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Until now, influences of different grinding mechanisms on specific energy consumption have been subject of many researches. In this regard, the technologies of impact and attrition milling have been compared by several studies. Although energy consumption is of major concern, the product properties or the behaviour of the components within the mixture may vary depending on the mechanism chosen. Such investigation is still missing for the dry stirred media milling. Moreover, its comparison with the conventional techniques regarding to this phenomenon is also lacking within the literature. This paper initially aims to provide an insight on components' interaction within ball milling and stirred milling and then comparison of the two outcomes. Within the scope, the first phase of grinding tests consisted of ball milling and stirred milling of calcite within a single and multi-component environment. For the mixtures, each component was separated via chemical analyses hence comparisons were made regarding to size reduction of the individuals. Further tests were performed with a copper ore to investigate the behaviours of the minerals by benefitting from MLA analyses. As a result, the two technologies were compared on the basis of energy consumption, components' interaction and their contributions to the liberation characteristics of the minerals. (c) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

This study investigated the specific milling energy of rectangular pine (Pinus sylvestris L.) boards using a new size reduction technology, which can produce fine wood powders in a single-step operation. Multilinear regression (MLR) analysis was used to model the milling energy of a multi-blade shaft mill through a designed series of experiments having three input parameters: the moisture content of the board, milling blade speed and board feeding speed. The observed specific milling energy ranged from 60 to 172 kWh t−1 [DM] and the MLR model showed it was proportional to the blade speed and the moisture content. The results suggest that multi-blade shaft milling is a two-dimension extension of singular circular blade milling with regard to work piece shape and sawblade teeth engagement effects. The findings were compared with the specific milling energy of pine logs obtained in a previous study.

Fruits and vegetables (F&V) are the second highest recommended foods, rich in antioxidants, vitamins and minerals, vital for building immunity against chronic diseases. F&V processing involves particle size reduction, for which different types of homogenizers, categorized as mechanical homogenizers, pressure homogenizers and ultrasonic homogenizers are used. The review discusses different types of homogenizers, their working mechanism, and application in F&V processing. Among mechanical homogenizers, knife mills are used for primary size reduction, ball mills for the micronization of dried F&V and rotor-stator homogenizers for emulsification. Use of the ultrasonic homogenizer is limited to extraction of bioactive compounds or as a pre-treatment for dehydration of F&V. High-pressure homogenizers are most widely used and reported due to the synergistic effect of homogenization and temperature increase, resulting in longer shelf-life and better physicochemical properties of the product. Additionally, the review also explains the effect of homogenization on the physicochemical, sensory and nutraceutical properties of the product.

The size reduction is a mandatory step in oil shale processing. In this study, the sensitivity of oil shale and its organic matters to the applied load in grinding was tested in a ball mill not onl...

The effects of high energy milling on the shape, size and low temperature sinterability of plate-like alumina powder was studied. The milling effects were studied under three different processing conditions, designed by varying the charge ratio and the milling medium. 10:1 and 20:1 ball to powder charge ratios were considered in wet and dry milling media, with powder samples collected after 4, 8, 16 and 32 h of milling. Analysis demonstrates that 20:1 wet milled powders underwent greatest size reduction with a final average particle size of 0.29 um and crystallite size of 10.13 nm. 20:1 wet milled powders were subsequently sintered at 1300 °C for 10 and 20 h. Results indicate that densification and hardness increased as a function of milling time, reaching to a maximum for 16 h milled samples with the least amount of porosity.

This research work presents the preparation of TiB2 nanopowders by molten-salt synthesis (MSS) technique from TiO2 and MgB2 as starting active materials and MgCl2 as a molten salt. The pure TiB2 nanopowders were finally prepared using 2M HCl aqueous solution to leach the synthesized samples. The effects of the firing temperature, firing time and reactants to salt ratio on the TiB2 nanopowders formation were examined. The results demonstrated that the TiB2 formation was completed even with reactants to salt mass ratio of 1:2 at 1000 ?C for 4 h. The TiB2 nanopowders synthesized with 1:2, 1:5 and 1:10 reactants to salt mass ratios have different particle sizes. Thus, the average particle sizes estimated from BET surface areas were 59, 55 and 46 nm for the samples synthesized with 1:2, 1:5 and 1:10 reactants to salts mass ratios, respectively. These results illustrated that the high concentration of MgCl2 plays a key role in the particles? size reduction. The above results assured that this research study presents a new low-temperature synthesis route for nano-sized metal diboride powders.

