scholarly journals Linear-polarized terahertz isolator by breaking the gyro-mirror symmetry in cascaded magneto-optical metagrating

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhiyu Tan ◽  
Fei Fan ◽  
Dan Zhao ◽  
Shanshan Li ◽  
Xianghui Wang ◽  
...  

Abstract To realize nonreciprocal transmission, it is necessary to break the time-reversal symmetry of the transmission system, but it is very challenging to keep the linear polarized (LP) input and output unchanged in the free space transmission system. Magnetized semiconductor InSb can realize terahertz (THz) nonreciprocal transmission for the two conjugated photonic spin states, but it cannot realize efficient one-way transmission of LP state due to gyro-mirror symmetry. In this work, by introducing a pair of orthogonal uniaxial anisotropies from the meta-gratings on both sides of InSb, both the gyro-mirror and time-reversal symmetries are broken for the LP state, thus making this cascaded grating–InSb–grating structure serves as a high-performance isolator for the LP light. The experiment results indicate isolation of 50 dB at 0.4 THz for the same LP input and output under a weak biased magnetic field of 0.17 T. Moreover, we further illustrate the factors affecting the isolation bandwidth of the device, also demonstrated another broadband structure with the 10 dB isolation bandwidth from 0.2–0.7 THz, and the relative bandwidth achieves 110%. The mechanisms of THz nonreciprocal transmission and polarization manipulation proposed in this work will contribute to the development of efficient THz magneto-optical devices.

2019 ◽  
Author(s):  
Сергей Крамаров ◽  
Sergey Kramarov ◽  
Сергей Ковалев ◽  
Sergey Kovalev ◽  
Сергей Соколов ◽  
...  

There is the current state of a question of creation of the indistinct and logical optical devices serving for development of high performance expert systems which will provide inquiries of experts from the most various areas is considered in the monograph. Use of the device of indistinct systems is caused by a tendency of increase in complexity of mathematical and formal models of actual systems and management processes which are bound to desire to increase their adequacy and to consider the increasing number of various factors affecting on decision-making processes. The main directions of researches which are given in the monograph are directed to development of basic elements of the optical computer. Authors of this work patented over 50 various indistinct and logical optical devices and ways of information processing with their use, many of which explicitly are considered in this monograph. Writing of the book was initiated by the tasks formulated within the SMART project (Satellite Monitoring – to the Fissile Development of Territories) where a number of the keyset problems, including adaptability of adoption of administrative decisions is considered. The book is intended for scientists, experts, graduate students and undergraduates specializing in the field of photonics, development indistinctly – logical methods and devices, and also for students of older years of physical and mathematical faculties and engineering higher education institutions on the corresponding specialties.


2021 ◽  
Vol 52 (S2) ◽  
pp. 572-575
Author(s):  
Bharat R. Acharya ◽  
Matthew Sousa ◽  
Ryan Fabick ◽  
Robert Taylor ◽  
David Rosen ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bayram Şahin ◽  
Gülnur İlgün ◽  
Seda Sönmez

PurposeThis study aims to identify the efficiency scores of hospitals affiliated to the Ministry of Health in Turkey between the years of 2010–2015 at provincial level and to reveal the factors that affect the efficiency scores.Design/methodology/approachThe two-stage data envelopment analysis (DEA) method was used to achieve the study purpose. In the first stage, DEA method based on input-oriented Charnes–Cooper–Rhodes (CCR) model was performed to calculate the efficiency scores of public hospitals at the provincial level between 2010 and 2015, and in the second stage, Tobit regression and linear regression analyses were used to identify whether the efficiency scores of provinces are affected by the input, output and control variables.FindingsUpon the analysis, the average efficiency scores of 81 provinces by years were found to vary between 0.79 and 0.89. According to both regression analyses, all of the input and output variables were found to have significant effects on the efficiency scores of provinces while only the population of province among the control variables was identified as the factor with an effect on the efficiency scores of provinces (p < 0.05).Practical implicationsThe results of this study are thought to guide health policymakers and managers in terms of both determining efficient and inefficient hospitals at the provincial level and revealing which variables should be taken into account in order to increase efficiency.Originality/valueThe study differs from previous studies on the efficiency of hospitals. First, although previous studies were generally descriptive studies to determine the efficiency level of hospitals, this study is an analytical study that tries also to show the factors affecting the efficiency of hospitals. In addition, while examining the effect of input and output variables on efficiency scores, control variables were also included in the study.


