Recent developments in micro- and nanofluidic catalytic reactors utilizing ultra-small spaces.

Recent developments in micro- and nano-technology have become the primary thrust of many new research opportunities in bioengineering to provide better imaging, diagnosis, therapeutic therapy, and monitoring progression of various diseases. Biology and Chemistry are becoming highly quantitative disciplines, dealing with deeply complex interacting factors. Engineered systems are increasingly integrating biological operability and capabilities into traditional methodology. Light matter interactions traditionally employed in Optical Physics has generated new fields in Biophysics and Bioengineering. These are unique challenges often requiring interdisciplinary collaborations among researchers with diversified expertise. Therefore, it is important to educate the next generation of undergraduate students to possess the technical knowledge within their core discipline, to cultivate opportunities for interdisciplinary problem solving and to prepare them for an industrial or graduate environment involving interdisciplinary research.

Due to unique optical and electrical properties, micro-/nano-structures have become an essential part of optoelectronic devices. Here, we summarize the recent developments in micro-/nano-structures fabricated by laser technologies for optoelectronic devices. The fabrication of micro-/nano-structures by various laser technologies is reviewed. Micro-/nano-structures in optoelectronic devices for performance improvement are reviewed. In addition, typical optoelectronic devices with micro-nano structures are also summarized. Finally, the challenges and prospects are discussed.

Flying insects are capable of flapping their wings to provide the required power and control forces for flight. A coordinated organizational system including muscles, wings, and control architecture plays a significant role, which provides the sources of inspiration for designing flapping-wing vehicles. In recent years, due to the development of micro- and meso-scale manufacturing technologies, advances in components technologies have directly led to a progress of smaller Flapping-Wing Nano Air Vehicles (FWNAVs) around gram and sub-gram scales, and these air vehicles have gradually acquired insect-like locomotive strategies and capabilities. This paper will present a selective review of components technologies for ultra-lightweight flapping-wing nano air vehicles under 3 g, which covers the novel propulsion methods such as artificial muscles, flight control mechanisms, and the design paradigms of the insect-inspired wings, with a special focus on the development of the driving technologies based on artificial muscles and the progress of the biomimetic wings. The challenges involved in constructing such small flapping-wing air vehicles and recommendations for several possible future directions in terms of component technology enhancements and overall vehicle performance are also discussed in this paper. This review will provide the essential guidelines and the insights for designing a flapping-wing nano air vehicle with higher performance.

Recent advances in intelligence technology have boosted the development of micro- Unmanned Air Vehicles (UAVs) including Sliver Fox, Shadow, and Scan Eagle for various surveillance and reconnaissance applications. These affordable and reusable devices have to fit a series of size, weight, and power constraints. Cameras used on such micro-UAVs are therefore mounted directly at a fixed angle without any motion-compensated gimbals. This mounting scheme has resulted in the so-called <i>jitter effect</i> in which jitter is defined as sub-pixel or small amplitude vibrations. The jitter blur caused by the jitter effect needs to be corrected before any other processing algorithms can be practically applied. Jitter restoration has been solved by various optimization techniques, including Wiener approximation, maximum <i>a-posteriori</i> probability (MAP), etc. However, these algorithms normally assume a spatial-invariant blur model that is not the case with jitter blur. Szu et al. developed a smart real-time algorithm based on auto-regression (AR) with its natural generalization of unsupervised artificial neural network (ANN) learning to achieve restoration accuracy at the sub-pixel level. This algorithm resembles the capability of the human visual system, in which an agreement between the pair of eyes indicates "signal", otherwise, the jitter noise. Using this non-statistical method, for each single pixel, a deterministic blind sources separation (BSS) process can then be carried out independently based on a deterministic minimum of the Helmholtz free energy with a generalization of Shannon's information theory applied to open dynamic systems. From a hardware implementation point of view, the process of jitter restoration of an image using Szu's algorithm can be optimized by pixel-based parallelization. In our previous work, a parallelly structured independent component analysis (ICA) algorithm has been implemented on both Field Programmable Gate Array (FPGA) and Application-Specific Integrated Circuit (ASIC) using standard-height cells. ICA is an algorithm that can solve BSS problems by carrying out the all-order statistical, decorrelation-based transforms, in which an assumption that neighborhood pixels share the same but unknown mixing matrix <b>A</b> is made. In this paper, we continue our investigation on the design challenges of firmware approaches to smart algorithms. We think two levels of parallelization can be explored, including pixel-based parallelization and the parallelization of the restoration algorithm performed at each pixel. This paper focuses on the latter and we use ICA as an example to explain the design and implementation methods. It is well known that the capacity constraints of single FPGA have limited the implementation of many complex algorithms including ICA. Using the reconfigurability of FPGA, we show, in this paper, how to manipulate the FPGA-based system to provide extra computing power for the parallelized ICA algorithm with limited FPGA resources. The synthesis aiming at the pilchard re-configurable FPGA platform is reported. The pilchard board is embedded with single Xilinx VIRTEX 1000E FPGA and transfers data directly to CPU on the 64-bit memory bus at the maximum frequency of 133MHz. Both the feasibility performance evaluations and experimental results validate the effectiveness and practicality of this synthesis, which can be extended to the spatial-variant jitter restoration for micro-UAV deployment.

