Humulus lupulus – a story that begs to be told. A review

The hop cones of the female plant of the common hop species Humulus lupulus L. are grown almost exclusively for the brewing industry. Only the cones of the female plants are able to secrete the fine yellow resinous powder (i.e. lupulin glands). It is in these lupulin glands that the main brewing principles of hops, the resins and essential oils, are synthesized and accumulated. Hops are of interest to the brewer since they impart the typical bitter taste and aroma to beer and are responsible for the perceived hop character. In addition to the comfortable bitterness and the refreshing hoppy aroma delivered by hops, the hop acids also contribute to the overall microbial stability of beer. Another benefit of the hop resins is that they help enhance and stabilize beer foam and promote foam lacing. In an attempt to understand these contributions, the very complex nature of the chemical composition of hops is reviewed. First, a general overview of the hop chemistry and nomenclature is presented. Then, the different hop resins found in the lupulin glands of the hop cones are discussed in detail. The major hop bitter acids (α‐ and β‐acids) and the latest findings on the absolute configuration of the cis and trans iso‐α‐acids are discussed. Special attention is given to the hard resins; the known δ‐resin is reviewed and the ε‐resin is introduced. Recent data on the bittering potential and the antimicrobial properties of both hard resin fractions are disclosed. Attention is also given to the numerous essential oil constituents as well as their contributions to beer aroma. In addition to the aroma contribution of the well‐known essential oil compounds, a number of recently identified sulfur compounds and their impact on beer aroma are reviewed. The hop polyphenols and their potential health benefits are also addressed. Subsequently, the importance of hops in brewing is examined and the contributions of hops to beer quality are explained. Finally, the beer and hop market of the last century, as well as the new trends in brewing, are discussed in detail. Hop research is an ever growing field of central importance to the brewing industry, even in areas that are not traditionally associated with hops and brewing. This article attempts to give a general overview of the different areas of hop research while assessing the latest advances in hop science and their impact on brewing. Copyright © 2014 The Institute of Brewing & Distilling     

Noise simulations of flap devices for wind turbine rotors

The rotor of a large diameter wind turbine experiences more substantial and more dynamic loads due to the fluctuating and heterogeneous wind field. The project SmartBlades 2.0 investigated rotor blade design concepts that alleviate aerodynamic loading using active and passive mechanisms. The present work evaluates the acoustics of the two load alleviating concepts separately, an inboard slat and an outboard flap, using the Fast Random Particle Mesh/Fast Multipole Code for Acoustic Shielding (FRPM/FMCAS) numerical prediction toolchain developed at DLR with input from the averaged flow field from RANS. The numerical tools produce a comparable flap side-edge noise spectrum with that of the measurement conducted in the Acoustic Wind Tunnel Braunschweig (AWB). The validated FRPM/FMCAS was then used to analyze the self-noise from a slat at the inboard section of a rotor blade with a 44.45 m radius and compared with that from the outboard trailing edge. Furthermore, the rotational effect of the rotor was included in the post-processing to emulate the noise observed at ground level. The findings show an increase in the slat's overall sound pressure level and a maximum radiation upwind of the wind turbine for the case with the largest wind speed that represents the off-design condition. In operational conditions, the slat adds at most 2 dB to the overall sound pressure level. The toolchain evaluates wind turbine noise with conventional or unconventional blade design, and the problem can be scaled up for a full-scale analysis. As such, the tools presented can be used to design low-noise wind turbines efficiently.     

VOC sorption and diffusion behavior of building materials

In this study 25 different building materials often used in timber constructions (wood based panels, gypsum boards, vapor barriers, adhesive tapes, insulation materials and sealants) were investigated with regard to their adsorption, desorption and diffusion behaviour towards volatile organic compounds (VOC). The materials were exposed to four, respectively five selected VOCs typically found in indoor air: hexanal, butyl acetate, p-xylene, nonane and α-pinene. Adsorption and desorption properties were investigated under static conditions, whereas the diffusion behavior was examined in a 0.225 m³ emission chamber with an air exchange rate of 1 h^?1. The results of the experiments indicate that some building products have a high potential to reduce VOCs in indoor air. Apart from the vapor barriers, two insulating materials and one plasterboard, all tested materials represented an adsorption efficiency of about 50 % or higher related to the injected VOC standards. Materials with high adsorption capacity bound substances strongly and desorbed them less, whereas less adsorbing materials acted inversely. The obtained results indicate that material properties and processing play a considerable role in diffusion behavior of building materials.     

