Miracle-dz/UniFAR-FTUs huggingface dataset:
Toxicological profile for ethylbenzene

DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. A Toxicological Profile for Ethylbenzene, Draft for Public Comment was released in October 2007. This edition supersedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary. For information regarding the update status of previously released profiles, contact ATSDR at: FOREWORD This toxicological profile is prepared in accordance with guidelines* developed by the Agency for Toxic Substances and Disease Registry (ATSDR) and the Environmental Protection Agency (EPA). The original guidelines were published in the Federal Register on April 17, 1987. Each profile will be revised and republished as necessary. The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects infonnation for these toxic substances described therein. Each peer-reviewed profile identifies and reviews the key literature that describes a substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies. The profile is not intended to be an exhaustive document; however, more comprehensive sources of specialty information are referenced. The focus of the profiles is on health and toxicologic infonnation; therefore, each toxicological profile begins with a public health statement that describes, in nontechnical language, a substance's relevant toxicological properties. Following the public health statement is infonnation concerning levels of significant human exposure and, where known, significant health effects. The adequacy of infonnation to detennine a substance's health effects is described in a health effects summary. Data needs that are of significance to protection of public health are identified by ATSDR. Each profile includes the following: (A) The examination, summary, and interpretation of available toxicologic infonnation and epidemiologic evaluations on a toxic substance to ascertain the levels of significant human exposure for the substance and the associated acute, subacute, and chronic health effects; (B) A determination of whether adequate infonnation on the health effects of each substance is available or in the process of development to detennine levels of exposure that present a significant risk to human health of acute, subacute, and chronic health effects; and (C) Where appropriate, identification of toxicologic testing needed to identifY the types or levels of exposure that may present significant risk of adverse health effects in humans. The principal audiences for the toxicological profiles are health professionals at the Federal, State, and local levels; …
A study of Moroccan pupils' difficulties at second Baccalaureat year in solving chemistry problems relating to the reactivity of ethanoate ions and to copper–aluminium cells

This paper investigates the difficulties that Moroccan pupils (18–19) of the second Baccalaureat year encountered in solving chemical equilibrium problems relating to ethanoate ions' reactivity with water and methanoic acid, and to copper–aluminum cells. The pupils were asked to provide answers to questions derived from two problems. The questions were classified into different tasks according to whether their answers required declarative and (or) procedural knowledge. The written responses evaluated and counted as the percentage of successful, failed and unprocessed tasks revealed that pupils completed with success tasks on the reactivity of ethanoate ions with water more easily than those of two other studied cases. The pupils encountered difficulties in appropriating procedural knowledge on equilibriums involved in ethanoate ions' reactivity with methanoic acid and in copper–aluminum cells. The impact of the tasks' organization on knowledge development seems to be not verified as it was shown in the hierarchy prevalence of problems from simple to complex ones.
Use of Wyckoff position splittings in the supercell model of crystals with point defects

The atomic sublattices occupying different Wyckoff positions in a host crystal are shown to be subdivided in the supercell model owing to the splitting of the occupied Wyckoff positions. The site symmetries of the split Wyckoff positions are in general different, which significantly increases the number of possible occupation schemes for impurities and defects in the supercell model. It is demonstrated that the use of the programs and retrieval tools of the Bilbao Crystallographic Server considerably simplifies the group-theoretical analysis of Wyckoff position splittings in the supercell model of a crystal with a point defect. Ab initio calculations of electronic states of single defects in ZnO (Zn and O neutral vacancies) within the supercell model are performed to demonstrate the influence of Wyckoff position splittings on the results.
Minimum Ultraviolet Light Dose Determination and Characterization of Stress Responses that Affect Dose for Listeria monocytogenes Suspended in Distilled Water, Fresh Brine, and Spent Brine

