Block Construction Research Articles

Earth eco-building: textile-reinforced earth block construction

Compacted earth block and adobe respond directly to the demands of sustainable building: low embodied energy, high specific heat capacity, inherent phase change properties, locally available in nearly all regions of the world. Because of its resistance to codification by traditional engineered quantification, however, earthen construction has remained largely relegated to the global south and, in Northern Europe, to bespoke small-market construction. Our research considers how the addition of natural fibre and recoverable textile components can lend compressed earth block building structural resilience and more predictable material qualities relative to human comfort and building longevity. Through our own and combinatory research, we have developed a decision tool to customize textile and fibre components to local climatic, soil and seismic conditions. The customized components, conceived as a kit of parts we have termed the ‘Just-Add-Earth Kit’, ship pre-templated to the site, serving to regulate construction, much like formwork or centering, but remaining in place after construction to serve as tensile reinforcing. The result is a carbon-neutral, locally appropriate construction with excellent interior climate characteristics as much at home in the developed world as in the developing world.

Stereoselective Palladium-Catalyzed Synthesis of Indolines via Intramolecular Trapping ofN-Ylides with Alkenes

Metal-catalyzed in situ functionalization of ammonium ylides has emerged as a mild and atom/step economy strategy for the construction of complex building blocks. Despite the success, these trapping reactions are limited to activated polar double bonds such as (α,β-unsaturated) carbonyl derivatives. Trapping of ammonium ylides with nonpolar double bonds, which allows the all-carbon quaternary center, is unprecedented. In this article, an efficient stereoselective palladium-catalyzed intramolecular trapping of N-ylides derived from o-vinylaniline and α-diazocarbonyl compounds has been accomplished, a carbenylative hydroamination of alkenes. The present reaction allows the synthesis of various tri- and tetrasubstituted indolines in good yield with high diastereoselectivity. Important features are the construction of two contiguous quaternary carbon centers via the formation of C–N and C–C bonds in a single operation, high diastereoselectivity, wide functional group tolerance, and high atom and step economy....

Eco-efficient alkali-activated cement based on red clay brick wastes suitable for the manufacturing of building materials

The objective of this study was to obtain hybrid-type binders at room temperature (25 °C) from the alkaline activation of a red clay brick waste and the addition of a reduced amount (≤30%) of Portland cement. Different types of activators were used, including solids (Na2SO4, Na2CO3, NaOH) and liquids (Na2SiO3xH2O). The results highlight the possibility of obtaining an eco-efficient, hybrid cement with compressive strengths of up to 102 MPa at 28 days and reductions of up to 73% in the global warming potential (expressed in kg·CO2·eq/MPa) associated with a Portland cement paste. Based on the optimum hybrid cement, a mortar was developed and used as a base material for the production of block and paver construction elements that comply with construction industry standards.

Design and Implementation of Quantum Dot Cellular Automata Based Irreversible and Reversible Logic Generator Block

Quantum Dot Cellular Automata has attracted a lot of attention due to its extremely small feature size and ultra low power consumption. It is a possible alternative for transistor based technology. This paper presents the construction of Irreversible and reversible Logic Generator Block using quantum dot cellular automata. QCA based Irreversible and irreversible Logic generator block generates the logic of various devices like 1-Bit comparator, 1-Bit Half Adder, 1-Bit Half Subtractor, AND gate, XOR gate, NOR gate and XNOR gate. Proposed design of QCA based LGB is cost effective and easy to fabricate due to absence of wire crossings in irreversible LGB and no information loss in reversible LGB. This block can be made more efficient by using control lines. Depending on individual value on control line, logic of individual device will be generated. QCADesigner 2.0.3 tool is used for design and simulation of QCA based Logic Generator Block. Similarly here Reversible logic based Logic generator block is proposed which will be able to generate different logic. Area requirement of Reversible LGB is 85% less as compared to Irreversible LGB. Reversible logic provides ideally zero power dissipation that is no information loss is there.

