Feasibility of the quantification of respirable crystalline silica by mass on aerosol sampling filters using Raman microscopy

Airborne respirable crystalline silica (RCS) is a hazard that can affect the health of workers and more sensitive measurements are needed for the assessment of worker exposure. To investigate the use of Raman microscopy for the analysis of RCS particulate collected on filters, aliquots of quartz or cristobalite suspended in isopropanol were pipetted onto silver filters. Samples were measured by arbitrarily selecting positions along the filter and collecting spectra at 50 discrete points. The calculated limits of quantification on test samples were between ~0.066 – 0.161 µg and 0.106 – 0.218 µg for quartz and cristobalite respectively. Three respirable quartz calibration dusts (A9950, NIST 1878 and Quin B) with different mass median aerodynamic particle sizes obtained similar Raman response relationships per unit mass. The difference between NIST 1878 and Quin B was not significant (p=0.22). The intermediate measurement precision of replicate samples was 10 - 25% over the measured range for quartz (0.25 – 10 µg) and could potentially be improved. Results from mixtures of quartz and cristobalite were within 10 % of their theoretical values. Results from samples of 5 % quartz in calcite were close to the theoretical quartz mass. The upper measurement limit for a mixture of 20 % RCS in the light absorbing mineral hematite (Fe2O3) was 5 µg. These data show that Raman spectroscopy is a viable option for the quantification of the mass of respirable crystalline silica on filters with a limit of detection approaching 1/10th of that obtained with other techniques. The improvement in sensitivity may enable the measurement of particulate in samples from low concentration environments (e.g. inside a mask) or from miniature samplers operating at low flow rates

Pengaruh Penambahan Abu Ampas Tebu Terhadap Karakteristik Tanah Lempung Ekspansif Di Bojonegoro

Cara untuk memperbaiki karakteristik tanah adalah adalah stabilisasi. Zat aditif yang digunakan sebagai stabilisator dalam penelitian ini adalah abu ampas tebu. Sementara itu, tanah lempung ekspansif yang digunakan adalah tanah dari Desa Ngasem, Kabupaten Bojonegoro. Dalam penelitian ini, digunakan penambahan campuran dengan kadar abu ampas tebu sebesar 8%, 10%, 12%, dan 14% dari berat total campuran. Hasil dari penelitian ini menunjukkan bahwa dengan adanya penambahan kadar 14% abu ampas tebu, batas cair menurun sebesar 26,65%, batas plastis menurun sebesar 35,94%, batas susut meningkat sebesar 940,425%, indeks plastisitas menurun sebesar 19,72%, specific gravity menurun sebesar 7,35%, kadar air optimum meningkat sebesar 23,35%, dan berat isi kering tanah menurun sebesar 13,85% dari kondisi tanah asli. Nilai CBR maksimum didapatkan pada penambahan 12% abu ampas tebu yaitu meningkat sebesar 150,68% pada CBR tak terendam dan 95,34% pada CBR terendam. Nilai pengembangan minimum didapatkan pada penambahan 8% abu ampas tebu yaitu menurun sebesar 94,57%. Pada pengujian pengembangan bebas, nilai pengembangan menurun sebesar 15,35%. Dengan 4 hari pemeraman, nilai CBR tak terendam meningkat sebesar 2,38% dari nilai CBR tak terendam tanpa pemeraman, nilai CBR terendam meningkat sebesar 15,25% dari nilai CBR terendam tanpa pemeraman, dan nilai pengembangan menurun sebesar 77,68% dari nilai pengembangan tanpa pemeraman. Dengan 14 hari pemeraman, nilai CBR tak terendam menurun sebesar 11,13% dari nilai CBR tak terendam tanpa pemeraman, nilai CBR terendam menurun sebesar 12,46% dari nilai CBR terendam tanpa pemeraman, dan nilai pengembangan menurun sebesar 100,298% dari nilai pengembangan tanpa pemeraman. Berdasarkan hasil penelitian tersebut, dapat disimpulkan bahwa abu ampas tebu berpengaruh terhadap peningkatan nilai CBR, penurunan nilai pengembangan, serta karakteristik yang lainnya. Kata

