Determination of dielectric properties of corn seeds from 1 to 100 MHz

The dielectric properties of corn seeds were determined in the ranges of 9.71-21.51% wet basis (w.b.) for moisture content, 772.5-902.2 kg/m³ for bulk density and 1-100 MHz for frequency of applied electric field using a coaxial capacitor sample holder. Effects of the parameters such as moisture content, bulk density and frequency on the dielectric properties were investigated. The dielectric constant, loss factor and loss tangent were greatly affected by the moisture content, frequency and bulk density. The moisture content was the most significant factor affecting the dielectric properties of corn seeds. The dielectric constant, loss factor and loss tangent increased with increasing moisture content and bulk density. The second and third-order polynomial equations were proposed to describe the existing relationship between dielectric properties and moisture content. Dielectric measurements provided new information concerning moisture content and bulk density dependent behaviour of dielectric properties of corn seeds that may be useful in sensing of the moisture content.     

转速对6061-T6铝合金搅拌摩擦搭接焊接头力学性能的影响(英文)

采用场发射扫描电子显微镜(FE-SEM),研究转速对厚度为5 mm的6061-T6铝合金搅拌摩擦搭接焊接头的宏观和微观组织、硬度、搭接头剪切性能和失效模式的影响。结果表明:在最低的转速度下,上模板和下模板具有十分相似的硬度分布。采用EDX分析发现,焊核区的断裂面中含有Fe的化合物。     

Activation of dispersed PtSn/C nanoparticles by tungsten oxide matrix towards more efficient oxidation of ethanol

A novel electrocatalytic system for oxidation of ethanol, in which carbon-supported PtSn nanoparticles were modified with ultra-thin films/deposits of tungsten oxide, was proposed, fabricated and characterized here using electrochemical as well as spectroscopic (X-ray diffraction) and microscopic (transmission electron) techniques. The enhancement effect was evident from comparative diagnostic electrochemical experiments utilizing WO₃-modified and bare (unmodified) PtSn nanoparticles in acid medium (0.5 mol dm⁻³ H₂SO₄) at room temperature in the presence of ethanol. It is noteworthy that, the chronoamperometric electrocatalytic currents measured at potentials as low as 0.3 V (vs. RHE) were significantly larger for WO₃-modified PtSn/C relative to bare PtSn/C. In another diagnostic “stripping” experiment, it was found that oxidation of CO-adsorbate occurred in the presence of WO₃ at potentials almost 100 mV lower in comparison to the unmodified system. The overall activation effect may have origin in interactions of tungsten oxide with tin (from PtSn alloy nanoparticles) leading to stabilization of the catalytic tin oxo species. WO₃ may also provide large population of reactive oxo groups at the Pt/Sn-based electrocatalytic interface.     

Coralyne Radiosensitizes A549 Cells by Upregulation of CDKN1A Expression to Attenuate Radiation Induced G2/M Block of the Cell Cycle

Coralyne is a synthetic analog of berberine related to protoberberine-isoquinoline alkaloids. Isoquinoline derivatives and analogs are renowned as potent radiosensitizers with potential medical application. In the present study, we investigated the effect of coralyne on the cell death, cytoskeletal changes and cell cycle progression of irradiated A549 cells. A clonogenic assay revealed that coralyne pretreatment decreased the viability of A549 cells in a time- and dose-dependent manner. Moreover, exposure to coralyne and ionizing radiation (IR) markedly altered the filamentous actin cytoskeletal architecture and integrin-β binding sites of A549 cells. Treatment with 1–25 µM coralyne in combination with 2 Gy of IR significantly reduced the percentage of cells in G2/M phase compared with 2 Gy IR alone. These results indicate that coralyne is a potent radiosensitizing agent that may find an application in medicine.     

Renewable energy sources for clean and sustainable energy policies in Turkey

Energy is an essential factor to achieve sustainable development. So, countries striving to this end are seeking to reassess their energy systems with a view towards planning energy programmes and strategies in line with sustainable development goals and objectives. As would be expected, the rapid expansion of energy production and consumption has brought with it a wide range of environmental issues at the local, regional and global levels. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. Turkey is an energy importing country with more than half of the energy requirement being supplied by imports, and air pollution is becoming a great environmental concern in the country. On the other hand, Turkey's geographical location has several advantages for extensive use of most of the renewable energy sources. In this regard, renewable energy resources appear the most efficient and effective solutions for clean and sustainable energy development in Turkey. This paper provides an overview of global energy use and renewables for clean and sustainable energy policies in Turkey.     

