Physical Size Reduction Research Articles

Soluplus® promotes efficient transport of meloxicam to the central nervous system via nasal administration

In our present series of experiments, we investigated the nasal applicability of the previously developed Soluplus® - meloxicam polymeric micelle formulation. Utilizing the nasal drug investigations, moderately high mucoadhesion was experienced in nasal conditions which alongside the appropriate physicochemical properties in liquid state, contributed to rapid drug absorption through human RPMI 2650 cell line. Ex vivo studies also confirmed that higher nasal mucosal permeation could be expected with the polymeric micelle nanoformulation compared to a regular MEL suspension. Also, the nanoformulation met the requirements to provide rapid drug permeation in less 1 h of our measurement. The non-toxic, non-cell barrier damaging formulation also proved to provide a successful passive transport across excides human nasal mucosa. Based on our in vivo investigations, it can be concluded that the polymeric micelle formulation provides higher meloxicam transport to the central nervous system followed by a slow and long-lasting elimination process compared to prior results where physical particle size reduction methods were applied. With these results, a promising solution and nanocarrier is proposed for the successful transport of non-steroidal anti-inflammatory drugs with acidic character to the brain.

Size Reduction and Performance Enhancement of Coplanar-Waveguide Resonators for Surface Plasmonic Applications

Coplanar waveguide (CPW) is partially integrated with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> -strip TLs at critical areas with locally strong electromagnetic field confinement. The new integration is shown to impact the propagation constant of the structure.The impacts of the added <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> -strip TL are theoretically discussed on a loaded CPW using the incident-reflected wave concept. It is mathematically shown that a specific phase is added to the phase of conventional CPWs by the proposed modification. The added phase is then used for physical size reduction and performance enhancement of the structure. Considering the propagation manipulation of the CPWs, the modified structure is researched as a unit cell for spoof surface plasmon polariton (SSPP).

COVID-19 Containment Measures at Childcare and Schools in 19 European Countries: An Observational Study on Local, Federal and National Policies.

Objectives: After childcare and schools have been closed in March 2020 to prevent the spread of COVID-19, they were open again in most European countries after the summer holidays till early autumn. Aim of this study is to give an overview and to compare COVID-19 childcare and school containment policies in 19 European countries. Methods: We collected data on containment measures among delegates of the European Academy of Pediatrics (EAP), through an online, closed questionnaire in the second half of October 2020. Results: Most policy has been formulated for secondary education. In all three settings policy was most often formulated for individual hygiene, cleaning of surfaces, exclusion of sick children, ventilation, distance between children and between children and teachers. In secondary schools, policy is formulated on face masks in and outside the class. School closure, cancellation of physical education and class size reduction are measures for which the fewest countries have formulated national policies. Conclusion: We recommend to accompany the opening of children’s facilities and schools by surveillance studies that further clarify questions about control measures implemented to halt COVID-19 pandemic.

Electrical Size Reduction of Microstrip Antennas by Using Defected Ground Structures Composed of Complementary Split Ring Resonator

In this study the effects of using defected ground structures (DGS) composed of a complementary split ring resonator (CSRR) and CSRR with dumbbell (CSRR-D) for rectangular microstrip antennas are investigated. On this aim, two different antennas, which are Antenna B having CSRR etched DGS and Antenna C having CSRR-D etched DGS are designed and fabricated in comparison with the ordinary rectangular patch antenna, which is Antenna A. In both Antennas B and C, CSRR structures are etched in the same position of the ground planes. On the other hand, another ordinary microstrip antenna, called Antenna D, is designed at resonance frequency of Antenna C. For the characterization; resonance frequencies, voltage standing wave ratios, percentage bandwidths, gains, ka values and gain radiation patterns are investigated both in simulations and experiments. The numerical analyses show that 29.39% and 44.49% electrical size reduction (ESR) ratios are obtained for Antenna B and Antenna C, respectively in comparison to Antenna A. The experimental results verify the ESR ratios with 29.15% and 44.94%. Supporting, Antenna C promises 68.12% physical size reduction (PSR) as it is compared with Antenna D. These results reveal that Antenna C is a good alternative for DGS based microstrip electrically small antennas.

