Industrial sugar beets to biofuel: Field to fuel production system and cost estimates

Specialized varieties of sugar beets (Beta vulgaris L.) may be an eligible feedstock for advanced biofuel designation under the USA Energy Independence and Security Act of 2007. These non-food industrial beets could double ethanol production per hectare compared to alternative feedstocks. A mixed-integer mathematical programming model was constructed to determine the breakeven price of ethanol produced from industrial beets, and to determine the optimal size and biorefinery location. The model, based on limited field data, evaluates Southern Plains beet production in a 3-year crop rotation, and beet harvest, transportation, and processing. The optimal strategy depends critically on several assumptions including a just-in-time harvest and delivery system that remains to be tested in field trials. Based on a wet beet to ethanol conversion rate of 110 dm³ Mg⁻¹ and capital cost of 128 M$ for a 152 dam³ y⁻¹ biorefinery, the estimated breakeven ethanol price was 507 $ m⁻³. The average breakeven production cost of corn (Zea mays L.) grain ethanol ranged from 430 to 552 $ m⁻³ based on average net corn feedstock cost of 254 and 396 $ m⁻³ in 2014 and 2013, respectively. The estimated net beet ethanol delivered cost of 207 $ m⁻³ was lower than the average net corn feedstock cost of 254–396$ m⁻³ in 2013 and 2014. If for a mature industry, the cost to process beets was equal to the cost to process corn, the beet breakeven ethanol price would be $387 m^-3 (587 $ m⁻³ gasoline equivalent).     

Investigating the influence of the counter Si-cell on the optoelectronic performance of high-efficiency monolithically perovskites/silicon tandem cells under various optical sources

Nowadays, tandem structures have become a valuable competitor to conventional silicon solar cells, especially for perovskite over silicon, as metal halides surpassed Si with tunable bandgaps, high absorption coefficient, low deposition, and preparation costs. This led to a remarkable enhancement in the overall efficiency of the whole cell and its characteristics. Consequently, this expands the usage of photovoltaic technology in various fields of applications not only under conventional light source spectrum in outdoor areas, i.e., AM1.5G, but also under artificial light sources found indoors with broadband intensity values, such as Internet of things (IoTs) applications to name a few. We introduce a numerical model to analyze perovskite/Si tandem cells (PSSTCs) using both crystalline silicon (c-Si) and hydrogenated amorphous silicon (a-Si:H) experimentally validated as base cells. All proposed layers have been studied with J-V characteristics and energy band diagrams under AM1.5G by using SCAPS-1D software version 3.7.7. Thereupon, the proposed architectures were tested under various artificial lighting spectra. The proposed structures of Li4Ti5O12/CsPbCl3/MAPbBr3/CH3NH3PbI3/Si recorded a maximum power conversion efficiency (PCE) of 25.25% for c-Si and 17.02% for a-Si:H, with nearly 7% enhancement concerning the Si bare cell in both cases.     

Impact of graphite impurities on the structure and optical properties of the sodium borate oxide glass

For the carbon-based glass fabrication/manufacture process, different amounts of pure graphite powder were added up to 100 wt.% of sodium tetraborate oxide (the weight of one mole of the sodium tetraborate is 381.372 g/mol) and then melted at 950 °C for 2 h before fast quenching in the air at RT. The resulted solids were examined by the XRD and SEM techniques, which confirmed the amorphous natures for studied samples. FTIR spectroscopy showed that some C-atoms are shared in the glass network as C–O and CO₂. In contrast, the UV–Vis showed that the increase in the graphite contents/impurities causes a red shift in the value of the optical edge and the value of Fermi energy. Also, the increase of the graphite impurities causes a decrease in the bandgap values of both direct and indirect electronic transitions. Both the values of Urbach energy and the metallization indicated an increase in the crystallinity degree as the graphite content increase. A graphite-based glass is a promising material for wide-scale applications.

     

Optical properties of lithium titanate as a potential layer in light harvesters

Journal of Materials Science: Materials in Electronics - Various solar cell architectures and materials are currently studied, seeking enhanced photon management mechanisms. Herein, we provide an...     

