Control System Design for Low PowerMagnetic Bearings in a Flywheel Energy Storage System

This paper presents a theoretical and experimental study on controller design for the AMBs in a small-scale flywheel energy storage system,where the main goals are to achieve low energy consumption and improved rotordynamic stability.A H-infinity optimal control synthesis procedure is defined for the permanent-magnet-biased AMB-rotor system with 4 degrees of freedom.Through the choice of design weighting functions,notch filter characteristics are incorporated within the controller to reduce AMB current components caused by rotor vibration at the synchronous frequency and higher harmonics.Experimental tests are used to validate the controller design methodology and provide comparative results on performance and efficiency.The results show that the H-infinity controller is able to achieve stable rotor levitation and reduce AMB power consumption by more than 40%(from 4.80 to 2.64 Watts)compared with the conventional PD control method.Additionally,the H-infinity controller can prevent vibrational instability of the rotor nutation mode,which is prone to occur when operating with high rotational speeds.

“There Are Many Cases That You Carry with You That Leave Scars”: Burnout and Secondary Trauma among Pediatric Residents in Routine and Covid Times

The current research joins previous studies in examining post-traumatic stress disorder (PTSD) and burnout among healthcare workers. The research focuses on the experiences of pediatric residents working in an emergency department both in normal times and during the Covid pandemic. Research conducted prior to and during the Covid pandemic outbreak shows negative psychological effects among healthcare workers. Most of that research was conducted within the positivistic-quantitative paradigm. The current study is qualitative and focuses on pediatric residents who provide medical services to a unique population in a peripheral region of Israel, namely the Bedouin-Arab population. The research questions are the following: What characterizes pediatric residents’ work, in general and during the pandemic? Do they show signs of burnout and secondary trauma? How do they perceive their work with the Bedouin-Arab population, especially during the pandemic? The study, conducted within the phenomenological genre, included 14 pediatric residents in a large hospital in Israel’s periphery. Semi-structured clinical interviews were employed, in addition to questionnaires that examined PTSD and burnout to enhance the reliability of the findings. The results show that all residents reported stressful incidents in which patients’ physical integrity was threatened. The residents described the special nature of the medical cases they treated in routine times and during the pandemic outbreak, which stems mostly from the specific characteristics the population of Israel’s periphery. While at the early stages of the pandemic, the residents experienced reduced work pressure, they reported substantial difficulties later in the crisis, which intensified their sense of physical and emotional stress. Most residents reported feeling inadequately prepared for dealing with traumatic events. According to the results, most residents displayed secondary trauma (12 participants in interviews and 11 in questionnaires), which can be classified into categories based on the DSM-5. In the interviews, all 14 participants reported various signs of burnout. The questionnaires indicated burnout symptoms among 10 participants. Giving a voice to pediatric residents, the study highlights the complexity of their routine work as well as their role during the Covid crisis. Based on the findings, recommendations have been made for policymakers. The study highlights the importance of raising awareness to the implications of the residents’ rough work conditions in routine and emergency times and to the need to develop social support and intervention programs that might improve their well-being during their professional work.

Surface-emitting lasers meet metasurfaces

The integration between vertical-cavity surface-emitting lasers and metasurfaces has been demonstrated to enable on-chip high-angle illumination for total internal reflection and dark-field microscopy. Such an ultracompact combined laser-beam shaper system provides a versatile illumination module for high-contrast imaging, thus leveraging biophotonics and lab-on-a-chip devices and facilitating life-science applications.

