scholarly journals Interleaved Boost Converter with ZVT-ZCT for the Main Switches and ZCS for the Auxiliary Switch

2020 ◽  
Vol 10 (6) ◽  
pp. 2033 ◽  
Author(s):  
Kuo-Ing Hwu ◽  
Jenn-Jong Shieh ◽  
Wen-Zhuang Jiang
Keyword(s):  
Boost Converter ◽  
Resonant Circuit ◽  
Second Phase ◽  
Current Sharing ◽  
Zero Current ◽  
Power Switches ◽  
Interleaved Boost Converter ◽  
The Difference ◽  
Two Phases ◽  
And Control

A soft-switching interleaved topology is presented herein and applied to the boost converter. The basic operating principle is that the main power switches are turned on at zero voltage and turned off at zero current via the same auxiliary resonant circuit whose switch is turned on from zero current. Furthermore, as compared to the traditional boost converter, the proposed topology has three additional auxiliary diodes, two additional auxiliary capacitors, one additional auxiliary inductor, and one additional auxiliary switch. On the other hand, since the interleaved control is adopted herein, the difference in current between the two phases exists. Hence, the cascaded control is utilized to regulate the output voltage to the desired voltage via the first phase, whereas the current-sharing control, based on half of the input current as the current reference for the second phase, is employed so as to make the load current extracted from the two phases as evenly as possible. In this paper, the effectiveness of the proposed topology and control strategy is demonstrated by some experimental results.

scholarly journals Two-Phase Interleaved Boost Converter with ZVT Turn-On for Main Switches and ZCS Turn-Off for Auxiliary Switches Based on One Resonant Loop

2020 ◽  
Vol 10 (11) ◽  
pp. 3881 ◽  
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Wen-Zhuang Jiang
Keyword(s):  
Boost Converter ◽  
System Stability ◽  
Two Phase ◽  
Turn On ◽  
Zero Current Switching ◽  
Zero Current ◽  
Interleaved Boost Converter ◽  
Two Phases ◽  
Zero Voltage ◽  
A Current

A two-phase interleaved boost converter with soft switching is proposed herein. By means of only one auxiliary circuit with two auxiliary switches having zero-current switching (ZCS) turn-on, two main switches are switched on with zero-voltage transition (ZVT) to enhance the overall efficiency. Moreover, a current-balancing circuit with a no current-balancing bus is utilized to render the load current extracted from the two phases as even as possible, so that the system stability is upgraded. In such a study, this converter, having the input of 24 V ± 10 % and the rated output of 36V/6A, was employed to demonstrate the effectiveness of such a converter by experiment.

scholarly journals Bioindicator demonstrates high persistence of sulfentrazone in dry soil1

2015 ◽  
Vol 45 (3) ◽  
pp. 326-332 ◽  
Author(s):  
Renato Coradello Lourenço ◽  
Saul Jorge Pinto de Carvalho
Keyword(s):  
Dose Response ◽  
Residual Effect ◽  
Second Phase ◽  
Response Curves ◽  
Sugarcane Crop ◽  
Phytotoxic Activity ◽  
Dry Soil ◽  
Two Phases ◽  
Preemergence Herbicides ◽  
And Control

ABSTRACTIn sugarcane crop areas, the application of preemergence herbicides with long residual effect in the soil has been frequently necessary. The herbicide persistence in the soil must be high especially because of applications during the dry season of the year, after sugarcane harvest. This study aimed at estimating the sulfentrazone persistence and dissipation in dry soil using bioindicator. Five experiments were carried out, divided into two phases. In the first phase, three dose-response curves were adjusted to select the best bioindicator to be adopted in the second phase. Niger was adopted due to its lower sensibility to sulfentrazone. In the second phase, a new dose-response curve was carried out, with six doses of sulfentrazone, in order to standardize the bioindicator sensibility to sulfentrazone. At the end, another experiment with six periods of sulfentrazone persistence in dry clay soil was developed. Persistence periods were: 182, 154, 125, 98 and 30 days. The bioindicator was seeded at the application day in treated plots and control. In this experiment, the sulfentrazone dose applied was 800 g ha-1. Niger was considered a good species to estimate the sulfentrazone persistence in dry soil. The sulfentrazone phytotoxic activity was identified up to 182 days after application, and its average dissipation rate was 2.15 g ha-1 day-1, with half-life higher than 182 days.

scholarly journals Biphasic pattern in the effect of severe measles infection; the difference between additive and multiplicative scale

