A Possible Eddy Retention Mechanism for Ichthyoplankton in Hecate Strait

1990 ◽  
Vol 47 (7) ◽  
pp. 1356-1363 ◽  
Author(s):  
William R. Crawford ◽  
Albert V. Tyler ◽  
Richard E. Thomson
Keyword(s):  
Retention Mechanism ◽  
Recruitment Rate ◽  
High Rate ◽  
Return Flow ◽  
High Productivity ◽  
Strong Current ◽  
Pelagic Larvae ◽  
Juvenile Habitat ◽  
Current Flows ◽  
Set Up

The cause of the high rate of production of groundfish in Hecate Strait is uncertain. It is likely that the large, shallow areas of the Strait contribute to the high productivity because of their suitability as juvenile habitat. In winter, however, when many groundfish species spawn, a strong current flows northward through the Strait into Dixon Entrance and likely carries many of the pelagic larvae out of the Strait. A recent study shows that the recruitment rate of Pacific cod varies inversely with this current, which is to be expected if the larvae are swept out of the Strait by the flow. We examine current and wind data from a variety of field programs in Hecate Strait, and find evidence for a return flow toward the southwest in Hecate Strait, counter to the wind-driven transport. This return flow is driven by the set-up of sea level along the Strait by the wind, and its strength increases with the intensity of southeast storm winds. We believe the return flow will recirculate a significant fraction of the larvae in the Strait, increasing their residence time sufficiently to allow settling out, thus enhancing recruitment.

Mathematical modelling of salt purification by recrystallization. A cross-current flow model and its comparison with the countercurrent arrangement

1986 ◽  
Vol 51 (11) ◽  
pp. 2489-2501
Author(s):  
Benitto Mayrhofer ◽  
Jana Mayrhoferová ◽  
Lubomír Neužil ◽  
Jaroslav Nývlt
Keyword(s):  
Flow Model ◽  
Current Flow ◽  
Countercurrent Flow ◽  
Flow Models ◽  
Multi Stage ◽  
Stage Crystallization ◽  
The Cross ◽  
Current Flows ◽  
Set Up ◽  
Cross Current

A model is derived for a multi-stage crystallization with cross-current flows of the solution and the crystals being purified. The purity of the product is compared with that achieved in the countercurrent arrangement. A suitable function has been set up which allows the cross-current and countercurrent flow models to be compared and reduces substantially the labour of computation for the countercurrent arrangement. Using the recrystallization of KAl(SO4)2.12 H2O as an example, it is shown that, when the cross-current and countercurrent processes are operated at the same output, the countercurrent arrangement is more advantageous because its solvent consumption is lower.

Experimental Study of a Full Forward Extrusion Process from Metal Strip

2012 ◽  
Vol 504-506 ◽  
pp. 587-592 ◽  
Author(s):  
Marion Merklein ◽  
Tommaso Stellin ◽  
Ulf Engel
Keyword(s):  
Extrusion Process ◽  
Metal Strip ◽  
Raw Material ◽  
High Rate ◽  
Process Chain ◽  
Forward Extrusion ◽  
Bulk Forming ◽  
Material Conditions ◽  
Set Up ◽  
Tooling System

A high rate of production of complex microparts is increasingly required by fields like electronics and micromechanics. Handling is one of the main problems, limiting those forming processes of small metal components consisting of multiple forming stages. A forming chain in which a metal strip acts both as raw material and support of the workpiece through the different stages of the process, is seen as a solution that radically simplifies the positioning of microparts. Each workpiece stays connected to the strip through all the forming steps, being separated just at the end of the process chain. In this work, a tooling system for the bulk forming from copper strips has been set up and employed in a full forward extrusion process of a micro-billet. The same die, with a diameter of 1 mm, has been used with three different strip thicknesses (1, 2 and 3 mm) and three different material conditions. The use of thinner and hard-as-rolled strips has resulted in achieving a higher ratio of the billet length to strip thickness.

