Poor Interconnectivity Research Articles

Solder joint shape optimization and thermal-mechanical reliability improvement for microwave RF coaxial connectors

Coaxial connectors are widely used in microwave RF components in wireless communication, aerospace, and other fields. However, the poor interconnection reliability between their inner conductors and circuit boards has been a key factor restricting their development. Thermal cycling and high temperature are the most common working loads for high-frequency devices and the failure generally takes place at the solder joint interface. Therefore this study investigated the solder joints thermal-mechanical reliability of coaxial connectors through a combination of numerical simulation and reliability experiments. Three innovative initial models were used to solve the shape simulation problem of solder joint in planar-curved composite structures. The optimal solder joint shape and structural parameters were obtained through finite element simulation, and the impact mechanism of different parameters on solder joint reliability was explained. After optimization, the maximum stress of the solder joint decreased by 44 % with thermal cycling, while the average stress decreased by 55 %. The reliability tests effectively verified the accuracy of the simulation. In addition, the 150 °C aging tests clarified the kinetics of the growth and evolution of intermetallic compounds in this solder joint structure. The results contribute to the advancement of coaxial connectors solder joints reliability and support the development of more robust and durable interconnects for microwave devices and digital communication systems.

Construction of gigantic highly-porous microcarriers as a three-dimensional cell culture platform

3D cell carriers with porous structures have the potential to promote cellular interactions and extracellular matrix remolding, making it a promising strategy to investigate the complex mechanisms behind drug treatments for tumors. Nevertheless, the applicability of currently reported porous microcarriers is still limited by the relatively small size and poor pore interconnectivity. Herein, a well-defined gigantic highly-porous poly(lactic-co-glycolic acid) (PLGA) microsphere (named LPMs) fabrication platform is reported. Utilizing this “LPMs” platform, arrays of well-uniform particles with sizes up to approximately 1000 µm are prepared in an orderly and controlled manner. The preparation matrix and crucial parameters affecting the particle size and pore size were established through extensive single-factor screening. It was also found that the loading of human gastric cancer cells MGC-803 to the LPMs cell carriers was facilitated not only by the increased pore size, but the particle size should also be enlarged along with the increased pore size. Through surface modification of gelatin on LPMs, cell loading could be dramatically enhanced, and microtissue-like structures were formed through cross-linking LPMs under extended 3D culture time. Under the guidance of these findings, we successfully constructed massive tumor cell carriers with 1000 µm LPMs, a preliminary prototype of a massive tumor tissue mimic. Together, the fabrication of these gigantic highly-porous microcarriers possibly allows for the high-efficiency 3D cell culture and represents the attractive potential of the construction of artificial tumor tissue models with massive and multiple-type cells.

Making radio, place, and the pandemic: A case study of college radio DZUP’s production response to COVID-19

This study examined how a college radio station responded to the prolonged social distancing measures imposed by the COVID-19 pandemic through practice and place-based approaches. DZUP, the radio station of the University of the Philippines Diliman was chosen for the study. Attention was given to the first year of the pandemic (March 2020–March 2021). Participant observation and focused interviews through online video conferencing were conducted to collect data for the study. The case study showed that DZUP was compelled to realign its programming and production practices to be able to stay on the air and serve its communities. In the process, several issues emerged including poor interconnectivity, the need for efficient equipment, the lack of technical skills needed for producing content on the part of some producers, and extended work schedules that affected the work-life balance of the producers. The study also revealed that the home as a place for making radio presented realities that tended to compromise the standards for aural production and delivery of content. The research highlighted the resiliency of radio in stepping up to the challenges brought by COVID-19.

Titanium nanotopography induces osteocyte lacunar-canalicular networks to strengthen osseointegration

