scholarly journals TO THE QUESTION OF DEFINING ERRORS ARISING IN THE ANALYSIS OF SHIP STABILITY IN SHIP COMPUTER SOFTWARE

2019 ◽  
pp. 7-15
Author(s):  
Irina Yakuta ◽  
Boris Samuilovich Guralnik
Keyword(s):  
Computer Software ◽  
Weather Conditions ◽  
Static Stability ◽  
Stability Diagram ◽  
Climatic Conditions ◽  
Center Of Gravity ◽  
Variable Load ◽  
Random Errors ◽  
Ship Stability ◽  
The Difference

The article shows the need to account the difference between real weather conditiona and weather parameters given in shipboard computer software. Taking into account the fact that climatic conditions in the oceans are getting severer, it is unsafe to rely on relevance and reliability of the shipboard software forecasts navigating in zones with extreme weather conditions. Having the opportunity on board to get enough accurate weather forecasts in advance a navigator can competently plan the future voyage and avoid the expected storm. It not always possible to calculate the divergence with the storm and a vessel can be affected by cyclonic activity for different reasons. The ships stability is considered reached if the weather criterion shows the area ratio b/a > 1 on a static stability diagram. The analysis showed that for this case b/a = 0.436, which is 2.3 times less the minimum allowable value. It is stated that in the course of a ship operation the displacement and heights of center of gravity increase on the empty ship. If the ship stability is controlled by calculations, there occur random errors of due to inaccuracy of evaluating variable load. An increase of displacement and a height of center of gravity of an empty ship, as well as accidental errors due to inaccuracy of evaluation of deadweight may reach in total over 100 tons for displacement and up to 0,20 m for elevation of center of gravity. This fact should be taken into account in the shipboard software analyses. There have been given examples of formulas determining the displacement errors and a height of center of gravity of the vessel under operational load

scholarly journals Local terrain-topography and thermal-properties influence on energy and mass balance of a snow cover

2011 ◽  
Vol 52 (58) ◽  
pp. 169-175 ◽  
Author(s):  
E.E. Adams ◽  
A.E. Slaughter ◽  
L. McKittrick ◽  
D.A. Miller
Keyword(s):  
Thermal Properties ◽  
Environmental Science ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Shortwave Radiation ◽  
Near Surface ◽  
Radiation Exchange ◽  
Digital Elevation ◽  
Model Account ◽  
The Difference

AbstarctSnow’s interaction with the environment is an important area in environmental science, particularly as climatic conditions change. We consider the local influence at the slope or smaller scale. Near-surface properties drive the dynamic interface with the atmosphere and with surrounding terrain. While accounting for topography, complex interactions involving energy and mass transfer at the snow surface are considered, using a computer simulation (RadTherm/RT). Digital elevation maps are used to numerically fabricate terrain features and vegetation, while applying appropriate thermal properties to specified terrain types. Conduction, convection radiation and phase change (for dry snow) are considered. Particularly relevant to this study are longwave infrared and shortwave radiation, which in the model account for shadowing, multiple reflective and emissive contributions. An example of a north-facing 30˚, snow-covered clearing bounded by trees is examined using measured meteorological conditions. Applying the same weather conditions, the model is used to examine the difference if the trees are assumed bare or covered with snow. Results indicate that, for the conditions considered, when trees are covered with snow, the open slope is cooler and the snow mass loss is less. Spatial variability across the slope is also noted. Differences are largely due to topographic radiation exchange.

scholarly journals Effect of the height of the greenhouse on the plant - climate relationship as a development parameter in mint (Mentha Spicata) crops in Colombia

2016 ◽  
Vol 36 (2) ◽  
pp. 6
Author(s):  
Nelson Bustamante Valencia ◽  
John Fabio Acuña Caita ◽  
Diego Luis Valera Martínez
Keyword(s):  
Crop Production ◽  
Crop Yields ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Mentha Spicata ◽  
Climatic Variations ◽  
Humidity Measurements ◽  
The Difference ◽  
The City ◽  
The Town

The aim of the study is to evaluate the effect of the height of the greenhouse on climatic conditions generated on a mint crop (Mentha spicata). The tests were conducted in the town of Carmen de Viboral, 40 minutes away from the city of Medellin (6º 05’ 09” N and 75º 20’ 19” W, 2150 m.a.s.l.). Three greenhouses with the same dimensions were used, changing only the gutter height in 2 m, 2,5 m and 3 m respectively. Temperature and relative humidity measurements were taken every 30 minutes for 3 years, time during which crop production was assessed. Statistical analyses were performed to determine climatic variations caused by the difference in height between the greenhouses, and to determine differences in production levels. The results indicate that, under the study conditions, the greenhouse height directly affects the weather conditions and the mint crop yields.