Paternity, relationship, sexual activity and fertility in testicular cancer (TC) survivors (TCS): Results from a single institution observational prospective study.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 380-380
Author(s):  
Davide Bimbatti ◽  
Francesco Pierantoni ◽  
Marco Maruzzo ◽  
Filippo Maria Deppieri ◽  
Aichi Msaki ◽  
...  
Keyword(s):  
Sexual Dysfunction ◽  
Premature Ejaculation ◽  
Relative Survival ◽  
High Dose Chemotherapy ◽  
High Rate ◽  
Interdisciplinary Management ◽  
High Dose ◽  
Family Status ◽  
Set Up ◽  
Status Data

380 Background: TC represents 1% of male neoplasms but it is the most common in young adults. Interdisciplinary management with chemotherapy, radiotherapy and surgery has led to a 10-year relative survival rate of up to 95%. These treatments (Tx) have short- and long-term side effects. While sexual dysfunction can reduce fertility, psychosocial distress can create relationship problems and finally affect the ability to procreate. Methods: From February 2020, we submitted a series of questionnaires to all the patients (pts) currently followed-up at the Istituto Oncologico Veneto free from TC recurrence for at least 2 years from the last Tx. International Index of Erectile Function (IIEF-15) and Premature Ejaculation Diagnostic Tool (PEDT) were used. We also set up a questionnaire to investigate paternity and family status. Data about disease and treatments were collected from medical records. Results: 84 TCS completed the questionnaires, clinical data are reported in the table below. 29,8% of pts fathered children before diagnosis with a strong correlation with older age at diagnosis (45,4 vs 30,8 years, p<0,001). After Tx, 14 pts had children: 9 of which naturally, 2 out 6 were successful via assisted reproductive technology (ART) (including one patient that received high-dose chemotherapy and stem cell transplantation), 3 via adoption. 89,3% of pts had stable relationships. Of pts who did not have children: 13,1% claimed to be due to lack of a partner, 39,3% claimed to be unready, while 14,3% had tried unsuccessfully to conceive. While 28,6% pts claim to currently have fertility issues, only 8,3% of pts reported to have these issues before diagnosis. 70,2% of pts performed a spermiogram after Tx, 10 pts had spermatogenic impairment. Higher rate of sexual dysfunction after Tx was detected by questionnaires while only 4 pts claimed to have had a pre-existing issue prior to TC diagnosis. PEDT shows that 38,1% had premature ejaculation and that in 22,6% this issue is highly probable. IIEF confirms a high rate of erectile dysfunction (14,3% severe and 10,7% mild or moderate). No correlations were identified between sexual dysfuntion and previous Tx. Conclusions: Most TCS had not planned fatherhood while 16,7% had children after Tx and 14.3% tried unsuccessfully to conceive. ART and adoption is possible but challenging and little used. PEDT and IIEF found high rates of sexual dysfunction but no association with previous Tx were found. [Table: see text]

Ciliary Activity and Oxygen uptake in Branchiostoma Lanceolatum(Pallas)

1965 ◽  
Vol 43 (1) ◽  
pp. 1-12
Author(s):  
W. A. M. COURTNEY ◽  
R. C. NEWELL
Keyword(s):  
Oxygen Uptake ◽  
High Rate ◽  
Ciliary Activity ◽  
Oxygen Utilization ◽  
Nervous Control ◽  
Pharyngeal Wall ◽  
Temperature Range ◽  
Zero Rate ◽  
Branchiostoma Lanceolatum ◽  
Set Up

1. The rate of oxygen uptake by single specimens of Branchiostoma lanceolatum has been shown to vary considerably. Some animals in sealed vessels at 50° C. were able to utilize the oxygen linearly down to less than 20% of air saturation. Others ceased to absorb oxygen at high saturations while yet others displayed two different rates in a sequence starting initially with a high rate. 2. There are three possible rates of oxygen utilization, as well as a zero rate, for an animal at any temperature between 10 and 19° C. Animals in gravel exhibit only two rates at lower temperatures. 3. The slowest rate varies exponentially with temperature but the two faster rates show a rapid increase between 10 and 15° C. with little change outside this temperature range. 4. The effect of size and temperature on the increased oxygen uptake during the faster rates of respiration are discussed. It is suggested that ciliary activity of the pharynx could be associated with the extra oxygen utilization. 5. It has been found that there are three inhalant stream velocities, a fast, a slow and a zero rate with no intermediate rates. 6. Study of the isolated portions of the pharyngeal wall confirm that the fast inhalant current is set by the activity of all the cilia to give a feeding stream. The slow stream is set up by the lateral cilia, which continue to beat when the frontal cilia and most of the lateral cilia have been inhibited by lowered oxygen concentrations. 7. The lateral cilia have been shown to be under nervous control and to be inhibited by pressure on the pharyngeal bars. This mechanism depends on the presence of a connexion between the pharyngeal bars and the endostyle.