Osteocyte network architecture is closely associated with bone turnover. The cellular mechanosensing system regulates osteocyte dendrite formation by enhancing focal adhesion. Therefore, titanium surface nanotopography might affect osteocyte network architecture and improve the peri-implant bone tissue quality, leading to strengthened osseointegration of bone-anchored implants. We aimed to investigate the effects of titanium nanosurfaces on the development of osteocyte lacunar-canalicular networks and osseointegration of dental implants. Alkaline etching created titanium nanosurfaces with anisotropically patterned dense nanospikes, superhydrophilicity, and hydroxyl groups. MLO-Y4 mouse osteocyte-like cells cultured on titanium nanosurfaces developed neuron-like dendrites with increased focal adhesion assembly and gap junctions. Maturation was promoted in osteocytes cultured on titanium nanosurfaces compared to cells cultured on machined or acid-etched micro-roughened titanium surfaces. Osteocytes cultured in type I three-dimensional collagen gels for seven days on nano-roughened titanium surfaces displayed well-developed interconnectivity with highly developed dendrites and gap junctions compared to the poor interconnectivity observed on the other titanium surfaces. Even if superhydrophilicity and hydroxyl groups were maintained, the loss of anisotropy-patterned nanospikes reduced expression of gap junction in osteocytes cultured on alkaline-etched titanium nanosurfaces. Four weeks after placing the titanium nanosurface implants in the upper jawbone of wild-type rats, osteocytes with numerous dendrites were found directly attached to the implant surface, forming well-developed lacunar-canalicular networks around the nano-roughened titanium implants. The osseointegration strength of the nano-roughened titanium implants was significantly higher than that of the micro-roughened titanium implants. These data indicate that titanium nanosurfaces promote osteocyte lacunar-canalicular network development via nanotopographical cues and strengthen osseointegration. Statement of significanceThe clinical stability of bone-anchoring implant devices is influenced by the bone quality. The osteocyte network potentially affects bone quality and is established by the three-dimensional (3D) connection of neuron-like dendrites of well-matured osteocytes within the bone matrix. No biomaterials are known to regulate formation of the osteocyte network. The present study provides the first demonstration that titanium nanosurfaces with nanospikes created by alkali-etching treatment enhance the 3D formation of osteocyte networks by promoting osteocyte dendrite formation and maturation by nanotopographic cues, leading to strengthened osseointegration of titanium implants. Osteocytes attached to the titanium nanosurfaces via numerous cellular projections. The success of osteocyte regulation by nanotechnology paves the way for development of epoch-making technologies to control bone quality.

Environmentally Friendly Polyamide Nanofiber Membranes with Interconnective Amphiphobic Channels for Seawater Desalination.

Seawater desalination is a promising and sustainable solution to alleviate freshwater scarcity; however, most existing desalination membranes suffer from poor channel interconnectivity and toxic solvent processing and encounter a tradeoff dilemma of salt rejection and water flux. Herein, we report a unique and facile one-step green solvent/nonsolvent spinning methodology to assemble environmentally friendly polyamide nanofiber membranes with a precisely designed interconnective/stable channel structure and surface anti-wettability for seawater desalination. Direct electrospinning without any post-treatments via in situ introduction of fluorinated chemicals enables highly interconnective amphiphobic channels within polyamide membranes, and the incorporation of nonsolvent (diacetone alcohol) into polyamide/solvent (ethanol) spinning solutions endows the green alcohol-based polyamide membranes with a stable bonding structure and small pore size. The resultant green solvent/nonsolvent-spun polyamide nanofiber membranes show impressive liquid entry pressure (120.5 kPa) and vapor permeation (12.5 kg m-2 d-1), achieving robust seawater desalination performance with a salt rejection of 99.97% and permeate flux of 47.4 kg m-2 h-1. The facile one-step solvent/nonsolvent spinning strategy, highly interconnective amphiphobic channels, and green solvent-based environmental friendliness in this work can open opportunities for future polyamide membranes for practical applications in water purification.

Current advancement of flexible dye sensitized solar cell: A review

In the last two decades, research on dye-sensitized solar cells (DSSCs) has shown tremendous improvement with promising findings. It has become one of the alternative options in replacing conventional silicon-based photovoltaics. Recently, a study towards the flexible form of solar cells has gained the attention of researchers. The features possess in DSSC such as high flexibility, light weight and environmentally friendly have made DSSC suitable for such purposes compared to rigid glass substrates. However, the biggest challenge faced by plastic-type substrates is temperature, where plastic substrates only withstand up to 150 °C before melting. In the DSSC fabrication process, temperatures as high as 400–500 °C are critically required for the purpose of material crystallization. With insufficient temperature during this process, poor interconnection between nanoparticles and increased electrode resistance will occur, thereby lowering the performance of plastic based DSSC. Here, we discuss the approaches that researchers have performed in solving the problem. Such approaches include the use of doctor blades, electrophoretic deposition, hydrothermal, peel and stick technique, and pulse laser deposition methods. In addition, this paper also discusses the most recent method which is additional procedure using Titanium(IV) tetraisopropoxide or UV-O3 treatment in the preparation of flexible DSSC. Several types of photoanode materials such as titanium dioxide, zinc oxide and graphene are also discussed in this paper.

