bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Evaluation of Land Administration System (LAS) of Nairobi Metropolitan Area, Kenya
Authors: Nyangweso Daniel Orongo , Gede Mátyás
Published: January 2022

This paper aims to evaluate the internal processes of the current land administration in Kenya based on the following parameters that include ownerships, transactions, transfers, inquiries, public records of maps as attributes, issues, and customer satisfaction using stakeholder surveys and focused group discussions. A framework tool was developed for evaluation and shared with potential respondents who were either clients or staff working at the Ministry of Lands to obtain an overview of the performance of the documentation and registration processes of the land administration system (LAS). Data collected were processed and analysed using SPSS 26. To ascertain data reliability, the Cronbach’s alpha test was performed, and a coefficient of 0.908 was calculated, which indicated the presence of high internal consistency of the questions and relevance of the study subjects for the participants. The findings revealed the presence of emerging issues where an average of approximately 28% of clients do not have an idea of land registration transactions. In addition, in Kenya, similarly to other national mapping agencies in the developing world, pre-independence laws have begun, which need to be upscaled or revised to sustain and effectively address issues noted on land administration and policy.
Local Factors Controlling Gully Development in a Mediterranean Environment
Authors: Martins Bruno , Nunes Adélia , Meira-Castro Ana , Lourenço Luciano , Hermenegildo Carlos
Published: January 2022

Gullies contribute very efficiently to soil loss and degradation, particularly in Mediterranean environments. While natural factors are involved in gully formation and further development, anthropic action is almost always an element. Knowledge of formation and development factors are important if soil protection strategies and measures are to be effective. In this paper, we identify the most important factors in the development of gullies in a Mediterranean setting based on a study of the Alva gully (central Portugal). Its development in the last four years is examined, based on a study of the modification of its morphological characteristics. The analysis was based on principal component analysis (PCA) to estimate the correlation between the quantitative characteristics, geomorphological processes, and biophysical variables. The results show that the main factors that seem to control the spatial variation of soil erosion are the soil penetration resistance, slope, slope shape, and vegetation cover.
Assessment of Recreational and Cultural Ecosystem Services Value of Islands
Authors: Zhao Na , Wang Hui , Zhong Jingqiu , Sun Dongqi
Published: January 2022

With the gradual expansion of benefits provided by islands to human wellbeing, it has become increasingly important to quantify the cultural ecosystem service functions of islands. In this study, the zone travel cost method (ZTCM) and individual travel cost method (ITCM) are used to assess the recreational and cultural ecosystem services value of the island region of Changhai County, China, and the recreational value of Xiaochangshan, Dachangshan, and Guanglu Islands based on questionnaire survey data. The results are as follows: (1) The overall recreational and cultural ecosystem services value of Changhai County in 2019 was 533.14 million USD, including a traveling cost of 395.71 million USD and consumer surplus of 137.43 million USD. (2) Further, based on the choice and consumption behaviors of tourists, multiple recreational values of the county were also inferred: the aesthetic experience presented the greatest contribution, while educational knowledge accounted for a lower percentage. (3) The recreational and cultural ecosystem services value 294.16, 60.03, and 143.26 million USD for Xiaochangshan, Dachangshan, and Guanglu Islands, respectively. Based on the findings of this study, future research will focus on the planning and development of Xiaochangshan Island tourism to maximize consumer surplus.
Research on the Planning of an Urban Ventilation Corridor Based on the Urban Underlying Surface Taking Kaifeng City as an Example
Authors: Liu Dandan , Zhou Shenghui , Wang Lijun , Chi Qian , Zhu Mengyao , Tang Weichao , Zhao Xiao , Xu Siqi , Ye Siyu , Lee Jay , Cui Yaoping
Published: January 2022

With the rapid development of urbanization, various urban problems such as air pollution, urban heat islands, poor ventilation, and so on have followed. Ventilation corridors can improve the internal ventilation conditions of a city and can effectively alleviate these urban problems. Taking Kaifeng as an example of a medium-sized city, this study used meteorological analysis and remote sensing (RS) technology and a geographical information system (GIS) to plan ventilation corridors. Through analysis of the thermal environment, the influential factors of the underlying surface (building density, road length, water length, vegetation coverage) and wind environment in Kaifeng, the compensation space and action space, and the comprehensive values of the ventilation potential in each region were determined. The results show that with the use of the single-window algorithm and Landsat8 data, high-resolution ground temperature can be retrieved. Moreover, although the ventilation potential value of Kaifeng in the northern part is better than that in the southern part, the temperature in the north is higher than that in the south. Through comparison and analysis of the location of the low-temperature zone, the air duct opening of the ventilation corridor can be determined and the source areas of three ecological ventilation corridors identified. According to the ventilation corridor air duct opening, the urban underlying surface and the dominant wind direction of Kaifeng city, two ventilation corridors located on the eastern and western sides of Kaifeng city were planned. This urban ventilation corridor planning method, which is based on temperature difference analysis and determination of the source area of the ventilation corridor, can provide a reference for the construction of an ecologically livable city.
Evaluating Communities’ Willingness to Participate in Ecosystem Conservation in Southeast Tibetan Nature Reserves, China
Authors: Xu Lingxia , Xu Wanyun , Jiang Chao , Dai Huxuan , Sun Qiaoqi , Cheng Kun , Lee Chun-Hung , Zong Cheng , Ma Jianzhang
Published: January 2022

