Direct Photo Research Articles

Crosslinking-induced patterning of MOFs by direct photo- and electron-beam lithography

Metal-organic frameworks (MOFs) with diverse chemistry, structures, and properties have emerged as appealing materials for miniaturized solid-state devices. The incorporation of MOF films in these devices, such as the integrated microelectronics and nanophotonics, requires robust patterning methods. However, existing MOF patterning methods suffer from some combinations of limited material adaptability, compromised patterning resolution and scalability, and degraded properties. Here we report a universal, crosslinking-induced patterning approach for various MOFs, termed as CLIP-MOF. Via resist-free, direct photo- and electron-beam (e-beam) lithography, the ligand crosslinking chemistry leads to drastically reduced solubility of colloidal MOFs, permitting selective removal of unexposed MOF films with developer solvents. This enables scalable, micro-/nanoscale (≈70 nm resolution), and multimaterial patterning of MOFs on large-area, rigid or flexible substrates. Patterned MOF films preserve their crystallinity, porosity, and other properties tailored for targeted applications, such as diffractive gas sensors and electrochromic pixels. The combined features of CLIP-MOF create more possibilities in the system-level integration of MOFs in various electronic, photonic, and biomedical devices.

Spectrophotometric determination of COD based on synergistic photocatalysis redox reaction using titanium dioxide nanoparticles and phosphomolybdic heteropoly acid

Chemical oxygen demand (COD) is one of the important indicators to measure the degree of organic pollution in water. In this work, a rapid spectrophotometric method for detection of COD was achieved based on the oxidation of organics in water by photogenerated holes or free radicals and the reduction of phosphomolybdic heteropolyacid by photogenerated electrons by using TiO2 nanoparticles as a photocatalyst. Taking potassium hydrogen phthalate as the COD standard, under the optimal conditions, the absorbance of reduced phosphomolybdic heteropoly acid was linear with COD in the range of 0.50–100 mg L −1. The detection limit for was COD detection was 0.171 mg L −1. The proposed methods was used for the determination of COD in real water samples, and the results were in general agreement with the national standard method. Compared with the direct photo initiated reduction of phosphomolybdic heteropoly acid without TiO2 nanoparticles, the photocatalytic reaction has better stability and higher efficiency.

Co-doped hydroxyapatite as photothermal catalyst for selective CO2 hydrogenation

The rational design and in deep understanding of efficient, affordable and stable materials to promote the light-assisted production of fuels and commodity chemicals is very appealing for energy crisis and climate change amelioration. Herein, we have prepared a series of Co-doped hydroxyapatite (HAP) catalysts with different Co content. The materials structure has been widely investigated by XRD, FT-IR, HRTEM, XPS, XAS, as well as computational simulations based on Density Functional Theory (DFT) with PBE functional. At low Co loading, there is a partial substitution of Ca cations in the HAP structure, while higher loadings promote the precipitation of small (∼ 2 nm) Co nanoparticles on the HAP surface. For the optimal Co content, a constant CO rate of 62 mmol·g−1·h−1 at 1 sun illumination and 400 °C, with the material being stable for 90 h. Visible and NIR photons have been determined responsible of the light-assisted activity enhanced. Mechanistic studies based on both experimental and DFT simulations show that H2 preferentially adsorbs to metallic Co, while CO2 adsorbs to the HAP surface oxygen. Moreover, both direct photo- and plasmon-driven contributions have been separated in order to study their mechanisms independently.

Core-satellite assembly of phase-changing material microcapsules enabled with broadband light absorption and localized surface plasmonic resonance for effective photothermal energy harvesting

