bluuebunny/crossref_metadata_2025 huggingface dataset:
Production and Some Energy Indicators in Semi-desert Biogeocenosis of the Ganikh-Airichai valley of Azerbaijan
Authors: Sariyeva G.
Published: September 2020

The results of phytoproductivity in dynamics and some energy indicators of Artemisetum–Ephemerosum and Alhagietum–Artemisosum on the territory of the Ganykh–Airichai valley of Azerbaijan are presented. These are typical semi-desert cenoses. Analysis of quantitative indicators of energy consumption in plant communities over the period of research showed that 2 types of weather and climatic conditions determined 2 contrasting periods of development. Data on the aboveground and underground biomass in the studied communities are given. A comparative analysis has been carried out.
Healthy Microbiota and Natural Functional Nutrition: Humoral and Cellular Immunity
Authors: Romanchuk N.
Published: September 2020

The human immune system and microbiota jointly evolve, and their balanced systemic interaction occurs throughout life. This close association of both overall composition and microbiota richness plays an important role in modulating host immunity and can influence the immune response in vaccination. The availability of innovative technologies, such as next-generation sequencing and correlated bioinformatics tools, allows deeper investigation of the cross-network relationships between the microbiota and human immune responses. A new managed healthy biomicrobiota and personalized functional and balanced “brain and microbiota” nutrition is a patient’s long-term medical program that allows the combined use of nutritional epigenetics and pharmacepigenetics, and most importantly, the prevention of polypharmacy. A functional food product using biomarkers and artificial intelligence technologies is a targeted nutrient medium for both the body as a whole and biomicrobiota in particular. Lifestyle and environmental factors leave epigenetic traces on our DNA that affect gene expression, some have protective effects and others are harmful. Genetic and epigenetic factors that ensure longevity and super-longevity require a reasonable new interaction with nature and society, and responsibility for future healthy generations. In the studies of P. I. Romanchuk, it was shown that an increase in the average life expectancy of a person and neuroendocrine changes in physiological and pathological aging, on the one hand, epigenetic factors and electromagnetic information load/overload, on the other hand, made a significant contribution to the circadian nature of the neural network interaction of the human brain with artificial intelligence. The microbiota is a key element potentially capable of affecting antigen functions to elicit a protective immune response and the ability of the immune system to adequately respond to antigenic stimulation (vaccine efficacy) by acting as an immunological modulator as well as a natural vaccine adjuvant. The mechanisms underlying the crosstalk between the gut microbiota and the immune system play a crucial role, especially at an early age (early gut microbiota forms immunological functions). New interactions, along with other genetic and environmental factors, lead to a certain composition and richness of the microbiota, which can diversify the individual response to vaccinations. Variations in microbial communities may partly explain the geographical heterogeneity in vaccination success, and a deep understanding of this dynamics may be a tool for improving immunization strategies.
Non-invasive assessment of left ventricular myocardial work in healthy subjects with echocardiography
Authors: Alekhin M. N. , Ivanov S. I. , Stepanova A. I.
Published: September 2020

Purpose: to evaluate the left ventricular (LV) echocardiographic indices of myocardial work using the LV pressure-strain loops method in healthy individuals.

Material and methods. The study included 50 healthy subjects (28 men, mean age: 44 ± 14 years). The inclusion criteria were the absence of any cardiovascular diseases and diabetes mellitus. After calculating global longitudinal strain (GLS) from speckle-tracking Echo and inserting values of brachial artery cuff blood pressure (BP), the vendor-specific module constructed non-invasive LV pressure-strain loops. The following parameters were calculated: global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE).

Results. The lowest values of GWI in men and women were 1382 mmHg% and 1821 mmHg%, the highest values were 2875 mmHg% and 2589 mmHg%, mean values were 2056 ± 326 mmHg% and 2109 ± 200 mmHg%, respectively. Mean values of GCW were 2292 ± 329 mmHg% in men and 2304 ± 211 mmHg% in women. The median and the highest value of GWW were 66 mmHg% and 313 mmHg% in men and 79,5 mmHg% and 172 mmHg% in women, respectively. The lowest value of GWE were 89% in men and 91% in women. GWI was significantly and naturally correlated only with systolic BP (r = 0,30, р = 0,03) and GLS (r = -0,72, р < 0,001). GCW was significantly correlated with systolic BP (r = 0,36, р = 0,01) and GLS (r = -0,72, р < 0,001) too, however, the negative relationship with the age of the patients was found (r = -0,27, р = 0,04). LV myocardial work indices did not significantly differ between men and women. Coefficients of variation for GWI, GCW and GWE did not exceed 10%, which is typical for good reproducible indices.

