scholarly journals PRODUKSI GAS HIDROGEN BERDASARKAN PENGARUH LUAS PENAMPANG TERHADAP KONSENTRASI LARUTAN ELEKTROLIT DAN SUPLAI ARUS DENGAN METODE ELEKTROLISIS

2021 ◽  
Vol 1 (11) ◽  
pp. 447-451
Author(s):  
Rifat Abdurahman ◽  
Rahma Eliza ◽  
Agus Manggala ◽  
Aisyah Suci Ningsih ◽  
Sahrul Effendy A

Pengembangan energi terbarukan menjadi fokus perhatian saat ini penggunaan sumber energi yang ramah lingkungan dan zero emission dengan pemanfaatan air untuk prosess pembuatan hidrogen melalui proses elektrolisis. Hidrogen adalah gas ringan (lebih ringan dari udara), tidak berwarna dan tidak berbau, jika terbakar tidak menunjukkan adanya nyala dan akan menghasilkan panas yang sangat tinggi, sehingga hidrogen mempunyai potensi yang sangat besar untuk dikembangkan sebagai sumber energi alternatif. Penelitian ini bertujuan untuk menganalisa pengaruh luas penampang dan  konsentrasi larutan elektrolit dengan variasi suplai arus listrik terhadap produksi gas hidrogen dengan metode  elektrolisis. Larutan elektrolit yang digunakan adalah larutan air garam (NaCl) dengan berlandaskan pada kadar salinitas air laut.  Berdasarkan penelitian yang telah dilakukan membuktikan bahwa semakin tinggi konsentrasi larutan elektrolit , semakin besar luas penampang dan semakin tinggi arus yang disuplai maka volume gas yang dihasilkan akan semakin banyak. Hasil yang diperoleh yaitu volume gas H2 tertinggi pada konsentrasi salinitas 35 ppt , elektroda ukuran 0,5 in dan kuat arus 35 ampere sebesar 2,118693 liter gas H2 dalam waktu 120 detik. efisiensi tertinggi didapat pada ukuran elektroda 2,0 in ,salinitas 35 ppt dengan kuat arus 15 ampere nilai yang didapat 99,16% dan daya tertinggi dicapai pada 406 watt pada ukuran elektroda 2,0 in, salinitas 35 ppt pada kuat arus 35 ampere   The development of renewable energy is currently the focus of attention on the use of environmentally friendly energy sources and zero emission by utilizing water for the hydrogen production process through the electrolysis process. Hydrogen is a light gas (lighter than air), colorless and odorless, if it burns it does not show a flame and will produce very high heat, so hydrogen has enormous potential to be developed as an alternative energy source. This study aims to analyze the effect of cross-sectional area and concentration of electrolyte solution with variations in the supply of electric current to the production of hydrogen gas by electrolysis method. The electrolyte solution used is a salt water solution (NaCl) based on the salinity of seawater. Based on the research that has been done, it is proven that the higher the concentration of the electrolyte solution, the greater the cross-sectional area and the higher the current supplied, the more gas volume will be produced. The result obtained is the highest H2 gas volume at salinity concentration of 35 ppt, electrode size of 0.5 inchi and current strength of 35 ampere of 2.118693 liters of H2 gas in 120 seconds. the highest efficiency is obtained at the electrode size of 2.0 inchi ,salinity 35 ppt with a current strength of 15 ampere the value obtained 99.16% and the highest power achieved at 406 Watts at the electrode size of 2.0 inchi, salinity 35 ppt at the current strength of 35 ampere

1982 ◽  
Vol 53 (5) ◽  
pp. 1220-1227 ◽  
Author(s):  
L. M. Taussig ◽  
L. I. Landau ◽  
S. Godfrey ◽  
I. Arad

