Hasil untuk "Technology (General)"

C. Rossby

Erik Arévalo, Ramón Herrera Hernández, Dimitrios Katselis et al.

Direct current motors are widely used in a plethora of applications, ranging from industrial to modern electric (and intelligent) vehicle applications. Most recent operation methods of these motors involve drives that are designed based on an adequate knowledge of the motor dynamics and circulating currents. However, in spite of its simplicity, accurate discrete-time models are not always attainable when utilising the Euler method. Moreover, these inaccuracies may not be reduced when estimating the currents and rotor speed in sensorless direct current motors. In this paper, we analyse three discretisation methods, namely the Euler, second-order Taylor method and second-order Runge–Kutta method, applied to three common types of direct current motor: separately excited, series, and shunt. We also analyse the performance of two of the most simple Bayesian filtering methods, namely the Kalman filter and the extended Kalman filter. For the comparison of the models and the state estimation techniques, we performed several Monte Carlo simulations. Our simulations show that, in general, the Taylor and Runge–Kutta methods exhibit similar behaviours, whilst the Euler method results in less accurate models.

Övgü Gencer

The blue crab (Callinectes sapidus, Rathbun 1896) has become a significant source of raw materials in biotechnology and nanotechnology due to the biomaterials present in its shell. Natural polymers such as chitin and chitosan, derived from the crab's shell, are particularly noteworthy for their environmentally friendly and biologically compatible properties. These biopolymers provide an innovative alternative in the synthesis of quantum dots (QDs). Quantum dots are favored in various applications, including biomedical imaging, environmental sensors, and energy storage, due to their superior optoelectronic properties. Chitosan obtained from blue crab shells acts as both a stabilizer and a coating agent in the green synthesis of quantum dots. This process minimizes the use of toxic chemicals, thus promoting environmental sustainability. Moreover, the antimicrobial and biodegradable properties of chitosan enhance its usability in biomedical applications. For instance, biocompatible carbon-based quantum dots have shown promising results in cancer diagnostics and drug delivery systems. The synthesis of quantum dots using biomaterials is more cost-effective and environmentally friendly compared to traditional methods. Furthermore, utilizing blue crab shells as a waste material contributes to both marine ecosystem preservation and the circular economy. These synthesis methods are reported to create a significant paradigm shift in the field of sustainable technology development. In conclusion, the synthesis of quantum dots using biomaterials derived from blue crabs has the potential to reduce environmental impacts while serving advanced technological applications. This approach significantly contributes to the development of biotechnological innovations and sustainable development goals.

I-Wei Ho, Chin-Chou Huang

Abstract Furosemide, a loop diuretic, is commonly used to treat fluid overload symptoms and heart failure. Drug-induced immune haemolytic anaemia is an unusual drug-adverse event. Furosemide-induced haemolysis is even rarer. This case report presents a 91-year-old male who developed acute haemolytic anaemia 3 days after initiating furosemide to treat myocardial infarction complicated with acute decompensated heart failure. He had increased lactate dehydrogenase and unconjugated bilirubin with undetectable haptoglobin, which indicated the destruction of red blood cells. Other causes for haemolytic anaemia, including hereditary, microangiopathic haemolytic anaemia, and paroxysmal nocturnal haemoglobinuria, were also excluded. He improved with drug cessation and a short course of glucocorticoids. This report aims to raise awareness of this rare complication caused by commonly prescribed drugs. Despite a negative result of a direct antiglobulin test, physicians must remain suspicious of drug-induced immune haemolytic anaemia in unclear cases of haemolysis.

Eunice Jia-Shiow Yuan, Shiau-Shian Huang, Chia-An Hsu et al.