Conclusion. The study presents values of the echocardiographic LV myocardial work indices, obtained with help of the LV pressure-strain loops method in healthy individuals. The natural correlation of LV myocardial work indices with strain and blood pressure was demonstrated, as well as a dependence on the age of the subjects and good reproducibility.
Climate Change and Forced Migration
Authors: Llain Arenilla Shirley , Hawkins Rada Cindy
Published: September 2020

The population of environmentally displaced people has increased recently, thus this article aims to address the challenges climate change may impose on Nation-States concerning human rights in relation to forced migration. The relationship between climate change and forced migration will be studied in order to present the problems arising from the allocation of international responsibility among States and the international protection (or the lack thereof) of “Climate Refugees” and stateless persons caused by the disappearance of Nation- States under climate change; solutions will be proposed under the existing International Human Rights Law.
A report of recurring pregnancy-induced Cushing's syndrome
Authors: Niafar Mitra , Bahrami Amir , Ghorbani Fatemeh , Aghamohammadzadeh Nasser , Sadra Vahideh , Nader Djalal Nader
Published: September 2020

Introduction: The incidence of pregnancy-induced
Cushing's syndrome (CS) is very low. However, the diagnosis of CS in pregnant
patients is very difficult because of an overlapping signs and symptoms. Case
report: Herein,
a 20-year-old pregnant patient was reported that was afflicted by gestational
CS during two pregnancies; termination of pregnancy was carried out in both
cases. Bilateral adrenal hypertrophy was reported in magnetic resonance
imaging. Following therapeutic abortion, signs of chemical evidence of CS was
thoroughly regressed within a few months after each abortion without any
treatment.

Conclusion: Due to the temporal relation between the
occurrence of CS after each pregnancy the diagnosis of gestational
hypercortisolism was made, and for further pregnancies bilateral adrenalectomy
was recommended.
Mind the Gap? Negative Tweets & Partisanship in the House of Representatives
Authors: Macdonald Maggie , Hua Whitney
Published: September 2020

How does the lack of institutional legislative power and influence in the House of Representatives shape politicians’ rhetoric? In previous work, we found evidence that members of Congress in the minority and the party opposing the president were more negative in the language they used on Twitter. In this project, we dive deeper into their negative tweets and theorize under what conditions we expect representatives to be more likely to use them. We offer a plan of how to leverage almost 2 million unique tweets made by representatives 2013-2018 to assess the impact of a representative’s political power, or lack thereof, on her use of different methods of strategic negative sentiment in her tweets. Given the increasing contention between the two parties on- and offline, it is unlikely that the use of negative rhetoric and its potentially harmful impact on American government and congress will decrease in the near future.
The Impact of Attitudes and Behaviors on Nurse Satisfaction, Well-being, and Outcomes of Patient Care
Authors: Rosenstein Alan H
Published: September 2020

Healthcare is a complex multidimensional system that depends upon effective communication and collaboration amongst all members of the health care team as the key ingredient for best patient care. In the current health care environment all health care providers are feeling the growing pressures on care delivery and the changing health dynamics which in many instances has negatively impacted their attitudes and behaviors toward medical care. Nursing is a key part of this process. In order to provide best patient care, affiliated organizations need to recognize how important staff satisfaction and engagement is to care continuity and provide the necessary resources and support to maintain staff physical, emotional, and behavioral well- being. The aim of the article is to review key literature findings to help organizations recognize the causes and consequences of stress and burnout and the importance of providing the appropriate support and resources to help nurses succeed.
RETRACTED: Chitosan-Coated Titanium Dioxide-Embedded Paclitaxel Nanoparticles Enhance Anti-Tumor Efficacy Against Osteosarcoma
Authors: Qu Yang , Kang Mingyang , Cheng Xueliang , Zhao Jianwu
Published: September 2020

Objective

Titanium dioxide nanoparticles (TiO2) nanoparticles have been widely explored in the prevention of cancer risk. Due to the difficult solubility of TiO2 nanoparticles, it is essential to synthesize new surfactants to increase its bioavailability and anti-tumor activity and reduce its cytotoxicity. Furthermore, oxidative and inflammation are closely associated with the osteosarcoma risk. Chitosan has biocompatibility, antioxidant and anti-inflammatory properties. The effects of chitosan-coated TiO2-embedded paclitaxel nanoparticles on an osteosarcoma model were explored.

Methods

An osteosarcoma model was established and chitosan-coated TiO2-embedded paclitaxel nanoparticles were prepared using a freeze-drying strategy. The morphological characteristics of nanoparticles were observed using scanning electron microscopy (SEM). The physicochemical properties of nanoparticle were evaluated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The cytotoxicity was tested by using human osteoblast cells hFob1.19 and osteosarcoma cells 143B. Osteosarcoma mice were treated with PBS buffer, paclitaxel, TiO2-embedded paclitaxel and chitosan-coated TiO2-embedded paclitaxel nanoparticles. The biomarkers of oxidative-inflammatory status, anti-tumor activities and survival rates of the model were measured.

Results

XRD analysis showed that the peaks of chitosan/TiO2 (anatase) were consistent with those of crystalline TiO2 and broad phase of chitosan. The FTIR spectrum indicated the relevant functional groups in TiO2. Chitosan-coated TiO2-embedded paclitaxel nanoparticles had good biocompatibility and improve antioxidant and anti-inflammatory properties in the osteosarcoma model. Chitosan-coated TiO2-embedded paclitaxel nanoparticles was less toxic to the cells hFob1.19 and more toxic to the cells 143B than TiO2-embedded paclitaxel nanoparticles. Chitosan-coated TiO2-embedded paclitaxel nanoparticles showed significant antitumor activity and increased the survival rate of the osteosarcoma model (P < 0.05).

