Sorption,solubility, and mass changes of hydroxyapatite‐containing composites in artificial saliva,food simulating solutions,tea, and coffee

The purpose of this study was to evaluate the influence of preparation/storage conditions on the sorption, solubility, and mass changes of new proposed hydroxyapatite‐containing resin‐based composites. Seventy cylindrical samples of composite were prepared according to the ISO 4049 and stored in different storage solutions (distilled water, artificial saliva, 10% ethanol, 3% acetic acid, heptane, tea, and coffee) for 7, 14, and 28 days at 37°C. Principal component analysis and analysis of the variance were used to determine the impact of the preparation and storage conditions (e.g., curing time, storage time, and type of storage solution) on the changes of stability of examined material. Sorption, solubility, and mass changes of examined samples were specified. The tendency of these changes depending on the curing time, storage time, and type of storage solutions were presented. Due to the observed behavior, three groups of storage solutions were distinguished: “aqueous,” acidic, and hydrophobic (“fat”) solutions. Investigated properties changed in different way, characteristic for each of the above groups. No general tendency of the influence of storage and curing time was observed. The type of storage solution has the greatest impact on the sorption, solubility, and mass changes of examined material. The influence of the curing and storage time may be neglected. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39856.     

Fertilizer caking: Mechanisms,influential factors,and methods of prevention

Most fertilizers have some tendency to form lumps or agglomerates (caking) during storage. The mechanism of caking in fertilizers is most often attributed to the formation of salt bridges and/or capillary adhesion. The severity of caking can be influenced by a number of factors, such as chemical composition, moisture content, particle structure, mechanical strength, hygroscopic properties, product temperature, ambient conditions, storage time, and storage pressure. The various methods of reducing or eliminating caking in fertilizers basically involve process control, storage/packaging conditions, and/or addition of anticaking agents.Caking mechanisms, factors that influence caking, and methods of prevention are discussed in this paper. Particular attention is given to the various types of anticaking agents and their modes of action. The paper also provides a fairly comprehensive list of commercially available anticaking agents and their producers.     

Assessment of resin adhesives aging by means of rheological parameters,Inverse Gas Chromatography,and FTIR

In this study, the rheological parameters as well as Flory–Huggins parameter determined by Inverse Gas Chromatography (IGC) were applied for assessment of the changes occurring during storage of the resole resin and their composites. It was proved that storage of resole and its composites at the low temperature (about 10°C) can slow significantly the process of their aging. Main idea of research was to determine time dependence of rheological properties for resole resin. These data should enable to extend shelf life of resin containing products. The rheological properties of samples were studied by the determination of flow curve. Share rate was changed from 10 to 500 1/s. Samples were examined in following intervals (increasing storage time): immediately after preparing the sample and then after storage, respectively: after two, four, eight, and twelve weeks. To extend shelf life of resin, it was mixed with different additives: zeolite Micro 20, Mg(OH)₂, PAF, synthetic zeolites: sodium form Z1, hydrogen form Z2. Flory–Huggins parameter determined by use of IGC let to assess physicochemical changes occurring in resole and its composites during storage. IGC turned out to be more sensitive method for assessment of changes occurring during resin aging than rheological measurements. FTIR technique was used to assess chemical changes occurring during resoles compositions storage. It indicated that oxidation reaction can occur during resoles composite aging.     

Volatiles from microwave-treated,stored soybeans

Soybeans were microwaved to inactivate enzymes and prevent oil deterioration during storage. Microwave time was varied from 4 to 10 min, in 2-min increments, and the treated and control soybeans were stored for 8 weeks at 40°C. Damage was monitored by analysis of peroxide value and free fatty acid content of the extracted oil and by volatile analysis of the full-fat meal and extracted oil. Volatiles were measured by multiple headspace extraction, and the formation of hexanal was monitored in both oil and meal. During storage of the control beans, peroxide value increased from 0.41 to 1.20 meq/kg, hexanal concentration changed from 29 to 94 ppb and free fatty acid content increased from 0.4 to 1.7%. Oils extracted from soybeans that were microwaved for 4 or 6 min had peroxide values of about 1 meq/kg and hexanal concentrations of 39–44 ppb after storage, indicating partial inactivation of lipoxygenase enzymes. However, soybeans that were microwaved for 8 min or more tended to oxidize during storage to a greater extent than the control soybeans, showing higher peroxide values and greater formation of hexanal in the samples. This suggests that soybeans microwave-treated in excess of 8 min are heat-damaged and susceptible to deterioration during storage. Free fatty acid content of the oils from all of the microwave-treated soybeans was about 0.4% initially, and did not increase with storage, indicating inactivation of hydrolytic enzymes. The mention of firm names or trade products does not imply that they are endorsed or recommended over other firms or similar products not mentioned.     