Southeast Tibet is significant in maintaining key ecological functions and providing irreplaceable ecosystem services but is also extremely vulnerable and susceptible to the impacts of human activities. Understanding the attitudes of local residents toward ecosystem conservation is considered essential for nature resource management. We therefore aimed to conduct an evaluation framework under hypothetical scenarios to measure communities’ willingness to participate in ecosystem conservation using the contingent valuation method (CVM). Second, this study determined the underlying factors that might affect local’s willingness to participate and then compared the willingness to pay (WTP) and willingness to work (WTW) for different types of nature reserves. We found that income, education, community attachment, and acceptance of a payment scheme are significant factors determining the average amount that residents are willing to pay for ecosystem conservation, while their income, acceptance of a work scheme, and education are significant factors influencing the average service time that residents are willing to devote to work. Our results revealed that community residents have considerable willingness to participate in ecosystem conservation, which points not only to the great value attached to the ecosystem service function of Southeast Tibet nature but also suggests that people’s willingness to participate is influenced by a conglomeration of socio-economic characteristics and their previous experience. The information herein can be used to implement conservation planning that involves community co-management and policymaking for sustainable development and will be beneficial to the dynamic conservation and adaptive management of Tibetan nature reserves.
Influences of Environmental Variables and Their Interactions on Chinese Farmland Soil Organic Carbon Density and Its Dynamics
Authors: Wu Zihao , Liu Yaolin , Li Guie , Han Yiran , Li Xiaoshun , Chen Yiyun
Published: January 2022

Farmland is one of the most important and active components of the soil carbon pool. Exploring the controlling factors of farmland soil organic carbon density (SOCD) and its sequestration rate (SOCDSR) is vital for improving carbon sequestration and addressing climate change. Present studies provide considerable attention to the impacts of natural factors and agricultural management on SOCD and SOCDSR. However, few of them focus on the interaction effects of environmental variables on SOCD and SOCDSR. Therefore, using 64 samples collected from 19 agricultural stations in China, this study explored the effects of natural factors, human activities, and their interactions on farmland SOCD and SOCDSR by using geographical detector methods. Results of geographical detectors showed that SOCD was associated with natural factors, including groundwater depth, soil type, clay content, mean annual temperature (MAT), and mean annual precipitation. SOCDSR was related to natural factors and agricultural management, including MAT, groundwater depth, fertilization, and their interactions. Interaction effects existed in all environmental variable pairs, and the explanatory power of interaction effects was often greater than that of the sum of two single variables. Specifically, the interaction effect of soil type and MAT explained 74.8% of the variation in SOCD, and further investigation revealed that SOCD was highest in Luvisols and was under a low MAT (<6 °C). The interaction effect of groundwater depth and fertilization explained 40.4% of the variation in SOCDSR, and fertilization was conducive to SOCD increase at a high groundwater depth (<3 m). These findings suggest that low soil temperature, high soil moisture, and fertilization are conducive to soil carbon accumulation. These findings also highlight the importance of agricultural management and interaction effects in explaining SOCD and SOCDSR, which promote our knowledge to better understand the variation of SOCD and its dynamics.
The Thickness of Talus Deposits in the Periglacial Area of SW Spitsbergen (Fugleberget Mountainside) in the Light of Slope Development Theories
Authors: Dolnicki Piotr , Grabiec Mariusz
Published: January 2022

Periglacial slopes are susceptible to recent climate change. The rate of morphogenetic processes depends on numerous factors. The most important of these is the warming of the air and ground, increased precipitation (extreme rainfall in particular), and the rate of snow cover decay. The dynamics of these processes may effectively modify contemporary slope development models. The paper shows the structure of selected talus slopes on a Fugleberget mountainside, based on field observations and radar (GPR) soundings. The results are then compared to classical slope models. The radar survey in April and May 2014 used a RAMAC CU II Malå GeoScience system equipped with a 30 MHz RTA antenna (Rough Terrain Antenna). Five GPR profiles of different lengths were obtained along the talus axes, transversally on Fugleberget and partly on the Hansbreen lateral moraine. According to the radar soundings, the maximum thickness of the debris deposits is 25–30 m. The thickness of the weathered material increases towards the talus cone’s terminal part, and debris deposits overlap marine sediments. The talus slopes’ morphometry shows that their current forms differ from standard slope models, which may be due to the significant acceleration of geomorphic processes resulting from climate change, including rapid warming in the last four decades.
Acknowledgment to Reviewers of Laws in 2021
Authors:   Laws Editorial Office
Published: January 2022

Rigorous peer-reviews are the cornerstone of excellence in academic publishing [...]
Novel Pharmacological Approaches to the Treatment of Depression
Authors: Elias Elias , Zhang Ariel Y. , Manners Melissa T.
Published: January 2022

