bluuebunny/crossref_metadata_2025_split huggingface dataset:
Techno-Economic Feasibility Analysis of a Hybrid Renewable Energy Supply Options for University Buildings in Saudi Arabia
Authors: Tazay Ahmad 
Published: November 2020

Abstract
This study presents a detailed feasibility analysis of technical and financial assessment for grid-connected Hybrid Renewable Energy System (HRES) configurations by including grid-only, HRES-only and grid-HRES at four different provinces in the Kingdom of Saudi Arabia (KSA), namely; (Al Baha University, University of Jeddah, Prince Sattam Bin Abdulaziz University, and Tabuk University). The objective of this paper is to search the possibility of supplying the load demand with the optimum system that has the lowest net present cost (NPC) and greenhouse emission CO2. The simulation results show that NPC of a proposed grid/PV system, at the current grid’s tariff, is more sufficient than other configurations with a result in a renewable fraction of more than 50%, a payback time of 17 years, and 54.3% reduction in CO2. The results also show that the integration of 62 kW PV array with the main grid is the best configuration that leads to the minimum cost of energy (COE) of 0.0688 $/kWh and the sell back energy of 9.16% of total energy consumption at Al Baha University. Besides, optimization modeling addresses that HRES-only system can supply the full load demand without power shortage (<0.1%) with a major contribution from solar PV by 78.5%, wind energy shares 11.3% of load demand, and 10.2% from battery banks. The developed analysis concludes that the objective function is feasible for the selected locations. The study has three novelties. Firstly, the required load at different locations of the university’s buildings at KSA is supplied by minimizing COE. The objective function is achieved by considering a combination of HRES. Then, it applies the sensitivity analysis for several cases such as payback time, gird’s tariff variation, and load demand change. Finally, the current analyses are applicable to any university at KSA and around the world.
Analysis of EMG Signals during Stance and Swing Phases for Controlling Magnetorheological Brake applications
Authors: Nazmi Nurhazimah , Azizi Abdul Rahman Mohd , Amri Mazlan Saiful , Adiputra Dimas , Bahiuddin Irfan , Kashfi Shabdin Muhammad , Afifah Abdul Razak Nurul , Hatta Mohammed Ariff Mohd 
Published: November 2020

Abstract
The development of ankle foot orthoses (AFO) for lower limb rehabilitation have received significant attention over the past decades. Recently, passive AFO equipped with magnetorheological brake had been developed based on ankle angle and electromyography (EMG) signals. Nonetheless, the EMG signals were categorized in stance and swing phases through visual observation as the signals are stochastic. Therefore, this study aims to classify the pattern of EMG signals during stance and swing phases. Seven-time domains features will be extracted and fed into artificial neural network (ANN) as a classifier. Two different training algorithms of ANN namely Levenberg-Marquardt (LM) and Scaled Conjugate Gradient (SCG) will be applied. As number of inputs will affect the classification performance of ANN, different number of input features will be employed. In this study, three participants were recruited and walk on the treadmills for 60 seconds by constant the speed. The ANN model was designed with 2, 10, 12, and 14 inputs features with LM and SCG training algorithms. Then, the ANN was trained ten times and the performances of each inputs features were measured using classification rate of training, testing, validation and overall. This study found that all the inputs with LM training algorithm gained more than 2% average classification rate than SCG training algorithm. On the other hand, classification accuracy of 10, 12 and 14 inputs were 5% higher than 2 inputs. It can be concluded that LM training algorithm of ANN was performed better than SCG algorithm with at least 10 inputs.
Lower bounds for regular genus and gem-complexity of PL 4-manifolds with boundary
Authors: Basak Biplab , Binjola Manisha 
Published: November 2020

Abstract
Let 𝑀 be a connected compact PL 4-manifold with boundary.
In this article, we give several lower bounds for regular genus and gem-complexity of the manifold 𝑀.
In particular, we prove that if 𝑀 is a connected compact 4-manifold with ℎ boundary components, then its gem-complexity

k
⁢

(
M
)

k(M)

satisfies the inequalities

k
⁢

(
M
)

≥

3
⁢
χ
⁢

(
M
)

+

7
⁢
m

+

7
⁢
h

-
10

k(M)\geq 3\chi(M)+7m+7h-10

and

k
⁢

(
M
)

≥

k
⁢

(

∂
⁡
M

)

