scholarly journals TURBULENT MIXING IN OMBAI STRAIT

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Yulianto Suteja ◽  
Mulia Purba ◽  
Agus S. Atmadipoera
Keyword(s):  
Turbulent Mixing ◽  
Water Mass ◽  
Tidal Energy ◽  
Previous Measurement ◽  
Homogeneous Layer ◽  
Indonesian Throughflow ◽  
Mixing Processes ◽  
Average Value ◽  
Cycle 24 ◽  
The One

<p><em>Ombai</em><em> Strait is one of the exit passages of Indonesian Throughflow (ITF) which conveys hotspot of strong internal tidal energy</em><em>. </em><em>Internal</em><em> tide is the one of main energy which causes mixing processes in the oceans and could lead to changes in water mass characteristics.</em><em> The purpose of this research was to estimate the turbulent mixing </em> <em> by using Thorpe analysis. Nine CTD cast were obtained for one tidal cycle (24 hours) in Ombai Strait. </em><em>The results showed the average value of the turbulent mixing is 833.</em><em>5 x 10<sup>-4</sup> m<sup>2</sup>s<sup>-1</sup></em><em>, the highest found in deep homogeneous layer (2383.4x 10<sup>-4</sup> m<sup>2</sup>s-1), followed by mixed surface layer (103.0</em><em> x 10<sup>-4</sup> m<sup>2</sup>s<sup>-1</sup></em><em>) and thermocline (14.2</em><em> x 10<sup>-4</sup> m<sup>2</sup>s<sup>-1</sup></em><em>). This Turbulent mixing value is much higher than the previous measurement in Indonesian Sea. This is presumably due to the strong internal tidal energy and its interaction with existing deep sill in Ombai Strait.</em></p> <p><em> </em></p> <strong>Keywords</strong>: <em>Indonesian throughflow (ITF)</em>, <em>Ombai Strait, turbulent mixing</em>

scholarly journals TURBULENT MIXING IN OMBAI STRAIT

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Yulianto Suteja ◽  
Mulia Purba ◽  
Agus S. Atmadipoera
Keyword(s):  
Turbulent Mixing ◽  
Water Mass ◽  
Internal Tide ◽  
Tidal Energy ◽  
Homogeneous Layer ◽  
Indonesian Throughflow ◽  
Mixing Processes ◽  
Average Value ◽  
Cycle 24 ◽  
The One

Ombai Strait is one of the exit passages of Indonesian Throughflow (ITF) which conveys hotspot of strong internal tidal energy. Internal tide is the one of main energy which causes mixing processes in the oceans and could lead to changes in water mass characteristics. The purpose of this research was to estimate the turbulent mixing by using Thorpe analysis. Nine CTD cast were obtained for one tidal cycle (24 hours) in Ombai Strait. The results showed the average value of the turbulent mixing is 833.5 x 10-4 m2s-1, the highest found in deep homogeneous layer (2383.4x 10-4 m2s-1), followed by mixed surface layer (103.0 x 10-4 m2s-1) and thermocline (14.2 x 10-4 m2s-1). This Turbulent mixing value is much higher than the previous measurement in Indonesian Sea. This is presumably due to the strong internal tidal energy and its interaction with existing deep sill in Ombai Strait. Keywords: Indonesian throughflow (ITF), Ombai Strait, turbulent mixing

scholarly journals Distribusi Percampuran Turbulen di Perairan Selat Alor (Distribution of Turbulence Mixing in Alor Strait)

2014 ◽  
Vol 19 (1) ◽  
pp. 43 ◽  
Author(s):  
Adi Purwandana ◽  
Mulia Purba ◽  
Agus S Atmadipoera
Keyword(s):  
Turbulent Mixing ◽  
Water Mass ◽  
Deep Layer ◽  
Bottom Topography ◽  
Eddy Diffusivity ◽  
Strong Mixing ◽  
Intermediate Water ◽  
Indonesian Throughflow ◽  
Average Value ◽  
Vertical Eddy

