bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ship Model Testing in Simulated Ice Flow Covered Waters
Authors: Aboulazm A. , Muggeridge D. 
Published: November 2022

The problem of ship resistance in ice floe infested waters has been investigated experimentally in the Towing Tank of Memorial University of Newfoundland. Ships and ice have been modelled to simulate the natural condition of ships sailing in waters covered with ice fragments.
Ships advancing in waters coveted with ice floes of moderate size, with less than 100% concentration and with no lateral pressure seldom break any ice. The ship and the ice floes have therefore, been treated in this investigation as freely floating rigid bodies. Both the ice floes and the ship have, therefore been modelled in accordance with Froude principles.
The ice cover was modelled using blocks of paraffin wax spread over the water surface. Slabs of wax were cut into small blocks having thickness and size in accordance with the required geometrical modelling scale. Wax blocks were spread over the water surface according to the required ice cover concentration. Ship models were towed in the tank at different speeds. The model resistance for each run was measured and recorded.
Results obtained from model testing experiments are presented in this paper. The results cover a number of ship model runs at different ship speeds, and for a variety of ice cover conditions. The results have been compared with ice floe resistance data available in the literature.
A Six Degree-of-Freedom Dynamic Test Facility: Concept and Feasibility
Authors: Mackay M. , Walker R. 
Published: November 2022

This paper outlines the requirements, concept and feasibility of a six degree-of-freedom test rig for dynamic experiments with captive models. The specifications are driven by the requirements of submarine testing, although the rig must also be fully capable of testing surface ship models. Large amplitude motions and rates are required in order to obtain the nonlinear stability derivatives.
The test rig was designed for operation on the carriage of the 200 meter towing tank at the Institute of Marine Dynamics, St. John's. It will accept submarine models up to 6 meters long, using a sting mount at the tail of the model to alleviate support interference, but modelling the propulsion system will generally require an alternative mounting arrangement. The principal actuators are hydraulically-driven ballscrew jacks, Under the control of a microcomputer. In addition to testing with harmonic motions, there is a capability for measuring forces and momenta for an arbitrary trajectory of the model, subject only to kinematic limitations.
Video Systems For Propeller Viewing Trials
Authors: Kennedy J. , Sponagle N. , Wheaton D. , MacDonald P. , Creaser R. 
Published: November 2022

Propeller viewing trials are a necessary adjunct to towing tank and cavitation tunnel tests, if a full assessment of propeller performance is to be made. Unfortunately, viewing trials are rare because of the expense and disruption caused by the installation of propeller viewing ports. Additionally, assessment of cavitation inception and other performance parameters is difficult because of the poor performance of the human eye under stroboscopic lighting.
The Defence Research Establishment Atlantic, in conjunction with its contractors, Networx Technologies and Eyretechnics Limited, has developed video systems to overcome many of the deficiencies of conventional viewing trials. The development of this system is described, from a concept demonstrator employing conventional viewing ports, to systems which are external to the hull. The external systems eliminate the need for viewing ports and can be installed by divers with the ship afloat. The current system, cperating with shaft synchronized stroboscopic lights, allows storage of selected propeller cavitation images for simultaneous or later display on conventional video equipment. Examples of installation and trial results are given.
Recent Developments at UNO (1986-89)
Authors: Latorre R. 
Published: November 2022

On July 23, 1987 the University of New Orleans (UNO) dedicated Its new engineering building which houses the 125ft 8 in x 15ft x 0-7ft deep Ship Offshore University Laboratory Towing Tank. This paper describes the developments from 1987-1989 as well as some of the future plans for the tank in the areas of
Teaching
Research
Technical Support.
Model and Full Scale Monitoring of a Jacket Docking over a Template
Authors: da Silva Sergio , Hirata Kazuo 
Published: November 2022

This work presents results of model tests and full scale monitoring of a jacket docking over a template.
In model tests the system composed by the jacket and the crane ship were expose to regular, transient and irregular waves. Jacket accelerations crane ship motions and guide loads were recorded at tests. Similar variables were monitored at full scale.
Differences in environmental conditions precluded a comparison between model tests and full scale monitoring. But some few conclusions were obtained as follows:
Crane ship rolling motions occurs in following seas. As a consequence, loads at guides perpendicular to wave direction become the same order of loads parallel to wave direction.
Loads at guides are changed significantly due to waves direction.
Current forces acting on jacket, simulated by a counterweight, increases the dynamic loads on guides.
Self-Propulsion Experiment for Icebreakers in Ice and Open Water
Authors: Molyneux W. 
Published: November 2022

