Infrared antenna-like structures in mammalian fur

Many small animals, including shrews, most rodents and some marsupials, have fur composed of at least four types of hair, all with distinctive and complex anatomy. A ubiquitous and unexplained feature is periodic, internal banding with spacing in the 6–12 µm range that hints at an underlying infrared function. One bristle-like form, called guard hair, has the correct shape and internal periodic patterns to function as an infrared antenna. Optical analysis of guard hair from a wide range of species shows precise tuning to the optimum wavelength for thermal imaging. For heavily predated, nocturnal animals the ability to sense local infrared sources has a clear survival advantage. The tuned antennae, spectral filters and waveguides present in guard hair, all operating at a scale similar to the infrared wavelength, could be a rich source of bio-inspiration in the field of photonics. The tools developed in this work may enable us to understand the other hair types and their evolution.

Download Full-text

Growth Response and Carbohydrate Status of Gibberellin-treated Spectral Filter-grown Chrysanthemum Plants

HortScience ◽

10.21273/hortsci.33.3.522c ◽

1998 ◽

Vol 33 (3) ◽

pp. 522c-522

Author(s):

Anuradha Tatineni ◽

Sonja L. Maki ◽

Nihal C. Rajapakse

Keyword(s):

Plant Height ◽

Growth Regulation ◽

Red Light ◽

Sucrose Phosphate Synthase ◽

Spectral Filter ◽

Spectral Filters ◽

Wide Range ◽

Ornamental Crops ◽

Carbohydrate Levels ◽

Carbohydrate Status

Interest in the use of non- (or less) chemical methods to reduce the height of ornamental crops has increased tremendously. Manipulation of greenhouse light quality is one alternative for plant growth regulation. We have shown that eliminating far-red light from the greenhouse environment with liquid CuSO4 spectral filters is effective in reducing the height of a wide range of plants though plant carbohydrate status is also altered under CuSO4 filter. In previous studies, application of GA3 reversed both the reduction of plant height and carbohydrate status of CuSO4 spectral filter grown plants. It has been proposed that GAs enhance the activity of the enzyme sucrose phosphate synthase to regulate carbohydrate levels. In the present study the role of exogenously applied GA19, GA1, and GA3 in overcoming the reduction of plant height and carbohydrate levels was investigated. Chrysanthemum plants were treated weekly for 4 weeks with saturating doses of GA19, GA1 and GA3 (25 μg) or the growth retardants paclobutrazol and prohexadione. GA1 was also applied with paclobutrazol and prohexadione to assess whether response to GAs is altered under CuSO4 filter. GA1 and GA3 promoted growth similarly under control or CuSO4 filter. GA19 was least effective in promoting growth under CuSO4 filter. In summary, these results suggest that gibberellin physiology is altered under spectral filters with the conversion of GA19 a possible point of regulation. The correlation between the carbohydrate status and the growth of the plants will be discussed.

Download Full-text

Comparison of Round Window Anatomy between Pediatric and Adult Population: A Perspective from Cochlear Implantation Surgery

Journal of Institute of Medicine ◽

10.3126/jiom.v42i3.37573 ◽

2020 ◽

Vol 42 (3) ◽

pp. 23-25

Author(s):

Rabindra B Pradhananga ◽

Bigyan R Gyawali ◽

Pabina Rayamajhi

Keyword(s):

Cochlear Implantation ◽

Adult Population ◽

Round Window ◽

Round Window Membrane ◽

Institute Of Medicine ◽

Statistical Association ◽

Complex Anatomy ◽

Wide Range ◽

Posterior Tympanotomy ◽

Round Window Niche

Introduction The round window is thought to be an ideal port for inserting electrodes during cochlear implantation. Considering its complex anatomy with an individual variation, this study aims to review the anatomy of round window based on the visibility of round window niche and round window membrane via posterior tympanotomy in pediatric and adult population who underwent cochlear implantation. MethodsThis was a retrospective observational study conducted at the Department of ENT-HNS, Institute of Medicine, Kathmandu, Nepal. Surgical notes of adult (>15 years) and pediatric cases (<15years) who underwent primary cochlear implantation from January 2015 to January 2018 were assessed for different grading of round window niche and round window membrane visibility via posterior tympanotomy. Cases with revision surgery and with incomplete documentation of intra-operative findings were excluded from the study. Statistical analysis was done using SPSS software version 25. We used Chi-square and Fisher’s exact tests to analyze the statistical association. ResultsType B round window niche (partially visible) was the most common variant seen in the pediatric group while in adults, both Type B (partially visible) and Type C (fully visible) round window niche were common. Compared to the adults, the pediatric group had good visibility of RWM. However, there was no statistical association between these observations. ConclusionThe round window has a wide range of anatomical variations with different levels of visibility of RWN and RWM in the different age groups. Although statistically insignificant, RWM visibility seemed to be better in pediatric cases compared to adults.