Mechanical properties of millet husk ash bitumen stabilized soil block

This study presents an investigation into the improvement of strength and durability properties of lateritic soil blocks using Millet Husk Ash (MHA) and Bitumen as additives so as to reduce its high cost and find alternative disposal method for agricultural waste. The lateritic soil samples were selected and treated with 0%, 10%, 15%, 20%, 30%, 40% and 50% of MHA by weight of laterite. The lateritic soil-MHA mixture was later admixed with 0%, 2%, 4%, 6%, 8%, 10%, 12% and 14% cut-back bitumen solution by weight of laterite. Both the natural lateritic soil, lateritic and MHA, and the blend of Soil, MHA and Bitumen were first subjected to physical and chemical analysis using X-Ray Fluorescence (XRF) and Scanning Electromagnetic Machine (SEM) to determine their engineering properties followed by the performance test on bricks cast with varying quantities of the additives. A total of one hundred and ninety two (192) cubes were tested for moisture absorption, erodability and compressive strength tests. The result of the test showed that MHA and Bitumen acted as pozzolana in performance test on the soil blocks. Up to 30% MHA – laterite and 20% MHA admixed with 8% laterite were found to give optimum compressive strength of 10.8N/mm2 and 10.9N/mm2 for the bricks produced. The result also showed that about 50% MHA blended with 14% Bitumen solution ensured water tight bricks. Thus the use of MHA as partial replacement of cement will provide an economic use of by-product and consequently produce a cheaper soil block construction without comprising its strength.Keywords: Millet husk, ash, bitumen, soil block, mechanical properties, compressive strength

Alien plant species establishment is associated with reduced soil acidity in the vicinity of concrete block structures1,2

Abstract We hypothesized that in the oligotrophic, acid soils of the New Jersey Pine Barrens, where native diversity and invasability appear to be low, the weathering of concrete block construction material over time has reduced resistance to plant species' invasion by reducing soil acidity. We also sought to determine whether alien species' success in disturbed Pine Barrens soil differs from that of the non–Pine Barrens North American plant species whose presence in the region is associated with anthropogenic soil disturbance. In the field, species richness of native Pine Barrens species, non–Pine Barrens species, and alien species was determined along with current-year aboveground biomass production and soil pH along transects extending from concrete block buildings and from paired control transects without concrete block buildings. Soil inorganic nitrogen was measured near and far from buildings. Additionally, a pot study using native soil amended with ground concrete was conducted to determine its eff...

Superconformal blocks for SCFTs with eight supercharges

We show how to treat the superconformal algebras with eight Poincaré super-charges in a unified manner for spacetime dimension 2 < d ≤ 6. This formalism is ideally suited for analyzing the quadratic Casimir operator of the superconformal algebra and its use in deriving superconformal blocks. We illustrate this by an explicit construction of the superconformal blocks, for any value of the spacetime dimension, for external protected scalar operators which are the lowest component of flavor current multiplets.

Disparities in developmental trajectories of visuo-spatial constructive ability in Williams syndrome patients with typical deletion on chromosome 7q11.23

Objective: Williams syndrome (WS) is known to have uneven cognitive abilities. The visuo-spatial cognition difficulties are distinct, but with some inter-individual phenotypic differences. Based on an examination of atypical deletions identified in WS patients with atypical cognitive deficits, the difficulty in visuo individual phenotypic differences. Based on an examination of atypical deletions identified in WS patients with atypical cognitive deficits, the difficulty in visuo-spatial cognition of WS patients has been attributed to a haploinsufficiency of some genes located on the deleted region in 7q11.23. We questioned the view that inter-individual differences in the visuo-spatial co cognitive ability arise only from variations in deletion and performed the fo following study. Methods: We investigated whether there were inter-individual differences in the developmental trajectories of the visuo-spatial constructive abilities by following up five unrelated WS patients with the same typical deletion on chromosome 7q11.23. The deletion includes the candidate genes contributing visuo-spatial difficulty in WS patients. We used tests with three-dimensional factors such as Benton’s three-dimensional block construction test, because these tests are considered to be more sensitive than those with only two-dimensional factors. Results: There were diverse inter-individual differences in the development of the visuo-spatial constructive abilities among the present participants who shared the same typical genomic deletion of WS. One of the participants, who used to show the visuo-spatial difficulty typical of WS, showed almost equivalent performances to typically developing adults in the visuo-spatial co construction tests with three dimensional factors at the last investigation. Conclusion: In the present study, we found a wide range of developmental trajectories in visuo-spatial constructive abilities even among the patients with a common deletion pattern of WS. The findings suggest the importance of longitudinal observation instead of simply a cross sectional study, and that attributing differences in the phenotypes entirely to genetic factors such as an atypical deletion may not be always correct.