1995 ◽  
Vol 58 (1) ◽  
pp. 91-94 ◽  
Author(s):  
J. E. LINE ◽  
R. E. BRACKETT

This study was conducted to investigate several factors affecting the removal of aflatoxin B1 by Flavobacterium aurantiacum NRRL B-184. A simple spectrophotometric procedure was evaluated and compared to an established high-performance liquid chromatography (HPLC) method and found to be useful for determining aflatoxin concentration in test solutions of phosphate buffer. Using the spectrophotometric method, 72-h cultures of F. aurantiacum were observed to remove more toxin from solution than 24-h cultures. Likewise, populations of 1010cells removed aflatoxin at a faster rate than did 109 cells, although the total amount removed did not differ. Transferring F. aurantiacum cultures in tryptic soy broth every 3 days for over 3 days for over 8 months had no apparent effect on their ability to remove measurable amounts of aflatoxin B1 from solution. Populations of 1 × 109 CFU/ml or less heat-inactivated F. aurantiacum were unable to remove aflatoxin B1 from phosphate buffer.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fumiya Osawa ◽  
Kazuhiro Marumoto

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Bin Zhou ◽  
ShuDao Zhang ◽  
Ying Zhang ◽  
JiaHao Tan

In order to achieve energy saving and reduce the total cost of ownership, green storage has become the first priority for data center. Detecting and deleting the redundant data are the key factors to the reduction of the energy consumption of CPU, while high performance stable chunking strategy provides the groundwork for detecting redundant data. The existing chunking algorithm greatly reduces the system performance when confronted with big data and it wastes a lot of energy. Factors affecting the chunking performance are analyzed and discussed in the paper and a new fingerprint signature calculation is implemented. Furthermore, a Bit String Content Aware Chunking Strategy (BCCS) is put forward. This strategy reduces the cost of signature computation in chunking process to improve the system performance and cuts down the energy consumption of the cloud storage data center. On the basis of relevant test scenarios and test data of this paper, the advantages of the chunking strategy are verified.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 356-357
Author(s):  
Olga Sharaskina

Abstract It is necessary to consider the factors affecting the dynamics and blood glucose (BG) level to maintain a horse’s high performance and health during intensive training. The study aimed to research the influence of the feeding regime on the change in BG level in the Orlov trotter horses during the period of intensive training (summer) in the conditions of the stud farm’s training center in the Kaluga region (Russia). Horses aged 2 to 4 years, stallions (n = 7), and mares (n = 5) received commercial mixed feed three times a day and grass hay in free access. Four times a week after lunch, horses are released into the paddock with cut grass. Blood was collected from the jugular vein. Blood was collected before morning feeding and then every hour until four h after morning and afternoon feeding. The dynamics of BG changes depending on the presence or absence of the grass paddock after feeding were evaluated. If horses remained in the stall after feeding, the BG level gradually increased, reaching a maximum (4.95 ± 0.21 mmol/L) 3 hours after feeding and was significantly higher (P ≤ 0.05) than when they were immediately moved to the paddock with grass. The maximum BG concentration in horses in the paddock was observed 1 hour after feeding (4.55 ± 0.21 mmol/L); it didn’t have significant differences with the BG level after 1 hour in “stall horses” (4.5 ± 0.14 mmol/L). Then the BG level of the “paddock horses” gradually decreased, and in the “stall horses” increased. No significant difference in BG levels was observed 4 hours after feeding. When horses can walk in a paddock after feeding concentrates and eat grass, blood glucose levels do not rise and tend to decrease.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2261
Author(s):  
Sarv Priya ◽  
Yanan Liu ◽  
Caitlin Ward ◽  
Nam H. Le ◽  
Neetu Soni ◽  
...  