To enhance the comprehensive photo-thermal energy accretion of the confined phase-changing materials (EPCM), engineered plasmonic nanoparticles (PG) and photosensitizer (PDA) were assimilated and structured in a core-satellite manner to form a highly active composite shell (DS-PDA/PG). In this communication, we devise a heterogeneous core-satellite assembly by the conjugation of the PCMs core and PG satellite assisted by a PDA arresting media. The constructed core-satellite can distinctly demonstrate superior photothermal performance compared to their respective precursor. This structural framework enunciates substantial improvement in photothermal energy conversion and heat dissipation mechanism due to the synergistic effect between the PG satellite and the PDA linker. Particularly, the heat channeling effect of PG nanoparticles onto the structured framework due to its localized surface plasmonic resonance (LSPR) mitigation which effectively dissipates heat to the encapsulating shell. The curated approach achieved a phase transition enthalpy of 139.20 J/g, with a thermal discrepancy of 28.89 ± 1.21 °C attaining an augmented photo to heat energy conversion efficiency of 96.95% due to wideband solar absorption and effective heat dissipation through the core-satellite assembly. The structured consolidation of PG and PDA was recognized to be a functional strategy that reinforce substantial improvements toward direct photo energy cultivation in an assortment of applications such as temperature management of greenhouses, solar water heating systems, solar cookers, and solar-thermal electricity generating systems. • A core-satellite assembly of PCM microcapsules was presented. • Broadband solar spectrum absorption on Uv–Vis–NIR range. • Efficient light to heat conversion through LSPR and molecule thermal vibration. • This work provides new insight into the PCM shell design for an effective solar-thermal conversion system. • Presented a new shell synergy insight for efficient light to the thermal conversion of EPCM.

Swirl 타입 노즐 적용 수소 전소 연소기 연구

A hydrogen combustor for applying to 5MWe-class small gas turbines was designed and experimentally investigated in this study. A swirl type, not a multi-tube type, which is widely used in the recently developed hydrogen combustor, was applied to this hydrogen combustor. The test was conducted at the inlet temperature of 410℃ which is derived from cycle analysis and at atmospheric pressure (1.35 barA). First, the ignition test was performed while switching from NG flame to hydrogen flame. Flame structures (from direct photo and OHSUP*/SUP chemiluminescence), NOSUBX/SUB emission and dynamic pressure were observed with varying adiabatic flame temperatures and fuel splits of FC1 and FC2. Lean blowout and flashback characteristics were investigated with varying equivalence ratio and flow velocity. Flame was converted from V-shaped flame to M-shaped flame as equivalence ratio increases and M-shaped one has higher NOSUBX/SUB emissions. NOSUBX/SUB emission is under 3 ppm (@15% O₂) at 1860 K of flame temperature which is equivalent or even lower level of NG combustors. It was found that the operating range from lean blowout to flashback is very wide.

Rancang Bangun Sistem Kehadiran Berbasis Mapping Location

Utilization of technology is an essensial needs of the Gunung Mas Cell Padang Counter for managing employee attendance data which is has many branches in the West Sumatra area. At this time the management of employee attendance data uses the Whatsapp application. This presence consist of the employee's entry and completion hours. The method of taking presence on WhatsApp is by using direct photo taking and using the share location feature to find out whether the employee is really at the location of the counter in concerned. The use of the WhatsApp application makes counter management overwhelmed and has difficulty checking the attendance of its employees because the data sent on WhatsApp is not properly organized. For that we need an information system that can solve this problem. With this Mapping Location-Based Attendance System Application, it is hoped that it can provide accurate and detailed reports on employee attendance and existence so that it will be easier for employees to provide proof of attendance and assist the management of the Gunung Mas Cell Padang Counter in managing employee attendance data so that it can run well and effective.

Versatile Micro and Nano Patterning Technique for TiO2 and TiN‐Based Sol–Gel Thin Films

AbstractThis paper describes a tailored and versatile technology route to achieve micro and nanopatterning of both TiO2 and TiN thin films using a direct photo patternable sol–gel approach combined with a rapid thermal annealing and nitridation process. The approach consists in multi‐scale structuring TiO2 using laser direct writing or mask/colloidal lithography on a wide range of substrates including materials and of diverse geometry. These patterned TiO2 layers can subsequently be converted into a micro‐structured metallic TiN layer using a direct rapid thermal nitridation process that results in metallic thin films (TiN). This work demonstrates the versatility of this complete chain of soft chemistry based new process for patterning TiO2 and TiN thin films thereby avoiding expensive processes such as etching and lift‐off, while preserving their diffractive properties and high thermal stability, that is, up to 1000 °C under vacuum. The process is compatible with different kinds of substrates of different shapes and sizes. These results pave the way for developing a cost‐effective and time‐saving approach to different cutting‐edge applications such as metasurfaces, sensors, and applications in the luxury and decoration sector.

