Atomic layer deposition (ALD) was used to deposit a laminate structure of alternating SiO2 and TiO2 monolayers onto a Si wafer. The resulting samples were analyzed in detail by X-ray photoelectron spectroscopy (XPS) revealing a distinct O 1s signature due to the presence of Si-O-Ti species. These findings are in good agreement with those reported for thin ALD films of TiO2 grown on SiO2.

An urgent need exist for developing handheld devices for rapid, sensitive, and specific detection method for pathogens. Here we demonstrate a rapid detection method for Gram-positive and Gram-negative bacteria using an impedance sensor array functionalized with antimicrobial peptides (AMPs). This impedance sensor screens pathogens in real-time and has comparable sensitivity with current detection methods like polymerase chain reaction (PCR) and immunoassay. Functionalized electrodes in array selectively bind to the corresponding bacteria strains, resulting in variations in the impedance modulus. Impedance variation is used to detect incubated bacterial cell concentration with a resolution of 1 cell µL-1. The dynamic range of detection for both Gram-positive and Gram-negative bacteria is found to be 103-106 cfu mL-1. Micropatterned electrodes modified with AMPs in an impedimetric array offer an excellent platform for rapid and selective detection of pathogens in contaminated water and food products.

We applied laser THz emission spectroscopy to study the effects of monolayer graphene on the THz emission from InAs. THz emission from graphene/InAs varies linearly with the laser excitation power in the low-intensity excitation regime. We found that unlike in graphene/SI-InP junctions, graphene and O2 adsorbates on graphene have no significant effect on the THz emission from graphene/InAs junctions because the THz radiation mechanism in InAs is by the photo-Dember effect, whereas for SI-InP is by the surge current effect. There is also a slight enhancement in the THz emission from both bare InAs and graphene/InAs by UV illumination, which is probably due to the additional photoexcited carriers by UV that somehow enhances the photo-Dember field.

A zinc-based metal-organic framework, MOF-177, was synthesized on the surface of benzoic acid functionalized reduced graphene oxide (BFG). Large amount of BFG (30wt %) slightly improved the stability of the MOF on the graphene surface, decreased the porosity of the composite, and resulted in 1mm long and 50µm wide microrods of MOF-177/BFG composites which act as a selective sensor for trinitrophenol compared to trinitrotoluene.

The electronic band structures of monolayer molybdenum dichalcogenides, MoS2, MoSe2, and MoTe2 under either uniaxial or biaxial strain are calculated using first-principles calculation with the GW method. The imposed uniaxial strain is in the zigzag direction in the honeycomb lattice whereas the imposed biaxial strain is in the zigzag and armchair directions. It is found that the band gaps of these dichalcogenides almost linearly increase with the decrease of the magnitude of compressive strain, reach their maxima at some compressive strain, and then decrease almost linearly with the increase of tensile strain. It is also found their maximum band gaps are direct bandgaps.

We have investigated the film morphology and photoluminescence properties of spin-coated CH3NH3PbI3-xClx films on mesoporous and compact TiO2 substrates. We observe that the perovskite film deposited on the mesoporous substrate composed of 20 nm TiO2 nanopaticles exhibits relatively uniform grain size, while the films deposited on the compact TiO2 substrate and the mesoporous substrate with large TiO2 nanoparticles (200 nm) show highly heterogeneous film morphology. The heterogeneity of film morphology has significant effect on the photoluminescence spectra and lifetime of the perovskite films. The result of time-resolved confocal microscopy unveils the relation between film structure and photoluminescence properties.

In this paper the effect of hybrid laser arc welding on longitudinal joints for pipes of 1.27cm thick is investigated. For the investigation, an API X70 steel was welded with the HLAW process and then subjected to tensile, bending and micro hardness tests under standards for pipe manufacturing. Images of the weld seams were taken to observe the structure and size of the weld zones. Analysis was made by light microscopy to determine the phases present in the weld zones and to observe if there is a variation of grain size in the weld zones that adversely affects the mechanical properties of the API X70 steel. Results show that the mechanical properties of the joints meet the requirements for their use in pipe manufacturing; one reason is the low thickness of the weld zone that barely affects the original properties of API X70 steel. Also the presence of bainite in the microstructure of weld zones provides resistance to the joints.

Organic films with a thickness of few nanometers are potentially useful components in many practical and commercial applications such as sensors, detectors, displays and electronic circuit components. In this context, the Langmuir-Blodgett (LB) method is one the most promising techniques for preparing these films.

