Approximating the asymptomatic infectious cases of the COVID-19 disease in Algeria and India using a mathematical model

In this research, we are interested in discussing the evolution of the COVID-19 infection cases and predicting the spread of COVID-19 disease in Algeria and India. To this aim, we will approximate the transmission rate in terms of the measures taken by the governments. The least square method is used with an accuracy of 95% for fitting the artificial solution with the real data declared by WHO for the purpose of approximating the density of asymptomatic individuals for COVID-19 disease. As a result, we obtained the different values of the basic reproduction number (BRN) corresponding to each measure taken by the governments. Moreover, we estimate the number of asymptomatic infected persons at the epidemic peak for each country. Further, we will determine the needed ICU beds (intense medical carte beds) and regular treatment beds. Also, we provide the outcome of governmental strategies in reducing the spread of disease. Combining all these components, we offer some suggestions about the necessity of using the recently discovered vaccines as Pfizer/Bioentec and Moderna for limiting the spread of the COVID-19 disease in the studied countries.

Construction of Modified CuO-Co3O4-ZnO Electrode for Acetone Detection in Breath

Acetone in breath can be used as a biomarker for noninvasive detection of diabetes. The acetone level in breath is substantially high for diabetic patients. In this study, mixed metal oxide nanocomposite of CuO-Co3O4 -ZnO was used for the electrochemical detection of acetone in artificial breath solution. The structural and morphological characterization of synthesized nanocomposite was done by XRD, RAMAN and SEM (EDAX) analysis. The electrochemical study was performed and the metal oxide modified electrode showed the sensitivity of 6.52 μA cm-2 ppm-1 towards the detection of acetone in the artificial solution.

Studi Kemampuan Perlit sebagai Adsorben untuk Menyisihkan Besi

West Sumetera pearlite can be utilized as an alternative adsorbent to remove metal from groundwater. Aim of this research is to investigate the capability of pearlite to remove ferrous (Fe) and manganese (Mn). Experiment was conducted using artificial solution. A column od 2.54 cm was filled with expamded pearlite. Diameter of pearlite is (0,180-0,150) mm and flow rate1 gpm/ft2. Depth of pearlite in the column was 85 cm, and weight was 160 gr. Sample was taken at 8 sampling points of ground water to determine range of Fe and Mn concentration in artificial solution. Range of Fe concentration is 1-10 mg/l, and range of Mn concentration is 0,1-2 mg/l. Experiment shows that adsorption capacity of pearlite is (4,01 x 10-6 1,84 x 10-5) mg Fe/mg perlit in Fe only solution. While adsorption capacity of pearlite is (4,01 x 10-6 1,84 x 10-5) mg Fe/mg perlit in Fe only solution. While in the Fe-Mn mixture artificial solution, adsorption capacity of pearlite is 1,36 x 10-5 to 1,44 x 10-5 mg Fe/mg perlit.Keywords: perlite, adsorbent, Fe, Mn, adsorption capacityABSTRAKPerlit yang ada di daerah Sumatera Barat dapat dimanfaatkan sebagai salah satu alternatif adsorben untuk menyisihkan logam-logam yang terkandung dalam air tanah. Pada penelitian ini ingin diketahui kemampuan perlit sebagai adsorben dalam menyisihkan logam besi dan mangan. Percobaan dilakukan dengan menggunakan larutan artifisial. Pada percobaan ini digunakan perlit dengan diameter (0,180-0,150) mm, kecepatan alir 1 gpm/ft2. Perlite dimasukkan ke dalam kolom berdiameter 2.54 cm, dengan kedalaman perlit 85 cm dan jumlah perlit yang dibutuhkan untuk mengisi kolom adalah 160 gram. Sampling air sumur pada 8 titik sampling dilakukan untuk menentukan rentang konsentrasi Fe, dan Mn. . Rentang yang ditetapkan untuk konsentrasi Fe adalah (1-10) mg/l, rentang konsentrasi Mn adalah ( 0,1-2) mg/l dan rentang konsentrasi kesadahan adalah (200-400) mg/l. Pada percobaan dengan larutan artifisial yang mengandung konsentrasi Fe saja didapatkan kapasitas adsorpsi berkisar (4,01 x 10-6 1,84 x 10-5) mg Fe/mg perlit. Pada percobaan larutan artifisial yang mengandung Fe dan Mn didapatkan kapasitas adsorpsi berkisar (1,36 x 10-5 - 1,44 x 10-5) mg Fe/mg perlit. Kata kunci: perlit, adsorben, Fe, Mn, kesadahan, kapasitas adsorpsi