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nhat Thanh Hoang Le ◽  
Nhan Thi Ho ◽  
Bryan Grenfell ◽  
Stephen Baker ◽  
Ronald B. Geskus
Keyword(s):  
Infectious Diseases ◽  
Hospital Admission ◽  
Measles Virus ◽  
Hospital Admissions ◽  
Admission Rate ◽  
Second Phase ◽  
Before And After ◽  
The Difference ◽  
Two Phases ◽  
Additive Scale

Abstract Background Infection with measles virus (MeV) causes immunosuppression and increased susceptibility to other infectious diseases. Only few studies reported a duration of immunosuppression, with varying results. We investigated the effect of immunosuppression on the incidence of hospital admissions for infectious diseases in Vietnamese children. Methods We used retrospective data (2005 to 2015; N = 4419) from the two pediatric hospitals in Ho Chi Minh City, Vietnam. We compared the age-specific incidence of hospital admission for infectious diseases before and after hospitalization for measles. We fitted a Poisson regression model that included gender, current age, and time since measles to obtain a multiplicative effect measure. Estimates were transformed to the additive scale. Results We observed two phases in the incidence of hospital admission after measles. The first phase started with a fourfold increased rate of admissions during the first month after measles, dropping to a level quite comparable to children of the same age before measles. In the second phase, lasting until at least 6 years after measles, the admission rate decreased further, with values up to 20 times lower than in children of the same age before measles. However, on the additive scale the effect size in the second phase was much smaller than in the first phase. Conclusion The first phase highlights the public health benefits of measles vaccination by preventing measles and immune amnesia. The beneficial second phase is interesting, but its strength strongly depends on the scale. It suggests a complicated interaction between MeV infection and the host immunity.

scholarly journals TWO PHASES IN THE DEVELOPMENT OF HEDWIG CONRAD-MARTIUS’ ONTOLOGICAL INVESTIGATION ON HUMAN BEING AND LIVING THINGS

2021 ◽  
Vol 10 (2) ◽  
pp. 398-424
Author(s):  
SIMONA BERTOLINI ◽  
Keyword(s):  
Structure Change ◽  
Second Phase ◽  
Human Being ◽  
Human Knowledge ◽  
Living Things ◽  
Ontological Categories ◽  
Biological Ontology ◽  
The Difference ◽  
Two Phases ◽  
Theoretical Results

Interest in the ontological constitution of living beings (with particular reference to the human being) characterizes the whole development of Hedwig Conrad-Martius’ philosophy. Several works written by the philosopher over the years deal with both the phenomenological description and the ontological foundation of the difference between plants, animals, and humans. Specifically, the ontological structure of the human being is investigated as a layered structure which presupposes those of plants and animals while overcoming them in a more complex and spiritual unity, on which human freedom and human knowledge depend. Although this topic maintains a crucial role in Conrad-Martius’ thought, the way the philosopher addresses it and the theoretical results of her phenomenological-ontological inquiry about it do not remain unchanged. Indeed, the ontological structure at the basis of phenomenal differences as well as the metaphysical foundations of this structure change over the decades. This paper aims at distinguishing between two phases, characterized by different ontological categories, through which Conrad-Martius’ anthropology and biological ontology develop. In the first phase, at the beginning of the twenties (precisely in her work Metaphysical Dialogues), the essential differences between plants, animals, and humans are explained with reference to a vital origin preceding the constitution of reality; to describe it Conrad-Martius employs terms such as “abyss” and “under-earthly realm.” In the second phase, exemplified by some writings published in the forties and the fifties, the reference to such a dimension disappears and the eidetic variety within the living world, including human specificity, is exclusively traced back to the finalistic substantiation of essences in the natural beings.

scholarly journals Mathematical model of transmission dynamics with mitigation and health measures for SARS-CoV-2 infection in European countries

2020 ◽  
Author(s):  
Shweta Sankhwar ◽  
Narender Kumar ◽  
Ravins Dohare
Keyword(s):  
Mathematical Model ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
European Countries ◽  
Transmission Dynamics ◽  
Second Phase ◽  
Geographical Regions ◽  
Two Phases ◽  
Spread Of Infection ◽  
And Control