Selat Alor merupakan kanal terdalam setelah Selat Ombai di kepulauan Alor. Kontribusinya sebagai salah satu celah keluar Arus Lintas Indonesia (Arlindo) belum banyak dikaji hingga saat ini. Selat Alor memisahkan Laut Flores dan Laut Sawu, dan memiliki sill yang tinggi di dalamnya, diduga turbulensi akibat interaksi antara aliran selat dengan topografi dasar dapat memicu percampuran dan memodifikasi properti massa air yang melaluinya. Tujuan dari penelitian ini adalah untuk mengkuantifikasi transformasi massa air yang melalui Selat Alor dan mengkaji kemungkinan percampuran di dalam selat berdasarkan estimasi sesaat properti percampuran, yakni percampuran turbulen menggunakan metode skala Thorpe. Penurunan CTD dilakukan di 15 stasiun di perairan Selat Alor. Diperoleh hasil bahwa kontur kedalaman yang menghubungkan Laut Flores dengan Laut Sawu adalah ~300 m pada kanal utama. Salinitas maksimum massa air Subtropis Pasifik Utara (NPSW) dar i Laut Flores di Selat Alor banyak mengalami reduksi akibat intensifnya percampuran yang diduga dipicu oleh topografi dasar dan aliran selat yang menghasilkan turbulensi. Lapisan salinitas maksimum Massa Air Subtropis Samudera Hindia Utara (NISW) pada σθ = 23,5-24,5 terdeteksi di bagian selatan selat (Laut sawu). Jejak massa air NISW menurun dan banyak tereduksi mendekati pintu selatan selat. Intrusi Massa Air Lapisan Menengah Samudera Hindia Utara (NIIW) juga dijumpai di lapisan bawah Laut Sawu, konsisten dengan profil arus pada lapisan bawah. Rata-rata nilai difusivitas vertikal eddy (Kρ)  di Selat Alor bagian utara memiliki orde of 10-3 m2 s-1, dan di bagian selatan memiliki orde bervariasi, 10-6-10-4 m2 s-1. Penyempitan celah Selat Alor diduga merupakan pemicu turbulensi tinggi aliran yang berkontribusi pada tingginya nilai difusivitas vertikal. Kata kunci: Arlindo, percampuran turbulen, difusivitas vertikal, Selat Alor Alor Strait is the deepest channel in Alor islands after Ombai Strait. Contribution of the strait as one of the secondary exit passages of Indonesian Throughflow (ITF) has not been studied yet. The strait separates Flores Sea and Sawu Sea, and is featured by the existence of high sill within the strait, suggested that turbulence due to interaction between strait flow and bottom topography could drive mixing and then modify the water mass properties. The purpose of this study is to investigate transformation of ITF water mass and turbulent mixing process with Thorpe scale method. A hydrographic survey has been carried out in July 2011, in which 15 CTD casts were lowered in the strait. The results show that Alor sill depth is about 300 ms in the main gate. Maximum salinity of NPSW from Flores Sea within Alor Strait is significantly reduced due to strong mixing, perhaps driven by bottom topography and strait flow which creates turbulence. NISW (Northern Indian Subtropical Water) with maximum salinity layer at σθ = 23,5-24,5 is dominant in the southern part of Alor Strait (i.e. Sawu Sea). The existence of NIIW (North Indian Intermediate Water) is also found in the deeper layer of Sawu Sea. The average value of vertical eddy diffussivity (Kρ) estimate in the thermocline layer and deep layer in northern part and central part of strait channel is within the order of 10-3 m2 s-1. Lower order of Kρ in the thermocline layer and deep layer were found in southern part of the Strait (Sawu Sea), ranging from 10-6 to 10-4 m2 s-1. These indicate that the existence of sills in the northern part and central part of Alor Strait could drive mixing significantly. Narrowing passage of Alor Strait probably contribute to the high value of vertical eddy diffusivity due to highly turbulence flow. Keywords: Indonesian Throughflow (ITF), turbulent mixing, vertical diffussivity, Alor Strait

scholarly journals Percampuran Turbulen Di Laut Sulawesi Menggunakan Estimasi Thorpe Analisis