Purpose: Coronavirus disease 2019 (COVID-19) has heavily impacted medical clinical education in Taiwan. Medical curricula have been altered to minimize exposure and limit transmission. This study investigated the effect of COVID-19 on Taiwanese medical students’ clinical performance using online standardized evaluation systems and explored the factors influencing medical education during the pandemic.Methods: Medical students were scored from 0 to 100 based on their clinical performance from 1/1/2018 to 6/31/2021. The students were placed into pre-COVID-19 (before 2/1/2020) and midst-COVID-19 (on and after 2/1/2020) groups. Each group was further categorized into COVID-19-affected specialties (pulmonary, infectious, and emergency medicine) and other specialties. Generalized estimating equations (GEEs) were used to compare and examine the effects of relevant variables on student performance.Results: In total, 16,944 clinical scores were obtained for COVID-19-affected specialties and other specialties. For the COVID-19-affected specialties, the midst-COVID-19 score (88.513.52) was significantly lower than the pre-COVID-19 score (90.143.55) (P<0.0001). For the other specialties, the midst-COVID-19 score (88.323.68) was also significantly lower than the pre-COVID-19 score (90.063.58) (P<0.0001). There were 1,322 students (837 males and 485 females). Male students had significantly lower scores than female students (89.333.68 vs. 89.993.66, P=0.0017). GEE analysis revealed that the COVID-19 pandemic (unstandardized beta coefficient=-1.99, standard error [SE]=0.13, P<0.0001), COVID-19-affected specialties (B=0.26, SE=0.11, P=0.0184), female students (B=1.10, SE=0.20, P<0.0001), and female attending physicians (B=-0.19, SE=0.08, P=0.0145) were independently associated with students’ scores.Conclusion: COVID-19 negatively impacted medical students' clinical performance, regardless of their specialty. Female students outperformed male students, irrespective of the pandemic.

Ketil Stølen

Pohsun Wang, Wu Song, Junling Zhou et al.

Confronting the age of artificial intelligence, exploring art through technology has become one of the directions of interdisciplinary development. Not only does artificial intelligence technology explore sustainability on a technical level; it can also take advantage of itself to focus on the visual perception of the living environment. People frequently interpret environmental features through their eyes, and the use of intuitive eye-tracking can provide effective data that can contribute to environmental sustainability in managing the environment and color planning to enhance the image of cities. This research investigates the visual responses of people viewing the historic city of Macau through an eye movement experiment to understand how the color characteristics of the physical environment are perceived. The research reveals that the buildings and plantings in the historic district of Macau are the most visible objects in the environment, while the smaller scale of St. Dominic’s Square, the Company of Jesus Square, and St. Augustine’s Square, which have a sense of spatial extension, have also become iconic environmental landscapes. This also draws visual attention and guides the direction of travel. The overall impressions of the Historic Centre of Macau, as expressed by the participants after the eye movement experiment, were mainly described as “multiculturalism”, “architectural style”, “traditional architecture”, “color scheme”, and “garden planting”. The 60 colors representing the urban color of Macau are then organized around these deep feelings about the environment. Therefore, for future inspiration, the 60 colors can be applied through design practice to create color expressions that fit the local characteristics, and thereby enhance the overall visual image of the city.

Alla G. Polyakova, Anna G. Soloveva, Petr V. Peretyagin et al.

The development of anti-pain technologies in the complex treatment of pain syndromes is one of the most urgent tasks of modern medicine. We undertook a placebo-controlled experimental study of the therapeutic potential of low-intensity laser radiation when applied to acupuncture points that are directly related to the autonomic nervous system. The adaptation effect of puncture photobiomodulation on the induction of stress-mediated autonomic reactions, oxidative metabolism and microcirculation in animals during the acute phase of pain stress was revealed. The data obtained are of interest for use in the complex rehabilitation of patients with pain syndromes.

Ji-Qiang Li, Yan Chen, Yong Biao Ma et al.

With the development of the hydrogen fuel cell automobile industry, higher requirements are put forward for the construction of hydrogen energy infrastructure, the matching of parameters and the control strategy of hydrogen filling rate in the hydrogenation process of hydrogenation station. Fuel for hydrogen fuel cell vehicles comes from hydrogen refueling stations. At present, the technological difficulty of hydrogenation is mainly reflected in the balanced treatment of reducing the temperature rise of hydrogen and shortening the filling time during the fast filling process. The Joule-Thomson (JT) effect occurs when high-pressure hydrogen gas passes through the valve assembly, which may lead to an increase in hydrogen temperature. The JT effect is generally reflected by the JT coefficient. According to the high pressure hydrogen in the pressure reducing valve, the corresponding JT coefficients were calculated by using the VDW equation, RK equation, SRK equation and PR equation, and the expression of JT effect temperature rise was deduced, which revealed the hydrogen temperature variation law in the process of reducing pressure. Make clear the relationship between charging parameters and temperature rise in the process of decompression; the flow and thermal characteristics of hydrogen in the process of decompression are revealed. This study provides basic support for experts to achieve throttling optimization of related pressure control system in hydrogen industry.