Understanding the mechanisms of the breakage of ore particles is important to predict the particle size distribution in size reduction operations. This paper aims to show the presence of common breakage modes in impact breakage and ball milling of the cement clinker and chromite samples. For that purpose, narrow size fractions of the two samples were broken in a drop-weight tester or ball mill by changing the degree of applied energy. Then the resultant size distributions were evaluated to seek evidence for the common breakage modes. The results showed that increasing the breakage energy will produce a systematic change in the shapes of the size distributions, suggesting a sequential set of breakage modes. The breakage is initially due to tensile stresses at low breakage energies and compressive stresses at high breakage energies. Further studies should be done to assess if these breakage modes occur at size-reduction of different ores.

The conditions of size reduction of particles of an emulsion disperse phase during its movement in the holes of the rotor and stator of a high-speed rotary disperser are studied. Analytical relationships that allow determination of the magnitude of tensile forces acting on the ends of the particle located on the sharp edge of the rotor hole were obtained. It is shown that the magnitude of tensile forces depends on the particle mass, angles of the hole edges, diameter, and angular speed of the rotor. As the rotation speed increases and the rotor hole edge angles decrease, the tensile forces acting on the particle ends increase, which increases the probability of its fragmentation into two parts.

This paper presents a new compact rectangular microstrip patch antenna with a superstrate element. This antenna operates at 2.4 GHz TM01 fundamental mode, which is suitable for WLAN applications. The patch area is reduced by 50% by placing three rectangular slots on the ground plane. In order to compensate for the decreased gain due to the size reduction, a high permittivity superstrate is used with 4mm thickness and 5mm height from the antenna surface. The proposed antenna offers the advantage of occupying half the area of the non-modified rectangular patch while it possesses the same broadside gain of 6-7dB. The trade-off is the additional antenna height due to the placement of the superstrate element.

Dried coal typically had certain Particle Size Distribution (PSD) resulting from the size reduction process. Effect of PSD to the compaction phenomenon was investigated on the binary mixtures of In...

This paper presents a brief review on the Rectangular Dielectric Resonator Antennas (RDRAs) for Sub-6 GHz band of frequencies. Various resonant modes, feeding mechanisms, bandwidth and gain enhancement techniques and size reduction methods have been discussed. Comparisons and advantages of dielectric resonator antenna over microstrip patch antenna have also been presented.

Pt-based electrocatalysts are considered as one of the most promising choices to facilitate the oxygen reduction reaction (ORR), and the key factor enabling their success is to reduce the required amount of platinum. Herein, we focus on illuminating both the theoretical mechanisms which enable enhanced and sustained ORR activity and the practical methods to achieve them in catalysts. The various multi-step pathways of ORR are firstly reviewed and the rate-determining steps based on the reaction intermediates and their binding energies are analyzed. We then explain the critical aspects of Pt-based electrocatalysts to tune oxygen reduction properties from the viewpoints of active sites exposure and altering the surface electronic structure, and further summarize representative research progress towards practically achieving these activity enhancements with a focus on platinum size reduction, shape control and core Pt elimination methods. We finally outline the remaining challenges and provide our perspectives with regard to further enhancing their activities.

In this paper, we have studied the effect of size reduction on charge ordering (CO) and magnetic phase separation in La0.5Ca0.5MnO3. The magnetic ground state at low temperature shifts from ferroma...

Grinding aids (GAs) have been an important advent in the comminution circuits. Over the last few decades, in order to address the high energy consumption and scarcity of potable water for mineral processing, chemical additives have become a promising alternative. Using GAs can have some advantages such as enhancing grinding efficiency, reducing water usage, improving material flowability, and narrowing the particle size distribution of the grinding products. A study on the effect of GAs on size reduction units is crucial for the beneficiation value chain of minerals and the impact on downstream processes. However, our understanding of the effects of these materials on the particle size reduction is quite limited. This article analyses the literature, which used GAs and provides a comprehensive review of their applications in the ore beneficiation processes. The outcomes of this investigation indicated that the current understanding on the mechanism of GA effects focuses only on their impacts on the product fineness and size distribution, and neglecting the aspect of energy expended and physicochemical environment. The application of GAs is mainly for rationalisation of energy where the type of reagent, pH, and ionic strength of the grinding environment is important. Gaps in knowledge of GAs are discussed in the context of addressing their use in the mineral industry, considering the mechanism of their effect, effect on grinding efficiency, and effect on the downstream processes. Addressing these gaps will pave the way for the application of GAs in improving size reduction efficiencies, which ultimately reduces environmental impacts.