scholarly journals Climate Suitable Conditions Index and Autochthonous Dengue Infections: an Early Warning Index

2021 ◽  
Author(s):  
Xinting Lu ◽  
Hilary Bambrick ◽  
Francesca D. Frentiu ◽  
Xiaodong Huang ◽  
Callan Davis ◽  
...  
Keyword(s):  
Regression Models ◽  
Negative Binomial ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Future Research ◽  
Dengue Case ◽  
Vector Species ◽  
Dengue Outbreak ◽  
The Difference ◽  
The Relationship

Abstract Background: Aedes aegypti is the primary vector of dengue and contributes to most major epidemics of this virus worldwide. Aedes albopictus is also blamed for certain epidemics, as the 2014 Guangdong dengue outbreak. In Guangdong province, Ae. albopictus is thought to be the dominant vector species, with Ae. aegypti absent from most areas. Whether or not primary mosquito vectors are present, optimal climatic conditions for dengue vector species may play a substantial role in epidemics of the virus. We hypothesise that although vector species are required to initiate and establish an outbreak, favourable weather conditions may then grow and perpetuate the outbreak via complex effects on vector sympatry or interactions.Methods: Vector spices-specific suitable conditions index (SCI) and autochthonous dengue case data were fitted to negative binomial (NB) regression models. After accounting for potential confounders, we assessed the relationship between SCI and autochthonous dengue cases. We assumed SCI interaction was a proxy for vector species sympatry and SCI difference a proxy for interspecies competition. Finally, we explored the relationship between these assumed conditions and the autochthonous dengue case. Results: Autochthonous dengue cases are associated negatively with SCI for Ae.albopictus and positively with SCI for Ae.aegypti. According to the NB regression models, autochthonous dengue cases increased 4% (Incident Rate Ratio (IRR): 1.04, 95% CI: 1.02, 1.06) for every unit increase in SCI for Ae. aegypti, but decreased by 3% (IRR: 0.97, 95% CI: 0.96, 0.99) for Ae. albopictus SCI. There was also an interaction between two SCIs and a positive effect of the difference in SCIs on autochthonous dengue cases. These findings support the hypothesis that vector sympatry and interactions may influence the risk of a dengue outbreak.Conclusions: Our results confirm the hypothesis that the dengue virus is more transmissible in regions with warmer weather conditions (high SCI for Ae. aegypti). SCI of Ae. aegypti would be a valuable index to predict dengue transmission even in the absence of Ae. aegypti but with Ae. albopictus present. The results also support that the SCI is beneficial for evaluating dengue outbreak risk in terms of vector sympatry and interactions in the absence of entomology data in future research.

PERSONALIZED APPROACH TO THE ORGANIZATION OF MEDICAL CARE FOR PATIENTS WITH WEATHER DEPENDENCE

2020 ◽  
pp. 35-39
Author(s):  
Klepikov O.V. ◽  
Kolyagina N.M. ◽  
Berezhnova T.A. ◽  
Kulintsova Ya.V.
Keyword(s):  
Medical Care ◽  
Cardiovascular System ◽  
Performance Indicators ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Outpatient Clinics ◽  
Vulnerable Groups ◽  
Pathological Effect ◽  
Weather Forecasts ◽  
Personalized Approach

Relevance. Today, in preventive medicine, climatic conditions that have a pathological effect on the functional state of a person are increasingly being updated. the occurrence of exacerbations of many diseases can be causally associated with various weather conditions. Aim: to develop the main tasks for improving the organization of medical care for weather-dependent patients with diseases of the cardiovascular system. Material and methods. The assessment of personnel, material and technical support and the main performance indicators of an outpatient clinic was carried out on the example of the Voronezh city polyclinic No. 18 to develop the main tasks for improving the organization of medical care for weather-dependent patients with diseases of the cardiovascular system. Results. The main personnel problem is the low staffing of district therapists and specialists of a narrow service. One of the priorities for reducing the burden on medical hospitals is the organization of inpatient replacement medical care on the basis of outpatient clinics. The indicators for the implementation of state guarantees for the outpatient network for 2018, which were fully implemented, are given. The analysis of the planned load performance by polyclinic specialists is presented. Cardiological and neurological services carry out measures to reduce the risk of exacerbations of diseases with cerebral atherosclerosis, hypertension, and major neurological nosologies. Conclusion. Improving the organization of medical care for weather-dependent patients with cardiovascular diseases are: informing patients about the sources of specialized medical weather forecasts in the region, organizing the work of the medical prevention office, implementing an interdepartmental approach to providing health care to the most vulnerable groups of the population.

