Effect of humic acids and the amount of mineral fertilizer on some characteristics of saline soil, growth and yield of broccoli plant under salt stress conditions

Saabunud / Received 09.04.2022 ; Aktsepteeritud / Accepted 19.06.2022 ; Avaldatud veebis / Published online 19.06.2022 ; Vastutav autor / Corresponding author: Duraid K. A. Al-Taey ; [email protected] (A pots experiment was undertaken to determine the combined effect of humic acids and mineral fertilizer on some characteristics of saline soil, growth, and yield components of broccoli. The experiment was conducted in a randomized complete block design with three replications. The first factor consists of two levels of humic acids, namely without humic acid (H0 = 0.00 g L–1 ) and humic acid application (H1 = 0.35 g L–1 ), while the second factor included nine fertilizer (92 kg N ha –1 , 200 kg P2O5 ha–1 , 150 kg K2O ha–1 ) application rates that were (100, 100, 100%), (120, 120, 120%), (120, 120, 100%), (80, 120, 120%), (100, 100, 120%), (80.100, 100%), (120, 80, 80%), (100, 80, 80%), (80, 80, 80%) which added as a percentage of original fertilizer recommendation taking the symbols of R1 to R9 respectively. The treatment R1 was designated as a control treatment. The results indicated that humic acid application (H1) and increasing the amount of applied mineral fertilizer (R2) reduced the hydraulic conductivity of the soil for different soil depths. Humic acid addition (H1) increased concentrations of calcium and magnesium while reducing sodium concentration compared to control (H0). Contrary to humic acid, increasing the supplied mineral fertilizer led to a reduction in concentrations of calcium and magnesium while increasing sodium concentration in the soil. The sodium adsorption in soil particles in the ground was decreased due to humic acid application while improving the mineral fertilizer. Humic acid (H1) combined with increasing the amount of chemical fertilizer (R2) gave the desirable results in decreasing the sulphate, chloride and bicarbonate in the soil profile. The addition of humic acid (H1) and increasing mineral fertilizer application (R2) led to a significant increase in plant height, leaf area and head weight of broccoli per plant. Similarly, the interaction between humic acids and chemical fertilizers (H1R2) led to a significant increase in plant height, leaf area and head weight of broccoli per plant

AC ship microgrids: control and power management optimization

At sea, the electrical power system of a ship can be considered as an islanded microgrid. When connected to shore power at berth, the same power system acts as a grid connected microgrid or an extension of the grid. Therefore, ship microgrids show some resemblance to terrestrial microgrids. Nevertheless, due to the presence of large dynamic loads, such as electric propulsion loads, keeping the voltage and frequency within a permissible range and ensuring the continuity of supply are more challenging in ship microgrids. Moreover, with the growing demand for emission reductions and fuel efficiency improvements, alternative energy sources and energy storage technologies are becoming popular in ship microgrids. In this context, the integration of multiple energy sources and storage systems in ship microgrids requires an efficient power management system (PMS). These challenging environments and trends demand advanced control and power management solutions that are customized for ship microgrids. This paper presents a review on recent developments of control technologies and power management strategies proposed for AC ship microgrids

Role of anatomical sites and correlated risk factors on the survival of orthodontic miniscrew implants:a systematic review and meta-analysis

Abstract Objectives The aim of this review was to systematically evaluate the failure rates of miniscrews related to their specific insertion site and explore the insertion site dependent risk factors contributing to their failure. Search methods An electronic search was conducted in the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Knowledge, Scopus, MEDLINE and PubMed up to October 2017. A comprehensive manual search was also performed. Eligibility criteria Randomised clinical trials and prospective non-randomised studies, reporting a minimum of 20 inserted miniscrews in a specific insertion site and reporting the miniscrews’ failure rate in that insertion site, were included. Data collection and analysis Study selection, data extraction and quality assessment were performed independently by two reviewers. Studies were sub-grouped according to the insertion site, and the failure rates for every individual insertion site were analysed using a random-effects model with corresponding 95% confidence interval. Sensitivity analyses were performed in order to test the robustness of the reported results. Results Overall, 61 studies were included in the quantitative synthesis. Palatal sites had failure rates of 1.3% (95% CI 0.3–6), 4.8% (95% CI 1.6–13.4) and 5.5% (95% CI 2.8–10.7) for the midpalatal, paramedian and parapalatal insertion sites, respectively. The failure rates for the maxillary buccal sites were 9.2% (95% CI 7.4–11.4), 9.7% (95% CI 5.1–17.6) and 16.4% (95% CI 4.9–42.5) for the interradicular miniscrews inserted between maxillary first molars and second premolars and between maxillary canines and lateral incisors, and those inserted in the zygomatic buttress respectively. The failure rates for the mandibular buccal insertion sites were 13.5% (95% CI 7.3–23.6) and 9.9% (95% CI 4.9–19.1) for the interradicular miniscrews inserted between mandibular first molars and second premolars and between mandibular canines and first premolars, respectively. The risk of failure increased when the miniscrews contacted the roots, with a risk ratio of 8.7 (95% CI 5.1–14.7). Conclusions Orthodontic miniscrew implants provide acceptable success rates that vary among the explored insertion sites. Very low to low quality of evidence suggests that miniscrews inserted in midpalatal locations have a failure rate of 1.3% and those inserted in the zygomatic buttress have a failure rate of 16.4%. Moderate quality of evidence indicates that root contact significantly contributes to the failure of interradicular miniscrews placed between the first molars and second premolars. Results should be interpreted with caution due to methodological drawbacks in some of the included studies

