Proof-of-concept for a segmented composite diving suit offering depth-independent thermal protection

2021 ◽  
Vol 51 (3) ◽  
pp. 295-298
Author(s):  
Aaron Demers ◽  
◽  
Shane Martin ◽  
Emil P Kartalov ◽  
◽  
...  

Heat loss is a major health hazard for divers. It can lead to hypothermia, organ damage, unconsciousness, and eventually death. Hence, thermal protection is essential for diver safety. Typically, protection is provided by wetsuits made of bubbled neoprene. However, neoprene shrinks with depth and loses thermal insulation capability, while thick neoprene suits make swimming exhausting. Herein, a proof-of-concept is presented for a solution to both problems: a ‘K-suit’ made of thermally-resistive composite segments attached to a thin neoprene suit. The segments are made of hollow glass microspheres embedded in carrier polymer thermally cured in 3D-printed molds based on 3D-scans of the diver’s body. The K-suit was compared in field trials with a 7 mm commercial neoprene suit by diving in pairs, while automated dataloggers registered pressure and temperature inside and outside both suits. The K-suit demonstrated +4ºC higher temperature difference than the 7 mm neoprene. Also, divers reported that the K-suit had the ergonomics of a 3 mm neoprene suit. These preliminary results represent a proof-of-concept for the K-suit and promise further improvements with potential impact on diver safety.

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1949
Author(s):  
Ling Ding ◽  
Wei Lu ◽  
Jiaqi Zhang ◽  
Chuncheng Yang ◽  
Guofeng Wu

Literature has reported the successful use of 3D printed polyetheretherketone (PEEK) to fabricate human body implants and oral prostheses. However, the current 3D printed PEEK (brown color) cannot mimic the vivid color of oral tissues and thus cannot meet the esthetical need for dental application. Therefore, titanium dioxide (TiO2) and ferric oxide (Fe2O3) were incorporated into PEEK to prepare a series of tooth-color and gingival-color PEEK composites in this study. Through color measurements and mechanical tests, the color value and mechanical performance of the 3D printed PEEK composites were evaluated. In addition, duotone PEEK specimens were printed by a double nozzle with an interface between tooth-color and gingival-color parts. The mechanical performance of duotone PEEK with two different interfaces (horizontal and vertical) was investigated. With the addition of TiO2 and Fe2O3, the colors of 3D printed PEEK composites become closer to that of dental shade guides. 3D printed PEEK composites generally demonstrated superior tensile and flexural properties and hence have great potential in the dental application. In addition, duotone 3D printed PEEK with a horizontal interfacial orientation presented better mechanical performance than that with a vertical one.


Author(s):  
Bruce A. Pint ◽  
Sebastien Dryepondt ◽  
Michael P. Brady ◽  
Yukinori Yamamoto ◽  
Bo Ruan ◽  
...  

Alumina-forming austenitic (AFA) steels represent a new class of corrosion- and creep-resistant austenitic steels designed to enable higher temperature recuperators. Field trials are in progress for commercially rolled foil with widths over 39 cm. The first trial completed 3000 hrs in a microturbine recuperator with an elevated turbine inlet temperature and showed limited degradation. A longer microturbine trial is in progress. A third exposure in a larger turbine has passed 16,000 hrs. To reduce alloy cost and address foil fabrication issues with the initial AFA composition, several new AFA compositions are being evaluated in creep and laboratory oxidation testing at 650–800 °C and the results compared to commercially fabricated AFA foil and conventional recuperator foil performance.


Separations ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 67
Author(s):  
Alena Šustková ◽  
Klára Konderlová ◽  
Ester Drastíková ◽  
Stefan Sützl ◽  
Lenka Hárendarčíková ◽  
...  

In our work, we produced PDMS-based microfluidic devices by mechanical removal of 3D-printed scaffolds inserted in PDMS. Two setups leading to the fabrication of monolithic PDMS-based microdevices and bonded (or stamped) PDMS-based microdevices were designed. In the monolithic devices, the 3D-printed scaffolds were fully inserted in the PDMS and then carefully removed. The bonded devices were produced by forming imprints of the 3D-printed scaffolds in PDMS, followed by bonding the PDMS parts to glass slides. All these microfluidic devices were then successfully employed in three proof-of-concept applications: capture of magnetic microparticles, formation of droplets, and isotachophoresis separation of model organic dyes.


2021 ◽  
Author(s):  
Germano MF Costa-Neto ◽  
Jose M F Crossa ◽  
Roberto F Fritsche-Neto

Quantitative genetics states that phenotypic variation is a consequence of genetic and environmental factors and their subsequent interaction. Here, we present an enviromic assembly approach, which includes the use of ecophysiology knowledge in shaping environmental relatedness into whole-genome predictions (GP) for plant breeding (referred to as E-GP). We propose that the quality of an environment is defined by the core of environmental typologies (envirotype) and their frequencies, which describe different zones of plant adaptation. From that, we derive markers of environmental similarity cost-effectively. Combined with the traditional genomic sources (e.g., additive and dominance effects), this approach may better represent the putative phenotypic variation across diverse growing conditions (i.e., phenotypic plasticity). Additionally, we couple a genetic algorithm scheme to design optimized multi-environment field trials (MET), combining enviromic assembly and genomic kinships to provide in-silico realizations of the future genotype-environment combinations that must be phenotyped in the field. As a proof-of-concept, we highlight E-GP applications: (1) managing the lack of phenotypic information in training accurate GP models across diverse environments and (2) guiding an early screening for yield plasticity using optimized phenotyping efforts. Our approach was tested using two non-conventional cross-validation schemes to better visualize the benefits of enviromic assembly in sparse experimental networks. Results on tropical maize show that E-GP outperforms benchmark GP in all scenarios and cases tested. We show that for training accurate GP models, the genotype-environment combinations' representativeness is more critical than the MET size. Furthermore, we discuss theoretical backgrounds underlying how the intrinsic envirotype-phenotype covariances within the phenotypic records of (MET) can impact the accuracy of GP and limits the potentialities of predictive breeding approaches. The E-GP is an efficient approach to better use environmental databases to deliver climate-smart solutions, reduce field costs, and anticipate future scenarios.