Introduction The carbon/air secondary battery (CASB) system is a promising large-capacity energy storage technology [1]. The CASB system utilizes a redox reaction of C + O2 ⇄ CO2 by solid oxide fuel cells/electrolysis cells (SOFCs/SOECs), namely a combination of rechargeable direct carbon fuel cells [1, 2] and CO2 electrolysis cells. Carbon and liquid CO2 are stored in and outside SOFCs/SOECs respectively. The advantages of the CASB system are high theoretical efficiency of close to 100%, high volumetric energy density of 1625 Wh L-1 based on carbon and liquid CO2 (25oC, 6.4 MPa), and high safety due to unflammable CO2 storage. On the fuel electrode side, the electrochemical reaction of 2CO2 + 4e- ⇄ 2CO + 2O2- and the thermochemical (Boudouard) reaction of 2CO ⇄ C + CO2 proceed. On the air electrode side, the electrochemical reaction of 2O2- ⇄ O2 + 4e- proceeds. The previous study [3] demonstrated the reaction mechanism and the charging-discharging for 10 cycles without degradation. However, the carbon deposition on the triple phase boundary (TPB) made an overpotential increase, and there remains a risk of degradation of the fuel electrode in the long term. To suppress overpotential or to avoid degradation, the carbon deposition area is required to separate from TPB. There are two ways considered, namely development of materials and systems for the CASB. We recently demonstrated that two kinds of fuel electrodes with different catalytic abilities, e.g. Ce0.9Gd0.1O2-δ (GDC) fuel electrode and Ni/GDC catalyst section, successfully controlled carbon deposition on the catalyst section selectively [4]. Controlling temperature is another way of separating carbon deposition area from TPB because the Boudouard equilibrium gas composition changes significantly in the range of 500oC to 900oC (Fig. 1). The lower the temperature, the lower the equilibrium partial pressure of CO. Therefore, lowering the temperature of the catalyst section enables selective carbon deposition on the catalyst. In this study, the objective is to propose the carbon deposition area-separated type CASB system controlling temperature and to demonstrate its charging-discharging. Experimental The experimental setup was composed of a cell and a catalytic fixed-bed reactor. Ni/ GDC fuel electrodes were fabricated on an 8 mol% Y2O3 – stabilized ZrO2 disc electrolyte (20 mm diameter, 0.25 mm thickness). La0.8Sr0.2MnO3/10mol%Sc2O3-1mol%CeO2–ZrO2 air electrodes were fabricated on the counter sides. A catalyst for the Boudouard reaction was put in a quartz tube. The temperature of the cell and the catalytic reactor was controlled to be 900oC and 670oC. For charging, CO 40 sccm and CO2 10 sccm were supplied on the fuel electrode side, and the exhausted gas was supplied to the catalytic reactor. For discharging, CO2 10 sccm was supplied to the catalytic reactor, and the exhausted gas was supplied on the fuel electrode side. For both charging and discharging, O2 100 sccm was supplied on the air electrode side, and a current density of 100 mA cm-2 was applied for a couple of hours. Results and discussion Repetitive charging and discharging for a couple of hours were successfully demonstrated. The discharge capacity was above 300 mAh, which is more than 10 times larger than the previous demonstration of the carbon deposition area-integrated type CASB system [3]. Because only CO2 was supplied during the discharging, deposited carbon in the catalytic reactor was mainly used for the fuel. In addition, the partial pressure of CO in the space close to the cell during the charging was not enough for thermochemical carbon deposition. Those results show that lowering the temperature of the catalyst section successfully made selective carbon deposition on the catalyst. Conclusion In this study, the carbon deposition area-separated type CASB system was proposed and its repetitive charging and discharging was demonstrated. Lowering the temperature of the catalytic reactor to the SOFCs/SOECs enables selective carbon deposition in the catalytic reactor. Avoiding carbon deposition on the fuel electrodes can radically improve the stability of the CASB system in the long term.