Rapid and annealing-free self-assembly of DNA building blocks for 3D hydrogel chaperoned by cationic comb-type copolymers

The construction and self-assembly of DNA building blocks are the foundation of bottom-up development of three-dimensional DNA nanostructures or hydrogels. However, most self-assembly from DNA components is impeded by the mishybridized intermediates or the thermodynamic instability. To enable rapid production of complicated DNA objects with high yields no need for annealing process, herein different DNA building blocks (Y-shaped, L- and L′-shaped units) were assembled in presence of a cationic comb-type copolymer, poly (L-lysine)-graft-dextran (PLL-g-Dex), under physiological conditions. The results demonstrated that PLL-g-Dex not only significantly promoted the self-assembly of DNA blocks with high efficiency, but also stabilized the assembled multi-level structures especially for promoting the complicated 3D DNA hydrogel formation. This study develops a novel strategy for rapid and high-yield production of DNA hydrogel even derived from instable building blocks at relatively low DNA concentrations, which would endow DNA nanotechnology for more practical applications.

Digitally Controlled Single-inductor Multiple-output Synchronous DC-DC Boost Converter with Smooth Loop Handover Using 55 nm Process

This paper reports on a single-inductor multiple-output step-up converter with digital control. A systematic analog-to-digital-controller design is explained. The number of digital blocks in the feedback path of the proposed converter has been decreased. The simpler digital pulse-width modulation (DPWM) architecture is then utilized to reduce the power consumption. This architecture has several advantages because counters and a complex digital design are not required. An initially designed unit-delay cell is adopted recursively for the construction of coarse, intermediate, and fine delay blocks. A digital limiter is then designed to allow only useful code for the DPWM. The input voltage is 1.8 V, whereas output voltages are 2 V and 2.2 V. A co-simulation was also conducted utilizing PowerSim and Matlab/Simulink, whereby the 55 nm process was employed in the experimental results to evaluate the performance of the architecture.

Vitamin B-12 status in infancy is positively associated with development and cognitive functioning 5 y later in Nepalese children

Background: Poor vitamin B-12 (cobalamin) status is widespread in South Asia. Insufficient vitamin B-12 status has been linked to poor neurodevelopment in young children.Objective: We measured the associations between vitamin B-12 status in infancy (2–12 mo) and the development and cognitive functioning in Nepalese children 5 y later.Design: Vitamin B-12 status was assessed in infancy with the use of plasma cobalamin, total homocysteine (tHcy), and methylmalonic acid (MMA). At 5 y of age, we measured development with the use of the Ages and Stages Questionnaire, 3rd edition (ASQ-3), and cognitive functioning by using the Developmental Neuropsychological Assessment, 2nd edition (NEPSY II), in 320 children. In regression models, we estimated the associations between vitamin B-12 status, including a combined indicator of vitamin B-12 status (3cB12) and scores on the ASQ-3 and NEPSY II subtests.Results: All markers of vitamin B-12 status with the exception of plasma cobalamin were significantly associated with the total ASQ-3 scores in the multiple regression models. A 1-unit increase in the 3cB12 score was associated with an increase in the total ASQ-3 score of 4.88 (95% CI: 2.09, 7.68; P = 0.001). Increases in both plasma tHcy and MMA (indicating poorer status) were associated with a decrease in scores on the NEPSY II affect recognition and geometric puzzle subtests. Each unit increment in 3cB12 scores was associated with increases of 0.82 (95% CI: 0.49, 1.14; P < 0.0005), 0.59 (95% CI: 0.10, 1.09; P = 0.020), and 0.24 (95% CI: 0.02, 0.47; P = 0.035) in the affect recognition, geometric puzzle, and block construction scores, respectively.Conclusions: Vitamin B-12 status in infancy is associated with development and performance on social perception tasks and visuospatial abilities at 5 y of age. The long-term effects of poor vitamin B-12 status in infancy need further investigation in randomized controlled trials.

The effect of Er:YAG laser irradiation on the bond stability of self-etch adhesives at different dentin depths

The aim of this study was to evaluate the effect of Er:YAG laser irradiation on the micro-shear bond strength of self-etch adhesives to the superficial dentin and the deep dentin before and after thermocycling. Superficial dentin and deep dentin surfaces were prepared by flattening of the occlusal surfaces of extracted human third molars. The deep or superficial dentin specimens were randomized into three groups according to the following surface treatments: group I (control group), group II (Er:YAG laser; 1.2 W), and group III (Er:YAG laser; 0.5 W). Clearfil SE Bond or Clearfil S3 Bond was applied to each group’s dentin surfaces. After construction of the composite blocks on the dentin surface, the micro-shear bond testing of each adhesive was performed at 24 h or after 15,000 thermal cycles. The data were analyzed using a univariate analysis of variance and Tukey’s test (p < 0.05). Laser irradiation in superficial dentin did not significantly affect bond strength after thermocycling (p > 0.05). However, deep-dentin specimens irradiated with laser showed significantly higher bond strengths than did control specimens after thermocycling (p < 0.05). Thermocycling led to significant deterioration in the bond strengths of all deep-dentin groups. The stable bond strength after thermocycling was measured for all of the superficial-dentin groups. No significant difference was found between the 0.5 and 1.2 W output power settings. In conclusion, the effect of laser irradiation on the bond strength of self-etch adhesives may be altered by the dentin depth. Regardless of the applied surface treatment, deep dentin showed significant bond degradation.