Prior radiomics studies have focused on two-class brain tumor classification, which limits generalizability. The performance of radiomics in differentiating the three most common malignant brain tumors (glioblastoma (GBM), primary central nervous system lymphoma (PCNSL), and metastatic disease) is assessed; factors affecting the model performance and usefulness of a single sequence versus multiparametric MRI (MP-MRI) remain largely unaddressed. This retrospective study included 253 patients (120 metastatic (lung and brain), 40 PCNSL, and 93 GBM). Radiomic features were extracted for whole a tumor mask (enhancing plus necrotic) and an edema mask (first pipeline), as well as for separate enhancing and necrotic and edema masks (second pipeline). Model performance was evaluated using MP-MRI, individual sequences, and the T1 contrast enhanced (T1-CE) sequence without the edema mask across 45 model/feature selection combinations. The second pipeline showed significantly high performance across all combinations (Brier score: 0.311–0.325). GBRM fit using the full feature set from the T1-CE sequence was the best model. The majority of the top models were built using a full feature set and inbuilt feature selection. No significant difference was seen between the top-performing models for MP-MRI (AUC 0.910) and T1-CE sequence with (AUC 0.908) and without edema masks (AUC 0.894). T1-CE is the single best sequence with comparable performance to that of multiparametric MRI (MP-MRI). Model performance varies based on tumor subregion and the combination of model/feature selection methods.


2014 ◽  
Vol 2014 (DPC) ◽  
pp. 000737-000767
Author(s):  
Cyprian Uzoh ◽  
Liang Wang ◽  
Zhuowen Sun ◽  
Andrew Cao ◽  
Bong-Sub Lee ◽  
...  

3D-IC has been increasingly adopted by the industry owing to its promise of higher device speed and package bandwidth, improved power consumption, reduced form factor, and lower cost for important applications over a wide range of industrial segments including image sensors, logic-memory and logic-logic integration, MEMS, integrated optical interposers and LEDs. This presentation is a systematic study of multiple experimental factors affecting the electrical performance, reliability and scalability of TSVs. Electrical modeling and simulation was used to determine the key factors influencing singal transmission and return losses in TSVs at high (&gt;1 GHz) frequencies. A variety of process modules and steps for the fabrication of through silicon vias were then systematically optimized to ensure high performance. The modules evaluated include TSV etch, TSV fill, chemical mechanical polishing (CMP), pad finish, bonding schemes, wafer thinning, via reveal, passivation, wiring and bumping. One example is the improvement of TSV profile and sidewall roughness through the optimization of DRIE parameters and wet chemical methods to reduce silicon sidewall roughness from that of a typical Bosch etch to less than 10nm which is critical for adhesion of barrier/seed layer and the final reliability of 2.5D packaging. Scalability of void-free via fill process with respect to TSV diameter and depth was addressed by using highly conformal barrier layers. Adhesion of Cu to the barrier layer was also improved upon detailed analysis to prevent delamination and improve reliability. A bottom up plating chemistry with significantly low impurity content was utilized to mitigate voids, seams and excessive overburden in the TSV. Its impact on stress and delamination issues and subsequent reliability failures was studied in details. The annealing process following TSV formation is systematically studied with varying conditions and characterized with metrology and electrical tests to investigate its effect on microstructure and material properties. The process parameters were tuned for CMP of Cu, adhesion and barrier layer without causing corrosion or delamination between adjacent layers. Process requirements for these modules in TSV process are closely related. This presentation will review the process module development in the context of their effects on the integrated TSV parameters (performance, reliability and scalability). We will also provide an in-depth discussion on process module optimization, electrical and mechanical characterization and cost reduction methodologies.


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