The Sulfolobus solfataricus Y-family DNA polymerase Dpo4 is a model for translesion replication and has been used in the analysis of individual steps involved in catalysis. The role of conformational changes has not been clear. Introduction of Trp residues into the Trp-devoid wild-type protein provided fluorescence probes of these events, particularly in the case of mutants T239W and N188W. With both mutants, a rapid increase in Trp fluorescence was observed only in the case of normal base pairing (G:C), was saturable with respect to dCTP concentration, and occurred in the absence of phosphodiester bond formation. A subsequent decrease in the Trp fluorescence occurred when phosphodiester bond formation was permitted, and these rates were independent of the dCTP concentration. This step is relatively slow and is attributed to a conformational relaxation step occurring after pyrophosphate release, which was measured and shown to be fast in a separate experiment. The measured rate of release of DNA from Dpo4 was rapid and is not rate-limiting. Overall, the measurements provide a kinetic scheme for Dpo4 different than generally accepted for replicative polymerases or proposed for Dpo4 and other Y-family polymerases: the initial enzyme.DNA.dNTP complex undergoes a rapid (18 s(-1)), reversible (21 s(-1)) conformational change, followed by relatively rapid phosphodiester bond formation (11 s(-1)) and then fast release of pyrophosphate, followed by a rate-limiting relaxation of the active conformation (2 s(-1)) and then rapid DNA release, yielding an overall steady-state kcat of <1 s(-1).

Advances in digital technology in Indonesia have driven significant transformation in the financial sector, one of which is through financial technology (fintech). This study aims to explore the role of fintech in supporting the development of Micro, Small, and Medium Enterprises (MSMEs) in the coastal area of Bengkulu City. The research uses a qualitative approach with observation, interviews, and documentation methods. The theory used is the public relations role theory by Cutlip, Center, and Broom (2006), which includes public opinion evaluation, organizational policy identification, and public relations activity planning. The results of the study indicate that fintech provides various benefits, such as ease of access to financial services, efficiency in financial management, and increased competitiveness of MSMEs. Solutions such as digital wallets, QR code-based payments, and microfinance help business actors overcome limitations in access to conventional banking. However, challenges such as low digital literacy, limited access to technology, high transaction costs, and inadequate internet infrastructure remain major obstacles.

As technical requirement for compaction of a reducer, we developed a high accuracy and low cost plastic micro reducer. This is used for very small information products, for example mobile-computer. The reducer is composed of three-stage gear train with a module of 0.1. With very fine EDM, the accuracy of the gear shape was improved, and the velocity fluctuation ratio reduced. In this paper, we would like to explain the technology of high accuracy and long operating life of this reducer using micro gears.

