Karina公司不断升级设备保持平稳增长

多年以前,哈萨克斯坦Karina公司首次推出厨房纸巾时,商店老板曾问道：“这么宽的卫生纸用来做什么？”当然这早已是陈年旧事。1991年,随着苏联解体,哈萨克斯坦独立,当地生活用纸行业蕴藏着诸多商机。作为中亚地区发展最为稳定和繁荣、消费主义盛行的国家之一,哈萨克斯坦最大的生活用纸综合生产商Karina公司迅速抓住了这一稳定的新兴生活用纸市场的商业机遇。     

Contraction of Investment Cast H13 Tool Steel Real Time Measurement

This paper presents the results of an investigation into the dimensional changes and variability of investment cast H13 tool steel. An experimental apparatus has been developed to measure the dimensional changes during the casting process. Investigating the dynamics of mould expansion and alloy contraction during investment casting, it has been possible to determine in greater detail the contributions of the cast alloy and the mould to the final contraction of unconstrained castings. Contraction and dimensional variability of the final cast product is defined and experimental estimations of the contributions of each stage of investment casting are made. A technique for combining the variability of sequential stages is discussed. The measured contraction appears to be non-uniform and dependent on the position along the casting.     

The rayleigh range of gaussian schell-model beams

Abstract

The concept of the Rayleigh range, well known in the theory of coherent beams, is generalized to a class of partially coherent beams. Curves are presented which show the dependence of the Rayleigh range on the spot size of the beam and on the spectral degree of coherence of the light in the plane of the waist.     

Toxic groundwater contaminants: an overlooked contributor to urban stream syndrome?

Screening for common groundwater contaminants was performed along eight urban stream reaches (100s-1000s of m) at approximately 25-75 cm below the streambeds. Four sites had known or suspected chlorinated-solvent plumes; otherwise no groundwater contamination was known previously. At each site, between 5 and 22 contaminants were detected at levels above guideline concentrations for the preservation of aquatic life, while several others were detected at lower levels, but which may still indicate some risk. Contaminants of greatest concern include numerous metals (Cd, Zn, Al, Cu, Cr, U), arsenic, various organics (chlorinated and petroleum), nitrate and ammonium, and chloride (road salt likely), with multiple types occurring at each site and often at the same sampling location. Substantial portions of the stream reaches (from 40 to 88% of locations sampled) possessed one or more contaminants above guidelines. These findings suggest that this diffuse and variable-composition urban groundwater contamination is a toxicity concern for all sites and over a large portion of each study reach. Synergistic toxicity, both for similar and disparate compounds, may also be important. We conclude that groundwater contaminants should be considered a genuine risk to urban stream aquatic ecosystems, specifically benthic organisms, and may contribute to urban stream syndrome.     

Comparative examination of Escherichia coli O157:H7 survival on romaine lettuce and in soil at two independent experimental sites

Little is known about the influence of abiotic factors such as climate and soil chemistry on the survival of Escherichia coli O157:H7 in field lettuce. We applied a nalidixic acid-resistant derivative of strain ATCC 700728 to field-grown romaine lettuce in two regions in Canada characterized by large variances in soil type and climate. Surviving populations in soil and on lettuce leaves were estimated on sorbitol MacConkey agar supplemented with nalidixic acid. Data were fitted with the Weibull decline function to permit comparison of decay rates in the two experimental sites. E. coli O157:H7 populations fell from 10? to <102 CFU/g on leaves, and <103 CFU/g in soil within 7 days after inoculation. Analysis revealed there was no significant difference between decay rates at the two experimental sites in either environment. The results of this study suggest that the inherent ecological fitness of E. coli O157:H7 ATCC 700728 determines the extent of survival in the production environment.     