Influence of Common Source and Word Line Electrodes on Program Operation in SuperFlash Memory

A theoretical study of the influence of word line and common source electrodes on the program operation in shrank SuperFlash memory is proposed. Numerical simulations demonstrate that the literature model defined for previous nodes is not always suitable, due to the continuous cell physical size reduction and to the consequent increment of capacitive coupling between the floating gate and adjacent electrodes. To get a deeper insight, an analytical model of the electric field in the region of source side injection is proposed. This model describes the impact of the cell physical and electrical parameters on the vertical and horizontal field components and highlights the strong dependence of the carrier injection on the technology node. Furthermore, the numerical and analytical models estimate the influence of the word line and common source electrodes on the time-to-program, the floating gate potential and the source side injection efficiency, taking into consideration, at the same time, their possible impact on the cell reliability.

Composting of starch-based bioplastic bags: small scale test of degradation and size reduction trend

In Italy, the majority of bioplastic bags used in food waste collection is made of starch-based biopolymer. The compostability of this material in a full-scale plant remains to be demonstrated, largely due to the fact that bioplastic bags are screened and removed together with conventional plastic bags during pre-treatment steps. The present research was performed on a small scale to study the degradation of starch-based bioplastics during composting. Evolution of the physical and chemical parameters of the material was evaluated by means of Fourier Transform Infrared (FTIR), experimental mass loss and granulometric trend. The results obtained suggested that fragmentation (physical size reduction of the material) occurred mainly during the thermophilic phase, while biodegradation (breakdown by microorganisms of an organic chemical into simpler, innocuous compounds) occurred during the curing phase. Based on the monitored parameters (TS, VS, pH, C/N and RI4), the composting process of the waste matrix ended after 55 days, but the degradation of bioplastics failed to achieve the regulatory standards for assessment of compostability (≤ 10% sized &gt; 2 mm). Experimental data revealed a linear trend for the fragmentation process and a duration of 100 days would be required to meet regulatory requirements.

The effect of pretreatment methods for improved biogas production from oil-palm empty fruit bunches (EFB): experimental and model

The production of biogas from solid wastes in addition to palm oil mill effluents is necessary due to the shortage of the effluents, operation of biogas plants at low to moderate capacities, and large amount of solid wastes, particularly oil-palm empty fruit bunches (EFB). However, the biogas production from raw EFB gives low yield. This study therefore aims to investigate the effect of EFB pretreatment methods on the improvement of biogas production. The pretreatment of EFB was carried out through chemical (NaOH solutions), physical (size reduction) and biological (activated sludge and bio-scrubber effluent) processes. The experimental data was tested against corrected Gompertz model. The results showed that size reduction and pretreatments of EFB with 7% w/v NaOH, activated sludge and bio-scrubber effluent could improve biogas yield significantly and differently. The highest yield of methane was 429.9 ml/g.VS, obtained from EFB with size reduction. For the pretreatments of EFB with 7% w/v NaOH, bio-scrubber effluent and activated sludge, the methane yields were 345.5, 326.4 and 297.3 ml/g.VS, respectively. Without pretreatment, the methane yield was only 226.0 ml/g.VS. The change in cellulose and lignin compositions of EFB after pretreatment is attributed to the improvement of biogas yield. It is economically interesting that the bio-scrubber effluent from palm oil mills can be recycled to treat EFB. In the modeling study, the corrected Gompertz model could fit all data sets reasonably well.

Optimization of MIS type Non-Volatile Memory Device with Al-Doped HfO2 as Charge Trapping Layer

The reduction in physical size of the Non-volatile memory (NVM) demands the use of high-k dielectrics due to loss in charge trapping behavior. The large bandgap of Al2O3 (∼7.0 eV) proves it suitable for blocking and tunneling layer, while the high dielectric constant of HfO2 proves it suitable for charge trapping layer (CTL). In this paper, we propose the application of Al doped HfO2 used as CTL. The doping concentration has been varied by varying the number of sub-cycles (sequential cycles of HfO2, Al2O3) by ALD system. The optical energy bandgap of Al doped HfO2 observed to be increases from 4.91−5.20 eV as the Al incorporation content increases with 1:9−1:4 ALD sub-cycles. Oxygen vacancy defect in the thin film decreased to 17.87% for 1:4-Al doped HfO2 sample as verified from the XPS. The increase in Al incorporation leads to charge loss towards silicon substrate due to high bandgap energy. In addition, charge traps are not well performed due to reduction of internal defects in the film. After 10 years, the NVM device with Al doped HfO2 (1:9) CTL has improved charge retention characteristics by 14% as compared to a normal HfO2 charge trap layer NVM device.