Abstract The pandemic of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) continue to pose a serious threat to global health resulting in disease COVID-19. No specific drug or vaccine is available against this infection. Therefore, the prevention is only way to reduce the spread of infection. The pandemic needs an enhanced mathematical model, therefore, we propose a SEIAJR compartmental mathematical model to estimate the basic reproduction number (R0 ) and the transmission dynamics of four European countries (Germany, United Kingdom, Switzerland and Spain). The proposed mathematical model incorporates mitigation and healthcare measures as recommended by ECDC (European Centre for Disease Prevention and Control). The simulation of proposed model is done in two phases. First-phase simulation estimates basic reproduction number and mitigation rate according to active infected cases in all four European countries. R0 estimate 2.82 - 3.3 for considered European countries. Second-phase simulation predicts the dynamics of infection on the estimated R0 with varying mitigation rate and constant healthcare rate. This study predicts that no more mitigation is required to invade the infection. The current mitigation and healthcare measures are enough to stop the propogation of infection, however, infection would last by end of July 2020. The developed mathematical model would also be applicable to portray the infection trasmission dynamics for other geographical regions with varying parameters.

Accuracy assessment of surgical planning and three-dimensional-printed patient-specific guides for orthopaedic osteotomies

2017 ◽  
Vol 231 (6) ◽  
pp. 499-508 ◽  
Author(s):  
Gwen Sys ◽  
Hannelore Eykens ◽  
Gerlinde Lenaerts ◽  
Felix Shumelinsky ◽  
Cedric Robbrecht ◽  
...  
Keyword(s):  
Accuracy Assessment ◽  
Average Distance ◽  
Three Dimensional ◽  
Patient Specific ◽  
Second Phase ◽  
Experimental Setup ◽  
Operative Planning ◽  
The Difference ◽  
Two Phases ◽  
Improved Accuracy

This study analyses the accuracy of three-dimensional pre-operative planning and patient-specific guides for orthopaedic osteotomies. To this end, patient-specific guides were compared to the classical freehand method in an experimental setup with saw bones in two phases. In the first phase, the effect of guide design and oscillating versus reciprocating saws was analysed. The difference between target and performed cuts was quantified by the average distance deviation and average angular deviations in the sagittal and coronal planes for the different osteotomies. The results indicated that for one model osteotomy, the use of guides resulted in a more accurate cut when compared to the freehand technique. Reciprocating saws and slot guides improved accuracy in all planes, while oscillating saws and open guides lead to larger deviations from the planned cut. In the second phase, the accuracy of transfer of the planning to the surgical field with slot guides and a reciprocating saw was assessed and compared to the classical planning and freehand cutting method. The pre-operative plan was transferred with high accuracy. Three-dimensional-printed patient-specific guides improve the accuracy of osteotomies and bony resections in an experimental setup compared to conventional freehand methods. The improved accuracy is related to (1) a detailed and qualitative pre-operative plan and (2) an accurate transfer of the planning to the operation room with patient-specific guides by an accurate guidance of the surgical tools to perform the desired cuts.

scholarly journals The effects of early zinc deficiency on DNA and protein synthesis in the rat

1970 ◽  
Vol 24 (4) ◽  
pp. 1053-1059 ◽  
Author(s):  
R. B. Williams ◽  
J. K. Chesters
Keyword(s):  
Food Consumption ◽  
Zinc Deficiency ◽  
Protein Metabolism ◽  
Initial Period ◽  
Zn Deficiency ◽  
Second Phase ◽  
Control Groups ◽  
Dna And Protein Synthesis ◽  
Two Phases ◽  
And Control

1. The effects of early zinc deficiency on DNA and protein metabolism of the liver, kidneys, testes and spleen of the young rat were studied. The investigations were carried out in two phases: before food consumption and growth were affected, and afterwards.2. The incorporation of [3H]thymidine into DNA was markedly affected by differences of less than a week in the age of the rats.3. Zn deficiency significantly reduced the incorporation of [3H]thymidine into DNA of liver, kidneys and spleen before growth and food consumption were affected. The degree of inhibition was of the order of 50% in the first 5 d. A similar but non-significant trend was observed for the testes.4. The incorporation of [3C]lysine into protein was not significantly affected in liver and testes during the initial period of Zn deficiency; the incorporation into kidneys and spleen was significantly inhibited but the magnitude of the effect was only of the order of 20% in 5d.5. One week after the start of the second phase, the concentration of DNA in liver, testes, and spleen of Zn-deficient animals was not significantly different from that in pair-fed controls. The DNA content of the kidneys was significantly reduced by the deficiency hut only to 97% of that in pair-fed animalsgiven the Zn-supplcmenteddiet. The incorporation of [3H]thymidine into DNA was not significantly different between deficient and control groups in any of the four organs investigated.

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