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This paper examines how steel fiber and the amount of lightweight expanded clay aggregate (LECA) affect the mechanical and microstructural properties of geopolymer concrete (GPC) made from fly ash after being heated. LECA has been used with different contents (0, 10, and 20%) as a partial replacement by weight of coarse aggregate. Steel fiber has been employed in GPC with volume fractions of 0 and 1%. A slump test was applied to examine the workability of fresh concrete. Compressive strength, splitting tensile strength, flexural strength, and elastic modulus tests also measured the mechanical properties. Furthermore, the microstructure characterization was also carried out by performing scanning electron microscopy (SEM). The findings suggest that including steel fiber and raising the LECA content in the mixture enhanced the strength’s retention following high-temperature exposure. After being exposed to a constant temperature of 800°C, GPC containing steel fiber and 20% LECA achieved the best result compared to the plain GPC in terms of decrease in mass, residual compressive and tensile strengths, residual flexural strength, and residual amount of elastic modulus: 6.04 and 4.39%; 27.08 and 39.27%; 37.6 and 47.02%; 16.07 and 30.3, and 2.17 and 6.19%, respectively.

Background Pseudomonas aeruginosa (P. aeruginosa) is widely distributed in air, soil, and water, human respiratory tract, intestinal tract, and skin. It can induce bloodstream infection, urinary tract infection, gastrointestinal tract infection, respiratory tract infection, etc. Conventional bacterial isolation, culture, and identification are time-consuming, and many false negative results, which cannot meet the needs of precise clinical diagnosis，and proper treatment. This study aims to develop a rapid isothermal amplification assay of Pseudomonas aeruginosa.Methods Specific primers were designed according to the National Center for Biotechnology Information (NCBI) database based on the highly conserved sequence of Pseudomonas aeruginosa virulence factor gene lecA, and a recombinase polymerase amplification (RPA) detection method was established. The sensitivity and specificity were calculated, as well as the collection and processing of clinical samples.Results The thermostatic amplification technique for Pseudomonas aeruginosa established in this paper allows nucleic acid detection within 10 minutes without cross-amplification with other bacterial strains. 27 P. aeruginosa infections were accurately detected in 300 clinical samples.Conclusion The rapid detection system based on thermostatic amplification had shown high sensitivity and specificity in this study, indicated that this method can effectively assist clinical bacterial detection.

This study investigates fresh and hardened self-compacting concrete properties. LECA will be used in place of coarse aggregate in (0, 20, 40, and 60) % proportions in a partial replacement. First, four SCC mixes were made based on LECA volume fraction and then the second group was made by adding 1% glass fiber by volume to group one's mixes. Hardened concrete after 7, 28, and 56 days was tested for density, water absorption, and (compressive, splitting tensile, and flexural) strengths. Results suggest that LECA increases workability. Rising LECA percentage decreases compressive strength; for 60% LECA, the decrease was (51.90, 45.34, and 41.26) % for 7, 28, and 56 days, respectively. With 60% LECA replacement, flexural strength decreased by (54.38, 33.80, and 32.78) % for 7, 28, and 56 days, respectively. Density drops significantly with LECA, reaching its lower density at (60) % of LECA. Water absorption rises with the increase of LECA. After adding glass fiber workability dropped significantly, and hardened characteristics improved. Compressive strength increased slightly compared to the same mixtures without glass fibers. At20% of LECA the compressive strength increased by (5.58%) at 28 days compared to (60%) LECA at which the compressive strength increased by (3.82%). Glass fiber addition increased flexural strength significantly compared to the same mixes without glass fibers. The mixture with (20%) LECA had the greatest increase (24.46%) in 28 days, compared to the mix with (60%) LECA (18.22%). Density increased slightly with glass fibers. Glass fibers increase water absorption compared to the same mixes without glass fiber.

This study describes an experimental research focusing on the behaviour of Lightweight Aggregate Wide Reinforced Concrete Beams (LAWRCB) using shear steel plates. This technique represents an inexpensive way which reduces structural and building complexities. Wide beams can provide adequate cross-sectional areas to meet the specified capacity in a shallower depth than a system of narrower beams placed similarly in the design. Also, WB treats the crowd of stirrups because the shear component provided by concrete is very small compared with high depth concrete Beams. This research is also trying to minimize the weight of a wide concrete beam using light weight concrete instead of using conventional concrete which has effects on the deflection, crack patterns, and load carrying capacity. This investigation consists of reviewing the previous work and an experimental program consisting of testing mixes to produce lightweight concrete. In addition, several simply supported wide beams with various parametric studies will be designed, cast, and tested. After the specimen tests are carried out, comparisons and discussions of the results will be made with code requirements.

Abstract In the present work, an exhaustive analysis of an Argentinian commercial LECA with a multi-technique approach was successfully carried out. Five sub-types of samples were considered to study the degree of macroscopic homogeneity of the LECAs, which presented observable differences in color and morphology. The microstructural, textural, and mineralogical features of the aggregates within each category were assessed and the differences among them were described and discussed. The density values of the samples studied were between 1.01 and 1.20 g/cm3 and porosity percentages were in the range of 24 to 33 %. The samples present a similar mineralogical composition with quartz and anorthite as the main crystalline phases and almost 50 wt. % of non-crystalline phase. In addition, some variations in the Rietveld quantification were analyzed. The main challenge of LECAs industrial production is to control the raw materials and the process to obtain homogeneous LECAs with similar performance. In this regard, this type of analysis is useful for establishing and comparing some characterization strategies to control, select, design, and evaluate new LECAs.