Block-Copolymer-Templated Hierarchical Porous Carbon Nanostructures with Nitrogen-Rich Functional Groups for Molecular Sensing.

The self-assembly of a block copolymer offers access to micellar nanodomains with tunable dimensions and structural diversity through control of such molecular parameters as the volume fraction and molecular mass. We fabricated hierarchical porous carbon (HPC) nanostructures with bundles of aggregated nanospheres and with nitrogen-rich functional groups through pyrolysis of diblock copolymer micelles in multiple layers. The resultant HPC nanostructures with a considerable specific surface area serve as an excellent substrate for surface-enhanced Raman spectroscopy (SERS), coupled with fluorescence quenching, for molecular sensing of physically adsorbed Rhodamine 6G. The abundant nitrogen atoms terminating on the surface of HPC nanostructures play a critical role in promoting a large Raman enhancement generated via a chemical mechanism. Most importantly, the observed enhancement factors show a clear dependence on the mesoscale porosity within HPC nanostructures, indicating that the chemical enhancement can be steadily tuned with control over the interfacial areas as a function of the nanosphere size. The unique architecture of HPC nanostructures based on the construction of a building block of a well-defined network of core-shell nanospheres provides a new design strategy for fabricating SERS substrates.

Performance Evaluation and Field Application of Red Clay Green Roof Vegetation Blocks for Ecological Restoration Projects

In this study, for restoration of ecological systems in buildings, porous vegetation red clay green roof blocks were designed for performance evaluation. Blast furnace slag (BFS; fine aggregates (agg.)), coarse aggregates, polyvinyl alcohol (PVA) fiber (hydrophilic fiber), and red clay (ecofriendly additive material) were applied to the construction of the porous vegetation red clay green roof blocks. A decrease in cement use is one way of reducing carbon emissions. To increase the water retentivity and the efficiency of roof vegetation blocks, blast furnace slag aggregates with excellent water absorptivity and polyvinyl alcohol fiber with a water absorption rate above 20% were added. In particular, the addition of polyvinyl alcohol fiber prevents performance reduction of the green roof vegetation blocks during freezing and melting in winter. Compressive strength, void ratio, and unit-mass tests were conducted to evaluate the performance of the roof vegetation blocks. After their application to roof vegetation, the effect of water purification was evaluated. According to the experimental results, the mix that satisfies the target performance of green roof vegetation blocks (compression strength above 8 MPa, void ratio above 20%, unit mass 2.0 kg/cm3 or below) is: cement = 128.95 kg/m3, BFS = 96.75 kg/m3, red clay = 96.75 kg/m3, water = 81.50 kg/m3, BFS agg. = 1450 kg/m3, PVA fiber = 1.26 kg/m3. The green roof vegetation blocks were designed using the mix that satisfied the target performance. To find the amount of attainable water due to rainfall, a rainfall meter was installed after application of the roof vegetation to measure daily rainfall and calculate the amount of attainable water. The results show that, for 1 mm of rainfall, it is possible to attain about 0.53 L of water per 1 m2. In addition, the water quality of effluents after application of roof vegetation was analyzed, and the results satisfied Class 4 of the River-life Environmental Standard for Availability of Agricultural Water.

Experimental studies of dynamic properties of Quaternary clayey soils

The recent significant development of technical infrastructures in Poland, along with the construction of tower blocks, roads, railways and underground rapid transit system, resulted in greater demands for investment projects as well as geotechnical data characterizing the variation of various soil parameters found in the subsoil. The most important parameter, which represents the stiffness of soil deposits, is the shear modulus G. Therefore, this study focused on determining the initial shear modulus of cohesive soils from the area of the capital of Poland. In this research, a set of the resonant column (RC) tests was performed and the influence of three selected factors, i.e. mean effective stress (p’), void ratio (e) and plasticity index (PI), on the low-amplitude shear modulus (G0) was presented and discussed. The results obtained from laboratory tests indicated that the stress state plays an important role for the small-strain shear modulus values of the Polish Quaternary cohesive soils. In contrast, there was no clear trend observed for the significant effect of e or PI on G0 for the studied soils. Based on the performed tests, the authors proposed the power-law relations for G0 versus p′ of the forms: G0=3.02p′0.68 and G0=0.82p′0.96.

