Effect of standby mode operation of some household appliances on disturbance voltage and current in frequency range of 9–150 kHz produced by other equipment in low voltage network
Most household appliances commercially available today on the market are equipped with the inverter technology favoring to its smaller size, advanced performance, and energy efficient. Notwithstanding its benefits, unfortunately, this technology may introduce current disturbance according to its relevant frequency switching and eventually degrades power quality. The switching frequency of inverter for household appliances is generally in the range of 9-150 kHz causing the disturbance and may influence the working performance of other appliances. The voltage and current disturbances in the frequency range of 9-150 kHz are not completely covered and currently subject to standardization work. Some household appliances can be operated in standby mode in order to display the time and setting information or to allow them to operate quickly even though it also gives a drawback regarding to its energy consumed. This study investigates the characteristics of standby mode operation of some appliances and its effect to the voltage and current disturbance in the frequency range of 9-150 kHz. The result shows that the standby mode operation of particular household appliances can filter and significantly reduce the voltage and current disturbance in the low voltage (LV) installation network for specific frequency in the range of 9-150 kHz.
The effect of mains voltage level variations on the disturbances produced by household appliances in the frequency range of 9–150 kHz
Many household appliances today are equipped with inverter technology which may generate disturbances in the frequency range within 9–150 kHz related to the frequency switching used. Since the regulations covering the disturbance in this frequency range are not applicable for all household appliances, the efforts to limit the disturbance produced by some household appliances are less. The voltage level in the low voltage mains network may vary over the time due to many aspects including load variations. This mains voltage variation may affect the disturbance produced by appliances in the frequency range within 9–150 kHz due to their working principles. The study is focused on observing the effect of mains voltage level variation to the disturbance produced by household appliances in the frequency range within 9–150 kHz. The characteristics of disturbance behavior related to the mains voltage level variation are useful to analyze and investigate the disturbance occurred in the network when many appliances are operated simultaneously which may be causing the voltage drop in the network. In this study, the mains voltage level supplied to the appliances is adjusted from 239V to 206V with the step voltage of 3V. The result shows that the disturbances produced by some household appliances are affected by the mains voltage level. The relationship between the disturbance produced and the mains voltage level variations are unique for each appliance.
The Alzheimer's Disease Home Hospice Knowledge Scale: development, validity and reliability.
BACKGROUND
Several instruments are available to assess knowledge about hospice care, but none specifically address knowledge about home hospice for persons with Alzheimer's disease (AD).


AIM
To develop and validate the Alzheimer's Disease Home Hospice Knowledge Scale (AD-HHK-S).


METHODS
A total of 107 Israeli family caregivers of persons with dementia (mean age=71.2; 73% female) participated in the study.


RESULTS
The AD-HHK-S included 28 true/false items assessing 3 areas of knowledge: knowledge about hospice, knowledge about home hospice, and knowledge about home hospice for AD. Good internal reliability was found, with Cronbach alpha ranging from 0.72 to 0.85. Good face, construct and predictive validity were found.


CONCLUSIONS
The AD-HHK-S proved to be a valid and reliable tool to assess knowledge about hospice care in the area of AD. It might provide an effective tool for palliative care nurses to communicate with family caregivers of persons with AD at the end of life.