scholarly journals Direct Observation of Growth Rate Dispersion in the Enzymatic Reactive Crystallization of Ampicillin

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 390
Author(s):  
Matthew A. McDonald ◽  
Andreas S. Bommarius ◽  
Martha A. Grover ◽  
Ronald W. Rousseau
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Crystal Surface ◽  
Enzyme Reaction ◽  
Crystal Form ◽  
Size Distributions ◽  
Complex Flow ◽  
Critical Supersaturation ◽  
The Individual ◽  
Ampicillin Trihydrate

Prediction and control of crystal size distributions, a prerequisite for production of consistent crystalline material in the pharmaceutical industry, requires knowledge of potential non-idealities of crystal growth. Ampicillin is one such medicine consumed in crystal form (ampicillin trihydrate). Typically it is assumed that all crystals of the same chemical and geometric type grow at the same rate, however a distribution of growth rates is often observed experimentally. In this study, ampicillin produced enzymatically is crystallized and a distribution of growth rates is observed as individual crystals are monitored by microscopy. Most studies of growth rate dispersion use complex flow apparatuses to maintain a constant supersaturation or imprecise measurements of size distributions to reconstruct growth rate dispersions. In this study, the controllable enzyme reaction enables the same information to be gathered from fewer, less complicated experiments. The growth rates of individual ampicillin trihydrate crystals were found to be normally distributed, with each crystal having an intrinsic growth rate that is constant in time. Differences in the individual crystals, such as different number and arrangement of dislocations and surface morphology, best explain the observed growth rates. There is a critical supersaturation below which growth is not observed, thought to be caused by reactants adsorbing to the crystal surface and pinning advancing growth steps. The distribution of critical supersaturation also suggests that individual crystals’ surface morphologies cause a distribution of growth rates.

scholarly journals Observations on the increase in size at moulting in the lobster (Homarus vulgaris M.-Edw.)

1958 ◽  
Vol 37 (3) ◽  
pp. 603-606 ◽  
Author(s):  
H. J. Thomas
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth Increment ◽  
American Lobster ◽  
Limited Data ◽  
Preliminary Results ◽  
Home Department ◽  
The Individual ◽  
Marine Laboratory

A knowledge of growth rates is a pre-requisite in estimating the effect of fishing upon the available stocks. In Crustacea, where there is no known means of establishing accurately the age of the individual, the importance of measuring the growth rate is increased whilst its determination is made more difficult. In Homarus vulgaris some experiments were undertaken by Dannevig (1936), and Wilder (1953) gives considerable data for the American lobster. Results suggest that the growth increment is not uniform in all latitudes. Experiments to augment the limited data available for H. vulgaris and to establish the increase in size at moulting in local lobster stocks were therefore undertaken by the Marine Laboratory of the Scottish Home Department at Aberdeen. A statement of some preliminary results was given in Report on the Fisheries of Scotland (Lucas, 1957, p. 58).

scholarly journals Growth rates of nucleation mode particles in Hyytiälä during 2003−2009: variation with particle size, season, data analysis method and ambient conditions

2011 ◽  
Vol 11 (24) ◽  
pp. 12865-12886 ◽  
Author(s):  
T. Yli-Juuti ◽  
T. Nieminen ◽  
A. Hirsikko ◽  
P. P. Aalto ◽  
E. Asmi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Growth Rates ◽  
Oxidation Rate ◽  
Particle Growth ◽  
Size Distributions ◽  
Analysis Method ◽  
Ambient Conditions ◽  
Nucleation Mode ◽  
20 Nm

