Impact of personality and intelligence on job satisfaction of assembly line and bench work - an industrial study

A study of the impact of machine-paced (M/P) and self-paced (S/P) work on job satisfaction of 28 female industrial assembly workers was evaluated in which M/P work was confounded with simplified work and the S/P job was confounded with enriched tasks. Results indicated the following:

1. 1. Over three-quarters of workers were more satisfied in S/P jobs, while only less than one-quarter were more satisfied in M/P jobs.

2. 2. The 16PF personality test effectively predicts (0·88 multiple correlation) the satisfaction ratios of M/P to S/P jobs.

Professional drivers: protection needed for a high-risk occupation

"On the job" motor vehicle deaths number more than 4,000 annually in the U.S. and comprise nearly one-third of all work-related deaths. Yet the Department of Labor has set no standards relating to on-the-road safety of the millions of workers whose jobs entail large amounts of driving, and Department of Transportation standards affecting occupational safety cover only drivers in interstate commerce. Drivers of some commercial vehicles, such as heavy trucks, are at special risk of injury because trucks have usually been exempted for many years from federal motor vehicle safety standards--such as standards for brakes and seatbelts--designed to prevent crashes or protect occupants in crashes. Observations based on a series of 150 fatal crashes involving tractor trailers illustrate the need for better protection of this large population of high-risk workers. Clarification of responsibility within the various federal agencies and application of available knowledge and technology are essential.     

The organization and postnatal development of the commissural projection of the rat somatic sensory cortex

Anterograde and retrograde tracing experiments have been used to demonstrate the origin and terminal distribution of commissural fibers in the first somatosensory cortex (SI) of the rat. The commissural fibers originate from pyramidal cells of all layers, but predominantly from layers III and V. The fibers terminate in a series of approximately vertical bands. In each of these there are concentrations of terminals extending from the inner portion of the molecular layer to the deep portion of layer III as well as in the superficial part of layer V, and in layer VI. Discrete vertical bands of cortex are reciprocally connected across the midline to give both the origin and terminal regions of the projection a patchy or "columnar" appearance. The commissural fibers arise from and terminate in areas of the cortex that lie between and alongside the aggregations of granule cells that distinguish SI of the rat. No commissural fibers terminate within the aggregations of layer IV cells themselves but the more superficial terminal ramifications may come to overlie these aggregations. A heterotopic projection to the contralateral second somatosensory cortex has been observed and is similar in form to the homotopic projection to SI. Many commissural fibers have crossed the midline in the corpus callosum by the day of birth but lie in the underlying white matter and do not enter the cortical plate until at least the third postnatal day. During the first postnatal week these fibers grow somewhat diffusely into the maturing cortex and their topographic and laminar pattern of distribution attains its adult characteristics by the end of the first week. Commissural axons, thus, arise from immature cells but the maturation of cell form seems to precede the ingrowth of these axons and the acquisition of commissural synapses.     

A bandwidth latency tradeoff for broadcast and reduction

The “fractional tree” algorithm for broadcasting and reduction is introduced. Its communication pattern interpolates between two well known patterns—sequential pipeline and pipelined binary tree. The speedup over the best of these simple methods can approach two for large systems and messages of intermediate size. For networks which are not very densely connected the new algorithm seems to be the best known method for the important case that each processor has only a single (possibly bidirectional) channel into the communication network.     

Separation of L‐aspartic acid and L‐glutamic acid mixtures for use in the production of bio‐based chemicals

BACKGROUND: Amino acids are promising feedstocks for the chemical industry due to their chemical functionality. They can be obtained by the hydrolysis of potentially inexpensive protein streams such as the byproduct of biofuel production. However, individual amino acids are required before they can be used for the further production of chemicals. Here, the separation of L‐aspartic acid (Asp) and L‐glutamic acid (Glu) mixture, which can be isolated from protein hydrolysis solutions at low pH or from electrodialysis of complex amino acid mixtures, was studied. RESULTS: Glu was converted into L‐pyroglutamic acid (pGlu) which can be separated from the mixture of Asp and Glu due to its higher solubility in water. The conversion was carried out under aqueous or melt conditions. Under aqueous conditions, the conversion was studied as a factor of time, temperature and the amount of Glu. The conversion was specific with high yield and not effected by Asp. After pGlu was separated from Asp and residual Glu by solubility difference, it can be transferred back to Glu through hydrolysis. CONCLUSION: The conversion of Glu to pGlu is specific and can be applied to separation Asp and Glu for their use in the production of bio‐based chemicals. Copyright © 2012 Society of Chemical Industry     