Conclusions

Chitosan improved anti-tumor potential of TiO2-embedded paclitaxel nanoparticles in the prevention of osteosarcoma.
Content of Trace Elements in Soil Fertilized with Potassium and Nitrogen
Authors: Wyszkowski Mirosław , Brodowska Marzena S.
Published: September 2020

The aim of the study was to determine the effect of increasing potassium fertilization (0, 140, 190, and 240 mg K2O/kg of soil) in the interaction with nitrogen fertilization (130 and 170 mg N/kg of soil) on the trace elements content in the typical, non-contaminated agricultural soil. The trace elements content in the soil depended on nitrogen and potassium fertilization. Potassium fertilization had a more significant effect on trace elements content in the soil fertilized at the same time with a lower nitrogen dose (130 mg N/kg soil). Increasing potassium fertilization increased the content of cadmium by 83% and lead by 32% and reduced the amounts of chromium by 10% and iron by 3% in the soil, particularly in the series with a lower nitrogen dose (130 mg N/kg soil). The effect of potassium fertilization on the content of other trace elements was less unambiguous since, for most of trace elements, lower doses of this fertilizer contributed to growth of trace element, while higher doses lead to a decrease in their accumulation in the soil. Nitrogen fertilization increased the contents of zinc and iron—3%, copper—9%, manganese—12%, chromium—15%, and cobalt—59%, while reducing the contents of cadmium and nickel—24% and lead—45%. Permissible standards for trace elements content in the soil have not been exceeded.
Effects of Sodium Formate and Calcium Propionate Additives on the Fermentation Quality and Microbial Community of Wet Brewers Grains after Short-Term Storage
Authors: Lv Jingyi , Fang Xinpeng , Feng Guanzhi , Zhang Guangning , Zhao Chao , Zhang Yonggen , Li Yang
Published: September 2020

The objective of this research was to examine the effect of sodium formate (SF) and calcium propionate (CAP) on the fermentation characteristics and microbial community of wet brewers grains (WBG) after short-term storage. In the laboratory environment, fresh WBG was ensiled with (1) no additive (CON), (2) sodium formate (SF, 3 g/kg fresh weight), and (3) calcium propionate (CAP, 3 g/kg fresh weight) for 20 days. After opening, fermentation characteristics, chemical composition, rumen effective degradability, and the microbial community of ensiled WBG were analyzed. The addition of CAP had no effect on pH and lactic acid concentration and increased the concentrations of propionic acid; the SF group had the lowest pH and acetic acid, butyric acid, and ammonia nitrogen contents and the highest lactic acid concentration. After fermentation, the SF group had the highest contents of dry matter (DM), water-soluble carbohydrates (WSCs), and neutral detergent fiber (NDF). The contents of the three nutrients in the CAP group were significantly higher than those in the CON group. The addition of the two additives had little influence on the crude protein (CP) and acid detergent fiber (ADF) contents of the ensiled WBG. Two additives elevated in situ effective degradability of DM and NDF compared with the parameters detected in the CON group; WBG ensiled with SF had higher effective in situ CP degradability than that in the CON and CAP groups. The results of the principal component analysis indicate that the SF group and two other groups had notable differences in bacterial composition. The analysis of the genus level of the bacterial flora showed that the content of Lactobacillus in the SF group was significantly higher than that in the two other treatment groups, while the content of Clostridium was significantly lower than that in the two other treatment groups. Therefore, the addition of sodium formate can suppress the undesirable microorganisms, improve the fermentation qualities, and ensure that WBG is well preserved after 20 days of ensiling.
Quality Assessment of 3D Printed Surfaces Using Combined Metrics Based on Mutual Structural Similarity Approach Correlated with Subjective Aesthetic Evaluation
Authors: Okarma Krzysztof , Fastowicz Jarosław , Lech Piotr , Lukin Vladimir
Published: September 2020

Quality assessment of the 3D printed surfaces is one of the crucial issues related to fast prototyping and manufacturing of individual parts and objects using the fused deposition modeling, especially in small series production. As some corrections of minor defects may be conducted during the printing process or just after the manufacturing, an automatic quality assessment of object’s surfaces is highly demanded, preferably well correlated with subjective quality perception, considering aesthetic aspects. On the other hand, the presence of some greater and more dense distortions may indicate a reduced mechanical strength. In such cases, the manufacturing process should be interrupted to save time, energy, and the filament. This paper focuses on the possibility of using some general-purpose full-reference image quality assessment methods for the quality assessment of the 3D printed surfaces. As the direct application of an individual (elementary) metric does not provide high correlation with the subjective perception of surface quality, some modifications of similarity-based methods have been proposed utilizing the calculation of the average mutual similarity, making it possible to use full-reference metrics without the perfect quality reference images, as well as the combination of individual metrics, leading to a significant increase of correlation with subjective scores calculated for a specially prepared dataset.
Qualitative Prediction Model for Dynamic Behavior of Ballasted Tracks
Authors: Choi Jung-Youl , Kim Sun-Hee
Published: September 2020

