On-Line Monitoring of Solutes in Dialysate Using Absorption of Ultraviolet Radiation: Technique Description

2002 ◽  
Vol 25 (8) ◽  
pp. 748-761 ◽  
Author(s):  
I. Fridolin ◽  
M. Magnusson ◽  
L.-G. Lindberg
Keyword(s):  
Potassium Phosphate ◽  
Individual Treatment ◽  
Uv Absorbance ◽  
Hemodialysis Session ◽  
Sodium Calcium ◽  
Radiation Technique ◽  
On Line ◽  
Spent Dialysate ◽  
Molecular Sizes ◽  
Set Up

Purpose The aim of this work was to describe a new optical method for monitoring solutes in a spent dialysate using absorption of UV radiation. Method The method utilises UV-absorbance determined in the spent dialysate using a spectrophotometrical set-up. Measurements were performed both on collected dialysate samples and on-line. During on-line monitoring, a spectrophotometer was connected to the fluid outlet of the dialysis machine, with all spent dialysate passing through a specially-designed cuvette for optical single-wavelength measurements. The concentrations of several substances of various molecular sizes, electrical charge, transport mechanism, etc. were determined in the dialysate and in the blood using standard laboratory techniques. The correlation coefficient between UV-absorbance of the spent dialysate and concentration of the substances in the spent dialysate and in the blood was calculated from data based on the collected samples. Results The obtained on-line UV-absorbance curve demonstrates the possibility to follow a single hemodialysis session continuously and to monitor deviations in the dialysator performance using UV-absorbance. The experimental results indicate a very good correlation between UV-absorbance and several small waste solutes removed such as urea, creatinine and uric acid in the spent dialysate and in the blood for every individual treatment at a fixed wavelength of 285 nm. Moreover, a good correlation between the UV-absorbance and substances like potassium, phosphate and β2-microglobulin was obtained. The lowest correlation was achieved for sodium, calcium, glucose, vitamin B12 and albumin. Conclusions A technique for on-line monitoring of solutes in the spent dialysate utilising the UV-absorbance was developed. On-line monitoring during a single hemodialysis session exploiting UV-absorbance represents a possibility to follow a single hemodialysis session continuously and monitor deviations in dialysis efficiency (e.g. changes in blood flow and clearance). The UV-absorbance correlates well to the concentration of several solutes known to accumulate in dialysis patients indicating that the technique can be used to estimate the removal of retained substances.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

WWW.TELD.NET: Online Courseware Engine for Teaching by Examples and Learning by Doing

2001 ◽  
Vol 29 (3) ◽  
pp. 219-235 ◽  
Author(s):  
G. Q. Huang ◽  
B. Shen ◽  
K. L. Mak
Keyword(s):  
Teaching And Learning ◽  
Virtual Classroom ◽  
Learning By Doing ◽  
General Purpose ◽  
Project Based Learning ◽  
Course Materials ◽  
Summative Assessments ◽  
On Line ◽  
Set Up ◽  
Electronic Delivery

TELD stands for “Teaching by Examples and Learning by Doing.” It is an on-line courseware engine over the World Wide Web. There are four folds of meanings in TELD. First, TELD represents a teaching and learning method that unifies a number of contemporary methods such as Problem-Based Learning (PBL) in medical education, Project-Based Learning (PBL) in engineering education, and Case Method (CM) in business education. Second, TELD serves as a Web server for hosting teaching and learning materials especially based on the TELD method. A variety of on-line facilities are provided for editing and uploading course materials such as syllabus, schedule, curriculum, examples of case study, exercises of mini-project, formative and summative assessments, etc. Third, TELD is a courseware search engine where educators are able to register their course materials and search for materials suitable for a particular course. In contrast with general-purpose search engines, TELD is set up for the special purpose of education. Therefore, the time and efforts spent on surfing are expected to be reduced dramatically. Finally, TELD is an on-line virtual classroom for electronic delivery of electronic curriculum materials. In addition to providing the lecture notes, TELD not only provides discussion questions for conducting in-class discussions and homework as formative assessment but also provides facilities for students to plan and submit their group work. This article presents an overview of the TELD courseware engine together with its background and underlying philosophy.

