Evaporation A Unit Operation in Pharmaceutical Industry

2021 ◽  
pp. 163-165
Author(s):  
Pradip D. Dhangar ◽  
Parth S. Patil ◽  
Rohit S. Jaiswal ◽  
Azam. Z. Shaikh
Keyword(s):  
Pharmaceutical Industry ◽  
Liquid Water ◽  
Vapour Phase ◽  
Daily Basis ◽  
Evaporation Process ◽  
Unit Operation ◽  
Objective Factor

There are many processes in life that are taken on a daily basis. There are some common ones that we don’t even notice happen every day. One such process is evaporation. This paper also presents on evaporation. To study more about evaporation and other related concepts. It was focus on objective, factor affecting evaporation. The main characteristics, as well as the application of evaporation in pharmaceutical industry of each method are indicated. Evaporation is a process by which liquid water goes directly into the vapour phase due to an increase in temperature. The evaporation process is widely used to make drugs, especially in the pharmaceutical industry. We want to know that on which bases evaporation process effectively works and plays an important role in pharma industry as well as other industries.

Drying as a Unit Operation in the Pharmaceutical Industry I

1963 ◽  
Vol 52 (3) ◽  
pp. 284-291 ◽  
Author(s):  
M.W. Scott ◽  
H.A. Lieberman ◽  
A.S. Rankell ◽  
F.S. Chow ◽  
G.W. Johnston
Keyword(s):  
Pharmaceutical Industry ◽  
Unit Operation

Investigation of Liquid Water Behaviors in Carbon Paper GDL for PEMFCs by Soft X-Ray Radiography

2011 ◽  
Author(s):  
Shohji Tsushima ◽  
Takashi Sasabe ◽  
Shuichiro Hirai
Keyword(s):  
Liquid Water ◽  
Water Film ◽  
Gas Diffusion ◽  
Spatial Inhomogeneity ◽  
Water Evaporation ◽  
Carbon Paper ◽  
Evaporation Process ◽  
X Ray ◽  
Gradual Disappearance ◽  
Thin Water Film

Liquid water behaviors in the porous gas diffusion layer used for PEMFCs were investigated by high-resolution soft X-ray radiography. We observed water evaporation process from the soaked carbon paper GDL and showed the gradual disappearance of liquid water with spatial inhomogeneity. The visualization of liquid water revealed that thin water film was retained in the GDL. This was also observed in the operating fuel cell. Our soft X-ray observation suggests that this thin water film formed in the carbon paper GDL possibly caused increase in the toutuosity of the GDL, resulting in deterioration of cell performance due to less mass transport in fuel cells.

Non-Equilibrium Thermodynamic Analysis of Flash Evaporation Process in Vacuum Ice Making

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Lingeng Zou ◽  
Xuelai Zhang
Keyword(s):  
Steady State ◽  
Water Vapor ◽  
Temperature Difference ◽  
Liquid Water ◽  
Chemical Potential ◽  
Evaporation Process ◽  
Flash Evaporation ◽  
Equilibrium Thermodynamics ◽  
Chemical Potential Difference ◽  
Non Equilibrium

AbstractTraditional equilibrium thermodynamics can only solve a few equilibrium processes composed of continuous stable equilibrium states. However, the vacuum flash evaporation process is a typical unsteady process. The study of non-equilibrium thermodynamics of the two-phase flow model is helpful to improve our understanding of the basic law of the flash evaporation process. Based on the theory of non-equilibrium thermodynamics, the flash chamber in the vacuum flash ice making system was studied in this paper, and the possibility of non-equilibrium steady state evaporation with superheat was obtained. The chemical potential difference between liquid water and water vapor under non-equilibrium steady state conditions was determined, and the corresponding evaporation entropy was calculated. It is shown that the results obtained by equilibrium thermodynamics are only related to the temperature difference, while the results obtained by non-equilibrium thermodynamics are not only related to the temperature difference, but also the state of the evaporation process. This is because non-equilibrium thermodynamics considers the cooling of liquid water and the evaporation of water vapor as a whole, taking into account the interaction between the two processes. However, the traditional equilibrium thermodynamics theory divides the steady state evaporation process into two independent processes and ignores the influence of each other.