Crystallization of Stoichiometric SbSI Glass

Congruent crystallization of antimony sulphoiodide (SbSI) glass of stoichiometric composition, which is prepared successfully for the first time using rapid melt‐quenching, has been investigated using differential scanning calorimetry (DSC). The results for glass powder show a glass transition at 127°C and two separate exothermal peaks with maxima around 140°C and 190°C. The ratio of the intensities of the exothermal peak at ~190°C to the peak at ~140°C increases as the particle size and heating rate are increased, but their total enthalpy remains constant at 62 ± 2 J/g for all DSC runs. Surface heating of the glass induced by a 520 nm CW laser shows two contracted regions: needle‐like crystalline formations at low temperature and bulk crystallization at high temperature. The observed phenomena and DSC results suggest two different kinds of crystallization of the SbSI phase: one‐dimensional crystallization at low temperature which starts from the sample surface and three‐dimensional bulk crystallization that continues the transformation to crystalline state at higher temperatures. The origin of the two different crystallizations can be traced to the strong anisotropy of the SbSI crystal structure due to the weak van der Waals interaction between covalent‐ionic chains (Sb₂S₂I₂)_n.     

Influence of polyimide precursor synthesis route and ortho-position functional group on thermally rearranged (TR) polymer properties: Conversion and free volume

Thermal rearrangement of polyimides with ortho-position groups to polybenzoxazoles and related structures has been of recent interest for producing gas separation membranes. This study explores the influence of synthesis route and ortho-position functional group on the thermal rearrangement process and the fractional free volume of thermally rearranged (TR) polymers produced from polyimides derived from 3,3′-dihydroxy-4,4′-diamino-biphenyl and 2,2′-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (HAB–6FDA). Acetate, propanoate, and pivalate ortho-position functional groups were considered. Thermogravimetric analysis (TGA) was used to study thermal rearrangement at temperatures between 350 and 450 °C, and evolved gases from TGA were analyzed via mass spectrometry to characterize the byproducts of thermal rearrangement and thermal degradation. CO₂ was the major byproduct of thermal rearrangement for all samples, and its evolution began well before the onset of thermal degradation. When non-hydroxyl ortho-position groups were present in the polymers, several byproducts other than CO₂ were also observed due to the loss of these ortho-position groups before thermal rearrangement. Free volume generally increased with increasing extent of thermal rearrangement, but precise values of free volume could not be accurately determined for polymers with propanoate and pivalate ortho-position functional groups due to uncertainties in the chemical structure of partially converted materials. For polymers with acetate and hydroxyl ortho-position groups, free volume could be determined within the uncertainty of density measurements. Thermal rearrangement behavior and free volume results for acetate containing polymers synthesized via different routes were very similar. Based on these results, the chemical structure of the ortho-position functional group has a larger impact on TR polymer properties than the polyimide precursor synthesis route.     

The polyurea structure and the role of Amine-Terminated Polyethers and Polyesters in Polyurethanes

