Limited research exists on the comparison of pulsed shortwave diathermy (PSWD) and instrument assisted soft tissue mobilization (IASTM). In addition, minimal research exists on the AcuForce® 7.0 and none of it examines the effects of the AcuForce® 7.0 on range of motion (ROM). This study focused on the comparison of PSWD and IASTM on hamstring flexibility and perceived patient comfort. Twenty male students, faculty, and staff (age 24.5 ± 5.7 years) participated. Active knee extension ROM with the hip flexed at 90º was measured before and after the intervention. Perceived patient comfort was measured after the intervention. The results showed significant increases in ROM in all subjects (p = 0.013). However, there were no significant differences between groups (p = 0.079). Also, there were no significant differences in perceived patient comfort. The results of this study support hamstring flexibility can be increased with the use of either PSWD or the AcuForce® 7.0.

This thesis deals with the basic theory of the electromagnetic field in the first part and the field interactions with biological tissues. Than describes shortwave diathermy as a technique used for purposes of medical treatment. The aim is to built a model of tissue heating in shortwave diathermy in COMSOL Multiphysics environment, so there is included a description of the programming environment, including the mathematical method that COMSOL uses for calculations. The output of the whole work is a model of the lower limb in the knee part and display the results after his diathermy heating.

This master’s thesis describes RF power amplifier design. The designed amplifier has been built. The first three chapters outline basics about radio frequency amplifiers. The basic theory needed for amplifier implementation is also described there. In the fourth chapter the power amplifier is designed. The design is based on the theoretical knowledge. Complete amplifier contains RF preamplifier, power amplifier and filters. The OrCAD PSpice, Ansoft Designer SV and EAGLE programs have been used for the design and verification of some sections of circuits. Measurement results of the built amplifier are in the fifth chapter. This thesis contains also the draft for laboratory exercise.

The knowledge of temperature and emissivity of the receiver are both critical for a solar tower power plant, in order to guarantee an efficient operation of the thermal receiver on the one hand, while monitoring any degradation of the receiver coating on the other hand. To make these measurements, a new thermographic system is currently being developed, using a multispectral camera working in the short wavelength infrared spectrum. This system applies the principle of ratio thermography, using a couple of narrow bandpass filters centered on atmospheric water absorption bands, at 1.4 and 1.9 µm, to reduce the influence of solar reflections on the measurement signal, making it sensitive to atmospheric conditions. In this thesis, a batch simulation approach is used to identify boundary atmospheric and operating conditions necessary to achieve temperature errors below 2 %, minimizing the influence of solar reflection. Furthermore the influence of atmospheric parameters on the sensitivity of ratio thermography is analyzed, in particular the validity of the gray body assumption. It is shown that the atmosphere has a critical influence on the measurement accuracy. A humid atmosphere and/or high zenith angle is necessary for making accurate measurements. Furthermore only receiver temperatures above 450◦C could be measured for the current system configuration, regardless of atmospheric conditions. Assuming negligible solar reflections, the validity of the gray body assumption is shown to be sensitive to the precipitable water vapor. A model based atmospheric compensation is therefore required to further improve the accuracy of ratio thermography.