On the Shape of Field-Ion Emitters

1976 ◽  
Vol 34 ◽  
pp. 520-521
Author(s):  
H.C. Eaton ◽  
B.N. Ranganathan ◽  
T.W. Burwinkle ◽  
R. J. Bayuzick ◽  
J.J. Hren
Keyword(s):  
Grain Boundary ◽  
Spherical Shape ◽  
Theoretical Strength ◽  
Evaporation Process ◽  
Field Evaporation ◽  
Geometric Information ◽  
Field Ion Microscopy ◽  
Considerable Error ◽  
True Shape ◽  
Ion Microscopy

The shape of the emitter is of cardinal importance to field-ion microscopy. First, the field evaporation process itself is closely related to the initial tip shape. Secondly, the imaging stress, which is near the theoretical strength of the material and intrinsic to the imaging process, cannot be characterized without knowledge of the emitter shape. Finally, the problem of obtaining quantitative geometric information from the micrograph cannot be solved without knowing the shape. Previously published grain-boundary topographies were obtained employing an assumption of a spherical shape (1). The present investigation shows that the true shape deviates as much as 100 Å from sphericity and boundary reconstructions contain considerable error as a result.Our present procedures for obtaining tip shape may be summarized as follows. An empirical projection, D=f(θ), is obtained by digitizing the positions of poles on a field-ion micrograph.

Characterization of GaAs/AlGaAs quantum wells and quantum wires by chemical lattice imaging

1994 ◽  
Vol 52 ◽  
pp. 736-737
Author(s):  
A. Carlsson ◽  
J.-O. Malm ◽  
A. Gustafsson
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Wires ◽  
Vapour Phase ◽  
Quantitative Information ◽  
Lattice Imaging ◽  
Vapour Phase Epitaxy ◽  
Metalorganic Vapour Phase Epitaxy ◽  
High Resolution Images

In this study a quantum well/quantum wire (QW/QWR) structure grown on a grating of V-grooves has been characterized by a technique related to chemical lattice imaging. This technique makes it possible to extract quantitative information from high resolution images.The QW/QWR structure was grown on a GaAs substrate patterned with a grating of V-grooves. The growth rate was approximately three monolayers per second without growth interruption at the interfaces. On this substrate a barrier of nominally Al0.35 Ga0.65 As was deposited to a thickness of approximately 300 nm using metalorganic vapour phase epitaxy . On top of the Al0.35Ga0.65As barrier a 3.5 nm GaAs quantum well was deposited and to conclude the structure an additional approximate 300 nm Al0.35Ga0.65 As was deposited. The GaAs QW deposited in this manner turns out to be significantly thicker at the bottom of the grooves giving a QWR running along the grooves. During the growth of the barriers an approximately 30 nm wide Ga-rich region is formed at the bottom of the grooves giving a Ga-rich stripe extending from the bottom of each groove to the surface.

Personal Audio System: Hearing Symptoms, Habits, and Sound Pressure Levels Measured in Real Ear and a Manikin

2020 ◽  
Vol 63 (6) ◽  
pp. 2016-2026
Author(s):  
Tamara R. Almeida ◽  
Clayton H. Rocha ◽  
Camila M. Rabelo ◽  
Raquel F. Gomes ◽  
Ivone F. Neves-Lobo ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Daily Basis ◽  
Cross Sectional Study ◽  
Normal Hearing ◽  
Chi Square ◽  
Cross Sectional ◽  
The Real ◽  
Significant Difference ◽  
Sound Pressure Levels ◽  
Audio System

Purpose The aims of this study were to characterize hearing symptoms, habits, and sound pressure levels (SPLs) of personal audio system (PAS) used by young adults; estimate the risk of developing hearing loss and assess whether instructions given to users led to behavioral changes; and propose recommendations for PAS users. Method A cross-sectional study was performed in 50 subjects with normal hearing. Procedures included questionnaire and measurement of PAS SPLs (real ear and manikin) through the users' own headphones and devices while they listened to four songs. After 1 year, 30 subjects answered questions about their usage habits. For the statistical analysis, one-way analysis of variance, Tukey's post hoc test, Lin and Spearman coefficients, the chi-square test, and logistic regression were used. Results Most subjects listened to music every day, usually in noisy environments. Sixty percent of the subjects reported hearing symptoms after using a PAS. Substantial variability in the equivalent music listening level (Leq) was noted ( M = 84.7 dBA; min = 65.1 dBA, max = 97.5 dBA). A significant difference was found only in the 4-kHz band when comparing the real-ear and manikin techniques. Based on the Leq, 38% of the individuals exceeded the maximum daily time allowance. Comparison of the subjects according to the maximum allowed daily exposure time revealed a higher number of hearing complaints from people with greater exposure. After 1 year, 43% of the subjects reduced their usage time, and 70% reduced the volume. A volume not exceeding 80% was recommended, and at this volume, the maximum usage time should be 160 min. Conclusions The habit of listening to music at high intensities on a daily basis seems to cause hearing symptoms, even in individuals with normal hearing. The real-ear and manikin techniques produced similar results. Providing instructions on this topic combined with measuring PAS SPLs may be an appropriate strategy for raising the awareness of people who are at risk. Supplemental Material https://doi.org/10.23641/asha.12431435

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