A Review of Electrically Conductive Cement Concrete Pavement for Sustainable Snow-Removal and Deicing: Road Safety in Cold Regions

Within cold U.S. regions, winter storms can cause interruptions in transportation networks, affecting transportation entities’ revenue streams. Conventional snow-removal methods on roadways efficiently remove snow and ice, yet their adverse environmental impacts further make winter maintenance more challenging. In response to these concerns, electrically conductive cement concrete (ECCC) pavement has become an effective alternative for deicing and snow melting on road surfaces. ECCC utilizes the Joule heating principles to effectively melt snow and ice by incorporating conductive elements into conventional concrete. This paper comprehensively reviews the current literature on ECCC pavement. Previous studies have diligently explored various aspects of ECCC pavement, including concrete conductivity enhancement, heat transfer processes, and meticulous performance assessments, ranging from controlled laboratory scale experiments to small-scale field evaluations. The conclusions drawn from these investigations highlight the potential of ECCC pavement to considerably enhance winter road maintenance, consequently improving road safety and minimizing traffic interruptions during winter storms. The present review emphasizes ECCC pavement as a promising paradigm for effectively addressing the complexities associated with winter road maintenance in colder regions. Moreover, its environmentally friendly deicing capabilities present a sustainable departure from conventional methodologies. However, certain limitations currently impede widespread adoption of ECCC pavement, mainly concerning optimizing cost-effective construction techniques, ensuring long-lasting durability, and enhancing energy efficiency. Addressing these limitations could accelerate the broader adoption of ECCC pavement, promoting safer and more sustainable winter transportation practices

Numerical study of the characteristics of CNG, LPG and Hydrogen turbulent premixed flames

Numerical simulations have proven itself as a significant and powerful tool for accurate prediction of turbulent premixed flames in practical engineering devices. The work presented in this thesis concerns the development of simulation techniques for premixed turbulent combustion of three different fuels, namely, CNG, LPG and Hydrogen air mixtures. The numerical results are validated against published experimental data from the newly built Sydney combustion chamber. In this work a newly developed Large Eddy Simulation (LES) CFD model is applied to the new Sydney combustion chamber of size 50 x 50 x 250 mm (0.625 litre volume). Turbulence is generated in the chamber by introducing series of baffle plates and a solid square obstacle at various axial locations. These baffles can be added or removed from the chamber to adapt various experimental configurations for studies. This is essential to understand the flame behaviour and the structure. The LES numerical simulations are conducted using the Smagorinsky eddy viscosity model with standard dynamic procedures for sub-grid scale turbulence. Combustion is modelled by using a newly developed dynamic flame surface density (DFSD) model based on the flamelet assumption. Various numerical tests are carried out to establish the confidence in the LES based combustion modelling technique. A detailed analysis has been carried out to determine the regimes of combustion at different stages of flame propagation inside the chamber. The predictions using the DFSD combustion model are evaluated and validated against experimental measurements for various flow configurations. In addition, the in-house code capability is extended by implementing the Lewis number effects. The LES predictions are identified to be in a very good agreement with the experimental measurements for cases with high turbulence levels. However, some disagreement were observed with the quasi-laminar case. In addition a data analysis for experimental data, regarding the overpressure, flame position and the flame speed is carried out for the high and low turbulence cases. Moreover, an image processing procedure is used to extract the flame rate of stretch from both the experimental and numerical flame images that are used as a further method to validate the numerical results. For the grids under investigation, it is concluded that the employed grid is independent of the filter width and grid resolution. The applicability of the DFSD model using grid-independent results for turbulent premixed propagating flames was examined by validating the generated pressure and other flame characteristics, such as flame position and speed against experimental data. This study concludes that the predictions using DFSD model provide reasonably good results. It is found that LES predictions were slightly improved in predicting overpressure, flame position and speed by incorporating the Lewis number effect in the model. Also, the investigation demonstrates the effects of placing multiple obstacles at various locations in the path of the turbulent propagating premixed flames. It is concluded that the pressure generated in any individual configuration is directly proportional to the number of baffles plates. The flame position and speed are clearly dependent on the number of obstacles used and their blockage ratio. The flame stretch extracted from both the experimental and numerical images shows that hydrogen has the highest stretch values over CNG and LPG. Finally, the regime of combustion identified for the three fuels in the present combustion chamber is found to lie within the thin reaction zone. This finding supports the use of the laminar flamelet modelling concept that has been in use for the modelling of turbulent premixed flames in practical applications

Towards Sustainability: A New Construction Method for Electrically Heated Rigid Pavement System