Recent evidence suggests that heat, a major byproduct of exercise, may be the mediator for many vascular adaptations that come from exercise. Thus, heat therapy that increases muscle temperature in a comparable way to exercise may be an advantageous alternative for enhancing cardiovascular health in individuals where treatment with exercise is either not possible or undesired. PURPOSE: Compare the effects of exercise and heat training on resistance artery function at rest and during exercise. METHODS: Thirty-five (18 female) healthy, untrained subjects completed a 6-week training program utilizing either high intensity knee extension (KE) exercise (40 min), localized heat therapy (pulsed shortwave diathermy; 120 min), or a sham heat therapy protocol (120 min). We randomly selected 8 subjects from each group to have a temperature probe inserted into their vastus lateralis muscle during one of their training sessions to evaluate the effect of the interventions on muscle temperature. We assessed resistance artery function at rest with the passive leg movement technique (PLM) prior to and after completion of the training protocols. We assessed peak exercise blood flow (KE peak flow) and peak power output (KE peak power) during the KE graded exercise test and prior to and after completion of the training protocols. RESULTS: Peak muscle treatment temperature was significantly different between all groups with those assigned to the diathermy heat training exhibiting a higher peak temperature (~40.80°C) than those in the exercise (~37.75°C, P < 0.001) and sham training groups (~36.10°C, P < 0.001). KE peak flow during PLM increased to the same extent (P = 0.625) in both the exercise (~10.5% increase, P = 0.009) and heating groups (~8.5% increase, P = 0.044); but tended to decrease in the sham group (P = 0.087). KE peak flow increased in the exercise group (~19%, P = 0.005), but did not change in the heat group (P = 0.523) and decreased in the sham group (~7%, P = 0.020). Peak vascular conductance during KE significantly increased by ~25% in the exercise (P = 0.030) and heat (P = 0.012) groups. KE peak power increased in the exercise group by ~27% (P = 0.001) but did not significantly change in the heat (P = 0.175) and sham groups (P = 0.111). The change in vascular function, assessed via PLM, showed a correlation with both ∆KE peak flow (R = 0.55, P = 0.01) and ∆KE peak power (R = 0.56, P = .010). Likewise, ∆KE peak flow showed a strong association with ∆KE peak power (R = 0.64, P < 0.001). CONCLUSION: Localized diathermy heat treatment increased resistance artery function at rest and during exercise to a similar extent as single-leg KE exercise training but did not yield significant improvements in performance. Thus, heat training mimics some but not all of the benefits associated with exercise and may be used to replace exercise treatment to some extent.

No description available.

The ionosphere is the conducting part of the upper atmosphere that plays a significant role in trans-ionospheric high frequency (HF, 3-30 MHz) radiowave propagation. Solar activities, such as solar flares, radiation storms, coronal mass ejections (CMEs), alter the state of the ionosphere, a phenomenon known as Sudden Ionospheric Disturbance (SID), that can severely disrupt HF radio communication links by enhancing radiowave absorption and altering signal frequency and phase. The Super Dual Auroral Radar Network (SuperDARN) is an international network of low-power HF coherent scatter radars distributed across the globe to probe the ionosphere and its relation to solar activities. In this study, we used SuperDARN HF radar measurements with coordinated spacecraft and riometer observations to investigate statistical characteristics and the driving mechanisms of various manifestations of solar flare-driven SIDs in HF observations. We begin in Chapter 2 with a statistical characterization of various effects of solar flares on SuperDARN observations. Simultaneous observations from GOES spacecraft and SuperDARN radars confirmed flare-driven HF absorption depends on solar zenith angle, operating frequency, and intensity of the solar flare. The study found flare-driven SID also affects the SuperDARN backscatter signal frequency, which produces a sudden rise in Doppler velocity observation, referred to as the ``Doppler flash'', which occurs before the HF absorption effect. In Chapter 3, we further investigate the HF absorption effect during successive solar flares and those co-occurring with other geomagnetic disturbances during the 2017 solar storm. We found successive solar flares can extend the ionospheric relaxation time and the variation of HF absorption with latitude is different depending on the type of disturbance. In Chapter 4, we looked into an inertial property of the ionosphere, sluggishness, its variations with solar flare intensity, and made some inferences about D-region ion-chemistry using a simulation study. Specifically, we found solar flares alter the D-region chemistry by enhancing the electron detachment rate due to a sudden rise in molecular vibrational and rotational energy under the influence of enhanced solar radiation. In Chapter 5, we describe a model framework that reproduces HF absorption observed by riometers. This chapter compares different model formulations for estimating HF absorption and discusses different driving influences of HF absorption. In Chapter 6, we have investigated different driving mechanisms of the Doppler flash observed by SuperDARN radars. We note two particular findings: (i) the Doppler flash is predominantly driven by a change in the F-region refractive index and (ii) a combination of solar flare-driven enhancement in photoionization, and changes in the zonal electric field and(or) ionospheric conductivity reduces upward ion-drift, which produces a lowering effect in the F-region HF radiowave reflection height. Collectively, these research findings provide a statistical characterization of various solar flare effects on the ionosphere seen in the HF observations, and insights into their driving mechanisms and impacts on ionospheric dynamics. / Doctor of Philosophy / The Earth's ionosphere, extending from about 60 km to 1000 km in altitude, is an electrically charged region of the upper atmosphere that exists primarily due to ionization by solar X-ray and extreme ultraviolet radiation. The ionosphere is an effective barrier to energetic electromagnetic (EM) radiation and charged particles originating from the Sun or any other extraterrestrial sources and protect us against harmful space radiation. High frequency (HF, 3-30 MHz) radio communication, broadly used for real-time medium and long-range communication, is strongly dependent on the state of the ionosphere, which is susceptible to solar activities, such as solar flares, solar energetic particles (SEPs), and coronal mass ejections (CMEs). Specifically, we are interested in the impacts of solar flares. In this study, we use Super Dual Auroral Radar Network (SuperDARN) HF radars, ground-based riometers, and coordinated spacecraft observations to investigate the driving mechanisms of various space weather impacts on the ionosphere and radiowave propagation following solar flares. We begin in Chapter 2 with a characterization of various kinds of ionospheric disturbances manifested in SuperDARN backscattered signal following solar flares. Specifically, we characterized HF absorption effects and frequency anomalies experienced by traveling radiowaves, also known as Shortwave Fadeout (SWF) and Sudden Frequency Deviations (SFDs), respectively. In SuperDARN HF radar observations, SFDs are recorded as a sudden enhancement in Doppler velocity, which is referred to as the ``Doppler flash''. In Chapter 3, we investigate a special event study that elucidates the nonlinear physics behind HF absorption caused by multiple simultaneous solar flares and flares co-occurring with SEPs and CMEs. In Chapter 4, we explore an inertial property of the ionosphere, known as sluggishness, and its dependence on solar flares can provide important information about the chemical proprieties of the ionosphere. We found that the enhanced solar radiation during a solar flare increases the molecular vibrational and rotational energy that in turn enhances the electron detachment rate and reduces ionospheric sluggishness. In Chapter 5, we describe a framework to estimate HF absorption observed by riometers following solar flares. We analyze the influence of different physical parameters, such as collision frequency and electron temperature, on HF absorption. In Chapter 6, we delved into the physical processes that drive the Doppler flash in SuperDARN observations following solar flares. We find, (i) the Doppler flash is predominately driven by change in the F-region refractive index and (ii) a combination of solar flare-driven enhancement in photoionization, and change in zonal electric field and(or) ionospheric conductivity reduces upward ion-drift, which produces a lowering effect in the F-region HF radiowave reflection height. Taken together, these research findings provide new insights into solar flare impacts on the ionosphere and could be used to improve forecasting of ionospheric space weather disturbances following solar flares.

