User-oriented evaluation of mechanical single-channel axial pipettes

Hand tools should be designed so that they are comfortable to use, fit the hand and are user-oriented. Six different manual, single-channel axial pipettes were evaluated for such objective outcomes as muscular activity, wrist postures and efficiency, as well as for subjective outcomes concerning self-assessed features of pipette usability and musculoskeletal strain. Ten experienced laboratory employees volunteered for the study. The results showed that light and short pipettes with better tool comfort resulted in reduced muscular activity and perceived musculoskeletal strain when they were compared with a long and heavy pipette. There were no differences in the efficiency between the different pipettes. Combining both the objective and subjective measures enabled a broader evaluation of product usability. The results of this study can be used both in product development and as information on which to base the purchase of new pipettes for laboratory work.     

Easyhaler® Multiple Dose Powder Inhaler—Practical and Effective Alternative to the Pressurized MDI

Due to the depletion of ozone layer linked to CFf propellants used in metered-dose inhalers (MDIs), alternative drug delivery systems for inhalation therapy of bronchial asthma is required. Dry powder inhalers have become a remarkable alternative to the MDIs. The research of powder delivery systems has strongly been focused on developing portable, preloaded multiple-dose powder inhalers, from which patients can reliably inhale several drug doses. Recently, a novel multiple-dose powder inhaler (Easyhaler®) has been developed. Easyhaler® is a suitable drug delivery system for various drugs already available or still under development. Optimum patient compliance is achieved by a design similar to the dose delivery system of the conventional MDI. In addition, the construction of the device allows high dose reproducibility and good in vitro and in vivo deposition of inhaled drug particles. Consequently, equal therapeutic efficacy, safety and tolerability with an MDI is documented in clinical trials. Thus the pharmaceutical, biopharmaceutical, and clinical features as well as the similar mode of use would facilitate a smooth transition from the freon based MDIs to the Easyhaler® multiple-dose powder inhaler.     

Biodegradation of novel amino acid derivatives suitable for complexing agents in pulp bleaching applications

The biodegradability of four novel diethanolamine derivative complexing agents was examined by using two biodegradation tests standardised by OECD (301B and 301F). Ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) were employed as reference substances. Biodegradation of the new complexing agents was studied both with unacclimated and acclimated inocula as well as by simulating wastewater treatment in sequencing batch reactors (SBRs). These new complexing agents were of technical grade, and therefore, the results are only indicative but these new compounds hold promise for use as complexing agents in the pulp and paper industry.The novel complexing agents were not readily biodegradable but they showed slight biodegradation. Around 10-30% degradation was found in the SBR where degradation was followed by measurement of concentration. Moreover the novel complexing agents did not have any negative impact on reactor performance as measured by chemical oxygen demand reduction. In the standardised biodegradation tests at best around 50% degradation was observed with the acclimated inoculum and in the prolonged test whereas EDTA and DTPA exhibited no biodegradation. The elevated degradation in acclimated sludge indicates that the water treatment plant microbes are capable of decomposing these molecules under favourable conditions. The total concentration of novel complexing agents decreased slightly during biodegradation tests, while the EDTA and DTPA concentrations remained stable.     

The development of situational interest during a digital mathematics game

The present study focused on 212 fifth graders' situational interest trajectories during an intervention with a digital mathematics game called Number Navigation. Our aims were to explore the development of situational interest whilst playing the game and to investigate the relationship between situational interest and individual math interest. Growth mixture model analyses showed that in the whole sample situational interest was stable within sessions but decreased across sessions. Three different situational interest trajectories were found. Situational interest trajectories were predicted by pre‐test individual interest. In turn, situational interest had an effect on post‐test individual interest. Students whose situational interest trajectories were stable (either high or low) presented no changes in individual interest, yet the individual interest of students whose situational interest was triggered but not maintained markedly decreased from pre‐test to post‐test. Results suggest that it is important to use game‐based learning not because games are believed to be “motivating”; rather, games with proven learning outcomes should be carefully selected.     

Removal of bis(2-ethylhexyl) phthalate at a sewage treatment plant

Bis(2-ethylhexyl) phthalate (DEHP) concentrations were measured at different stages in a full-scale sewage treatment plant (STP) and mass balances were calculated. The DEHP load to treatment process coming from the sewer system and the internal load comprising returned supernatants and filtrate from sludge treatment and excess secondary sludge were at the same level. The DEHP removal efficiency from the water phase at the STP was on average 94% of sewage DEHP, the main removal process being sorption to primary and secondary sludges. On average 29% of DEHP was calculated to be removed in the biological nitrifying-denitrifying activated sludge process, which was much less than expected from laboratory biodegradation studies described in literature. Monoethylhexyl phthalate, the primary biotransformation product of DEHP, was not detected at any treatment stage. Approximately 32% of DEHP in sewage was removed during anaerobic digestion of the sludge, while 32% remained in the digested and dewatered sludge.     