Theoretical, experimental, analytical, and statistical evaluations were performed to predict and assess the dynamic behavior of a ballasted track, such as the track support stiffness, track impact factor, or dynamic wheel–rail forces. Field measurements were then performed to evaluate the dynamic behavior of the ballasted track and its components. A qualitative prediction model was then developed to predict and assess track performance as a function of dynamic wheel-rail force and variation in track support stiffness. The developed two-degree-of-freedom dynamic track model can define the rail pad and ballast stiffness ranges based on designed and measured values. Using the proposed model, qualitative analysis results are presented as a discrete space of various track responses and parameters, rather than as single values. The proposed model was then validated using field measurements, which demonstrated that the proposed model predicted the vertical rail displacement and rail bending stress within approximately 2–5% of the obtained field measurements. Overall, the developed qualitative prediction model allows the dynamic response of in-service ballasted tracks to be estimated as a function of the rail pad and ballast stiffness using only a simple field measurement.
Assessment of Strength Development at Hardened Stage on High-Strength Concrete Using NDT
Authors: Lee Taegyu , Lee Jaehyun , Choi Hyeonggil
Published: September 2020

This study proposes model formulae for predicting the strength of concrete by analyzing the relationships between the results of nondestructive testing (NDT) methods and the compressive strength of concrete specimens at the hardened stage. Further, NDT of concrete molds and mock-up specimens was conducted using NDT methods (rebound hammer, ultrasonic pulse velocity). The water/cement (W/C) ratios were set to 0.48, 0.41, and 0.33 to achieve concrete strengths within the compressive strength range of 24–60 MPa. The evaluation parameters included the fresh concrete properties, compressive strength (mold and core), temperature history, maturity, rebound value, and ultrasonic pulse velocity. Evaluation results indicated that the reliability of existing models, based on the rebound and ultrasonic pulse velocity, is significantly low on high-strength concrete of 40 MPa or higher, and cannot satisfy the ±20% error range. Consequently, this study proposes a regression equation of the concrete strength based on the experimental rebound and ultrasonic pulse velocity values in a 24–60 MPa range, which offers satisfactory reliability.
Serum BDNF’s Role as a Biomarker for Motor Training in the Context of AR-Based Rehabilitation after Ischemic Stroke
Authors: Koroleva Ekaterina S. , Tolmachev Ivan V. , Alifirova Valentina M. , Boiko Anastasiia S. , Levchuk Lyudmila A. , Loonen Anton J. M. , Ivanova Svetlana A.
Published: September 2020

Background: brain-derived neurotrophic factor (BDNF) may play a role during neurorehabilitation following ischemic stroke. This study aimed to elucidate the possible role of BDNF during early recovery from ischemic stroke assisted by motor training. Methods: fifty patients were included after acute recovery from ischemic stroke: 21 first received classical rehabilitation followed by ‘motor rehabilitation using motion sensors and augmented reality’ (AR-rehabilitation), 14 only received AR-rehabilitation, and 15 were only observed. Serum BDNF levels were measured on the first day of stroke, on the 14th day, before AR-based rehabilitation (median, 45th day), and after the AR-based rehabilitation (median, 82nd day). Motor impairment was quantified clinically using the Fugl–Meyer scale (FMA); functional disability and activities of daily living (ADL) were measured using the Modified Rankin Scale (mRS). For comparison, serum BDNF was measured in 50 healthy individuals. Results: BDNF levels were found to significantly increase during the phase with AR-based rehabilitation. The pattern of the sequentially measured BDNF levels was similar in the treated patients. Untreated patients had significantly lower BDNF levels at the endpoint. Conclusions: the fluctuations of BDNF levels are not consistently related to motor improvement but seem to react to active treatment. Without active rehabilitation treatment, BDNF tends to decrease.
Pre- and Post-Surgical Dysphagia in Adults with Tumors of the Posterior Fossa: A Prospective Blinded Study
Authors: Lapa Sriramya , Quick-Weller Johanna , Nasari Christiane , Dziewas Rainer , Gessler Florian , Wagner Marlies , Warnecke Tobias , Hattingen Elke , Seifert Volker , Konczalla Jürgen
Published: September 2020

Background: While swallowing disorders are frequent sequela following posterior fossa tumor (PFT) surgery in children, data on dysphagia frequency, severity, and outcome in adults are lacking. The aim of this study was to investigate dysphagia before and after surgical removal of PFT. Additionally, we tried to identify clinical predictors for postsurgical swallowing disorders. Furthermore, this study explored the three-month outcome of dysphagic patients. Methods: In a cohort of patients undergoing PFT surgery, dysphagia was prospectively assessed pre- and postoperatively using fiberoptic endoscopic evaluation of swallowing. Patients with severe dysphagia at discharge were re-evaluated after three months. Additionally, clinical and imaging data were collected to identify predictors for post-surgical dysphagia. Results: We included 26 patients of whom 15 had pre-operative swallowing disorders. After surgery, worsening of pre-existing dysphagia could be noticed in 7 patients whereas improvement was observed in 2 and full recovery in 3 subjects. New-onset dysphagia after surgery occurred in a minority of 3 cases. Postoperatively, 47% of dysphagic patients required nasogastric tube feeding. Re-evaluation after three months of follow-up revealed that all dysphagic patients had returned to full oral intake. Conclusion: Dysphagia is a frequent finding in patients with PFT already before surgery. Surgical intervention can infer a deterioration of impaired swallowing function placing affected patients at temporary risk for aspiration. In contrast, surgery can also accomplish beneficial results resulting in both improvement and full recovery. Overall, our findings show the need of early dysphagia assessment to define the safest feeding route for the patient.
Study on Lamb Waves in a Composite Phononic Crystal Plate
Authors: Yuan Lili , Zhao Peng , Ding Yong , Ding Benjie , Du Jianke , Ma Tingfeng , Wang Ji
Published: September 2020

