scholarly journals Geographical Analysis of Repeat Cold Waves in Kurdistan Region for the Period 2000-2017

2021 ◽  
Vol 8 (2) ◽  
pp. 310-344
Author(s):  
Luqman Wsw Omer ◽  
Mohammed Qader Rasool
Keyword(s):  
Geographical Distribution ◽  
Atmospheric Pressure ◽  
Minimum Temperature ◽  
Temperature Fluctuation ◽  
Pressure Effect ◽  
Long Waves ◽  
Kurdistan Region ◽  
Geographical Analysis ◽  
Cold Waves ◽  
Different Types

  In this paper, we investigated changes in cold waves in Kurdistan region over the period 2000–2017. Cold waves it means decrease 5oc minimum temperature degree at least from the average monthly minimum temperature for this month and continues for 3 days consecutive at least. The study found 132 cold waves repeat in Kurdistan region, that is 112 waves were the type of shortwave it means %84.85 of them were shortwaves, 18 waves medium and only 2 waves were the type of long waves. About severity of the temperature of cold waves the study also, found different types, for example in all cold waves about %67.42 or 89 waves were from the type of moderate waves, 30 waves strong and 13 waves were extreme. About of the cold days over the period of time include 904 threshold cold waves, in this number 530 days were in the type of the cold day of cold waves, and 374 days were the Temperature fluctuation of cold days. As well as the paper found that the annual repetition cold waves vary from month to month, and the season to season, it was found that cold waves were highest in spring and lowest in summer. The most geographical distribution of system atmospheric pressure effect on the weather and cold waves in study area is The Siberian Heights.

scholarly journals Enzyme-catalyzed reactions in different types of high-pressure enzymatic reactors

2006 ◽  
Vol 12 (3) ◽  
pp. 159-163
Author(s):  
Mateja Primozic ◽  
Maja Habulin ◽  
Muzafera Paljevac ◽  
Zeljko Knez
Keyword(s):  
High Pressure ◽  
Atmospheric Pressure ◽  
Ceramic Membranes ◽  
Stirred Tank ◽  
Optimal Temperature ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Humicola Insolens ◽  
Different Types ◽  
Hydrolysis Of

The enzyme-catalyzed hydrolysis of carboxy-methyl cellulose (CMC) was performed in three different types of reactors; in a batch stirred-tank reactor (BSTR) operating at atmospheric pressure, in a high-pressure batch stirred-tank reactor (HP BSTR) and in a high-pressure continuous tubular-membrane reactor (HP CTMR). In the high-pressure reactors aqueous SC CO2 was used as the reaction medium. The aim of our research was optimization of the reaction parameters for reaction performance. All the reactions were catalyzed by cellulase from Humicola insolens. Glucose production in the high-pressure batch stirred-tank reactor was faster than in the BSTR at atmospheric pressure. The optimal temperature for the reaction performed in the BSTR at atmospheric pressure was 30?C, while the optimal temperature for the reaction performed in SC CO2 was 32?C. The influence of the application of tubular ceramic membranes in the high-pressure reaction system was studied on the model reaction of CMC hydrolysis at atmospheric pressure and in SC CO2. The reaction was catalyzed by cellulase from Humicola insolens covalently linked to the surface of the ceramic membrane. The hydrolysis of CMC in SC CO2 and at atmospheric pressure was performed for a long time period. The reaction carried out in SC CO2 was more productive than the reaction performed at atmospheric pressure.

scholarly journals Associations of environmental variables with different types of stroke

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
V Vaiciulis ◽  
J Vencloviene ◽  
R Radisauskas ◽  
D Kranciukaite-Butylkiniene ◽  
A Tamosiunas ◽  
...  
Keyword(s):  
North Atlantic ◽  
Atmospheric Pressure ◽  
Circulatory System ◽  
Haemorrhagic Stroke ◽  
Weather Variables ◽  
Different Types ◽  
The Impact ◽  
Change In Mean ◽  
New Evidence ◽  
Stroke Register