Vinyl ester resin: Rheological behaviors,curing kinetics,thermomechanical, and tensile properties

The effects of isothermal temperature on the curing extent, gel time, dynamic rheological behaviors, and mechanical properties of vinyl ester resins (VERs) were systematically studied. Although, the curing extent was observed increase with increasing the operating temperature, the study of residual heat of cured VERs indicated that the final curing extent depended on the postcuring process. The values of shear storage and loss modulii at gel point were observed to decrease with increasing both the isothermal temperature and heating rate, which were associated with the formation of microgels during the gelation process. With increasing isothermal temperature and heating rate, the microgel did not have enough time to grow well, causing a reduced shear storage and loss modulii at the gel time. The storage and loss modulii of the cured VERs were also studied and shown that with temperature increased to the glass transition, both modulii were first decreased and then increased. © 2013 American Institute of Chemical Engineers AIChE J, 60: 266–274, 2014     

Hydrophobic recovery of repeatedly plasma-treated silicone rubber. Part 2. A comparison of the hydrophobic recovery in air,water, or liquid nitrogen

Surfaces of medical grade silicone rubber (Q7-4750, Dow Corning) were modified by repeated (six times) RF plasma treatments using various discharge gases: oxygen, argon, carbon dioxide, and ammonia. The treated samples were stored for a period of 3 months in ambient air, water, or liquid nitrogen. Subsequently, the temporal behavior of the effects of the plasma treatment on the physicochemical surface properties of the silicone rubber was investigated using water contact angle measurements and X-ray photoelectron spectroscopy (XPS). Hydrophobic recovery during 3 months storage in ambient air was considerable and nearly complete for all four plasmas used. Hydrophobic recovery was almost completely suppressed during storage in liquid nitrogen, and only a minor increase of around 10° in advancing water contact angle was observed for all four plasma treatments. Also during storage of treated samples in water, hydrophobic recovery was minimal and initiated again by returning the treated samples to ambient air. XPS analyses showed that argon, carbon dioxide, and ammonia plasma-treated silicone rubber all had increased carbon percentages at the expense of oxygen and silicon after storage in water, or in liquid nitrogen, compared with after storage in ambient air. Interestingly, the carbon content of oxygen plasma-treated silicone rubber decreased during storage in water, or in liquid nitrogen, compared with storage in ambient air, while its oxygen and silicon percentages increased.     

Changes in the tocopherol content of almond,pecan and macadamia kernels during storage

The individual tocopherols present in almond, pecan and macadamia nuts were determined by HPLC. Changes in tocopherol content during 16-months' storage at 30°C and 55% relative humidity were related to keeping quality. The large amount of total tocopherols, mainly α-tocopherol, in almonds accounted for their good storage ability. Pecan nuts with less total tocopherols and mainly γ-tocopherol became rancid after 4 months' storage and macadamia nuts, with practically no tocopherols, were rancid after 2 months' storage. Total tocopherol content decreased in all nuts during storage, possibly as a result of its inhibitory function during auto-oxidation.     

Dynamic viscoelastic properties of CaCO3 filled,closed cell microcellular copoly (ethylene/octene) vulcanisates Effect of blowing agent,temperature, and strain

Abstract

Dynamic mechanical analysis of precipitate CaCO₃ filled, closed cell microcellular ethylene–octene copolymer vulcanisates has been studied as a function of temperature and double strain amplitude. Experiments were carried out over the temperature range – 100 to 100°C. Strain dependent isothermal dynamic mechanical analysis was performed for double strain amplitude 0·09–5%. The log of storage modulus bears a simple relationship with the log of density for both solid and closed cell microcellular rubber. The slope of the line is found to be temperature dependent. The relative storage modulus decreases with decreasing relative density. The eect of blowing agent and filler loading on storage modulus and loss tangent were also studied. Cole–Cole plots of microcellular vulcanisates show a circular arc relationship with density. Plots of loss tangent against storage modulus were found to exhibit a linear relationship. Hysteresis and strain work also bear a linear relationship.     

Shaped Refractory Products-Packing, Marking, Transportation and Storage

1 Scope
This standard specifies the technical requirement of the packing, marking, transportation and storage of shaped refractory products.     

Physicochemical,Textural and Viscoelastic Properties of Palm Diacylglycerol Bakery Margarine During Storage

Physicochemical, textural and viscoelastic properties of palm diacylglycerol (PDG) bakery margarines (DOS720, DOS721 and DOS711) and commercial margarine (CM) throughout a 3-month storage period were evaluated and compared. All the margarines had significant (P < 0.05) increments in slip melting point (SMP), solid fat content (SFC) and hardness during storage with CM having the highest overall increment followed by margarines DOS711, DOS 721 and DOS720. The smaller increments are mainly due to the ability of PDG to delay polymorphic transformation from β′ to β form. In terms of viscoelastic properties, all margarines had a higher degree of firmness which may probably be due to rearrangement of the fat crystals into a three-dimensional scaffolding network upon storage. In terms of melting behavior, storage has no effects on all margarines with the exception of margarine DOS711. The melting behavior of margarine DOS711 displayed a probability of oil exudation during storage. As for polymorphic transformation, CM had the earliest polymorphic transformation with only β crystals after 8 weeks of storage. PDG bakery margarines managed to retard the transformation to more than 10 weeks of storage for DOS711 and 12 weeks of storage for DOS720 and DOS721.     