This research aims to produce lightweight self-compacting concrete (LWSCC) using lightweight expanded clay aggregate (LECA) as coarse aggregate. The additional aim is to study the influence of steel fiber and hybrid fibers (steel and polypropylene (PP)) on the properties of LWSCC in fresh and hardened state. Furthermore, compressive, tensile, and flexural strengths of LWSCC specimens (with and without fibers) are tested after being subjected to the fire exposure. In this study, four LWSCC mixtures with different fiber percentages (0 % fiber, 1 % steel, 0.75 % steel + 0.25 % PP, and 0.5 % steel + 0.5 % PP) are prepared and tested. The specimens were burned at temperatures 25, 300, 400, and 600 °C. The results show that all mixtures have excellent resistance to segregation and high ability to filling and passing. The presence of fibers slightly reduced the workability of LWSCC. The mechanical properties of LWSSC decrease with increasing temperature. The results show that mixtures containing fibers have good mechanical qualities and spalling resistance compared to mixtures without fibers when exposed to fire.

The durability of geopolymer concrete containing Ground Granulated Blast Furnace Slag (GGBS) and Rice Husk Ash (RHA), along with Lightweight Expanded Clay Aggregate (LECA), was investigated. Six different LWGPC mixtures were made with NaOH molarities of 8, 10, and 12M. For each molarity, two combinations of source materials were selected: 100% GGBS (G) and 80% GGBS with 20% RHA (RG). In all the mixtures, coarse aggregate was substituted with 35% LECA. LWGPC mixtures were exposed to 3% HCl, 5% MgSO4, and 3.5% NaCl for studying the durability properties. The test results demonstrate that 100% GGBS with 12M NaOH (12G) outperformed all other mixtures. The residual compressive strength of 12G mix LWGPC specimens after six months of exposure was found to be 86.4% in an acid environment, 90.6% in a sulfate environment, and 91.4% in a salt environment. The elemental composition analyzed using EDAX reveals that silica, alumina, calcium, and sodium are the predominant elements that form a dense microstructure with N-A-S-H, C-A-S-H, and C-S-H. Further, the inner properties of the specimens exposed to chemicals were examined using MATLAB R2023b and ImageJ 1.54f based on SEM images. The SEM image showed that the porosity of LWGPC specimens ranged from 0.5194 to 0.6748 µm, signifying an enhanced durability performance. The experimental results and microstructural analysis show that the LWGPC incorporating RHA and GGBS with LECA offers a superior performance, making it a promising solution for sustainable and durable construction.

A versatile building material, foamed concrete is made of cement, fine aggregate, and foam combined with coarse aggregate. This study provides a description of how constant coarse aggregate replacement (50%) of LECA and foamed concrete, which are lightweight concrete types, by zeolite as a filler and PEG-400 as a plasticizer, water retention agent, and strength enhancer affect the mechanical properties of the cement. A study that examined the characteristics of cellular lightweight concrete in both its fresh and hardened forms was carried out for both foamed concrete and LECA concrete. In order to do this, a composite of zeolite and polyethylene glycol 400 was made using the direct absorption method, and no leakage was seen. Zeolite was loaded to a level of 10% and 20% of the total weight in cement, while 400 g/mol PEG was used at levels of 1%, 1.5%, and 2% of the cement’s weight. Various mixtures having a dry density of 1250 kg/m3 were produced. Properties like dry density, splitting tensile strength, and compressive strength were measured. An increase in the amount of PEG400–zeolite was seen to lower the workability, or slump, of both foamed and LECA concrete, while the replacement of aggregate by zeolite resulted in an exponential drop in both compressive and flexural strengths.

Concrete quality control tests usually focus on the compressive strength of concrete, while neglecting other important properties such as impact and explosion resistance, which are essential for creating resilient concrete structures. Additionally, in the process of refining sugarcane, Bagasse, a yellow fiber that is considered a waste product, is produced. Khuzestan province alone produces around one million tons of Bagasse annually, which leads to environmental concerns. To address these issues, this research investigates the mechanical properties and impact resistance of concrete containing lightweight LECA aggregates and Bagasse fibers under compressive and impact loads. Initially, a target mix scheme is determined, and samples are made and tested after curing without the addition of Bagasse and LECA. Then, samples are made with the mentioned mixing design and the combination of Bagasse and LECA by weight ratio of (Bagasse unit, LECA unit). Additionally, samples using LECA (without Bagasse) with 10%, 20%, and 30% replacement of aggregates are made and tested after curing. Compressive and impact tests are performed on all samples in accordance with regulations using appropriate testing machines and procedures. Results indicate that concrete containing lightweight LECA and Bagasse fibers has a higher impact resistance than ordinary concrete, and that the use of LECA in concrete can create structural lightweight concrete.

Core mitochondrial processes such as the electron transport chain, protein translation and the formation of Fe–S clusters (ISC) are of prokaryotic origin and were present in the bacterial ancestor of mitochondria. In animal and fungal models, a family of small Leu-Tyr-Arg motif-containing proteins (LYRMs) uniformly regulates the function of mitochondrial complexes involved in these processes. The action of LYRMs is contingent upon their binding to the acylated form of acyl carrier protein (ACP). This study demonstrates that LYRMs are structurally and evolutionarily related proteins characterized by a core triplet of α-helices. Their widespread distribution across eukaryotes suggests that 12 specialized LYRMs were likely present in the last eukaryotic common ancestor to regulate the assembly and folding of the subunits that are conserved in bacteria but that lack LYRM homologues. The secondary reduction of mitochondria to anoxic environments has rendered the function of LYRMs and their interaction with acylated ACP dispensable. Consequently, these findings strongly suggest that early eukaryotes installed LYRMs in aerobic mitochondria as orchestrated switches, essential for regulating core metabolism and ATP production.