Evaluation of training in patient handling and moving skills among hospital and home care personnel

The aim of the study was to evaluate the training programme in patient handling and moving skills according to the Stockholm Training Concept. The evaluation focused on work technique, musculoskeletal problems, job strain and the experience of the person being transferred. The training programme consisted of two models of learning: traditional groups and quality circles. Fifty-one people employed at geriatric hospitals and in primary care, participated in the training programme. For the evaluation, the participants were video-recorded in one standardized transfer situation: moving the patient from bed to wheelchair, before and after the training. The participants' work technique during the patient transfer was assessed using seven items. A questionnaire covering individual factors, physical exertion, job strain, and musculoskeletal problems, was filled in by the participants before training and also six months after. The results showed improvements in six of the seven work technique items, directly after training. A decrease in the participants' physical exertion during transfers of patients from 'bed to chair' was shown six months after completion of the training programme. There was no significant decrease in the participants' musculoskeletal problems and job strain after training. Ninety-eight per cent of the participants were positive about having participated in the training. Training in patient handling and moving skills led to improved work technique. The participants improved their transfer technique and experienced less discomfort during the transfer, and patients experienced greater comfort and safety when being transferred.     

Evaluation of surface and bulk characteristics of cellulose I powders in relation to compaction behavior and tablet properties

The particle properties and solid-state characteristics of two celluloses, Avicel PH101 and cellulose obtained from the alga Cladophora sp., were evaluated and related to the compaction behavior and the properties of the tablets made from them. The surface area of the celluloses was measured at different levels of penetration capacity, ranging from external surface area of particles to molecular texture with Blaine permeametry, Kr-gasadsorption, and solid-state NMR. The important cellulose fibril surface area was best reflected by solid-state NMR, although for the Cladophora cellulose, Kr-gas adsorption also resulted in a surface area of the order of what has been suggested earlier on the basis of the cellulose fibril dimensions. The difference in fibril dimension and, thereby, the fibril surface area of the two celluloses was shown to be the primary factor in determining their properties and behavior. Properties such as the crystallinity and the tablet disintegration could be related to the fibril dimensions. The Cladophora cellulose resulted in rather strong compacts that still disintegrated rapidly. The irregular surface morphology of the particles and the fragmenting behavior of Cladophora probably contributed to the strength of the tablets.     

Use of information on the manufacture of samples for the optical characterization of multilayers through a global optimization

We present a procedure for the optical characterization of thin-film stacks from spectrophotometric data. The procedure overcomes the intrinsic limitations arising in the numerical determination of many parameters from reflectance or transmittance spectra measurements. The key point is to use all the information available from the manufacturing process in a single global optimization process. The method is illustrated by a case study of solgel applications.     

Usability issues concerning child restraint system harness design

A study was conducted to assess usability issues relating to child restraint system (CRS) harness design. Four convertible child restraint systems representing a wide variety of design features were used. Forty-two participants installed two child test dummies in both forward- and rear-facing configurations either inside or outside a test vehicle. Observer-scored checklists determined the degree to which each harness was installed correctly. Participant-scored questionnaires evaluated the 'ease-of-use' of various design features. While the percentage of correct installations exceeded 83% for all designs when installed in the forward-facing configuration, in the rear-facing position (that intended for children under 9-10 kg), there was a significant (between 65 and 89%) percentage of incorrect installations for all models. This finding is of particular interest and may be indicative of a more generalized problem with 'convertible' CRS designs when they are used in the rear-facing configuration. Furthermore, while certain design features were perceived by users as providing significantly better protection in the event of a collision, these also tended to be the features that were misused most often. The benefits and costs of various design features are discussed, and a method to test harness design usability is presented.     

Inhibition of suckling in weaning-age rats: A possible serotonergic mechanism.

Four experiments studied the nature, development, and specificity of serotonergic involvement in the control of suckling behavior in Sprague-Dawley rat pups from 10 to 35 days of age. During development, suckling normally declines after 10 days and is abandoned after 30 days. It was found that (a) methysergide, a serotonin (5-hydroxytryptamine, 5-HT) receptor blocker, reinstated suckling behavior in pups 15 days of age and older; (b) quipazine, a 5-HT receptor agonist, inhibited suckling of pups 10 days of age and older; (c) methysergide pretreatment blocked the quipazine inhibition of suckling; and (d) metergoline, another 5-HT blocker, also stimulated suckling, and fenfluramine, a 5-HT releaser, blocked suckling in deprived pups. Data support the hypothesis that a serotonergic inhibitory mechanism modulates the suckling of weaning-age rats. These pharmacological manipulations of 5-HT appear to alter specific components of suckling behavior involved in its initiation and maintenance but do not appear to alter a general hunger system. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential attitude change in nonprofessional experience: An experimental comparison.

Manipulated 3 components of training and supervision of undergraduate nonprofessionals working with youthful offenders: specific intervention skills vs natural helping styles, frequency of training/supervision meetings, and size of training/supervision groups. Effects of varying these components were then observed on the nonprofessionals' attitudes toward themselves, the target population, and other relevant areas. 134 undergraduates served as Ss, 49 of whom were controls. Ss using their natural helping styles of intervention were significantly more disillusioned about themselves and the juvenile justice system across time; those receiving training in specific intervention skills felt more positive. Comparisons of these results with those found in other nonprofessional programs, as well as implications for professionals in helping careers, are discussed. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)