Generation of Silver Nanoparticles by the Pin-Hole DC Plasma Source with and without Gas Bubbling

Silver nanoparticles were produced using the pin-hole discharge generated by dc non-pulsing high voltage directly in silver nitrate solutions. Sodium nitrate was alternatively added to increase solution conductivity and decrease input energy for the discharge breakdown. Argon or oxygen was bubbled through the discharge region. Comparative experiments were evaluated by UV-VIS spectrometry. Formation of silver nanoparticles with the average size of 100 nm was confirmed by SEM/EDS analysis

SAMPLE TEMPERATURE DURING CORROSION REMOVAL BY LOW PRESSURE LOW-TEMPERATURE HYDROGEN RF PLASMA

Abstract. The plasma chemical reduction of corrosion layers from archaeological metallic objects is developing since the late 70 th . Contemporary, it is used in some museums, but the optimal treatment conditions are not fully known yet. Treated object temperature is one of the most critical points because metallographic changes can be initiated by elevated temperatures and thus the unique historical information can be lost. Temperature increases due to the direct inductive heating in the discharge as well as by the interaction of the surface with plasma active particles. In the case of samples prepared in acidic corrosion environment, the maximal temperature of the samples with the incrustation was lower than of samples without incrustation treated under the same conditions because the incrustation layers decrease the direct interaction of plasma active particles with the corrosion layers. In contrary, in the case of brass samples prepared in the ammonia atmosphere, the incrustation had an opposite effect due to intense heating of the sample during the reaction with oxygen presented in the outer corrosion layers. The maximal sample temperature was directly proportional to the linear size (or the third root of weight) of the treated sample

Influence of diaphragm configuration on DC diaphragm discharge breakdown in electrolyte solution

International audienc

TALE-directed local modulation of H3K9 methylation shapes exon recognition.

In search for the function of local chromatin environment on pre-mRNA processing we established a new tool, which allows for the modification of chromatin using a targeted approach. Using Transcription Activator-Like Effector domains fused to histone modifying enzymes (TALE-HME), we show locally restricted alteration of histone methylation modulates the splicing of target exons. We provide evidence that a local increase in H3K9 di- and trimethylation promotes inclusion of the target alternative exon, while demethylation by JMJD2D leads to exon skipping. We further demonstrate that H3K9me3 is localized on internal exons genome-wide suggesting a general role in splicing. Consistently, targeting of the H3K9 demethylase to a weak constitutive exon reduced co-transcriptional splicing. Together our data show H3K9 methylation within the gene body is a factor influencing recognition of both constitutive and alternative exons

Characterization of novel pin-hole based plasma source for generation of discharge in liquids supplied by DC non-pulsing voltage

International audienceA recently presented novel plasma source generating discharge in liquids based on the pin-hole discharge configuration is characterized in detail. The system is supplied by DC non-pulsing high voltage of both polarities in NaCl water solutions at a conductivity range of 100-15 000 μS/cm. The discharge itself shows self-pulsing operation. The discharge ignition is observed in micro bubbles by transient discharge followed by a glow discharge in positive polarity at lower conductivities propagating inside the bubbles. At high conductivities, the glow regime is particularly replaced by a more energetic sequence of transient discharges followed by a shorter glow mode operation. The transient regime probability and its intensity are higher in the negative discharge polarity. The transient discharge produces acoustic waves and shock waves, which are observed at the moment of the bubble cavitation. The average gas temperature of 700-1500 K was calculated from the lowest OH (A-X) 0-0 band transitions. The average electron concentrations of 10 20-10 23 m −3 were calculated from H α and H β line profiles. Finally, the production of a chemically active species is determined by hydrogen peroxide energy yields related to the energy consumption of the whole interelectrode system. All these quantities are dependent on the solution conductivity, the discharge polarity, and the applied power. Supplementary material for this article is available onlin

Palynology research of water reservoirs of later mediaeval and post-mediaeval deserted villages in West Bohemia, Czech Republic

This paper presents palynological research of sediments in artificial water reservoirs from deserted later mediaeval villages in the Pilsen Region, Czech Republic. Coring and test-pitting of these features have shown that in some cases, their preserved fills are formed by wet sediments providing the ideal conditions for paleoecological record. Pollen profile analysis from four sites has allowed us to reconstruct the natural environment of mediaeval villages in order to asses land use and human impact on vegetation. Pollen data also recorded forest succession following the desertion of the settlement, vegetation succession and changes in forest management in the Modern Era based on spruce cultivation. In one case, the pollen profile reflects the subsequent reestablishment of the village in the post-mediaeval period and its final abandonment during the Thirty Years’ War

Studi Tentang Quality Of Service Yang Dilakukan Oleh PT. Texascom Hitek System Di Surabaya

Sejalan dengan kemajuan teknologi di segala bidang, menyebabkan terjadinya perubahan dalam lingkungan ekonomi, sosial dan budaya yang mengakibatkan berubahnya pola hidup dalam masyarakat. Masyarakat dewasa ini sangat memerlukan alat-alat bantu yang dapat mendukung daya kerjanya agar semakin optimal. Salah satu dari alat bantu tersebut adalah komputer. Hal ini sangat disadari oleh para produsen komputer dan merupakan peluang bisnis yang menguntungkan. Dengan banyaknya merek yang menawarkan produknya maka persaingan pun sangat ketat. Dengan adanya persaingan dalam memasarkan produk yang dihasilkan timbullah ungkapan sebagai motto yang dilakukan untuk memuaskan keinginan konsumen yaitu "pembeli adalah raja". Pandangan ini dikembangkan dalam rangka untuk dapat mencapai sasaran pemasaran yaitu keuntungan badan usaha jangka panjang melalui pembinaan pelanggan dengan memberikan kepuasan bagi keinginan dalam pemenuhan kebutuhan konsumen ..