by Wong Chun Kau, Jolly. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 84-88). / ABSTRACT --- p.1 / ACKNOWLEDGEMENT --- p.3 / Chapter 1. --- INTRODUCTION --- p.7 / Chapter 1.1 --- Land Mobile Radio (LMR) Communications / Chapter 1.2 --- Paramilitary Communications Security / Chapter 1.3 --- Voice Scrambling Methods / Chapter 1.4 --- Digital Voice Encryption / Chapter 1.5 --- Digital Secure LMR / Chapter 2. --- DESIGN GOALS --- p.20 / Chapter 2.1 --- System Concept and Configuration / Chapter 2.2 --- Operational Requirements / Chapter 2.2.1 --- Operating conditions / Chapter 2.2.2 --- Intelligibility and speech quality / Chapter 2.2.3 --- Field coverage and transmission delay / Chapter 2.2.4 --- Reliability and maintenance / Chapter 2.3 --- Functional Requirements / Chapter 2.3.1 --- Major system features / Chapter 2.3.2 --- Cryptographic features / Chapter 2.3.3 --- Phone patch facility / Chapter 2.3.4 --- Mobile data capability / Chapter 2.4 --- Bandwidth Requirements / Chapter 2.5 --- Bit Error Rate Requirements / Chapter 3. --- VOICE CODERS --- p.38 / Chapter 3.1 --- Digital Speech Coding Methods / Chapter 3.1.1 --- Waveform coding / Chapter 3.1.2 --- Linear predictive coding / Chapter 3.1.3 --- Sub-band coding / Chapter 3.1.4 --- Vocoders / Chapter 3.2 --- Performance Evaluation / Chapter 4. --- CRYPTOGRAPHIC CONCERNS --- p.52 / Chapter 4.1 --- Basic Concepts and Cryptoanalysis / Chapter 4.2 --- Digital Encryption Techniques / Chapter 4.3 --- Crypto Synchronization / Chapter 4.3.1 --- Auto synchronization / Chapter 4.3.2 --- Initial synchronization / Chapter 4.3.3 --- Continuous synchronization / Chapter 4.3.4 --- Hybrid synchronization / Chapter 5. --- DIGITAL MODULATION --- p.63 / Chapter 5.1 --- Narrowband Channel Requirements / Chapter 5.2 --- Narrowband Digital FM / Chapter 5.3 --- Performance Evaluation / Chapter 6. --- SYSTEM IMPLEMENTATION --- p.71 / Chapter 6.1 --- Potential EMC Problems / Chapter 6.2 --- Frequency Planning / Chapter 6.3 --- Key Management / Chapter 6.4 --- Potential Electromagnetic Compatibility (EMC) Problems / Chapter 7. --- CONCLUSION --- p.80 / LIST OF ILLUSTRATIONS --- p.81 / REFERENCES --- p.82 / APPENDICES --- p.89 / Chapter I. --- Path Propagation Loss(L) Vs Distance (d) / Chapter II. --- Speech Quality Assessment Tests performed / by Special Duties Unit (SDU)