Download Full-text

Infrared: A Key Technology for Security Systems

Advances in Optical Technologies ◽

10.1155/2012/838752 ◽

2012 ◽

Vol 2012 ◽

pp. 1-15 ◽

Cited By ~ 8

Author(s):

Carlo Corsi

Keyword(s):

Thermal Imaging ◽

Energy Savings ◽

Low Cost ◽

Far Infrared ◽

Building Structures ◽

Security Systems ◽

Infrared Wavelength ◽

Security Applications ◽

Medical Diagnostic ◽

Military Systems

Infrared science and technology has been, since the first applications, mainly dedicated to security and surveillance especially in military field, besides specialized techniques in thermal imaging for medical diagnostic and building structures and recently in energy savings and aerospace context. Till recently the security applications were mainly based on thermal imaging as surveillance and warning military systems. In all these applications the advent of room temperature, more reliable due to the coolers avoidance, low cost, and, overall, completely integrable with Silicon technology FPAs, especially designed and tailored for specific applications, smart sensors, has really been impacted with revolutionary and new ideas and system concepts in all the infrared fields, especially for security applications. Lastly, the advent of reliable Infrared Solid State Laser Sources, operating up to the Long Infrared Wavelength Band and the new emerging techniques in Far Infrared Submillimeter Terahertz Bands, has opened wide and new areas for developing new, advanced security systems. A review of all the items with evidence of the weak and the strong points of each item, especially considering possible future developments, will be reported and discussed.

Download Full-text

Photoluminescence Imaging and Wavelength Analysis of Basal Plane Frank-Type Defects in 4H-SiC Epilayers

Materials Science Forum ◽

10.4028/www.scientific.net/msf.725.15 ◽

2012 ◽

Vol 725 ◽

pp. 15-18 ◽

Cited By ~ 4

Author(s):

Isaho Kamata ◽

Xuan Zhang ◽

Hidekazu Tsuchida

Keyword(s):

Basal Plane ◽

Partial Dislocation ◽

Near Infrared ◽

Stacking Fault ◽

Profile Measurement ◽

Infrared Wavelength ◽

Visible Light Range ◽

Wide Range ◽

Fault Region ◽

Narrow Emission

Frank-type defects on a basal plane have been investigated using photoluminescence (PL) imaging microscopy and wavelength profile measurement. A wide range of emission in the near-infrared wavelength was observed from a Frank partial dislocation at the edge of the defect, while a narrow emission at around the visible light range was obtained from a stacking fault region. The emissions from a stacking fault region of three kinds of basal plane Frank-type defects were confirmed to have different wavelengths depending on their stacking structures.

Download Full-text

Ion Beam Sputter Deposition of Refractory Metal Oxides

MRS Proceedings ◽

10.1557/proc-354-529 ◽

1994 ◽

Vol 354 ◽

Cited By ~ 1

Author(s):

B.E. Kempf ◽

H.W. Dinges ◽

A. PÖcker

Keyword(s):

Near Infrared ◽

Filter Design ◽

Ion Beam ◽

Optical Filter ◽

Pure Metal ◽

Ion Beam Sputtering ◽

Infrared Wavelength ◽

Wide Range ◽

Beam Sputtering ◽

Ion Beam Sputter Deposition

AbstractOxides of hafnium, niobium, tantalum, and zirconium are deposited by ion beam sputtering of the pure metal targets using CO2 as working gas. The resulting thin films are amorphous, featureless smooth and of excellent adherence to semiconductor substrates. Despite a certain content of carbon they are highly transparent in the visible and near infrared wavelength range as determined by spectroscopic ellipsometry. Their wide range of refractive indices makes them suitable for multilayer optical filter design.