2021 ◽  
Vol 24 (2) ◽  
pp. 211-222
Author(s):  
Hadi Hermansyah ◽  
Agus Saleh Atmadipoera ◽  
Tri Prartono ◽  
Indra Jaya ◽  
Fadli Syamsudin
Keyword(s):  
Turbulent Mixing ◽  
Large Scale ◽  
Near Field ◽  
Tidal Energy ◽  
Eddy Diffusivity ◽  
Internal Tides ◽  
Strong Mixing ◽  
Ocean Energy ◽  
Average Value ◽  
Vertical Diffusivity

Dissipation of internal tides will cause mixing, The mixing process at sea plays a key role in controlling large-scale circulation and ocean energy distribution. The purpose of this research was to estimate the turbulent mixing values  (vertical eddy diffusivity) of water mass using Thorpe analysis. The results showed that the  location where strong mixing occurred in the “near-field” area around Sangihe Island with vertical diffusivity value . Even in areas far-field(far from the generating site) are found vertical diffusivity , the result of internal propagation tides dissipation. Based on the result of the observation, it shows that the level of kinetic energy of eddy turbulen dissipation (ε) in the Sulawesi Sea on all layers has an average value of . The value of ε in the thermocline layer is greatest  compared to the mixed surface layer and the almost homogeneous deep layer, the increase in mixing in the area near the ridge due to the closer water column to the base topography. The average turbulent rate of , the strongest fluctuation of value occurs in the thermocline layer, ranging from  to  with an average of about . The value of this turbulent mixing is higher than the previous measurements in some Indonesian ocean. This is allegedly due to the existence of a strong internal tidal energy and its interaction with topography in the Sulawesi Sea.Disipasi dari pasang surut internal akan menyebabkan terjadinya percampuran, proses percampuran di laut memainkan peran kunci dalam mengendalikan sirkulasi skala besar dan distribusi energi lautan. Tujuan dari penelitian ini adalah untuk mengestimasi nilai percampuran turbulen (difusivitas eddy vertikal) massa air dengan analisis Thorpe. Hasil penelitian ini menunjukkan bahwa percampuran yang kuat terjadi di area sekitar Pulau Sangihe-Talaud dengan nilai difusivitas vertikal . Bahkan pada area yang jauh dari pusat pembangkitan ditemukan difusivitas vertikal , hasil disipasi propagasi pasang surut internal. Berdasarkan hasil pengamatan menunjukan bahwa rata-rata tingkat energi kinetik disipasi turbulen eddy  Laut Sulawesi pada semua lapisan adalah . Nilai  di lapisan termoklin paling besar  dibandingkan dengan lapisan permukaan tercampur dan lapisan dalam yang hampir homogen, peningkatan percampuran di daerah dekat ridge disebabkan makin mendekatnya kolom air dengan topografi dasar. Rata-rata nilai percampuran turbulen sebesar , fluktuasi nilai yang paling kuat terjadi di lapisan termoklin, yang berkisar yaitu antara  sampai  dengan rerata sekitar . Nilai percampuran turbulen ini lebih tinggi dibandingkan dengan pengukuran sebelumnya di beberapa perairan Indonesia. Hal ini diduga karena adanya energi pasang surut internal yang kuat serta interaksinya dengan topografi yang ada di Laut Sulawesi.

Turbulent Mixing in Raja Ampat Sea

2017 ◽  
Vol 862 ◽  
pp. 9-15 ◽  
Author(s):  
Aditya Pamungkas ◽  
Ivonne M. Radjawane ◽  
Hadikusumah
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Turbulent Mixing ◽  
Richardson Number ◽  
Complex Geometry ◽  
Energy Dissipation Rate ◽  
Diffusivity Coefficient ◽  
Indonesian Throughflow ◽  
Average Value ◽  
Vertical Diffusivity

Raja Ampat Sea has a complex geometry and passed by Indonesian Throughflow (ITF) causing a very dynamic water condition, that condition also amplified by turbulent mixing. To gain better understanding of process and extent of turbulent mixing in Raja Ampat Sea, this research calculate Brunt-Vaisala frequency, Richardson number, turbulent kinetic energy dissipation rate and vertical diffusivity coefficient. The data obtained from Expedition Widya Nusantara (EWIN) by P2O-LIPI in the territorial of Raja Ampat Sea on 14-24 November 2007, by using 12 out of 33 observation stations. From this research, it is known that in 0-40 m (mixed layer) and 250-400 m (deep layer) have Richardson number (Ri) less than 0.25 and high vertical diffusivity coefficient (Kv), It proves a strong turbulent mixing occurs at those depth. Furthermore, Raja Ampat Sea has strong turbulent mixing with average value of turbulent kinetic energy is 2.64 WKg-1and vertical diffusivity coefficient is 1.65x10-3 m2s.