In the paper, a phononic crystal plate composed of a magnetorheological elastomer with adjustable band gaps in the low frequency range is constructed. The dispersion relations of Lamb waves are studied by the supercell plane wave expansion method. The transmission responses as well as the displacement fields of Lamb waves are calculated by the finite element method. The influence of geometric parameters on the band gaps, the regulation effect of the volume ratio of Fe particles and the bias magnetic field on the band gaps are analyzed. Based on the numerical results, we find that the volume ratio of Fe particles and the magnetic field affect the band gap effectively. The location and width of the band gaps can be adjusted within a broad frequency range by varying the geometric parameters and magnetic field. We can control the band gap, achieve an appropriate and wide low band gap by selecting proper geometric parameters and applying an external contactless magnetic field to deal with complicated and changeable engineering environment. The results are useful for understanding and optimizing the design of composite vibration isolation plates.
A-DVM: A Self-Adaptive Variable Matrix Decision Variable Selection Scheme for Multimodal Problems
Authors: Mollinetti Marco Antonio Florenzano , Gatto Bernardo Bentes , Neto Mário Tasso Ribeiro Serra , Kuno Takahito
Published: September 2020

Artificial Bee Colony (ABC) is a Swarm Intelligence optimization algorithm well known for its versatility. The selection of decision variables to update is purely stochastic, incurring several issues to the local search capability of the ABC. To address these issues, a self-adaptive decision variable selection mechanism is proposed with the goal of balancing the degree of exploration and exploitation throughout the execution of the algorithm. This selection, named Adaptive Decision Variable Matrix (A-DVM), represents both stochastic and deterministic parameter selection in a binary matrix and regulates the extent of how much each selection is employed based on the estimation of the sparsity of the solutions in the search space. The influence of the proposed approach to performance and robustness of the original algorithm is validated by experimenting on 15 highly multimodal benchmark optimization problems. Numerical comparison on those problems is made against the ABC and their variants and prominent population-based algorithms (e.g., Particle Swarm Optimization and Differential Evolution). Results show an improvement in the performance of the algorithms with the A-DVM in the most challenging instances.
Investigation of Forced Convection Enhancement and Entropy Generation of Nanofluid Flow through a Corrugated Minichannel Filled with a Porous Media
Authors: Aminian Ehsan , Moghadasi Hesam , Saffari Hamid , Gheitaghy Amir Mirza
Published: September 2020

Corrugating channel wall is considered to be an efficient procedure for achieving improved heat transfer. Further enhancement can be obtained through the utilization of nanofluids and porous media with high thermal conductivity. This paper presents the effect of geometrical parameters for the determination of an appropriate configuration. Furthermore, the optimization of forced convective heat transfer and fluid/nanofluid flow through a sinusoidal wavy-channel inside a porous medium is performed through the optimization of entropy generation. The fluid flow in porous media is considered to be laminar and Darcy–Brinkman–Forchheimer model has been utilized. The obtained results were compared with the corresponding numerical data in order to ensure the accuracy and reliability of the numerical procedure. As a result, increasing the Darcy number leads to the increased portion of thermal entropy generation as well as the decreased portion of frictional entropy generation in all configurations. Moreover, configuration with wavelength of 10 mm, amplitude of 0.5 mm and phase shift of 60° was selected as an optimum geometry for further investigations on the addition of nanoparticles. Additionally, increasing trend of average Nusselt number and friction factor, besides the decreasing trend of performance evaluation criteria (PEC) index, were inferred by increasing the volume fraction of the nanofluid (Al2O3 and CuO).
Prognostics and Health Management for the Optimization of Marine Hybrid Energy Systems
Authors: Tang Wenshuo , Roman Darius , Dickie Ross , Robu Valentin , Flynn David
Published: September 2020

