• Title/Summary/Keyword: Trace analysis

Search Result 1,357, Processing Time 0.034 seconds

Development of Analytical Technology Using the HS-SPME-GC/FID for Monitoring Aromatic Solvents in Urine

  • Lee, Mi-Young;Chung, Yun Kyung;Shin, Kyong-Sok
    • Mass Spectrometry Letters
    • /
    • v.4 no.1
    • /
    • pp.18-20
    • /
    • 2013
  • Headspace solid phase micro-extraction gas chromatography/flame ionization detection (HS-SPME-GC/FID) method was compared with headspace gas chromatography/mass selective detection (HS-GC/MS). Organic solvent-spiked urine as well as urine samples from workspace was analyzed under optimal condition of each method. Detection limit of each compound by HS-SPME-GC/FID was $3.4-9.5{\mu}g/L$, which enabled trace analysis of organic solvents in urine. Linear range of each organic solvent was $10-400{\mu}g/L$, with fair correlation coefficient between 0.992 and 0.999. The detection sensitivity was 4 times better than HS-GC/MS in selected ion monitoring (SIM) mode. Accuracy and precision was confirmed using commercial reference material, with accuracy around 90% and precision less than 4.6% of coefficient of variance. Among 48 urine samples from workplace, toluene was detected from 45 samples in the range of $20-324{\mu}g/L$, but no other solvents were found. As a method for trace analysis, SPME HS GC/FID showed high sensitivity for biological monitoring of organic solvent in urine.

Odor Classification and Source Analysis using Pseudo Inverse (Pseudo Inverse를 이용한 악취분류와 악취원 분석)

  • Yu, Suk-Hyun;Park, Sang-Jin;Koo, Youn-Seo;Kwon, Hee-Yong
    • Journal of Korea Multimedia Society
    • /
    • v.13 no.8
    • /
    • pp.1171-1182
    • /
    • 2010
  • In this paper, odor classification and source analysis methods are proposed to trace odor sources in th air at the specific place and period. It is necessary to generate representative patterns in order to classify the various odors efficiently. We, therefore, create 67 kinds of odor representative patterns measured from the main sources. considering the air mixed with various odors, several mixed representative patterns for odor sources are generated with the combination of two or three different odors. In addition, the weight of odor sources for an odor from a civil complaint region are computed using pseudo inverse method. As a result, we can trace and identify the odor sources to lead to a specific odor and the contribution of each source. The results of this study will be useful for settling the civil complaint related with odors.

Biochemical and Trace Mineral Analysis of Silajit Samples From Pakistan

  • Shafiq Muhammad Imtiaz;Nagra Saeed Ahmad;Batool Nayab
    • Nutritional Sciences
    • /
    • v.9 no.3
    • /
    • pp.190-194
    • /
    • 2006
  • Silajit is a blackish brown pitch-like gummy substance. It is an important Unani and Ayurvedic medicine widely used in the treatment of many diseases and as nutritional supplement It is found in certain mountainous regions of Pakistan, Afghanistan, India, Nepal, Australia and Russia. Silajit samples of Pakistani origin were obtained from different sources and analyzed for their physical characteristics and biochemical & elemental composition. X-ray diffraction studies on Silajit showed that it is an amorphous substance and has no crystalline structure. Also, pH studies of Silajit (2 g/L of water) indicated that it was slightly acidic in nature and ranged from 3.45 to 7.23. Conductivity ranged from 157.7 to 330. Amino acid analysis revealed that Silajit contained lysine and alanine in higher amounts than all other amino acids and ranged from 1456 to 2240 and 68 to $1615{\eta}mole/g$, respectively. Mean concentration of arsenic, mercury, cadmium, lead, copper and zinc was 73.15, 104.92, 0.496, 3.89, 4.04 and 17.23 ppm, respectively. Silajit samples were also analyzed for calcium, potassium and sodium.