Chipping is a big problem when it enters the guard ring or die active area, because the size of chipping is bigger than Defect-Free Zone (DFZ). Thus, the smaller of chipping size, the better the quality, but chipping free is the best [1]. At present, the selling price of semiconductor products (especially on the IC product) is not too expensive as before, while the size of the package is getting smaller and smaller with higher density. Many companies interested in ultra-thin wafers (i.e. very thin wafers having thicknesses less than 100μm [2]). And also interested in increasing die per wafer (DPW) to have a competitive product cost. This increases the difficulty in the wafer sawing process because increasing die per wafer causes a narrow width of the saw-street meaning that the size of DFZ will be very narrow [3]. For the factory in this case study, customers provide the new revision of ultra-thin wafers (50μm) with the width of saw-streets at 60μm. This is narrower than the width of the existing saw-streets (80μm), which means that the current condition of the sawing process might not be suitable for this narrow saw streets of ultra-thin wafers. As a result, the approach to remedy this situation is conducted under the Six Sigma approach.

The influence of using nanofluids on heat transfer augmentation and characteristics of fluid flow in rectangular cross sectional microchannel heat sink (MCHS) is numerically investigated for single and double stack microchannels at uniform heat flux, q = 100 W/cm2 and Reynolds number ranging from 200 to 1500. In this study, alumina–water (Al2O3-H2O) nanofluid with different nanoparticle volume concentrations from 1% to 5% was used as a coolant for the MCHS. The three-dimensional steady, laminar flow and heat transfer governing equations are solved by finite volume method using ANSYS-Fluent 18.2. The MCHS performance is evaluated in terms of temperature profile, heat transfer coefficient, pressure drop, pumping power and volume reduction. The results reveal that increasing the nanoparticles concentration improves the cooling process. The maximum heat transfer augmentation in the current study was achieved at the highest concentration of 5%. For example, at this concentration the temperature was reduced by 7.3% using single stack microchannel. However, 33.5% temperature reduction was achieved using double stack microchannels. Also, it results in an increase in the heat transfer coefficient by 13.12% compare to that of the pure water. On the other hand, for a single stack at nanoparticle concentration of 5%, both pressure drop and power increased by 10% and 8%, respectively. Because of the significant influence of the nanofluid on the improvement of the cooling process, an estimation of the volume reduction was made. It was found that 62.6% volume reduction for single stake at concentration 5% can be achieved.

Aim: To study the effects of different sizes of groundnut shell on biogas and methane yields using batch reactor at mesophilic temperature. Place and Duration of Study: The laboratory experiment was carried out at the Laboratory of the Department of Agricultural Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria, between August and October, 2018. Methodology: Batch experiment was set up for a period of 35 days with substrate reduced to 2, 4 and 6 mm sizes. The digesters were subjected to anaerobic digestion at mesophilic condition and the gas produced were collected with graduated gas sampling bottles dipped in measuring cylinders already filled with red liquid. The total gas produced was analyzed using gas analyzer to give the percentage composition of the gas components and Enwuff equation was used to calculate the biogas and methane yields of organic dry matter and fresh mass of the samples. Results: The total gas volume of 482.5, 605.0 and 732.5 ml were recorded for the sizes 2, 4 and 6 mm respectively. The organic dry matter biogas yields were 357.1, 514.31 and 324.5 lNkg-1oDM for treatment 2, 4 and 6 mm respectively; while organic dry matter methane produced were 222.41, 298.41 and 211.31 CH4kg-1oDM for 2, 4 and 6 mm, respectively. The fresh mass biogas yields were 147.6, 180.7 and 177.3 lNkg-1FM and fresh mass methane yield were 919, 104.8 and 115.4 lNCH4 kg-1FM for 2, 4 and 6 mm, respectively. Conclusion: Considering the yields recorded, the experiment shows that size reduction had effect on biogas yields and it is an important factor to be considered in biogas production. Treatment with particle size 4 mm seems to be the ideal size when considered the yields in terms of organic dry matter and fresh mass basis.

Conventional rolling for reinforced bar comprises of systematic size reduction during manufacturing. During rolling, compressible forces of rolls at every stage is applied for plastic deformation of material. These forces deform the grains as a result of elongated grains and decreased grain size at the final stage of rolling. In this work the grain size and hardness at different stages of rolling was investigated from metallurgical and mechanical perspective. The results showed that the hardness is dependent on grain size and the Hall-Petch equation was employed for the same. For the present study, the calculated Hall-Petch equation is H = 56.98 + 112.51d-1/2.

A novel wearable textile Radio Frequency Identification (RFID) tag based on an eighth-mode substrate integrated waveguide cavity is presented. Antenna size reduction for effective operation in the [865-870]-MHz RFID UHF band is obtained by exploiting the H-field symmetry planes of a cylindrical Substrate Integrated Waveguide (SIW) cavity. High isolation from the human body and excellent robustness with respect to variations in antenna-body distance are achieved using an energy-based design strategy, aiming to reduce ground plane size. The resulting tag exhibits very low manufacturing complexity and may be produced at low-cost. Design and simulations were performed using CST Microwave Studio, and a prototype of the tag has been manufactured and tested in a real environment.