The rapidly developing interest in nanofluidic analysis, which is used to examine liquids ranging in amounts from the attoliter to the femtoliter scale, correlates with the recent interest in decreased sample amounts, such as in the field of single-cell analysis. For general nanofluidic analysis, the fact that a pressure-driven flow does not limit the choice of solvents (aqueous or organic) is important. This study shows the first pressure-driven liquid chromatography technique that enables separation of atto- to femtoliter sample volumes, with a high separation efficiency within a few seconds. The apparent diffusion coefficient measurement of the unretentive sample suggests that there is no increase in the viscosity of toluene in the extended nanospace, unlike in aqueous solvents. Evaluation of the normal phase separation, therefore, should involve only the examination of the effect of the small size of the extended nanospace. Compared to a conventionally packed high-performance liquid chromatography column, the separation here results in a faster separation (4 s) by 2 orders of magnitude, a smaller injection volume (10(0) fL) by 9 orders, and a higher separation efficiency (440,000 plates/m) by 1 order. Moreover, the separation behavior agrees with the theory showing that this high efficiency was due to the small and controlled size of the separation channel, where the diffusion through the channel depth direction is fast enough to be neglected. Our chip-based platform should allow direct and real-time analysis or screening of ultralow volume of sample.

Biotechnology and BioengineeringVolume 23, Issue 11 p. 2641-2645 Communications To The EditorFree Access Production of cellulase from trichoderma reesei in fed-batch fermentation from soluble carbon sources A. L. Allen, A. L. Allen Enzyme and Biochemical Engineering Group Environmental Sciences and Engineering Division Science and Advanced Technology Laboratory US Army Natick Research and Development Laboratories Natick, Massachusetts 01760Search for more papers by this authorR. E. Mortensen, R. E. Mortensen Enzyme and Biochemical Engineering Group Environmental Sciences and Engineering Division Science and Advanced Technology Laboratory US Army Natick Research and Development Laboratories Natick, Massachusetts 01760Search for more papers by this author A. L. Allen, A. L. Allen Enzyme and Biochemical Engineering Group Environmental Sciences and Engineering Division Science and Advanced Technology Laboratory US Army Natick Research and Development Laboratories Natick, Massachusetts 01760Search for more papers by this authorR. E. Mortensen, R. E. Mortensen Enzyme and Biochemical Engineering Group Environmental Sciences and Engineering Division Science and Advanced Technology Laboratory US Army Natick Research and Development Laboratories Natick, Massachusetts 01760Search for more papers by this author First published: November 1981 https://doi.org/10.1002/bit.260231119Citations: 34AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume23, Issue11November 1981Pages 2641-2645 ReferencesRelatedInformation

In order to meet DOE's goals of developing low-emissions coal-based power systems, PCI has further developed and adapted it's Rich-Catalytic Lean-burn (RCL{reg_sign}) catalytic reactor to a combustion system operating on syngas as a fuel. The technology offers ultra-low emissions without the cost of exhaust after-treatment, with high efficiency (avoidance of after-treatment losses and reduced diluent requirements), and with catalytically stabilized combustion which extends the lower Btu limit for syngas operation. Tests were performed in PCI's sub-scale high-pressure (10 atm) test rig, using a two-stage (catalytic then gas-phase) combustion process for syngas fuel. In this process, the first stage consists of a fuel-rich mixture reacting on a catalyst with final and excess combustion air used to cool the catalyst. The second stage is a gas-phase combustor, where the air used for cooling the catalyst mixes with the catalytic reactor effluent to provide for final gas-phase burnout and dilution to fuel-lean combustion products. During testing, operating with a simulated Tampa Electric's Polk Power Station syngas, the NOx emissions program goal of less than 0.03 lbs/MMBtu (6 ppm at 15% O{sub 2}) was met. NOx emissions were generally near 0.01 lbs/MMBtu (2 ppm at 15% O{sub 2}) (PCI's target) over a range on engine firing temperatures. In addition, low emissions were shown for alternative fuels including high hydrogen content refinery fuel gas and low BTU content Blast Furnace Gas (BFG). For the refinery fuel gas increased resistance to combustor flashback was achieved through preferential consumption of hydrogen in the catalytic bed. In the case of BFG, stable combustion for fuels as low as 88 BTU/ft{sup 3} was established and maintained without the need for using co-firing. This was achieved based on the upstream catalytic reaction delivering a hotter (and thus more reactive) product to the flame zone. The PCI catalytic reactor was also shown to be active in ammonia reduction in fuel allowing potential reductions in the burner NOx production. These reductions of NOx emissions and expanded alternative fuel capability make the rich catalytic combustor uniquely situated to provide reductions in capital costs through elimination of requirements for SCR, operating costs through reduction in need for NOx abating dilution, SCR operating costs, and need for co-firing fuels allowing use of lower value but more available fuels, and efficiency of an engine through reduction in dilution flows.

