scholarly journals The effects of free water on snow gliding

1987 ◽  
Vol 92 (B7) ◽  
pp. 6301 ◽  
Author(s):  
David M. McClung ◽  
Garry K. C. Clarke
Keyword(s):  
Free Water ◽  
Snow Gliding

scholarly journals Full-depth avalanche occurrences caused by snow gliding, Coquihalla, British Columbia, Canada

1999 ◽  
Vol 45 (151) ◽  
pp. 539-546 ◽  
Author(s):  
Jennifer Clarke ◽  
David McClung
Keyword(s):  
British Columbia ◽  
Stainless Steel ◽  
Ground Surface ◽  
Free Water ◽  
Important Influence ◽  
Reliable Indicator ◽  
Climate Data ◽  
Cascade Mountains ◽  
Sloping Ground ◽  
Snow Gliding

AbstractSnow glide is the translational slip of the entire snowpack over a sloping ground surface, and it is thought that rapid rates of snow glide precede full-depth avalanches. The nature of avalanches that release at the ground makes them difficult to predict and difficult to control using explosives.On-slope instrumentation comprised of stainless-steel "glide shoes" was used to measure rates of snow glide for two winters on a bedrock slope adjacent to the Coquihalla Highway, Cascade Mountains, British Columbia, Canada. Climate data and avalanche occurrences were recorded by the British Columbia Ministry of Transportation and Highways.Our results show that the supply of free water to the snow/ground interface by rain or snowmelt is the most important influence on full-depth avalanche release. Full-depth avalanche release responds to rainfall and snowmelt events within 12-24 hours. Occasionally, full-depth avalanches occur unexpectedly during clear, cold periods. Snowmelt by radiation is thought to contribute enough meltwater during these cold periods to induce higher rates of snow glide and full-depth avalanche release. The results also indicate that snow glide alone is not a reliable indicator for full-depth avalanche release.

scholarly journals Full-depth avalanche occurrences caused by snow gliding, Coquihalla, British Columbia, Canada

1999 ◽  
Vol 45 (151) ◽  
pp. 539-546 ◽  
Author(s):  
Jennifer Clarke ◽  
David McClung
Keyword(s):  
British Columbia ◽  
Stainless Steel ◽  
Ground Surface ◽  
Free Water ◽  
Important Influence ◽  
Reliable Indicator ◽  
Climate Data ◽  
Cascade Mountains ◽  
Sloping Ground ◽  
Snow Gliding

AbstractSnow glide is the translational slip of the entire snowpack over a sloping ground surface, and it is thought that rapid rates of snow glide precede full-depth avalanches. The nature of avalanches that release at the ground makes them difficult to predict and difficult to control using explosives.On-slope instrumentation comprised of stainless-steel "glide shoes" was used to measure rates of snow glide for two winters on a bedrock slope adjacent to the Coquihalla Highway, Cascade Mountains, British Columbia, Canada. Climate data and avalanche occurrences were recorded by the British Columbia Ministry of Transportation and Highways.Our results show that the supply of free water to the snow/ground interface by rain or snowmelt is the most important influence on full-depth avalanche release. Full-depth avalanche release responds to rainfall and snowmelt events within 12-24 hours. Occasionally, full-depth avalanches occur unexpectedly during clear, cold periods. Snowmelt by radiation is thought to contribute enough meltwater during these cold periods to induce higher rates of snow glide and full-depth avalanche release. The results also indicate that snow glide alone is not a reliable indicator for full-depth avalanche release.

Microwave resonance method for measuring microliter volumes of free moisture in aviation fuels

2020 ◽  
pp. 49-56
Author(s):  
Vitaly V. Volkov ◽  
Michael A. Suslin ◽  
Jamil U. Dumbolov
Keyword(s):  
Solid Surface ◽  
Free Water ◽  
Resonance Method ◽  
Cavity Resonator ◽  
Maximum Error ◽  
Aviation Fuel ◽  
Fuel Quality ◽  
Microwave Resonance ◽  
Free Moisture ◽  
Microwave Losses

One of the conditions for ensuring the safety of air transport operation is the quality of aviation fuel refueled in aircraft. Fuel quality control is a multi-parameter task that includes monitoring the free moisture content. Regulatory documents establish the content of free water no more than 0.0015% by weight. It is developed a direct electrometric microwave resonance method for controlling free moisture in aviation fuels, which consists in changing the shape of the water drops by pressing them on a solid surface inside a cylindrical cavity resonator. This can dramatically increase dielectric losses. Analytical and experimental analysis of the proposed method is carried out. The control range from 0,5 to 30 μl of absolute volume of moisture in aviation fuels with a maximum error of not morethan 25 % is justified. The sensitivity of the proposed method for monitoring microwave losses in free moisture drops transformed into a thin layer by pressing is an order of magnitude greater than the sensitivity of the method for monitoring microwave losses in moisture drops on a solid surface in a resonator. The proposed method can be used as a basis for the development of devices for monitoring the free moisture of aviation fuels in the conditions of the airfield and laboratory. The direction of development of the method is shown.

EFEKTIVITAS TANAMAN GENJER DALAM MENURUNKAN BOD DAN COD LIMBAH CAIR TAHU HASIL PROSES ANAEROB

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Muhammad Irvan Nurliansyah
Keyword(s):  
Water Surface ◽  
Free Water ◽  
Surface Flow ◽  
Free Water Surface

ABSTRAK Limbah cair tahu merupakan limbah cair yang berasal dari proses pembuatan tahu. Limbah cair tahu mengandung senyawa organik yang tinggi. Pembuangan limbah cair tahu secara langsung ke badan air tanpa dilakukan pengolahan dapat mempengaruhi dan mencemari lingkungan. Suatu cara untuk menanggulangi permasalahan tersebut adalah melakukan pengolahan limbah cair tahu. Salah satu alternatif pengolahan limbah cair tahu yang dapat digunakan adalah fitoremediasi menggunakan tanaman genjer. Penelitian ini bertujuan untuk mengetahui efisiensi pengolahan dan efektivitas waktu tinggal pengolahan limbah cair tahu menggunakan tanaman genjer dalam menurunkan BOD dan COD effluen hasil proses pengolahan anaerob limbah cair tahu. Metode yang digunakan dalam penelitian ini adalah fitoremediasi menggunakan tanaman genjer pada sistem lahan basah buatan Free Water Surface flow dengan waktu tinggal 3 hari, 5 hari dan 7 hari. Hasil penelitian menunjukkan bahwa efisiensi pengolahan secara fitoremediasi pada hari ke 3 untuk BOD dan COD berturut-turut sebesar 21,28% dan 16,13%. Pada hari ke 5 efisiensi pengolahan yang diperoleh untuk BOD dan COD berturut-turut sebesar 52,60% dan 45,93% sedangkan efisiensi pengolahan pada hari ke 7 untuk BOD dan COD berturut-turut sebesar 76,42% dan 70,74%. Waktu tinggal efektif yang diperoleh pada penelitian ini adalah  7 hari dengan nilai BOD dan COD telah berada dibawah baku mutu yaitu berturut-turut sebesar 72,72 mg/l dan 213,33 mg/l.   Kata kunci : limbah cair tahu, fitoremediasi, tanaman genjer, efisiensi pengolahan, waktu tinggal

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