Graphene growth on Ge(100)/Si(100) substrates by CVD method

The successful integration of graphene into microelectronic devices is strongly dependent on the availability of direct deposition processes, which can provide uniform, large area and high quality graphene on nonmetallic substrates. As of today the dominant technology is based on Si and obtaining graphene with Si is treated as the most advantageous solution. However, the formation of carbide during the growth process makes manufacturing graphene on Si wafers extremely challenging. To overcome these difficulties and reach the set goals, we proposed growth of high quality graphene layers by the CVD method on Ge(100)/Si(100) wafers. In addition, a stochastic model was applied in order to describe the graphene growth process on the Ge(100)/Si(100) substrate and to determine the direction of further processes. As a result, high quality graphene was grown, which was proved by Raman spectroscopy results, showing uniform monolayer films with FWHM of the 2D band of 32 cm−1

Patterning of graphene on silicon-on-insulator waveguides through laser ablation and plasma etching

We present the use of femtosecond laser ablation for the removal of monolayer graphene from silicon-on-insulator (SOI) waveguides, and the use of oxygen plasma etching through a metal mask to peel off graphene from the grating couplers attached to the waveguides. Through Raman spectroscopy and atomic force microscopy, we show that the removal of graphene is successful with minimal damage to the underlying SOI waveguides. Finally, we employ both removal techniques to measure the contribution of graphene to the loss of grating-coupled graphene-covered SOI waveguides using the cut-back method. This loss contribution is measured to be 0.132 dB/μm

Pee power urinal-microbial fuel cell technology field trials in the context of sanitation

This paper reports on the pee power urinal field trials, which are using microbial fuel cells for internal lighting. The first trial was conducted on Frenchay Campus (UWE, Bristol) from February-May 2015 and demonstrated the feasibility of modular MFCs for lighting, with University staff and students as the users; the next phase of this trial is ongoing. The second trial was carried out during the Glastonbury Music Festival at Worthy Farm, Pilton in June 2015, and demonstrated the capability of the MFCs to reliably generate power for internal lighting, from a large festival audience (∼1000 users per day). The power output recorded for individual MFCs is 1-2 mW, and the power output of one 36-MFC-module, was commensurate of this level of power. Similarly, the real-time electrical output of both the pee power urinals was proportional to the number of MFCs used, subject to temperature and flow rate: the campus urinal consisted of 288 MFCs, generating 75 mW (mean), 160 mW (max) with 400 mW when the lights were connected directly (no supercapacitors); the Glastonbury urinal consisted of 432 MFCs, generating 300 mW (mean), 400 mW (max) with 800 mW when the lights were connected directly (no supercapacitors). The COD removal was >95% for the campus urinal and on average 30% for the Glastonbury urinal. The variance in both power and urine treatment was due to environmental conditions such as temperature and number of users. This is the first time that urinal field trials have demonstrated the feasibility of MFCs for both electricity generation and direct urine treatment. In the context of sanitation and public health, an independent power source utilising waste is essential in terms of both developing and developed world

Residual Metallic Contamination of Transferred Chemical Vapor Deposited Graphene

Integration of graphene with Si microelectronics is very appealing by offering potentially a broad range of new functionalities. New materials to be integrated with Si platform must conform to stringent purity standards. Here, we investigate graphene layers grown on copper foils by chemical vapor deposition and transferred to silicon wafers by wet etch and electrochemical delamination methods with respect to residual sub-monolayer metallic contaminations. Regardless of the transfer method and associated cleaning scheme, time-of-flight secondary ion mass spectrometry and total reflection x-ray fluorescence measurements indicate that the graphene sheets are contaminated with residual metals (copper, iron) with a concentration exceeding 10$^{13}$ atoms/cm$^{2}$. These metal impurities appear to be partly mobile upon thermal treatment as shown by depth profiling and reduction of the minority charge carrier diffusion length in the silicon substrate. As residual metallic impurities can significantly alter electronic and electrochemical properties of graphene and can severely impede the process of integration with silicon microelectronics these results reveal that further progress in synthesis, handling, and cleaning of graphene is required on the way to its advanced electronic and optoelectronic applications.Comment: 26 pages, including supporting informatio

High efficacy and safety of VTD as an induction protocol in patients with newly diagnosed multiple myeloma eligible for high dose therapy and autologous stem cell transplantation : a report of the Polish Myeloma Study Group

The present retrospective analysis evaluated the efficacy and safety of the VTD (bortezomib, thalidomide, dexamethasone) regimen in 205 newly‑diagnosed patients with multiple myeloma (MM) eligible for high dose therapy and autologous stem cell transplantation (HDT/ASCT) in routine clinical practice. With a median of 6 cycles (range, 1‑8), at least partial response was achieved in 94.6% and at least very good partial response (VGPR) was achieved in 67.8% of patients. Peripheral neuropathy (PN) grade 2‑4 was observed in 28.7% of patients. In 72% of patients undergoing stem cell mobilization one apheresis allowed the number of stem cells sufficient for transplantation to be obtained. Following HDT/ASCT the sCR rate increased from 4.9 to 14.4% and CR from 27.8 to 35.6%. The results demonstrated that VTD as an induction regimen was highly efficient in transplant eligible patients with MM with increased at least VGPR rate following prolonged treatment (≥6 cycles). Therapy exhibited no negative impact on stem cell collection, neutrophils and platelets engraftment following ASCT. Therapy was generally well tolerated and PN was the most common reason of dose reduction or treatment discontinuation

A review into the use of ceramics in microbial fuel cells

© 2016 The Authors. Microbial fuel cells (MFCs) offer great promise as a technology that can produce electricity whilst at the same time treat wastewater. Although significant progress has been made in recent years, the requirement for cheaper materials has prevented the technology from wider, out-of-the-lab, implementation. Recently, researchers have started using ceramics with encouraging results, suggesting that this inexpensive material might be the solution for propelling MFC technology towards real world applications. Studies have demonstrated that ceramics can provide stability, improve power and treatment efficiencies, create a better environment for the electro-active bacteria and contribute towards resource recovery. This review discusses progress to date using ceramics as (i) the structural material, (ii) the medium for ion exchange and (iii) the electrode for MFCs