Role of L -shell single and double core-hole production and decay in m -fold ( 1≤m≤6 ) photoionization of the Ar+ ion

Multiple ionization of the ${\mathrm{Ar}}^{+}(3{s}^{2}3{p}^{5})$ ion by a single photon has been investigated in the photon-energy range 250--1800 eV employing the photon-ion merged-beams technique. Absolute partial cross sections were measured for all ${\mathrm{Ar}}^{(1+m)+}$ product-ion channels with $1\ensuremath{\le}m\ensuremath{\le}6$ covering a size range from several tens of Mb down to a few b. Narrow $2p$-subshell excitation resonances were observed in all channels up to quadruple ionization at a photon-energy bandwidth of 52 meV. Double excitations involving a $2p$ and a $3s$ or $3p$ electron were also studied at high resolution and the measurements of the broad $2s$ excitation resonances directly showed their natural widths. Contributions of direct photo double ionization (PDI) to the production of the highest final Ar ion charge states are revealed, with PDI of the $2s$ subshell being mainly responsible for the production of ${\mathrm{Ar}}^{7+}$. The experiment made use of the PIPE setup installed at beamline P04 of the PETRA III synchrotron light source of DESY in Hamburg. The measurements were supported by theoretical calculations to identify the main contributions to the observed cross sections. Comparisons of theory and experiment show remarkable agreement but also hint to additional ionization mechanisms that are not considered in the theoretical models such as core ionization accompanied by excitations with subsequent Auger decays leading to net $m$-fold ionization with $m\ensuremath{\ge}4$.

Effect of Jet-Jet Angle on Combustion Process of Diesel Spray in an RCEM

<div class="section abstract"><div class="htmlview paragraph">The effects of jet-jet angle on the combustion process were investigated in an optical accessible rapid compression and expansion machine (RCEM) under various injection conditions and intake oxygen concentrations. The RCEM was equipped with an asymmetric six-hole nozzle having jet-jet angles of 30° and 45°. High-speed OH* chemiluminescence imaging and direct photo imaging using the Mie scattering method captured the transient evolution of the spray flame, characterized by lift-off length and liquid length. The RCEM operated at 1200 rpm. The injection timing was -5°ATDC, and the in-cylinder pressure and temperature were 6.1 MPa and 780 K at the injection timing, respectively, which achieved a short ignition delay. The effects of injection pressure, nozzle hole diameter, and oxygen concentration were investigated. The results show that the liquid and lift-off length of the jet-jet angle of 30° were shorter than those of the jet-jet angle of 45°, irrespective of injection conditions and oxygen concentration. Particularly, when the injection rate was high with high injection pressure and a large nozzle hole, the liquid and lift-off length rapidly and simultaneously decreased, but when the injection pressure was low or the nozzle hole diameter was small, the lift-off length decreased first, and then the liquid length decreased.</div></div>

Development of a portable cold air plasma jet device and observation of its photo ionization process

Photo ionization plays a critical role in the formation and propagation of atmospheric pressure plasma jet plumes. But in experiments, it is very difficult to observe the photo ionization due to its relative lower density of photo electrons. In the present study, we develop a portable cold air plasma jet device and observe the ionization wave in a dc spark air plasma jet. The discharge images acquired by an ICCD camera show that the ionization wave front performs as a quickly moving bright ball. Breakdown could take place at another side of the quartz plate or pork tissue layer (6 mm thick), which suggests that the ionization should be attributed to photo ionization. The laser schlieren images indicate there is propagation of a shock wave along with the plasma bullet. Based on the photo ionization theory and the photo-electric measurement, the direct photo ionization and multistage photo ionization are the main factors in charge of generating the cold air plasma jet. In addition, the plasma jet outside of the cathode nozzle is colder than 320 K and can be touched safely by a human. In view of the plasma jet including a large amount of active particles, such as NO, O, OH, emitted photons, etc, the proposed portable cold air plasma jet device could be qualified for plasma bio-medicine applications.