Foodborne illnesses caused by Listeria monocytogenes have long been associated with ready-toeat (RTE) meats contaminated after the primary thermal process has been applied. It is believed that brine solutions used to chill cooked RTE products may serve as a reservoir for L. monocytogenes becoming a potential point of post-processing contamination for RTE meats. Recirculating ultraviolet light (UV) systems are being used to inactivate L. monocytogenes in chill brines; however very little has been reported on the dose response of healthy and stressed L. monocytogenes to UV in brine solutions. The objectives of this research were to determine 1) minimum dose of UV required to inactivate L. monocytogenes in distilled water, fresh brine, undiluted spent brine, and diluted spent brine, 2) if adaptation to food processing stresses affects the dose response, and 3) if the acquisition of antibiotic resistance mechanisms provides resistance to ultraviolet light 4) effect of stress adaptation on survival in brine solutions. After UV exposure, populations were reduced as follows from greatest to least: water > fresh brine > 5% spent brine > 35% spent brine > 55% spent brine > 100% spent brine (P ≤ 0.05). There were no population differences between acid stressed and antibiotic resistant or healthy and heat shocked (P > 0.05). However, acid-stressed and sulfanilamide-resistant were more resistant to UV light than healthy and heat shocked L. monocytogenes (P ≤ 0.05). Survival in brine solutions (no UV) followed the trend, from greatest to least (P ≤ 0.05): sulfanilamide-resistant > acidstressed > healthy > heat-shocked. Population estimates decreased from initial inoculation to final sampling for each cell type suspended in spent brine (P ≤ 0.05), but only healthy and heatshocked cells suspended in fresh brine were significantly reduced (P ≤ 0.05). Knowledge of UV dosing required to control L. monocytogenes in brines used during RTE meat processing, and a greater understanding of the interactions that may influence dose will aid manufacturers in establishing appropriate food safety interventions for these products.
Color Change and Consumer Preferences towards Color of Heat-Treated Korean White Pine and Royal Paulownia Woods

Heat treatment of wood is an attractive alternative environmentally-friendly treatment to add value of less valuable woods by improving color, dimensional stability, and natural durability. To improve the color properties of Korean white pine (Pinus koraiensis) and royal paulownia (Pauwlonia tomentosa), we treated the woods at 160°C, 180°C, 200°C, and 220°C for 2 hours. Color change after heat treatment was evaluated using the CIE-Lab color system and survey was conducted to determine the consumer preferences towards color of heat-treated wood. Lightness (L*) decreased with increasing temperature and the higher degree of change was obtained in royal paulownia. The red/green chromaticity (a*) in both wood decreased after heat treatment at 160°C, and constantly increased after heat treatment at 180°C to 220°C. Yellow/blue chromaticity (b*) in Korean white pine tended to increase after heat treatment at 160°C, then decreased gradually afterwards. In royal paulownia, b* values linearly increased with increasing temperature. Overall color change (ΔE*) increased with increasing temperature with higher degree obtained in royal paulownia. Samples with the clamps in both wood species showed lower degree of the change in L*, a*, b and ΔE*. The results of the consumer preferences test showed that the darker colors of heat-treated woods were more preferred by consumers compared to the lighter colors of untreated woods. Consequently, heat treatment could enhance the color properties of Korean white pine and royal paulownia woods for value added products.
Reversible Photochemical Transformation of S and H2 Mixture to (H2S)2H2 at High Pressures

We report the reversible photochemical transformation of sulfur–hydrogen mixture to (H2S)2H2, which occurs through an expanded state of photoactive a-S phase of sulfur at 4 GPa. Upon further compression, the photoproduct (H2S)2H2 undergoes a phase transition at 17 GPa, and 40 GPa. The pressure-induced Raman changes indicate that the phase transition from phase I to II at 17 GPa is associated with the proton-ordering process in (H2S)2H2, evident by the profound splitting of S–H and H–H vibrational modes, whereas the transition at 40 GPa is accompanied by the disappearance of all the S–H stretching and bending modes and partial dissociation to sulfur. With increase in pressure, the molar volume of (H2S)2H2 is substantially larger than that of S + H2 mixtures, suggesting the significance of photochemical effect in order to drive the reaction from S + H2 to (H2S)2H2. In addition, we have also provided the thermal- and pressure-induced effect in the mixtures using confocal Raman spectroscopy. From our results,.
EFEITOS DA ADUBAÇÃO NITROGENADA NO SORGO SACARINO BRS511

