Optimizing the Runoff Estimation with HEC-HMS Model Using Spatial Evapotranspiration by the SEBS Model

Most of the commonly used hydrological models do not account for the actual evapotranspiration (ETa) as a key contributor to water loss in semi-arid/arid regions. In this study, the HEC-HMS (Hydrologic Engineering Center Hydrologic Modeling System) model was calibrated, modified, and its performance in simulating runoff resulting from short-duration rainfall events was evaluated. The model modifications included integrating spatially distributed ETa, calculated using the surface energy balance system (SEBS), into the model. Evaluating the model’s performance in simulating runoff showed that the default HEC-HMS model underestimated the runoff with root mean squared error (RMSE) of 0.14 m³/s (R²?=?0.92) while incorporating SEBS ETa into the model reduced RMSE to 0.01 m³/s (R²?=?0.99). The integration of HECHMS and SEBS resulted in smaller and more realistic latent heat flux estimates translated into a lower water loss rate and a higher magnitude of runoff simulated by the HECHMS model. The difference between runoff simulations using the default and modified model translated into an average of 95,000 m³ runoff per rainfall event (equal to seasonal water requirement of ten-hectare winter wheat) that could be planned and triggered for agricultural purposes, flood harvesting, and groundwater recharge in the region. The effect of ETa on the simulated runoff volume is expected to be more pronounced during high evaporative demand periods, longer rainfall events, and larger catchments. The outcome of this study signifies the importance of implementing accurate estimates of evapotranspiration into a hydrological model.

     

Surface characterization and biological properties of regular dentin,demineralized dentin,and deproteinized dentin

Bone autografts are often used for reconstruction of bone defects; however, due to the limitations of autografts, researchers have been in search of bone substitutes. Dentin is of particular interest for this purpose due to high similarity to bone. This in vitro study sought to assess the surface characteristics and biological properties of dentin samples prepared with different treatments. This study was conducted on regular (RD), demineralized (DemD), and deproteinized (DepD) dentin samples. X-ray diffraction and Fourier transform infrared spectroscopy were used for surface characterization. Samples were immersed in simulated body fluid, and their bioactivity was evaluated under a scanning electron microscope. The methyl thiazol tetrazolium assay, scanning electron microscope analysis and quantitative real-time polymerase chain reaction were performed, respectively to assess viability/proliferation, adhesion/morphology and osteoblast differentiation of cultured human dental pulp stem cells on dentin powders. Of the three dentin samples, DepD showed the highest and RD showed the lowest rate of formation and deposition of hydroxyapatite crystals. Although, the difference in superficial apatite was not significant among samples, functional groups on the surface, however, were more distinct on DepD. At four weeks, hydroxyapatite deposits were noted as needle-shaped accumulations on DemD sample and numerous hexagonal HA deposit masses were seen, covering the surface of DepD. The methyl thiazol tetrazolium, scanning electron microscope, and quantitative real-time polymerase chain reaction analyses during the 10-day cell culture on dentin powders showed the highest cell adhesion and viability and rapid differentiation in DepD. Based on the parameters evaluated in this in vitro study, DepD showed high rate of formation/deposition of hydroxyapatite crystals and adhesion/viability/osteogenic differentiation of human dental pulp stem cells, which may support its osteoinductive/osteoconductive potential for bone regeneration.     

PVT‐compensated low‐voltage and low‐power CMOS LNA for IoT applications

In this paper, a low‐noise amplifier (LNA) with process, voltage, and temperature (PVT) compensation for low power dissipation applications is designed. When supply voltage and LNA bias are close to the subthreshold, voltage has significant impact on power reduction. At this voltage level, the gain is reduced and various circuit parameters become highly sensitive to PVT variations. In the proposed LNA circuit, in order to enhance efficiency at low supply voltage, the cascade technique with g_m boosting is used. To improve circuit performance when in the subthreshold area, the forward body bias technique is used. Also, a new PVT compensator is suggested to reduce sensitivity of different circuit's parameters to PVT changes. The suggested PVT compensator employs a current reference circuit with constant output regarding temperature and voltage variations. This circuit produces a constant current by subtracting two proportional to absolute temperature currents. At a supply voltage of 0.35 V, the total power consumption is 585 μW. In different process corners, in the proposed LNA with PVT compensator, gain and noise figure (NF) variations are reduced 10.3 and 4.6 times, respectively, compared to a conventional LNA with constant bias. With a 20% deviation in the supply voltage, the gain and noise NF variations decrease 6.5 and 34 times, respectively.     