Microfluidic devices, or "lab-on-a-chip" systems for single cell analysis represent a new field of micro-total analysis systems (&#956;TAS) that could not only perform a task quicker, and more accurately than conventional methods, but could also incorporate additional tools to the study of biological variability in a population by allowing researchers to directly examine the contents of a multitude of single cells from the population under study. Realizing such a device, presents several engineering challenges to the fields of micro-machining, micromanipulation and analytical bio-chemistry. The device needs to be able to accurately and efficiently select, manipulate and analyze volumes represented by a single cell without diluting the contents. For this purpose, optical tweezers and scissors were implemented to select single cells on a microchip, bring the cell to a desired location, and lyse the cell using the optical scissors. Channels were engineered in the device using a molecular fluorine (F₂) laser. Each channel's cross-section is approximately the size of an individual cell (10&#956;m wide and deep). This paper, describes the manipulation of cells on a microchip using optical tweezers and the injection of the cellular contents by optical scissors from a single cell into 10&#956;m channels.

Metabolism is an interconnecting network of metabolite consumption and creation. Metabolomics has focused on metabolite concentrations in metabolic networks. Fluxomics is also required in the study of metabolism and quantifies the flux of substrate through each reaction step or a series of reaction steps (i.e., metabolic pathway or cycle), and ultimately is required for energy balance equations of the system. The primary noninvasive method of quantifying fluxes in living systems is by in vivo 13C nuclear magnetic resonance (NMR) spectroscopy. The present state of noninvasive in vivo NMR technology allows for just four simultaneous flux measurements of metabolic pathways: gluconeogenesis, glycogen synthesis, glycolysis, and citric acid cycle. Since the liver is the gatekeeper and metabolic center for the animal, in vivo fluxomics of liver is extensively reviewed. Additionally, other organ systems studies are discussed demonstrating interorgan cycles, such as the Cori and Randall cycles. This review discusses the basics of in vivo fluxomics focusing on the general details of the NMR experimental protocol and required hardware/software needed to analyze the data.Currently, there are two general methods for determining multiple flux rates. The dynamic method entails acquiring serial time points, whereas the static method is a single measurement in which flux through metabolic pathways is quantified by isotopomer (i.e., isotope isomers) analysis. The flux data are analyzed by mathematical models to calculate the global flux measurement (in silico fluxomics), and create a mass balance of the biosystem. Models are especially useful for inferring various metabolic states of the system, which are affected by drugs, toxicants, or pathology. As with all in silico models, increasing the number of empirically derived concentrations and fluxes into the model greatly increases the accuracy and utility of the model. NMR spectroscopy (NMRS) is inherently insensitive compared to other analytical modalities, limiting the temporal resolution of the dynamic in vivo measurements. To address the NMR sensitivity, several technological advances have been made. First, magnets are now at higher magnetic field strengths. Second, the technique of dynamic nuclear polarization (DNP) of substrates increases the signal for 13C up to five orders of magnitude.In vivo fluxomics requires a broad knowledge of biochemistry, in vivo NMRS, and metabolic modeling. Therefore, this chapter is intended as a handbook for upper division undergraduate students and graduate students in biochemistry or engineering and relates the basics of electrical and biochemical engineering and animal handling. The chapter is intended for use in an introductory graduate course on NMR-based fluxomics for physical scientist.

Emerging trends and advances in valorization of lignocellulosic biomass to biofuels

Recent advances in biofilm technologies for breeding wastewater treatment: Fundamentals, performance and impacts of antibiotics