scholarly journals Optimum three-point linkage set up for improving the quality of soil spectra and the accuracy of soil phosphorus measured using an on-line visible and near infrared sensor

2009 ◽  
Vol 103 (1) ◽  
pp. 144-152 ◽  
Author(s):  
A.M. Mouazen ◽  
M.R. Maleki ◽  
L. Cockx ◽  
M. Van Meirvenne ◽  
L.H.J. Van Holm ◽  
...  
Keyword(s):  
Near Infrared ◽  
Soil Phosphorus ◽  
Infrared Sensor ◽  
On Line ◽  
Set Up

scholarly journals Political Culture and Treatment Strategies in the Nordic Countries

1996 ◽  
Vol 13 (5-6) ◽  
pp. 240-252
Author(s):  
Jan E. Grindheim
Keyword(s):  
Cultural Theory ◽  
Nordic Country ◽  
Methadone Treatment ◽  
Group Analysis ◽  
Treatment Strategies ◽  
Nordic Countries ◽  
Individual Treatment ◽  
Heroin Addicts ◽  
Set Up ◽  
Strong Control

Taking as a point of departure Mary Douglas' grid-group analysis, elaborated on by Aaron Wildavsky in his cultural theory, the article explores the variations in the development of methadone treatment programmes in the Nordic countries from the mid-1960's to the mid-1990's. In Sweden, the first Nordic country to start an organized treatment of heroin addicts with methadone in 1966, the strategy has been characterized by many rules and strong control. In Denmark, methadone treatment was introduced in the late 1960's, and it has been characterized by few rules and weak control. In Norway, methadone treatment was banned in 1979, after some years of occasional experiments. But the spread of HIV among intravenous heroin addicts altered the attitudes and a small and highly regulated program was set up in the beginnings of the 1990's. In Finland, the attitude has been reserved, primarily due to the small population of heroin addicts. The organized treatment in the 1970's was limited, and still is, as it was set up again in 1995. In spite of the differences, however, there are two main patterns of harmonization that should be noticed. Firstly, as a result of HIV, regulated programmes have been developed in all four countries in the 1990's. Secondly, the prevailing abstinence-oriented philosophy has been questioned and supplemented by harm-reducing measures. Today, there is a stronger tendency to treat drug addicts as clients in the Nordic welfare state, entitled to individual treatment in the countries' general health and welfare systems.

Portal imaging for evaluation of daily on-line set up errors and off-line organ motion for radiotherapy of carcinoma of prostate

1998 ◽  
Vol 42 (1) ◽  
pp. 293
Author(s):  
H. Alasti ◽  
C. Catton ◽  
N. Middlemiss ◽  
G. Ottewell ◽  
L. Green ◽  
...  
Keyword(s):  
Organ Motion ◽  
Portal Imaging ◽  
On Line ◽  
Set Up ◽  
Line Organ

Developing a Class Session Using Audio and Video Streaming

2000 ◽  
pp. 103-116
Author(s):  
Al Bento
Keyword(s):  
Video Streaming ◽  
Streaming Media ◽  
Media Streaming ◽  
Class Session ◽  
On Line ◽  
The Media ◽  
Media Server ◽  
Set Up ◽  
Streaming Media Server

The objective of this chapter is to describe the process of creating audio and video streaming content for an on-line class session1 . An overall model of audio and video streaming is described, together with the media streaming process, in the introduction. The next parts of the chapter discuss how to create a class session with audio streaming only, audio and graphics, and audio and video. The chapter ends with a discussion on how to set up a streaming media server.

scholarly journals Optical Method for Cardiovascular Risk Marker Uric Acid Removal Assessment during Dialysis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jana Holmar ◽  
Ivo Fridolin ◽  
Fredrik Uhlin ◽  
Kai Lauri ◽  
Merike Luman
Keyword(s):  
Uric Acid ◽  
Uv Absorbance ◽  
Chemical Laboratory ◽  
Dialysis Treatment ◽  
Mean Values ◽  
Double Beam ◽  
Multi Wavelength ◽  
Spent Dialysate ◽  
Treatment Procedures ◽  
Absorbance Spectra