The organization of the zebrafish pallium from a hodological perspective.

We studied the connections (connectome) of the adult zebrafish pallium using carbocyanine dye tracing and ancillary anatomical methods. The everted zebrafish pallium (dorsal telencephalic area, D) is composed of several major zones (medial, lateral, dorsal, central, anterior, and posterior) distinguishable by their topography, cytoarchitecture, immunohistochemistry, and genoarchitecture. Our comprehensive study reveals poor interconnectivity between these pallial areas, especially between medial (Dm), lateral/dorsal (Dl, Dd), and posterior (Dp) regions. This suggests that the zebrafish pallium has dedicated modules for different neural processes. Pallial connections with extrapallial regions also show compartmental organization. Major extratelencephalic afferents come from preglomerular nuclei (to Dl, Dd, and Dm), posterior tuberal nucleus (to Dm), and lateral recess nucleus (to Dl). The subpallial (ventral, V) zones dorsal Vv, Vd, and Vs, considered homologues of the striatum, amygdala, and pallidum, are mainly afferent to Dl/Dd and Dp. Regarding the efferent pathways, they also appear characteristic of each pallial region. Rostral Dm projects to the dorsal entopeduncular nucleus. Dp is interconnected with the olfactory bulbs. The central region (Dc) defined here receives mainly projections from Dl-Dd and projects toward the pretectum and optic tectum, connections, which help to delimiting Dc. The connectome of the adult pallium revealed here complements extant studies on the neuroanatomical organization of the brain, and may be useful for neurogenetic studies performed during early stages of development. The connectome of the zebrafish pallium was also compared with the pallial connections reported in other teleosts, a large group showing high pallial diversity.

Investigating the manufacturing technology and durability of lime mortars from Amaiur Castle (Navarre, Spain): A chemical–mineralogical and physical study

Mineralogical, chemical and physical characterization of archaeological lime mortars from different structures at Amaiur Castle (Navarre, Spain) was accomplished in order to comprehend their durability. Mortars from the south-west of the 16th century filling and bastion, and the south-east mortars of the17th century bastion are the most susceptible to deterioration due to their textural features. The high porosity and water absorption capacity, the poor interconnection of pores and slow drying are the main factors contributing to deterioration of mortar at Amaiur Castle. The mineralogical study enabled an approach to the technological knowledge used in the lime mortar manufacturing process at Amaiur Castle. Hydrotalcite and hydromagnesite identified in the mortar binder support the use of the traditional hot-mixing method during mortar manufacturing. This work provides valuable references for the formulation of compatible repair mortars to ensure suitable conservation of the castle as well as of other ancient structures built with similar materials.

Pore structure and sorption capacity investigations of Ediacaran and Lower Silurian gas shales from the Upper Yangtze platform, China

The shale gas potential of Ediacaran and Lower Silurian shales from the Upper Yangtze platform is assessed in this study with a focus on the contributions of clay minerals and organic matter to sorption capacity. For this purpose, a multidisciplinary assessment was carried out using petrophysical, mineralogical, petrographic and geochemical methods. In terms of TOC contents (4.2%), brittle mineral contents (68.6%) and maximum gas storage capacities (0.054–0.251 mmol/g) Ediacaran shales from this study show comparable properties to other producing shale gas systems although the thermal maturity is extremely high (VRr = 3.6%). When compared to lower Silurian shales from the same region, it is evident that (1) deeper maximum burial and (2) a lack of silica-associated preservation of the pores resulted in a relatively lower mesopore volume, higher micropore volume fraction and lower overall porosity (Ediacaran shales: 1.4–4.6%; Silurian shales: 6.2–7.4%). Gas production is therefore retarded by poor interconnectivity of the pore system, which was qualitatively demonstrated by comparing experimental gas uptake kinetics. TOC content exhibits a prominent control on sorption capacity and micropore volume for both shales. However, different contributions of clay minerals to sorption capacity were identified. This can partly be attributed to different clay types but is likely also related to burial-induced recrystallisation and different origins of illite. Additionally, it was shown that variations in sorption capacity due to incorrect estimates of clay mineral contribution are in the same range as variations due to differences in thermal maturity.Article highlightsPore structure and gas storage characteristics are evaluated for the first time for Ediacaran Shales from the Upper Yangtze platformDue to a lower free gas storage capacity and diffusivity, the Ediacaran shale can be regarded as a less favorable shale gas prospect when compared to the Silurian shaleClay mineral contribution to sorption capacity is evaluated taking clay mineralogy into considerationMaturity-related changes of organic matter sorption capacity have been discussed on the basis of a compiled data set

