Production of DL-Methionine from Corn Syrup via Biosynthesis with Corynebacterium glutamicum

DL-methionine is an important feed additive for poultry and swine diets. The amino acid is not produced by animals so it can only be obtained through diet. Methionine is important for protein growth and helps the health of livestock. Recent increase in meat consumption in Latin America and Asia, along with a growing consumer concern of animal welfare, has driven a growth in the methionine market. The methionine market is predicted to continue to grow for at least another five years (Methionine Market 2019). The proposed design is for a process that produces DL-methionine by fermentation with the bacteria, Corynebacterium glutamicum. The plant has a capacity of 250 kilotonnes/year and will be located in Cedar Rapids, IA. According to a 20 year profitability analysis, it has an estimated IRR of 16.43% and in 2042 it has an NPV of $5,650,200. In the third production year, the ROI will be 25.97$3.60/kg

Multibit-Generating Pulsewidth-Based Memristive-PUF Structure and Circuit Implementation

As Internet of Things (IoT) devices have evolved, physical unclonable functions (PUFs) have become a popular solution for hardware security. In particular, memristor devices are receiving attention as suitable candidates for reliable PUFs because they can be integrated into nano-cross point array circuits with ultra-high efficiency. However, it has been found that typical 1-bit generating PUFs consume too many challenge–response pairs (CRPs) to generate a single response. This issue has to be overcome to construct a strong and reliable PUF with a large number of valid CRPs. We suggest a bank design and quantizing entropy source method for constructing a multibit-generating PUF. In this paper, we propose a new pulsewidth-based memristive PUF (pm-PUF) architecture that incorporates analog memristor devices and a nano-cross point array. We describe the architecture’s circuit implementation and its operating process in detail. We also evaluate the inter and intra performances of the pm-PUF in terms of randomness, diffuseness, uniqueness, and steadiness to show that the proposed pm-PUF will be a promising solution for a high-density hardware security system

Economic and Ecological Impacts of Adjusting the Age-Class Structure in Korean Forests: Application of Constraint on the Period-to-Period Variation in Timber Production for Long-Term Forest Management

South Korea’s successful reforestation efforts over the past 50 years have led to abundant forest resources. However, intensive reforestation during the 1970s and 1980s skewed the forests’ age distribution towards forest stands aged 30 years or older, which results in an unbalanced distribution of age-class, requiring redistribution with harvest and effective regeneration plans to produce a sustained yield of timber as well as long term ecological benefits. During this conversion process, variations in timber production can occur, causing economic and ecological risks if excessive. To prevent these likely risks, permissible levels of increase and decrease in timber production can be restricted in the planning phase. In determining the appropriate variation rate in timber production, it is necessary to understand the impacts of variation in timber production on forest management. This study performed a sensitivity analysis to evaluate the economic and ecological impacts of constraining the period-to-period variation in timber production. A multi-objective linear programming (MOLP) forest management planning model was utilized to study forests in Mt. Gari, South Korea. Nine management alternatives were set with different levels of variation rate in timber production and further constraints. The total volume and net present value (NPV) of timber production, carbon storage, and water storage were analyzed for each alternative. As timber production variation rates decreased, the amount of timber production increased and forest carbon storage decreased; furthermore, NPV diminished as variation constraints strengthened. These differences were mainly caused by selection of regeneration species according to the constraint on variation in timber production. If the variation rate was strictly restricted, the area of timber species with short rotation age increased during conversion period, in order to reduce the gap of timber production between periods. At the latter part of planning horizon, the area of broad-leaved trees was enlarged as the burden of adjusting age-class structure reduced. The appropriate variation rate in timber production was determined to be 30%, based on considerations regarding the economic and ecological impact of the variation on the forest

Economic and Ecological Impacts of Adjusting the Age-Class Structure in Korean Forests: Application of Constraint on the Period-to-Period Variation in Timber Production for Long-Term Forest Management