Preliminary Study on the Elemental Quantification of in Ambient Liquid Samples of Microliter Volume Using the In-air Micro-PIXE Technique

  • Ma, Chang-Jin;Lim, Cheol-Soo;Sakai, Takuro
    • Asian Journal of Atmospheric Environment
    • /
    • v.11 no.1
    • /
    • pp.54-60
    • /
    • 2017
  • Quantifying the trace elements in infinitesimal ambient liquid samples (e.g., single raindrop, cloud/fog water, and the soluble fraction extracted from the particles collected for a short time) is an important task for understanding formation processes, heating/cooling rates, and their health hazards. The purpose of this study is to employ an in-air micro PIXE system for quantitative analysis of the trace elements in a thimbleful of reference liquid sample. The bag type liquid sample holder originally designed with $10{\mu}m$ thick $Mylar^{(R)}$ film retained the original shape without any film perforation and apparent peaks of film blank by the end of the analysis. As one of tasks to be solved, the homogeneity of the elemental distribution in liquid reference species was verified by the X-ray line profiles for several references. It was possible to resolve the significant peaks for whole target elements corresponding to the channel number of micro-PIXE spectrum. The calibration curves for the six target elements (Si, S, Cl, Fe, Ni, and Zn) in standard solutions were successfully plotted by concentration (ppm) and ROI of interest net counts/dose (nC).

A Study on Kinematic Analysis and Stitch Performance Evaluation of Industrial Lock Stitch Sewing Machine (공업용 본봉 제봉기의 기구해석 및 봉황성능평가에 관한 연구)

  • 전경진;신대영;홍창섭
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1994.10a
    • /
    • pp.288-297
    • /
    • 1994
  • The sewing machine is one of the oldest machine that has ever used, which is related with clothes' life. Modern sewing machines are divided into three groups by the sititch character, which are the lock stitch sewing machine group, the over lock sewing machine group and the specical sewing machine group. The lock stitch sewing machine have being used more than any others, which is also good model to study. This work is part of the improvement of an industrial lock stitch(ILS) sewing machine's design. The research objectives are the kinematic analysis and evaluations of stitch performance. The feed dog and the needle extreme's motion, which are important two part's motion in the sewing machine, are characterized by the stitch process and the needle trace. The needle trace is formulated as the stitch spacing, the stitch spacing's ratio(the static characteristic), and the stitch's phase difference(the dynamic characteristic). The tested ILS sewing machine is evaluated as a good static characteristic and a bad dynamic characteristic. Namely, a stitch spacing's ratio is 0.01~0.063(mm/mm) and a stitch's phase difference ratio is 0.06~0.13(mm/mm).

  • PDF

A Error Analysis of Scanning for Topological Data Construction in Geographic Information Systems (GIS의 지형자료 구축을 위한 SCANNING 방법의 오차분석)

  • Yoo, Hwan-Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.10 no.2
    • /
    • pp.37-44
    • /
    • 1992
  • Although scanners are much more expensive than other input devices expect for some low quality devices, raster scanner and vectorizing softwares have been used and will be used as a means for the data entry in GIS. In this study, the accuracy of raster data and vectorizing in data entry by scanning technology, the coverage generation are investigated. As a result, the deterioration of spatial resolution can be improved by using the histogram analysis and the line enhancement when we scan a map at a lower dpi. It is to be desired that a raster scanner dpi is selected 150 dpi or 200 dpi among five densities (75 dpi, 150, dpi, 200 dpi, 300 dpi, 400 dpi) in view of the storage of raster data and the RMSE of coverage generation. Also, it was very important role of the choice of trace parameters to trace raster data in the vectorizing procedure.