Calculation of the internal thermal resistance and ampacity of3-core screened cables with fillers

All 3-core cables require fillers to fill the space between insulated cores and the belt insulation or a sheath. The equations given in IEC 287 and in the Neher-McGrath paper (1957) for the internal thermal resistance of 3-core cables were developed for paper insulated cables. For such cables, it was assumed that the insulation and filler materials have the same thermal resistivities. In reality, in 3-core cables a variety of materials are used as fillers. The majority of these will have a higher thermal resistivity than the insulation. In the previous paper, a new formula was developed to compute the value of the internal thermal resistance of belted cables taking into account the thermal resistivity of the filler. In this paper, screened cables are considered and a new formula for the computation of the internal thermal resistance of such cables is presented. The effect of filler resistivity on cable ampacity is also discussed     

Novel composite polymeric electrolytes with surface-modified inorganic fillers

Surface-modified inorganic powders were applied as additives to plain salt-in-polymer polymeric electrolytes in order to enhance their properties and make them applicable in all-solid-state Li-polymer primary and secondary cells. These fillers consisted of alumina and titania powders (coarse and nano-sized) with superacidic groups introduced onto their surface. Then they were added to low and high molecular weight poly(ethylene oxide) (PEODME 500 and PEO 4,000,000) together with lithium perchlorate (LiClO₄, lithium tetraoxochlorate(VII)). In this way several different composite electrolytes were obtained that exhibited excellent stability versus lithium metal electrode and high lithium transference number. Herein the preparation procedure is described and preliminary results given.     

The effect of par‐baking and frozen storage time on the quality of cup cake

The effects of frozen storage and initial baking time of par‐baked cake on baking loss, volume, moisture, colour and textural properties of cake obtained after thawing and rebaking were investigated. Cakes, par‐baked at 175 °C for 15, 20 and 25 min, were stored at ?18 °C for 3, 6 and 9 months. After storage, par‐baked cakes were thawed and rebaked at 175 °C for 10, 15 and 20 min. Baking loss, moisture content, L and +b colour values, firmness, gumminess and chewiness of the resulting full‐baked cakes were significantly affected by both par‐baking and frozen storage time, while specific volume, cohesiveness, springiness and resilience values were significantly affected by frozen storage time. The increase in the time of frozen storage of the par‐baked cake leads to a decrease in the quality of the rebaked cake, namely an increase of baking loss and cake crumb firmness, and a loss in the moisture content and specific volume. Moisture of cake crumb, L and +b colour values, firmness, gumminess and chewiness significantly increased as the par‐baking time increased. However, regarding baking loss, specific volume, moisture content and textural properties, 3‐month intermediate storage at ?18 °C and 20‐min initial baking time gave the best result among the cakes produced by using the two‐step baking procedure.     

Voltage-mode multifunction filter with mutually independent Q and \omega _0 control feature using VDDDAs

The paper focuses on the application possibilities of the newly presented voltage differencing active building block called voltage differencing differential difference amplifier. Using this active element, a multifunction frequency filter is designed featuring the possibility of mutually independent control of quality factor Q and characteristic frequency \(\omega _0\) by means of active elements. The structure of the filter is based on the idea of the Akerberg-Mossberg (AM) filter, i.e. the integrators in the structure are always realized only by two active elements. This fact results in better phase compensation for the filter. Compared to the AM opamp based filter, the newly proposed structure features high-impedance inputs, low-impedance output, and all basic frequency responses. The performance of the proposed structure has been verified by SPICE simulations using the TSMC \(0.18\,\upmu \hbox {m}\) level-7 SCN018 CMOS process parameters with \(\pm 0.9\,\hbox {V}\) supply voltage.     

Benzene-induced hydro(solvo)thermal synthesis of Cu and Zn coordination polymers based on 1,3-benzenedicarboxylate

Hydro(solvo)thermal reactions of Cu(NO₃)₂·2.5H₂O or Zn(NO₃)₂·6H₂O with 1,3-H₂bdc provided two structurally different coordination polymers; a 2D network “metallacalixarene” based on the paddlewheel-type cluster with the formula [Cu(1,3-bdc)·H₂O]·H₂O (1) and a 3D framework [Zn(1,3-bdc)] (2), respectively. The use of a base was unnecessary in this synthesis; however, the presence of benzene played a crucial role in the crystallization of the desired products and could act as a template molecule in the synthesis of polymer (1). The unsaturated apical sites in the Cu₂ cluster of polymer (1) were occupied by water molecules, what consequently led to the structural decomposition of the framework after exposing the sample in air, which was not the case of the Zn-coordination polymer (2).