Blocking Elements Research Articles

Effect of Correlated Building Blockages on the Ergodic Capacity of mmWave Systems in Urban Scenarios

The millimeter waves (mmWave) bands, considered to support the forthcoming generation of mobile communications technologies, have a well-known vulnerability to blockages. Recent works in the literature analyze the blockage probability considering independence or correlation among the blocking elements of the different links. In this letter, we characterize the effect of blockages and their correlation on the ergodic capacity. We carry out the analysis for urban scenarios, where the considered blocking elements are buildings that are primarily parallel to the streets. We also present numerical simulations based on actual building features of the city of Chicago to validate the obtained expressions.

Setting and Testing of the Out-of-Step Protection at Mongolian Transmission System

Modern distance relays have integrated numerous protection functions, including power-swing blocking and out-of-step or pole-slip tripping functions. The main purpose of the power-swing blocking function is to differentiate faults from power swings and block distance or other relay elements from operating during stable or unstable power swings. Most power-swing blocking elements are based on traditional methods that monitor the positive sequence impedance rate. The required settings for the power-swing blocking elements could be difficult to calculate in many applications, particularly those where fast swings can be expected. For these cases, extensive stability studies are necessary to determine the fastest rate of possible power swings. This paper presents a detailed step-by-step method for settings calculation of out-of-step (OOS) protection, both blocking and tripping functions considering a generic two-source system. Then the method is applied to define the protection relay settings installed at the interconnection between the Russian and Mongolian power systems, as it is crucial to feed the demand-rich Mongolian power system. In this paper, a specific impedance method is used for defining the OOS protection settings. This paper innovates by testing the settings using the recordings of the major events of 15 September 2018 in two approaches: hybrid co-simulation and cyber-physical. Both tests have demonstrated the appropriate performance of the proposed settings and proving the proposed methodology works appropriately.

Towards a traceable divider for composite voltage waveforms below 1\xa0kV

In the framework of the European Project 19NRM07 HV-com2 supporting the standardization in high-voltage testing with composite and combined wave shapes, a divider to employ in a test set-up for validation of electrical devices submitted to composite voltages below 1 kV has been developed at the Istituto Nazionale di Ricerca Metrologica (INRIM) and currently is under extensive testing. After a simulation stage, an available divider has been modified to comply with the IEC 60,060 requirements in terms of step response and scale factor. To be suitably fast in replying to step voltages, an adjustment of the components of the low-voltage arm has been made. The divider has been calibrated with traceability to the relevant INRIM National Standards and characterized exploiting its scale factor at different voltages and frequencies. The divider has been then inserted in a set-up with a sinusoidal generator, an impulse generator and coupling–blocking elements to carry out tests at low voltages (below 1 kV) with single voltages. In these tests, the divider showed a satisfactory attitude as converting device and its scale factor is traceable with suitable uncertainty.

Full\u2010scale shake\u2010table tests on two unreinforced masonry cavity\u2010wall buildings: effect of an innovative timber retrofit

Two full-scale building specimens were tested on the shake-table at the EUCENTRE Foundation laboratories in Pavia (Italy), to assess the effectiveness of an innovative timber retrofit solution, within a comprehensive research campaign on the seismic vulnerability of existing Dutch unreinforced masonry structures. The buildings represented the end-unit of a two-storey terraced house typical of the North-Eastern Netherlands, a region affected by induced seismicity over the last few decades. This building typology is particularly vulnerable to earthquake excitation due to lack of seismic details and irregular distribution of large openings in masonry walls. Both specimens were built with the same geometry. Their structural system consisted of cavity walls, with interior load-bearing calcium-silicate leaf and exterior clay veneer, and included a first-floor reinforced concrete slab, a second-floor timber framing, and a roof timber structure supported by masonry gables. A timber retrofit was designed and installed inside the second specimen, providing an innovative sustainable, light-weight, reversible, and cost-effective technique, which could be extensively applied to actual buildings. Timber frames were connected to the interior surface of the masonry walls and completed by oriented strands boards nailed to them. The second-floor timber diaphragm was stiffened and strengthened by a layer of oriented-strand boards, nailed to the existing joists and to additional blocking elements through the existing planks. These interventions resulted also in improved wall-to-diaphragm connections with the inner leaf at both floors, while steel ties were added between the cavity-wall leaves. The application of the retrofit system favored a global response of the building with increased lateral capacities of the masonry walls. This paper describes in detail the bare and retrofitted specimens, compares the experimental results obtained through similar incremental dynamic shake-table test protocols up to near-collapse conditions, and identifies damage states and damage limits associated with displacements and deformations.