Decarbonization of marine transport is a key global issue, with the carbon emissions of international shipping projected to increase 23% to 1090 million tonnes by 2035 in comparison to 2015 levels. Optimization of the energy system (especially propulsion system) in these vessels is a complex multi-objective challenge involving economical maintenance, environmental metrics, and energy demand requirements. In this paper, data from instrumented vessels on the River Thames in London, which includes environmental emissions, power demands, journey patterns, and variance in operational patterns from the captain(s) and loading (passenger numbers), is integrated and analyzed through automatic, multi-objective global optimization to create an optimal hybrid propulsion configuration for a hybrid vessel. We propose and analyze a number of computational techniques, both for monitoring and remaining useful lifetime (RUL) estimation of individual energy assets, as well as modeling and optimization of energy use scenarios of a hybrid-powered vessel. Our multi-objective optimization relates to emissions, asset health, and power performance. We show that, irrespective of the battery packs used, our Relevance Vector Machine (RVM) algorithm is able to achieve over 92% accuracy in remaining useful life (RUL) predictions. A k-nearest neighbors algorithm (KNN) is proposed for prognostics of state of charge (SOC) of back-up lead-acid batteries. The classifier achieved an average of 95.5% accuracy in a three-fold cross validation. Utilizing operational data from the vessel, optimal autonomous propulsion strategies are modeled combining the use of battery and diesel engines. The experiment results show that 70% to 80% of fuel saving can be achieved when the diesel engine is operated up to 350 kW. Our methodology has demonstrated the feasibility of combination of artificial intelligence (AI) methods and real world data in decarbonization and optimization of green technologies for maritime propulsion.
Cost Analysis of Optimized Islanded Energy Systems in a Dispersed Air Base Conflict
Authors: Pearson Jay , Wagner Torrey , Delorit Justin , Schuldt Steven
Published: September 2020

The United States Air Force has implemented a dispersed air base strategy to enhance mission effectiveness for near-peer conflicts. Asset dispersal places many smaller bases across a wide geographic area, which increases resupply requirements and logistical complexity. Hybrid energy systems reduce resupply requirements through sustainable, off-grid energy production. This paper presents a novel hybrid energy renewable delivery system (HERDS) model capable of (1) selecting the optimal hybrid energy system design that meets demand at the lowest net present cost and (2) optimizing the delivery of the selected system using existing Air Force cargo aircraft. The novelty of the model’s capabilities is displayed using Clark Air Base, Philippines as a case study. The HERDS model selected an optimal configuration consisting of a 676-kW photovoltaic array, an 1846-kWh battery system, and a 200-kW generator. This hybrid energy system predicts a 54% reduction in cost and an 88% reduction in fuel usage, as compared to the baseline Air Force system. The HERDS model is expected to support planners in their ongoing efforts to construct cost-effective sites that minimize the transport and logistic requirements associated with remote installations. Additionally, the results of this paper may be appropriate for broader civilian applications.
Decarbonisation Using Hybrid Energy Solution: Case Study of Zagazig, Egypt
Authors: Akrami Mohammad , Gilbert Samuel J. , Dibaj Mahdieh , Javadi Akbar A. , Farmani Raziyeh , Salah Alaa H. , Fath Hassan E. S. , Negm Abdelazim
Published: September 2020

In this study, an analysis is carried out to determine the optimal application of multiple renewable energy resources, namely wind and solar, to provide electricity requirements for green smart cities and environments. This was done to determine the potential of renewable energy to provide clean, economically viable energy for the case study of Zagazig, located at 30°34′ N 31°30′ E in the North East of Egypt. The relevant data surrounding the production of energy were collected, including the meteorological data from NASA, and specifications regarding renewable resources including solar panels, wind turbines, and storage batteries. Then a hybrid model was constructed consisting of Photovoltaics (PV) panels, wind turbines, a converter, and storage batteries. Once the model was constructed, meteorological data were added alongside average daily demand and cost of electricity per kWh. The optimal solution for Zagazig consisted of 181,000 kW of solar panels feeding directly into the grid. This system had the lowest Net Present Cost (NPC) of the simulations run of US$1,361,029,000 and a net reduction of 156,355 tonnes of CO2 per year.
Application of Microemulsion Systems in the Formulation of Biodegradable Pre-Flush Fluid for Primary Cementing
Authors: Araújo Elayne A. , Caminha Thaine T. , Paiva Evanice M. , Silva Raphael R. , Freitas Júlio Cézar O. , Garnica Alfredo Ismael C. , Curbelo Fabíola D. S.
Published: September 2020

Oil well cleanup fluids (pre-flushes) are intermediate fluids pumped ahead of the cement slurry; they are able to clean the well walls by removing the filter cake formed by the drilling fluid, and leave the surface water-wet. This work’s main objective was to use biodegradable microemulsion systems as cleanup fluids in order to reduce the environmental impact. Three microemulsion systems were formulated, each composed of an oil phase, a surfactant and three different aqueous phases: glycerol, glycerol:water (mass ratio 1:1), and fresh water. The results show that all microemulsion systems were effective with 100% filter cake removal, with a removal time of less than 60 s. The wettability test and fluid compatibility analyses exhibited advantageous performances, without phase separation, variations in viscosity, gelation, or flocculation. The compressive strength and X-ray diffractometry (XRD) analysis showed the influence of the glycerol on the cement slurry properties, with the compressive strength resistance ranging from 8.0 to 10.7 MPa, and resulted in the formation of portlandite.
Numerical Investigation of a Free-Piston Hydrogen-Gasoline Engine Linear Generator
Authors: Zhang Ziwei , Feng Huihua , Zuo Zhengxing
Published: September 2020

