A review of growth stage deficit irrigation affecting sticky maize production

The shortage of water resources influences the future sustainability of sticky Maize (Zea mays L.) production. Deficit irrigation (DI) – a water management strategy – has gained much attention from scientists because of enhanced water use efficiency (WUE). Nonetheless, in reality, when applying this technique, its impact on yield and economic returns should be considered. Through an analytical literature review, this study examined the effect of growth stage DI on Maize production factors, i.e. yield, WUE, and economic returns. The results revealed that Maize’s WUE could be improved with the lowest reduction in yield as water stress was imposed during the vegetative or maturation growth stages. Therefore, the profitable returns could be reached even if the yield was reduced; however, the economic return was sensitive to commodity prices. The present review addressed that the Maize flexible capacities under growth stage water stress presented an opportunity for the optimization of irrigated water and profit preservation by accurately judging the managing time of irrigation implementation

Seismic Earth Pressure Development in Sheet Pile Retaining Walls: A Numerical Study

The design of retaining walls requires the complete knowledge of the earth pressure distribution behind the wall. Due to the complex soil-structure effect, the estimation of earth pressure is not an easy task; even in the static case. The problem becomes even more complex for the dynamic (i.e., seismic) analysis and design of retaining walls. Several earth pressure models have been developed over the years to integrate the dynamic earth pressure with the static earth pressure and to improve the design of retaining wall in seismic regions. Among all the models, MononobeOkabe (M-O) method is commonly used to estimate the magnitude of seismic earth pressures in retaining walls and is adopted in design practices around the world (e.g., EuroCode and Australian Standards). However, the M-O method has several drawbacks and does not provide reliable estimate of the earth pressure in many instances. This study investigates the accuracy of the M-O method to predict the dynamic earth pressure in sheet pile wall. A 2D plane strain finite element model of the wall-soil system was developed in DIANA. The backfill soil was modelled with Mohr-Coulomb failure criterion while the wall was assumed behave elastically. The numerically predicted dynamic earth pressure was compared with the M-O model prediction. Further, the point of application of total dynamic force was determined and compared with the static case. Finally, the applicability of M-O methods to compute the seismic earth pressure was discussed

Coagulation for treatment of swine slaughterhouse wastewater

In this study, wastewater taken from the Nam Phong swine slaughterhouse, Ho Chi Minh City, was used to evaluate the treatment efficiency of common coagulants, including Alum (Aluminum Sulfate - Al2(SO4)3.18H2O), Poly-Aluminum Chloride (PAC), and Ferrous Sulfate (FeSO4.7H2O), using a jar-test system. The experiments were conducted using the one-factor-at-a-time method to examine three variables which are pH, stirring speed, and coagulant dosage. The results showed that both Alum and PAC perform over 90% removal of colour, turbidity, COD, and total phosphorus (TP) from slaughterhouse wastewater at pH 7 with a stirring speed of 75 revolutions per minute (RPM) and average coagulant dosages of 450 mg/L for Alum and 550 mg/L for PAC. Meanwhile, under the appropriate conditions of pH equal to 10 and 75 RPM with a chemical dosage of 350 mg/L, COD and TP removal efficiencies by Ferrous Sulfate exceed 87%, but those of turbidity and colour only reach 25%. This finding could be a promising coagulation method as a pre-treatment for the swine slaughterhouse wastewater

Failure Mechanism of True 2D Granular Flows

Most previous experimental investigations of two-dimensional (2D) granular column collapses have been conducted using three-dimensional (3D) granular materials in narrow horizontal channels (i.e., quasi-2D condition). Our recent research on 2D granular column collapses by using 2D granular materials (i.e., aluminum rods) has revealed results that differ markedly from those reported in the literature. We assume a 2D column with an initial height of h0 and initial width of d0, a defined as their ratio (a =h0/d0), a final height of h , and maximum run-out distance of d . The experimental data suggest that for the low a regime (a <0.65) the ratio of the final height to initial height is 1. However, for the high a regime (a >0.65), the ratio of a to (d-d0)/d0, h0/h , or d/d0 is expressed by power-law relations. In particular, the following power-function ratios (h0/h=1.42a^2/3 and d/d0=4.30a^0.72) are proposed for every a >0.65. In contrast, the ratio (d-d0)/d0=3.25a^0.96 only holds for 0.65< a1.5. In addition, the influence of ground contact surfaces (hard or soft beds) on the final run-out distance and destruction zone of the granular column under true 2D conditions is investigated.Comment: 8 page

Technical Feasibility of Cultivating Local Seaweed Species in Inland Saline Water of Western Australia