Emissions of CH4, N2O, NH3 and odorants from pig slurry during winter and summer storage

Manure storage contributes significantly to greenhouse gas (GHG), NH₃ and odour emissions from intensive livestock production. A pilot-scale facility with eight 6.5-m³ slurry storage units was used to quantify emissions of CH₄, N₂O, NH₃, and odorants from pig slurry during winter and summer storage. Pig slurry was stored with or without a straw crust, and with or without interception of precipitation, i.e., four treatments, in two randomized blocks. Emissions of total reduced S (mainly H₂S) and p-cresol, but not skatole, were reduced by the straw crust. Total GHG emissions were 0.01–0.02 kg CO₂ eq m^?3 day^?1 during a 45-day winter storage, and 1.1–1.3 kg CO₂ eq m^?3 day^?1 during a 58-day summer storage period independent of storage conditions; the GHG balance was dominated by CH₄ emissions. Nitrous oxide emissions occurred only during summer storage where, apparently, emissions were related to the water balance of the surface crust. An N₂O emission factor for slurry storage with a straw crust was estimated at 0.002–0.004. There was no evidence for a reduction of CH₄ emissions with a crust. Current Intergovernmental Panel on Climate Change recommendations for N₂O and CH₄ emission factors are discussed.     

微生物凝固天然橡胶加速贮存期间分子量与Po和PRI的变化研究

对微生物凝固天然橡胶在加速贮存过程中分子量,PO和PRI的变化进行了研究,结果表明:随着贮存时间的增加,微生物凝固天然橡胶的分子量逐渐增大,PO值也随之增大,而PRI值则逐渐减小。PO与分子量成正比关系,PRI与分子量成反比关系。     

Concept,Design and Manufacture of a Prototype Hydrogen Storage Tank Based on Sodium Alanate

In the framework of the EC project STORHY (Hydrogen Storage for Automotive Applications), the prototype of a solid storage tank for hydrogen based on sodium alanate was developed. A storage tank containing 8 kg sodium alanate was designed and manufactured with the objective of fast refueling. To obtain the optimum design of the storage tank a simulation tool was developed and validated by experiments with a laboratory‐scale tubular reactor. Application of the simulation tool to different storage concepts and geometries yielded the final design. The chosen concept is modular, enabling simple scale‐up. This is the basis for the future development of fuel cell vehicle storage tanks containing 5 kg of hydrogen.     

Noble metal (Pd, Ru, Rh, Pt, Au, Ag) doped graphene hybrids for electrocatalysis

Metal decorated graphene materials are highly important for catalysis. In this work, noble metal doped-graphene hybrids were prepared by a simple and scalable method. The thermal reductions of metal doped-graphite oxide precursors were carried out in nitrogen and hydrogen atmospheres and the effects of these atmospheres as well as the metal components on the characteristics and catalytic capabilities of the hybrid materials were studied. The hybrids exfoliated in nitrogen atmosphere contained a higher amount of oxygen-containing groups and lower density of defects on their surfaces than hybrids exfoliated in hydrogen atmosphere. The metals significantly affected the electrochemical behavior and catalysis of compounds that are important in energy production and storage and in electrochemical sensing. Research in the field of energy storage and production, electrochemical sensing and biosensing as well as biomedical devices can take advantage of the properties and catalytic capabilities of the metal doped graphene hybrids.     

Mycoflora,aflatoxins and free fatty acids in California cottonseed during 1967–1968

In central California, neither fungal infections nor aflatoxins are significant problems in cottonseed during the receiving and storage seasons. However, in southern California, the 1967 harvest contained a relatively high percentage of seed which were invaded before harvest by fungi, includingAspergillus flavus. Seed infection and concentrations of aflatoxins in seed increased significantly during the time between harvest and storage in southern California. For a short time during storage, seed infection byA. flavus increased because of the moisture the seed received late in the season; however, aflatoxin concentrations in seed did not increase in storage. The aflatoxin content of the seed removed from storage was a reflection of the relative amount of aflatoxins the seed contained when they were received for storage. In 1967, the conditions that existed in the large, densely packed seed pile did not favor accummulation of aflatoxins in seed, even thoughA. flavus was active.     