Influence of meteorological factors on potato yield in the conditions of the Right-Bank Forest-steppe

2018 ◽  
Vol 1 (94) ◽  
pp. 55-61
Author(s):  
R.O. Myalkovsky
Keyword(s):  
Meteorological Factors ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Potato Yield ◽  
High Yield ◽  
Forest Steppe ◽  
Potato Tubers ◽  
Middle Aged ◽  
Lower Yield ◽  
The Right

Goal. The purpose of the research was to determine the influence of meteorological factors on potato yield in the conditions of the Right Bank Forest-steppe of Ukraine. Methods.Field, analytical and statistical. Results.It was established that among the mid-range varieties Divo stands out with a yield of 42.3 t/ha, Malin white – 39.8 t/ha, and Legend – 37.1 t/ ha. The most favourable weather and climatic conditions for the production of potato tubers were for the Divo 2011 variety with a yield of 45.9 t/ha and 2013 – 45.1 t/ha. For the Legenda variety 2016, the yield of potato tubers is 40.6 t/ha and 2017 – 43.2 t/ha. Malin White 2013 is 41.4 t/ha and 2017 42.1 t/ha. The average varieties of potatoes showed a slightly lower yield on average over the years of research. However, among the varieties is allocated Nadiyna – 40.3 t/ha, Slovyanka – 37.2 t/ ha and Vera 33.8 t/ha. Among the years, the most high-yielding for the Vera variety was 2016 with a yield of 36.6 t/ha and 2017 year – 37.8 t/ha. Varieties Slovyanka and Nadiyna 2011 and 2012 with yields of 42.6 and 44.3 t/ha and 46.5 and 45.3 t/ha, respectively. Characterizing the yield of potato tubers of medium-late varieties over the years of research, there was a decrease in this indicator compared with medium-early and middle-aged varieties. However, the high yield of the varieties of Dar is allocated – 40.0 t/ha, Alladin – 33.6 t/ha and Oxamit 31.3 t/ha. Among the years, the most favourable ones were: for Oxamit and Alladin – 2011 – 33.5 and 36.5 t/ha, and 2017 – 34.1 and 36.4 t/ha, respectively. Favourable years for harvesting varieties were 2011 and 2012 with yields of 45.7 and 45.8 t/ha. Thus, the highest yield of potato tubers on average over the years of studies of medium-early varieties of 41.2-43.3 t / ha were provided by weather conditions of 2011 and 2017 years, medium-ripe varieties 41.0-41.1 - 2012 and 2011, medium- late 37,6-38,5 t / ha - 2012 and 2011, respectively.

Optimal Command for Photovoltaic Systems in Real Outdoor Weather Conditions

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Hafsa Abouadane ◽  
Abderrahim Fakkar ◽  
Benyounes Oukarfi
Keyword(s):  
Maximum Power Point Tracking ◽  
Accurate Determination ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point

The photovoltaic panel is characterized by a unique point called the maximum power point (MPP) where the panel produces its maximum power. However, this point is highly influenced by the weather conditions and the fluctuation of load which drop the efficiency of the photovoltaic system. Therefore, the insertion of the maximum power point tracking (MPPT) is compulsory to track the maximum power of the panel. The approach adopted in this paper is based on combining the strengths of two maximum power point tracking techniques. As a result, an efficient maximum power point tracking method is obtained. It leads to an accurate determination of the MPP during different situations of climatic conditions and load. To validate the effectiveness of the proposed MPPT method, it has been simulated in matlab/simulink under different conditions.

scholarly journals Characteristics of Extratropical Cyclones That Cause Tornadoes in Italy: A Preliminary Study

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 180
Author(s):  
Eigo Tochimoto ◽  
Mario Marcello Miglietta ◽  
Leonardo Bagaglini ◽  
Roberto Ingrosso ◽  
Hiroshi Niino
Keyword(s):  
Environmental Conditions ◽  
Convective Available Potential Energy ◽  
Static Stability ◽  
Extratropical Cyclones ◽  
Cool Season ◽  
Southeastern Us ◽  
Different Seasons ◽  
The Difference ◽  
Upper Level ◽  
Strong Evaporation

Characteristics of extratropical cyclones that cause tornadoes in Italy are investigated. Tornadoes between 2007 and 2016 are analyzed, and statistical analysis of the associated cyclone structures and environments is performed using the JRA-55 reanalysis. Tornadoes are distributed sporadically around the cyclone location within a window of 10° × 10°. The difference in the cyclone tracks partially explains the seasonal variability in the distribution of tornadoes. The highest number of tornadoes occur south of the cyclone centers, mainly in the warm sector, while a few are observed along the cold front. Composite mesoscale parameters are examined to identify the environmental conditions associated with tornadoes in different seasons. Potential instability is favorable to tornado development in autumn. The highest convective available potential energy (CAPE) in this season is associated with relatively high-temperature and humidity at low-levels, mainly due to the strong evaporation over the warm Mediterranean Sea. Upper-level potential vorticity (PV) anomalies and the associated cold air reduce the static stability above the cyclone center, mainly in spring and winter. On average, the values of CAPE are lower than for US tornadoes and comparable with those occurring in Japan, while storm relative helicity (SREH) is comparable with US tornadoes and higher than Japanese tornadoes, indicating that the environmental conditions for Italian tornadoes have peculiar characteristics. Overall, the conditions emerging in this study are close to the high-shear, low-CAPE environments typical of cool-season tornadoes in the Southeastern US.