. The primary goal of this investigation is to study the effect of using mono and hybrid fibers on the fresh and hardened characteristics of Lightweight Self-Compacting Concrete (LWSCC). Slump flow test, L-box test, sieve segregation test, and V-funnel test were used to evaluate the workability of LWSCC. The mechanical characteristics of LWSCC were assessed by using compressive strength, splitting strength, and flexural strength. Four mixtures using two types of fiber: Steel fiber (St) and polypropylene fiber (PP) (0% fiber, 1% (St), 0.75% (St) +0.25% (PP), 0.5% (St) +0.5% (PP)) were made. According to the results, (St) fiber and hybrid fiber addition to LWSCC reduced its workability, although the values of tests were still within the acceptable range stander of EFNARC. The findings indicated a decrease in the values of slump flow and L-box test by adding mono and hybrid fibers to the LWSCC mixture. While the T500mm and V_ funnel tests increased by adding mono and hybrid fibers to LWSCC mixture. The results also indicate that the utilisation of (St) fiber and hybrid fibers had a significant effect on the mechanical characteristics of LWSCC. Where the flexural and splitting strengths significantly increase with the addition of (St) and hybrid fibers to the LWSCC mix.

Concrete developed from light expanded clay aggregate (LECA) and glass fiber has good performance, durability, and sustainability. Towards this, the experimental investigation was designed to study cubes, cylinders, and simply supported beams. Four mixtures had LECA volume of 0%, 75%, 85%, and 95% as coarse aggregate replacement and glass fiber content volume of 2% (N, L75, L85, and L95), and the other two mixtures had 75% LECA and glass fiber content of 1% and 1.5% (L75-F1 and L75-F1.5). Results compared to normal concrete showed the weight reduction of samples while adding more glass fiber caused slump reduction in contrast to LECA. Increasing glass fiber volume in the mixture had a negative influence on tensile strength while causing compressive strength enhancement. Moment resistance and energy absorption capacity of L85 were enhanced by 7.5% and 10.3%, respectively. For L75-F1 specimens, the beam stiffness and ductility were enhanced by 14.8% and 14.3%, respectively. Finally, using more glass fibers did not necessarily result in improved mechanical properties. More ideal properties can be obtained by controlling the LECA content and glass fibers ratio. After conducting tests, narrowing down the glass fiber content range up to 2%, along with LECA content of 75% and 85%, is highly recommended for obtaining the best behavior of glass fiber-reinforced LECA concrete.

In spite of the demonstrated efficacy of basalt stone powder as a cost-effective and readily available additive in enhancing the mechanical properties and durability of ordinary-weight concrete, its application in Structural Lightweight Concrete (SLWC) remains unexplored. This study introduced a mixing design for SLWC incorporating Light Expanded Clay Aggregates (LECAs) and basalt stone powder with a subsequent evaluation of its strength and durability characteristics. The experimental procedure involved creating various samples, considering differing proportions of cement, water, basalt stone powder, sand, LECA, superplasticizer, and aerating agent. The compressive strength and density of the 28-day-cured concrete specimens were determined. An optimal SLWC with a compressive strength of 42 MPa and a density of 1715 kg/m3 was identified. The flexural and tensile strength of the optimal SLWC exceeded those of ordinary-weight concrete by 6% and 3%, respectively. Further evaluation revealed that the optimal SLWC exhibited 1.46% water absorption and an electrical resistivity of 139.8 Ohm.m. Notably, the high porosity of LECA contributed to the low durability of SLWC. To address this, cost-effective external coatings of emulsion and fiberglass were applied to enhance the durability of the SLWC. Four coating scenarios, including one-layer bitumen, two-layer bitumen, three-layer bitumen, and three-layer bitumen with fiberglass, were investigated. The measurements of electrical resistance and compressive strength revealed that the use of three layers of emulsion bitumen and fiberglass improved the durability of the concrete by over 90% when the SLWC was exposed to severe chloride attack. Consequently, the durability of the SLWC with an external coating surpassed that of ordinary-weight concrete.

In some construction industries, there are difficulties in achieving the required concrete compaction, Self-compaction is an alternative option. Working with self-compaction self-curing concrete requires a unique approach. This study aims to examine the possibility of producing self- compacting concrete with normal and high self-cure rates. This research observed how both the self- curing and self-compacting concrete behaved under normal and high-strength conditions. Two stages were prepared for this investigation. The first stage of this research studied the effect of a curing agent on the fundamental characteristics of both normal-strength and high-strength self-compacting concrete, with the aim of achieving self-curing self-compacting concrete. The primary variables of this study include the grade of concrete, the type of curing agent, the reinforcing bars, and the dosage of these variables. In the second stage, reinforced concrete beams were cast with one of the two proposed concrete types, and their behavior was studied. The findings were analyzed in terms of the beginning cracking loads, the ultimate loads, and the crack patterns of the testing beams. According to the results, both the normal-strength and the high-strength varieties of self-curing self-compacting concrete are effective in providing structural features, which are absent from the processes of curing and compacting. Curing chemicals are utilized to mitigate the process of water evaporation in self-compacting concrete, hence enhancing the water retention capabilities of self-compacting concretes that possess enough hardened concrete characteristics.

