Using identification method to modelling short term luminous flux depreciation of LED luminaire to reducing electricity consumption.

Reducing electricity consumption is currently one of the most significant global issues. Luminaires and light sources are characterised by relatively low rated power values. However, due to their high number, they account for a noticeable share of the total volume of electricity consumption. When the LED lamp/luminaire is switched-on, it emits a higher luminous flux and receives more power from the mains supply than when the thermal conditions have stabilized. This phenomenon is called short-term luminous flux depreciation. The lighting design process on photometric data obtained for steady-state operating conditions is based, on once the luminous flux has stabilized. Therefore, it is possible to design the control algorithm of the LED luminaire in such a way as to reduce this phenomenon, which will result in measurable savings of electrical energy. The paper proposes the use of a method to identify the short-term luminous flux depreciation of LED luminaires. The model was then used to simulate the operation of a control algorithm limiting the phenomenon of short-term luminous flux depreciation.

3-Methylglutaconic aciduria, a frequent but underrecognized finding in carbamoyl phosphate synthetase I deficiency.

The urea cycle disorder carbamoyl phosphate synthetase I deficiency is an important differential diagnosis in the encephalopathic neonate. This intoxication type inborn error of metabolism often leads to neonatal death or severe and irreversible damage of the central nervous system, even despite appropriate treatment. Timely diagnosis is crucial, but can be difficult on routine metabolite level. Here, we report ten neonates from eight families (finally) diagnosed with CPS1 deficiency at three tertiary metabolic centres. In seven of them the laboratory findings were dominated by significantly elevated urinary 3-methylglutaconic acid levels which complicated the diagnostic process. Our findings are both important for the differential diagnosis of patients with urea cycle disorders and also broaden the differential diagnosis of hyperammonemia associated with 3-methylglutaconic aciduria, which was earlier only reported in TMEM70 and SERAC1 defect.