scholarly journals Phase-Modulated Standing Wave Interferometer

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 12
Author(s):  
Ingo Ortlepp ◽  
Eberhard Manske ◽  
Jens-Peter Zöllner ◽  
Ivo W. Rangelow

Standing wave interferometers (SWIs) show enormous potential for miniaturization because of their simple linear optical set-up, consisting only of a laser source, a measuring mirror and two standing wave sensors for obtaining quadrature signals. To reduce optical influences on the standing wave and avoid the need for an exact and long-term stable sensor-to-sensor distance, a single-sensor set-up was developed with a phase modulation by forced oscillation of the measuring mirror. When the correct modulation stroke is applied, the harmonics in the sensor signal can be used for obtaining quadrature signals for phase demodulation and direction discrimination.

Author(s):  
O.L. Krivanek ◽  
J. TaftØ

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.


Author(s):  
Vijay Krishnamurthi ◽  
Brent Bailey ◽  
Frederick Lanni

Excitation field synthesis (EFS) refers to the use of an interference optical system in a direct-imaging microscope to improve 3D resolution by axially-selective excitation of fluorescence within a specimen. The excitation field can be thought of as a weighting factor for the point-spread function (PSF) of the microscope, so that the optical transfer function (OTF) gets expanded by convolution with the Fourier transform of the field intensity. The simplest EFS system is the standing-wave fluorescence microscope, in which an axially-periodic excitation field is set up through the specimen by interference of a pair of collimated, coherent, s-polarized beams that enter the specimen from opposite sides at matching angles. In this case, spatial information about the object is recovered in the central OTF passband, plus two symmetric, axially-shifted sidebands. Gaps between these bands represent "lost" information about the 3D structure of the object. Because the sideband shift is equal to the spatial frequency of the standing-wave (SW) field, more complete recovery of information is possible by superposition of fields having different periods. When all of the fields have an antinode at a common plane (set to be coincident with the in-focus plane), the "synthesized" field is peaked in a narrow infocus zone.


2011 ◽  
Vol 48 (No. 1) ◽  
pp. 20-26
Author(s):  
M. Birkás ◽  
T. Szalai ◽  
C. Gyuricza ◽  
M. Gecse ◽  
K. Bordás

This research was instigated by the fact that during the last decade annually repeated shallow disk tillage on the same field became frequent practice in Hungary. In order to study the changes of soil condition associated with disk tillage and to assess it is consequences, long-term tillage field experiments with different levels of nutrients were set up in 1991 (A) and in 1994 (B) on Chromic Luvisol at Gödöllö. The effects of disk tillage (D) and disk tillage combined with loosening (LD) on soil condition, on yield of maize and winter wheat, and on weed infestation were examined. The evaluation of soil condition measured by cone index and bulk density indicated that use of disking annually resulted in a dense soil layer below the disking depth (diskpan-compaction). It was found, that soil condition deteriorated by diskpan-compaction decreased the yield of maize significantly by 20 and 42% (w/w), and that of wheat by 13 and 15% (w/w) when compared to soils with no diskpan-compaction. Averaged over seven years, and three fertilizer levels, the cover % of the total, grass and perennial weeds on loosened soils were 73, 69 and 65% of soils contained diskpan-compaction.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2681
Author(s):  
Kedir Mamo Besher ◽  
Juan Ivan Nieto-Hipolito ◽  
Raymundo Buenrostro-Mariscal ◽  
Mohammed Zamshed Ali

With constantly increasing demand in connected society Internet of Things (IoT) network is frequently becoming congested. IoT sensor devices lose more power while transmitting data through congested IoT networks. Currently, in most scenarios, the distributed IoT devices in use have no effective spectrum based power management, and have no guarantee of a long term battery life while transmitting data through congested IoT networks. This puts user information at risk, which could lead to loss of important information in communication. In this paper, we studied the extra power consumed due to retransmission of IoT data packet and bad communication channel management in a congested IoT network. We propose a spectrum based power management solution that scans channel conditions when needed and utilizes the lowest congested channel for IoT packet routing. It also effectively measured power consumed in idle, connected, paging and synchronization status of a standard IoT device in a congested IoT network. In our proposed solution, a Freescale Freedom Development Board (FREDEVPLA) is used for managing channel related parameters. While supervising the congestion level and coordinating channel allocation at the FREDEVPLA level, our system configures MAC and Physical layer of IoT devices such that it provides the outstanding power utilization based on the operating network in connected mode compared to the basic IoT standard. A model has been set up and tested using freescale launchpads. Test data show that battery life of IoT devices using proposed spectrum based power management increases by at least 30% more than non-spectrum based power management methods embedded within IoT devices itself. Finally, we compared our results with the basic IoT standard, IEEE802.15.4. Furthermore, the proposed system saves lot of memory for IoT devices, improves overall IoT network performance, and above all, decrease the risk of losing data packets in communication. The detail analysis in this paper also opens up multiple avenues for further research in future use of channel scanning by FREDEVPLA board.


