scholarly journals Pressure Dependence of the Crystallization Rate for the S-Enantiomer and a Racemic Mixture of Ibuprofen

Author(s):  
Kajetan Koperwas ◽  
Wenkang Tu ◽  
Frédéric Affouard ◽  
Karolina Adrjanowicz ◽  
Filip Kaskosz ◽  
...  
1988 ◽  
Vol 100 ◽  
Author(s):  
G. Q. Lu ◽  
E. Nygren ◽  
M. J. Aziz ◽  
D. Turnbull ◽  
C. W. White

ABSTRACTWe have measured the pressure dependence of the solid phase epitaxial growth (SPEG) rate of self-implanted Si (100) by using the in-situ time-resolved reflectivity technique [1] in a hightemperature and high-pressure diamond anvil cell (DAC). With fluid argon as the pressure transmission medium, a clean and perfectly hydrostatic pressure environment is achieved around the sample. The external heating geometry employed in the DAC provides a uniform temperature across the sample. At temperatures in the range of 530 – 550 °C and pressure up to 50 kbars (5 GPa), the growth rate is enhanced by up to a factor of ten over that at 1 atmosphere pressure. The results are characterized by a negative activation volume of approximately −3.0 cm3/mole (−27% of the atomic volume). These preliminary results show a significantly weaker pressure dependence than does the previous work of Nygren et al. [2], who found an activation volume of −8.7 cm3/mole. The implications of these results for the nature of the defect responsible for thermal SPEG and irradiation enhanced SPEG is discussed.


Soft Matter ◽  
2020 ◽  
Vol 16 (19) ◽  
pp. 4625-4631 ◽  
Author(s):  
R. Casalini ◽  
T. C. Ransom

In materials with a constant scaling parameter γS, the Isomorph γI is found to vary with pressure, demonstrating γS ≠ γI.


1978 ◽  
Vol 39 (C6) ◽  
pp. C6-37-C6-38 ◽  
Author(s):  
C. N. Archie ◽  
T. A. Alvesalo ◽  
J. E. Bethold ◽  
J. D. Reppy ◽  
R. C. Richardson

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-97-C6-98
Author(s):  
R. Jochemsen ◽  
V. V. Goldman ◽  
Isaac F. Silvera

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-323-C6-325
Author(s):  
C. Carlone ◽  
N. K. Hota ◽  
H. J. Stolz ◽  
M. Elbert ◽  
H. Kuzmany ◽  
...  

MISSION ◽  
2019 ◽  
pp. 54-57
Author(s):  
Marco Riglietta ◽  
Paolo Donadoni ◽  
Grazia Carbone ◽  
Caterina Pisoni ◽  
Franca Colombi ◽  
...  

In Italy, at the end of the 1970s, methadone hydrochloride was introduced for the treatment of opioid use disorder, in the form of a racemic mixture consisting of levomethadone and dextromethadone.In 2015 Levometadone was introduced, a new formulation marketed in Italy for the treatment of opioid use disorder in 2015.The article aims to bring the experience of an Italian Addiction Centre back to the use of this new formulation in the "real life" analyzing the efficacy, the trend of adverse events and pharmacological iterations in a context in which the treated population often uses besides the opiates, cocaine and alcohol, are burdened by a relevant physical and psychic comorbidity and frequently have a prescribed polypharmacy.


2020 ◽  
pp. 43-47
Author(s):  
S.V. Prudius ◽  
◽  
N.L. Hes ◽  
A.M. Mylin ◽  
V.V. Brei ◽  
...  

In recent years, numerous researchers have focused on the development of catalytic methods for processing of biomass-derived sugars into alkyl lactates, which are widely used as non-toxic solvents and are the starting material for obtaining monomeric lactide. In this work, the transformation of fructose into methyl lactate on Sn-containing catalyst in the flow reactor that may be of practical interest was studied. The supported Sn-containing catalyst was ob-tained by a simple impregnation method of granular γ-Al2O3. The catalytic ex-periments were performed in a flow reactor at temperatures of 160-190 °C and pressure of 3.0 MPa. The 1.6-9.5 wt.% fructose solutions in 80% aqueous methanol were used as a reaction mixture. It was found that addition to a reac-tion mixture of 0.03 wt.% potassium carbonate leads to the increase in selec-tivity towards methyl lactate on 15% at 100% conversion of fructose. Prod-ucts of the target reaction С6Н12О6 + 2СН3ОН = 2С4Н8О3 + 2Н2О were ana-lyzed using 13C NMR method. The following process conditions for obtaining of 65 mol% methyl lactate yield at 100% fructose conversion were found: use of 4.8 wt.% fructose solution in 80% methanol, 180 °С, 3.0 МПа and a load on catalyst 1.5 mmol C6H12O6/mlcat/h at contact time of 11 minutes. The cata-lyst productivity is 2.0 mmol C4H8O3/mlcat/h and the by-productі are 1,3-dihydroxyacetone dimethyl acetal (20%) and 5-hydroxymethylfurfural (10%). It should be noted that a racemic mixture of L- and D-methyl lactates has been obtained by conversion of D-fructose on the SnO2/Al2O3 catalyst. The SnO2/Al2O3 catalyst was found to be stable for 6 h while maintaining full fruc-tose conversion at 55–70% methyl lactate selectivity. After regeneration the catalyst completely restores the initial activity.


2020 ◽  
pp. 123-126
Author(s):  
В.В. Кожемякин ◽  
Р.А. Иванов ◽  
Е.С. Игнатьева

Работа посвящена расчетно-теоретическому исследованию работы блока инжекторов. Рассмотрен пароводяной струйный аппарат, который применяется в качестве средства циркуляции теплоносителя первого контура. Подвод дополнительного потока осуществляется на цилиндрическом участке с внезапным расширением сечения через перемычку. Для достижения поставленной цели разработана программа для ЭМВ, в которой смоделирована зависимость давления от нагрузки в контуре, а также проведено расчетно-теоретическое исследование влияние гидравлического сопротивления на расход перемычки. В данной работе рассмотрены только рабочие режимы, т.е. все инжекторы работают как насосы. В ходе работы было установлено, что при нагрузке в 30% увеличиваются коэффициенты инжекции пароводяного струйного аппарата, но характер работы перемычек не меняется. Так же было установлено, что расход через перемычку меняется не пропорционально коэффициенту гидравлического сопротивления перемычки. The paper is devoted to the computational and theoretical study of the injector block operation. A steam-water jet apparatus is considered, which is used as a means of circulating the primary circle coolant. The additional flow is supplied on the cylindrical section with a sudden expansion of the cross-section through the bridge. To achieve this goal, a computer program was developed that modeled the pressure dependence on the load in the circuit, and also a theoretical study of the influence of hydraulic resistance on the flow of the jumper was conducted. In this paper, only operating modes are considered, i.e. all the injectors function as pumps. In the process of the research, it was found that at a load of 30%, the injection coefficients of the steam-water jet apparatus increase, but the nature of the work of the jumpers does not change. It was also found out that the flow rate through the jumper does not change in proportion to the coefficient of hydraulic resistance of the jumper.


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