Detection of beeswax adulterations using concentration guide‐values

The concentrations of 102 chemical compounds (saturated and unsaturated hydrocarbons, palmitates, total and free acids, total hydroxyacids, total and free alcohols, acidic monoesters and monoesterified 1,2,3‐propanetriols) have been determined by GC/FID on white and yellow comb beeswax of Apis mellifera from different regions of Spain. Guide‐value ranges are proposed for its characterization and to discriminate adulterated foundation beeswax sheets. The concentrations of many compounds resulted to be statistically different for white and yellow beeswaxes, while the observation of concentrations out of normal in some marketed foundation beeswax sheets suggested their adulteration. However, the measurement of anomalous concentrations in foundation beeswax sheets did not imply necessarily their rejection by the bees.     

Canadian beeswax: Analytical values and composition of hydrocarbons, free acids and long chain esters

Physical and chemical properties of 80 samples of Canadian yellow unrefined beeswax have been determined. Mean values were: melting point, 64.3 C; acid value, 18.7; ester value, 72.6; ratio number 3.89; saponification cloud point 62.5 C; and hydrocarbon content, 15.3%. There was no significant variation due to geography or climate. Values were very similar to those of U.S. beeswax and were within the specifications of National Formulary XIII, except that 21 samples had ester values in the range 70–72. A more accurate specification for ester value would be 70–77 instead of 72–77. Hydrocarbons, free fatty acids and long chain esters were analyzed by gas liquid chromatography, and the limiting values found make possible improved detection and estimation of adulterants. The upper limits for C₁₆ and C₁₈ acids were 5.8 and 3.3%, respectively, of the total free acids. Issued as NRCC No. 12779.     

Canadian beeswax: Analytical values and composition of hydrocarbons,free acids and long chain esters

Physical and chemical properties of 80 samples of Canadian yellow unrefined beeswax have been determined. Mean values were: melting point, 64.3 C; acid value, 18.7; ester value, 72.6; ratio number 3.89; saponification cloud point 62.5 C; and hydrocarbon content, 15.3%. There was no significant variation due to geography or climate. Values were very similar to those of U.S. beeswax and were within the specifications of National Formulary XIII, except that 21 samples had ester values in the range 70–72. A more accurate specification for ester value would be 70–77 instead of 72–77. Hydrocarbons, free fatty acids and long chain esters were analyzed by gas liquid chromatography, and the limiting values found make possible improved detection and estimation of adulterants. The upper limits for C₁₆ and C₁₈ acids were 5.8 and 3.3%, respectively, of the total free acids.     

Biofuel ethanol adulteration detection using an ultrasonic measurement method

Hydrous ethanol is a worldwide used biofuel. According to Brazilian regulations, the concentration of ethanol in hydrous ethanol can be accepted at a maximum concentration of 93.8% and a minimum of 92.6% by mass. The aim of this study is to identify the possible changes in hydrous ethanol fuel using ultrasonic attenuation and propagation velocity. The experiments were performed in the Laboratory of Ultrasound of the Brazilian National Institute of Metrology (Inmetro). The experiments and uncertainties in the methodology were evaluated according to the Guide to the Expression of Uncertainty in Measurement, JCGM 100:2008. The test samples used in this study were mixtures of ethanol and water with ethanol concentrations varying from 89.84% to 93.71% by mass; and a commercial fuel ethanol bought from a local distributor. The correlation coefficient between ethanol concentrations and ultrasonic propagation velocity was 0.99 (in modulus), and the maximum combined uncertainty was 0.60 m s^?1. Considering attenuation, the correlation coefficient was 0.97, and the maximum combined uncertainty was 0.085 dB cm^?1. However, its signal is not stable resulting an unreliable parameter. Within the tested concentration range, the highest concentration that is statistically different (p < 0.002, α = 5%) from 92.60% is 92.25%, considering propagation velocity as parameter. To validate the methodology, a commercial ethanol fuel was tested using the proposed method as well as the gas chromatography analytical method (gold standard). Result was statistically identical for propagation velocity when compared to the gold standard.     

Physico‐chemical parameters for the characterization of pure beeswax and detection of adulterations

Pure beeswaxes produced in different climatic regions of Spain have been characterized by the determination of nine physico‐chemical parameters: density, acid, saponification, ester, ratio number, iodine, peroxide, melting point and ash content values. The official methods of analysis to determine density and saponification values in fats and oils were not suitable for beeswaxes; alternative methods are proposed in this work for both parameters. After verifying the precision of the methods and the value guidelines, the usefulness of the physico‐chemical parameters to detect adulterations with paraffin, stearic acid, carnauba wax and tallow was tested: adulteration percentages of 5%, or higher, were commonly detected. Marketed foundation beeswax sheets, rejected or badly accepted by the bees, were also analyzed to discuss their quality; 25 out of 27 beeswax sheets show anomalous values for at least one parameter.     

