Advances in Forensic Sedimentology

2022 ◽  
pp. 37-47
Author(s):  
Elhoucine Essefi

Forensic sedimentology is a relatively recently realized field. Sedimentological methods used to solve cases have evolved as the field has developed, beginning with simple identification of minerals and progressing to the examination of individual grains using highly advanced scanning electron microscopes. More simple methods, such as color analysis, are still used today, but in addition, forensic sedimentologists look at surface textures and grain size distribution. For instance, quartz grains were used in a forensic technique as sediment fingerprint. The particle size distribution is one of the important tests when analysing sediments and soils in geological studies. For forensic work, the particle size distribution of sometimes very small samples requires precise determination using a rapid and reliable method with a high resolution. FRITSCH laser granulometer offers rapid and accurate sizing of particles in the range 0.04–2000 μm for a variety of sample types, including soils, unconsolidated sediments, dusts, powders, and other particulate materials.

2019 ◽  
Vol 8 (4) ◽  
pp. 137
Author(s):  
Ahdiyatul Fauza ◽  
Kis Djamiatun ◽  
Ahmad Ni'matullah Al-Baarri

Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan saat sebelum dan setelah pengeringan buah Okra. Analisis fisik meliputi analisis warna dan PSD (Particle Size Distribution). Analisis kimia meliputi uji pH, conductivity dan TDS (Total Disolve Solid). Uji aktivitas antioksidan dilakukan dengan metode DPPH. Analisis data warna menggunakan uji korelasi. Data PSD, uji pH, konduktivitas, TDS, dan aktivitas antioksidan disajikan secara deskriptif. Hasil penelitian menunjukkan bahwa pengeringan buah Okra menjadi tepung Okra, tidak merusak aktivitas antioksidan. Proses pengeringan tepung Okra meningkatkan derajat kecerahan Okra dengan hasil uji statistik nilai L* <0,0001 dan a* 0,0002 (p<0,05). Distribusi ukuran partikel tepung Okra lebih kecil sehingga mudah larut dalam air. Buah Okra memiliki pH yang lebih asam yang mengakibatkan konduktivitasnya menjadi lebih tinggi sehingga padatan yang terlarut (kation, anion, mineral) juga semakin tinggi. Kesimpulannya, aktivitas antioksidan tepung buah Okra dapat diidentifikasi baik sebelum maupun setelah pengeringan dan proses pengeringan dapat berhasil memelihara aktivitas antioksidannya.This study aims to determine the physical, chemical, and antioxidant activities before and after drying the Okra fruit. Color analysis and PSD (Particle Size Distribution) were measured for physical analysis. pH test, conductivity, and TDS (Total Disolve Solid) was also measured as chemical analysis. Antioxidant activity was tested using DPPH. Color data was analyzed using correlation test. PSD data, pH test, conductivity, TDS, and antioxidant activity were presented descriptively. The results showed that drying Okra fruit to produce Okra flour did not damage antioxidant activity. The drying process of Okra flour brightening the color of the Okra fruit and in accordance with the statistical test that was resulted value of L* <0.0001 and a* 0,0002 (p <0.05). The particle size distribution of Okra flour was categorized as small. A much more acidic pH and higher in conductivity were found in the fresh Okra. As conclusion, antioxidant activity of Okra flour could be determined and the drying may be applied since able to maintain antioxidant activity in Okra flour.


2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda

1995 ◽  
Vol 5 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Christine M. Woodall ◽  
James E. Peters ◽  
Richard O. Buckius

1998 ◽  
Vol 84 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Takashi INOUE ◽  
Yuzo HOSOI ◽  
Koe NAKAJIMA ◽  
Hiroyuki TAKENAKA ◽  
Tomonori HANYUDA

2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.


2018 ◽  
Vol 60 (2) ◽  
pp. 202-208 ◽  
Author(s):  
Hao Yan ◽  
Jixiong Zhang ◽  
Jiaqi Wang ◽  
Nan Zhou ◽  
Sheng Zhang

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