Dust-climate interaction over the Middle East and North Africa (MENA) has long been studied, as it is the "dustiest" region on earth. However, the quantitative and qualitative understanding of the role of dust direct radiative effect on MENA climate is still rudimentary. The present dissertation investigates dust direct radiative effect on MENA climate during summer with a special emphasis on the sensitivity of climate response to dust shortwave absorption, which is one of the most uncertain components of dust direct radiative effect. Simulations are conducted with and without dust radiative effect, to differentiate the effect of dust on climate. To elucidate the sensitivity of climate response to dust shortwave absorption, simulations with dust assume three different cases of dust shortwave absorption, representing dust as a very efficient, standard and inefficient shortwave absorber. The non-uniformly distributed dust perturb circulations at various scales. Therefore, the present study takes advantage of the high spatial resolution capabilities of an Atmospheric General Circulation Model (AGCM), High Resolution Atmospheric Model (HiRAM), which incorporates global and regional circulations. AMIP-style global high-resolution simulations are conducted at a spatial resolution of 25 km. A significant response in the strength and position of the local Hadley circulation is predicted in response to meridionally asymmetric distribution of dust and the corresponding radiative effects. Significant responses are also found in regional circulation features such as African Easterly Jet and West African Monsoon circulation. Consistent with these dynamic responses at various scales, the tropical rainbelt across MENA strengthens and shifts northward. Similarly, the temperature under rainbelt cools and that over subtropical deserts warms. Inter-comparison of various dust shortwave absorption cases shows that the response of the MENA tropical rainbelt is extremely sensitive to the strength of shortwave absorption. Further analyses reveal that the sensitivity of the rainbelt stems from the sensitivity of the multi-scale circulations that define the rainbelt. Importantly, the summer precipitation over the semi-arid strip south of Sahara, including Sahel, increases in response to dust radiative effect. The maximum response and sensitivity are predicted over this region. The sensitivity of the responses over Sahel, especially that of precipitation, is comparable to the mean state. Locally, the precipitation increase reaches up to 50% of the mean, while dust is assumed to be a very efficient absorber. As the region is characterized by the "Sahel drought", the predicted precipitation sensitivity to the dust loading over this region has a wide-range of socioeconomic implications. The present study, therefore, suggests the importance of reducing uncertainty in dust shortwave absorption for a better simulation and interpretation of the MENA climate in general, and of Sahel in particular.

In this paper we will deal involving short-wave radio station and its control by the sequencer. Mostly it will be a time delay of the PA and the antenna switching relay in the transmitter (TX) to receiver (RX) side. Time delays will be controlled programmatically using ATmega 16 microprocessor, which will form part of the main control sequencer. The delay will set the total time of keying in messages, when we take into account the loss due to delayed first symbol. Keying will be done from several sources, among the main sources will be ordered from keying the radio, telegraph keys, and PC. The transmission signal is used amplitude modulation (SSB) in the CB zone.