Application of Tree Graph Method for Reducing the Total Time of Tool Changing in Milling and Boring Machine Tools

2013 ◽  
Vol 371 ◽  
pp. 431-435 ◽  
Author(s):  
Claudiu Obreja ◽  
Gheorghe Stan ◽  
Lucian Adrian Mihaila ◽  
Marius Pascu
Keyword(s):  
Machine Tools ◽  
Design Method ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Tree Graph ◽  
Cnc Machine ◽  
High Productivity ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up

With a view of increasing the productivity on CNC machine tools one of the main solution is to reduce, as much as possible, the auxiliary time consumed with the set-up and replacement of the tools and work pieces engaged in the machining process. Reducing the total time of the tool changing process by the automatic tool changer system can be also achieved through minimizing the number of movements needed for the actual exchange of the tool, from the tool magazine to the machine spindle (the optimization of the tool changing sequences). This paper presents a new design method based on the tree-graph theory. We consider an existing automatic tool changing system, mounted on the milling and boring machining centre, and by applying the new method we obtain all the possible configurations to minimize the tool changing sequence of the automatic tool changer system. By making use of the method proposed we obtain the tool changing sequences with minimum necessary movements needed to exchange the tool. Reconfiguring an existing machine tool provided with an automatic tool changer system by making use of the proposed method leads to obtaining the smallest changing time and thus high productivity.

scholarly journals Improving the performance of 241Am-Be for PGNAA applications using a proper shielding for neutron source and the NaI detector

2010 ◽  
Vol 25 (3) ◽  
pp. 205-211 ◽  
Author(s):  
Hamed Panjeh ◽  
Hashem Hakimabad ◽  
Lalle Motavalli
Keyword(s):  
Gamma Rays ◽  
Energy Region ◽  
Gamma Ray ◽  
Region Of Interest ◽  
High Rate ◽  
Prompt Gamma ◽  
Peak Resolution ◽  
Set Up ◽  
Gamma Ray Detector

The gamma ray spectrum resolution from a 241Am-Be source-based prompt gamma ray activation analysis set-up has been observed to increase in the energy region of interest with enclosing the NaI detector in a proper neutron and gamma ray shield. We have investigated the tact that the peak resolution of prompt gamma rays in the region of interest from the set-up depends on the source activity to the great extent, size and kind of the detector and the geometry of the detector shield. In order to see the role of a detector shield, five kinds of the detector shield were used and finally the proper kind was introduced. Since the detector shield has an important contribution in the reduction of the undesirable and high rate gamma rays coming to the gamma ray detector, a good design of a proper shield enables the elimination of the unwanted events, such as a pulse pile-up. By improving the shielding design, discrete and distinguishable photoelectric peaks in the energy region of interest have been observed in the spectrum of prompt gamma rays.

Non-Equilibrium Phenomena in Liquids and Solutions

2004 ◽  
Author(s):  
W. Ronald Fawcett
Keyword(s):  
Cold Water ◽  
Metallic Copper ◽  
Hot Water ◽  
Uniform Density ◽  
Local Concentration ◽  
Hot Plate ◽  
Copper Electrodes ◽  
Current Flows ◽  
Set Up ◽  
Isothermal Water

The topics considered up to this point have involved liquids and solutions at equilibrium. Attention is now turned to systems which are not at equilibrium, and the processes which occur spontaneously in such systems. The physical phenomena involved can be quite complex, so that the task faced in early experiments was to separate the various processes and understand the physical properties of the system which govern them. Consider what happens when a beaker of pure isothermal water is placed on a hot plate. The water near the bottom rises in temperature and a temperature gradient is set up. As a result heat flows from the bottom of the beaker, producing a gradual increase in temperature in the water at a given height above the bottom. In addition, the temperature varies with distance, being highest at the bottom and lowest at the top. Eventually, the temperature of the water in the beaker is uniform and equal to that of the hot plate, assuming that the water does not boil. However, the flow of heat is not the only process resulting from the heat source. The density of the hot water is less than that of the cold water, so that a convection process is set up in order to achieve uniform density. Convection results in cold water moving down into the hot region so that the flow of water molecules assists the flow of heat. The changes which occur in this system cannot be understood without considering both processes. A system undergoing an irreversible change involving an electrolyte is electrolysis in an electrochemical cell. When current flows between two copper electrodes in an aqueous solution of CuSO4 the charge in solution is carried by migration of Cu2+ ions moving in one direction and SO42− ions moving in the opposite. At the cathode, the incoming Cu2+ ions are reduced to metallic copper, thereby lowering the concentration of these ions in the electrode’s vicinity. At the anode, Cu metal is oxidized to produce Cu2+ ions in the solution, so that the local concentration of cations is increased.