South Korea's successful reforestation efforts over the past 50 years have led to abundant forest resources. However, intensive reforestation during the 1970s and 1980s skewed the forests' age distribution towards forest stands aged 30 years or older, which results in an unbalanced distribution of age-class, requiring redistribution with harvest and effective regeneration plans to produce a sustained yield of timber as well as long term ecological benefits. During this conversion process, variations in timber production can occur, causing economic and ecological risks if excessive. To prevent these likely risks, permissible levels of increase and decrease in timber production can be restricted in the planning phase. In determining the appropriate variation rate in timber production, it is necessary to understand the impacts of variation in timber production on forest management. This study performed a sensitivity analysis to evaluate the economic and ecological impacts of constraining the period-to-period variation in timber production. A multi-objective linear programming (MOLP) forest management planning model was utilized to study forests in Mt. Gari, South Korea. Nine management alternatives were set with different levels of variation rate in timber production and further constraints. The total volume and net present value (NPV) of timber production, carbon storage, and water storage were analyzed for each alternative. As timber production variation rates decreased, the amount of timber production increased and forest carbon storage decreased; furthermore, NPV diminished as variation constraints strengthened. These differences were mainly caused by selection of regeneration species according to the constraint on variation in timber production. If the variation rate was strictly restricted, the area of timber species with short rotation age increased during conversion period, in order to reduce the gap of timber production between periods. At the latter part of planning horizon, the area of broad-leaved trees was enlarged as the burden of adjusting age-class structure reduced. The appropriate variation rate in timber production was determined to be 30%, based on considerations regarding the economic and ecological impact of the variation on the forest.Y

Indentation-induced cracking behavior of a Cu(In,Ga)Se2 films on Mo substrate

Cu(In,Ga)Se2 (CIGS) light absorption films were synthesized by co-sputtering method on Mo/soda-lime glass, and the mechanical behavior of the films was investigated by nanoindentation. The Young's modulus and hardness of the films were approximately 88.5 ± 2.2 and 5.89 ± 0.23 GPa, respectively. The comparison graph of indentation load–displacement curve with the curve based on the theoretical elastic films, while considering the curvature of the indenter tip, revealed that cracks initiated in the CIGS films at approximately 25 mN indentation load. The transmission electron microscopy (TEM) analysis revealed that most of the cracks exhibited intergranular fracture, and the fracture toughness of the films was ~0.22 MPa√m, which is greater than the brittleness of soda-lime glass. Both Palmqvist radial and lateral cracks are observed. Results also reveal that the indentation pressure caused grain subdivision (before cracking initiated), and indentation stress may be absorbed by relatively less dense microstructures of the films

The proper timing of virtual reality experience for reducing preoperative anxiety of pediatric patients: A randomized clinical trial

Background: The virtual reality (VR) experience of an operation room (OR) prior to anesthesia and surgery has been known to reduce the anxiety and distress of pediatric patients. However, the proper timing needed for this is unknown. This randomized clinical study aimed to evaluate the proper timing of a VR tour of an OR (a few days before vs. immediately before anesthesia) to reduce the anxiety in a pediatric patient undergoing elective surgery. Methods: The children from the ages of 4-10 years old were randomly divided into three groups. The control group received standard verbal information about the process of anesthesia and surgery 10 min before anesthesia. The VR A group experienced a VR tour at the outpatient clinic a few days before anesthesia, whereas the VR B group experienced the tour 10 min before anesthesia at the reception area of the OR. The 4-min VR video used in this study showed the experience of Pororo, an animation character, entering the OR and undergoing anesthesia. We evaluated the anxiety of children using the modified Yale preoperative anxiety scale (m-YPAS), the anxiety of caregivers using Beck anxiety inventory (BAI), and caregivers' satisfaction. Results: The m-YPAS of the VR B group was significantly lower than that of the control and VR A groups (p = 0.001), whereas there was no statistically significant difference in BAI (p = 0.605) among the 3 groups. The score of caregivers' satisfaction with the overall process of anesthesia and surgery was higher in VR A group than in the control and VR B groups (p = 0.054). Conclusion: The VR experience of an OR immediately before anesthesia was more effective than standard verbal information or a VR tour at the outpatient clinic a few days before anesthesia in reducing the anxiety and distress of children prior to surgery.N

