Immersion Length Research Articles

Total ammonia nitrogen leaching from feed pellets used in salmon aquaculture

Summary The total amount of ammonia nitrogen (TAN) leaching from Atlantic salmon (Salmo salar L.) feed pellets was determined under controlled laboratory conditions. The leaching was successfully explained by means of a first order kinetic equation: , where a was the maximum TAN leached and k was the velocity of the process. Then ta was defined as the time at which a was reached, which was obtained from the equation prediction. The interaction between pellet size and immersion length significantly influenced TAN leaching: the smaller the pellet and the longer the immersion times, the higher the leaching (a). However, pellet size did not influence k or ta, although k tended to be higher and ta lower for larger pellets. TAN leaching from feed pellets depends on the protein content and contact surface. As the surface/volume ratio (S/V) increases with pellet size while the protein content decreases, it was hypothesized that S/V influences k whereas the protein content has a greater effect on a.

Development of an atomic-force-microscope-based hanging-fiber rheometer for interfacial microrheology

A new interfacial microrheology technique using atomic force microscope (AFM) as a force sensor is developed. The probe used for microrheology contains a long vertical glass fiber with one end glued onto a rectangular shaped cantilever beam and the other end immersed through a water-air interface. The motion of the modified cantilever can be accurately described by the Langevin equation for a damped harmonic oscillator, from which we obtain the friction coefficient xi of the glass fiber in contact with the water. It is found that xi contains two contributions. One is generated by the bulk fluid, which increases with the immersion length of the glass fiber. The other contribution comes from the contact line between the water-air interface and the glass fiber, which is obtained by an extrapolation of the measured xi at the limit of zero immersion length. The experiment thus demonstrates an application of AFM in the studies of interfacial microrheology and contact line dynamics.

Settling velocity and total ammonia nitrogen leaching from commercial feed and faecal pellets of gilthead seabream (Sparus aurataL. 1758) and seabass (Dicentrarchus labraxL. 1758)

The physico-chemical characteristics of particulate wastes of Sparus aurata and Dicentrarchus labrax were investigated. Changes in the dimensions, settling velocity and total ammonia nitrogen (TAN) leached from commercial feed pellets were investigated after soaking. Also, the settling velocity and TAN leached from faecal pellets of these fish were assessed at 15 and 25 °C. The settling velocity of feed pellets was influenced positively by pellet weight and negatively by immersion length as a result of changes in pellet dimensions after soaking. The settling velocity of faecal pellets was determined by pellet weight. The experimental design did not allow identification of any consistent effect of water temperature on settling velocity. Total ammonia nitrogen leaching over time from feed and faecal pellets was successfully explained by means of a first-order kinetic equation. For feed pellets, water temperature significantly affected the speed of the process and the time at which the maximum TAN leached was reached, but did not influence the maximum TAN leached. Leaching was related to feed pellet size, and so the smaller the pellet, the higher the leaching. Total ammonia nitrogen leaching from faecal pellets was greater per unit weight than in feed pellets. However, neither water temperature nor fish species influenced TAN leaching from faeces.

Effect of fabrication process parameters on the apex‐radius of STM tungsten nanotip

Scanning tunneling microscope (STM) has found a wide application in nanoscience and nanotechnology. This microscope uses an ultra-sharp metallic tip for image acquisition. Resolution of STM images depends largely on the radius of the tip apex; the smaller the radius the higher the resolution. In the present research, an experimental set-up was designed and implemented for fabrication of STM tungsten nanotip using electrochemical-etching method with the aim of optimization of nanotip fabrication process parameters by using Taguchi method. These parameters are electrolyte concentration, immersion length of the tungsten wire, inner diameter of the cathode tube, and the process voltage. It was found that the optimum level of the process parameters for gaining minimum radius of the nanotip apex is electrolyte concentration of 2 M/lit, wire immersion length of 4 mm, cathode tube inner diameter of 55 mm, and voltage of 3.5 V within the range of experiments. By setting the process parameters on the optimum level, the radius of the nanotip apex was decreased by five times in comparison to the mean value of the experimental results. The radius of the nanotip apex was improved down to about 10 nm under the optimum conditions. SCANNING 31: 65-74, 2009. (c) 2009 Wiley Periodicals, Inc.