Compact wideband multi-section quarter-wave-like transformers

ABSTRACTThis paper proposes a novel design technique of the compact wideband transformer based on the quarter-wave-like transformer (QWLT) theory and the approximate theory of small reflections (ATSR). The ATSR for multi-section QWLTs is applied for analysing characteristics of multi-section QWLTs. The prototypes of two-section QWLTs operating at 2.4 GHz with 25% physical size reduction, comparing to that of the corresponding of wideband multi-section quarter-wave transformer (QWT), are implemented. It is found that measured results are matched reasonably well with results of the ATSR for multi-section QWLTs. In addition, the two-section QWLT prototypes provide slightly less bandwidth compared to that of the corresponding wideband multi-section QWT.

Channel Characteristics and Wireless Telemetry Performance of Transplanted Organ Monitoring System Using Ultrawideband Communication

Recently, wireless implanted applications have attracted considerable interest in the medical domain due to their capability to offer healthcare sensing and monitoring. One such promising application is the wireless monitoring of transplanted organs, particularly a transplanted liver. Ultrawideband (UWB) technology is well suited for wireless implanted applications since it allows physical size reduction, as well as increased longevity of the implanted devices. However, because of the high attenuation of UWB signals inside the human body, it is necessary to examine their propagation characteristics and demonstrate the feasibility of such an application. In this paper, an investigative study involving the liver implanted wireless telemetry link using UWB technology is presented. Measurements using multilayer phantoms and simulations using a human digital model have been conducted within the frequency band of 4.5–6.5 GHz. Multilayer phantom measurements have demonstrated the attenuations ranging between –50 and –100 dB over the considered frequency band. A path loss model at the liver area has been obtained from the simulations. Also, the numerical results have shown that the attenuation variation due to respiration-induced organ movements was within 30-dB range with respect to the largest organ movement distance of 40 mm, which emphasized the influence of organ movements on the in-body attenuations. Our preliminary link budget evaluation of liver–skin surface communication link, including the effect of shadowing and organ movements, estimated that it is possible to achieve a high data rate of 10 Mb/s with a bit error rate of 10−3 at a distance of about 40 mm.

Quantitative assessment of wideband antenna geometry modifications for size-reduction-oriented design

Incorporation of various topological modifications to basic antenna structures is a common strategy in the context of size-reduction-oriented design. Modifications can be applied to the ground plane, the feed line, and/or antenna radiator, and may lead to achieving smaller physical dimensions of the antenna at hand. Unfortunately, various topology alteration options are normally reported on a case-to-case basis; systematic comparisons of different modification types are lacking in the literature. In this paper, thorough investigations of selected topological changes in terms of their effect on antenna size reduction are carried out. Numerical experiments are performed using two ultra-wideband monopoles. In order to ensure a fair comparison, for each antenna topology, all geometry parameters are rigorously optimized to obtain the minimum footprint while maintaining acceptable electrical performance. The results clearly indicate the advantage of feed line modifications (56% average physical size reduction) over a ground plane and radiator ones (43% and 2.15% respectively). Experimental validations confirming the numerical findings are also provided.

Design and Optimization of Piezoelectric MEMS Vibration Energy Harvesters Based on Genetic Algorithm

Low-power electronic applications are normally powered by batteries, which have to deal with stringent lifetime and size constraints. To enhance operational autonomy, energy harvesting from ambient vibration by microelectromechanical systems (MEMS) has been identified as a vivid solution to this universal problem. This paper proposes an automated design and optimization methodology with minimum human efforts for MEMS-based piezoelectric energy harvesters. The analytic equations for estimating the harvested voltage by the unimorph piezoelectric energy harvesters are presented with their accuracy validated by using the finite element method (FEM) simulation and prototype measurement. Thanks to their high accuracy, we use these analytic equations as fitness functions of genetic algorithm (GA), an evolutionary computation method for optimization problems by mimicking biological evolution. Our experimental results show that the GA is capable of optimizing multiple physical parameters of piezoelectric energy harvesters to considerably enhance the output voltage. This harvesting efficiency improvement is also desirably coupled with physical size reduction as preferred for the MEMS design process. To demonstrate capability of the proposed optimization method, we have also included a commercial optimization product (i.e., COMSOL optimization module) in our comparison study. The experiments show that our proposed GA-based optimization methodology offers higher effectiveness in the magnitude improvement of harvested voltage along with less runtime compared with the other optimization approaches. Furthermore, the effects of geometry optimization on mechanical and electrical properties (e.g., resonant frequency, stiffness, and internal impedance) are also studied and an effective solution to producing maximum power from unimorph piezoelectric harvesters is proposed.