An icebreaker propulsion system has to be versatile in order to perform at optimum efficiency in all operating conditions. It must be economical when steaming in open water, and yet deliver large thrusts in the bollard condition. It must also withstand the loads imposed by the fee, which can be in the form of a steady load during tee milling, or a transient load due to tee impact. All these factors combine in a complicated manner, and physical model experiments are currently the best method available for studying the problem. An experiment program to predict the propulsive performance of an icebreaker must therefore address both the open water and icebreaking aspects, in an accurate and efficient manner.
This paper discusses some techniques developed to predict the propulsive performance of large ice­breakers, using models in a refrigerated tee basin and a towing tank. It is based on some experiments recently carried out at the Institute for Marine Dynamics (IMO). in St. John's, Newfoundland and the results are used for illustration purposes throughout this paper.
An Examination of Axisymmetric Propeller-Hull Interaction Effects and Their Impact on the Design of Propeller-Vehicle Systems
Authors: Uhlman James 
Published: November 2022

It has been recognized for some time that the interaction between the flow past a vehicle hull with that through the vehicle's propulsor is significant in the sense that the loads experienced by the propulsor and the hull can be drastically alterred by the interaction. Traditionally these interactions have been taken into account empirically. More recently simple interaction models have begun to be used 10 obtain more accurate theoretical predictions of these effects. Herein is contained a program which advances the state-of-the-art by integrating currently available models to calculate these interaction effects directly.
Separate numerical models presently exist for the calculation of the flow about an axisymmetric body and for the flow through a propeller. The present program, APHIPS (Axisymmetric Propeller-Hull Interaction Program System), employs a boundary-integral model for the axisymmetric potential flow about the vehicle hull, a finite-difference model for the axisymmetric boundary-layer flow along the hull and a full three-dimensional boundary-integral model for the calculation of the potential flow through the propeller. These three flow models interact and the solution of each modifies the solution of the other two. The final equilibrium achieved represents the flow solution about the hull-propeller system with all the interactions taken into account.
The APHIPS program has been employed to predict the interaction of the hull and propeller flows about bodies of Navy interest for which experimental measurements exist. The results of the numerical calculation have been compared with the experimental findings for validation and the agreement has been found to be good. Preliminary investigations into the nature and magnitude of the flow interactions have also been performed. Examination of these results indicates that the interactions can be quite significant and can therefore have a large impact on the design of propeller-vehicle systems.
An Investigation into Effect of Hull Form on the Wake Wave Generated by Low Speed Vessels
Authors: Renilson M. , Lenz S. 
Published: November 2022

The erosion caused by vessel wake has for many years caused problems in restricted waterways (See for example Camfield et al. [1980]). It has generally been assumed that the errosive qualities of a wake wave pattern is related to the maximum wave height of that pattern. (Nanson et al, [1987]).
In order to investigate the effect of hull shape on the size of the wave, model and full scale experiments were carried out by the Ship Hydrodynamics Centre at the Australian Maritime College.
Roll Damping For Small Fishing Vessels
Authors: Bass D. , Haddara K. 
Published: November 2022

The successes of Naval Architects in predicting ship motions in waves, have been mainly confined to motions other than roll. For roll motions it has long been recognized that roll damping for wave encounter frequencies near the natural roll frequency is not only an extremely significant parameter but also very difficult to predict accurately. Because of the need to consider viscous flow (or even 'slightly viscous flow') to correctly model roll damping phenomena, there is still some way to go before an adequate numerical model of the hydrodynamics of roll is forthcoming. For this reason empirical and semi-empirical methods have played and will continue to play an important role in the prediction of roll motions. For small fishing vessels with deep skegs, hard chines and nonstandard hull shapes, the prediction of roll damping is particularly difficult due to lack of available data bases, semi- empirical formulae, and of course adequate theoretical models. It was for this reason that the present study was undertaken. In all, six small fishing vessels will be studied, each of which lies in the 'less-than 25 meter' class. They are all of similar dimensions but have varying hull forms ranging from the angular (e.g. model '363') to the rounded hull form of '366' (see figure 1).
Apart from providing a data base for the estimation of damping for different hull forms, the study will be used in the analysis of mathematical and/or numerical methods for the prediction of roll damping that the authors hope to develop (or hope will be developed) in the future. The present paper describes preliminary investigations of roll damping characteristics for just 3 of the boats. The methodology employed was that of the classical roll decay test with an innovative feature-namely the use of a newly developed method of analysis which enabled the authors to obtain the non- dimensional damping coefficient from the complete roll decay curve taken over just one full cycle. This method of analysis is based on an energy approach and is explained in [l]. Using this approach, the roll damping moment dependence on the initial roll angle is easy to obtain. The emphasis in this paper is a 'frequency domain' analysis of the results with equivalent linear damping as the primary target. The advantage of the simple decay test is that it allows for analysis in both the frequency and time domains. A study of the results in the time domain will be presented in a later paper. The simplicity of the roll decay experiment also means that many experiments can be perfomed and regression analysis carried out on the results. Over one thousand such tests were performed for the three models in this study. The body plans for the three models are shown in figures 1 (a), (b), (c), and their particulars are given in Table l.
In the experiments the models were attached to a dynamometer with just 2 degrees of freedom; the model was free to roll and heave, but restrained in all other modes.
Swath Resistance in Waves with Associated Steady and Dynamic Responses
Authors: Chun H. , Djattniko E. , McGregor R. , Ferguson A. 
Published: November 2022