scholarly journals Thinner Sea Ice Contribution to the Remarkable Polynya Formation North of Greenland in August 2018

2021 ◽  
Author(s):  
Xiaoyi Shen ◽  
Chang-Qing Ke ◽  
Bin Cheng ◽  
Wentao Xia ◽  
Mengmeng Li ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Reanalysis Data ◽  
Mean Value ◽  
Ocean Model ◽  
North Coast ◽  
Average Value ◽  
The North ◽  
Wind Sea ◽  
The One

AbstractIn August 2018, a remarkable polynya was observed off the north coast of Greenland, a perennial ice zone where thick sea ice cover persists. In order to investigate the formation process of this polynya, satellite observations, a coupled ice-ocean model, ocean profiling data, and atmosphere reanalysis data were applied. We found that the thinnest sea ice cover in August since 1978 (mean value of 1.1 m, compared to the average value of 2.8 m during 1978–2017) and the modest southerly wind caused by a positive North Atlantic Oscillation (mean value of 0.82, compared to the climatological value of −0.02) were responsible for the formation and maintenance of this polynya. The opening mechanism of this polynya differs from the one formed in February 2018 in the same area caused by persistent anomalously high wind. Sea ice drift patterns have become more responsive to the atmospheric forcing due to thinning of sea ice cover in this region.

scholarly journals TEMPERATURE AND HEART RATE IN PTEROTRACHEA AND TIEDEMANNIA

1925 ◽  
Vol 9 (2) ◽  
pp. 269-284 ◽  
Author(s):  
Otto Glaser
Keyword(s):  
Heart Rate ◽  
High Temperatures ◽  
Synthetic Process ◽  
Average Value ◽  
Oxidative Reactions ◽  
Limax Maximus ◽  
The One ◽  
Lower Limits ◽  
Co2 Excretion ◽  
Do So

1. For the heart rate in Pterotrachea coronata, intermediate temperatures disclose a thermal increment of 11,200 ±. This value is identical with the one reported by Crozier and Stier for the lamelli-branch, Anodonta. In the pteropod, Tiedemannia neapolitana the same temperatures typically reveal in the heart rate a µ value of 16,200 ± This agrees quantitatively with 16,300 found by Crozier and Stier for the heart of the slug, Limax maximus. 2. At high temperatures the average value of µ for Pterotrachea is 7,300: for Tiedemannia, 7,400. The corresponding averages at the lower limits are 22,000 and 23,000. 3. The great variability found near the edges of the temperature field are explicable in two ways. During intermissions characteristic of high temperatures and occurring also at low, we can assume a restorative process; while at both the upper and lower limits we may, in addition, find that reactions assume control which under ordinary circumstances never do so. Special evidence indicates that the highest temperatures employed, 27°C., and the lowest, 4°C., caused no irreversible changes in mechanism. 4. The theoretical analysis of the experimental facts makes use of Meyerhof's conception of carbohydrate metabolism and projects the cyclical nature of rhythm into the substrate of control. Assuming as a source of energy an original supply of material O, the value of 22,000 ± is assigned provisionally to a mobilization hydrolysis while 11,200 ± and 16,000 ± are attached to oxidative reactions influenced respectively by OH' and possibly Fe, or some other catalyst. The lowest value, 7,300 ± is assumed to indicate a synthetic process (lactic acid → glycogen?), possibly limited by CO2 excretion. In the present state of our knowledge, this distribution and interpretation seems to account reasonably for the experimental facts, but until we know more about the neurogenic controls, is entitled to rank only as an hypothesis.