Snow and ice damage to U.S. airport pavements, particularly in colder regions, poses an ongoing challenge, resulting in significant annual economic losses. Traditional snow removal methods are often perceived as cost-prohibitive, driving the quest for cost-effective alternatives to mitigate the adverse impacts on pavement sustainability. In response, this research investigates an innovative construction approach utilizing an electrically conductive composite (ECC) comprised of waterborne polyurethane (WPU) and graphite (Gp). The ECC is applied to a portland cement concrete (PCC) substrate using the parallel stripe technique, safeguarded by an additional layer of conventional concrete to withstand the friction caused by tires. This study rigorously assesses the resistive heating performance of two types of specimens: exposed and sandwiched under varying conditions. Some critical factors that affect the results include Gp concentrations in ECC preparation, ECC thickness, spacing between ECC stripes, applied voltages, and testing at both room temperature and the challenging -17°C freezing temperature. The ECC with a Gp content of 22.5\% Vol. emerges as the most promising ECC for the sustainable construction of heated pavement systems (HPS). The exposed specimen demonstrates an impressive 19.94°C/hr increase in surface temperature, while the sandwiched specimen shows a substantial 15.46°C/hr increase, representing a promising outcome. The results challenge the conventional HPS practice of modifying pavement materials with embedded heating elements and underscore the potential of a more sustainable construction method. This study provides innovative insights and highlights the feasibility of economically viable, enduring solutions to address winter weather challenges on airport runways. By emphasizing that this construction method can minimize the potential annual costs associated with snow removal from the pavement, this research paves the way for developing more sustainable strategies

Initial investigation of generating electricity from concrete

Cement heat of hydration (HH) can be problematic especially in mass concrete structures as it causes thermal stresses that can lead to failure. Previous and current research has focused on minimizing the HH and mitigating its effects. The methods currently used for treating the HH in mass concreting varies between using: adding supplementary material to concrete, precooling of aggregates and mixing water, post-cooling of concrete, insulation of concrete members, and placement of concrete in thin lifts. These methods result in adding more cost and time to the construction project. This research sheds the light on a new approach in treating the cement HH. The paper presents initial experimentations conducted to dissipate the HH from the body of a concrete structure and convert it to electricity. This research should prove useful in laying the foundation for the development of more sustainable construction methods for mass concreting

Effect of Insecticides on Natural-Enemies

Pesticides management options for control of invertebrate pests in many parts of the world. Despite an increase in the use of pesticides, crop losses due to pests have remained largely unchanged for 30–40 years. Beyond the target pests, broad-spectrum pesticides may affect non-target invertebrate species, including causing reductions in natural enemy population abundance and activity, and competition between pest species. Assays of invertebrates against weathered residues have shown the persistence of pesticides might play an important part in their negative impacts on natural enemies in the field. A potential outcome of frequent broad-spectrum pesticide use is the emergence of pests not controlled by the pesticides but benefiting from reduced mortality from natural enemies and competitive release, commonly known as secondary pests

Hybrid and Adaptive P&O Maximum Power Point Tracking Techniques for PV Generation Systems

Maximum power point tracking (MPPT) techniques work to track the maximum power from the PV cell. A lot of conventional MPPT techniques, such as the perturb and observe (P&O), succeed in catch the maximum power point (MPP) with a good performance. However, they suffer many problems during fast varying weather conditions, where slow time response and high oscillations are dominant. Also, it is difficult to select the right direction for new steps. This article illustrates two new P&O MPPT techniques for PV generation systems. They operate on the power-voltage (P-V) curve under different weather conditions. The first is an adaptive perturb and observe (A-PO) technique, which changes the perturbation step-size adeptly to deal with the rapidly varying weather conditions. The second is a hybrid perturb and observe technique (H-PO), which uses a variable step-size according to the location of the operating point relative to the MPP. The MATLAB/SIMULINK software is used to study the truth of the proposed techniques. The results demonstrate that both techniques attain the MPP faster than the conventional techniques and at a reduced oscillation rate

Hidroksiureja i srčane posljedice u djece s bolešću srpastih stanica

Cardiac complications in sickle cell disease patients are widely expected. They may be related to iron deposition, anaemia or vasculitis. Hydroxyurea is a known drug that decreases haemoglobin (Hb) S levels. The objective of the study was to assess the effect of hydroxyurea on cardiac sequelae in children with sickle cell disease. Sixty-five sickle cell disease children were enrolled in the study; 37 of them were on regular follow up and hydroxurea treatment, whereas 28 were not. All patients underwent echocardiography and N-terminal pro-brain natriuretic peptide (NT-proBNP) assay. Plasma levels of NTproBNP were significantly lower in sickle cell patients who were on hydroxyurea treatment than in those without this therapy (p=0.03). NTproBNP levels showed significant correlations with Hb (r=-0.72, p<0.05) and HbS levels (r=0.54, p<0.05). Significant positive correlations were detected between NTproBNP and echocardiography findings (r=0.64, p<0.01) including left ventricular mass index (r=0.78, p<0.01). In conclusion, hydroxyurea may reduce cardiac complications in children with sickle cell disease.Srčane komplikacije su vrlo vjerojatne u bolesnika s bolešću srpastih stanica, a mogu biti povezane s odlaganjem željeza, anemijom ili vaskulitisom. Hidroksiureja je lijek koji snižava razine hemoglobina (Hb) S. Cilj istraživanja bio je procijeniti učinak hidroksiureje na srčane posljedice u djece s bolešću srpastih stanica. U studiju je bilo uključeno 65 djece s bolešću srpastih stanica, od kojih je 37 bilo na terapiji hidroksiurejom uz redovito praćenje, a preostalih 28 nije primalo ovu terapiju. U svih bolesnika učinjena je ehokardiografija i test NT-proBNP. Razine NT-proBNP u plazmi bile su značajno niže u bolesnika s bolešću srpastih stanica koji su primali terapiju hidroksiurejom nego u onih bez ove terapije (p=0,03). Razine NT-proBNP pokazale su značajnu korelaciju s razinama Hb (r=-0,72, p<0,05) i HbS (r=0,54, p<0,05). Značajna pozitivna korelacija utvrđena je između NT-proBNP i ehokardiografskih nalaza (r=0,64, p<0,01) uključujući indeks mase lijeve klijetke (r=0,78, p<0,01). Zaključno, hidroksiureja može smanjiti srčane komplikacije kod djece s bolešću srpastih stanica