A series of tank tests were conducted to compare the hydrodynamic performances of single and twin strut SWATH models with forward speeds. The measurements were the added resistance in regular head waves of frequency of 0.3 to 1.6 Hz together with associated dynamic responses (heaving, pitching and surging) and steady responses (sinkage and trim).
Also, stationary tests were performed to measure the motion responses for the two models in head, quartering and beam seas. The measurements of the bending moment at the cross deck mid section of both models in beam seas were included. Some of these hydrodynamic properties for both models are compared with the computational results based on a 3-D diffraction theory. The main purpose of this paper is to compare the single and twin strut SWATH ship from the hydrodynamic performance point of view.
Seakeeping Tests of a Swath Model in a small Towing Tank
Authors: Ninh P. , Li J. , Hsiung C. 
Published: November 2022

The Technical University of Nova Scotia, Halifax, Nova Scotia has a small ship-model towing tank located in the Civil Engineering Hydraulic Laboratory, currently being used by the Ship Hydrodynamics Research Group.The dimension of the tank is lm x lm x 30m. A carriage is driven by a 1/4 horsepower constant torque DC motor. It can reach a maximum velocity of 2.44 m/s (8 ft/s) and sustain a maximum model resistance of 9.1 kgs (20 lbs). The motor control unit permits the carriage to be run in both forward and reverse directions at the same speed with a maximum acceleration or deceleration of 1.22 m/s^2 (4 ft/s^2) as shown in Fig. 1.
A precisely computer-controlled wave-making system has been purchased from Edinburgh Design Ltd., U.K. and recently installed in the tank. It has two wave-makers, one at each end. Either one can act as a wave-maker or a wave-absorber (Figs. 2 and 3). The system can make progressive waves or standing waves, as well as regular waves or irregular waves. The maximum wave height is about 0.3 m (1 ft) and the frequency range for sinusoidal wave generation is from 0.2 hz to 2 hz.
A motion measurement device was developed in-house for the two-degree of freedom of motions. In particular, heave and pitch displacements could be measured simultaneously. It consisted of a LVDT (linear variable differential transformer) and a RVDT (rotational variable differential transformer) of 10% linearity. The LVDT was mounted on the carriage just above the model and the RVDT was attached directly at the base of the heave staff. The model was attached to one end of the heave staff by a connecting device. This device was designed in a way such that only one rotational motion, pitch was permitted. The heave staff was made of a square aluminum rod and guided by eight high-precision roller bearings housed in a PVC block. This rod, in tum, allowed the model to move in heave only. Except heave assembly is shown in the schematic arrangement (Fig. 4) and Fig. 5.
The hull form chosen for this seakeeping test was a SWATH 4A hull with the sectional area curve and the waterplane curve shown in Fig. 6 [l). The model used in the present study was constructed of balsa wood to a scale factor of 1:153 (Fig. 7). A list of principal particulars is given in Table 1. The model was ballasted to the design waterline. Longitudinal CG was measured by weighing the model on a weighing scale, vertical CG was measured through an inclining experiment, and the radius of gyration was determined by swinging the model in pitch with the pivotal method.
Evaluation of Histopathological Diagnosis and Determination of Grades and Stages in Breast Cancer
Authors: Nur Fateha , Badruddoza Shah Md. , Asafudullah S. M. 
Published: November 2022

Background: Breast cancer is the most frequent neoplasm in women. According to American Cancer Society in 2019, an estimated 268,600 new cases of invasive breast cancer was diagnosed among women in USA. In Bangladesh, breast cancer has rapidly become the number one cancer in female pushing cervical cancer to second position.
Objective: To evaluate histopathological diagnosis and determination of grades and stages in breast cancer.
Methods: This cross-sectional descriptive type of study was conducted in the Department of Pathology, Rajshahi Medical College. Forty-five untreated cases of breast cancer were included in this study between the period of July 2019 to June 2021 and paraffin embedded sections were obtained from representative mastectomy specimen. The sections were stained with hematoxylin and eosin stain followed by evaluation of angiogenesis by using CD34 antibody.
Results: According to histopathological grade 51.1% belonged to grade III followed by 28.9% grade II and 20% grade I. Histological stage showed most of the cases was stage II (48.9 %) followed by stage I (26.7 %) then stage III (24.4 %). Upon statistical analysis, a significant relation was obtained between MVD with increasing histologic grades and stages.
Conclusion: In conclusion we can say that histological stage showed most of the cases was stage II followed by stage I then stage III.
Inflammatory Mediators (CA125, CRP) and Uric Acid in Association with Severity of Preeclampsia in North Kordofan State, Western Sudan
Authors: Suliman Naglaa Abdelbasit , Awadalla Khidir Elamin , Bakheit Khalid Hussein , Mohamed Abdelrahim Osman 
Published: November 2022

