Hibiscus sabdariffa L. calyces’ and argon DBD plasma: potential eco-friendly cleaners for fire-damaged silver gelatin prints

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Laila M. Elattar ◽  
Sawsan S. Darwish ◽  
Usama M. Rashed ◽  
Maha Ahmed Ali ◽  
Shaimaa M. Eldeighdye
Keyword(s):  
Aqueous Extract ◽  
Plasma Potential ◽  
Contact Method ◽  
Hibiscus Sabdariffa ◽  
Cleaning Efficiency ◽  
Dbd Plasma ◽  
Content Type ◽  
Noncontact Method ◽  
Barrier Discharge Plasma ◽  
Ar Plasma

Purpose This paper aims at examining the potentiality of using Hibiscus sabdariffa L. calyces’ (Hs) aqueous extract to remove soot stains from the surface of fire-damaged silver gelatin prints. It further studies the cleaning efficiency and impact of both a contact method and a noncontact method with argon dielectric barrier discharge plasma (DBD Ar. plasma) on the different properties of silver gelatin prints. Accordingly, it prompts using economic, eco-friendly materials and methods in the photograph conservation field. Design/methodology/approach To achieve the aims of this paper, four silver gelatin prints were stained with soot and treated with the (Hs) aqueous extract as a contact method and DBD Ar. plasma combined with the aqueous extract as a noncontact method. The assessment was carried out using digital microscopy, atomic force microscopy and spectrophotometer to study the efficiency of the tested treatments and their impact on the surface of the photographs. FTIR was used to monitor the state of the binder after cleaning. Furthermore, the pH and the mechanical properties were measured. Findings The contact method resulted in lower concentrations of (Hs) extract that efficiently cleaned the surface without causing any stains or damage to the treated photographs. The noncontact method (plasma with an aqueous extract) proved to be less effective in cleaning and made the binder more susceptible to deterioration. Originality/value This paper reveals the success of (Hs) aqueous extract in cleaning soot on vulnerable photographs’ surfaces.

Aqueous extract of Hibiscus Sabdariffa calyx modulates gentamicin activity in rats

2016 ◽  
Vol 3 (3) ◽  
pp. 178-187
Author(s):  
A.L Adedej ◽  
◽  
O.T Adedosu ◽  
J.A Badmus ◽  
G.E Adeleke ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Hibiscus Sabdariffa

Testicular effects of sub-chronic administration of Hibiscus sabdariffa calyx aqueous extract in rats

2004 ◽  
Vol 18 (2) ◽  
pp. 295-298 ◽  
Author(s):  
Orish Ebere Orisakwe ◽  
Danladi Chiroma Husaini ◽  
Onyenmechi Johnson Afonne
Keyword(s):  
Aqueous Extract ◽  
Chronic Administration ◽  
Hibiscus Sabdariffa

Plasma actuation effect on a NACA 4412 airfoil

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Burak Karadag ◽  
Cem Kolbakir ◽  
Ahmet Selim Durna
Keyword(s):  
Reynolds Number ◽  
Flow Separation ◽  
Open Loop ◽  
Electrode Configuration ◽  
Small Scale ◽  
Low Velocity ◽  
Dbd Plasma ◽  
Content Type ◽  
Plasma Actuation ◽  
Electric Wind

Purpose This paper aims to investigate the effects of a dielectric barrier discharge (DBD) plasma actuator (PA) qualitatively on aerodynamic characteristics of a 3 D-printed NACA 4412 airfoil model. Design/methodology/approach Airflow visualization study was performed at a Reynolds number of 35,000 in a small-scale open-loop wind tunnel. The effect of plasma actuation on flow separation was compared for the DBD PA with four different electrode configurations at 10°, 20° and 30° angles of attack. Findings Plasma activation may delay the onset of flow separation up to 6° and decreases the boundary layer thickness. The effects of plasma diminish as the angle of attack increases. Streamwise electrode configuration, in which electric wind is produced in a direction perpendicular to the freestream, is more effective in the reattachment of the airflow compared to the spanwise electrode configuration, in which the electric wind and the free stream are in the same direction. Practical implications The Reynolds number is much smaller than that in cruise aircraft conditions; however, the results are promising for low-velocity subsonic airflows such as improving control capabilities of unmanned aerial vehicles. Originality/value Superior efficacy of spanwise-generated electric wind over streamwise-generated one is demonstrated at a very low Reynolds number. The results in the plasma aerodynamics literature can be reproduced using ultra-low-cost off-the-shelf components. This is important because high voltage power amplifiers that are frequently encountered in the literature may be prohibitively expensive especially for resource-limited university aerodynamics laboratories.