+

3
⁢
χ
⁢

(
M
)

+

4
⁢
m

+

6
⁢
h

-
9

k(M)\geq k(\partial M)+3\chi(M)+4m+6h-9

, and its regular genus

G
⁢

(
M
)

\mathcal{G}(M)

satisfies the inequalities

G
⁢

(
M
)

≥

2
⁢
χ
⁢

(
M
)

+

3
⁢
m

+

2
⁢
h

-
4

\mathcal{G}(M)\geq 2\chi(M)+3m+2h-4

and

G
⁢

(
M
)

≥

G
⁢

(

∂
⁡
M

)

+

2
⁢
χ
⁢

(
M
)

+

2
⁢
m

+

2
⁢
h

-
4

\mathcal{G}(M)\geq\mathcal{G}(\partial M)+2\chi(M)+2m+2h-4

, where 𝑚 is the rank of the fundamental group of the manifold 𝑀.
These lower bounds enable to strictly improve previously known estimations for regular genus and gem-complexity of a PL 4-manifold with boundary.
Further, the sharpness of these bounds is also shown for a large class of PL 4-manifolds with boundary.
Conical dielectric resonator antenna for terahertz applications
Authors: Yaduvanshi Rajveer S. , Nishtha  
Published: November 2020

Abstract
Conical Terahertz DRA (dielectric resonator antenna) have been designed and investigated at terahertz spectrum i.e. 10 THz. Lower terahertz frequency band is useful for high data speed communication and upper band is used for optical sensors and free space wireless communications. Novelty in this work is to open up research in. terahertz. A unique geometry based dual band terahertz DRA with mathematical formulations has been proposed. The comprehensive analysis in terahertz regime have been worked out with S11, VSWR, radiation pattern and efficiency using conical TDRA. The conical terahertz DRA is designed at 10 THz frequency with 4.9 dBi, gain with bore sight radiation pattern. The equivalent circuit of conical terahertz DRA have been evaluated for dynamic impedance showing frequency dependence nature.
Optical spherical dielectric resonator antenna for sensing and wireless communication
Authors: Yaduvanshi Rajveer S. , Yadav Rama Krishna , Katiyar Saurabh , Kumar Suresh , Parthasarathy Harish 
Published: November 2020

AbstractIn this article, Terahertz spherical dielectric resonator antenna (DRA) is mathematically formulated and simulated at 511 THz for LiDAR and retinal photoreceptor applications. Titanate DR element is used at optical design frequency. It is validated with good S11, radiation pattern and 5.6 dBi gain plots using HFSS simulator. Unique mathematical formulation on super directivity and radiated states is formulated for the first time. The proximity coupled feed is used with laser Gaussian beam excitation. The silver nano waveguides is used to provide feed mechanism to terahertz DRA. This DR design at optical frequency can be used for wireless sensing and communication applications. It has novel geometry.
The relationship between heat flow and seismicity in global tectonically active zones
Authors: Cheng Changxiu , Hui Chun , Yang Jing , Shen Shi 
Published: November 2020

AbstractThis study aims to analyze the complex relationship between heat flow and seismicity in tectonically active zones worldwide. The problem was quantitatively analyzed by using a geographic detector method, which is well suited for analyzing nonlinear relationships in geography. Moreover,β-value that describes the frequency-magnitude distribution is used to represent the seismicity. The results showed that heat flow (HF) = 84 mW/m2is a critical point for the relevant mechanisms of heat flow with seismicity in these zones. When HF < 84 mW/m2, the heat flow correlates negatively with theβ-value, with a correlation degree of 0.394. Within this interval, buoyant is a primary control on the stress state and earthquake size distribution. Large earthquakes occur more frequently in subduction zones with younger slabs that are more buoyant. Due to zones with a high ratio of large earthquake corresponds to lowβ-values, high heat flow values correspond to lowβ-values. When HF > 84 mW/m2, the heat flow correlates positively with theβ-value, with a correlation degree of 0.463. Within this interval, the increased heat flow decreases the viscosity of the rock plate and then reduces the stress. Lower stress would correspond to a smaller earthquake and then a higherβ-value. Therefore, high heat flow values correspond to highβ-values. This research would be conducive to understand the geologic activity and be helpful to determine the accuracy and timeliness of seismic hazard assessment.
Agriculture and land use in the North of Russia: Case study of Karelia and Yakutia
Authors: Naumov Alexey , Akimova Varvara , Sidorova Daria , Topnikov Mikhail 
Published: November 2020