Control of pore-size distribution on CO2 adsorption volume and kinetics in Gondwana coals: Implications for shallow-depth CO2 sequestration potential

We report experimental CO2 adsorption isotherms and diffusion-related parameters of fresh coal samples from Jharia (350–360 m) and South Karanpura (50–60 m) coalfields, India at three different temperatures (28, 35 and 45 °C) and up to 4 MPa CO2 pressures. The results confirm that temperature possesses an inverse relationship with the excess adsorption volume. Data modelling with the Langmuir and Dubinin-Radushkevich (D-R) equations show the D-R equation better predicts the experimental excess adsorption data. A conversion of the excess adsorbed volume to absolute adsorption further reveals that the modified D-R equation is even a better model to estimate absolute adsorption than the conventional D-R equation. Adsorption kinetics data indicate that temperature has a positive influence on the adsorption rate. We determined the diffusion coefficients of CO2 in these coals using the unipore model, which suggest that it increases with pressure and temperature. Effective diffusivity and diffusion-time maintain a direct and inverse relationship, respectively, with the elevation of temperature. The experimental adsorbed volume and kinetics data are correlated with the corresponding pore-size distribution of the samples. Shallow depth South Karanpura samples have lower average pore diameter, higher volumetric proportion of micropores and surface area compared to those of higher depth Jharia coal samples. Lower adsorption volume and sluggish adsorption kinetics in Jharia coals result from a small surface area and relatively sparse distribution of semi open-ended micropores with poor interconnection. Based on our experimental observations, we discuss and suggest the potential and possible conditions for CO2 sequestration in the Permian Gondwana coalfields, India.

Bone tissue regeneration: The role of finely tuned pore architecture of bioactive scaffolds before clinical translation

Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth. However, it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity. Here, the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model. The 6% Mg-substituted wollastonite (CSi-Mg6) powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography, displaying designed constant pore strut and tailorable pore height (200, 320, 450, 600 μm), were investigated thoroughly in the bone regeneration process. Together with detailed structural stability and mechanical properties were collaboratively outlined. Both μCT and histological analyses indicated that bone tissue ingrowth was retarded in 200 μm scaffolds in the whole stage (2–16 weeks) but the 320 μm scaffolds showed appreciable bone tissue in the center of porous constructs at 6–10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks. Interestingly, the neo-tissue ingrowth was facilitated in the 450 μm and 600 μm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage. These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo. Simultaneously, this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.

Telemedicine During the COVID-19 in Italy: A Missed Opportunity?

In the time of COVID-19 epidemic, Italy was found unprepared to manage lockdown patients with chronic diseases, due to limited availability and diffusion of large-scale telemedicine solutions. The scattered distribution and heterogeneity of available tools, the lack of integration with the electronic health record of the national health system, the poor interconnection between telemedicine services operating at different levels, the lack of a real multidisciplinary approach to the patient's management, the heavy privacy regulations, and lack of clear guidelines, together with the lack of reimbursement, all hinder the implementation of effective telemedicine solutions for long-term patients' management. This COVID-19 epidemic should help promote better use and a larger integration of telemedicine services in the armamentarium of health care services. Telemedicine must no longer be considered as an option or add-on to react to an emergency.

Effects of macropore size in carbonate apatite honeycomb scaffolds on bone regeneration.