Influence of turbulent mixing processes on new particle formation: first results

1997 ◽  
Vol 28 ◽  
pp. S27-S28 ◽  
Author(s):  
V. Jaenisch ◽  
F. Stratmann ◽  
P.H. Austin ◽  
D.A. Hegg
Keyword(s):  
Turbulent Mixing ◽  
Particle Formation ◽  
New Particle Formation ◽  
Mixing Processes ◽  
First Results

scholarly journals Tensile Strength of NaCl Ice

1962 ◽  
Vol 4 (31) ◽  
pp. 25-52 ◽  
Author(s):  
W. F. Weeks
Keyword(s):  
Tensile Strength ◽  
Sea Ice ◽  
Fresh Water ◽  
Eutectic Point ◽  
Water Ice ◽  
Average Value ◽  
Freshwater Ice ◽  
The One ◽  
Image Position ◽  
Bodies Of Water

AbstractTo resolve some of the factors causing strength variation in natural sea ice, fresh water and five different NaCl–H2O solutions were frozen in a tank designed to simulate the one-dimensional cooling of natural bodies of water. The resulting ice was structurally similar to lake and sea ice. The salinity of the salt ice varied from 1‰ to 22‰. Tables of brine volumes and densities were computed for these salinities in the temperature range 0° to −35° C. The ring-tensile strength σ of fresh-water ice was found to be essentially temperature independent from −10° to −30°C., with an average value of 29.6±8.5 kg./cm.2at −10° C. The strength of salt ice at temperatures above the eutectic point (–21.2° C.) significantly decreases with brine volumev;. The σ–axis intercept of this line is comparable to the a values determined for fresh ice indicating that there is little, if any, difference in stress concentration between sea and lake ice as a result of the presence of brine pockets. The strength of ice containing NaCl.2H2O is slightly less than the strength of freshwater ice and is independent of the volume of solid salt and the ice temperature. No evidence was found for the existence of either phase or geometric hysteresis in NaCl ice. The strength of ice at sub-eutectic temperatures, however, is decreased appreciably if the ice has been subjected to temperatures above the eutectic point; this is the result of the redistribution of brine during the warm-temperature period. Short-term cooling produces an appreciable (20 per cent) decrease in strength, in fresh-water and NaCl.2H2O ice. The present results are compared with tests on natural sea ice and it is suggested that the strength of freshwater ice is a limit which is approached but not exceeded by cold sea ice and that the reinforcement of brine pockets by Na2SO4.10H2O is either lacking or much less than previously assumed.

Depression impact on the sexual desire

2011 ◽  
Vol 26 (S2) ◽  
pp. 1549-1549
Author(s):  
M. Lourenço ◽  
L.P. Azevedo ◽  
J.L. Gouveia
Keyword(s):  
Sexual Desire ◽  
Depressive Symptomatology ◽  
Psychiatric Patients ◽  
Severe Depression ◽  
List Type ◽  
Sexual Performance ◽  
Average Value ◽  
Treatment Of Depression ◽  
The One ◽  
The Relationship

IntroductionDepression as a pathology and the side effects of pharmacology therapy have been pointed proven to be as responsible for the lack of sexual desire. Among the drugs used in the treatment of depression, anti-depressives are the ones mostly connected to sexual dysfunction.Aims /objectivesTo study the relationship between depression and its impact on the sexual desire in psychiatric patients.MethodsThe chosen sample is composed of 89 subjects, 73 females and 16 males, with ages ranging from 21 to 70 years, who present with depressive symptomatology (mild to moderate symptomatology (MMS) and severe symptomatology (SS).To each patient 3 instruments were applied: 1)Questionnaire used to collect demographic and clinical data from the sample;2)Instrument of estimation of the depression degree (BDI - Beck Depression Inventory);3)Instrument of valuation of the sexual desire (SDS - Sexual Desire Scale).ResultsDepression average value obtained with BDI was 25.58 (SD = 11.86). The majority was satisfied with their marital relationship (72.7% and 52.9%, respectively), and the group with most sexual damaged (actual sexual performance regarding sexual desire) being the one with severe depression (54.5% versus 82.4%, respectively). Regarding total SDS value, the group with MMD present with higher levels of sexual desire (M = 54.93; DP = 14.56) than the group with SD (M = 41.82; DP = 11.86).ConclusionsThis study presents an exploratory character and the obtained results revealed that depressive symptomatology severity is directly related with sexual desire, by saying the higher the depression's severity is the lower sexual desire will be.

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