Abstract
Despite harsh climate, agriculture on the northern margins of Russia still remains the backbone of food security. Historically, in both regions studied in this article – the Republic of Karelia and the Republic of Sakha (Yakutia) – agricultural activities as dairy farming and even cropping were well adapted to local conditions including traditional activities such as horse breeding typical for Yakutia. Using three different sources of information – official statistics, expert interviews, and field observations – allowed us to draw a conclusion that there are both similarities and differences in agricultural development and land use of these two studied regions. The differences arise from agro-climate conditions, settlement history, specialization, and spatial pattern of economy. In both regions, farming is concentrated within the areas with most suitable natural conditions. Yet, even there, agricultural land use is shrinking, especially in Karelia. Both regions are prone to being affected by seasonality, but vary in the degree of its influence. Geographical location plays special role, and weaknesses caused by remoteness to some extent become advantage as in Yakutia. Proximity effect is controversial. In Karelia, impact of neighboring Finland is insignificant compared with the nearby second Russian city – Saint Petersburg.
Parabolic trough solar collectors: A general overview of technology, industrial applications, energy market, modeling, and standards
Authors: Tagle-Salazar Pablo D. , Nigam Krishna D.P. , Rivera-Solorio Carlos I. 
Published: November 2020

AbstractMany innovative technologies have been developed around the world to meet its energy demands using renewable and nonrenewable resources. Solar energy is one of the most important emerging renewable energy resources in recent times. This study aims to present the state-of-the-art of parabolic trough solar collector technology with a focus on different thermal performance analysis methods and components used in the fabrication of collector together with different construction materials and their properties. Further, its industrial applications (such as heating, cooling, or concentrating photovoltaics), solar energy conversion processes, and technological advancements in these areas are discussed. Guidelines on commercial software tools used for performance analysis of parabolic trough collectors, and international standards related to performance analysis, quality of materials, and durability of parabolic trough collectors are compiled. Finally, a market overview is presented to show the importance and feasibility of this technology. We believe the compilation of reviews related to the above aspects will further provide impetus for the development of this technology in the near future.
Characterizations and analysis of the antioxidant, antimicrobial, and dye reduction ability of green synthesized silver nanoparticles
Authors: Riaz Muhammad , Ismail Muhammad , Ahmad Bashir , Zahid Nafeesa , Jabbour Ghassan , Khan Muhammad Shafiq , Mutreja Vishal , Sareen Shweta , Rafiq Aftab , Faheem Muhammad , Shah Muhammad Musaddiq , Khan M. I. , Bukhari Syed Ali Imran , Park Jeongwon 
Published: November 2020

AbstractThe current study was conducted to assess the potential of ginger rhizome extract (Zingiber officinale) for the synthesis of silver nanoparticles (AgNPs) through the green method and its mitigating activity against pathogenic bacterial strains. AgNPs were synthesized through a simple one-step approach and characterized by UV-Visible (UV-Vis) spectroscopy, powder X-ray diffraction (PXRD), transmission electronic microscopy (TEM), and energy dispersive X-rays spectroscopy (EDS). PXRD and TEM results of AgNPs showed the face central cubic structures and predominantly spherical structures with a size of 6.5 nm. EDS analysis confirms the elemental silver in nanoparticles. Moreover, the impact of the pH, as well as temperature, during the synthesis of AgNPs has also been investigated. At 25°C and pH 5, there was no significant peak for AgNPs in the absorption spectra. However, with an increase in temperature from 25°C to 85°C and pH 5 to pH 11, particles started attaining the spherical shape of different sizes due to an increase in the reduction rate. The AgNPs displayed effective results against selected pathogenic strains,Pseudomonas aeruginosa(MTCC 424), Methicillin-resistantStaphylococcus aureus(ATCC 43300), and fungusCandida albicans(KACC 30003). The prepared AgNPs exhibited excellent antioxidant activity and catalytic reduction of methyl orange with the pseudo-first-order rate constant of 3.9 × 10−3.
Effectiveness of six different methods in green synthesis of selenium nanoparticles using propolis extract: Screening and characterization
Authors: Hatami Roghayeh , Javadi Afshin , Jafarizadeh-Malmiri Hoda 
Published: November 2020