Dentre as diversas materias-primas renovaveis disponiveis para producao de etanol destaca-se o sorgo sacarino, que se assemelha a cana de acucar, sua producao promove duas fontes de renda: o etanol e o uso bagaco para a geracao de energia. O sorgo sacarino pode ser colhido durante a entressafra da cana de acucar, beneficiando a industria sucroenergetica, que nao ficaria sem materia prima para a producao de etanol nesse periodo. O objetivo do trabalho foi analisar o efeito da adubacao nitrogenada na producao de sorgo sacarino BRS511. O delineamento experimental foi inteiramente casualizado com 4 repeticoes. Foram utilizadas cinco doses de Nitrogenio em cobertura (0, 50, 100, 150, 200 kg ha-1). As seguintes caracteristicas foram analisadas: altura das plantas; numero de folhas, diâmetro dos colmos, comprimento dos colmos, comprimento das paniculas. As variaveis de crescimento do sorgo sacarino BRS 511 nao apresentaram efeitos significativos para os parâmetros avaliados (altura das plantas, comprimento do colmo, comprimento da panicula, numero de folhas, diâmetro do colmo e massa fresca total), para as condicoes de Jaboticabal. A adubacao utilizando-se a dose de 100 kg de N ha-1, obtiveram a maior quantidade de massa fresca, que corresponde a 71.021 kg ha-1
Valuable metals recovery by molten salts electrolysis.

As the currently available methods for recycling of valuable metals from batteries and old electronics (commonly called eWaste) are in need of improvement, this project focuses on the development of a novel valuable metals recovery method by electrolysis in molten salts. The process proposed consists of three steps: metal oxides dissolution in borate salts, liquid-liquid interface ion transfer between the borate and chloride layer, and electrodeposition from the chloride phase. Inherent borate salts stability and its affinity to metals, coupled with the chloride salts large electrochemical window enables a stable and efficient (semi)-continuous process concept to be explored. Two electrolytic cell concepts akin to an industrial set-up were designed. The first composed of three interconnected chambers each for one of the three steps of the process, or a simpler, single-vessel solution relying on the immiscibility of the molten phases. For the needs of a laboratory scale testing the smaller, one vessel solution has been assembled. The proposed recycling method is a novel solution for the recovery of valuable metals considered and evaluated in this work; Co, Cu, Ni, and Mn, present in most Li-ion and Ni-MH batteries, but also other metals suitable for electrodeposition present in the eWaste or other metal-rich waste streams. The process proposed was designed, evaluated and resulted in a successful recovery of all of the metals considered. Novel and promising experimental data on the metal oxides dissolution in molten borate salts is reported. Boron oxide salts were assessed, with the sodium borate achieving significant metals concentrations ranging from 4-20 wt%. Metals distribution between the oxide and halide layers was evaluated, and was found to be biased towards the borate layer due to its structure resulting in high metal affinity, with the metal ions concentration in the chloride layer around 1 wt% for the evaluated salts combination. This enables the sodium borate phase to work as a buffer, feeding the dissolved metal required for the electrodeposition into the chloride layer sustaining the process. Liquid-liquid interface transfer and diffusion phenomena in the melt as well as the metal electrodeposition parameters were studied using a range of (electro)-analytical methods, validating the main steps of the proposed metal recovery process. The system was evaluated in a three-electrode set-up (WE: tungsten, CE; graphite, QRE: tungsten) and the formal redox reaction potentials were reported for the following feedstock: Co2O3 [-0.733/-1.848 V], CuO [-1.297/-2.375 V], Mn2O3 [-1.552 V] and NiO [-1.734 V] versus chlorine evolution. The recovered metals were analysed and found to form high purity (~99 %) dendritic deposits (SA/V of 950 cm-1), which also supports the assumption of a diffusion controlled process. This marks the successful outcome of this proof-of-concept process, providing a feasible, alternative valuable metals recovery method design.
Authentication of three related herbal species (Curcuma ) by DNA barcoding