Major depressive disorder is one of the most prevalent mental health disorders. Monoamine-based antidepressants were the first drugs developed to treat major depressive disorder. More recently, ketamine and other analogues were introduced as fast-acting antidepressants. Unfortunately, currently available therapeutics are inadequate; lack of efficacy, adverse effects, and risks leave patients with limited treatment options. Efforts are now focused on understanding the etiology of depression and identifying novel targets for pharmacological treatment. In this review, we discuss promising novel pharmacological targets for the treatment of major depressive disorder. Targeting receptors including N-methyl-D-aspartate receptors, peroxisome proliferator-activated receptors, G-protein-coupled receptor 39, metabotropic glutamate receptors, galanin and opioid receptors has potential antidepressant effects. Compounds targeting biological processes: inflammation, the hypothalamic-pituitary-adrenal axis, the cholesterol biosynthesis pathway, and gut microbiota have also shown therapeutic potential. Additionally, natural products including plants, herbs, and fatty acids improved depressive symptoms and behaviors. In this review, a brief history of clinically available antidepressants will be provided, with a primary focus on novel pharmaceutical approaches with promising antidepressant effects in preclinical and clinical studies.
Acknowledgment to Reviewers of Life in 2021
Authors:   Life Editorial Office
Published: January 2022

Rigorous peer-reviews are the basis of high-quality academic publishing [...]
Microangiopathy in Inflammatory Diseases—Strategies in Surgery of the Lower Extremity
Authors: Biehl Christoph , Biehl Lotta , Tarner Ingo Helmut , Müller-Ladner Ulf , Heiss Christian , Heinrich Martin
Published: January 2022

Background: Patients with an inflammatory disease frequently develop chronic angiopathy of the capillaries. Due to this pathology, there is an increased rate of complications in lower extremity surgical procedures. It is not uncommon for microangiopathic wound healing disorders to cause deep infections and fistulas, which lead to prolonged courses and hospitalizations. In addition, adhesions and ossifications of the contractile elements occur regularly. This sometimes results in serious limitations of the mobility of the patients. The study aims to present the results of a combination of vacuum and physical therapy. Patient and methods: A retrospective study of six patients with systemic sclerosis undergoing joint-related procedures of the lower extremity between 2015 and 2020 was performed. In addition to characterization of the patients and therapy, special attention was paid to cutaneous wound healing, affection of the fascia and displacement layers, and sclerosis of the muscle and tendon insertion. Results: The characterized structures (skin, tendon, fascia) show pathological changes at the microangiopathic level, which are associated with delayed healing and less physical capacity. Early suture removal regularly results in secondary scar dehiscence. With a stage-adapted vacuum therapy with sanitation of the deep structures and later on a dermal vacuum system, healing with simultaneous mobilization of the patients could be achieved in our patient cohort. Conclusion: In the case of necessary interventions on the lower extremity, such as trauma surgery, additional decongestive measures in the sense of regular and sustained lymphatic therapy and adapted physiotherapy are indispensable.
Influence of Immune Parameters after Enterococcus faecium AL41 Administration and Salmonella Infection in Chickens
Authors: Revajová Viera , Benková Terézia , Karaffová Viera , Levkut Martin , Selecká Emília , Dvorožňáková Emília , Ševčíková Zuzana , Herich Róbert , Levkut Mikuláš
Published: January 2022

Immune response of day-old chicks infected with Salmonella Enteritidis PT4 and preventive administration of Enterococcus faecium AL41 were studied using hematology and flow cytometry of immunocompetent cells in blood, cecum, bursa and spleen for 11 days, and included 220 animals divided into four groups (n = 55). E. faecium AL41 was administered for 7 days to EF and EFSE groups and on day 4 SE and EFSE groups were infected with Salmonella Enteritidis. Values of monocytes at 4 dpi significantly increased in EFSE and lymphocytes at 7 dpi in EF groups. Blood CD3, CD4, CD8 and IgM lymphocytes improved in EF and EFSE groups and IgA in EF group at 4 dpi. Phagocytic activity of probiotic groups was improved in both samples. Cecal IEL and LPL lymphocytes showed at 7 dpi stimulation of CD3, CD4 and CD8 subpopulations in probiotic groups, especially in EFSE group, IgA IEL and IgA with IgM LPL in EF groups. Bursa Fabricii at 7 dpi presented overstimulation of IgG subpopulation in SE group, spleen CD3 and CD8 in EF and EFSE groups. E. faecium AL41 revealed the protective effect and positive influence on the local and systemic immune response in Salmonella Enteritidis PT4 infected chickens.
Photobiomodulation for Lowering Pain after Tonsillectomy: Low Efficacy and a Possible Unexpected Adverse Effect
Authors: Celsi Fulvio , Staffa Paola , Lamba Martino , Castro Veronica , Chermetz Maddalena , Orzan Eva , Sagredini Raffaella , Barbi Egidio
Published: January 2022

Background: Tonsillectomy is one of the most common surgical procedures performed in children as a treatment for obstructive sleep apnea due to tonsil hypertrophy or highly recurrent tonsillitis. Odynophagia, associated with food refusal for the first few days, is a common post-operative complaint. Available drugs for pain management, while efficacious, present some drawbacks, and a novel strategy would be welcome. Photobiomodulation (PBMT), in this context, can represent a possible choice, together with pharmacological therapy. The aim of this study was to evaluate PBMT effects compared to standard pain therapy on nociceptive sensation at different time points and administration of painkiller. Methods: A registered, controlled, randomized, double-blind clinical trial was performed. Twenty-two patients were recruited and divided into laser-treated (T) or untreated (UT) groups, based on random assignment. In T group, immediately after tonsillectomy, performed with cold dissection technique, laser light was applied to the surgery site (using a Cube 4 from Eltech K-Laser s.r.l., Treviso, Italy), and then hemostasis was performed using bismuth subgallate paste. In C group, the same procedure was performed, except that laser light was switched off. The primary outcome was the difference in pain scores between subject receiving photobiomodulation (PBMT) and subjects receiving standard care after 24 h; the secondary outcomes were pain scores at awakening and at 48 h together with distress (delirium) at awakening. Results: Two patients from the T group experienced a post-surgery bleeding, and one of them required revision of the hemostasis under general anesthesia. A preliminary analysis of pain sensation reported by the patients or caregivers did not show differences between treated and untreated subjects. Conclusion: These data suggest that PBMT could increase post-surgical bleeding.
Acknowledgment to Reviewers of Logistics in 2021
Authors:   Logistics Editorial Office
Published: January 2022