Othman Abdullah Almatroud, Viet-Thanh Pham, Giuseppe Grassi et al.

The use of the advancements in memristor technology to construct chaotic maps has garnered significant research attention in recent years. The combination of memristors and nonlinear terms provides an effective approach to proposing novel maps. In this study, we have leveraged memristors and sine terms to develop three-dimensional maps, capable of processing special fixed points. Additionally, we have conducted an in depth study of a specific example (TDMM<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>1</mn></msub></semantics></math></inline-formula> map) to demonstrate its dynamics, feasibility, and application for lightweight encryption. Notably, our general approach could be extended to develop higher-dimensional maps, including four- and five-dimensional ones, thereby opening up the possibility to create numerous higher-dimensional maps.

Hsueh-Chi S. Yen, Qikai Xu, Danny M. Chou et al.

Mohamed Heweidak, Bidur Kafle, Riyadh Al-Ameri

Composite slab systems have become increasingly popular over the last few decades because of the advantages of merging the two building materials, profiled steel sheets and concrete. The profiled composite slab’s performance depends on the composite interaction at the longitudinal direction of the concrete–steel interface. Geopolymer concrete has emerged over the last few years as a potential sustainable construction material, with 80% less carbon dioxide emissions than cementitious concrete. Recently, self-compacted geopolymer concrete (SCGC) has been developed, synthesised from a fly ash/slag ratio equal to 60/40, micro fly ash (5%), anhydrous sodium metasilicate solid powder as the alkali-activator and a water/solid content ratio equal to 0.45. The production of SCGC eliminates the need for an elevated temperature during curing and high corrosive alkali-activator solutions, as in traditional geopolymer concrete. The bond characteristics of the profiled composite slab system incorporated with the SCGC mix have not yet been thoroughly investigated. The cost-effectiveness of small-scale tests has popularised its usage by many researchers as an alternative technique to large-scale testing for assessing composite slab load shear capacity. In this paper, small-scale push tests were conducted to investigate the load slip behaviour of the SCGC composite slab compared to the normal concrete (NC) composite slab, with targeted compressive strengths of 40 and 60 MPa. The results indicate that SCGC has better chemical adhesion with profiled steel sheets than NC. Additionally, the profiled composite slab incorporated with SCGC possesses higher ultimate strength and toughness than the normal concrete composite slab.

Gérard P. Cachon, P. Harker

Jianwen Liao, Harold P. Welsch

P. Kinget

H. Hashemi, A. Hajimiri

Ihsan ur Rasheed, Dr Aman ullah

ABSTRACT The civilized and the cultured world today is facing a difficult time with the economy. Regardless of its success, every nation seems to be confused regarding this matter. The poor are increasing in their poverty and the rich are increasing in their wealth. Especially during this time of the pandemic (COVID-19), throughout the world you see poverty and economic depression becoming normalized. Furthermore, today’s leaders promise their people that they will make sure that not a single person will be deprived of receiving the necessary provisions. However, with the unequal distribution of wealth, the conditions that are coming forth are not worth talking about. The benefactor of every creation-be it a Muslim or Non-Muslim, a human being or or an animal, an Arab or a non-Arab, our beloved Prophet ﷺ has shown us the correct example of economy and also how to apply it in the world fourteen hundred years ago in such a way where no other example can match his example until the day of resurrection. Other religions and systems have directed mankind in one of two ways: either leading them to stay hungry and in poverty and promising them that this way is the epitome of monasticism thus bringing bright attention to monasticism, or luring them into saving money continuously after earning it. However, Islam is one of the only religions that motivates people to spend money on others more then hoarding it. This is to a point where hoarding money and being stingy with it is both a crime and blameworthy in Islam. Islam also cultivates such a desire in the people’s hearts where Muslims spending money in the path of Allah ﷻ consider it a means of success for themselves. The following lines will bring forth a discussion of general guardianship and serving the creation in Islam as well as other Abrahamic religions through the lens of a thoroughly researched and comparative paper.

WANG Xiaofan, WU Yong, ZHANG ZHONG Lili et al.