Abstract. The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the lifetime of these particles and their ability to become climatically relevant. Diameter growth rates (GR) of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003–2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using particle size distributions measured with a Differential Mobility Particle Sizer (DMPS), a Balanced Scanning Mobility Analyzer (BSMA) and an Air Ion Spectrometer (AIS). Two GR analysis methods were tested. The particle growth rates were also compared to an extensive set of ambient meteorological parameters and trace gas concentrations to investigate the processes/constituents limiting the aerosol growth. The median growth rates of particles in the nucleation mode size ranges with diameters of 1.5–3 nm, 3–7 nm and 7–20 nm were 1.9 nm h−1, 3.8 nm h−1, and 4.3 nm h−1, respectively. The median relative uncertainties in the growth rates due to the size distribution instrumentation in these size ranges were 25%, 19%, and 8%, respectively. For the smallest particles (1.5–3 nm) the AIS data yielded on average higher growth rate values than the BSMA data, and higher growth rates were obtained from positively charged size distributions as compared with negatively charged particles. For particles larger than 3 nm in diameter no such systematic differences were found. For these particles the uncertainty in the growth rate related to the analysis method, with relative uncertainty of 16%, was similar to that related to the instruments. The growth rates of 7–20 nm particles showed positive correlation with monoterpene concentrations and their oxidation rate by ozone. The oxidation rate by OH did not show a connection with GR. Our results indicate that the growth of nucleation mode particles in Hyytiälä is mainly limited by the concentrations of organic precursors.

Dimension control in bacteria

1974 ◽  
Vol 20 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Edward G. Sedgwick ◽  
Richard J. L. Paulton
Keyword(s):  
Growth Rate ◽  
Bacillus Subtilis ◽  
Cell Size ◽  
Growth Rates ◽  
Individual Cell ◽  
Cell Number ◽  
Cell Arrangement ◽  
Dimension Control ◽  
Constant Cell ◽  
The Individual

The effect of nutrition on the relation between growth rate and cell arrangement, cell size, and macro-molecular composition in Bacillus subtilis is described in comparison to earlier observations with other bacteria. Improvements in nutrition resulted in faster growth rates but, although the mass and size of the replicating unit (i.e. cell number/chain) also increased, there was no change in the mass or size of the individual cell. This constant cell size and variable cell arrangement in B. subtilis is in contrast to other bacteria and requires new proposals for the control of cell size and arrangement in different bacteria.

scholarly journals Nucleation mode growth rates in Hyytiälä during 2003–2009: variation with particle size, season, data analysis method and ambient conditions

2011 ◽  
Vol 11 (7) ◽  
pp. 21267-21317
Author(s):  
T. Yli-Juuti ◽  
T. Nieminen ◽  
A. Hirsikko ◽  
P. P. Aalto ◽  
E. Asmi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Growth Rates ◽  
Oxidation Rate ◽  
Particle Growth ◽  
Size Distributions ◽  
Analysis Method ◽  
Ambient Conditions ◽  
Nucleation Mode ◽  
20 Nm

Abstract. The condensational growth rate of aerosol particles formed in atmospheric new particle formation events is one of the most important factors influencing the life time of these particles and their ability to become climatically relevant. Diameter growth rates (GR) of nucleation mode particles were studied based on almost 7 yr of data measured during the years 2003–2009 at a boreal forest measurement station SMEAR II in Hyytiälä, Finland. The particle growth rates were estimated using particle size distributions measured with a Differential Mobility Particle Sizer (DMPS), a Balanced Scanning Mobility Analyser (BSMA) and an Air Ion Spectrometer (AIS). Two GR analysis methods were tested. The particle growth rates were also compared to an extensive set of ambient meteorological parameters and trace gas concentrations to investigate the processes/constituents limiting the aerosol growth. The median growth rates of particles in the nucleation mode size ranges with diameters of 1.5–3 nm, 3–7 nm and 7–20 nm were 1.9 nm h−1, 3.8 nm h−1, and 4.3 nm h−1, respectively. The median relative uncertainties in the growth rates due to the size distribution instrumentation in these size ranges were 25 %, 19 %, and 8 %, respectively. For the smallest particles (1.5–3 nm) the AIS data yielded on average higher growth rate values than the BSMA data, and higher growth rates were obtained from positively charged size distributions as compared with negatively charged particles. For particles larger than 3 nm in diameter no such systematic differences were found. For these particles the main uncertainty of the growth rate was related to the analysis method, as the values obtained with the two methods had a median difference of 35 %. The growth rates of 7–20 nm particles showed correlation with monoterpene concentrations and their oxidation rate by ozone. The oxidation rate by OH did not show a connection with GR. Our results indicate that the growth of nucleation mode particles in Hyytiälä is mainly limited by the concentrations and O3-oxidation of organic precursors.