In this paper we present the design and fabrication of a two-antenna array to resonate at 5.8 GHz, a frequency that satisfies a host of applications, especially those associated with the ISM band, but including IoT applications. The design incorporates several techniques to improve figures of merit and reduce its size. The array presents a measured bandwidth of 617 MHz (from 5.503 to 6.120 GHz, or 10.63% about the central frequency) when built on a thin substrate, and of 455 MHz (from 5.517 to 5.972 GHz; 7.84%) when fabricated using a thicker one. The simulated gains were of 6.89 dBi and 7.63 dBi, whereas the measured ones were 6.7 dBi and 7.2 dBi, respectively. Size reduction is better than 30% and the simulated efficiencies are higher than 90%.

Graphene oxide (GO) is widely considered as a graphene precursor when chemically reduced. Nevertheless, through the precise control of two parameters: lateral size and oxidation degree, GO can be useful in many applications as modified graphene oxide or functional reduced graphene oxide. Commonly, the decrease in GO lateral size, involves a change in the C/O ratio and therefore a modification in a large number of characteristics. Here, a simple but effective approach to synthesize GO with lateral dimensions below 100 nm and without modification of its chemical, optical and electronic features is presented. The use of a sonifier at low temperature allows to rapidly reduce the lateral size in ∼82% while preserving the C/O ratio and consequently the chemical stability, the band gap, the electronic energy levels and the functionality. This method will allow several applications from biomedicine to energy, where reliable reduced size of GO is required.

This paper aims to perform laser assisted size reduction to nanoparticles of gold (Au) sputtered layer on titanium (Ti) base material using an innovative method that could potentially be applied in novel blood contact and thromboresistive devices in the living body, such as ventricular assist devices (VADs). The enrichment of the surface layer of titanium with gold nanoparticles, due to its bioproperties, may contribute to the reduction of inflammatory reactions and infections occurring mainly in the first postoperative period causing implant failure. The possibility of obtaining superficial size reduction and/or bonding of nano gold particles with Ti micromachining by picosecond laser treatment was evaluated. The quantitative assessment of the particles has been made using SEM and are depicted on the histograms, whereby the appropriate number of particles determine the antibacterial properties and health safety. The initial analysis of micromachining process of the prepared material was focused on power-depth dependence by confocal microscopy. The evaluation of gold particles was conducted using scanning electron microscopy (SEM) using SE and QBSD detectors with energy dispersive spectroscopy (EDS) analysis. Attempts to reduce the deposited gold coating to the size of Au nanoparticles and to melt them into titanium matrix using a laser beam have been successfully completed. There seems to be no strict relationship between particle size distribution of gold onto Ti, probably due to too low energy to excite titanium enough, resulting from difference in Ti and Au melting point temperatures. However, the obtained results allow continuation of pilot studies for augmented research and material properties analysis in the future.

Control rod blades are comprised of a stainless steel sheath, which contains neutron absorber tubes (filled with boron carbide powder). During decommissioning, the first stage of size reduction consists of cutting the connector (bottom portion) of the control rod, while the second stage consists of separating the blades of the control rod by cutting through the tie rod. The last stage consists of segmenting the control rod blades by cutting through absorber tubes. In this study, the control rod blades segmentation (last stage of size reduction) is investigated using an actual control rod (unused). During the experiments, we used a forming press on the cut locations followed by a plasma arc cutting underwater. The purpose of this cutting technique is to minimize the scattering of boron carbides into water by using the stainless sheath melt to seal the absorber tubes. After the segmentation, we confirmed the sealing of the absorber tubes by visually examining the cut cross-sections. The water analysis showed that the boron carbide scattering was relatively low (only 0.07% of the total boron carbides was scattered). Finally, we confirmed that the off-gas emission is considerably reduced by using Argon plasma instead of Argon-Hydrogen plasma.

A novel out-of-plane integration of multilayer strip-resonators is proposed. This kind of structure retains the merit of traditional in-plane integrated ones – simple and compact-sized, meanwhile, achieves the same amount of coupling with smaller horizontal space between resonators. Further miniaturisation of the previous bandpass filters (BPFs) can be realised by re-designing them based on the proposed structure. This Letter gives an example of an S-band BPF. A 52.4% size reduction is achieved by out-of-plane integration of resonators, while maintaining a comparable performance to the previous in-plane integrated design.