Rigorous peer-reviews are the basis of high-quality academic publishing [...]
2,2-Dichloro-N-[5-[2-[3-(4-methoxyphenyl)-5-phenyl-3,4-dihydro-2H-pyrazol-2-yl]-2-oxoethyl]sulfanyl-1,3,4-thiadiazol-2-yl]acetamide
Authors: Yushyn Ihor , Holota Serhii , Lesyk Roman
Published: January 2022

The pharmacophore hybridization approach is widely used for the design of drug-like small molecules with anticancer properties. In the present work, a “cost-effective” approach to the synthesis of the novel non-condensed pyrazoline-bearing hybrid molecule with 1,3,4-thiadiazole and dichloroacetic acid moieties is proposed. The 5-amino-1,3,4-thiadiazole-2-thiol was used as a starting reagent, and the synthetic strategy includes stepwise alkylation of the sulfur atom and acylation of the nitrogen atom to obtain the target title compound. The structure of the synthesized 2,2-dichloro-N-[5-[2-[3-(4-methoxyphenyl)-5-phenyl-3,4-dihydro-2H-pyrazol-2-yl]-2-oxoethyl]sulfanyl-1,3,4-thiadiazol-2-yl]acetamide (yield 90%) was confirmed by 1H, 13C, 2D NMR and LC-MS spectra. Anticancer activity in “60 lines screening” (NCI DTP protocol) was studied in vitro for the title compound.
Design, Metallurgical Features, and Mechanical Behaviour of NiTi Endodontic Instruments from Five Different Heat-Treated Rotary Systems
Authors: Martins Jorge N. R. , Silva Emmanuel J. N. L. , Marques Duarte , Pereira Mário Rito , Vieira Victor T. L. , Arantes-Oliveira Sofia , Martins Rui F. , Braz Fernandes Francisco , Versiani Marco
Published: January 2022

The current study aimed to compare the F1 endodontic instruments from five different heat-treated rotary systems regarding their design, metallurgical properties, and mechanical performance. Five F1 root canal shaping instruments (ProTaper Gold [PTG], Premium Taper Gold, Go-Taper Flex, EdgeTaper Platinum, and Super Files Blue)—plus, a conventional ProTaper Universal (PTU)—which were evaluated regarding their design, nickel/titanium ratio, phase transformation temperatures, microhardness, cyclic fatigue, and torsional and bending strengths. Mood's median test was used for the statistical comparison with a significance set at 5%. The instruments were similar regarding the nickel/titanium ratio and overall design. Go-Taper Flex had the closest transformation temperatures to PTG. PTU and Go-Taper Flex had the highest microhardness (408.3 and 410.5 HVN). The time to fracture of Super Files Blue was three and seven times higher than PTG and PTU, respectively. No difference was observed in the maximum torque to fracture among PTG (1.30 N·cm) and the other systems, except for the Premium Taper Gold (1.05 N·cm) and Go-Taper Flex (1.10 N·cm). Significantly lower bending loads than PTG (269.2 gf) were observed for the EdgeTaper Platinum (158.3 gf) and Premium Taper Gold (103.5 gf) instruments. Super Files Blue outperformed PTG in the cyclic fatigue test, while EdgeTaper Platinum and Premium Taper Gold were more flexible. Premium Taper Gold and Go-Taper Flex showed lower torsional strength.
Nanometers-Thick Ferromagnetic Surface Produced by Laser Cutting of Diamond
Authors: Setzer Annette , Esquinazi Pablo D. , Buga Sergei , Georgieva Milena T. , Reinert Tilo , Venus Tom , Estrela-Lopis Irina , Ivashenko Andrei , Bondarenko Maria , Böhlmann Winfried , Meijer Jan
Published: January 2022

In this work, we demonstrate that cutting diamond crystals with a laser (532 nm wavelength, 0.5 mJ energy, 200 ns pulse duration at 15 kHz) produced a ≲20 nm thick surface layer with magnetic order at room temperature. We measured the magnetic moment of five natural and six CVD diamond crystals of different sizes, nitrogen contents and surface orientations with a SQUID magnetometer. A robust ferromagnetic response at 300 K was observed only for crystals that were cut with the laser along the (100) surface orientation. The magnetic signals were much weaker for the (110) and negligible for the (111) orientations. We attribute the magnetic order to the disordered graphite layer produced by the laser at the diamond surface. The ferromagnetic signal vanished after chemical etching or after moderate temperature annealing. The obtained results indicate that laser treatment of diamond may pave the way to create ferromagnetic spots at its surface.
Prosthetic Materials Used for Implant-Supported Restorations and Their Biochemical Oral Interactions: A Narrative Review
Authors: Ionescu Roxana Nicoleta , Totan Alexandra Ripszky , Imre Marina Meleșcanu , Țâncu Ana Maria Cristina , Pantea Mihaela , Butucescu Mihai , Farcașiu Alexandru Titus
Published: January 2022