The pore architecture of scaffolds is a critical factor for angiogenesis and bone regeneration. Although the effects of scaffold macropore size have been investigated, most scaffolds feature macropores with poor uniformity and interconnectivity, and other parameters (e.g., microporosity, chemical composition, and strut thickness) differ among scaffolds. To clarify the threshold of effective macropore size, we fabricated honeycomb scaffolds (HCSs) with distinct macropore (i.e., channel) sizes (~100, ~200, and ~300μm). The HCSs were composed of AB-type carbonate apatite with ~8.5% carbonate ions, i.e., the same composition as human bone mineral. Their honeycomb architecture displayed uniformly sized and orderly arranged channels with extremely high interconnectivity, and all the HCSs displayed ~100-μm-thick struts and 0.06cm3g-1 of micropore volume. The compressive strengths of HCSs with ~100-, ~200-, and ~300-μm channels were higher than those of reported scaffolds, and decreased with increasing channel size: 62±6, 55±9, and 43±8MPa, respectively. At four weeks after implantation in rabbit femur bone defects, new bone and blood vessels were formed in all the channels of these HCSs. Notably, the ~300-μm channels were extensively occupied by new bone. We demonstrated that high interconnectivity and uniformity of channels can decrease the threshold of effective macropore size, enabling the scaffolds to maintain high mechanical properties and osteogenic ability and serve as implants for weight-bearing areas.

Experimental Investigation of the Dependence of Accessible Porosity and Methane Sorption Capacity of Carbonaceous Shales on Particle Size

Crushing and grinding of carbonaceous shale samples is likely to enhance the accessibility of pores and embedded organic matter as compared to the intact rock. This may lead to an overestimation of the total (volume and sorptive) gas storage capacity. In order to investigate the importance of these effects we have measured unconfined apparent grain densities (helium pycnometry) and methane sorption capacities (high-pressure methane excess sorption) of four carbonaceous shales (Cambro-Ordovician Alum Shale, Jurassic Kimmeridge Clay, Jurassic/Cretaceous Bazhenov Shale, and Late Cretaceous Eagle Ford Shale) as a function of particle size. Measurements were first conducted on 38 mm diameter core plugs, which then were crushed and milled to successively smaller particle sizes (<10 mm, <2 mm, <64 μm, and <1 μm). Apparent grain densities of the smallest particle fractions of the Alum, Bazhenov and Kimmeridge samples were consistently higher by 0.5 to 1% than apparent grain densities of the original sample plugs. Methane excess sorption capacity increased significantly for particle sizes <64 μm for the Alum and <1 μm for the Bazhenov and Kimmeridge samples while no significant changes upon grinding were observed for the Eagle Ford Shale. For the Bazhenov Shale, the apparent grain density increased slightly from 2.446 g/cm3 to 2.450 g/cm3 upon particle size reduction from <64 μm to <1 μm while the maximum sorption capacity (“Langmuir volume”) increased substantially from 0.11 mmol/g to 0.19 mmol/g. Similarly, for the Kimmeridge Clay and Alum Shale, a slight increase of the apparent grain density from 1.546 g/cm3 to 1.552 g/cm3 and from 2.362 g/cm3 to 2.385 g/cm3, respectively, was accompanied by increases in sorption capacity from 0.37 mmol/g to 0.45 mmol/g and from 0.14 mmol/g to 0.185 mmol/g, respectively. The increase in sorption capacity indicates an opening of a considerable amount of micropores with large internal surface area upon physical disruption of the rock fabric and/or removal of included fluids. It may also be due to increased swelling abilities of clay minerals and organic matter upon destruction of the stabilizing rock fabric with decreasing particle size. Grain density and sorption isotherms measured on small particle sizes are likely to overestimate the gas storage capacities and the amounts of producible gas-in-place since under field conditions (largely undisrupted rock fabric), significant portions of this storage capacity are essentially inaccessible. Poor interconnectivity of the pore system and slow, diffusion-controlled transport will massively retard gas production. Based on these findings, particle sizes >64 μm should be used for porosity and sorption measurements because they are more likely to retain the properties of the rock fabric in terms of accessible pore volume and sorptive storage capacity.