Optimization of STM/FIM nanotip aspect ratio based on the Taguchi method

This paper presents optimization of electrochemical etching parameters to achieve the optimum aspect ratio of the scanning tunneling microscopy/field ion microscopy tungsten nanotip by using Taguchi method. The combination of optimum level of process parameters was obtained by using the analysis of signal-to-noise ratio. The level of importance of the process parameters on the nanotip aspect ratio was determined by using analysis of variance. It was found that the optimum level of process parameters are electrolyte concentration of 2 M/lit, wire immersion length of 2.5 mm, cathode tube inner diameter of 40 mm, and voltage of 3.5 V. Within the range of experiments and the process parameters in terms of impact significance were found to be electrolyte concentration, process voltage, wire immersion length, and inner diameter of cathode tube, respectively. By using the optimum level of the process parameters, the nanotip aspect ratio was enhanced by 263% in comparison to the mean value of the experimental results. The nanotip aspect ratio of up to 163:1 was obtained in the present research.

The PBS Historical House Series: Where Historical Reality Succumbs to Reel Reality

THE PBS HISTORICAL HOUSE SERIES: WHERE HISTORICAL REALITY SUCCUMBS TO REEL REALITY INTRODUCTION: When PBS aired first of British-themed and produced historical series, 1900 House, in June 2000, network described project as classy voyeurism and place where the sci-fi of time travel meets true-life drama.1 The success of 1900 House has since led other Anglo-American productions, including 1940s House (2000), Frontier House (2001), Manor House (2002), and Colonial House (2003), and even PBS 's own version of reality dating (albeit in corsets and wigs), Regency House Party (2004) and paying homage romantic ideal of American cowboy Texas Ranch House (2006). Determined distinguish series from other reality programs aired on commercial networks, PBS producer Beth Hoppe insists that this is only one something offer. We're exploring history. No one else is doing that.2 But these experiments in time travel involve much more than re-enacting particular moments in British and American past. As families and individuals who volunteer for these series quickly discover, they cannot leave behind their 21st century mindset, nor do producers want them to; after all, that is what makes these programs true life drama and entertaining and accessible TV for which critics have praised them. Indeed, as Hoppe explains, ensuing tensions between participants, as they struggle adapt unfamiliar living conditions and values, come[s] from modern people with modern ideas trying put themselves in a time in history when things were very different.3 The PBS reality house series (also described by Hoppe as hands-on-history) is part of an on-going trend of Heritage Industry in popular culture in which public can safely revisit, critique, and learn lessons of past. For example, tourists can explore 19th century industrial villages in England; sit in a trench or air raid shelter in London's Imperial War Museum, or witness how New England lived by touring Plimouth Plantation. For a few hours, history buffs can indulge their nostalgia for these sometimes hard but good old days. But these interactive museums also present a very distinct and tidied picture of these pasts, sans rats, smallpox epidemics, falling bombs, and other historical dangers. What makes PBS reality house experiments more authentic than such interactive museums is total immersion process and length of time volunteers spend in their historical contexts, ranging from three five months. In these televised experiments, volunteers do have struggle for their subsistence, submit authority, rely on older medical remedies, and abandon their modern dress for uncomfortable, and oftentimes dirty, period costuming. Despite these inconveniences, volunteers are surprised by ease with which they take up their assigned roles-the submissive lady's maid, class-conscious butler, domineering husband. Yet, volunteers never fully become their roles, as they adapt their historical identities their 21st century mentalities and experiences, as exhibited by servants of Manor House mouthing off their master or colonists in Colonial House refusing cheat their Native American trading partners. Heritage critic Robert Hewison argues that what is created by historical reenactment projects (and we can include historical House series in this category) is simulacra, i.e., image rather than reality.4 Similarly, David Lowenthal notes that more past is appreciated for its own sake, less relevant or real it becomes. In fact, ultimate goal of series is not revere past but rather to enlarge our sense of contemporary at expense of realizing its connection with past.5 Manor House producer, Caroline Ross-Perie, attests this intended outcome. …