Cathode Electrolyte Interphase-Forming Additive for Improving Cycling Performance and Thermal Stability of Ni-Rich LiNi_<i>x</i>Co_<i>y</i>Mn_{1–<i>x</i>–<i>y</i>}O₂ Cathode Materials

High-capacity Ni-rich LiNixCoyMn1–x–yO2 (NCM) has been investigated as a promising cathode active material for improving the energy density of lithium-ion batteries (LIBs); however, its practical application is limited by its structural instability and low thermal stability. In this study, we synthesized tetrakis(methacryloyloxyethyl)pyrophosphate (TMAEPPi) as a cathode electrolyte interphase (CEI) additive to enhance the cycling characteristics and thermal stability of the LiNi0.8Co0.1Mn0.1O2 (NCM811) material. TMAEPPi was oxidized to form a uniform Li+-ion-conductive CEI on the cathode surface during initial cycles. A lithium-ion cell (graphite/NCM811) employing a liquid electrolyte containing 0.5 wt % TMAEPPi exhibited superior capacity retention (82.2% after 300 cycles at a 1.0 C rate) and enhanced high-rate performance compared with the cell using a baseline liquid electrolyte. The TMAEPPi-derived CEI layer on NCM811 suppressed electrolyte decomposition and reduced the microcracking of the NCM811 particles. Our results reveal that TMAEPPi is a promising additive for forming stable CEIs and thereby improving the cycling performance and thermal stability of LIBs employing high-capacity NCM cathode materials

Gender differences in Korean adolescents who died by suicide based on teacher reports

Abstract Background We investigated the characteristics of adolescents who committed suicide in South Korea, and how these characteristics differed by gender. Method Data from middle and high school students who committed suicide between 2014 and 2016 were analyzed. We evaluated differences in suicide method and place, personal characteristics, and school life characteristics by gender using the Chi square test and t test. Results Jumping from a high place was the most common suicide method for both male and female students. A significantly greater proportion of female adolescents had experienced depressive symptoms, previous self-injury, previous suicide attempts, and had problems with school attendance and peers. Additionally, they were more likely to be classified as high risk according to a school-based mental health screening test and to utilize professional mental health treatment services. Conclusion Our results demonstrate that adolescents who committed suicide exhibited gender differences in personal characteristics and school life. These characteristics might aid in the development of adolescent suicide policies and intervention programs

Conversion of high-spin iron(III)-alkylperoxo to iron(IV)-oxo species via O-O bond homolysis in nonheme iron models

International audienceThe mechanism of the alkylperoxo O-O bond cleavage of low-spin iron(III)-alkylperoxo species has been well established in nonheme iron models. In contrast, the alkylperoxo O-O bond cleavage in nonheme high-spin iron(III)-alkylperoxo species binding an axial ligand has yet to be elucidated. Herein, we report the synthesis and characterization of mononuclear nonheme high-spin iron(III)-alkylperoxo complexes each bearing an N-tetramethylated 13-membered macrocyclic ligand (13-TMC), [FeIII(OOC(CH3)3)-(13-TMC)]2+ and [FeIII(OOC(CH3)2C6H5)(13-TMC)]2+. The high-spin iron(III)-alkylperoxo complexes were converted to an iron(IV)-oxo complex at a fast rate upon addition of thiocyanate (NCS ) via the formation of a short-lived intermediate. This intermediate was identified as a high-spin iron(III)-alkylperoxo complex binding a thiocyanate ion as an axial ligand by characterizing it with various spectroscopic methods and density functional theory (DFT) calculations. We have also provided strong evidence that conversion of the high-spin iron(III)-alkylperoxo complex to its corresponding iron(IV)-oxo complex occurs via O-O bond homolysis. Thus, we have concluded that the role of the axial ligand binding to a high-spin iron(III)-alkylperoxo complex is to facilitate the alkylperoxo O-O bond cleavage via the "push effect", which has been well established in heme enzymes. To the best of our knowledge, the present study reports the first clear example showing the O-O bond homolysis of a high-spin iron(III)-alkylperoxo complex and the axial ligand effect on the alkylperoxo O-O bond cleavage in nonheme iron models