The psbA-trnH intergenic region was studied for authenticating Curcuma longa and its two related species (Curcuma sichuanensis and Curcuma chuanhuangjiang). The sequences were analyzed by means of Neighbor-Joining to improve the phylogenetic resolution of these three Curcuma species. The genetic diversity of these three species is 0.009 to 0.014 (< 0.05). The results show that partial population specimens of C. sichuanensis originate from the cultivated mutation of C. longa; and retain the C. chuanhuangjiang as an individual species. The differentiation is engendered between the wildness and cultivated specimens within C. longa species. Key words: Curcuma, Radix Curcumae, related species, DNA barcoding, psbA-trnH, phylogeny.
The Microwave-assisted Synthesis of Polyethersulfone (PES) as A Matrix in Immobilization of Candida antarctica Lipase B (Cal-B)

Candida antarctica lipase B (Cal-B) has been widely used in the hydrolysis reaction. However, it has some weaknesses, such as: forming of the heavy emulsion during the process, which is difficult to resolve and has no reusability. Therefore, it needs to be immobilized into a suitable matrix. One of the suitable supporting materials is polyethersulfone (PES) and its synthesis becames the objective of this paper. The PES was synthesized via a polycondensation reaction between hydroquinone and 4,4'-dichlorodiphenylsulfonein N-methylpyrrolidone (NMP) as solvent using Microwave Assisted Organic Synthesis (MAOS) method at170 °C for 66 minutes using an irradiation power of 300 watt. The synthesized PES was characterized by FTIR and 1 H-NMR (500 MHz, DMSO-d6). Then the PES membrane was prepared from 20 % of the optimized mixtures of PES, PSf (polysulfone), and PEG (polyethylene glycol) dissolved in 80 % NMP. The Cal-B was immobilized on the PES membrane by mixing it in a shaker at 30 °C and 100 rpm for 24 h using phosphate buffered saline (PBS). The identification of the immobilized Cal-B was done by using FTIR-ATR spectroscopy and SEM micrographs. The results of Lowry assay showed that the ‘Cal-B immobilized’ blended-membrane has a loading capacity of 91 mg/cm 2 in a membrane surface area of 17.34 cm 2 . In this work, the activity of immobilized Cal-B was twice higher than the native enzyme in p-NP (p-Nitrophenolpalmitate) hydrolyzing. The results indicated that the synthesized PES showed a good performance when used as a matrix in the immobilization of Cal-B. Copyright © 2017 BCREC Group. All rights reserved Received: 15 th November 2016; Revised: 27 th May 2017; Accepted: 24 th May 2017 ; Available online: 23 rd October 2017; Published regularly : December 2017 How to Cite : Widhyahrini, K. , Handayani, N. , Wahyuningrum, D. , Nurbaiti, S. , Radiman, C.L. (2017). The Microwave-assisted Synthesis of Polyethersulfone (PES) as A Matrix in Immobilization of Candida antarctica Lipase B (Cal-B). Bulletin of Chemical Reaction Engineering & Catalysis , 12(3): 343-350 (doi:10.9767/bcrec.12.3.774.343-350)
Electrical properties of n- and p-type 4H-SiC formed by ion implantation into high-purity semi-insulating substrates

Phosphorus or aluminum ions were directly implanted into semi-insulating 4H-SiC substrates with no epitaxial layers to form n- or p-type layers, respectively, with doping densities in the range from 1017 to 1019 cm−3. The electrical properties of these implanted layers annealed at 1650 °C were characterized by Hall effect measurements in the temperature range of 160–900 K. The electrical activation ratios of implanted dopants were 88–98%. The density of compensating defects was higher in Al+-implanted layers than in P+-implanted ones. The mobilities of the implanted layers were mostly comparable to those of epitaxial layers in the doping range investigated.
Intake assessment of the food additives nitrite (E 249 and E 250) and nitrate (E 251 and E 252)