Numerical analysis on thermal crack initiation due to non-homogeneous solder coating on the round strip interconnection of photo-voltaic modules

Solar energy is one of the most widely used renewable energy sources, with photo-voltaic (PV) solar cells/panels now utilized as an important energy source. The strip interconnection between solar cells (used for collecting current from solar cells) is a key PV module component; as poor interconnection reliability can lead to PV module failure. Multi-Busbar is a new type of interconnection which incorporates several round copper wires to help increase the energy conversion and transmission efficiency of PV modules and also to reduce the material costs. The non-homogeneity of the solder coating on the wires (resulting from manufacturing process faults), is one of the main factors that is responsible for the poor connections between the wire and the silver pads; which adversely impacts on the interconnection strength and long term reliability. This paper concerns an investigation of the effect of solder coating non-homogeneity on the thermo-mechanical response of round wires used for PV module interconnections. The study evaluates the two main parameters of non-homogeneity (out of centre value and direction), and also investigates the effect of geometrical parameters. The Extended Finite Element Method in ABAQUS software was used to determine the micro-crack initiation temperature and location for a given joint design. The results show that the cracking temperature is most affected by the direction of solder coating non-homogeneity and the downward vertical direction of out of centre positioning of copper in the solder coating leads to the most reduction in cracking temperature (up to 21%).

Mechanical energy and thermal effect controlled micropore nucleation and growth mechanism in oriented high density polyethylene

Aiming to reveal the effects of mechanical energy and thermal effect on micropore nucleation and growth in oriented high density polyethylene (HDPE) film, stress relaxation after cold stretching was imposed at low and elevated temperature with strain holding constant, respectively, and corresponding structure evolution was tracked by in situ and ex situ small angle X-ray scattering (SAXS). It was found that stress-induced density fluctuation during cold stretching could be completely recovered as soon as the stress was unloaded, which was called as micropore embryo. Mechanical energy release at low temperature can promote micropore nucleation after an induction period. However, the growth of micropore nuclei is inhomogeneous, developing as non-uniform micropores with poor interconnectivity during hot stretching. While during temperature elevation, micropore embryos can be converted into evenly distributed micropores together with formation of fibrils, which can supply growth sites for through pores during hot stretching. Consequently, microporous membranes with narrow micropore size distribution and good permeability could be obtained after the subsequent hot stretching.

MBG-Modified β-TCP Scaffold Promotes Mesenchymal Stem Cells Adhesion and Osteogenic Differentiation via a FAK/MAPK Signaling Pathway.

The β-TCP scaffold has been widely used as a bone graft substitute, but the traditional PMMA molding method-induced undesirable mechanical strength and poor interconnectivity still have not been addressed until now. In this study, a MBG-based PU foam templating method was developed to fabricate β-TCP scaffolds with desirable microtopography. The MBG gel, as both binder and modifier, prepared by a modified sol-gel method with controlled viscosity is incorporated with β-TCP powder and thereafter is impregnated into PU foam. The resultant hybrid scaffolds exhibited interconnected macropores (200-500 μm) and distinctive micropores (0.2-1.5 μm), especially for the TCP/25MBG (with 25 wt % content MBG). As expected, the compression strength of β-TCP/MBG composite scaffolds was enhanced with increasing MBG content, and TCP/50MBG (with 50 wt % content MBG) exhibited almost 100-fold enhancement compared to the pure β-TCP. Intriguingly, the cell affinity and osteogenic capacity of rBMSCs were also dramatically improved the best on TCP/25MBG. Further investigation found that the subtle, grainy-like microtopography, not the chemical composition, of the TCP/25MBG favored the adsorption of Fn and expression of integrin α5β1 and further facilitated FA formation and the expression of p-FAK, following activation of the MAPK/ERK signaling pathway and ultimately upregulated expression of osteogenic genes. Further in vivo experiments confirmed the promoted osteogenesis of TCP/25MBG in vivo. The results suggest that such a novel MBG-based PU foam templating method offers new guidance to construct hierarchically porous scaffolds, and the prepared MBG-modified β-TCP scaffold will have great potential for future use in bone tissue regeneration.

Silver Nanowire-IZO-Conducting Polymer Hybrids for Flexible and Transparent Conductive Electrodes for Organic Light-Emitting Diodes.

Solution-processed silver nanowire (AgNW) has been considered as a promising material for next-generation flexible transparent conductive electrodes. However, despite the advantages of AgNWs, some of their intrinsic drawbacks, such as large surface roughness and poor interconnection between wires, limit their practical application in organic light-emitting diodes (OLEDs). Herein, we report a high-performance AgNW-based hybrid electrode composed of indium-doped zinc oxide (IZO) and poly (3,4-ethylenediowythiophene):poly(styrenesulfonate) [PEDOT:PSS]. The IZO layer protects the underlying AgNWs from oxidation and corrosion and tightly fuses the wires together and to the substrate. The PEDOT:PSS effectively reduces surface roughness and increases the hybrid films’ transmittance. The fabricated electrodes exhibited a low sheet resistance of 5.9 Ωsq−1 with high transmittance of 86% at 550 nm. The optical, electrical, and mechanical properties of the AgNW-based hybrid films were investigated in detail to determine the structure-property relations, and whether optical or electrical properties could be controlled with variation in each layer’s thickness to satisfy different requirements for different applications. Flexible OLEDs (f-OLEDs) were successfully fabricated on the hybrid electrodes to prove their applicability; their performance was even better than those on commercial indium doped tin oxide (ITO) electrodes.