The purpose of this study is to outline relevant elements regarding the biochemical interactions between prosthetic materials used for obtaining implant-supported restorations and the oral environment. Implant-supported prostheses have seen unprecedented development in recent years, benefiting from the emergence of both new prosthetic materials (with increased biocompatibility and very good mechanical behavior), and computerized manufacturing technologies, which offer predictability, accuracy, and reproducibility. On the other hand, the quality of conventional materials for obtaining implant-supported prostheses is acknowledged, as they have already proven their clinical performance. The properties of PMMA (poly (methyl methacrylate))—which is a representative interim material frequently used in prosthodontics—and of PEEK (polyether ether ketone)—a biomaterial which is placed on the border between interim and final prosthetic use—are highlighted in order to illustrate the complex way these materials interact with the oral environment. In regard to definitive prosthetic materials used for obtaining implant-supported prostheses, emphasis is placed on zirconia-based ceramics. Zirconia exhibits several distinctive advantages (excellent aesthetics, good mechanical behavior, biocompatibility), through which its clinical applicability has become increasingly wide. Zirconia’s interaction with the oral environment (fibroblasts, osteoblasts, dental pulp cells, macrophages) is presented in a relevant synthesis, thus revealing its good biocompatibility.
Hot Deformation Behavior and Microstructural Evolution Based on the Processing Map of Dual-Phase Mg-Li Based Alloy
Authors: Guo Jiangtao , Guo Shengli , Shen Yazhao , Li Defu
Published: January 2022

The deformation behavior of the as-extruded Mg-Li-Al-Zn-Si alloy was studied by conducting a hot compression test, with a temperature range of 180–330 °C and a strain rate range of 0.01–10 s−1. The constitutive relationship of flow stress, temperature, and strain rate was expressed by the Zener–Hollomon parameter and included the Arrhenius term. By considering the effect of strain on the material constants, the flow stress at 240–330 °C could be precisely predicted with the constitutive equation (incorporating the influence of strain). A processing map was established at the strain of 0.7. The unsafe domains that are characterized by uneven microstructures were detected at low temperatures (<230 °C) or high temperatures (>280 °C), with high strain rates (>1 s−1). The optimum hot deformation region was obtained at a medium temperature (270–300 °C), with a peak power dissipation efficiency of 0.44. The microstructural evolution in different domains is investigated. The unstable domains are characterized by a non-uniform flow behavior and uneven microstructure. The observation showed that the dynamic recrystallization (DRX) process could easily occur at the safe domain with high power dissipation efficiency. For the α-phase, some features of continuous dynamic recrystallization can be found. The triple points serve as prominent nucleation sites for the β-phase DRX grains and the growth in the grains was carried out by subgrain boundary migration. The microstructure exhibits characteristics of discontinuous dynamic recrystallization.
10-Methacryloyloxydecyl Dihydrogen Phosphate (10-MDP)-Containing Cleaner Improves Bond Strength to Contaminated Monolithic Zirconia: An In-Vitro Study
Authors: Awad Mohamed M. , Alhalabi Feras , Alzahrani Khaled Mosfer , Almutiri Majed , Alqanawi Fawaz , Albdiri Lafi , Alshehri Abdullah , Alrahlah Ali , Ahmed Mohammed H.
Published: January 2022

Contamination of zirconia restorations before cementation can impair the resin–zirconia bonding durability. The objective of this study was to evaluate the effect of human saliva or blood decontamination with 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing cleaner on the resin–zirconia shear bond strength (SBS). Methods: A total of 220 zirconia specimens were prepared and air-abraded and randomly distributed into 11 groups (n = 20 per group). Except for the control group (no contamination), zirconia specimens were contaminated with either human saliva (five groups) or blood (five groups), and then subjected to one of five cleaning methods: water rinsing, 38% phosphoric acid etchant (Pulpdent Corp., Watertown, MA, USA), 70% isopropanol alcohol (Avalon Pharma, Riyadh, Saudi Arabia), Ivoclean (Ivoclar Vivadent, Schaan, Lichtenstein) and Katana Cleaner (Kuraray Noritake, Tokyo, Japan). The resin–zirconia SBS was tested at 24 h and after thermocycling (10 k cycles). Three-way ANOVA followed by Tukey’s multiple comparisons test were utilized to analyze the SBS data. Failure modes were evaluated using a scanning electron microscope. Results: Both blood and saliva significantly affected resin–zirconia SBS as contaminants. After thermocycling, there was no statistically significant difference between SBS obtained after decontamination with the Katana Cleaner (blood, 6.026 ± 2.805 MPa; saliva, 5.206 ± 2.212 MPa) or Ivoclean (blood, 7.08 ± 3.309 MPa; saliva, 6.297 ± 3.083 MPa), and the control group (no contamination, 7.479 ± 3.64 MPa). Adhesive and mixed failures were the most frequent among the tested groups. Conclusion: Both 10-MDP-containing cleaner (Katana Cleaner) and zirconium oxide-containing cleaner (Ivoclean) could eliminate the negative effect of saliva and blood contamination on resin–zirconia SBS.
Modeling the Nonlinear Deformation of Highly Porous Cellular Plastics Filled with Clay Nanoplatelets
Authors: Lagzdiņš Aivars , Zilaucs Alberts , Beverte Ilze , Andersons Jānis
Published: January 2022