Influence of PEDOT:PSS Coating Thickness on the Performance of Stimulation Electrodes

AbstractPoly(3,4‐ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) is a conducting polymer commonly used to coat the electrodes of biomedical devices to reduce impedance and improve charge injection. The stimulation performance of such electrodes depends on coating thickness due to the volumetric properties of the conducting polymer. Here, the influence of PEDOT:PSS coating thickness on impedance, charge injection, and electrode stability is examined. The results show that stacking spin‐coated layers is a reliable method to control coating thickness without introducing electronic or ionic blocking elements in between layers. Besides improving the polymer‐electrolyte interaction due to a higher capacitance, thicker coatings can endure more stimulation pulses and withstand higher voltages without loss of performance, thus enhancing the lifetime of the electrode. This work presents fundamental insights into the coupling of PEDOT:PSS coated electrodes with electrolytes and provides guidance in the development of organic bioelectronic stimulation devices for optimum performance and longevity.

Analysis of Blocking in mmWave Cellular Systems: Application to Relay Positioning

Within the framework of 5G, blockage effects occurring in the mmWave band are critical. Previous works describe the effects of blockages in isolated and multiple links for simple blocking objects, modeled with mathematical tools such as stochastic geometry and random shape theory. Our study uses these tools to characterize a scenario with N links, including the possible correlation among them in terms of blocking for several models of blocking objects. We include numerical evaluations highlighting that assuming independence among the links' blocking elements is a too-brief simplification and does not accurately describe the real scenario. This paper also applies the formulation developed for the case of N links to optimize the relay positioning in mmWave cells for coverage enhancement, that is, to minimize the communication failure probability. We also show that both link budget and blockages affect the optimum positioning of the relays as they are both essential for successful transmission.

ДИЗАЙН-ПРОЕКТУВАННЯ АВТОРСЬКОЇ КОЛЕКЦІЇ ОДЯГУ В РОМАНТИЧНОМУ СТИЛІ

Purpose. Artistic design and production of the author couture collection using constructive and compositional signs romantic style. Methodology. The basic principles of the systematic approach to artistic design of the author couture collection such as literary-analytical research and associative stylization of the source of creativity were used in the process. Results. Using of floral motives in an artistic and compositional solution of the modern women closthing were analyzed and systemized. The main principles of creation the clothes in a romantic style were determined. The main stages of sources of creativity stylization such as peony flowers are determined, the collection of couture in a romantic style is produced, and the main peculiarities of the designed collection are described. Scientific novelty. Systematized the constructive and compositional signs of the modern clothes in a romantic style was developed ty the range, silhouette, figure blocking, color spectrum, materials, prints, decorative and constructive elements, decoration. Practical significance. The trends were analyzed, the modern designers’ collections were reviewed and the main artistic and compositive peculiarities of the romantic style in modern clothing were determined. The main substyles of a romantic style in the modern clothing were found. Identified ways of using floral motives using in artistic and compositive solution in modern clothing was developed. The classification is fundamental for designing of the couture collection with a natural source of creativity. Artistic and compositional base of designing of couture collection in a romantic style using the floral motives as the source of creativity were developed.

Dynamic DNA-controlled "stop-and-go" assembly of well-defined protein domains on RNA-scaffolded TMV-like nanotubes.

A DNA-based approach allows external control over the self-assembly process of tobacco mosaic virus (TMV)-like ribonucleoprotein nanotubes: their growth from viral coat protein (CP) subunits on five distinct RNA scaffolds containing the TMV origin of assembly (OAs) could be temporarily blocked by a stopper DNA oligomer hybridized downstream (3') of the OAs. At two upstream (5') sites tested, simple hybridization was not sufficient for stable stalling, which correlates with previous findings on a non-symmetric assembly of TMV. The growth of DNA-arrested particles could be restarted efficiently by displacement of the stopper via its toehold by using a release DNA oligomer, even after storage for twelve days. This novel strategy for growing proteinaceous tubes under tight kinetic and spatial control combines RNA guidance and its site-specific but reversible interruption by DNA blocking elements. As three of the RNA scaffolds contained long heterologous non-TMV sequence portions that included the stopping sites, this method is applicable to all RNAs amenable to TMV CP encapsidation, albeit with variable efficiency most likely depending on the scaffolds' secondary structures. The use of two distinct, selectively addressable CP variants during the serial assembly stages finally enabled an externally configured fabrication of nanotubes with highly defined subdomains. The "stop-and-go" strategy thus might pave the way towards production routines of TMV-like particles with variable aspect ratios from a single RNA scaffold, and of nanotubes with two or even more adjacent protein domains of tightly pre-defined lengths.

