ABSTRACT
Coatings deposited on a material surface are effective way of changing its surface properties. For increasing or decreasing radiation heat transfer, coatings with high or low emissivity are used. Measurement of spectral emissivity is a fundamental step to effective use of coatings for this application. Up to now the measurement methods are focused on bulk samples and mainly opaque ones. Here we present a method enabling measurement of emissivity of semitransparent coating itself, although it is deposited on a substrate. The method is based on measurement of transmittance and reflectance using an integration sphere system and Fourier transform infrared (FTIR) spectrometer for samples with two different coating thicknesses deposited on transparent substrates. Measured transmittance of the coating indicates spectral regions of potential emissivity differences using different substrates. From all the measured values, spectral emissivity can be characterized for different coating thicknesses. The spectral range of the method is from 2 µm to 20 µm. The measurement is done at ambient temperature enabling measurement of samples sensitive to heating like biomedical or nanocoatings. The method was validated on known bulk samples and an example of semitransparent coating measurement is shown on high-temperature high-emissivity coating.
ABSTRACT
OBJECTIVE: Diabetes in pregnancy is associated with increased risks of maternal as well as foetal complications. METHODS: Retrospective data on 96 women and their 96 newborns were anonymously statistically analysed to assess pregnancies of type 1 diabetes (T1D) women managed in our hospital in past nine years. The outcomes of the neonates were divided into three categories according to the clinical status, presence of congenital abnormalities and infant's treatment. RESULTS: We found out that the outcome of newborn infants associated with maternal HbA1c before gestation as well as during the whole course of pregnancy (p < 0.02 for all). Surprisingly, neonatal outcome was strongly associated with the maternal BMI (p < 0.05). In our model, a lowering of BMI by one grade led to an 18% increase in the chance that the newborn will have no health problems. We did not observe an important worsening of chronic diabetic complications in mothers; however, regarding maternal clinical status, we found that preeclampsia occurrence was strongly and independently connected to HDL level (p < 0.01). CONCLUSION: Our data demonstrate that lower pregestational BMI could substantially improve T1D mothers' pregnancy outcome. Lower HDL levels in T1D mothers during pregnancy correlate with higher risk of preeclampsia development.