Genome-wide analysis identifies 12 loci influencing human reproductive behavior.

The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits

Flow instability in shock tube due to shock wave-boundary layer-contact surface interactions, a numerical study

This paper describes numerical simulation of transient flow conditions in shock tube. A two dimensional time accurate Navier-Stokes CFD solver for shock tube applications is developed to perform the numerical investigations. The solver was developed based on the dimensions of a newly built short-duration high speed flow test facility at Universiti Tenaga Nasional 'UNITEN' in Malaysia. The facility has been designed, built, and commissioned in such a way so that it can be used as a free piston compressor, shock tube, shock tunnel and gun tunnel interchangeably. Different values of diaphragm pressure ratios P4/P1 are applicable in order to get wide range of Mach number. In this paper, in order to obtain better understanding of the processes involved, CFD simulations were performed for selected cases and the results are analyzed in details. The shock wave motion was traced and in order to investigate the flow stability, details two dimensional effects were investigated. It was observed that the flow becomes unstable due to shock wave-boundary layer-contact surface interactions after shock reflected off the tube end

Experimental Investigation of the Pebble Bed Structure by using Gamma Ray Tomography

High-energy gamma-ray computed tomography (CT scanner system) has been used to study, for the first time, the structure of the pebble bed in terms of cross-sectional time-averaged void and solids distributions, and their radial profiles along the bed height. The pebble beds were packed with pebbles of glass spheres of diameter of d1 = 0.0127 m, d₂ = 0.0254 m and d₃ = 0.05 m in a Plexiglas cylinder with diameter of D = 0.3048 m, with D/d1 = 24, D/d₂ = 12 and D/d₃ = 6, respectively. The average void fraction of these beds were ε¯1=0.389,ε¯2=0.40 and ε¯3=0.43, respectively. It was found that the void and solids distribution depends on pebble size, the bed diameter and the packing method. The void radial profiles vary with the bed height for larger pebbles at the measured axial levels (0.0762, 0.1524, and 0.2286 m from the bed base). However, adding additional bed height on the top of the original one did not show any influence on the average voids and their radial profiles at the same measured axial levels. The experimental results indicated that void variations are normally distributed in the bulk region of the packed bed

The Effects of Area Contraction on Shock Wave Strength and Peak Pressure in Shock Tube

This paper presents an experimental investigation into the effects of area contraction on shock wave strength and peak pressure in a shock tube. The shock tube is an important component of the short duration, high speed fluid flow test facility, available at the Universiti Tenaga Nasional (UNITEN), Malaysia. The area contraction was facilitated by positioning a bush adjacent to the primary diaphragm section, which separates the driver and driven sections. Experimental measurements were performed with and without the presence of the bush, at various diaphragm pressure ratios, which is the ratio of air pressure between the driver (high pressure) and driven (low pressure) sections. The instantaneous static pressure variations were measured at two locations close to the driven tube end wall, using high sensitivity pressure sensors, which allow the shock wave strength, shock wave speed and peak pressure to be analysed. The results reveal that the area contraction significantly reduces the shock wave strength, shock wave speed and peak pressure. At a diaphragm pressure ratio of 10, the shock wave strength decreases by 18%, the peak pressure decreases by 30% and the shock wave speed decreases by 8%

Pebble Bed Nuclear Reactor Structure Study: A Comparison of the Experimental and Calculated Void Fraction Distribution

The structure of the pebbles in the pebble bed nuclear reactors plays an important role in their performance as it affects the neutron streaming and the wall channeling of the coolant flow. In this study, the structure of a one foot diameter pebble bed reactor that was measured experimentally by gamma ray computed tomography (CT) in our laboratory in terms of void cross-sectional distribution and radial profiles has been used to evaluate the predictions of the void fractions of the reported empirical and analytical correlations. It can be seen that there is an agreement between the experimental results and the exponential expression for the void fraction with the use of the smaller spherical pebbles diameter (D/dp = 24) as compared to those of larger diameters