OleF: an Inverse-Free Online Cipher. An Online SPRP with an Optimal Inverse-Free Construction

Online ciphers, in spite of being insecure against an sprp adversary, can be desirable at places because of their ease of implementation and speed. Here we propose a single-keyed inverse-free construction that achieves online sprp security with an optimal number of blockcipher calls. We also include a partial block construction, without requiring any extra key.

Phase transitions for a planar quadratic contact process

We study a two dimensional version of Neuhauser's long range sexual reproduction model and prove results that give bounds on the critical values λf for the process to survive from a finite set and λe for the existence of a nontrivial stationary distribution. Our first result comes from a standard block construction, while the second involves a comparison with the “generic population model” of Bramson and Gray (1991) [3]. An interesting new feature of our work is the suggestion that, as in the one dimensional contact process, edge speeds characterize critical values. We are able to prove the following for our quadratic contact process when the range is large but suspect they are true for two dimensional finite range attractive particle systems that are symmetric with respect to reflection in each axis. There is a speed c(θ) for the expansion of the process in each direction. If c(θ)>0 in all directions, then λ>λf, while if at least one speed is positive, then λ>λe. It is a challenging open problem to show that if some speed is negative, then the system dies out from any finite set.

Anterior Lumbar Interbody Fusion Integrated Screw Cages: Intrinsic Load Generation, Subsidence, and Torsional Stability.

To perform a repeatable idealized in vitro model to evaluate the effects of key design features and integrated screw fixation on unloaded surface engagement, subsidence, and torsional stability. We evaluated four different stand-alone anterior lumbar interbody fusion (ALIF) cages with two, three, and four screw designs. Polyurethane (saw-bone) foam blocks were used to simulate the vertebral bone. Fuji Film was used to measure the contact footprint, average pressure, and load generated by fixating the cages with screws. Subsidence was tested by axially loading the constructs at 10 N/s to 400 N and torsional load was applied +/-1 Nm for 10 cycles to assess stability. Outcome measures included total subsidence and maximal torsional angle range. Cages 1, 2, and 4 were symmetrical and produced similar results in terms of contact footprint, average pressure, and load. The addition of integrated screws into the cage-bone block construct demonstrated a clear trend towards decreased subsidence. Cage 2 with surface titanium angled ridges and a keel produced the greatest subsidence with and without screws, significantly more than all other cages ( P < 0.05). Angular rotation was not significantly affected by the addition of screws ( P < 0.066). A statistically significant correlation existed between subsidence and reduced angular rotation across all cage constructs ( P = 0.018). Each stand-alone cage featured unique surface characteristics, which resulted in differing cage-foam interface engagement, influencing the subsidence and torsional angle. Increased subsidence significantly reduced the torsional angle across all cage constructs.

Tissue microarray: physical and chemical parameters involved in the construction of recipient blocks

ABSTRACT Introduction: Tissue microarray (TMA) is considered an innovative method in several fields, with a great diversity of applications and advantages over traditional histomorphometric techniques. The most important advantage that TMA offers is the simultaneous evaluation of a large number of specimens from a limited source of material. However, TMA exhibits a high rate of non-viable samples in the final stages of the process, which compromise their use in analyzes that can not be repeated. Objective: Considering this disadvantage, the objective of this study was to optimize the methodology to maximize the viability of the samples, as well as to increase the efficiency of the technique. Material and methods: For this purpose, several variables involved in the construction of the recipient blocks, including paraffin composition, diameter, spacing distance, localization and type of the tissue samples in the block were tested in order to establish correlations between the quality of the values and the parameters studied. Results: The results showed that the blocks built with polymer-enriched paraffin, subjected to the fusion protocol at 37oC, associated to a tempering, and constructed with one millimeter diameter samples and 1000 µm spacing between tissues, produced slides whith superior features. Conclusion: The data obtained from the physical and chemical adjustments of the TMA recipient blocks provided vital information that, when applied in TMA research projects, may reduce the losses associated with the method.

An optoelectronic fuel level sensor

The block and schematic construction diagrams of a new optoelectronic fuel level sensor are considered. The operating principle of the sensor is based on registering the intensity value of the optical path reflected from the mirror, located on the reservoir bottom.