Highly Efficient Double-Layer Diffraction Microstructures Based on New Plastics and Molded Glasses

Within the framework of rigorous diffraction theory, the maximum possible incidence angles of radiation on two-layer sawtooth relief-phase microstructures in the visible (0.4 ≤ λ ≤ 0.7 μm) spectral range are compared. Optical materials for the layers of these microstructures are selected from a database of 47 plastics and 165 molded glasses. It is shown that when the ratio of the spatial period of the microstructure to the effective depth of the relief is greater than 20, the achievable angles within which the diffraction efficiency exceeds 0.95 lie in a wide range from 18.5° to 40.5° for single-relief structures and 7.5° to 22.3° for structures with two internal reliefs. The best results for purely plastic microstructures are obtained when the plastic CMT and the indium tin oxide nanocomposite in polymethylmethacrylate are used.

A pilot cohort study assessing the feasibility of complete revascularization with balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

Balloon pulmonary angioplasty improves prognosis by alleviating pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension, even with incomplete revascularization. However, hypoxia or the requirement for pulmonary vasodilators often remain even after pulmonary hypertension relief. With this cohort study, we aimed to examine whether complete revascularization by additional balloon pulmonary angioplasty on residual lesions, even after pulmonary hypertension relief, could resolve hypoxia or the requirement for pulmonary vasodilators. During complete revascularization with balloon pulmonary angioplasty in 42 patients with chronic thromboembolic pulmonary hypertension, we investigated therapeutic effects at baseline (T1), pulmonary hypertension relief phase (T2), and at 6 months post-final balloon pulmonary angioplasty (T3). The pulmonary hypertension relief phase was defined as the first time that a mean pulmonary artery pressure ≤ 25 mmHg or pulmonary vascular resistance ≤ 240 dyn-s/cm5 was reached in right heart catheterization before balloon pulmonary angioplasty. The partial pressure of oxygen increased progressively over T1, T2, and T3 (59.2±8.5, 69.0±9.7, and 80.0±9.5 mmHg, respectively; P<0.001 T2 vs. T3). Minimum oxygen saturation levels during the 6-minute walk distance test were 87% (81‒89%), 88% (84‒92%), and 91% (89‒93.3%), respectively (P<0.001 T2 vs. T3), with gradual increase in the 6-minute walk distance (346±125 m, 404±90 m, 454±101 m, respectively; P<0.001 T2 vs. T3). The percentages of patients using pulmonary vasodilators (54.8%, 45.2%, 4.8%, respectively; P<0.001 T2 vs. T3) and requiring oxygen therapy (26%, 26%, 7%, respectively; P = 0.008 T2 vs. T3) decreased significantly without hemodynamic exacerbation or major complications. Despite the discontinuation of pulmonary vasodilators, mean pulmonary artery pressure improved (36.0 [31.0‒41.3], 21.4±4.2, 18.5±3.6 mmHg, respectively; P<0.001 T2 vs. T3). Complete revascularization with balloon pulmonary angioplasty beyond pulmonary hypertension relief benefits patients with chronic thromboembolic pulmonary hypertension; it may improve oxygenation and exercise capacity, and reduce the need for pulmonary vasodilators and oxygen therapy.

Functional Clothing for Natural Disaster Survivors

Natural disasters occur in increasing intensity and frequency. When disasters occur, several humanitarian agencies are mobilized to provide relief aid. Donated clothing is deployed as a response to donors’ perceptions of need; however, these donations may be climatically and culturally unsuitable, creating a glut of clothing that not only undermines the domestic economy but also consumes scarce resources. This research investigates survivors’ clothing needs during the relief phase of natural disasters in order to improve current aid protocol. The study is accomplished by needs analysis focus groups with survivors, including interviews with relief aid volunteers and aid administrating agencies. Using these data, a prototype is designed using the Functional, Expressive and Aesthetic design framework as proposed by Lamb and Kallal (1992). It will provide groundwork for humanitarian agencies and future academic study in the field of functional apparel research for disaster situations.

Functional Clothing for Natural Disaster Survivors

Natural disasters occur in increasing intensity and frequency. When disasters occur, several humanitarian agencies are mobilized to provide relief aid. Donated clothing is deployed as a response to donors’ perceptions of need; however, these donations may be climatically and culturally unsuitable, creating a glut of clothing that not only undermines the domestic economy but also consumes scarce resources. This research investigates survivors’ clothing needs during the relief phase of natural disasters in order to improve current aid protocol. The study is accomplished by needs analysis focus groups with survivors, including interviews with relief aid volunteers and aid administrating agencies. Using these data, a prototype is designed using the Functional, Expressive and Aesthetic design framework as proposed by Lamb and Kallal (1992). It will provide groundwork for humanitarian agencies and future academic study in the field of functional apparel research for disaster situations.

Влияние побочных дифракционных порядков на качество изображения, формируемого рефракционно-дифракционной оптической системой среднего ИК диапазона

The image formed by a refractive-diffractive optical system for the mid-IR range (3–5 µm) is investigated. The effect of the side diffraction orders of the diffractive corrector on the quality of this image near the optical axis is estimated both by computer simulation and experimentally. It is shown that the side diffraction orders of a single-layer sawtooth relief-phase microstructure will not noticeably affect the image quality under the following condition: the diffraction efficiency of the microstructure at the central wavelength of the operating spectral range is close to unity, and within the entire indicated spectral range it does not drop below 0.67.

Регистрация высокочастотных рельефно-фазовых голографических структур на фотоматериале ПФГ-04

A new variant of processing photographic plates for holography based on dichromed gelatin PFG-04 (produced by JSC "Slavich Company", Pereslavl-Zalessky) for the manufacture of high-frequency relief–phase holographic gratings with a spatial frequency up to 1500 mm-1 is proposed. The technology is based on the selective destructive effect of short-wave UV radiation on gelatin and subsequent etching of the layer with various reagents. For the first time, relief-phase high-frequency holographic gratings with a maximum diffraction efficiency of 67% were obtained on PFG-04 photographic plates.

Исследование механизма записи мультиплексных брэгговских дифракционных решеток с планарным вводом-выводом оптического излучения в стеклянных световодах

The article describes the recording of multiplex Bragg diffraction gratings for optical lightguide displays using an optical replication method with a phase mask. The lightguides in the experiment were made of photo-thermo-refractive glass. A photoresist relief-phase diffraction grating was used as a phase mask. Based on angle multiplexing, a compact augmented reality display was implemented.