Design of Measurement System of the Center of Gravity

2013 ◽  
Vol 706-708 ◽  
pp. 733-736
Author(s):  
Fang Li
Keyword(s):  
Measurement System ◽  
Center Of Gravity ◽  
Actual Position ◽  
Ideal Position ◽  
The Future ◽  
The Difference ◽  
New System ◽  
The Ideal

It is very difficult to confirm the position of the center of gravity irregular object.This paper introduces a new system,which can be used in measuring and adjusting of the center of gravity.The irregular object was put on the support parts,then the center of gravity was given.When the actual position was compared with the ideal position,the difference was given. Until actual position and ideal position were coincided,the machining was continuing. Matlab was programmed in this measure system. It will be applied widely in the future.

Angular Momentum Requirements of the Twisting and Nontwisting Forward 1 1/2 Somersault Dive

1987 ◽  
Vol 3 (1) ◽  
pp. 47-62 ◽  
Author(s):  
Ross H. Sanders ◽  
Barry D. Wilson
Keyword(s):  
Angular Momentum ◽  
High Speed ◽  
Center Of Gravity ◽  
Transverse Axis ◽  
Free Position ◽  
High Speed Cinematography ◽  
The Difference ◽  
Hip Flexion ◽  
Commonwealth Games

This study investigated the in-flight rotation of elite 3m springboard divers by determining the angular momentum requirement about the transverse axis through the divers center of gravity (somersault axis) required to perform a forward 1 1/2 somersault with and without twist. Three elite male divers competing in the 1982 Commonwealth Games were filmed using high-speed cinematography while performing the forward 1 1/2 somersault in the pike position and the forward 1 1/2 somersault with one twist in a free position. The film was digitized to provide a kinematic description of each dive. An inclined axis technique appeared to be the predominant means of producing twist after takeoff from the board. The angular momentum about the somersault axis after takeoff was greater for the forward 1 1/2 somersault with twist than the forward 1 1/2 somersault without twist for all three divers. The difference in angular momentum between the two dives of each diver ranged from 6% to 19%. The most observable difference between the dives during the preflight phases was the degree of hip flexion at takeoff. There was more hip flexion at takeoff in 5132D than 103B for all three divers. This difference ranged from 9° to 18° (mean = 14°).

scholarly journals Initial-Condition Sensitivities and the Predictability of Downslope Winds

2009 ◽  
Vol 66 (11) ◽  
pp. 3401-3418 ◽  
Author(s):  
Patrick A. Reinecke ◽  
Dale R. Durran
Keyword(s):  
Wave Breaking ◽  
Initial Conditions ◽  
Static Stability ◽  
Synoptic Scale ◽  
Wind Speeds ◽  
Downslope Winds ◽  
First Case ◽  
Downslope Wind ◽  
The Difference ◽  
Strong Winds

Abstract The sensitivity of downslope wind forecasts to small changes in initial conditions is explored by using 70-member ensemble simulations of two prototypical windstorms observed during the Terrain-Induced Rotor Experiment (T-REX). The 10 weakest and 10 strongest ensemble members are composited and compared for each event. In the first case, the 6-h ensemble-mean forecast shows a large-amplitude breaking mountain wave and severe downslope winds. Nevertheless, the forecasts are very sensitive to the initial conditions because the difference in the downslope wind speeds predicted by the strong- and weak-member composites grows to larger than 28 m s−1 over the 6-h forecast. The structure of the synoptic-scale flow one hour prior to the windstorm and during the windstorm is very similar in both the weak- and strong-member composites. Wave breaking is not a significant factor in the second case, in which the strong winds are generated by a layer of high static stability flowing beneath a layer of weaker mid- and upper-tropospheric stability. In this case, the sensitivity to initial conditions is weaker but still significant. The difference in downslope wind speeds between the weak- and strong-member composites grows to 22 m s−1 over 12 h. During and one hour before the windstorm, the synoptic-scale flow exhibits appreciable differences between the strong- and weak-member composites. Although this case appears to be more predictable than the wave-breaking event, neither case suggests that much confidence should be placed in the intensity of downslope winds forecast 12 or more hours in advance.

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