The free-piston engine linear generator (FPELG) is being investigated by many researchers because of its high thermal efficiency and its variable compression ratio. However, all researchers focused on the FPELG characteristics with mono-fuel. Therefore, in this paper, the performance of the FPELG that has adopted gasoline with hydrogen as fuel is investigated. The method of coupling the zero-dimensional dynamics model with the multi-dimensional CFD (Computational Fluid Dynamics) combustion model was applied during the simulation process. According to the results, the piston TDC (Top Dead Center), the piston peak piston velocity, and the system operation frequency show a negative correlation with the increase of hydrogen fractions. However, the peak in-cylinder pressure was increased with the hydrogen volume fraction increase, due to the fast flame speed and short combustion duration characteristics of hydrogen. Meanwhile, the indicated efficiency of the free-piston engine was increased from 32.3% to 35.3% with the hydrogen volume fraction change from 0% to 4.5%, when the free-piston engine operates at stoichiometric conditions with fixed ignition timing. In addition, with the ignition timing advance increase, the piston TDC was decreased. The peak piston velocity and the peak in-cylinder pressure were in negative correlation with the ignition timing advance. While the engine indicated that the efficiency was increased with the equivalent degree of ignition timing from 20° to 16°. Therefore, the ignition timing of the FPELG under the spark-ignition combustion mode is supposed to be an effective and practical control variable.
Characterization of Thermophysical Properties of Phase Change Materials Using Unconventional Experimental Technologies
Authors: Martínez Arnold , Carmona Mauricio , Cortés Cristóbal , Arauzo Inmaculada
Published: September 2020

The growing interest in developing applications for the storage of thermal energy (TES) is highly linked to the knowledge of the properties of the materials that will be used for that purpose. Likewise, the validity of representing processes through numerical simulations will depend on the accuracy of the thermal properties of the materials. The most relevant properties in the characterization of phase change materials (PCM) are the phase change enthalpy, thermal conductivity, heat capacity and density. Differential scanning calorimetry (DSC) is the most widely used technique for determining thermophysical properties. However, several unconventional methods have been proposed in the literature, mainly due to overcome the limitations of DSC, namely, the small sample required which is unsuitable for studying inhomogeneous materials. This paper presents the characterization of two commercial paraffins commonly used in TES applications, using methods such as T-history and T-melting, which were selected due to their simplicity, high reproducibility, and low cost of implementation. In order to evaluate the reliability of the methods, values calculated with the proposed alternative methods are compared with the results obtained by DSC measurements and with the manufacturer’s technical datasheet. Results obtained show that these non-conventional techniques can be used for the accurate estimation of selected thermal properties. A detailed discussion of the advantage and disadvantage of each method is given.
Modeling of an Integrated Thermoelectric Generation–Cooling System for Thermoelectric Cooler Waste Heat Recovery
Authors: Yu Jia , Zhu Qingshan , Kong Li , Wang Haoqing , Zhu Hongji
Published: September 2020

This paper focuses on the problem of thermoelectric cooler waste heat recovery and utilization, and proposes taking the waste heat together with the original heat source as the input heat source of the integrated thermoelectric generation–cooling system. By establishing an analytic model of this integrated thermoelectric generation–cooling system, the steady-state and transient thermal effects of this system are analyzed. The steady-state analysis results show that the thermoelectric generator’s actual heat source is about 20% larger than the intrinsic heat source. The transient analysis results prove that the current of thermoelectric power generation and the cold end temperature of the system show a nonlinear change rate with time. The cold end temperature of the system has a maximum value. Under different intrinsic heat sources, this maximum value can be reached between 1 s and 2.5 s.
A Forecasting-Based Control Algorithm for Improving Energy Managment in High Concentrator Photovoltaic Power Plant Integrated with Energy Storage Systems
Authors: Salimbeni Andrea , Porru Mario , Massidda Luca , Damiano Alfonso
Published: September 2020

The High Concentrator Photovoltaic (HCPV) technology, due to its high efficiency, is considered one of the most promising solutions for the exploitation of sun-irradiation-based Renewable Energy Sources (RES). Nevertheless, the HCPV production is strictly connected to the Direct Normal Irradiation (DNI) making this photovoltaic technology more sensible to cloudiness than traditional ones. In order to mitigate the power intermittence and improve production programmability, the integration between Energy Storage Systems (ESSs) and HCPV, resorting to forecasting algorithms, has been investigated. Specifically, a local weather forecasting algorithm has been used for estimating the daily time evolution of DNI, air Temperature (T), Wind Speed (WS), and Air Mass (AM). These data are subsequently processed by means of an accurate HCPV model for the estimation of one day-ahead daily power production profile. The processing of HCPV forecasted generation by means of a properly tuned filter-based algorithm allows one day-ahead the definition of power profiles of ESS and power plant respectively, considering also the ESS constraints and the characteristic of the implemented real-time control algorithm. The effectiveness of the proposed forecasting model and control algorithm is verified through a simulation study referring to the solar power plant constituted by HCPV and ESS installed in Ottana, Italy. The results highlight that the application of the proposed approach lessens the power fluctuation effect caused by HCPV generation preserving the batteries at the same time. The feasibility and advantages of the proposed approach are finally presented.
Numerical Modelling and Experimental Validation of Twin-Screw Expanders
Authors: Vimalakanthan Kisorthman , Read Matthew , Kovacevic Ahmed
Published: September 2020