Study of functional characteristics for safety system check valve using scaled model

The paper provides results of experimental scale model studies of functional characteristics of a check valve used in the safety system of a liquid metal cooled reactor. The proposed check valve design with a hollow ball as a blocking element has a number of substantial advantages compared with the most widely spread valves with disc type flaps used as blocking elements. The advantages are valve operation independent of functioning of other safety systems and absence of friction pairs. The need to conduct experimental studies is determined both by the novelty of the proposed check valve design and by absence of verified computational validation methods for functioning of this type of valves. In this connection, the paper presents a computational validation method for hydrodynamic parameters of the proposed check valve design and similitude parameters describing hydrodynamic characteristics of the check valve – numeric values of the similitude parameters were obtained through calculations made by the ANSYSCFX commercial hydrodynamic code. The paper describes the experimental model of the check valve with two alternative options for the blocking element – one in the form of a hollow ball in a support bowl; and another one, in the form of a semi sphere on a guide rod going through the support sleeve on the valve spindle. Provided is a brief description of the test facility. Hydrodynamic characteristics of the check valve model obtained in experimental studies are shown in diagrams as functions of some design and operation parameters of the model.

Hi-Fi SELEX: A High-Fidelity Digital-PCR Based Therapeutic Aptamer Discovery Platform.

Current technologies for aptamer discovery typically leverage the systematic evolution of ligands by exponential enrichment (SELEX) concept by recursively panning semi-combinatorial ssDNA or RNA libraries against a molecular target. The expectation is that this iterative selection process will be sufficiently stringent to identify a candidate pool of specific high-affinity aptamers. However, failure of this process to yield promising aptamers is common, due in part to (i) limitations in library designs, (ii) retention of non-specific aptamers during screening rounds, (iii) excessive accumulation of amplification artifacts, and (iv) the use of screening criteria (binding affinity) that does not reflect therapeutic activity. We report a new selection platform, High-Fidelity (Hi-Fi) SELEX, that introduces fixed-region blocking elements to safeguard the functional diversity of the library. The chemistry of the target-display surface and the composition of the equilibration solvent are engineered to strongly inhibit non-specific retention of aptamers. Partition efficiencies approaching 10(6) are thereby realized. Retained members are amplified in Hi-Fi SELEX by digital PCR in a manner that ensures both elimination of amplification artifacts and stoichiometric conversion of amplicons into the single-stranded library required for the next selection round. Improvements to aptamer selections are first demonstrated using human α-thrombin as the target. Three clinical targets (human factors IXa, X, and D) are then subjected to Hi-Fi SELEX. For each, rapid enrichment of ssDNA aptamers offering an order-nM mean equilibrium dissociation constant (Kd) is achieved within three selection rounds, as quantified by a new label-free qPCR assay reported here. Therapeutic candidates against factor D are identified.

Methodology of Computer-Assistant Optimization Positioning of Fixing Elements on Plate Body Undergoing Rotational Forces

3 Chernivtsi regional clinical hospital, Ukraine Abstract. There was concerned suggested methodology of optimal choice variant positioning of fixing and blocking screws on plate body for fixing bone fragments in cases of transverse diaphyseal fractures to prevent rotational forces. It was described the possibility to determine optimal positioning of fixing and blocking elements in cases of using 3, 4, 5 screw fixings on each plate side. The finite elements method allows appreciating parameters of stress-stain state fixing device material for various sets of allocation fixing and blocking screws on plate body. Enumeration of possibilities combinations of blocking and fixing screws positions were reviewed by mean of combinatory apparatus. The comparable analysis of derived calculation results was performed in similar study for plate osteosynthesis of identical fracture with strain-compression deformities. Results of performed research allow elaborating practical recommendations for orthopaedic doctors and improving quality of treatment patients.