The aim of this study was to estimate the concentration of uric acid (UA) optically by using the original and processed ultraviolet (UV) absorbance spectra of spent dialysate. Also, the effect of using several wavelengths (multi-wavelength algorithms) for estimation was examined. This paper gives an overview of seven studies carried out in Linköping, Sweden, and Tallinn, Estonia. A total of 60 patients were monitored over their 188 dialysis treatment procedures. Dialysate samples were taken and analysed by means of UA concentration in a chemical laboratory and with a double-beam spectrophotometer. The measured UV absorbance spectra were processed. Three models for the original and three for the first derivate of UV absorbance were created; concentrations of UA from the different methods were finally compared in terms of mean values and SD. The mean concentration (micromol/L) of UA was49.7±23.0measured in the chemical laboratory, and48.9±22.4calculated with the best estimate among all models. The concentrations were not significantly different (P≥0.17). It was found that using a multi-wavelength and processed signal approach leads to more accurate results, and therefore these approaches should be used in future.

On-Line Industrial 3D Measurement Techniques for Large Volume Objects

2005 ◽  
Vol 295-296 ◽  
pp. 423-430 ◽  
Author(s):  
Ji Gui Zhu ◽  
S.H. Ye ◽  
Xue You Yang ◽  
Xing Hua Qu ◽  
C.J. Liu ◽  
...  
Keyword(s):  
Large Volume ◽  
Measurement Techniques ◽  
Integrated System ◽  
3D Measurement ◽  
Digital Cameras ◽  
Combined Use ◽  
Small Set ◽  
Close Range ◽  
On Line ◽  
Set Up

Rapid progress in modern manufacturing demands for better measurement technique with on-line characteristics. This paper presents a systematic visual solution for on-line industrial 3D measurement. The solution comprises two parts, a multi-sensor visual inspecting station (MSVIS) and a digital close-range visual inspecting station (DCVIS). MSVIS is an integrated system with many sensors. It can meet the requirement of application with sparse measuring points distributed within a large volume. DCVIS only contains two digital cameras with one or more projectors. It has high relative accuracy and a small set up volume and is suitable for applications with dense measuring points. The combined use of MSVIS and DCVIS can provide a general solution for on-line industrial 3D measurement.

Rapid Photon-Excited Energy-Dispersive X-Ray Fluorescence Analysis for Solid and Liquid Mineralogical Samples

1975 ◽  
Vol 19 ◽  
pp. 267-272 ◽  
Author(s):  
W. Ratyński ◽  
J. Parus ◽  
J. Tys ◽  
A. Ciszek
Keyword(s):  
Fluorescence Analysis ◽  
Semiconductor Detectors ◽  
X Rays ◽  
Copper Ore ◽  
X Ray ◽  
Large Numbers ◽  
Important Benefit ◽  
Versatile Tool ◽  
On Line ◽  
Set Up

X-ray fluorescence spectroscopy is new becoming a tool in research and. industry. Semiconductor detectors are proving valuable in measuring fluorescent X rays, and so are providing a versatile tool for rapid multielement analysis of many types of samples. This paper will mainly be concerned with, different types of copper ore. An experimental setup has been designed to determine Cu, Fe and Pb of concentration ranging from 0.1 to 20, to 5, and to 4 percent, respectively, with analytical precision of 20% relative at 0.1% Cu, and 3% relative at 20% Cu. For excitation a 100 mCi Pu-238 source and/or a low power air-cooled X-ray tube were used. Data acquisition and “on-line” evaluation for each sample takes about 100 seconds. Electronics blocks and sub-systems used In the set-up are available commercially. The most important benefit to be obtained from the setup is the ability to provide precise, reproducible determinations of large numbers of samples day after day.

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