Focaal ◽  
2009 ◽  
Vol 2009 (54) ◽  
pp. 89-96 ◽  
Author(s):  
Projit Bihari Mukharji

The reflections in this article were instigated by the repeated and brutal clashes since 2007 between peasants and the state government’s militias—both official and unofficial—over the issue of industrialization. A communist government engaging peasants violently in order to acquire and transfer their lands to big business houses to set up capitalist enterprises seemed dramatically ironic. De- spite the presence of many immediate causes for the conflict, subtle long-term change to the nature of communist politics in the state was also responsible for the present situation. This article identifies two trends that, though significant, are by themselves not enough to explain what is happening in West Bengal today. First, the growth of a culture of governance where the Communist Party actively seeks to manage rather than politicize social conflicts; second, the recasting of radical political subjectivity as a matter of identity rather than an instigation for critical self-reflection and self-transformation.


2018 ◽  
Vol 67 (1) ◽  
pp. 91-103
Author(s):  
László Simon ◽  
Marianna Makádi ◽  
György Vincze ◽  
Zsuzsanna Uri ◽  
Katalin Irinyiné Oláh ◽  
...  

A small-plot long-term field fertilization experiment was set up in 2011 with willow (Salix triandra x Salix viminalis ’Inger’) grown as an energy crop in Nyíregyháza, Hungary. The brown forest soil was treated three times (in June 2011, May 2013, May 2016) with municipal biocompost (MBC), municipal sewage sludge compost (MSSC) or willow ash (WA), and twice (June 2011, May 2013) with rhyolite tuff (RT). In late May – early June 2016 urea (U) and sulphuric urea (SU) fertilizers were also applied to the soil as top-dressing (TD). These fertilizers and amendments were also applied to the soil in 2016 in the combinations; MBC+SU, RT+SU, WA+SU and MSSC+WA. All the treatments were repeated four times. In July 2016 the highest nitrogen concentrations in willow leaves were measured in the U (3.47 m/m%) and SU (3.01 m/m%) treatments, and these values were significantly higher than the control (2.46 m/m%). An excess of nitrogen considerably reduced the Zn uptake of the leaves, with values of 39.5 μg g-1 in the U treatment, 53.4 μg g-1 in the SU treatment, and 63.5 μg g-1 in the control. All other amendments or TDs, except for WA, enhanced the specific potassium concentrations in willow leaves compared to the control. No significant quantities of toxic elements (As, Ba, Cd, Pb) were transported from soil amendments or TDs to the willow leaves. In July 2016 the most intensive leaf chlorophyll fluorescence was observed in the MSSC and MSSC+WA treatments.


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
R Mistry

Abstract Introduction Scarring is the final common pathway for healing within the skin. Scars can be itchy, painful, tight, and disfiguring. Despite advances in surgery there is currently no reliably effective treatment for reducing or preventing scarring. The primary aim of this research is to assess the currently available models for scarring and evaluate/further develop the utility of current assessment tools, in an effort to design a pilot randomised control trial (RCT) for silicone gel treatment of scars. Method A systematic review of scar models in humans and animals. Examination of currently used subjective and objective scar assessment tools in a plastic surgery scar clinic. A retrospective cohort study assessing long-term scar outcomes in paediatric burn patients. Results Limitations and drawbacks of many existing methods to assess scar treatments were found. No statistically significant difference in long-term scarring outcomes was found between paediatric burns patients treated surgically versus conservatively. A RCT for silicone gel sheeting in the treatment of scars was set up and successful in recruitment. Conclusions Here, we have demonstrated difficulties in establishing a scientific scar treatment model; and created a pilot study that will help to provide high-quality evidence for the efficacy of silicone gel sheeting as a treatment for scars.