The Reaction Injection Molding (RIM) technology has made it possible to master the fast reaction of di- and polyamines with di- and polyisocyanates, leading to the preferred polyurea structure. Telechelics with amino end groups are gaining increased interest for the manufacture of polyurethane-polyurea materials by this technology. They make it possible to substitute all urethane groups in the elastomers with urea groups. The telechelics which are considered are amine-terminated polyethers (ATPE) and polyesters based on the typical soft-segment forming polycondensation polymers which are widely used in polyurethane chemistry. Isocyanate-terminated prepolymers of toluene diisocyanate and polyether polyols can be hydrolyzed in aqueous alkaline media via the carbamate intermediate to the amineterminated prepolymers. The reactivity of these aromatic ATPEs was ideally fit for the RIM process. ATPEs by the hydrolysis process are somewhat limited if products with low viscosities are required. In the reaction of chloro-nitrobenzenes with polyether polyols followed by the hydrogenation of the nitro groups of the terminal phenoxy moieties, we found a path for the synthesis of low viscosity aromatic ATPEs. Capping of polyether polyols with acetoacetate groups and subsequent reaction of the acetoacetylated polyethers with amines, leads to polyethers with terminal imine or enamine groups, which are derivates of aminocrotonic acid. We determined that this approach is a universal method for the synthesis of a large variety of aromatic as well as aliphatic ATPEs with low viscosities. Trifluoroacetic acid turned out to be the ideal catalyst for the reaction of the acetoacetylated polyethers with aromatic diamines, one amino group forming the imine link, the second one remaining intact and providing the desired reactivity towards isocyanates. Aliphatic diamines do not require a catalyst for this reaction. They lead to aminocrotonates with aliphatic amino groups that have high reactivity towards isocyanates, which is to be expected from aliphatic amines. The reaction of the chloroformates of polyether polyols with diamines can also be used to synthesize a variety of ATPEs. We recently developed an approach to low viscosity ATPEs having secondary amino end groups. The hydroxyl groups of the polyether polyols are converted to chloride or methanesulfonyl. The polyethers terminated with these leaving-groups are reacted with primary aliphatic or aromatic amines to give the secondary ATPEs in very good yields.     

Effect of lubricating oil contamination on evaporation in refrigerants R12 and R22

An investigation has been made into the effect of oil concentration on evaporation heat transfer coefficients in refrigerant-oil mixtures flowing in a horizontal tube. A new correlation is presented for heat transfer coefficients in convective evaporation of refrigerant-oil mixtures that predicts the results of the present study within approximately ±20%. The paper reports measurements of evaporation heat transfer coefficients in refrigerants R12 and R22, both oil-free and with two concentrations of Shell Clavus 32 oil. A 1·8 m long ⅜ in O/D copper tube (8·05 mm I/D) was used, at evaporation temperatures of −5°C, 0°C and +5°C. Heat flux and mixture mass velocity were kept constant at 2500 W m⁻² and 155 kg m⁻² s⁻¹, respectively, and measured coefficients were in the range of 1400 to 3900 W m⁻² K⁻¹. The results showed that, for a complete evaporator, 2% oil may be expected to increase the heat transfer coefficient by 12%, but 10% oil returns the coefficient to oil-free values.     

Development and validation of a new LC–MS/MS method for the simultaneous determination of six major ergot alkaloids and their corresponding epimers. Application to some food and feed commodities

A liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous determination of six major ergot alkaloids, ergometrine, ergosine, ergotamine, ergocornine, ergokryptine and ergocristine, as well as their corresponding epimers in food and feed samples. The method involves extraction under alkaline conditions and subsequent clean-up by applying a simple and rapid liquid–liquid partitioning procedure prior to LC–MS/MS analysis. Evaluation of the method revealed good linearity, accuracy and precision. The limits of quantification varied from 0.1 to 1 μg/kg depending on the analyte and matrix. The average extraction and clean-up recoveries in different matrices were between 45 (only for ergometrine in biscuit) and 90%. The uncertainty associated with the analytical method was not higher than 51% and 30%, at concentration levels of 2.5 and 150 μg/kg respectively. Analyte epimerization proved to be minimal during the analytical procedure. The method has been successfully applied to the determination of ergot alkaloids in some Belgian food and feed commodities. Ergot alkaloids were found in 104 out of 122 samples investigated. Ergosine was the most frequently occurring alkaloid, while the highest levels were observed for ergotamine, ergocristine or ergosine, depending on the product type. The total alkaloid content in positive samples varied from 1 to 1145 μg/kg.