Positive displacement machines have been identified as appropriate expanders for small-scale power generation systems such as Organic Rankine Cycles (ORCs). Screw expanders can operate with good efficiency in working fluids under both dry and two-phase conditions. Detailed understanding of the fluid expansion process is required to optimise the machine design and operation for specific applications, and accurate design tools are therefore essential. Using experimental data for air expansion, both CFD and chamber models have been applied to investigate the influence of port flow and leakage on the expansion process. Both models are shown to predict pressure variation and power output with good accuracy. The validated chamber model is then used to identify the optimal volume ratio and rotational speed for experimental conditions.
Wind Farm and Resource Datasets: A Comprehensive Survey and Overview
Authors: Menezes Diogo , Mendes Mateus , Almeida Jorge Alexandre , Farinha Torres
Published: September 2020

The use of clean and renewable energy sources is increasingly important, for economic and environmental reasons. Wind plays a key role among renewable energy sources. Hence, the location, monitoring and maintenance of wind turbines are areas that have received more and more attention in recent years. The paper presents a survey of datasets of wind resources, wind farm installed capacity and wind farm operation, which contain generous amounts of data. Those datasets are important tools, freely available for analysis of wind resources and study of the performance of wind turbines. A short analysis of one of the datasets is also presented, identifying different operational regions, and the ones more likely to aggregate failures. Principal Component Analysis (PCA) is used to study wind turbines’ behavior.
Renewable Energy Curtailment: Prediction Using a Logic-Based Forecasting Method and Mitigation Measures in Kyushu, Japan
Authors: Bunodiere Alex , Lee Han Soo
Published: September 2020

High variable renewable energy (VRE) penetration led to the first-ever VRE curtailment in Japan, occurring in Kyushu in October 2018. Since then, there has been an average of 3% solar curtailment, with a peak of 13.7% in April 2019, resulting in approximately ¥9.6 billion of wasted energy. The VRE curtailment is expected to worsen as VRE penetration continues to increase along with nuclear energy increment in line with Japan’s 2030 energy goals. To prevent this curtailment and increase energy stability, a novel, logic-based forecasting method using hourly supply/demand data was developed. Initially, inaccurate results were returned; however, after several rounds of calibration that adjusted the quartile value of the max/min operating windows, the overall accuracy of this method was increased to 97% of real curtailment. This calibrated model was then used to test several curtailment mitigation scenarios. Some scenarios increased curtailment, while the two most successful scenarios, which reduced the installed nuclear capacity either seasonally or totally, limited curtailment by 95% and 97%, respectively. Another scenario with increased grid interconnection between regions reduced curtailment by 79%. Moreover, it would provide other benefits by unifying the national grid thereby increasing disaster resistance, reducing curtailment, improving grid flexibility and allowing for higher VRE penetrations. Currently, the situation is worsening, and some actions are required to reduce the curtailment and to achieve its 2030 energy goals in Japan. The mitigation measures studied by the logic method could be recommended to be referred to.
Effect of Beauveria bassiana Fungal Infection on Survival and Feeding Behavior of Pine-Tree Lappet Moth (Dendrolimus pini L.)
Authors: Kovač Marta , Lacković Nikola , Pernek Milan
Published: September 2020

Research highlights: The pine-tree lappet moth, Dendrolimus pini, can cause serious needle defoliation on pines with outbreaks occurring over large geographical areas. Under laboratory conditions, the promising potential of the naturally occurring entomopathogenic fungus Beauveria bassiana was tested against D. pini larvae as a biological control method. Background and objectives: The aim of this study was to investigate the most effective concentration and treatment dose of B. bassiana conidial suspension and how it affected the survival and feeding behavior of the pest. Materials and methods: The first experiment applied the fungal suspension directly on the back of selected larvae, and in the second experiment, sporulating cadavers obtained in the first experiment were placed into Petri dishes with healthy individuals. Different doses per larvae [µL] and spore suspension concentration [spores/µL]) were used. The second experiment was designed to investigate the horizontal transmission of fungi by exposing individual caterpillars to a cadaver covered in B. bassiana mycelia. Mortality rates were analyzed by Chi-squared tests using absolute values for total mortality and B. bassiana- attributed mortality. The lethal time and feeding-disruption speed were analyzed with parametric and non-parametric tests with the aim to determine whether statistically significant differences were observed between treatments. Results: Analysis of lethal time revealed that the 20 µL dose and 7.9 × 104 concentration yielded highest mortality, but also the average dieback rate of 9.4 days was significantly faster compared to all other treatments. In order to see whether insects stopped feeding after infection with B. bassiana, larvae weight loss was examined. Results showed that effective treatments induced change in the feeding behavior of infected larvae. The feeding disruption caused by the 20 µL treatment occurred on average 5.5 days after exposure or 3.9 days before the final dieback of larvae.