Rigid low-density plastic foams subjected to mechanical loads typically exhibit a nonlinear deformation stage preceding failure. At moderate strains, when the geometrical nonlinearity is negligible, such foam response is predominantly caused by the nonlinearity of deformation of their principal structural elements—foam struts. Orientational averaging of stresses in foam struts enables estimation of the stresses taken up by foams at a given applied strain. Based on a structural model of highly porous anisotropic cellular plastics filled with clay nanoplatelets and the orientational averaging, a method for calculating their nonlinear deformation is derived in terms of structural parameters of the porous material, the mechanical properties of the monolithic polymer, and filler particles and their spatial orientation. The method is applied to predicting the tensile stress-strain diagrams of organoclay-filled low-density rigid polyurethane foams, and reasonable agreement with experimental data is demonstrated.
Effect of Er on Microstructure and Corrosion Behavior of Al–Zn–Mg–Cu–Sc–Zr Aluminum Alloys
Authors: Xing Qingyuan , Wu Xiaohui , Zang Jinxin , Meng Linggang , Zhang Xingguo
Published: January 2022

In this study, the influence of Er addition on the microstructure, type transformation of second phases, and corrosion resistance of an Al–Zn–Mg–Cu alloy were explored. The results revealed that the added Er element could significantly refine the alloy grains and change the second-phase composition at the grain boundary of the alloy. In the as-cast state, the Er element significantly enhanced the corrosion resistance of the alloy due to its refining effect on the grains and second phases at the grain boundary. The addition of the alloying element Er to the investigated alloy changed the type of corrosion attack on the alloy’s surface. In the presence of Er, the dominant type of corrosion attack is pitting corrosion, while the alloy without Er is prone to intergranular corrosion attack. After a solution treatment, the Al8Cu4Er phase was formed, in which the interaction with the Cu element and the competitive growth relation to the Al3Er phase were the key factors influencing the corrosion resistance of the alloy. The anodic corrosion mechanism of the Al8Cu4Er and Al3Er phases evidently lowered the alloy corrosion rate, and the depth of the corrosion pit declined from 197 μm to 155 μm; however, further improvement of corrosion resistance was restricted by the morphology and size of the Al8Cu4Er phase after its formation and growth; therefore, adjusting the matching design of the Cu and Er elements can allow Er to improve the corrosion resistance of the Al–Zn–Mg–Cu aluminum alloy to the greatest extent.
Prediction of Concrete Fragments Amount and Travel Distance under Impact Loading Using Deep Neural Network and Gradient Boosting Method
Authors: Kim Kyeongjin , Kim WooSeok , Seo Junwon , Jeong Yoseok , Lee Meeju , Lee Jaeha
Published: January 2022

In the present study, the amount of fragments generated and their travel distances due to vehicle collision with concrete median barrier (CMB) was analyzed and predicted. In this regard, machine learning was applied to the results of numerical analysis, which were developed by comparing with field test. The numerical model was developed using smoothed particle hydrodynamics (SPH). SPH is a mesh-free method that can be used to predict the amount of fragments and their travel distances from concrete structures under impact loading. In addition, deep neural network (DNN) and gradient boosting machine (GBM) were also employed as machine learning methods. In this study, the results of DNN, GBM, and numerical analysis were then compared with the conducted field test. Such comparisons revealed that numerical analysis generated lower error than both DNN and GBM. When prediction results of both the amount of fragments and their travel distances were considered, the result of DNN showed smaller errors than that of GBM. Therefore, in studies where machine learning is used to predict the amount of fragments and their travel distances, careful selection of an appropriate method from the various available machine learning methods such as DNN, GBM, and random forest is absolutely important.
A Review of End-Effector Research Based on Compliance Control
Authors: Dai Ye , Xiang Chaofang , Qu Wenyin , Zhang Qihao
Published: January 2022

The end-effector is a key device for direct contact and operation between the operator and the workpiece, and its mechanical structure will directly affect the quality of the machine and expand its application. The theoretical research and technical implementation of the end-effector for compliance control are facing a lot of urgent challenges to be solved, therefore, the research results of active compliance control of robot end-effectors have a very broad application prospect. This paper describes the design and research results of different end-effectors under impedance-based control, hybrid force/position control, and intelligent flexible control methods, respectively. Under each control method, the structural characteristics and the optimized control scheme under different drives are introduced. Finally, key techniques for achieving compliance control are derived by summarizing, which broadens the engineering applications and provides methods and ideas for future research.
A Review of Sensors Used on Fabric-Handling Robots
Authors: Kaltsas Petros I. , Koustoumpardis Panagiotis N. , Nikolakopoulos Pantelis G.
Published: January 2022