朝鮮半島の将来に日本が貢献できることー米・日・朝鮮半島を勘案した日本の政策オプションとはー

articl

薫の聖性

departmental bulletin pape

Urinary arsenic excretion profiles and associated dietary factors in Japanese women from a coastal area in Chiba Prefecture

Background: Seafood and seaweed are part of the daily diet in Japan. Despite the essential nutrients they provide, concerns have been raised regarding the various forms of arsenic (As) in these foods. Because populations living in coastal areas have better access to seafood and seaweed, it is important to study their level of exposure to As from these dietary sources. Objectives: To examine the urinary As excretion profiles of and identify dietar y factors possibly associated with urinary As in Japanese women living in Choshi, a coastal area in Chiba prefecture. Methods: Daily nutrient intake was assessed by a diet history questionnaire (DHQ) and urinary As species were determined by high performance liquid chromatography–inductively coupled plasma-mass spectrophotometry (HPLC-ICP-MS) in 92 participants, followed by statistical analyses of the data obtained. Results: The geometric mean (GM) of total urinary As was 248.3μg/g creatinine (μg/g cre). The main As metabolites in the urine were the organic compounds arsenobetaine (AsBe)(GM 163.4μg/g cre) and dimethylarsinic acid (DMA; GM 49.6μg/g cre). The urinary inorganic As (iAs) concentration was low (GM 1.8μg/g cre). Analysis on toxicologically relevant As species showed that the proportion of iAs, monomethylarsonic acid (MMA), and DMA were 3.4％, 3.1％, and 91.6％ (GM), respectively, after removing AsBe and other As species from total As. Spearman’s correlation coefficients showed that seafood and seaweed intake was significantly correlated with％iAs (r=-0.34; r=-0.36, respectively), ％MMA (r=-0.25; r=-0.28, respectively), and％DMA (r=0.33; r=0.37, respectively). Intake of B vitamins, vitamin C, and soy isoflavones showed significant negative correlations with％iAs and％MMA, but positive correlations with％DMA. Conclusions: Japanese women from the coastal area of Choshi are exposed to low-level iAs. Their intake of B vitamins and vitamin C was associated with proportions of urinary As species. We identified for the first time associations between estimated soy isoflavones intake and the proportion of urinary As species.departmental bulletin pape

Energy transfer in porous-silicon/laser-dye composite evidenced by polarization memory of photoluminescence

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The Motif of Fishing in A Farewell to Arms

Article群馬県立女子大学紀要　18,(53)-(64),1997departmental bulletin pape

Child Health in Day-Nurseries and Day-Nursery Guidelines

P(論文)On March 28, 2008, the Day Nursery Guidelines (hereafter "Guidelines") were revised. The authorwas fortunate to have the opportunity of participating in the work of revising the Guidelines threetimes, including this most recent time. This latest revision was conducted in accordance with a Ministerialnotice and involved not simple day nursery guidelines but their most basic functions. Regarding theGuidelines revised in such circumstances, this paper explains in particular the sections which have thedeepest connection with health and safety in day nurseries. It understands the meaning of children'shealth in day nurseries and on that basis discusses health and safety that is necessary practice in daynurseries.The Guidelines define "hoiku (day care)" as the integration of "nurture and protection" and "education."If one considers "education" from the viewpoint of child health, I would like to interpret it asthe provision of knowledge and skills to children as the maintenance and advance of the child's healthis established. On this basis, children can themselves learn to work at maintaining and advancing theirhealth.Child health in day nurseries is the realization of the support in child raising that is most sought byparents and families. The author hopes that the significance of the most recent revision will be properlyunderstood so that the care staff at day nurseries, especially the young care staff, will have a deepinterest in the health of children.departmental bulletin pape

Connotation of China’s “Going Global” Strategy

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Effect of Variations in Embouchures Produced by Syllabic Images on the Acoustic Characteristics of Sounds Generated by Saxophones: A Comparison Using Spectral Analyses

departmental bulletin pape