  • PDF

Analysis of Cadmium in Blood using SH(Smith-Hieftje) and $D_2$ Arc Background Correction Methods by Graphite Furnace Atomic Absorption Spectrophotometer (Smith-Hieftje(SH) 및 $D_2$ 바탕보정장치가 부착된 흑연로 원자흡수분광법을 이용한 혈액 중 카드뮴 분석)

  • Lee, Seok Ki;Kim, Poong Zag;Joung, Chang Ung
    • Journal of the Korean Chemical Society
    • /
    • v.40 no.3
    • /
    • pp.196-201
    • /
    • 1996
  • The analysis of trace cadmium in blood by using 10 folds diluted samples with 1% Triton X-100 and Fork platform tube at the ashing temperature of 500$^{\circ}C$ has been performed by GFAAS. In this study, good analytical results were obtained from peak area and peak height methods. The detection limits of SH and $D_2$ arc background correction are 0.02 ng/mL and 0.01 ng/mL, respectively. Relative standard deviation is within 5% at the level of 1.0 ng/mL.

  • PDF

Analysis Framework using Process Mining for Block Movement Process in Shipyards (조선 산업에서 프로세스 마이닝을 이용한 블록 이동 프로세스 분석 프레임워크 개발)

  • Lee, Dongha;Bae, Hyerim
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.39 no.6
    • /
    • pp.577-586
    • /
    • 2013
  • In a shipyard, it is hard to predict block movement due to the uncertainty caused during the long period of shipbuilding operations. For this reason, block movement is rarely scheduled, while main operations such as assembly, outfitting and painting are scheduled properly. Nonetheless, the high operating costs of block movement compel task managers to attempt its management. To resolve this dilemma, this paper proposes a new block movement analysis framework consisting of the following operations: understanding the entire process, log clustering to obtain manageable processes, discovering the process model and detecting exceptional processes. The proposed framework applies fuzzy mining and trace clustering among the process mining technologies to find main process and define process models easily. We also propose additional methodologies including adjustment of the semantic expression level for process instances to obtain an interpretable process model, definition of each cluster's process model, detection of exceptional processes, and others. The effectiveness of the proposed framework was verified in a case study using real-world event logs generated from the Block Process Monitoring System (BPMS).

The Contribution of Social Media Value to Company's Financial Performance: Empirical Evidence from Indonesia

  • MIQDAD, Muhammad;OKTAVIANI, Siska Aprilia
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.8 no.1
    • /
    • pp.305-315
    • /
    • 2021
  • This article aims to explore the contribution of social media value to a company's financial performance in a digital environment economy since the awareness of companies and investors in the use of social media opens up new mechanisms for disseminating information. Quantitative method is used in this study with Multivariate Analysis of Variance as the analysis tool. The data used is secondary data gathered from Indonesia Stock Exchange (IDX) using 308 companies as samples. In the multivariate test, four kinds of multivariate significance tests were carried out, namely Pillai Trace, Wilk Lambda, Hotelling's Trace, and Roy's Largest Root. It was found that social media value has a small contribution in the difference of the level of profitability and the value of the company in Indonesia, but it doesn't have a contribution to the difference of the level of liquidity. The contribution was an implication of online Word of Mouth (WOM) motives which are interrelated with signal theory and as additional information for investors in relation to single-person decision theory. This study provides an insight into the importance of social media management considering that the world of digital economy will continue to develop, so companies in Indonesia need to take advantage of these opportunities.

The Role of Forensic Engineering in the Diagnosis of Electrocution Fatalities: Two Case Reports

  • Mohammad Alqassim;Raneem Ewiss;Hamdah Al Ali
    • Safety and Health at Work
    • /
    • v.14 no.1
    • /
    • pp.124-130
    • /
    • 2023
  • The increase in the number of fatal electric accidents over the years has escalated the demand for specialized forensic engineers to determine their relevant technical causes. Likewise, the complexities associated with identifying the causes of electrocution accidents have prompted the General Department of Forensic Science and Criminology at Dubai Police to adopt a new methodology to diagnose electrocution accidents, consisting of an approach that involves medico-legal examination, electrical diagnosis of the evidence, and trace evidence analysis. This paper will discuss the application of the adopted method in further detail by unfolding two case reports. The first report outlines a case in which a worker got electrocuted at a construction site while attempting to turn on a lamp. The second case report involves the death of a technician in a workshop after trying to disconnect a washing machine from its plug. The methodology was utilized during the investigation of both cases, which were attended by the appointed forensic engineers and showed promising results.