Design Guideline for Hydropower Plants Using One or Multiple Archimedes Screws

The Archimedes/Archimedean screw generator (ASG) is a fish-friendly hydropower technology that could operate under a wide range of flow heads and flow rates and generate power from almost any flow, even wastewater. The simplicity and low maintenance requirements and costs make ASGs suitable even for remote or developing areas. However, there are no general and easy-to-use guidelines for designing Archimedes screw power plants. Therefore, this study addresses this important concern by offering a simple method for quick rough estimations of the number and geometry of Archimedes screws in considering the installation site properties, river flow characteristics, and technical considerations. Moreover, it updates the newest analytical method of designing ASGs by introducing an easier graphical approach that not only covers standard designs but also simplifies custom designs. Besides, a list of currently installed and operating industrial multi-Archimedes screw hydropower plants are provided to review and explore the common design properties between different manufacturers. On top of that, this study helps to improve one of the biggest burdens of small projects, the unscalable initial investigation costs, by enabling everyone to evaluate the possibilities of a green and renewable Archimedes screw hydropower generation where a flow is available.

Joining of Electrodes to Ultra-Thin Metallic Layers on Ceramic Substrates in Cryogenic Sensors

Microjoining technologies are crucial for producing reliable electrical connections in modern microelectronic and optoelectronic devices, as well as for the assembly of electronic circuits, sensors, and batteries. However, the production of miniature sensors presents particular difficulties, due to their non-standard designs, unique functionality and applications in various environments. One of the main challenges relates to the fact that common methods such as reflow soldering or wave soldering cannot be applied to making joints to the materials used for the sensing layers (oxides, polymers, graphene, metallic layers) or to the thin metallic layers that act as contact pads. This problem applies especially to sensors designed to work at cryogenic temperatures. In this paper, we demonstrate a new method for the dynamic soldering of outer leads in the form of metallic strips made from thin metallic layers on ceramic substrates. These leads can be used as contact pads in sensors working in a wide temperature range. The joints produced using our method show excellent electrical, thermal, and mechanical properties in the temperature range of 15–300 K.

Pragmatic Approach toward Catalytic CO Emission Mitigation in Fluid Catalytic Cracking (FCC) Units

The need to mitigate the environmental footprints of refineries in a sustainable and economical way is widely accepted, yet there appears to be a lack of a unilateral pragmatic approach towards CO oxidation to CO2 among the refining community. In this work we share CO promoter design strategies that can afford a tangible and immediate CO conversion efficiency increase without a need for additional precious metal loading. The key focus is on the support material architecture that is essential to boost the CO conversion and reduce the NOx generation in the FCC unit. It was demonstrated that the suppression of Pt sintering as well as the enhancement of the oxygen mobility on the catalyst surface can afford an ~40% lower cost of Pt and ~20% lower usage rate compared to current industry-standard designs.

A Study on Pre Engineered Building And Conventional Steel Structure

The Pre-Engineered Building (PEB) is being used for making new concept buildings using the new ‘green material’ -steel. Steel framed construction is fast growing in popularity due to relatively simple and standard designs, structural form for its flexibility. This methodology is versatile not only due to its quality prefabrication and pre-designing, but also due to its light weight and economical construction. Pre-Engineered Building is preferred for its optimization of steel about 20 to 30 percent which is efficient from conventional steel building(CSB). In this study an commercial structure is analyzed, designed and compared PEB with the Conventional steel building. Also have considered various applications of the pre-engineered building. One model each for PEB and CSB for a length of 45m ,width 20m, clear height 6m, mezzanine floor for a bay and having slope of 5.71 degree(PEB) and 11.3 degree (CSB) using IS 800-2007 both structures are designed. Parametric study is carried out to assess the performance. The economy of the structure is discussed in terms of its weight.