While in most industries, most processes are automated and human workers have either been replaced by robots or work alongside them, fewer changes have occurred in industries that use limp materials, like fabrics, clothes, and garments, than might be expected with today’s technological evolution. Integration of robots in these industries is a relatively demanding and challenging task, mostly because of the natural and mechanical properties of limp materials. In this review, information on sensors that have been used in fabric-handling applications is gathered, analyzed, and organized based on criteria such as their working principle and the task they are designed to support. Categorization and related works are presented in tables and figures so someone who is interested in developing automated fabric-handling applications can easily get useful information and ideas, at least regarding the necessary sensors for the most common handling tasks. Finally, we hope this work will inspire researchers to design new sensor concepts that could promote automation in the industry and boost the robotization of domestic chores involving with flexible materials.
Improvement of Steady State Performance of Voltage Control in Switched Reluctance Generator: Experimental Validation
Authors: Touati Zeineb , Pereira Manuel , Araújo Rui Esteves , Khedher Adel
Published: January 2022

This paper presents a voltage control approach to a Switched Reluctance Generator (SRG) using a Proportional Integral (PI) controller. The principle of operation is described and the considerations in the design of controller are discussed. A current loop transfer function of an SRG with power converter has been systematically derived in order to obtain a small-signal model for the generator. The generated voltage is controlled by manipulation of the setpoint of the current control of the generator. The entire voltage loop controller and current control have been simulated and tested with a 250 W SRG prototype. The control law of the control system was implemented on a digital signal processor (TMS320F28379D). To verify the feasibility of the proposed voltage control, the performances are evaluated by numerical simulations and experimental tests with an 8/6 SRG for different rotational speeds and resistive loads. Experimental results demonstrate that the DC output voltage from SRG can be controlled well using a simple linear controller.
Energy Efficiency Optimization for Machining of Wood Plastic Composite
Authors: Zhu Zhaolong , Buck Dietrich , Guo Xiaolei , Xiong Xianqing , Xu Wei , Cao Pingxiang
Published: January 2022

Enhancing energy efficiency is the key to realizing green manufacturing. One major area of interest in this regard is the improvement of energy efficiency of machine tools during the production of building materials. This project focuses on energy efficiency during the spiral milling of wood plastic composites. To this end, a response surface method was adopted to develop a model and establish the relationship between energy efficiency and milling conditions. Analysis of variance based on individual factors as well as two-factor interactions was performed to gauge their effects on energy efficiency. It was found that milling depth was positively correlated to power efficiency, while spiral angle and feed per tooth displayed non-monotonic behavior. An attempt was made to predict milling conditions that will yield the greatest material removal rate and power efficiency. For wood plastic composites subjected to up-milling, it was determined that a feed per tooth of 0.1 mm, milling depth of 1.5 mm, and spiral angle of 70° were ideal. Considering the potential improvements in energy efficiency and surface quality that these process parameters will bring, it is strongly recommended for use in the industrial machining of wood plastic composites.
Acknowledgment to Reviewers of Machines in 2021
Authors:   Machines Editorial Office
Published: January 2022

Rigorous peer-reviews are the basis of high-quality academic publishing [...]
Acknowledgment to Reviewers of Machine Learning and Knowledge Extraction in 2021
Authors:   Machine Learning and Knowledge Extraction Editorial Office
Published: January 2022

Rigorous peer-reviews are the basis of high-quality academic publishing [...]
Exact Traveling Waves of a Generalized Scale-Invariant Analogue of the Korteweg–de Vries Equation
Authors: Alzaleq Lewa’ , Manoranjan Valipuram , Alzalg Baha
Published: January 2022

In this paper, we study a generalized scale-invariant analogue of the well-known Korteweg–de Vries (KdV) equation. This generalized equation can be thought of as a bridge between the KdV equation and the SIdV equation that was discovered recently, and shares the same one-soliton solution as the KdV equation. By employing the auxiliary equation method, we are able to obtain a wide variety of traveling wave solutions, both bounded and singular, which are kink and bell types, periodic waves, exponential waves, and peaked (peakon) waves. As far as we know, these solutions are new and their explicit closed-form expressions have not been reported elsewhere in the literature.
A Cuboid Registers Topic, Activity and Competency Data to Exude Feedforward and Continuous Assessment of Competencies
Authors: Mínguez-Aroca Francisco , Moll-López Santiago , Llobregat-Gómez Nuria , Sánchez-Ruiz Luis M.
Published: January 2022

Evaluating competencies achieved by students within a subject and its different topics is a multivariable and complex task whose outcome should provide actual information on their evolution. A relevant feature when a continuous assessment (CA) rules this evaluation is to track their learning process so that pertinent feedforward may be harnessed to proactively promote improvement when required. As this process is performed via a number of activities, such as lectures, problem solving, and lab practice, different competencies are developed, depending on the recurrence and type of conducted activity. Measuring and registering their achievement is the leitmotif of competency-based assessment. In this paper, we assemble topic, activity and competency data into a 3D matrix array to form what we call a TAC cuboid. This cuboid showcases a detailed account of each student evolution, aiding instructors and students to design and follow, respectively, an individualized curricular strategy within a continuous and aligned assessment methodology, which facilitates each student to adequately modify his/her level of development of each competency. In addition, we compare the TAC cuboids’ usage in grading a mathematics subject versus a traditional CA method as well as when a dynamical continuous assessment approach is considered to measure the achievement of mathematical competencies.
GPS: A New TSP Formulation for Its Generalizations Type QUBO
Authors: Gonzalez-Bermejo Saul , Alonso-Linaje Guillermo , Atchade-Adelomou Parfait
Published: January 2022