用NMR研究洋葱碳吸附水后的抗磁性（英文）

对洋葱状碳缺陷位吸附水分子的1H化学位移进行测试,并比较块状水和石墨烯、氧化石墨烯和纳米金刚石吸附水的化学位移。纳米金刚石和氧化石墨烯绝缘体的1H共振位置与块状水接近,然而石墨烯和洋葱碳吸附水呈现明显的化学位偏移,这是由导电的石墨烯片层抗磁屏蔽效应所致。质子的化学位移和抗磁性之间存在显著的相关性。

Affinity-induced covalent protein-protein ligation via the SpyCatcherSpyTag interaction

Production of economically viable bioethanol is potentially an environmentally and financially worthwhile endeavor.One major source for fermentable sugars is lignocellulose.However,lignocellulosic biomass is difficult to degrade,owing to its inherent structural recalcitrance.Cellulosomes are complexes of cellulases and associated polysaccharide-degrading enzymes bound to a protein scaffold that can efficiently degrade lignocellulose.Integration of the enzyme subunits into the complex depends on intermodular cohesin-dockerin interactions,which are robust but nonetheless non-covalent.The modular architecture of these complexes can be used to assemble artificial designer cellulosomes for advanced nanotechnological applications.Pretreatments that promote lignocellulose degradation involve high temperatures and acidic or alkaline conditions that could dismember designer cellulosomes,thus requiring separation of reaction steps,thereby increasing overall process cost.To overcome these challenges,we developed a means of covalently locking cohesin-dockerin interactions by integrating the chemistry of SpyCatcher-SpyTag approach to target and secure the interaction.The resultant cohesin-conjugated dockerin complex was resistant to high temperatures,SDS,and urea while high affinity and specificity of the interacting modular components were maintained.Using this approach,a covalently locked,bivalent designer cellulosome complex was produced and demonstrated to be enzymatically active on cellulosic substrates.The combination of affinity systems with SpyCatcher-SpyTag chemistry may prove of general use for improving other types of protein ligation systems and creating unconventional,biologically active,covalently locked,affinity-based molecular architectures.

Smart Grid Communication Technologies

The smart grid is a new generation of standard power distribution grid. The communication infrastructure is critical for the successful operation of the modern smart grids. The use of communication technologies ensures the reduction of energy consumption, optimal operation of the smart grid and coordination between all smart grids’ components from generation to the end users. This paper presents an overview of existing communication technologies such as ZigBee, WLAN, cellular communication, WiMAX, Power Line Communication (PLC), their implementation in smart grids, advantages and disadvantages. Moreover, the paper shows comparison of communication infrastructure between the legacy grid and the smart grid and smart grid communication standards. The paper also presents research challenges and future trends in communication systems for smart grid application.

Advances in nano silver-based biomaterials and their biomedical applications

Silver nanoparticles are among the most widely researched and used for nanotechnology-derived structures due to their extraordinary inherent optical properties,chemical stability,catalytic activity,and high conductivity.These idiosyncratic properties can be attributed to their unique physico-chemical characteristics,such as ultrafine sizes,high surface area,diverse shapes,and strong localized surface plasmon resonance.These distinctive features can be tailored using various physical,chemical,and biological synthesis methods.Various physical techniques are viable for producing silver nanoparticles on a large scale,but they suffer from drawbacks such as high-power con-sumption,expensive set-up,and limited control over nanoparticle size distribution.Chemical methods provide benefits like high yield,consistent shape and size distribution,and cost efficiency,but the residual toxicity of the chemicals involved hinders their biological applications.Biological synthesis approaches effectively overcome the limitations of both physical and chemical methods by eliminating the need for hazardous chemicals,requiring less energy,enabling diverse nanoparticle morphologies,and offering eco-friendliness and exceptional biocom-patibility.The novel and promising properties of nanosilver-based biomaterials have been demonstrated to be suitable for a wide range of pharmacological and therapeutic biomedical applications.Their extensive application in wound healing,dentistry,cardiovascular disease treatment,nerve tissue engineering,cancer treatment,and biosensing can be attributed to their inherent antimicrobial and antibiofilm activity,antithrombotic properties,potential for nerve regeneration,photothermal conversion efficiency and sensitivity,respectively.This review discusses the different methods employed for synthesising silver nanoparticles and focuses on using nanosilver-based biomaterials for various biomedical applications.