Critical Review and Improvement of Bank Protection Methods in Nepalese Rivers

This paper reviews performance of bank protection works constructed over the last decades along the major rivers in Nepal. The study reveals main reasons of early spurs failure in five major rivers - Koshi, Narayani, West Rapti, Karnali and Mahakali. The overview finds design deficiency as the main reason of failure of bank protection works. The methodology incorporates a combination of field visits and a review of design reports, master plans. The study finds bank protection works along the major rivers in Nepal consist almost exclusively of spurs often combined with revetments in between, made of gabions filled with boulders. Also, the launching aprons are constructed of gabions. The lifetime of these bank protection works is less than 10 years and often much shorter. Designs are based on standard designs from Indian standards, developed for normal alluvial rivers. The study recommends initiating a bank protection pilot project to identify the cause of failure of the bank protection works and to test remedial measures for the sustainability enhancement of river protection works in future.

Investigation into the Structural, Chemical and High Mechanical Reforms in B4C with Graphene Composite Material Substitution for Potential Shielding Frame Applications

In this work, boron carbide and graphene nanoparticle composite material (B4C–G) was investigated using an experimental approach. The composite material prepared with the two-step stir casting method showed significant hardness and high melting point attributes. Scanning electron microscopy (SEM), along with energy dispersive X-ray spectroscopy (EDS) analysis, indicated 83.65%, 17.32%, and 97.00% of boron carbide + 0% graphene nanoparticles chemical compositions for the C-atom, Al-atom, and B4C in the compound studied, respectively. The physical properties of all samples’ B4C–G like density and melting point were 2.4 g/cm3 density and 2450 °C, respectively, while the grain size of B4C–G was in the range of 0.8 ± 0.2 µm. XRD, FTIR, and Raman spectroscopic analysis was also performed to investigate the chemical compositions of the B4C–G composite. The molding press composite machine was a fabrication procedure that resulted in the formation of outstanding materials by utilizing the sintering process, including heating and pressing the materials. For mechanical properties, high fracture toughness and tensile strength of B4C–G composites were analyzed according to ASTM standard designs. The detailed analysis has shown that with 6% graphene content in B4C, the composite material portrays a high strength of 134 MPa and outstanding hardness properties. Based on these findings, it is suggested that the composite materials studied exhibit novel features suitable for use in the application of shielding frames.

Development of a System of Standard Designs in Industrial Construction

The use of standard designs in construction is a topical subject of research within the frame of project management. Construction projects, especially industrial construction ones, are characterized by a great diversity of design and other solutions. Just about any new project produces new ways of resolving issues and involves looking for optimum constructive, planning, and other solutions. There arises the need to coordinate all parts of the work with the client, although essentially there is nothing particularly novel about the project, as many of the issues were already resolved in past activity. Quite naturally, many construction companies will look for tried-and-true solutions and strive for the unification and standardization of design work. This paper describes a set of tools for implementing a system of standard designs and proposes a set of ways to achieve one’s key design objectives.

ANALYSIS OF DURABILITY OF REINFORCED CONCRETE STRUCTURES OF BRIDGES ACCORDING TO THEIR TYPICAL DESIGNS

Thousands of bridges built in the 20th century are operated on Ukrainian roads. In the limited funding of the road industry of Ukraine, the age of highway bridges is constantly increasing, the number of defects in structures is growing. The largest number of defects is concentrated in the bridge spans. The main part of the bridge spans consists of prefabricated reinforced concrete beams, manufactured in factories of reinforced concrete structures according to standard designs developed in the middle of the last century. As a result of long-term operation of bridges, the shortcomings of these designs which reduce the service life of bridge spans and bridges in general are revealed. The systematic approach is required to study this process. The Analytical Expert Bridge Management System (AESUM) operates in the Ukravtodor system. This software complex accumulates all the information on the results of inspections (certification) of bridges on public roads. The special module AESUM – a database of standard designs of bridge spans which is constantly updated was developed to make decisions on repair works taking into account the features of structures on standard designs, to store this information in a single complex, in electronic form. Standard designs of reinforced concrete bridge spans built and operated on the roads of Ukraine are considered, and a comparative analysis of the features of these designs is performed taking into account the impact on the safety of bridge operation, their main features and shortcomings are given. The concept of rank of the standard design on durability is entered. A formula for estimating the durability of bridge span of a standard design using this concept is proposed. The analysis of durability of bridge span is performed. A number of problematic standard designs have been identified. Keywords: road bridge, standard designs, durability.