AbstractSelenium nanoparticles (Se NPs) were fabricated with propolis hydro-alcoholic extract and six different methods, namely, hydrothermal, microwave irradiation, ultrasonication, UV radiation, self-assembling, and conventional heating. Results indicated that antioxidant activity, turbidity, pH, and brix values of the provided hydroalcoholic propolis extract were 85.8%, 2.235% a.u., 4.1, and 3.2°Bx, respectively. Gas chromatography analysis revealed that approximately 38 bioactive compounds were detected in the provided extract within 40 min of retention time, including chalcone. Results also revealed that each method had advantage in fabrication of Se NPs compared to others, but spherical Se NPs with overall appropriate physicochemical attributes of particle size (50–60 nm), polydispersity index (0.362), zeta potential (−41.8 mV), maximum broad absorption peak (321 nm), and antioxidant activity (12.4%) were synthesized using the ultrasonication method with a frequency of 20 kHz and a power of 300 W for 10 min.
Effect of different types of soil tillage for sunflower on some soil physical characteristics. Part II: bulk density and soil temperature
Authors: Peter Yankov , Miglena Drumeva 
Published: November 2020

Abstract
The investigation was carried out during 2014–2016 in the land of General Toshevo, the South Dobrudzha region of Bulgaria on slightly leached chernozem soil type. The effect of the types of soil tillage for sunflower given bellow was followed: ploughing at 24–26 cm, chisel-plough at 24–26 cm, disking with disk harrow at 10–20 cm and direct sowing (no-tillage) on the bulk density, the moisture content and the temperature of soil. The additional soil tilths of the areas subjected to ploughing, chisel-ploughing and disking with disc harrow included double spring pre-sowing cultivation with harrowing. To destroy the emerging weeds in the variant with direct sowing, a total herbicide was applied. The investigated physical parameters of soil were followed during three main stages of sunflower development: emergence, flowering and technical maturity. The bulk density of soil was determined by soil samples taken from the 0–10, 10–20 and 20–30 cm layers. The soil temperature was read at 800, 1200 and 1600 h to depth 2, 5, 10, 15, 20 and 25 cm with classical soil thermometer. For evaluation of the results dispersion and regression analyses were used. In the slightly leached chernozem soil type, the conventional ploughing leads to lower bulk density in the cultivated soil profile. Under minimal tillage, slight increase of bulk density of the layer underlying the cultivated one was observed over time. The bulk density under tillage without turning of the soil layer and no-tillage was changed and formed primarily under the influence of physical and climatic factors, and under minimal tillage – under the cultivated layer. Under all investigated types of soil tillage, bulk density increased down the soil profile. Replacing ploughing with tillage without turning of the soil layer, minimal and no-tillage lead to decrease of soil temperature. The most significant differences were observed in the 0–10 layer, which, on its part, conditioned accumulation and transfer of thermal energy along the soil profile. The soil temperature decreased with the reduction of the number and depth of the soil tillage operations. The temperature amplitudes between the surface layer and the underlying soil horizons in the areas with ploughing, chisel ploughing minimal and no-tillage were lower. The results concerning the values of the investigated physical properties of soil under different types of soil tillage were statistically significant at different levels of P.
Thiol-based redox switches in the major pathogen Staphylococcus aureus
Authors: Linzner Nico , Loi Vu Van , Fritsch Verena Nadin , Antelmann Haike 
Published: November 2020

Abstract

Staphylococcus aureus is a major human pathogen, which encounters reactive oxygen, nitrogen, chlorine, electrophile and sulfur species (ROS, RNS, RCS, RES and RSS) by the host immune system, during cellular metabolism or antibiotics treatments. To defend against redox active species and antibiotics, S. aureus is equipped with redox sensing regulators that often use thiol switches to control the expression of specific detoxification pathways. In addition, the maintenance of the redox balance is crucial for survival of S. aureus under redox stress during infections, which is accomplished by the low molecular weight (LMW) thiol bacillithiol (BSH) and the associated bacilliredoxin (Brx)/BSH/bacillithiol disulfide reductase (YpdA)/NADPH pathway. Here, we present an overview of thiol-based redox sensors, its associated enzymatic detoxification systems and BSH-related regulatory mechanisms in S. aureus, which are important for the defense under redox stress conditions. Application of the novel Brx-roGFP2 biosensor provides new insights on the impact of these systems on the BSH redox potential. These thiol switches of S. aureus function in protection against redox active desinfectants and antimicrobials, including HOCl, the AGXX® antimicrobial surface coating, allicin from garlic and the naphthoquinone lapachol. Thus, thiol switches could be novel drug targets for the development of alternative redox-based therapies to combat multi-drug resistant S. aureus isolates.
Reactor engineering calculations with a detailed reaction mechanism for the oxidative coupling of methane
Authors: Rivera Sonya , Molla Andrin , Pera Phillip , Landaverde Michael , Barat Robert 
Published: November 2020

