OPTICAL INVESTIGATIONS OF PHASE TRANSITIONS IN (NH4) 2 SbF5 CRYSTAL

Results of optical thickness and refractive indices measurements for (NH4)2SbF5 crystal in the temperature range 100-310 K are presented. The measurements were done with interference method using He-Ne laser (λ = 632.8 nm). At To = 292 K and Ta = 168 K two continuous phase transitions with critical indices /3 1 = 0.38 and β2 ≤ 0.57 were observed. Additional anomaly of temperature changes of interference order with maximum at Ta 132 K were found. This anomaly resembles a diffused transition. Temperature-averaged values of derivatives of refractive indices dn g /dT = -3.3 x 10 -5 K and dn m /dT = -2.9 x 10 -5 K -1 evidenced a decrease in optical anisotropy (birefringence) along the b-axis on heating run

Factors that impact on access to water and sanitation for older adults and people with disability in rural South Africa: An occupational justice perspective

Limited access to water and sanitation is a risk to health, dignity, and ability to engage in occupations. This article aims to: 1) discuss the current and historical factors affecting access to water and sanitation in rural South Africa, and 2) explore the occupational implications of water access, particularly for older adults and people with disability in rural South Africa. A literature review was carried out through searching JSTOR, Scopus, and MEDLINE databases and using framework analysis to interpret the retrieved documents. This paper also reports a thematic analysis of semi-structured interviews, conducted in 2012 in a rural area of South Africa. Environmental, political, social-economic and attitudinal factors were identified as impacting water access and occupation, in both the documentary analysis and the semi-structured interviews. Due to South Africa’s history, injustice has occurred in the forms of occupational apartheid and occupational deprivation. We argue that supply systems must enable people to easily access more water than is essential for survival, so that people can participate in meaningful and productive occupations. Therefore, access to water should be considered part of an occupational right. Recognising this right will be an integral step in ensuring that water supplies are improved to support better livelihoods, and to achieve economic and social empowerment, and quality of life for all, in line with many of the United Nations’ new Sustainable Development Goals

Crystal optical method for temperature measuring

A new crystal optical method for temperature measuring based on the sign inversion of birefringence ∆n and temperature dependence of ∆n(T) is substantiated. The respective characteristics of some crystals are presented, which confirm good metrological and exploitation properties of the method. It is noted that the method solves some problems which arise in thermometry based on thermoelectricity and thermoresistance. The proposed method also gives better possibilities for measuring the temperature in hard conditions (in the region of high electric and magnetic fields, rotating workpieces etc.).Обгрунтовується новий кристалооптичний метод вимірювання температури на базі інверсії знаку двозаломлення ∆n та температурної залежності ∆n(T). Наведено відповідні характеристики деяких кристалів, які підтверджують високі метрологічні та експлуатаційні характеристики методу. Відзначається, що метод розв’язує деякі проблеми, що виникають перед термометрією на базі термоелектрики і термоопору, а також відкриває більш високі можливості вимірювань температури у важких умовах (в області високих електричних та магнітних полів, деталей, що обертаються і ін.)