Comparison of alginate and pectin based beads for production of poultry probiotic cells

A comparative study on the stability and potential of alginate and pectin based beads for production of poultry probiotic cells using MRS medium in repeated batch fermentation was conducted. The bead cores, made of three types of materials, i.e., ca-alginate, ca-pectinate and ca-alginate/pectinate, were compared. The effect of single and double layer coatings using chitosan and core material, respectively, on the bead stability and cell production were also studied. The pectin based beads were found to be more stable than that of the alginate beads and their stability was further improved by coating with chitosan. The cell concentration in pectin based beads was comparable to that in the alginate beads. On the other hand, pectin based beads gave significantly lower cell concentration in the growth medium for the initial fermentation cycles when compared to the alginate beads. In conclusion, pectin was found to be potential encapsulation material for probiotic cell production owing to its stability and favourable microenvironment for cell growth.     

Anomalous linewidth behavior in short-cavity single-frequency fiber lasers

An experimental investigation of the anomalous linewidth behavior in a distributed feedback fiber laser is presented. It is found that not only does the linewidth deviate from the Schawlow-Townes linewidth formula by increasing with pump and laser power, but it also varies significantly with the pumping configuration. These observations have potentially important implications for the design and operation of such fiber lasers.     

A randomized clinical trial of the nonsteroidal eyedrop diclofenac after strabismus surgery

OBJECTIVE: This study aimed to compare the anti-inflammatory and analgesic effects of topical diclofenac sodium 0.1% (Voltaren) with prednisolone sodium phosphate 1% ophthalmic solution after strabismus surgery. DESIGN: A prospective, double-masked, randomized, two-center clinical trial. PARTICIPANTS: Eighty eyes of 52 patients undergoing strabismus surgery were examined. INTERVENTION: For 1 week after surgery, the eye that was operated on received one drop of either diclofenac or prednisolone four times a day. MAIN OUTCOME MEASURES: The diclofenac- and prednisolone-treated eyes were compared on postoperative days 3 and 7 with respect to signs of inflammation (e.g., erythema, edema, discharge), patient comfort, and conjunctival incisional healing. RESULTS: On postoperative day 7, in eyes that received prednisolone, the conjunctival defects were larger (P = 0.004) and more frequent (P = 0.02). For all subjects, despite adequate statistical power, there was no statistically significant difference in inflammatory scores between eyes that received diclofenac or prednisolone. In cases of bilateral surgery, however, there was less postoperative erythema and edema in the diclofenac-treated eyes. CONCLUSIONS: In the first week after strabismus surgery, topical diclofenac proved at least as effective as prednisolone in controlling inflammation and discomfort with less delay in incisional wound healing. Topical diclofenac, a nonsteroidal anti-inflammatory agent, may be considered for use after strabismus surgery in place of corticosteroids.     

On the microstructure of micro-pins manufactured by a novel progressive microforming process

Microforming is defined as the process of production of metallic micro-parts with at least two dimensions in sub-millimeter range. Many of these microforming processes have been investigated in laboratory-scale, which is not suitable for industrial applications. In this work, the feasibility of producing copper micro-pins using a novel progressive microforming process is demonstrated. This process has a good potential for mass production of micro-parts. The material flow behavior and the microstructure of the formed micro-pins were investigated by means of optical microscopy and simulation. From this study of material flow behavior with respect to different process conditions (die diameter, die design and punch diameters used), it will be shown how the respective material flow behavior in the progressive forming process influenced the microstructure evolution in the formed micro-pin. It was found in the experimental results that there is a soft zone on the micro-pins surface under specific process conditions. The microhardness results were consistent with the microstructural observations. Simulation was employed to understand the material flow direction under the punch during the microforming process and evaluate the position of the neutral zone in the disk-shape head of the micro-pin produced. This understanding of the neutral zone position with relation to the metal dead-zone as well as the material flow behavior was necessary to explain the dead-zone leakage in the microstructure and the occurrence of the soft zone. By decreasing the punch to die diameter ratio, and also choosing a die without entrance fillet radius, it was shown that the soft zones at the pin surface could be either minimized or entirely removed.     