scholarly journals ANALYZING FLOW ENERGY POTENTIAL OF THE BOSPHORUS STRAIT

2018 ◽  
pp. 76
Author(s):  
Mehmet Özturk ◽  
Cihan Sahin ◽  
Yalcin Yuksel
Keyword(s):  
Black Sea ◽  
Lower Layer ◽  
The Black Sea ◽  
Sea Of Marmara ◽  
Energy Potential ◽  
Flow Energy ◽  
Strong Current ◽  
Layered Flow ◽  
Current Flows ◽  
Current Energy

Ocean currents represent a potentially notable, currently untapped, reservoir of energy. The regions with strong current velocities such as narrow straits connecting two water bodies exhibit high current energy (power) potential especially where the water depths are relatively shallow (EECA, 2009). The Bosphorus, connecting the Black Sea to the Sea of Marmara, is a typical narrow sea strait that generally exhibits a two-layered flow pattern: the upper layer current flows south towards the Sea of Marmara while the underlying current flows in opposite direction towards the Black Sea (Yüksel et al., 2008). The predominant mechanisms for the upper and lower layer flows are the higher water level of the Black Sea and the denser water of the Sea of Marmara, respectively.

Braking Solution for a Hydraulically Driven Linear Pallet Changer Mechanism

2014 ◽  
Vol 657 ◽  
pp. 485-489
Author(s):  
Lucian Mihăilă ◽  
Gheorghe Stan
Keyword(s):  
Medium Size ◽  
Kinematic Parameters ◽  
Two Stage ◽  
High Productivity ◽  
Counter Pressure ◽  
Pressure Limitation ◽  
Automatic Tool Changer ◽  
Hydraulic Cylinders ◽  
Automatic Tool ◽  
Set Up

The use of machining centres is predominant in the case of small and medium size batch manufacturing, their advantages being materialised in high productivity. The productivity is owed, mainly, to the small auxiliary times consumed with the tool and material change, times which are served by the automatic tool changer system and the automatic pallet changer. The purpose of this article researches aims to determine the kinematic parameters of an hydraulically driven linear pallet changer in two cases (when the deceleration is carried out through a throttle and when the deceleration is made through a new solution). Thus, an experimental set-up, which matches an hydraulically driven linear pallet changer, was designed and built. The experiments aimed toward using a classic braking method of hydraulic cylinders and a new two-stage braking with counter-pressure limitation.

Determination of Fracture Toughness by Single and Double Action Tensile Impact Fracture Tests

2016 ◽  
Vol 715 ◽  
pp. 101-106
Author(s):  
Zoltan Major ◽  
Matei Miron ◽  
Imre Kallai
Keyword(s):  
Fracture Toughness ◽  
Fracture Behavior ◽  
Loading Rate ◽  
Testing Machine ◽  
Peak Load ◽  
High Rate ◽  
Test Set ◽  
Data Scatter ◽  
Fracture Tests ◽  
Set Up

The characterization of the loading rate dependence of the fracture behavior of polymers is of prime theoretical and practical interest for supporting demanding engineering applications. To gain more insight into the high rate fracture behavior of polymers, fracture tests were performed under tensile loading conditions up to 12 m/s loading rate using a neat model polymer (PVC grey) in this study. A conventional single actuator test set-up for compact tension C(T) specimens was developed based on the previous experience of the authors and implemented on a new high rate servohydraulic testing machine. In addition, a novel double action test set-up was developed by applying two twin actuators and implemented in a rigid horizontal test frame. The conventional load and force measurement was extended by instrumented test specimens and by a high speed optical strain analysis system for both set-ups. Force based fracture toughness values using the peak load values, KIcPL and displacement based values using the critical crack opening displacement (CTOD) KICCTOD were determined up to a loading rate of 10 m/s. While the KIcPL values decreased up to a loading rate 103 MPam1/2s-1 an increase with a high data scatter was observed above them. Corresponding to the CTOD values the calculated KICCTOD values revealed a slight decrease and moderate data scatter up to the maximal loading rate.

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