scholarly journals Platelet size in man

Blood ◽  
1975 ◽  
Vol 46 (3) ◽  
pp. 321-336 ◽  
Author(s):  
JM Paulus
Keyword(s):  
Growth Rate ◽  
Volume Change ◽  
Age Distribution ◽  
Cell Populations ◽  
Size Distributions ◽  
Maturation Time ◽  
Platelet Size ◽  
The Mean ◽  
The Individual ◽  
Size Heterogeneity

Abstract The shape and parameters of platelet size distributions were studied in 50 normal persons and 97 patients in order to test the proposed thesis that platelet size heterogeneity results mainly from aging in the circulation. This thesis was contradicted (1) by size distributions of age-homogeneous, newly-born cell populations which were lognormal with increased (instead of decreased) dispersion of volumes and (2) by the macrothrombocytosis found in some populations with normal age distribution. For these reasons, thrombocytopoiesis appeared to play the major role in determining platelet size. A model was built in which the volume variation of platelet territories due to megakaryocyte growth and membrane demarcation at each step of maturation was a random proportion of the previous value of the volume. This model explains the lognormal shape of both newborn and circulating platelet size distributions. It also implies that (1) the mean and standard deviation of platelet logvolumes depend on the rates of volume change of the individual platelet territories (growth rate minus demarcation rate) as well as on megakaryocyte maturation time; (2) platelet hyperdestruction causes an increase in the mean and dispersion of the rates of territory volume change; (3) Mediterranean macrothrombocytosis and some hereditary macrothrombocytotic thrombocytopenias or dysthrombocytopoieses reflect a diminished rate of territory demarcation, and (4) platelet size heterogeneity is caused mainly by the variations in territory growth and demarcation and not by aging in the circulation.

scholarly journals Size and time-resolved growth rate measurements of 1 to 5 nm freshly formed atmospheric nuclei

2012 ◽  
Vol 12 (7) ◽  
pp. 3573-3589 ◽  
Author(s):  
C. Kuang ◽  
M. Chen ◽  
J. Zhao ◽  
J. Smith ◽  
P. H. McMurry ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Survival Probability ◽  
Strong Dependence ◽  
Particle Diameter ◽  
Particle Growth ◽  
Size Distributions ◽  
Electrical Mobility ◽  
Time Resolved ◽  
Condensation Particle Counter

Abstract. This study presents measurements of size and time-resolved particle diameter growth rates for freshly nucleated particles down to 1 nm geometric diameter. Novel data analysis methods were developed, de-coupling for the first time the size and time-dependence of particle growth rates by fitting the aerosol general dynamic equation to size distributions obtained at an instant in time. Size distributions of freshly nucleated total aerosol (neutral and charged) were measured during two intensive measurement campaigns in different environments (Atlanta, GA and Boulder, CO) using a recently developed electrical mobility spectrometer with a diethylene glycol-based ultrafine condensation particle counter as the particle detector. One new particle formation (NPF) event from each campaign was analyzed in detail. At a given instant in time during the NPF event, size-resolved growth rates were obtained directly from measured size distributions and were found to increase approximately linearly with particle size from ~1 to 3 nm geometric diameter, increasing from 5.5 ± 0.8 to 7.6 ± 0.6 nm h−1 in Atlanta (13:00) and from 5.6 ± 2 to 27 ± 5 nm h−1 in Boulder (13:00). The resulting growth rate enhancement Γ, defined as the ratio of the observed growth rate to the growth rate due to the condensation of sulfuric acid only, was found to increase approximately linearly with size from ~1 to 3 nm geometric diameter. For the presented NPF events, values for Γ had lower limits that approached ~1 at 1.2 nm geometric diameter in Atlanta and ~3 at 0.8 nm geometric diameter in Boulder, and had upper limits that reached 8.3 at 4.1 nm geometric diameter in Atlanta and 25 at 2.7 nm geometric diameter in Boulder. Nucleated particle survival probability calculations comparing the effects of constant and size-dependent growth indicate that neglecting the strong dependence of growth rate on size from 1 to 3 nm observed in this study could lead to a significant overestimation of CCN survival probability.