Abstract Background Air temperature (T) and atmospheric pressure (AP) are among the most closely studied weather variables; increases, decreases, and fluctuations in both have been significantly linked to numerous stroke subtypes. We decided to detect the association between daily numbers of ischaemic stroke (IS) and haemorrhagic stroke (HS) and daily North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices and monthly indices of Quasi-Biennal Oscillation (QBO). Methods The study was conducted in Kaunas city from 2000 to 2010. Kaunas stroke register presented daily numbers of IS, subarachnoid haemorrhages (SAH), and intracerebral haemorrhages (ICH). We evaluated the association between these types of stroke and NAO, AO, and QBO indices (NAOI, AOI, and QBOI) by applying Poisson regression, adjusting for month and other weather variables. Results During the study period, we analysed 3,992 cases (2,205 men and 1,787 women) with stroke. IS composed 3,199 (80.1%), ICH 533 (13.4%), and SAH - 260 (6.5%). A change in mean daily atmospheric pressure (AP) of > 3.9 hPa and QBOI <-27 were associated with the risk of SAH (RRs with 95% CI were, respectively, 1.54 (1.18-2.03), and 1.68 (1.06-2.66)). The risk of HS was associated with daily increases in AP and QBOI <8.37 (p < 0.05). The risk of IS was negatively associated with AOI (RR = 0.97 (0.94-0.99). During November-March, NAOI >0 was associated with HS (RR = 1.29 (1.03-1.62)), and a negative association between NAOI and IS (RR = 0.91 (0.84-0.98)) was found. Conclusions The results of our study provided new evidence that the NAO, AO, and QBO pattern may affect the risk of stroke. The impact of these teleconnection indices is not identical for different types of stroke. Key messages This abstract is part of publication, which will be published later on. In some cases, environmental impact is not essential, but quite often determines the course of various diseases, especially of the circulatory system.

Investigation of Combustion Oscillations in a Lean Gas Turbine Model Combustor

2007 ◽  
Author(s):  
Olaf Diers ◽  
Denis Schneider ◽  
Melanie Voges ◽  
Peter Weigand ◽  
Christoph Hassa
Keyword(s):  
Atmospheric Pressure ◽  
Acoustic Pressure ◽  
Particle Image ◽  
Operating Conditions ◽  
Operating Point ◽  
Image Velocimetry ◽  
Different Types ◽  
Mass Flows ◽  
Combined Data

This contribution is a continuation of ASME-GT2006-90300. While still working at atmospheric pressure, the range of operating conditions was extended to more realistic reduced mass flows to reproduce the engine pressure loss and air preheat up to 700K. The thermoacoustic behaviour of the burner was mapped over that operating range. Two different types of oscillations were observed for flames anchored at the nozzle or lifted from it. Both exhibited a frequency dependence on the Strouhal number for constant reduced mass flows. For a selected operating point with the lifted flame at a preheat temperature of 600K and a reduced mass flow of 0.3kg K0.5/(s bar), the thermoacoustic behaviour of the burner was characterised by phase locked Particle Image Velocimetry as well as phase locked OH- and OH-T- LIF measurements and correlated to the acoustic pressure signal obtained by microphones. The combined data showed pulsating combustion being supported through periodic reignition of the main flame zone by a recirculating volume of hot, OH-rich gas, the cycle time being connected to the observed frequency. The characterization of the preheated operating point was completed with a heat balance investigation quantifying the non-adiabatic combustion conditions of the uncooled combustor.

scholarly journals DC Electrical Ageing of XLPE under Hydrostatic Pressure

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Fadila Benlizidia Lalam ◽  
Faouzi Djemmal
Keyword(s):  
Hydrostatic Pressure ◽  
Direct Current ◽  
Atmospheric Pressure ◽  
Pressure Effect ◽  
Power Model ◽  
Lifetime Data ◽  
Confidence Bounds ◽  
Polyethylene Films ◽  
Thermally Activated ◽  
Thermally Activated Process

The experimental electrical ageing, of cross-linked polyethylene films 100 μm thick, was investigated under high hydrostatic pressure of 300 bar and at atmospheric pressure. The tests are conducted on direct current (dc) for up to 1000 h ageing and at temperature of 70°C. The use of the Weibull statistic, with the estimation of confidence bounds at 90%, has shown that the hydrostatic pressure has a real effect on the lifetime. These lifetime data are qualitatively analyzed with the inverse power model. It was found that thermally activated process is able to describe the pressure effect on the electrical ageing of XLPE.