This study investigates the development of sustainable precast concrete sandwich wall panels using alternative materials. This study explores the partial replacement of natural aggregates with Lightweight Expanded Clay Aggregate (LECA) and marble waste aggregate while utilizing fly ash as a partial cement substitute. The experimental panels were constructed using self-compacting concrete mixes with varying proportions of these materials. The panels consisted of two steel fiber-reinforced concrete wythes joined by basalt fiber-reinforced polymer connectors, with expanded polystyrene insulation. Full-scale wall panels underwent flexural testing according to ASTM standards. The results indicate that alternative materials affect panel performance in terms of strength, ductility, and energy absorption. Panels with 20% LECA exhibited the best thermal performance, achieving a U-value of 0.363 W/m2·K, surpassing the energy code standards. The mixture containing 100% marble waste exhibited the highest flexural strength. Sustainable panels were estimated to be 28% cheaper in terms of raw material costs than conventional panels. The study achieved significant CO2 savings of approximately 240 kg per ton of concrete when 30% of cement was replaced with fly ash. These findings underscore the viability of incorporating sustainable materials into precast concrete sandwich panels, offering a promising path toward more environmentally conscious and energy-efficient building practices.

The ability to produce load-bearing masonry units adopting ACI 211.1 mix design using (1:3.2:2.5) as (cement: fine aggregate: coarse aggregate) with slump range (25-50mm) which can conform (dimension, absorption, and compressive strength) within IQS 1077/1987 requirements type A was our main goal of the study. The ability to use low cement content (300 kg/m3) to handle our market price products since the most consumption in wall construction for low-cost buildings was encouraging. The use of (10 and 20%) of LECA as partial volume replacement of coarse aggregate to reduce the huge weight of masonry blocks can also be recommended. The types of production of the load-bearing masonry units were A and B for (10 and 20%), respectively. Finally, the use of the spray curing method was the more suitable simulation of reality and easier for factory producers, taking into consideration that the increasing curing time from 14 days (recommended in IQS 1077/1987) to 28 days may be led to conversation masonry type from B to A as in R20%-300.

The dichotomy that separates prokaryotic from eukaryotic cells runs deep. The transition from pro- to eukaryote evolution is poorly understood due to a lack of reliable intermediate forms and definitions regarding the nature of the first host that could no longer be considered a prokaryote, the first eukaryotic common ancestor, FECA. The last eukaryotic common ancestor, LECA, was a complex cell that united all traits characterising eukaryotic biology including a mitochondrion. The role of the endosymbiotic organelle in this radical transition towards complex life forms is, however, sometimes questioned. In particular the discovery of the asgard archaea has stimulated discussions regarding the pre-endosymbiotic complexity of FECA. Here we review differences and similarities among models that view eukaryotic traits as isolated coincidental events in asgard archaeal evolution or, on the contrary, as a result of and in response to endosymbiosis. Inspecting eukaryotic traits from the perspective of the endosymbiont uncovers that eukaryotic cell biology can be explained as having evolved as a solution to housing a semi-autonomous organelle and why the addition of another endosymbiont, the plastid, added no extra compartments. Mitochondria provided the selective pressures for the origin (and continued maintenance) of eukaryotic cell complexity. Moreover, they also provided the energetic benefit throughout eukaryogenesis for evolving thousands of gene families unique to eukaryotes. Hence, a synthesis of the current data lets us conclude that traits such as the Golgi apparatus, the nucleus, autophagosomes, and meiosis and sex evolved as a response to the selective pressures an endosymbiont imposes.

Punching shear is the most important problem in flat slabs, which usually requires strengthening for safety reasons. One of the most popular strengthening methods is the employment of shear reinforcement. Also, in order to reduce the self-weight of slabs, lightweight aggregate concrete as well as the bubble deck technology were used in this research. To study the influence of shear reinforcement type on lightweight aggregate voided slab behavior under punching shear, three slabs having the same geometrical and mechanical properties, with different shear reinforcement type (hook, inclined bar and stud) were cast and prepared for testing. As well as a control specimen with no shear reinforcement was used for comparison reason. The results showed that the inclined shear reinforcement has the most positive influence on slab behavior, between the three types of reinforcement that were adopted in the experimental work.

Abstract Background Eukaryotic gene expression is controlled by a number of RNA-binding proteins (RBP), such as the proteins from the Puf (Pumilio and FBF) superfamily (PufSF). These proteins bind to RNA via multiple Puf repeat domains, each of which specifically recognizes a single RNA base. Recently, three diversified PufSF proteins have been described in model organisms, each of which is responsible for the maturation of ribosomal RNA or the translational regulation of mRNAs; however, less is known about the role of these proteins across eukaryotic diversity. Results Here, we investigated the distribution and function of PufSF RBPs in the tree of eukaryotes. We determined that the following PufSF proteins are universally conserved across eukaryotes and can be broadly classified into three groups: (i) Nop9 orthologues, which participate in the nucleolar processing of immature 18S rRNA; (ii) ‘classical’ Pufs, which control the translation of mRNA; and (iii) PUM3 orthologues, which are involved in the maturation of 7S rRNA. In nearly all eukaryotes, the rRNA maturation proteins, Nop9 and PUM3, are retained as a single copy, while mRNA effectors (‘classical’ Pufs) underwent multiple lineage-specific expansions. We propose that the variation in number of ‘classical’ Pufs relates to the size of the transcriptome and thus the potential mRNA targets. We further distinguished full set of PufSF proteins in divergent metamonad Giardia intestinalis and initiated their cellular and biochemical characterization. Conclusions Our data suggest that the last eukaryotic common ancestor (LECA) already contained all three types of PufSF proteins and that ‘classical’ Pufs then underwent lineage-specific expansions.