scholarly journals New particle formation events in semi-clean South African savannah

2011 ◽  
Vol 11 (7) ◽  
pp. 3333-3346 ◽  
Author(s):  
V. Vakkari ◽  
H. Laakso ◽  
M. Kulmala ◽  
A. Laaksonen ◽  
D. Mabaso ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Growth Rate ◽  
Particle Size ◽  
Sulphuric Acid ◽  
Growth Rates ◽  
Formation Rate ◽  
Particle Formation ◽  
Size Distributions ◽  
New Particle Formation ◽  
Particle Formation And Growth

Abstract. This study is based on 18 months (20 July 2006–5 February 2008) of continuous measurements of aerosol particle size distributions, air ion size distributions, trace gas concentrations and basic meteorology in a semi-clean savannah environment in Republic of South Africa. New particle formation and growth was observed on 69% of the days and bursts of non-growing ions/sub-10 nm particles on additional 14% of the days. This new particle formation frequency is the highest reported from boundary layer so far. Also the new particle formation and growth rates were among the highest reported in the literature for continental boundary layer locations; median 10 nm formation rate was 2.2 cm−3 s−1 and median 10–30 nm growth rate 8.9 nm h−1. The median 2 nm ion formation rate was 0.5 cm−3 s−1 and the median ion growth rates were 6.2, 8.0 and 8.1 nm h−1 for size ranges 1.5–3 nm, 3–7 nm and 7–20 nm, respectively. The growth rates had a clear seasonal dependency with minimum during winter and maxima in spring and late summer. The relative contribution of estimated sulphuric acid to the growth rate was decreasing with increasing particle size and could explain more than 20% of the observed growth rate only for the 1.5–3 nm size range. Also the air mass history analysis indicated the highest formation and growth rates to be associated with the area of highest VOC (Volatile Organic Compounds) emissions following from biological activity rather than the highest estimated sulphuric acid concentrations. The frequency of new particle formation, however, increased nearly monotonously with the estimated sulphuric acid reaching 100% at H2SO4 concentration of 6 · 107 cm−3, which suggests the formation and growth to be independent of each other.

scholarly journals New particle formation events in semi-clean South African savannah

2010 ◽  
Vol 10 (12) ◽  
pp. 30777-30821 ◽  
Author(s):  
V. Vakkari ◽  
H. Laakso ◽  
M. Kulmala ◽  
A. Laaksonen ◽  
D. Mabaso ◽  
...  
Keyword(s):  
Growth Rate ◽  
Sulphuric Acid ◽  
Growth Rates ◽  
Formation Rate ◽  
Particle Formation ◽  
Size Distributions ◽  
New Particle Formation ◽  
Air Mass ◽  
History Analysis ◽  
Particle Formation And Growth

Abstract. This study is based on 18 months (20 July 2006–5 February 2008) of continuous measurements of aerosol particle size distributions, air ion size distributions, trace gas concentrations and basic meteorology in a semi-clean savannah environment in Republic of South Africa. New particle formation and growth was observed on 69% of the days and bursts of non-growing ions/sub-10 nm particles on additional 14% of the days. The new particle formation and growth rates were among the highest reported in the literature for continental boundary layer locations; median 10 nm formation rate was 2.2 cm−3s−1 and median 10–30 nm growth rate 8.9 nm h−1. The median 2 nm ion formation rate was 0.5 cm−3s−1 and the median ion growth rates were 6.2, 8.0 and 8.1 nm h−1 for size ranges 1.5–3 nm, 3–7 nm and 7–20 nm, respectively. Three different approaches were used to study the origin of the formation and growth rates: seasonal variation, air mass history analysis and estimated sulphuric acid contribution to the growth. The growth rates had a clear seasonal dependency with minimum during winter and maxima in spring and late summer and the air mass history analysis indicated the highest formation and growth rates to be associated with the area of highest VOC (Volatile Organic Compounds) emissions rather than the highest estimated sulphuric acid concentrations. The relative contribution of estimated sulphuric acid to the growth rate was decreasing with increasing particle size and could explain more than 20% of the observed growth rate only for the 1.5–3 nm size range. The implication is that the sulphuric acid alone is not enough to explain the growth, but the highest growth rates seem to originate in VOC emissions following from biological activity. The frequency of new particle formation, however, increased nearly monotonously with the estimated sulphuric acid reaching 100% at H2SO4 concentration of 4×107cm−3, which suggests the formation and growth to be independent of each other.