SU‐F‐P‐08: Medical Physics Perspective On Radiation Therapy Quality and Safety Considerations in Low Income Settings

Purpose:The last few years have seen a significant growth of interest in the global radiation therapy crisis. Various organizations are quantifying the need and providing aid in support of addressing the shortfall existing in many low‐to‐middle income countries (LMICs). The Lancet Oncology Commission report (Lancet Oncol. Sep;16(10):1153‐86, 2015) projects a need of 22,000 new medical physicists in LMICs by 2035 if there is to be equal access globally. With the tremendous demand for new facilities, equipment and personnel, it is very important to recognize quality and safety considerations and to address them directly.Methods:A detailed examination of quality and safety publications was undertaken. A paper by Dunscombe (Front. Oncol. 2: 129, 2012) reviewed the recommendations of 7 authoritative reports on safety in radiation therapy and found the 12 most cited recommendations, summarized in order of most to least cited: training, staffing, documentation/standard operating procedures, incident learning, communication/questioning, check lists, QC/PM, dosimetric audit, accreditation, minimizing interruptions, prospective risk assessment, and safety culture. However, these authoritative reports were generally based on input from high income contexts. In this work, the recommendations were analyzed with a special emphasis on issues that are significant in LMICs.Results:The review indicated that there are significant challenges in LMICs with training and staffing ranking at the top in terms quality and safety.Conclusion:With the recognized need for expanding global access to radiation therapy, especially in LMICs, and the backing by multiple support organizations, quality and safety considerations must be overtly addressed. While multidimensional, training and staffing are top priorities. The use of outdated systems with poor interconnectivity, coupled with a lack of systematic QA in high patient load settings are additional concerns. Any support provided to lower resourced settings must address the multiple facets associated with these quality and safety indicators.

Anodic formation of highly ordered TiO2 nanotube arrays on conducting glass substrate: Effect of titanium film thickness

Highly ordered TiO2 nanotube arrays were successfully fabricated using ammonium fluoride electrolyte by galvanostatic anodization technique. The nanotube arrays were grown perpendicular to the titanium film deposited onto conducting glass substrate. The effect of the different titanium film thicknesses on the morphology, optical, and electrical properties of TiO2 nanotube arrays is investigated. It is found that the titanium film thickness is a crucial parameter for achieving highly ordered TiO2 nanotube arrays. Morphological investigations on the nanotube arrays reveal that anodization of 1.5 μm thick titanium films leads to formation of pores at the upper layer of the film with nonuniform pore size distribution and poor interconnectivity. Instead, anodization of 2.5 and 2.0 μm thick titanium films with the same conditions leads to formation of highly ordered TiO2 nanotube arrays with uniform size and sharp clear tubular structures, which are well connected to each other. The absorbance and optical band gap of the TiO2 nanotube arrays are also inferred from the diffuse reflectance spectra.Highly ordered TiO2 nanotube arrays were successfully fabricated using ammonium fluoride electrolyte by galvanostatic anodization technique. The nanotube arrays were grown perpendicular to the titanium film deposited onto conducting glass substrate. The effect of the different titanium film thicknesses on the morphology, optical, and electrical properties of TiO2 nanotube arrays is investigated. It is found that the titanium film thickness is a crucial parameter for achieving highly ordered TiO2 nanotube arrays. Morphological investigations on the nanotube arrays reveal that anodization of 1.5 μm thick titanium films leads to formation of pores at the upper layer of the film with nonuniform pore size distribution and poor interconnectivity. Instead, anodization of 2.5 and 2.0 μm thick titanium films with the same conditions leads to formation of highly ordered TiO2 nanotube arrays with uniform size and sharp clear tubular structures, which are well connected to each other. The absorbance and optical band ...