The Calibration of Air-flow Apparatus for the Determination of the Fibre Diameter of Wool

There is a general algorithm for the determination of practicable starting allocations of colours to the two sides of a 4 × 4 box pick-at-will loom, but its convenience in use varies greatly. An improvement is indicated, but a simpler and more efficient algorithm is suggested for the one-empty-box case, for which the general algorithm is least satisfactory.

Two of the constraints of weft patterning on such 4 × 4 box looms are examined, largely by using the general algorithm. First, the maximum number of practicable starting allocations is determined for any given number of weft colours and any smaller number of box-pairs. Next, it is shown that there is a possibility that a weft repeat may be unweavable with one shuttle per colour if the number of picks in the reduced repeat is not less than the number of shuttle boxes in use.

In contrast to the genera! case, if there is only one empty shuttle box, the box plan that minimizes the number of large box movements for a given weft repeat can rapidly be determined by using a microcomputer.     

34—WITHDRAWAL FORCES IN THE PROCESSING OF WOOL SLIVERS: PART II: THE INFLUENCE OF VARIATIONS IN GILLING ON THE WITHDRAWAL FORCE

An account is given of the use of withdrawal-force measurements to determine the extent of fibre alignment in slivers. It is shown that a direct relation between withdrawal force and percentage noil exists. Several variations in the preparation of slivers were investigated, namely, the number of gillings, the draft during gilling, and the direction of feed.     

Improved Methods of Determining Fibre Density

An account is given of an investigation of the effects of fibre type (rayon, acrylic fibre, wool, and cotton) and dimensions on the properties of needled fabrics, the test methods used being those described in a previous paper. Some fabrics show a stick-slip behaviour in extension; others deform smoothly. Rayon webs consolidate more easily on needling than Courtelle or wool webs. Longer fibres give higher fabric strengths. Finer fibres also give higher strength, unless fibre damage occurs. The influence of fibre friction is discussed.     

37—THE SURFACE TOPOGRAPHY OF CHEMICALLY TREATED WOOL FIBRES

An account is given of experiments in which wool fibres were subjected to a large variety of chemical treatments considered as being representative of those commonly used in industrial finishing. For treatments designed to produce shrink-resistance, samples of similarly treated fabrics, subsequently subjected to a felting test (based on the International Wool Secretariat Specification 7), showed the area shrinkage to be within acceptable limits.

Qualitative scanning-electron-microscope studies revealed relatively little damage to the surface topography of wool fibres when treatments were applied at the ‘normal’ level.

When some of the treated fibres were subjected to a wash test (International Organization for Standardization No. 2), partial fragmentation of the cuticle occurred after chlorination and bleaching with hydrogen peroxide. However, little damage was observed after the wash test made on fibres treated at ‘normal’ levels.     

A Clamp for the Tensile Testing of Fibre Bundles

A theoretical analysis has been developed in which it has been assumed that the two-stage process that occurs during the relaxation of wool yarns leads to the same change in structure as a single dry-relaxation process. In the present paper, a detailed experimental evaluation of the theory is reported whereby its predictions are compared with results obtained for wool semi-worsted carpet yarns spun at various twist levels.     

30—YARN HAIRINESS: A SURVEY OF RECENT LITERATURE AND A DESCRIPTION OF A NEW INSTRUMENT FOR MEASURING YARN HAIRINESS

This paper is intended to supplement one published in 1966 containing a survey of the literature on yarn hairiness, and the review of the literature is brought up-to-date at the time of writing.

A new electronic instrument for measuring yarn hairiness is outlined. This apparatus enables three parameters to be obtained directly and simultaneously, these being hairiness, hair length, and yarn diameter.     

低共熔溶剂液相微萃取技术测定5种杀菌剂农药残留分析方法

本文建立了低共熔溶剂液相微萃取高效液相色谱法测定5种杀菌剂(三唑醇、嘧霉胺、三唑酮、烯唑醇、嘧菌环胺)的农药残留分析方法,以苯酚作为氢键给体,氯化胆碱作为氢键受体组合而成的低共熔溶剂作为提取溶剂,THF作为分散剂,形成浑浊小液滴,目标分析物被萃取到微量的DESs相中,经过离心,吸取DESs相进高效液相色谱分析。对影响萃取效率的重要因素进行选择和优化。研究表明,氯化胆碱与苯酚在1:2的比率形成的低共熔溶剂萃取效果最好,同时,在最佳的萃取条件(样品容量为5 mL,DES2为150μL,THF为150μL,超声时间为20 min,离心时间为10 min)下进行添加回收率实验,回收率在73.7%～102.3%之间,相对标准偏差(RSD)为0.7%～7.1%,最小检出限(LOD)0.026～0.052μg/L。为实际检测残留农药提供安全可靠的提取和分离技术,减少有机溶剂的使用对环境及人体健康构成的危害。     