The high pressure homogenizer (HPH) in pharmaceutical industry is specifically used for size reduction, mixing, and stabilization of dispersions or droplets. In HPH, liquid is passed through a narrow gap under high pressure where the different processing parameters lead to changes in globule/particle size. Understanding these processing parameters with a view to its pharmaceutical applications will be useful in producing a consistent and predefined quality of pharmaceuticals. A systematic literature review using the available knowledge space was conducted by publications available on the subject matter until 2018. The keywords used in different combinations like “high pressure homogenization,” “pharmaceuticals,” and “process parameters of HPH” were searched in databases of web of science, PubMed, and Scopus. The collected data was systematically analyzed. The review findings revealed the importance of understanding the basics engineering involved in construction of the HPH instrument, which included the types of pressure pumps and piston pumps, geometry and design of valves, O rings, and impact rings in HPH. Getting into the vertical knowledge obtained, the mechanism of droplet fragmentation and other critical processing parameters were shown to be affecting the product output from HPH. The review gives an insight to the understanding of processing parameters and colloidal principles involved in achieving the different pharmaceutical applications by the formulations formulated using the HPH.

We have demonstrated here the study of memory effect, relaxation and interaction of hydrothermally grown La0.7Sr0.3MnO3 (LSMO-0.3) nanowires (NWs) and its bulk form synthesized by using polymeric precursor route. Magnetic relaxation measurement has been performed and the analysis shows the existence of two relaxation times in both the cases. It has been observed that both the samples show signature of magnetic memory effect and prefer magnetized state. Curie temperature of La0.7Sr0.3MnO3 (LSMO-0.3) NWs is decreased compared to its bulk form due to finite size effects.

The product fineness indicator t10 and the pre-weakening degree indicator percentage change of A * b value (CAb) were used to described the two aspects of the breakage result of processing with pre-weakening effect. However, there lacks a method to evaluate the ‘overall’ breakage degree with a single index. It was observed that when the high voltage pulse breakage (HVP breakage or HVPB) induced cracks inside pre-weakened particles were consumed during impact breakage, the breakage characteristics of the progeny particles are the same to raw ore particles. Based on this phenomenon, the concepts of equivalent size Sie and equivalent size reduction t10e are proposed. Raw ore particles of size Sie is ‘equivalent’ to pre-weakened particles of size Si in terms of their impact breakage product size distribution. Therefore the value of Si and the consequently derived t10e can be used to evaluate the overall breakage degree of pre-weakened particles. The calculation procedure of Sie and t10e is demonstrated in the context of HVP breakage. It is found that the impact breakage product of pre-weakened particles can be well predicted from Sie. In addition to the evaluation of overall breakage degree of pre-weakening processing, this method also has potential to apply in the simulation of comminution circuits with pre-weakening processing and the development of breakage model for processing with pre-weakening effect.

Wasabi paste is very popular worldwide because of its unique aroma and taste, which is produced from wasabi powder. In the present work, wasabi was ball-milled for 10, 20, 30, 40 and 50 min to obtain different particle size of powder, and the influence of ball milling time on the quality of wasabi paste was investigated. The product quality attributes such as color, water and isothiocyanate contents, chlorophyll content, rheology properties, flavor and sensory values were determined. Results shown that the best wasabi paste could be produced by ball-milling wasabi for 30 min yielding a particle size of 499.1 ± 36.1 nm, with the highest isothiocyanate, chlorophyll content and sensory scores as well as the best color properties. This work demonstrated that high quality wasabi paste could be produced by selecting proper ball milling time of the raw wasabi material to get proper particle size.

This study aims to investigate the effect of combined mechanical and ultrasonic milling on the size reduction of talc. Firstly, the talc sample was wet ground in a stirred media mill for five different times (30, 60, 90, 120, and 150 min), and the optimum result was subsequently achieved with treatment by ultrasonication. The effects of amplitude (20, 35, and 50 μm), solid content (2.5, 5, 7.5, and 10%), and sonication time (60, 120, and 240 min) on the sizes of the final product were investigated. The pre-milling by wet grinding caused a decrease in the grinding resistance of talc. Sequential ultrasonic treatment, which was applied to the talc sample, generated smaller particles in comparison to those acquired by stirred media milling alone. Experimental results were assessed based on the product particle size (d10, d50), reduction ratio, and specific energy consumption. Submicron particles prepared by ultrasonic treatment were perfectly stable compared to stirred media milling alone as investigated in terms of particle size. In addition, the effects of mechanical and ultrasonic milling on structural properties of talc particles were characterized by XRD analysis.