Internal leachate quality in a municipal solid waste landfill: vertical, horizontal and temporal variation and impacts of leachate recirculation

The aim of this study was to monitor and characterise internal leachate quality at a Finnish municipal solid waste landfill (Lahti, Kujala, in operation for approximately 50 years) to provide information about its horizontal and vertical variation as well as effects of leachate recirculation on leachate quality. The study area (approximately 4 h) of the landfill had 14 monitoring wells for leachate quality monitoring over a 2-year period. The leachate was monitored for COD, BOD, TKN, NH₄–N, Cl, pH and electric conductivity. The results showed high horizontal and vertical variability in leachate quality between monitoring wells, indicating that age and properties of waste, local conditions (e.g., water table) and degradation and dilution processes have a marked effect on local leachate quality. The mean COD values (642–8037 mg/l) and mean BOD/COD ratios (0.08–0.17) from the different monitoring wells were typical of landfills in the methanogenic phase of degradation. The leachate in the monitoring wells was notably more concentrated than the leachate effluent used for leachate recirculation. In the landfill as a whole the effects of the leachate recirculation on leachate quality, although difficult to distinguish from those caused by other factors, appeared to be minor during the study period.     

超音速火焰喷涂碳化物粒径不同的WC-10Co4Cr涂层在粗细磨粒下的磨损性能

改进的ASTM G65橡胶轮测试方法可采用220nm二氧化钛颗粒和368μm的砂粒分别在潮湿和干燥条件下使用。在由碳化物粒径不同(传统和亚微米)的两种粉末所制备的WC-CoCr涂层上开展试验,研究碳化物大小和磨损介质特性对涂层磨损性能的影响。采用扫描电镜对同一位置磨损前后的低倍和高倍形貌进行观察,并分析了涂层的磨损机理。结果表明:磨损机理取决于碳化物和磨粒的相对大小。在样品上进行磨损定量分析,通过调整碳化物尺寸可改善磨损性能,测试涂层的一些力学性能用于对比。     

Real‐Time Label‐Free Monitoring of Nanoparticle Cell Uptake

The surface plasmon resonance technique in combination with whole cell sensing is used for the first time for real‐time label‐free monitoring of nanoparticle cell uptake. The uptake kinetics of several types of nanoparticles relevant to drug delivery applications into HeLa cells is determined. The cell uptake of the nanoparticles is confirmed by confocal microscopy. The cell uptake of silica nanoparticles and polyethylenimine–plasmid DNA polyplexes is studied as a function of temperature, and the uptake energies are determined by Arrhenius plots. The phase transition temperature of the HeLa cell membrane is detected when monitoring cell uptake of silica nanoparticles at different temperatures. The HeLa cell uptake of the mesoporous silica nanoparticles is energy‐independent at temperatures slightly higher than the phase transition temperature of the HeLa cell membrane, while the uptake of polyethylenimine–DNA polyplexes is energy‐dependent and linear as a function of temperature with an activation energy of Ea = 62 ± 7 kJ mol^?1 = 15 ± 2 kcal mol^?1. The HeLa cell uptake of red blood cell derived extracellular vesicles is also studied as a function of the extracellular vesicle concentration. The results show a concentration dependent behavior reaching a saturation level of the extracellular vesicle uptake by HeLa cells.     

Why organizations adopt information system process innovations: a longitudinal study using Diffusion of Innovation theory

Abstract.  This paper identifies factors that affected over 200 information system (IS) process innovation adoption decisions in three organizational environments over a period that spanned four decades. The analysis is based on Rogers's (1995) theory of Diffusion of Innovations (DOI). The results show that several DOI factors strongly affect IS process innovation adoption. These include user need recognition, availability of technological infrastructure, past experience, own trials, autonomous work, ease of use, learning by doing and standards. Yet, a large number of IS process innovation adoptions followed no discernible pattern.     

Nanocrystalline WC-Co HVAF Coatings by Utilizing Novel Powder Manufacturing Route Using Water-Soluble Raw Materials

In this study, nanostructured WC-Co coatings were produced using experimental nanocrystalline WC-12Co and WC-24Co powders produced by a novel chemical synthesis route. Test coatings were produced using HVAF spraying keeping the temperature as low as possible during the deposition in order to avoid decomposition of the nanocarbides. In experimental powders, two different Co incorporation methods were used: a conventional way in which cobalt was incorporated as a metallic Co powder and a chemical synthesis way in which cobalt acetate was used as a cobalt source. When using cobalt acetate, it decomposes to metallic cobalt during the process. Experimental powders in which cobalt acetate has been used as cobalt source resulted poor deposition efficiency. With warmer parameters, powders resulted better DE, but significant WC decarburization and the dissolution into the matrix phase occurred. Powders in which Co has been introduced as Co powder showed enhanced DE enabling spraying with decreased temperature and higher particle velocity, resulting in coatings with less WC decomposition. Especially, an experimental powder in which Co has been incorporated both as Co powder and as Co-Ac results very fine nanocarbide structure with significantly less WC decomposition having a hardness value of 1201 HV0.3, even with 24% Co.