A method for the detection of carbonyl compounds in wine: Glyoxal and methylglyoxal

Wine aldehydes were identified as O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine derivatives by GC-MS or with a GC-electron-capture detector. This method has been used to evaluate levels of glyoxal and methylglyoxal in wine. Reproducibility and linearity studies gave satisfying results. Glyoxal and methylglyoxal are formed during fermentation. Among the factors affecting their production, high musts pH increased the levels found in the corresponding wines. Various microorganisms of the wine such as Saccharomyces cerevisiae and Leuconostoc ænos can produce glyoxal and methylglyoxal. The concentrations in Sherry wines were particularly high. Because of the toxicological properties of these substances, their determination and the knowledge of their metabolism by wine microorganisms are very important.     

Comparing different gas chromatographic methods for the quantification of bisphenol A (BPA) trace levels in paper and cardboard products from the market

Bisphenol A (BPA; 4,4?-(propane-2,2-diyl)diphenol), a suspected endocrine disruptor with weak estrogenic activity, is used in a variety of consumer products, including paper and cardboard products used as food contact materials. The present study compared four different gas chromatographic methods for the analysis of BPA in paper and cardboard food packages. Eighteen different food packages were extracted and BPA was determined using two different derivatisation reactions – trimethylsilylation with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) and halide alkylation with pentafluorobenzoyl chloride (PFBOCl) – and four different separation and detection techniques. The BSTFA derivatives were quantified with (1) GC-MS in single-ion monitoring (SIM) mode with electron ionisation (EI-GC-MS) and (2) GC-MS/MS in multiple reaction monitoring (MRM) mode using electron ionisation (EI-GC-MS/MS); while the PFBOCl derivatives were quantified with (3) GC-MS using electron ionisation (EI-GC-MS) as well as (4) GC-MS with negative chemical ionisation (NCI-GC-MS). All developed methods showed good linearity (R² > 0.9938), precision (CV < 4.5% for reproducibility; CV < 2.2% for repeatability) and sensitivity, with limits of detection (LODs) between 0.02 µg kg^?1 for the pentafluorobenzoyl derivatives measured with the NCI-GC-MS method and 6 µg kg^?1 for the pentafluorobenzoyl derivatives determined with EI-GC-MS. Levels of BPA in the samples were in agreement for all methods, ranging from values below the limit of quantitation (LOQ) to 11.9 mg kg^?1 paper. In a last step, the maximum potential migration into food products was calculated for all tested paper and cardboard samples, assuming a ‘worst case’ scenario of 100% migration.     

A study on kinetics of beer ageing and development of methods for predicting the time to detection of flavour changes in beer

The kinetics of beer ageing were studied based on the development of beer stale flavour with storage time. Results showed that the beer ageing rates at 50 and 60°C were 30.0 and 56 times as fast as those at room temperature, respectively. Based on these findings, two methods (method A and B) for predicting the ‘time to detection of flavour change’ (TDFC) of beer were developed. TDFC is the beer shelf‐life in terms of flavour stability. In method A, beers were stored in a 50°C water bath and the intensity of beer ageing was scored daily. Thus, the range of TDFC of the beer was acquired according to the maximum number of days within which the intensity of beer ageing was ≤2 and the minimum number of days within which the intensity of beer ageing was >2. In method B, the 2‐thiobarbituric acid (TBA) values of a beer were determined before and after 1 day of storage in a 50°C water bath, and the TDFC of the beer was calculated using the equation: where ΔTBA is the increment of TBA value during 1 day of storage at 50°C. Both methods were simple, rapid and accurate. Copyright © 2015 The Institute of Brewing & Distilling     

自制固相萃取柱-超高效液相色谱-串联质谱法同时测定果蔬中的8 种真菌毒素

建立基于自制固相萃取柱的样品净化-超高效液相色谱-串联质谱同时测定果蔬中8 种主要真菌毒素的方法,包括链格孢毒素、展青霉素、赭曲霉毒素A及橘青霉素。样品经80%乙腈溶液提取、离心后,通过自制固相萃取柱（HLB＋MCX）排除杂质干扰,流出液经氮吹至近干后,直接用超高效液相色谱-串联质谱进行测定,基质外标法定量。在较宽的线性范围内,8 种毒素的线性相关系数（r2）均不小于0.99,定量限为1～5 μg/kg,在3 个不同添加水平下的加标回收率为76.0%～102.7%,相对标准偏差为0.8%～4.7%。该法灵敏度高,操作简单﹑快速,适用于苹果、樱桃和番茄等果蔬中痕量真菌毒素的测定。