Optimizing Energy Utilization in Cement Plant Operations

With the increased cost of energy, use of energy in cement plants must be reduced. Various means of reducing energy use in existing plants by changes in plant practices are suggested, with estimates of the magnitude of the major reductions.     

Overview of emerging nonvolatile memory technologies

Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices.     

Influence of A-site Ba substitution on microwave dielectric properties of (BaxMg1−x)(A0.05Ti0.95)O3 (A=Zr,Sn) ceramics

The microwave dielectric properties of (Ba_xMg_1−x)(A_0.05Ti_0.95)TiO₃ (A=Zr, Sn) ceramics were investigated with regard to substitution of Ba for Mg of A-site. The microwave dielectric properties were correlated with the Ba content. With an increase in Ba content from 0.01 to 0.1, the dielectric constant and the τ_f value increased, but the Q×f value decreased. The sintered (Ba_xMg_1−x)(Zr_0.05Ti_0.95)TiO₃ (called B_xMZT) ceramics had a permittivity in the range of 19.1−20.6, quality factor from 180,000 to 25,000 GHz, and variation in temperature coefficient of resonant frequency from −35 to −39 ppm/°C with increasing composition x. For sintered (Ba_xMg_1−x)(Sn_0.05Ti_0.95)TiO₃ (called B_xMST) ceramics, the dielectric constant increased from 19 to 20.5, Q×f value increased from 120,000 to 37,000 (GHz), and the τ_f value increased from −50 to −3.3 ppm/°C as the x increased from 0.01 to 0.1. When A=Sn and x=0.1, (Ba_0.1Mg_0.9)(Sn_0.05Ti_0.95)TiO₃ ceramics exhibited dielectric constant of 20.5, Q×f value of 37,000 (GHz), and a near-zero τ_f value of −3.3 ppm/°C sintered at 1210 °C for 4 h.     

1. The Data Librarian: laboratories today—the need for the Librarian

This first part of ‘The Data Librarian’ describes the current situation in analytical laboratories and the need for the Data Librarian. The second part of the paper (Liscouski, J., 1997, Journal of Automatic Chemistry, 19, 199-204) will examine the features of the Data Librarian.     

Isothermal and non-isothermal kinetic and safety parameter evaluation of tert-butyl(2-ethylhexyl)monoperoxy carbonate by differential scanning calorimetry

Tert-butyl(2-ethylhexyl)monoperoxy carbonate (TBEHC) 95 mass% is intrinsically a very unstable substance that can induce self-decomposition even under normal atmospheric condition. During storage, TBEHC 95mass% can release an enormous amount of heat if the temperature is higher than the recommended storage temperature, due to the self-accelerating reaction having been ignited. In this study, TBEHC 95mass% was tested by differential scanning calorimetry (DSC) under five heating rates (1, 2, 4, 6, and 8 °C/min) and four isothermal conditions (120, 125, 130, and 135 °C) to evaluate the basic kinetic and safety parameters of time to maximum rate (TMR), self-accelerating decomposition temperature (SADT), and temperature of no return (TNR). Under runaway reaction TBEHC 95 mass% releases a great quantity of heat. This study establishes an important guiding principle for related manufacturing processes worldwide.     

Formation of Highly Aligned,Single‐Layered,Hollow Fibrous Assemblies and the Fabrication of Large Pieces of PLLA Membranes

Large pieces of paper‐thin PLLA membranes are prepared and characterized as single‐layered hollow fibrous assemblies with an extremely high degree of fiber alignment. The diameter of the electrospun hollow fibers is in the range of some tens of micrometers with a wall thickness of a few micrometers. They are best described as 2D arrays of highly aligned microtubes. The mechanical properties of the membranes are studied. A processing map is constructed using the applied electric field strength and the concentration (viscosity) of the electrospinning dope. The influence of factors such as the field strength and weight and viscosity of the jetted solutions is discussed. The results will help in the future fabrication of highly anisotropic scaffolds for tissue engineering applications.

     

The impact of synthetic biology in chemical engineering—Educational issues

This paper describes the development of synthetic biology as a distinct entity from current industrial biotechnology and the implications for a future based on its concepts. The role of the engineering design cycle, in synthetic biology is established and the difficulties in making and exact analogy between the two emphasised. It is suggested that process engineers can offer experience in the application of synthetic biology to the manufacture of products which should influence the approach of the synthetic biologist. The style of teaching for synthetic biology appears to offer a new approach at undergraduate level and the challenges to the education of process engineers in this technology are raised. Possible routes to the development of synthetic biology teaching are suggested.     

Improving the self-sintering of mesocarbon-microbeads for the manufacture of high performance graphite-parts

Fine spherical mesocarbon-microbeads (MCMBs), having average particle sizes of 24.57, 11.69 and 10.74 μm, were mixed with various amounts of solid-resins (with high β-resin contents) to prepare graphite-matrixes in self-sintering reactions. The results indicate that the self-sintering reactions of the MCMBs can be significantly improved by enhancing the contacting-pattern of the mixture. MCMBs with smaller particle sizes favor self-sintering reactions and can be used to form high-quality graphite-matrixes. In addition, the self-sintering reactions are strongly dependent on the β-resin content of the raw materials. The bending strength of the graphite-matrixes increases, while the density of the graphite-matrixes decreases, with an increase of the β-resin content in the raw materials. The optimum β-resin content in the mixtures needed to obtain high density graphite-matrixes is approximately 5.0 wt.%.     

Improved thin film stability of differently formulated,printed, and crosslinked polymer layers against successive solvent printing

Interface control remains a top challenge of solution-processed organic light emitting diodes (OLED) stacks since the device performance heavily relies on it. Film stability of an inkjet deposited and crosslinked layer against subsequent exposure to a suitable inkjet printed solvent has been investigated. Impact of processing solvent (solvent used to prepare the polymer layer) on solution-cast thin film properties has already been shown for polymer films. To our knowledge, this study is the first one analyzing thin films stability against solvent exposure using technology relevant materials processed via inkjet printing (IJP). The outcome of this research showed that the stability of the crosslinked films is affected by the solvent used for ink formulation. These findings are of great interest for multilayered semiconductors devices, such as OLEDs, field-effect transistors and dye-sensitized solar cells. Differential scanning calorimetry (DSC) was used to quantify the efficiency of the polymer crosslinking reaction in pure powder and in thin films, as processed from different solvents. Crosslinking efficiency measured by DSC correlated well with the deformation induced by the solvent and observed on layer surfaces. The interaction in solution between polymer and solvent has also been evaluated to explain its impact on thin film stability against successive solvent printing. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48895.