In this work, we report the synthesis and characterization of three new amphiphilic organometallic compounds with ferrocene units, which consist of one ferrocenyl aminocarbene with the general formula FcC=Cr(CO)5NH(CH2)15CH3, and two ferrocenyl amides with the general formula FcC=MNH(CH2)15CH3 where M = S or Se. These new derivatives have been synthesized to study the influence of long alkyl side chain and the hydrophilic head on the film organization behavior at the air-water interface.

The Langmuir-Blodgett (LB) technique was focused for building ordered nanostructures in molecular assemblies of ferrocenyl derivatives, which are apt to form a stable and transferable monolayer film. The π-A isotherm, hysteresis, Brewster angle microscopy (BAM) and film stability were used to characterize the behavior of a monolayer film at the air-water interface. Z- type LB films were prepared from molecular monolayers which were transferred onto glass substrates. These films were characterized by atomic force microscopy (AFM), UV-Visible spectra and X-ray diffraction (DRX) techniques.

Rosette nanotubes (RNTs) are tubular architectures generated through the hierarchical self-assembly of the guanine-cytosine (G∧C) motif 1 or 2 (Figure 1). Motif 2 differs from 1 by the substitution at the N-atom in the G-ring with a C-atom as shown in red. In this paper, we prepare a new tricyclic G∧C base 3 from a functionalized derivative of 2 and demonstrate its self-assembly into fluorescent helical RNTs in N,N-dimethylformamide (DMF). The self-assembly and fluorescent properties of RNTs 3 were established using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-visible spectroscopy.

Carbon nanotubes (CNTs) have unique thermal/electrical/mechanical properties and high aspect ratios. Growth of CNTs directly onto reactive material substrates (such as metals and carbon based foam structures, etc.) to create a micro-carbon composite layer on the surface has many advantages: possible elimination of processing steps and resistive junctions, provision of a thermally conductive transition layer between materials of varying thermal expansion coefficients, etc. Compared to growing CNTs on conventional inert substrates such as SiO2, direct growth of CNTs onto reactive substrates is significantly more challenging. Namely, control of CNT growth, structure, and morphology has proven difficult due to the diffusion of metallic catalysts into the substrate during CNT synthesis conditions. In this study, using a chemical vapor deposition method, uniform CNT layers were successfully grown on copper foil and carbon foam substrates that were pre-coated with an appropriate buffer layer such as Al2O3 or Al. SEM images indicated that growth conditions and, most notably, substrate surface pre-treatment all influence CNT growth and layer structure/morphology. The SEM images and pull-off testing results revealed that relatively strong bonding existed between the CNT layer and substrate material, and that normal interfacial adhesion (0.2‒0.5 MPa) was affected by the buffer layer thickness. Additionally, the thermal properties of the CNT/substrate structure were evaluated using a laser flash technique, which showed that the CNT layer can reduce thermal resistance when used as a thermal interface material between bonded layers.

We report the implementation of an automated reel-to-reel fluidic self-assembly system based on surface-tension driven self-assembly for macroelectronics application. The reported system incorporates precisely controlled and automated agitation, web moving, component recycling, and dispensing system. The system enables continuous parallel assembly of semiconductor chips at a high rate (15,000 chips per hour using 2.5 cm wide web) and assembly yield (>99%) under optimal condition. In principle, scaling to any throughput should be possible considering the parallel nature of self-assembly. The process overcomes the limitations on area and throughput of prior methods. It provides a new platform for macroelectronics to enable the integration of microscopic high performance inorganic semiconductors on flexible substrates with any desired location, pitch, and integration density. As an example we demonstrate the fabrication of a solid state area lighting module.

Light Emitting Diodes (LEDs) have recently gained importance in the experimental practice of photovoltaic (PV) devices. LEDs have already been proposed as the alternative to conventional xenon or halogen based solar simulators. Multi-junction PV devices use coloured LEDs in experimental tools as well: LEDs can transform a conventional solar simulator in a spectrally adjustable simulator for spectral characterization of multi-junction modules. Other useful applications include evaluating the dependence of the electrical parameters on the average photon energy and spectral responsivity measurements of multi-junction PV devices.