scholarly journals Platelet size in man

Blood ◽  
1975 ◽  
Vol 46 (3) ◽  
pp. 321-336 ◽  
Author(s):  
JM Paulus
Keyword(s):  
Growth Rate ◽  
Volume Change ◽  
Age Distribution ◽  
Cell Populations ◽  
Size Distributions ◽  
Maturation Time ◽  
Platelet Size ◽  
The Mean ◽  
The Individual ◽  
Size Heterogeneity

The shape and parameters of platelet size distributions were studied in 50 normal persons and 97 patients in order to test the proposed thesis that platelet size heterogeneity results mainly from aging in the circulation. This thesis was contradicted (1) by size distributions of age-homogeneous, newly-born cell populations which were lognormal with increased (instead of decreased) dispersion of volumes and (2) by the macrothrombocytosis found in some populations with normal age distribution. For these reasons, thrombocytopoiesis appeared to play the major role in determining platelet size. A model was built in which the volume variation of platelet territories due to megakaryocyte growth and membrane demarcation at each step of maturation was a random proportion of the previous value of the volume. This model explains the lognormal shape of both newborn and circulating platelet size distributions. It also implies that (1) the mean and standard deviation of platelet logvolumes depend on the rates of volume change of the individual platelet territories (growth rate minus demarcation rate) as well as on megakaryocyte maturation time; (2) platelet hyperdestruction causes an increase in the mean and dispersion of the rates of territory volume change; (3) Mediterranean macrothrombocytosis and some hereditary macrothrombocytotic thrombocytopenias or dysthrombocytopoieses reflect a diminished rate of territory demarcation, and (4) platelet size heterogeneity is caused mainly by the variations in territory growth and demarcation and not by aging in the circulation.

Ice in Clouds Experiment—Layer Clouds. Part I: Ice Growth Rates Derived from Lenticular Wave Cloud Penetrations

2011 ◽  
Vol 68 (11) ◽  
pp. 2628-2654 ◽  
Author(s):  
Andrew J. Heymsfield ◽  
Paul R. Field ◽  
Matt Bailey ◽  
Dave Rogers ◽  
Jeffrey Stith ◽  
...  
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Growth Rates ◽  
Wind Direction ◽  
Ice Nucleation ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Ice Growth ◽  
Ice Particles ◽  
Rate Of Increase

Abstract Lenticular wave clouds are used as a natural laboratory to estimate the linear and mass growth rates of ice particles at temperatures from −20° to −32°C and to characterize the apparent rate of ice nucleation at water saturation at a nearly constant temperature. Data are acquired from 139 liquid cloud penetrations flown approximately along or against the wind direction. A mean linear ice growth rate of about 1.4 μm s−1, relatively independent of particle size (in the range 100–400 μm) and temperature is deduced. Using the particle size distributions measured along the wind direction, the rate of increase in the ice water content (IWC) is calculated from the measured particle size distributions using theory and from those distributions by assuming different ice particle densities; the IWC is too small to be measured. Very low ice effective densities, <0.1 g cm−3, are needed to account for the observed rate of increase in the IWC and the unexpectedly high linear growth rate. Using data from multiple penetrations through a narrow (along wind) and thin wave cloud with relatively flat airflow streamlines, growth rate calculations are used to estimate where the ice particles originate and whether the ice is nucleated in a narrow band or over an extended period of time. The calculations are consistent with the expectation that the ice formation occurs near the leading cloud edge, presumably through a condensation–freezing process. The observed ice concentration increase along the wind is more likely due to a variation in ice growth rates than to prolonged ice nucleation.

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