57,491 research outputs found
Orientation distribution and electrophoretic motions of rod-like particles in a capillary
No full textWe consider motions of charged rod-like particles in a capillary under the action of externally applied electric field as a model problem for the electrophoresis through a capillary. Since the electrophoretic velocity through the capillary is dependent upon the particle orientation relative to the electric field, the probability distribution function for the particle orientation is determined from the Smoluchowski equation. In the statistical equation considered here, the random rotary Brownian potential is balanced with the potentials from both electrical and hydrodynamic origins. First, the dipole moment associated with the asymmetrical distribution of particle surface charges and that induced by the external electric field are calculated by utilizing slender body theory. The results are strictly valid under the conditions that the contribution from double-layer distortion is negligible, which is typical of charged macromolecules in aqueous media. The dipole moments are expressed in terms of the particle charge (or zeta potential) distribution, external field strength, and aspect ratio of the particle. The two distinct dipole moments incorporate into the Smoluchowski equation for the particle orientation distribution which in turn determines the electrophoretic mobility. Finally, the particle velocity in a capillary is simply given as superposition of the electrophoretic velocity and the electroosmotic velocity which is driven by the surface charges on the capillary wall. (C) 1996 Academic Press, Inc.This work has been supported partly by a grant from Korea Research
Foundation. The authors also appreciate financial support from Bioprocess
Engineering Research Center at KAIST
Deteksi Salmonella sp. pada Telur Ayam Buras yang Dijual sebagai Campuran Jamu Di Kecamatan Sidoarjo
No full textPenelitian ini bertujuan untuk memberikan informasi tentang ada tidaknya cemaran Salmonella sp. Pada telur ayam buras yang dijual sebagai campuran jamu di kecamatan Sidoarjo. Sampel yang digunakan dalam penelitian adalah sebanyak 36 butir telur ayam buras yang diambil secara random menggunakan metode Stratified random sampling dari 18 toko penjual jamu dan atau pedagang jamu tradisional keliling di Kecamatan Sidoarjo. Penanaman pada media dilakukan dengan cara menambahkan kuning telur ke dalam media penyubur bakteri Salmonella sp.yaitu Tetrathionate broth, setelah itu diinokulasikan pada media Salmonella Shigella Agar, dilanjutkan dengan uji pewarnaan Gram dan uji biokimia yang meliputi penanaman pada media Triple Sugar Iron Agar, Sulfit Indol Motility, Simmon Citrat Agar dan Urea Agar. Sampel diduga terkontaminasi Salmonella sp. Jika terdapat pertumbuhan Salmonella sp.pada media yang digunakan. Hasil penelitian pada bulan Agustus sampai dengan September 2008 didapatkan bahwa 5,56% dari 36 sampel telur ayam buras yang dijual sebagai campuran jamu di Kecamatan Sidoarjo positif tercemar Salmonella sp.
Salmonella sp, Telur ayam buras, Jamu
Hybos digitiformis Yang & Yang 1987, sp. nov.
No full text1. Hybos digitiformis Yang & Yang, 1987 Hybos digitiformis Yang &Yang, 1987: 168. Type locality: China: Tibet, Bomi. Distribution. China (Tibet). Remarks. This species was described by Yang & Yang (1987) from only 1 ♂ collected in Tibet. Its female is still unknown. It can be easily separated from H. flavitibialis sp. nov. by the hind femur with one row of very short spinose ventral setae and hypandrium apically obtuse with a short finger-like subapical lateral process (Yang & Yang 2004, figs 224, 226).Published as part of Li, Zhu, Wang, Ning & Yang, Ding, 2014, New species of Hybos Meigen from Northwest China (Diptera: Empidoidea, Hybotinae), pp. 166-180 in Zootaxa 3786 (2) on page 168, DOI: 10.11646/zootaxa.3786.2.5, http://zenodo.org/record/22962
Alebroides strumae Yu & Yang, sp. nov.
No full textA. strumae Yu & Yang, sp. nov. Distribution. China (Tibet).Published as part of Yu, Xiaofei & Yang, Maofa, 2014, Four new species of Alebroides Matsumura (Hemiptera: Cicadellidae: Typhlocybinae) from China, pp. 248-262 in Zootaxa 3780 (2) on page 252, DOI: 10.11646/zootaxa.3780.2.2, http://zenodo.org/record/23041
Alebroides spanner Yu & Yang, sp. nov.
No full textA. spanner Yu & Yang, sp. nov. Distribution. China (Guizhou).Published as part of Yu, Xiaofei & Yang, Maofa, 2014, Four new species of Alebroides Matsumura (Hemiptera: Cicadellidae: Typhlocybinae) from China, pp. 248-262 in Zootaxa 3780 (2) on page 252, DOI: 10.11646/zootaxa.3780.2.2, http://zenodo.org/record/23041
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