This study aims to examine the effect of high temperatures on lightweight geopolymer concrete (LWGC) and lightweight ordinary concrete (LWOC) made of natural pumice and lightweight expanded clay aggregate (LECA) with the addition of trapped air. To this end, a geopolymer concrete matrix has been synthesized by the alkali-activation of fly ash (FA) and granulated blast furnace slag (GBFS). The geopolymer concrete samples were cured for 24 h at a temperature of 80 °C. To study the properties of fresh concrete, slump and slump flow tests and unit weight were applied. The mechanical properties were also measured by the compressive strength, splitting tensile, flexural strength, and elastic modulus tests. High temperatures of 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, 600 °C, 700 °C, and 800 °C were applied on the geopolymer concrete samples to obtain the residual compressive strength. In general, pumice and LECA can be used as an alternative to the dolomite aggregate to produce LWGC and LWOC. The mixture F-50D50P-A achieved the lowest of unit weight of 1660 kg/m, a slump flow of 555 mm, and compressive strength of 32.9 MPa at 91-days. Lightweight geopolymer concrete containing 50 % fly ash and 50 % GBSF achieved the best compressive strength test results. The results showed a similarity in the behaviour of LWGC with LWOC under the influence of all the variables applied in this study.

Lightweight concrete (LWC) has been used successfully in building constructions for many years due to its physical properties and its lightweight with high thermal insulation and durability. Recently, this work was done on a new type of concrete: lightweight self-compacting concrete (LWSCC) that combines the feature of lightweight and self-compacting concrete simultaneously. In this study, light expanded clay aggregate (LECA) was used as coarse aggregate in (LWSCC) mixtures, using nano-silica as a partial replacement of cement with three percent (0.5, 0.75, and 1%) by mass of cement. They were tested to evaluate these values of fresh characteristics through slump flow time and diameter, L-box, and segregation tests. The results of the fresh concrete tests showed a decrease in the workability of the concrete in the mixtures containing nano-silica due to the increase in fine materials in the mixture. The effects of nano-silica on the hardened properties of (LWSCC) such as compressive strength, flexural strength, splitting tensile strength, oven-dry density, and scanning electron microscopy (SEM), have improved. The mixtures containing nano-silica were investigated and compared with the reference mixture, where the results of the tests showed a significant improvement in the mechanical properties by (17.35, 16.27, 11.73, and 3.82%) for each of the compressive strength, flexural strength, splitting tensile strength and oven dry density respectively. In the presence of nano-silica, the replacement percentage of 1% recorded the best results in all tests at 90 days of curing.

For many years, lightweight concretes (LWC) have been utilized successfully in the construction of buildings because of their low specific weight, high thermal insulation capacity, and sound insulation. The development that led to lightweight self-compacting concrete (LWSCC) is a significant step forward in recent years. These concrete chains self-compacting concrete's beneficial properties with lightweight concrete. The purpose of this experimental investigation is to determine how the internal sulfates attack effect fresh and hard properties of lightweight self-compacting concrete (LWSCC) made by using lightweight expanded clay aggregate (LECA) before and after the addition of 0.5 volume fraction (Vf) of steel fibers. In fine aggregate, several concrete mixes were cast in different SO3 percentages (0.34, 2, 4, and 6%). The fresh properties of LWSCC concrete were tested, such as (slump, sieve segregation resistance, and L-box test). The hard properties of LWSCC were (Compressive, splitting tensile strength, flexural strength, oven-dried density, and modules of elasticity). The results showed that the presence of SO3 in fine aggregate affects the properties of LWSCC. A significant decrease in fresh properties of LWSCC mixes with (2, 4, and 6%) of SO3 in fine aggregate. In addition, the mechanical properties (compressive St., splitting tensile St., flexural St., density, and modulus of elasticity) decreased as curing age increased, and SO3% increased. When sulfate percent rose from (0.34% to 2%, 4%, and 6%) in compressive St., the reduction was (16.53, 22.45, and 26.47%) at 120 days. Adding 0.5% Vf of steel fiber enhanced the mechanical properties of LWSCC.

Abstract Background The nuclear envelope (NE) that encapsulates the nuclear genome is a double lipid bilayer with several integral and peripherally associated proteins. It is a characteristic feature of the eukaryotes and acts as a hub for a number of important nuclear events including transcription, repair, and regulated gene expression. The proteins associated with the nuclear envelope mediate the NE functions and maintain its structural integrity, which is crucial for survival. In spite of the importance of this structure, knowledge of the protein composition of the nuclear envelope and their function, are limited to very few organisms belonging to Opisthokonta and Archaeplastida supergroups. The NE composition is largely unknown in organisms outside these two supergroups. Results In this study, we have taken a comparative sequence analysis approach to identify the NE proteome that is present across all five eukaryotic supergroups. We identified 22 proteins involved in various nuclear functions to be part of the core NE proteome. The presence of these proteins across eukaryotes, suggests that they are traceable to the Last Eukaryotic Common Ancestor (LECA). Additionally, we also identified the NE proteins that have evolved in a lineage specific manner and those that have been preserved only in a subset of organisms. Conclusions Our study identifies the conserved features of the nuclear envelope across eukaryotes and provides insights into the potential composition and the functionalities that were constituents of the LECA NE.

Abstract Background Recently, important discoveries regarding the archaeon that functioned as the “host” in the merger with a bacterium that led to the eukaryotes, its “complex” nature, and its phylogenetic relationship to eukaryotes, have been reported. Based on these new insights proposals have been put forward to get rid of the three-domain Model of life, and replace it with a two-domain model. Results We present arguments (both regarding timing, complexity, and chemical nature of specific evolutionary processes, as well as regarding genetic structure) to resist such proposals. The three-domain Model represents an accurate description of the differences at the most fundamental level of living organisms, as the eukaryotic lineage that arose from this unique merging event is distinct from both Archaea and Bacteria in a myriad of crucial ways. Conclusions We maintain that “a natural system of organisms”, as proposed when the three-domain Model of life was introduced, should not be revised when considering the recent discoveries, however exciting they may be.