Optimisation of Lighting Parameters of Irradiation in Light Culture of Lettuce Plants Using LED Emitters

The results of the ending phase of photo biological studies of capacity of lettuce and basil grown in conditions of a phytotron with irradiation by radiation of different ratio of fractions in the red-blue and blue-green-red regions of photosynthetic active radiation (PAR) are presented. The spectral variants of PAR providing the maximum or near to maximum capacity of the specified cultures are found. The complex and multiple-valued nature of effect of main PAR spectral regions on photo energetic and photo regulatory processes in plants providing their capacity is highlighted, which makes it impossible to determine common unified requirements to optimal parameters of artificial irradiation for growing of plants. These requirements shall be defined on the basis of direct photo biological experiments with main species of agricultural plants and be the most important element of the general photo culture macro technology. The general principles of fulfilment of the specified requirements to PAR spectra of phytoemitters are reviewed, including with consideration of setting of normal vision conditions for personnel of greenhouses and other protected ground structures.

Direct photo transformation of tetracycline and sulfanomide group antibiotics in surface water: Kinetics, toxicity and site modeling

The direct photo-transformation of widely used antibiotics, including Tetracycline (TTC), chlortetracycline (CTC), sulfamethoxazole (SMX) and sulfamethazine (SMZ) were quantified for surface water by using artificial UV irradiation. The photolysis rate is directly proportional to the overlap between the absorption spectrum of the solution and the spectrum of the terrestrial sunlight. Increasing overlap fraction of Tetracycline (TC) group than Sulfanomide (Sulfa) group, the transformation of TC group is certified much faster than the sulfa group. The speciation of TC and Sulfa group antibiotics are pH-dependent and consequently influence its light adsorption spectrum. And the toxicity of the four target antibiotics along the photo-transformation was assessed. In field aquatic environment, a temporal- and spatial half-life model described the behavior of the antibiotics in water column of victoria harbour could be validated by using experimentally obtained quantum yield with the target field meteorological data. The modeling results indicated the photolysis rate of different kind of antibiotics varied differently along season, daily time and water depth. Summer, midday and surface layer of water body would be the time- and space-highlight spot in which the phototransformation are the dominant process for antibiotics concentration depletion. Seasonal variety would be enhanced for sulfa-group kind antibiotics, which having only tail overlapped with irradiation spectrum. Daily averaged half-lives of TC group were relatively stable, while the sulfa group antibiotics were found to vary from about 300 to 750 h, dependent on the seasonal change.

Control and measurement of doctoring angle at deformed state in doctoring apparatus for printed electronics

In printed electronics, the performance of printed devices depends on the quality of the printed patterns, or printability. It depends on the printing ink, the printing equipment, and printing conditions. Therefore, for reliable printed patterns with high printability, the printing conditions should be optimized and then maintained at constant values. Among the various printing conditions, parameters related to the doctoring process are important in gravure printing. In this study, the doctoring angle is redefined by the contact angle between the master plate and the doctor blade at the deformed state rather than the undeformed initial angle. The doctoring apparatus, capable of varying the angle of the doctor blade by controlling the position of the blade at the desired position, is developed. To estimate the doctoring angle in the deformed state without measurement from the photo image, mathematical model that calculates the doctoring angle in the deformed state using only geometric properties are derived. The doctoring angles based on the proposed mathematical model are compared with those measured from direct photo images for verifying the proposed method. In addition, the effect of the doctoring angle on the printability of the printed patterns is examined qualitatively through an experiment.

Stabilization of a lifted diffusion hydrocarbon flame by an external periodic electric field

Results of studying the influence of periodic application of a weak electric field on diffusion combustion of gaseous hydrocarbons are presented. The main attention is paid to investigating the effect of the electric field parameters on flame stabilization. Two types of electric fields are considered: (1) with a pulsed-periodic variation of the field strength in time and a constant configuration of force lines (pulsed-periodic electric field); (2) with a change in the field configuration in time and a constant field strength (electric field with a time-varying configuration). Direct photo and video recording was used, as well as spectrozonal registration of the natural luminescence of the flame (at wavelengths of emission of excited radicals OH* and CH*). It is shown that the region of flame stabilization (ignition point) tends to the place with the maximum strength of the electric field. The effect of the electric field with a time-varying configuration on combustion is the flame stabilization in the plane of electrodes and local intensification of combustion.