In this paper, a new substrate integrated waveguide (SIW) structure is introduced. This structure uses some oblique slots on the top surface of the conventional SIW structure. These slots reduce the cut off frequency without affecting the width of the SIW structure. The results show that these slots are non-radiative. A prototype of the proposed structure which is named Fishbone SIW structure, is simulated, fabricated and measured. The measured results show that the proposed structure achieves an insertion loss of 0.7 ± 0.5 dB, return loss of better than 10 dB from 3.2 to 5.4 GHz and size reduction of about 40 % . To further size reduction, the half mode of the Fishbone SIW structure which is named HM-Fishbone SIW structure is designed and fabricated. This structure achieves a return loss of better than 10 dB from 3 to 5.5 GHz and an insertion loss of 0.8 ± 0.6 dB. The measured results of the proposed structures are in good agreement with the simulated ones. The results show the ability of the Fishbone SIW and HM-Fishbone SIW structures in term of size reduction.

The design of a novel differential shorted patch antenna (DSPA) from a normal single-ended shorted patch antenna (SPA) is presented. It is shown that the DSPA has a smaller electrical size than the SPA. A transmission-line model is proposed to explain the reduced resonant size of the DSPA. A size reduction ratio of the DSPA to the SPA is defined and evaluated. It is found that the size reduction ratio mainly depends on the substrate thickness and the patch shape and slightly on the substrate dielectric constant. The simulated and measured results are given for both DSPA and SPA. The size reduction of the DSPA with respect to the SPA was experimentally validated.

A high selective dual band and miniaturized electromagnetic band gap (EBG) unit cell is presented in this paper. The analysis and characterization of the new cell are explained. The modified compact EBG unit cell is based on cutting two inverted U-shaped slots inside the typical mushroom-like EBG. The modified EBG has a 70% size reduction. The dual-band functionality of the structure is confirmed by applying it in a dual-notch ultra-wideband antenna (3.1–10.6 GHz), and the notch frequencies are 5.2 and 5.8 GHz. The dual-band functionality has advantages of a highly selective bandpass between them. The antenna can suppress interference frequencies in less than 100 MHz bandwidth without affecting the antenna performance in the whole bandwidth. Presented results are addressed in terms of circuit modeling, 3D full-wave simulations, and measurements.

In this study, two compact ultra-wideband (UWB) frequency selective surface (FSS) reflectors, which combine the branch loading method with the design of the traditional FSS, are proposed for antenna gain enhancement application. The working mechanism of the proposed FSS reflectors is analysed by the equivalent circuit model. The first FSS reflector, which is a 10 × 10 array with 8.25 mm × 8.25 mm unit size, not only enhances the gain of the UWB antenna, but also guarantees a constant gain with only 0.5 dB variation across the whole operation band. To further reduce the reflector size, a more compact FSS reflector with 6.25 mm × 6.25 mm unit size is designed by printing similar patterns on both sides of a single-layer dielectric slab. Compared to the first structure, the second reflector can realise a 25% size reduction and the same gain variation in the entire UWB frequency range. The only compromise is a 0.5 dB gain decrease. Finally, a good agreement between the measured and simulated results proves the feasibility of the authors' design.

Twin-screw melt granulation (TSMG) was applied to process a powder blend consisting of 80% gabapentin (GABA) and 20% hydroxypropyl cellulose. The effect of screw profile and processing conditions on the process-induced transformation and chemical degradation of gabapentin was studied. When a neutral kneading block was used, gabapentin underwent polymorphic transformation. A forward kneading block in combination with processing under torque conditions was required to minimize chemical degradation and to inhibit polymorphic transformation of gabapentin. Both the size of the extruded granules and gabapentin degradant level correlated positively with the specific rate, the ratio between feed rate and screw speed. At higher specific rate, the barrel was filled to a greater extent. The material packing and compressive forces were enhanced, as proven by the increased rupturing of CAMES® sensor beads and GABA crystal size reduction. This resulted in more interaction between the powder particles and facilitated granule growth. Simultaneously, this also resulted in higher degradant level. To attain adequate tabletability, the specific rate must reach a threshold value. The development of an optimum TSMG process requires balancing processing parameters based on the physical and chemical stability of GABA as well as its tabletability.

A smaller microstrip antenna design is essential for current and future wireless applications. For the design proposed in this article, researchers achieved size reduction when a circular microstrip patch is loaded with a metamaterial structure using a complementary split ring resonator (CSRR) with partially loaded nonuniform metasurfaces (NUMSs) on a ground plane. The designed antenna achieved a size reduction of 74% compared to a conventional microstrip antenna. The proposed antenna, resonating at 6.22 GHz, is designed, fabricated, and tested, and the measured results are then compared with the simulations as well as with the designs reported in the literature. The proposed antenna can be used for wireless applications, such as an indoor base-station antenna for vehicle-tovehicle communications.