Abstract
The oxidative coupling of methane (OCM) is a potential option for conversion of excess natural gas to higher value products or useful feedstocks. The preferred or ideal OCM stoichiometry is: 2CH4 + O2 → C2H4 + 2H2O, but real OCM produces a variety of species. Using a detailed mechanism from the literature for OCM over a La2O3/CeO2 catalyst that combines coupled elementary gas phase and surface reactions, a reactor engineering study has been done. Adiabatic packed bed reactor (PBR, modeled as plug flow) and continuous stirred tank reactor (CSTR, perfect mixing) simulations using this mechanism are presented. Each reactor simulation used the same total number of catalyst sites. Process variables included CH4/O2 feed ratio (7, 11), feed temperature (843–1243 K), and feed rate. All runs were conducted at 1.01E5 Pa pressure. The results show the CSTR produces high conversions at much lower feed temperatures than those required by the PBR. Once full PBR “light off” occurs, however, its CH4 conversions exceed CSTR. The simulations reveal OCM over this catalyst at these conditions gives a mixture of synthesis gas (CO, H2) and C2Hx (primarily C2H4 plus small quantities of C2H6 and C2H2). The CSTR favors the production of synthesis gas, while the PBR favors C2Hx. Within the suite of CSTR cases, C2Hx is favored at the lowest feed temperature and highest CH4/O2 feed ratio.
Development and scaled-up simulation of an automated electrical energy management system for passageway illumination
Authors: Odetoye Oyinlolu Ayomidotun , Afolabi Akindele Segun , Akinola Olubunmi Adewale 
Published: November 2020

Abstract
Buildings account for much of the world’s energy consumption; thus, it is important to develop ways, not just to harness more of the energy in the universe, but also to make system of devices in buildings more energy-efficient. Occupancy-based illumination is an emerging trend in energy management, but research in this field has mostly been focused on illumination of rooms and workspaces in building interiors. To the best of the authors’ knowledge, there is virtually no literature on the energy optimisation of depersonalised spaces such as passageways. This paper explores the development and evaluation of a controller-based model for illumination of passageways in buildings, where relatively-large number of depersonalized luminaires are usually found and automation might prove especially beneficial. After development, testing and scaled-up simulations, results show that occupancy-based illumination of exterior corridors and semi-covered passages in buildings is feasible, economical, has significant energy savings, and is worthy of consideration for modern buildings.
Effects of phenolic compounds from blueberry leaves on the thermal decomposition of trimethylamine oxide in squid extract
Authors: Li Yingchang , Du Fengxia , Song Suzhen , Li Shuangyan , Yang Xianqing , Yi Shumin 
Published: November 2020

Abstract
The effects of chlorogenic acid and quercetin-3-D-galactoside on the decomposition of trimethylamine oxide (TMAO) in squid extract and the main mechanism of inhibition of thermal decomposition were studied. The results indicated that chlorogenic acid and quercetin-3-D-galactoside could inhibit decomposition of TMAO in squid extract. The amount of TMAO was increased by 11.79 and 15.76% in squid extract treated with chlorogenic acid and quercetin-3-D-galactoside from 0 and 2.5 g/L, respectively. The contents of trimethylamine (TMA), dimethylamine (DMA), and formaldehyde (FA) were significantly decreased with increasing contents of chlorogenic acid and quercetin-3-D-galactoside. There were many free radicals in squid extract at high temperatures; however, the free radical signals were weakened after the addition of chlorogenic acid and quercetin-3-D-galactoside therein. This implied that chlorogenic acid and quercetin-3-D-galactoside could inhibit the thermal decomposition of TMAO in squid extract, which was associated with the scavenging of their free radicals. This result provides a theoretical basis for the development and utilization of blueberry leaf extract as an efficient FA inhibitor for aquatic products.