Photo-Electrochemical Etching in the Process of Direct H2 Generation by Illumination of GaN-Based Material Structures Immersed in Water

Hydrogen is considered a promising candidate for energy storage. We investigated the cleanest way for hydrogen production by direct photo electrolysis of water with GaN/AlGaN based p-n structures used as working electrodes. Besides the H2 production rate, an important consideration is the material etching (corrosion) that accompanies the photo-electrochemical process. The GaN-based structures were grown on sapphire substrates by the chloride hydride vapor phase epitaxy and used as a photo anode immersed into an aqueous electrolyte. For a p-n GaN/AlGaN structure we observed a H2 production rate of 0.6 mL/cm2×h. Corrosion of the electrode proceeds in two steps. First, there is a near vertical etching process, which is associated with defects in the material and penetrates deep into the structure. Subsequently, the process involves etching of n-type layers in lateral direction resulting in the formation of voids and cavities. The lateral etching is due to net positive charges arising from the spontaneous and piezoelectric polarization in the structure and positively charged ionized donors in the space charge region of the p-n junction.

Ultra‐Fast Continuous‐Flow Photo Degradation of Organic Peroxide Explosives for Their Efficient Conversion into Hydrogen Peroxide and Possible Application

AbstractFast, quantitative, and efficient direct photo degradation of organic peroxide explosives (HMTD, MEKP, TATP) using characteristic continuous‐flow UV radiation was investigated in aqueous solutions and achieved in less than 30 s.

Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters.

Vibtrational energy harvesting using photo-patternable piezoelectric nanocomposite cantilevers

Here we report on fabricating photo-patternable polymer nanocomposite cantilevers for harvesting electrical energy from mechanical vibrations. The optimized piezoelectric polymer nanocomposite enables direct photo patterning and, therefore, easy fabrication of microcantilevers eliminating expensive etching steps. Integrating piezoelectric zinc oxide (ZnO) nanoparticles (NPs) with optimum weight fraction into a photosensitive SU-8 polymer matrix not only retains the highly desired piezoelectric and semiconducting properties of the ZnO, but also combines the photo-patternability and the optical transparency of the SU-8. The maximum output power produced by nanocomposite cantilevers was 0.025μW across a resistive load of 100kΩ with peak to peak voltage of ∼140mV at a resonance frequency of 4kHz. This inexpensive platform offers design flexibility and ease of fabrication for harvesting mechanical vibrations.

Direct Share: Photo Management System Based on Round-robin Concept-driven User Preference Feedback

As the size of camera modules is decreasing and as the computing performance of portable devices is improving, taking photos has become a part of daily life. However, existing photo management programs and products that manage such photos still require extensive user effort to facilitate the sharing and browsing of images. It is especially difficult for novice users to manage and share photos. In this paper, we develop a round-robin concept-driven user preference feedback mechanism for achieving direct photo sharing, instant display, and easy management using optimized user controls and user preference-driven classification. Compared with commercial photo management systems, our proposed solution provides new features: optimized user controls, direct sharing and instant display, and user preference feedback driven classification. These new features boost the round-robin concept-driven user preference feedback. This paper proposes a photo finder that automatically searches for photos in storage spaces or cameras. The proposed photo finder relies on user preference feedback to share photos by leveraging user preferences, and the round-robin connection transmits photos to the family?s digital photo frame or web album by arbiter. The proposed method saves time and spares users the effort required for photo management. Moreover, this method does not merely direct photo sharing and simple photo management, but it also increases the satisfaction level of users viewing the photos.

Momentum imaging of the photo double ionization of ethylene molecules: A kinematically complete experiment

The direct photo double ionization (PDI) is a process that arises essentially because of the electron correlation. We investigated the PDI of ethylene near its threshold in order to unravel unique and important intertwining of electron correlation in inter-shell and intra-shell cases and the subsequent molecular dynamics. Using the COLTRIMS technique, we were able to detect two ejected electrons in coincidence with nascent photo-fragments (two CH2+ ions). From this we derived the angular distributions of the emitted photoelectrons in reference to the fixed-in-space molecular axis and the linear polarization of the incoming light (40eV).