On the other hand, the application of the dilation operator to an image produces an output image, which shows where the SE hits the objects in the image. All other MM operations can be expressed in terms of erosion and dilation [8]. For instance, the notion behind the opening operator is to dilate an eroded image in order to recover as much as possible of the eroded image. In contrast, the closing operator erodes a dilated image so as to recover the initial shape of image structures that have been dilated. The filtering properties of the opening and closing are based on the fact that, depending on the size and shape of the considered SE, not all structures from the original image will be recovered when these operators are applied. MM operations have found success in different application domains, including remote sensing [15].Although MM operators were originally defined for binary images, they have been extended to gray-tone (mono-channel) images by viewing these data as an imaginary topographic relief; in this regard, the brighter the gray tone, the higher the corresponding elevation [8]. It follows that, in grayscale morphology, each 2-D gray tone image is viewed as if it were a digital elevation model (DEM). In practice, set operators directly generalize to gray-tone images. For instance, the intersection �� (respectively,
The concept of pH was first introduced by S?rensen in 1909 [1]. Over the past century, Gemcitabine manufacturer measurements of pH have become arguably the most numerous analytical measurements made [2-5]. Examples of areas where pH measurements are frequently made involve chemical and drug manufacture, blood gas determinations, effluent discharge control, food and drink processing and water purity. It is therefore essential to ensure the validity and traceability of these measurements [6, 7].Primary pH standard values are determined from an electrochemical cell arrangement known as the ��Harned cell�� which does not contain a liquid junction and relies on well characterised Ag/AgCl reference electrodes for operation [8]. The Harned cell has the potential to be a primary method for the absolute measurement of pH, providing that it can conform to the accepted definition of a primary method [9] that requires a methodology and operation that can be completely described and understood, for which a complete uncertainty statement can be written down in terms of SI units.The long and short term stability of Ag/AgCl reference electrodes is of paramount importance for accurate pH measurement as a small change in the potential of a Ag/AgCl reference electrode makes a significant contribution to the measurement uncertainty. Therefore in an attempt to select a set of similar reference electrodes and reduce the risk of changes in potential between electrodes, it is common practice to reject individual reference electrodes which differ from the average of the group by more than 100 micro volts [4].