SILVER NANOPARTICICLES FROM ENTOMOPATHOGENIC FUNGI AGAINST THE SPINY BOLLWORM, EARIAS INSULANA IN MAIZE CROP

The spiny bollworm, (SBW) Earias insulana (Lepidoptera: Noctuidae) is considered one of the most important corn pests in the world. It causes severe damage, resulting in a great loss in both quality and quantity of Maize yield. The study aimed to evaluate the virulence of fungal spores and silver nanoparticles (AgNPs) from entomopathogenic fungi (EPF) on E. insulana under laboratory conditions. Concentrations of the fungal spores and the silver nanoparticles were prepared from Metarhizium anisopliae, Beauveria bassiana, and Verticillium lecanii. Metarhizium anisopliae isolated from larvae and adults of the beet moth and Beauveria bassiana isolated from the beet beetle. The compound was used Bio Catch (V. lecanii). The concentration of EPF used was (1x106 spores/ ml). Hundred larvae and pupae were used for each treatment, divided into 5 groups, and kept at 24&plusmn;2 &ordm;C and 65&plusmn;5 % R.H. Silver nanoparticles were synthesized. The nano-particle solution was sprinkled over the filter paper and incubated at 24&plusmn;2&ordm;C for 3 days. The mortality rate was recorded 2 days after the treatment and mortality percentage was calculated. One-way ANOVA was used to compare the effects of the experimental and control treatments. The results showed that the three EPF achieved (47&ndash;70%) mortality rates within 6 days in larvae stage. B. bassiana and M. anisopliae were the most effective ones than V. lecanii. Spores of B. bassiana increased larvae mortality. The larvae mortality rate was (70 %) higher than the control. Pupae mortality rate was 65 % achieved in 6 days when treated with B. bassiana, (60 %) with M. anisopliae and (50%) with V. lecanii. B. bassiana was more effective on E. insulana than M. anisopliae and V. lecanii. The Ag NPs synthesized through applications of spore suspension and biosynthesized silver nanoparticles showed efficacy against E. insulana, different stages

BIOLOGICAL AND FEEDING ACTIVETIES OF THE PINK CORN BORER, SESAMIA CRETICALED.TREATED BY PLANT EXTRACTS

Background: Maize plants are infested with many insect pests. The corn borer, namely: the greater sugarcane borer (the pink borer), Sesamia cretica Led. is one of the most injurious insects infesting maize in Egypt and all over the world. Results: Results illustrated that the mortality percentage within 48 hours of S. cretica after feeding 4th instar larvae on maize leaves treated with various plant extracts with alcohol or petroleum- ether shows varying degrees of mortality percentages. Petroleum ether extract of Cressa cretica was extremely effective, causing 87.5% mortality. Petroleum ether extracts of Amborosia maritima, Calotropis procera, and alcohol extract of C. cretica, causing 77.5% mortality. The effectiveness may be due to the presence of diverse chemical groups in these plant extracts with toxic to the larvae of the pink borer. On the other hand, extracts of Lycopersicum esculentum, Lotus glenoid, Aerva javanica, Carpobrotus edulis, Capsium annum, and Cassia senna have been minimum toxic effect and causing 7.5, 10.0, 12.5, and 12.5 % mortality, respectively. The influence of minimal toxic plant extracts as antifeedant to the pink borer (S. cretica) was studied. Food consumption varied depending on the feeding time and extracts tested. The feeding ratio of S. cretica on the different extracts was significantly different. The anti-feeding activity of extracts appears to have had a higher effect than its toxicity

Value Engineering and Its Applications in Civil Engineering

Value engineering (VE) can be a very valuable tool in the field of civil engineering and the construction industry. VE has tremendous benefits in both cost-saving and project improvement areas. Between the pay-offs and wide variety of applications, it is unsurprising that more firms are adopting the principles of VE in the design and construction phases of their projects. Many studies have been conducted on the invention of new tools for VE while others focused on the application aspect of VE in different engineering domains. This paper presents an overview of VE and its applications in the field of civil engineering. The study should prove useful for future researchers who wish to update their knowledge with the latest status of the state of art of VE application in civil engineering