2021 ◽  
Vol 12 ◽  
pp. 215013272098771
Author(s):  
S. M. Rashed Ul Islam ◽  
Tahmina Akther ◽  
Md. Abdullah Omar Nasif ◽  
Sharmin Sultana ◽  
Saif Ullah Munshi

SARS-CoV-2 initially emerged in Wuhan, China in late 2019. It has since been recognized as a pandemic and has led to great social and economic disruption globally. The Reverse Transcriptase Real-Time Polymerase Chain Reaction (rtRT-PCR) has become the primary method for COVID-19 testing worldwide. The method requires a specialized laboratory set up. Long-term persistence of SARS-CoV-2 RNA in nasopharyngeal secretion after full clinical recovery of the patient is regularly observed nowadays. This forces the patients to spend a longer period in isolation and test repeatedly to obtain evidence of viral clearance. Repeated COVID-19 testing in asymptomatic or mildly symptomatic cases often leads to extra workload for laboratories that are already struggling with a high specimen turnover. Here, we present 5 purposively selected cases with different patterns of clinical presentations in which nasopharyngeal shedding of SARS-CoV-2 RNA was observed in patients for a long time. From these case studies, we emphasized the adoption of a symptom-based approach for discontinuing transmission-based precautions over a test-based strategy to reduce the time spent by asymptomatic and mildly symptomatic COVID-19 patients in isolation. A symptom-based approach will also help reduce laboratory burden for COVID-19 testing as well as conserve valuable resources and supplies utilized for rtRT-PCR testing in an emerging lower-middle-income setting. Most importantly, it will also make room for critically ill COVID-19 patients to visit or avail COVID-19 testing at their convenience.


Author(s):  
Saubhagya Kumar Jena ◽  
Lipsa Mishra ◽  
Sushree Samiksha Naik ◽  
Shahnawaz Khan

AbstractObjectiveTo explore the perception on PCOS and its prevalence among adolescent and young women.MethodsThe study was conducted over 2 year period in a tertiary care teaching hospital from Eastern India. A pre-formed, validated questionnaire was used to record the details. Descriptive statistics was used to report the findings.ResultsOf 965 young patients with mean (SD) age 20.64 (2.1) years, 27 (2.79 %) were aware of an entity called PCOS. Awareness among adolescents with PCOS was 25.9 % (7/27). All aware patients belonged to the urban sector with professionals constituting around 48%, of which 11% were students. The major source of information among aware patients was from doctors (40.7%), and friends and Internet (25.9%); rest being from books, newspapers, and teachers. Majority (70%) were aware that diet restriction and exercise were the primary modalities of treatment, whereas, only 3.7% knew about the role of contraceptive pills in PCOS.ConclusionsAwareness regarding PCOS among the young women is very low mainly in the rural set up. Doctors and health staffs should play a major role in spreading awareness of the entity to prevent long term complications.


2021 ◽  
Author(s):  
Otmane Khalfaoui ◽  
laurent Dezileau ◽  
Jean-Philippe Degeai ◽  
Maria Snoussi

<p>The Atlantic coast of Morocco has been confronted with several marine submersion events. Historically, some of them have resulted in significant economic and human damage, including the 1755 AD event (known as the tsunami of Lisbon). This indicates the need to implement adaptation and mitigation strategies, based on long-term studies of these extreme events to deduce their spatial and temporal variability. Using two cores (TAH17-1 and TAH17-3) collected from the Tahaddart estuary (NW of Morocco), this work aims to identify deposits, set up by these high energy events during the mid to late Holocene period. The sedimentological, geochemical and geochronological analyses carried out on these geological archives show two fining-upward sequences, indicating a progressive change from a purely sandy marine facies, between 6500 and 3500 BP, to another finer and more terrigenous one. The fine sedimentation, which has dominated in the estuary during the last 3500 years, has facilitated the recording of several marine submersion events in the form of isolated sandy layers. Chronological data have made it possible to date four deposits. Two (1-E1 and 3-E1) were put in place about 250 years ago, which corresponds, according to historical records, to the 1755 AD Lisbon tsunami. Two other deposits (1-E13 and 1-E14) are dated around 3200 BP and represent unknown submersion events on the Moroccan Atlantic coast.</p>


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