Recent digital fabrication tools have opened up accessibility to personalized rapid prototyping; however, such tools are limited to product-scale objects. The materials currently available for use in ...3D printing are too fine for large-scale objects, and CNC gantry sizes limit the scope of printable objects. In this paper, we propose a new method for printing architecture-scale objects. Our proposal includes three developments: (i) a construction material consisting of chopsticks and glue, (ii) a handheld chopstick dispenser, and (iii) a printing guidance system that uses projection mapping. The proposed chopstickglue material is cost effective, environmentally sustainable, and can be printed more quickly than conventional materials. The developed handheld dispenser enables consistent feeding of the chopstickglue material composite. The printing guidance system --- consisting of a depth camera and a projector --- evaluates a given shape in real time and indicates where humans should deposit chopsticks by projecting a simple color code onto the form under construction. Given the mechanical specifications of the stickglue composite, an experimental pavilion was designed as a case study of the proposed method and built without scaffoldings and formworks. The case study also revealed several fundamental limitations, such as the projector does not work in daylight, which requires future investigations.
The preparation and characterization of mechanoresponsive, 3D‐printed composites are reported using a dual‐printing setup for both, liquid dispensing and fused‐deposition‐modeling. The here reported ...stress‐sensing materials are based on high‐ and low molecular weight mechanophores, including poly(ε‐caprolactone)‐, polyurethane‐, and alkyl(C11)‐based latent copper(I)bis(N‐heterocyclic carbenes), which can be activated by compression to trigger a fluorogenic, copper(I)‐catalyzed azide/alkyne “click”‐reaction of an azide‐functionalized fluorescent dye inside a bulk polymeric material. Focus is placed on the printability and postprinting activity of the latent mechanophores and the fluorogenic “click”‐components. The multicomponent specimen containing both, azide and alkyne, are manufactured via a 3D‐printer to place the components separately inside the specimen into void spaces generated during the FDM‐process, which subsequently are filled with liquids using a separate liquid dispenser, located within the same 3D‐printing system. The low‐molecular weight mechanophores bearing the alkyl‐C11 chains display the best printability, yielding a mechanochemical response after the 3D‐printing process.
The preparation and characterization of mechanoresponsive, 3D‐printed composites are reported using a dual‐printing setup for both, liquid dispensing and fused‐deposition‐modeling. Printability and postprinting activity of the latent mechanophores and the fluorogenic “click”‐components are demonstrated. The low‐molecular weight mechanophores bearing the alkyl‐C11 chains display the best printability, yielding mechanochemical response after the 3D‐printing process.
Application of microfluidics offers numerous advantages in the field of radiochemistry and could enable dramatic reductions in the cost of producing radiotracers for positron emission tomography ...(PET). Droplet-based microfluidics, in particular, requires only microgram quantities of expensive precursors and reagents (compared to milligram used in conventional radiochemistry systems), and occupies a more compact footprint (potentially eliminating the need for specialized shielding facilities,
i.e.
hot cells). However, the reported platforms for droplet radiosynthesis have several drawbacks, including high cost/complexity of microfluidic reactors, requirement for manual intervention (
e.g.
for adding reagents), or difficulty in precise control of droplet processes. We describe here a platform based on a particularly simple chip, where reactions take place atop a hydrophobic substrate patterned with a circular hydrophilic liquid trap. The overall supporting hardware (heater, rotating carousel of reagent dispensers,
etc.
) is very simple and the whole system could be packaged into a very compact format (about the size of a coffee cup). We demonstrate the consistent synthesis of
18
Ffallypride with high yield, and show that protocols optimized using a high-throughput optimization platform we have developed can be readily translated to this device with no changes or re-optimization. We are currently exploring the use of this platform for routine production of a variety of
18
F-labeled tracers for preclinical imaging and for production of tracers in clinically-relevant amounts by integrating the system with an upstream radionuclide concentrator.
An ultra-compact microdroplet platform was developed for multi-step synthesis of radiolabeled tracers for positron emission tomography (PET).
Inkjet Printing in Liquid Environments Zhang, Yanzhen; Li, Dege; Liu, Yonghong ...
Small (Weinheim an der Bergstrasse, Germany)
14, Issue:
27
Journal Article
Peer reviewed
Inkjet printing (IJP) is an old but still vivifying technique for flexible and cost‐effective printing of various kinds of functional inks. Normally, IJP can only work in gaseous environments. Here, ...it is shown that traditional piezoelectric IJP can be performed in liquid environments with a totally different droplet dispensing and manipulating mechanism. With the same piezoelectric nozzle, the volume of the droplets printed in a carrier liquid can be thousands of times smaller than those printed in air. Therefore, this work demonstrates a working mode of traditional IJP with a highly improved resolution opening possibilities for novel applications of the IJP technique.