Silver Nanoparticles Inhibit Sodium Uptake in Juvenile Rainbow Trout (Oncorhynchus mykiss)

The silver ion (Ag(+)) is well documented to be a potent inhibitor of sodium (Na(+)) transport in fish. However, it has not been determined whether silver nanoparticles (Ag NPs) elicit this same effect and, if so, if the NP itself and/or the dissociation of ionic Ag(+) causes this effect. Citrate-capped Ag NPs were dialyzed in water to determine the dissolution rate of ionic Ag(+) from the NPs and the maximum concentration of free Ag(+) released from the NPs was used as a paired Ag(+) control to distinguish NP effects from ionic metal effects. The maximum concentration of ionic Ag(+) released from these NPs over 48 h was 0.02 μg l(-1). Juvenile rainbow trout were exposed to 1.0 mg l(-1) citrate-capped Ag NPs and dialyzed citrate-capped Ag NPs or 10 μg l(-1) and 0.02 μg l(-1) ionic Ag(+) (as AgNO(3)) as controls. Both nondialyzed and dialyzed Ag NPs and 10 μg l(-1) ionic Ag(+) significantly inhibited unidirectional Na(+) influx by over 50% but had no effect on unidirectional Na(+) efflux. Na(+),K(+)-ATPase was significantly inhibited by the Ag NPs with no discernible effect on carbonic anhydrase activity. This study is the first to show that sodium regulation is disrupted by the presence of citrate-capped Ag NPs, and the results suggest that there are nanospecific effects.     

Effect of sexual maturation on thermal stability, viscoelastic properties, and texture of female rainbow trout, Oncorhynchus mykiss, fillets

The nutrient and energy demand of sexual maturation in many fish cultivars causes structural change to key contractile proteins and thereby, affects fillet firmness. Thermal denaturation and viscoelastic properties of white muscle from diploid (2N; fertile) and triploid (3N; sterile) female rainbow trout were investigated at 6 age endpoints from July 2008 through spawning in March 2009. Differential scanning calorimetry showed, in March, that the actin denaturation temperature (T(max,actin)) of 2N females was higher than that observed in 3N females (78.17 versus 77.27 °C). From 35 to 45 °C, viscoelastic measurement revealed that muscle from 2N females and younger fish (July, 16 mo) had greater elasticity (lower tan δ) than muscle from 3N females and older fish (November to March; 20 to 24 mo), respectively. The highest elastic response and the firmest fillets were observed in July. Raw fillets were softer (Allo-Kramer shear; P < 0.05) from September to January (288.77 g/g on average) than those collected in July (475.15 g/g) and March (366.79 g/g). Soft fillets became firmer after cooking except for January samples. Greater cook yield and softer fillets were observed in January compared to December. Lipid accumulation in 3N females may lubricate muscle fibers and protect them from losing functionality during the spawning season for animals on a high plane of nutrition. PRACTICAL APPLICATION: The relationship between fish maturation, measured as egg development, and chemical characteristics of fillets from fertile and sterile fish was evaluated. Thermal denaturation and viscoelastic characterization revealed changes in stability and gelling properties of muscle proteins that were related to changes in fillet texture.     

An LFT approach to parameter estimation

In this paper we consider a unified framework for parameter estimation problems. Under this framework, the unknown parameters appear in a linear fractional transformation (LFT). A key advantage of the LFT problem formulation is that it allows us to efficiently compute gradients, Hessians, and Gauss–Newton directions for general parameter estimation problems without resorting to inefficient finite-difference approximations. The generality of this approach also allows us to consider issues such as identifiability, persistence of excitation, and convergence for a large class of model structures under a single unified framework.     

Large-Scale Tracing of Ground Water with Sulfur Hexafluoride

Sulfur hexafluoride (SF6) was injected into a 9 km reach of the Santa Ana River in Orange County, CA, over a period of two weeks. The entire flow of this river, which averaged 2.8 m3 s?1, percolated into the ground in the field area. The tracer was monitored at wells near the river to determine subsurface flow patterns and flow times with an accuracy much greater than could be achieved using numerical simulations of ground-water flow. During the experiment, SF6 effectively tagged 3.7 × 106 m3 of water. The tracer plume was mapped in the subsurface for 18 months and indicates that linear ground-water velocities averaged about 2 km year?1. The tracer reached two wells adjacent to the river (about 200 m away) within three weeks, giving evidence that SF6 was not retarded significantly relative to the ground-water flow. This is in agreement with previous laboratory experiments.     

入门级消费者的货比三家

TWICE：什么样的特性从消费型数码相机上移到了数码单反上？在入门级市场上表现如何？