In a previous study, we reported on a novel (prototype) real-time patient dosimeter with non-toxic phosphor sensors. In this study, we developed new types of sensors that were smaller than in the previous prototype, and clarified the clinical feasibility of our newly proposed dosimeter. Patient dose measurements obtained with the newly proposed real-time dosimeter were compared with measurements obtained using a calibrated radiophotoluminescence glass reference dosimeter (RPLD). The reference dosimeters were set at almost the same positions as the new real-time dosimeter sensors. We found excellent correlations between the reference RPLD measurements and those obtained using our new real-time dosimeter (r2 = 0.967). However, the new type of dosimeter was found to underestimate radiation skin dose measurements when compared with an RPLD. The most probable reason for this was the size reduction in the phosphor sensor of the new type of dosimeter. We believe that, as a result of reducing the phosphor sensor size, the backscattered X-ray irradiation was underestimated. However, the new dosimeter can accurately determine the absorbed dose by correcting the measured value with calibration factors. The calibration factor for the new type dosimeter was determined (by linear regression) to be ~1.15. New real-time patient dosimeter design would be an effective tool for the real-time measurement of patient skin doses during interventional radiology treatments.

Fused Deposition Modeling (FDM) with Poly(lactic Acid) plus (PLA+) is frequently used in rapid prototyping and 3D printing of complex shapes. Owing to their light weight, manufacturability and cost effectiveness, thermoplastic parts made by FDM are increasingly used in several applications ranging from tissue engineering to consumer goods industry. Understanding the size effects on the strength of these parts is essential to extend their use in the microsystem applications. This paper studies the effect of scale on the mechanical properties and failure mechanisms of a 3D printed parts made by FDM. Process parameter such as extrusion temperature, infill density, infill pattern, print speed, layer thickness and nozzle diameter were kept consistent for this experiment. Five samples each with a square cross-sectional area of side lengths of 2mm, 4mm, 6mm, and 10mm were subjected to a tensile test. It was observed that parts with a smaller cross-sectional area experienced ductile failure as opposed to brittle fracture in larger cross-sectional area. Failure is shown to occur at sections where the geometry changes for brittle fractures while it occurs at the center of the parts displaying ductile failure. Results of the tensile test show a non-uniform ultimate yield strength across the four sizes. Crystallization of the material due to nozzle temperature at extrusion could be a contributing factor to failure discrepancies. Increase in the cycle time is theorized to improve the layer to layer adhesion of the part thereby affecting its mode of failure.

Intensified vibratory milling is a nanonisation and micronisation technology which can be used to enable the oral bioavailability of poorly soluble compounds. The generated nano- and microsuspensions entail a large surface area which enhances the compounds dissolution rate, yet this large surface area is thermodynamically unfavourable and hence spontaneous destabilisation may occur, i.e. physical instability. Stability studies on suspensions manufactured via intensified vibratory milling have, to the best of our knowledge, not been reported in the literature before. An extended stability study was, therefore, executed with 30 bedaquiline suspensions milled with the intensified vibratory mill under various process settings. The particle size distribution was measured immediately after production, after four weeks of storage at 5 °C and after eleven weeks of storage at 5 °C with laser diffraction and scanning electron microscopy. In addition, a caking test was applied to scrutinise the redispersibility of the prevailing sediments. One sample whose sediment proved to be redisperible, demonstrated a peculiar trend during storage where a narrowing of the particle size distribution and a general particle size reduction was detected which opposed the conventional stability tendencies, i.e. stability or Ostwald ripening. This enigmatic trend was further explored via a repetitive analysis with laser diffraction and in a further phase, with an orthogonal particle sizing technique. Still, no matter the frequency nor technique, a narrowing particle size distribution was observed. To the best of our knowledge, this article, for the first time in the pharmaceutical literature, reports a narrowing particle size distribution of a micronised suspension containing an organic compound. Inevitably, this trend might shed a fundamental new light on the stability trends, exposed by suspensions post-micronisation by high energy milling. ispartof: INTERNATIONAL JOURNAL OF PHARMACEUTICS vol:603 ispartof: location:Netherlands status: published

We report on the increase in spin re-orientation transition temperature (TSR) and Neel temperature (TN) in Nd0.95Gd0.05FeO3 compound, by substituting Gd3+ ions at the A-site of NdFeO3. Structural and magnetic properties of Nd1−xGdxFeO3 (x = 0, 0.03 and 0.05 mol%) have been analysed by employing solid-state reaction method. Crystallite size reduction and lattice contraction have been observed with increase in Gd substitution in NdFeO3. M–H curves depict strong ferromagnetic behaviour of Nd1−xGdxFeO3 with a non-saturating and large coercive hysteresis loops. The crystallite size of Nd1−xGdxFeO3 influences the magnetic property, resulting in the ferromagnetic behaviour with higher M and Hc values at room temperature and low temperatures.