Dual-position excitation technique in flow control over an airfoil at low speeds

2018 ◽  
Vol 30 (9) ◽  
pp. 4141-4154
Author(s):  
Abbas Ebrahimi ◽  
Majid Hajipour ◽  
Kamran Ghamkhar
Keyword(s):  
Flow Control ◽  
Shear Layer ◽  
Control Method ◽  
Lift Coefficient ◽  
Shear Layers ◽  
Control Flow ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Surface Shear ◽  
Content Type

PurposeThe purpose of this paper is to control flow separation over a NACA 4415 airfoil by applying unsteady forces to the separated shear layers using dielectric barrier discharge (DBD) plasma actuators. This novel flow control method is studied under conditions which the airfoil angle of attack is 18°, and Reynolds number based on chord length is 5.5 × 105.Design/methodology/approachLarge eddy simulation of the turbulent flow is used to capture vortical structures through the airfoil wake. Power spectral density analysis of the baseline flow indicates dominant natural frequencies associated with “shear layer mode” and “wake mode.” The wake mode frequency is used simultaneously to excite separated shear layers at both the upper surface and the trailing edge of the airfoil (dual-position excitation), and it is also used singly to excite the upper surface shear layer (single-position excitation).FindingsBased on the results, actuations manipulate the shear layers instabilities and change the wake patterns considerably. It is revealed that in the single-position excitation case, the vortices shed from the upper surface shear layer are more coherent than the dual-position excitation case. The maximum value of lift coefficient and lift-to-drag ratio is achieved, respectively, by single-position excitation as well as dual-position excitation.Originality/valueThe paper contributes to the understanding and progress of DBD plasma actuators for flow control applications. Further, this research could be a beneficial solution for the promising design of advanced low speed flying vehicles.

scholarly journals Polymerization of D-Ribose in Dielectric Barrier Discharge Plasma

Plasma ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Yingying Li ◽  
Rida Atif ◽  
Ketao Chen ◽  
Jiushan Cheng ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Dielectric Barrier Discharge ◽  
Discharge Plasma ◽  
Barrier Discharge ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Dielectric Barrier Discharge Plasma ◽  
Dbd Plasma ◽  
Dielectric Barrier ◽  
Ionization Time ◽  
Barrier Discharge Plasma

Dielectric barrier discharge (DBD) plasma has been found to uniquely polymerize ribose that is not usually subject to polymerization since molecules that tend to polymerize almost always possess at least a π-bond. The polymer was analyzed via nuclear magnetic resonance (NMR) spectra, matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectroscopy and Fourier-Transform inferred spectroscopy (FTIR), and it was found that dehydration occurs during polymerization.

scholarly journals HeadBanger: controlling switchable software with head gesture

2016 ◽  
Vol 10 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Matthew Oppenheim
Keyword(s):  
Design Methodology ◽  
Contact Method ◽  
User Group ◽  
Control Software ◽  
Content Type ◽  
Target User ◽  
Test Platform ◽  
Virtual Target ◽  
Head Gestures ◽  
Practical Implications

Purpose – The purpose of this paper is to present a novel non-contact method of using head movement to control software without the need for wearable devices. Design/methodology/approach – A webcam and software are used to track head position. When the head is moved through a virtual target, a keystroke is simulated. The system was assessed by participants with impaired mobility using Sensory Software’s Grid 2 software as a test platform. Findings – The target user group could effectively use this system to interact with switchable software. Practical implications – Physical head switches could be replaced with virtual devices, reducing fatigue and dissatisfaction. Originality/value – Using a webcam to control software using head gestures where the participant does not have to wear any specialised technology or a marker. This system is shown to be of benefit to motor impaired participants for operating switchable software.

scholarly journals Hibiscus sabdariffa Aqueous Leaf Extract Reverses Hematological Alterations in Phenylhydrazine Anemic Wistar Rats

2020 ◽  
pp. 30-38
Author(s):  
E. B. Umoren ◽  
T. A. Kolawole ◽  
I. Wopara ◽  
O. G. Adebayo ◽  
B. Ben-Azu ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Leaf Extract ◽  
Hemoglobin Concentration ◽  
Control Group ◽  
Mean Corpuscular Hemoglobin ◽  
Hibiscus Sabdariffa ◽  
Aqueous Leaf Extract ◽  
Group 3 ◽  
Group 2 ◽  
Hb Concentration