A Study on Corrosion Behavior of Carbon Steel in Artificial Solution of Geopolymer Paste by Open Circuit Potential

This paper presents an experimental study on corrosion of carbon steel as reinforcement bar in artificial solution of geopolymer paste by Open Circuit Potential (OCP). The OCP measurements have been used in reinforcement bar concrete studies for many years to determine the corrosion behavior of materials. OCP is the potential of the working electrode relative to the reference electrode when no current or potential is being applied to cell. The OCP of reinforcement bar was recorded with time and this experiment has been done for 30 days. A copper/copper sulfate (Cu/CuSO4) reference electrode with a potential V-SHE of +0.318 V (at 25oC) was used in this study. The pH of geopolymer concrete was observed to be in the range of 11.5 to 12.5 depending on the formulations. Thus, in this study the artificial solutions of geopolymer paste that were used are pH 11, pH 12 and pH 13. It has been found that the potential values of three solutions were fluctuated from the beginning until day 30. The highest potential value was indicated by pH 13 whereas the maximum value is 0.542 V and minimum value is 0.205 V while pH 11 shows the lowest potential value with the maximum value 0.356 V and the minimum value-0.047 V. However, all the redox potential values for pH 11, pH 12 and pH 13 were located at passivity region, Fe2O3. The Fe2O3 is the stable phase in which this oxide acts as a protective film or passive layer in this region. It would be expected to provide some protection against corrosion. Keywords: corrosion, artificial solution, geopolymer paste, reinforcement bar, open circuit potential, passivity

PENGARUH JENIS ANODA PADA PROSES PEMULIHAN LOGAM NIKEL DARI TIRUAN AIR LIMBAH ELECTROPLATING MENGGUNAKAN SEL ELEKTRODEPOSISI

EFFECT OF ANODES TYPES ON NICKEL RECOVERY FROM SYNTHETIC ELECTROPLATING WASTE ELECTRODEPOSITION CELLS. A study concerning the recovery of nickel from electroplating wastewater artificial solution. The study was conducted with a batch system using electrodeposition cell consisting of two spaces separated by water hyacinth leaf, copper cathode plate, H2SO4 solution anolyte, catholyte solution of NiSO4 plus NaCl supporting electrolyte and anode varied. Electrodeposition performed at the direct current of 5V power for 4 hours each run. The research objective was to obtain the best anode in nickel electrodeposition process of electroplating waste artificial solution. Graphite, stainless steel type AISI 316 and the lead were used as a variation of the anode. Concentration of nickel in the catholyte at baseline 2200 mg/L. The results showed that the anode was a graphite anode with best value decreased by 72.44% nickel concentration, deposition of nickel on the cathode of 0.188 grams and specific energy values ​​of 6.1625 kWh/kg.nickel. Telah dilakukan penelitian tentang pemulihan logam nikel dari larutan tiruan air limbah electroplating. Penelitian dilakukan dengan sistem batch menggunakan sel elektrodeposisi yang terdiri dari dua ruang yang dipisahkan dengan daun eceng gondok, katoda pelat tembaga, anolit larutan H2SO4, katolit larutan NiSO4 ditambah elektrolit pendukung larutan NaCl dan anoda divariasikan. Elektrodeposisi dilakukan pada listrik searah sebesar 5V selama 4 jam setiap tempuhan. Tujuan penelitian adalah memperoleh anoda terbaik pada proses elektrodeposisi nikel dari larutan tiruan limbah electroplating. Grafit, Stainless Steel tipe AISI 316 dan timbal digunakan sebagai variasi jenis anoda. Konsentrasi nikel dalam katolit pada awal penelitian 2200 mg/L. Hasil penelitian menunjukkan bahwa anoda grafit merupakan anoda yang paling baik dengan nilai penurunan konsentrasi nikel sebesar 72,44%, deposisi nikel di katoda sebesar 0,188 gram dan nilai energi spesifik sebesar 6,1625 kWh/kg.nikel.