Starman or Sterrenman: An acquisitional perspective on the social meaning of English in Flanders

Objective: This paper reports on an experiment conducted with 174 Flemish children in three age groups, namely first, third and fifth year of primary school, aiming to assess the social meaning children associate with English-sourced lexemes in Belgian Dutch. Method: The children were presented with 2 versions of a cartoon hero developed specifically for this study: Sterrenman, who only uses Dutch words, and Starman, who uses English alternatives for 17 content words in the cartoon’s script. Relying on extensive pretesting, we adapted standard designs and instrumentation from social psychology (the matched guise technique) and language acquisition research to gauge the children’s appreciation of the two heroes, their understanding of the English and Dutch vocabulary used in the script, and their level of language awareness. Findings: The key findings are: rather than an incremental increase in favorable social meaning for English from the first to the third age group under scrutiny, we see a decline of the prestige of Dutch in the oldest age group; the children’s level of language awareness, receptive vocabulary knowledge and age seem associated with their overall appreciation of Sterrenman and Starman; working with children from various age groups inevitably entails methodological risks. Originality: This is a first and hence exploratory study on the acquisition of the social meaning of English lexemes by EL2 children and their ensuing progressing bilingualism. Implications: Overall, the study helps us contribute to both the recent socio-pragmatic turn in anglicism research and to the upcoming field of developmental sociolinguistics, revealing the transition points in children’s acquisition of the social meaning of contact-induced variation and change.

Meta-Analysis of PD-L1 Expression As a Predictor of Survival After Checkpoint Blockade

PURPOSE Programmed cell death receptor ligand 1 (PD-L1) expression is the most studied biomarker to predict the efficacy of immune checkpoint inhibitors (ICIs), but its clinical significance is controversial. We estimated the distribution of PD-L1 expression scores (ie, tumor proportion score or combined proportion score) and the relationship between PD-L1 levels and ICIs’ impact on overall survival (OS). METHODS We reconstructed, pooled, and analyzed individual-level data on 7,617 patients with cancer from 14 randomized clinical trials. The effects of ICIs were quantified using differences in 24-month restricted mean survival times (ΔRMSTs; ie, the increase in life expectancy truncated at 2 years associated with ICI therapy). In a simulation study, we compared standard randomized clinical trial designs with a trial design that leverages meta-analytic results like ours. RESULTS Approximately 93% of patients had a PD-L1 expression ≤ 5% (66% of patients) or > 50% (27% of patients). OS improves with ICIs regardless of PD-L1 expression level, which predicts the benefits’ magnitude. For patients with non–small-cell lung cancer (NSCLC), ΔRMSTs ranged from 1.4 months (95% probability interval [PI], 0.7 to 2.2 months) for PD-L1 expression ≤ 1% to 4.1 months (95% PI, 3.2 to 5.2 months) for PD-L1 expression > 80%. For patients with non-NSCLC tumors, ΔRMSTs ranged from 0.8 months (95% PI, −0.1 to 1.7 months) to 2.3 months (95% PI, 1.3 to 4.4 months), again for PD-L1 expression levels of ≤ 1% and > 80%, respectively. Simulations suggested that designs tailored to meta-analytic results can detect the effects of ICIs in PD-L1 subgroups with higher probability (> 15%) than standard designs. CONCLUSION The practice of dichotomizing the range of PD-L1 expression scores is inadequate for patient stratification. Meta-analytic estimates of the distribution of PD-L1 scores and subgroup-specific treatment effects can improve the designs of future trials of ICIs.