Physical pretreatment of biogenic-rich trommel fines for fast pyrolysis

Energy from Waste (EfW) technologies such as fluidized bed fast pyrolysis, are beneficial for both energy generation and waste management. Such technologies, however face significant challenges due to the heterogeneous nature, particularly the high ash contents of some municipal solid waste types e.g. trommel fines. A study of the physical/mechanical and thermal characteristics of these complex wastes is important for two main reasons; (a) to inform the design and operation of pyrolysis systems to handle the characteristics of such waste; (b) to control/modify the characteristics of the waste to fit with existing EFW technologies via appropriate feedstock preparation methods. In this study, the preparation and detailed characterisation of a sample of biogenic-rich trommel fines has been carried out with a view to making the feedstock suitable for fast pyrolysis based on an existing fluidized bed reactor. Results indicate that control of feed particle size was very important to prevent problems of dust entrainment in the fluidizing gas as well as to prevent feeder hardware problems caused by large stones and aggregates. After physical separation and size reduction, nearly 70wt% of the trommel fines was obtained within the size range suitable for energy recovery using the existing fast pyrolysis system. This pyrolyzable fraction could account for about 83% of the energy content of the ‘as received’ trommel fines sample. Therefore there was no significant differences in the thermochemical properties of the raw and pre-treated feedstocks, indicating that suitably prepared trommel fines samples can be used for energy recovery, with significant reduction in mass and volume of the original waste. Consequently, this can lead to more than 90% reduction in the present costs of disposal of trommel fines in landfills. In addition, the recovered plastics and textile materials could be used as refuse derived fuel.

THz-TDS using a photoconductive free-space linear tapered slot antenna transmitter.

A near-field edge-coupled photoconductive free-space linear tapered slot antenna has been constructed as a planar alternative to the standard photoconductive switch coupled to a silicon substrate lens. The temporal response along the optical axis is investigated to ensure the structure itself does not introduce pulse distortion which would fundamentally limit the usefulness of the structure. Experimental results show that a 1.6 THz bandwidth with a ≈50dB dynamic range is achievable with the new structure which is comparable to our reference experiment with a standard silicon substrate lens. The investigated structure has the added benefit of a potential substantial physical size reduction and can also be used to excite waveguides in the near-field.

The Use of Novel PET Tracers to Image Breast Cancer Biologic Processes Such as Proliferation, DNA Damage and Repair, and Angiogenesis.

The balance between proliferation and cell death is pivotal to breast tumor growth. Because of a combination of environmental and genetic factors leading to activation of oncogenes or inactivation of tumor suppressor genes, these processes become deregulated in cancer. PET imaging of proliferation, angiogenesis, and DNA damage and repair offers the opportunity to monitor therapeutic efficacy to detect changes in tumor biology that may precede physical size reduction and simultaneously allows the study of intratumoral and intertumoral heterogeneity.This review examines recent developments in breast cancer imaging using novel probes. The probes discussed here are not licensed for routine use and are at various stages of development ranging from preclinical development (e.g., the DNA repair marker γH2AX) to clinical validation in larger studies (such as the proliferation probe 3'-deoxy-3'-(18)F-fluorothymidine [(18)F-FLT]). In breast cancer, most studies have focused on proliferation imaging mainly based on (18)F-labeled thymidine analogs. Initial studies have been promising; however, the results of larger validation studies are necessary before being incorporated into routine clinical use. Although there are distinct advantages in using process-specific probes, properties such as metabolism need careful consideration, because high background uptake in the liver due to glucuronidation in the case of (18)F-FLT may limit utility for imaging of liver metastases.Targeting angiogenesis has had some success in tumors such as renal cell carcinoma; however, angiogenesis inhibitors have not been particularly successful in the clinical treatment of breast cancer. This could be potentially attributed to patient selection due to the lack of validated predictive and responsive biomarkers; the quest for a successful noninvasive biomarker for angiogenesis could solve this challenge. Finally, we look at cell death including apoptosis and DNA damage and repair probes, the most well-studied example being (18)F-annexin V; more recently, probes that target caspase endoproteases have been developed and are undergoing early clinical validation studies.Further clinical studies including analysis of test-retest variability are essential to determine sensitivity and future utility of these probes in breast cancer.