高性能碳基储能材料的设计、合成与应用

电化学储能器件的性能很大程度上决定于其电极材料。碳材料具有来源广泛、化学稳定性好、易于调控、环境友好等优点,被广泛应用于各类能量存储系统,但仍存在能量密度低、倍率性能差等问题。本文从碳材料孔结构调控、杂原子掺杂、与金属氧化物复合三个角度,综述了构建高性能碳基储能材料的设计合成策略,介绍了其在锂/钠离子二次电池、超级电容器等领域的研究进展,对几种方法策略的优缺点进行了总结,并对未来的研究方向进行了展望。本文对高性能碳基储能电极材料的设计开发具有积极意义。     

曝气气浮+ASBR+SBR+Fenton+混凝沉淀处理化学储运废水

针对某企业运营的化学储运废水,采用"曝气气浮+ASBR+SBR+Fenton氧化+混凝沉淀"工艺进行废水处理。工程运行结果表明,出水水质能稳定达到广东省水污染物排放限值(DB44/26-2001)第二时段一级排放标准要求,实际运行成本为4.61元/m^3,实现了化学储运废水稳定达标排放。     

Dynamic viscoelastic properties of carbon black loaded closed-cell microcellular ethylene-propylene-diene rubber vulcanizates: Effect of blowing agent,temperature frequency,and strain

Dynamic mechanical analysis of carbon black loaded solid and closed-cell microcellular ethylene-propylene-diene (EPDM) vulcanizates was studied at four frequencies of 3.5, 11, 35, and 110 Hz and temperatures from −100 to 150°C. A plot of the log of the storage modulus bears a linear relationship with the log of density for solid as well as closed-cell microcellular rubber. The slope of the line is found to be temperature-dependent. The relative storage modulus decreases with decrease in the relative density. It was also observed that the storage modulus and tan δ are both frequency- and temperature-dependent. The storage modulus results are superposed to form master curves of the modulus vs. Iog temperature-reduced frequency, using shift factors calculated by the Arrhenius equation. Strain-dependent isothermal dynamic mechanical analysis was carried out for DSA varying from 0.07 to 5%. The effect of blowing agent loading on the storage modulus (E′) and loss tangent (tan δ) were also studied. Cole-Cole plots of microcellular rubber shows a circular arc relationship with the density. Plots of tan δ against E′ were found to exhibit a linear relationship. © 1996 John Wiley & Sons, Inc.     

Multifunctionalization of novolac epoxy resin and its influence on dielectric,thermal properties,viscoelastic, and aging behavior

In this article, novolac epoxy was functionalized using p‐hydroxybenzoic acid as pendent groups, which offered weak acidic environment and were cured with methyl etherified amino resin (HMMM). Its chemical structure was characterized by Fourier transform infrared (FT‐IR), ¹H nuclear magnetic resonance (¹H NMR) and differential scanning calorimeter (DSC). To comprehensively investigate its performance, HMMM was used as a curing agent. The modified epoxy exhibited higher storage modulus, lower thermal expansion coefficient, better moisture resistance, better resistance to degradation and lower dielectric constant. Furthermore, the aging behavior was investigated using dynamic mechanical analysis and scanning electron microscopy, which showed that the activation energy of glass transition increased after aging and cured MDEN was more difficult to age. Moreover, the relation between storage modulus and curing rate was established; the low curing rate of MDEN decreased the growth rate of storage modulus and reduced the internal stress, which was beneficial for processing. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40157.     

Differences in Oxidative Stability,Sensory Properties,and Volatile Compounds of Pepper Aromatized Sunflower Oils Prepared by Different Methods during Accelerated Storage

The study aims to compare the differences in the oxidative stability, sensory properties, and volatile compounds during accelerated storage of pepper aromatized sunflower oil (PASO) samples prepared by maceration method (PASO-M), co-pressing method (PASO-C), and direct addition method (PASO-A), respectively. The results exhibit that their oxidative stability is in the relative order: PASO-A > PASO-C > PASO-M. Meanwhile, the PASO-A sample is the most preferable aromatized sunflower oil by consumers according to sensory analysis. In addition, a total of 83 volatile compounds are identified in the three PASO samples during the storage, and the principal component analysis (PCA) shows that their volatile compounds are quite different at the initial stage of the storage. Still, they are similar among each other from the middle of storage period. As consequence, the aromatized sunflower oil sample prepared by the direct-addition method during the storage possesses better oxidative stability and sensory attributes, and there is not much difference among their volatile compounds, indicating that the aromatized sunflower oil prepared by direct-addition method can be developed as promising aromatized sunflower oil. Practical applications: This study shows that aromatization increases oxidative stability and sensory properties of sunflower oil. By this way some sunflower oils with special sensory properties are obtained: special smell and taste, special color, etc. These peppers aromatized sunflower oils can be used to increase taste and smell in some dishes. For example, they can be used in some salads and some roast meats to give more taste and color.