Single-crystalline rutile with porous and complex structure can be produced by tuning reaction conditions so as to maintain low titania solubility. X-ray diffraction, high-resolution transmission electron microscopy, and cryogenic transmission electron microscopy results are consistent with the hypothesis that oriented aggregation of anatase crystals precedes rutile nucleation and growth from anatase nanocrystal interfaces. The product rutile retains morphological and microstructure features consistent with an aggregation-based phase transformation because coarsening, or monomer-by-monomer growth, is suppressed under these conditions of low titania solubility.

A dual experimental and numerical top-down approach is applied to investigate the link between osteocyte morphology and mechanical perception of their environment at the progenitor and mature stages. The numerical model is based on explicit tissue morphology discretization to identify bone diffuse damage at the cellular scale. The in vitro experimental model presents a live allograft bone system where a patient progenitor or mature osteocytes were reseeded in fresh human donor cortical bone tissues subjected to mechanical loading. The live systems behaved mechanically as fresh bone and the cells spatially reorganized in vitro as in vivo. The system under mechanical load also showed an adaptation of the calcium membrane transport rate to the expected in vivo mechanical load detected by bone cells at different stages of differentiation.

The development of efficient large-area organic light emitting diodes (OLED) requires reliable and easily processable charge generation layers (CGL) with low excess voltage drop and high optical transparency. OVPD offers the advantage of a precise control of layer morphology, composition and thickness and is a powerful method for the deposition of advanced OLED designs. In this work, electrical doping of organic semiconductors using OVPD is investigated and applied to stacked OLED utilizing inorganic/organic CGL. The organic p-type dopant NDP-9 of Novaled GmbH is used for doping the hole transport material N,N‘-diphenyl-N,N‘-bis(1-naphthylphenyl)-1,1‘-biphenyl-4,4‘-diamine (α-NPD) in an AIXTRON OVPD tool. A doping concentration of 8 vol.% of NDP-9 in α-NPD is found optimal for hole injection as well as conductivity. This dopant concentration was employed in CGL with the structure: electron transport material/LiF/Al/α-NPD:8 vol.% NDP-9. External quantum efficiencies (EQE) of 15%, 35% and 50% and luminous efficiencies of 37 lm/W, 45 lm/W and 45 lm/W at 1000 cd/m2 are demonstrated for single, double- and triple-unit green phosphorescent OLED, respectively.

The protected agriculture has gained great importance worldwide in the past 10 years. For example in the case of production in greenhouse conditions, that records an annual growth of 20%.

An important aspect greenhouse production is the medium used for growth of the plant, which may be an organic or inorganic substrate.

One of the advantages of the use of regional substrates is the availability and lower cost, and further organic in gives the tendency to manage sustainable production systems.

The organic substrates alone or in mixtures improve conditions for plant growth in terms of physical, chemical and biological as a perspective.

A wide variety of materials that can be used as agricultural substrates, but there are criteria to be considered for its election as: plant requirements, conforming as possible to the ideal characteristics of a substrate and effect on the environment.

Overall, we can summarize that a substrate for growing plants is any material that can provide attachment, oxygen and enough water for optimal development of the same, or in nutrient case requirements can be covered with a single material or combination with others.

In this paper the tomato crop is presented comparing two production systems to determine the yield and fruit quality under plastic cover, high densities of drip irrigation and using the tezontle as substrate, as this provides good drainage, almost no contribution nutrients and slightly neutral PH. And also allows us to transplant to a larger pot without disturbing the root and provides the necessary aeration.

Currently, the research team is systematically studying the oxide compounds present in the ternary system In2O3-TiO2-MgO in order to analyze its thermoluminescent (TL) response. The oxide Mg1.5InTi0.5O4 present in this system was synthesized by a solid state reaction at 1350 °C in air. The X-ray powder diffraction pattern showed a spinel-type structure for this compound. In this work, this spinel, as well as its TL properties when exposed to beta particles, are being reported for the first time. The glow curve is simple and wide with a TL maximum located at 203 °C at 21.33 Gy. The peak shows a shift to lower temperatures and it increases its intensity, as the irradiation dose increases. The lineal behavior was observed between 10.66 to 341 Gy, and no saturation signs were observed. The relative sensitivity variation was 2.7% and standard deviation after ten consecutive irradiation - TL readout cycles was 1 %. The minimum detectable dose was 5.65 Gy for this spinel-type oxide [3]. These results suggest the possible application of Mg1.5InTi0.5O4 in dosimetry.