Suitability of Different Food Grade Materials for the Encapsulation of Some Functional Foods Well Reported for Their Advantages and Susceptibility

Functional foods find a very important place in the modern era, where different types of cancer, diabetes, cardiovascular diseases, etc. are on a high. Irrespective of the abundance of bioactive components in different fruits and vegetables, their low solubility in aqueous solution, vulnerability to destruction in different environmental and gastrointestinal conditions and a low intestinal absorption becomes a concern. Because it is quite difficult to commercialize non food materials for the food encapsulation purposes due to their safety concerns in the human body, scientists in the recent times have come up with the idea of encapsulating the different bioactive components in different food grade materials that are able to safeguard these bioactive components against the different environmental and gastrointestinal conditions and ensure their safe and targeted delivery at their absorption sites. Different food grade encapsulation materials including various oligosaccharides, polysaccharides (starch, cyclodextrins, alginates, chitosan, gum arabic, and carboxymethyl cellulose) and proteins and their suitability for encapsulating various bioactive components like flavonoids (catechins, rutin, curcumin, hesperetin, and vanillin), nonflavonoids (resveratrol), carotenoids (β-carotene, lycopene, and lutein), and fatty acids (fish oil, flaxseed oil, and olive oil) of high medical and nutritional value are reviewed here.     

Multi carrier energy systems and energy hubs: Comprehensive review,survey and recommendations

In this paper, the multi carrier energy (MCE) systems are reviewed from different point of views including mathematical models, integrated components and technologies, uncertainty management, planning objectives, environmental pollution, resilience, and robustness. The basic of MCE systems is formed by combination of cooling, heating and power (CCHP). The natural gas and electricity are the main inputs to MCE systems and the cooling, heating, and electricity are the common outputs. The regular energy converters in the MCE systems are combined heat and power (CHP), gas boiler, absorption-electrical chillers, power to gas (P2G) and fuel-cell. The generic energy storages are electrical, heating, cooling, hydrogen, carbon dioxide (CO₂) and hydro systems.     

Properties of PET/clay nanocomposite films

Polyethylene terephthalate (PET) nanocomposite films were prepared by cast extrusion followed by uniaxial stretching, using chill rolls. Transmission electron microscopy (TEM) and wide angle X‐ray diffraction (WAXD) showed that the clay layers were aligned in the machine direction (MD) in the PET/clay nanocomposite (PCN) films. Differential scanning calorimetry (DSC) showed that PCN films have higher crystallinity than the neat PET films, possibly due to the nucleating role of the silicate layers. The PCN films became hazier as the clay content increased, but the film transparency remained in the acceptable range. Oxygen permeability of the PCN films decreased by 23% compared to the neat PET film. This is comparable with predictions of models proposed in the literature. Silicate incorporation brought about 20% increase in the tensile modulus, while the puncture and tear propagation resistance were reduced, due to brittleness of the PCN films. The measured modulus (1.7 GPa) was somewhat smaller than the values predicted using the Pseudoinclusion model (2.1 GPa). POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Rheological,crystal structure,barrier, and mechanical properties of PA6 and MXD6 nanocomposite films

In this study, rheological, crystal structure, barrier, and mechanical properties of polyamide 6 (PA6), poly(m‐xylene adipamide) (MXD6) and their in situ polymerized nanocomposites with 4 wt % clay were studied. The extent of intercalation and exfoliation as well as type of crystals, crystallinity, and thermal transitions were investigated using X‐ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. Dynamic rheological measurements revealed that incorporation of nanoclay significantly increases complex viscosity of MXD6 nanocomposites at low frequencies, which was related to the formation of a nanoclay network and exchange reaction between MXD6 chains. The comparative study of dynamic characteristics (G′ (ω) and G″ (ω)) for aliphatic and aromatic polyamide nanocomposites with their neat resins as well as the relaxation spectra for both polymer systems confirmed the possibility of the aforementioned phenomena. Although, the crystallinity of MXD6 films was lower as compared to PA6 films, the permeability to oxygen was more than 5 times better for the former. Incorporating 4 wt% clay enhanced the barrier property, tensile modulus, and yield stress of PA6 and MXD6 nanocomposite films in both machine and transverse directions without sacrificing much puncture and tear resistances. The PA6‐based films showed higher tear and puncture strength as compared to MXD6 films. POLYM. ENG. SCI., 54:2617–2631, 2014. © 2013 Society of Plastics Engineers     

Experimental study of onset of subcooled annular flow boiling

An experimental study on the onset of nucleate boiling (ONB) is performed for water annular flow to provide a systematic database for low pressure and velocity conditions. A parametric study has been conducted to investigate the effect of pressure, inlet subcooling, heat and mass flux on flow boiling. The test section includes a Pyrex tube with 21 mm inner diameter and a stainless steel (SS-304) rod with outer diameter of 6 mm. Pressure, heat and mass flux are in the range of 1.73 < P < 3.82 bar, 40 < q < 450 kW/m² and 70 < G < 620 kg/m² s, respectively. The results illustrate that inception heat flux is extremely dependent on pressure, inlet subcooling temperature and mass flux; for example in pressure, velocity and inlet subcooling as 3.27 bar, 230 kg/m² s and 41.3 °C; consequently q_w,ONB is 177.3 kW/m². In other case with higher inlet temperature of 71.5 °C and with P, 3.13 bar and G, 232 kg/m² s the inception heat flux reached to 101.6 kW/m². The data of ONB heat flux are over estimated from the existing correlation, and maximum deviation of wall superheat (ΔT_w,ONB) from correlations is 30%. Experimental data of inception heat flux are within 22% of that predicted from the correlation.