Flexibility improvement of epoxy nanocomposites thin films using various flexibilizing additives

Epoxy thin films have attracted substantial research attention in the electronic industry because of their excellent thermo-mechanical properties, ease of processing, chemical resistance capability combined with superior electrical insulation, and favorable economics. However, the major drawback of epoxy systems comes from their brittleness, which causes poor resistance to crack, low impact strength, and low toughness. The present paper reports on the effects of the addition of different types of flexibilizers; flezibilizing resin (FR-1), polyol resin (FR-2), and toughening resin (FR-3), and synthetic diamond (SD) nanofillers, on the mechanical, thermo-mechanical, and thermal stability properties of epoxy nanocomposite thin films. The addition of flexibilizing additives into the epoxy matrix results in a major enhancement in flexibility as identified by the improvement in elongation at break. FR-1 and FR-3, which contain silicone elastomers, cause less severe degradation on the tensile modulus and strength compared with FR-2. The addition of SD helps increase the stiffness of epoxy nanocomposite thin films and improves their thermal stability but decreases their flexibility.     

Pump-noise-induced linewidth contributions in distributed feedback fiber lasers

We investigate experimentally and theoretically the linewidth of an Er-Yb-doped distributed feedback fiber laser. We find that two noise sources are mainly responsible for the observed behavior, fundamental thermal noise at low pump power levels and temperature fluctuations induced by pump intensity noise at higher powers. Potential techniques to overcome these limitations are discussed.     

Effect of age and loading rate on human cervical spine injury threshold

STUDY DESIGN: Statistical analysis of human cadaver cervical spine compression experiments. OBJECTIVES: To quantify the cervical spine compressive injury threshold as a function of the person's age, gender, and external loading rate. SUMMARY OF BACKGROUND DATA: Results of epidemiologic studies have indicated that most survivors of cervical spinal cord injury have spinal column fractures and dislocations that result from a compression or compression-flexion force vector. Cervical spinal column injury thresholds are dependent on many factors. Delineation of the injury thresholds according to age, gender, and loading rate is necessary to improve clinical assessments and prevention strategies. METHODS: Twenty-five human cadaver head-neck compression tests were included in the analysis. Two statistical models were used to quantify the effects of age, gender, and loading rate on the force required to induce failure in the cervical spine. A multiple linear regression model provided a direct equation that quantified the effects of the variables, and a proportional hazards model was used to quantify probability of injury with each factor. RESULTS: The regression model had a correlation coefficient of 0.87. There was an interactive effect between age and loading rate: Increasing age reduced the effect of loading rate and at approximately 82 years, loading rate had no effect. Men were consistently 600 N stronger than women. The 50% probability of failure for a 50-year-old man at a 4.5-m/sec loading rate was approximately 3.9 kN. Differences in probability curves followed the same trends as seen in the regression model. CONCLUSIONS: The effects of age on cervical spine injury threshold are coupled with the rate of loading experienced through the external force vector that causes the trauma. Assessment of injury mechanisms and thresholds should be based on the person's age, gender, and loading rate to determine treatment and prevent injuries.     

Work measurement for estimating food preparation time of a bioregenerative diet

During space missions, such as the prospective Mars mission, crew labor time is a strictly limited resource. The diet for such a mission (based on crops grown in a bioregenerative life support system) will require astronauts to prepare their meals essentially from raw ingredients. Time spent on food processing and preparation is time lost for other purposes. Recipe design and diet planning for a space mission should therefore incorporate the time required to prepare the recipes as a critical factor. In this study, videotape analysis of an experienced chef was used to develop a database of recipe preparation time. The measurements were highly consistent among different measurement teams. Data analysis revealed a wide variation between the active times of different recipes, underscoring the need for optimization of diet planning. Potential uses of the database developed in this study are discussed and illustrated in this work.     

Quality assessment of stereoscopic image by 3D structural similarity

Multimedia Tools and Applications - Objective image quality assessment is proposed with the intention to substitute human-rated subjective evaluation by using computational method. Several types of...     

345-mW 1836-nm single-frequency DFB fiber laser MOPA

We demonstrate an in-band-pumped continuous-wave single-frequency distributed-feedback (DFB) fiber laser emitting at a wavelength of 1836 nm with an output power of /spl sim/5 mW. The laser is subsequently amplified to 345 mW using a master-oscillator power amplifier configuration. To the best of the authors' knowledge, this is the first report of a Tm-co-doped single-frequency DFB fiber laser that is in-band pumped at 1565 nm. The laser is confirmed to operate in a single mode, using a scanning Fabry-Pe/spl acute/rot interferometer.