Nitrate and nitrite are authorised as preservatives in certain food products, such as salami, ham (nitrite) and cheese (nitrate). They prevent food spoilage and protect the consumer against food-borne pathogens. Next to that, nitrate and nitrite play a role in food colour retention and contribute to flavour formation of the food. RIVM estimated that the nitrate intake of the population aged 2 to 79 years does not exceed the acceptable daily intake (ADI). The intake of nitrite, however, exceeded the ADI. Because of the conservative assumptions, the real intake will probably much lower. Refinement is needed to obtain a more realistic intake assessment. RIVM calculated the intake of nitrite and nitrate using the maximum permitted levels as laid down in the European Regulation on food additives. These levels are mostly expressed as maximum ingoing amounts. The actual concentration in food as consumed differs from the ingoing amounts because of chemical processes during processing and storage of foods. The nitrite concentration decreases, but derivatives, such as nitrosamines, may be generated. Analytical values of nitrite in meat products are desired to refine the intake assessment of nitrite. Some other European countries used analytical values of nitrite for their intake assessments. These studies showed lower nitrite intake estimates that remained below the ADI. Chronic intake of high levels of nitrate, nitrite or their derivatives (such as nitrosamines) may have negative effects on health. Nitrate may hamper growth of young children and nitrite may have a negative effect on heart and lung functioning. Some nitrosamines (but not all) may induce cancer. RIVM did not perform an intake assessment of nitrosamines, because recent analytical data of these substances in food were not available. Analytical values of nitrosamines in food products are also desired to assess whether problems could be expected by current food additive use of nitrate and nitrite. The study was performed on the initiative of the Dutch Ministry of Health, Welfare and Sport (VWS). The research described in this report is part of the programme on the development of an efficient system for monitoring intake of food additives (conform article 27 of EU Regulation 1333/2008).
Impact of Class-Wide Peer-Tutoring Strategy on Secondary School Slow Learners’ Performance in Redox Reactions in Funtua, Katsina StateNigeria

The performance of senior secondary school students in chemistry has been very poor over the years in Nigeria. Teachers’ use of inappropriate instructional strategies and students varied abilities has been identified responsible for this problem. This study examined the impact of Class-Wide Peer-Tutoring Strategy on secondary school slow learners’ performance in redox reactions in Funtua Education Zone, Katsina State, Nigeria. Quasi– experimental design was adopted for the study. The study involved a population of 977 SS2 Students. A of sample of 108 slow learners drawn from two secondary schools were used. Three research hypotheses guided the study. Treatment involved teaching experimental group by trained peer tutors using CWPT while the control group was taught by the teacher using lecture method. Redox Performance Test (REPT) duly validated by experts with a reliability coefficient of 0.85 obtained using test retest method was used for data collection. Hypotheses were tested using t-test at 0.05 levels of significance. Results revealed that slow learners taught by peer tutors using CWPT performed significantly better than those taught by the teachers using lecture method. The study recommended that chemistry teachers should be train through workshops, seminars and conferences on the use of class-wide peer-tutoring strategy in teaching and learning of chemistry.
Calculation of self-diffusion coefficients of the [BMIM][TFSA]/water system by molecular dynamics simulation

Abstract We performed a molecular dynamics simulation to calculate the self-diffusion coefficients of 1-Butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and water in a water–ionic liquid mixture. We then compared the simulated self-diffusion coefficients of cation, anion and water molecules with experimental data and with simulated data from the literature. Although the simulation overestimated the self-diffusion coefficients of ions, the simulated results qualitatively reproduced the enhancement of the self-diffusion coefficients of water as the water molar fraction increased. We also calculated the radial distribution functions to investigate the solution structure, i.e. the clustering of water molecules. The clustering of water in ionic liquid was found to play an important role in the enhancement of the diffusion of water molecules in the ionic liquid.