A novel analytical method to detect adulteration of virgin olive oil by other oils

The present study focuses on the olefinic region of the ¹³C nuclear magnetic resonance (¹³C NMR) spectrum of virgin olive oil which shows 12 peaks resonating between 127.5 and 130 ppm. These peaks are assigned to the most abundant unsaturated fatty acid moieties of the olive oil, oleic and linoleic acids, which are present in α and β positions of the glycerol backbone. With the use of an internal reference pyrazine, the 12 peaks were integrated and their areas were expressed in mmol/g of virgin olive oil. The intensities of the 12 observed peaks were affected when an authentic virgin olive oil was mixed with a seed oil. This observation was used to develop a semiquantitative method to detect adulteration of virgin olive oil by other oils based on ¹³C NMR spectroscopy.     

复合电沉积的影响因素

根据国内外电沉积金属基复合镀层的研究结果,综述了微粒特性、镀液组成、工艺条件以及其它因素对复合电沉积的影响。提出今后应继续加强在复合电沉积机理方面的研究,以便更深刻、更准确地理解和掌握复合电沉积的各种影响因素,从而更好地对复合电沉积的工艺研究和应用给予指导。     

影响酶洗涤效果因素的探讨

介绍了加酶洗涤剂的发展以及酶在洗涤剂中的应用。探讨了加酶洗涤剂中表面活性剂及其浓度、洗涤温度和洗涤时间对洗涤效果的影响,pH值对酶活性的影响。对影响酶洗涤效果的各种因素进行了阐述。并论述了酶在洗涤剂中的其他应用。     

Use of unsaponifiable matter for detection of ghee adulteration with other fats

Gas liquid chromatography (GLC) was used for the detection of lard and margarine added to buffalo and cow ghee. The chromatograms of the unsaponifiable matter could be divided into two parts representing hydrocarbons and sterols. Hydrocarbons were fractionated by GLC into 3–6 different compounds depending on the lipid origin. The sterols were cholesterol and β-sitosterol. The content of cholesterol in lipid samples was in the following decreasing order: cow > buffalo > lard > margarine. With β-sitosterol, the concentration order was: margarine > buffalo > cow > lard. The ratios of total hydrocarbons to total sterols in the unsaponifiable matter for margarine and lard were the most different for the various lipids. Adulteration of cow and buffalo ghee with various levels of lard or margarine caused significant changes in the unsaponifiable compounds. It is possible to determine the extent of admixture of lard or margarine to either cow or buffalo ghee by applying a simple regression equation for each unsaponifiable component. Hence, an examination of unsaponifiable matter appears to provide a rapid and simple laboratory method for the detection of ghee adulteration.     

影响E玻璃熔制质量的因素

在无碱玻璃纤维池窑拉丝生产过程中,从原料选择、配合料制备、窑炉熔化到纤维成型,影响拉丝作业的因素有很多,笔者根据本厂玻纤池窑生产的实践经验,就有关因素作一简单介绍,与同行交流。     

Factors affecting peanut butter preference

A sensory evaluation test with 320 subjects provided information pertinent to the preference of peanut butters. Results of paired preference test indicated that more than half the subjects (59%) preferred the “old fashioned” sample; flavor (aroma and taste) would have to be the primary reason since particle size was nearly the same in the prepared test samples. Chi-square tests of independence showed that the preference for the “old fashioned” sample was dependent on age (P<.05) and sensory attributes of flavor and textural perception (P<.05). Results of the survey showed that 47% of the total responding subjects listed “crunchy” peanut butter as their favorite type. Selection of one’s favorite brand of commercial peanut butter was found to be based primarily on its particle size.     

Factors affecting properties of sol-gel films

A relationship between the refractive index, the mirror reflection factor, the Vickers microhardness, and the chemical resistance of sol-gel films and the film thickness, inclination to crystallization, structural specifics, and composition is established.     

真空冷凝器及其优化设计应考虑的因素

叙述了真空冷凝器(主要是管壳式真空冷凝器)的型式和特点,真空系统内设备间的相互作用,并特别指出了在设计优化和安装时应注意的事项。     

影响工业与公共设施(I&I)洗衣的洗涤因素及洗涤程序

水洗是以水为介质进行的洗涤,其去污作用可用一个简式表述为:     

影响磷酸二铵造粒的因素

讨论中和度、料浆密度、二次补氨、造粒温度、造粒时间、返料等工艺指标对磷铵造粒的影响程度与状况,以期获得外观好、养分合格(主要指氮)的磷酸二铵产品。     

影响丙烯酸酯类共聚物性能的因素

综述了乳化剂用量、核、中间层、壳、粒子粒径及粒径分布等对具有核壳结构的丙烯酸酯类共聚物性能的影响。选择适量的乳化剂和交联剂，合适的反应工艺，控制丙烯酸酯类共聚物粒径及粒径分布，是得到具有良好性能丙烯酸酯类共聚物的必要条件。     

影响焦炭质量的因素分析

焦炭的质量主要取决于配合煤性质和工艺条件。配合煤的性质主要是结焦性、煤的粘结性对焦炭强度的影响较大;炼焦煤的性质影响焦炭的灰分、硫分等化学组成,影响焦炭强度。炼焦的工艺条件是水分、灰分、细度、堆密度等;结焦时间影响焦炭冷态、热态性能和显微特性。