A hybrid CAD-based construction site layout planning system using genetic algorithms

The efficient layout planning of a construction site is a fundamental task to any project undertaking. In an attempt to enhance the general practice of layout planning of construction sites, the paper introduces a novel approach for producing the sought layouts. This approach integrates the highly sophisticated graphical capabilities of computer-aided design (CAD) platforms with the robust search and optimization capabilities of genetic algorithms (GAs). In this context, GAs are utilized from within the CAD environment to optimize the location of temporary facilities on site. The functional interaction between GAs and CAD and the details of the GA-based layout optimization procedure are presented. A fully automated computer system is further developed to demonstrate the practicality of the chosen approach. In order to evaluate the system's performance, a local construction project with a 24,000m² site is used. The automated system produced highly satisfactory results and showed notable flexibility through its CAD-based input/output media.     

Creating round focused micro-jets from rectangular nozzles

Journal of Mechanical Science and Technology - A focused jet is an axisymmetric jet of liquid surrounded by an outer coaxial gas jet. The gas jet is typically used to compress the liquid jet in the...     

Characterization of polyethyleneterephthalate (PET) based proton exchange membranes prepared by UV-radiation-induced graft copolymerization of styrene

Polymer electrolyte membranes (PEMs) were successfully prepared by simultaneous ultraviolet (UV) radiation-induced graft copolymerization of styrene (35 vol.% concentration) onto poly(ethyleneterephthalate) (PET) film, followed by sulfonation on the styrene monomer units in the grafting chain using 0.05 M chlorosulfonic acid (ClSO₃H). The radiation grafting and the sulfonation have been confirmed by titrimetric and gravimetric analyses as well as Fourier Transform Infrared (FTIR) spectroscopy. The maximum ion-exchange capacity (IEC) of the PEM was measured to be 0.04385 mmol g⁻¹ at its highest level of grafting and sulfonation. They exhibited high thermal and mechanical properties as well as oxidative stability. They are highly stable in H₂SO₄ solutions and can be used in the acidic fuel cells. The membranes showed low water uptake as well as low proton conductivity than Nafion. In this study, the preparation of PEMs from commodity-type polymers is found to be very inexpensive and is a suitable candidate for applications in fuel cells.     

A numerical analysis of cooling water temperature of two-stage adsorption chiller along with different mass ratios

This paper deals with the performance investigation of a silica gel/water based on two-stage, four-bed adsorption chiller with different mass allocation between upper and lower beds employing the re-heat scheme. The innovative chiller is powered by waste heat or renewable energy source of temperature between 50 °C and 90 °C with a coolant of inlet temperature 30 °C for air conditioning purpose. The performance of the four-bed adsorption chiller employing the re-heat scheme is compared with that of the two-stage conventional chiller with the re-heat scheme using equal mass allocation. Results show that cooling capacity can be improved with the optimum allocation of adsorbent mass to the upper beds than that of lower beds. Besides, it is observed that the cooling capacity can be improved up to 10.78% while the cooling water temperature is at 20 °C.     

Relative life cycle economic analysis of stand-alone solar PV and fossil fuel powered systems in Bangladesh with regard to load demand and market controlling factors

In this paper, relative life cycle economic analysis (LCEA) of stand-alone solar PV modules is performed with respect to portable fossil fuel driven power sources to test their commercial prospects in remote regions of Bangladesh which do not have a direct access to grid supply. Overall life time expenditures related to the power projects are analyzed and compared with the help of net present worth (NPW) theory. The influence of market controlling factors like government subsidies, excess inflation over the general trend, and price hike are established with case study of medium-scale petrol–diesel generators (0.8–10 kW) and solar photovoltaic modules (100 Wp). It is found that the cost effectiveness of conventional or ‘green’ power driven sources depends on kW rating of generators and daily demand on customer-end in the context of a developing country like Bangladesh. The demand coverage which would determine the commercial viability of renewable and non-renewable sources is calculated considering pragmatic power rating of generators available in the local market. This study is intended to assist planning of financial matters with regard to installing small to medium scale renewable projects in remote localities of Bangladesh.     

Ambient Protection of Few‐Layer Black Phosphorus via Sequestration of Reactive Oxygen Species

Few‐layer black phosphorous (BP) has emerged as a promising candidate for next‐generation nanophotonic and nanoelectronic devices. However, rapid ambient degradation of mechanically exfoliated BP poses challenges in its practical deployment in scalable devices. To date, the strategies employed to protect BP have relied upon preventing its exposure to atmospheric conditions. Here, an approach that allows this sensitive material to remain stable without requiring its isolation from the ambient environment is reported. The method draws inspiration from the unique ability of biological systems to avoid photo‐oxidative damage caused by reactive oxygen species. Since BP undergoes similar photo‐oxidative degradation, imidazolium‐based ionic liquids are employed as quenchers of these damaging species on the BP surface. This chemical sequestration strategy allows BP to remain stable for over 13 weeks, while retaining its key electronic characteristics. This study opens opportunities to practically implement BP and other environmentally sensitive 2D materials for electronic applications.     

Current and future interventions for improving poultry health and poultry food safety and security: A comprehensive review

Poultry is thriving across the globe. Chicken meat is the most preferred poultry worldwide, and its popularity is increasing. However, poultry also threatens human hygiene, especially as a fomite of infectious diseases caused by the major foodborne pathogens (Campylobacter, Salmonella, and Listeria). Preventing pathogenic bacterial biofilm is crucial in the chicken industry due to increasing food safety hazards caused by recurring contamination and the rapid degradation of meat, as well as the increased resistance of bacteria to cleaning and disinfection procedures commonly used in chicken processing plants. To address this, various innovative and promising strategies to combat bacterial resistance and biofilm are emerging to improve food safety and quality and extend shelf-life. In particular, natural compounds are attractive because of their potential antimicrobial activities. Natural compounds can also boost the immune system and improve poultry health and performance. In addition to phytochemicals, bacteriophages, nanoparticles, coatings, enzymes, and probiotics represent unique and environmentally friendly strategies in the poultry processing industry to prevent foodborne pathogens from reaching the consumer. Lactoferrin, bacteriocin, antimicrobial peptides, cell-free supernatants, and biosurfactants are also of considerable interest for their prospective application as natural antimicrobials for improving the safety of raw poultry meat. This review aims to describe the feasibility of these proposed strategies and provide an overview of recent published evidences to control microorganisms in the poultry industry, considering the human health, food safety, and economic aspects of poultry production.     

An Efficient Memory Organization for High-ILP Inner Modem Baseband SDR Processors

This paper presents a memory organization for SDR inner modem baseband processors that focus on exploiting ILP. This memory organization uses power-efficient, single-ported, interleaved scratch-pad memory banks to provide enough bandwidth to a high-ILP processors. A system of queues in the memory interface is used to resolve bank conflicts among the single-ported banks, and to spread long bursts of conflicting accesses to the same bank over time. Bank address rotation is used to spread long bursts of conflicting accesses over multiple banks. All proposed techniques have been implemented in hardware, and are evaluated for a number of different wireless communication standards. For the 11a|n benchmarks, the overhead of stall cycles resulting from unresolved bank conflicts can be reduced to below 2% with the proposed organization. For 3GPP-LTE, the most demanding wireless standard we evaluated, the overhead is reduced to less than 0.13%. This is achieved with little energy and area overhead, and without any bank-aware compiler support.