In the present study, lightweight expanded clay aggregate (LECA) coated with iron oxide was investigated as a low cost sorbent to remove from wastewater. Iron oxide coated LECA (IOCL) as a new sorbent was tested for its efficiency as sorbent using operational parameters such as contact time, the initial pH of the solutions, and sorbent dosage concentration in batch systems. The adsorption characteristics of the natural LECA and IOCL were investigated through scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), and X-ray diffraction (XRD) analysis. The maximum sorption efficiency was found to be 96% for IOCL at an initial pH of 6.0 and a sorbent dosage of 5 . The results revealed that the sorption kinetic data were well fitted to a pseudo second–order kinetic model. The experimental data showed that sorption was considerably high on IOCL and the new sorbent is an economical method for Ni (II) removal from effluents and aqueous media.

The mechanical properties of concrete containing self-curing agents are investigated in this paper. In this study, two materials were selected as self-curing agents with different amounts, and the addition of silica fume was studied. The self-curing agents were, pre-soaked lightweight aggregate (Leca); 0.0%, 10%, 15%, and 20% of volume of sand; or polyethylene-glycol (Ch.); 1%, 2%, and 3% by weight of cement. To carry out this study the cement content of 300, 400, 500 kg/m3, water/cement ratio of 0.5, 0.4, 0.3 and 0.0%, 15% silica fume of weight of cement as an additive were used in concrete mixes. The mechanical properties were evaluated while the concrete specimens were subjected to air curing regime (in the laboratory environment with 25 °C, 65% R.H.) during the experiment. The results show that, the use of self-curing agents in concrete effectively improved the mechanical properties. The concrete used polyethylene-glycol as self-curing agent, attained higher values of mechanical properties than concrete with saturated Leca. In all cases, either 2% Ch. or 15% Leca was the optimum ratio compared with the other ratios. Higher cement content and/or lower water/cement ratio lead(s) to more efficient performance of self-curing agents in concrete. Incorporation of silica fume into self-curing concrete mixture enhanced all mechanical properties, not only due to its pozzolanic reaction, but also due to its ability to retain water inside concrete.

Internal curing of concrete by the use of pre-saturated lightweight aggregates or polyethylene-glycol is well established method of counteracting self-desiccation and autogenous shrinkage. This study was carried out to compare among concretes without or with silica fume (SF) along with chemical type of shrinkage reducing admixture, polyethylene-glycol (Ch), and leca as self-curing agents for water retention even at elevated temperature (50 °C) and their durability. The cement content of 400 kg/m3, silica fume of 15% by weight of cement, polyethylene-glycol of 2% by weight of cement, pre-saturated lightweight aggregate (leca) 15% by volume of sand and water with Ch/binder ratio of 0.4 were selected in this study. Some of the physical and mechanical properties were determined periodically up to 28 days in case of exposure to air curing in temperature of (25 °C) and (50 °C) while up to 6 months of exposure to 5% of carbon dioxide and wet/dry cycles in 8% of sodium chloride for durability study. The concrete mass loss and the volumetric water absorption were measured, to evaluate the water retention of the investigated concretes. Silica fume concrete either without or with Ch gave the best results under all curing regimes; significant water retention and good durability properties.

In this study the effect of two different curing-agents has been examined in order to compare them for optimizing the performance of concrete. The first used type is the Pre-soaked lightweight aggregate (leca) with different ratios; 0.0%, 10%, 15% and 20% of volume of sand, and the second type is a chemical agent of polyethylene-glycol (Ch.) with different percentages; 1%, 2% and 3% of weight of cement. In the test programme performed in this study, three cement content; 300, 400 and 500 kg/m3, three different water-cement ratios; 0.5, 0.4, and 0.3, and two magnitudes of silica fume as a pozzolanic additive; 0.0% and 15% of cement weight, were used. The physical properties of concrete were evaluated at different ages, up to 28 days. The concrete specimens are subjected to dry-air curing regime (25 °c) during the experiment. The results show that the use of self-curing agent (Ch.) in concrete effectively improves the physical properties compared with conventional concrete. On the other hand, up to 15% saturated leca was effective while 20% saturated leca was effective for permeability and mass loss but adversely affects the sorptivity and volumetric water absorption. Self-curing agent Ch. was more effective than self-curing agent leca. In all cases, both 2% Ch. and 15% leca were the optimum values. Higher cement content and/or lower water–cement ratio leads to more effective results of self-curing agents in concrete. Incorporation of silica fume into concrete mixtures enhances all physical properties.

Leca lightweight particles are used for structural and semi structural concrete in different countries. In Iran it is usually used as Mass lightweight concrete, blokes and partitions. In this research an experimental work carried out using Leca concrete to assess its physical and mechanical properties and possibility of constructing high strength lightweight concrete to use as structural element in marine environment. Using leca, microsilica gel (silica soot plus super plasticizer) and cement type II, structural high cement content semi lightweight concrete was constructed. Then different characteristics such as specific weight, percentage of abrasion strength, compressive strength, specific gravity of fresh and hard concrete and intensity of bare steel bar corrosion by comparing bar corrosion potential in lightweight and ordinary concrete was obtained. The results show that the leca concrete is in the range of lightweight concrete and is suitable as semi structural and structural element. Furthermore it is found that this kind of lightweight concrete in corrosive environment behaves similar to or better than ordinary concrete. Therefore it can be used in onshore and offshore structures.