THE FREEZING POINTS OF HIGH PURITY METALS AS PRECISION TEMPERATURE STANDARDS: IV. INDIUM: THERMAL ANALYSES ON THREE GRADES OF CADMIUM

1958 ◽  
Vol 36 (9) ◽  
pp. 1131-1147 ◽  
Author(s):  
E. H. McLaren
Keyword(s):  
High Purity ◽  
Pressure Effect ◽  
Thermal Analyses ◽  
Freezing Temperature ◽  
Liquidus Point ◽  
Characteristic Structure ◽  
Melting Temperatures ◽  
Two Samples ◽  
Different Types ◽  
Precision Temperature

An investigation of the freezing and melting temperatures of a sample of high purity indium (Cominco 99.999+ %) has been made. Plateaux of essentially constant (< ± 0.0001 °C) temperature with durations for over 1 hour are readily obtained on the cooling curves of induced freezes on this metal. The standard deviation of the plateau temperature (liquidus point) from a series of 24 induced freezes was ±0.0001 °C. The pressure effect on the freezing temperature of indium was found to be 0.0049 °C for 1 atm. Alloy melting ranges were measured following different types of freezing.An extensive intercomparison of liquidus points and alloy melting ranges has been made on a sample of 99.99% cadmium and two samples of 99.999+ % cadmium from different suppliers. The liquidus points of the high purity samples were indistinguishable using precision resistance thermometry but one sample melted over a slightly smaller range of temperature than the other. Both these samples showed minor arrests on melting curves after induced freezing and detailed analyses of the melting contours after various types of freezing indicated some evidence of characteristic structure inside a range of 0.002 °C.

Atmospheric Pressure Helium Plasma Jet with Different Types of Discharge Setup

2012 ◽  
Author(s):  
Sahar Hosseinzadeh Kassani ◽  
Changsik Yoon ◽  
Changyoung Lee ◽  
Honggu Choi ◽  
Kyunghwan Oh
Keyword(s):  
Atmospheric Pressure ◽  
Plasma Jet ◽  
Helium Plasma ◽  
Different Types

Impact of Orifice Angle Configurations on the Droplet Atomization Enhancement of Diesel Fuel in a Group-Hole Nozzle

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Hyun Kyu Suh ◽  
Chang Sik Lee
Keyword(s):  
Diesel Fuel ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Sauter Mean Diameter ◽  
Spray Tip Penetration ◽  
Different Types ◽  
Time Distance ◽  
Atomization Characteristics ◽  
Spray Velocity ◽  
The Relationship

This paper presents the effect of orifice configuration on the droplet atomization characteristics of diesel fuel injected through different types of group-hole nozzle angles, which are converged (θ=−3 deg), parallel (θ=0 deg), and diverged (θ=+3 deg) orifices in atmospheric pressure and room temperature condition (0.1 MPa, 293 K). It was revealed that the parallel hole nozzle has the largest Sauter mean diameter (SMD) value and both sprays from diverged and converged hole nozzles show better atomization. A comparison of spray tip penetration illustrates that as the orifice angle is converged, spray tip penetration becomes longer, and it must be the reason for the fast spray velocity. These results can confirm the relationship among time, distance, and velocity. Therefore, it can be concluded that the droplet atomization enhancement can be expected in the converged nozzle spray rather than in the parallel and diverged nozzle sprays based on the results of smaller SMD, faster velocity, better air utilization, and higher percentage of small size of droplets in the measuring area.

The Natural Vacuum Desalination Technology in Seawater Desalination

2014 ◽  
Vol 675-677 ◽  
pp. 851-855 ◽  
Author(s):  
Xiao Hua Liu ◽  
Xin Chun Zhang ◽  
Ya Qin Fang ◽  
Ming Ming Zhu
Keyword(s):  
Low Temperature ◽  
Water Column ◽  
Physical Model ◽  
Future Development ◽  
Atmospheric Pressure ◽  
High Water ◽  
Seawater Desalination ◽  
Different Types ◽  
Desalination Technology

Seawater desalination technology is an important way to solve the freshwater shortage problem. Natural vacuum desalination (NVD) technology generates very low pressure environment in the headspace of 10 meters high water column. The weight of the water column is balanced by atmospheric pressure, and low-temperature desalination proceeds in the headspace. NVD technology drives the desalination process without any mechanical pumping, and requires relatively inferior quality of device material and simple structures. In this paper, the basic theory of NVD technology is introduced and physical model is described. Research progresses of different types of NVD technologies are summarized, and the method of increasing freshwater production is pointed out. This paper also illustrates the outlook on future development of NVD technology.

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