This research investigated the technical feasibility of cultivating local seaweed species from Perth region in potassium-fortified inland saline waters (ISW). Different levels of potassium fortification into the ISW were essential for their culture and out of six seaweed species studied, Ulva lactuca, Lomentaria catenata and two Sargassum spp. could successfully be cultured in 33 to 100% potassium-fortified ISW. Seasonality, nutrient enrichments, pH and temperature were able to influence different seaweed species to different degrees

The γbb‾\gamma b\overline{b} production via γ∗γ∗\gamma^{*}\gamma^{*} collisions at the ILC and LHC

Taking into account of the mixing of Higgs-radion in the Randall-Sundrum model and the vector anomalous couplings, we investigate the production of $b\overline{b}$ associated with the photon through $\gamma^{*}\gamma^{*}$ collisions at the International Linear Collider (ILC) and Large Hadron Collider (LHC). The total cross-section depends strongly on the vacuum expectation value (VEV) of the radion field $\Lambda_{\phi}$, the radion mass $m_{\phi}$, the parameters of anomalous couplings. The result shows that the total cross-section in $\gamma b\overline{b}$ production at the LHC is much larger than that at the ILC. The production cross-section gives the largest value at the dominated state, $m_{\phi} = m_{h} = 125$ GeV.Comment: 11 pages, 4 figures, 4 table

Optical engineering of iii-nitride nanowire light-emitting diodes and applications

Applications of III-nitride nanowires are intensively explored in different emerging technologies including light-emitting diodes (LEDs), laser diodes, photodiodes, biosensors, and solar cells. The synthesis of the III-nitride nanowires by molecular beam epitaxy (MBE) is investigated with significant achievements. III-nitride nanowires can be grown on dissimilar substrates i.e., silicon with nearly dislocation free due to the effective strain relaxation. III-nitride nanowires, therefore, are perfectly suited for high performance light emitters for cost-effective fabrication of the advanced photonic-electronic integrated platforms. This dissertation addresses the design, fabrication, and characterization of III-nitride nanowire full-color micro-LED (µLED) on silicon substrates for µLED display technologies, high-efficient ultraviolet (UV) LEDs, and spectral engineering for narrow band LEDs. In this dissertation, InGaN/AlGaN nanowire µLEDs were demonstrated with highly stable emission which can be varied from the blue to red spectrum. Additionally, by integrating full-color emissions in a single nanowire, phosphor-free white-color µLEDs are achieved with an unprecedentedly high color rendering index of ~ 94. Such high-performance µLEDs are perfectly suitable for the next generation high-resolution micro-display applications. Moreover, the first demonstration of two-step surface passivation using Potassium Hydroxide (KOH) and Ammonium Sulfide (NH4)2Sx is reported. The photoluminescence, electroluminescence, and optical power of the 335 nm AlGaN nanowire UV LEDs show improvements by 49%, 83%, and 65%, respectively. Such enhanced performance is attributed to the mitigation of the surface nonradiative recombination on the nanowire surfaces. A combination of KOH and (NH4)2Sx treatment shows a promising approach for high efficiency and high power AlGaN nanowire UV LEDs. The LEDs with narrow spectra are highly desirable light sources for precisely controlled applications such as phototherapy. In this regard, we have further demonstrated narrow spectral nanowire LEDs using on-chip integrated bandpass filters. To achieve narrow band spectra, the bandpass filters are designed and fabricated using all-dielectric and metal-dielectric multilayers for visible and UV regions, respectively. They are fabricated onto LED devices as a single photonic platform to achieve the narrow band LEDs for innovative applications like phototherapy for wound healing

Removal of inorganic nutrient and organic carbon from wastewater of Binh Dien market using the green alga Chlorella sp.

Traditional markets play a major role in socio-economics and constitutes a significant aspect of Vietnamese culture. However, wastewater streams discharged from the markets are generally characterized by a lot of inorganic nutrients and organic substances originated from fresh food processing units. They could lead to serious water contamination if discharged without proper treatment. This study applied microalgae Chlorella sp. for eliminating inorganic nutrients (NO3--N, NH4+-N and PO43--P) and organic carbon (Chemical oxygen demand-COD) from wastewater of the Binh Dien market. The removal efficiencies reached for NH4+-N > 86%, for NO3--N > 72%, and for PO43--P > 69%, respectively, at algal density of 49 x 104 cell mL-1, and for COD > 96% at algal density of 35 x 104 cell mL-1 after five cultivating days. The effluence satisfied the Vietnamese standard, column B, of the National technical regulation on industrial wastewater (QCVN 40:2011/BTNMT). The results demonstrated that the culture system composed of green algal Chlorella sp. could be a potential candidate for the removal of nutrients and organic carbon by a wastewater treatment process from the Binh Dien market