Harmonic analysis of shear deformable orthotropic cracked plates using the Boundary Element Method

In this work, the modal and harmonic analysis of orthotropic shear deformable cracked plates using a direct time-domain Boundary Element Method formulation based on the elastostatic fundamental solution of the problem is presented. The Radial Integration Method was used for the treatment of domain integrals involving distributed domain applied loads and those related with inertial mass forces. Numerical examples are presented to demonstrate the efficiency and accuracy of the proposed formulation.     

Assessing the optoelectronic behavior of soiled silicon photovoltaic cell under harsh environmental conditions

In the current study, a monocrystalline Si photovoltaic (PV) cell was modeled using solar cell capacitance simulator (SCAPS) to demonstrate the optoelectronic performance of the cell under harsh environmental conditions. Harsh conditions are simulated in terms of wind speed and temperature fluctuations within the presence of a dust layer. All models are evaluated with respect to a bare model with no dust layer accumulated and operating under standard test conditions (STC). Accordingly, the PV under-test characteristics have been estimated under continuous wind speed and temperature variations. An interesting behavior for the cell operation under relatively high temperatures with an accumulated dust layer was observed. The short circuit current increased by 61.5% with decreasing open-circuit voltage by 47.3%, showing an overall positive trend for the power harvested. Such behavior contradicts the average temperature performance of cells without dust layer accumulation. A detailed justification is illustrated, where the heat transfer rate with dust accumulation highlighted an incremental increase concerning the bare cell by 14.57%.     

Microwave-assisted synthesis of Co-doped SnO2/rGO for indoor humidity monitoring

The evaluation of indoor humidity is challenging compared to other environmental parameters such as light intensity, temperature, sound and so forth. The proper selection of sensing materials and structural tuning will lead to high-performance humidity sensors. Herein, the SnO₂/rGO and SnO₂/rGO doped with Co nanocomposite were produced by microwave route. The obtained nanocomposite was characterized by XRD, SEM, EDAX, DTA, TGA, FTIR, Raman, and HRTEM. The successful incorporation of Co onto the rGO/SnO₂ is affirmed by the XRD and supported with matching SEM and TEM outcomes where nanoscale particles exist. FTIR reveals the existence of the CC stretching band at ～1570 cm^?1 indicating graphene network sustaining upon reduction. Micro-pores presence is claimed by the adsorption-desorption isotherm curve. The humidity sensing behavior of both structures was evaluated in a wide range of humidity (11–97% RH). The obtained results confirmed that best working frequency for highest humidity change is 50 Hz. Furthermore, upon doping the SnO₂/rGO composite with Co, sensitivity, the response time and recovery time has improved reaching 52 s and 100 s respectively.     

Evaluation of the electrical and dielectric behavior of the apatite layer formed on the surface of hydroxyapatite/hardystonite/copper oxide hybrid nanocomposites for bone repair applications

The work aimed to prepare nanocomposites with good electrical and mechanical properties and acceptable bioactivity behavior to be suitable for bone repair applications. In this context, hydroxyapatite (HA) and hardystonite (HT) were prepared by mechanochemical synthesis method. Subsequently, nanocomposites of different contents of HA, HT and copper oxide (CuO) were prepared, sintered and characterized by X-ray diffraction (XRD) technique and scanning electron microscopy (SEM). In addition, bioactivity was evaluated in vitro after treatment in simulated body fluid (SBF) and HA layer formation was confirmed by SEM in conjunction with energy dispersive X-ray analysis (EDX). The electrical and dielectric properties were measured before and after treatment in SBF solution. Elastic and physical properties were also measured. The results clarified that the sintering temperature used along with the successive increase of HT and CuO contents achieved good densification behavior and better mechanical properties, especially compressive strength, to avoid the stress-shielded bone effect. Also, HT and CuO positively enhanced the electrical conductivity and reduced the dielectric properties of nanocomposites prepared. The latter results have a great role in promoting fracture healing. Based on the above results, the prepared nanocomposites are promising for potential use in bone repair applications.