Does Gait with an Ankle Foot Orthosis Improve or Compromise Minimum Foot Clearance?

The purpose of this study was to investigate if the use of an ankle foot orthosis in passive mode (without actuation) could modify minimum foot clearance, and if there are any compensatory mechanisms to enable these changes during treadmill gait at a constant speed. Eight participants walked on an instrumented treadmill without and with an ankle foot orthosis on the dominant limb at speeds of 0.8, 1.2, and 1.6 km/h. For each gait cycle, the minimum foot clearance and some gait linear kinematic parameters were calculated by an inertial motion capture system. Additionally, maximum hip and knee flexion and maximum ankle plantar flexion were calculated. There were no significant differences in the minimum foot clearance between gait conditions and lower limbs. However, differences were found in the swing, stance and step times between gait conditions, as well as between limbs during gait with orthosis (p < 0.05). An increase in hip flexion during gait with orthosis was observed for all speeds, and different ankle ranges of motion were observed according to speed (p < 0.05). Thus, the use of an ankle foot orthosis in passive mode does not significantly hinder minimum foot clearance, but can change gait linear and angular parameters in non-pathological individuals.

Intracavity losses effect on mode-locking in a waveguide laser with graphene saturable absorber

A single-wavelength compact diode-pumped solid-state laser based on a single-mode waveguide with a diameter of 20 µm and graphene saturable absorber is presented in this work. The total reflection coefficient of the intracavity interferometer has a significant effect on the level of intracavity losses. By accurate controlling the intracavity losses a stable continuous wave passive mode-locking at wavelength of 1064 nm with a pulse repetition rate of 9.5 GHz was obtained.

Using the Telemetry System as an Element of the Engine Operation Monitoring System of UAS

The article presents an engineering approach that allows us to collect engine operation characteristics using built-in telemetry mechanisms, filled with the passive recording system. As a result of the development of the solution, the characteristics of the engine operation were obtained under real conditions, and the universal registration tool was built with a wider application than simply the registration of the engine operating parameters. The development of the solution allowed measurements to be obtained in a passive mode using a distributed architecture for engine monitoring and engine operation characteristics, which would be difficult to obtain and archive without logger production, especially during flight tests.

Artificial ground freezing using solar-powered thermosyphons

Thermosyphons are an artificial ground-freezing technique that has been used to stabilize permafrost since the 1960s. The largest engineered structure that uses thermosyphons to maintain frozen ground is the Trans Alaska Pipeline, and it has over 124,000 thermosyphons along its approximately 1300 km route. In passive mode, thermosyphons extract heat from the soil and transfer it to the environment when the air temperature is colder than the ground temperature. This passive technology can promote ground cooling during cold winter months. To address the growing need for maintaining frozen ground as air temperatures increase, we investigated a solar-powered refrigeration unit that could operate a thermosyphon (nonpassive) during temperatures above freezing. Our tests showed that energy generated from the solar array can operate the refrigeration unit and activate the hybrid thermosyphon to artificially cool the soil when air temperatures are above freezing. This technology can be used to expand the application of thermosyphon technology to freeze ground or maintain permafrost, particularly in locations with limited access to line power.

Passively mode-locked in Er-doped fiber laser based on semi-metallic InBi saturable absorber

Two-dimensional materials have drawn great interest for their applications in mode-locking owning to their unique optical nonlinearities. However, most of these 2D materials are semi-conductor. In this study, a new kind of semimetal Indium bismuth (InBi) is reported which is a topological nodal-line semimetal with exotic physical properties. The InBi nanomaterials was prepared through liquid phase exfoliation method with average thickness of 32.8 nm. The saturable absorption property was measured and passive mode-locking operation was achieved successfully in Er-doped fiber laser. It exhibits a modulation depth of 3.21%, a saturable intensity of 100 MW/cm2, and a pulse width about 859.97 fs corresponding to the central wavelength of 1562.27 nm and 3-dB bandwidth of 2.98 nm. The experimental results open a new avenue for the use of semimetals InBi nanomaterials in lasers and photonics applications.

Does Productive Mean Active? The Behavior of Occasional and Serial Academic Inventors in Patenting Processes

Previous literature has attributed differences in individuals’ inventive productivity to a range of environmental, organizational and individual traits. However, the behavior of individuals with different inventive productivity has not been empirically explored in detail. Based on interviews with twenty Swedish academic inventors of diverse patenting experience, this paper analyses how serial and occasional inventors acted in patent initiation, patent application and subsequent patent management for specific inventions. Two modes of behavior are identified: passive and active. Individuals’ inventive productivity was not aligned with behavioral mode, with both modes of behavior exhibited by occasional as well as serial academic inventors. Individual academic inventors also varied in mode of behavior across different patent processes. These findings suggest that commonly used volume-based classifications of academic inventors obscure potentially relevant behavioral differences. This insight has implications for contemporary policy and organizational practice. It also highlights the need for further investigation of when academic inventors assume an active or passive mode of behavior in processes of academic commercialization.