Development of the Monitoring System of Plasma Behavior Using a CCD Camera in the GAMMA 10 Tandem Mirror

In the central-cell of the GAMMA 10 tandem mirror, a medium-speed camera (CCD camera, 400 frames per second, 216× 640 pixel) has been installed for the observation of plasma behavior. This camera system is designed for monitoring the plasma position and movement in the whole discharge duration. The captured two-dimensional (2-D) images are automatically displayed just after the plasma shot and stored sequentially shot by shot. This system has been established as a helpful tool for optimizing the plasma production and heating systems by measuring the plasma behavior in several experimental conditions. The camera system shows that the intensity of the visible light emission on the central-cell limiter accompanied by central electron cyclotron heating (C-ECH) correlate with the wall conditioning and immersion length of a movable limiter (iris limiter) in the central cell.

Silver halide fiber-based evanescent-wave liquid droplet sensing with room temperature mid-infrared quantum cascade lasers

Quantum cascade lasers and unclad silver halide fibers were used to assemble mid-infrared fiber-optics evanescent-wave sensors suitable to measure the chemical composition of liquid droplets. The laser wavelengths were chosen to be in the regions which offer the largest absorption contrast between constituents inside the mixture droplets. A pseudo-Beer-Lambert law fits well with the experimental data. Using a 300microm diameter fiber with a 25 mm immersion length, the signal to noise ratios correspond to 1 vol.% for alpha-tocophenol in squalane and 2 vol.% for acetone in aqueous solution for laser wavenumbers of 1208 cm-1 and 1363 cm-1, respectively.

Buckling and postbuckling of a long, hanging column lowered into a fluid

A long, hanging column is lowered into a fluid. Depending on the immersion length, densities and flexural rigidity, the column may or may not buckle. The stability criteria are found in terms of Bessel and Airy functions. There exists a maximum stable penetration depth. Post-buckling shapes are also integrated.

Laboratory scale electroplating and processing of long lengths of in situ Cu3Sn superconductors

Abstract The high temperature gradient solidification (HTGS) system for continuous casting of 12.7 mm diameter rods of in situ Cu-Nb is briefly reviewed. A laboratory scale continuous tin electroplating system is described and used to evaluate the effect of various parameters of the alkaline and acid baths plating process. Tin electroplating is shown to be simple and reliable. With an 8 m immersion length production speeds of ∼ 1 m min −1 are possible in an alkaline bath at 80°C. An acid bath gives satisfactory tinning deposits with a production speed of up to 3 m min −1 at room temperature.

Capacitive modulation of micropipet impedance.

Quantitative theoretical and experimental evidence is presented suggesting that the saline-filled, glass micropipets employed in microvascular pressure measurements behave electrically as simple, parallel resistor-capacitor combinations in which the capacitance is dependent upon the length of the pipet in contact with the conductive fluid surrounding the tip. Changes in the apparent pipet impedance arising from modest alterations in the immersion length are sufficient to cause zero-level shifts in the measured pressure.

Effects of Electrical Connections and Phasing in Electrical Glass Melting Systems

Three general problem areas are considered. They are electrode immersion length, parallel electrode effects, and power density distribution. Use is made of data from operating furnaces, water models, and mathematical analysis.

STUDIES ON SPINNING MECHANISM OF VISCOSE

According to our series of studies, a new theory on the spinning mechanism of modified viscose has been proposed.In this paper, the courses of coagulation, regeneration and stretching of modified viscose were investigated in details with the following results:(1) The degree of gel swelling of the spinning filaments lowers as the length of spin bath immersion is increased and come up to the equilibrium degree at a certain length of immersion.(2) The residual γ-value of the spinning filaments decreases as the length of spin bath immersion is increased.(3) At a certain point of the longer immersion length, that is, the lower residual γ-value than that of the equilibrium gel swelling, the stretchability rises to maximum and the highest tenacity is obtained.Based on these facts, the mechanism of the fiber formation of modified viscose is discussed applying the theory of rubber elasticity.