Ball mill is the widely used comminution device for the size reduction of iron ore particles, yet the underlying mechanisms of heat transfer and thermal breakage inside the mills heretofore are not deeply understood. Therefore, the Discrete element method was carried out to study the effect of operating parameters on charge temperature, and the batch grinding experiments of iron ores were conducted to verify the heating temperatures using a laboratory ball mill. Results show that increasing mill speed will result in the charge temperature increasing initially and then decreasing. The temperature fields of the charge and load behavior remain approximately the same for the different ball filling. The main findings of this study are that the heating temperature can contribute to enhancing the breakage behavior of iron ore particles, and correspondingly the optimal feed sizes for different heating temperatures are determined to be 2.48 mm, 2.63 mm, 2.78 mm, and 3.59 mm, respectively.

Advanced electronic materials 0, 2001069 (2021). doi:10.1002/aelm.202001069, Published by Wiley-VCH Verlag GmbH & Co. KG, Weinheim

The glass relaxation under ambient conditions is essential for understanding the nature of glass state, and has stimulated scientific and general public interests for centuries. However, owing to the extremely slow dynamics, experimental characterization of glass relaxation at ambient temperatures is quite challenging, and often takes several years. Here we report evident relaxation of metallic glasses at room temperature within the observation time of less one month when the feature size of glasses is reduced. The relaxation dynamics shows a size dependence similar to that on temperature, and an equivalence between size and temperature on affecting the relaxation dynamics is established. We also showed that a MG film with a feature size of ~ 10 nm at room temperature has a fast relaxation dynamics equivalent to that of a bulk MG near the glass transition temperature, indicating that the liquid-like behavior in glasses can be induced by size reduction.

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.

The main objective of this work was to synthesize phase pure double perovskites Ba2NiTeO6 (BNTO) and Ba2NiWO6 (BNWO) in nanocrystalline form and to reveal the impact of nanocrystallinity on their magnetic and dielectric properties. The studied double perovskites were synthesized in nanocrystalline form by employing a citrate sol-gel route. A detailed investigation of their structure and properties using X-ray powder diffraction, scanning electron microscopy, Raman spectroscopy technique, energy-dispersive X-ray spectroscopy, SQUID magnetometry and electrical measurements is carefully described. Rietveld refinement of X-ray powder diffraction patterns revealed phase purity of both compounds: BNTO is trigonal (R-3m) while BNWO is cubic (Fm-3m). Raman spectroscopy studies reveal optical phonons that correspond to vibrations of Te6+/W6+O6 octahedra, while scanning electron microscopy images show irregular plate-like nanocrystals. Magnetic property measurements speak in favor of antiferromagnetic order but, in both compounds, size reduction affected their properties. BNTO has Néel temperature (TN) of 10.3 K which is higher than previously reported for its bulk form. Magnetic ground state of BNWO can be explained as canted antiferromagnetism with TN = 48.2 K. Room temperature measurements of dielectric constants at various frequencies suggest that these materials are high-κ dielectrics with low dielectric loss. The Nyquist plot reveals depressed a semicircle arc typical for non-Debye type of relaxation phenomena for BNWO ceramic, whereas for BNTO ceramic an almost straight line of Zʹʹ versus Z' has been observed, indicating its high insulating behavior. To conclude, size-dependent properties of studied double perovskites are discussed, introducing a possibility for implementation in electronic devices.

This study proposes a simple artificial magneto-dielectric (MD) antenna with a split-ring resonator (SRR) loaded in an array configuration. This SRR element is used to realize the MD characteristic that is beneficial for antenna miniaturization. The simulation of material permittivity and permeability is conducted to ensure that the proposed SRR-array configuration has the expected MD characteristic. Configurations of SRR in arrays of 3×3, 5×5, 7×7, and 9 × 9 are realized to obtain its radiation characteristics when embedded in the antenna ground plane. A rectangular patch antenna is used in this study. Based on the simulation, the proposed antenna with an SRR array of 5×5 achieves excellent MD characteristics with high permittivity and permeability of 32.44 and 51.39, respectively. Furthermore, a microstrip antenna loaded with the SRR 5×5 arrays are fabricated on RT/duroid 5880 substrate. It has a dimension of 0.31λ0 × 0.26λ0. The simulation and measurement results of the proposed antenna show a fractional bandwidth of 4.79% and 5.2% at 1.5 GHz; and a maximum gain of 5.20 dB and 4.95 dB, respectively. Good agreement between the simulated and the measured results was achieved.