Introduction: Inflammatory mediators could be laboratory markers of preeclampsia, as the induction of an inflammatory process within the placenta may trigger the expression of cancer antigen 125(CA125), C-reactive protein (CRP) and uric acid (UA). Regarding the pathophysiology of pre-eclampsia, there is defective trophoblastic invasion of uteroplacental blood vessels that leads to placental ischemia, and induction of an inflammatory process within the placenta.
Objective: To evaluate the association of serum levels of cancer antigen (CA125), C-reactive protein (CRP) and serum uric acid with the Severity of Preeclampsia.
Materials and Methods: The study recruited 200 singleton Sudanese pregnant women. These participants were divided into two groups: control (n = 100) and cases (n = 100). The cases were further subdivided into; mild preeclampsia (n =46), and severe preeclampsia (n = 54). The study groups were well-matched in maternal age, gestational age and body mass index. Blood samples were taken for measurement of serum cancer antigen-CA125, uric acid and C - reactive protein using immune- assay and enzymatic automated chemical analysis.
Results: The mean levels of cancer antigen-CA125 in mild and severe preeclampsia groups were; 21.94±5.08 (IU/ml) and 40.77±9.82 (IU/ml) respectively, which were significantly higher, (P<0.001) in comparison with the control group (16.88±7.36 (IU/ml). The mean levels of C-reactive protein in mild and severe preeclampsia were; 15.17±5.35 (mg/L), 31.49±12.56 (mg/L) respectively. There was significant difference in their levels, compared to the control group (4.79±1.78 (mg/L), (P<0.01). Also, the mean levels of uric acid in mild and severe cases were; 6.44±1.98 and 7.37±2.00 which was significantly higher, in comparison with the control (4.00±0.61); (P<0.001). The level of uric acid also, showed significant difference within the case (severe and mild) group (P<0.05). CA125, CRP and UA level‎s correlated positively with Mean Arterial blood pressure (MAP), (r>0.7; P < 0.001). ROC curve validate the utility of these biomarker for the detection of preeclampsia severity (AUC>0. 8; P < 0.001).
Conclusion: Serum cancer antigen 125(CA125), C- reactive protein and uric acid in studied preeclampsia groups were found to be significantly higher compared with the control group, and the rises were directly associated with the severity of preeclampsia.
Modelling the Relationship between Weather Variables and Yellow Stem Borer Population: A Count Data Modelling Approach
Authors: Reddy Bojjareddy Nanda Kumar , Rathod Santosha , Kallakuri Supriya , Sridhar Yerram , Admala Meena , Malathi Seetalam , Pandit Pramit , Jyostna Bellamkonda 
Published: November 2022

Aim: This study was conducted to model the relationship between discrete dependent variable (yellow stem borer population) and continuous weather variables.
Data Description: The yellow stem borer (YSB) population and standard meteorological week (SMW) wise weather variables (temperature, relative humidity, rainfall and sunshine hours) data of Warangal centre (Telangana state) generated under All India Co-Ordinated Rice Improvement Project (AICRIP) from 2013-2021 were considered for the study. The YSB population were recorded daily using light trap with an incandescent bulb and are counted as weekly cumulative catches.
Methodology: The weekly cumulative trapped YSB populations and weekly averages of climatological data were considered as inputs to the models under consideration. In this study the classical linear regression i.e. step-wise multiple linear regression and count regression models such as Poisson, negative binomial, zero inflated Poisson and zero inflated negative binomial regression models were employed.
Result: The empirical results revealed that the zero inflated count regression models viz., zero inflated Poisson regression and zero inflated negative binomial regression models performed better compared to the classical linear regression, Poisson and negative binomial regression models, further the negative binomial regression model outperformed all models as it yielded lowest mean square error (MSE) and highest R2 values. The average percentage reduction in accuracy of zero-inflated negative binomial regression model over classical model was around 4 percent.
Conclusion: Based on the results obtained in this study, it is concluded that the zero inflated models performs better compared to classical models as they are unable to handle the presence of excess zeroes, as a result provides more prediction error and lower R2 values. Further, the models developed in this study will be of great assistance in identifying the factors influencing occurrence of YSB population in rice.