synthetic zeolites. Based on the obtained results, zeolites prepared from a perlite by-product material are promising soil amendments. However, their application to real soils needs to be thoroughly evaluated according to specific properties of the given soil due to a potential pH increase and elevated salinity levels caused by leaching of exchangeable cations.

Large-scale inference of correlation among mixed-type biological traits with phylogenetic multivariate probit models

Inferring concerted changes among biological traits along an evolutionary history remains an important yet challenging problem. Besides adjusting for spurious correlation induced from the shared history, the task also requires sufficient flexibility and computational efficiency to incorporate multiple continuous and discrete traits as data size increases. To accomplish this, we jointly model mixed-type traits by assuming latent parameters for binary outcome dimensions at the tips of an unknown tree informed by molecular sequences. This gives rise to a phylogenetic multivariate probit model. With large sample sizes, posterior computation under this model is problematic, as it requires repeated sampling from a high-dimensional truncated normal distribution. Current best practices employ multiple-try rejection sampling that suffers from slow-mixing and a computational cost that scales quadratically in sample size. We develop a new inference approach that exploits: (1) the bouncy particle sampler (BPS) based on piecewise deterministic Markov processes to simultaneously sample all truncated normal dimensions, and (2) novel dynamic programming that reduces the cost of likelihood and gradient evaluations for BPS to linear in sample size. In an application with 535 HIV viruses and 24 traits that necessitates sampling from a 12,840-dimensional truncated normal, our method makes it possible to estimate the across-trait correlation and detect factors that affect the pathogen’s capacity to cause disease. This inference framework is also applicable to a broader class of covariance structures beyond comparative biology.

Comparative effectiveness of exercise training program in patients with heart failure: protocol for a systematic review of randomised controlled trials and network meta-analysis

IntroductionHeart failure (HF) is an end-stage of numerous heart diseases including hypertension, coronary heart disease and arrhythmia, in which the heart is unable to perform its circulatory function with sufficient...

Multifunctional Hydroxyapatite-based Nanoparticles for Biomedicine: Recent Progress in Drug Delivery and Local Controlled Release

As calcium phosphate micro/nano-structures (CPMNS) have been suggested, many protocols have been exploited to design new formulations. CPMNS are similar to a bone mineral from the point of view of structure and chemical composition. Some of them, such as hydroxyapatite (HAp), have been commercialized, and they demonstrated sufficient efficiency as hard tissue replacements for various purposes. Due to their biocompatibility, bioaccumulation, bioactivity, osteogenic activity, and anticancer properties, as well as great resemblance to body organs such as bones, these substances are suitable options for the diagnosis and treatment of various diseases. Therefore, recent advances of HAp applications in drug delivery for various diseases, such as cancer, bone disease, and tooth inflammation, are reviewed. Moreover, their implementation for several kinds of drugs, including anticancer, anti-inflammatory, antibiotics, growth factors and analgesics, is investigated.