Download Full-text

Medical thermography: capabilities and perspectives

Kazan medical journal ◽

10.17816/kmj2018-264 ◽

2018 ◽

Vol 99 (2) ◽

pp. 264-270 ◽

Cited By ~ 1

Author(s):

A M Morozov ◽

E M Mokhov ◽

V A Kadykov ◽

A V Panova

Keyword(s):

Human Body ◽

Thermal Imaging ◽

Diagnostic Method ◽

High Efficiency ◽

Clinical Medicine ◽

Modern Medicine ◽

Wide Range ◽

History Of ◽

Further Development ◽

Physical Principles

Medical thermography is a modern diagnostic method that is currently gaining popularity due to high informative value and non-invasiveness. The aim of the study was to review the capabilities and prospects of medical thermography in modern medicine. The analysis of domestic and foreign literature on the application of medical thermography methods for the period of 2012-2017 was performed. The article presents the capabilities of imaging in various fields of medicine, evaluates the prospects of further development of the method, advances and disadvantages of thermography were identified. It also provides the review of the application of medical infrared thermography in clinical medicine. The experience of thermography application in various medical fields was investigated: angiology, otolaryngology, surgery, neurology, obstetrics and gyenecology, etc. Apart from medical aspects of this topic, the article discusses the history of medical thermography as well as provides the physical principles of this method. At present, thermal imaging can solve a wide range of problems: determining the presence of changes in the human body, and, as a result, the probability of pathology development, monitoring the effectiveness of treatment and rehabilitation. Every year more and more studies are carried out, confirming the high efficiency, reliability and safety of thermography, thermographic screenings are suggested, that can be assumed as prediction of future method's popularity.

Download Full-text

High-Resolution Thermal Imaging and Analysis of TIG Weld Pool Phase Transitions

Sensors ◽

10.3390/s20236952 ◽

2020 ◽

Vol 20 (23) ◽

pp. 6952

Author(s):

Nicholas Boone ◽

Matthew Davies ◽

Jon Raffe Willmott ◽

Hector Marin-Reyes ◽

Richard French

Keyword(s):

Phase Transitions ◽

High Resolution ◽

Weld Pool ◽

Thermal Imaging ◽

Near Infrared ◽

Imaging System ◽

Travel Speed ◽

Tig Welding ◽

Infrared Radiance ◽

Wide Range

Tungsten inert gas (TIG) welding is a well-established joining process and offers the user flexibility to weld a large range of materials. Ultra-thin turbine tipping is an important application for TIG welding that is exceptionally challenging due to the wide range of variables needed to accurately control the process: slope times, arc control, travel speed, etc. We offer new insight into weld pool characteristics, utilizing both on- and off-line measurements of weld tracks. High-resolution thermal imaging yields spatially and temporally resolved weld pool phase transitions coupled with post-weld photographs, which gives a novel perspective into the thermal history of a weld. Our imaging system is filtered to measure a 10 nm window at 950 nm and comprises a commercial Sigma lens to produce a near-infrared (NIR) camera. The measured near-infrared radiance is calibrated for temperature over the range of from 800 to 1350 °C.

Download Full-text

OpenSim Moco: Musculoskeletal optimal control

PLoS Computational Biology ◽

10.1371/journal.pcbi.1008493 ◽

2020 ◽

Vol 16 (12) ◽

pp. e1008493

Author(s):

Christopher L. Dembia ◽

Nicholas A. Bianco ◽

Antoine Falisse ◽

Jennifer L. Hicks ◽

Scott L. Delp

Keyword(s):

Motion Tracking ◽

Model Fitting ◽

Assistive Device ◽

Direct Collocation ◽

Complex Anatomy ◽

Musculoskeletal Models ◽

Wide Range ◽

Walking Motion ◽

Tracking Motion ◽

Kinematic Loops

Musculoskeletal simulations are used in many different applications, ranging from the design of wearable robots that interact with humans to the analysis of patients with impaired movement. Here, we introduce OpenSim Moco, a software toolkit for optimizing the motion and control of musculoskeletal models built in the OpenSim modeling and simulation package. OpenSim Moco uses the direct collocation method, which is often faster and can handle more diverse problems than other methods for musculoskeletal simulation. Moco frees researchers from implementing direct collocation themselves—which typically requires extensive technical expertise—and allows them to focus on their scientific questions. The software can handle a wide range of problems that interest biomechanists, including motion tracking, motion prediction, parameter optimization, model fitting, electromyography-driven simulation, and device design. Moco is the first musculoskeletal direct collocation tool to handle kinematic constraints, which enable modeling of kinematic loops (e.g., cycling models) and complex anatomy (e.g., patellar motion). To show the abilities of Moco, we first solved for muscle activity that produced an observed walking motion while minimizing squared muscle excitations and knee joint loading. Next, we predicted how muscle weakness may cause deviations from a normal walking motion. Lastly, we predicted a squat-to-stand motion and optimized the stiffness of an assistive device placed at the knee. We designed Moco to be easy to use, customizable, and extensible, thereby accelerating the use of simulations to understand the movement of humans and other animals.