Multibeam SIW Slotted Waveguide Antenna System Fed by a Compact Dual-Layer Rotman Lens

A multibeam antenna system fed by a compact Rotman lens is presented in multilayer substrate integrated waveguide (SIW) technology. The lens is implemented in two layers using a new transition based on several star-shaped coupling slots and an SIW integrated reflector. Compared to standard rectangular coupling slots, this transition is broadband and maximizes power transfer between the two layers of the lens regardless the position of the beam port along the focal arc of the Rotman lens. The radiating part is an array of 15 slotted waveguides. These waveguides are centrally fed to enhance their bandwidth and reduce the “long line effect.” To validate the proposed concepts, an antenna system has been prototyped at 24.15 GHz. The designed transition leads to a physical size reduction of about 50% for the Rotman lens, and more than 33% for the antenna footprint compared to standard single-layer implementations. The experimental results demonstrate a scanning range of $\pm {33}^\circ $ and a 4% bandwidth for $\text{VSWR} ; the isolation between input ports is better than $- {10}\;\text{dB}$ .

Super-miniaturized Wilkinson power divider using cross-connect meander microstrip lines and conductive vias

A novel three-dimensional (3-D) folded two-way microstrip lines (ML) is proposed for realizing the super-miniaturization of electron devices. The 3-D structure realized with two-way folded ML, which consists of several groups of cross-connected ML and conductive vias, has the potential to have an advanced performance than the corresponding conventional, meandering, and 3-D one-way ML. It can be arranged longer ML in limited spaces. Physical size reduction of the transmission line segments is from λ/4 to λ/32. The Wilkinson power divider (WPD) is designed to operate at the frequency of 433 MHz, has a return loss better than −29 dB, an insertion loss less than 0.28 dB, and isolation larger than +30 dB. The physical size has been reduced by 98.39% when compared with the conventional WPD. Design method about the folded two-way ML is presented for the first time.

Design, development and microwave inter-comparison of dual slot antenna configurations for localized hepatic tumor management.

Slot antennas are generally preferred for localized liver cancer treatment modalities due to desired radiation characteristics. An iterative thermal/microwave numerical routine is used to analyze regular and miniature slot antenna configurations at 5.8 GHz. A thermal/microwave solver determines the specific absorption rate to malignant tissues as a pre- processing step to compute microwave solution in terms of propagation wave number, return loss and insertion loss. The regular and miniature dual slots antenna geometries were then developed to estimate the return loss characteristics against antennas slot lengths at a constant frequency of 5.8 GHz. Results reveal that the regular geometry has return loss less than -5 dB as compared to <-25 dB return loss for miniature slot antenna configuration. Furthermore, 5.8 GHz antenna geometry provides physical size reduction up to 50 %, lower fabrication cost and is a better minimally invasive choice due to further packed thermal ablation spots.

Innovative Inorganic Synthesis

I am delighted to introduce this Special Issue of Inorganics; the first themed issue of the journal and one dedicated to Innovative Inorganic Synthesis. [...]

COMPACT QUASI SELF-COMPLEMENTARY ELLIPTICAL DISC MONOPOLE ANTENNA WITH TAPERED MICROSTRIP FEED LINE

In this paper a compact elliptical disc monopole antenna with tapered microstrip feed line for UWB application is proposed. The antenna is designed using the quasi self -complementary technique for attaining electrical as well as physical size reduction. A triangular notch is included in the ground plane for impedance matching between the antenna and the RF front end. The adoption of this miniaturization technique has narrowed the impedance bandwidth of the antenna in the UWB range but lead to an additional operating bandwidth in Ku band thereby exhibiting dual band behavior. This reduction in the bandwidth in the UWB range was overcome by using the tapered microstrip feed line configuration. The antenna exhibited a wide impedance bandwidth extending beyond the UWB range and hence could be used for both UWB as well as Ku band applications. The antenna has a physical dimension of 16mm X 25mm corresponding to an electrical size of 0.24λ and was designed on an FR4 substrate with er of 4.7. It is seen that the antenna proposed here has led to 62% size reduction with a percentage impedance bandwidth of 123.46% when compared with the conventional elliptical disc monopole antenna.