Background: Antibiotic in environment can be accumulated in soil and sediment and then adversely affect the ecosystem function as well as decrease the natural degradation rate of pollutants by producing a antibiotic-resistant microorganisms. The antibiotic-resistant genes can also transfer to drinking water resources and then, leading untreatable human disease. Methods: Natural LECA was supported from rural resources and washed with deionized water for several time and then used as natural adsorbent. The adsorbents were characterized with a scanning electron microscope (SEM), Fourier Transform Infrared spectroscopy (FTIR), X-ray fluorescence spectroscopy (XRF) and X ray diffract meter (XRD). All experiments were conducted in a batch reactor. Various parameters such as initial adsorbent mass (2, 4, 6, 8 and 10 g/L), initial antibiotic concentration (50, 100, 150 and 200 mg/L), initial solution pH (3, 5, 7, 9, and 11) and contact time (1-210 min) were investigated. Results: The Results of present work showed the high removal efficiency of the adsorbent for adsorption of Tetracycline from aqueous solution. Higher removal efficiency was observed for Tetracycline at pH 3, 180 min contact time, 10 g/L of adsorbent dose and 200 mg/L of initial antibiotic concentration. In optimum condition, up to 49% of tetracycline was removed. Conclusion: Overall, the results of the present work well demonstrated that natural LECA as an inexpensive adsorbent could remove effectively the antibiotics namely Tetracycline from aqueous solution.

The possibility of ammonium ion removal from aqueous solution using light expanded clay aggregate (LECA) was investigated in this work. FESEM and XRF analyses are used to determine the sorbent characterization. The influences of some effective parameters on ammonium ion adsorption process such as initial pH (3–9), initial ammonium ion concentration (10–100 mg/L), temperature (15–45 °C), and the contact time (0–180 min) were studied. Also, the equilibrium behavior of LECA in ammonium ion removal was investigated in the temperature range of 15–45 °C. The results showed that the equilibrium data were fitted well with two Langmuir and Freundlich isotherm models in all the studied temperature range. The maximum monolayer adsorption capacity estimated by Langmuir isotherm was obtained from 0.229 to 0.254 (mg/g). The required contact time to achieve the equilibrium condition was 150 min. Also, the regression coefficients of the kinetic models and more conformity of the experimental adsorption capacity (qexp) to the calculated adsorption capacity (qcal) were confirmed that the experimental data follow the pseudo-second-order kinetic model. The controlling rate of NH4+ adsorption process by the Webber–Morris model was proved both by film diffusion and intra-particle diffusion models.

Background: Water filtration units have been faced problems in water turbidity removal related to their media, which is determined by qualitative indices. Moreover, Current qualitative indices such as turbidity and escaping particle number could not precisely determine the efficiency of the media in water filtration, so defining new indices is essential. In this study, the efficiency of Anthracite-Silica and LECA-Silica media in turbidity removal were compared in different operating condition by using modified qualitative indices.Methods: The pilot consisted of a filter column (one meter depth) which consisted of a layer of LECA (450 mm depth) and a layer of Silica sand (350 mm depth. Turbidities of 10, 20, and 30 NTU, coagulant concentrations of 4, 8, and 12 ppm and filtration rates of 10, 15, and 20 m/h were considered as variables.Results: The LECA-Silica media is suitable media for water filtration. Averages of turbidity removal efficiencies in different condition for the LECA-Silica media were 85.8±5.37 percent in stable phase and 69.75±3.37 percent in whole operation phase, while the efficiency of total system were 98.31±0.63 and 94.49±2.97 percent, respectively.Conclusion: The LECA layer efficiency in turbidity removal was independent from filtration rates and due to its low head loss; LECA can be used as a proper medium for treatment plants. Results also showed that the particle index (PI) was a suitable index as a substitute for turbidity and EPN indices.

Backgrounds and Objectives: Improvement of water quality standards and inability of mono layer filters in producing such quality caused researchers attended to multi layer filters. Due to specific characteristics of anthracite and leca can improve removal of organic materials and Surface over flow rate. The aim of this research was evaluation performance of dual media filters (anthracite/leca) in removing of organic materials and turbidity from Ahvaz Water treatment plant.Materials and Methods: In this study two pilots built for investigation of mono layer filter and dual media filter performance. The researcher used sand in structures media of mono layer filter and composition of anthracite, sand and leca in structures media of dual media filter, respectively.In this study single and dual layer filter pilot examined in term of organic matter and turbidity removal efficiency.Results: Results indicated that removal of organic matter by single layer filter (sand), dual media filter (anthracite and sand), dual media filter (leca and sand) was 7%,12%,4/2% respectively. And also Turbidity removal by single layer filter(sand), dual media filter (anthracite and sand), dual media filter (leca and sand) was also 69%, 80%, 74% respectively.Conclusion: Results of this study showed that upgrading of Single layer to dual layer with anthracite and leca media can‘t show a significant affect in TOC removal.

In this research, the capability of the moving bed biofilm reactor (MBBR) for the treatment of aniline wastewater has been investigated. This compound is found in effluents from chemical, dye, pigment, herbicide, pharmaceutical, plastic, and paint industries. The moving bed biofilm reactor was developed to adopt the best features of the activated sludge process as well as those of the biofilter processes. In this study, a cylindrical moving bed biofilm reactor with an approximate capacity of 5 liters was used. The effects of LECA (Light Expanded Clay Aggregate) filling ratio and retention times (RT) of 8, 24, 48, and 72 hr were investigated on removal efficiency for different influent COD values. The best removal efficiency of 91% was obtained for a COD level of 2000 mg/L after 72 hour. Other experiments were conducted to evaluate the removal efficiency of the reactor under a decreased carrier volume of 30% and under continuous loading. NMR test results confirmed the capability of the reactor in the biodegradation of aniline. The capability of the reactor was also evaluated by feeding an organic shock that resulted in satisfactory performance of MBBR. The results showed that Grau and Stover-Kincannon were the best models to describe the biological kinetic data in this study.