2021 ◽  
Vol 10 (01) ◽  
pp. 11-16
Author(s):  
Mohd Abid ◽  

The scope of Unani medicine is increasing day by day as people are becoming more interested in herbal and organic world. However, Unani (herbal) knowledge needs to be coupled with scientific documented research done to verify its efficacy. The aim of this paper is to provide updated knowledge on hypertension and its management in the Unani system of medicine. Hypertension is a major health hazard globally especially in developed countries. In the Unani system of medicine, there are mudirrat (diuretics) to reduce body fluids and minerals, and musakkin (relaxants) and munawwim (sedatives) are also advised by Unani physicians to reduce anxiety. Unani physician, Razi recommends venesection for this particular ailment. Unani physicians have given the concept of hypertension as “Imtila-ba-Hasb-ul-Auiya” and have said that this occurs due to sue-e-mizaj damwi and comes under the heading of Imtila. Literally ‘Imtala’ means gathering and fullness of the body with madda (fluids). To be precise, it means there is a buildup of normal or abnormal fluids in the body. Unani physicians were all aware of the concept of Zaghta e damwi (blood pressure). Systole as ‘Zaghta-e-Inqabazi’ and diastole as ‘Zaghta-e-Inbesati’ is well depicted in the Unani literature. Most of the world’s population, mainly in developing countries, use herbal medicines for primary health care because of their ancient tradition, culture, and minor side effects. Various kinds of research have been conducted regarding the hypotensive and antihypertensive therapeutic values of local medicinal plants in the recent past, and they have provided evidence for the antihypertensive effects of some of these plants.


2021 ◽  
Author(s):  
◽  
Caitlin Bruce

<p>New Zealand is ranked among the top nations in waste production, including a million tonnes of plastic waste. Currently, there are methods for recycling plastic within New Zealand but these methods can be expensive and time-consuming, resulting in most of the plastic being thrown into the landfill. Because plastic does not fully degrade, it ends up in the ocean and other waterways, poisoning the water with toxins. The purpose of this research is to provide a solution to reducing plastic waste by creating an alternative method of recycling that utilises new technologies such as additive manufacturing, to create a building material that fits into the concept of the circular economy. The findings of this research explored the recycling of plastic by collecting plastic waste such as PLA (Polylactic Acid) from old 3D printed models. The plastic was recycled into filament for additive manufacturing (AM) and used to print building tile, establishing an initial proof of concept for the use of recycled plastic as a potential building material.</p>


Author(s):  
Swaha Satpathy ◽  
Arjun Patra ◽  
Bharti Ahirwar

AbstractPostmenopausal osteoporosis, a silent epidemic, has become a major health hazard, afflicting about 50% of postmenopausal women worldwide and is thought to be a disease with one of the highest incidences in senile people. It is a chronic, progressive condition associated with micro-architectural deterioration of bone tissue that results in low bone mass, decreased bone strength that predisposes to an increased risk of fracture. Women are more likely to develop osteoporosis than men due to reduction in estrogen during menopause which leads to decline in bone formation and increase in bone resorption activity. Estrogen is able to suppress the production of proinflammatory cytokines like interleukin (IL)-1, IL-6, IL-7 and tumor necrosis factor (TNF-α). This is why these cytokines are elevated in postmenopausal women. In this review article we have made an attempt to collate the various methods and parameters most frequently used for screening of antiosteoporotic activity in postmenopausal osteoporosis. Pertaining to ovariectomized animal model, this is the most appropriate model for studying the efficacy of different drugs to prevent bone loss in postmenopausal osteoporosis.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 367 ◽  
Author(s):  
Nehar Celikkin ◽  
Simone Mastrogiacomo ◽  
X. Walboomers ◽  
Wojciech Swieszkowski

Bone tissue engineering is a rapidly growing field which is currently progressing toward clinical applications. Effective imaging methods for longitudinal studies are critical to evaluating the new bone formation and the fate of the scaffolds. Computed tomography (CT) is a prevailing technique employed to investigate hard tissue scaffolds; however, the CT signal becomes weak in mainly-water containing materials, which hinders the use of CT for hydrogels-based materials. Nevertheless, hydrogels such as gelatin methacrylate (GelMA) are widely used for tissue regeneration due to their optimal biological properties and their ability to induce extracellular matrix formation. To date, gold nanoparticles (AuNPs) have been suggested as promising contrast agents, due to their high X-ray attenuation, biocompatibility, and low toxicity. In this study, the effects of different sizes and concentrations of AuNPs on the mechanical properties and the cytocompatibility of the bulk GelMA-AuNPs scaffolds were evaluated. Furthermore, the enhancement of CT contrast with the cytocompatible size and concentration of AuNPs were investigated. 3D printed GelMA and GelMA-AuNPs scaffolds were obtained and assessed for the osteogenic differentiation of mesenchymal stem cells (MSC). Lastly, 3D printed GelMA and GelMA-AuNPs scaffolds were scanned in a bone defect utilizing µCT as the proof of concept that the GelMA-AuNPs are good candidates for bone tissue engineering with enhanced visibility for µCT imaging.


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