CSL: Configurable Fault Tolerant Serial Links for Inter-die Communication in 3D Systems

Three dimensional (3D) integrated systems become a reality nowadays, as Thru-Silicon-Via (TSV) technologies mature. 3D integration promises significant performance and energy efficiency improvements by reducing the signal travel distances and integrating more capabilities on a single chip. High integration costs, thermal management, and poor reliability and yield are major challenges of TSV based 3D chips. High structural and parametric fault rates due to manufacturing defects makes it difficult to achieve high interconnect yield using only spare-based repair solutions. In this paper we address the TSV yield issue by implementing the inter-die links of 3D chips as Configurable fault-tolerant Serial Links (CSLs). When there are not enough available functional TSVs, faults are tolerated by performing data serialization. CSLs help reduce chip costs by improving the TSV yield with very few or no spares at all. For 3D Networks-on-Chip (3D NoCs) we show that the CSL yield improvement comes with moderate area overheads (~12–26%) and small performance penalties (less than 5% average latency overhead).     

The state of strain in single GaN nanocolumns as derived from micro-photoluminescence measurements

In the present paper, studies on the state of strain in single and ensembles of nanocolumns investigated by photoluminescence spectroscopy will be presented. The GaN nanocolumns were either grown in a bottom-up approach or prepared in a top-down approach by etching compact GaN layers grown on Si(111) and sapphire (0001) substrates. Experimental evidence for strain relaxation of the nanocolumns was found. The difference and development of the strain value for different nanocolumns could be verified by spatially resolved micro-photoluminescence on single nanocolumns separated from their substrate. A common D0X spectral position at 3.473 eV was found for all separated single GaN nanocolumns independent of the substrate or processing technique used, as expected for a relaxed system.     

Enhancement of Corrosion Resistance Properties of Electrodeposited Ni/nano-TiC Composite Layers

This paper presents novel results on the effects of the dispersion of titanium carbide nanoparticles (50 nm mean diameter) into a nickel-plating electrolyte on the corrosion behavior of the nanocomposite layers obtained. The Ni/nano-TiC layers are compared with pure nickel layers obtained at the same electrodeposition parameters with 60 mA·cm⁻² current density and 10 min deposition time. The comparative corrosion performances are investigated using a three-electrode electrochemical cell in a solution (mixed boric acid with lithium hydroxide), which simulates the primary water circuit of pressurized water reactors (PWRs). Open circuit potential measurement and electrochemical impedance spectroscopy were employed as the electrochemical methods, using an electrochemical workstation connected to an electrochemical cell, as well as a PC with software to drive the experimental work. The results clearly revealed enhanced corrosion properties for the Ni/nano-TiC hybrid layers as compared to the pure Ni layers. The significantly improved corrosion behavior can be attributed to the TiC nanoparticles embedded into the Ni matrix, which have the effect of insulating centers at the composite layer/corrosive solution interface.     

New Pyrrole Derivatives as Promising Biological Agents: Design,Synthesis, Characterization,In Silico,and Cytotoxicity Evaluation

The current study describes the synthesis, physicochemical characterization and cytotoxicity evaluation of a new series of pyrrole derivatives in order to identify new bioactive molecules. The new pyrroles were obtained by reaction of benzimidazolium bromide derivatives with asymmetrical acetylenes in 1,2-epoxybutane under reflux through the Huisgen [3 + 2] cycloaddition of several ylide intermediates to the corresponding dipolarophiles. The intermediates salts were obtained from corresponding benzimidazole with bromoacetonitrile. The structures of the newly synthesized compounds were confirmed by elemental analysis, spectral techniques (i.e., IR, ¹H-NMR and ¹³C-NMR) and single-crystal X-ray analysis. The cytotoxicity of the synthesized compounds was evaluated on plant cells (i.e., Triticum aestivum L.) and animal cells using aquatic crustaceans (i.e., Artemia franciscana Kellogg and Daphnia magna Straus). The potential antitumor activity of several of the pyrrole derivatives was studied by performing in vitro cytotoxicity assays on human adenocarcinoma-derived cell lines (i.e., LoVo (colon), MCF-7 (breast), and SK-OV-3 (ovary)) and normal human umbilical vein endothelial cells (HUVECs). The obtained results of the cytotoxicity assessment indicated that the tested compounds had nontoxic activity on Triticum aestivum L., while on Artemia franciscana Kellogg nauplii, only compounds 2c and 4c had moderate toxicity. On Daphnia magna, 4b and 4c showed high toxicity; 2a, 2b, and 2c moderate to high toxicity; only 4a and 4d were nontoxic. The compound-mediated cytotoxicity assays showed that several pyrrole compounds demonstrated dose- and time-dependent cytotoxic activity against all tested tumor cell lines, the highest antitumor properties being achieved by 4a and its homologue 4d, especially against LoVo colon cells.     

Eco-friendly flame retardant epoxy nanocomposites based on polyphosphonate and halloysite nanotubes

The preparation of a novel polyphosphonate (PSFR) is described here, starting from phenylphosphonic dichloride and an equimolecular mixture containing equal amounts of two bisphenols, namely 4,4′-dihydroxydiphenyl sulfone and 2-(6-oxido-6H-dibenzo<c,e><1,2>oxaphosphorin-6-yl)-1,4-benzenediol, following the polycondensation reaction in solution. Then, new environmental-friendly nanocomposites having improved flame retardancy have been prepared by incorporating PSFR and halloysite nanotubes (HNTs) into epoxy resin. The effect of PSFR and HNTs contents on the chemical and physical characteristics of epoxy nanocomposites was investigated. The success of the reactions was monitored by infrared spectroscopy (FTIR) while microscopic related techniques (SEM) gave information on the morphology of the products. The thermosets exhibit glass transition temperatures in the range of 62.4–97.1°C and thermal decomposition temperatures in the interval of 296–359°C. The appearance of the char residues obtained by pyrolysis was studied by SEM measurements. The flammability behavior has been studied by microscale combustion calorimetry (MCC) tests. A considerable improvement in the flame retardancy of the thermosets was obtained by simultaneous incorporation of HNTs (10 wt%) and PSFR (equivalent of 1 wt% P) into epoxy resin.