We propose a new Quadratic Unconstrained Binary Optimization (QUBO) formulation of the Travelling Salesman Problem (TSP), with which we overcame the best formulation of the Vehicle Routing Problem (VRP) in terms of the minimum number of necessary variables. After, we will present a detailed study of the constraints subject to the new TSP model and benchmark it with MTZ and native formulations. Finally, we will test whether the correctness of the formulation by entering it into a QUBO problem solver. The solver chosen is a D-Wave_2000Q6 quantum computer simulator due to the connection between Quantum Annealing and QUBO formulations.
Identification of Linear Time-Invariant Systems with Dynamic Mode Decomposition
Authors: Heiland Jan , Unger Benjamin
Published: January 2022

Dynamic mode decomposition (DMD) is a popular data-driven framework to extract linear dynamics from complex high-dimensional systems. In this work, we study the system identification properties of DMD. We first show that DMD is invariant under linear transformations in the image of the data matrix. If, in addition, the data are constructed from a linear time-invariant system, then we prove that DMD can recover the original dynamics under mild conditions. If the linear dynamics are discretized with the Runge–Kutta method, then we further classify the error of the DMD approximation and detail that for one-stage Runge–Kutta methods; even the continuous dynamics can be recovered with DMD. A numerical example illustrates the theoretical findings.
An Adaptive Protection Scheme Based on a Modified Heap-Based Optimizer for Distance and Directional Overcurrent Relays Coordination in Distribution Systems
Authors: Abdelhamid Mohamed , Kamel Salah , Ahmed Emad M. , Agyekum Ephraim Bonah
Published: January 2022

This paper proposes an adaptive protection scheme (APS) based on the original heap-based optimization (HBO) and a modified HBO (MHBO). APS is used to solve protection relays coordination problems that include directional overcurrent relays (DOCRs) as well as the distance relay’s second zone times. The complexity of the coordination problem increases with the impact of distributed generators (DGs) switching (ON/OFF). Topological changes in grid configuration frequently occur in distributing networks, equipped with DGs, causing changes in the values and direction of short circuit currents. This issue becomes a challenge for protection systems to avoid relays miscoordination and save a network’s reliability. In the proposed MHBO, the Original HBO is modified by three points, population are divided into subgroups, then they are unified into one group gradually, those subgroups are exchanging some search agents between themselves, these search agents are called travelling agents, and the last one is about, upgrading an internal equation in the original algorithm. For validating the proposed relays coordination, the IEEE 8-bus test system, and the IEEE 14-bus distribution network are selected as case studies. The obtained simulated results of the proposed algorithm show better performance compared with those obtained by the previous algorithms.
Modeling and Optimization of a Compression Ignition Engine Fueled with Biodiesel Blends for Performance Improvement
Authors: Alahmer Ali , Rezk Hegazy , Aladayleh Wail , Mostafa Ahmad O. , Abu-Zaid Mahmoud , Alahmer Hussein , Gomaa Mohamed R. , Alhussan Amel A. , Ghoniem Rania M.
Published: January 2022

Biodiesel is considered to be a promising alternative option to diesel fuel. The main contribution of the current work is to improve compression ignition engine performance, fueled by several biodiesel blends. Three metrics were used to evaluate the output performance of the compression ignition engine, as follows: brake torque (BT), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE), by varying two input parameters (engine speed and fuel type). The engine speeds were in the 1200–2400 rpm range. Three biodiesel blends, containing 20 vol.% of vegetable oil and 80 vol.% of pure diesel fuel, were prepared and tested. In all the experiments, pure diesel fuel was employed as a reference for all biodiesel blends. The experimental results revealed the following findings: although all types of biodiesel blends have low calorific value and slightly high viscosity, as compared to pure diesel fuel, there was an improvement in both BT and brake power (BP) outputs. An increase in BSFC by 7.4%, 4.9%, and 2.5% was obtained for palm, sunflower, and corn biodiesel blends, respectively, as compared to that of pure diesel. The BTE of the palm oil biodiesel blend was the lowest among other biodiesel blends. The suggested work strategy includes two stages (modeling and parameter optimization). In the first stage, a robust fuzzy model is created, depending on the experimental results, to simulate the output performance of the compression ignition engine. The particle swarm optimization (PSO) algorithm is used in the second stage to determine the optimal operating parameters. To confirm the distinction of the proposed strategy, the obtained outcomes were compared to those attained by response surface methodology (RSM). The coefficient of determination (R2) and the root-mean-square-error (RMSE) were used as comparison metrics. The average R2 was increased by 27.7% and 29.3% for training and testing, respectively, based on the fuzzy model. Using the proposed strategy in this work (integration between fuzzy logic and PSO) may increase the overall performance of the compression ignition engine by 2.065% and 8.256%, as concluded from the experimental tests and RSM.
Multiple Periodicity in a Predator–Prey Model with Prey Refuge
Authors: Lu Weijie , Xia Yonghui
Published: January 2022

We consider a delayed prey–predator model incorporating a refuge with a non-monotone functional response. It is supposed that prey can live in the predatory region and prey refuge, respectively. Based on Mawhin’s coincidence degree and nontrivial estimation techniques for a priori bounds of unknown solutions to the operator equation Lv=λNv, we prove the existence of multiple periodic solutions. Finally, an example demonstrates the feasibility of our main results.