Download Full-text

Echocardiographic assessment of the right heart in adults: a practical guideline from the British Society of Echocardiography

Echo Research and Practice ◽

10.1530/erp-19-0051 ◽

2020 ◽

Vol 7 (1) ◽

pp. G19-G41 ◽

Cited By ~ 1

Author(s):

Abbas Zaidi ◽

Daniel S Knight ◽

Daniel X Augustine ◽

Allan Harkness ◽

David Oxborough ◽

...

Keyword(s):

Right Ventricular ◽

Response To Therapy ◽

British Society ◽

Right Heart ◽

Functional Changes ◽

Complex Anatomy ◽

Clinical Scenarios ◽

Wide Range ◽

The Right ◽

And Function

The structure and function of the right side of the heart is influenced by a wide range of physiological and pathological conditions. Quantification of right heart parameters is important in a variety of clinical scenarios including diagnosis, prognostication, and monitoring response to therapy. Although echocardiography remains the first-line imaging investigation for right heart assessment, published guidance is relatively sparse in comparison to that for the left ventricle. This guideline document from the British Society of Echocardiography describes the principles and practical aspects of right heart assessment by echocardiography, including quantification of chamber dimensions and function, as well as assessment of valvular function. While cut-off values for normality are included, a disease-oriented approach is advocated due to the considerable heterogeneity of structural and functional changes seen across the spectrum of diseases affecting the right heart. The complex anatomy of the right ventricle requires special considerations and echocardiographic techniques, which are set out in this document. The clinical relevance of right ventricular diastolic function is introduced, with practical guidance for its assessment. Finally, the relatively novel techniques of three-dimensional right ventricular echocardiography and right ventricular speckle tracking imaging are described. Despite these techniques holding considerable promise, issues relating to reproducibility and inter-vendor variation have limited their clinical utility to date.

Download Full-text

Airborne Mid-Infrared Cavity enhanced Absorption spectrometer (AMICA)

10.5194/amt-2021-28 ◽

2021 ◽

Cited By ~ 1

Author(s):

Corinna Kloss ◽

Vicheith Tan ◽

J. Brian Leen ◽

Garrett L. Madsen ◽

Aaron Gardner ◽

...

Keyword(s):

Atmospheric Measurements ◽

Mid Infrared ◽

Infrared Wavelength ◽

Enhanced Absorption ◽

Cavity Output ◽

Wide Range ◽

Research Aircraft ◽

Electronic Hardware ◽

Scientific Questions ◽

Absorption Spectrometer

Abstract. We describe the Airborne Mid-Infrared Cavity enhanced Absorption spectrometer (AMICA) designed to measure trace gases in situ on research aircraft using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS). AMICA contains two largely independent and exchangeable OA-ICOS arrangements, allowing for the simultaneous measurement of multiple substances in different infrared wavelength windows tailored to scientific questions related to a particular flight mission. Three OA-ICOS setups have been implemented to measure OCS, CO2, CO and H2O at 2050 cm−1, O3, NH3 and CO2 at 1035 cm−1, and HCN, C2H2 and N2O at 3331 cm−1. The 2050 cm−1 setup has been fully characterized in the lab and successfully used for atmospheric measurements during two campaigns with the research aircraft M55-Geophysica and one with the German HALO aircraft. Nominal measurement precision is 30 ppt for OCS, 1 ppm for CO2, 3 ppb for CO and 100 ppm for H2O. The 1035 and 3331 cm−1 arrangements have only partially been characterized and are still in development. The ~100 kg instrument with a typical in-flight power consumption of about 500 VA is dimensioned to fit into one 19 inch rack typically used for deployment inside the aircraft cabin. Its rugged design and a pressurized and temperature stabilized compartment containing the sensitive optical and electronic hardware also allow for deployment in payload bays outside the pressurized cabin even at high altitudes of 20 km. A sample flow system with two parallel proportional solenoid valves of different size orifices allows for precise regulation of cavity pressure over the wide range of inlet port pressures encountered between the ground and maximum flight altitudes. Sample flow on the order of 1 SLM maintained by an exhaust-side pump limits the useful time resolution to about 2.5 s (corresponding to the average cavity flush time).

Download Full-text