Response Surfaces, Blocking and Split Plots: An Industrial Experiment Case Study

ABSTRACT This case study is from an experiment done on a step of a manufacturing process. The objective of the experiment is to determine the appropriate levels of three factors to optimize two responses in order to ensure that the manufactured product meets customer requirements. The experiment performed is more complex than standard experimental designs because it has aspects of response surface, blocking, and split-plot elements that pose unique analysis challenges. These challenges include determination of the appropriate error term for significance testing and checking of model assumptions. We illustrate the correct analysis including the residual analysis and multiple response optimization.

Context differences reveal insulator and activator functions of a Su(Hw) binding region.

Insulators are DNA elements that divide chromosomes into independent transcriptional domains. The Drosophila genome contains hundreds of binding sites for the Suppressor of Hairy-wing [Su(Hw)] insulator protein, corresponding to locations of the retroviral gypsy insulator and non-gypsy binding regions (BRs). The first non-gypsy BR identified, 1A-2, resides in cytological region 1A. Using a quantitative transgene system, we show that 1A-2 is a composite insulator containing enhancer blocking and facilitator elements. We discovered that 1A-2 separates the yellow (y) gene from a previously unannotated, non-coding RNA gene, named yar for y-achaete (ac) intergenic RNA. The role of 1A-2 was elucidated using homologous recombination to excise these sequences from the natural location, representing the first deletion of any Su(Hw) BR in the genome. Loss of 1A-2 reduced yar RNA accumulation, without affecting mRNA levels from the neighboring y and ac genes. These data indicate that within the 1A region, 1A-2 acts an activator of yar transcription. Taken together, these studies reveal that the properties of 1A-2 are context-dependent, as this element has both insulator and enhancer activities. These findings imply that the function of non-gypsy Su(Hw) BRs depends on the genomic environment, predicting that Su(Hw) BRs represent a diverse collection of genomic regulatory elements.

Remote control of gene transcription

In this review, we look at the most recent studies of DNA elements that function over long genomic distances to regulate gene transcription and will discuss the mechanisms genes employ to overcome the positive and negative influences of their genomic neighbourhood in order to achieve accurate programmes of expression. Enhancer elements activate high levels of transcription of linked genes from distal locations. Recent technological advances have demonstrated chromatin loop interactions between enhancers and their target promoters. Moreover, there is increasing evidence that these dynamic interactions regulate the repositioning of genes to foci of active transcription within the nucleus. Enhancers have the potential to activate a number of neighbouring genes over a large chromosomal region, hence, their action must be restricted in order to prevent activation of non-target genes. This is achieved by specialized DNA sequences, termed enhancer blockers (or insulators), that interfere with an enhancer's ability to communicate with a target promoter when positioned between the two. Here, we summarize current models of enhancer blocking activity and discuss recent findings of how it can be dynamically regulated. It has become clear that enhancer blocking elements should not be considered only as structural elements on the periphery of gene loci, but as regulatory elements that are crucial to the outcome of gene expression. The transcription potential of a gene can also be susceptible to heterochromatic silencing originating from its chromatin environment. Insulator elements can act as barriers to the spread of heterochromatin. We discuss recent evidence supporting a number of non-exclusive mechanisms of barrier action, which mostly describe the modulation of chromatin structure or modification.

CTCF-dependent enhancer blockers at the upstream region of the chicken alpha-globin gene domain.

The eukaryotic genome is partitioned into chromatin domains containing coding and intergenic regions. Insulators have been suggested to play a role in establishing and maintaining chromatin domains. Here we describe the identification and characterization of two separable enhancer blocking elements located in the 5' flanking region of the chicken alpha-globin domain, 11-16 kb upstream of the embryonic alpha-type pi gene in a DNA fragment harboring a MAR (matrix attachment region) element and three DNase I hypersensitive sites (HSs). The most upstream enhancer blocking element co-localizes with the MAR element and an erythroid-specific HS. The second enhancer blocking element roughly co-localizes with a constitutive HS. The third erythroid-specific HS present within the DNA fragment studied harbors a silencing, but not an enhancer blocking, activity. The 11 zinc-finger CCCTC-binding factor (CTCF), which plays an essential role in enhancer blocking activity in many previously characterized vertebrate insulators, is found to bind the two alpha-globin enhancer blocking elements. Detailed analysis has demonstrated that mutation of the CTCF binding site within the most upstream enhancer blocking element abolishes the enhancer blocking activity. The results are discussed with respect to special features of the tissue-specific alpha-globin gene domain located in a permanently open chromatin area.