【Background and Objective】 Magnetizing the water prior to irrigation is a new technology developed over the past decades in China. The objective of this paper is to investigate how different irrigation water sources alter the effects of the magnetization on photosynthesis, physiological and biochemical characteristics, as well as the yield of lettuce. 【Method】 The experiment was conducted in a solar greenhouse with the Italian lettuce taken as the model plant. It consisted of non-magnetization (M0) and magnetization (M1); added to these are three irrigation water sources: fresh water (T1), reclaimed water (T2) and saline water (T3). Overall, there were six treatments which were arranged in the greenhouse by a randomized block design. For each treatment, we measured the net photosynthetic rate, transpiration rate, antioxidant enzyme activity, mineral element, yield and water use efficiency of the lettuce. 【Result】 Effects of the three water sources after magnetization on crop growth were different. For a given water source, there was no significant difference in the net photosynthetic rate between magnetization and non-magnetization in the early and late growth stage, but in the middle growth stage the magnetized fresh water and the reclaimed water increased the net photosynthetic rate of the crop by 11.16% and 14.73%, respectively. Saline water irrigation reduced the net photosynthetic rate at significant level, and there was no significant difference in net photosynthetic rate between the fresh water and reclaimed water irrigation. Magnetizing the fresh water, reclaimed and saline water increased the transpiration rate, despite not at significant, but they significantly boosted the activities of SOD by 18.08%, 12.77% and 14.68% respectively, the activities of POD by 20.97%, 18.14% and 16.99% respectively, and the activities of CAT by 22.54%, 23.09% and 18.55% respectively. In the meantime, magnetizing the fresh water and the reclaimed water increased the total nitrogen in the lettuce leaves by 7.71% and 6.83%, respectively. Magnetization also altered the content of P, Ca, Mg, Na and K in the leaves, with the alterations varying with water sources. For yield, magnetizing the fresh and the reclaimed water increased the yield by 9.42% and 10.15% at significant level, respectively, magnetizing the saline water did not lead to a noticeable change in the yield. M1T1 was most effective in improving yield and the above-ground dry mass, whereas M0T3 was the least effective. Compared with M0T3, M1T1 increased the yield and the above-ground dry mass by 33.44% and 31.29%, respectively. Depending on water sources, magnetization could also increase water use efficiency by 5.03%~11.65%. 【Conclusion】 Magnetizing the water in irrigating lettuce was beneficial to its physiological and biochemical activities such as photosynthesis and antioxidant enzyme activity, thereby increasing yield and water use efficiency. But the improvement depends on water sources. In our study, magnetizing the fresh water and the reclaimed water was more effective than the saline water.

Malwina Mularczyk, Izabela Michalak, Krzysztof Marycz

Bioactive compounds of natural origin are gaining increasing popularity. High biological activity and bioavailability, beneficial effects on health and safety of use are some of their most desirable features. Low production and processing costs render them even more attractive. Microorganisms have been used in the food, medicinal, cosmetic and energy industries for years. Among them, microalgae have proved to be an invaluable source of beneficial compounds. <i>Haematococcus pluvialis</i> is known as the richest source of natural carotenoid called astaxanthin. In this paper, we focus on the cultivation methods of this green microalga, its chemical composition, extraction of astaxanthin and analysis of its antioxidant, anti-inflammatory, anti–diabetic and anticancer activities. <i>H. pluvialis</i>, as well as astaxanthin can be used not only for the treatment of human and animal diseases, but also as a valuable component of diet and feed.

Noritaka Fukunaga, Sho Sanami, Hiroya Kitasaka et al.

Abstract Purpose To establish an automated pronuclei determination system by analysis using deep learning technology which is able to effectively learn with limited amount of supervised data. Methods An algorithm was developed by explicitly incorporating human observation where the outline around pronuclei is being observed in determining the number of pronuclei. Supervised data were selected from the time‐lapse images of 300 pronuclear stage embryos per class (total 900 embryos) clearly classified by embryologists as 0PN, 1PN, and 2PN. One‐hundred embryos per class (a total of 300 embryos) were used for verification data. The verification data were evaluated for the performance of detection in the number of pronuclei by regarding the results consistent with the judgment of the embryologists as correct answers. Results The sensitivity rates of 0PN, 1PN, and 2PN were 99%, 82%, and 99%, respectively, and the overlapping 2PN being difficult to determine by microscopic observation alone could also be appropriately assessed. Conclusions This study enabled the establishment of the automated pronuclei determination system with the precision almost equivalent to highly skilled embryologists.