Maximal flows at functional residual capacity (VmaxFRC) from partial expiratory flow-volume (PEFV) curves (achieved with rapid compression of the chest) were obtained on 11 healthy newborn babies. Mean VmaxFRC, size corrected by dividing absolute values by measured thoracic gas volume, was 1.90 TGV's/s. Specific upstream conductances were high, and the cross-sectional area of the flow-limiting segment was estimated to be approximately 0.30 cm2 in the three infants on whom recoil pressures at FRC were also measured. The cross-sectional area of the major bronchi in the neonate is approximately 0.26–0.30 cm2. PEFV curves were convex to the volume axis. Many of the neonates increased their flows while breathing a helium-oxygen gas mixture. These results suggest 1) size-corrected flows are higher in the neonate than in older children or adults; 2) the site of the flow-limiting segment at FRC during maximal expiratory maneuvers is in large proximal airways, similar to the adult; and 3) the relationship of airway size to parenchymal size may be similar in neonates and adults or, in fact, airways may be larger, relative to parenchyma, in neonates. These physiological data do not support the hypothesis, based on pathological studies, that peripheral airways are disproportionately smaller (when compared with central airways) in infants than in adults.


2012 ◽  
Vol 509 ◽  
pp. 203-208 ◽  
Author(s):  
Chang Jun Sun ◽  
Li Juan Qin ◽  
Shao Peng Wu ◽  
Guo Liang Sun ◽  
Lei Chen

This paper focuses on an optimized research about materials and size of electrode of self-monitoring asphalt concrete. It can be easily observed and analyzed the sensitivity of the test and resistivity fluctuations by studying the changes of output resistivity in different electrode embedded in the self-monitoring asphalt concrete. Based on the above method, we can select the proper electrode for the self-monitoring asphalt concrete. The results indicate that the output resistivity of self-monitoring asphalt concrete have much more fluctuation than which used stainless steel mesh as electrode material when choosing the iron mesh as electrode material. Meanwhile, the results demonstrate that the measured output resistivity of self-monitoring asphalt concrete is the most stable when the electrode size is 40~60% of cross-sectional area.


1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.


2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.


Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by


2016 ◽  
Vol 3 (4) ◽  
Author(s):  
R. C. BHARATI

Data on fruit count corresponding to primary, secondary and tertiary branches of a randomly selected guava CV. Allahabad Safeda were recorded from the guava orchard of Horticultural Research Station, Birauli. The proposed sampling scheme in which the selection probabilities are based on length of braches between two forking points was compared with equal probability(PE), probability proportional to the number of branches(PPN), probability proportional to the cross sectional area (PPA) and probability proportional to volume (PPV) method of sampling and found to be more efficient.


2006 ◽  
Vol 7 (3) ◽  
pp. 163-174 ◽  
Author(s):  
Myoung-Ae Choe ◽  
Gyeong Ju An ◽  
Yoon-Kyong Lee ◽  
Ji Hye Im ◽  
Smi Choi-Kwon ◽  
...  

This study examined the effects of daily low-intensity exercise following acute stroke on mass, Type I and II fiber cross-sectional area, and myofibrillar protein content of hind-limb muscles in a rat model. Adult male Sprague-Dawley rats were randomly assigned to 1 of 4 groups (n = 7-9 per group): stroke (occlusion of the right middle cerebral artery [RMCA]), control (sham RMCA procedure), exercise, and stroke-exercise. Beginning 48 hours post-stroke induction/sham operation, rats in the exercise group had 6 sessions of exercise in which they ran on a treadmill at grade 10 for 20 min/day at 10 m/min. At 8 days poststroke, all rats were anesthetized and soleus, plantaris, and gastrocnemius muscles were dissected from both the affected and unaffected sides. After 6 sessions of exercise following acute ischemic stroke, the stroke-exercise group showed the following significant (p < .05) increases compared to the stroke-only group: body weight and dietary intake, muscle weight of affected soleus and both affected and unaffected gastrocnemius muscle, Type I fiber cross-sectional area of affected soleus and both affected and unaffected gastrocnemius muscle, Type II fiber cross-sectional area of the unaffected soleus, both affected and unaffected plantaris and gastrocnemius muscle, Type II fiber distribution of affected gastrocnemius muscle, and myofibrillar protein content of both affected and unaffected soleus muscle. Daily low-intensity exercise following acute stroke attenuates hind-limb muscle atrophy in both affected and unaffected sides. The effects of exercise are more pronounced in the soleus and gastrocnemius as compared to the plantaris muscle.


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