Background: The extract of Hibiscus sabdariffa commonly known as Sobo is widely consumed for its nutritional and health benefits. This study investigated the effect of aqueous leaf extract of  H. sabdariffa on anemic condition caused by phenylhydrazine in rats. Materials and Methods: Thirty (30) rats used for this study were divided into three groups of 10 rats each. Group 1 received distilled water and served as control. Group 2 received phenylhydrazine (40 mg/kg, i.p.). Group 3 was treated with phenylhydrazine (40 mg/kg, i.p.) 30 minutes prior to administration of (200 mg/kg, p.o.) aqueous extract of H. sabdariffa (Sobo) once daily for 14 days. At the end, 2 ml blood samples were collected through cardiac puncture into clean sample bottles containing ethylenediamine tetra acetic acid (EDTA) for hematological analyses. Results: Sobo significantly increased (P<0.05) hemoglobin (Hb) concentration and packed cell volume (PCV) in the phenylhdrazine-treated rats. Also, Sobo significantly (P<0.05) increased total white blood cell (TWBC) in phenylhydrazine administered rats. However, the extract did not produce any significant effect on mean corpuscular hemoglobin concentration (MCHC) relative to control and anemic groups. Conclusion: The findings from this study revealed that the aqueous extract of H. sabdariffa demonstrates anti-anemic effect in rats treated with phenylhydrazine, suggesting its ethno-pharmacological beneficial effect in anemic conditions.

scholarly journals Diuretic Activity of Hibiscus sabdariffa L. in Wistar Rats

2018 ◽  
Vol 9 ◽  
pp. 10-17
Author(s):  
Arsene Mea ◽  
Stanilas Sedagbande ◽  
Kouakou Jean Claude Abo ◽  
Gohi Parfait Kahou Bi ◽  
Koffi Joseph N'guessan
Keyword(s):  
Urinary Excretion ◽  
Aqueous Extract ◽  
Scientific Evidence ◽  
Pharmacological Study ◽  
Scientific Work ◽  
Hibiscus Sabdariffa ◽  
Wistar Strain ◽  
Experimental Protocols ◽  
High Concentrations ◽  
State Of Affairs

The diuretic effect of aqueous extract of Hibiscus sabdariffa has always been noted by the early botanists who studied the plant. On the other hand, very little scientific work to confirm this state of affairs has been done. In this pharmacological study, we provide scientific evidence to previous observations. Using an electrolyte analyzer to evaluate urinary volume and ions and appropriate experimental protocols on wistar strain rats, we have shown that: The aqueous extract of Hibiscus sabdariffa (AEHS) administered at doses of 200, 500 and 700 mg / kg BW induces a dose-dependent and significant increase in urinary excretion in rats. This increase was 12.75 ± 1.971 mL / kg, 23.20 ± 2.082 mL / kg and 29.42 ± 2.097 mL / kg BW, respectively is after 24 hours. That is a respective increase of 55.5, 182 and 333% compared to the control. The aqueous extract of Hibiscus sabdariffa (AEHS) uses at the dose of 700 mg / kg BW results in a reduction of the first urination time by 26.30% compared to the control. The determination of electrolytes in rats treated with 700 mg / kg BW after 24 hours showed high concentrations of sodium, potassium and chlorine in the urine. These different concentrations are for sodium of 72.51%, potassium of 76.54% and 58.81% for chlorine relative to the concentration of the controls. Compared to AEHS, hydrochlorothiazide at 25 mg / kg BW results in urinary excretion of 80.79% sodium, 85.30% potassium and 75.97% chlorine. Similarly with furosemide uses at 20 mg / kg BW), the concentrations are 86% sodium, 79% potassium and 71.58% chlorine. Compared with control rats, the Na + / K + ratio did not vary significantly in the treated animals. AEHS is therefore a diuretic substance like hydrochlorothiazide and furosemide.

scholarly journals Enhancement the Sensitivity of waveguide Coated ZnO thin films: Role of Plasma Irradiation

2020 ◽  
Vol sceeer (3d) ◽  
pp. 93-98
Author(s):  
Marwan Younus ◽  
Muayad Ahmed ◽  
Ghazwan Ali
Keyword(s):  
Thin Films ◽  
Glucose Solution ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Dielectric Barrier Discharge Plasma ◽  
Dbd Plasma ◽  
Plasma Irradiation ◽  
Before And After ◽  
Barrier Discharge Plasma

In this study, Dielectric Barrier Discharge plasma irradiation (DBD) is applied to treatment and improve the properties of the ZnO thin film deposited on the glass substrate as a sensor for glucose detection. The ZnO is prepared via a sol-gel method in this work. ZnO is irradiated by the DBD high voltage plasma to improve of its sensitivity. The optical properties, roughness and surface morphology of the waveguide coated ZnO thin films before and after DBD plasma irradiation are studied in this work. The results showed a significant improvement in the performance of the sensor in the detection of concentrations of glucose solution after plasma irradiation. Where the largest value in sensitivity was equal to 62.7 when the distance between electrodes was 5 cm compared to the sensitivity before irradiation, which was equal to 92. The high response showed in results demonstrating that the fabricated waveguide coated ZnO after plasma irradiation has the excellent potential application as a sensor to detect small concentration of glucose solution.

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