Improvements have been in previous least-squares regression analyses of infrared spectra for the quantitative estimaiton of conecntratons of multicomponent mixtures. Spectral baselines are fitted by least-squares methods, and overlaping spectral features are accouted for in the fitting procedure. Selection peaks above a threshold value reduces computation time and data storage requirements. Four weighted least-squares methods incorporating different baseline assumptions were investigated using FT-IR spectra of the three pure xylene ismers and their mixtures. By fitting only regions of the spectra that follow Beer's Law, accurate resulta can be obtained using three of the fitting methods even when baselines are not corected to zero. Accurate results can also be obtained using one of the fits even in the presence of Beer's Law deviations. This is a consequence of pooling the weighted results for each spectral peak such that the greatest weighting is automatically given to those peaks that adhere to Beer's Law. It has been shown with the xylene spectra that semiquantitative results can be obtained even when all the major components are not known or when expected components are not present. This improvements over previous methods greatly expands the utility of quantitative least-squares analyses.
- CIC Photonics, Inc.
- Application of new least-squares methods for the quantitative ...
Return on Investment Using MANTECH Multi-Parameter Analysis Systems - Case Study
Since 2008 Eurofins has been using MANTECH systems at various facilities around the world. Their first system ran 200,000 samples in five years. The unit analyzed 7 different parameters per sample and operated 24 hours/day, 7 days/week. This generated €5,000,000 in revenue. Their initial investment was €60,000. The system discussed in this case study analyses pH, conductivity, alkalinity (speciated), turbidity and absolute color from a single 50ml tube. The cost per sample was 0.91 Euros. After factoring...
Sound recording to characterize outdoor tap water use events
Obtaining disaggregated water use at the home typically involves expensive smart metering. In this study, water use events at the outdoor tap were captured using recorded sound. Outdoor taps at 10 homes were fitted with small-sized microphones and digital sound recorders. Sound files recorded over a 1-month period were used in the analysis. In the preliminary analysis, a human operator browsed through the sound recordings, picking out tap use events based on visually recognizable waveform and spectrogram features,...
Monitoring of typical pumps and aerator in a water treatment plant
The wireless vibration network of Wi-care system consists of the communication between three components; the transmitter, the range extender and the receiver. The transmitter is fixed on the machine and transmits the vibration and the temperature data at the measurement point. The second element of the Wi-care wireless network is the range extender, its function is to transmit vibration and temperature data over long distances to the receiver. The third part of the communication path is the receiver/gateway which...
TOC analyzer for airports
During winter, de-icing processes at airports necessitate storm water and de-icing water management. Especially due to adhesive (sticky) substances, strongly fluctuating concentrations and a lot of chemicals, the monitoring systems itself must be tailor-made to fight this water analysis challenge. LAR `s QuickTOCairport is an application-specific online total organic carbon (TOC) analyzer that meets these tough requirements. The sample is injected via a robot-driven injection system to the oven – without...
Model-based methodology for the design of optimal control strategies in MBR plants
This paper proposes a model-based methodology that allows synthesising the most appropriate strategies for optimising the operation of wastewater treatment plants (WWTPs). The methodology is applied with the aim of maximising the nitrogen removal in membrane bioreactors (MBRs). The proposed procedure is based on a systematic approach composed of four steps. First, a sensitivity analysis of the input variables is carried out in order to obtain a first assessment of the potential for operational improvements. Then,...