The Moving Bed Biofilm Reactor (MBBR) has been recently used in industrial and municipal wastewater treatment. MBBR is a kind of Bio-Filter with light packed bed. In this study, a mineral packing bed called Leca, a light expanded clay aggregate, was used as a biological support in the treatment of wastewater. The main objective of this study was to evaluate packed media for preparation of suitable beds for biological activity. Seventy percent of the reactor volume was filled with the packing media. Synthetic wastewater was made using sugar beet factory effluent. The influent COD in the range of 800 to 3200 mg/L was injected into the reactor at retention times of 12.16 and 24 hours. The results show that MBBR reactor is capable of removing 82% of soluble COD at a loading rate of 1.766 kg COD/m2. However, it was found that reducing the retention time from 24 h to 16 h and 12 h, reduces COD removal efficiency from 82% to 76% and 66%, respectively. It was also found that 78.2% of the overall COD removal is due to biofilm activity and the rest is related to the activity of the submerged microorganism.

Drying of clay is simulated by a one-dimensional model. The background of the work is to form a better basis for investigation of the drying process in production of clay-based building materials. A model of one-dimensional heat and mass transfer in porous material is used and modified to simulate drying of clay particles. The convective terms are discretized by first-order upwinding, and the diffusive terms are discretized by central differencing. DASSL was used to solve the set of algebraic and differential equations. The different simulations show the effect of permeability, initial moisture content and different boundary conditions. Both drying of a flat plate and a spherical particle are modelled.

Background: Water filtration units have been faced problems in water turbidity removal related to their media, which is determined by qualitative indices. Moreover, Current qualitative indices such as turbidity and escaping particle number could not precisely determine the efficiency of the media in water filtration, so defining new indices is essential. In this study, the efficiency of Anthracite-Silica and LECA-Silica media in turbidity removal were compared in different operating condition by using modified qualitative indices. Methods: The pilot consisted of a filter column (one meter depth) which consisted of a layer of LECA (450 mm depth) and a layer of Silica sand (350 mm depth. Turbidities of 10, 20, and 30 NTU, coagulant concentrations of 4, 8, and 12 ppm and filtration rates of 10, 15, and 20 m/h were considered as variables. Results: The LECA-Silica media is suitable media for water filtration. Averages of turbidity removal efficiencies in different condition for the LECA-Silica media were 85.8±5.37 percent in stable phase and 69.75±3.37 percent in whole operation phase, while the efficiency of total system were 98.31±0.63 and 94.49±2.97 percent, respectively. Conclusion: The LECA layer efficiency in turbidity removal was independent from filtration rates and due to its low head loss; LECA can be used as a proper medium for treatment plants. Results also showed that the particle index (PI) was a suitable index as a substitute for turbidity and EPN indices.

Abstract Background The Anaphase Promoting Complex or Cyclosome (APC/C) is the largest member of the ubiquitin ligase [E3] family. It plays a crucial role in the control of the cell cycle and cell proliferation by mediating the proteolysis of key components by the proteasome. APC/C is made of a dozen subunits that assemble into a large complex of ~1.5 MDa, which interacts with various cofactors and targets. Results Using comparative genomic and phylogenetic approaches, we showed that 24 out of 37 known APC/C subunits, adaptors/co-activators and main targets, were already present in the Last Eukaryotic Common Ancestor (LECA) and were well conserved to a few exceptions in all present-day eukaryotic lineages. The phylogenetic analysis of the 24 components inferred to be present in LECA showed that they contain a reliable phylogenetic signal to reconstruct the phylogeny of the domain Eucarya. Conclusions Taken together our analyses indicated that LECA had a complex and highly controlled modern-like cell cycle. Moreover, we showed that, despite what is generally assumed, proteins involved in housekeeping cellular functions may be a good complement to informational genes to study the phylogeny of eukaryotes.

ABSTRACT Self-Compacting Concrete (SCC) flows around obstructions by its self-weight to fill entirely and self-consolidate (without any need for vibration), without any part of disconnection and chunking. The eradication of the need for consolidation leads to better quality concrete and substantial improvement of running conditions. The fresh state of SCC mixes will usually have huge amount of fine fillers, including cement, and produce excessively high compressive strength concrete. In order to overcome the workability problem Super Plasticizer (SP) and Viscosity Modifying Agent (VMA) are used. Here, the workability admixtures are fixed at a constant rate of 2% based on the weight of cement. This technique examines special applications in cases of bottleneck reinforced sections, rafts, tunnel linings, highly reinforced columns, underwater repairs, bridge piers and placements. LECA and Vermiculite have high porosity, and are added to concrete mixtures to create a lightweight concrete mix. An attempt has been made to develop a combination of self-compacting and self-curing concrete with each 5% and 10% of LECA and Vermiculite as a partial replacement to fine aggregate. As there was no proper mix design for the development of this modern concrete, the design has been carried out based on EFNARC specifications for the design strength of M40 grade concrete. The porosity of light weight aggregate provide source of water for internal curing of concrete which enhances concrete strength and durability. Based on more trials, it was noticed that the concrete with 10% of LECA and Vermiculite in individual provides good results.