Norepinephrine as a possible transmitter involved in synaptic transmission in frog taste organs and Ca dependence of its release.

In order to explore the role of catecholamine and Ca2+ in the synaptic transmission from taste cells to sensory nerve terminals, the effects of various agents added to an artificial solution perfusing the lingual artery on the frog taste nerve responses were examined. The injection of reserpine or guanetidine, which are catecholamine-depleting agents, led to a great reduction of the frog taste nerve responses. The addition of catecholamines to the perfusing solution did not practically enhance the spontaneous impulse discharges, but did recover the response to all the taste stimuli examined. Norepinephrine was most effective and is the most likely candidate for the transmitter. The enhancement of the responses by norepinephrine was suppressed by desipramine, cocaine, or imipramine, which suggests that the enhancement was brought about by incorporation of norepinephrine into taste cells. In a previous paper (Nagahama, S., Y. Kobatake, and K. Kurihara, 1982. J. Gen. Physiol. 80:785), we showed that the responses to the stimuli of one group depended on Ca2+, cGMP, and cAMP added to the perfusing solution and those to the stimuli of another group did not depend on these agents. After the injection or addition of reserpine to the lingual artery, which probably modified injection or addition of reserpine to the lingual artery, which probably modified the permeability of the artery, the responses to the stimuli of the latter group also came to exhibit dependences on these agents, which indicates that the responses to all the taste stimuli have dependences on Ca2+, cGMP, and cAMP.

Effect of Ca2+, cyclic GMP, and cyclic AMP added to artificial solution perfusing lingual artery on frog gustatory nerve responses.

The lingual artery of the bullfrog was perfused with artificial solution and the effects of Ca2+, Ca-channel blockers (MnCl2 and verapamil), cGMP, and cAMP added to the perfusing solution of the gustatory nerve responses were examined. The responses to chemical stimuli of group 1 (CaCl2, NaCl, distilled water, D-galactose, and L-threonine) applied to the tongue surface were greatly decreased by a decrease in Ca2+ concentration in the perfusing solution, suppressed by the Ca-channel blockers, enhanced by cGMP, and suppressed by cAMP. The responses to chemical stimuli of group 2 (quinine hydrochloride, theophylline, ethanol, and HCl) were practically not affected by a decrease in Ca2+ concentration, the Ca-channel blockers, cGMP, and cAMP. The responses to the stimuli of group 1 seem to be induced by Ca influx into a taste cell that is triggered by depolarization and modulated by the cyclic nucleotides in a taste cell. The responses to group 2 seem to be induced without accompanying Ca influx.

D-Glucose enhancement of water reabsorption in proximal tubule of the rat kidney

Water reabsorption in the proximal convoluted tubule of the rat kidney was examined by in vivo microperfusion techniques in order to examine the effect of D-glucose within the tubular lumen. When tubules were perfused with a balanced artificial solution containing Na, K, Cl, HCO3, urea, and D-glucose, absolute reabsorption averaged 4.01 +/- 0.24 nl/min per mm. Addition of D-glucose to the NaCl perfusate enhanced water reabsorption to values similar to those obtained with the balanced artificial perfusate. The enhanced water reabsorption consequent to the addition of D-glucose to the NaCl perfusion solution was completely inhibited by addition of phloridzin to the perfusate. The addition of an unabsorbed hexose, 2-deoxy-D-glucose, to the NaCl perfusate failed to enhance water reabsorption, whereas the addition of an incompletely reabsorbed sugar that is not metabolized, 3-O-methyl-D-glucose, resulted in partial enhancement of theabsolute rate of water reabsorption. These studies demonstrate that D-glucose has the specific effect of augmenting water reabsorption in the proximal tubule of the rat kidney.