Inkjet printing (IJP) normally works in gaseous environments. Here, it is shown that traditional piezoelectric IJP can be performed in liquid environments with a totally different droplet dispensing and manipulating mechanism. With the same nozzle, the volume of the droplets printed in a carrier liquid can be thousands of times smaller than those printed in air.
Presentation on project work and progress between March 2017 and March 2018 given at the DOE Hydrogen and Fuel Cells Program 2018 Annual Merit Review and Peer Evaluation Meeting.
Nepal suffers from high burden of antimicrobial resistance (AMR) due to inappropriate use of antibiotics. The main objective of this study was to explore knowledge, attitude and practices of ...antibiotics uses among patients, healthcare workers, laboratories, drug sellers and farmers in eight districts of Nepal. A cross-sectional survey was conducted between April and July 2017. A total of 516 individuals participated in a face-to-face interview that included clinicians, private drug dispensers, patients, laboratories, public health centers/hospitals and, livestock and poultry farmers. Out of 516 respondents, 62.8% (324/516) were patients, 16.9% (87/516) were clinicians, 6.4% (33/516) were private drug dispensers. A significant proportion of patients (42.9%; 139/324) thought that fever could be treated with antibiotics. Majority (79%; 256/324) of the patients purchased antibiotics over the counter. The knowledge of antibiotics used among patients increased proportionately with the level of education: literate only AOR = 1.4 (95% Cl = 0.6-4.4), versus secondary education (8-10 grade) AOR = 1.8 (95% Cl = 1.0-3.4). Adult patients were more aware of antibiotic resistance. Use of antibiotics over the counter was found high in this study. Knowledge, attitude and practice related to antibiotic among respondents showed significant gaps and need an urgent effort to mitigate such practice.
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•Developing of a SIMULINK model for BG regulation in TIDM patient.•Design of artificial pancreas based on the SMGC/SE to regulate BG levels.•Kalman filter is integrated into the ...controller to enhance the control performance.•Evaluating the control performance under the process and sensor noise.•The comparative analysis has been done to justify the control performance.
Optimal closed loop control of blood glucose (BG) level has been a major focus for the past so many years to realize an artificial pancreas for type-I diabetes mellitus (TIDM) patients. There is an urgency for controlled drug delivery system to design with appropriate controller not only to regulate the BG level, but also for other chronic clinical disorders requiring continuous long term medication. As a solution to the above problem, a novel sliding mode Gaussian controller with state estimation (SMGC/SE) is proposed, whose gains dynamically vary with respect to the error signal. For the designing of the SMGC/SE, a nonlinear TIDM patient model is linearized as a 9th order state-space model with a micro-insulin dispenser. This controller is evaluated and compared with other recently published control techniques. Obtained results clearly reveal the better performance of the proposed method to regulate the BG level within the normoglycaemic range in terms of accuracy and robustness.
Monodisperse ZrO2 ceramic beads with size larger than 1 mm have been prepared by an improved micro‐droplet spray forming process, through which a compressor and a dispenser were employed to produce ...droplets continuously. Furthermore, the slurry recipe and drying temperature have been optimized to enhance the sphericity and smoothness of the beads. The sintered ZrO2 ceramic beads present promising mechanical performance, including a relative density of 84.6%, a crush strength of 256.2 ± 36.6 N as well as a Vickers hardness of 1344.4 ± 58.3 HV. Such procedure reveals great potential in mass production of ceramic beads.
Plant functioning and survival in drylands are affected by the combination of high solar radiation, high temperatures, low relative humidity, and the scarcity of available water. Many ...ecophysiological studies have dealt with the adaptation of plants to cope with these stresses in hot deserts, which are the territories that have better evoked the idea of a dryland. Nevertheless, drylands can also be found in some other areas of the Earth that are under the Mediterranean-type climates, which imposes a strong aridity during summer. In this review, plant species from hot deserts and Mediterranean-type climates serve as examples for describing and analyzing the different responses of trees and shrubs to aridity in drylands, with special emphasis on the structural and functional adaptations of plants to avoid the negative effects of high temperatures under drought conditions. First, we analyze the adaptations of plants to reduce the input of energy by diminishing the absorbed solar radiation through (i) modifications of leaf angle and (ii) changes in leaf optical properties. Afterwards, we analyze several strategies that enhance the ability for heat dissipation through (i) leaf size reduction and changes in leaf shape (e.g., through lobed leaves), and (ii) increased transpiration rates (i.e., water-spender strategy), with negative consequences in terms of photosynthetic capacity and water consumption, respectively. Finally, we also discuss the alternative strategy showed by water-saver plants, a common drought resistance strategy in hot and dry environments that reduces water consumption at the expense of diminishing the ability for leaf cooling. In conclusion, trees and shrubs living in drylands have developed effective functional adaptations to cope with the combination of high temperature and water scarcity, all of them with clear benefits for plant functioning and survival, but also with different costs concerning water use, carbon gain, and/or leaf cooling.
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